FR2500179A1 - Silvered image formation - using emulsion sensitive to silver halogen(s) pressurised sheet and polymer retardant - Google Patents

Abstract

The process produces a slivered image which is enveloped and stabilised. A photographic product is exposed and on a support is a coating of photosensitive emulsion, sensitive to silver halogens. A basic treatment soln. is applied to the exposure. Pressure is applied to a treatment sheet and a silver halogen developer is incorporated in the treatment solution. The sheet has a transparent support on which are applied, successively, a stabilising layer and a retarding layer for the silvered image. This contains a polymer acting until the end of the developing action.

Description

The present invention, due to the collaboration of Messrs GEHIN Guy, Michel, François BREDOUX, Jean-Marie, GAUTIER Patrice,
Jean-Pierre, Lucien and HATIF Philippe, Raoul, and realized in the
Services of the Applicant, relates to a process for forming a silver image with rapid stabilization, and more particularly to a process, which uses a silver halide photographic product, a treatment sheet and a basic treatment solution which is applied between the exposed photographic product and the treatment sheet, a process which makes it possible to rapidly obtain a developed and stabilized silver image. The present invention further relates to a composite photographic product useful for carrying out this method.

 Black-and-white transfer-diffusion methods are well known in the prior art and are described, for example, in U.S. Patents 2,352,014, 2,543,181, 3,020,155 and 2,861,885, but the image obtained by these methods is a silver image formed by diffusion-transfer on a receiver sheet which is either peelable from the initially photosensitive product or remains integrated therewith. The residual silver image in the initially photosensitive product is not usually used. However, this residual silver image may be used, as mentioned, for example, in French Patent 1,270,774, which describes a process for developing and fixing an argentic image in a silver halide photosensitive product which comprises applying to the exposed photosensitive product a treatment sheet which comprises a layer, containing developmentally grown seeds, impregnated with a developer-fix solution. This produces a negative silver image, developed and fixed in the emulsion layer and a positive image transferred to the receiver product.

 Also disclosed in the prior art are non-diffusion transfer photographic processing methods using black and white silver halide photographic processing sheets. Swiss Patent 115,331 discloses developer sheets and fixing sheets which comprise a support on which are applied either a basic solution of a developer or a solution of a fixer. For the implementation of these treatment sheets, an exposed silver halide photosensitive product is moistened, which is then applied under pressure in contact with the developing sheet. The latter is then separated, and a developed silver image is thus obtained. After washing the photographic product developed, a fixing sheet is applied under pressure and held until a film image developed and fixed is obtained.

 Transparent treatment sheets are also known which are applied under pressure to photographic products exposed and impregnated with development-fixing solutions> treatment sheets which remain laminated on the processed photographic products. French Patent 2,074,361 describes, for example, a treatment sheet consisting of a transparent film on which are successively applied a neutralization layer containing an acidic polymer and a retarded polymer layer. This treatment sheet is applied under pressure to a silver halide photosensitive product exposed and then impregnated with a developer-fix solution. A unitary product is thus obtained comprising a negative analogue image, developed and fixed.

However, development-fixing solutions do not exhibit a very high storage stability and it would be desirable to be able to use basic treatment solutions containing either only a basic compound, or possibly, furthermore, a silver halide developer. basic solutions which are much more stable than the above-mentioned developmental solutions.

 The method for forming a stabilized and developed silver image according to the invention comprises (a) imagewise exposing a photographic product comprising a support having at least one silver halide light-sensitive emulsion layer coated thereon (b) applying a basic treatment solution to the exposed polymeric product; and (c) applying a treatment sheet at least one silver halide developer both incorporated in the photographic material and in the photographic material. the treatment solution, and is characterized in that a treatment sheet comprising a transparent support on which a stabilizing layer containing at least one silver halide stabilizing agent and a retarding layer which contains a polymer which delays the stabilization of the silver image until the end of the development of the emulsion layer (s) with silver halides. At the end of the treatment, a stabilized and developed silver image is obtained in a unitary composite photographic product.

