U.S. patent number 3,647,460 [Application Number 05/038,483] was granted by the patent office on 1972-03-07 for method of producing photographic images by rapid processing.
This patent grant is currently assigned to Gevaert-Agfa N.V.. Invention is credited to Henri Depoorter, Theofiel Hubert Ghys, Emiel Alexander Hofman.
United States Patent |
3,647,460 |
Hofman , et al. |
March 7, 1972 |
METHOD OF PRODUCING PHOTOGRAPHIC IMAGES BY RAPID PROCESSING
Abstract
A rapid process for producing a photographic image is disclosed
wherein the photographic silver halide element comprises as light
absorbing antihalation or filter dye, a dye of the formula:
##SPC1## Wherein: p stands for 1, 2 or 3, Each of R.sub.1 and
R.sub.2 is an aryl group, and M is a cation. The dye is very
rapidly discharged upon processing of the exposed element and
leaves no stains in the processed element. The dye is, therefore,
particularly suitable for use in a photographic silver halide film
element in which upon exposure a stable silver image is formed in
the least possible time by "stabilization processing" which
comprises developing the exposed element and treating the developed
element with a stabilizing solution.
Inventors: |
Hofman; Emiel Alexander
(Mortsel, BE), Ghys; Theofiel Hubert (Kontich,
BE), Depoorter; Henri (Mortsel, BE) |
Assignee: |
Gevaert-Agfa N.V. (Mortsel,
BE)
|
Family
ID: |
10261880 |
Appl.
No.: |
05/038,483 |
Filed: |
May 18, 1970 |
Foreign Application Priority Data
|
|
|
|
|
May 30, 1969 [GB] |
|
|
27,576/69 |
|
Current U.S.
Class: |
430/355; 430/405;
430/428; 430/513; 430/566; 430/963; 430/372; 430/421; 430/438;
430/523; 430/567 |
Current CPC
Class: |
G03C
1/832 (20130101); G03C 5/26 (20130101); Y10S
430/164 (20130101) |
Current International
Class: |
G03C
5/26 (20060101); G03C 1/83 (20060101); G03c
005/30 (); G03c 001/84 (); G03c 001/06 () |
Field of
Search: |
;96/95,84,50,61,48QP,76,66I |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Torchin; Norman G.
Assistant Examiner: Kelley; Mary F.
Claims
We claim:
1. Method of producing photographic images by rapid processing of
an imagewise exposed photographic material comprising a transparent
hydrophobic film support and a light-sensitive silver halide
emulsion layer, wherein said photographic material comprises a
water-permeable colloid layer comprising a dye corresponding to the
following general formula: ##SPC9##
wherein:
p stands for 1, 2 or 3,
each of R.sub.1 and R.sub.2 stands for an aryl group, and
M stands for a cation.
2. Method according to claim 1, wherein said rapid processing
includes a stabilization step and each of the processing steps
wherein an aqueous processing liquid is applied takes less than 15
seconds at ambient temperature.
3. Method according to claim 2, wherein said rapid processing
comprises in order a development step, a stabilizing step, a fixing
step and a rinsing step.
4. Method according to claim 1, wherein said processing is carried
out at a temperature of at least 30.degree. C. and each of the
processing steps wherein an aqueous processing liquid is applied
takes less than 1 min. at 30.degree. C.
5. Method according to claim 2, wherein said processing steps are
carried out in an automatic processing apparatus in which the
imagewise exposed photographic material is conducted from one
processing station to the other.
6. Method according to claim 2, wherein each processing step lasts
from 2 to 8 seconds.
7. Method according to claim 2, wherein the silver halide emulsion
is a silver chloride emulsion, a silver chlorobromide emulsion, a
silver chloroiodide emulsion or a silver chlorobromoiodide emulsion
having at least 90 mole percent of silver chloride, the average
silver halide grain size being comprised between 1 and 3
microns.
8. Method according to claim 1, wherein the light-sensitive
material comprises (a) developing substance(s) in effective contact
with the silver halide emulsion layer and/or in the latter layer
itself.
9. Method according to claim 8, wherein said developing substances
are hydroquinone and a 3-pyrazolidinone developing substance.
10. Method according to claim 1, wherein the total amount of
developing substance(s) is present in the photographic material and
the development is activated by means of an alkaline processing
solution substantially free from developing substances.
11. Method according to claim 1, wherein the said water-permeable
colloid layer comprises a dye corresponding to the formula:
##SPC10##
or an alkali metal salt or lead salt thereof.
