U.S. patent application number 10/895233 was filed with the patent office on 2005-01-27 for manufacturing method of a tray container, and the tray container itself.
This patent application is currently assigned to Konica Minolta Medical & Graphic, Inc.. Invention is credited to Goi, Katsunori.
Application Number | 20050016889 10/895233 |
Document ID | / |
Family ID | 33487660 |
Filed Date | 2005-01-27 |
United States Patent
Application |
20050016889 |
Kind Code |
A1 |
Goi, Katsunori |
January 27, 2005 |
Manufacturing method of a tray container, and the tray container
itself
Abstract
A manufacturing method of a tray container for housing a
plurality of photothermographic material sheets, comprising a step
of: pressing and heating a paperboard, using dies to produce the
tray container, wherein temperature of the dies is greater than
180.degree. C., and pressing force is 180-230 kgf/cm.sup.2 (18-23
Mpa).
Inventors: |
Goi, Katsunori; (Kanagawa,
JP) |
Correspondence
Address: |
MUSERLIAN, LUCAS AND MERCANTI, LLP
475 PARK AVENUE SOUTH
15TH FLOOR
NEW YORK
NY
10016
US
|
Assignee: |
Konica Minolta Medical &
Graphic, Inc.
Tokyo
JP
|
Family ID: |
33487660 |
Appl. No.: |
10/895233 |
Filed: |
July 19, 2004 |
Current U.S.
Class: |
206/455 ;
206/524.1 |
Current CPC
Class: |
B31B 50/592 20180501;
G03C 1/498 20130101; G03C 3/00 20130101 |
Class at
Publication: |
206/455 ;
206/524.1 |
International
Class: |
B65D 085/84 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 25, 2003 |
JP |
JP2003-201503 |
Claims
What is claimed is:
1. A manufacturing method of a tray container for housing a
plurality of photothermographic material sheets, comprising a step
of: pressing and heating a paperboard, with dies to produce the
tray container, wherein temperature of the dies is greater than
180.degree. C., and pressing force is 180-230 kgf/cm.sup.2 (18-23
Mpa).
2. The manufacturing method of the tray container in claim 1,
wherein moisture content of the tray container after pressing is
less than 3.0 wt %.
3. The manufacturing method of the tray container in claim 1,
wherein a material for the tray container is selected from among
coated cardboard, corrugated fiberboard and synthetic paper.
4. A tray container for housing a plurality of photothermographic
material sheets, wherein the tray container is manufactured of
paperboard with the dies by pressing and heating, and wherein
temperature of the dies is greater than 180.degree. C., and
pressing force is 180-230 kgf/cm.sup.2 (18-23 Mpa).
5. The tray container for housing a plurality of photothermographic
material sheets in claim 4, wherein moisture content of the tray
container after pressing is less than 3.0 wt %.
6. The tray container for housing a plurality of photothermographic
material sheets in claim 4, wherein a material of the tray
container is selected from among coated cardboard, corrugated
fiberboard and synthetic paper.
7. The tray container for housing a plurality of photothermographic
material sheets in claim 4, comprising: a base on which the
photothermographic material sheets are stacked; and a short wall
centered on each of the four sides of the base, integral and
perpendicular to the base.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a manufacturing method of a
tray for containing a plurality of photothermographic materials,
and to the tray container itself.
[0002] In the medical and printing/plate making fields, waste
solution generated by the wet process of image forming materials is
a very cumbersome problem, and in recent years, reduction of the
processing waste solution has become an increasingly greater goal.
This has led to technology of photothermographic materials wherein
effective exposure can be performed by a laser imager and a laser
image setter, and wherein black images with high resolution and
high sharpness can be produced.
[0003] Regarding this technology, well known are methods described
in U.S. Pat. Nos. 3,152,904, 3,487,075, and "Dry Silver
Photographic Materials" on page 48 of The Handbook of Imaging
Materials, Marcel Dekker, Inc. 1991. Since these imaging materials
are developed at high temperature, greater than 80.degree. C., they
are called photothermographic materials. Processing chemicals of
the traditional liquid type are not used at all for these
photothermographic materials, and therefore it is possible to
provide a system which is very simple and does not deteriorate the
natural environment.
[0004] End-products of these photothermographic materials are
packaged and marketed in a light-proof bag. The bag, packaging the
photothermographic materials, is called the packing bag, and
condition under which the photothermographic materials is placed in
the packing bag is called photothermographic materials package, in
which the photothermographic materials is contained in a tray
container within the packing bag.
[0005] Material of the resin sheet container for the
photothermographic material is disclosed in Patent Documents 1 and
2, tray container containing the resin sheets is disclosed in
Patent Documents 3-6, and a tray container containing a humidity
controlling material is disclosed in Patent Document 7.
[0006] Patent Document 1: Japanese Tokkai 2000-89416
[0007] Patent Document 2: Japanese Patent 31460006
[0008] Patent Document 3: Japanese Tokkai 2002-31875
[0009] Patent Document 4: Japanese Jitukaihei 6-41246
[0010] Patent Document 5: Japanese Tokkaihei 6-87139
[0011] Patent Document 6: Japanese Tokkai 2002-62625
[0012] Patent Document 7: Japanese Tokkaihei 9-290937
[0013] In regard to the material for the resin sheet container
carrying the photothermographic materials, as disclosed in Patents
Documents 1 and 2, employed is a method in which a molded resin
tray container is employed, in which the photothermographic
materials are carried, which is covered with a plastic film
employing an adhesive agent. This method assuredly protects the
photothermographic materials, however, after use, the hard resin
tray container, which is very voluminous, is not easily scrapped.
Still further, since the resin sheet is adhered to the tray
container which is based on a paper material, it is not practical
to dispose of it for separated trash collection, because
incompatible materials, namely paper and plastic, remain after use.
Still further in a method wherein the above humidity controlling
material is attached to the tray container, as disclosed in Patent
Document 8, though the humidity controlling material is attached to
the tray to control the humidity of the photographic material, the
humidity controlling material is rather costly, which drives up the
production cost.
SUMMARY OF THE INVENTION
[0014] The present invention was achieved with a view of overcoming
these problems, and the objective of the present invention is to
provide a manufacturing method of a tray container and the tray
container itself, by which performance degradation (about
photographic fog and sensitivity) of photothermographic materials
is controlled, and which can be discarded without bothering about
separation of the used tray container into burnable and unburnable
trash, and which can be produced inexpensively compared to
conventional methods.
[0015] In order to solve the above problems and thereby attain the
objective, the invention is structured as below.
[0016] Structure 1
[0017] A manufacturing method of a tray container for housing a
plurality of photothermographic material sheets, including a step
of pressing and heating a paperboard, with dies to produce the tray
container, wherein temperature of the dies is greater than
180.degree. C., and pressing force is 180-230 kgf/cm.sup.2 (18-23
Mpa).