 For carrying out the process according to the invention, it is possible to use (1) the photographic product (2) the treatment sheet and (3) the basic treatment solution, separately, or a composite photographic product can be used which includes these three elements.

 The silver halide composite photographic material according to the invention comprises at least (1) a silver halide photosensitive element (2) a treatment sheet and (3) a frangible capsule containing a basic treatment solution and is characterized in that the treatment sheet comprises a transparent support on which a stabilizing layer containing at least one silver halide stabilizing agent and a retarding layer containing a polymer which delays the stabilization of the silver image is successively applied. until the end of the development of the silver halide photosensitive element. At least one silver halide developing agent is incorporated either in the photosensitive element or in the treatment solution. The basic treatment solution is released from the frangible capsule after the imagewise exposure between the photosensitive element (s). and the treatment sheet, by lamination of the composite photographic product, thereby obtaining a developed and stabilized silver image.

 As mentioned above, the stabilizing layer of the treatment sheet contains at least one silver salt stabilizing agent which can be any silver halide complexing agent capable of reacting with ions. money to make them insensitive to light and form a transparent compound.

The complexing agents useful in the treatment sheet can be defined by the usual definition of silver halide solvents. The solvents of silver halides are defined as compounds which, in aqueous solution at 60 C, can dissolve a mass
of silver halides that is more than ten times greater than that
can dissolve water at 600C.

Solvents of silver halides particularly useful com
take thiosulfates soluble in water, such as -thiosulfate
sodium, potassium thiosulfate, ammonium thiosulfate,
thiocyanates soluble in water such
sodium thiocyanate, potassium thiocyanate, ammonium thiocyanate, and diacids containing sulfur atoms, or
amides containing sulfur atoms soluble in water.One can also advantageously use diols
soluble in water, for example the compounds that correspond to the
following formula:
HO (CH2CH2z) CH OH
where p represents an integer from 2 to 13, Z represents an oxy atom
gene or sulfur, so that at least one third of the Z atoms are
sulfur atoms and that there are at least two consecutively
the compound, which are sulfur atoms.

Particularly advantageous diols also include those
correspond to the following formula
HO (-CH2CH2X) c-1 (-CH2CH2X1) d-1 (CH2CH2X) e-1 (-CH2CH2X1) f-1
(CH2CH2X) g-1-CH2CH2OH
where X and X1 represent an oxygen or sulfur atom, in such a way
that when X represents an oxygen atom} X1 represents an atom of
sulfur, and when X represents a sulfur atom, X1 represents a
oxygen atom, and each of the indices c, d, e, f, and g represents a number
an integer from 1 to 15, so that the sum c + d + e + f + g represents
an integer from 6 to 19 and at least one-third of the total sum
atoms X plus atoms X1 represents sulfur atoms and that at
at least two of the consecutive atoms X and / or X in the compound are
sulfur atoms.

Examples of useful diols include the following compounds
(1) 3,6-dithia-1,8-octanediol
HOCH2CH2SCH2CH2SCH2CH2OH;
(2) 3,6,3-trithia-1,11-unddcanediol
HOCH2CH2SCH2CH2SCH2CH2SCH2CH2OH;
(3) 3,6,9, 12-tetrathia-1,14-tetradecanediol
HO (CH 2 CH 2 s) 4 CH 2 CH 2 OH;
(4) 9-oxa-3,6,9,12,15-tetrathia-1,17-heptadecanediol
HO (CH 2 CH 2 S) CH 2 CH 2 O (CH 2 CH 2 S) 2 CH 2 CH 2 OH;
(5) 9,12-dioxa-3,6,15,18-tetrathia-1,20-eicosanediol HO (CH 2 CH 2 S) 2 (CH 2 CH 2 O) 2 (CH 2 CH 2 S) 2 (CH 2 OH);
2 2 2 2 2 2 2 2 2 20H)
(6) 3,6-dioxa-9,12-dithia-1,14-tetradecanediol
HO (CH 2 CH 2 O) 2 (CH 2 CH 2 S) 2 CH 2 CH 2 OH;
(7) 3,12-dioxa-6,9-dithia-1,14-tetradecanediol
HOCH2CH2O (CH2CH2S) 2CH2CH2OCH2CH2OH;
(8) 3,18-dioxa-6,9,12,15-tetrathia-1,20-eicosanediol
HOCH2CH20 (CH2CH2S) CH2CH, OCH2CH70H OH
(9) 12,18-dioxa-3,6,15,21,24,27-heptathia-1,2,3-nonaeosanediol
HO (CH2CH2S) 3CH2CH2OCH2CH2SCH2CH2O (CH2CH2S) -CH2CH2OH
(10) 6,9,15,18-Tetrathia-3,12,21-trioxa-1,2,3-tri-cosanediol
HOCH2CH2O (CH2CH2S) 2CH2CH2O (CH2CH2S) 2CH2CH2-OCH2CH2OH.

