U.S. patent application number 10/701687 was filed with the patent office on 2004-05-13 for production process of silver halide emulsion.
This patent application is currently assigned to FUJI PHOTO FILM CO., LTD.. Invention is credited to Ihama, Mikio, Ikari, Shinji, Mitsui, Tetsuro, Nakatsugawa, Haruyasu, Takahashi, Kazutaka.
Application Number | 20040091826 10/701687 |
Document ID | / |
Family ID | 28658868 |
Filed Date | 2004-05-13 |
United States Patent
Application |
20040091826 |
Kind Code |
A1 |
Ikari, Shinji ; et
al. |
May 13, 2004 |
Production process of silver halide emulsion
Abstract
A process for producing a photosensitive silver halide emulsion
is disclosed, comprising silver halide grains and a dispersion
medium, said process comprising steps of adding a water-soluble
silver solution, an aqueous alkali halide solution and an aqueous
solution of gelatin having a molecular weight of 5,000 to 30,000 or
less to a mixing vessel different from a reactor for the production
of emulsion to prepare silver halide fine grains, adding the silver
halide fine grains to the reactor for the production of emulsion to
grow silver halide grains, and ultrafiltering the silver halide
grains during the addition of silver halide fine grains, wherein
50% or more of the entire projected area of said emulsion grains is
occupied by silver halide tabular grains having an aspect ratio of
10 or more and a thickness of 0.15 .mu.m or less.
Inventors: |
Ikari, Shinji; (Kanagawa,
JP) ; Ihama, Mikio; (Kanagawa, JP) ;
Nakatsugawa, Haruyasu; (Kanagawa, JP) ; Mitsui,
Tetsuro; (Kanagawa, JP) ; Takahashi, Kazutaka;
(Kanagawa, JP) |
Correspondence
Address: |
SUGHRUE MION, PLLC
2100 PENNSYLVANIA AVENUE, N.W.
SUITE 800
WASHINGTON
DC
20037
US
|
Assignee: |
FUJI PHOTO FILM CO., LTD.
|
Family ID: |
28658868 |
Appl. No.: |
10/701687 |
Filed: |
November 6, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10701687 |
Nov 6, 2003 |
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10252371 |
Sep 24, 2002 |
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6682882 |
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Current U.S.
Class: |
430/569 |
Current CPC
Class: |
G03C 1/047 20130101;
G03C 1/0051 20130101; G03C 2001/0055 20130101; G03C 2001/0357
20130101; G03C 2200/43 20130101; G03C 2001/0153 20130101; G03C
2200/60 20130101; B33Y 80/00 20141201; G03C 2001/0157 20130101;
G03C 2001/03552 20130101 |
Class at
Publication: |
430/569 |
International
Class: |
G03C 001/025; G03C
001/035 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 26, 2001 |
JP |
P.2001-294137 |
Claims
What is claimed is:
1. A process for producing a photosensitive silver halide emulsion
comprising silver halide grains and a dispersion medium, said
process comprising steps of adding a water-soluble silver solution,
an aqueous alkali halide solution and an aqueous solution of
gelatin having a molecular weight of 5,000 to 30,000 or less to a
mixing vessel different from a reactor for the production of
emulsion to prepare silver halide fine grains, adding the silver
halide fine grains to the reactor for the production of emulsion to
grow silver halide grains, and ultrafiltering the silver halide
grains during the addition of silver halide fine grains, wherein
50% or more of the entire projected area of said emulsion grains is
occupied by silver halide tabular grains having an aspect ratio of
10 or more and a thickness of 0.15 .mu.m or less.
2. The process for producing a silver halide emulsion as claimed in
claim 1, wherein the silver halide grains present in the reactor
for the production of emulsion are ultrafiltered under variable
temperature conditions before the addition of said silver halide
fine grains.
3. The process for producing a silver halide emulsion as claimed in
claim 1, wherein the residence time of said water-soluble silver
salt, aqueous alkali halide solution and aqueous gelatin solution
in a mixing space of said mixing vessel is from 0.001 to 10
seconds.
4. The process for producing a silver halide emulsion as claimed in
claim 1, wherein said mixing vessel comprises a stirring tank and
at least two stirring blades in the stirring tank, an aqueous
solution of water-soluble silver salt and an aqueous solution of
water-soluble halide are supplied through supply ports provided in
the stirring tank of the mixing vessel, the stirring state in
mixing the aqueous solutions supplied is controlled by the stirring
blades having no rotary shaft protruding through a wall of the
stirring tank and disposed to space at the positions facing each
other in the stirring tank, and the silver halide fine grains
produced after the completion of stirring treatment are discharged
from the discharge port provided in the stirring tank.
5. The process for producing a silver halide emulsion as claimed in
claim 1, wherein the average equivalent-circle diameter of said
silver halide fine grains is 40% or more of the number average
thickness of said silver halide tabular grains under growing.
6. The process for producing a silver halide emulsion as claimed in
claim 1, wherein the coefficient of variation in the
equivalent-circle diameter of said silver halide fine grains is 30%
or less.
7. The process for producing a silver halide emulsion as claimed in
claim 1, wherein 50% or more of the entire projected area is
occupied by grains having an equivalent-circle diameter of 3.0
.mu.m or more.
8. The process for producing a silver halide emulsion as claimed in
claim 1, wherein 70% or more of the entire projected area is
occupied by hexagonal tabular grains having an epitaxial projection
part at least at one apex.
9. The process for producing a silver halide emulsion as claimed in
claim 1, wherein said emulsion is produced through nucleation,
ripening and growth steps and the total silver concentration in the
silver halide emulsion at the start of ripening step is from 0.0015
to 0.15 mass %.
10. The process for producing a silver halide emulsion as claimed
in claim 1, wherein the reactor temperature in the nucleation step
of adding an aqueous silver solution and an aqueous halide solution
is 5.degree. C. or less.
11. A process for producing a silver halide emulsion through
nucleation, ripening and growth steps, said silver halide emulsion
being a photosensitive silver halide emulsion comprising silver
halide grains and a dispersion medium, wherein 50% or more of the
entire projected area of grains is occupied by silver halide
tabular grains having an aspect retio of 10 or more, the total
silver concentration in the silver halide emulsion at the start of
ripening step is from 0.0015 to 0.15 mass %, and ultrafiltration is
used in a part of the emulsion preparation steps.
12. The process for producing a silver halide emulsion through
nucleation, ripening and growth steps as claimed in claim 11,
wherein the reactor temperature in the nucleation step of adding an
aqueous silver solution and an aqueous halide solution is from 0 to
5.degree. C.
13. The process for producing a silver halide emulsion through
nucleation, ripening and growth steps as claimed in claim 11,
wherein the silver halide tabular grains have an equivalent-circle
diameter of 3.0 .mu.m or more and a thickness of 0.15 .mu.m or
less.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a production process of a
silver halide emulsion, more specifically, the present invention
relates to a production process of a thinner tabular grain
emulsion.
BACKGROUND OF THE INVENTION
[0002] Tabular silver halide grains having a large light-receiving
area are widely used as a photosensitive element. For increasing
the light-receiving efficiency of the tabular silver halide grain,
the smaller grain thickness is more preferred. The preparation of
silver halide grains comprises two main steps of nucleation for
forming grains working out to nuclei for growth, and grain growth.
For the nucleation, a method of directly adding a water-soluble
silver solution and an aqueous alkali halide solution to a reactor
having a stirring unit of various types is used. However, the
grains as nuclei in the course of growth pass through a high
supersaturation region in the vicinity of a port for adding silver
ion or halide ion and this causes a harmful effect that the tabular
grains are increased in thickness. To overcome this problem,
JP-A-10-43570 (the term "JP-A" as used herein means an "unexamined
published Japanese patent application") and JP-A-2000-338620
disclose a method of adding a water-soluble silver solution, an
aqueous alkali halide solution and an aqueous dispersion medium
solution to an outside mixing vessel different from the reactor of
undertaking the growth, thereby continuously forming silver halide
fine grains, adding the silver halide fine grains to the reactor,
and growing the grains as nuclei while dissolving the silver halide
fine grains. However, the methods disclosed cannot produce silver
halide fine grains having a narrow distribution and are not
satisfied for obtaining thinner tabular grains.
[0003] On the other hand, in the production of silver halide grains
of a silver halide emulsion, the total of the amount of water
containing a dispersion medium necessary for stirring, the amount
of water-soluble silver solution, the amount of aqueous alkali
halide solution and the amount of additives is designed to be lower
than the maximum liquid amount of a reactor. In the case of
increasing the production amount and elevating the productivity,
the production amount per once operation can be increased by
increasing the concentrations of water-soluble silver salt and
aqueous alkali halide solution occupying the majority of the liquid
amount. However, the concentrations of water-soluble silver
solution and halide ion are appropriately determined to obtain
intended silver halide grains and if these concentrations are
increased, not only the grain size, grain shape and grain size
distribution are changed but also the photographic properties such
as fog, sensitivity and gradation are adversely affected. In order
to eliminate these adverse effects, it is necessary to remove the
added aqueous solutions together with unnecessary salts while not
changing the concentrations of water-soluble silver solution and
aqueous alkali halide solution added. For this purpose, a method of
using dehydrating and desalting apparatuses during the growth is
disclosed in U.S. Pat. Nos. 4,334,012 and 5,242,597, European
Patents 795,455 and 843,206, JP-A-11-231449, JP-A-11-237703,
JP-A-11-352618, JP-A-2000-56420, JP-A-2000-56421, JP-A-2000-66320,
JP-A-2001-56518, JP-A-2001-59994 and JP-A-2001-100348. However,
according to these methods, a water-soluble silver solution and an
aqueous alkali halide solution are directly added to a reactor and
thick tabular grains are disadvantageously produced.
SUMMARY OF THE INVENTION
[0004] The object of the present invention is to provide a process
for producing a tabular silver halide grain emulsion having high
sensitivity and low fog and more reduced in the thickness.
[0005] In the present invention, silver halide fine grains which
are continuously prepared and supplied can be made to have a
monodisperse grain size distribution immediately before the
addition and by using the silver halide fine grains, a tabular
grain emulsion more reduced in thickness than in conventional
techniques can be prepared.
[0006] The object of the present invention has been attained by the
following (1) to (16):
[0007] (1) A process for producing a photosensitive silver halide
emulsion comprising silver halide grains and a dispersion medium,
the process comprising adding a watersoluble silver solution, an
aqueous alkali halide solution and an aqueous solution of gelatin
having a molecular weight of 5,000 to 30,000 or less to a mixing
vessel different from a reactor for the production of emulsion to
prepare silver halide fine grains, adding the silver halide fine
grains to the reactor for the production of emulsion to grow silver
halide grains, and ultrafiltering the silver halide grains during
the addition of silver halide fine grains, wherein 50% or more of
the entire projected area of the emulsion grains is occupied by
silver halide tabular grains having an aspect ratio of 10 or more
and a thickness of 0.15 pm or less.
[0008] (2) The process for producing a silver halide emulsion as
described in (1), wherein the silver halide grains present in the
reactor for the production of emulsion are ultrafiltered under
variable temperature conditions before the addition of the silver
halide fine grains.
[0009] (3) The process for producing a silver halide emulsion as
described in (1) or (2), wherein the residence time of the
water-soluble silver salt, aqueous alkali halide solution and
aqueous gelatin solution in a mixing space of the mixing vessel is
from 0.001 to 10 seconds.
[0010] (4) The process for producing a silver halide emulsion as
described in any one of (1) to (3), wherein the mixing vessel
comprises a stirring tank and at least two stirring blades in the
stirring tank, an aqueous solution of water-soluble silver salt and
an aqueous solution of water-soluble halide are supplied through
supply ports provided in the stirring tank of the mixing vessel,
the stirring state in mixing the aqueous solutions supplied is
controlled by the stirring blades having no rotary shaft protruding
through a wall of the stirring tank and disposed with a space at
the positions facing each other in the stirring tank, and the
silver halide fine grains produced after the completion of stirring
treatment are discharged from the discharge port provided in the
stirring tank.
[0011] (5) The process for producing a silver halide emulsion as
described in any one of (1) to (4), wherein the average
equivalent-circle diameter of the silver halide fine grains is 40%
or more of the number average thickness of the silver halide
tabular grains under growing.
[0012] (6) The process for producing a silver halide emulsion as
described in any one of (1) to (5), wherein the coefficient of
variation in the equivalent-circle diameter of the silver halide
fine grains is 30% or less.
[0013] (7) The process for producing a silver halide emulsion as
described in any one of (1) to (6), wherein 50% or more of the
entire projected area is occupied by grains having an
equivalent-circle diameter of 3.0 .mu.m or more.
[0014] (8) The process for producing a silver halide emulsion as
described in any one of (1) to (7), wherein 70% or more of the
entire projected area is occupied by hexagonal tabular grains
having an epitaxial projection part at least at one apex.
[0015] (9) The process for producing a silver halide emulsion as
described in any one of (1) to (8), wherein the emulsion is
produced through nucleation, ripening and growth steps and the
total silver concentration in the silver halide emulsion at the
start of ripening step is from 0.0015 to 0.15 mass%.
[0016] (10) The process for producing a silver halide emulsion as
described in any one of (1) to (9), wherein the reactor temperature
in the nucleation step of adding an aqueous silver solution and an
aqueous halide solution is 5.degree. C. or less.
[0017] (11) A process for producing a silver halide emulsion
through nucleation, ripening and growth steps, the silver halide
emulsion being a photosensitive silver halide emulsion comprising
silver halide grains and a dispersion medium, wherein 50% or more
of the entire projected area of grains is occupied by silver halide
tabular grains having an aspect ratio of 10 or more, the total
silver concentration in the silver halide emulsion at the start of
ripening step is from 0.0015 to 0.15 mass%, and ultrafiltration is
used in a part of the emulsion preparation steps.
[0018] (12) The process for producing a silver halide emulsion
through nucleation, ripening and growth steps as described in (11),
wherein the reactor temperature in the nucleation step of adding an
aqueous silver solution and an aqueous halide solution is from
5.degree. C. or less.
[0019] (13) The process for producing a silver halide emulsion
through nucleation, ripening and growth steps as described in (11),
wherein the silver halide tabular grains have an equivalent-circle
diameter of 3.0 .mu.m or more and a thickness of 0.15 .mu.m or
less.
[0020] (14) The process for producing a silver halide emulsion as
described in any one of (1) to (3), wherein in the mixing vessel,
an aqueous solution of water-soluble silver salt and an aqueous
solution of water-soluble halide are supplied through supply ports
provided in a closed stirring tank of the mixing vessel, the
stirring state in mixing the aqueous solutions supplied is
controlled by at least two stirring blades having no rotary shaft
protruding through a wall of the stirring tank and disposed with a
space at the positions facing each other in the stirring tank, and
the silver halide fine grains produced after the completion of
stirring treatment are discharged from the discharge port provided
in the closed stirring tank sealed in the periphery of the rotary
shaft.
[0021] (15) The process for producing a silver halide emulsion as
described in any one of (1) to (3), wherein in the mixing vessel,
at least one of the water-soluble silver solution and the aqueous
alkali halide solution is turned into a linear jet stream having a
high flow rate and those two kinds of solutions are mixed within a
short time to continuously form silver halide grains.
[0022] (16) The process for producing a silver halide emulsion as
described in any one of (1) to (3), wherein the mixing vessel
comprises a first channel for passing the water-soluble silver
solution and a second channel for passing the aqueous alkali halide
solution, those two channels are disposed to partially contact with
each other, those two fluids each forms substantially a thin layer,
an open interface is formed between those two fluids, those two
thin layers each has a thickness of 1 to 500 micrometer in the
normal direction of their contact interface, and silver ion and
halide ion diffuse and move between those two thin layers to cause
a reaction of silver ion and halide ion, thereby continuously
producing silver halide grains.
[0023] (17) The process for producing a silver halide emulsion as
described in any one of (1) to (5), wherein the percentage by
number of twin crystal grains in the silver halide fine grains is
15% or less.
BRIEF DESCRIPTION OF DRAWINGS
[0024] FIG. 1 is a cross-sectional view schematically showing the
apparatus according to the practical embodiment of the present
invention.
[0025] FIG. 2 is a cross-sectional view schematically showing the
production process in the mixing vessel according to the practical
embodiment of the present invention.
[0026] FIG. 3 is a perspective view schematically showing the
structure of magnetic coupling used in the stirring unit of the
mixing vessel according to the practical embodiment of the present
invention. FIG. 4 is a perspective view showing the action of tic
coupling shown in FIG. 3.
[0027] 1 Reactor
[0028] 2 Stirring Blade
[0029] 3 Dispersion medium
[0030] 4 Silver addition pipeline
[0031] 5 Halide addition pipeline
[0032] 6 Chemicals addition pipeline
[0033] 7 Reaction solution sampling pipeline
[0034] 8 Reaction solution sampling valve
[0035] 9 Liquid supply pipeline
[0036] 10 Pump
[0037] 11 Supply valve
[0038] 12 Supply pressure gauge
[0039] 13 Ultrafiltration membrane module
[0040] 14 Liquid reflux pipeline
[0041] 15 Reflux pressure gauge
[0042] 16 Reflux valve
[0043] 17 Reflux flow meter
[0044] 18 Liquid permeation pipeline
[0045] 19 Permeation pressure gauge
[0046] 20 Permeation valve
[0047] 21 Permeation flow meter
[0048] 22 Permeated solution storage vessel
[0049] 23 Permeated solution
[0050] 24 Backwash pipeline
[0051] 25 Backwash pump
[0052] 26 Backwash valve
[0053] 27 Check valve
[0054] 28 Mixing vessel
[0055] 30 Mixing vessel
[0056] 31, 32, 33 Liquid supply port
[0057] 34 Liquid discharge port
[0058] 35 Stirring tank
[0059] 36 Tank body
[0060] 37 Seal plate
[0061] 38, 39 Stirring blades
[0062] 40, 41 Outer magnets
[0063] 42, 43 Motors
[0064] 44 Central axis of rotation
[0065] 45 Double side bipolar magnet
[0066] 46 Bilateral bipolar magnet
[0067] L Line of magnetic force
DETAILED DESCRIPTION OF THE INVENTION
[0068] In the present invention, the silver halide tabular grains
means a gain where one or more twin plane is crystallographically
present. This twin plane is present in parallel to the face (main
plane) having a maximum area of the grain. In the present
invention, the tabular grain is preferably a grain having one or
two sheet of this twin plane.
[0069] The diameter and thickness of the grain of the present
invention can be determined by an electron microphotograph of
grains according to the method described in U.S. Pat. No.
4,434,226. More specifically, the thickness of the grain can be
easily determined by depositing a metal from the oblique direction
of a grain together with a latex for reference, measuring the
length of the shadow thereof on an electron microphotograph, and
calculating the thickness with reference to the length of the
shadow of latex. The silver halide grain of the present invention
satisfies the condition that in the entire projected area of grains
observed through an electron microscope, from 50 to 100% have an
average aspect (a ratio of the diameter of the main plane of a
grain to the thickness of the grain) of 10 or more, preferably from
20 to 200. The thickness of the silver halide grain is preferably
from 0.01 to 0.15 .mu.m, more preferably 0.1 .mu.m or less. The
average aspect ratio can be determined by averaging the aspect
ratios of all tabular grains but in a simple method, the average
aspect ratio can also be determined as a ratio of the average
diameter to the average thickness of all tabular grains. The
diameter of the main plane is preferably from 1 to 10 .mu.m, more
preferably from 3.0 to 10 .mu.m.
[0070] The emulsion of the present invention is preferably
monodisperse. The coefficient of variation in the equivalent-circle
diameter of the projected area of all silver halide grains is
preferably 25% or less, more preferably 20% or less. The
coefficient of variation in the equivalent-circle diameter as used
herein means a value obtained by dividing the standard deviation of
the distribution of equivalent circle diameters of individual
silver halide grains by the average equivalent-circle diameter.
[0071] The tabular silver halide grain of the present invention
preferably has a halogen composition of silver iodobromide, silver
bromide, silver chlorobromide or silver chloroiodobromide. Also,
the grain of the present invention preferably has a dislocation
line inside the grain.
[0072] The dehydration and desalting techniques by ultrafiltration
for use in the present invention are described in Research
Disclosure, Vol. 102, Item 10298, and ibid., Vol. 131, Item 13122.
These techniques are also disclosed in U.S. Pat. No. 4,334,012,
5,164,092 and 5,242,597, European Patents 795,455 and 843,206,
JP-A-8-278580 and JP-A-11-231449.
[0073] The membrane module obtained by integrating the membrane
used as the ultrafiltration membrane for use in the present
invention into a container includes a tubular module, a hollow yarn
module, a pleated module, a spiral module, a flat membrane module
and a plate & frame module. Among these, a hollow yarn module
and a flat membrane module are preferred.
[0074] For the ultrafiltration membrane for use in the present
invention, various materials can be used. As for the main material
for useful ultrafiltration membranes, for example,
polyacrylonitrile, polysulfone, polyimide, polyethersulfone,
cellulose acetate, polyvinyl chloride, polyvinyl acetate, polyvinyl
alcohol and ceramics such as aluminum oxide are preferably
used.
[0075] A fractional molecular weight is an index for the
performance of the ultrafiltration membrane for use in the present
invention. The fractional molecular weight is a molecular weight of
giving a blocking percentage (a percentage obtained by dividing the
difference between the concentration of supplied solution and the
concentration of permeated solution by the concentration of
supplied solution) of 90% or more. A fractional molecular weight of
not passing silver halide grains but passing unnecessary salts or
dispersions is preferred. If the fractional molecular weight is
small, the flow rate of the solution permeated through the
ultrafiltration membrane decreases. Therefore, an optimal
fractional molecular weight must be selected. The useful fractional
molecular weight is from 1,000 to 1,000,000, preferably from 3,000
to 100,000.
[0076] The pore size of the ultrafiltration membrane is preferably
from 0.005 to 10 .mu.m, more preferably from 0.01 to 1 .mu.m.
[0077] FIG. 1 is a conceptual view showing one example of
dehydration and desalting of a silver halide emulsion performed
using ultrafiltration of the present invention. In FIG. 1, a
reaction solution containing silver halide grains in a reactor 1 is
stirred by a stirrer 2 and transferred to an ultrafiltration
membrane 12 through a liquid supply pipeline 9, a pump 10 and a
supply valve 12. The reaction solution containing silver halide
grains passes through the ultrafiltration membrane while partially
discharging water, salts and the like through a liquid permeation
pipeline 18, a permeation valve 20 and a permeation flow meter 21.
At this time, a check valve 27 is closed. The remaining reaction
solution containing silver halide grains is returned to the
original reactor 1 through a liquid reflux pipeline 14, a reflux
valve 16 and a reflux flow meter 17. Before and after the passing
of the reaction solution through the ultrafiltration membrane,
pressure gauges 12, 15 and 19 are provided. In order to return the
silver halide grains remaining on the ultrafiltration membrane, a
part of the permeated solution may be passed to the ultrafiltration
module through a backwash pipeline 24, a backwash pump 25, a
backwash valve 26, a check valve 27, a permeation valve 20 and a
liquid permeation pipeline 18 after the completion of
ultrafiltration, so that the silver halide grains adsorbed to the
ultrafiltration membrane can be returned to the original reactor
through the liquid reflux pipeline 14, the reflux valve 16 and the
reflux flow meter 17. The permeated solution as an aqueous solution
for backwash may be replaced by water, an aqueous solution prepared
by diluting the permeated solution with water, or an aqueous
solution after the pBr is adjusted.
[0078] In the ultrafiltration of the present invention, the reflux
and permeation flow rates can be controlled by controlling the
reflux valve or permeation valve. The permeation flow rate can be
increased by increasing the flow rate of pump or by throttling the
reflux valve to increase the reflux flow rate and elevating the
supply pressure. For increasing the permeation amount, a method of
connecting two or more ultrafiltration modules in parallel or in
series and thereby increasing the membrane area is preferred.
[0079] In the case of using the ultrafiltration of the present
invention, the dispersion medium added to the reactor is preferably
gelatin. The molecular weight of gelatin directly added to the
reactor is not limited but as the gelatin concentration is higher,
the viscosity becomes higher and the permeation flow rate in the
ultrafiltration becomes lower, therefore, the gelatin concentration
must be controlled.
[0080] When a low molecular weight gelatin which passes through the
ultrafiltration membrane is used for the gelatin used in the mixing
vessel, the gelatin can be passed through the ultrafiltration
membrane and the concentration of gelatin in the reactor can be
prevented from increasing. The molecular weight of gelatin used in
the mixing vessel can be made lower by means of enzymolysis and
thereby the viscosity can be decreased. The average molecular
weight is from 5,000 to 30,000. Furthermore, the effect on the
thickness of tabular grain can be variously changed by the chemical
modification of gelatin. In order to obtain thin tabular silver
halide grains, an oxidation treatment, a succination treatment and
a trimellitation treatment can be preferably used.
[0081] It is also preferred to perform the ultrafiltration of the
present invention at a stage before the growth by fine grains. The
formation of tabular grains includes a step of elevating the
reactor temperature to ripen the produced grains as nuclei. By
performing this step, tabular grains undergoing growth by fine
grains can be formed. In the present invention, for the purpose of
scale-up, the ultrafiltration is preferably performed in this
ripening step to effect dehydration and desalting. For scaling up
the production of emulsion, if the concentrations of water-soluble
silver solution and aqueous alkali halide solution are merely
elevated at the formation of nuclei, the nuclei produced aggregate
and the grain size distribution is changed for the worse. When
dehydration and desalting are performed by ultrafiltration after
the nuclei are produced at optimal concentrations of water-soluble
silver solution and aqueous alkali halide solution, a large amount
of nuclei can be formed without worsening the grain size
distribution.
[0082] The ultrafiltration of the present invention can be used
other than the above-described step.
[0083] The average grin size of silver halide fine grains prepared
in the mixing vessel for use in the present invention is described
below.
[0084] In order to allow tabular grains to grow while maintaining
the small thickness, an appropriate low supersaturation degree
condition is necessary, where the preference of growth in the side
surface direction is sufficiently high during the growth and
ripening does not occur inside the tabular grain or among tabular
grains. As the fine particle size is larger, the equilibrium
solubility becomes lower and therefore, a low supersaturation state
can be more easily realized, however, if the fine grain size is too
large, the time necessary for the growth is prolonged or the fine
grain remains due to Ostwald ripening among fine grains and
depending on the conditions, ripening is generated inside the
tabular grain or among tabular grains. Accordingly, fine grains
having no small size region must be appropriately added and the
number average equivalent-circle diameter of fine grains must be
changed as the tabular grains grow. For this purpose, the number
average equivalent-circle diameter of silver halide fine grains for
use in the present invention is preferably 40% or more of the
number average thickness of tabular grains under growing. Under the
above-described conditions in the present invention, the most
appropriate equivalent-circle diameter of fine grain changes
depending on the halogen composition of fine grain, the percentage
in number of twin grains, the pH, the pAg, the temperature and the
like. Particularly, in the case where the percentage in number of
twin grains is small, fine grains having twin less remain and
larger fine grains can be added. In the case where the percentage
in number of twins is small, the number average equivalent-circle
diameter of silver halide fine grains prepared immediately before
the addition of the present invention is preferably at least 45% or
more of the number average thickness of tabular grains under
growing. In the present invention, the percentage in number of
twins is preferably 15% or less, more preferably 10% or less, still
more preferably 5% or less.
[0085] The equivalent-circle diameter of the silver halide fine
grain can be determined by the direct observation using an electron
microscope and is determined as a diameter of a circle having the
same projected area. The fine grain is readily increased in the
size due to ripening or the like and therefore, the fine grains to
be added are observed after stopping the change of grain using a
ripening inhibitor or a growth inhibitor. Or, the silver halide
fine grains to be added are immediately placed on a mesh for the
electron microscope observation and after immediately removing the
water content, observed. By performing the electron microscope
observation at a temperature of -100.degree. C. or less, the
observation of silver halide fine grains is facilitated. The
equivalent-circle diameter is determined on 1,000 grains or more
and from the values obtained, the number average equivalent-circle
diameter and the coefficient of variation in the equivalent-circle
diameter can be determined. The percentage in number of twin grains
in the silver halide fine grains can be determined by growing the
fine grain emulsion at a temperature of 40.degree. C. or less,
preferably 35.degree. C. or less, without causing no formation of
new nuclei under high supersaturation condition until a clear grain
shape is shown and observing the photograph of replica of the
grains taken by a transmission electron microscope. This is
described in detail in JP-A-2-146033.
[0086] The halogen composition of the silver halide fine grain for
use in the present invention is selected from silver bromide,
silver iodobromide, silver chloride, silver chlorobromide, silver
iodide, silver chloroiodide and silver chloroiodobromide. Among
these, silver iodobromide having a silver iodide content of 1 to 5
mol % is preferred.
[0087] The silver halide fine grain for use in the present
invention is also preferably used for the preparation of halide
fine grains as nuclei before the growth.
[0088] In the present invention, the residence time of the
water-soluble silver solution, aqueous alkali halide solution and
aqueous dispersion medium solution in the mixing tank of the mixing
vessel means a value obtained by dividing the liquid amount of the
mixing vessel by the rate (volume per second) in supplying halide
fine grains under the conditions that the fine grains are being
prepared in a stable state. In the present invention, the residence
time in the mixing vessel is from 0.001 to 10 seconds, preferably
from 0.001 to 3 seconds, more preferably from 0.001 to 0.5
seconds.
[0089] In the mixing vessel for use in the present invention,
silver halide fine grains can be prepared by adding a water-soluble
silver salt, an aqueous alkali halide solution and a dispersion
medium solution. At this time, these three solutions may be added
separately or the dispersion medium solution and the aqueous alkali
halide solution may be mixed and then added.
[0090] In the present invention, the water-soluble silver solution
is preferably an aqueous silver nitrate solution. The aqueous
alkali halide solution for use in the present invention is usually
an aqueous solution of potassium bromide, sodium bromide, potassium
chloride, sodium chloride, potassium iodide, sodium iodide or a
mixture thereof.
[0091] The concentrations of the water-soluble silver solution and
the aqueous alkali halide solution added to the mixing vessel for
use in the present invention are, in the case of using these
solutions for grains as nuclei, preferably 4 mol/liter or less,
more preferably 1 mol/liter or less, most preferably 0.2 mol/liter
or less. In the case of using these aqueous solutions for the
growth, a high-concentration aqueous solution is preferred in view
of productivity and the concentrations are preferably from 0.5 to 4
mol/liter, more preferably 1.0 mol/liter or more. The temperature
of the aqueous solutions is preferably from 5 to 75.degree. C. In
the case where the silver halide grains obtained by the process of
the present invention are used as nuclei, the concentrations of the
aqueous solutions are preferably 4 mol/liter or less, more
preferably 1 mol/liter or less, most preferably 0.2 mol/liter or
less. In the case of using the grains for the growth, a
high-concentration aqueous solution is preferred in view of
productivity and the concentrations are preferably from 0.5 to 4
mol/liter, more preferably from 1.0 to 4 mol/liter. The temperature
of the water-soluble silver solution, aqueous alkali halide
solution and aqueous dispersion medium solution added is preferably
from 5 to 75.degree. C.
[0092] The dispersion medium used in the mixing vessel of the
present invention is gelatin having an average molecular weight of
5,000 to 30,000. This gelatin greatly affects the probability of
generation of twins in the silver halide grains produced and
therefore, the preferred concentration of the aqueous gelatin
solution varies depending on the use end of the silver halide fine
grains produced. In the case where the silver halide fine grains
are used as nuclei in the preparation of tabular silver halide
grains, a parallel double twin nucleus is necessary and the
concentration of the aqueous gelatin solution must be adjusted so
that a desired probability of generation of twins can be achieved.
The gelatin concentration is preferably selected such that when an
aqueous silver salt solution and an aqueous halide salt solution
are mixed, the gelatin amount becomes from 0.03 to 0.4 g, more
preferably from 0.03 to 0.3 g, per g of silver. In the case of
using the silver halide fine grains for the growth, the silver
halide grains added are preferably dissolved without delay. For
this purpose, the proportion of twin nuclei is preferably smaller
and the concentration of the aqueous gelatin solution is preferably
higher. The concentration of the aqueous gelatin solution is
preferably adjusted such that gelatin is added to a concentration
of 0.2 to 1 g, more preferably 0.3 g or more, most preferably 0.4 g
of more, per g of silver nitrate.
[0093] In the present invention, the following three mixing vessels
are preferred and these are described one by one.
[0094] (1) Mixing Vessel of Stirring Solutions Using Two or More
Rotary Shafts in Closed Stirring Tank
[0095] As shown in FIG. 2, a water-soluble silver solution, an
aqueous alkali halide solution and, if desired, an aqueous
dispersion medium solution are introduced to a mixing vessel 30
installed outside the reactor through addition systems (supply
ports) 31, 32 and 33, respectively (in this case, if desired, the
aqueous dispersion medium solution may be added after mixing it
with the water-soluble silver solution and/or the aqueous alkali
halide solution). These solutions are rapidly and vigorously mixed
in the mixing vessel and immediately introduced to the reactor
through a system (discharge port) 34 to form silver halide fine
grains in the reactor. At this time, the emulsion discharged from
the mixing vessel may be once reserved in a separate vessel and
added later to the reactor. After the completion of fine grain
formation in the reactor, a water-soluble silver solution, an
aqueous alkali halide solution and, if desired, an aqueous
dispersion medium solution are further introduced to the mixing
vessel 30 through addition systems 31, 32 and 33, respectively (in
this case, if desired, the aqueous dispersion medium solution may
be added after mixing it with the water-soluble silver solution
and/or the aqueous alkali halide solution). These solutions are
rapidly and vigorously mixed in the mixing vessel, and immediately
and continuously introduced to the reactor 1 through the addition
system 34 and homogenized in the reactor.
[0096] One practical embodiment of the mixing vessel of the present
invention is described below. If a driving shaft is fixed to
stirring blades and the stirring blades are rotated at a high speed
by a driving apparatus outside the mixing vessel as in conventional
techniques, sealing of the mixing tank and the driving shaft is
very difficult. In the present invention, this problem is solved by
using no driving shaft but as described below, rotating the
stirring blades using the magnetic induction generated between the
stirring blade and an outer magnet connected with magnetic
coupling. In FIG. 2, the stirring tank 35 is constructed by a
stirring tank body 36 with the central axis being vertically
directed and seal plates 37 working as tank walls sealing top and
bottom opening ends of the tank body 36. The tank body 36 and the
seal plate 37 are formed of a nonmagnetic material having excellent
magnetic permeability. The stirring blades 38 and 39 are disposed
with a space to face each other at the top and bottom ends in the
stirring tank 35 and driven to rotate in the converse direction
from each other. The stirring blades 38 and 39 each constitutes a
magnetic coupling C with an outer magnet 40 or 41 disposed outside
the tank wall (seal plate 37) adjacent to the stirring blade 38 or
39. That is, stirring blades 38 and 39 are connected to outer
magnets 40 and 41, respectively, by a magnetic force and operated
to rotate in the converse direction from each other by
rotation-driving outer magnets 40 and 41 using independent motors
42 and 43, respectively.
[0097] Furthermore, in FIG. 2, the mixing vessel comprises a
stirring tank 35 having solution supply ports 31, 32 and 33 for
supplying a water-soluble silver solution, an aqueous alkali halide
solution and, if desired, an aqueous dispersion medium solution to
be stirred and a discharge port 34 for discharging the silver
halide fine grain emulsion after the completion of stirring
treatment, and a pair of stirring blades 38 and 39 as stirring
means which are rotation-driven in the stirring tank 35 and thereby
control the stirring state of solutions in the stirring tank 35. As
for the shape of the mixing vessel 28, a cylindrical form is often
used but rectangular, hexagonal and various other forms may be
used. The paired stirring blades are disposed with a space to face
each other at the top and bottom ends in the stirring tank 35 and
driven to rotate in the converse direction from each other. In FIG.
2, this paired stirring blades are vertically disposed to face each
other but may be horizontally disposed to face each other or may be
diagonally disposed. In FIG. 2, a pair of two stirring blades are
disposed at the positions facing each other but two or more pairs
of an even number of four or more conversely rotating stirring
blades may be used or an odd number (including one) of stirring
blades not forming a pair may also be used. Also, by the combined
use of an even number of conversely rotating stirring blades making
a pair and an odd number (including one) of stirring blades, more
efficient stirring can be practiced.