12. Method according to claim 1, wherein the said water-permeable
colloid layer comprises the following dyes: ##SPC11##
13. Photographic light-sensitive material suitable for
stabilization processing comprising a transparent hydrophobic film
support, at least one light-sensitive silver halide emulsion layer,
a silver halide developing agent present either in the said
emulsion layer or in a colloid layer in water-permeable
relationship with the said emulsion layer and a water-permeable
colloid layer which comprises a dye corresponding to the general
formula: ##SPC12##
wherein:
p stands for 1, 2 or 3, each of R.sub.1 and R.sub.2 stands for an
aryl group and
M stands for a cation.
14. Photographic light-sensitive material according to claim 13,
which comprises hydroquinone and/or a 3-pyrazolidinone developing
agent.
15. Photographic material according to claim 13, wherein said
silver halide emulsion is a silver chloride emulsion, a silver
chlorobromide emulsion, a silver chloroiodide emulsion or a silver
chlorobromoiodide emulsion having at least 90 mole percent of
silver chloride, the average silver halide grain size being
comprised between 1 and 3 microns.
16. Photographic material according to claim 13, wherein said dye
is the dye corresponding to the following formula: ##SPC13##
or an alkali metal or lead salt thereof.
17. Photographic material according to claim 13, wherein said
water-permeable colloid layer comprises the dyes having the
following formulas ##SPC14##
Description
The present invention relates to rapid processing of photographic
light-sensitive material, especially to the use of light-absorbing
antihalation or filter dyes in photographic materials that are
subjected to rapid processing.
The normal processing of photographic materials involves the
development of the exposed silver halide to a silver image, the
treatment of the developed material with an acid bath in order to
stop the development, the conversion of the unexposed silver halide
to a soluble salt by fixation and the removal of the soluble silver
salt formed by washing with water.
These various steps require a relatively long time and, therefore,
various means have been proposed whereby the speed of processing
can be enhanced. Disregarding the role of various ingredients,
e.g., the role of developing agents that are incorporated into the
photographic material in lieu of in the developing solution whereby
development can be effected more rapidly, these means include the
use of higher concentrations, the use of higher temperatures and
the recourse to more intense agitations.
In order to enhance the processing speed without it being necessary
to have recourse to the above measures of completing the various
processing steps more quickly, the above normal processing can be
modified e.g., in that one or more steps are combined or one or
more steps are eliminated and other steps included. A very
convenient modified method of photographic treatment which is
nowadays widely employed for producing the photographic record in
the least possible time and with a minimum of effort and equipment
is the so-called "stabilization processing". By "stabilization
processing" the unexposed and undeveloped silver halide is
converted into light-inert complexes with the aid of a stabilizing
solution containing stabilizing agents which obviate the necessity
of subsequent washing. The fundamental difference between
conventional and stabilization processing is, therefore, that
whereas in the former the usual silver thiosulphate complexes
formed during fixing must be washed out, in the latter the silver
complexes are left in the emulsion.
In rapid processing, whether this is effected by the so-called
stabilization processing or by other known techniques such as the
use of highly concentrated processing solutions, the use of higher
temperatures, the recourse to more intense agitations, etc., the
photographic material owing to the short processing steps, which
last generally less than 1 minute should meet various requirements
which are not necessary in ordinary processing, wherein each of the
processing steps lasts several minutes.
For instance, it is desirable to provide in photographic film
material an antihalation layer situated on either side of the film
support carrying the light-sensitive emulsion layer(s). It was
observed that most of the antihalation dyes as commonly used in
regular roll and sheet films which are completely and irreversibly
decolorized and destroyed or removed during normal processing, are
unsatisfactory for use in film material intended for being
processed rapidly in that they leave stains in the processed
material because they are not rapidly enough discharged or
incompletely discharged in the too short lasting processing
steps.
It has now been found that dyes corresponding to the following
general formula: ##SPC2##
wherein:
p stands for 1, 2or 3,
each of R.sub.1 and R.sub.2 stands for aryl including substituted
aryl such as aryl substituted by a halogen atom such as chlorine or
by a carboxy or sulpho group in acid or salt form, and
M stands for a cation e.g., a hydrogen cation, a metal cation or an
onium cation of inorganic or organic nature such as ammonium and
pyridinium,
are completely and sufficiently rapidly discharged to be suitable
for use in photographic materials that are subjected to rapid
processing.
Thus the present invention relates to a method of producing
photographic images by rapid processing an imagewise exposed
photographic material comprising a transparent hydrophobic film
support and at least one silver halide emulsion layer the said
material comprising a water-permeable colloid layer containing a
dye corresponding to the above general formula.