[0018] Based on structure 1, the tray container is manufactured of
the paperboard in the dies by pressing and heating, and if
stipulated pressing condition of the tray container is met,
pressing is achieved under high temperature and high pressure,
whereby moisture and impurities included in the paperboard are
evaporated during the pressing process, and thereby, any adverse
influence to the photothermographic materials is minimized, without
adhering a resin sheet onto contact areas between the tray
container and the photothermographic materials. Further, since
moisture content can be controlled to a certain amount without
adhering a humidity control material onto the tray container, it is
possible to minimize the performance degradation (about
photographic fog and sensitivity) of the photothermographic
materials. Still further, it is possible to discard the tray
container, without bothering about separation of the components of
the used tray container into burnable and unburnable trash. Still
further, since the tray container is less bulky than the prior art,
it is an effective way to reduce waste products. Still further the
tray container can be produced inexpensively compared to the
conventional methods.
[0019] Structure 2
[0020] The manufacturing method of the tray container of structure
1, wherein the moisture content of the tray container after
pressing is less than 3.0 wt %.
[0021] Based on structure 2, by specifying the moisture content, it
is possible to reduce impurities (being primarily formalin and
hydrochloric acid-vinyl acetate copolymers) to a maximum of 100
ppm, whereby it is possible to improve the performance (fog level)
of the photothermographic material.
[0022] Structure 3
[0023] The manufacturing method of the tray container of structure
1 or 2, wherein the material of the tray container is selected from
among coated cardboard, corrugated fiberboard and synthetic
paper.
[0024] Based on structure 3, material of the tray container is
selected from among coated cardboard, corrugated fiberboard and
synthetic paper, whereby the user can readily discard the used tray
container, without bothering about separation of the used tray
container into burnable and/or unburnable trash.
[0025] Structure 4
[0026] A tray container for storing plural photothermographic
materials, wherein the tray container is manufactured of a
paperboard with dies by pressing and heating, and wherein a
pressing condition is that temperature of the dies is greater than
180.degree. C., and the pressing force is 180-230 kgf/cm.sup.2
(18-230 Mpa).
[0027] Based on structure 4, the tray container is manufactured of
the paperboard with dies by pressing and heating, and moisture and
impurities included in the paperboard are evaporated during the
pressing, and thereby, the influence to the photothermographic
materials can be controlled without attaching a resin sheet at
contact areas between the tray container and the photothermographic
materials. Further, since moisture content can be controlled under
a specified amount without attaching the humidity control material
to the tray container, it is possible to control performance
degradation (about photographic fog and sensitivity) of the
photothermographic materials. Still further, it is easier to
discard the tray container, without bothering about separation of
the used tray container into burnable and unburnable trash. Still
further, since the tray container is reduced in volume and
discarded, which is effective in the reduction of waste products.
Still further the tray container can be produced inexpensively
compared to conventional methods.
[0028] Structure 5
[0029] The tray container of structure 4, wherein the moisture
content of the tray container after pressing is less than 3.0 wt
%.
[0030] Based on structure 5, by specifying the moisture content, it
is possible to reduce impurities (being mainly formalin and
hydrochloric acid-vinyl acetate copolymers) to a maximum of 100
ppm, whereby it is possible to improve the performance (fog level)
of the photothermographic material.
[0031] Structure 6
[0032] The tray container of structure 4 or 5, wherein material of
the tray container is selected from among coated cardboard,
corrugated fiberboard and synthetic paper.
[0033] Based on structure 6, wherein material of the tray container
is selected from among coated cardboard, corrugated fiberboard and
synthetic paper, therefore, the user can more readily discard the
used tray container, without bothering about separation of the used
tray container into burnable and unburnable trash.
[0034] Structure 7
[0035] The tray container of structures 4-6, including a base on
which the photothermographic material sheets are stacked, and a
short wall centered on each of the four sides of the base, integral
and perpendicular to the base.
[0036] Based on structure 7, the tray container protects and
supports the stacked photothermographic material sheets.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] FIG. 1 shows an example for manufacturing the
photothermographic material package.
[0038] FIG. 2 shows a manufacturing method of the tray container,
in which FIG. 2(a) shows placing of a paperboard, FIG. 2(b) shows
clamping of the paperboard, and FIG. 2(c) shows the shaped
product.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0039] The embodiment of the manufacturing method of the tray
container and the embodiment of the tray container itself of the
present invention will now be explained. The invention is not
limited to the present invention. Further the present embodiment
shows the most preferable example, and the meaning of the
vocabulary relating to the present invention is not limited
thereto.
[0040] FIG. 1 shows an example for manufacturing the packaged
photothermographic materials of the present invention, where
numeral 1 shows plural stacked sheets of photothermographic
materials, and numeral 2 shows a tray container to align and
protect the plural stacked sheets of photothermographic materials.
Plural stacked sheets of photothermographic materials 1 are placed
on base 5 of tray container 2 and stored in package bag 3, which
makes up packaged photothermographic materials 4.
[0041] Tray container 2 has four short walls 2a-2d and base 5 to
align and protect stacked photothermographic materials 1. Tray
container 2 protects the four side surfaces as well as the bottom
surface of stacked photothermographic materials 1, and contains
stacked photothermographic materials 1, secured by the surrounding
four short walls 2a-2d.
[0042] Tray container 2 which houses a plurality of
photothermographic materials 1 is produced in such a manner that
paperboard 10 is subjected to pressing and heating by employing
dies 11, shown in FIG. 2. Dies 11 are composed of female die 11a
and male die 11b. Paperboard 10 is placed between heated female die
11a and male die 11b (see FIG. 2(a)), after which paperboard 10 is
clamped between female die 11a and male die 11b (see FIG. 2(b)),
and then paperboard 10 is released from female die 11a and male die
11b, resulting in pressed tray container 2.
[0043] The pressing condition for shaping this tray container 2 is
that the temperature of dies 11 is greater than 180.degree. C., and
the clamping pressure of die 11 is 180-230 kgf/cm.sup.2 (18-23
Mpa). Basically, female die 11a and male die 11b are heated with
the same temperature, however a temperature difference of
.+-.10.degree. C. is acceptable during pressing. Further
pre-hardened steel is generally used for creating die 11. Still
further, regarding the press machine for clamping dies 11,
preferably used is one with power of 350-1,000 kgf/cm.sup.2.
[0044] The material of tray container 2 is selected from among
coated cardboard, corrugated fiberboard and synthetic paper,
therefore, the user can discard the used tray container, without
bothering about separation of the used tray container 2 to a
burnable and unburnable trash.
[0045] Regarding paperboard 10, preferably used are waste paper or
recycled paper such as coated cardboard or manila paperboard in
which both surfaces are coated with virgin pulp, and further is
fiberboard in which corrugated paperboards is adhered by a flute or
liner. Further, synthetic paper (paper in which PE resin is
impregnated to less than 20%) is used, in order to improve
shapability.
[0046] Since tray container 2 is manufactured of paperboard 10 with
dies 11 by pressing and heating, and further the pressing condition
for tray container 2 is such that the temperature of the dies 11 is
greater than 180.degree. C., and the pressing force is 180-230
kgf/cm.sup.2 (18-23 Mpa), whereby paperboard 10 is shaped into a
pressed piece, which is not deformed and keeps its fixed form.
Further, since moisture and impurities included in paperboard 10
are evaporated during the pressing process, any adverse influence
upon photothermographic materials 1 is controlled, without adhering
the resin sheet on contact areas between tray container 2 and
photothermographic materials 1.