[0098] In the mixing vessel of the present invention, when stirring
blades facing each other in the mixing vessel are driven, the
stirring blades must be rotated at a high speed for realizing a
higher mixing efficiency. The rotation number is 1,000 rpm or more,
preferably 3,000 or more, more preferably 5,000 rpm or more.
[0099] FIG. 3 shows the structure of the magnetic coupling C at the
bottom end of the stirring tank 35. In this magnetic coupling C
according to one practical embodiment, as shown in the Figure, a
double side bipolar magnet 45 disposed such that an N pole face and
an S pole face run in parallel to the central axis 44 of rotation
and are superposed to interpose the central axis 44 of rotation, is
used for each of the stirring blades 38 and 39 constituting the
magnetic coupling C. For the outer magnet 41, a bilateral bipolar
magnet (U-shaped magnet) 46 is used, where an N pole face and an S
pole face stand abreast at the symmetrical positions with respect
to the central axis 44 of rotation on the plane orthogonal to the
central axis 44 of rotation. In this magnetic coupling C, in
contrast with the above case, even if a double side bipolar magnet
45 is used as the outer magnet 41 and a bilateral bipolar magnet 36
as stirring blades 38 and 39, the same operation effect can be
obtained.
[0100] In the above-described magnetic coupling C, the line L of
magnetic force connecting the outer magnet 41 with the stirring
blades 38 and 39 is as shown in FIG. 4(a) and, for example, as
compared with the magnetic flux formed in the case of constituting
the magnetic coupling using bilateral bipolar magnets by
themselves, the magnetic flux diameter connecting magnets each
other can be doubled. At the same time, on rotating the outer
magnet 41, the magnetic flux deflects as shown in FIG. 4 (b) and
the magnetic coupling can be invested with flux viscosity which
prevents the cutting of magnetic flux. Therefore, the connection
strength as coupling is greatly improved and high-speed rotation of
stirring blades 38 and 39 becomes possible by the use of a high
rotary motor for the motors 42 and 43.
[0101] The stirring in the mixing vessel of the present invention
may be performed by rotating the paired stirring blades in the same
direction or in the converse direction but is preferably performed
by the rotation in the converse direction. As for the rotation
number, the stirring blades may be driven by the same rotation
number or by the different rotation numbers.
[0102] For the mixing vessel of the present invention, a mixing
vessel having a rotation shaft protruding through the stirring tank
of the mixing vessel and sealed in the periphery of this rotation
shaft is also preferably used. Also in this case, a pair of
stirring blades may be rotated in the same or converse direction
but are preferably rotated in the converse direction. As for the
rotation number, the stirring blades may be driven by the same
rotation number or by the different rotation numbers.
[0103] In the present invention, an aqueous protective colloid
solution is added to the mixing vessel and for this addition, the
following methods are used.
[0104] a. An aqueous dispersion medium solution is added alone to a
mixing vessel. The concentration of the aqueous dispersion medium
solution is 0.5% or more, preferably from 1% to 20%. The flow rate
thereof is at least from 20% to 300%, preferably .from 50% to 200%,
of the sum of flow rates of a water soluble silver solution and an
aqueous alkali halide solution.
[0105] b. An aqueous dispersion medium solution is incorporated
into an aqueous alkali halide solution. The concentration of
dispersion medium is 0.4% or more, preferably from 1% to 20%.
[0106] c. A dispersion medium is incorporated into a water-soluble
silver solution. The concentration of dispersion medium is 0.4% or
more, preferably from 1% to 20%. In the case of using gelatin as
the dispersion medium, gelatin silver is formed from silver ion and
gelatin and silver colloid is produced by photolysis and pyrolysis.
Therefore, a water-soluble silver solution and a gelatin solution
are preferably added immediately before use.
[0107] These methods a, b and c may be used individually or in
combination, or three methods may be used at the same time.
[0108] (2) Mixing Vessel of Stirring Solutions turned into Linear
Jet Stream
[0109] In the mixing vessel of the present invention, silver halide
fine grains can be prepared by adding and mixing a water-soluble
silver solution, an aqueous alkali halide solution and an aqueous
dispersion medium solution which are turned into linear jet
streams. The aqueous dispersion solution may be added to either one
of the water-soluble silver solution and the aqueous alkali halide
solution or those three solutions may be mixed separately.
[0110] The flow rate of the solution added as the jet stream to the
mixing vessel of the present invention is preferably 100 m/sec or
more, more preferably 250 m/sec or more, and most preferably 500
m/sec or more.
[0111] In the mixing vessel of the present invention, the diameter
of the capillary for mixing the solutions is preferably 20 times or
less, more preferably 10 times or less, and most preferably 7 times
or less, the diameter of the port for adding the linear jet stream.
The length of the capillary for mixing the solutions is preferably
10 times or more, more preferably 50 times or more, and most
preferably 100 times or more, the diameter thereof. The capillary
may have a recess on the inside. When the solution added flows
through the capillary, the recess converts the flow into finer
turbulence to cause more homogeneous mixing. In the case of
performing the mixing by a jet stream having a high flow rate, the
apparatus is preferably equipped with a cooler, because the
temperature of the mixed solution elevates.
[0112] In the mixing vessel of the present invention, the mixing of
the water-soluble silver solution and the aqueous alkali halide
solution is preferably not accompanied by mechanical stirring. When
accompanied by the mechanical stirring, the mixing can be hardly
performed without causing circulation. Furthermore, in the case
where the mixing time is as short as 0.1 second or less, thorough
mixing can be hardly attained by the mechanical stirring.
[0113] In the mixing vessel of the present invention, the
water-soluble silver solution and the aqueous alkali halide
solution both may be turned into a linear jet stream and then
mixed, or while turning one of these solutions into a linear jet
stream, another may be mixed utilizing the negative pressure of the
jet stream.
[0114] As the mixing method satisfying the requirements of the
present invention, a high-pressure homogenizer (DeBEE 2000)
manufactured by BEE INTERNATIONAL Co. may be applied. Using the
dual field process of this homogenizer, one of the water-soluble
silver solution and the aqueous alkali halide solution can be
turned into a high speed jet stream and then mixed with another
solution. When a high pressure is applied to the aqueous solution
turned into a jet stream, a high kinetic energy is imparted to the
solution and thereby, two solutions can be mixed within an
extremely short time. According to this method, circulation of
allowing the solution added to again return to the vicinity of the
addition port does not occur and furthermore, the mechanical
stirring is not necessary because the added solution has a
sufficiently high kinetic energy.
[0115] (3) Mixing Vessel utilizing Laminar Flow
[0116] In the mixing vessel of the present invention, a laminar
flow is utilized. The water-soluble silver solution and the aqueous
alkali halide solution each is finely divided into lamellas to
allow these two solutions to contact at a wider area, whereby ion
can be uniformly diffused within a short time and more rapid and
more uniform mixing can be realized. The transfer of ion by
diffusion is given as a product of a diffusion coefficient and a
concentration gradient by the following formula according to the
Fick's law of showing the relationship with the change of
concentration in aging:
t.about.dl.sup.2/D
[0117] wherein D is a diffusion constant, dl is the thickness of
lamella and t is a mixing time.
[0118] According to the formula above, the mixing time t is
proportional to the square of lamella thickness dl. Therefore, the
mixing time can be very effectively shortened by reducing the
thickness of lamella.
[0119] In the present invention, the expected effect can be
realized by using Microreactor manufactured by IMM (Institute fur
Mikrotechnik Mianz). The details on Microreactor are described in
W. Ehrfeld, V. Hessel and H. Loewe, Microreactor, 1st ed.,
Wiley-VCH (2000). That is, the principle thereof is in the
multilamination and subsequent diffusion mixing.
[0120] The fluids of water-soluble silver solution and aqueous
alkali halide solution pass through slits running into each other
and having a thickness on the order of tens of microns and thereby
are divided into a large number of lamella fluids. At the outlets
of slits, these solutions come into contact in a wide area in the
direction normal to their flowing direction and immediately, silver
ion and halide ion start diffusing. The mixing by diffusion
completes within a short time and by the ionic reaction
simultaneously occurred, silver halide fine grains are formed.
[0121] In the mixing vessel of the present invention, the thickness
of the lamella is, in the direction normal to its flowing
direction, from 1 to 500 .mu.m, preferably from 1 to 100 .mu.m,
more preferably from 1 to 50 .mu.m. In the present invention, the
mixing time using the laminar flow is less than 0.5 seconds,
preferably less than 100 milli-seconds, more preferably less than
50 milli-seconds.
[0122] A micromixer which is the mixing vessel of the present
invention is an apparatus having a channel with an equivalent
diameter of 1 mm or less. The term "equivalent diameter" as used in
the present invention is also called an equivalent (diameter) size
and is a term used in the field of mechanical engineering. Imagine
a circular tube equivalent to a pipeline (in the present invention,
the channel) having an arbitrary cross-sectional shape. Then, the
diameter of the equivalent tube is called an equivalent diameter.
The equivalent diameter is defined as d.sub.eq=4A/p, wherein A is
the cross-sectional area of pipeline and p is the length of wetted
perimeter of the pipeline (perimeter length). When this is applied
to the circular tube, this equivalent diameter agrees with the
diameter of the circular tube. The equivalent diameter is used for
presuming the fluidity or thermal conductance properties of the
pipeline based on the data of equivalent circular tube and
represents a spatial scale (representative length) of a phenomenon.
The equivalent diameter is d.sub.eq=4a.sup.2/4a=a for an
equilateral square tube having a side a, d.sub.eq=a/3.sup.1/2 for
an equilateral triangle tube having a side a, and d.sub.eq=2h for a
flow between parallel plates having a path height h (see, Nippon
Kikai Gakkai (compiler), Kikai Kogaku Jiten (Dictionary of
Mechanical Engineering), Maruzen (1997)).
[0123] The channel in the mixing vessel of the present invention is
formed on a solid substrate by a fine working technique. Examples
of the material used include metal, silicon, Teflon, glass, ceramic
and plastic. In the case where resistance against heat, pressure
and solvent is required, the material is preferably metal, silicon,
Teflon, glass or ceramic, more preferably metal. Examples of the
metal include nickel, aluminum, silver, gold, platinum, tantalum,
stainless steel, hastelloy (Ni-Fe alloy) and titanium. Among these,
preferred are stainless steel, hastelloy and titanium because of
their high corrosion resistance. In the case of conventional batch
system reaction apparatuses, an apparatus where the metal (e.g.,
stainless steel) surface is lined with glass is used in treating an
acidic substance. Also in the Microreactor, the metal surface may
be coated with glass. On the metal, not only glass but also a
different metal or other material may be coated according to the
purpose. Also, a metal or glass may be coated on a material other
than metal, for example, ceramic.
[0124] Representative examples of the fine working technique for
forming a channel of the mixing vessel of the present invention
include LIGA technique using X-ray lithography, high aspect ratio
photolithography using EPON SU-8, microdischarge working
(.mu.-EDM), high aspect ratio working of silicon by Deep RIE, hot
emboss working, stereolithography, laser working, ion beam working
and mechanical microcutting work using a micro-tool made of a hard
material such as diamond. These techniques may be used individually
or in combination. Among these fine working techniques, preferred
are LIGA technique using X-ray lithography, high aspect ratio
photolithography using EPON SU-8, microdischarge working (.mu.-EDM)
and mechanical micro-cutting work.
[0125] In assembling the micromixer which is the mixing vessel of
the present invention, a junction technique is often used. The
junction technique in general is roughly classified into solid
phase junction and liquid phase junction. Representative examples
of the junction method commonly used include, as solid phase
junction, pressure junction and diffusion junction, and as liquid
phase junction, welding, eutectic junction, soldering and adhesion.
The assembling is preferably performed by a high-precision junction
method which is not accompanied by deterioration of the material
due to high-temperature heating or destruction of fine structures
such as channel due to large deformation and can maintain the
dimensional precision. Examples of the technique therefor include
silicon direct junction, anodic junction, surface activation
junction, direct junction using hydrogen bond, junction using an
aqueous HF solution, Au-Si eutectic junction and void-free
adhesion.
[0126] The equivalent diameter of the channel used for the mixing
vessel of the present invention is 1 mm or less, preferably from 10
to 500 .mu.m, more preferably from 20 to 300 .mu.m. The length of
channel is not particularly limited but is preferably from 1 to
1,000 mm, more preferably from 10 to 500 mm.
[0127] The channel for use in the present invention is not limited
to one channel but if desired, many channels may be provided in
parallel (numbering-up) to increase the amount processed. In the
present invention, the reaction is performed in the course of
passing through the channel, namely, in the flow.
[0128] The channel of the micromixer which is the mixing vessel of
the present invention may be subjected to a surface treatment, if
desired. Particularly, in the case of operating an aqueous
solution, there may arise a problem of adhesion of the sample to
glass or silicon and therefore, the surface treatment is important.
The fluid in the micro-size channel is preferably controlled
without integrating movable parts requiring a complicated
production process. For example, when hydrophilic and hydrophobic
regions are provided in the channel by the surface treatment, the
fluid can be operated utilizing the difference in the surface
tension acting at the boundary between those regions.
[0129] For introducing and mixing a reagent or sample into the
micro-size channel in the micromixer which is the mixing vessel of
the present invention, a fluid control function is necessary.
Particularly, the behavior of fluid in the micro region has
different properties from those in the macro scale and therefore, a
control system suitable for the micro scale must be considered. The
fluid control system includes, in the classification by morphology,
continuous flowing system and liquid droplet (liquid plug) system
and in the classification by driving force, electrical driving
system and pressure driving system. These systems are described in
detail below.
[0130] In handling a fluid, a continuous flowing system is most
widely used. In the control of fluid by the continuous flowing
system, it is common to entirely fill the inside of channel of the
microreactor with a fluid and drive the fluid as a whole by a
pressure source prepared outside, such as syringe pump. In this
case, one advantage is that a control system can be realized by a
relatively simple set-up, however, there are problems that an
operation involving a plurality of steps or exchange of sample is
difficult, the latitude in the system construction is narrow, and
the dead volume is large because the driving medium is the solution
itself. The liquid droplet (liquid plug) system is a different
system from the continuous flowing system. In this system, liquid
droplets partitioned by air are moved inside the reactor or in the
channel reaching the reactor and individual liquid droplets are
driven by the air pressure. At this time, a vent structure of
allowing an air between the liquid droplet and the channel wall or
between liquid droplets to escape outside according to the
necessity or a valve structure for keeping the pressure in the
branched channel independent from other portions must be provided
in the inside of the reactor system. Furthermore, since the liquid
droplets are operated by controlling the pressure difference, a
pressure control system comprising a pressure source and a
changeover valve must be constructed in the outside. As such, the
liquid droplet system is slightly complicated in the apparatus
construction or reactor structure, however, a multi-stage operation
of individually operating a plurality of liquid droplets and
sequentially performing several reactions can be performed and
therefore, the latitude in the system construction is
broadened.
[0131] As for the driving system for performing the control of
fluid, commonly and widely employed are an electrical driving
method where a high voltage is applied to both ends of the channel
to generate an electroosmosis flow and the fluid is moved by the
flow, and a pressure driving method where a pressure source is
prepared in the outside and the fluid is moved by applying a
pressure. The difference between these two methods is as follows.
For example, the fluid is known to behave to give a flat
distribution for the flow rate profile in the cross section of
channel in the case of electrical driving system and to give a
hyperbolic distribution with the flow rate being high in channel
center part and low in the wall surface part in the case of
pressure driving system. For the purpose of moving the fluid while
keeping the shape of sample plug or the like, the electrical
driving system is suitable. In performing the electrical driving
system, the inside of channel must be filled with a fluid and
therefore, a continuous flowing system must be employed. However,
the fluid can be operated by the electrical control and therefore,
a relatively complicated treatment of, for example, continuously
changing the mixing ratio of two kinds of solutions and forming a
concentration gradient with the passage of time is realized. In the
case of the pressure driving system, the control can be attained
irrespective of electrical properties of the fluid and secondary
effects of affecting the substrate, such as heat generation or
electrolysis, do not occur. Therefore, the application range of
this system is broad. However, a pressure source must be prepared
in the outside and the response properties in the operation change
according to the size of dead volume in the pressure system,
therefore, automatization of complicated treatments is
necessary.
[0132] The method for the control of fluid is appropriately
selected according to the purpose but preferred is a pressure
driving method using a continuous flowing system.
[0133] The temperature of the micromixer which is the mixing vessel
of the present invention may be controlled by placing the apparatus
as a whole in a container under temperature control. Or, by
providing a heater structure such as metal resistance wire or
polysilicon in the apparatus, a thermal cycle of using the heater
structure for heating and performing the cooling by spontaneous
cooling may be performed. The sensing of the temperature is
performed as follows. In use of a metal resistance wire, the same
resistance wire as the heater is additionally provided and the
temperature is sensed based on the change in the resistance value.
In use of polysilicon, the sensing is performed using a
thermocouple. The heating and cooling may also be performed from
the outside by contacting a Peltier device with the reactor. The
method used is selected according to the use end or the material of
the reactor body.
[0134] Among the above-described three kinds of mixing vessels,
preferred are (1) a mixing vessel of stirring solutions using two
or more rotary shafts in a closed stirring tank and (2) a mixing
vessel of stirring solutions turned into a linear jet steam.
[0135] In the emulsion according to the production process of the
present invention, 50% or more of the entire projected area is
preferably occupied by tabular grains having an epitaxial junction
at least at one apex part of six apex parts of a hexagon. More
preferably, 70% or more of the entire projected area is preferably
occupied by tabular grains having an epitaxial junction at least at
one apex part of six apex parts of a hexagon. The apex part as used
herein means, in a fan portion centered in one apex on viewing a
tabular grain from the vertical direction with respect to the main
plane and defined by two sides constituting that apex, the area
within a radius corresponding to 1/3 of the length of the shorter
side out of those two sides. In the case where the main plane of
the tabular grain has a rounded triangular or hexagonal shape, the
apex and side of the main plane are the apex and side of an
imaginary triangle or hexagon formed by extending respective sides.
Unlike the above-described epitaxial emulsion, an epitaxial
junction is usually formed on sides other than in the main plane or
apex part of a tabular grain.
[0136] The epitaxial emulsion preferred in the present invention
can be judged as follows. On an electron microphotograph by a
replica of tabular grains, 100 or more grains are selected and
classified into three groups, a grain having an epitaxial junction
at one or more apex part, a group having an epitaxial junction only
on side or main plane, and a grain having no epitaxial junction. An
emulsion where 50% or more of the entire projected area is occupied
by grains having an epitaxial junction at one or more apex comes
under the epitaxial emulsion preferred in the present invention. An
emulsion where 90% or more of the entire projected area is occupied
by the abovedescribed epitaxial grains is more preferred.
[0137] The epitaxial part is silver chloride, silver chlorobromide
or silver iodochlorobromide. The silver chloride content of the
epitaxial part is preferably 1 mol % or more higher than that of
the host tabular grain (a grain as a substrate before the junction
of an epitaxial part). The silver chloride content is more
preferably 10 mol % or more higher than that of the host tabular
grain. However, the silver chloride content of the epitaxial part
is 50 mol % or less. The silver bromide content of the epitaxial
part is preferably 30 mol % or more, more preferably 50 mol % or
more, and the silver iodide content of the epitaxial part is
preferably from 1 to 20 mol %. The silver amount of the epitaxial
part is preferably from 1 to 10 mol %, more preferably from 2 to 7
mol %, based on the silver amount of the host tabular grain.
[0138] In the emulsion produced by the present invention, 70% or
more of the entire projected area is preferably occupied by tabular
grains having at least one dislocation line in the epitaxial part.
Preferably, 80% or more of the entire projected area is occupied by
tabular grains having at least one dislocation line in the
epitaxial part. In the emulsion of the present invention, 70% or
more of the entire projected area is occupied by tabular grains
having network dislocation lines in the epitaxial part. Most
preferably, 80% or more of the entire projected area is occupied by
tabular grains having network dislocation lines in the epitaxial
part. The network dislocation lines as used herein means that a
plurality of dislocation lines which cannot be counted are
intercrossed. In a tabular grain having an epitaxial junction at
two or more apex parts, it is not always necessary that a
dislocation line is present in the epitaxial parts. Insofar as one
dislocation line, preferably network dislocation lines, is
contained in the epitaxial part joined at least at one apex part,
the emulsion is the epitaxial emulsion preferred in the present
invention. Preferably, 70% or more of the epitaxial part present at
the apex part contains network dislocation lines.
[0139] In the present invention, 70% or more of the entire
projected area preferably has no dislocation line other than in the
epitaxial junction part. The dislocation line provides a
preferential deposition site for the epitaxial deposition and
inhibits the formation of an epitaxial tabular grain of the present
invention. Preferably, 70% or more of the entire projected area has
0 dislocation line. Here, the epitaxial-deposited site is excluded.
Most preferably, 90% or more of the entire projected area has 0
dislocation line. The dislocation line of a tabular grain can be
observed by a direct method using a transmission electron
microscope at a low temperature described, for example, in J.F.
Hamilton, Phot. Sci. Eng., Vol. 11, page 57 (1967) and T. Shiozawa,
J. Soc. Phot. Sci. Japan, Vol. 35, page 213 (1972). More
specifically, silver halide grains taken out from an emulsion while
taking care not to impose a pressure high enough to cause
generation of a dislocation line on grains are placed on a mesh for
the observation by an electron microscope and the sample cooled to
prevent the damage (e.g., print out) by an electron beam is
observed according to a transmission process. At this time, as the
thickness of the grain is larger, the electron beam is more
difficult to transmit. Therefore, a highpressure type (200 kV or
more for a grain having a thickness of 0.25 .mu.m) electron
microscope is used for more clearly observing the grains. From a
photograph of grains obtained by such a method, the site and number
of dislocation lines when viewed from the vertical direction with
respect to the main plane can be determined on each grain.
[0140] In the emulsion of the present invention, 70% or more,
preferably 80% or more, of the entire projected area is occupied by
tabular grains having an epitaxial junction protruded toward the
side face direction of an epitaxial junction host tabular grain
which has a terrace-like epitaxial junction on the main plane at
the apex part of a host tabular grain. A tabular grain having an
epitaxial junction protruded toward the side face direction of a
host tabular grain from the apex on the main plane and a tabular
grain having a terrace-like epitaxial junction on the main plane at
the apex part of a host tabular grain are distinguished as follows.
From a replica process electron microphotograph of tabular grains,
100 or more grains are selected and a grain where the area of the
portions not overlapping the apex part and protruded toward the
side face direction occupies 60% or more of the entire projected
area of epitaxial parts per one grain is defined as a tabular grain
having an epitaxial junction protruded toward the side face
direction of a host tabular grain. Unless this shape is kept by
control after the epitaxial deposition, the epitaxial depositions
are re-oriented and thereby, the dislocation line disappears.
[0141] The epitaxial tabular emulsion satisfying the
above-described conditions, which is preferred in the present
invention, can be lowered in the pBr of the emulsion. The pBr can
be lowered to 3.5 or less and thereby, the storability can be
remarkably improved.
[0142] The preparation process of the epitaxial emulsion preferred
in the present invention is specifically described below. The
preparation of host tabular grain and the preparation of epitaxial
part are described in detail.
[0143] The host tabular grain necessary for the preparation of the
epitaxial emulsion of the present invention is described below. The
host tabular grain of the present invention is preferably a
multi-structure grain where the silver iodide distribution has a
double or greater structure. The term "silver iodide distribution
has a structure" as used herein means that the difference in the
silver iodide content among respective structures is 0.5 mol % or
more, preferably 1 mol % or more. In the present invention, the
term "outermost layer" of a host tabular grain means a layer phase
present in the most outside of a multiple structure regarding the
silver iodide distribution. The structure regarding the silver
iodide distribution can be fundamentally determined by the
calculation using the formulation values in the preparation process
of grain. At the interface between respective structures, the
silver iodide content may abruptly change or gradually change. For
confirming this, the above-described EPMA method is effective,
though the measurement precision in the analysis must be taken
account of. By this means, the silver iodide distribution in grain
when a tabular grain is viewed from the direction vertical to the
main plane can be analyzed. Also, by using a sample after hardening
the sample and cutting it into an ultrathin specimen using a
microtome, the silver iodide distribution in grain on the cross
section of a tabular grain can be analyzed.
[0144] In the present invention, the outermost layer of a host
tabular grain preferably has a silver iodide content of 10 mol % or
more. The outermost layer preferably occupies 20% or less, more
preferably from 5 to 20%, of the entire silver amount and the
silver iodide content thereof occupies from 15 to 30 mol %. Here,
the ratio of the outermost layer means a ratio of the silver amount
used for the preparation of the outermost layer to the silver
amount used for obtaining a final grain in the preparation of a
host tabular grain. The ratio of the silver iodide content means a
molar ratio in percentage of the silver iodide amount used for the
preparation of the outermost layer to the silver amount used for
the preparation of the outermost layer. The distribution thereof
may be or may not be uniform. In the case where the silver iodide
content distribution is not uniform, the silver iodide content is
an average value in the outermost layer. More preferably, the
outermost layer occupies from 10 to 15% of the entire silver amount
and the silver iodide content occupies from 15 to 25 mol %.
[0145] Examples of silver halide solvent which can be used in the
present invention include (a) organic thioethers described in U.S.
Pat. Nos. 3,271,157, 3,531,286 and 3,574,628, JP-A-54-1019 and
JP-A-54-158917, (b) thiourea derivatives described in
JP-A-53-82408, JP-A-55-77737 and JP-A-55-2982, (c) silver halide
solvents having a thiocarbonyl group interposed between an oxygen
or a sulfur atom and a nitrogen atom described in JP-A-53-144319,
(d) imidazoles described in JP-A-54-100717, (e) sulfites, (f)
ammonia and (g) thiocyanates.
[0146] Preferred solvents are thiocyanates, ammonia and
tetramethylthiourea. The amount of the solvent used varies
depending on the kind of the solvent but, for example, in the case
of thiocyanate, the amount is preferably from 1.times.10.sup.-4 to
1.times.10.sup.-2 mol per mol of silver halide.
[0147] The method for changing the plane index of a side face of
the tabular grain emulsion is described in EP-A515,894. A
polyalkylene oxide compounds described, for example, in U.S. Pat.
No. 5,252,453 may also be used. Use of plane index modifiers
described, for example, in U.S. Pat. Nos. 4,680,254, 4,680,255,
4,680,256 and 4,684,607 is an effective method. The photographic
spectral sensitizing dyes commonly used can also be used as the
plane index modifier same as above.
[0148] In the present invention, the host tabular grain preferably
has no dislocation line. By using in combination the nucleation,
ripening and growth steps which are described in detail above, the
dislocation line can be eliminated.
[0149] The epitaxial junction necessary for the preparation of the
epitaxial emulsion preferred in the present invention is described
in detail below. The epitaxial deposition may be immediately
performed after the formation of host tabular grains or may be
performed after normal desalting subsequent to the formation of
host tabular grains.
[0150] The host tabular grain emulsion before the epitaxial
deposition preferably contains gelatin having a molecular weight
distribution measured according to PAGI method such that a high
molecular weight component having a molecular weight of about
2,000,000 or more is in the range from 5 to 30% and a low molecular
weight component having a molecular weight of about 100,000 or less
is in the range of 55% or less, more preferably gelatin having a
molecular weight distribution measured according to PAGI method
such that a high molecular weight component having a molecular
weight of about 2,000,000 or more is in the range from 5 to 15% and
a low molecular weight component having a molecular weight of about
100,000 or less is in the range of 50% or less. At the time of
performing the epitaxial junction, the high molecular weight
gelatin is added in an amount of 10 mass% (weight%) or more,
preferably 30 mass% or more, more preferably 50 mass% or more,
based on the entire gelatin amount. The addition of this gelatin
before the coating is also effective but the effect is small.
[0151] The gelatin for use in the present invention may be
subjected to various modification treatments described below.
Examples of the modified gelatin include phthalated gelatin with an
amino group being modified, succinated gelatin, trimellited
gelatin, pyromellited gelatin, esterified gelatin with a carboxyl
group being modified, amidated gelatin, formulated gelatin with an
imidazole group being modified, oxidation-treated gelatin reduced
in the methionine group, and reduction-treated gelatin increased in
the methionine group.
[0152] Other than these, hydrophilic colloid can also be used.
[0153] Examples of the hydrophilic colloid which can be used
include proteins such as gelatin derivatives, graft polymers of
gelatin to other polymer, albumin and casein; sugar derivatives
such as cellulose derivatives (e.g., hydroxyethylcellulose,
carboxymethylcellulose, cellulose sulfates), sodium alginate and
starch derivatives; and various synthetic hydrophilic polymer
substances including homo- or copolymers such as polyvinyl alcohol,
polyvinyl alcohol partial acetal, poly-N-vinylpyrrolidone,
polyacrylic acid, polymethacrylic acid, polyacrylamide,
polyvinylimidazole and polyvinylpyrazole. As for the gelatin, not
only lime-treated gelatin but also acidtreated gelatin and
enzyme-treated gelatin described in Bull. Soc. Sci. Photo. Japan,
No. 16, page 30 (1966) may be used. Also, hydrolysate and
enzymolysate of gelatin may be used.
[0154] For the preparation of epitaxial emulsion, the pH, the pAg,
and the species, concentration and viscosity of gelatin are
selected. Particularly, the pH is important and the pH is
preferably from 4 to 5.5, more preferably from 4.5 to 5. By setting
the pH to this range, the epitaxial deposition can be uniformly
performed among grains and the effect of the present invention can
be remarkably brought out.
[0155] A sensitizing dye is preferably used as the epitaxial
junction site indicator. The position for the epitaxial deposition
can be controlled by selecting the amount and kind of dye used. The
dye is preferably added in an amount of 50 to 90% of the saturation
coverage. The dye used here includes a cyanine dye, a merocyanine
dye, a complex cyanine dye, a complex merocyanine dye, a holopolar
cyanine dye, a hemicyanine dye, a styryl dye and a hemioxonol dye.
Among these dyes, particularly useful are the dyes belonging to
cyanine dye. To these dyes, any nucleus usually used for cyanine
dyes as a basic heterocyclic nucleus can be applied. Examples of
the nucleus include a pyrroline nucleus, an oxazoline nucleus, a
thiazoline nucleus, a pyrrole nucleus, an oxazole nucleus, a
thiazole nucleus, a selenazole nucleus, an imidazole nucleus, a
tetrazole nucleus, a pyridine nucleus, a nucleus resulting from
fusion of an alicyclic hydrocarbon ring to the above-described
nucleus, and a nucleus resulting from fusion of an aromatic
hydrocarbon ring to the above-described nucleus, such as indolenine
nucleus, benzindolenine nucleus, indole nucleus, benzoxazole
nucleus, naphthoxazole nucleus, benzothiazole nucleus,
naphthothiazole nucleus, benzoselenazole nucleus, benzimidazole
nucleus and quinoline nucleus. On the carbon atom of these nuclei,
a substituent may be present. The above-described sensitizing dyes
may also be used for the purpose of spectral sensitization.
[0156] These sensitizing dyes may be used either individually or in
combination of two or more thereof. The combination of sensitizing
dyes is often used for the purpose of supersensitization.
Representative examples thereof are described in U.S. Pat. Nos.
2,688,545, 2,977,229, 3,397,060, 3,522,052, 3,527,641, 3,617,293,
3,628,964, 3,666,480, 3,672,898, 3,679,428, 3,703,377, 3,769,301,
3,814,609, 3,837,862 and 4,026,707, British Patents 1,344,281 and
1,507,803, JP-B-43-4936 (the term "JP-B" as used herein means an
"examined Japanese patent publication"), JP-B-53-12375,
JP-A-52-110618 and JP-A-52-109925.
[0157] Together with the sensitizing dye, a dye which itself has no
spectral sensitization effect or a substance which absorbs
substantially no visible light, but which exhibits
supersensitization may be added simultaneously or separately.
[0158] When the silver iodide content in the extreme surface layer
of the outermost layer of a host tabular grain is set higher than
that of the outermost layer at the adsorption of a sensitizing dye,
this is preferred for the preparation of epitaxial emulsion. In
advance of the addition of a sensitizing dye, iodide ion is added.
The above-described AgI fine grain emulsion is preferably added to
increase the silver iodide content on the surface of the host
tabular grain. This enables uniform distribution of the silver
iodide content among grains and uniform adsorption of a sensitizing
dye, whereby the epitaxial emulsion of the present invention can be
prepared. The amount of the iodide ion or silver iodide added is
preferably from 1.times.10.sup.-4 to 1.times.10.sup.-2 mol, more
preferably from 1.times.10.sup.-3 to 5.times.10.sup.-3 mol, per mol
of the silver amount of the host tabular grain.
[0159] The epitaxial part may be formed by a method of
simultaneously adding a solution containing halide ion and a
solution containing AgNO.sub.3, a method of separately adding these
solutions, or a method of appropriately combining this addition
with the addition of AgCl fine grain, AgBr fine grain or AgI fine
grain having a grains size smaller than the host tabular grain or
with the addition of mixed crystal grains thereof. The addition
time in adding an AgNO.sub.3 solution is preferably 30 seconds to
10 minutes, more preferably from 1 to 5 minutes. For the formation
of an epitaxial emulsion, the concentration of the silver nitrate
solution added is preferably 1.5 mol/liter or less, more preferably
0.5 mol/liter or less. At this time, the stirring in the system
must be efficiently performed and the viscosity in the system is
preferably lower.
[0160] The silver amount in the epitaxial part is preferably from 1
to 10 mol %, more preferably from 2 to 7 mol %, based on the silver
amount of the host tabular grain. If the silver amount in the
epitaxial part is too small, an epitaxial emulsion cannot be
prepared, whereas if it is too large, the epitaxial emulsion
becomes unstable.
[0161] At the formation of the epitaxial part, the pBr is
preferably 3.5 or more, more preferably 4.0 or more. The
temperature is preferably 35 to 45.degree. C. At this formation of
epitaxial part, a hexacyano metal complex is preferably doped.
[0162] Among hexacyano metal complexes, those containing iron,
ruthenium, osmium, cobalt, rhodium, iridium or chromium are
preferred. The amount of the metal complex added is preferably from
10.sup.-9 to 10.sup.-2, more preferably from 10.sup.-8 to
10.sup.-4, per mol of silver halide. The metal complex can be added
after dissolving it in water or an organic solvent. The organic
solvent preferably has miscibility with water. Examples of the
organic solvent include alcohols, ethers, glycols, ketones, esters
and amides.
[0163] The metal complex is particularly preferably a hexacyano
metal complex represented by the following formula (I). By the use
of an emulsion using a hexacyano metal complex, an effect of giving
a light-sensitive material having high sensitivity and even when
the light-sensitive material is stored for a long period time,
preventing the generation of fog can be obtained.
[M(CN).sub.6].sup.n- (I)
[0164] (wherein M is iron, ruthenium, osmium, cobalt, rhodium,
iridium or chromium, and n is 3 or 4).
[0165] Specific examples of the hexacyano metal complex are set
forth below.
[0166] (I-1) [Fe(CN) .sub.6].sup.4-
[0167] (I-2) [Fe(CN) .sub.6].sup.3-
[0168] (I-3) [Ru(CN) .sub.6].sup.4-
[0169] (I-4) [Os(CN) .sub.6].sup.4-
[0170] (I-5) [Co(CN) .sub.6].sup.3-
[0171] (I-6) [Rh (CN) .sub.6].sup.3-
[0172] (I-7) [Ir(CN) .sub.6].sup.3-
[0173] (I-8) [Cr(CN) .sub.6].sup.4-
[0174] The counter cation of the hexacyano metal complex is
preferably miscible with water and has adaptability for the
operation of precipitating the silver halide emulsion. Examples of
the counter cation include an alkali metal ion (e.g., sodium ion,
potassium ion, rubidium ion, cesium ion, lithium ion), ammonium ion
and alkylammonium ion.
[0175] The preparation of the host silver halide tabular grain of
the present invention comprises three steps of nucleation, ripening
and growth. In the nucleation step, silver halide grains working
out to nuclei are prepared by adding a water-soluble silver
solution and an aqueous halide solution to an aqueous solution
containing a protective colloid such as gelatin, a halide and the
like, which is in a amount sufficiently large for stirring the
reaction solution. At this time, the water-soluble silver solution
and the aqueous halide solution are preferably added
simultaneously.
[0176] The water-soluble silver solution for use in the present
invention is preferably an aqueous silver nitrate solution. As the
aqueous halide solution used in the present invention, an aqueous
solution of potassium bromide, sodium bromide, potassium chloride,
sodium chloride, potassium iodide, sodium iodide and a mixture
thereof is used.