The dyes of use according to the present invention are particularly
suitable for use in photographic material that will be processed by
"stabilization processing" according to which each of the
processing steps wherein an aqueous processing liquid is applied
takes less than 15 seconds at ambient temperature. They are also
suitable for use in photographic material that will be processed at
increased temperature, say of at least 30.degree. C., by the normal
steps of photographic processing, according to which each of the
processing steps wherein an aqueous processing liquid is applied
takes less than 1 minute at 30.degree. C.
The processing time referred to is the period of time elapsing from
the beginning of a processing step to the end of this step i.e.,
when a stop-treatment or another processing step starts. This
period of time mostly is somewhat longer than the period of time
during which the processing liquid is really applied, except for
the rinsing step which has to be considered as being finished when
no further amount of aqueous rinsing liquid is supplied
anymore.
Examples of particularly suitable dyes for use in accordance with
the present invention are: ##SPC3##
The dyes of use according to the present invention can be
incorporated into the colloid composition for forming an
antihalation layer of a photographic material according to any
technique known to those skilled in the art. The following is a
mere description of some appropriate techniques:
An alkali salt of a dye according to the present invention is
dissolved in water, whereupon the solution obtained is dispersed,
occasionally in the presence of a wetting agent, in a hydrophilic
colloid composition preferably a gelation solution. With a mixture
so obtained, layers can be coated in which, in most cases, the dye
is not fast to diffusion.
Layers with broad spectral absorption, in which the dye is fast to
diffusion, can be obtained, provided the dye contains no sulphonic
acid group, when one equivalent of a water-soluble salt, which
forms water-insoluble salts with the dye, e.g., silver nitrate or
lead nitrate, is added to the hydrophilic colloid composition
before, during or after the addition of the aqueous solution of the
alkali salts of the dyes.
The dyes according to the present invention that contain no
sulphonic acid group can also be incorporated when using a
dispersion of said dye in a hydrophilic colloid, obtained in one of
the following ways:
a. a solution of the dye, in its free carboxylic acid form, in a
suitable organic water-miscible and/or water-immiscible solvent, is
dispersed in a hydrophilic colloid solution, preferably an aqueous
gelatin solution, occasionally in the presence of a wetting agent.
For more details about such dispersing techniques, there can be
referred to United Kingdom Pat. Spec. Nos. 791,219 filed Nov. 9,
1955 by Kodak 1,098,594, 1,099,414, 1,099,415, 1,099,416 and
1,099,417 all filed Jan. 25, 1965 by Gevaert-Agfa N.V., to United
States Pat. Spec. No. 2,304,940 of Leopold D. Mannes and Leopold
Godowsky, Jr., issued Dec. 15, 1942, to French Pat. No. 1,555,663
filed Oct. 20, 1967 by Gevaert-Agfa N.V. and to Belgian Pat. No.
Spec. 722,026 filed Oct. 9, 1968 by Gevaert-Agfa N.V.
b. a suspension of the dye in water is finely ground in a mill,
e.g., a colloid ball mill, occasionally in the presence of a
wetting agent; the hydrophilic colloid can be added before or after
the milling process.
The colloids or mixtures of colloids used in the hydrophilic
colloid compositions, into which the dyes are dispersed, may be of
any type as commonly used in photographic materials, e.g., gelatin,
casein, polyvinyl alcohol, poly-N-vinyl pyrrolidone, carboxymethyl
cellulose, sodium alginate, etc., gelatin being however favored.
Before coating, other ingredients such as coating aids and
hardening agents, may be added to the composition of the
antihalation dyes of use according to the invention.
The light-sensitive material for use in carrying out the method of
the present invention may be whatever type of light-sensitive
silver halide material.
Various silver salts may be used as light-sensitive salt, e.g.,
silver bromide, silver iodide, silver chloride or mixed silver
halides e.g., silver chloro-bromide, silver chloro-iodide, silver
bromoiodide and silver chlorobromoiodide.
It is also possible that two or more silver halide emulsion layers
are present which depends on the kind of the reproduction system
involved. The silver halide emulsion layers may comprise all kinds
of ingredients usual in the art, e.g., developing compounds such as
hydroquinone, a 3-pyrazolidinone developing compound and a
p-aminophenol developing compound or mixtures of at least two of
these three types of developing compounds, further preservatives
for developing compounds, development accelerators, stabilizing
agents, fog inhibitors, sensitizers, color couplers, hardeners or
latent hardeners which are effective in an alkaline medium only,
softening agents, latices, matting agents, coating aids, etc. On
top of the photographic material a protective layer may be provided
as generally known in the art.
