EP0195979A2 - Heat-developable colour-photographic material - Google Patents

Abstract

Using the recording material which contains, in a common binder layer, in the form of separate complex coacervates a plurality of coordinations of different spectral sensitivity, consisting of a) a silver halide, if appropriate in combination with a non-photosensitive silver salt, b) a dye donor and c) if appropriate, further auxiliaries, and which has a yellow filter layer above the said binder layer, a blue-sensitive coordination being more sensitive by at least 0.5 log l.t units than the other coordinations, dye images having improved colour separation are obtained by heat-development.

Description

• a) einem lichtempfindlichen Silberhalogenid der betreffenden Spektralempfindlichkeit, gegebenenfalls in Kombination mit einem im wesentlichen nicht lichtempfindlichen Silbersalz und
• b) einer nicht diffundierenden farbgebenden Verbindung, die als Folge der Entwicklung durch Wärmebehandlung einen diffusionsfähigen Farbstoff freizusetzen vermag, enthält wobei das Silberhalogenid in wenigstens einer der genannten Zuordnungen überwiegend blauempfindlich ist

The invention relates to a color photographic recording material which can be developed by heat treatment and has a light-sensitive binder layer which, in the form of separate complex coacervates, each has several different spectrally sensitive associations

• a) a light-sensitive silver halide of the spectral sensitivity in question, optionally in combination with a substantially non-light-sensitive silver salt and
• b) a non-diffusing coloring compound, which is able to release a diffusible dye as a result of the development by heat treatment, the silver halide being predominantly blue-sensitive in at least one of the mentioned assignments

It is known to produce colored images by heat treatment using suitable color photographic recording materials. Particularly suitable as color-imparting compounds are those which can be embedded in the layer of a photographic recording material in a non-diffusing form and which, as a result of the development, can release a diffusible dye (color releaser). The particular suitability of such color releasers is based on the fact that the imagewise released dyes can be transferred to special image-receiving layers with the formation of a brilliant color image which is not overlaid with disruptive image silver or silver halide and accordingly does not require any aftertreatment. Combining the heat development process with the color diffusion process thus results in an advantageous rapid process for producing colored images. A suitable recording material for this is described, for example, in DE-A-32 15 485.

According to this publication, a recording material having a layer which contains a combination of silver halide, silver benzotriazole, a color releaser and guanidine trichloroacetate (base donor) is exposed imagewise and then subjected to heat treatment in contact with an image-receiving sheet, the imagewise released dye being transferred to the image-receiving sheet. For the production of multi-colored images, several such combinations must be present, the silver halide in each of these combinations being sensitive to a different spectral range of light and, in accordance with its spectral sensitivity, containing a color releaser which releases a dye of a different color, usually a color that is complementary is to the color of the light for which the silver halide in question is predominantly sensitive. Such assignments can be arranged in different layers one above the other; however, it is often observed with such an arrangement that sufficient heat transfer from the photosensitive layer furthest from the image-receiving layer is difficult to achieve in the heat development

This is remedied by the use of so-called packet emulsions, of which several, each with different spectral sensitivity, are contained in a single light-sensitive layer as a so-called "mixed comulsion". Each of these packet emulsions consists in a Bindemittefphase dispersed particles - ( "packets") in which photosensitive silver halide of a particular spectral sensitivity and a spectrally associated color-providing compound, for example a color coupler or a dye releasing compound are combined (US-A-2 698 79 _4, DE -A-26 45 656). This technology, which has been known for a very long time, has already been applied to the heat development process (DE-A-32 32 674), but is known to bring with it the problem that the red or. green-sensitive emulsion components, in addition to their sensitized sensitivity (for red or green light) due to their intrinsic sensitivity, are also considerably sensitive to blue light and therefore only provide inadequate color rendering. In conventional multi-layer color photographic recording materials, this problem can be solved by arranging a yellow filter layer between the blue-sensitive layer (intrinsic sensitivity) on the one hand and the red or. green-sensitive layers - (sensitized sensitivity) on the other hand. However, this measure does not apply to single-layer multicolor recording materials. The color rendering can, however, be improved by adding a yellow dye to the red or green-sensitive emulsion portions is introduced - (GB-A-475 191, US-A-2 168 182). In the case of a layer thickness, as is necessary for achieving sufficient color densities, the red or. green-sensitized emulsion portions, especially in the lower area of the layer, showed a considerable decrease in the sensitivity to blue. In addition, the desired yellow filter effect on the red or. green-sensitive packets mainly limited to the lower layer areas. The same result naturally also arises if the yellow fifter dye is not in the particles of the red or green-sensitive emulsion components, but is contained in the common binder phase As a compromise, US-A-2 168 182 also describes a recording material in which the mixed-emulsion layer contains only red-sensitive and green-sensitive packets and is overlaid with a blue-sensitive silver halide emulsion layer, with the two layers a yellow filter layer is located in both light-sensitive layers

Such a layer arrangement, with which good color rendering without loss of blue sensitivity could be achieved using chromogenic processes, is, as already mentioned, not suitable for the heat development process.

Attempts have also been made to use filter dyes entirely in the case of single-layer multicolor materials based on mixed comulsions in order to avoid a reduction in the sensitivity to blue while at the same time improving the color rendering (US Pat. No. 2,618,553). Here, a silver halide with the highest possible intrinsic sensitivity, for example silver bromide, is used for the blue-sensitive emulsion components, and for the red- or. green-sensitive, sensitized emulsion components use a silver halide with the lowest possible sensitivity, for example silver chloride. This method, which can be used well with conventional silver halide emulsions in the sensitivity range of approx. 10 ^-1 to 10- ² erg / cm ² , is also not suitable for the heat development process because the emulsion systems used there, for example silver behenate / behenic acid or silver benzotriazolate, each partially converted to silver halide, have a very much lower sensitivity with 10 ^-1 to 10 ³ erg / cm ² . Here, the use of chloride instead of bromide or a mixture of bromide and iodide is prohibited for the conversion in order not to lose basic sensitivity again. It is also for those in question here hydrophilic emulsion systems, for example silver benzotriazolate in gelatin as a binder, a conversion to AgCI is generally no longer possible due to the solubility product ratios.

The invention is based on the object of specifying a color photographic recording material which can be developed by heat treatment and which provides multicolored images with improved color rendering, in particular improved color separation.

The object is achieved with a recording material which has a mixed-emulsion layer which is over or under-layered (depending on the direction of exposure) with a yellow filter layer and in which a plurality of differently spectrally sensitive emulsion components are contained, each with spectrally assigned color separators, at least one of the said emulsion components being blue-sensitive and a higher one Has sensitivity than the green or red-sensitive emulsion components.

• a) einem lichtempfindlichen Silberhalogenid der betreffenden Spektralempfindlichkeit, gegebenenfalls in Kombination mit einem im wesentlichen nicht lichtempfindlichen Silbersalz,
• b) einer nichtdiffundierenden farbgebenden Verbindung, die als Folge der Entwicklung durch Wärmebehandlung einen diffusionsfähigen Farbstoff freizusetzen vermag, und
• c) gegebenenfalls weiteren Hilfsstoffen
  enthält, wobei das Silberhalogenid in wenigstens einer der genannten Zuordnungen blauempfindlich ist, dadurch gekennzeichnet, daß eine Gelbfilterschicht über oder unter der lichtempfindlichen Bindemittelschicht so angeordnet ist, daß bei der bildmäßigen Belichtung das Licht durch die Gelbfilterschicht in die lichtempfindliche Bindemittelschicht gelangt, und daß das Silberhalogenid der blauempfindlichen Zuordnung um mindestens 0,5 log 1 ^* t-Einheiten empfindlicher ist als das Silberhalogenid in den übrigen Zuordnungen.