[0177] In the present invention, the silver concentration
(concentration of all silvers contained in the emulsion) of the
reaction solution after the addition of a water-soluble silver
solution in the nucleation step before the initiation of ripening
step is from 0.0015 to 0.015 mass %, more preferably from 0.005 to
0.013 mass %. The concentration of the water-soluble silver
solution added at the nucleation is preferably from 0.001 to 10
mass %, more preferably from 0.01 to 1 mass %. At the addition of
the water-soluble silver solution and the aqueous halide solution,
the temperature of the reactor is preferably from -0 to 30.degree.
C., more preferably from 0 to 5.degree. C. By diluting the
water-soluble silver salt in the nucleation step or performing the
nucleation at a low temperature, fine nuclei can be formed and this
is effective for the reduction in the thickness of silver halide
tabular grain. A combination use of these two methods is more
effective. These methods are effective particularly for preparing
tabular grains having a large size and a small grain thickness. The
composition of the aqueous halide solution is preferably
iodobromide having an iodide content of 0 to 10 mol %, more
preferably from 0 to 5 mol %, still more preferably from 0 to 3 mol
%.
[0178] The protective colloid for use in the nucleation step is
preferably gelatin having a small methionine content described in
U.S. Pat. Nos. 4,713,320 and 4,942,120, more preferably a low
molecular weight gelatin. It is also preferred to perform the
nucleation at a high pBr as described in U.S. Pat. No. 4,914,014.
Specifically, the pBr is preferably from 2 to 7, more preferably
from 2 to 5. The pBr as used herein means a logarithm of a
reciprocal of the bromide ion concentration. The nucleation is
preferably performed within a short period of time described in
JP-A-2-222940, more preferably within 1 minute.
[0179] In the ripening step of the tabular grain emulsion of the
present invention, the ripening may be performed in the presence of
a low-concentration base described in U.S. Pat. No. 5,254,453 or at
a pH described in U.S. Pat. No. 5,013,641. A polyalkylene oxide
compound described in U.S. Pat. Nos. 5,147,771, 5,147,772,
5,147,773, 5,171,659, 5,210,013 and 5,252,453 may be added in the
ripening step or in the later growth step. In the present
invention, the ripening step is preferably performed at a
temperature of 50 to 80.degree. C. Immediately after the nucleation
or until the completion of ripening, additional gelatin is
preferably added. The gelatin is preferably a modified gelatin
where 95% or more of the amino group is succinated or
trimellited.
[0180] In the present invention, the silver halide tabular grain
preferably contains in the inside thereof a coordination metal
complex or metal ion containing a metal belonging to the elements
of Groups III to XIV of the periodic table. The metal of the
coordination metal complex or metal ion may be selected from the
elements of Groups III to XIV in the periodic table having Group
numbers of I to XVIII from the left. The metal is preferably
selected from the metals belonging to the elements of Groups IV, V
and VI of the periodic table, more preferably from vanadium,
chromium, manganese, iron, cobalt, nickel, niobium, molybdenum,
ruthenium, rhodium, palladium, tantalum, tungsten, rhenium, osmium,
iridium, platinum and lead. The metal is particularly preferably an
iridium complex. The metal may be used as a metal ion in the form
of a metal salt such as ammonium salt, acetate, nitrate, sulfate,
phosphate and hydroxide, however, by using the meal as a
mononuclear coordination metal salt such as six-coordinated complex
salt or four-coordinated complex salt, or as a polynuclear or
multinuclear metal complex salt, the performance owing to the
ligand or complex salt structure can also be brought out. Preferred
examples of the ligand include anionic ligands such as fluoride
ion, chloride ion, bromide ion, iodide ion, oxide ion, sulfide ion,
selenide ion, telluride ion, cyanide ion, thiocyanide ion,
selenocyanide ion, tellurocyanide ion, cyanate ion, nitride ion and
azide ion, neutral ligands such as water, carbonyl, nitrosyl,
thionitrosyl and ammonia, and organic ligands containing one or
more carbon-carbon, carbon-hydrogen or carbon-nitrogen-hydrogen
bond, such as 4,4'-bipyridine, pyrazine and thiazole disclosed in
U.S. Pat. No. 5,360,712.
[0181] Specific examples of the metal ion include those described
in Comprehensive Coordination Chemistry, Pergamon Press (1987).
[0182] Among these metal ions, preferred are hexacyano metal
complexes such as hexacyanoiron complex and hexacyanoruthenium
complex.
[0183] For doping the coordination metal complex or metal ion of
the present invention into a silver halide grain, the coordination
metal complex or metal ion is preferably added directly to the
reaction solution during the formation of silver halide grains or
added to the reaction solution during the grain formation after
adding it to a solution containing halide ion for forming silver
halide grains or other solution. Furthermore, various addition
methods may be used in combination.
[0184] The coordination metal complex or metal ion capable of
satisfying the requirements in the present invention may be
incorporated into a silver halide grain in the same concentration
per mol of silver as conventionally used for the doping of
transition metals. Concentrations over a very wide range are known
and the coordination metal complex or metal ion may be used in a
concentration from a low concentration of 10.sup.-10 mol per mol of
silver disclosed in JP-A-51-107129 to a high concentration of
10.sup.-3 mol per mol of silver disclosed in U.S. Pat. Nos.
3,687,676 and 3,690,891. The effective concentration greatly varies
depending on the content of halide in the grain, the coordination
complex or metal ion selected, the oxidation state thereof, the
kind of ligand, if present, and the desired photographic
effects.
[0185] In the present invention, an iridium complex is also
preferably used in combination as the metal complex which can be
incorporated into a silver halide grain. The iridium complex
includes trivalent iridium complex and tetravalent iridium complex.
Examples thereof include hexachloroiridium(III) complex salt,
hexachloroiridium(IV) complex salt, hexabromoiridium(III) complex
salt, hexabromoiridium(IV) complex salt, hexaiodoiridium(III)
complex salt, hexaiodoiridium(IV) complex salt,
aquapentachloroiridium(III) complex salt,
aquapentachloroiridium(IV) complex salt, aquapentabromoiridium(III)
complex salt, aquapentabromoiridium(IV) complex salt,
aquapentaiodoiridium(III) complex salt, aquapentaiodoiridium(IV)
complex salt, diaquatetrachloroiridium(III- ) complex salt,
diaquatetrachloroiridium(IV) complex salt,
diaquatetrabromoiridium(III) complex salt,
diaquatetrabromoiridium(IV) complex salt,
diaquatetraiodoiridium(III) complex salt,
diaquatetraiodoiridium(IV) complex salt,
triaquatrichloroiridium(III) complex salt,
triaquatrichloroiridium(IV) complex salt,
triaquatribromoiridium(III) complex salt,
triaquatribromoiridium(IV) complex salt, triaquatriiodoiridium(III)
complex salt, triaquatriiodoiridium(IV) complex salt,
hexamineiridium(III) complex salt and hexamineiridium(IV) complex
salt, however, the present invention is by no means limited
thereto.
[0186] The amount of the iridium complex added is preferably from
10.sup.-8 to 10.sup.-3 mol, more preferably from 10.sup.-5 to
10.sup.-4 mol, per mol of silver halide.
[0187] After the epitaxial deposition, the above-described
sensitizing dye and/or an antifoggant and/or a stabilizer which are
described later are preferably added to the silver halide
emulsion.
[0188] In the present invention, after the epitaxial deposition,
the pBr is preferably lowered. The pBr at 40.degree. C. is
preferably lowered to 3.5 or less. The pBr of the emulsion at
40.degree. C. is more preferably 3.0 or less, still more preferably
2.5 or less. The pBr is lowered fundamentally by adding bromide ion
such as KBr and NaBr.
[0189] After the epitaxial deposition, water washing is usually
performed.
[0190] The temperature at the water washing can be selected
according to the purpose but is preferably selected in the range
from 5 to 50.degree. C. The pH at the water washing can also be
selected according to the purpose but is preferably selected from 2
to 10, more preferably from 3 to 8. The pAg at the water washing
can also be selected according to the purpose but is preferably
selected from 5 to 10. The water washing method may be selected
from the noodle water washing, the dialysis using a semipermeable
membrane, the centrifugal separation, the coagulation precipitation
and the ion exchanging. In the case of coagulation precipitation,
the method can be selected from a method of using a sulfate, a
method of using an organic solvent, a method of using a
water-soluble polymer and a method of using a gelatin
derivative.
[0191] The emulsion of the present invention is preferably
chemically sensitized (preferably after the epitaxial
precipitation). One of the chemical sensitization methods which can
be preferably used in the present invention is the sole use of
chalcogenide sensitization or noble metal sensitization, or a
combination of these sensitization methods. The chemical
sensitization may be performed using active gelatin as described in
T.H. James, The Theory of the Photographic Process, 4th ed., pp.
67-76, Macmillan (1977), or may be performed using sulfur,
selenium, tellurium, gold, platinum, palladium, iridium or a
combination of two or more of these sensitizing dyes at a pAg of 5
to 10, a pH of 5 to 8 and a temperature of 30 to 80.degree. C. as
described in Research Disclosure, Vol. 120, 12008 (April 1974),
Research Disclosure, Vol. 34, 13452 (June 1975), U.S. Pat. Nos.
2,642,361, 3,297,446, 3,772,031, 3,857,711, 3,901,714, 4,266,018
and 3,904,415, and British Patent 1,315,755.
[0192] In the noble metal sensitization, a salt of noble metal such
as gold, platinum, palladium and iridium may be used. Among these,
gold sensitization, palladium sensitization and a combination use
thereof are preferred. In the gold sensitization, known compounds
such as chloroauric acid, potassium chloroaurate, potassium
aurithiocyanate, gold sulfide and gold selenide may be used. The
palladium compound means a divalent or tetravalent palladium salt.
Preferred palladium compounds are represented by the formula:
R.sub.2PdX.sub.6 or R.sub.2PdX.sub.4, wherein R represents a
hydrogen atom, an alkali metal atom or an ammonium group and X
represents a halogen atom selected from chlorine, bromine and
iodine atoms. Specifically, K.sub.2PdCl.sub.4,
(NH.sub.4).sub.2PdCl.sub.6, Na.sub.2PdCl.sub.4,
(NH.sub.4).sub.2PdCl.sub.4, Li.sub.2PdCl.sub.4, Na.sub.2PdCl.sub.6
and K.sub.2PdBr.sub.4 are preferred. The gold compound and
palladium compound are preferably used in combination with a
thiocyanate salt or a selenocyanate salt.
[0193] Examples of the sulfur sensitizer which can be used include
hypo, thiourea-base compounds, rhodanine-base compounds and
sulfur-containing compounds described in U.S. Pat. Nos. 3,857,711,
4,266,018 and 4,054,457. The chemical sensitization can also be
performed in the presence of a so-called chemical sensitization
aid. Useful examples of the chemical sensitization aid include
compounds known to inhibit fog in the course of chemical
sensitization and increase sensitivity, such as azaindene,
azapyridazine and azapyrimidine. Examples of the chemical
sensitization aid modifier are described in U.S. Pat. Nos.
2,131,038, 3,411,914 and 3,554,757, JP-A-58-126526 and Duffin,
Chemistry of Photographic Emulsion, supra, pp. 138-143.
[0194] For the emulsion of the present invention, gold
sensitization is preferably used in combination. The amount of the
gold sensitizer is preferably from 1.times.10.sup.-4 to
1.times.10.sup.-7 mol. more preferably from 1.times.10.sup.-5 to
5.times.10.sup.-7 mol, per mol of silver halide. The amount of the
palladium compound is preferably from 1.times.10.sup.-3 to
5.times.10.sup.-7 mol per mol of silver halide. The amount of
thiocyanate compound or selenocyanate compound is preferably from
5.times.10.sup.-2 to 1.times.10.sup.-6 mol per mol of silver
halide.
[0195] The amount of the sulfur sensitizer which is preferably used
for the silver halide grain of the present invention is preferably
from 1.times.10.sup.-4 to 1.times.10.sup.-7 mol, more preferably
from 1.times.10.sup.-5 to 5.times.10.sup.-7 mol, per mol of silver
halide.
[0196] The sensitization preferred for the emulsion of the present
invention includes selenium sensitization. In the selenium
sensitization, known labile selenium compounds may be used and
specifically, selenium compounds such as colloidal metal selenium,
selenoureas (e.g., N,N-dimethylselenourea, N,N-diethylselenourea),
selenoketones and selenoamides may be used. In some cases, the
selenium sensitization is preferably used in combination with
sulfur sensitization, noble metal sensitization, or both
thereof.
[0197] In the tellurium sensitization, a labile tellurium compound
is used and the labile tellurium compounds described in
JP-A-4-224595, JP-A-4-271341, JP-A-4-333043, JP-A-5-303157,
JP-A-6-27573, JP-A-6-175258, JP-A-6-180478, JP-A-6-208184,
JP-A-6-208186, JP-A-6-317867, JP-A-7-140579, JP-A-7-301879 and
JP-A-7-301880 may be used.
[0198] Specific examples thereof include phosphine tellurides
(e.g., normal-butyl-diisopropylphosphine telluride,
triisobutylphosphine telluride, tri-normalbutoxyphosphine
telluride, triisopropylphosphine telluride), diacyl (di)tellurides
(e.g., bis(diphenylcarbamoyl) ditelluride,
bis(N-phenyl-N-methylcarbamoyl) ditelluride,
bis(N-phenyl-N-methylcarbamoyl) telluride,
bis(N-phenyl-Nbenzylcarbamoyl) telluride, bis(ethoxycarbonyl)
telluride), telluroureas (e.g., N,N'-dimethylethylenetellurourea),
telluroamides and telluroesters. Among these, preferred are
phosphine tellurides and diacyl (di)tellurides.
[0199] The photographic emulsion of the present invention may
contain various compounds for the purpose of preventing fog during
the production process, storage or photographic processing of a
light-sensitive material or stabilizing the photographic
performance. That is, a large number of compounds known as an
antifoggant or a stabilizer may be added, such as thiazoles (e.g.,
benzothiazolium salt), nitroimidazoles, nitrobenzimidazoles,
chlorobenzimidazoles, bromobenzimidazoles, mercaptothiazoles,
mercaptobenzothiazoles, mercaptobenzimidazoles,
mercaptothiadiazoles, aminotriazoles, benzotriazoles,
nirobenzotriazoles, mercaptotetrazoles (particularly
1-phenyl-5-mercaptotetrazole), mercaptopyrimidines,
mercaptotriazines (for example, thioketo compounds such as
oxazolinethione) and azaindenes (for example, triazaindenes,
tetraazaindenes (particularly 4-hydroxy substituted
(1,3,3a,7)tetraazaindenes) and pentaazaindenes). For example, those
described in U.S. Pat. Nos. 3,954,474 and 3,982,947 and
JP-B52-28660 may be used. One preferred compound is the compound
described in JP-A-63-212932. The antifoggant or stabilizer can be
added at various stages, for example, before, during or after the
grain formation, during the washing with water, during the
dispersion after the water washing, during the epitaxial formation,
before, during or after the chemical sensitization, or before the
coating, in accordance with the purpose. The antifoggant or
stabilizer may be used not only for exerting the effect of
preventing fog or stabilizing the emulsion by adding it during the
preparation of emulsion but also for various purposes of
controlling the crystal wall of grain, decreasing the grain size,
lowering the grain solubility, controlling the chemical
sensitization or controlling the dye arrangement.
[0200] In the present invention, a salt of metal ion is preferably
allowed to be present during the preparation of emulsion according
to the purpose, for example, during the grain formation, epitaxial
formation, desalting or chemical sensitization or before the
coating. In the case of doping into a grain, the metal ion salt is
preferably added during the grain formation, and in the case of use
for the modification of grain surface or as a chemical sensitizer,
the metal ion salt is preferably added after the grain formation
but before the completion of chemical sensitization. The metal ion
salt may be doped throughout the grain or may be doped only to the
core or shell part of the grain. Examples of the metal which can be
used include Mg, Ca, Sr, Ba, Al, Sc, Y, La, Cr, Mn, Fe, Co, Ni, Cu,
Zn, Ga, Ru, Rh, Pd, Re, Os, Ir, Pt, Au, Cd, Hg, Ti, In, Sn, Pb and
Bi. These metals can be added as long as they are in the form of a
salt soluble at the grain formation, such as ammonium salt,
acetate, nitrate, sulfate, phosphate, hydroxide, six-coordinated
complex salt or four-coordinated complex salt. Examples thereof
include CdBr.sub.2, CdCl.sub.2, Cd(NO.sub.3).sub.2,
Pb(NO.sub.3).sub.2, Pb(CH.sub.3COO).sub.2, K.sub.3[Fe(CN).sub.6] ,
(NH.sub.4).sub.4[Fe(CN).su- b.6], K.sub.3IrCl.sub.6,
(NH.sub.4).sub.3RhCl.sub.6 and K.sub.4Ru(CN).sub.6. The ligand of
the coordination compound can be selected from halo, aquo, cyano,
cyanate, thiocyanate, nitrosyl, thionitrosyl, oxo and carbonyl.
Only one of these metal compounds may be used but two or more
thereof may be used in combination.
[0201] The metal compound is preferably added after dissolving it
in water or an appropriate solvent such as methanol and acetone.
For stabilizing the solution, a method of adding an aqueous
solution of hydrogen halide (e.g., HCl, HBr) or an alkali halide
(e.g., KCl, NaCl, KBr, NaBr) may be employed. If desired, an acid,
an alkali or the like may be added. The metal compound may be added
to the reactor before the grain formation or may be added during
the grain formation. Furthermore, the metal compound may be added
to a water-soluble silver salt (e.g., AgNO.sub.3) or an aqueous
solution of alkali halide (e.g., NaCl, KBr, KI) and then
continuously added during the formation of silver halide grains. In
addition, a solution may be prepared separately from the
water-soluble silver salt or alkali halide and continuously added
at an appropriate time during the grain formation. A combination
use of various addition methods is also preferred.
[0202] The silver halide photographic emulsion of the present
invention is preferably subjected to reduction sensitization during
grain formation, after grain formation but before chemical
sensitization, or during or after chemical sensitization.
[0203] For performing the reduction sensitization, a method of
adding a reduction sensitizer to the silver halide emulsion, a
method called silver ripening where the emulsion is grown or
ripened in a low pAg atmosphere at a pAg of 1 to 7, or a method
called high pH ripening where the emulsion is grown or ripened in a
high pH atmosphere at a pH of 8 to 11 may be selected. Also, two or
more of these methods may be used in combination.
[0204] The method of adding a reduction sensitizer is preferred
because the reduction sensitization level can be delicately
controlled.
[0205] Known examples of the reduction sensitizer include stannous
chloride, ascorbic acid and its derivatives, amine and polyamines,
hydrazine derivatives, formamidinesulfinic acid, silane compounds
and borane compounds. In the present invention, the reduction
sensitization may be performed using a reduction sensitizer
selected from these known reduction sensitizers, and two or more
compounds may also be used in combination. Preferred compounds as
the reduction sensitizer are stannous chloride, thiourea dioxide,
dimethylamineboran, and ascorbic acid and its derivatives. The
amount of the reduction sensitizer added depends on the conditions
in the production of emulsion and therefore, must be selected but
is suitably from 10.sup.-7 to 10.sup.-3 mol per mol of silver
halide.
[0206] The reduction sensitizer is dissolved, for example, in water
or an organic solvent such as alcohols, glycols, ketones, esters
and amides, and then added during the grain growth. The reduction
sensitizer may be previously added to the reactor but is preferably
added at an appropriate time during the grain growth. Also, the
reduction sensitizer may be previously added to an aqueous solution
of water-soluble silver slat or water-soluble alkali halide and the
silver halide grains may be precipitated using this aqueous
solution. It is also preferred to add a solution of reduction
sensitizer in parts as the grain grows or continuously add the
solution over a long period of time.
[0207] During the preparation of the emulsion of the present
invention, an oxidizing agent for silver is preferably used. The
term "oxidizing agent for silver" as used herein means a compound
having a function of acting on metal silver to convert it into
silver ion. In particular, a compound capable of converting very
small silver grains by-produced during the formation and chemical
sensitization of silver halide grains into silver ion is useful.
The silver ion produced here may form a silver salt difficultly
soluble in water, such as silver halide, silver sulfide and silver
selenide, or may form a silver salt easily soluble in water, such
as silver nitrate. The oxidizing agent for silver may be an
inorganic material or an organic material. Examples of the
inorganic oxidizing agent include ozone, hydrogen peroxide and
adducts thereof (e.g., NaBO.sub.2.H.sub.2O.sub.2.3H.sub.2O,
2NaCO.sub.3.3H.sub.2O.sub.2,
Na.sub.4P.sub.2O.sub.7.2H.sub.2O.sub.2,
2Na.sub.2SO.sub.4.H.sub.2O.sub.2.- 2H.sub.2O), peroxy acid salts
(e.g., K.sub.2S.sub.2O.sub.8, K.sub.2C.sub.2O.sub.6,
K.sub.2P.sub.2O.sub.8), peroxy complex compounds (e.g.,
K.sub.2[Ti(O.sub.2)C.sub.2O.sub.4].3H.sub.2O,
4K.sub.2SO.sub.4.Ti(O.sub.2)OH.SO.sub.4.2H.sub.2O, Na.sub.3[VO
(O.sub.2) (C.sub.2H.sub.4) .sub.2].6H.sub.2O) oxygen acid salts
such as permanganate (e.g. , KMnO.sub.4) and chromate (e.g. ,
K.sub.2Cr.sub.2O.sub.7), halogen elements such as iodine and
bromine, perhalogenates (e.g., potassium periodate), salts of metal
having a high valency (e.g., potassium hexacyanoferrate), and
thiosulfonates.
[0208] Examples of the organic oxidizing agent include quinones
such as p-quinone, organic peroxides such as peracetic acid and
perbenzoic acid, and compounds which release active halogen (for
example, N-bromosuccinimide, Chloramine T, Chloramine B).
[0209] Among these oxidizing agents, preferred in the present
invention are inorganic oxidizing agents such as ozone, hydrogen
peroxide and an adduct thereof, halogen element and thiosulfonate,
and organic oxidizing agents such as quinones. In a preferred
embodiment, the abovedescribed reduction sensitization is used in
combination with the oxidizing agent for silver. A method of using
the oxidizing agent and then performing the reduction
sensitization, a method reversed thereto, and a method of allowing
both to be present at the same time may be selected. The method may
be applied in the grain formation step or in the chemical
sensitization step.
[0210] The light-sensitive material produced by using the silver
halide emulsion obtained in the present invention may be sufficient
if at least one blue-sensitive silver halide emulsion layer, at
least one green-sensitive silver halide emulsion layer and at least
one red-sensitive silver halide emulsion layer are provided on a
support and at least one of the blue-sensitive layer, the
green-sensitive layer and the red-sensitive layer is constructed by
two or more layers different in the sensitivity from each other.
The number and order of the silver halide emulsion layers and the
light-insensitive layer are not particularly limited. A typical
example is a silver halide photographic light-sensitive material
having on a support at least one color sensitive layer comprising a
plurality of silver halide emulsion layers substantially the same
in the color sensitivity but different in the light sensitivity,
where the light-sensitive layer is a unit light-sensitive layer
having color sensitivity to any one of blue light, green light and
red light. In a multilayer silver halide color photographic
light-sensitive material, unit light-sensitive layers are generally
arranged in the order of a red-sensitive layer, a green-sensitive
layer and a blue-sensitive layer from the support side. However,
depending upon the purpose, this arrangement order may be reversed
or a layer having different light sensitivity may be interposed
between the layers having the same color sensitivity.
[0211] Also, a light-insensitive layer such as an interlayer may be
provided between the above-described silver halide light-sensitive
layers or as an uppermost or lowermost layer.
[0212] This light-insensitive layer may contain a coupler and a DIR
compound described in JP-A-61-43748, JP-A-59-113438,
JP-A-59-113440, JP-A-61-20037 and JP-A-61-20038, and may contain a
color mixing inhibitor commonly used.
[0213] The plurality of silver halide emulsion layers constituting
each unit light-sensitive layer preferably employ a two-layer
structure consisting of high-speed emulsion layer and low-speed
emulsion layer as described in German Patent 1,121,470 and British
Patent 923,045. Usually, these emulsion layers are preferably
arranged such that the light sensitivity sequentially becomes lower
toward the support. A light-insensitive layer may also be provided
between respective halide emulsion layers. It is also possible to
provide a low-speed emulsion layer farther from the support and
provide a high-speed emulsion layer closer to the support as
described in JP-A-57-112751, JP-A62-200350, JP-A-62-206541 and
JP-A-62-206543.
[0214] Specific examples of the layer arrangement include, from the
remotest side from the support, an order of low-speed
blue-sensitive layer (BL)/high-speed blue-sensitive layer
(BH)/high-speed green-sensitive layer (GH)/low-speed
green-sensitive layer (GL)/high-speed red-sensitive layer
(RH)/low-speed red-sensitive layer (RL), an order of
BH/BL/GL/GH/RH/RL and an order of BH/BL/GH/GL/RL/RH.
[0215] Furthermore, as described in JP-B-55-34932, a layer
arrangement of blue-sensitive layer/GH/RH/GL/RL in this order from
the remotest side from the support may also be employed. In
addition, as described in JP-A-56-25738 and JP-A-62-63936, a layer
arrangement of blue-sensitive layer/GL/RL/GH/RH in this order from
the remotest side from the support may also be employed.
[0216] Other examples include an arrangement consisting of three
layers different in the light sensitivity described in
JP-B-49-15495, where a silver halide emulsion layer having highest
light sensitivity is provided as an upper layer, a silver halide
emulsion layer having light sensitivity lower than that of the
upper layer is provided as an intermediate layer and a silver
halide emulsion layer having light sensitivity lower than that of
the intermediate layer is provided as a lower layer so as to
sequentially decrease the light sensitivity toward the support.
Even in this layer structure consisting of three layers different
in the light sensitivity, the layers having the same color
sensitivity may be provided in the order of medium-speed emulsion
layer/high-speed emulsion layer/low-speed emulsion layer from the
remote side from the support as described in JP-A-59-202A64.
[0217] In addition, the layers may also be provided in the order of
high-speed emulsion layer/low-speed emulsion layer/medium-speed
emulsion layer or low-speed emulsion layer/medium-speed emulsion
layer/high-speed emulsion layer.
[0218] The layer arrangement may be changed as described above also
in the case of structures consisting of four or more layers.
[0219] As described above, various layer structures and
arrangements may be selected according to the purpose of respective
light-sensitive materials.
[0220] In the light-sensitive material of the present invention,
various additives described above are used but various additives
other than those may also be used according to the purpose.
[0221] These additives are more specifically described in Research
Disclosure, Item 17643 (December, 1978), ibid., Item 18716
(November, 1979) and ibid., Item 308119 (December, 1989). The
pertinent portions are shown together in the table below.
1 Kind of Additives RD17643 RD18716 RD308119 1. Chemical p. 23 p.
648, right p. 996 sensitizer col. 2. Sensitivity p. 648, right
increasing agent col. 3. Spectral pp. 23-24 p. 648, right p. 996,
right sensitizer, col. to p. 649, to p. 998, supersensitizer right
col. right 4. Brightening agent p. 24 p. 647, right p. 998, right
col. 5. Antifoggant, pp. 24-25 p. 649, right p. 998, right
stabilizer col. to p. 1000, right 6. Light absorbent, pp. 25-26 p.
649, right p. 1003, left filter dye, UV col. to p. 650, to right
absorbent left col. 7. Stain inhibitor p. 25, p. 650, left to p.
1002, right right right cols. col. 8. Dye Image p. 25 p. 1002,
right Stabilizer 9. Hardening agent p. 26 p. 651, left p. 1004,
right col. to p. 1005, left 10. Binder p. 26 p. 651, left p. 1003,
right to p. 1005, left to p. 1004, right 11. Plasticizer, p. 27 p.
650, right p. 1006, left lubricant col. to right 12. Coating aid,
pp. 26-27 p. 650, right p. 1005, left surfactant col. to p. 1006,
left 13. Antistatic agent p. 27 p. 650, right p. 1006, right col.
to p. 1007, left 14. Matting agent p. 1008, left to p. 1009,
left
[0222] Furthermore, in order to prevent the deterioration of the
photographic performance due to formaldehyde gas, a compound
capable of reacting with and thereby fixing the formaldehyde
described in U.S. Pat. Nos. 4,411,987 and 4,435,503 is preferably
added to the light-sensitive material.
[0223] In the present invention, various color couplers can be
used. Specific examples thereof are described in the patents cited
in supra Research Disclosure, No. 17643, VIIC to G, and ibid., No.
307105, VII-C to G.
[0224] Preferred examples of the yellow coupler include those
described in U.S. Pat. Nos. 3,933,501, 4,022,620, 4,326,024,
4,401,752 and 4,248,961, JP-B-58-10739, British Patents 1,425,020
and 1,476,760, and U.S. Pat. Nos. 3,973,968, 4,314,023 and
4,511,649, and EP-A-249473.
[0225] As the magenta coupler, 5-pyrazolone-base compounds and
pyrazoloazole-base compounds are preferred. In particular,
preferred are those described in U.S. Pat. Nos. 4,310,619 and
4,351,897, European Patent 73,636, U.S. Pat. Nos. 3,061,432 and
3,725,067, Research Disclosure, No. 24220 (June, 1984),
JP-A-60-33552, Research Disclosure, No. 24230 (June 1984),
JP-A-60-43659, JP-A-61-72238, JP-A-60-35730, JP-A-55-118034,
JP-A-60-185951, U.S. Pat. Nos. 4,500,630, 4,540,654 and 4,556,630,
and WO88/04795.
[0226] The cyan coupler includes naphthol-base couplers and
phenol-base couplers. Preferred are those described in U.S. Pat.
Nos. 4,052,212, 4,146,396, 4,228,233, 4,296,200, 2,369,929,
2,801,171, 2,772,162, 2,895,826, 3,772,002, 3,758,308, 4,334,011
and 4,327,173, German Patent (OLS) No. 3,329,729, EP-A-121365,
EP-A-249453, U.S. Pat. Nos. 3,446,622, 4,333,999, 4,775,616,
4,451,559, 4,427,767, 4,690,889, 4,254,212 and 4,296,199, and
JP-A-61-42658.
[0227] Typical examples of the polymerized dye-forming coupler are
described in U.S. Pat. Nos. 3,451,820, 4,080,211, 4,367,282,
4,409,320 and 4,576,910, British Patent 2,102,137, and
EP-A-341188.
[0228] As the coupler which provides a colored dye having an
appropriate diffusibility, those described in U.S. Pat. No.
4,366,237, British Patent 2,125,570, European Patent 96,570 and
German Patent Application (OLS) No. 3,234,533 are preferred.
[0229] As the colored coupler for correcting unnecessary absorption
of the colored dye, those described in Research Disclosure, No.
17643, Item VII-G, ibid., No. 307105, Item VII-G, U.S. Pat. No.
4,163,670, JP-B-57-39413, U.S. Pat. Nos. 4,004,929 and 4,138,258,
and British Patent 1,146,368 are preferred. Also, couplers of
correcting unnecessary absorption of the colored dye by a
fluorescent dye released upon coupling described in U.S. Pat. No.
4,774,181 and couplers containing as a splitting-off group a dye
precursor group capable of reacting with a developing agent to form
a dye described in U.S. Pat. No. 4,777,120 may be preferably
used.
[0230] Compounds which release a photographically useful residue
upon coupling can also be preferably used in the present invention.
With respect to the DIR coupler which releases a development
inhibitor, preferred examples thereof include those described in
the patents cited in supra RD17643, Item VII-F and ibid., No.
307105, Item VII-F, JP-A-57-151944, JP-A-57-154234, JP-A-60-184248,
JP-A-63-37346, JP-A-63-37350, and U.S. Pat. Nos. 4,248,962 and
4,782,012.
[0231] With respect to the coupler which imagewise releases a
nucleating agent or a developing accelerator at the time of
development, those described in British Patents 2,097,140 and
2,131,188, JP-A-59-157638 and JP-A-59-170840 are preferred. Also,
compounds which release a fogging agent, a development accelerator,
a silver halide solvent or the like by the oxidation-reduction
reaction with an oxidation product of a developing agent described
in JP-A60-107029, JP-A-60-252340, JP-A-1-44940 and JP-A-1-45687 are
preferred.
[0232] Other examples of the compounds which can be used in the
light-sensitive material of the present invention include competing
couplers described in U.S. Pat. No. 4,130,427, polyequivalent
couplers described in U.S. Pat. Nos. 4,283,472, 4,338,393 and
4,310,618, DIR redox compound-releasing couplers, DIR
coupler-releasing couplers, DIR coupler-releasing redox compounds
and DIR redox-releasing redox compounds described in JP-A-60-185950
and JP-A-62-24252, couplers which release a dye capable of
retrieving the color after the release described in EP-A-173302 and
EP-A-313308, bleach accelerator-releasing couplers described in RD.
Nos. 11449 and 24241, and JP-A61-201247, ligand-releasing couplers
described in U.S. Pat. No. 4,555,477, leuco dye-releasing couplers
described in JP-A-63-75747, and fluorescent dye-releasing couplers
described in U.S. Pat. No. 4,774,181.
[0233] The couplers for use in the present invention can be
incorporated into the light-sensitive material by various known
dispersion methods.
[0234] Examples of the high boiling point solvent which is used in
the oil-in-water dispersion method are described, for example, in
U.S. Pat. No. 2,322,027.
[0235] Specific examples of the high boiling point organic solvent
having a boiling point of 175.degree. C. or more at atmospheric
pressure, which is used in the oil-in-water dispersion method,
include phthalic acid esters (e.g., dibutyl phthalate, dicyclohexyl
phthalate, di-2-ethylhexyl phthalate, decyl phthalate,
bis(2,4-di-tert-amylphenyl) phthalate, bis(2,4-di-tert-amylphenyl)
isophthalate, bis(l,1-diethylpropyl) phthalate); phosphoric acid or
phosphonic acid esters (e.g., triphenyl phosphate, tricresyl
phosphate, 2-ethylhexyldiphenyl phosphate, tricyclohexyl phosphate,
tri-2-ethylhexyl phosphate, tridodecyl phosphate, tributoxyethyl
phosphate, trichloropropyl phosphate, di-2-ethylhexylphenyl
phosphonate); benzoic acid esters (e.g., 2-ethylhexyl benzoate,
dodecyl benzoate, 2-ethylhexyl-p-hydroxy benzoate); amides (e.g.,
N,N-diethyldodecanamide, N,N-diethyllaurylamide,
Ntetradecylpyrrolidone); alcohols or phenols (e.g., isostearyl
alcohol, 2,4-di-tert-amylphenol); aliphatic carboxylic acid esters
(e.g., bis(2-ethylhexyl) sebacate, dioctyl azelate, glycerol
tributyrate, isostearyl lactate, trioctyl citrate); aniline
derivatives (e.g., N,N-dibutyl2-butoxy-5-tert-octylaniline); and
hydrocarbons (e.g., paraffin, dodecylbenzene,
diisopropylnaphthalene). As an auxiliary solvent, for example, an
organic solvent having a boiling point of about 30.degree. C. or
more, preferably from 50 to about 160.degree. C., may be used.
Typical examples thereof include ethyl acetate, butyl acetate,
ethyl propionate, methyl ethyl ketone, cyclohexanone, 2-ethoxyethyl
acetate and dimethylformamide.
[0236] The process and effects of the latex dispersion method and
specific examples of the latex for impregnation are described, for
example, in U.S. Pat. No. 4,199,363, and German Patent Application
(OLS) Nos. 2,541,274 and 2,541,230.
[0237] The color light-sensitive material preferably contains an
antiseptic or fungicide of various types and examples thereof
include phenethyl alcohol and those described in JP-A-63-257747,
JP-A-62-272248 and JP-A-1-80941, such as
1,2-benzoisothiazolin-3-one, n-butyl-p-hydroxybenzoate, phenol,
4-chloro-3,5-dimethylphenol, 2-phenoxyethanol and
2-(4-thiazolyl)benzimidazole.
[0238] The present invention can be applied to various
light-sensitive materials but is preferably applied to various
color light-sensitive materials. Representative examples thereof
include color negative film for common use or motion picture, color
reversal film for slide or television, color paper, color positive
film, and color reversal paper. Particularly, the present invention
can also be preferably used for color dupe film.
[0239] Suitable examples of the support which can be used in the
present invention include those described in supra RD, No. 17643,
page 28, ibid., No. 18716, from page 647, right column to page 648,
left column, and ibid., No. 307105, page 879.
