EP0207401A2 - Heat-developing process and auxiliary sheet suited therefor - Google Patents

Abstract

The process using an integral colour-photographic recording material, which contains, on a preferably transparent support, both an image-receiving layer and light-sensitive binder layers with silver halide and allocated dye donors, if appropriate with a light-reflecting pigment layer arranged between the image-receiving layer and light-sensitive layers, can be carried out as a single-step development process with synchronously proceeding silver halide development and dye transfer, if an auxiliary sheet is used which contains, in a binder layer, a promoter of thermal development and diffusion. Preferably, the promoter of thermal development and diffusion is already liquid under normal conditions and is dispersed in a micro-encapsulated form in the binder layer.

Description

The invention relates to a heat development process in which an imagewise exposed color photographic recording material which contains a laminate of an image receiving layer and a light-sensitive part with at least one light-sensitive silver halide-containing binder layer and at least one associated color-providing compound on a common layer support is heated in contact with an auxiliary sheet containing a thermal development and diffusion promoting agent dispersed in a binder layer.

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 non-diffusing form in the layer of a photographic recording material 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 containing 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, whereby the image-released dye is 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 the light and, according to its spectral sensitivity, containing a color releaser which releases a dye of a different color, usually a color that is complementary is the color of the light for which the silver halide in question has a predominant sensitivity. Such assignments can be arranged one above the other in different layers.

A sufficient amount of water or other hydrophilic medium is required to ensure rapid and complete development, including dye diffusion. This is generally accomplished by swelling the recording material with the photosensitive layer (s) and the image-receiving sheet, or both, with water before contacting and heating them. The conventional humidification measures make the process cumbersome and time-consuming; Above all, careful drying is required to remove excess humidifier. This is all the more true because of the greater number of layers on a support and the greater overall layer thickness when the image-receiving layer and light-sensitive layers are arranged on a common support to form an integral photothermographic recording material.

It is also known to incorporate the moisture required as a transfer solvent in the form of water of crystallization or in microencapsulated form into the photographic recording material. However, this poses particular difficulties when the image-receiving layer and light-sensitive layers form an integral recording material, be it that due to the size of the microcapsules, depending on the arrangement in the recording material, either the imagewise exposure or the dye diffusion is disturbed, or that if water of crystallization is used, there is a risk of the water being released prematurely, which would impair the stability of the recording material.

The invention has for its object to provide a simplified heat development process with which dry, color-intensive images can be obtained in a very short time, an integral photothermographic recording material which contains both the image-receiving layer and the light-sensitive layers on a common support being used, and where in particular, the use of liquid baths and the resulting prolonged drying treatment is avoided.

The present invention relates to a heat development process for producing colored images, in which an imagewise exposed color photographic recording material, consisting of a laminate arranged on a support of at least one image-receiving layer which can be colored by diffusible dyes, and at least one binder layer, the light-sensitive silver halide, optionally in combination with a contains essentially non-light-sensitive silver salt and which is assigned a non-diffusing coloring compound which, as a result of the development, is able to release a diffusible dye by heat treatment in The presence of a thermal development and diffusion requirement agent is developed, characterized in that the heat treatment is carried out while the color photographic recording material is in surface contact on the coating side with an applied auxiliary sheet which contains at least one thermal development and diffusion promoting agent in dispersed form in a binder layer.

In the method according to the invention, therefore, an auxiliary sheet is used which contains a dispersion of at least one thermal development and diffusion promoting agent in a binder layer, in an amount sufficient to heat a medium in the color photographic recording material which is favorable for the development and diffusion processes create. For this purpose, the exposed recording material, which contains both an image-receiving layer and at least one light-sensitive layer with the required light-sensitive substances and the associated coloring compounds on a preferably transparent layer support, is brought into surface contact with the auxiliary sheet on the coating side and heated in the process. As a result of the heating, the development and diffusion promoting agent passes from the auxiliary sheet into the layers of the recording material, so that the development and diffusion processes can take place there.

Transparent or opaque carrier materials can be used as the substrate for the auxiliary sheet used according to the invention. Layer supports made of polyethylene terephthalate (polyester) are suitable, for example. There is a binder layer on the substrate in which the thermal development and diffusion promoting agent is dispersed.