The invention relates to a color photographic recording material which can be developed by heat treatment and has a light-sensitive binder layer which, in the form of separate complex coacervates, each has several different spectrally sensitive assignments

• a) a light-sensitive silver halide of the spectral sensitivity in question, optionally in combination with a substantially non-light-sensitive silver salt,
• (b) a non-diffusing coloring compound which, as a result of the development by heat treatment, is able to release a diffusible dye, and
• c) optionally other auxiliaries
  contains, wherein the silver halide is sensitive to blue in at least one of the said assignments, characterized in that a yellow filter layer is arranged above or below the light-sensitive binder layer so that the light passes through the yellow filter layer into the light-sensitive binder layer during imagewise exposure, and that the silver halide the blue-sensitive assignment is at least 0.5 log 1 ^* t units more sensitive than the silver halide in the other assignments.

With the recording material according to the invention, multicolored images with good color rendering, in particular improved color separation, can be produced in a simple manner by heat treatment, which, according to the wishes and depending on the coloring compounds used, either in a negative-positive or in a positive-positive relationship the scanned original (if the pictures are positive). The images are particularly characterized by uniformly low minimum color densities (veils) in the different colors.

The recording material contains, as a light-sensitive layer on a dimensionally stable support, a binder layer in which all light-sensitive substances and all coloring compounds are contained in the form of the complex coacervates mentioned. The recording material further contains a yellow filter layer adjacent to the photosensitive layer. The latter is arranged so that the exposure light passes through the yellow filter layer into the light-sensitive layer. Typically, the yellow filter layer is over the photosensitive layer; however, if the support is transparent, it can also be arranged under the photosensitive layer
be. The yellow filter layer has an optical density (for blue light) between 0.5 and 1.2, preferably between 0.7 and 0.9. It can contain yellow colloidal silver or suitable yellow organic dyes in the usual way.

If the yellow filter layer is arranged above the photosensitive layer, it can be equipped with additional functions by incorporating suitable additives. The yellow filter layer can take on the function of a hardening layer if hardening agents are added to its casting solution, for example formaldehyde, succinaldehyde, glutaraldehyde, N, N ', N "-trisacryloylhexahydro-1,3,5-triazine, mucochloric acid, halogen-substituted aldehydes. The yellow filter layer can be formed by suitable additives as an adhesive and contact layer, by adding suitable polymers or polymer mixtures to it, and finally it can also contain hard particles of an inorganic or organic nature as matting agents or spacers.

The light-sensitive layer of the recording material according to the invention contains several of the complex coacervates mentioned, each of these complex coacervates being assigned to a different spectral region of the light and containing as essential components at least one light-sensitive silver halide and at least one non-diffusing color-providing compound which, as a result of the development by heat treatment is able to release a diffusible dye. As a rule, the light-sensitive silver halide is present in combination with a further essentially non-light-sensitive silver salt.

A complex coacervate is understood to mean a dispersion form in which a mixture of the essential constituents is enclosed in a common covering made of a hardened binder. Such dispersions are also called packet emulsions. They are obtained by complex coacervation.

The term "complex coacervation" means the occurrence of two phases when mixing an aqueous solution of a polycationic colloid and a polyanionic colloid, a concentrated colloid phase (hereinafter referred to as a complex coacervate) and a diluted colloid phase (hereinafter referred to as an equilibrium solution) ) are formed due to an electrical interaction. The complex coacervate is separated from the equilibrium solution in the form of droplets and appears as a white turbidity. When complex coacervation is performed in the presence of a solid such as silver halide or fine oil droplets, it is generally believed that the complex coacervate includes the solid or the droplets inside colloidal particles. As a result of this, a dispersion of coacervate particles is obtained in which the solid (in the present case the light-sensitive silver halide and optionally the essentially non-light-sensitive silver salt) and oily droplets of a solution of the organic constituents (in the present case the color releasing agent and possibly other auxiliaries) are included. It is then hardened with a hardening agent so that the original shape of the particles is not destroyed in the following steps for producing the photographic recording material, such as producing the casting solution and coating. The dispersion is expediently cooled to a temperature of 25 ° C. or below, preferably 10 ° C. or below, before curing, whereby a good quality packet emulsion is obtained.

A method for producing a packet emulsion in which a color-forming substance is incorporated by complex coacervation is described, for example, in US Pat. Nos. 3,276,869 and 3,396,026.

The hydrophilic colloids that can be used in complex coacervation can be divided into two groups. A first group includes compounds containing a nitrogen atom; an aqueous solution thereof has a negative charge at a pH higher than its isoelectric point and a positive charge at a pH lower than its isoelectric point (i.e. a cationic compound or polymer). Examples of these compounds include gelatin, casein, albumin, hemoglobin, polyvinylpyrrolidone. A second group includes compounds of which an aqueous solution always has a negative charge regardless of pH (i.e. an anionic compound). Examples of these compounds include a natural colloid such as sodium alginate, gum arabic, agar agar, pectin, konjac, a synthetic polymer with an acidic group or an alkaline salt thereof, such as a copolymer of vinyl methyl ether or ethylene and maleic anhydride, carboxymethyl cellulose, polyvinyl sulfonic acid, a condensation product of naphthalenesulfonic acid and formalin or a gelatin derivative in which a part which would be capable of carrying a positive charge is blocked by esterification. Preferred examples of the anionic polymer which can be used according to the invention include compounds having repeating units, the carboxylate and / or contain sulfonate groups and have a molecular weight of not less than 1000, preferably not less than 3000. Of the compounds belonging to these two groups, gelatin, agar agar, sodium alginate can be gelled by cooling. Gelatin is particularly suitable for the production of the package emulsion, since it can be gelled by cooling and easily hardened with a hardening agent.

A combination of gelatin and an anionic polymer is preferably used to carry out the complex coacervation. The amount of the colloidal substances used varies depending on the charge density of the substances at the time of the coacervate formation. However, the colloid of one group is generally used in an amount ranging from 1/20 to 20 times the amount by weight of the colloid of the other group. It is preferable to use a weight ratio of 0.5: 1 to 4: 1 in a combination of gelatin and gum arabic and a weight ratio of 10: 1 to 40: 1 in a combination of gelatin and a condensation product of naphthalenesulfonic acid and formafin.

The following four conditions are required to effect complex coacervation.

First, the concentration of the hydrophilic colloid in both the first group and the second group must be in the range of 0.5 to 6%, preferably 1 to 4%.

Second, the pH must not be above 5.5. The size of the packet emulsion particles largely varies depending on the pH value, but also fundamentally on the degree of mixing. The optimum pH value varies depending on the type of colloid used, but in most cases in the range from 5.2 to _4, 0, preferably from 5.0 to 4.5. The size of the packet emulsion particles used is usually in the range from 1 to 100 μm, preferably from 2 to 60 μm and particularly preferably from 5 to 30 μm.