[0240] In the light-sensitive material, the total thickness of all
hydrophilic colloidal layers on the side having emulsion layers is
preferably 28 .mu.m or less, more preferably 23 .mu.m or less,
still more preferably 18 .mu.m or less, particularly preferably 16
.mu.m or less. The film swelling rate T.sub.1/2 is preferably 30
seconds or less, more preferably 20 seconds or less. The "film
thickness" as used herein means a film thickness determined under
the control of humidity (2 days) at a temperature of 25.degree. C.
and a relative humidity of 55%. The film swelling rate T.sub.1/2
can be determined by a method known in this technical field, for
example, by means of a swellometer described in A. Green et al.,
Photogr. Sci. and Eng., Vol. 19, No. 2, pp. 124-129. The film
swelling rate T.sub.1/2 is defined as a time spent until half the
saturated film thickness is reached, where the saturated film
thickness is 90% of the maximum swelled film thickness reached on
the processing with a color developer at 30.degree. C. for 3
minutes and 15 seconds.
[0241] The film swelling rate T.sub.1/2 can be adjusted by adding a
film hardening agent to gelatin used as a binder or changing the
aging conditions after the coating.
[0242] In the light-sensitive material, a hydrophilic colloidal
layer (hereinafter referred to as a "back layer") having a total
dry thickness of 2 to 20 .mu.m is preferably provided on the side
opposite the side having emulsion layers. This back layer
preferably contains, for example, the above-described light
absorbent, filter dye, ultraviolet absorbent, antistatic agent,
hardening agent, binder, plasticizer, lubricant, coating aid and
surface active agent. The back layer preferably has a percentage
swelling of 150 to 500%.
[0243] The color photographic light-sensitive material can be
developed by an ordinary method described in supra RD, No. 17643,
pp. 28-29, ibid., No. 18716, page 651, from left to right columns,
and ibid., No. 307105, pp. 880-881.
[0244] The color developer for use in the development processing of
the light-sensitive material of the present invention is preferably
an alkaline aqueous solution mainly comprising an aromatic primary
amine color developing agent. As the color developing agent, an
aminophenol-base compound is useful but a p-phenylenediamine-base
compound is preferred and representative examples thereof include
3-methyl-4-amino-N,N-diethylaniline,
3-methyl-4-amino-N-ethyl-N-.beta.-hy- droxyethylaniline,
3-methyl-4-amino-N-ethyl-N-.beta.-methanesulfonamidoeth- ylaniline,
3-methyl-4-amino-N-ethyl-.beta.-methoxyethylaniline, and sulfates,
hydrochlorides and ptoluenesulfonates thereof. Among these,
particularly preferred is a sulfate of
3-methyl-4-amino-N-ethyl-N-.beta.-- hydroxyethylaniline. If
desired, these compounds can be used in combination of two or more
thereof.
[0245] The color developer in general contains, for example, a pH
buffering agent such as carbonate, borate or phosphate of an alkali
metal, and a development inhibitor or antifoggant such as chloride
salt, bromide salt, iodide salt, benzimidazoles, benzothiazoles and
mercapto compounds. The color developer may also contain, if
desired, a preservative of various types, such as hydroxylamine,
diethylhydroxylamine, sulfite, hydrazines (e.g.,
N,N-biscarboxymethylhydr- azine), phenylsemicarbazides,
triethanolamine and catecholsulfonic acids; an organic solvent such
as ethylene glycol and diethylene glycol; a development accelerator
such as benzyl alcohol, polyethylene glycol, quaternary ammonium
salts and amines; a dye-forming coupler; a competing coupler; an
auxiliary developing agent such as 1-phenyl-3-pyrazolidone; a
tackifying agent; and a chelating agent of various types, including
aminopolycarboxylic acid, aminopolyphosphonic acid, alkylphosphonic
acid and phosphonocarboxylic acid. Representative examples of the
chelating agent include ethylenediaminetetraacetic acid,
nitrilotriacetic acid, diethylenetriaminepentaacetic acid,
cyclohexanediaminetetraacetic acid, hydroxyethyliminodiacetic acid,
1-hydroxyethylidene-1,1-diphosphonic acid,
nitrilo-N,N,N-trimethylenephosphonic acid,
ethylenediamine-N,N,N,N-- tetramethylenephosphonic acid,
ethylenediamine-di(o-hydroxyphenylacetic acid) and salts
thereof.
[0246] In the case of performing reversal processing, the color
development is usually performed after black-and-white development
is performed. The black-and-white developer can use, for example,
known black-and-white developing agents individually or in
combination, such as dihydoxybenzenes (e.g., hydroquinone),
3-pyrazolidones (e.g., 1-phenyl-3-pyrazolidone) and aminophenols
(e.g., N-methyl-p-aminophenols)- . The color developer and the
black-and-white developer each usually has a pH of 9 to 12.
Although the replenishing amount of these developers varies
depending on the color photographic light-sensitive material
processed, it is generally 3 liter (hereinafter, "liter" is
sometimes denoted as "L") or less per m.sup.2 of the
light-sensitive material and when the bromide ion concentration in
the replenisher is lowered, the replenishing amount can be reduced
even to 500 ml (hereinafter, "milli-liter" is sometimes denoted as
"mL") or less. In the case of reducing the replenishing amount, the
contact area of the processing solution with air is preferably
reduced to prevent evaporation or air oxidation of the
solution.
[0247] The contact area of the photographic processing solution
with air in a processing tank can be shown by an opening ratio
defined below. 1 Opening ratio = [ contact area [ cm 2 ] of
processing solution with air ) ] [ volume of processing solution (
cm 3 ) ]
[0248] The opening ratio defined above is preferably 0.1 or less,
more preferably from 0.001 to 0.05. The opening ratio can be
reduced, for example, by a method of providing a shielding material
such as floating lid on the surface of the photographic processing
solution in the processing tank, a method of using a movable lid
described in JP-A-1-82033 or a slit development processing method
described in JP-A63-216050. The opening ratio is preferably reduced
not only in two steps of color development and black-and-white
development but also in all subsequent steps such as bleaching,
bleach-fixing, fixing, water washing and stabilization. The
replenishing amount can also be reduced by using means for
suppressing the accumulation of bromide ion in the developer.
[0249] The color development time is usually set to from 2 to 5
minutes, however, the processing time can be further shortened by
setting high temperature and high pH conditions and using a color
developing agent in a high concentration.
[0250] After color development, the photographic emulsion layer is
usually subjected to bleaching. The bleaching may be performed
simultaneously with fixing (bleach-fixing) or these may be
performed separately. For the purpose of attaining rapid
processing, a processing method of performing bleaching and then
bleach-fixing may also be used. Furthermore, a method of performing
the processing in a bleach-fixing bath consisting of two continued
tanks, a method of performing fixing before the bleach-fixing or a
method of performing bleaching after the bleach-fixing may be
freely selected and used according to the purpose. Examples of the
bleaching agent include compounds of a polyvalent metal such as
iron(III), peracids (particularly, sodium persulfate is suitable
for cinematic color negative film), quinones and nitro compounds.
Representative examples of the bleaching agent include organic
complex salts of iron(III), for example, complex salts with an
aminopolycarboxylic acid such as ethylenediaminetetraacetic acid,
diethylenetriaminepentaacetic acid, cyclo-hexanediaminetetraacetic
acid, methyliminodiacetic acid, 1,3-diaminopropanetetraacetic acid
or glycol ether diaminetetraacetic acid, and complex salts with
citric acid, tartaric acid or malic acid. Among these,
aminopolycarboxylic acid ferrate complex salts including
ethylenediaminetetraacetato ferrate complex salt and
1,3-diaminopropanetetraacetato ferrate complex salt are preferred
in view of rapid processing and prevention of environmental
pollution. The aminopolycarboxylic acid ferrate complex salts are
particularly useful for both the bleaching solution and the
bleach-fixing solution. The bleaching solution or bleach-fixing
solution using the aminopolycarboxylic acid ferrate complex salt
usually has a pH of from 4.0 to 8 but the processing may be
performed at a lower pH for attaining rapid processing.
[0251] A bleaching accelerator may be used, if desired, in the
bleaching solution, the bleach-fixing solution or a prebath
thereof. Specific examples of useful bleaching accelerators include
compounds described in the following specifications: for example,
compounds having a mercapto group or a disulfide group described in
U.S. Pat. No. 3,893,858, German Patent Nos. 1,290,812 and
2,059,988, JP-A-53-32736, JP-A-53-57831, JP-A-53-37418,
JP-A-53-72623, JP-A-53-95630, JP-A-53-95631, JP-A-53-104232,
JP-A-53-124424, JP-A-53-141623, JP-A-53-18426 and Research
Disclosure, No. 17129 (July, 1978); thiazolidine derivatives
described in JP-A-51-140129; thiourea derivatives described in
JP-B-45-8506, JP-A-52-20832, JP-A53-32735 and U.S. Pat. No.
3,706,561; iodide salts described in German Patent 1,127,715 and
JP-A-58-16235; polyoxyethylene compounds described in German Patent
Nos. 966,410 and 2,748,430; polyamine compounds described in
JP-B-45-8836; compounds described in JP-A-49-40943, JP-A-49-59644,
JP-A-53-94927, JP-A-54-35727, JP-A-55-26506 and JPA-58-163940; and
bromide ion. Among these, compounds having a mercapto group or a
disulfide group are preferred in view of their large acceleration
effect and in particular, the compounds described in U.S. Pat. No.
3,893,858, German Patent No. 1,290,812 and JP-A-53-95630 are
preferred. Also, the compounds described in U.S. Pat. No. 4,552,884
are preferred. The bleaching accelerator may also be incorporated
into the light-sensitive material. The bleaching accelerator is
particularly effective in bleach-fixing a color light-sensitive
material for photographing.
[0252] In addition to the above-described compounds, the bleaching
solution or bleach-fixing solution preferably contains an organic
acid so as to prevent bleaching stains. Particularly, the organic
acid is preferably a compound having an acid dissociation constant
(pKa) of 2 to 5 and specific examples thereof include acetic acid,
propionic acid and hydroxyacetic acid.
[0253] Examples of the fixing agent for use in the fixing solution
or bleach-fixing solution include thiosulfates, thiocyanates,
thioether-base compounds, thioureas and a large quantity of iodide
salt. Among these, thiosulfates are commonly used and in
particular, ammonium thiosulfate can be most widely used. A
combination use of a thiosulfate with, for example, a thiocyanate,
a thioether-base compound or a thiourea is also preferred. The
preservative for the fixing solution or bleach-fixing solution is
preferably a sulfite, a bisulfite, a carbonyl bisulfite or a
sulfinic acid compound described in EP-A-294769. Furthermore, the
fixing solution or bleach-fixing solution preferably contains an
aminopolycarboxylic acid or organic phosphonic acid of various
types for the purpose of stabilizing the solution.
[0254] In order to adjust the pH,. the fixing solution or
bleach-fixing solution preferably contains a compound having a pKa
of 6.0 to 9.0, more preferably an imidazole such as imidazole,
1-methylimidazole, 1-ethylimidazole and 2-methylimidazole, in an
amount of 0.1 to 10 mol/liter.
[0255] The total desilvering time is preferably shorter within the
range of not causing desilvering failure. The desilvering time is
preferably from 1 to 3 minutes, more preferably from 1 to 2
minutes. The processing temperature is from 25 to 50.degree. C.,
preferably from 35 to 45.degree. C. In this preferred temperature
range, the desilvering rate is improved and generation of stains
after the processing can be effectively prevented.
[0256] In the desilvering step, the stirring is preferably
intensified as much as possible. Specific examples of the method
for intensifying the stirring include a method of colliding a jet
stream of a processing solution against the emulsion surface of the
light-sensitive material described in JP-A-62-183460, a method of
increasing the stirring effect using rotary means described in
JP-A-62-183461, a method of increasing the stirring effect by
moving the light-sensitive material while contacting the emulsion
surface with a wiper blade disposed in the solution to cause
turbulence on the emulsion surface, and a method of increasing the
circulation flow rate of the processing solution as a whole. Such
means for intensifying the stirring is effective in all of
bleaching solution, bleach-fixing solution and fixing solution. The
intensification of stirring is considered to increase the supply
rate of the bleaching agent or fixing agent into the emulsion layer
and, as a result, elevate the desilvering rate. The above-described
means for intensifying the stirring is more effective when a
bleaching accelerator is used and in this case, the acceleration
effect can be remarkably increased or the fixing inhibitory action
by the bleaching accelerator can be eliminated.
[0257] The automatic developing machine used for developing the
light-sensitive material preferably has light-sensitive material
conveying means described in JP-A-60-191257, JP-A-60-191258. and
JP-A-60-191259. As described in JP-A-60-191257 above, such
conveying means can extremely reduce the amount of a processing
solution carried over from a previous bath to a post bath and
provides a high effect of preventing a processing solution from
deteriorating in the capability. This effect is particularly
effective for reducing the processing time or decreasing the
replenishing amount of a processing solution in each step.
[0258] After the desilvering, the silver halide color photographic
light-sensitive material is generally subjected to water washing
and/or stabilization. The amount of washing water in the water
washing step can be set over a wide range according to the
properties (attributable to, for example, a material used such as
coupler) or use of the light-sensitive material and additionally
according to the temperature of washing water, the number of water
washing tanks (number of stages), the replenishing system such as
countercurrent or co-current system, or other various conditions.
Among these, the relationship between the number of water washing
tanks and the amount of water in a multi-stage countercurrent
system can be determined according to the method described in
Journal of the Society of Motion Picture and Television Engineers,
Vol. 64, pp. 248-253 (May, 1955).
[0259] According to the multi-stage countercurrent system described
in the above-described publication, the amount of washing water may
be greatly reduced but the increase in the residence time of water
in the tank causes a problem, for example, bacteria proliferate and
the floats generated adhere to the light-sensitive material. For
solving such a problem, a method of reducing calcium ion and
magnesium ion described in JP-A-62-288838 can be very effectively
used in the processing of the color light-sensitive material of the
present invention. It is also effective to use, for example, an
isothiazolone compound or a thiabendazole described in
JP-A-57-8542, a chlorine-base bactericide such as chlorinated
sodium isocyanurate, or a bactericide such as benzotriazole
described in Hiroshi Horiguchi, Bokin, Bobai-Zai no Kagaku
(Chemistry of Bactericides and Fungicides), Sankyo Shuppan (1986),
Biseibutsu no Mekkin, Sakkin, Bobai-Gijutsu (Sterilizing,
Disinfecting and Fungicidal Technology for Microorganisms),
compiled by Eisei Gijutsu Kai, issued by Kogyo Gijutsu Kai (1982),
and Bokin-Bobai Zai Jiten (Handbook of Bactericides and
Fungicides), compiled by Nippon Bokin Bobai Gakkai (1986).
[0260] The washing water for use in the processing of the
light-sensitive material has a pH of 4 to 9, preferably from 5 to
8. The washing water temperature and the water washing time may be
variously set according to, for example, the properties and use of
the light-sensitive material but the temperature and the processing
time are generally from 15 to 45.degree. C. and from 20 seconds to
10 minutes, preferably from 25 to 40.degree. C. and from 30 seconds
to 5 minutes, respectively. The light-sensitive material of the
present invention can also be processed directly with a stabilizing
solution in place of the above-described water washing. In such a
stabilization processing, any known method described in
JP-A-57-8543, JP-A-58-14834 and JP-A-60-220345 can be used.
[0261] In some cases, the stabilization processing may be further
performed following the above-described water washing. An example
thereof is a stabilization bath containing a dye stabilizer and a
surfactant, which is used as a final bath in the processing of a
color light-sensitive material for photographing. Examples of the
dye stabilizer include aldehydes such as formalin and
glutaraldehyde, N-methylol compounds, and hexamethylene-tetramine
or aldehyde sulfite adducts. This stabilization bath may also
contain various chelating agents and fungicides.
[0262] The overflow solution accompanying the replenishing of
washing water and/or stabilizing solution can be re-used in other
processing steps such as desilvering step.
[0263] In the processing using, for example, an automatic
developing machine, if each processing solution is concentrated due
to evaporation, water is preferably added to correct the
concentration.
[0264] In the silver halide color photographic light-sensitive
material, a color developing agent may be incorporated so as to
simplify the processing and increase the processing rate. In order
to incorporate the color developing agent, various precursors of
the color developing agent are preferably used. Examples thereof
include indoaniline-base compounds described in U.S. Pat. No.
3,342,597, Schiff base-type compounds described in U.S. Pat. No.
3,342,599, Research Disclosure, No. 14850 and ibid., No. 15159,
aldol compounds described in ibid., No. 13924, metal salt complexes
described in U.S. Pat. No. 3,719,492 and urethane-base compounds
described in JP-A-53-135628.
[0265] In the silver halide color light-sensitive material, a
1-phenyl-3-pyrazolidone of various types may be incorporated, if
desired, for the purpose of accelerating the color development.
Typical examples of the compound are described in JP-A-56-64339,
JP-A-57-144547 and JP-A-58-115438.
[0266] Each processing solution is used at a temperature of 10 to
50.degree. C. The standard temperature is usually from 33 to
38.degree. C. but a higher temperature may be used to accelerate
the processing and thereby shorten the processing time, or on the
contrary, a lower temperature may be used to improve the image
quality or the stability of processing solution.
[0267] The silver halide light-sensitive material of the present
invention can be applied also to heat-developable light-sensitive
materials described in U.S. Pat. No. 4,500,626, JP-A-60-133449,
JP-A-59-218443, JP-A-61-238056 and EP-A-210660.
[0268] Furthermore, the silver halide color photographic
light-sensitive material can be effectively applied to a film unit
with a lens described in JP-B-2-32615 and JP-B-U3-39784 (the term
"JP-B-U" as used herein means an "examined Japanese utility model
publication") and in this case, the effect is more readily brought
out.
EXAMPLE
[0269] The present invention is described in greater detail below
by referring to Examples, however, the present invention should not
be construed as being limited thereto.
Example I
[0270] (Comparison I-1)
[0271] In a reactor, 3 liter of an aqueous solution (pH: 5)
containing 1.08 g of potassium bromide and 2.1 g of low molecular
weight gelatin (molecular weight: 15,000) was charged and kept
40.degree. C. While stirring the aqueous solution, 20 ml of (a) an
aqueous 0.87 mol/liter silver nitrate solution and 20 ml of (b) an
aqueous 0.87 mol/liter potassium bromide solution were added
thereto by a double jet method over 40 seconds. After the addition,
2.2 g of potassium bromide was added to the reaction solution and
the temperature was elevated to 60.degree. C. over 35 minutes.
During the elevation of temperature, the reaction solution was
dehydrated and desalted to a volume of 1 liter using an
ultrafiltration apparatus shown in FIG. 1. After the elevation of
temperature, an aqueous dispersion medium solution containing 35 g
of oxidation-treated gelatin and 300 ml of water was added and
thereto, 2,916 ml of (c) an aqueous 0.53 mol/liter silver nitrate
solution and (d) a mixed solution of 0.56 mol/liter potassium
bromide and potassium iodide (Br:I=95:5) were added by a controlled
double jet method over 237 minutes while keeping the silver
potential at -60 mV. During the addition of solutions (c) and (d),
the reaction solution was dehydrated and desalted to a final volume
of 3 liter using an ultrafiltration apparatus shown in FIG. 1. At
this time, when 70% of silver nitrate was added, 8.times.10.sup.-8
mol/mol.-Ag of K.sub.3IrCl.sub.6 was added and doped into the grain
under growth and before the completion of grain growth, yellow
prussiate of potash was doped into the portion of 90 to 97% in
terms of silver amount of the grain to have a concentration of
3.times.10.sup.-4 mol/mol-Ag as a local concentration. After the
completion of addition of solutions (c) and (d), the emulsion was
cooled to 35.degree. C. and washed by a normal flocculation method
and thereto, 70 g of lime-treated ossein gelatin was added and
dissolved to adjust the pAg and the pH to 8.7 and 6.5,
respectively, thereby obtaining Emulsion I-A.
[0272] The ultrafiltration module used in the ultrafiltration
apparatus was flat membrane Centramate Nova Series (fractional
molecular weight: 30,000) produced by Pall. At this time, the
reflux flow rate was 1 liter/min, the permeation flow rate was from
24 to 57 ml/min, the supply pressure was 0.09 MPa, the reflux
pressure was 0.05 MPa and the permeation pressure was 0 MPa.
[0273] (Invention I-1)
[0274] Emulsion I-B was prepared in the same manner as Emulsion I-A
except that the solution (c) and (e) a mixed solution of 0.56
mol/liter potassium bromide and potassium iodide (Br:I=95:5) in
which low molecular weight gelatin (molecular eight: 15,000) was
added to a concentration of 5% were added to a mixing vessel
(residence time: 6.6 seconds) shown in FIG. 2 where stirring blades
having no rotary shaft protruding through the wall of a closed
stirring tank and connected with a magnetic coupling were rotated
in the converse direction, to prepare silver halide fine grains
(average grain size: 0.020 .mu.m), the obtained silver halide fine
grains were added to a reactor and during the addition, a mixed
solution of 1 mol/liter potassium bromide and potassium iodide
(Br:I=95:5) was added to keep the silver potential in the reactor
at -60 mV.
[0275] (Invention I-2)
[0276] Emulsion I-C was prepared in the same manner as Emulsion I-A
except that the solutions (c) and (e) were added to a mixing vessel
(residence time: 1.1 seconds) shown in FIG. 2 where stirring blades
having a rotary shaft directly connected with a motor and sealed
were rotated in the converse direction in the stirring tank, to
prepare silver halide fine grains (average grain size: 0.016
.mu.m), the prepared silver halide fine grains were added to a
reactor and during the addition, a mixed solution of 1 mol/liter
potassium bromide and potassium iodide (Br:I=95:5) was added to
keep the silver potential in the reactor at -60 mV.
[0277] (Invention I-3)
[0278] Emulsion I-D was prepared in the same manner as Emulsion I-A
except that the solutions (c) and (e) were mixed to produce silver
bromide fine grains by applying high-pressure homogenizer DEBEE
2000 manufactured by BEE INTERNATIONAL as a mixing vessel, the
solution (c) was turned into a linear jet stream using the dual
field process of the apparatus, the jet stream was produced by
passing the solution through pores having a diameter of 0.1 mm
under pressure of an ejection pressure of 9.8.times.10.sup.7 Pa,
the solution (c) was added at an addition rate of 280 ml/min and a
flow rate of 600 m/sec, the solution (e) was added through another
addition port while controlling the flow rate by a piston at an
addition rate of 280 ml/min, thereby attaining mixing in a
residence time of 0.012 seconds without causing circulation or
being accompanied by mechanical stirring, the thus-prepared silver
halide fine grains (average grain size: 0.013 .mu.m) were added to
a reactor and during the addition, a mixed solution of 1 mol/liter
potassium bromide and potassium iodide (Br:I=95:5) was added to
keep the silver potential in the reactor at -60 mV.
[0279] (Invention I-4)
[0280] Emulsion I-E was prepared in the same manner as Emulsion I-D
except that in the preparation of Emulsion I-D, the solutions (c)
and (e) after mixing were mixed by fixing a capillary having a
diameter of 1 mm in the inside. At this time, the residence time
was 0.01 second and the average grain size of silver halide fine
grains was 0.012 .mu.m.
[0281] (Invention I-5) Emulsion I-F was prepared in the same manner
as Emulsion I-A except that Microreactor (interdigital single
mixing device) manufactured by IMM (Institute fur Mikrotechnik
Mianz) was used as a mixing vessel, the solutions (c) and (e) were
added to the Microreactor by a syringe pump and mixed, the
residence time here was 10 seconds, the prepared silver halide fine
grains (average grain size: 0.015 .mu.m) were added to a reactor
and during the addition, a mixed solution of 1 mol/liter potassium
bromide and potassium iodide (Br:I=95:5) was added to keep the
silver potential in the reactor at -60 mV.
[0282] (Invention I-6)
[0283] Emulsion I-G was prepared in the same manner as Emulsion I-B
except that in the preparation of Emulsion I-B, hollow yarn
membrane SLP-1053 (fractional molecular weight: 10,000) produced by
Asahi Chemical Industry Co., Ltd. was used for the ultrafiltration
module. At this time, the reflux flow rate was 12 liter/min, the
permeation flow rate was from 21 to 43 ml/min, the supply pressure
was 0.06 MPa, the reflux pressure was 0.03 MPa and the permeation
pressure was 0 MPa.
[0284] The percentage of tabular grains, the equivalent-circle
diameter, the coefficient of variation in the equivalent-circle
diameter, the average thickness and the aspect ratio of each of
Emulsions I-A to I-G prepared above are shown together in Table
1.
[0285] Here, the coefficient of variation in the equivalentcircle
diameter is obtained by dividing the standard deviation of the
equivalent-circle diameter of grains by the equivalent-circle
diameter and shown by a percentage.
2TABLE 1 Coefficient of Variation in Percentage Equivalent-
Equivalent- of Tabular Circle Circle Average Grains Diameter
Diameter Thickness Aspect Emulsion (%) (.mu.m) (%) (.mu.m) Ratio
I-A 97 1.28 36 0.075 17.1 Comparison I-B 98.2 1.35 29 0.062 21.8
Invention I-C 99 1.4 28 0.063 22.2 " I-D 99.2 1.28 29 0.06 21.3 "
I-E 99.3 1.27 24 0.059 21.5 " I-F 98.2 1.37 30 0.066 20.8 " I-G
98.3 1.34 29 0.062 21.6 "
[0286] As seen from Table 1, according to the present invention,
tabular grains being monodisperse with a small coefficient of
variation in the equivalent-circle diameter and having a high
aspect ratio can be prepared. As the size of silver halide fine
grains prepared in the mixing vessel is smaller, tabular grains
having a smaller coefficient of variation in the equivalent-circle
diameter can be prepared.
Example II
[0287] Emulsions I-A to I-G each was heated to a temperature of
56.degree. C. and subjected to optimal chemical sensitization by
adding Sensitizing Dyes I, II and III shown below, Compound I shown
below, potassium thiocyanate, chloroauric acid, sodium thiosulfate
and N,N-dimethyl selenourea. However, the sensitizing dyes were
used each as a solid fine dispersion prepared by the method
described in JP-A-11-52507. More specifically, 0.8 mass parts
(i.e., weight parts) of sodium nitrate and 3.2 mass parts of sodium
sulfate were dissolved in 43 parts of ion exchanged water and 13
mass parts of the sensitizing dye was added and dispersed at
60.degree. C. for 20 minutes using a dissolver blade at 2,000 rpm,
thereby obtaining a solid dispersion of sensitizing dye. 1
[0288] On a cellulose triacetate film support having provided
thereon a subbing layer, chemically sensitized Emulsion I-A, I-B,
I-C, I-D, I-E, I-F or I-G prepared above was coated under the
coating conditions shown in Table 2 below and a protective layer
was provided, thereby obtaining coated samples.
3TABLE 2 Emulsion Coating Conditions (1) Emulsion layer Emulsion:
Each emulsion (2.1 .times. 10.sup.-2 mol/m.sup.2 as silver)
Coupler: 2 (1.5 .times. 10.sup.-3 mol/m.sup.2) 3 (1.1 .times.
10.sup.-4 mol/m.sup.2) Tricresyl phosphate (1.10 g/m.sup.2) Gelatin
(2.30 g/m.sup.2) (2) Protective layer
2,4-Dichloro-6-hydroxy-s-triazine sodium salt (0.08 g/m.sup.2)
Gelatin (1.80 g/m.sup.2)
[0289] These samples were left standing for 14 hours under the
conditions of 40.degree. C. and a relative humidity of 70% and
thereafter, exposed for {fraction (1/100)} second through gelatin
filter SC-50 manufactured by Fuji Photo Film Co., Ltd. and a
continuous wedge.
[0290] The samples were processed using Negative Processor FP-350
manufactured by Fuji Photo Film Co., Ltd. by the following method
(until the cumulative replenishing amount of solution became thrice
the tank volume of mother solution).
[0291] (Processing Method)
4 Processing Processing Temperature Replenishing Step Time
(.degree. C.) Amount* (mL) Color development 3 min 15 sec 38 45
Bleaching 1 min 00 sec 38 20 overflow of bleaching solution was
wholly passed to bleach-fixing tank Bleach-fixing 3 min 15 sec 38
30 Water washing (1) 40 sec 35 countercurrent piping system from
(2) to (1) Water washing (2) 1 min 00 sec 35 30 Stabilization 40
sec 38 20 Drying 1 min 15 sec 55 *The replenishment amount was per
1.1-m length in 35-mm width (corresponding to one roll of 24
Ex.).
[0292] The composition of each processing solution was as
follows.
5 Tank Solution Replenisher (g) (g) (Color Developer)
Diethylenetriaminepentaacet- ic 1.0 1.1 acid
1-Hydroxyethylidene-1,1- 2.0 2.0 diphosphonic acid Sodium sulfite
4.0 4.4 Potassium carbonate 30.0 37.0 Potassium bromide 1.4 0.7
Potassium iodide 1.5 mg -- Hydroxylamine sulfate 2.4 2.8
4-[N-Ethyl-N-(.beta.-hydxoxyethyl)- 4.5 5.5 amino]-2-methylaniline
sulfate Water to make 1.0 L 1.0 L pH (adjusted by potassium 10.05
10.10 hydroxide and sulfuric acid) (Bleaching Solution) Tank
solution and replenisher were common (unit: g). Ammonium
ethylenediaminetetraacetato 120.0 ferrate dihydrate Disodium
ethylenediaminetetraacetate 10.0 Ammonium bromide 100.0 Ammionium
nitrate 10.0 Bleaching accelerator: 0.005 mol
(CH.sub.3).sub.2N--CH.sub.2--CH.s- ub.2S--S--CH.sub.2CH.sub.2--
N(CH.sub.3).sub.2.2HCl Aqueous ammonia (27%) 15.0 mL Water to make
1.0 L pH (adjusted by aqueous ammonia and nitric 6.3 acid)
(Bleach-Fixing Solution) Ammonium ethylenediaminetetraacetato 50.0
-- ferrate dihydrate Disodium ethylenediaminetetraacetate 5.0 2.0
Sodium sulfite 12.0 20.0 Aqueous ammonium thiosulfate 240.0 mL
400.0 mL solution (700 g/L) Aqueous ammonia (27%) 6.0 mL -- Water
to make 1.0 L 1.0 L pH (adjusted by aqueous ammonia 7.2 7.3 and
acetic acid)
[0293] (Washing Water)
[0294] Tank solution and replenisher were common.
[0295] Tap water was passed through a mixed bed column filled with
an H-type strongly acidic cation exchange resin (Amberlite IR-120B,
produced by Rhom and Haas) and an OHtype anion exchange resin
(Amberlite IR-400, produced by the same company) to reduce the
calcium and magnesium ion concentrations each to 3 mg/L or less and
thereto 20 mg/L of sodium isocyanurate dichloride and 0.15 g/L of
sodium sulfate were added. The resulting solution had a pH of 6.5
to 7.5.
6 (Stabilizing Solution) Tank solution and replenisher were common
(unit: g). Sodium p-toluenesulfinate 0.03
Polyoxyethylene-p-monononylphenyl ether 0.2 (average polymerization
degree: 10) Disodium ethylenediaminetetraacetate 0.05
1,2,4-Triazole 1.3 1,4-Bis(1,2,4-triazol-1-ylmethyl)piperazine 0.75
Water to make 1.0 L pH 8.5
[0296] The development processing dependency was evaluated by
changing the processing time of color development. The processed
samples were measured on the density using a green filter.
[0297] The results obtained are shown together in Table 3. The
sensitivity is expressed by a reciprocal of the exposure amount
necessary for obtaining an optical density of fog+0.2 and shown as
a relative value to the value of Emulsion I-A which is taken as
100.
7 TABLE 3 Emulsion Sensitivity Fog I-A 100 0.023 Comparison I-B 120
0.022 Invention I-C 122 0.021 " I-D 123 0.020 " I-E 125 0.020 " I-F
120 0.022 " I-G 121 0.022 "
[0298] As apparently seen from Table 3, by using the emulsion
produced by the production process of the present invention, a
light-sensitive material low in the fog and high in the sensitivity
can be obtained.
Example III
[0299] (Comparison III-1)
[0300] In a reactor, 1 liter of an aqueous solution (pH: 5)
containing 0.36 g of potassium bromide and 0.7 g of low molecular
weight gelatin (molecular weight: 15,000) was charged and kept
40.degree. C. While stirring the aqueous solution, 20 ml of an
aqueous 0.29 mol/liter silver nitrate solution and 20 ml of an
aqueous 0.29 mol/liter potassium bromide solution were added
thereto by a double jet method over 40 seconds. After the addition,
an aqueous solution containing 2.2 g of potassium bromide was added
to the reaction solution and the temperature was elevated to
60.degree. C. over 35 minutes. After the elevation of temperature,
an aqueous dispersion medium solution containing 35 g of
oxidation-treated gelatin and 300 ml of water was added and then,
972 ml of an aqueous 0.53 mol/liter silver nitrate solution and a
mixed solution of 0.56 mol/liter potassium bromide and potassium
iodide (Br:I=97:3) were added directly to the reactor by a
controlled double jet method over 79 minutes while keeping the
silver potential at -60 mV, thereby performing the grain growth. At
this time, when 70% of silver nitrate was added, 8.times.10.sup.-8
mol/mol-Ag of K.sub.3IrCl.sub.6 was added and doped into the grain
under growth and before the completion of grain growth, yellow
prussiate of potash was doped into the portion of 90 to 97% in
terms of silver amount of the grain to have a concentration of
3.times.10.sup.-4 mol/mol-Ag as a local concentration. After the
completion of addition of silver nitrate solution, the emulsion was
cooled to 35.degree. C. and washed by a normal flocculation method
and thereto, 70 g of lime-treated ossein gelatin was added and
dissolved to adjust the pAg and the pH to 8.7 and 6.5,
respectively, thereby obtaining Emulsion III-a.
[0301] (Comparison III-2)
[0302] In a reactor, 3 liter of an aqueous solution (pH: 5)
containing 1.08 g of potassium bromide and 2.1 g of low molecular
weight gelatin (molecular weight: 15,000) was charged and kept
40.degree. C. While stirring the aqueous solution, 20 ml of an
aqueous 0.87 mol/liter silver nitrate solution and 20 ml of an
aqueous 0.87 mol/liter potassium bromide solution were added
thereto by a double jet method over 40 seconds. After the addition,
an aqueous solution containing 2.2 g of potassium bromide was added
to the reaction solution and the temperature was elevated to
60.degree. C. over 35 minutes. During the elevation of temperature,
the reaction solution was dehydrated to a volume of 1 liter using
an ultrafiltration apparatus shown in FIG. 1 (the ultrafiltration
module was hollow yarn membrane SLP-1053 (fractional molecular
weight: 10,000) produced by Asahi Chemical Industry Co., Ltd.).
After the- elevation of temperature, an aqueous dispersion medium
solution containing 35 g of oxidation-treated gelatin and 300 ml of
water was added and then, 2,916 ml of an aqueous 0.53 mol/liter
silver nitrate solution and a mixed solution of 0.56 mol/liter
potassium bromide and potassium iodide (Br:I=97:3) were added
directly to the reactor by a controlled double jet method over 237
minutes while keeping the silver potential at -60 mV, thereby
performing the grain growth. During this addition, the reaction
solution was dehydrated to a final volume of 3.3 liter using an
ultrafiltration apparatus shown in FIG. 1 (the ultrafiltration
module was hollow yarn membrane SLP-1053 (fractional molecular
weight: 10,000) produced by Asahi Chemical Industry Co., Ltd.). At
this time, when 70% of silver nitrate was added, 8.times.10.sup.-8
mol/mol-Ag of K.sub.3IrCl.sub.6 was added and doped into the grain
under growth and before the completion of grain growth, yellow
prussiate of potash was doped into the portion of 90 to 97% in
terms of silver amount of the grain to have a concentration of
3.times.10.sup.-4 mol/mol-Ag as a local concentration. After the
completion of addition of silver nitrate solution, the emulsion was
cooled to 35.degree. C. and washed by a normal flocculation method
and thereto, 70 g of lime-treated ossein gelatin was added and
dissolved to adjust the pAg and the pH to 8.7 and 6.5,
respectively, thereby obtaining Emulsion III-b.
[0303] (Comparison III-3)
[0304] Emulsion III-c was prepared in the same manner as Emulsion
III-a except that in the grain growth of Emulsion II-a, 1,945 ml of
Fine Grain Emulsion M dissolved at 40.degree. C. was added over 79
minutes while keeping the silver potential at -60 mV using a mixed
solution of 1.2 mol/l potassium bromide and potassium iodide
(Br:I=97:3).