[0047] Still further, since moisture content can be controlled to a
certain amount without adhering a humidity control material in tray
container 2, it is possible to minimize the performance degradation
(about photographic fog and sensitivity) of photothermographic
materials 1. Yet further, it is possible to discard the tray
container, without bothering about separation of used tray
container 2 into burnable and unburnable trash. In addition, since
tray container 2 is reduced in volume and then discarded, it is
effective in reducing waste. Also tray container 2 can be produced
inexpensively compared to the conventional method.
[0048] Since the moisture content of the tray container after the
pressing is less than 3.0 wt %, and by specifying the moisture
amount, it is possible to reduce impurities (being mainly formalin
and hydrochloric acid-vinyl acetate copolymers) to less than 100
ppm, whereby it is possible to improve the performance (fog level)
of the photothermographic material.
[0049] For package bag 3, used is a bag with light shielding and
damp-proofing characteristics. Package bag 3 can be formed of any
materials which have such light shielding and damp-proofing
characteristics, or any materials to which the light shielding and
damp-proofing characteristics can be provided. Regarding materials
having such damp-proofing characteristic, preferably employed is a
laminated sheet wherein a polyethylene film is positioned on the
interior surface. In order to provide the light shielding
characteristic, carbon black is included in any layer of the above
laminated sheet, or aluminum foil is placed on the surface thereof,
or aluminum is vacuum-evaporated onto the surface of the laminated
sheet.
[0050] Photothermographic materials to which this invention is
applied will now be described.
[0051] It is preferable that photothermographic materials of this
invention are formed in such a manner that a photographic
constitution layer comprising organic silver salts, photosensitive
silver halide, and silver ion reducing agents is formed on a
support employing solvent coating, and comprises at least one
protective layer on the aforesaid photographic composition layer.
Further a so-called single-sided photosensitive material is
preferred which comprises a backing layer on the side opposite the
support.
[0052] In addition, a preferred embodiment is that the photographic
constitution layer of photothermographic materials is comprised of
a photosensitive layer and a non-photosensitive layer, in which the
photosensitive layer incorporates organic silver salts as well as
photosensitive silver halide grains, while the non-photosensitive
layer incorporates reducing agents.
[0053] (Photosensitive Silver Halide) Silver halide grains function
as a photo-sensor. In this invention, in order to reduce white
turbidity after forming images and to achieve higher image quality,
the average grain diameter is preferably quite small, being at most
0.20 .mu.m, more preferably 0.02-0.15 .mu.m, and still more
preferably 0.03-0.1 .mu.m.
[0054] Average grain diameter, as described herein, refers to the
edge length of a silver halide grain when it is in the form of
normal crystals such as a cube or octahedron. On the other hand,
when they are not in such normal crystals, for example, in the case
of spherical, rod-shaped, or tabular grains, the diameter refers to
one of the sphere which has the same volume as each of those.
[0055] Further, it is preferable that silver halide grains are
monodipsersed grains. Monodipsersed grains, as described herein,
refer to those in which the degree of monodispersion, determined by
the formula below, is preferably a maximum of 40 percent, more
preferably a maximum of 30 percent, and most preferably a maximum
of 20 percent.
Degree of monodispersion=(standard deviation of grain
diameter)/(average value of grain diameter).times.100
[0056] The shape of silver halide grains is not particularly
limited. However, it is preferable that the ratio of the plane
occupied by a Miller index [100] plane is high. The aforesaid ratio
is preferably a minimum of 50 percent, is more preferably a minimum
of 70 percent, and is most preferably a minimum of 80 percent. It
is possible to determine the ratio of the Miller index [100] plane,
based on T. Tani, J. Imaging Sci., 29, 165 (1985), in which the
ratio is determined utilizing adsorption dependency onto a [111]
plane and a [100] plane during adsorption of sensitizing dyes.
[0057] The average grain diameter of the aforesaid monodipsersed
grains is preferably a maximum of 0.1 .mu.m, is more preferably
0.01-0.1 .mu.m, and is most preferably 0.02-0.08 .mu.m.
[0058] Another preferred silver halide grain is a tabular grain.
Tabular grains, as described herein, refer to those at an aspect
ratio (being r/h) of at least 3, wherein r (in .mu.m) represents a
grain diameter which is the square root of the projected area of
the grain and h (also in .mu.m) represents the thickness in the
vertical direction. Of these, grains at an aspect ratio of 3-50 are
preferred.
[0059] The diameter of tabular grains is preferably a maximum of
0.1 .mu.m, but is more preferably 0.01-0.08 .mu.m. These grains are
described in U.S. Pat. Nos. 5,264,337, 5,314,798, and 5,320,958,
whereby it is possible to readily prepare targeted tabular
grains.
[0060] In silver halides, halogens are not particularly limited,
and any of silver chloride, silver chlorobromide, silver
chloroiodobromide, silver bromide, silver iodobromide and silver
iodide may be employed. Of these, silver bromide, silver iodide, or
silver iodobromide is preferred, while silver bromide or silver
iodobromide is more preferred, but silver iodobromide is most
preferred. The content of silver iodide is preferably 0.1-40 mol
percent, and is more preferably 0.1-10 mol percent. The
distribution of halogen concentration in a grain may be uniform, or
may vary stepwise. Alternatively, grains may be employed in which
the halogen concentration continuously varies. A preferred
embodiment is that silver halide grains are employed which have a
core/shell structure having a high silver iodide content ratio in
the interior of the grain.
[0061] Photographic emulsions employed in this invention can be
prepared employing the methods described in P. Glafkides, Chimie et
Physique Photographique (published by Paul Montel Co., 1967), G. F.
Duffin, Photographic Emulsion Chemistry (published by The Focal
Press, 1966), and V. L. Zelikman, et al., Making and Coating
Photographic Emulsion (published by The Focal Press, 1964). Namely,
any of an acid method, a neutral method, or an ammonia method may
be employed. Further, when silver halide is formed by allowing
soluble silver salts to react with soluble halides, a single-jet
mixing method, a double-jet mixing method and combinations of these
may be employed.
[0062] The above-mentioned silver halide may be incorporated into
an image forming layer employing any of those methods. At that
time, silver halide is arranged to be in the vicinity of reducible
silver sources.
[0063] Further, silver halide may be prepared by converting some or
all silver of organic acid silver salts, via a reaction of the
organic acid silver salts, with halogen ions. Alternatively, silver
halide may be prepared in such a manner that silver halide is
prepared in advance, and the resulting silver halide is added to a
solution for preparing organic silver salts.
[0064] It is preferable that the content of silver halide are
commonly 0.75-30 percent by weight with respect to the organic
silver salts.
[0065] It is preferable that silver halide employed in this
invention comprises ions or complex ions of metals which belong to
Groups VIB, VIIB, VIII, and IB in the periodic table which include
transition metals. Preferred as the above metals are Cr and W (both
in Group VIB); Re (in Group VIIB); Fe, Co, Ni, Ru, Rh, Pd, Os, Ir,
and Pt (all in Group VIII); and Cu and Au (both in Group IB). Of
these, when employed in printing and plate-making photosensitive
materials, it is preferable that the metals are selected from Rh,
Re, Ru, IR, or Os.
[0066] It is possible to introduce these metals into silver halide
in the form of complexes. In this invention, it is preferable that
transition metal complexes are the six-coordinate complexes,
represented by the general formula below.