Third, the temperature of the system must be higher than the solidification temperature of the aqueous colloid solution. In the case of gelatin, the temperature must not be below 35 ° C and is preferably in the range from 40 to 55 ° C.

Fourth, the amount of co-existing inorganic salt must not exceed a certain critical value that is characteristic of the type of salt.

The preparation of the packet emulsion by complex coacervation is generally carried out by one of the following two methods

According to the first method, hydrophilic colloids, each selected from the first group and the second group, are mixed in a suitable ratio and an aqueous solution thereof is prepared in a concentration of 1 to 4% by weight. The temperature of the solution is in kept in the range of 35 to 60 ° C, and the pH is kept above 5.5. The pH is reduced by adding an acid to cause coacervation.

According to the second method, a temperature (not less than 35 ° C.) and a pH (not more than 5.5) are maintained under conditions under which the coacervation can take place, and an aqueous hydrophilic colloid solution with a concentration of at least 6 at first % By weight is diluted by adding warm water until the concentration suitable for coacervate formation is reached

However, if a packet emulsion is made according to the first or second method or both, the amount of the packet emulsion is very small compared to the volume of the diluted continuous phase of the hydrophilic colloid. Therefore, a large amount of binder e.g. Gelatin can be added so that the emulsion can be used directly for coating. Various methods can be used to concentrate and dry the packet emulsion. According to a known method, the dilute colloid solution, which contains a packet emulsion dispersed, is filtered. According to another method, the colloid solution is left to precipitate the packet emulsion. The supernatant liquid is then removed by decanting. A centrifuge separator can also be used for accelerated precipitation. In addition, to completely remove water, the packet emulsion can be atomized using spray drying methods such as are known, for example, for the production of microcapsules.

Examples of curing agents that can be used to prepare the packet emulsion according to the invention include chromium salts (for example chromium alum, chromium acetate), aldehydes (for example formaldehyde, glyoxal, glutaraldehyde), N-methylol compounds - (for example dimethylolurea, methyloldimethylhydantoin), dioxane derivatives (for example 2.3 Dihydroxydioxane), active vinyl compounds (for example 1,3,5-triacryloythexahydro-s-triazine, 1,3-vinylsulfonyl-2-propanol), active halogen compounds (for example 2,4-dichloro-6-hydroxy-s-triazine), and mucohalogenic acids (e.g. mucochloric acid, mucophenoxychloric acid). These curing agents can be used individually or as a mixture.

The use of packet emulsions according to the invention enables the combination of several emulsion components of different spectral sensitivity, including the relevant color releasers, in a single binder layer, without losing the spectral assignment and thereby causing a color distortion. This is possible because of the amount of exposure of a particular silver halide particle is almost exclusively decisive for the extent of the dye release from that color releaser which is in the same coacervate particle (package) as the silver halide. The use of packet emulsions thus enables the accommodation of a blue-sensitive, a green-sensitive and a red-sensitive silver halide emulsion with any additional, essentially non-light-sensitive silver salt and spectrally assigned color separators in the same binder layer, without fear of serious color changes.

The light-sensitive silver halide can consist of silver chloride, silver bromide, silver iodide or mixtures thereof and have a particle size between 0.02 and 2.0 IJ, m, preferably between 0.1 and 1.0 µm. It can be in the form of an unsensitized silver halide or it can also be chemically and / or spectrally sensitized by suitable additives. The amount of light-sensitive silver halide in the respective layer can be between 0.01 and 5.0 g per m ', or even more. For conversion type emulsions, the actual amount of silver halide used, due to its catalytic function (as exposed silver halide) in some embodiments, is mainly in the lower part of the range given. For emulsion systems which consist of a mixture of silver halide and organic silver salt, the amount of silver halide used is mainly in the upper range: preferably 0.25-1.0 g / m ² for each emulsion fraction ^.

The essentially non-light-sensitive silver salt can be, for example, a silver salt which is comparatively stable to light, e.g. trade an organic silver salt. Suitable examples include the silver salts of aliphatic or aromatic carboxylic acids and the silver salts of nitrogen-containing heterocycles; also silver salts of organic mercapto compounds.

Preferred examples of silver salts of aliphatic carboxylic acids are silver behenate, silver stearate, silver oleate, silver laurate, silver caprate, silver myristate, silver palmitate, silver maleate, silver tartrate, silver furoate, silver linolate, silver adipate, silver sebacate, silver sulfate, for example, Hydroxyl groups or thioether groups can be substituted.

Examples of silver salts of aromatic carboxylic acids and other compounds containing carboxyl groups include silver benzoate, silver 3,5-dihydroxybenzoate, silver o-methylbenzoate, silver m-methylbenzoate, silver p-methylbenzoate, silver 2,4-dichlorobenzoate, silver acetamidobenzoate, silver gallate, Silver tannate, silver phthalate, silver terephthalate, silver salicylate, silver phenylacetate, silver pyromellitate, silver salts of 3-carboxymethyl-4-methyl-4-thiazolin-2-thione or similar heterocyclic compounds. Silver salts of organic mercaptans, e.g. the silver salts of 3-mercapto-4-phenyl-1,2,4-triazole, 2-mercaptobenzimidazole, 2-mercapto-5-aminothidediazole, 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, 2-mercaptooxadiazole, mercaptotriazine, thioglycolic acid, furthermore the silver salts of dithiocarboxylic acids, such as the silver salt of dithioacetate

The silver salts of compounds having an imino group are also suitable. Preferred examples include the silver salts of benzotriazole and its derivatives, e.g. Silver salts of alkyl and / or halogen substituted benzotriazoles, e.g. the silver salts of methylbenzotriazole, 5-chlorobenzotriazole, as well as the silver salts of 1,2,4-triazole, 1-H-tetrazole, carbazole, saccharin and silver salts of imidazole and its derivatives.

The application amount of essentially non-photosensitive silver salt according to the present invention is in the respective layer between 0.05 and 5 g per m ² . The substantially non-photosensitive silver salt and the photosensitive silver salt can furthermore be present in the coacervate particles next to one another as separate particles or in a combined form which can be produced, for example, by treating an essentially non-photosensitive silver salt in the presence of halide ions, whereby on the surface of the particles of the essentially non-light-sensitive silver salt by double reaction - (conversion) form light-sensitive centers of light-sensitive silver halide. For this, reference is made to US-A 3,457,075.

The essentially non-light-sensitive silver salt serves as a reservoir for metal ions, which are reduced to elemental silver when heat is developed in the presence of a reducing agent under the catalytic influence of the imagewise exposed silver halide and thereby serve as an oxidizing agent (for the reducing agent present).

Another essential component in the coacervate particles of the recording material according to the invention is a non-diffusing coloring compound which, as a result of a redox reaction taking place during development, is able to release a diffusible dye and which is referred to below as a color releasing agent.

The dye releasers used according to the invention can be a variety of connection types, all of which are distinguished by a link which is redox-dependent in terms of their bond strength and which links a dye residue to a carrier residue containing a ballast residue

In this context, a summary of the subject area in Angew. Chem. Lnt.