Preferably the method of the present invention is carried out in an
automatic compact processing apparatus in which the photographic
material may be guided automatically and at a constant speed from
one processing unit to the other in such a way that the processing
time in each processing unit does not last longer than 15 seconds
at room temperature in the case of stabilization processing and not
longer than 1 minute at 30.degree. C. in the case of conventional
processing at increased temperature at least above 30.degree. C.
The processing liquids may be applied according to whatever
technique known in the art, e.g., by dipping the photographic
material in the processing liquid, or by applying this liquid by
means of a licking roller, by spraying, or from a pod which is
ruptured at the moment the processing liquid has to be spread all
over the photographic material. In carrying out the method of the
present invention in an automatic processing unit it is also
possible to keep the photographic material motionless and to apply
the successive processing liquids automatically. The exposure unit
may form part of the processing apparatus or may be mounted
separately.
Although the present invention is concerned with whatever type of
rapid processing of photographic black and white or color material,
comprising a transparent hydrophobic supporting member and a silver
halide emulsion layer, it relates especially to the formation of
black-and-white images by the so-called "stabilization processing"
system.
For a comprehensive survey of stabilization processing of
photographic material and of the stabilizing agents suitable for
use in said processing in order to form with the unexposed silver
halide light-inert silver complexes that need not be washed out,
there can be referred to A. A. Newman, "The Chemistry of
Stabilization Processing" Brit.Jl.Phot., 1009, 1967 as well as to
the literature referred to therein.
Stabilization processing usually comprises only a development
station and a stabilizing station. This two-bath stabilization
processing is particularly suitable when quick results are more
important than negatives or positives or archival stability.
Indeed, since according to the two-bath stabilization processing no
washing takes place the images obtained still comprise chemical
components such as the developing agents used either in oxidized or
unoxidized form; the dyes used for extending the spectral
sensitivity of the silver halide material, the silver complexes
formed during the stabilization treatment, etc. These components
may be subject to degradation and produce stain on ageing
particularly in the high-light areas of the image.
Therefore, in order to obtain really permanent copies it is
possible to include a post-stabilization treatment such as a normal
fixing station followed by a rinsing station. Fixing and rinsing
which in normal processing last several minutes can here be reduced
to some seconds.
The dyes of use according to the present invention are particularly
suitable for use in photographic film material that will be
processed by the two-bath stabilization processing, which may be
followed by common fixing and rinsing.
Therefore, the preferred embodiment of the method of the invention
for producing photographic images by rapid processing comprises the
steps of treating an imagewise exposed light-sensitive material
comprising a transparent hydrophobic film support, a rapidly
developable silver halide emulsion layer and an antihalation layer
containing a dye corresponding to the above general formula
situated on either side of the support i.e., either on the emulsion
side of the support or on the back of the support, with a solution
effecting development of the exposed silver halide and with a
stabilizing solution by which the residual unexposed silver halide
is converted into a light-inert silver complex. This preferred
embodiment of the method of the present invention may further
include the steps of treating the developed and stabilized image
with a common fixing solution followed by rinsing.
A stabilization processing method comprising the successive steps
of developing stabilizing, fixing and rinsing the imagewise exposed
silver halide material has been described in our copending United
Kingdom Pat. application 46,444/67 filed Oct. 11, 1967 by
Gevaert-Agfa N.V. According to this what can be called four-bath
stabilization processing it is possible to produce in a rapid way,
say in less than 1 minute, photographic images with archival
stability.
As compared with conventional processing, the method according to
copending United Kingdom Patent application 46,444/67 filed Oct.
11, 1967 by Gevaert-Agfa N.V. possesses the advantages of providing
permanent copies more rapidly. By the insertion of the
stabilization step before the fixing step, the fixing time can be
reduced considerably i.e., to a few seconds where otherwise fixing
takes several minutes at ambient temperature.
In accordance with the invention the successive processing stations
of the preferred embodiment of the method of the invention are
arranged in such a way that at a constant transporting speed of the
light-sensitive material the processing time lasts from 1 to 15
seconds and preferably from 2 to 8 seconds for each of the
processing liquids used. This means that when the method of the
invention wherein a light-sensitive material is used having an
antihalation layer comprising a dye corresponding to the above
general formula is for instance based on the above four-bath
stabilization processing, the total processing time is always
comprised between 4 and 60 seconds, which is properly low, even
with respect to the maximum processing time. The total processing
time can even be reduced by applying generally known techniques for
accelerating photographic treatments, e.g., by raising the
temperature of at least one of the processing liquids, preferably
the developing or development activating liquid and/or the
fixer.