Useful water-soluble sulfur-containing diacids include the compounds corresponding to the following formula HOOCCH2- (SCH2CH2) 4SCH2COOH,
Wherein q represents an integer of 1 to 3, the alkali metal salts of these acids being also useful.

Examples of these diacids containing sulfur include the following compounds
(1) ethylene-bis-thioglycolic acid
HOOCCH2SCH2CH2SCH2COOH;
(2) 3,6,9-trithiahendecanedioic acid
HOOCCH2 (SCH2CH2) 2SCH2COOH COOH
(3) 3,6,9,12-Tetradiatetradecanedioic acid
HOOCCH2 (SCH2) 3SCH2COOH;
(4) disodium salt of ethylene bis-thioglycolic acid
(5) dipotassium salt of ethylene-bis-thioglycolic acid
(6) diammonium salt of ethylene bis-thioglycolic acid
(7) disodium salt of 3,6,9-trithiahendecanedioic acid
(8) disodium salt of 3,6,9,12-tetrathiadetradecanedioic acid.

 The stabilizing agent contained in the treatment sheet must essentially be compatible with the hydrophilic binder used. Particularly useful stabilizing agents include: 5- (2-hydroxyethyl) tetrahydro-s-triazin-2 (1H) thione, thioacetamide, 1,3-di-2-hydroxyethyl-imidazolin-2-thione, imidazolin-2-thione, 1-methylimidazolin-2-thione, 4-methylimidazolin-2-thione, 4-hydroxymethyl-thiazolin-2-thione, imidazole-2-thione, S, S-di -2-hydroxyethylethane thiol, the ammonium salt of 5- (2-sulfoethyl) hexahydro-1,3,5-triazin-2-thione and 5- (2-carboxyethyl) hexahydro-1,3,5-triazine-2- thione, etc.

 Stabilizing agents, as described in PSA Journal, section B, p. 59-61, August 1950, especially thioglycolic acid, monothiohydroquinone, thiosalicylic acid, etc.

Finally, useful stabilizers are those that form
and colorless / light stable film complexes which are further soluble in water so that they can be removed from the film by washing after lamination of the treatment sheet.

 The stabilizing agent may be present in the treatment sheet at a wide variety of concentrations, but it is advantageously present at a level of between about 1 mmol / m 2 and 100 mmol / m 2.

 The stabilizing layer of the treatment sheet of the composite photographic product according to the invention comprises at least one hydrophilic binder in which the stabilizing agent as described above is dissolved or dispersed. Useful hydrophilic binders include gelatin, polyvinyl alcohol, polyacrylic acid as well as natural and synthetic hydrophilic colloid binders recommended for the preparation of conventional photographic product layers.

 As mentioned above, the treatment sheet of the composite photographic product according to the invention comprises, applied on the stabilization layer as defined above, a retarding layer which usually comprises a polymer which makes it possible to delay the stabilization of unexposed and unexposed silver halides until the development of the silver image is substantially complete.