Ed. Engl. 22 (1983), 191-209, in which the most important of the known systems are described. Redox-active color releasers of the formula have proven to be particularly advantageous

BALLAST REDOX DYE, in what mean BALLAST a ballast remnant

REDOX is a redox-active group, i.e. a group which is oxidizable or reducible under the conditions of alkaline development and, depending on whether it is in the oxidized or in the reduced state, is subject to different degrees to an elimination reaction, a nucleophilic displacement reaction, a hydrolysis or another cleavage reaction, with the result that the Remainder DYE is split off, and

DYE the rest of a diffusible dye, e.g. a yellow, purple or teal dye, or the rest of a dye precursor.

Such residues are to be regarded as ballast residues which make it possible to store the color releasers according to the invention in a diffusion-resistant manner in the hydrophilic colloids usually used in photographic materials. For this purpose, organic radicals are generally suitable, which contain straight-chain or branched aliphatic groups with generally 8 to 20 carbon atoms and optionally also carbocyclic or heterocyclic optionally aromatic groups. These radicals are either directly or indirectly connected to the rest of the molecule, for example via one of the following groups: -NHCO-, -NHSO ₂ -, -NR-, where R is hydrogen or alkyl, -0-or -S-. In addition, the ballast residue can also contain water-solubilizing groups, such as sulfo groups or carboxyl groups, which can also be in anionic form. Since the diffusion properties depend on the molecular size of the total compound used, it is sufficient in certain cases, for example if the total molecule used is large enough, to use shorter-chain residues as ballast residues.

Redox-active carrier residues of the BALLAST-REDOX structure and corresponding color releasers are known in a wide variety of embodiments. A detailed description can be dispensed with here with regard to the above-mentioned overview article in Angew. Chem. Int. Ed. Engl. 22 (1983) 191-209.

For the sake of explanation only, some examples of redox-active carrier residues are listed below, from which a dye residue is split off in accordance with an image-related oxidation or reduction:

The groups enclosed in brackets are functional groups of the dye residue and are separated together with this from the remaining part of the carrier residue. The functional group can be a substituent which can have a direct influence on the absorption and, if appropriate, complex formation properties (for example a post-complexable chromophore) of the released dye. On the other hand, the functional group can also be separated from the chromophore of the dye by an intermediate link or a link. Finally, the functional group together with the intermediate member may also be of importance for the diffusion and pickling behavior of the released dye. Suitable intermediate members are, for example, alkylene or arylene groups.

In principle, the residues of dyes of all classes of dyes are suitable as dye residues insofar as they are sufficiently diffusible to diffuse from the light-sensitive layer of the light-sensitive material into an image-receiving layer. For this purpose, the dye residues with one or more alkali-solubilizing groups. Suitable alkali-solubilizing groups include carboxyl groups, sulfo groups, sulfonamide groups and aromatic hydroxyl groups. Such alkali-solubilizing groups can already be pre-formed in the dye releasers used according to the invention or can only result from the cleavage of the dye residue from the carrier residue which contains ballast groups. Of dyes that are particularly suitable for the process according to the invention, mention should be made of: azo dyes, azomethine dyes, anthraquinone dyes, phthalocyanine dyes, indigo dyes, triphenylmethane dyes, including dyes that are complexed or complexable with metal ions.

The residues of dye precursors are to be understood as the residues of those compounds which, in the course of photographic processing, in particular under the conditions of heat development, either by oxidation, by coupling, by complex formation or by exposure of an auxochromic group in a chromophoric system, for example by saponification, can be converted into dyes. Dye precursors in this sense can be leuco dyes, couplers or dyes that are converted into other dyes during processing. Unless a distinction between dye residues and the residues of dye precursors is of essential importance, the latter are also to be understood below as dye residues.

• US-A-3 227 550, US-A-3 443 939, USA-A-3 443 940, DE-A-19 30 215, DE-A-22 42 762, DE-A-24 02 900, DE-A-24 06 664, DE-A-25 05 248, DE-A-25 43 902, DE-A-26 13 005, DE-A-26 45 656, DE-A-28 09 716, DE-A-28 23 159, BE-A-861 241, EP-A-0 004 399, EP-A-0 004 400, DE-A-30 08 588, DE-A-30 4 669, GB-A-80 12 242.

Suitable color releasing agents are described, for example, in:

• US-A-3 227 550, US-A-3 443 939, USA-A-3 443 940, DE-A-19 30 215, DE-A-22 42 762, DE-A-24 02 900, DE- A-24 06 664, DE-A-25 05 248, DE-A-25 43 902, DE-A-26 13 005, DE-A-26 45 656, DE-A-28 09 716, DE-A- 28 23 159, BE-A-861 241, EP-A-0 004 399, EP-A-0 004 400, DE-A-30 08 588, DE-A-30 4 669, GB-A-80 12 242 .

In some embodiments of the invention, the color releasers can be present as oxidisable or couplable color releasers, in others as reducible color releasers. Depending on whether the dye is released from the oxidized or from the reduced form of the color releasing agent, negative or positive illumination is obtained from the original when conventional negative-working silver halide emulsions are used. You can therefore create positive or negative images by selecting suitable color releasing systems.

If the color releaser is oxidizable, then it itself represents a reducing agent which is directly or indirectly with the participation of electron transfer agents (ETA) through the imagewise exposed silver halide or through the essentially non-photosensitive silver salt under the catalytic action of the imagewise exposed Silver halide is oxidized. This creates a pictorial differentiation in terms of the ability to release the diffusible dye. If, on the other hand, the color releaser is reducible, then it is expediently used in combination with a reducing agent present in a limited amount, a so-called electron donor compound or an electron donor precursor compound, which in this case, in addition to the color releaser, the light-sensitive silver halide and optionally the essentially non-light-sensitive silver salt in the The same caacervate particles are contained. Even when reducible color separators are used in combination with electron donor compounds, the participation of electron transfer agents generally proves to be favorable.

worin bedeuten

• R^r Alkyl oder Aryl;
• R² Alkyl, Aryl oder eine Gruppierung, die zusammen mit R³ einen ankondensierten Ring vervollständigt;
• R' Wasserstoff, Alkyl, Aryl, Hydroxyl, Halogen wie Chlor oder Brom, Amino, Alkylamino, Dialkylamino einschließlich cyclischer Aminogruppen (wie Piperidino, Morpholino), Acylamino, Alkylthio, Alkoxy, Aroxy, Sulfo, oder eine Gruppierung, die zusammen mit R² einen ankondensierten Ring vervollständigt;
• R⁴ Alkyl;
• R⁵ Alkyl oder vorzugsweise Wasserstoff;
• A den Rest eines diffusionsfähigen Farbstoffes oder Farbstoffvorläufers;
  ein bivalentes Bindeglied der Formel -R-(L)p-(R)q-, worin R einen Alkylenrest mit 1 -6 C-Atomen oder einen gegebenenfalls substituierten Arylen-oder Aralkylenrest bedeutet und wobei die beiden Reste R die gleiche Bedeutung oder voneinander verschiedene Bedeutungen haben können; L -O-, -CO-, -CONR⁶-, -SO₂NR⁵-, -O-CO-NR⁶-, -S-, -SO-oder -SO₂-(R⁶ = Wasserstoff oder Alkyl);
• p 0 oder 1;
• q 0 oder 1;
• m 0 oder 1,
  und wobei mindestens einer der Reste R', R², R³ und R⁴ einen Ballastrest enthält