[0305] (Comparison III-4)
[0306] Emulsion III-d was prepared in the same manner as Emulsion
III-a except that in the grain growth of Emulsion II-b, 5,835 ml of
Fine Grain Emulsion M dissolved at 40.degree. C. was added over 237
minutes while keeping the silver potential at -60 mV using a mixed
solution of 1.2 mol/l potassium bromide and potassium iodide
(Br:I=97:3).
[0307] Preparation of Fine Grain Emulsion M
[0308] In a reactor, 0.16 g of potassium bromide, 160 g of low
molecular weight gelatin (molecular weight: 15,000), 18 ml of 0.5
mol/liter sulfuric acid and 3,920 ml of distilled water were
charged and kept at 35.degree. C. While stirring the mixture, 477
ml of an aqueous 1.37 mol/liter silver nitrate solution and 487 ml
of an aqueous 1.37 mol/liter potassium bromide solution were added
by a double jet method at a constant flow rate over 45 seconds.
Thereafter, 1,588 ml of an aqueous 0.96 mol/liter silver nitrate
solution was added over 20 minutes and at the same time, a mixed
solution of 0.96 mol/liter potassium bromide and potassium iodide
(Br:I=97:3) was added by a controlled double jet method while
keeping the pAg at 8.1. The average grain size was 0.040 .mu.m and
the coefficient of variation in the grain size was 35%.
[0309] (Comparison III-S)
[0310] Emulsion III-e was prepared in the same manner as Emulsion
III-a except that in the grain growth of Emulsion III-a, 972 ml of
an aqueous 0.53 mol/liter silver nitrate solution and 972 ml of a
mixed solution of 0.50 mol/liter potassium bromide and potassium
iodide (Br:I=97:3) in which gelatin (molecular weight: 100,000) was
added to a concentration of 5% were added to a mixing vessel
(residence time: 6.6 seconds) shown in FIG. 2 where stirring blades
having no rotary shaft protruding through the wall of closed
stirring tank and connected with magnetic coupling were rotated in
the converse direction, to prepare silver halide fine grains
(average grain size: 0.023 .mu.m) and while keeping the silver
potential at -60 mV by adding a mixed solution of 1.2 mol/liter
potassium bromide and potassium iodide (Br:I=97:3) to the reactor,
the prepared silver halide fine grains were added to the reactor
over 79 minutes, thereby performing the grain growth.
[0311] (Comparison III-6)
[0312] Emulsion III-f was prepared in the same manner as Emulsion
III-a except that in the grain growth of Emulsion III-b, 2,916 ml
of an aqueous 0.53 mol/liter silver nitrate solution and 2,916 ml
of a mixed solution of 0.50 mol/liter potassium bromide and
potassium iodide (Br:I=97:3) in which gelatin (molecular weight:
100,000) was added to a concentration of 5% were added to a mixing
vessel (residence time: 6.6 seconds) shown in FIG. 2 where stirring
blades having no rotary shaft protruding through the wall of closed
stirring tank and connected with magnetic coupling were rotated in
the converse direction, to prepare silver halide fine grains
(average grain size: 0.023 .mu.m) and while keeping the silver
potential at -60 mV by adding a mixed solution of 1.2 mol/liter
potassium bromide and potassium iodide (Br:I=97:3) to the reactor,
the prepared silver halide fine grains were added to the reactor
over 237 minutes, thereby performing the grain growth.
[0313] (Comparison III-7)
[0314] Emulsion III-g was prepared in the same manner as Emulsion
III-a except that in the grain growth of Emulsion III-a, 972 ml of
an aqueous 0.53 mol/liter silver nitrate solution and 972 ml of a
mixed solution of 0.50 mol/liter potassium bromide and potassium
iodide (Br:I=97:3) in which gelatin (molecular weight: 20,000) was
added to a concentration of 5% were added to a mixing vessel
(residence time: 6.6 seconds) shown in FIG. 2 where stirring blades
having no rotary shaft protruding through the wall of closed
stirring tank and connected with magnetic coupling were rotated in
the converse direction, to prepare silver halide fine grains
(average grain size: 0.023 .mu.m) and while keeping the silver
potential at -60 mV by adding a mixed solution of 1.2 mol/liter
potassium bromide and potassium iodide (Br:I=97:3) to the reactor,
the prepared silver halide fine grains were added to the reactor
over 79 minutes, thereby performing the grain growth.
[0315] (Invention III-1)
[0316] Emulsion III-h was prepared in the same manner as Emulsion
III-b except that in the grain growth of Emulsion III-a, 2,916 ml
of an aqueous 0.53 mol/liter silver nitrate solution and 2,916 ml
of a mixed solution of 0.50 mol/liter potassium bromide and
potassium iodide (Br:I=97:3) in which gelatin (molecular weight:
20,000) was added to a concentration of 5% were added to a mixing
vessel (residence time: 6.6 seconds) shown in FIG. 2 where stirring
blades having no rotary shaft protruding through the wall of closed
stirring tank and connected with magnetic coupling were rotated in
the converse direction, to prepare silver halide fine grains
(average grain size: 0.023 .mu.m) and while keeping the silver
potential at -60 mV by adding a mixed solution of 1.2 mol/liter
potassium bromide and potassium iodide (Br:I=97:3) to the reactor,
the prepared silver halide fine grains were added to the reactor
over 237 minutes, thereby performing the grain growth.
[0317] The percentage of tabular grains, the equivalentcircle
diameter, the coefficient of variation in the equivalent-circle
diameter, the average thickness and the aspect ratio of each of
Emulsions III-a to III-h prepared are shown together in Table
4.
8TABLE 1 Coefficient of Variation in Percentage Equivalent-
Equivalent- of Tabular Circle Circle Average Grains Diameter
Diameter Thickness Aspect Emulsion (%) (.mu.m) (%) (.mu.m) Ratio
III-a 98.0 1.27 39 0.077 16.5 Comparison III-b 97.1 1.29 37 0.076
17.0 " III-c 98.2 1.30 35 0.075 17.3 " III-d 98.3 1.31 34 0.078
16.8 " III-e 96.8 0.98 40 0.094 10.4 " III-f 96.5 0.97 38 0.096
10.1 " III-g 98.5 1.38 30 0.066 20.9 " III-h 99.0 1.48 24 0.063
23.5 Invention
[0318] As se n from Table 4, tabular grains being monodisperse with
a small coefficient of variation in the equivalent-circle diameter
and having a high aspect ratio can be prepared by the present
invention.
Example IV
[0319] In the same manner as in Example 2, chemical sensitization
and spectral sensitization were optimally performed and each
emulsion was coated. The photographic performance was compared.
[0320] The results obtained are shown together in Table 5. The
exposure was expressed by a reciprocal of the exposure amount
necessary for obtaining an optical density of fog+1.0 and shown by
a relative value to the value of Emulsion III-a which was taken as
100.
9 TABLE 5 Emulsion Sensitivity Fog III-a 100 0.022 Comparison III-b
101 0.024 " III-c 104 0.023 " III-d 108 0.025 " III-e 83 0.024 "
III-f 82 0.025 " III-g 110 0.022 " III-h 125 0.020 Invention
[0321] As seen from Table 5, tabular grains having highsensitivity
and low fog can be prepared by the present invention.
Example V
[0322] The production process of emulsion of the present invention
is described in detail below.
[0323] (Preparation of Emulsion V-a)
[0324] 1,192 mL of an aqueous solution containing 0.9 g of KBr and
4.2 g of oxidation-treated low molecular weight gelatin having an
average molecular weight of 20,000 was stirred while keeping at
35.degree. C. Thereto, 33.4 ml of an aqueous AgNO.sub.3 (1.0 g)
solution and 53.1 ml of an aqueous solution containing KBr (0.9 g)
and oxidation-treated low molecular weight gelatin (0.37 g) having
an average molecular weight of 20,000 were added over 52 seconds.
The temperature was elevated to 75.degree. C. and then, 18 ml of an
aqueous solution containing 1.83 g of KBr was added. Thereafter,
130 ml of an aqueous solution containing 16 g of succinated gelatin
having an average molecular weight of 100,000 was added and then,
200 ml of an aqueous solution containing 12 g of sodium catechol
disulfonate was added. Subsequently, as the first growth, silver
halide fine grains prepared by adding 854 ml of an aqueous
AgNO.sub.3 (136.0 g) solution, KBr in an equimolar concentration
and an aqueous solution (containing 3 mol % of KI) of low molecular
weight oxidation-treated gelatin (81.6 g) having a molecular weight
of 15,000 to a mixing vessel shown in FIG. 2 where stirring blades
having no rotary shaft protruding the wall of a closed stirring
tank and connected with magnetic coupling were rotated in the
converse direction, were continuously added to a reactor. The
silver potential was kept at 0 mV to the saturated calomel
electrode by separately adding a KBr solution. In the fine grains
added, the number average equivalent-circle diameter was 0.019
.mu.m, the coefficient of variation in the equivalent-circle
diameter was 35% and the percentage by number of twin grains was
14%. By the growth here, the average thickness of tabular grains
became 0.047 .mu.m. During the growth, 10 ml of an aqueous solution
containing potassium hexachloroiridate (0.2 mg) was added. At the
completion of addition of AgNO.sub.3, 10 ml of an aqueous solution
containing sodium benzenethiosulfonate (2 mg) was added.
Thereafter, the solution was bailed out to a volume of 608 ml.
Then, as the second growth, silver halide fine gains were prepared
by adding 689 ml of an aqueous AgNO.sub.3 (82.7 g) solution, KBr in
an equimolar concentration and an aqueous solution (containing 3
mol % of KI) of low molecular weight oxidation-treated gelatin
(49.6 g) having a molecular weight of 15,000 to the same mixing
vessel as in the first growth and added to the reactor. The silver
potential was kept at 0 mV to the saturated calomel electrode by
separately adding a KBr solution. In the fine grains added, the
number average equivalent-circle diameter was 0.025 .mu.m, the
coefficient of variation in the equivalent-circle diameter was 31%
and the percentage by number of twin grains was 12%. By the growth
here, the average thickness of tabular grains became 0.061 .mu.m.
Then, as the third growth, silver halide fine gains were prepared
by adding 519 ml of an aqueous AgNO.sub.3 (83.0 g) solution, KBr in
an equimolar concentration and an aqueous solution (containing 3
mol % of KI) of low molecular weight oxidation-treated gelatin
(49.8 g) having a molecular weight of 15,000 to the same mixing
vessel as in the first growth and added to the reactor. The silver
potential was kept at 0 mV to the saturated calomel electrode by
separately adding a KBr solution. In the fine grains added, the
number average equivalent-circle diameter was 0.028 .mu.m, the
coefficient of variation in the equivalent-circle diameter was 32%
and the percentage by number of twin grains was 15%.
[0325] Thereafter, 100 ml of an aqueous solution containing 11 g of
gelatin was added. This gelatin was obtained by crosslinking an
alkali-treated ossein first extraction gelatin (in the molecular
weight distribution measured by PAGI method, the high molecular
weight component was 2.5% and the low molecular weight component
was 60.0%) starting from cow bone. In the molecular weight
distribution measured by the PAGI method, the high molecular weight
component was 12.4% and the low molecular weight component was
48.3%. After lowering the temperature to 40.degree. C., 5.97 ml of
phenoxyethanol was added and further, 20 ml of an aqueous KI (0.16
g) solution was added. Thereto, Sensitizing Dyes IV, V and VI were
added at a molar ratio of 69:30:1 to a proportion of 70% of the
saturated coverage. Here, the sensitizing dyes were used as a solid
fine dispersion prepared by the method described in JP-A-11-52507.
More specifically, 0.8 mass parts of sodium nitrate and 3.2 mass
parts of sodium sulfate were dissolved in 43 mass parts of ion
exchanged water and 13 mass parts of the sensitizing dye was added
and dispersed at 60.degree. C. for 20 minutes using a dissolver
blade at 2,000 rpm, thereby obtaining a solid dispersion of
sensitizing dye. After adding 15 ml of an aqueous solution
containing potassium hexacyanoruthenate(II) (2.0 mg), 100 ml of an
aqueous AgNO.sub.3 (7.77 g) solution and 100 ml of an aqueous
solution containing KBr (2.85 g), KI (0.54 g) and NaCl (2.35 g)
were added by a double jet method over 2 minutes. Thereafter, 12 ml
of Epitaxial Part Shape Stabilizer I (62 mg) was added and then
normal water washing was performed. At this time, the temperature
was kept at 35.degree. C. After adding 59 g of the above-described
gelatin, the pH at 40.degree. C. was adjusted to 6.5 and the silver
potential was adjusted to 80 mV to the saturated calomel electrode
using an aqueous NaCl solution. After adding Epitaxial Part Shape
Stabilizer/Storability Improver II (5 mg), the temperature was
elevated to 68.degree. C. and then, chemical sensitization was
optimally performed by adding 0.5.times.10.sup.-4 mol of potassium
thiocyanate, 1.1.times.10.sup.-6 mol of chloroauric acid,
0.38.times.10.sup.-5 mol of sodium thiosulfate and
1.0.times.10.sup.-6 mol of N,N-dimethylselenourea per mol of silver
halide. Antifoggant I (6.4.times.10.sup.-4 mol) was added and the
chemical sensitization was completed.
[0326] Emulsion V-a thus prepared was tabular grains such that the
coefficient of variation in the equivalent-circle diameter was 27%,
the number average equivalent-circle diameter was 4.20 .mu.m and
the number average thickness was 0.067 .mu.m. In this emulsion, 90%
or more of the entire projected area was occupied by hexagonal
tabular grains where the ratio of the length of a side having a
maximum length to the length of a side having a minimum length was
1.5 or less and an epitaxial junction was present at all of six
apex parts. The emulsion was observed by a transmission electron
microscope at a low temperature, as a result, 90% or more of the
entire projected area was occupied by grains having no dislocation
line in the main plane part except for the epitaxial part and
having network dislocation lines in the epitaxial part. In this
grain, the outermost layer having a silver iodide content of 12%
occupied 12% in terms of silver. The epitaxial part occupied 4.5%
in terms of silver and had a composition of AgBr(52)Cl(40)I(8).
Furthermore, 90% or more of the entire projected area was within
30% of the average silver chloride content and 30% of the average
silver iodide content. 4
[0327] (Preparation of Emulsion V-b)
[0328] Emulsion V-b was prepared almost in the same manner as in
the preparation of Emulsion V-a except that the procedure from the
nucleation until the third growth was changed as follows.
[0329] An aqueous solution (1,192 mL) containing 0.161 g of KBr and
2.41 g of low molecular weight oxidation-treated gelatin having an
average molecular weight 20,000 was kept at 35.degree. C. and
stirred. Thereto, 33.4 ml of an aqueous AgNO.sub.3 (0.179 g)
solution and 53.1 ml of an aqueous solution containing KBr (0.161
g) and low molecular weight oxidation-treated gelatin (0.066 g)
having an average molecular weight of 20,000 were added over 52
seconds. After elevating the temperature to 75.degree. C., 18 ml of
an aqueous solution containing 0.33 g of KBr was added, 130 ml of
an aqueous solution containing 8 g of succinated gelatin having an
average molecular weight of 100,000 was added, and then 200 ml of
an aqueous solution containing 2.15 g of sodium catechol
disulfonate was added. Thereafter, as the first growth, silver
halide fine grains prepared by adding 854 ml of an aqueous
AgNO.sub.3 (24.34 g) solution, KBr in an equimolar concentration
and an aqueous solution (containing 3 mol % of KI) of low molecular
weight oxidation-treated gelatin (24.34 g) having a molecular
weight of 15,000 to a mixing vessel shown in FIG. 2 where stirring
blades having no rotary shaft protruding the wall of a closed
stirring tank and connected with magnetic coupling were rotated in
the converse direction, were continuously added to a reactor. The
silver potential was kept at 0 mV to the saturated calomel
electrode by separately adding a KBr solution. In the fine grains
added, the number average equivalent-circle diameter was 0.021
.mu.m, the coefficient of variation in the equivalent-circle
diameter was 28% and the percentage by number of twin grains was
9%. By the growth here, the average thickness of tabular grains
became 0.044 .mu.m. During the growth, 10 ml of an aqueous solution
containing potassium hexachloroiridate (0.04 mg) was added. At the
completion of addition of AgNO.sub.3, 10 ml of an aqueous solution
containing sodium benzenethiosulfonate (0.36 mg) was added.
Together with this first growth, ultrafiltration was performed. The
ultrafiltration module used for the ultrafiltration apparatus was
flat membrane Centramate Nova Series (fractional molecular weight:
30,000) produced by Pall. The reflux flow rate was 1 liter/min, the
supply pressure was 0.09 MPa, the reflux pressure was 0.05 MPa and
the permeation pressure was 0 MPa. At this time, the liquid volume
was 608 ml. Then, as the second growth, silver halide fine gains
were prepared by adding 689 ml of an aqueous AgNO.sub.3 (82.7 g)
solution, KBr in an equimolar concentration and an aqueous solution
(containing 3 mol % of KI) of low molecular weight
oxidation-treated gelatin (82.7 g) having a molecular weight of
15,000 to the same mixing vessel as in the first growth and added
to the reactor. The silver potential was kept at 0 mV to the
saturated calomel electrode by separately adding a KBr solution. In
the fine grains added, the number average equivalent-circle
diameter was 0.026 .mu.m, the coefficient of variation in the
equivalent-circle diameter was 27% and the percentage by number of
twin grains was 7%. By the growth here, the average thickness of
tabular grains became 0.052 .mu.m. Then, as the third growth,
silver halide fine gains were prepared by adding 519 ml of an
aqueous AgNO.sub.3 (83.0 g) solution, KBr in an equimolar
concentration and an aqueous solution (containing 3 mol % of KI) of
low molecular weight oxidation-treated gelatin (83.0 g) having a
molecular weight of 15,000 to the same mixing vessel as in the
first growth and added to the reactor. The silver potential was
kept at 0 mV to the saturated calomel electrode by separately
adding a KBr solution. In the fine grains added, the number average
equivalent-circle diameter was 0.028 .mu.m, the coefficient of
variation in the equivalent-circle diameter was 29% and the
percentage by number of twin grains was 7%. The thusprepared
Emulsion V-b was tabular grains where the coefficient of variation
in the equivalent-circle diameter was 29%, the number average
equivalent-circle diameter was 4.60 .mu.m and the number average
thickness was 0.056 .mu.m.
[0330] (Preparation of Emulsion V-c)
[0331] Emulsion V-c was prepared almost in the same manner as in
the preparation of Emulsion V-a except that the procedure from the
first growth until the third growth was changed as follows.
[0332] As the first growth, silver halide fine grains prepared by
adding 854 ml of an aqueous AgNO.sub.3 (136.0 g) solution, KBr in
an equimolar concentration and an aqueous solution (containing 3
mol % of KI) of low molecular weight oxidation-treated gelatin (136
g) having a molecular weight of 15,000 to a mixing vessel shown in
FIG. 2 where stirring blades having no rotary shaft protruding the
wall of a closed stirring tank and connected with magnetic coupling
were rotated in the converse direction, were continuously added to
a reactor. The silver potential was kept at 0 mV to the saturated
calomel electrode by separately adding a KBr solution. In the fine
grains added, the number average equivalent-circle diameter was
0.013 .mu.m, the coefficient of variation in the equivalent-circle
diameter was 35% and the percentage by number of twin grains was
15%. By the growth here, the average thickness of tabular grains
became 0.053 .mu.m. During the growth, 10 ml of an aqueous solution
containing potassium hexachloroiridate (0.2 mg) was added. At the
completion of addition of AgNO.sub.3, 10 ml of an aqueous solution
containing sodium benzenethiosulfonate (2 mg) was added.
Thereafter, the solution was bailed out to a volume of 608 ml.
Then, as the second growth, silver halide fine gains were prepared
by adding 689 ml of an aqueous AgNO.sub.3 (82.7 g) solution, KBr in
an equimolar concentration and an aqueous solution (containing 3
mol % of KI) of low molecular weight oxidation-treated gelatin
(49.6 g) having a molecular weight of 15,000 to the same mixing
vessel as in the first growth and added to the reactor. The silver
potential was kept at 0 mV to the saturated calomel electrode by
separately adding a KBr solution. In the fine grains added, the
number average equivalent-circle diameter was 0.013 .mu.m, the
coefficient of variation in the equivalent-circle diameter was 32%
and the percentage by number of twin grains was 13%. By the growth
here, the average thickness of tabular grains became 0.070 .mu.m.
Then, as the third growth, silver halide fine gains were prepared
by adding 519 ml of an aqueous AgNO.sub.3 (83.0 g) solution, KBr in
an equimolar concentration and an aqueous solution (containing 3
mol % of KI) of low molecular weight oxidation-treated gelatin
(83.0 g) having a molecular weight of 15,000 to the same mixing
vessel as in the first growth and added to the reactor. The silver
potential was kept at 0 mV to the saturated calomel electrode by
separately adding a KBr solution. In the fine grains added, the
number average equivalent-circle diameter was 0.014 .mu.m, the
coefficient of variation in the equivalent-circle diameter was 36%
and the percentage by number of twin grains was 15%. The
thus-prepared Emulsion V-c was tabular grains where the coefficient
of variation in the equivalent-circle diameter was 25%, the number
average equivalent-circle diameter was 4.0 .mu.m and the number
average thickness was 0.1 .mu.m.
[0333] The characteristic values of Emulsions V-a, V-b and V-c are
shown in Table 6. As apparent from the results in Table 6, the
large size tabular grain can be more reduced in the thickness by
the production process of the present invention.
10TABLE 6 Coefficient of variation Presence Number in of Average
Number Equivalent- Name Absence Equivalent- Average Circle of of
Circle Thick- Diameter of Emul- Ultrafil- Diameter ness All Grains
sion tration (.mu.m) (.mu.m) (%) V-a none 4.20 0.067 27 Comparison
V-b done 4.60 0.056 29 Invention V-c none 4.0 0.1 25 Comparison
[0334] On a cellulose triacetate film support having provided
thereon a subbing layer, chemically sensitized emulsions prepared
above each was coated under the coating conditions shown in Table 2
and a protective layer was provided, thereby obtaining Samples
V-801, V-802 and V-803.
[0335] Each sample was exposed for {fraction (1/100)} second
through Gelatin Filter SC-50 produced by Fuji Photo Film Co., Ltd.
and a continuous wedge and then processed by the method described
in Example II.
[0336] The processed samples were measured on the density by a
green filter. The sensitivity value at a density of fog+0.2 and the
fog value obtained are shown in Table 7.
11 TABLE 7 Sample Name of No. Emulsion Fog Sensitivity VI-801 a
0.22 120 Comparison VI-802 b 0.22 139 Invention VI-803 c 0.24 100
Comparison * The sensitivity is shown relatively to Sample No. 803
of which sensitivity is taken as 100.
[0337] As apparent from the results in Table 7, a highsensitive
emulsion can be obtained by the production process of the present
invention.
Example VI
[0338] This Examples is performed to verify the effect of the
emulsion produced by the production process of the present
invention in a multilayer color photographic lightsensitive
material.
[0339] Silver Halide Emulsions Em-A to Em-M were prepared as
follows.
[0340] (Production Process of Em-A)
[0341] 42.2 L of an aqueous solution containing 31.7 g of low
molecular weight gelatin having a molecular weight of 15,000, which
was phthalated to a phthalation ratio of 97%, and 31.7 g of KBr was
kept at 35.degree. C. and vigorously stirred. Thereto, 1,583 mL of
an aqueous solution containing 316.7 g of AgNO.sub.3 and 1,583 mL
of an aqueous solution containing 221.5 g of KBr and 52.7 g of low
molecular weight gelatin having a molecular weight of 15,000 were
added by a double jet method over 1 minute. After the completion of
addition, 52.8 g of KBr was immediately added and then, 2,485 mL of
an aqueous solution containing 398.2 g of AgNO.sub.3 and 2,581 mL
of an aqueous solution containing 291.1 g of KBr were added by a
double jet method over 2 minutes. After the completion of addition,
44.8 g of KBr was immediately added. Thereafter, the temperature
was elevated to 40.degree. C. and the ripening was performed. After
the completion of ripening, 923 g of gelatin having a molecular
weight of 100,000 phthalated to a phthalation ratio of 97% and 79.2
g of KBr were added and then, 15,947 mL of an aqueous solution
containing 5,103 g of AgNO.sub.3 and an aqueous KBr solution were
added by a double jet method over 10 minutes while accelerating the
flow rate such that the final flow rate became 1.4 times the
initial flow rate. At this time, the silver potential was kept at
-60 mV to the saturated calomel electrode. After water washing, the
emulsion was adjusted by adding gelatin such that the pH was 5.7,
the pAg was 8.8, the mass in terms of silver per kg of emulsion was
131.8 g and the mass of gelatin was 64.1 g. This emulsion was used
as a seed emulsion.
[0342] 1,211 mL of an aqueous solution containing 46 g of
phthalated gelatin having a phthalation ratio of 97% and 1.7 g of
KBr was kept at 75.degree. C. and vigorously stirred. Thereto, 9.9
g of the seed emulsion prepared above was added and then 0.3 g of
modified silicone oil (L7602, a product of Nippon Unicar) was
added. After adjusting the pH to 5.5 by adding H.sub.2SO.sub.4,
67.6 mL of an aqueous solution containing 7.0 g of AgNO.sub.3 and
an aqueous KBr solution were added by a double jet method over 6
minutes while accelerating the flow rate such that the final flow
rate became 5.1 times the initial flow rate. At this time, the
silver potential was kept at -20 mV to the saturated calomel
electrode. After adding 2 mg of sodium benzene-thiosulfonate and 2
mg of thiourea dioxide, 328 mL of an aqueous solution containing
105.6 g of AgNO.sub.3 and an aqueous KBr solution were added by a
double jet method over 56 minutes while accelerating the flow rate
such that the final flow rate became 3.7 times the initial flow
rate. At this time, an AgI fine grain emulsion having a grain size
of 0.037 .mu.m was simultaneously added to have a silver iodide
content of 27 mol % while accelerating the flow rate and at the
same time, keeping the silver potential at -50 mV to the saturated
calomel electrode. Then, 121.3 mL of an aqueous solution containing
45.6 g of AgNO.sub.3 and an aqueous KBr solution were added by a
double jet method over 22 minutes. At this time, the silver
potential was kept at +20 mV to the saturated calomel
electrode.
[0343] The temperature was elevated to 82.degree. C. and the silver
potential was adjusted to -80 mV by adding KBr. Thereafter, the
above-described AgI fine grain emulsion was added in an amount of
6.33 g in terms of the mass of KI. After the completion of
addition, 206.2 mL of an aqueous solution containing 66.4 g of
AgNO.sub.3 was immediately added over 16 minutes. For 5 minutes at
the initial stage of addition, the silver potential was kept at -80
mV by an aqueous KBr solution. The obtained emulsion was washed
with water washing and then gelatin was added to adjust the pH to
5.8 and the pAg to 8.7 at 40.degree. C. After adding Compounds 11
and 12, the temperature was elevated to 60.degree. C. Thereafter,
Sensitizing Dyes 11 and 12 were added and then, potassium
thiocyanate, chloroauric acid, sodium thiosulfate and
N,N-dimethylselenourea were added, thereby optimally performing the
chemical sensitization. At the completion of chemical
sensitization, Compounds 13 and 14 were added. The "optimally
performing chemical sensitization" as used herein means that
sensitizing dyes and compounds each was added in an amount ranging
from 10.sup.-1 to 10.sup.-8 mol per mol of silver halide. 5
[0344] (Production Process of Em-B)
[0345] 1,192 mL of an aqueous solution containing 0.96 g of low
molecular weight gelatin and 0.9 g of KBr was kept at 40.degree. C.
and vigorously stirred. Thereto, 37.5 mL of an aqueous solution
containing 1.49 g of AgNO.sub.3 and 37.5 mL of an aqueous solution
containing 1.05 g of KBr were added by a double jet method over 30
seconds. After adding 1.2 g of KBr, the temperature was elevated to
75.degree. C. and the ripening was performed. After the completion
of ripening, 35 g of trimellited gelatin having a molecular weight
of 100,000 where the amino group was chemically modified by a
trimellitic acid was added and the pH was adjusted to 7. Thereto, 6
mg of thiourea dioxide was added and then, 116 mL of an aqueous
solution containing 29 g of AgNO.sub.3 and an aqueous KBr solution
were added by a double jet method while accelerating the flow rate
such that the final flow rate became 3 times the initial flow rate.
At this time, the silver potential was kept at -20 mV to the
saturated calomel electrode. Thereafter, 440.6 mL of an aqueous
solution containing 110.2 g of AgNO.sub.3 and an aqueous KBr
solution were added by a double jet method over 30 minutes while
accelerating the flow rate such that the final flow rate became 5.1
times the initial flow rate. At this time, the AgI fine grain
emulsion used in the preparation of Em-A was simultaneously added
to have a silver iodide content of 15.8 mol % while accelerating
the flow rate and at the same time, keeping the silver potential at
0 mV to the saturated calomel electrode.
[0346] Thereto, 96.5 mL of an aqueous solution containing 24.1 g of
AgNO.sub.3 and an aqueous KBr solution were added by a double jet
method over 3 minutes. At this time, the silver potential was kept
at 0 mV. After adding 26 mg of sodium thiosulfate, the temperature
was elevated to 55.degree. C. and the silver potential was adjusted
to -90 mV by adding an aqueous KBr solution. Thereafter, the
above-described AgI fine grain emulsion was added in an amount of
8.5 g in terms of the mass of KI. After the completion of addition,
228 mL of an aqueous solution containing 57 g of AgNO.sub.3 was
immediately added over 5 minutes. At this time, the potential was
adjusted by the aqueous KBr solution to become +20 mV at the
completion of addition. The obtained emulsion was washed with water
washing and chemically sensitized almost in the same manner as
Em-A.
[0347] (Production Process of Em-C)
[0348] 1,192 mL of an aqueous solution containing 0.9 g of KBr and
1.02 g of phthalated gelatin having a molecular weight of 100,000
and a phthalation ratio of 97% and containing 35 .mu.mol/g of
methionine was kept at 35.degree. C. and vigorously stirred.
Thereto, 42 mL of an aqueous solution containing 4.47 g of
AgNO.sub.3 and 42 mL of an aqueous solution containing 3.16 g of
KBr were added by a double jet method over 9 seconds. After adding
2.6 g of KBr, the temperature was elevated to 63.degree. C. and the
ripening was performed. After the completion of ripening, 41.2 g of
trimellited gelatin having a molecular weight of 100,000 used in
the preparation of Em-B and 18.5 g of NaCl were added. The pH was
adjusted to 7.2 and then, 8 mg of dimethylaminoborane was added.
Thereafter, 203 mL of an aqueous solution containing 26 g of
AgNO.sub.3 and an aqueous KBr solution were added by a double jet
method while accelerating the flow rate such that the final flow
rate became 3.8 times the initial flow rate. At this time, the
silver potential was kept at -30 mV to the saturated calomel
electrode.
[0349] Thereafter, 440.6 mL of an aqueous solution containing 110.2
g of AgNO.sub.3 and an aqueous KBr solution were added by a double
jet method over 24 minutes while accelerating the flow rate such
that the final flow rate became 5.1 times the initial flow rate. At
this time, the AgI fine grain emulsion used in the preparation of
Em-A was simultaneously added to have a silver iodide content of
2.3 mol % while accelerating the flow rate and at the same time,
keeping the silver potential at -20 mV to the saturated calomel
electrode. Thereto, 10.7 mL of an aqueous 1N potassium thiocyanate
solution was added and then, 153.5 ml of an aqueous solution
containing 24.1 g of AgNO.sub.3 and an aqueous KBr solution were
added by a double jet method over 2 minutes and 30 seconds. At this
time, the silver potential was kept at 10 mV. Thereafter, the
silver potential was adjusted to -70 mV by adding an aqueous KBr
solution. Subsequently, the above-described AgI fine grain emulsion
was added in an amount of 6.4 g in terms of the mass of KI. After
the completion of addition, 404 mL of an aqueous solution
containing 57 g of AgNO.sub.3 was immediately added over 45
minutes. At this time, the potential was adjusted by the aqueous
KBr solution to become -30 mV at the completion of addition. The
obtained emulsion was washed with water washing and chemically
sensitized almost in the same manner as Em-A.
[0350] (Production Process of Em-D)
[0351] Em-D was prepared almost in the same manner as Em-C except
that in the preparation of Em-C, the amount of AgNO.sub.3 added at
the nucleation was changed to 2.3 times and the potential was
adjusted by an aqueous KBr solution such that the potential became
+90 mV at the completion of the final addition of 404 mL of an
aqueous solution containing 57 g of AgNO.sub.3.
[0352] (Production Process of Em-E)
[0353] 1,200 mL of an aqueous solution containing 0.75 g of low
molecular weight gelatin having a molecular weight of 15,000, 0.9 g
of KBr and 0.2 g of modified silicone oil used in the preparation
of Em-A was kept at 39.degree. C., adjusted to a pH of 1.8 and
vigorously stirred. Thereto, an aqueous solution containing 0.45 g
of AgNO.sub.3 and an aqueous KBr solution containing 1.5 mol % of
KI were added by a double jet method over 16 seconds. At this time,
the excess concentration of KBr was kept constant. The temperature
was elevated to 54.degree. C. and the ripening was performed. After
the completion of ripening, 20 g of phthalated gelatin having a
molecular weight of 100,000 and a phthalation ratio of 97% and
containing 35 .mu.mol/g of methionine was added. The pH was
adjusted to 5.9 and then, 2.9 g of KBr was added. Thereto, 288 mL
of an aqueous solution containing 28.8 g of AgNO.sub.3 and an
aqueous KBr solution were added by a double jet method over 53
minutes. At this time, the AgI fine grain emulsion used in the
preparation of Em-A was simultaneously added to have a silver
iodide content of 4.1 mol % and the silver potential was kept at
-60 mV to the saturated calomel electrode. After adding 2.5 g of
KBr, an aqueous solution containing 87.7 g of AgNO.sub.3 and an
aqueous KBr solution were added by a double jet method over 63
minutes while accelerating the flow rate such that the final flow
rate became 1.2 times the initial flow rate. At this time, the
above-described AgI fine grain emulsion was simultaneously added to
have a silver iodide content of 10.5 mol % while accelerating the
flow rate and keeping the silver potential at -70 mV.
[0354] Thereafter, 1 mg of thiourea dioxide was added and then, 132
mL of an aqueous solution containing 41.8 g of AgNO.sub.3 and an
aqueous KBr solution were added by a double jet method over 25
minutes. The addition of the aqueous KBr solution was controlled
such that the potential became +20 mV at the completion of
addition. Subsequently, 2 mg of sodium benzenethiosulfonate was
added, the pH was adjusted to 7.3, the silver potential was
adjusted to -70 mV by adding KBr and then the above-described AgI
fine grain emulsion was added in an amount of 5.73 g in terms of
the mass of KI. After the completion of addition, 609 mL of an
aqueous solution containing 66.4 g of AgNO.sub.3 was immediately
added over 10 minutes. For 6 minutes at the initial stage of
addition, the silver potential was kept at -70 mV by an aqueous KBr
solution. The obtained emulsion was washed with water and adjusted
to a pH of 6.5 and a pAg of 8.2 at 40.degree. C. by adding gelatin.