More details as regards the preferred embodiment of the method of
the invention and the photographic materials used will be given
hereinafter.
The photographic material of use according to the method of the
present invention comprises at least one silver halide emulsion
layer. As noted above various silver halides may be used as
light-sensitive silver halide. However, in stabilization processing
the silver halide emulsion layer(s) is (are) preferably pure silver
chloride emulsions or silver chloro-bromide or silver
chloro-bromo-iodide emulsions having at least 90 mole percent of
silver chloride and having an average silver halide grain size
which is comprised between 1 and 3 microns. An emulsion layer of
this type is characterized in that the latent image produced on
imagewise exposure is fully developed within 10 seconds upon
contact of the solution effecting development with the imagewise
exposed silver halide grains. Increasing the development energy by
applying generally known techniques such as raising the temperature
and the pH value of the said solution and enlarging the
concentration of the active ingredients of the said solution, does
not substantially effect the development rate of this type of
silver halide emulsion layer.
Silver halide emulsions with a rather strong gradation for the
reproduction of line work may be used as well as silver halide
emulsions having a softer gradation and being suited for the
reproduction of continuous tone originals.
The silver halides are dispersed in the common hydrophilic colloids
e.g., gelatin, casein, polyvinyl alcohol, carboxymethyl cellulose,
alginic acid, etc., gelatin being however favored.
The silver halide emulsion layer, preferably being a gelatino
silver halide emulsion layer, is applied to a common photographic
film support of a transparent hydrophobic synthetic polymeric
material e.g., a cellulose triacetate support, a polyester support
such as a polyethylene terephthalate support, etc. The support may
be provided with one or more suitable subbing layer(s) for ensuring
a good adherence of the light-sensitive silver halide emulsion
layer to the support.
An antihalation layer comprising a dye corresponding to the above
general formula is provided either on the back of the support or on
the side carrying the light-sensitive silver halide emulsion
layer(s). When the antihalation layer is situated between the
emulsion layer(s) and the support the said antihalation layer may
serve as subbing layer for the silver halide emulsion. In addition
to the antihalation dyes corresponding to the above general formula
other rapidly decolorizable antihalation dyes may also be provided
in the said antihalation layer. For instance, for this purpose the
dye marketed under the name PANGELB by Farbwerke Hoechst, A.G.,
Frankfurt, W.-Germany and having the following formula:
##SPC4##
has been found particularly suitable.
The light-sensitive material may further comprise one or more
auxiliary layers such as an antistatic layer, a protective layer,
etc. It is also possible, in order to obtain an increase of the
gradation and of the maximum density of the image produced as well
as a sensitivity gain of the reproduction system involved, to
provide between the support and the emulsion layer(s) one or more
intermediate hydrophilic colloid layers having a total weight
comprised between 2 and 8 g. per sq.m.
This or one of these hydrophilic intermediate layers may serve as
carrier for the antihalation dyes of use according to the present
invention. For more details as regards this hydrophilic
intermediate layer there can be referred to our copending United
States Pat. application 814,165 filed Apr. 7, 1969 for "Method of
producing photographic images by rapid processing".
The light-sensitive material may further comprise any kind of usual
ingredients. Into the silver halide emulsion layer and/or in
another colloid layer in water-permeable relationship with the said
emulsion layer preferably at least part and even the total amount
of developing substance(s) is incorporated, often together with a
preservative for said developing substance(s). By incorporating the
total amount of the developing agents in the photographic materials
themselves in lieu of the developing solution, development can be
activated by means of a mere alkaline activator bath, which by the
absence of developing agent(s) is better keepable.
In accordance with the present invention, there is therefore also
provided as novel composition light-sensitive silver halide film
material comprising a film support, at least one light-sensitive
silver halide emulsion layer, a silver halide developing agent
present either in the said emulsion layer or in a colloid layer in
water-permeable relationship with the said emulsion layer and an
antihalation layer comprising a dye corresponding to the above
general formula which is situated on either side of the said film
support.
Developing substances that have proved to be especially suitable
for the purpose of the present invention are hydroquinones and
3-pyrazolidinone developing compounds. These types of developing
compounds are generally known in the art and thus need no further
explanation. Preferably both types of developing compounds are
incorporated into the light-sensitive material together. Mostly
hydroquinone and/or an alkylated hydroquinone is applied in an
amount of from about 200 mg. to about 3 g. per sq.m, and the
3-pyrazolidinone developing compound in an amount of from about 50
to about 400 mg. per sq.m. The hydroquinone developing compound is
mostly incorporated into the silver halide emulsion layer itself;
the 3-pyrazolidinone developing substance preferably is
incorporated into the silver halide emulsion layer and/or into a
layer on top of the silver halide emulsion layer. Normally also
preservatives for the developing substances present are
incorporated into the light-sensitive material. As suitable
preservatives may be mentioned water-soluble organic and inorganic
bisulphites such as formaldehyde-bisulphite and potassium
metabisulphite.