A recording material according to the invention which contains reducible color releasers of the following formula I is suitable, for example, for producing positive color images of positive originals (originals) when using negative working silver halide emulsions

in what mean

• R ^r alkyl or aryl;
• R ^{2 is} alkyl, aryl or a group which together with R ^{3 completes} a fused ring;
• R 'is hydrogen, alkyl, aryl, hydroxyl, halogen such as chlorine or bromine, amino, alkylamino, dialkylamino including cyclic amino groups (such as piperidino, morpholino), acylamino, alkylthio, alkoxy, aroxy, sulfo, or a group together with R ² completed a condensed ring;
• R ⁴ alkyl;
• R ^{5 is} alkyl or preferably hydrogen;
• A the rest of a diffusible dye or dye precursor;
  a bivalent link of the formula -R- (L) p- (R) q-, in which R is an alkylene radical having 1 -6 carbon atoms or an optionally substituted arylene or aralkylene radical and where the two radicals R have the same meaning or from one another can have different meanings; L -O-, -CO-, -CONR ⁶ -, -SO ₂ NR ⁵ -, -O-CO-NR ⁶ -, -S-, -SO or -SO ₂ - (R ⁶ = hydrogen or alkyl) ;
• p 0 or 1;
• q 0 or 1;
• m 0 or 1,
  and wherein at least one of the radicals R ', R ² , R ³ and R ⁴ contains a ballast radical

The alkyl radicals represented by R ', R ² , R ³ and R ⁵ in formula I can be straight-chain or branched and generally contain up to 18 carbon atoms. Examples are methyl, n-propyl, tert-butyl, tetradecyl, octadecyl. The aryl radicals represented by the radicals R ', R ² and R ^{3 mentioned} are, for example, phenyl groups which can be substituted, for example by long-chain alkoxy groups.

In an acylamino radical represented by R ³ , the acyl group is derived from aliphatic or aromatic carboxylic or sulfonic acids. The fused-on rings completed by R ² and R ³ are preferably carbocyclic rings, for example fused-on benzene or bicyclo- [2,2,1] -heptene rings.

An alkyl radical represented by R ⁴ can be straight-chain or branched, substituted or unsubstituted and contain up to 21 C atoms. Examples are methyl, nitromethyl, phenylmethyl (benzyl), heptyl, tridecyl; Pentadecyl, heptadecyl, -C ₂₁ H ₄₃ .

Preferred embodiments of the color releasers used according to the invention are those in which R ', R' and R ^{3 together} in a quinoid carrier radical contain no more than 8, in particular not more than 5, carbon atoms, and R ^{4 is} an alkyl radical with at least 11 carbon atoms represents.

Preferred embodiments are furthermore those in which R 'is an alkoxyphenyl radical having at least 12 C atoms in the alkoxy group and R ² , R ³ , R ⁴ together contain no more than 8 C atoms.

worin

• R', R², R³, R⁴ und R⁵ die für Formel I angegebene Bedeutung haben.

These color releasers contain a diffusion-releasable quinoid carrier residue of the formula bound to the dye residue

wherein

• R ', R ² , R ³ , R ⁴ and R ^{5 have} the meaning given for formula I.

Examples of such paint releasers which are preferably used in the context of the present invention are listed below.

Derivatives of hydroquinone, benzisoxazolone, p-aminophenol or ascorbic acid (e.g. ascorbyl palmitate), which have little or no diffusion, have been described as electron donor compounds, for example - (DE-A-28 09 716).

Further examples of electron donor compounds are known from DE-A-29 47 425, DE-A-30 06 268, DE-A-31 30 842, DE-A-31 44 037, DE-A-32 17 877, EP-A- 0 124 915 and Research Disclosure No. 24 305 (July 1984). It has been found that the electron donor compounds mentioned also meet the requirements imposed on them under the conditions of heat development and are therefore also suitable as electron donor compounds for the recording material of the present invention. Particularly suitable are those electron donor compounds which are formed in the layer from corresponding electron donor precursor compounds only under the conditions of heat development, i.e. Electron donor compounds that are only in a masked form in the recording material before development, in which they are practically ineffective. Under the conditions of heat development, the electron donor compounds, which are initially ineffective, are then converted into their effective form, for example by hydrolytically cleaving off certain protective groups.

worin bedeuten

• R' einen carbocyclischen oder heterocyclischen aromatischen Ring;
• R², R³, R⁴ gleiche oder verschiedene Substituenten, und zwar Wasserstoff, Alkyl, Alkenyl, Aryl, Alkoxy Alkylthio, Amino oder
• R³ und R⁴ vervollständigen zusammen einen ankondensierten, insbesondere carbocyclischen Ring und wobei mindestens einer der Substituenten R', R², R³ und R⁴ einen die Diffusion erschwerenden Ballastrest enthält;
  
  worin bedeuten:
• R' eine carbocyclische oder heterocyclische aromatische Gruppe, und
• R² Wasserstoff, Alkyl, Alkenyl oder Acyl wobei wenigstens einer der Substituenten R' und R² einen Ballastrest enthält;
  
  worin bedeuten
• R' eine Kohlenwasserstoffgruppe
• R², R', R⁴, R^S gleiche oder verschiedene Substituenten und zwar Kohlenwasserstoffgruppen, Halogen oder Alkoxy, der R⁴ und R⁵ vervollständigen zusammen einen ankondensierten, insbesondere carbocyclischen Ring, wobei wenigstens einer der Substituenten R', R², R³, R⁴ und R⁵ einen Ballastrest enthält.

For the purposes of the present invention, the electron donor precursor compounds mentioned are therefore also to be understood as electron donor compounds. Particularly suitable electron donor compounds are, for example, those of the following general formulas II, III and IV.

in what mean

• R 'is a carbocyclic or heterocyclic aromatic ring;
• R ² , R ³ , R ^{4 are} identical or different substituents, namely hydrogen, alkyl, alkenyl, aryl, alkoxy alkylthio, amino or
• R ³ and R ⁴ together complete a fused-on, in particular carbocyclic ring and wherein at least one of the substituents R ', R ² , R ³ and R ^{4 contains} a ballast residue which complicates the diffusion;
  
  in which mean:
• R 'is a carbocyclic or heterocyclic aromatic group, and
• R ^{2 is} hydrogen, alkyl, alkenyl or acyl wherein at least one of the substituents R 'and R ² contains a ballast radical;
  
  in what mean
• R 'is a hydrocarbon group
• R ² , R ', R ⁴ , R ^{S are} identical or different substituents, namely hydrocarbon groups, halogen or alkoxy, the R ⁴ and R ⁵ together complete a fused-on, in particular carbocyclic ring, at least one of the substituents R', R ² , R ³ , R ⁴ and R ⁵ contains a ballast residue.