Then, Compounds 11 and 12 were added, the temperature was elevated
to 56.degree. C., and the above-described AgI fine grain emulsion
was added in an amount of 0.0004 mol per mol of silver. Thereafter,
Sensitizing Dyes 13 and 14 were added and then potassium
thiocyanate, chloroauric acid, sodium thiosulfate and
N,Ndimethylselenourea were added, thereby optimally performing the
chemical sensitization. At the completion of chemical
sensitization, Compounds 13 and 14 were added. 6
[0355] (Production Process of Em-F)
[0356] Em-F was prepared almost in the same manner as Em-E except
that in the preparation of Em-E, the amount of AgNO.sub.3 added at
the nucleation was changed to 4.12 times and the sensitizing dyes
were changed to Sensitizing Dyes 12, 15, 16 and 17. 7
[0357] (Production Process of Em-G)
[0358] 1,200 mL of an aqueous solution containing 0.70 g of low
molecular weight gelatin having a molecular weight of 15,000, 0.9 g
of KBr, 0.175 g of KI and 0.2 g of modified silicone oil used in
the preparation of Em-A was kept at 33.degree. C., adjusted to a pH
of 1.8 and vigorously stirred. Thereto, an aqueous solution
containing 1.8 g of AgNO.sub.3 and an aqueous KBr solution
containing 3.2 mol % of KI were added by a double jet method over 9
seconds. At this time, the excess concentration of KBr was kept
constant. The temperature was elevated to 62.degree. C. and the
ripening was performed. After the completion of ripening, 27.8 g of
trimellited gelatin having a molecular weight of 100,000 and
containing 35 pmol/g of methionine, where the amino group was
chemically modified by a trimellitic acid, was added. The pH was
adjusted to 6.3 and then, 2.9 g of KBr was added. Thereto, 270 mL
of an aqueous solution containing 27.58 g of AgNO.sub.3 and an
aqueous KBr solution were added by a double jet method over 37
minutes. At this time, an AgI fine grain emulsion having a grain
size of 0.008 .mu.m, which was prepared by mixing an aqueous
solution of low molecular weight gelatin having a molecular weight
of 15,000, an aqueous AgNO.sub.3 solution and an aqueous KI
solution in a separate chamber having a magnetic coupling
induction-type stirring machine described in JP-A-10-43570
immediately before the addition, was simultaneously added to have a
silver iodide content of 4.1 mol % and the silver potential was
kept at -60 mV to the saturated calomel electrode.
[0359] After adding 2.6 g of KBr, an aqueous solution containing
87.7 g of AgNO.sub.3 and an aqueous KBr solution were added by a
double jet method over 49 minutes while accelerating the flow rate
such that the final flow rate became 3.1 times the initial flow
rate. At this time, the above-described AgI fine grain emulsion
prepared by mixing those aqueous solutions immediately before the
addition was simultaneously added to have a silver iodide content
of 7.9 mol % while accelerating the flow rate and keeping the
silver potential at -70 mV. Thereafter, 1 mg of thiourea dioxide
was added and then, 132 mL of an aqueous solution containing 41.8 g
of AgNO.sub.3 and an aqueous KBr solution were added by a double
jet method over 20 minutes. The addition of the aqueous KBr
solution was controlled such that the potential became +20 mV at
the completion of addition. The temperature was elevated to
78.degree. C., the pH was adjusted to 9.1, and then the potential
was adjusted to -60 mV by adding KBr. Subsequently, the AgI fine
grain emulsion used in the preparation of Em-A was added in an
amount of 5.73 g in terms of the mass of KI. After the completion
of addition, 321 mL of an aqueous solution containing 66.4 g of
AgNO.sub.3 was immediately added over 4 minutes. For 2 minutes at
the initial stage of addition, the silver potential was kept at -60
mV by an aqueous KBr solution. The obtained emulsion was washed
with water and chemically sensitized almost in the same manner as
Em-F.
[0360] (Production Process of Em-H)
[0361] An aqueous solution containing 17.8 g of ion exchanged
gelatin having a molecular weight of 100,000, 6.2 g of KBr and 0.46
g of KI was kept at 45.degree. C. and vigorously stirred. Thereto,
an aqueous solution containing 11.85 g of AgNO.sub.3 and an aqueous
solution containing 3.8 g of KBr were added by a double jet method
over 45 seconds. The temperature was elevated to 63.degree. C.,
then 24.1 g of ion exchanged gelatin having a molecular weight of
100,000 was added, and ripening was performed. After the completion
of ripening, an aqueous solution containing 133.4 g of AgNO.sub.3
and an aqueous KBr solution were added by a double jet method over
20 minutes while accelerating the flow rate such that the final
flow rate became 2.6 times the initial flow rate. At this time, the
silver potential was kept at +40 mV to the saturated calomel
electrode.
[0362] Also, 10 minutes after the initiation of addition, 0.1 mg of
K.sub.2IrCl.sub.6 was added. Thereafter, 7 g of NaCl was added and
then, an aqueous solution containing 45.6 g of AgNO.sub.3 and an
aqueous KBr solution were added by a double jet method over 12
minutes. At this time, the silver potential was kept at +90 mV.
Over 6 minutes from the initiation of addition, 100 ml of an
aqueous solution containing 29 mg of yellow prussiate of potash was
added. Then, 14.4 g of KBr was added and 6.3 g of the AgI fine
grain emulsion used in the preparation of Em-A was added in an
amount of 6.3 g in terms of the mass of KI. After the completion of
addition, an aqueous solution containing 42.7 g of AgNO.sub.3 and
an aqueous KBr solution were immediately added by a double jet
method over 11 minutes. At this time, the silver potential was kept
at +90 mV. The obtained emulsion was washed with water and
chemically sensitized almost in the same manner as Em-F.
[0363] (Production Process of Em-I)
[0364] Em-I was prepared almost in the same manner as in the
preparation of Em-H except that the temperature at the nucleation
was changed to 35.degree. C.
[0365] (Production Process of Em-J)
[0366] 1,200 mL of an aqueous solution containing 0.9 g of KBr and
0.38 g of phthalated gelatin having a molecular weight of 100,000
and a phthalation ratio of 97% was kept at 60.degree. C, adjusted
to a pH of 2 and vigorously stirred. Thereto, an aqueous solution
containing 1.96 g of AgNO.sub.3 and an aqueous solution containing
1.67 g of KBr and 0.172 g of KI were added by a double jet method
over 30 seconds. After the completion of ripening, 12.8 g of
trimellited gelatin having a molecular weight of 100,000 and
containing 35 .mu.m/g of methionine, where the amino group was
chemically modified by a trimellitic acid, was added. The pH was
adjusted to 5.9 and then, 2.99 g of KBr and 6.2 g of NaCl were
added. Thereafter, 60.7 mL of an aqueous solution containing 27.3 g
of AgN0.sub.3 and an aqueous KBr solution were added by a double
jet method over 31 minutes. At this time, the silver potential was
kept at -50 mV to the saturated calomel electrode. Thereafter, an
aqueous solution containing 65.6 g of AgNO.sub.3 and an aqueous KBr
solution were added by a double jet method over 37 minutes while
accelerating the flow rate such that the final flow rate became 2.1
times the initial flow rate. At this time, the AgI fine grain
emulsion used in the preparation of Em-A was simultaneously added
to have a silver iodide content of 6.5 mol % while accelerating the
flow rate and at the same time, keeping the silver potential at -50
mV to the saturated calomel electrode.
[0367] Thereto, 1.5 mg of thiourea dioxide was added and then, 132
mL of an aqueous solution containing 41.8 g of AgNO.sub.3 and an
aqueous KBr solution were added by a double jet method over 13
minutes. At this time, the addition of the aqueous KBr solution was
controlled such that the silver potential became +40 mV at the
completion of addition. Then, 2 mg of sodium benzenethiosulfonate
was added and the silver potential adjusted to -100 mV by adding
KBr. Subsequently, the above-described AgI fine grain emulsion was
added in an amount of 6.2 g in terms of the mass of KI. After the
completion of addition, 300 mL of an aqueous solution containing
88.5 g of AgNO.sub.3 was immediately added over 8 minutes. At this
time, the potential was adjusted by the addition of the aqueous KBr
solution to become +60 mV at the completion of addition. The
obtained emulsion was washed with water and then gelatin was added
to adjust the pH to 6.5 and the pAg to 8.2 at 40.degree. C. After
adding Compounds 11 and 12, the temperature was elevated to
61.degree. C. Thereafter, Sensitizing Dyes 18, 19, 20 and 21 were
added and then, K.sub.2IrCl.sub.6, potassium thiocyanate,
chloroauric acid, sodium thiosulfate and N,N-dimethylselenourea
were added, thereby optimally performing the chemical
sensitization. At the completion of chemical sensitization,
Compounds 13 and 14 were added. 8
[0368] (Production Process of Em-K)
[0369] 1,200 mL of an aqueous solution containing 4.9 g of low
molecular weight gelatin having a molecular weight of 15,000 and
5.3 g of KBr was kept at 60.degree. C. and vigorously stirred.
Thereto, 27 mL of an aqueous solution containing 8.75 g of
AgNO.sub.3 and 36 mL of an aqueous solution containing 6.45 g of
KBr were added by a double jet method over 1 minute. The
temperature was elevated to 75.degree. C. and then, 21 mL of an
aqueous solution containing 6.9 g of AgNO.sub.3 was added over 2
minutes. Thereafter, 26 g of NH.sub.4NO.sub.3 and 56 mL of 1N NaOH
were sequentially added and then ripening was performed. After the
completion of ripening, the pH was adjusted to 4.8. Thereto, 438 mL
of an aqueous solution containing 141 g of AgNO.sub.3 and 458 mL of
an aqueous solution containing 102.6 g of KBr were added by a
double jet method while accelerating the flow rate such that the
final flow rate became 4 times the initial flow rate. Subsequently,
the temperature was lowered to 55.degree. C. and then, 240 mL of an
aqueous solution containing 7.1 g of AgNO.sub.3 and an aqueous
solution containing 6.46 g of KI were added by a double jet method
over 6 minutes. After adding 7.1 g of KBr, 4 mg of sodium
benzenethiosulfonate and 0.05 mg of K.sub.2IrCl.sub.6 were added.
Thereto, 177 mL of an aqueous solution containing 57.2 g of
AgNO.sub.3 and 223 mL of an aqueous solution containing 40.2 g of
KBr were added by a double jet method over 8 minutes. The obtained
emulsion was washed with water and chemically sensitized almost in
the same manner as Em-J.
[0370] (Production Process of Em-L)
[0371] Em-L was prepared almost in the same manner as in the
preparation of Em-K except that the temperature at the nucleation
was changed to 40.degree. C.
[0372] (Production Process of Em-M)
[0373] Em-M was prepared almost in the same manner as Em-J except
that the chemical sensitization was performed almost in the same
manner as Em-F.
[0374] The characteristic values of silver halide emulsions Em-A to
Em-M are shown together in Table 8.
12TABLE 8 Equivalent- Distance Circle between Percentage Diameter
Thickness Aspect Twin Faces of Tabular I Content (.mu.m) (.mu.m)
Ratio (.mu.m) Grains Ratio of (mol %) Coefficient Coefficient
Coefficient Coefficient Occupying (100) Coefficient Surface of of
of of in Entire Face to of Cl I Name of Variation Variation
Variation Variation Projected Side Variation Content Content
Emulsion (%) (%) (%) Tabularity (%) Area (%) Face (%) (mol %) (mol
%) Em-A 1.9823 0.19828 1035 51 0.01432 92 23 1517 0 4.3 Em-B 1.3025
0.10827 1238 111 0.01330 93 22 1116 0 3.6 Em-C 1.0027 0.08326 1237
145 0.01230 93 18 48 1 1.8 Em-D 0.7531 0.07518 1029 133 0.01027 91
33 48 2 1.9 Em-E 2.0231 0.10119 2042 198 0.01333 99 20 77 0 2.4
Em-F 0.5426 0.07718 2033 260 0.01326 99 23 77 0 2.5 Em-G 1.0818
0.07215 1519 208 0.00822 97 23 65 0 2.0 Em-H 0.4416 0.2213 29 9
0.01318 90 38 36 2 1 Em-I 0.3317 0.16513 212 12 0.01318 88 42 36 2
1 Em-J 0.8318 0.12220 1522 123 0.01219 98 23 56 1 1.8 Em-K 1.0916
0.15618 719 45 0.01316 99 22 37 0 2.7 Em-L 0.8417 0.12018 719 58
0.01316 99 25 37 0 2.7 Em-M 1.8318 0.12220 1522 123 0.01219 98 23
56 1 1.8
[0375] (1) Support
[0376] The support used in this Example was prepared by the
following method.
[0377] 100 Mass parts of polyethylene-2,6-naphthalate polymer and 2
mass parts of Tinuvin P.326 (produced by Geigy) as an ultraviolet
absorbent were dried, melted at 300.degree. C., extruded from a
T-die, stretched longitudinally to 3.3 times at 140.degree. C.,
then stretched transversely to 3.3 times at 130.degree. C., and
heat fixed at 250.degree. C. for 6 seconds to obtain a PEN
(polyethylene naphthalate) film having a thickness of 90 .mu.m. To
this PEN film, a blue dye, a magenta dye and a yellow dye (I-1,
I-4, I-6, I-24, I-26, I-27 and II-5 described in JIII Journal of
Technical Disclosure, No. 94-6023) were added each in an
appropriate amount. Furthermore, the film was wound around a
stainless steelmade core having a diameter of 20 cm and imparted
with heat history of 110.degree. C. for 48 hours to obtain a
support difficult of having curling habit.
[0378] 2) Coating of Undercoat Layer
[0379] Both surfaces of the support obtained above were subjected
to corona discharge treatment, UV discharge treatment and glow
discharge treatment. Then, an undercoat solution comprising 0.1
g/m.sup.2 of gelatin, 0.01 g/m.sup.2 of sodium
.alpha.-sulfodi-2-ethylhexylsuccinate, 0.04 g/m.sup.2 of salicylic
acid, 0.2 g/m.sup.2 of p-chlorophenol, 0.012 g/m.sup.2 of
(CH.sub.2.dbd.CHSO.sub.2CH.sub.2CH.sub.2NHCO) .sub.2CH.sub.2 and
0.02 g/m.sup.2 of a polyamide-epichlorohydrin polycondensate was
coated (10 ml/m.sup.2, using a bar coater) on each surface to
provide an undercoat layer in the side of high temperature at the
stretching. The drying was performed at 115.degree. C. for 6
minutes (rollers and conveyance device in the drying zone all were
heated at 115.degree. C.).
[0380] 3) Coating of Back Layer
[0381] On one surface of the undercoated support, an antistatic
layer, a magnetic recording layer and a slipping layer each having
the following composition were provided as the back layer.
[0382] 3-1) Coating of Antistatic Layer
[0383] The antistatic layer was provided by coating 0.2 g/m.sup.2
of a fine particle powder dispersion of tin oxide-antimony oxide
composite having an average particle size of 0.005 .mu.m (secondary
aggregate particle size: about 0.08 .mu.m) and a resistivity of
5.omega..multidot.cm together with 0.05 g/m.sup.2 of gelatin, 0.02
g/m.sup.2 of (CH.sub.2.dbd.CHSO.sub.2CH.sub.2CH.sub.2NHCO)
.sub.2CH.sub.2, 0.005 g/m.sup.2 of poly(polymerization degree:
10)oxyethylene-p-nonylphenol and resorcin.
[0384] 3-2) Coating of Magnetic Recording Layer
[0385] Using a bar coater, 0.06 g/m.sup.2 of cobalt-.gamma.-iron
oxide (specific surface area: 43 m.sup.2/g, longer axis: 0.14
.mu.m, single axis: 0.03 .mu.m, saturation magnetization: 89 emu/g,
Fe.sup.2+/Fe.sup.3+=6/94, the surface was treated with aluminum
oxide and silicon oxide to 2 mass% based on iron oxide) subjected
to a covering treatment with 3-poly(polymerization degree:
15)oxyethylene-propyloxytrim- ethoxysilane (15 mass %) was coated
together with 1.2 g/m.sup.2 of diacetyl cellulose (iron oxide was
dispersed by an open kneader and a sand mill), 0.3 g/m.sup.2 of
C.sub.2H.sub.5C(CH.sub.2OCONH--C.sub.6H.sub.- 3(CH.sub.3)NCO).sub.3
as a hardening agent and acetone, methyl ethyl ketone and
cyclohexanone as solvents to obtain a magnetic recording layer
having a layer thickness of 1.2 .mu.m. Silica particle (0.3 .mu.m)
as a matting agent and aluminum oxide (0.15 .mu.m) as an abrasive
subjected to a covering treatment with 3-poly(polymerization
degree: 15)oxyethylene-propyloxytrimethoxysilane (15 mass%) were
added each to 10 mg/M.sup.2. The drying was performed at
115.degree. C. for 6 minutes (rollers and conveyance device in the
drying zone all were heated at 115.degree. C.). The increase in the
color density of the magnetic recording layer D.sup.B by X-light
(blue filter) was about 0.1, the saturation magnetization moment of
the magnetic recording layer was 4.2 emu/g, the coercive force was
7.3.times.10.sup.4 A/m and the angular ratio was 65%.
[0386] 3-3) Preparation of Slipping Layer
[0387] Diacetyl cellulose (25 mg/m.sup.2) and a mixture of
C.sub.6H.sub.13CH (OH) C.sub.10H.sub.20COOC.sub.40H.sub.81
(Compound a, 6
mg/M.sup.2)/C.sub.50H.sub.101(CH.sub.2CH.sub.2O).sub.16H (Compound
b, 9 mg/m.sup.2) were coated. This mixture was prepared by melting
the compounds in xylene/propylene monomethyl ether (1/1) at
105.degree. C. and pouring and dispersing the melt in propylene
monomethyl ether (10-fold amount) at normal temperature. The
resulting mixture was formed into a dispersion (average particle
size: 0.01 .mu.m) in acetone and then added. Silica particle (0.3
.mu.m) as a matting agent and alumina oxide (0.15 .mu.m) covered
with 3-poly(polymerization degree:
15)oxyethylenepropyloxytrimethoxysilane (15 mass %) as an abrasive
were added each to 15 mg/m.sup.2. The drying was performed at
115.degree. C. for 6 minutes (rollers and the conveyance device in
the drying zone all were heated at 115.degree. C.). The slipping
layer had excellent capabilities such that the coefficient of
dynamic friction was 0.06 (stainless steel ball: 5 mm.phi.; load:
100 g; speed: 6 cm/min), the coefficient of static friction was
0.07 (by clip method) and the coefficient of dynamic friction
between the emulsion surface and the slipping layer, which will be
described later, was 0.12.
[0388] 4) Coating of Light-Sensitive Layer
[0389] Layers each having the following composition were coated one
on another in the side opposite the back layer provided above to
prepare a color negative light-sensitive material Sample 901.
[0390] (Composition of Light-Sensitive Layer)
[0391] The main materials used in each layer are classified as
follows.
[0392] ExC: cyan coupler
[0393] ExM: magenta coupler
[0394] ExY: yellow coupler
[0395] UV: ultraviolet absorbent
[0396] HBS: high-boiling point organic solvent
[0397] H: gelatin hardening agent
[0398] (Specific Compounds are Noted by the Numeral affixed to the
Symbol and Chemical Formulae are Shown Later.)
[0399] Numerals corresponding to respective components each shows a
coated amount expressed by the unit of g/m.sup.2. In the case of
silver halide, the coated amount is shown in terms of silver.
13 First Layer: (First Antihalation Layer) Black Colloidal Silver
as silver 0.155 Surface fogged AgBrI (2) as silver 0.01 of 0.07
.mu.m Gelatin 0.87 ExC-1 0.002 ExC-3 0.002 Cpd-2 0.001 HBS-1 0.004
HBS-2 0.002 Second Layer: (Second Antihalation Layer) Black
Colloidal Silver as silver 0.066 Gelatin 0.407 ExM-1 0.050 ExF-1
2.0 .times. 10.sup.-3 HBS-1 0.074 Solid Disperse Dye ExF-2 0.015
Solid Disperse Dye ExF-3 0.020 Third Layer: (Interlayer) AgBrI (2)
of 0.07 .mu.m as silver 0.020 ExC-2 0.022 Polyethyl acrylate latex
0.085 Gelatin 0.294 Fourth Layer: (Low-speed Red-Sensitive Emulsion
Layer) Em-K as silver 0.323 ExC-1 0.109 ExC-3 0.044 ExC-4 0.072
ExC-5 0.011 ExC-6 0.003 Cpd-2 0.025 Cpd-4 0.025 HBS-1 0.17 Gelatin
0.80 Fifth Layer: (Medium-speed Red-Sensitive Emulsion Layer) Em-L
as silver 0.21 Em-J as silver 0.62 ExC-1 0.14 ExC-2 0.026 ExC-3
0.020 ExC-4 0.12 ExC-5 0.016 ExC-6 0.007 Cpd-2 0.036 Cpd-4 0.028
HBS-1 0.16 Gelatin 1.18 Sixth Layer: (High-speed Red-Sensitive
Emulsion Layer) Emulsion V-a of Example V as silver 1.47 ExC-1 0.18
ExC-3 0.07 ExC-6 0.029 ExC-7 0.010 ExY-5 0.008 Cpd-2 0.046 Cpd-4
0.077 HBS-1 0.25 HBS-2 0.12 Gelatin 2.12 Seventh Layer:
(Interlayer) Cpd-1 0.089 Solid Disperse Dye ExF-4 0.030 HBS-1 0.050
Polyethyl acrylate latex 0.83 Gelatin 0.84 Eighth Layer: (Layer for
Imparting Interimage Effect to Red-Sensitive Layer) Em-E as silver
0.560 Cpd-4 0.030 ExM-2 0.096 ExM-3 0.028 ExY-1 0.031 ExG-1 0.006
HBS-1 0.085 HBS-3 0.003 Gelatin 0.58 Ninth Layer: (Low-speed
Green-Sensitive Emulsion Layer) Em-G as silver 0.39 Em-H as silver
0.28 Em-I as silver 0.35 ExM-2 0.36 ExM-3 0.045 ExG-1 0.005 HBS-1
0.28 HBS-3 0.01 HBS-4 0.27 Gelatin 1.39 Tenth Layer: (Medium-speed
Green-Sensitive Emulsion Layer) Em-F as silver 0.20 Em-G as silver
0.25 ExC-6 0.009 ExM-2 0.031 ExM-3 0.029 ExY-1 0.006 ExM-4 0.028
ExG-1 0.005 HBS-1 0.064 HBS-3 2.1 .times. 10.sup.-3 Gelatin 0.44
Eleventh Layer: (High-speed Green-Sensitive Emulsion Layer) Em-M as
silver 0.99 ExC-6 0.004 ExM-1 0.016 ExM-3 0.036 ExM-4 0.020 ExM-5
0.004 ExY-5 0.003 ExM-2 0.013 ExG-1 0.005 Cpd-4 0.007 HBS-1 0.18
Polyethyl acrylate latex 0.099 Gelatin 1.11 Twelfth Layer: (Yellow
Filter Layer) Yellow Colloidal Silver as silver 0.047 Cpd-1 0.16
Oil-Soluble Dye ExF-5 0.010 Solid Disperse Dye ExF-6 0.010 HBS-1
0.082 Gelatin 1.057 Thirteenth Layer: (Low-speed Blue-Sensitive
Emulsion Layer) Em-B as silver 0.18 Em-C as silver 0.20 Em-D as
silver 0.07 ExC-1 0.041 ExC-8 0.012 ExY-1 0.035 ExY-2 0.71 ExY-3
0.10 ExY-4 0.005 Cpd-2 0.10 Cpd-3 4.0 .times. 10.sup.-3 HBS-1 0.24
Gelatin 1.41 Fourteenth Layer: (High-speed Blue-Sensitive Emulsion
Layer) Em-A as silver 0.75 ExC-1 0.013 ExY-2 0.31 ExY-3 0.05 ExY-6
0.062 Cpd-2 0.075 Cpd-3 1.0 .times. 10.sup.-3 HBS-1 0.10 Gelatin
0.91 Fifteenth Layer: (First Protective Layer) AgBrI (2) of 0.07
.mu.m as silver 0.30 UV-1 0.21 UV-2 0.13 UV-3 0.20 UV-4 0.025 F-18
0.009 F-19 0.005 F-20 0.005 HBS-1 0.12 HBS-4 5.0 .times. 10.sup.-2
Gelatin 2.3 Sixteenth Layer: (Second Protective Layer) H-1 0.40 B-1
(Diameter: 1.7 .mu.m) 5.0 .times. 10.sup.-2 B-2 (Diameter: 1.7
.mu.m) 0.15 B-3 0.05 S-1 0.20 Gelatin 0.75
[0400] Furthermore, in order to improve storability,
processability, pressure resistance, antifungal and microbicidal
property, antistatic property and coatability, W-1 to W-5, B-4 to
B-6, F-1 to F-18, iron salt, lead salt, gold salt, platinum salt,
palladium salt, iridium salt, ruthenium salt and rhodium salt were
appropriately added to each layer. Also, in the preparation of
Sample VI-901, calcium in the form of an aqueous calcium nitrate
solution was added in an amount of 8.5.times.10.sup.-3 g to the
coating solution for the eighth layer and in an amount of
7.9.times.10.sup.-3 g to the coating solution for the eleventh
layer, per mol of silver halide.
[0401] Samples VI-902 to VI-903 were prepared by changing Emulsion
V-a prepared in Example V for the six layer to Emulsions V-b and
V-c, respectively. Preparation of Dispersion of Organic Solid
Disperse Dye:
[0402] ExF-3 was dispersed by the following method. That is, 21.7
mL of water, 3 mL of a 5% aqueous solution of sodium
p-octylphenoxyethoxyethoxy- ethanesulfonate and 0.5 g of a 5%
aqueous solution of p-octylphenoxypolyoxyethylene ether
(polymerization degree: 10) were charged into a 700-mL pot mill and
thereto 5.0 g of Dye ExF-3 and 500 ml of zirconium oxide beads
(diameter: 1 mm) were added. The contents were dispersed for 2
hours using a BO-Type vibration ball mill manufactured by Chuo Koki
K.K. After the dispersion, the contents were taken out and added to
8 g of an aqueous 12.5% gelatin solution and thereafter, beads were
removed by filtration to obtain a gelatin dispersion of the dye.
The thus-obtained fine dye particles had an average particle
diameter of 0.24 .mu.m.
[0403] The solid dispersion of ExF-4 was obtained in the same
manner. The fine dye particles obtained had an average particle
diameter of 0.45 .mu.m. ExF-2 was dispersed by the
microprecipitation dispersing method described in Example 1 of
EP-A-549489. The average particle diameter was 0.06 .mu.m.
[0404] The solid dispersion of ExF-6 was dispersed by the following
method.
[0405] To 2,800 g of a wet cake of ExF-6 containing 18% or water,
4,000 g of water and 376 g of a 3% solution of W-2 were added and
stirred to obtain a slurry of ExF-6 having a concentration of 32%.
Then, 1,700 mL of zirconia beads having an average particle size of
0.5 mm were filled in Ultraviscomill (UVM-2) manufactured by Imex
and the slurry was passed therethrough and pulverized at a
peripheral speed of about 10 m/sec and a discharge amount of 0.5
L/min for 8 hours. The average particle size was 0.52 .mu.m.
[0406] The compounds used for forming each layer are shown below.
910111213141516
[0407] Each sample was exposed for {fraction (1/100)} second
through Gelatin Filter SC-39 (a long wavelength light transmitting
filter with a cut-off wavelength of 390 nm) produced by Fuji Photo
Film Co., Ltd. and a continuous wedge. The development was
performed as follows using an automatic developing machine FP-360B
manufactured by Fuji Photo Film Co., Ltd. which was modified not to
flow the overflow solution of the bleaching bath to the post bath
but to discharge all to the waste solution tank. In this FP-360B,
an evaporation correcting means described in JIII Journal of
Technical Disclosure, No. 94-4992 was mounted.
[0408] The processing steps and the composition of each processing
solution are shown below.
14 (Processing Step) Processing Replenishing Tank Processing
Temperature Amount* Volume Step Time (.degree. C.) (mL) (L) Color
development 3 min 5 sec 37.8 20 11.5 Bleaching 50 sec 38.0 5 5
Fixing (1) 50 sec 38.0 -- 5 Fixing (2) 50 sec 38.0 8 5 Water
washing 30 sec 38.0 17 3 Stabilization (1) 20 sec 38.0 -- 3
Stabilization (2) 20 sec 38.0 15 3 Drying 1 min 30 sec 60.0
*Replenishing amount was per 1.1 m of 35 mm-width light-sensitive
material (corresponding to 1 roll of 24 Ex.).
[0409] The stabilizing solution and the fixing solution each was in
a countercurrent system of from (2) to (1) and the overflow
solution of washing water was all introduced into the fixing bath
(2). The amount of developer carried over into the bleaching step,
the amount of bleaching solution carried over into the fixing step
and the amount of fixing solution carried over into the water
washing step were 2.5 mL, 2.0 mL and 2.0 mL, respectively, per 1.1
m of 35 mm-width light-sensitive material. The cross-over time was
6 seconds in each interval and this time is included in the
processing time of the previous step.
[0410] The open area of the above-described processing machine was
100 cm.sup.2 for the color developer, 120 cm.sup.2 for the
bleaching solution and about 100 cm.sup.2 for other processing
solutions.
[0411] The composition of each processing solution is shown
below.
15 Tank Solution Replenisher (g) (g) (Color Developer)
Diethylenetriaminepentaacetic 3.0 3.0 acid Disodium
catechol-3,5-disulfonate 0.3 0.3 Sodium sulfite 3.9 5.3 Potassium
carbonate 39.0 39.0 Disodium N,N-bis(2-sulfonato- 1.5 2.0 ethyl)
hydroxylamine Potassium bromide 1.3 0.3 Potassium iodide 1.3 mg --
4-Hydroxy-6-methyl-1,3,3a,7- 0.05 -- tetrazaindene Hydroxylamine
sulfate 2.4 3.3 2-Methyl-4-[N-ethyl-N-.beta.-hydroxy- 4.5 6.5
ethylamino]aniline sulfate Water to make 1.0 L 1.0 L pH (adjusted
by potassium 10.05 10.18 hydroxide and sulfuric acid) (Bleaching
Solution) Ammonium 1,3-diaminopropane- 113 170 tetraacetato ferrate
monohydrate Ammonium bromide 70 105 Ammonium nitrate 14 21 Succinic
acid 34 51 Maleic acid 28 42 Water to make 1.0 L 1.0 L pH [adjusted
by aqueous ammonia] 4.6 4.0
[0412] (Fixing Solution (1): tank solution)
[0413] A 5:95 (by volume) mixed solution of the bleaching tank
solution above and the fixing tank solution shown below (pH:
6.8).
16 (Fixing Solution (2)) Tank Solution Replenisher (g) (g) Aqueous
ammonium thiosulfate 240 ml 720 ml solution (750 g/L) Imidazole 7
21 Ammonium methanethiosulfonate 5 15 Ammonium methanesulfinate 10
30 Ethylenediaminetetraacetic acid 13 39 Water to make 1.0 L 1.0 L
pH [adjusted by aqueous ammonia 7.4 7.45 and acetic acid]
[0414] (Washing Water)
[0415] Tap water was passed through a mixed bed column filled with
an H-type strongly acidic cation exchange resin (Amberlite IR-120B,
produced by Rhom and Haas) and an OHtype strongly basic anion
exchange resin (Amberlite IR-400, produced by the same company) to
reduce the calcium and magnesium ion concentrations each to 3 mg/L
or less and then thereto 20 mg/L of sodium isocyanurate dichloride
and 150 mg/L of sodium sulfate were added. The resulting solution
had a pH of 6.5 to 7.5.
17 (Stabilizing Solution) Tank solution and replenisher were
common. (unit: g) Sodium p-toluenesulfinate 0.03
Polyoxyethylene-p-monononylphenyl 0.2 ether (average polymerization
degree: 10) Sodium 1,2-benzoisothiazolin-3- 0.10 one Disodium
ethylenediaminetetra- 0.05 acetate 1,2,4-Triazole 1.3
1,4-Bis(1,2,4-triazol-1-yl- 0.75 methyl)piperazine Water to make
1.0 L pH 8.5
[0416] The results are shown in Table 9.
18 TABLE 9 Name of Sample Emulsion of No. Sixth Layer Fog
Sensitivity VI-901 V-a 0.18 114 Comparison VI-902 V-b 0.18 130
Invention VI-903 V-c 0.18 100 Comparison
[0417] As apparently seen from Table 9, a silver halide emulsion
having high-sensitivity with the fog on the equal level can be
prepared by using an emulsion produced according to the production
process of the present invention.
Example VII
[0418] The production process of emulsion of the present invention
is described in detail below. (Preparation of Emulsion VII-a)
[0419] 1,100 mL of an aqueous solution containing 0.32 g of KBr and
1.38 g of oxidation-treated low molecular weight gelatin having an
average molecular weight of 20,000 was stirred while keeping at
5.degree. C. Thereto, 200 ml of an aqueous AgNO.sub.3 (1.0 g)
solution and 200 ml of an aqueous solution containing KBr (0.7 g)
and oxidation-treated low molecular weight gelatin (3.3 g) having
an average molecular weight of 20,000 were added over 15 seconds.
After adding 120 ml of an aqueous solution containing 2.6 g of KBr,
the temperature was elevated to 75.degree. C. and then, 200 ml of
an aqueous solution containing 12 g of sodium catechol disulfonate
was added. At this time, the liquid volume was 1,950 ml.
Subsequently, as the first growth, 1,000 ml of an aqueous
AgNO.sub.3 (231.4 g) solution and an aqueous KBr solution having an
equimolar concentration were added by a double jet method while
acceleration the flow rate. At this time, the liquid volume was
3,980 ml. During the addition, the silver potential was kept at -20
mV to the saturated calomel electrode. In the course of addition,
10 ml of an aqueous solution containing potassium hexachloroiridate
(0.2 mg) was added. At the completion of addition of AgNO.sub.3, 10
ml of an aqueous solution containing sodium benzenethiosulfonate (2
mg) was added.
[0420] Thereafter, as the outermost layer growth, 100 ml of an
aqueous AgNO.sub.3 solution (34.1 g) and 100 ml of an aqueous KBr
solution containing KI were added. The concentration of KI was
adjusted to give a silver iodide content of 12 mol %. At this time,
the silver potential was kept at 30 mV to the saturated calomel
electrode.
[0421] Thereafter, 100 ml of an aqueous solution containing 14 g of
gelatin was added. This gelatin was obtained by crosslinking an
alkali-treated ossein first extraction gelatin (in the molecular
weight distribution measured by PAGI method, the high molecular
weight component was 2.5% and the low molecular weight component
was 60.0%) starting from cow bone. In the molecular weight
distribution measured by the PAGI method, the high molecular weight
component was 12.4% and the low molecular weight component was
48.3%. At this time, the liquid volume was 4,290 ml. After lowering
the temperature to 40.degree. C., 9.7 ml of phenoxyethanol was
added and further, 20 ml of an aqueous KI (0.27 g) solution was
added. Thereto, Sensitizing Dyes IV, V and VI were added at a molar
ratio of 69:30:1 to a proportion of 70% of the saturated coverage.
Here, the sensitizing dyes were used as a solid fine dispersion
prepared by the method described in JP-A-11-52507. More
specifically, 0.8 mass parts of sodium nitrate and 3.2 mass parts
of sodium sulfate were dissolved in 43 mass parts of ion exchanged
water and 13 mass parts of the sensitizing dye was added and
dispersed at 60.degree. C. for 20 minutes using a dissolver blade
at 2,000 rpm, thereby obtaining a solid dispersion of sensitizing
dye. After adding 15 ml of an aqueous solution containing potassium
hexacyanoruthenate(II) (3.2 mg), 100 ml of an aqueous AgNO.sub.3
(12.66 g) solution and 100 ml of an aqueous solution containing KBr
(4.66 g), KI (0.88 g) and NaCl (3.83 g) were added by a double jet
method over 2 minutes.
[0422] Thereafter, 15 ml of Epitaxial Part Shape Stabilizer I (80
mg) was added. At this time, the liquid volume was 4,650 ml.
Subsequently, normal water washing was performed.
[0423] Here, the temperature was kept at 35.degree. C. After adding
77 g of the above-described gelatin, the pH at 40.degree. C. was
adjusted to 6.5 and the silver potential was adjusted to 80 mV to
the saturated calomel electrode using an aqueous NaCl solution.
After adding Epitaxial Part Shape Stabilizer/Storability Improver
II (6 mg), the temperature was elevated to 68.degree. C. and then,
chemical sensitization was optimally performed by adding
0.7.times.10.sup.-4 mol of potassium thiocyanate,
1.4.times.10.sup.-6 mol of chloroauric acid, 0.5.times.10.sup.-5
mol of sodium thiosulfate and 1.2.times.10.sup.-6 mol of
N,N-dimethylselenourea per mol of silver halide. Antifoggant I
(8.3.times.10.sup.-4 mol) was added and the chemical sensitization
was completed.