Die erfindungsgemäß zur Anwendung gelangenden thermischen Entwicklungs- und Diffusionsförderungsmittel sind aber keineswegs auf die bisher bekannten thermischen Lösungsmittel beschränkt, d.h. auf solche Verbindungen, die bei Normalbedingungen fest sind und erst bei der Temperatur der Wärmebehandlung flüssig werden. Erfindungsgemäß kommen auch, und zwar sogar bevorzugt, solche Verbindungen in Betracht, die bereits bei Normalbedingungen flüssig sind. Diese Verbindungen sollen aber gleichfalls hydrophilen Charakter haben. die letztgenannten bei Normalbedingungen flüssigen Verbindungen zeichnen sich gleichfalls durch hohe dielektrische Konstante sowie strukturell durch -S0₂- oder -CO-Gruppen bzw. besonders bevorzugt durch OH-Gruppen aus.Suitable thermal development and diffusion promoting agents according to the present invention are, for example, compounds which have become known from the literature on heat development processes as so-called thermal solvents, which are generally understood to mean non-hydrolyzable organic compounds which are solid under normal conditions , but melt when heated up to the temperature of the heat treatment and thereby supply a liquid medium in which the development processes can run faster. 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, such as, for example, its oleic acid ester, beeswax, monostearin, compounds with a high dielectric Constant which have a -S0 ₂ or -CO group, such as acetamide, lactams, succinamide, ethyl carbamate, urea, methylsulfonamide, ethylene carbonate, and also polar substances, as described ben in 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. In the in EP-A -0 1 ₁ 9 615 described hydrophilic thermal solvents are certain nitrogen-containing heterocyclic compounds or compounds with at least one -CO-, -SO ₂ -, -N ⁱ 0 or -OH group. The groups mentioned therefore represent characteristic structural features of the development and diffusion promotion agents used according to the invention, the groups -CO- and -S0 _{2 being present} in particular in one of the following groups:

The thermal development and diffusion promoting agents used according to the invention are by no means restricted to the thermal solvents known hitherto, ie to those compounds which are solid under normal conditions and only become liquid at the temperature of the heat treatment. According to the invention, those compounds which are already liquid under normal conditions are also, and in fact are preferred. However, these compounds should also have a hydrophilic character. the last-mentioned compounds which are liquid under normal conditions are likewise distinguished by high dielectric constants and structurally by -S0 ₂ - or -CO groups or particularly preferably by OH groups.

Water, ethylene glycol, glycerin and other well-solubilizing solvents are suitable examples of such thermal development and diffusion promoting mill according to the invention, which are liquid under normal conditions.

The thermal development and diffusion promoting agents are dispersed in the binder layer of the auxiliary sheet according to the invention, and in any case, if they are compounds which are solid under normal conditions, the customary dispersion methods can be used. The thermal development and diffusion promoting agents can, for example, be added to the solution or dispersion (casting solution) of a binder in the form of a solution or dispersion in an easily removable solvent. Suitable methods for this are known to the person skilled in the art. In particular, if the thermal development and diffusion promoting agent according to the invention is a compound that is liquid under normal conditions, an incorporation method is preferably used in which the compound in question is added to the binder and contained therein in small capsules (microcapsules) made of a polymeric material is dispersed.

This method also makes it possible to produce an auxiliary sheet according to the invention from liquids, which feels dry and solid under normal conditions and is nevertheless capable of releasing the compounds in question when heated to the temperature of the heat development set, the release can take place in various ways, for example by melting the capsule material or blowing up the capsule wall, or by thermal diffusion through the capsule wall. Methods for encapsulating liquids (microencapsulation) are known to the person skilled in the art. For example, reference can be made to the monograph "Microcapsule Processing and Technology" by A. Kondo, Marcel Dekker Inc. New York and Basel.

Suitable liquid thermal development and diffusion promoting agents according to the invention, which are used in encapsulated form, are, for example, water, glycerol and mixtures thereof, it being possible to use other well-solubilizing solvents instead of glycerol or in addition. A suitable capsule material is, for example, polystyrene. Water can also be added to the binder layer of the auxiliary sheet in the form of water of crystallization; in this case there is no need for encapsulation. The same also applies to other hydrophilic liquids which can be bound as ligands in the crystal lattice of crystallizing substances.

The amount of thermal development and diffusion promoting agent in the auxiliary sheet depends of course on the number and thickness of the layers in the recording material used and the most favorable amount can be determined in a particular case by a series of tests. In general, it is sufficient if the thermal development and diffusion promoting agent is present in the auxiliary sheet in an amount of 1 to 4 g / m ² .

The binder of the auxiliary sheet as well as the binder of the layers of the color photographic recording material can be both hydrophobic and hydrophilic binders, but the latter are preferred. Gelatin is preferably used. However, this can be replaced in whole or in part by other natural or synthetic binders. On natural binders e.g. Alginic acid and its derivatives such as salts, esters or amides, cellulose derivatives such as carboxymethyl cellulose, alkyl cellulose such as hydroxyethyl cellulose, starch and its derivatives and caragenates are suitable. Synthetic binders include polyvinyl alcohol, partially saponified polyvinyl acetate and polyvinyl pyrrolidone.