General Formula [ML.sub.6]m
[0067] wherein M represents a transition metal selected from Groups
VIB, VIIB, VIII, or IB, L represents a crosslinking ligand, and m
represents 0, -1, -2, or -3.
[0068] Listed as specific examples of the ligand represented by L
are halides (fluorides, chlorides, bromides, and iodides) and
cyanates; each ligand of cyanato, thiocyanato, selenocyanato,
tellurocyanato, azide, and aquo; nitrosyl and thionitrosyl. Of
these preferred are aquo, as well as nitrosyl, and thionitrosyl. In
the case of the presence of an aquo ligand, it is preferable that
one or two ligands are occupied. L may be the same or
different.
[0069] Particularly preferred specific examples of M include
rhodium (Rh), ruthenium (Ru), rhenium (Re), and osmium (Os).
[0070] Specific examples of transition metal coordinated complexes
are listed below.
[0071] 1: [RhCl.sub.6].sup.3- 2: [RuCl.sub.6].sup.3- 3:
[ReCl.sub.6].sup.3- 4: [RuBr.sub.6].sup.3- 5: [OsCl.sub.6].sup.3-
6: [CrCl.sub.6].sup.4- 7: Ru(NO)Cl.sub.5).sup.2- 8:
[RuBr.sub.4(H.sub.2O)].s- up.2- 9: [Ru(NO)
(H.sub.2O)Cl.sub.4].sup.- 10: [RhCl.sub.5(H.sub.2O)].sup.- 2- 11:
[Re(NO)Cl.sub.5].sup.2- 12: [Re(NO.sub.9CN.sub.5)].sup.2- 13:
[Re(NO)ClCN.sub.4].sup.2- 14: [Rh(NO).sub.2Cl.sub.4].sup.- 15:
[Rh(NO) (H.sub.2O)Cl.sub.4].sup.- 16: [Ru(NO)CN5].sup.2- 17:
[Fe(CN)6].sup.3 - 18: [Rh(NSD)Cl.sub.5].sup.2- 19:
[Os(NO)Cl.sub.5].sup.2- 20: [CrNOCl.sub.5].sup.2- 21:
[RE(NO)Cl.sub.5].sup.-2 22: [OS(NS)Cl.sub.4(SeCN).sup.2- 23:
[Ru(NS)Cl.sub.5].sup.2- 24: [Re(NS)Cl.sub.4(SeCN).sup.2- 25:
[Os(NS)Cl(SCN).sub.4].sup.2- and 26: (Ir(NO)Cl.sub.5].sup.2-. These
metal ions or complex ions may be employed individually or in
combinations of at least two of the same kind or different kinds of
metals.
[0072] The content of these ions or complex ions is commonly
1.times.10.sup.-9-1.times.10.sup.-2 mol per mol of sliver halide,
and is preferably 1.times.10.sup.18-10.sup.-4 mol.
[0073] It is preferable that compounds, which provide these metal
ions or complex ions, are added during formation of silver halide
grains and thereby are incorporated into the silver halide grain.
These may be added during any preparation stage of silver halide
grains such as nuclei formation, growth, physical ripening, and
prior to or after chemical ripening. However, addition is
preferably carried out especially during the stage of nuclei
formation, growth, and physical ripening, is more preferably
carried out during the stage of nuclei formation and growth, and is
most preferably carried out during, the stage of nuclei
formation.
[0074] When added, a composition may be divided into several
portions and added intermittently. It is thereby possible to
achieve uniform incorporation in a sliver halide grain. As
described in JP-A Nos. 63-29603, 2-306236, 3-167545, 4-76534,
6-110146, and 5-273683, it is possible to carry out incorporation
resulting distribution in a grain. Preferably, it is possible to
result in distribution in the interior of the grain.
[0075] These metal compounds may be added after being dissolved in
water or suitable organic solvents (for example, alcohols, ethers,
glycols, ketones, esters, and amides). Addition is carried out
employing a method in which a water-based metal compound
composition or an aqueous solution, in which metal compounds are
dissolved together with NaCl and KCl, is added to a water-soluble
silver salt solution or a water-soluble halide solution, a method
in which when a silver salt solution and a halide solution are
mixed employing a double- jet method, addition is carried out as a
third aqueous solution, whereby silver halide grains are formed
employing a triple-jet method, a method in which during formation
of grains, an aqueous solution of metal compounds in a necessary
amount is charged into a reaction vessel, or a method in which
during preparation of silver halides, other silver halide grains
which have been doped with metal ions or complex ions is added and
dissolved. Of these, the method is particularly preferred in which
a water-based metal compound composition or an aqueous solution, in
which metal compounds are dissolved together with NaCl and KCl, is
added to a water-soluble halide solution. Addition onto the surface
of grains may be carried out immediately after grain formation,
during or at termination of physical ripening, or during chemical
ripening, an aqueous solution of metal compounds of the necessary
amount is charged into a reaction vessel.
[0076] It is preferable that the photosensitive silver halide
grains of this invention are washed to remove water-soluble
salts.
[0077] Photosensitive silver halide grains employed in this
invention may undergo chemical sensitization employing various
methods and particularly undergo chemical sensitization employing
chalcogen compounds. Chemical sensitization employing chalcogen
compounds may be carried out employing a sulfur sensitization
method, a selenium sensitization method, or a tellurium
sensitization method.
[0078] The addition of sensitizers employed in this invention may
be carried out at any time such as during formation of silver
halide grains, prior to desalting after formation of grains, or
after desalting, but is preferably carried out during formation of
grains or after desalting.
[0079] Photosensitive silver halide grains employed in this
invention may be spectrally sensitized to the desired wavelength
employing spectral sensitizers. Usable spectral sensitizers include
cyanine dyes, merocyanine dyes, composite cyanine dyes, composite
merocyanine dyes, homopolar cyanine dyes, hemicyanine dyes, styryl
dyes, and hemioxonol dyes.
[0080] Any of the nuclei commonly employed in dyes may be available
in these dyes. Namely, employed may be a pyyroline 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, and a pyridine nucleus, and
in addition, nuclei, which are prepared by combining the above
nuclei with an aliphatic hydrocarbon ring, such as an indolenine
nucleus, a benzindolenine nucleus, an indole nucleus, a benzoxazole
nucleus, a naphthoxazole nucleus, a benzothiazole nucleus, a
naphthothiazole nucleus, a benzoselenazole nucleus, a benzimidazole
nucleus, and a quinoline nucleus. These nuclei may be substituted
on a carbon atom.
[0081] Applied to the cyanine dyes or merocyanine dyes may be 5- or
6-membered heterocyclic nuclei such as a pyrazolone-5-one nucleus,
a thiohydantoin nucleus, a 2-thioxazoline-2 nucleus, a 4-dione
nucleus, a thiazoline-2,4-dione nucleus, a rhodanine nucleus, or a
thiobarbituric acid nucleus as a nucleus having a ketomethine
structure. Specifically, it is possible to use those described on
pages 2 and 3 of Research Disclosure, Volume 176, RD 17643 (issued
December 1978), and U.S. Pat. Nos. 4,425,424 and 4,425,426.