[0424] Emulsion VII-a obtained was tabular grains such that the
average equivalent-circle diameter was 1.78 .mu.m, the coefficient
of variation in the equivalent-circle diameter was 27%, the average
thickness was 0.143 .mu.m and the average aspect ratio was 12.4. In
this emulsion, 90% or more of the entire projected area was
occupied by hexagonal tabular grains where the ratio of the length
of a side having a maximum length to the length of a side having a
minimum length was 1.5 or less and an epitaxial junction was
present at all of six apex parts. The emulsion was observed by a
transmission electron microscope at a low temperature, as a result,
90% or more of the entire projected area was occupied by grains
having no dislocation line in the main plane part except for the
epitaxial part and having network dislocation lines in the
epitaxial part. In this grain, the outermost layer having a silver
iodide content of 12% occupied 12% in terms of silver. The
epitaxial part occupied 4.5% in terms of silver and had a
composition of AgBr(52)Cl(40)I(8). Furthermore, 90% or more of the
entire projected area was within 30% of the average silver chloride
content and 30% of the average silver iodide content.
[0425] (Preparation of Emulsion VII-b)
[0426] Emulsion VII-b was prepared almost in the same manner as
Emulsion VII-a except that the first growth was changed as follows.
The chemical sensitization and the like were appropriately
optimized according to the surface area of emulsion grain. As the
first growth, silver halide fine grains prepared by adding 1,000 ml
of an aqueous AgNO.sub.3 (231.4 g) solution kept at 25.degree. C.
and 1,000 ml of an aqueous solution containing. KBr (162.0 g) and
78 g of oxidation-treated gelatin having a molecular weight of
10,000 and kept at 25.degree. C. to a mixing vessel shown in FIG. 2
where stirring blades having no rotary shaft protruding through the
wall of a closed stirring tank and connected with magnetic coupling
were rotated in the converse direction, were continuously added to
a reactor. The silver potential was kept at -20 mV to the calomel
electrode by separately adding a KBr solution. At this time, the
liquid volume was nearly 3,980 ml. In the fine grains added, the
number average equivalent-circle diameter was 0.015 .mu.m and the
coefficient of variation in the equivalent-circle diameter was
36%.
[0427] (Preparation of Emulsion VII-c)
[0428] Emulsion VII-c was prepared almost in the same manner as
Emulsion VII-a except that the first growth was changed as follows.
The chemical sensitization and the like were appropriately
optimized according to the surface area of emulsion grain. As the
first growth, silver halide fine grains prepared by adding 1,000 ml
of an aqueous AgNO.sub.3 (231.4 g) solution kept at 10.degree. C.
and 1,000 ml of an aqueous solution containing KBr (162.0 g) and
108 g of oxidationtreated gelatin having a molecular weight of
15,000 and kept at 15.degree. C. to a mixing vessel shown in FIG. 2
where stirring blades having no rotary shaft protruding through the
wall of a closed stirring tank and connected with magnetic coupling
were rotated in the converse direction, were continuously added to
a reactor. The silver potential was kept at -20 mV to the calomel
electrode by separately adding a KBr solution. At this time, the
liquid volume was nearly 3,980 ml. In the fine grains added, the
number average equivalent-circle diameter was 0.014 .mu.m and the
coefficient of variation in the equivalent-circle diameter was
32%.
[0429] (Preparation of Emulsion VII-d)
[0430] Emulsion VII-d was prepared almost in the same manner as
Emulsion VII-a except that the first growth was changed as follows.
The chemical sensitization and the like were appropriately
optimized according to the surface area of emulsion grain. As the
first growth, silver halide fine grains prepared by adding 1,000 ml
of an aqueous AgNO.sub.3 (231.4 g) solution kept at 10.degree. C.
and 1,000 ml of an aqueous solution containing KBr (153.9 g) and
108 g of oxidationtreated gelatin having a molecular weight of
15,000 and kept at 15.degree. C. to a mixing vessel shown in FIG. 2
where stirring blades having no rotary shaft protruding through the
wall of a closed stirring tank and connected with magnetic coupling
were rotated in the converse direction, were continuously added to
a reactor. The silver potential was kept at -20 mV to the calomel
electrode by separately adding a KBr solution. At this time, the
liquid volume was nearly 3,980 ml. In the fine grains added, the
number average equivalent-circle diameter was 0.014 .mu.m and the
coefficient of variation in the equivalent-circle diameter was
28%.
[0431] (Preparation of Emulsion VII-e)
[0432] Emulsion VII-e was prepared almost in the same manner as
Emulsion VII-a except that the first growth was changed as follows.
The chemical sensitization and the like were appropriately
optimized according to the surface area of emulsion grain. As the
first growth, silver halide fine grains prepared by adding 2,500 ml
of an aqueous AgNO.sub.3 (231.4 g) solution kept at 15.degree. C.
and 2,500 ml of an aqueous solution containing KBr (153.9 g) and
108 g of oxidation-treated gelatin having a molecular weight of
15,000 and kept at 20.degree. C. to a mixing vessel shown in FIG. 2
where stirring blades having no rotary shaft protruding through the
wall of a closed stirring tank and connected with magnetic coupling
were rotated in the converse direction, were continuously added to
a reactor. The silver potential was kept at -20 mV to the calomel
electrode by separately adding a KBr solution. Together with this
first growth, ultrafiltration was performed. The ultrafiltration
module used for the ultrafiltration apparatus was flat membrane
Centramate Nova Series (fractional molecular weight: 30,000)
produced by Pall. The reflux flow rate was 1 liter/min, the
permeation flow rate was from 24 to 57 ml/min, the supply pressure
was 0.09 MPa, the reflux pressure was 0.05 MPa and the permeation
pressure was 0 MPa. After the first growth, the liquid volume was
nearly 3,980 ml. In the fine grains added, the number average
equivalent-circle diameter was 0.014 .mu.m and the coefficient of
variation in the equivalent-circle diameter was 23%.
[0433] (Preparation of Emulsion VII-f)
[0434] Emulsion VII-f was prepared almost in the same manner as
Emulsion VII-a except that the first growth was changed as follows.
The chemical sensitization and the like were appropriately
optimized according to the surface area of emulsion grain. As the
first growth, silver halide fine grains prepared by adding 3,000 ml
of an aqueous AgNO.sub.3 (231.4 g) solution kept at 15.degree. C.
and 3,000 ml of an aqueous solution containing KBr (149.0 g), KI
(6.8 g) and 207 g of oxidation-treated gelatin having a molecular
weight of 15,000 and kept at 20.degree. C. to a mixing vessel shown
in FIG. 2 where stirring blades having no rotary shaft protruding
through the wall of a closed stirring tank and connected with
magnetic coupling were rotated in the converse direction, were
continuously added to a reactor. The silver potential was kept at
-20 mV to the calomel electrode by separately adding a KBr
solution. Together with this first growth, ultrafiltration was
performed. The ultrafiltration module used for the ultrafiltration
apparatus was flat membrane Centramate Nova Series (fractional
molecular weight: 30,000) produced by Pall. The reflux flow rate
was 1 liter/min, the permeation flow rate was from 24 to 57 ml/min,
the supply pressure was 0.09 MPa, the reflux pressure was 0.05 MPa
and the permeation pressure was 0 MPa. After the first growth, the
liquid volume was nearly 3,980 ml. In the fine grains added, the
number average equivalent-circle diameter was 0.014 .mu.m and the
coefficient of variation in the equivalent-circle diameter was
19%.
[0435] (Preparation of Emulsion VII-g)
[0436] Emulsion VII-g was prepared almost in the same manner as
Emulsion VII-a except that the first growth was changed as follows.
The chemical sensitization and the like were appropriately
optimized according to the surface area of emulsion grain. As the
first growth, silver halide fine grains prepared by adding 4,000 ml
of an aqueous AgNO.sub.3 (231.4 g) solution kept at 30.degree. C.
and 4,000 ml of an aqueous solution containing KBr (149.0 g), KI
(6.8 g) and 323 g of oxidation-treated gelatin having a molecular
weight of 15,000 and kept at 30.degree. C. to a mixing vessel shown
in FIG. 2 where stirring blades having no rotary shaft protruding
through the wall of a closed stirring tank and connected with
magnetic coupling were rotated in the converse direction, were
continuously added to a reactor. The silver potential was kept at
-20 mV to the calomel electrode by separately adding a KBr
solution. Together with this first growth, ultrafiltration was
performed. The ultrafiltration module used for the ultrafiltration
apparatus was hollow yarn membrane SLP-1053 (fractional molecular
weight: 10,000) produced by Asahi Chemical Industry Co., Ltd. At
this time, the reflux flow rate was from 3 to 12 liter/min and the
permeation flow rate was 38 ml/min. After the first growth, the
liquid volume was nearly 3,980 ml. In the fine grains added, the
number average equivalent-circle diameter was 0.016 .mu.m and the
coefficient of variation in the equivalent-circle diameter was
9%.
[0437] The characteristic values of Emulsions VII-a to VII-g are
shown in Table 10. As apparently seen from the results in Table 10,
a monodisperse tabular grain emulsion more reduced in the thickness
can be obtained by the production process of the present
invention.
19 TABLE 10 Tabular Grain Coefficient of Fine Grain Added Average
Variation in Coefficient Number Coefficient Equivalent- Equivalent-
Average of variation Sample Average of Variation Circle Circle
Diameter Thickness in Thickness No. Emulsion Size (.mu.m) (%)
Diameter (.mu.m) (%) (.mu.m) (%) VII-801 VII-a -- -- 1.78 27 0.143
38 VII-802 VII-b 0.015 36 2.53 27 0.071 31 VII-803 VII-c 0.014 32
2.73 26 0.061 31 VII-804 VII-d 0.014 28 2.77 23 0.059 26 VII-805
VII-e 0.014 23 3.28 20 0.042 21 VII-806 VII-f 0.014 19 3.41 20
0.039 20 VII-807 VII-g 0.016 9 3.71 18 0.033 18
[0438] In each of Emulsions VII-b to VII-g, 90% or more of the
entire projected area was occupied by hexagonal tabular grains
where the ratio of the length of a side having a maximum length to
the length of a side having a minimum length was 1.5 or less and an
epitaxial junction was present at all of six apex parts. The
emulsions were observed by a transmission electron microscope at a
low temperature, as a result, 90% or more of the entire projected
area was occupied by grains having no dislocation line in the main
plane part except for the epitaxial part and having network
dislocation lines in the epitaxial part. Emulsions VII-b to VII-g
all were a grain where the outermost layer having a silver iodide
content of 12% occupied 12% in terms of silver. The epitaxial part
occupied 4.5% in terms of silver and had a composition of
AgBr(52)Cl(40)I(8). Furthermore, 90% or more of the entire
projected area was within 30% of the average silver chloride
content and 30% of the average silver iodide content.
[0439] On a cellulose triacetate film support having provided
thereon a subbing layer, chemically sensitized emulsions prepared
above each was coated under the coating conditions shown in Table 2
and a protective layer was provided, thereby obtaining Samples
VII-801 to VII-807.
[0440] Each sample was left standing under the conditions of
40.degree. C. and a relative humidity of 70% for 14 hours, then
exposed for {fraction (1/100)} second through Gelatin Filter SC-50
produced by Fuji Photo Film Co., Ltd. and a continuous wedge and
processed in the same manner as above.
[0441] The processed samples were measured on the density by a
green filter. Also, samples stored for 14 days under the condition
of 50.degree. C. and a relative humidity of 60% before the exposure
were measured in the same manner and evaluated on the
storability.
[0442] The sensitivity value at a density of fog+0.2 and the fog
value obtained are shown in Table 11.
20 TABLE 11 Sample No. Emulsion Fog Sensitivity VII-801 VII-a
Comparison 0.28 100 VII-802 VII-b Comparison 0.23 122 VII-803 VII-c
Comparison 0.23 129 VII-804 VII-d Invention 0.19 164 VII-805 VII-e
Invention 0.14 212 VII-806 VII-f Invention 0.13 221 VII-807 VII-g
Invention 0.10 253
[0443] As apparent from the results in Table 11, the silver halide
emulsions produced by the production process of the present
invention have low fog and high-sensitivity.
Example VIII
[0444] This Examples is performed to verify the effect of the
emulsion produced by the production process of the present
invention in a multilayer color photographic lightsensitive
material.
[0445] Samples VIII-901 to VIII-907 were prepared in the same
manner as in Example VI except that Emulsion V-a of the sixth layer
was changed to Em-J, and Em-K of the fourth layer was changed to
Emulsions VIII-a to VIII-g, respectively.
[0446] These samples were subjected to a hardening treatment under
the conditions of 40.degree. C. and a relative humidity of 70% for
14 hours and then, exposed and processed in the same manner as in
Example VI.
[0447] The results are shown in Table 12.
21TABLE 12 Sample Sensitivity at No. Emulsion Fog Density of Fog +
2.0 VIII-901 VIII-a Comparison 0.23 100 VIII-902 VIII-b Comparison
0.21 118 VIII-903 VIII-c Comparison 0.21 118 VIII-904 VIII-d
Invention 0.19 142 VIII-905 VIII-e Invention 0.17 164 VIII-906
VIII-f Invention 0.17 181 VIII-907 VIII-g Invention 0.16 196
[0448] As apparent from Table 12, a light-sensitive material having
low fog and high sensitivity can be obtained by using the emulsion
produced according to the production process of the present
invention.
Example IX
[0449] The production process of emulsion of the present invention
is described in detail below.
[0450] (Preparation of Emulsion IX-a)
[0451] 1,691 mL of an aqueous solution containing 0.128 g of KBr
and 2.38 g of oxidation-treated low molecular weight gelatin having
an average molecular weight of 20,000 was stirred while keeping at
5.degree. C. Thereto, 47.4 mL of an aqueous AgNO.sub.3 (0.178 g)
solution and 75.3 mL of an aqueous solution containing KBr (0.414
g) and oxidation-treated low molecular weight gelatin (0.068 g)
having an average molecular weight of 20,000 were added over 52
seconds. The temperature was elevated to 75.degree. C. and then, 18
mL of an aqueous solution containing 1.83 g of KBr was added.
Thereto, 130 mL of an aqueous solution containing 16 g of
succinated gelatin having an average molecular weight of 100,000
was added and then, 200 mL of an aqueous solution containing 12 g
of sodium catechol disulfonate was added. At this time, the liquid
volume was 1,930 mL. Subsequently, as the first growth, silver
halide fine grains prepared by adding 854 mL of an aqueous
AgNO.sub.3 (24.2 g) solution and an aqueous KBr solution having an
equimolar concentration (containing 3 mol % of KI and 15.1 g of
oxidation-treated low molecular gelatin having an average molecular
weight of 20,000) to a mixing vessel shown in FIG. 2 where stirring
blades having no rotary shaft protruding through the wall of a
closed stirring tank and connected with magnetic coupling were
rotated in the converse direction, were continuously added to a
reactor. The silver potential was kept at 0 mV to the saturated
calomel electrode by separately adding a KBr solution. In the fine
grains added, the number average equivalent-circle diameter was
0.015 .mu.m and the coefficient of variation in the
equivalent-circle diameter was 29%. Together with this first
growth, ultrafiltration was performed. The ultrafiltration module
used for the ultrafiltration apparatus was flat membrane Centramate
Nova Series (fractional molecular weight: 30,000) produced by Pall.
The reflux flow rate was 1 L/min, the supply pressure was 0.09 MPa,
the reflux pressure was 0.05 MPa and the permeation pressure was 0
MPa. At this time, the liquid volume was 1,845 mL. In the course of
growth, 10 mL of an aqueous solution containing potassium
hexachloroiridate (0.2 mg) was added. At the completion of addition
of AgNO.sub.3, 10 mL of an aqueous solution containing sodium
benzenethiosulfonate (2 mg) was added. Thereafter, as the second
growth, silver halide fine grains were prepared by adding 816 mL of
an aqueous AgNO.sub.3 solution (98.0 g) and an aqueous KBr solution
having an equimolar concentration (containing 3 mol % of KI and
61.3 g of oxidation-treated low molecular weight gelatin having an
average molecular weight of 20,000) to a mixing vessel same as in
the first growth and added to a reactor. The silver potential was
kept at 0 mV to the saturated calomel electrode by separately
adding a KBr solution. In the fine grains added, the number average
equivalent-circle diameter was 0.017 .mu.m and the coefficient of
variation in the equivalent-circle diameter was 36%. Together with
this second growth, ultrafiltration was performed. The conditions
were the same as in the first growth. At this time, the liquid
volume was 2,750 mL. Furthermore, as the third growth, the
additions and ultrafiltration were performed under thoroughly the
same conditions as in the second growth. At this time, the liquid
amount was 3,500 mL. Thereafter, 100 mL of an aqueous solution
containing 14 g of gelatin was added. This gelatin was obtained by
crosslinking an alkali-treated ossein first extraction gelatin (in
the molecular weight distribution measured by PAGI method, the high
molecular weight component was 2.5% and the low molecular weight
component was 60.0%) starting from cow bone. In the molecular
weight distribution measured by the PAGI method, the high molecular
weight component was 12.4% and the low molecular weight component
was 48.3%. At this time, the liquid volume was 3,695 mL. After
lowering the temperature to 40.degree. C., 7.76 mL of
phenoxyethanol was added and further, 20 mL of an aqueous KI (0.21
g) solution was added. Thereto, Sensitizing Dyes IV, V and VI were
added at a molar ratio of 69:30:1 to a proportion of 70% of the
saturated coverage. Here, the sensitizing dyes were used as a solid
fine dispersion prepared by the method described in JP-A-11-52507.
More specifically, 0.8 mass parts of sodium nitrate and 3.2 mass
parts of sodium sulfate were dissolved in 43 mass parts of ion
exchanged water and 13 mass parts of the sensitizing dye was added
and dispersed at 60.degree. C. for 20 minutes using a dissolver
blade at 2,000 rpm, thereby obtaining a solid dispersion of
sensitizing dye. After adding 15 mL of an aqueous solution
containing potassium hexacyanoruthenate(II) (2.6 mg), 100 mL of an
aqueous AgNO.sub.3 (10.1 g) solution and 100 mL of an aqueous
solution containing KBr (3.7 g), KI (0.7 g) and NaCl (3.06 g) were
added by a double jet method over 2 minutes. Thereafter, 12 ml of
Epitaxial Part Shape Stabilizer I (80 mg) was added. At this time,
the liquid volume was 4,180 mL. Subsequently, normal water washing
was performed. Here, the temperature was kept at 35.degree. C.
After adding 77 g of the above-described gelatin, the pH at
40.degree. C. was adjusted to 6.5 and the silver potential was
adjusted to 80 mV to the saturated calomel electrode using an
aqueous NaCl solution. After adding Epitaxial Part Shape
Stabilizer/Storability Improver II (6 mg), the temperature was
elevated to 68.degree. C. and then, chemical sensitization was
optimally performed by adding 0.7.times.10.sup.-4 mol of potassium
thiocyanate, 1.4.times.10.sup.-6 mol of chloroauric acid,
0.5.times.10.sup.-5 Mol of sodium thiosulfate and
1.2.times.10.sup.6 mol of N,Ndimethylselenourea per mol of silver
halide. Antifoggant I (8.3.times.10.sup.-4 mol) was added and the
chemical sensitization was completed.
[0452] Emulsion IX-a obtained was tabular grains such that the
coefficient of variation in the equivalent-circle diameter of all
grains was 29%, the average equivalentcircle diameter was 5.6 .mu.m
and the average thickness was 0.048 .mu.m. In this emulsion, 80% or
more of the entire projected area was occupied by tabular grains
having an equivalent-circle diameter of 5.0 .mu.m or more and an
average thickness of 0.055 .mu.m or less. Also, 90% or more of the
entire projected area was occupied by hexagonal tabular grains
where the ratio of the length of a side having a maximum length to
the length of a side having a minimum length was 1.5 or less and an
epitaxial junction was present at all of six apex parts. The
emulsion was observed by a transmission electron microscope at a
low temperature, as a result, 90% or more of the entire projected
area was occupied by grains having no dislocation line in the main
plane part except for the epitaxial part and having network
dislocation lines in the epitaxial part. In this grain, the
outermost layer having a silver iodide content of 12% occupied 12%
in terms of silver. The epitaxial part occupied 4.5% in terms of
silver and had a composition of AgBr(52)Cl(40)I(8). Furthermore,
90% or more of the entire projected area was within 30% of the
average silver chloride content and 30% of the average silver
iodide content.
[0453] (Preparation of Emulsion IX-b)
[0454] 1,192 mL of an aqueous solution containing 0.9 g of KBr and
4.2 g of oxidation-treated low molecular weight gelatin having an
average molecular weight of 20,000 was stirred while keeping at
35.degree. C. Thereto, 33.4 mL of an aqueous AgNO.sub.3 (1.0 g)
solution and 53.1 mL of an aqueous solution containing KBr (0.9 g)
and oxidation-treated low molecular weight gelatin (0.37 g) having
an average molecular weight of 20,000 were added over 52 seconds.
The temperature was elevated to 75.degree. C. and then, 18 mL of an
aqueous solution containing 1.83 g of KBr was added. Thereto, 130
mL of an aqueous solution containing 16 g of succinated gelatin
having an average molecular weight of 100,000 was added and then,
200 mL of an aqueous solution containing 12 g of sodium catechol
disulfonate was added. At this time, the liquid volume was 1,628
mL. Subsequently, as the first growth, silver halide fine grains
prepared by adding 854 mL of an aqueous AgNO.sub.3 (136.0 g)
solution and an aqueous KBr solution having an equimolar
concentration (containing 3 mol % of KI and 85 g of
oxidation-treated low molecular gelatin having an average molecular
weight of 20,000) to a mixing vessel shown in FIG. 2 where stirring
blades having no rotary shaft protruding through the wall of a
closed stirring tank and connected with magnetic coupling were
rotated in the converse direction, were continuously added to a
reactor. The silver potential was kept at 0 mV to the saturated
calomel electrode by separately adding a KBr solution. In the fine
grains added, the number average equivalent-circle diameter was
0.015 .mu.m and the coefficient of variation in the
equivalent-circle diameter was 29%. At this time, the liquid volume
was 3,394 mL. In the course of growth, 10 mL of an aqueous solution
containing potassium hexachloroiridate (0.2 mg) was added. At the
completion of addition of AgNO.sub.3, 10 mL of an aqueous solution
containing sodium benzenethiosulfonate (2 mg) was added.
Thereafter, the solution was bailed out to a volume of 608 mL.
Then, as the second growth, silver halide fine grains were prepared
by adding 816 mL of an aqueous AgNO.sub.3 solution (98.0 g) and an
aqueous KBr solution having an equimolar concentration (containing
3 mol % of KI) to a mixing vessel same as in the first growth and
added to a reactor. The silver potential was kept at 0 mV to the
saturated calomel electrode by separately adding a KBr solution. In
the fine grains added, the number average equivalent-circle
diameter was 0.017 .mu.m and the coefficient of variation in the
equivalent-circle diameter was 36%. At this time, the liquid volume
was 2,299 mL. Furthermore, as the third growth, silver halide fine
grains were prepared by adding an aqueous AgNO.sub.3 solution (98.0
g) and an aqueous KBr solution having an equimolar concentration
(containing 3 mol % of KI and 61.3 g of oxidation-treated low
molecular weight gelatin having an average molecular weight of
20,000) to a mixing vessel same as in the first growth and added to
a reactor. The silver potential was kept at 0 mV to the saturated
calomel electrode by separately adding a KBr solution. In the fine
grains added, the number average equivalent-circle diameter was
0.018 .mu.m and the coefficient of variation in the
equivalent-circle diameter was 39%. At this time, the liquid volume
was 3,500 mL and the same amount of AgNO.sub.3 was contained in the
same amount of solution as in Emulsion IX-a. The subsequent steps
were performed in the same manner as in the preparation of Emulsion
IX-a. The thus-prepared Emulsion IX-b was tabular grains such that
the coefficient of variation in the equivalent-circle diameter of
all grains was 26%, the average equivalent-circle diameter was 3.8
.mu.m and the average thickness was 0.095 .mu.m. In this emulsion,
45% of the entire projected area was occupied by tabular grains
having an equivalent-circle diameter of 4.0 .mu.m or more and an
average thickness of 0.10 .mu.m or less.
[0455] The characteristic values of Emulsions IX-a and IX-b are
shown in Table 13. As apparently seen from the results in Table 13,
a large size tabular grain can be more reduced in the thickness by
the production process of the present invention.
22TABLE 13 Percentage of Grains Having Equivalent- Circle Diameter
of 4 .mu.m or Coefficient more and of Variation Thickness of in
Equivalent- Name 0.1 .mu.m or less Circle of Presence or in Entire
Diameter Emul- Absence of Projected of All sion Ultrafiltration
Area (%) Grains (%) A done 80% or more 29% Invention B none 45% 26%
Comparison
[0456] On a cellulose triacetate film support having provided
thereon a subbing layer, chemically sensitized emulsions prepared
above each was coated under the coating conditions shown in Table 2
and a protective layer was provided, thereby obtaining Samples
IX-801 and IX-802.
[0457] Each sample exposed for {fraction (1/100)} second through
Gelatin Filter SC-50 produced by Fuji Photo Film Co., Ltd. and a
continuous wedge and processed in the same manner as in Example
II.
[0458] The processed samples were measured on the density by a
green filter. The sensitivity value at a density of fog+0.2 and the
fog value obtained are shown in Table 14. TABLE 14
23 TABLE 14 Sample No. Emulsion Fog Sensitivity IX-801 IX-a 0 148
Invention IX-802 IX-b 0 100 Comparison
[0459] Fog shows the increment from Sample IX-802 of which fog is
taken as 0.
[0460] Sensitivity is shown relatively to Sample IX-802 of which
sensitivity is taken as 100.
[0461] As apparent from the results in Table 14, a silver halide
emulsion having high sensitivity can be obtained by the production
process of the present invention.
Example X
[0462] This Examples is performed to verify the effect of the
emulsion produced by the production process of the present
invention in a multilayer color photographic light-sensitive
material.
[0463] Samples X-901 and X-902 were prepared in the same manner as
in Example VI except that Emulsion V-a of the sixth layer was
changed to Emulsions IX-a and IX-b, respectively.
[0464] These samples were exposed and processed in the same manner
as in Example VI.
[0465] The results are shown in Table 15.
24 TABLE 15 Sample Emulsion of No. Sixth Layer Fog Sensitivity
X-901 IX-a 0 130 Invention X-902 IX-b 0 100 Comparison
[0466] Fog shows the increment from Sample X-902 of which fog is
taken as 0.
[0467] Sensitivity is shown relatively to Sample X-902 of which
sensitivity is taken as 100.
[0468] As apparent from Table 15, a light-sensitive material having
high sensitivity can be obtained by using the emulsion produced
according to the production process of the present invention.
Example XI
[0469] The silver halide photographic emulsion of the present
invention is described in detail below.
[0470] (Preparation of Emulsion XI-a)
[0471] 1,100 mL of an aqueous solution containing 0.32 g of KBr and
1.38 g of oxidation-treated low molecular weight gelatin having an
average molecular weight of 20,000 was stirred while keeping at
5.degree. C. Thereto, 200 ml of an aqueous AgNO.sub.3 (1.0 g)
solution and 200 ml of an aqueous solution containing KBr (0.7 g)
and oxidation-treated low molecular weight gelatin (3.3 g) having
an average molecular weight of 20,000 were added over 15 seconds.
After adding 120 ml of an aqueous solution containing 2.6 g of KBr,
the temperature was elevated to 75.degree. C. and then, 130 ml of
an aqueous solution containing 18 g of succinated gelatin having an
average molecular weight of 100,000 was added. Thereafter, 200 ml
of an aqueous solution containing 12 g of sodium catechol
disulfonate was added. At this time, the liquid volume was 1,950
ml. Subsequently, as the first growth, 1,000 ml of an aqueous
AgNO.sub.3 (231.4 g) solution and an aqueous KBr solution having an
equimolar concentration were added by a double jet method while
acceleration the flow rate. At this time, the liquid volume was
3,980 ml. During the addition, the silver potential was kept at -20
mV to the saturated calomel electrode. In the course of addition,
10 ml of an aqueous solution containing potassium hexachloroiridate
(0.2 mg) was added. At the completion of addition of AgNO.sub.3, 10
ml of an aqueous solution containing sodium benzenethiosulfonate (2
mg) was added.
[0472] Thereafter, as the outermost layer growth, 100 ml of an
aqueous AgNO.sub.3 solution (34.1 g) and 100 ml of an aqueous KBr
solution containing KI were added. The concentration of KI was
adjusted to give a silver iodide content of 12 mol %. At this time,
the silver potential was kept at 30 mV to the saturated calomel
electrode. Subsequently, 100 ml of an aqueous solution containing
14 g of gelatin was added. This gelatin was obtained by
crosslinking an alkali-treated ossein first extraction gelatin (in
the molecular weight distribution measured by PAGI method, the high
molecular weight component was 2.5% and the low molecular weight
component was 60.0%) starting from cow bone. In the molecular
weight distribution measured by the PAGI method, the high molecular
weight component was 12.4% and the low molecular weight component
was 48.3%. At this time, the liquid volume was 4,290 ml. After
lowering the temperature to 40.degree. C., 9.7 ml of phenoxyethanol
was added and further, 20 ml of an aqueous KI (0.27 g) solution was
added. Thereto, Sensitizing Dye VII was added to a proportion of
20% of the saturated coverage and then, Sensitizing Dyes VIII, IX
and X were added at a molar ratio of 45:40:15 to a proportion of
60% of the saturated coverage. Here, the sensitizing dyes were used
as a solid fine dispersion prepared by the method described in
JP-A-11-52507. More specifically, 0.8 mass parts of sodium nitrate
and 3.2 mass parts of sodium sulfate were dissolved in 43 mass
parts of ion exchanged water and 13 mass parts of the sensitizing
dye was added and dispersed at 60.degree. C. for 20 minutes using a
dissolver blade at 2,000 rpm, thereby obtaining a solid dispersion
of sensitizing dye. After adding 15 ml of an aqueous solution
containing potassium hexacyanoruthenate(II) (3.2 mg), 100 ml of an
aqueous AgNO.sub.3 (12.66 g) solution and 100 ml of an aqueous
solution containing KBr (4.66 g), KI (0.88 g) and NaCl (3.83 g)
were added by a double jet method over 2 minutes. Thereafter, 15 ml
of Epitaxial Part Shape Stabilizer I (180 mg) was added. At this
time, the liquid volume was 4,650 ml. Subsequently, water washing
was performed by a normal coagulation precipitation method. Here,
the temperature was kept at 35.degree. C. After adding 77 g of the
above-described gelatin, the pH at 40.degree. C. was adjusted to
6.5 and the silver potential was adjusted to 80 mV to the saturated
calomel electrode using an aqueous NaCl solution.
[0473] Emulsion XI-a obtained was tabular grains such that the
average equivalent-circle diameter was 1.78 .mu.m, the coefficient
of variation in the equivalent-circle diameter was 27%, the average
thickness was 0.143 .mu.m and the average aspect ratio was 12.4. In
this emulsion, 90% or more of the entire projected area was
occupied by hexagonal tabular grains where the ratio of the length
of a side having a maximum length to the length of a side having a
minimum length was 1.5 or less and an epitaxial junction was
present at all of six apex parts. The emulsion was observed by a
transmission electron microscope at a low temperature, as a result,
90% or more of the entire projected area was occupied by grains
having no dislocation line in the main plane part except for the
epitaxial part and having network dislocation lines in the
epitaxial part. In this grain, the outermost layer having a silver
iodide content of 12% occupied 12% in terms of silver. The
epitaxial part occupied 4.5% in terms of silver and had a
composition of AgBr(52)Cl(40)I(8). Furthermore, 90% or more of the
entire projected area was within 30% of the average silver chloride
content and 30% of the average silver iodide content. 17
[0474] (Preparation of Emulsion XI-b)
[0475] Emulsion XI-b was prepared by making the following change in
the preparation of Emulsion XI-a. Ultrafiltration was performed at
40.degree. C. in place of the water washing by a normal coagulation
precipitation method and thereafter, the gelatin concentration, the
pH and the silver potential were adjusted in the same manner as in
the preparation of Emulsion XI-a.
[0476] The ultrafiltration module used for the ultrafiltration
apparatus was hollow yarn membrane SLP-1053 (fractional molecular
weight: 10,000) produced by Asahi Chemical Industry Co., Ltd. At
this time, the reflux flow rate was from 3 to 12 liter/min and the
permeation flow rate was 27 ml/min.
[0477] The characteristic values of Emulsion XI-b were the same as
those of Emulsion XI-a.
[0478] (Preparation of Emulsion XI-a-1)
[0479] After adding Epitaxial Part Shape Stabilizer/ Storability
Improver II (6 mg) to Emulsion XI-a at 40.degree. C., the
temperature was elevated to 50.degree. C. and then, chemical
sensitization was optimally performed by adding 0.7.times.10.sup.-4
mol of potassium thiocyanate, 2.8.times.10.sup.-6 mol of
chloroauric acid, 0.9.times.10.sup.-5 mol of sodium thiosulfate and
2.16.times.10.sup.-6 mol of N,N-dimethylselenourea per mol of
silver halide. After 75 minutes from the addition of sodium
thiosulfate, Antifoggant I (8.3.times.10.sup.-4 mol) was added and
the chemical sensitization was completed by lowering the
temperature to 40.degree. C.
[0480] (Preparation of Emulsion XI-a-2)
[0481] After adding Epitaxial Part Shape Stabilizer/ Storability
Improver II (6 mg) to Emulsion XI-a at 40.degree. C., the
temperature was elevated to 58.degree. C. and then, chemical
sensitization was optimally performed by adding 0.7.times.10.sup.-4
mol of potassium thiocyanate, 1.8.times.10.sup.-6 mol of
chloroauric acid, 0.65.times.10.sup.-5 mol of sodium thiosulfate
and 1.56.times.10.sup.-6 mol of N,N-dimethylselenourea per mol of
silver halide. After 75 minutes from the addition of sodium
thiosulfate, Antifoggant I (8.3.times.10.sup.-4 mol) was added and
the chemical sensitization was completed by lowering the
temperature to 40.degree. C.
[0482] (Preparation of Emulsion XI-a-3)
[0483] After adding Epitaxial Part Shape Stabiliz r/ storability
Improver II (6 mg) to Emulsion XI-a at 40.degree. C., the
temperature was elevated to 68.degree. C. and then, chemical
sensitization was optimally performed by adding 0.7.times.10.sup.-4
mol of potassium thiocyanate, 1.4.times.10.sup.-6 mol of
chloroauric acid, 0.5.times.10.sup.-5 mol of sodium thiosulfate and
1.2.times.10.sup.-6 mol of N,N-dimethylselenourea per mol of silver
halide. After 25 minutes from the addition of sodium thiosulfate,
Antifoggant I (8.3.times.10.sup.-4 mol) was added and the chemical
sensitization was completed by lowering the temperature to
40.degree. C.
[0484] (Preparation of Emulsion XI-a-4)
[0485] After adding Epitaxial Part Shape Stabilizer/ Storability
Improver II (6 mg) to Emulsion XI-a at 40.degree. C., the
temperature was elevated to 72.degree. C. and then, chemical
sensitization was optimally performed by adding 0.7.times.10.sup.-4
mol of potassium thiocyanate, 1.0.times.10.sup.-6 mol of
chloroauric acid, 0.4.times.10.sup.-5 mol of sodium thiosulfate and
1.0.times.10.sup.-6 mol of N,N-dimethylselenourea per mol of silver
halide. After 10 minutes from the addition of sodium thiosulfate,
Antifoggant I (8.3.times.10.sup.-4 mol) was added and the chemical
sensitization was completed by lowering the temperature to
40.degree. C.
[0486] (Preparation of Emulsion XI-a-5)
[0487] After the preparation of Emulsion XI-a-1, Sensitizing Dye
VII was added at 40.degree. C. to a proportion of 35% of the
saturated coverage and then Sensitizing Dye VIII was added to a
proportion of 45% of the saturated coverage. The light absorption
intensity of this Emulsion was 135 and this reveals that multilayer
adsorption of sensitizing dyes was achieved.
[0488] (Preparation of Emulsion XI-a-6)
[0489] After the preparation of Emulsion XI-a-2, Sensitizing Dye
VII was added at 40.degree. C. to a proportion of 35% of the
saturated coverage and then Sensitizing Dye VIII was added to a
proportion of 45% of the saturated coverage. The light absorption
intensity of this Emulsion was 135 and this reveals that multilayer
adsorption of sensitizing dyes was achieved.
[0490] (Preparation of Emulsion XI-a-7)
[0491] After the preparation of Emulsion XI-a-3, Sensitizing Dye
VII was added at 40.degree. C. to a proportion of 35% of the
saturated coverage and then Sensitizing Dye VIII was added to a
proportion of 45% of the saturated coverage. The light absorption
intensity of this Emulsion was 135 and this reveals that multilayer
adsorption of sensitizing dyes was achieved.