Examples of hydrophobic binders are polymers made from polymerizable ethylenically unsaturated monomers such as alkyl acrylates, alkyl methacrylates, styrene, vinyl chloride, vinyl acetate, acrylonitrile and acrylamides. Such polymers can be used in latex form, for example.

In addition to the thermal development and diffusion promotion agents according to the invention, the auxiliary sheet, and here preferably in the binder layer, which also contains the thermal development and diffusion promotion agents, can contain further auxiliaries which are also beneficial for the development processes taking place during the heat treatment.

These are essentially electron transfer agents and base donors. Such auxiliaries can also be at least partially contained in the color photographic recording material and are therefore explained in detail below in the description of the color photographic recording material. Suitable base donors are, for example, compounds of the sodium benzotriazolate type which crystallize as a complex with various amounts of water (up to 24 mol H ₂ 0) and which are described in US Pat. No. 4,418,139, but only as H ₂ 0 donors there . The alkali salts of other organic compounds with a similarly high pK _a value are equally suitable as base donors.

Over the binder layer of the auxiliary sheet, which according to the invention contains the development and diffusion promoting agents and optionally other auxiliary substances, a further hardened binder layer, e.g. a hardened gelatin layer may be arranged.

The color photographic recording material used in the method according to the invention is of the integral type, i.e. it contains both the image-receiving layer and the light-sensitive layers on a common substrate. The laminate formed from the layers mentioned is preferably arranged on the support so that the image-receiving layer faces the support and the light-sensitive layers face away from the support.

In the method according to the invention, the image-receiving layer is thus arranged on the same layer support as the light-sensitive element (single 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.

Furthermore, 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, for example in gelatin, polyvinylpyrrolidone, completely or partially hydrolyzed cellulose esters. Of course, some binders can also act as mordants, for example polymers of nitrogen-containing, optionally quaternary bases, such as N-methyl-4-vinylpyridine, 4-vinylpyridine, 1-vinylimidazole, as described, for example, in US Pat. No. 2,484,430. Others Useful pickling binders 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, other binders, for example gelatin, will be added to the last-mentioned pickling binders.

The light-sensitive part of the color photographic recording material used in the heat development process according to the invention comprises at least one binder layer which contains a light-sensitive silver halide, optionally in combination with a substantially non-light-sensitive silver salt, and which is associated with a non-diffusing color-providing compound which provides a diffusible dye by heat development can.

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 μm, 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 2.0 g per m ² , the actual amount of the silver halide used, due to its catalytic function (as exposed silver halide) in some embodiments, mainly in the lower part of the stated Area moved.

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 fumarate, silver tartrate, silver furoate, silver linolate, silver adipate, silver sebacate, silver succinate, silver acetate or silver acetate. The carboxylic acids on which these silver salts are based can be substituted, for example, by halogen atoms, hydroxyl groups or thioether groups.

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. Are also suitable Silver salts of organic mercaptans, for example the silver salts of 3-mercapto-4-phenyl-1,2,4-triazole, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, 2-mercaptooxadiazole, mercaptotriazine, thioglycolic acid, and also the silver salts of dithio , 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, and also the silver salts of 1,2,4-triazole, 1-H-tetrazole, carbazole, saccharin and silver salts of imidazole, benzimidazole and their 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-light-sensitive silver salt and the light-sensitive silver halide can be present side by side as separate particles or in a combined form, which can be produced, for example, by treating a substantially non-light-sensitive silver salt in the presence of halide ions, the surface of which Particles from the essentially non-photosensitive Lichen silver salt by double conversion (conversion) form photosensitive centers from photosensitive silver halide. For this purpose, 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 component of the light-sensitive part of the recording material used in the heat development process 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. Int. Ed. Engl. 22 (1983), 191-209, in which the most important of the known systems are described.

worin bedeuten

Als Ballastreste sind solche Reste anzusehen, die es ermöglichen, die erfindungsgemäßen Farbabspalter in den üblicherweise bei fotografischen Materialien verwendeten hydrophilen Kolloiden diffusionsfest einzulagern. Hierzu sind vorzugsweise organische Reste geeignet, die im allgemeinen geradkettige oder verzweigte aliphatische Gruppen mit im allgemeinen 8 bis 20 C-Atomen und gegebenenfalls auch carbocyclische oder heterocyclische gegebenenfalls aromatische Gruppen enthalten. Mit dem übrigen Molekülteil sind diese Reste entweder direkt oder indirekt, z.B. über eine der folgenden Gruppen verbunden: -NHCO-, NHS0₂-, -NR-, wobei R Wasserstoff oder Alkyl bedeutet, -0- oder -S-. Zusätzlich kann der Ballastrest auch wasserlöslichmachende Gruppen enthalten, wie z.B. Sulfogruppen oder Carboxylgruppen, die auch in anionischer Form vorliegen können. Da die Diffusionseigenschaften von der Molekülgröße der verwendeten Gesamtverbindung abhängen, genügt es in bestimmten Fällen, z.B. wenn das verwendete Gesamtmolekül groß genug ist, als Ballastreste auch kürzerkettige Reste zu verwenden.Redox-active color releasers of the formula have proven to be particularly advantageous

in what mean

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 preferred, which in all contain generally 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-, NHS0 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 omitted here with regard to the above-mentioned article in the app. Chem. Int. Ed. Engl. 22 (1983) 191-209.