Examples of suitable electron donor compounds which can be used in the context of the present invention are listed below

While the silver salt in the different emulsion parts differs in terms of spectral sensitivity and the color releaser in the different emulsion parts in terms of the color of the dye released, this does not necessarily also apply to the electron donor compound which may be present. The electron donor compound can therefore be the same for all three assignments. It can also be wholly or partly contained in the common binder phase, although it is also preferred to include it in the coacervate particles together with the silver salt and the color releaser.

The silver halide in the different emulsion parts (assignments) is sensitized differently according to the respective assignment to a color releasing agent or the color of the dye released from it. According to the invention, the blue-sensitive emulsion component has a higher sensitivity than the other emulsion components, but the sensitivity essentially results from the totality of the constituents contained in the individual coacervate particles of the emulsion component in question, i.e. also taking into account the filter effect of the colored compounds contained in the coacervate particles the silver halide. According to the invention, the blue-sensitive emulsion component for blue light is at least 0.5 log I · t units more sensitive than the green-sensitive emulsion component for green light or the red-sensitive emulsion component for red light. The sensitivity advantage of the blue-sensitive emulsion component is preferably in the range from 0.7 to 0.9 log I • t units.

Methods for determining the sensitivity of the individual emulsion components are known to the person skilled in the art. Measures are also known to the person skilled in the art, with which he specifically select a difference in sensitivity between the blue-sensitive emulsion portion on the one hand and the green or. red-sensitive emulsion components, on the other hand, can be set to the desired level, as can be seen from the following overview:

In addition, there is the possibility of changing the sensitivity of the green or to specifically press the red-sensitive emulsion portion, e.g. by adding stabilizers, whereby this measure can also be used in combination with one or more of the measures already shown.

Finally, you can also take advantage of the optical filtering effect of the color releasers contained in the coacervate particles by using the green or red-sensitive emulsion components use color releasers which absorb a considerable proportion of the light effective in these emulsion components, while for the blue-sensitive emulsion component color releasers with only a low absorption for blue light are used; the image dye released from the latter color releaser undergoes a shift in the absorption maximum during development ("shifted dye" -US-A-3 854 945).

In addition to the constituents already mentioned, the light-sensitive binder layer of the color photographic recording material according to the invention may contain further constituents and auxiliaries which are beneficial, for example, for carrying out the heat treatment and the color transfer which takes place here. These further constituents or auxiliary substances are preferably contained in the common binder phase of the light-sensitive layer or in one of the other layers.

Such auxiliaries are, for example, auxiliary developers. These auxiliary developers generally have developing properties for exposed silver halide; In the present case, they primarily have a beneficial effect on the reactions taking place between the exposed silver salt (= silver salt in the presence of exposed silver halide) and the reducing agent, the reducing agent being identical to the latter when using oxidizable color releasers, or in the case the use of reducible color releasers in turn reacts with the color releasers. Since these reactions consist mainly of transferring electrons, the auxiliary developers are also referred to as electron transfer agents (ETA)

Examples of suitable auxiliary developers include hydroquinone, pyrocatechol, pyrogallol, hydroxylamine, ascorbic acid, 1-phenyl-3-pyrazolinone and their derivatives. Since the auxiliary developers have a catalytic function, it is not necessary for them to be present in stoichiometric amounts. In general, it is sufficient if they are present in the layer in amounts of up to 112 moles per mole of color releaser. The incorporation into the layer can take place, for example, from solutions in water-soluble solvents or in the form of aqueous dispersions which have been obtained using oil formers.

Other auxiliaries are, for example, basic substances or compounds which are able to provide basic substances under the influence of the heat treatment. Sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, sodium acetate and organic bases, in particular amines such as trialkylamines, hydroxyalkylamines, piperidine, morpholine, dialkylaniline, p-toluidine, 2-picoline, guanidine and their salts, in particular salts with aliphatic carboxylic acids, are to be mentioned here, for example. By making the basic substances available, a suitable medium is created during the heat treatment in the light-sensitive layer and the adjacent layers in order to ensure the release of the diffusible dyes from the ink cleavers and their diffusion into the image-receiving layer.

Das bei der Erwärmung freigesetzte Wasser begünstigt die für die Bilderzeugung erforderlichen Entwicklungs-und Diffusionsvorgänge.Other auxiliaries are, for example, compounds which are able to release water under the action of heat. In particular, inorganic salts containing water of crystallization come into question, for example

The water released during the heating process favors the development and diffusion processes required for image generation.

Other auxiliaries are, for example, the so-called thermal solvents, which are generally understood to mean non-hydrolyzable organic compounds which are solid under normal conditions, but which melt when heated to the temperature of the heat treatment and thereby deliver a liquid medium in which the development processes can take place more quickly. Such thermal solvents can act as diffusion accelerators, for example. Preferred examples of the thermal solvents include polyglycols, as described, for example, in US Pat. No. 3,347,675, for example polyethylene glycol with an average molecular weight of 1500 to 20,000, derivatives of polyethylene oxide, for example its oleic acid ester, beeswax, monostearin, compounds with a high dielectric constant, which have a - SO ₂ or --CO group, such as acetamide, succinamide, ethyl carbamate, urea, methylsulfonamide, ethylene carbonate, and also polar substances, as described in the US -A-3 667 959, the lactone of 4-hydroxybutanoic acid or 4-hydroxybutyric acid, dimethyl sulfoxide, tetrahydrothiophene-1,1-dioxide and 1,10-decanediol, methyl anisate, biphenyl suberate etc., as described in Research Disclosure, pages 26 to 28 (December 1976) etc.

The development of the imagewise exposed color photographic recording material of the invention comprises the substeps of silver halide development, generation of an imagewise distribution of diffusible dyes and D ⁱ f-fusion transfer of this imagewise distribution in the image receiving layer It is initiated that subjecting the exposed recording material to a heat treatment in which. the photosensitive binder layer is brought to an elevated temperature, for example in the range from 80 to 250 ° C., for a time of about 0.5 to 300 s. As a result, suitable conditions for the development processes, including dye diffusion, are created in the recording material without the need to supply a liquid medium, for example in the form of a developer bath. During development, dyes which are diffusible in terms of image are released from the color releasers and transferred to an image-receiving layer which is either an integral part of the color photographic recording material according to the invention or is in contact with it at least during the development period

Image-wise silver development, dye release and color transfer take place synchronously in a one-step development process.

In addition, the color image formation with the color photographic recording material according to the invention can also be carried out in a two-step development process, silver halide development and dye release taking place in a first step, followed in a second step by color image transfer from the photosensitive part to an image receiving part brought into contact with it , e.g. by heating to a temperature between 50 and 150 ° C., preferably to 70 to 90 ° C., in which case diffusion aids (solvents) can be applied externally before the photosensitive part and the image receiving part are laminated.

The image-receiving layer can accordingly be arranged on the same layer support as the light-sensitive element (single sheet material) or on a separate layer support (two-sheet material). It essentially consists of a binder which contains mordants for the determination of the diffusible dyes released from the non-diffusing paint releasers. Long-chain quaternary ammonium or phosphonium compounds, e.g. those as described in US-A-3,271,147 and US-A-3,271,148.