[0492] (Preparation of Emulsion XI-a-8)
[0493] After the preparation of Emulsion XI-a-4, Sensitizing Dye
VII was added at 40.degree. C. to a proportion of 35% of the
saturated coverage and then Sensitizing Dye VIII was added to a
proportion of 45% of the saturated coverage. The light absorption
intensity of this Emulsion was 135 and this reveals that multilayer
adsorption of sensitizing dyes was achieved.
[0494] (Preparation of Emulsion XI-b-1) Emulsion XI-b-1 was
prepared by changing Emulsion XIa to XI-b in the preparation of
Emulsion XI-a-5.
[0495] The light absorption intensity of this Emulsion was 155 and
this reveals that multilayer adsorption of sensitizing dyes was
achieved.
[0496] (Preparation of Emulsion XI-b-2)
[0497] Emulsion XI-b-2 was prepared by changing Emulsion XIa to
XI-b in the preparation of Emulsion XI-a-6.
[0498] The light absorption intensity of this Emulsion was 155 and
this reveals that multilayer adsorption of sensitizing dyes was
achieved.
[0499] (Preparation of Emulsion XI-b-3)
[0500] Emulsion XI-b-3 was prepared by changing Emulsion XIa to
XI-b in the preparation of Emulsion XI-a-7.
[0501] The light absorption intensity of this Emulsion was 155 and
this reveals that multilayer adsorption of sensitizing dyes was
achieved.
[0502] (Preparation of Emulsion XI-b-4)
[0503] Emulsion XI-b-4 was prepared by changing Emulsion XIa to
XI-b in the preparation of Emulsion XI-a-8.
[0504] The light absorption intensity of this Emulsion was 155 and
this reveals that multilayer adsorption of sensitizing dyes was
achieved.
[0505] On a cellulose triacetate film support having provided
thereon a subbing layer, chemically sensitized emulsions prepared
above each was coated under the coating conditions shown in Table 2
and a protective layer was provided, thereby obtaining Samples
XI-501 to XI-512.
[0506] Each sample was left standing under the conditions of
40.degree. C. and a relative humidity of 70% for 14 hours, then
exposed for {fraction (1/100)} second through Gelatin Filter SC-50
produced by Fuji Photo Film Co., Ltd. and a continuous wedge and
processed in the same manner as in Example II.
[0507] The processed samples were measured on the density by a
green filter.
[0508] The sensitivity value at a density of fog+0.2 and the fog
value obtained are shown in Table 16.
25TABLE 16 Multi- Sen- layer si- Sample Ad- Ultra- tivity Fog No.
Emulsion sorption filtration Value Value .gamma. XI-501 a-1
(Comparison) X X 100 0.13 100 XI-502 a-2 (Comparison) X X 113 0.13
108 XI-503 a-3 (Comparison) X X 132 0.10 121 XI-504 a-4
(Comparison) X X 141 0.09 136 XI-505 a-5 (Comparison) .largecircle.
X 106 0.10 53 XI-506 a-6 (Comparison) .largecircle. X 128 0.10 98
XI-507 a-7 (Comparison) .largecircle. X 163 0.09 118 XI-508 a-8
(Comparison) .largecircle. X 171 0.08 136 XI-509 b-1 (Comparison)
.largecircle. .largecircle. 111 0.10 46 XI-510 b-2 (Invention)
.largecircle. .largecircle. 142 0.10 92 XI-511 b-3 (Invention)
.largecircle. .largecircle. 186 0.09 118 XI-512 b-4 (Invention)
.largecircle. .largecircle. 192 0.08 136
[0509] As apparent from the results in Table 16, the emulsions of
the present invention have low fog, high sensitivity, high .gamma.
value and high contrast.
[0510] On comparison among Samples XI-501 to XI-504, among Samples
XI-505 to XI-508 and among Samples XI-509 to XI-512, it is seen
that as the chemical sensitization temperature is higher according
to the present invention, the fog is lower and the sensitivity and
.gamma. values are higher.
[0511] On comparison of Samples XI-501 to XI-504 with Samples
XI-505 to XI-508, it is seen that in conventional chemical
sensitization, the multilayer adsorption of sensitizing dyes incurs
extreme reduction of the y value, whereas according to the present
invention, high sensitivity and high .gamma. value are
maintained.
[0512] On comparison of Samples XI-505 to XI-508 with Samples
XI-509 to XI-512, it is seen that the abovedescribed effect is more
outstanding in the emulsion subjected to ultrafiltration.
Example XII
[0513] The effect of chemical sensitization at a high temperature
on the emulsion having an epitaxial protrusion of the present
invention is described in greater detail below.
[0514] (Preparation of Emulsion XII-c)
[0515] 1,100 mL of an aqueous solution containing 0.87 g of KBr and
0.95 g of oxidation-treated low molecular weight gelatin having an
average molecular weight of 20,000 was stirred while keeping at
35.degree. C. Thereto, an aqueous AgNO.sub.3 (3.0 g) solution and
an aqueous solution containing KBr (2.1 g) and oxidation-treated
low molecular weight gelatin (28 g) having an average molecular
weight of 20,000 were added over 55 seconds. After adding an
aqueous solution containing 2.6 g of KBr, the temperature was
elevated to 52.degree. C. During this elevation of temperature,
ultrafiltration was performed and thereby, the solution was
concentrated to reduce the volume to a half. The ultrafiltration
module used for the ultrafiltration apparatus was hollow yarn
membrane SLP-1053 (fractional molecular weight: 10,000) produced by
Asahi Chemical Industry Co., Ltd. At this time, the reflux flow
rate was from 3 to 12 liter/min and the permeation flow rate was 56
ml/min.
[0516] An aqueous solution containing 28 g of oxidationtreated
gelatin having an average molecular weight of 100,000 was added and
then, an aqueous solution containing 71 g of sodium catechol
disulfonate was added. Thereafter, as the first growth, an aqueous
AgNO.sub.3 (231.4 g) solution and an aqueous KBr solution were
added by a double jet method while acceleration the flow rate. At
this time, the silver potential was kept at -20 mV to the saturated
calomel electrode. In the course of addition, an aqueous solution
containing potassium hexachloroiridate (0.1 mg) was added. At the
completion of addition of AgNO.sub.3, an aqueous solution
containing sodium benzenethiosulfonate (2 mg) was added.
Thereafter, as the outermost layer growth, an aqueous AgNO.sub.3
solution (34.1 g) and an aqueous KBr solution containing KI were
added over 14 minutes. The concentration of KI was adjusted to give
a silver iodide content of 12 mol %. At this time, the silver
potential was kept at 30 mV to the saturated calomel electrode.
[0517] After lowering the temperature to 40.degree. C., 9.7 ml of
phenoxyethanol was added and further, an aqueous KI (0.47 g)
solution was added. Thereto, Sensitizing Dye VII was added to a
proportion of 20% of the saturated coverage and then, Sensitizing
Dyes VIII, IX and X were added at a molar ratio of 45:40:15 to a
proportion of 60% of the saturated coverage. After adding an
aqueous solution containing potassium hexacyanoruthenate(II) (12.6
mg), AgI ultrafine grains prepared immediately before the addition
were added in an amount of 0.21 g in terms of KI and then, an
aqueous AgNO.sub.3 (12.66 g) solution and an aqueous solution
containing KBr (5.29 g) and NaCl (3.83 g) were added by a double
jet method over 2 minutes and 12 seconds. Thereafter, Epitaxial
Part Shape Stabilizer I (240 mg) was added and then, water washing
by ultrafiltration was performed at 40.degree. C.
[0518] The ultrafiltration module used for the ultrafiltration
apparatus was hollow yarn membrane SLP-1053 (fractional molecular
weight: 10,000) produced by Asahi Chemical Industry Co., Ltd. At
this time, the reflux flow rate was from 3 to 12 liter/min and the
permeation flow rate was 18 ml/min. During the ultrafiltration, the
temperature was kept at 40.degree. C. After adding 31 g of gelatin,
the pH at 40.degree. C. was adjusted to 5.8 and the silver
potential was adjusted to 75 mV to the saturated calomel electrode
using an aqueous NaCl solution.
[0519] (Preparation of Emulsion XII-c-1)
[0520] After adding Epitaxial Part Shape Stabilizer/ Storability
Improver II (6 mg), the temperature was elevated to 50.degree. C
and then, chemical sensitization was optimally performed by adding
1.1.times.10.sup.-4 mol of potassium thiocyanate,
7.15.times.10.sup.-6 Mol of chloroauric acid, 2.47.times.10.sup.-5
mol of sodium thiosulfate and 6.11.times.10.sup.-6 mol of
N,N-dimethylselenourea per mol of silver halide. After 55 minutes
from the addition of sodium thiosulfate, Antifoggant I
(6.1.times.10.sup.-4 mol) was added and the chemical sensitization
was completed by lowering the temperature to 40.degree. C.
Thereafter, Sensitizing Dye VII was added to a proportion of 40% of
the saturated coverage and Sensitizing Dye VIII was added to a
proportion of 60% of the saturated coverage. The light absorption
intensity was 165 and this reveals that multilayer adsorption of
sensitization dyes was achieved.
[0521] The emulsion obtained was tabular grains such that the
average equivalent-circle diameter was 0.75 .mu.m, the coefficient
of variation in the equivalent-circle diameter was 28%, the average
thickness was 0.075 .mu.m and the average aspect ratio was 10.0. In
this emulsion, 90% or more of the entire projected area was
occupied by grains having an epitaxial protrusion at least at one
apex part.
[0522] As seen from FIG. 2, the epitaxial part adheres not only in
the main plane direction of the tabular grain but also by
protruding toward the direction parallel to the main plane.
[0523] (Preparation of Emulsion XII-c-2)
[0524] After adding Epitaxial Part Shape Stabilizer/ Storability
Improver II (6 mg), the temperature was elevated to 72.degree. C.
and then, chemical sensitization was optimally performed by adding
1.1.times.10.sup.-4 mol of potassium thiocyanate,
4.02.times.10.sup.-6 mol of chloroauric acid, 1.24.times.10.sup.-5
mol of sodium thiosulfate and 3.05.times.10.sup.-6 mol of
N,N-dimethylselenourea per mol of silver halide. After 12 minutes
from the addition of sodium thiosulfate, Antifoggant I
(6.1.times.10.sup.-4 mol) was added and the chemical sensitization
was completed by lowering the temperature to 40.degree. C.
Thereafter, Sensitizing Dye VII was added to a proportion of 40% of
the saturated coverage and Sensitizing Dye VIII was added to a
proportion of 60% of the saturated coverage. The light absorption
intensity was 165 and this reveals that multilayer adsorption of
sensitization dyes was achieved.
[0525] The emulsion obtained was tabular grains such that the
average equivalent-circle diameter was 0.75 .mu.m, the coefficient
of variation in the equivalent-circle diameter was 28%, the average
thickness was 0.075 .mu.m and the average aspect ratio was 10.0. In
this emulsion, 80% or more of the entire projected area was
occupied by grains having an epitaxial protrusion at least at one
apex part. As seen from FIG. 3, the epitaxial part mainly adheres
in the main plane direction of the tabular grain and on little
occasion, adheres by protruding toward the direction parallel to
the main plane.
[0526] Emulsions XII-c-1 and XII-c-2 each was coated in the same
manner as in Example XI to prepare Samples XII-601 and XII-602.
These samples were exposed, processed and evaluated on the
photographic properties in the same manner as in Example XI. At
this time, the progress of development was simultaneously evaluated
by changing the color development time. The results are shown in
Table 17.
26TABLE 17 Color Development Tim 1 minute and 15 2 minutes and 45
second second Sensi- Sensi- Sample tivity Fog tivity Fog No.
Emulsion Value Value .gamma. Value Value .gamma. XII-601 XII-c-1
100 0.07 100 142 0.16 146 (Comparison) XII-602 XII-c-2 198 0.07 138
210 0.16 153 (Invention)
[0527] As apparent from Table 17, the emulsion of the present
invention has high sensitivity, high .gamma. value and high
contrast. From the comparison of color development time, it is seen
that the emulsion of the present invention exhibits high
sensitivity and high .gamma. value even when the development time
is short. That is, the emulsion of the present invention can be
very rapidly developed.
Example XIII
[0528] (Preparation of Emulsion XIII-a)
[0529] 845 mL of an aqueous solution containing 0.064 g of
potassium bromide and 1.19 g of oxidation-treated low molecular
weight gelatin having an average molecular weight of 20,000 was
stirred while keeping at 5.degree. C. Thereto, 28.7 mL of an
aqueous silver nitrate (0.36 g) solution and 37.7 mL of an aqueous
solution containing potassium bromide (0.83 g) and
oxidation-treated low molecular weight gelatin (0.136 g) having an
average molecular weight of 20,000 were added over 52 seconds to
perform the nucleation of silver halide grains. Here, the silver
concentration before starting the ripening step was 0.025 mass %.
The temperature was elevated to 75.degree. C. and then, 9 mL of an
aqueous solution containing 0.92 g of potassium bromide was added.
Thereto, 65 mL of an aqueous solution containing 8 g of succinated
gelatin having an average molecular weight of 100,000 was added and
then, 100 mL of an aqueous solution containing 6 g of sodium
catechol disulfonate was added. Subsequently, as the first growth,
silver halide fine grains prepared by adding 427 mL of an aqueous
silver nitrate (12.1 g) solution and an aqueous potassium bromide
solution having an equimolar concentration (containing 3 mol % of
iodide and 15.1 g of oxidation-treated low molecular gelatin having
an average molecular weight of 20,000) to a mixing vessel shown in
FIG. 2 where stirring blades having no rotary shaft protruding
through the wall of a closed stirring tank and connected with
magnetic coupling were rotated in the converse direction, were
continuously added to a reactor. The silver potential was kept at 0
mV to the saturated calomel electrode by separately adding an
aqueous potassium bromide solution. In the fine grains added, the
number average equivalent-circle diameter was 0.015 .mu.m and the
coefficient of variation in the equivalent-circle diameter was 28%.
In the course of growth, 5 mL of an aqueous solution containing
potassium hexachloroiridate (0.1 mg) was added. Thereafter, as the
second growth, silver halide fine grains were prepared by adding
408 mL of an aqueous silver nitrate (49.0 g) solution and an
aqueous potassium bromide solution having an equimolar
concentration (containing 3 mol % of iodide and 30.7 g of
oxidation-treated low molecular weight gelatin having an average
molecular weight of 20,000) to a mixing vessel same as in the first
growth and added to a reactor. The silver potential was kept at 0
mV to the saturated calomel electrode by separately adding a
potassium bromide solution. In the fine grains added, the number
average equivalent-circle diameter was 0.017 .mu.m and the
coefficient of variation in the equivalent-circle diameter was 36%.
Furthermore, as the third growth, the additions were performed
under thoroughly the same conditions as in the second growth.
Thereafter, 50 mL of an aqueous solution containing 7 g of gelatin
was added. This gelatin was obtained by crosslinking an
alkali-treated ossein first extraction gelatin (in the molecular
weight distribution measured by PAGI method, the high molecular
weight component was 2.5% and the low molecular weight component
was 60.0%) starting from cow bone. In the molecular weight
distribution measured by the PAGI method, the high molecular weight
component was 12.4% and the low molecular weight component was
48.3%. After lowering the temperature to 40.degree. C., 3.88 mL of
phenoxyethanol was added and further, 10 mL of an aqueous potassium
iodide (0.11 g) solution was added. Thereto, Sensitizing Dyes IV, V
and VI were added at a molar ratio of 69:30:1 to a proportion of
70% of the saturated coverage. Here, the sensitizing dyes were used
as a solid fine dispersion prepared by the method described in
JP-A-11-52507. More specifically, 0.8 mass parts of sodium nitrate
and 3.2 mass parts of sodium sulfate were dissolved in 43 mass
parts of ion exchanged water and 13 mass parts of the sensitizing
dye was added and dispersed at 60.degree. C. for 20 minutes using a
dissolver blade at 2,000 rpm, thereby obtaining a solid dispersion
of sensitizing dye. After adding 7.5 mL of an aqueous solution
containing potassium hexacyanoruthenate(II) (1.3 mg), 50 mL of an
aqueous silver nitrate (0.35 g) solution and 50 mL of an aqueous
solution containing potassium bromide (1.9 g), potassium iodide
(0.35 g) and sodium chloride (1.53 g) were added by a double jet
method over 2 minutes.
[0530] Thereafter, 6 ml of Epitaxial Part Shape Stabilizer I (40
mg) was added. Subsequently, normal water washing was performed.
Here, the temperature was kept at 35.degree. C. After adding 37.5 g
of the above-described gelatin, the pH at 40.degree. C. was
adjusted to 6.5 and the silver potential was adjusted to 80 mV to
the saturated calomel electrode using an aqueous sodium chloride
solution. After adding Epitaxial Part Shape Stabilizer/Storability
Improver II (3 mg), the temperature was elevated to 68.degree. C.
and then, chemical sensitization was optimally performed by adding
0.7.times.10.sup.-4 mol of potassium thiocyanate,
1.4.times.10.sup.-6 mol of chloroauric acid, 0.5.times.10.sup.-5
mol of sodium thiosulfate and 1.2.times.10.sup.-6 mol of
N,N'-dimethylselenourea per mol of silver halide. Antifoggant I
(8.3.times.10.sup.-4 mol) was added and the chemical sensitization
was completed.
[0531] (Preparation of Emulsion XIII-b)
[0532] 1,691 mL of an aqueous solution containing 0.128 g of
potassium bromide and 2.38 g of oxidation-treated low molecular
weight gelatin having an average molecular weight of 20,000 was
stirred while keeping at 5.degree. C. Thereto, 47.4 mL of an
aqueous silver nitrate (0.71 g) solution and 75.3 mL of an aqueous
solution containing potassium bromide (1.66 g) and
oxidation-treated low molecular weight gelatin (0.272 g) having an
average molecular weight of 20,000 were added over 52 seconds to
perform the nucleation of silver halide grains. Here, the silver
concentration before staring the ripening step was 0.025 mass %.
The temperature was elevated to 75.degree. C. and then, 18 mL of an
aqueous solution containing 1.83 g of potassium bromide was added.
Thereto, 130 mL of an aqueous solution containing 16 g of
succinated gelatin having an average molecular weight of 100,000
was added and then, 200 mL of an aqueous solution containing 12 g
of sodium catechol disulfonate was added. During this elevation of
temperature, ultrafiltration was performed. The ultrafiltration
module used for the ultrafiltration apparatus was hollow yarn
membrane SLP-1053 (fractional molecular weight: 10,000) produced by
Asahi Chemical Industry Co., Ltd. At this time, the reflux flow
rate was 5 liter/min, the supply pressure was 0.03 MPa, the reflux
pressure was 0.01 MPa, the permeation pressure was 0 MPa and the
permeation flow rate was from 40 to 60 ml/min. Subsequently, as the
first growth, silver halide fine grains prepared by adding 854 mL
of an aqueous silver nitrate (24.2 g) solution and an aqueous
potassium bromide solution having an equimolar concentration
(containing 3 mol % of iodide and 15.1 g of oxidation-treated low
molecular gelatin having an average molecular weight of 20,000) to
a mixing vessel shown in FIG. 2 where stirring blades having no
rotary shaft protruding through the wall of a closed stirring tank
and connected with magnetic coupling were rotated in the converse
direction, were continuously added to a reactor. The silver
potential was kept at 0 mV to the saturated calomel electrode by
separately adding a KBr solution. In the fine grains added, the
number average equivalent-circle diameter was 0.015 .mu.m and the
coefficient of variation in the equivalent-circle diameter was 28%.
Together with the first growth, ultrafiltration was performed under
the same conditions as above. In the course of growth, 10 mL of an
aqueous solution containing potassium hexachloroiridate (0.2 mg)
was added. At the completion of addition of the aqueous silver
nitrate solution, 10 mL of an aqueous solution containing sodium
benzenethiosulfonate (2 mg) was added. Thereafter, as the second
growth, silver halide fine grains were prepared by adding 816 mL of
an aqueous silver nitrate (98.0 g) solution and an aqueous
potassium bromide solution having an equimolar concentration
(containing 3 mol % of iodide and 61.3 g of oxidation-treated low
molecular weight gelatin having an average molecular weight of
20,000) to a mixing vessel same as in the first growth and added to
a reactor. The silver potential was kept at 0 mV to the saturated
calomel electrode by separately adding a KBr solution. In the fine
grains added, the number average equivalent-circle diameter was
0.017 .mu.m and the coefficient of variation in the
equivalent-circle diameter was 36%. Together with this second
growth, ultrafiltration was performed. The ultrafiltration
conditions were the same as in the first growth. Furthermore, as
the third growth, the additions were performed thoroughly under the
same conditions as in the second growth and together with the
growth, ultrafiltration was performed under the same conditions as
above. At this time, the liquid volume was 3,500 mL. Thereafter,
100 mL of an aqueous solution containing 14 g of gelatin was added.
This gelatin was obtained by crosslinking an alkali-treated ossein
first extraction gelatin (in the molecular weight distribution
measured by PAGI method, the high molecular weight component was
2.5% and the low molecular weight component was 60.0%) starting
from cow bone. In the molecular weight distribution measured by the
PAGI method, the high molecular weight component was 12.4% and the
low molecular weight component was 48.3%. After lowering the
temperature to 40.degree. C., 7.76 ml of phenoxyethanol was added
and further, 20 ml of an aqueous potassium iodide (0.21 g) solution
was added. Thereto, Sensitizing Dyes Iv, V and VI were added at a
molar ratio of 69:30:1 to a proportion of 70% of the saturated
coverage. Here, the sensitizing dyes were used as a solid fine
dispersion prepared by the method described in JP-A-11-52507. More
specifically, 0.8 mass parts of sodium nitrate and 3.2 mass parts
of sodium sulfate were dissolved in 43 mass parts of ion exchanged
water and 13 mass parts of the sensitizing dye was added and
dispersed at 60.degree. C. for 20 minutes using a dissolver blade
at 2,000 rpm, thereby obtaining a solid dispersion of sensitizing
dye. After adding 15 mL of an aqueous solution containing potassium
hexacyanoruthenate(II) (2.6 mg), 100 mL of an aqueous silver
nitrate (10.1 g) solution and 100 mL of an aqueous solution
containing potassium bromide (3.7 g), potassium iodide (0.7 g) and
sodium chloride (3.06 g) were added by a double jet method over 2
minutes.
[0533] Thereafter, 12 mL of Epitaxial Part Shape Stabilizer I (80
mg) was added. At this time, the liquid volume was 4,180 mL. Then,
normal water washing was performed. At this time, the temperature
was kept at 35.degree. C. After adding 77 g of the above-described
gelatin, the pH at 40.degree. C. was adjusted to 6.5 and the silver
potential was adjusted to 80 mV to the saturated calomel electrode
using an aqueous sodium chloride solution. After adding Epitaxial
Part Shape Stabilizer/Storability Improver II (6 mg), the
temperature was elevated to 68.degree. C. and then, chemical
sensitization was optimally performed by adding 0.7.times.10.sup.-4
mol of potassium thiocyanate, 1.4.times.10.sup.-6 mol of
chloroauric acid, 0.5.times.10.sup.-5 mol of sodium thiosulfate and
1.2.times.10.sup.-6 mol of N,N'-dimethylselenourea per mol of
silver halide. Antifoggant I (8.3.times.10.sup.-4 Mol) was added
and the chemical sensitization was completed.
[0534] (Preparation of Emulsion XIII-c)
[0535] Emulsion XIII-c was prepared in the same manner as Emulsion
XIII-a except that in the nucleation of Emulsion XIII-a, the
amounts of silver nitrate, potassium bromide and oxidation-treated
low molecular weight gelatin were changed to 0.178 g, 0.414 g and
0.032 g, respectively. At this time, the silver concentration
before starting the ripening step was 0.012 mass %.
[0536] (Preparation of Emulsion XIII-d)
[0537] Emulsion XIII-d was prepared in the same manner as Emulsion
XIII-b except that in the nucleation of Emulsion XIII-b, the
amounts of silver nitrate, potassium bromide and oxidation-treated
low molecular weight gelatin were changed to 0.356 g, 0.828 g and
0.136 g, respectively. At this time, the silver concentration
before starting the ripening step was 0.012 mass %.
[0538] (Preparation of Emulsion XIII-e)
[0539] Emulsion XIII-e was prepared in the same manner as Emulsion
XIII-a except that in the nucleation of Emulsion XIII-a, the
amounts of silver nitrate, potassium bromide and oxidation-treated
low molecular weight gelatin were changed to 0.089 g, 0.207 g and
0.016 g, respectively. At this time, the silver concentration
before starting the ripening step was 0.0062 mass %.
[0540] (Preparation of Emulsion XIII-f)
[0541] Emulsion XIII-f was prepared in the same manner as Emulsion
XIII-b except that in the nucleation of Emulsion XIII-b, the
amounts of silver nitrate, potassium bromide and oxidation-treated
low molecular weight gelatin were changed to 0.178 g, 0.414 g and
0.068 g, respectively. At this time, the silver concentration
before starting the ripening step was 0.0062 mass %.
[0542] (Preparation of Emulsion XIII-g)
[0543] Emulsion XIII-g was prepared in the same manner as Emulsion
XIII-a except that in the nucleation of Emulsion XIII-a, the
amounts of silver nitrate, potassium bromide and oxidation-treated
low molecular weight gelatin were changed to 0.044 g, 0.104 g and
0.017 g, respectively. At this time, the silver concentration
before starting the ripening step was 0.0012 mass %.
[0544] (Preparation of Emulsion XIII-h)
[0545] Emulsion XIII-h was prepared in the same manner as Emulsion
XIII-b except that in the nucleation of Emulsion XIII-b, the
amounts of silver nitrate, potassium bromide and oxidation-treated
low molecular weight gelatin were changed to 0.089 g, 0.207 g and
0.016 g, respectively. At this time, the silver concentration
before starting the ripening step was 0.0012 mass %.
[0546] Data regarding the grain size of Emulsions XIII-a to XIII-h
are shown in Table 18. In the table, the nonparallel twin ratio is
a ratio of non-parallel twin grains to the number of all silver
halide grains and a value expressed by a percentage.
27TABLE 18 Silver Average Coefficient of Concentration Equivalent-
Variation in Coefficient Non- Before Starting Circle Equivalent-
Average of Variation Parallel Ripening Step Diameter Circle
Thickness in Thickness Twin Ratio Emulsion (mass %) (.mu.m)
Diameter (%) (.mu.M) (%) (%) XIII-a 0.025 5.3 32 0.093 29 25
Comparison XIII-b 0.025 5.4 31 0.082 26 23 " XIII-c 0.012 5.5 28
0.048 22 19 Invention XIII-d 0.012 5.4 28 0.048 21 18 " XIII-e
0.0062 5.8 29 0.048 23 18 " XIII-f 0.0062 5.7 29 0.047 21 19 "
XIII-g 0.0012 6.4 38 0.088 29 24 Comparison XIII-h 0.0012 6.7 36
0.078 28 23 "
[0547] As apparent from the results in Table 18, when the silver
concentration before starting the ripening step is within the range
of the present invention, a tabular grain emulsion having a small
grain thickness, being monodisperse and reduced in non-parallel
twin grains can be prepared.
[0548] In Emulsions XIII-a to XIII-h, 90% or more of the entire
projected area was occupied by hexagonal tabular grains where the
ratio of the length of a side having a maximum length to the length
of a side having a minimum length was 1.5 or less and an epitaxial
junction was present at all of six apex parts. The emulsions were
observed by a transmission electron microscope at a low
temperature, as a result, 90% or more of the entire projected area
was occupied by grains having no dislocation line in the main plane
part except for the epitaxial part and having network dislocation
lines in the epitaxial part. In this grain, the outermost layer
having a silver iodide content of 12% occupied 12% in terms of
silver. The epitaxial part occupied 4.5% in terms of silver and had
a composition of AgBr(52)Cl(40)I(8). Furthermore, 90% or more of
the entire projected area was within 30% of the average silver
chloride content and 30% of the average silver iodide content.
[0549] On a cellulose triacetate film support having provided
thereon a subbing layer, chemically sensitized emulsions prepared
above each was coated under the coating conditions shown in Table 2
and a protective layer was provided, thereby obtaining Samples
XIII-801 and XIII-808.
[0550] These samples each was left standing under the conditions of
40.degree. C. and a relative humidity of 70% for 14 hours, then
exposed for {fraction (1/100)} second through Gelatin Filter SC-50
produced by Fuji Photo Film Co., Ltd. and a continuous wedge and
processed in the same manner as in Example II.
[0551] The processed samples were measured on the density by a
green filter. Also, samples stored under the conditions of
50.degree. C. and a relative humidity of 60% for 14 days before the
exposure were measured in the same manner and evaluated on the
storability.
[0552] The sensitivity value at a density of fog+0.2 and the fog
value obtained are shown in Table 19.
28 TABLE 19 Sample No. Emulsion Fog Sensitivity XIII-801 XIII-a
0.28 100 Comparison XIII-802 XIII-b 0.27 105 " XIII-803 XIII-c 0.15
180 Invention XIII-804 XIII-d 0.14 193 " XIII-805 XIII-e 0.16 182 "
XIII-806 XIII-f 0.14 190 " XIII-807 XIII-g 0.25 110 Comparison
XIII-808 XIII-h 0.26 102 "
[0553] As apparent from the results in Table 19, the silver halide
emulsion produced by the production process of the present
invention has low fog and high sensitivity.
Example XIV
[0554] This Examples is performed to verify the effect of the
emulsion produced by the production process of the present
invention in a multilayer color photographic lightsensitive
material.
[0555] Samples XIV-901 to XIV-908 were prepared in the same manner
as in Example VI except that Emulsion V-a of the sixth layer was
changed to Em-J and Emulsion Em-K of the fourth layer was changed
to Emulsions VIII-a to VIII-h, respectively.
[0556] These samples were subjected to a hardening treatment under
the conditions of 40.degree. C. and a relative humidity of 70% for
14 hours, and then exposed and processed in the same manner as in
Example VI.
[0557] The results are shown in Table 20.
29 TABLE 20 Sample No. Emulsion Fog Sensitivity XIV-901 XIV-a 0.28
100 XIV-902 XIV-b 0.27 105 XIV-903 XIV-c 0.15 180 XIV-904 XIV-d
0.14 193 XIV-905 XIV-e 0.16 182 XIV-906 XIV-f 0.14 190 XIV-907
XIV-g 0.25 110 XIV-908 XIV-h 0.26 102
[0558] As apparent from Table 15, a light-sensitive material having
low fog and high sensitivity can be obtained by using the emulsion
produced according to the process of the present invention.
Example XV
[0559] (Preparation of Emulsion XV-a)
[0560] Emulsion XV-a was prepared in the same manner as Emulsion
XIII-a of Example XIII except that the nucleation temperature was
changed to 35.degree. C. and the amounts of silver nitrate,
potassium bromide and oxidation-treated low molecular weight
gelatin at the nucleation were changed to 0.089 g, 0.207 g and
0.034 g, respectively.
[0561] (Preparation of Emulsion XV-b)
[0562] Emulsion XV-b was prepared in the same manner as Emulsion
XIII-b of Example XIII except that the nucleation temperature was
changed to 35.degree. C. and the amounts of silver nitrate,
potassium bromide and oxidation-treated low molecular weight
gelatin at the nucleation were changed to 0.178 g, 0.414 g and
0.068 g, respectively.
[0563] (Preparation of Emulsions XV-c to XV-l)
[0564] Emulsions XV-c to XV-l were prepared in the same manner as
Emulsions XV-a and XV-b by changing the nucleation temperature and
the amount of silver nitrate, potassium bromide and
oxidation-treated low molecular. weight gelatin at the nucleation
to give the conditions shown in Table 21 below.
[0565] The shapes of grains are shown together in Table 21.
30TABLE 21 Coefficient of Average Average Variation in Silver
Tabular Grain Equivalent- Equivalent- Nucleation Concentration
Thickness Circle Circle Diameter Temperature at Nucleation Emulsion
(.mu.m) Diameter (.mu.m) (%) (.degree. C.) Step (mass %)
Ultrafiltration XV-a 0.057 4.9 36 35 0.0062 none XV-b 0.055 4.9 34
35 0.0062 done XV-c 0.115 4.4 35 35 0.062 none XV-d 0.113 4.3 34 35
0.062 done XV-e 0.050 5.5 33 10 0.0062 none XV-f 0.049 5.6 32 10
0.0062 done XV-g 0.109 4.8 34 10 0.062 none XV-h 0.107 4.7 33 10
0.062 done XV-I 0.048 5.8 29 5 0.0062 none XV-j 0.047 5.7 29 5
0.0062 done XV-k 0.094 5.2 32 5 0.062 none XV-l 0.086 5.3 31 5
0.062 done
[0566] As apparent from the results in Table 21, when the
nucleation temperature is lowered, the average tabular grain
thickness decreases and at the same time, the coefficient of
variation in the equivalent-circle diameter decreases. Furthermore,
when the silver halide concentration in the nucleation and ripening
steps, silver halide grains reduced not only in the average tabular
grain thickness but also in the coefficient of variation in the
equivalent-circle diameter are obtained.
[0567] In Emulsions XV-a to XV-l, 90% or more of the entire
projected area was occupied by hexagonal tabular grains where the
ratio of the length of a side having a maximum length to the length
of a side having a minimum length was 1.5 or less and an epitaxial
junction was present at all of six apex parts. The emulsions were
observed by a transmission electron microscope at a low
temperature, as a result, 90% or more of the entire projected area
was occupied by grains having no dislocation line in the main plane
part except for the epitaxial part and having network dislocation
lines in the epitaxial part. In the grains, the outermost layer
having a silver iodide content of 12% occupied 12% in terms of
silver. The epitaxial part occupied 4.5% in terms of silver and had
a composition of AgBr(52)Cl(40)I(8). Furthermore, 90% or more of
the entire projected area was within 30% of the average silver
chloride content and 30% of the average silver iodide content.
[0568] On a cellulose triacetate film support having provided
thereon a subbing layer, these emulsions which were subjected to
chemical sensitization in the same manner as in Example XIII each
was coated and a protective layer was provided, thereby obtaining
Samples XV-801 to XV-812 (see, Table 22 below).
[0569] Each processed sample was measured on the density by a green
filter.
31 TABLE 22 Sample No. Emulsion Fog Sensitivity XV-801 XV-a 0.23
100 XV-802 XV-b 0.24 105 XV-803 XV-c 0.25 84 XV-804 XV-d 0.25 88
XV-805 XV-e 0.24 115 XV-806 XV-f 0.23 118 XV-807 XV-g 0.23 94
XV-808 XV-h 0.24 96 XV-809 XV-i 0.18 132 XV-810 XV-j 0.17 137
XV-811 XV-k 0.22 102 XV-812 XV-l 0.22 105
[0570] The sensitivity is the sensitivity at a density of fog+0.2
and shown as a relative value to Sample XV-801 of which sensitivity
is taken as 100.
[0571] As apparent from the results in Table 22, when the
nucleation temperature is lowered, the sensitivity/fog ratio is
improved. Furthermore, by reducing the silver halide concentration
in the nucleation and ripening steps, higher effects are
obtained.
Example XVI
[0572] This Examples is performed to verify the effect of the
emulsion produced by the production process of the present
invention in a multilayer color photographic lightsensitive
material.
[0573] Samples XVI-901 to XVI-912 were prepared in the same manner
as in Example VI except that Emulsion V-a prepared in Example V of
the sixth layer was changed to Emulsion Em-J and Emulsion Em-K of
the fourth layer was changed to Emulsions XV-a to XV-l,
respectively.
32 TABLE 23 Sample No. Emulsion Fog Sensitivity XV-901 XV-a 0.25
100 XV-902 XV-b 0.24 103 XV-903 XV-c 0.27 91 XV-904 XV-d 0.26 92
XV-905 XV-e 0.23 111 XV-906 XV-f 0.25 108 XV-907 XV-g 0.24 92
XV-908 XV-h 0.25 94 XV-909 XV-i 0.19 123 XV-910 XV-j 0.18 125
XV-911 XV-k 0.23 98 XV-912 XV-l 0.24 100
[0574] As apparent from the results in Table 23, a lightsensitive
material having low fog and high sensitivity can be obtained by
using the silver halide emulsion produced according to the
production process of the present invention.
[0575] While the invention has been described in detail and with
reference to specific embodiments thereof, it will be apparent to
one skilled in the art that various changes and modifications can
be made therein without departing from the spirit and scope
thereof.
* * * * *