For the sake of explanation only, a few 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 of the released dye. On the other hand, the functional group can also be separated from the chromophore of the dye by an intermediate member or a connecting member. 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 can be provided 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 or can only result from the cleavage of the dye residue from the carrier residue containing ballast groups. On suitable dyes, to be mentioned: azo dyes, azomethine dyes, anthraquinone dyes, phthalocyanine dyes, indigoid dyes, triphenylmethane dyes, including those 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, be it 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 is made between dye residues and the residues of dye precursors, the latter should also 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 14 669, 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 14 669, GB-A-80 12 242.

In some embodiments of the heat development method according to 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 using conventional negative working silver halide emulsions. You can therefore create positive or negative images by selecting suitable color releasing systems.

DE-A-26 45 656 is described, for example, in DE-A-26 45 656 which is particularly suitable for the heat-developable recording materials according to the invention. Examples include the following:

Farbabs ^p age 1

Paint release 2

Color saver 3

Other suitable oxidizable paint releasers are described, for example, in DE-A-22 42 762, DE-A-25 05 248, DE-A-26 13 005, GB-A-80 12 242.

Examples include the following:

Paint release 4

Paint splitter 5

Paint splitter 6

If the color splitter can be oxidized, then it itself represents a reducing agent which, directly or indirectly, with the participation of electron transfer agents (electron transfer agent, 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 possibly the essentially non-light-sensitive silver salt in the same binder layer is included. Even in the case of using reducible color separators in combination with electron donor compounds, the participation of electron transfer agents can prove to be favorable.

worin bedeuten

• R¹ Alkyl oder Aryl;
• R² Alkyl, Aryl oder eine Gruppierung, die zusammen mit R³ einen ankondensierten Ring vervollständigt;
• R³ 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;
• _R ⁴ Alkyl;
• R⁵ Alkyl oder vorzugsweise Wasserstoff;
• A den Rest eines diffusionsfähigen Farbstoffes oder Farbstoffvorläufers;
• X 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 Aralkylrest bedeutet und wotei die beiden Reste R die gleiche Bedeutung oder voneinander verschiedene Bedeutung haben können;
• L -O-, -CO-, -CONR^6-, -SO₂NR^6-, -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^l, R² ₉ 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 (original) when using negative working silver halide emulsions:

in what mean

• R ^{1 is} alkyl or aryl;
• R ^{2 is} alkyl, aryl or a group which together with R ^{3 completes} a fused ring;
• R ^{3 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;
• X is a bivalent link of the formula -R- (L) p- (R) _q -, in which R is an alkylene radical having 1-6 C atoms or an optionally substituted arylene or aralkyl radical and the two radicals R have the same meaning or can have different meanings from each other;
• L -O-, -CO-, -CONR ^6- , -SO ₂ NR ^6- , -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 ¹ , R ² ₉ R ³ and R ⁴ contains a ballast radical.

The alkyl radicals represented by R ¹ , 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 represented by the radicals R ¹ , R ² and R ^{3 mentioned} Aryl radicals 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 ¹ , R ² and R ^{3 are combined} in a quinoid carrier residue. not contain more than 8, in particular not more than 5 carbon atoms, and R ^{4 represents} an alkyl radical with at least 11 carbon atoms.

Preferred embodiments are furthermore those in which R ^{i 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 R¹, R² ₉ R³, R4 und R⁵ die für Formel II angegebene Bedeutung haben.These color releasers contain a diffusion-releasable quinoid carrier residue of the formula bound to the dye residue

wherein R ¹ , R ² ₉ R ³ , R4 and R ^{5 have} the meaning given for formula II.

Such reducible dye releasers and others which are also suitable in the context of the present invention are described, for example, in DE-A-28 09 716, EP-A-0 004 399, DE-A-30 08 588, DE-A-30 14 669. Examples include the following:

Paint release 7

Paint splitter 8

Paint release 9

Paint release 10

Paint release 11

The electron donor compound used in combination with a reducible color releasing agent also serves as a reducing agent for the silver halide, the essentially non-photosensitive silver salt and the color releasing agent. Because the essentially non-light-sensitive silver salt and the color releaser compete with each other to a certain extent in the oxidation of the electron donor compound, but the latter is superior to the latter in any case in the presence of exposed silver halide, the silver halide present becomes determinant for that in accordance with a previous imagewise exposure Image areas within which the color releaser is converted into its reduced form by the electron donor compound.