Further, sensitizing dyes may be dissolved employing ultrasonic
vibration described in U.S. Patent No. 3,485,634. In addition,
employed as methods in which sensitizing dyes are incorporated into
an emulsion upon being dissolved or dispersed may be those
described in U.S. Pat. Nos. 3,482,981, 3,585,195, 3,469,087,
3,425,835, 3,342,605, 3,660,101, and 3,658,546; as well as British
Patent Nos. 1,271,329 and 1,121,174. These sensitizing dyes may be
employed individually or in combinations. Combinations of
sensitizing dyes are particularly employed to achieve
supersensitization. Combinations which exhibit usable
supersensitization as well as substances which exhibit
supersensitization are described on page 23 of RD 17643 Item J
(issued December 1978).
[0082] (Organic Silver Salts) Organic silver salts usable in this
invention are silver salts which are relatively stable for light
but are silver salts which form silver images upon being heating at
80.degree. C. or higher in the presence of exposed photo-catalysts
(such as photographic silver salts) or reducing agents.
[0083] Organic silver salts may be any of the organic substances
which comprise sources capable of reducing silver ions. Silver
salts of organic acids, particularly long chain aliphatic
carboxylic acids (having preferably 10-30 carbon atoms and more
preferably 15-28 carbons atoms), are preferred.
[0084] Organic or inorganic silver salts in which the ligand
exhibits a stability constant in the range of 4.0-10.0 are also
preferred. It is essential that silver source substances are
incorporated into a photosensitive layer in an amount of about 5-
about 30 percent by weight. Preferred organic silver salts include
silver salts of organic compounds containing a carboxyl group.
These examples include, but are not limited to, silver salts of
aliphatic carboxylic acids as well as silver salts of aromatic
carboxylic acids. Preferred examples of silver salts of aliphatic
carboxylic acids include silver behenate, silver stearate, silver
arachidate, silver oleate, silver laurate, silver caproate, silver
myristate, silver palmitate, silver maleate, silver fumarate,
silver tartarate, silver linoleate, silver butyrate, and silver
camphorate, as well as mixtures thereof. It is also possible to
employ silver salts of compounds having a mercapto group or a
thione group, and derivatives thereof. Preferred examples of these
include a 3-mercapto-4-phenyl-1,2,4-- triazole silver salt, a
2-mercaptobenzimidazole silver salt, a
2-mercapto-5-aminothiadiazole silver salt, a
2-(ethylglycolamido)benzothi- azole silver salt, thioglycolic acid
silver salts such as S-alkylthioglycolic acid (wherein the alkyl
group has 12-22 carbon atoms) silver salts, dithiocarboxylic acid
silver salts such as a dithioacetic acid silver salt, a thioamide
silver salt, a 5-carboxyl-1-methyl-2-phenyl- -4-thiopyridine silver
salt, a mercaptotriazine silver salt, a 2-mercaptobenzoxazole
silver salt, silver salts described in U.S. Pat. No. 4,123,274, for
example, silver salts of 1,2,4-mercaptothiazole derivatives such as
a 3-amino-5-benzylthio-1,2,4-thiazole silver salt, and silver salts
of thione compounds described in U.S. Patent No. 3,301,678, such as
a 3-(3-carboxyethyl)-4-methyl-4-thazoline-2-thione silver salt. In
addition, it is possible to use silver salts of compounds
containing an imino group. Preferred examples of these compounds
include benzotriazole silver salts and derivatives thereof, for
example, a benzotriazole silver salt such as a methylbenzotriazole
silver, halogen substituted benzotriazole silver salts such as
5-chlorobenzotriasole silver, and a 1,2,4-triazole or 1-H-tetrazole
silver salt as well as silver salts of imidazole derivatives
described in U.S. Pat. No. 4,220,709. Further, it is possible to
use various silver acetylide compounds described in U.S. Pat. Nos.
4,761,361 and 4,775,613.
[0085] In this invention, of the above, a preferred silver source
is silver behenate and more preferred is a mixture with silver
stearate or silver arachidate. The proportion of silver stearate is
commonly 0-70 mol percent with respect to silver behenate, and is
preferably 10-30 mol percent, while the proportion of silver
arachidate is commonly 0-70 mol percent with respect to silver
behenate, and is preferably 30-60 mol percent.
[0086] Organic silver salt compounds are prepared by mixing
water-soluble silver compounds with compounds which form complexes
with silver. Mixing is preferably carried out by the use of a
normal mixing method, a reverse mixing method, a double-jet mixing
method, and a controlled double-jet mixing method described in JP-A
No. 9-127643.
[0087] In this invention, it is preferable that the average grain
diameter of organic silver salts is at most 1 .mu.m, and the
aforesaid silver salts are monodispersed. The average grain
diameter of organic silver salts, as described herein, refers to
the diameter of a sphere having the same volume as the grain in the
case in which organic silver salt grains are, for example,
spherical, rod-shaped, or tabular. The average grain diameter is
preferably 0.01-0.8 .mu.m, and is particularly preferably 0.05-0.5
.mu.m. Further, monodispersion, as described herein, is as defined
for silver halide grains, and the degree of monodispersion is
preferably 1-30 percent.
[0088] In this invention, mixing methods of photosensitive silver
halide with an organic sliver salt, as well as mixing conditions
thereof, are not particularly limited as long as the effects of
this invention are sufficiently exhibited. Preferred mixing methods
include a method in which photosensitive silver halide and the
organic silver salt, which have been separately prepared, are
mixed, a method in which photosensitive silver halide which has
been prepared is added at any timing to an organic silver salt
during its preparation, and a method in which silver halide is
prepared by mixing an organic silver salt which has been prepared
with halogenating agents. A more preferred mixing method is one in
which photosensitive silver halide which has been prepared is mixed
with an organic acid and thereafter, the organic acid is subjected
to formation of a silver salt.
[0089] In this invention, in order to realize the specified optical
density, it is preferable that the total amount of silver halide
and organic salts is 0.3-1.5 g per m.sup.2, in terms of silver.
Further, the amount of silver halide with respect to the total
silver amount is at most 50 percent in terms of weight ratio, is
preferably at most 25 percent, and is more preferably in the range
of 0.1-15 percent.
[0090] (Silver Ion Reducing Agents) Silver ion reducing agents are
reducing agents for organic silver salts. Reducing agents usable in
the present invention may be any of the substances capable of
reducing silver ions to metallic silver, and are preferably organic
substances. Conventional photographic developing agents such as
Phenidone, hydroquinone, and catechol are useful, but hindered
phenol reducing agents are preferred.
[0091] It is preferable that reducing agents are present in the
range of 1-10 percent by weight with respect to the photographic
constitution layer (being the image forming layer). In the case in
which photosensitive materials are comprised of a multilayer, when
reducing agents are added to layers other than the emulsion layer,
an addition amount of about 2- about 15 percent by weight, which is
slightly more than the aforesaid amount, tends to be preferred.