Certain metal salts and their hydroxides, which form poorly soluble compounds with the acid dyes, can also be used. Polymeric mordants should also be mentioned here, such as those described in DE-A-23 15 304, DE-A-26 31 521 or DE-A-29 41 818. The dye mordants are dispersed in the mordant layer in one of the usual hydrophilic binders. eg in gelatin, polyvinyl pyrrolidone, completely or partially hydrolysed cellulose esters. Of course, some binder may act as a mordant, such as polymers of nitrogen-containing, optionally quaternary bases, such as N-methyl-4-vinylpyridine, 4-vinylpyridine, 1-vinylimidazole as described for example in US-A-2 484 ₄ 30th Further usable binding agents are, for example, guanylhydrazone derivatives of alkyl vinyl ketone polymers, as described, for example, in US Pat. No. 2,882,156, or guanylhydrazone derivatives of acylstyrene polymers, as described, for example, in DE-A-20 09 498. In general, however, the latter binding agents are used add other binders, such as gelatin.

If the image-receiving layer remains in layer contact with the light-sensitive element even after development has been completed, there is usually an alkali-permeable, pigment-containing light-reflecting binder layer between them, which serves as an optical separation between negative and positive, and serves as an aesthetically pleasing background for the transferred positive color image. In this case, the yellow filter layer used according to the present invention is on the side of the light-sensitive layer which lies opposite the pigment-containing light-reflecting binder layer. If the image-receiving layer is arranged between the support and the photosensitive element and is separated from the latter by a pre-formed light-reflecting layer, either the support must be transparent so that the color transfer image produced can be viewed through it, or the photosensitive element together with the light-reflecting layer of the image-receiving layer are removed to expose the latter. However, the image-receiving layer can also be present as the uppermost layer in an integral color photographic recording material, in which case the exposure is expediently carried out by means of transparent layer supports.

example 1 Preparation of the silver salt emulsions Emulsion 1

17.0 g of AgNO ₃ , dissolved in 200 ml of 45 ° C. warm water, became within 2 minutes a 45 ° C. warm solution of 20.0 g of gelatin in 1000 ml of water, which contained 13.0 g of benzotriazole (BTA) , metered in with stirring. The mixture was then stirred for 5 minutes. The pH was adjusted to 5.0 with 5% NA ₂ CO ₃ solution. The mixture was flocculated by adding 20 ml of a 10% polystyrene sulfonic acid solution, cooling to 25 ° C. and adding 10% sulfuric acid (up to pH 3.0 to 3.5) and then washing three times with 1000 ml of water each time. The flocculate was heated to 45 ° C., adjusted to pH 6.0 with 5% Na ₂ CO ₃ solution, mixed with 5 ml of 1% aqueous phenol solution and brought to a final weight of 435 g by adding water.

Emulsion 2

34.0 g of AgNO ₃ dissolved in 200 ml of water were metered in over the course of 10 minutes to a 50 ° C. solution of 40.0 g of gelatin, 23.7 g of KBr and 1.66 g of KI. Then 20 minutes at ₅ 0 ° C was stirred and then cooled to 35 ° C. 40 ml of a 10% polystyrene sulfonic acid solution was added dropwise and then it was cooled to 20 ° C. By adding 10% sulfuric acid (up to pH 3.0 to 3.5) was flocculated and washed three times with 700 ml of water each. Then 0 ° C was heated to ₄ and adjusted with 10% sodium hydroxide to pH 6.0. Final weight 1171 g.

Example 2 Manufacture of the Dispergate Dispersant 1 (cyan paint releasing agent)

50 g of dye releaser 3 (cyan) were dissolved in a mixture of 40 g of cresyl phosphate and 35 g of palmitic acid diethylamide and dispersed in 1260 g of 6% aqueous gelatin solution in the presence of 2.6 g of sodium dodecylbenzenesulfonate.

Dispersant 2 (magenta paint releasing agent)

50 g of color releaser 12 (magenta) were dissolved in a mixture of 64 g of tricresyl phosphate and 21 g of diethyl laurylamide and dispersed in 833 g · 6% aqueous gelatin solution in the presence of 1.7 g of sodium dodecylene benzenesulfonate. Dispersant 3 (color releaser yellow)

50 g of color releaser 4 (yellow) were dissolved in a mixture of 47 g of tricresyl phosphate and 46 g of palmitic acid diethylamide and dispersed in the presence of 3.0 g of sodium dodecylbenzenesulfonate in 1280 g of 6% aqueous gelatin solution

Disperse 4 (electron donor compound)

50 g of compound ED-1 (electron donor compound) were dissolved in 50 g of palmitic acid diethylamide and dispersed in 540 g of 10% aqueous gelatin solution in the presence of 0.1 g of sodium dodecylbenzenesulfonate

Dispersant 5 (auxiliary developer)

50 g of the compound of the following formula

wurden in 100 g Diethyllauramid gelöst und in Gegenwart von 0,2 g Natriumdodecylbenzolsolfonat in 1000 g 10%iger wäßriger Gelatinelösung dispergiert

were dissolved in 100 g of diethyl lauramide and dispersed in 1000 g of 10% aqueous gelatin solution in the presence of 0.2 g of sodium dodecylbenzenesol fonate

Disperse 6 (filter yellow)

In 84 ml of water, 0.3 g of sodium dodecybenzene sulfonate was dissolved and 16.3 g of a 40% disperse of cholanyl yellow (from Höchst) were dispersed. A casting solution was prepared from the yellow filter dispersate (dispersate 6) thus obtained as follows: 83.7 g of dispersant 6 aqueous solution of gelatin were dispersed in 136 g of 15% and diluted with ₁ 00 ml of water

Example 3 Production of the package emulsions PE-1 (cyan)

34.4 g of emulsion 2 were melted at 40 ° C. and spectrally sensitized by adding a 0.1% strength methanolic solution of a red sensitizer in an amount of 4x10 ⁻⁴ mol per mol of silver halide and digested for 70 min at 40 ° C. Then 25. 6 g of emulsion 1 and 35 ml of water at 40 ° C. were added, and 44.8 g of disperse 1 (cyan) and 11.2 g of disperse 4 were added, and 55 ml of a 10% strength gum arabic solution were added and the mixture was stirred for 15 minutes , whereupon 140 ml of 40 ° C warm water were added dropwise within 4 min. By slowly metering in 1% acetic acid, the pH is adjusted to 4.8 and stirring is continued for 15 min. With continued stirring, the mixture is then rapidly cooled to about 8 ° C. and a solution of 0.55 g of chromium alum in 160 ml of water is metered in within 4 min Stirring is continued at 8 ° C for 1 to 1 1/2 hours. Centrifugation and separation from the supernatant liquid gave 49 g of PE-1 (cyan) with an average particle size of about 7 µm.

PE-2 (magenta)

• Grünsensibilisator (4x10^-4 Mol pro Mol Silberhalogenid) anstelle von Rotsensibilisator, 24,3 g Dispergat 2 (magenta) anstelle von Dispergat 1.

PE-2 was also produced in an analogous manner to that described for PE-1, but with the following special features:

• Green sensitizer (4x10 ^-4 moles per mole of silver halide) instead of red sensitizer, 24.3 g of disperse 2 (magenta) instead of disperse 1.