The electron donor compound, which is present in a limited amount, is subjected to under the conditions of development, in the present case when the imagewise exposed color photographic recording material is heated in contact with the auxiliary sheet used according to the invention, in accordance with the extent of the exposure under the catalytic effect of the latent image nuclei produced by exposure in the silver halide the essentially non-photosensitive silver salt and the photosensitive silver halide oxidize and are consequently no longer available for reaction with the color releaser. This creates an image-like distribution of unused electron donor compound.

• 1. - das im wesentlichen nicht lichtempfindliche Silbersalz bzw. Silberhalogenid in Abwesenheit von Latentbildkeime,
• 2. - das im wesentlichen nicht lichtempfindliche Silbersalz bzw. Silberhalogenid in Gegenwart von Latentbildkeimen,
• 3. - den Farbabspalter.

The reaction between the electron donor compound and the color releaser required for the release of the diffusible dyes can naturally only take place where the electron donor compound has not previously been consumed by other reactions, for example in the present case by the imagewise oxidation by the essentially non-light-sensitive silver salt. An important prerequisite for the imaging mechanism according to this embodiment of the present invention is accordingly a suitably graded reactivity of those components which are potentially suitable for reaction with the reducing agent present in the layer, namely the electron donor compound. The components in question are

• 1. the essentially non-light-sensitive silver salt or silver halide in the absence of latent image nuclei,
• 2. the essentially non-light-sensitive silver salt or silver halide in the presence of latent image nuclei,
• 3. - the paint splitter.

It proves to be extremely favorable that, under the conditions of heat development, the components mentioned have the desired graded reactivity with regard to the reaction with the electron donor compound and that the reducing power of the latter is dimensioned such that the essentially non-photosensitive silver salt is absent through them practically not of latent image nuclei, but is reduced comparatively quickly in the presence of latent image nuclei and that the color releasing agent is reduced comparatively slowly but faster than the essentially non-photosensitive metal salt (in the absence of latent image nuclei).

Derivatives of hydroquinone, benzisoxazolone, p-aminophenol or ascorbic acid (e.g. ascorbyl palmitate) which have not or only little diffusing have been described as electron donor compounds (DE-A-28 09 716).

Further examples of electron donor compounds are described in 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 and EP-A- 0 124 915 known. It has been shown that the electron donor compounds mentioned also meet the requirements placed on them under the conditions of heat development and are therefore also suitable as electron donor compounds in the context of the present invention. Particularly suitable are those electron donor compounds which are formed from the corresponding electron donor precursor compounds only under the conditions of heat development in the layer, i.e. Electron donor compounds which are present in the recording material before development only in a capped form 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.

Die genannten wesentlichen Bestandteile den bei dem erfindungsgemäßen Verfahren verwendeten Aufzeichnung.- materials, nämlich das lichtempfindliche Silberhalopenid, das gegebenenfalls vorhandene im wesentlichen nicht lichtempfindliche reduzierbare Silbersalz und der Farbabspalter, gegebenenfalls in Kombination mit einer Elektronendonorverbindung liegen nebeneinander in einem Bindemittel dispergiert vor. Hierbei kann es sich ebenso wie bei dem erfindungsgemäßen Hilfsblatt gleichermaßen um hydrophobe wie hydrophile Bindemittel handeln, letztere sind jedoch bevorzugt und vorzugsweise wird Gelatine verwendet, die aber auch hier ganz oder teilweise durch andere natürliche oder synthetische Bindemittel ersetzt werden kann.In the present case, the electron donor precursor compounds mentioned are also understood as electron donor compounds. A suitable electron donor compound is, for example, a compound of the following formula

The above-mentioned essential constituents of the recording materials used in the process according to the invention, namely the light-sensitive silver halopenide, the possibly non-light-sensitive reducible silver salt and the color releaser, optionally in combination with an electron donor compound, are dispersed next to one another in a binder. As with the auxiliary sheet according to the invention, these can be hydrophobic and hydrophilic binders alike, but the latter are preferred and gelatin is preferably used, but here as well it can be replaced in whole or in part by other natural or synthetic binders.