[0092] In photothermographic materials, it is possible to use a
wide variety of reducing agents. Examples include phenylamidoxime,
amidoxime such as 2-thienylamidoxime and p-phenoxyphenylamidoxime;
azines such as 4-hyroxy-3,5-dimethoxybenzaldehydeazine;
combinations of aliphatic carboxylic acid arylhydrazide and
ascorbic acid such as a combination of
2,2'-bis(hydroxymethyl)propionyl-.beta.-phenylhydrazide and
ascorbic acid; a combination of polyhydroxybenzene and
hydroxylamine, reducton and/or hydrazine (for example, a
combination of hydroquinone, bis(ethoxyethyl)hydroxylamine,
piperidinohexose reducton or formyl-4-methylphenylhydrazine);
hydroxamic acids such as phenylhydroxamic acid,
p-hydroxyphenylhydroxamic acid and .beta.-aniline hydroxamic acid;
combinations of azine and sulfoneamidophenol (for example,
phenothiazine and 6-dichloro-4-benzenesulfoneamidophenol);
.alpha.-cyanophenyl acetate derivatives such as
ethyl-.alpha.-cyano-2-met- hylphenyl acetate or
ethyl-.alpha.-cyanophenyl acetate; bis-.beta.-naphthols exemplified
by 2,2'-dihydroxy-1,1'-binaphthyl,
6,6'-dibromo-2,2'-dihydroxy-1,1'-binaphthyl, and
bis(2-hydroxy-1-naphthyl- )methane: combinations of
bis-.beta.-naphthol and 1,3-dihydroxybenzene derivatives (for
example, 2,4-dihydroxybenzophenone or 2',4'-dihydtoxyacetophenone);
5-pyrazolones such as 3-methyl-1-phenyl-5-pyrazolone; reductons
exemplified by dimethylaminohexose reduction,
anhydrodihydroaminohexose reduction, and
anhydrodihydropiperidonehexose reduction; sulfoneamidophenol
reducing agents such as 2,6-dichloro-4-benzenesulfonamidophenol and
p-benzenesulfonamidophenol; 2-phenylindan-1,3-dione; chromans such
as 2,2-dimethyl-7-t-butyl-6-hydroxychroman; 1,4-dihyropyridine such
as 2,6-dimethoxy-3,5-dicarboethoxy-1,4-dihydropyridine; bisphenols
(for example, bis(2-hydroxy-3-t-butyl-5-methylphenyl)methane,
2,2-bis(4-hydroxy-3-methylphenyl)propane,
4,4-ethylidene-bis(2-t-butyl-6-- methylphenol), and
2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane); ascorbic acid
derivatives (for example, 1-ascorbyl palmitate and ascorbyl
stearate); aldehydes and ketones such as benzyl and acetyl;
3-pyrazolidones and certain kinds of indan-1,3-diones. (Binders)
Binders suitable for photothermographic materials of this invention
are transparent or translucent and commonly colorless natural
polymers, synthetic polymers as well as copolymers, and others such
as any media which form films. Examples include gelatin, gum
Arabic, poly(vinyl alcohol), hydroxyethylcellulose, cellulose
acetate, cellulose acetate butyrate, poly(vinylpyrrolidone),
casein, starch, poly(acrylic acid), poly(methylmethacrylic acid),
poly(vinyl chloride), poly(methacrylic acid), copoly(styrene-maleic
anhydride), copoly(styrene-acrylonitrile),
copoly(styrene-butadiene), poly(vinyl acetals) (for example,
poly(vinyl formal) and poly(vinyl butyral)), poly(esters),
poly(urethanes), phenoxy resins, poly(vinylidene chloride),
poly(epoxides), poly(carbonates), poly(vinyl acetate), cellulose
esters, and poly(amides) They may be hydrophilic or
hydrophobic.
[0093] (Other Additives) In this invention, it is preferable that
matting agents are incorporated into the photosensitive layer side,
and in order to minimize abrasion on images, matting agents are
disposed on the surface of photosensitive materials. Further, it is
preferable that the aforesaid matting agents are incorporated in an
amount of 0.5-10 percent by weight with respect to the total
binders.
[0094] Materials of the matting agents employed in this invention
may be either organic or inorganic. Employed as inorganic materials
may be, for example, silica described in Swiss Patent No. 330,158,
glass powder described in French Patent No. 1,296,995, and
carbonates of alkaline earth metals or cadmium and zinc described
in British Patent No. 1,173,181.
[0095] Employed as organic materials may be organic matting agents
such as starch described in U.S. Pat. No. 2,322,037, starch
derivatives described in Belgian Patent No. 625,451 as well as
British Patent No. 981,198, polyvinyl alcohol described in Japanese
Patent Publication No. 44-3643, styrene or polymethacrylate
described in Swiss Patent No. 330,158, polyacrylonitrile described
in U.S. Pat. No. 3,079,257, and polycarbonate described in U.S.
Pat. No. 3,022,169.
[0096] The shape of matting agent particles may be either regular
or irregular. However, those which are regular and spherical are
preferably employed.
[0097] The size of matting agent particles is represented by the
diameter of a sphere which has the same volume as each matting
agent particle. The particle diameter of matting agent, as
described in the present invention, refers to the aforesaid sphere
equivalent diameter. The average particle diameter of matting
agents employed in the present invention is preferably 0.5-10
.mu.m, and is more preferably 1.0-8.0 .mu.m. Further, the variation
coefficient of a particle size distribution is preferably a maximum
of 50 percent, is more preferably a maximum of 40 percent, and is
most preferably a maximum of 30 percent.
[0098] Herein, the variation coefficient of the particle size
distribution refers to the value represented by the formula
below.
(standard deviation of particle diameter)/(average value of
particle diameter).times.100
[0099] Matting agents according to this invention may be
incorporated into any of the constitution layers. However, in order
to achieve the objective of the present invention, the matting
agents are preferwbly incorporated into the constitution layers
other than the photosensitive layer, and are more preferably
incorporated into the outermost layer, viewed from the support.
[0100] The matting agents according to this invention may be added
by the use of a method in which matting agents are previously
dispersed into a liquid coating composition and subsequently
coated, or a method in which after coating a liquid coating
composition, matting agents are sprayed prior to completion of
drying. Further, in the case in which a plurality of matting agents
is added, both methods may be simultaneously employed.
[0101] The photothermographic materials of this invention are
stable at normal temperature. However, when after exposure, heating
at a high temperature (for example, 80-220.degree. C.), development
is carried out. Upon being heated, silver is formed through a
oxidation-reduction reaction between organic silver salts
(functioning as an oxidizing agent) and reducing agents. This
oxidation-reduction reaction is accelerated by the catalytic action
of the latent image formed in silver halide through exposure.
Silver formed by the reaction of the organic silver salts in the
exposed area provides a black image. Thus an image is formed in
contrast to the unexposed area. This reaction process proceeds
without supply of a processing solution, such as water, from the
exterior.
[0102] In order to control the amount or wavelength distribution of
light which is transmitted through a photosensitive layer, a filter
layer may be formed on the same side as the photosensitive layer or
on the opposite side. Dyes or pigments may be incorporated into the
photosensitive layer. Preferred as dyes are the compounds described
in JP-A No. 7-11184.
[0103] In addition to the aforesaid components, incorporation of
additives known as "color toner" which enhances images,
occasionally results in advantage. As described in U.S. Pat. Nos.
3,080,254, 3,847,612, and 4,123,282, color toners are prior art
materials in photographic techniques.