After separation by centrifugation, 41 g of PE-2 (magenta) with an average particle size of approx. 10 µm were obtained. PE-3 (yellow)

• Blausensibilisator (8x10^-4 Mol pro Mol Silberhalogenid) anstelle von Rotsensibilisator,
• 34,2 g Dispergat 3 (gelb) anstelle von Dispergat 1.

PE-3 was also produced in an analogous manner to that described for PE-1, but with the following special features:

• Blue sensitizer (8x10 ^-4 mol per mol silver halide) instead of red sensitizer,
• 34.2 g of dispersion 3 (yellow) instead of dispersion 1.

After centrifugal separation, 55 g of PE-3 (yellow) with an average particle size of about 5 µm were obtained. PE-4 (cyan)

PE-4 was also produced in an analogous manner to that described for PE-1, but with the following particularity

An additional 16.4 g of disperse 6 were added to the mixture of emulsion and disperse 1.

Yield: 45 g PE-5 (magenta)

PE-5 was also produced in an analogous manner to that described for PE-2, but with the following particularity

An additional 16.4 g of disperse 6 were added to the mixture of emulsion and disperse 2.

Yield: 39 g.

The following spectral sensitizers were used.

Grünsensibilisator:

Red sensitizer

Green sensitizer:

Von jeder der genannten Paketemulsionen PE-₁, PE-2, PE-3, PE-4, PE-5 wurde eine Teilgießlösung wie folgt hergestellt Jede der Paketemulsionen wurde mit 100 ml Wasser 10 min. homogenisiert und mit 40 ml einer 10%igen wäßrigen Guanidintrichloracetat-Lösung, 4 ml Netzmittel Triton X 100 (4%ig), 18,4 g Dispergat 5 (Hilfsentwickler) und einer Lösung von 19 g Gelatine in 170 ml Wasser versetztBlue sensitizer:

A partial casting solution was prepared from each of the packet emulsions PE- ₁ , PE-2, PE-3, PE-4, PE-5 mentioned as follows. Each of the packet emulsions was washed with 100 ml of water for 10 minutes. homogenized and mixed with 40 ml of a 10% aqueous guanidine trichloroacetate solution, 4 ml of Triton X 100 wetting agent (4%), 18.4 g of dispersant 5 (auxiliary developer) and a solution of 19 g of gelatin in 170 ml of water

Example 4

• 1. Eine Beizschicht mit 2 g Polyurethanbeize aus 4,4'-Diphenylmethandiisocyanat und N-Ethyldieihanolamin, quatemiert mit Epichlorhydrin gemäß DE-A-26 31 521, Beispiel ₁, und 2 g Gelatine.
• 2. Eine lichtreflektierende Schicht mit 20 g Ti0₂ und 2 g Gelatine.
• 3. Eine Schutzschicht mit 1 g Gelatine.

The image-receiving part of a photographic recording material for the color diffusion transfer process was produced by successively applying the following layers on a transparent substrate made of polyethylene terephthalate. The quantities given relate in each case to 1 m ²

• 1. A pickling layer with 2 g of polyurethane pickle from 4,4'-diphenylmethane diisocyanate and N-ethyldieihanolamine, quaternized with epichlorohydrin according to DE-A-26 31 521, Example ₁ , and 2 g of gelatin.
• 2. A light reflecting layer with 20 g Ti0 ₂ and 2 g gelatin.
• 3. A protective layer with 1 g gelatin.

The image-receiving material thus obtained is used in the following examples as a coating base for the production of integral recording materials. It is also suitable as a separate image receiving sheet

Example 5 Material ₁ (according to the invention)

Using the coating underlay (image receiving part) with layers ₁ , 2 and 3 described in Example 4, a photographic recording material according to the invention was produced by coating with the following layers

_4th Mixing of partial casting solutions of package emutations PE-1, PE-2 and PE-3 (see Example 3) in a ratio of 1: 1: 1.3;

Wet application 300 µm.

5. Casting solution from yellow filter dispersate (see Example 2);

Wet order 40 um.

6. Hardening layer

Example 6

Material 2 (comparison)

• 4. Abmischung von Teilgießlösungen der Paketemulsionen PE-4, PE-5 und PE-3 (vgl. Beispiel 3) im Verhältnis ₁:1:1,3;

For comparison, a photographic recording material was produced using the coating base (image receiving part) described in Example 4 by coating with the following further layers

• 4. Mixing of partial casting solutions of the package emulsions PE-4, PE-5 and PE-3 (cf. Example 3) in a ratio of ₁ : 1: 1.3;

Wet order 300 um. 5. Hardening layer Example 7

The photographic recording materials described in Examples 5 and 6 were exposed through a combination of separation filters (with gray scale) with red, green and blue light, to determine the D _m i _n and Dmax values of Mischkomemulsion with light of each respective spectrum third of a normal exposure and a total exposure was carried out with light from the other two thirds of the spectrum. The recording materials were then heated to 137 ° C. for 60 s using a heatable drum, then left to swell in water for 30 s and finally heated to 75 ° C. on a heating bench for 60 s. The D _min and D _max values were determined using a computer densitometer of the color wedges transferred to the image-receiving layer (Table 1).

The absolute yellow filter densities in the two recording materials (material 1 and material 2) were identical. It can be seen from Table 1 that both the Dmin values and the Dmax values of the color transfer were comparable in the recording material according to the invention. In the comparison material without the separate yellow filter layer according to the invention, this was probably true for the D _max values, but not also for the Dmin values. The comparison material had a high yellow veil that was intolerable.

Claims (5)

1. Color photographic recording material which can be developed by heat treatment and has a light-sensitive binder layer which, in the form of separate complex coacervates, comprises several different spectrally sensitive assignments each a) a light-sensitive silver halide of the spectral sensitivity in question, optionally in combination with a substantially non-light-sensitive silver salt, b) a non-diffusing coloring compound which, as a result of the development by heat treatment, is able to release a diffusible dye and c) optionally contains further auxiliaries, the silver halide being sensitive to blue in at least one of the abovementioned classifications,
characterized in that a yellow filter layer is arranged above or below the light-sensitive binder layer such that the light passes through the yellow filter layer into the light-sensitive binder layer during imagewise exposure, and that the silver halide in the blue-sensitive assignment by at least 0.5 log I • t- Units is more sensitive than the silver halide in the other assignments. 2. Recording material according to claim 1, characterized in that the light-sensitive binder layer contains a blue-sensitive, a green-sensitive and a red-sensitive assignment, each of these assignments a) a light-sensitive silver halide of the relevant spectra sensitivity, optionally in combination with an essentially non-light-sensitive silver salt, (b) a non-diffusing coloring compound which, as a result of the development by heat treatment, is able to release a diffusible dye, and c) optionally comprises further auxiliaries and the silver halide in the blue-sensitive assignment is at least 0.5 log 1 ^e t-unit more sensitive than the silver halide in the green-sensitive and in the red-sensitive assignment. 3. Recording material according to claim ₁ or 2, characterized in that a reducible color releaser is used as the non-diffusing color compound, in combination with a non-diffusing electron donor compound. 4. Recording material according to claim 1, characterized in that the silver halide in the blue-sensitive assignment by 0.7 -0.9 log l ^e t units is more sensitive than the silver halide in the other assignments. 5. Recording material according to claim 4, characterized in that the yellow filter layer has a density of 0.7-0.9.