For the production of monochrome color images, the light-sensitive binder layer contains one or more color releasers associated with the light-sensitive silver halide and optionally the non-light-sensitive silver salt, from which dyes of a specific color are released. The overall resulting color can be obtained by mixing several dyes. In this way it is also possible to produce black and white images by precisely coordinating the mixing of several color separators of different colors. For the production of multicolored color images, the color photographic recording material used in the method according to the invention contains several, ie generally three, assignments of color releasers and in each case differently sensitized to different spectrums Silver halide, wherein preferably the absorption range of the dye released from the dye releaser essentially coincides with the range of the spectral sensitivity of the assigned silver halide. The different assignments of color releaser and assigned silver halide can be accommodated in different binder layers of the color photographic recording material, preferably between these different binder layers there are separating layers made of a water-permeable binder, for example gelatin, which essentially have the function of separating the different assignments from one another and to counteract color distortion in this way. In such a case, the color photographic recording material used in the method according to the invention contains, for example, a light-sensitive binder layer in which the silver halide contained therein is predominantly red-sensitive due to spectral sensitization, a further light-sensitive binder layer in which the silver halide contained therein is mainly green-sensitive due to spectral sensitization, and a third light-sensitive binder layer in which the silver halide contained therein is predominantly blue-sensitive due to its inherent sensitivity or due to spectral sensitization. The electron donor compounds optionally contained in the three light-sensitive layers can be the same or different. Each of the above-mentioned assignments of photosensitive silver halide, essentially non-photosensitive silver salt (if present) and color releasers can also be used in the form of a so-called complex coacervate.

A complex coacervate is understood to mean a form of dispersion 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 through 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 dilute 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, a dispersion of coacervate particles is obtained in which the solid (in the present case, the photosensitive silver halide and ge optionally the essentially non-photosensitive silver salt) and oily droplets of a solution of the organic constituents (in the present case the paint releasing agent and optionally further 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. Conveniently, the dispersion prior to curing at a temperature of 25 ^* C or below, preferably 10 ^* C or chilled below, whereby a packet emulsion of good quality is obtained.

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

The use of packet emulsions makes it possible to combine several emulsion components of different spectral sensitivity, including the relevant colorate splitters, in a single binder layer, without losing the spectral assignment and thereby causing color falsification. This is possible because the degree of exposure of a particular silver halide particle becomes almost exclusively the determining factor for the degree of dye release from the color releaser which is in the same coacervate particle (package) as the silver halide. The use of packet emulsions thus enables a blue-sensitive, a green-sensitive and a red-sensitive silver halide emulsion to be accommodated with any essentially non-light-sensitive silver salt and spectrally assigned color separators in the same binder layer without fear of serious color falsification,

In addition to the constituents already mentioned, the color photographic recording material used in the process according to the invention may contain further constituents and auxiliary substances which are beneficial, for example, for carrying out the heat treatment and the color transfer which takes place in the process. These further constituents or auxiliary substances can be contained in a light-sensitive layer or in a non-sensitive layer. However, as already mentioned, they can also be contained in whole or in part in the auxiliary sheet used according to the invention.

Such auxiliary substances 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 oxi in the case of use The detachable paint splitter is identical to the latter, or, in the case of the use of reducible paint splitter, in turn reacts with the paint splitter. Since this reaction consists mainly of electron transfer, 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 1/2 mole per mole of color releaser. The incorporation into the layer can, for example, from solutions in water-soluble solvents or in the form of aqueous. Dispersions that were obtained using oil formers take place.

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 alipha, are to be mentioned here, for example table carboxylic acids. By providing the basic substances, 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 color releasers and their diffusion into the image-receiving layer.

Between the image-receiving layer and the light-sensitive layers of the color photographic recording material used in the invention, an opaque light-reflecting layer which is permeable to alkali and the thermal development and diffusion promoting agent according to the invention is expediently arranged. This layer essentially has the function of shielding or covering the (negative) color image formed and remaining in the photosensitive part during development from the viewing side and at the same time providing an aesthetically pleasing image background for the positive color image generated in the image receiving layer. This can be achieved in a known manner by means of a binder layer which contains a light, in particular white pigment, for example Ti0 ₂ . It goes without saying that with this configuration of the support, the recording material must be transparent.

However, if the light-sensitive part is separated from the image-receiving layer by means of a suitable peel-off layer after the development of heat, such an opaque light-reflecting intermediate layer is unnecessary and the support of the recording material does not necessarily have to be transparent.

The development of the imagewise exposed color photographic recording material is initiated according to the invention by subjecting it to a heat treatment in contact with the auxiliary sheet according to the invention, in which the layers are heated to an elevated temperature, for example in the range of 80, for a period of about 0.5 to 300 s up to 250 ^* C. Here, the thermal development and diffusion promoting agents are released in the auxiliary sheet and reach the layers of the recording material, where they create suitable conditions for the development processes, including dye diffusion, without the need to supply a liquid medium, for example in the form of a developer bath. During development, dyes that are diffusible in terms of image are released from the colorate splitters and transferred to the image-receiving layer, which is an integral part of the color photographic recording material.