 This retardation layer may comprise any polymer customarily used in the retardation layers of photographic products, such as partially hydrolysed polyvinyl acetate, etc., as described in US Patent 3,039,873. barrier-retardant layers as described in Belgian Patent 853,612. Useful polymers are hydrolyzable polymers, particularly those which are slowly hydrolysed by the treatment solution.

 Examples of useful hydrolyzable polymers include cellulose derivatives such as cellulose acetate phthalate, cellulose acetohexahydrophthalate, cellulose acetate stearate, cellulose triacetate, cellulose acetate butyrate and mixtures of these cellulose esters. vinyl and acrylic polymers, such as phenyl polyacrylate, cyanomethyl polyacrylate, etc., polyesters, polycarbonates and polyurethanes, etc., as described in the review "Research Disclosure" article No. 12,331, July 1974.

This retardation layer is advantageously applied at a thickness of at least 1 m to 10 m, advantageously from 2 m to 5 m, but this thickness may vary according to various parameters such as the polymer substance used, the power of the developer used and its value. pH, etc.

In a particularly advantageous embodiment, the treatment sheet comprises a neutralization layer containing an acidic polymer, disposed between the stabilizing layer and the retarding layer, an acidic polymer layer which makes it possible to lower the pH of the treatment solution which has through the retardation layer before it reaches the stabilization layer. According to this advantageous embodiment, the treatment sheet of the composite photographic product according to the invention comprises a transparent support on which are applied successively a layer containing a stabilizing agent, a neutralization layer containing an acidic polymer and a retarding layer. Examples of useful acid polymers include polyacrylic acid, copolymers of n-butyl acrylate and acrylic acid, polymers of styrenesulfonic acids, vinyl polyhydropophthalates, polyacrylic acids, copolymers of methyl vinyl ether and polyvinyl ether. maleic anhydride, as well as other neutra agents
as described in the journal "Research Disclosure" article No. 12,331, July 1974.

 The treatment sheet may further include other photographic adjuvants such as coating aids, sequestering agents, and the like.

Any conventional silver halide developing agent may be used in the composite photographic products of this invention, including hydroquinones, pyrocatechols, aminophenols, 3-pyrazolidones, etc., or mixtures thereof. These developers can be incorporated into the following photographic products
the invention, either in free form or in the form of precursors, the developers being released from their precursors by the basic activator.

Examples of such precursors are the acetates of hydroquinone and alkylhydroquinones,
acetates of 3-pyrazolidones, p-aminophenol salts such as
N-methyl-p-aminophenol sulfate or N-methylp-aminophenol trifluoroacetate, etc. These developers or their precursors may be incorporated into the silver halide light-sensitive emulsion layer (s) or an adjacent layer. These developers can be incorporated as solutions in suitable solvents or as dispersions as described in U.S. Patent 2,592,368 and French Patent 1,505,778.

Examples of silver halide developers particularly useful in photographic products according to the invention
include 3-pyrazolidone developers, including 1-phenyl-3-pyrazolidone, 1-phenyl-4,4-dimethyl-3-pyrazolidine, 1-phenyl-4-hydroxymethyl-4- methyl-3-pyrazolidone, 1-p-tolyl-3-pyrazolidone, p-chlorophenyl-3-pyrazo
lidone, lp-tolyl-4,4-dimethyl-3-pyrazolidone, etc.

Other useful developers include the developers of the hydroquinone class, including the alkylhydroquinones, such as
methyl or ethylhydroquinone, arylhydroquinones, alkoxyhydroquinones, halohydroquinones, acylhydroquinones, caxboxyhydroquinones, acyloxyhydroquinones and the like. It is also possible to use the aminophenol class developers, including
p-aminophenol sulphate, N-methyl-p-aminophenol sulphate or trifluoroacetate, N, N-dimethyl-p-aminophenol sulphate, diaminophenols, and the like.