[0104] Examples of color toners include phthalimide and
N-hydroxyphthalimide; succinimide, and pyrazoline-5-one, and cyclic
imides such as quinazoline, 3-phenyl-2-pyrazoline-5-one,
1-phenylurazole, quinazoline, and 2,4-thiazolizinedione;
naphthalimides (for example, N-hydroxy-1,8-naphthalimide); cobalt
complexes (for example, cobalthexamine trifluoroacetate);
mercaptans exemplified by 3-mercapto-1,2,4-triazole,
2,4-dimercaptopyrimidine, 3-mercapto-4,5-diphenyl-1,2,4-triazole,
and 2,5-dimercapto-1,3,4-thiadiaz- ole;
N-(aminomethyl)aryldicarboxyimides (for example,
(N,N-dimethylaminomethyl)phthalimide and
N,N-(dimethylaminomethyl)-naphth- alene-2,3-dicarboxyimide); and
blocked pyrazole, isothiuronium derivatives and certain kinds of
photofading agents (for example,
N,N'-hexamethylenebis(1-carbamoyl-3,5-dimethylpyrazole),
1,8-(3,6-diazaoctane)bis(isothiuronium trifluoroacetate) and
2-trobromomethylsulfonyl)-(benzothiazole); and
3-ethyl-5[(3-ethyl-2-benzo-
thiazolinilidene)-1-methylethylidene]-2-thio-2,4-oxazolidinedione;
phthalazine; phthalazinone, phthalazinone derivatives or metal
salts, or derivatives of 4-(1-naphthyl)phthalazinone,
6-chlorophthalazinone, 5,7-methoxyphthalazinone, and
2,3-dihydro-1,4-phthalazinedione; combinations of phthalazine and
phthalic acid derivatives (for example, phthalic acid,
4-methylphthalic acid, 4-nitrophthalic acid, and
tetrachlorophthalic anhydride); quinazolinedione, benzoxazine or
naphthoxazine derivatives; rhodium complexes, which not only
function as a color toner, but also function as an in situ halide
ion source for producing silver halide, such as ammonium
hexachlororhodate (III), rhodium bromide, rhodium nitrate, and
potassium hexachlororhodate (III); inorganic peroxides and
persulfates such as ammonium sulfide peroxide and hydrogen
peroxide; benzoxazine-2,4-diones such as 1,3-benzoxazine-2,4-dio-
ne, 8-methyl-1,3-benzoxazine-2,4-dione, and
6-nitro-1,3-benzoxazine-2,4-di- one; pyrimidines and asymmetric
triazines (for example, 2,4-dihydroxypyrimidine,
2-hydroxy-4-aminopyrimidine; azauracil and tetraazapentalene
derivatives (for example, 3.6-dimercapto-1,4-diphenyl-1-
H,4H,-2,3a,5,6a-tetraazapentalene, and
1,4-di(o-chlorophenyl)-3,6-dimercap- to-1H, 4H-2,3a,
5,6a-tetraazapentalene.
[0105] In this invention, preferred as color toners are
phthalazinone or phthalazine, and combinations with phthalic acid
derivatives are further preferred. Of these, preferred are
combinations of phthalazine with 4-methylphthalic acid,
tetrachlorophthalic acid, or tetrachlorophthalic anhydride.
[0106] In the photothermographic materials of this invention,
incorporated may be antifogging agents. Known as the most effective
antifogging agents are mercury ions. The use of mercury compounds
in photosensitive materials as an antifogging agent is disclosed in
U.S. Pat. No. 3,589,903.
[0107] However, mercury compounds are not environmentally
preferable. Mercury-free antifogging agents are preferred which are
disclosed, for example, in U.S. Pat. Nos. 4,546,075 and 4,452,885,
and JP-A No. 59-57234.
[0108] Particularly preferred mercury-free antifogging agents are
heterocyclic compounds provided with at least one substituent
represented by --C(X.sub.1) (X.sub.2) (X.sub.3) (wherein X.sub.1
and X.sub.2 each represent a halogen atom, and X.sub.3 represents a
hydrogen atom or a halogen atom), which are disclosed in U.S. Pat.
Nos. 3,874,946 and 4,756,999. Examples of preferably employed
antifogging agents include the compounds described in Paragraph
Nos. [0062] and [0063] of JP-A No. 9-90550.
[0109] In addition, more preferable antifogging agents are
disclosed in U.S. Pat. No. 5,028,523, and British Patent
Application Nos. 92221383.4, 9300147.7, and 9311790.1.
[0110] The photosensitive layer may be comprised of a plurality of
layers. For controlling gradation, layer order may be either a high
speed layer/low speed layer or a high speed layer/low speed
layer.
[0111] In order to achieve the specified optical density after
photographic processing and to minimize deformation of images after
photographic processing, supports employed in this invention are
preferably plastic films (comprised, for example, of polyethylene
terephthalate, polycarbonate, polyimide, nylon, cellulose
triacetate, and polyethylene terephthalate).
[0112] Of these, listed as preferable supports are plastic supports
comprised of polyethylene terephthalate (hereinafter referred to as
PET) and styrene based polymers having a syndiotactic
structure.
[0113] The thickness of supports is preferably about 50- about 300
.mu.m, and is more preferably 70-180 .mu.m.
[0114] Further, it is possible to use plastic supports which have
been thermally treated. Thermal treatment of supports, as described
herein, refers to operations in which after casting a support, the
resulting support is heated at a temperature higher than the glass
transition point of the support, preferably at a temperature at
least 35.degree. C. higher, and more preferably at a temperature at
least 40.degree. C. higher prior to coating of a photosensitive
layer. However, when heated at a temperature exceeding the melting
point of the support, no desired effects of the present invention
are exhibited.
[0115] Employed as casting methods and subbing methods with regard
to the supports according to the present invention may be those
known in the art. However, it is preferable to use the methods
described in Paragraphs [0030]-[0070] of JP-A No. 9-50094.
[0116] In this invention, in order to improve physical properties
as well as photographic performance, it is preferable to provide a
backing layer in the photosensitive materials. Binders suitable for
the backing layer of this invention are transparent or translucent
and commonly colorless natural polymers, synthetic polymers as well
as copolymers, and others such as media which form films. Examples
include gelatin, gum Arabic, poly(vinyl alcohol),
hydroxyethylcellulose, cellulose acetate, cellulose acetate
butyrate, poly(vinylpyrrolidone), casein, starch, poly(acrylic
acid), poly(methylmethacrylic acid), poly(vinyl chloride),
poly(methacrylic acid), copoly(styrene-maleic anhydride),
copoly(styrene-acrylonitrile), copoly(styrene-butadiene),
poly(vinyl acetals) (for example, poly(vinyl formal) and poly(vinyl
butyral)), poly(esters), poly(urethanes), phenoxy resins,
poly(vinylidene chloride), poly(epoxides), poly(carbonates),
poly(vinyl acetate), cellulose esters, and poly(amides). Binders
may be coated employing water, organic solvents or emulsions.
[0117] It is possible to incorporate various auxiliaries into the
photothermographic materials of this invention, and useful are, for
example, accelerators, acutance dyes, stabilizers, surface active
agents, lubricants, covering aids, halogen supplying agents,
polyhalogen compounds as well as mercapto compounds, leuco dyes,
chelating agents, plasticizers, UV absorbers, and various other
additives.
[0118] Further, it is possible to preferably apply various
techniques, processing, formulations, as well as additives and
addition methods thereof, which are known in the art, to the
aforesaid processing methods and production methods. Various
additives may be incorporated into any of photosensitive layers,
non-photosensitive layers or other composition layers.