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

The auxiliary sheet can remain in contact with the recording material or be separated again after development is complete. The color transfer image is visible through the transparent substrate.

example 1 Polystyrene capsules with glycerin / water (1: 1)

200 ml of water were mixed with 250 ml of glycerin and 50 ml of 10% aqueous gelatin solution. Half of this mixture was added with vigorous stirring within 5 min to 200 ml of a 30'C warm 10% solution of polystyrene in chloroform. The mixture was then stirred for about 5 minutes until droplets of about 5 μm were obtained. The remaining half of the above mixture was added all at once. The chloroform was evaporated by heating to 75-80 ° C with continued stirring. The capsule suspension obtained was cooled to 30 to 35 ° C., suction filtered and washed with 300 ml glycerol / water (1: 1).

Yield: 40 g polystyrene capsules containing glycerol / water (1: 1) approx. 20 g.

Example 2 Auxiliary sheet

250 g of an emulsate from 1000 g of 5% aqueous gelatin, 8 g of 75% paste from sodium dodecylbenzenesulfonate, 100 g of paladinol and 3.5 g of phenol were melted and mixed with 40 g of polystyrene capsules from Example 1 and 30 g of sodium benzotriazole homogenized in a high-speed mixer and then degassed. The casting solution was coated on a layer of polyethylene terephthalate (wet layer thickness 100 μm), covered with gelatin (1 g / m ² ) and cured.

Example 3 Preparation of the silver salt emulsions Emulsion 1

17.0 g of AgNO ₃ , dissolved in 100 ml of water at 45 ° C., became a 45 ° C. solution of 20.0 g of gelatin in 1000 ml of water which contained 13.0 g of benzotriazole (BTA) within 2 minutes , metered in with stirring. The mixture was then stirred for 5 minutes. A solution of 1.0 g KBr and 0.66 g KI in 100 ml 45 ° C warm water was metered in over 5 min. The pH was adjusted to 5.0 using 5% Na ₂ CO ₃ solution. By adding 20 ml of a 10 Xigen polystyrene sulfonic acid solution, cooling to 25 ° C. and addition of 10% strength sulfuric acid (up to pH 3.0 to 3.5) were flocculated and then washed 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 CQ ₃ solution, mixed with 5 ml of 1% aqueous phenol solution and brought to a final weight of 500 g by addition.

Emulsion 2

Preparation as for emulsion 1, with the exception that no KBr / KI solution was added. Final weight 435 g.

Emulsion 3

34.0 g of AgN0 ₃ dissolved in 200 ml of water were metered in over the course of 10 min to a 50 ° C. solution of 40.0 g of gelatin, 23.7 g of KBr and 1.66 g of KI. The mixture was then stirred at 50 ° C for 20 min and then cooled to 35 ° C. 40 ml of a 10 Xigen polystyrene sulfonic acid solution was added dropwise and then it was cooled to 20 ° C. The mixture was flocculated by adding 10% strength sulfuric acid (up to pH 3.0 to 3.5) and washed three times with 700 ml of water each time. The mixture was then heated to 40 ° C. and adjusted to pH 6.0 with 10% sodium hydroxide solution. Final weight 1171 g.

Example 4

Manufacture of the Dispergate

Dispersant 1 (cyan paint releasing agent)

50 g of dye releaser 7 (cyan) were dissolved in a mixture of 40 g of tricresyl 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 10 (magenta) were dissolved in a mixture of 64 g of tricresyl phosphate and 21 g of diethyl laurylamide and dispersed in 833 g of 6% aqueous gelatin solution in the presence of 1.7 g of sodium dodecylbenzenesulfonate.

Dispersant 3 (color releasing agent yellow)

50 g of color releaser 11 (yellow) were dissolved in a mixture of 47 g of tricresyl phosphate and 46 g of diethylamide of palmitic acid 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)

100 g of the compound of the formula below were dissolved in 200 g of diethyl lauramide and dispersed in 1000 g of 10% gelatin solution with the addition of 4.7 g of a 75% Xigen paste of sodium dodecylbenzenesulfonate.

Example 5

Production of the package emulsions

PE-1 (cyan)

34.4 g of emulsion 3 were melted at 40 ° C. and spectrally sensitized by adding a 0.1% methanolic solution of a red sensitizer in an amount of 8 × 10 ^-4 mol per mol of silver halide and digested at 40 ° C. for 70 min. Then 25.6 g of emulsion 2 and 35 ml of 40 ° C warm water were added. 44.8 g of disperse 1 (cyan) and 11.2 g of disperse 4 were then added.