Other common ingredients incorporated into the light-sensitive
material are sensitizers (chemical and/or optical), hardeners,
softening agents, development accelerators, preservatives,
antistaining agents, latices, dispersing agents, etc.
For instance, the light-sensitive emulsion may be chemically as
well as optically sensitized. They may be chemically sensitized by
effecting the ripening in the presence of small amounts of sulphur
containing compounds such as allyl thiocyanate, allyl thiourea,
sodium thiosulphate, etc. The emulsions may also be sensitized by
means of reductors for instance tin compounds as described in
French Patent No. 1,146,955 filed Apr. 11, 1956 by Gevaert
Photo-Producten N.V. and in Belgian Pat. No. 568,687 filed June 18,
1958 by Gevaert Photo-Producten N.V., imino-amino methane sulphinic
acid compounds as described in United Kingdom Pat. No. 789,823
filed Apr. 29, 1955 by Gevaert Photo-Producten N.V., and small
amounts of noble metal compounds such as of gold, platinum,
palladium, iridium, ruthenium and rhodium. Further the
light-sensitive emulsions may be sensitized by addition of
development accelerators as for example compounds of the
polyoxyalkylene type such as alkylene oxide condensation products
as described among others in United States Pat. No. 2,531,832 of
William Alexander Stanton, issued Nov. 28, 1950 and U.S. Pat. No.
2,533,990 of Ralph Kingsley Blake, issued Dec. 12, 1950, in United
Kingdom Patent Nos. 920,637 filed May 7, 1959, 940,051 filed Nov.
1, 1961, 945,340 filed Oct. 23, 1961 all three by Gavaert
Photo-Producten N.V., 991,608 filed June 14, 1916 by Kodak and in
Belgian Patent No. 648,710 filed June 2, 1964 by Gevaert
Photo-Producten N.V., and onium derivatives of amino-N-oxides as
described in French Patent No. Spec. 1,498,724 filed Oct. 3, 1966
by Gevaert-Agfa N.V.
According to the preferred embodiment of the method of the present
invention the light-sensitive material after imagewise exposure
which may occur by means of an exposure station which is either
coupled to the processing station or wholly separated therefrom,
may be transported automatically and at a substantially constant
speed for processing e.g., by means of rollers and guideways.
First, it may be transported through a developing or activating
station. Such a station may consist of a tray containing the
developing or activating liquid through which the light-sensitive
material is transported, in other words the light-sensitive
material may be wetted by dipping. The developing or activating
liquid can also be applied by means of a lick-roller taking up said
liquid on its surface and applying it uniformly to the whole
emulsion side of the light-sensitive material. The developing or
activating liquid may also be comprised in a kind of bottle from
which again and again an accurately measured amount is supplied to
the light-sensitive material, e.g., by spraying or by uniform
spreading. Further, the developing or activating liquid may be
contained in a pod, which is embodied in the light-sensitive
material or applied hereto later on, and which at the development
stage is ruptured, so that the content is uniformly spread over the
part of the photographic material to be developed. The term
developing or activating station is thus very broad and encompasses
any way of effecting the development of the light-sensitive
material.
Also the stabilizing station as well as all possible further
treating stations have to be taken in their broad sense. For a
detailed description of different suitable practical embodiments
for these processing stations reference is made to the detailed
description given hereabove with respect to the developing or
activating station. For the processing time in each of the
processing stations there can be referred to the detailed
description given hereinbefore.
The development applied in carrying out the preferred embodiment of
the method of the present invention is preferably an energetic
surface development. The high energy is required in order to allow
the development to proceed quickly and may be obtained by properly
alkalizing the developing or activating liquid (pH 10-12), and/or
by using (a) high-energy developing substance(s) or a combination
of developing substances, which as a consequence of their
superadditive action is very energetic such as a combination of a
hydroquinone and a 3-pyrazolidinone developing substance as already
referred to above. The concentration of the alkaline substance(s)
and developing substance(s) in the developing liquid is generally
known in the art and needs no further explanation. Suitable
alkaline substances for the developing or activating liquid are
sodium hydroxide, sodium carbonate, trisodium phosphate and strong
organic alkaline substances. The developing or activating liquid
further may comprise usual ingredients such as preservatives,
compounds releasing halide ions, toning agents and thickeners, so
that a developing or activating paste may be obtained.