Particularly useful developers are those which reduce the developable silver halide more rapidly e. presence of the basic activator that they do not broadcast when they are
These developers contain substituents capable of reducing their tendency to diffusion. Developers of this type
include developers of the class of 3-pyrazolidones previously mentioned, as well as developers of the class of dihydroxybenzenes, trihydroxybenzenes and aminophenols, substituted on their aromatic rings by radicals selected from the group consisting of
aliphatic radicals, including branched aliphatic radicals> 3 to 18 carbon atoms, such as propyl, isopropyl>n-butyl> tert-butyl, hexyl, dodecyl, pentadecyl, octadecyl, etc., arylaliphatic radicals of 7 to 20 atoms of eerbono, aromatic radicals and cycloaliphatic radicals.

Examples of such little difffusible developers include
1,2-dihydroxy-3-cyclohexylbenzene, 1,4-dihydroxy-2-cyclohexylbenzene,
1,4-dihydroxy-2-isopropylbenzene and 15β-hydroxy-2-tert-butylbenzene, 1-4-dihydroxy-2-dodecylbenzene, 1,2-dihydroxy-3-benzylbenzene;
benzene, and the sulfate of 4-amino-3-pen # adenylphenol. ballasted
As mentioned above, we incorporate these developers! in the form of solutions or dispersions, in the binders used in the preparation of the layers of the photographic products according to the invention, these binders being, for example, gelatin, polyvinyl alcohol or hydrolysed cellulose esters, etc. For a title in silver, the composite photographic product according to the invention, between 10 mg / dm and 50 mg / dm, the embedded developer, for example of the class of 3-pyrazolidones or p-aminophenols, is usually between 5 mg / dm 2 and 25 mg / dm 2.

The silver halide emulsions which can be used according to the present invention are well known and are described, for example, in
Licensing Index, Vol. 92, December 1971, publication 9232, page 107, paragraph I "Emulsions types". These emulsions may be chemically and spectrally sensitized, as described on page 107, paragraph III and pages 108-109, paragraph XV in the publication cited above. The emulsions may be protected against haze formation and may be stabilized to avoid loss of sensitivity during storage, using the substances described on page 107, paragraph V of the above publication. Emulsions may contain developing, tanning agents, coating agents, as described on pages 107-108, paragraph IV, paragraph VII and paragraph XII of the publication cited above. The emulsions furthermore optionally contain plasticizers, binders and filter dyes, as described in paragraph XI page 108, in paragraph VIII on page 108, and in the paragraph
In addition, the emulsion layers as well as the other layers of the photographic product according to the invention can contain various adjuvants which are incorporated using the techniques described on page 109, paragraph XVII of the French patent application. this same article and finally the emulsions can be applied according to the different coating techniques mentioned on page 109, paragraph XVIII of this publication. More particularly, the composite photographic products according to the invention contain either negative image-forming silver halide emulsions, such as radiographic emulsions, or direct positive emulsions.

 The supports of the photosensitive elements of the composite photographic products according to the invention can be very varied. It is possible, for example, to use cellulose nitrate films, cellulose acetate films, polyacetalvinyl films, polystyrene films, polyethylene terephthalate films, polycarbonate films or polyolefin films, for example polyethylene films. or polypropylene, etc. The thickness of the support is generally between about 50% and 200%. Paper carriers can also be used, as well as partially acetylated paper carriers, or coated with a layer of barite sulfate or a polymer of an α-olefin, such as polyethylene.

The frangible capsule that contains the basic treatment solution that is incorporated in the composite photographic product according to the invention
This is similar to frangible capsules used in photographic products giving images by instantaneous development.

 Useful basic treatment solutions include conventional basic activators having a pH of from 8 to 14, preferably from 10 to 14. The basic compound used may be sodium hydroxide, sodium carbonate, an amine such as diethylamine etc. The photographic products according to the invention can be developed at various temperatures, for example at temperatures between 100.degree. C. and 40.degree. C., for relatively short periods of time, which can vary from 10 to 5 minutes, advantageously from 30 to 100.degree. s to 3 minutes.