EXAMPLES
[0119] Tray containers which house a plurality of
photothermographic materials were produced in such a manner that
paperboard was subjected to heat pressing employing a die. Pressing
conditions during prewsing of the tray containers were as
follows.
[0120] Employed as paper was coated cardboard (NEW-DV, 450
g/m.sup.2, coated on both sides, manufactured by Hokuetsu Paper
Mills, Ltd.), and tray containers were shaped under the following
conditions. Employed as a pressing machine was Mini Test Press at a
maximum pressing pressure of 350 kgf/cm.sup.2, manufactured by Toyo
Seiki Seisaku-Sho, Ltd.).
[0121] Further, prior to pressing, the coated cardboard was allowed
to hold moisture. In order that paper fibers exhibited flexibility
and were subjected to deformation of corners of the container,
board paper was allowed to absorb moisture by the use of a
humidifier. The moisture content was determined by the use of the
drying method specified in JIS P 8129. Table 1 shows the
results.
1TABLE 1 Residual Pressing Moisture Number Tempera- Pressing
Content of Evalua- ture Pressure (weight Film Film Film tion
(.degree. C.) (Wpa) percent) Speed Fog Scars Level 100 150 6.2
-0.22 -0.22 50 bad 120 150 4.4 -0.16 -0.17 33 bad 140 150 4.0 -0.14
-0.09 25 bad 160 150 3.8 -0.10 -0.05 17 bad 180 150 3.0 -0.03 -0.02
14 bad 200 150 2.4 -0.01 -0.01 12 bad 220 150 2.0 0 0 4 bad 240 150
1.5 0 0 2 bad 100 180 5.8 -0.22 -0.22 4 bad 120 180 4.2 -0.16 -0.17
2 bad 140 180 3.9 -0.14 -0.09 0 bad 160 180 3.4 -0.10 -0.05 0 bad
180 180 2.7 -0.02 -0.01 0 good 200 180 2.0 0 0 0 good 220 180 1.5 0
0 0 good 240 180 1.0 0 0 0 good 100 200 5.3 -0.20 -0.20 1 bad 120
200 3.8 -0.12 -0.14 1 bad 140 200 3.3 -0.07 -0.08 0 bad 160 200 2.8
-0.04 -0.03 0 bad 180 200 2.1 0 0 0 good 200 200 1.5 0 0 0 good 220
200 1.1 0 0 0 good 240 200 0.7 0 0 0 good 100 230 4.5 -0.18 -0.19 0
bad 120 230 3.0 -0.10 -0.13 0 bad 140 230 2.5 -0.06 -0.05 0 bad 160
230 2.1 -0.04 -0.03 0 bad 180 230 1.6 0 0 0 good 200 230 1.1 0 0 0
good 220 230 0.7 0 0 0 good 240 230 0.2 0 0 0 good 100 250 4.5
-0.17 -0.18 0 bad 120 250 3.0 -0.09 -0.11 0 bad 140 250 2.5 -0.06
-0.05 0 bad 160 250 2.1 -0.04 -0.03 0 bad 180 250 0.2 0 +0.05 0 bad
200 250 0.1 +0.06 +0.06 0 bad 220 250 0.0 +0.14 +0.09 0 bad 240 250
0.0 +0.22 +0.12 0 bad
[0122] The above results showed the following. When the pressing
temperature was at least 180.degree. C. and the shaping pressure
was at least 180 kgf/cm.sup.2 (18 MPa), the moisture content of
paper resulted in a maximum of 3.0 weight percent, whereby a
decrease in speed and fogging due to paper moisture was eliminated.
Further, it was noted that the amount of volatile components which
were assumed to be generated together with moisture was very small,
resulting in a decrease of desired effects of the film. However,
under a shaoing pressure of at most 180 kgf/cm.sup.2 (18 MPa), the
walls of the tray container were not completely formed and film
sheets rub each other in the package, resulting in scarring of the
photosensitive surface, whereby product quality was degraded. Still
further, it was noted that when the shaping pressure exceeded 230
kgf/cm.sup.2 (23 MPa), paper moisture was completely removed, but
the paper was subjected to burning which decreased film speed and
fogging. Consequently, it was noted that at a pressure of 180-230
kgf/cm.sup.2 (18-23 MPa) and at least 180.degree. C., it was
possible to shape more acceptable tray containers for films.
[0123] (Evaluation Methods)
[0124] (1) Vibration and Development Method
[0125] Measurement method of the number of scars on film: A tray
container containing 100 sheets of a photothermographic material
(Konica Medical Film SD-P14*17 Size) were packaged in a moisture
resistant bag. The resulting package was subjected to test by the
use of a vibration testing machine (at 23.degree. C. and 55
percent, an amplitude of 3 mm at an acceleration of 0.8 G, and for
2 hours). Thereafter, the resulting sheets were subjected to half
solid image exposure at an exposure amount of 40 percent and
developed at 125.degree. C., using a Konica Laser Imager (Drypro
752).
[0126] (2) Evaluation method of film quality
[0127] Measurement of the number of scars: The number of scars of a
length of at least 1 mm per film sheet (a size of 354.times.430 mm)
was recorded and all 100 film sheets were evaluated. Subsequently,
an average value was calculated.
[0128] Film speed: Speed obtained by developing a blank film was
designated as S2. When the speed of a sample film differed from S2
by more than .+-.0.03, it was judged that speed variation had
occurred, in which "+" represented an increase in speed, while "-"
represented a decrease in speed.
[0129] Film fog: Fog resulting from developing a blank film was
designated as Dmin. When the fog of a sample film differed from
Dmin by more than .+-.0.03, it was judged that fog variation had
occurred, in which "+" represented an increase in fog, while "-"
represented a decrease in fog.
[0130] As noted above, in the invention described in Structures 1
and 4, a tray container is produced in such a manner that board
paper is subjected to heat pressing by the use of a die, during
pressing of the aforesaid tray container, pressing conditions are
specified, and pressing is carried out at high temperature and high
pressure to volatilize moisture as well as impurities contained in
the paper, whereby it is possible to retard undesirable effects to
a photothermographic material without adhering a resinous sheet to
portions of the tray container which come into contact with the
aforesaid photothermographic material. Further, it is possible to
maintain the moisture amount at less than the definite value
without adhering a humidity control material onto the tray
container, whereby it is possible to retard degradation of
performance (fog and speed) of the aforesaid photothermographic
material due to the moisture. Still further, it is possible for
customers to dispose, after use, tray containers without worrying
whether they are combustible or not. In addition, since it is
possible to dispose tray containers resulting in a decrease in
volume, reduction of waste is effectively carried out due to the
lower bulk volume, and it is also possible to reduce cost of tray
containers compared to conventional methods.
[0131] In the invention described in Structures 2 and 5, by
specifying the moisture amount after pressing of the tray
containers, it is possible to reduce impurities (being formalin and
hydrochloric acid-vinyl acetate copolymers) to a maximum of 100
ppm, whereby it is possible to improve the performance (fog level)
of the photothermographic material.
[0132] In the invention described in Structures 3 and 6, materials
of the tray container are selected from coated cardboard,
corrugated cardboard, and synthetic paper, and it is also possible
for customers to dispose, after use, tray containers without
worrying whether they are combustible or not.
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