The stabilizing liquid for carrying out the next processing step in
the preferred embodiment of the method of the invention is an
aqueous liquid containing a suitable stabilizing agent. By
"stabilizing" agent any compound is understood that is capable of
converting light-sensitive silver halide grains in substantially
light-insensitive complexes, which are water-insoluble or
substantially water-soluble. As noted above, these light-inert
complexes need not be removed from the developed and stabilized
silver halide emulsion layer by subsequent washing. However, if
desired the water-soluble complexes may be removed by washing.
Suitable stabilizing agents of the class that forms water-insoluble
light-insensitive complexes with silver halide grains are compounds
belonging to the general class of compounds represented by the
general formula RSH, wherein R is any aliphatic, aromatic, or
heterocyclic radical. Compounds of this class include thioglycolic
acid, monothiohydroquinone, thiosalicylic acid, etc. Suitable
stabilizing agents that form substantially water-soluble complexes
with silver halide are thiosemicarbazide, acetylthiourea,
sulphonated thiourea, sulphonated thiosemicarbazides,
allylthiourea, and water-soluble thiocyanates. The water-soluble
thiocyanates more especially potassium and ammonium thiocyanate are
the best suited compounds for the purpose of the present
embodiment. The stabilizing solution is an aqueous solution
comprising preferably from about 20 to about 300 g. of stabilizing
agent per liter. Preferably this solution is slightly acidified.
The stabilizing solution may furthermore contain any usual
ingredients such as a preservative for the image produced etc.
By the development or activating station and the stabilization
station a fully developed and stabilized print is obtained in less
than 30 seconds but as noted above, in order to obtain really
permanent copies the stabilization station may be followed by a
common fixing station and a rinsing station.
The treatment in a fixing station comprises a treatment with an
aqueous fixer i.e., an aqueous solution of a compound forming with
silver halide water-soluble complexes, which can be easily and
completely removed from a developed silver halide emulsion layer by
normal washing. Suitable fixing agents are the water-soluble
thiosulphates especially ammonium thiosulphate and sodium
thiosulphate. The fixing agent is mostly present in an amount of
from 50 to 300 g. per liter of fixer. Just as the stabilizing
solution the fixer in most cases is slightly acidic. It may
comprise some further ingredients such as sulphites and
bisulphites.
The rinsing station serves to eliminate the silver halide complexes
formed. This is mostly done by means of water, preferably common
tap water to which a calcium-sequestering compound has been added,
e.g., the trisodium salt of ethylenediamine-tetraacetic acid,
demineralized or distilled water which may contain wetting agents.
Rinsing can proceed according to any usual technique.
For the treatment in the various processing stations the imagewise
exposed silver halide material is preferably transported
automatically and at a substantially constant speed. During this
transport the successive processing steps are carried out. In
addition to the above four processing steps, other pretreatments,
intermediate treatments or after-treatments may be applied in
carrying out the preferred embodiment of the present invention. So
a development-stopping treatment may be inserted. It is often
advantageous to eliminate the surplus liquid in one or more of the
processing steps, e.g., by means of a doctor knife or a pair of
pressure rollers between which the light-sensitive material is led.
After rinsing, the light-sensitive material may be dried, e.g., by
means of a device blowing hot air; or by bringing the material is
contact with a heated plate. In most cases, however, no additional
treatments are carried out and the total processing remains limited
to the processing steps described above. The processing stations
may be arranged separately but mostly are grouped in a compact unit
wherein the light-sensitive material is automatically carried from
one unit to another at a constant speed. Preferably the units just
consist of a tray containing the liquid through which the
light-sensitive material is transported.
The following examples illustrate the present invention.
EXAMPLE 1
A cellulose triacetate film support was provided at one side with a
gelatin antihalation layer comprising dyestuff 2 and at the other
side with a gelatin-cellulose nitrate subbing layer, a gelatin
intermediate layer having a dry weight of 4.0 g. per sq.m, a
light-sensitive gelatin silver halide emulsion layer containing
hydroquinone and 1-phenyl-3-pyrazolidinone and a gelatin antistress
layer comprising 1.5 g. of gelatin per sq.m.
The antihalation layer was coated from a solution having the
following composition:
gelatin 80 g. dyestuff 2 2.5 g. 40 % aqueous formalin 2 ml. 10 %
aqueous saponine 20 ml. water to make 1 liter
This composition, after adjustment of the pH to 6.0 was coated pro
rata of 50 g./sq.m. so that 4 g. of gelatin and 0.125 g. of
dyestuff were present per sq.m.