 When using a diffusible silver halide developer which is diffusible in the basic activator, it may be advantageous to apply a viscous basic activator in contact with the photosensitive element via the treatment sheet. This basic viscous activator comprises, in addition to the basic components, a thickening agent such as a water-soluble cellulose derivative, such as hydroxyethyl cellulose or an alkali metal salt of carboxymethylcellulose.

The viscous base activator usually contains 1/100 to 5/100 by weight of thickening agent and its viscosity is preferably between 0.1 P1 and 200 P1.

 As mentioned above, it is also possible to introduce the silver halide developing agent (s) in the basic activator instead of incorporating them into the photosensitive element, the basic activator then being in the form of of a usual photographic developer.

 According to an advantageous embodiment, the composite photographic product according to the invention is a double-sided radiographic film which comprises (1) a photosensitive element consisting of a film support on both sides of which is applied a radiographic emulsion layer ( 2) a treatment sheet on each photosensitive emulsion layer and (3) a frangible capsule placed between each photosensitive emulsion layer and each treatment sheet, the constituent elements of this dual radiographic film being as described above.

 According to another advantageous embodiment, the composite photographic product according to the invention comprises a photosensitive element which contains a silver halide emulsion layer to which a developer, for a small amount, and a balias # reducing agent are associated, for a great reason, photosensitive element as described in the French patent application 78 00627.

 For the use of the composite photographic product according to the invention, it is sufficient, after the exposure following an image, to pass it between two pressure rollers, which allows to release the basic treatment solution of the frangible capsule and of spreading it between the photosensitive element and the treatment sheet, the development and stabilization reactions being carried out as described above and making it possible rapidly to obtain a developed and stabilized silver image in a unitary photographic product, the treatment sheet remaining applied to the initially photosensitive element.

The stabilized silver image is stable in storage in the unit photographic product. However, the stability of the preservation image can be improved by laminating the treatment sheet and washing the photographic product carrying the image.

 From the above description, it appears that the implementation of the composite photographic product according to the invention is extremely simple, the treatment being carried out without external contact with treatment solutions and the product bearing the final stabilized image is a composite product. unit. This implementation can be easily automated and quick access.

 The following examples illustrate the invention.

EXAMPLE 1
A Kodak X-OMAT GR silver halide light-sensitive film is exposed in a sensitometer, then a viscous developer solution, defined below, at a thickness of 220 μm is applied to the exposed side of the photosensitive film and finally applied. pressurizing the stabilization sheet by lamination between two pressure rollers.

The developer comprises the following constituents
- Sodium sulphite 40 g
- Potassium bromide 10 g
- Potassium hydroxide 28 g
- Hydroquinone 30 g
1-Phenyl-3-pyrazolidone 1.2 g
- 5-Methylbenzotriazole 0.1 g
- Hydroxyethylcellulose 10 g
- Water qs 1 1
To prepare the treatment sheet, a stabilizing layer comprising N-hydroxy-2-ethyl-tetrahydro-triazinethione of 175 mg / sec was successively applied to a polyethylene terephthalate film 100 m thick. dm2 and gelatin at 150 mg / dm2 and a retarding layer containing cellulose diacetate at 2 mg / dm2.

Three minutes after the lamination, a stable stabilized developed and stabilized silver image is obtained in a unitary composite photographic product, whose sensitometric characteristics determined after 3 hours of lamination, are represented in Table I below:
TABLE I

<tb> dwarf <SEP><SEP> D.axDiscrimination <SEP>
<tb> .4 <SEP><SEP> 2.0 <SEP> 1.6
<Tb>
If you want to archive the formed image, we film the sheet
After 3 minutes of treatment, the film carrying
the image and we obtain a fixed silver image, stable in conservation.

EXAMPLE 2
The procedure of Example 1 is reproduced, using the same
treatment sheet than the one described in this example but
the silver halide light-sensitive product is used as a silver halide
Kodabrom II paper sample containing hydroquinone and ulvante as integrated silver halide developers:
to the following composition: pyrazolidone, and, as a treatment solution, the basic activator
- Potassium hydroxide 28 g
- Hydroxyethylcellulose 10 g
Water q # sp i 1
Two minutes and thirty seconds after the lamination, we obtain a silver image developed and stabilized. The film is then film-coated and the photographic paper is washed and a developed and fixed image is obtained, the sensitometric characteristics of which are shown in Table II.

TABLE II

<tb><SEP> Dmin <SEP><SEP> Dmax <SEP> Discrimination
<tb> 0.10 <SEP><SEP> 1.8 <SEP> 1.7
<Tb>
EXAMPLE 3
A radiographic film is prepared, as described in the French patent application 78 00627, which has the following structure (the titers are in mg / dm2)
Gelatin overlay (10)
Silver halide emulsion layer
Ag (47,2) Developer (4,6) DOH (73.4) Gelatin (33.6
Polyethylene terephthalate support 100 μm thick
The silver halide photosensitive emulsion is a conventional radiographic emulsion. The incorporated developer which is used as a precursor (or blocked developer) is N-methyl-p-aminophenol trifluoroacetate. The DOH ballast reducing agent is 2,5-di-iso-octyl-hydroquinone.

A sample of this radiographic film is exposed and treated as described in Example 1, but on the one hand, a basic treatment solution is used which has the following composition
- Potassium hydroxide 28 g
- Potassium bromide 10 g
- Hydroxyethylcellulose 10 g
- Water qs 1 1
and, on the other hand, a processing sheet is used which comprises a support of polyethylene terephthalate of 100 μm thickness on which are applied, successively, a stabilizing layer which contains N-hydroxy-2-ethyl tetrahydrotriazinethione at 175 mg / dm 2 and gelatin at 150 mg / dm, a neutralization layer which contains an acidic polymer, such as the copolymer of butyl acrylate and acrylic acid at 70 ~ Zc, whose copolymer titre is equal to 100 mg / dm and a retardation layer which contains cellulose diacetate at 2 mg / dm.

 Three minutes after the lamination, we obtain a developed and stabilized silver image of good quality. The sensitometric characteristics are determined 30 minutes after the laminations shown in Table III.

TABLE III

<tb> Dmin <SEP><SEP> end <SEP><SEP> Dmax <SEP><SEP> Discrimination
<tb> 1.0 <SEP> 3.3 <SEP> 2,3
<Tb>
EXAMPLE 4
A photographic film is prepared which has the following structure (the titles are in mg / dm2)
Gelatin overlay (10)
Silver halide emulsion layer
Ag (41.5) Hydroquinone (15) Gelatin (32)
Polyethylene terephthalate support
Two samples of this film are exposed and treated as described in Example 1, but on the one hand, a basic treatment solution is used which has the following composition
- Potassium hydroxide 56 g
- Potassium bromide 10 g
- Hydroxyethylcellulose 10 g
- Water qs 1 1
and, on the other hand, a treatment sheet is used which comprises a stabilizing layer which contains thiosalicylic acid at 130 mg / dm and gelatin at 120 mg / dm and a retarding layer which contains a retard polymer that is a poly
lactone, as 3 mg / dm.

A film sample is laminated against the treatment sheet in the presence of the treatment solution, at 210C, for 2 minutes, 30 seconds.
and for the second sample, the reaction is carried out at 35 ° C. for 1 minute 30 seconds.

The sensitometric characteristics which are very sensitive are determined
identical for both samples and are shown in Table IV below.

TABLE IV

<tb> Dmin <SEP><SEP><SEP><SEP> Dmax <SEP> f <SEP> Discrimination <SEP> f
<tb><SEP> 0.20 <SEP> 3.30 <SEP> 3.10
<Tb>
On the other hand, a control test similar to the preceding tests is carried out, but in which the treatment sheet does not contain a stabilizing agent, and after development, the treatment sheet is film-coated and the film is fixed in a solution. fixing.