The silver halide emulsion used was a rapidly developable silver
chlorobromoiodide (98 mole percent chloride, 1.8 mole percent
bromide and 0.2 mole percent iodide) emulsion having an average
grain size of about 1.8 micron and a ratio of gelatin to silver
nitrate of 0.75 and comprising as spectral sensitizer the dye
having the following structural formula: ##SPC5##
It was applied in such a way that per sq.m 2 g. of hydroquinone,
0.3 g. of 1-phenyl-3-pyrazolidinone and an amount of silver halide
equivalent to 5.0 g. of silver nitrate were present.
The light-sensitive material was imagewise exposed to a line
original whereupon it was guided in a compact automatic processing
unit at a constant speed in order through the following two
processing solutions at room temperature:
1. Acticator liquid sodium hydroxide 30 g. sodium sulphite 50 g.
potassium bromide 2 g. water to make 1000 ml.
2. Stabilizing liquid ammonium thiocyanate 250 g. sodium
metabisulphite 20 g. water to make 1000 ml.
sulphuric acid to adjust the pH to 4.5.
The total time of processing was about 10 seconds. A fully
developed and stabilized print was obtained; the colored
antihalation layer was completely and irreversibly decolorized.
EXAMPLE 2
A photographic film material was prepared as described in example
1, with the difference that now the dye having the following
formula: ##SPC6##
the antihalation layer was coated from a solution having the
following composition:
gelatin 80 g. dyestuff 1 0.5 g. dyestuff 2 2.5 g. Pangelb 2 g. 40 %
aqueous formalin 2 ml. 10 % aqueous saponine 20 ml. water to make 1
liter
This composition, after adjustment of the pH to 6.0 was coated pro
rata of 50 g./sq.m. so that 4 g. of gelatin, 25 mg. of dyestuff 1,
125 mg. of dyestuff 2 and 100 mg. of Pangelb were present per
sq.m.
The material was exposed and processed as described in example 1
with the difference that the following two additional processing
solutions were included:
3. A fixer sodium thiosulphate 200 g. potassium metabisulphite 25
g. water to make 1000 ml.
4. A rinsing liquid consisting of demineralized water.
The total processing time was 16 seconds (i.e., 4 seconds for each
of the processing liquids).
A permanent and nontacky print was obtained; the antihalation layer
was completely and irreversibly decolorized.
EXAMPLE 3
A photographic film material was prepared as described in example
1, with the difference that now the antihalation layer was coated
from a solution having the following composition:
gelatin 80 g. dyestuff 5 (added from a 2 % dispersion in 2 %
gelatin prepared by means of a swinging mill) 6 g. 40 % aqueous
formalin 2.5 ml. 10 % aqueous saponin 15 ml. water to make 1
liter
The composition, after adjustment of the pH to 6.0, was coated pro
rata of 50 g./sq.m. so that 4 g. of gelatin and 300 mg. of dyestuff
5 were present per sq.m.
The material was processed as described in example 2. The
antihalation layer was completely and irreversibly decolorized.
EXAMPLE 4
A subbed polyester support was provided with a layer of the same
composition as described in example 3.
The material obtained was processed at 35.degree. C. in the
following way:
1. Treatment for 22 seconds with the following developing
composition (pH 11.05 ):
water 800 ml. potassium hydroxide 40 % 80 ml. anhydrous potassium
carbonate 20 g. potassium metabisulphite 40 g. hydroquinone 12 g.
1-phenyl-3-pyrazolidinone 1 g. potassium bromide 2 g. water to make
1,000 ml.
2. Rinsing for 22 seconds.
3. Fixing for 25 seconds in an aqueous composition comprising per
liter 20 g. of sodium bisulphite and 170 g. of ammonium
thiosulphate (pH 5.2).
4. Rinsing for 50 seconds.
The antihalation layer was completely and irreversibly
decolorized.
EXAMPLE 5
A series of antihalation layers were coated on a film support. Each
layer contained per sq.m 4 g. of gelatin and an amount of
antihalation dye as listed in the table below. The antihalation
layers were processed either as described in example 1 (processing
A: "two-bath stabilization processing"), or as described in example
2 (processing B: "four-bath stabilization processing"), or as
described in example 4 (processing C: conventional "rapid
processing" at increased temperature).
The percentual residual staining, measured at .lambda. max. of the
dystuff, listed in the table below, was determined:
1. directly after processing, and
2. except for processing C, after storage for 5 days at 20.degree.
C. and 90 percent of relative humidity. ##SPC7## ##SPC8##
* * * * *