The sensitometric layer obtained is quite comparable to the curves obtained with the products according to the invention.

Claims (10)

1 - Process for forming a developed and stabilized silver image,  where (a) a photographic product consisting of  a support on which at least one emulsion layer is applied  photosensitive to silver halides, (b) a solution of  basic treatment on the photographic product exposes, and then (c)  applies pressure to a treatment sheet, at least one developed  silver halide being incorporated either in the product  photographic, either in the treatment solution, characterized in  what is used a treatment sheet comprising a support  transparent layer on which a layer of  stabilization containing at least one halogen stabilizer  silver creatures and a retarding layer that contains a polymer  which delays the stabilization of the silver image until the end of  development of the silver halide emulsion layer or layers.  imidazolin-2-thione, imidazolin-2-thione> 1-methylimidazoline  s-triazine-2 (1H) thione, thioacetamide, 1,3-di-2-hydroxyethyl)  selected from the group consisting of 5- (2-hydroxyethyl) tetrahydro-  a treatment sheet that includes a stabilizing agent 2 - Process according to claim 1, characterized in that it uses  2-thione, 4-methylimidazolin-2-thione, 4-hydroxymethyl-  thiazolin-2-thione, imidazole-2-thione, S, S-di-2-hydroxyethyl;  ethane diol, the ammonium salt of 5- (2-sulfoethyl) hexahydro-  1,3,5-triazin-2-thione, 5- (2-carboxyethyl) hexahydo-1,3,5-  triazine-2-thione and thiosalicylic acid. 3 - Process according to any one of claims 1 and 2,  characterized by using a treatment sheet that includes  a retardation layer which contains a polymer selected from  cellulose esters, vinyl and acrylic polymers,  polyesters, polylactones and polyurethanes. 4 - Process according to any one of claims 1 to 3,  characterized by using a treatment sheet which  further comprises a neutralization layer, which contains a  acid polymer applied between the stabilizing layer and the  retardation layer. 5 - Process according to claim 4, characterized in that the  acid polymer is selected from the group consisting of polyacid  acrylic, copolymers of n-butyl acrylate and acry acid  the polymers of styrene # sulfonic acids, polyhydro  vinyl genophthalates, methacrylic polyacids and  copolymers of methylvinylether and maleic anhydride. 6 - Process according to any one of claims 1 to 5,  characterized in that a treatment solution is used which is  a basic activator whose pH value is between 10  and 14. 7 - Composite photographic product for carrying out a process  image forming apparatus according to any of the claims  1 to 6, which comprises (1) at least one photosensitive member at  silver halides (2) a treatment sheet and (3) a means  to introduce, after exposure, a basic treatment solution  between the photoseasible element and the treatment sheet, at least  a silver halide developer being incorporated either in  the photosensitive element is in the treatment solution, carac  characterized in that the treatment sheet comprises a trans carrier  parent on which a layer of stabi is successively applied  containing at least one halide stabilizer  of silver and a retarding layer that contains a polymer that  delays the stabilization of the silver image until the end of  development of the silver halide photosensitive element. 8 - composite photographic product according to claim 7,  characterized in that it comprises two photosensitive elements  applied on both sides of the same support, two sheets of  treatment and two frangible capsules each containing a solution  of treatment and disposed respectively facing each photo element  sensitive, so as to release during processing their content between  each photosensitive element and its adjacent treatment sheet.  9 - Composite photographic product conforming to any of the  Claims 7 and 8, characterized in that the treatment sheet  further comprises a neutralization layer, which contains a  acid polymer applied between the stabilizing layer and the  retardation layer. 10 - Composite photographic product according to any one of  Claims 7 to 9, characterized in that the photosensitive element  comprises a silver halide emulsion layer to which  are associated a developer of silver halides, in quantity  very much lower than would be needed to reduce  the developable silver halides and a ballasted reducing agent  in sufficient quantity to ensure regeneration of the developer,  such that the desired silver density is obtained.