55 ml of a 10% gum arabic solution were then added and the mixture was stirred for 15 minutes, after which 140 ml of 40 ° C. warm water were added dropwise over the course of 4 minutes. The pH was adjusted to 4.8 by slowly adding 1% acetic acid and stirring was continued for 15 min. with continued stirring, the mixture was then rapidly cooled to about 8 ° C. and a solution of 0.55 g of Chromalann in 160 ml of water was metered in over the course of 4 minutes. Stirring was 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 approximately 7 μm.

PE-2 (magenta)

• Grünsensibilisator (8 x 10^-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 (8 x 10 ^-4 mol per mol 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 approximately 10 μm were obtained.

PE-3 (yellow)

• Blausensibilisator (8 x 10^-4 mol pro mol Silberhalogenid) anstelle von Rotsensibilisator,
• 32,2 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 (8 x 10 ^-4 mol per mol silver halide) instead of red sensitizer,
• 32.2 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)

• anstelle der Abmischung der Emulsionen 2 und 3 wurden 59 g Emulsion 1 verwendet.

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

• instead of mixing emulsions 2 and 3, 59 g of emulsion 1 were used.

Yield: 45 g.

PE-5 (magenta)

In a manner analogous to that described for PE-2, PE-5 was also prepared, but 59 g of emulsion 1 were used instead of the mixture of emulsions 2 and 3.

Yield: 39 g.

PE-6 (yellow)

PE-6 was also prepared in an analogous manner to that described for PE-3, but 59 g of emulsion 1 were used instead of the mixture of emulsions 2 and 3.

Yield: 51 g.

PE-7 (cyan)

PE-7 was also prepared in an analogous manner to that described for PE-1, but 68.9 g of emulsion 3 were used instead of the mixture of emulsions 2 and 3.

PE-8 (magenta)

PE-8 was also prepared in an analogous manner to that described for PE-2, but 68.9 g of emulsion 3 were used instead of the mixture of emulsions 2 and 3.

Yield: 43 g.

PE-9 (yellow)

PE-9 was also prepared in an analogous manner to that described for PE-3, but 68.9 g of emulsion 3 were used instead of the mixture of emulsions 2 and 3.

Yield: 53 g.

The following spectral sensitizers were used.

Red sensitizer:

Green sensitizer:

Blue sensitizer:

Example 6

• 1. Eine Beizschicht mit 2 g Polyurethanbeize aus 4,4'-Diphenylmethandiisocyanat und N-Ethyldiethanolamin, quaterniert mit Epichlorhydrin gemäß DE-A-2 631 521, Beispiel 1, und 2 g Gelatine.
• 2. Eine lichtreflektierende Schicht mit 13 g Ti0₂ und 1,3 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 made of 4,4'-diphenylmethane diisocyanate and N-ethyldiethanolamine, quaternized with epichlorohydrin according to DE-A-2 631 521, Example 1, and 2 g of gelatin.
• 2. A light reflecting layer with 13 g Ti0 ₂ and 1.3 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.

Example 7

Using the coating underlay (image receiving part) with layers 1, 2 and 3 described in Example 6, a photographic recording material (material 1) was prepared as follows.

34.4 g of emulsion 3 were melted at 40 ° C. and spectrally sensitized by adding a 0.1% methanolic solution of the red sensitizer (example 5) in an amount of 8 × 10 ^-4 mol per mol of silver halide and for 70 min at 40 ° C digested. Then 25.6 g of Emulsion 2 and 35 ml of warm water were added. 44.8 g of disperse 1, 11.2 g of disperse 4, 40 ml of a 10% strength aqueous solution of guanidine trichloroacetate, 4 ml of Triton X® wetting agent, 4% strength (alkylaryl polyether alcohol; manufacturer Rohm & Haas Company, Philadelphia) were also added, 18.4 g of Disperse 5 (auxiliary developer) and a solution of 19 g of gelatin in 170 ml of water. The coating solution thus obtained was applied as a fourth layer to the coating base described above with a wet layer thickness of 100 μm. After drying, a gelatin protective layer of 1 g / m ^{2 was} applied as the fifth layer.

Material 1 thus produced was (after drying) exposed to red light behind a gray wedge and then laminated with the auxiliary sheet described in Example 2, then heated uniformly to 110 ° C. for 4 minutes. A blue-green transmission image with a minimum density (Dmin) 0.78 and a maximum density (Dmax) 1.20 was produced in the image-receiving layer through the transparent layer support. If material 1 was stored at room temperature for 4 weeks before exposure, then virtually unchanged Dmin and Dmax values were obtained with 0.81 and 1.24.

Example 8

Using the coating underlay described in Example 6 with the layers 1, 2 and 3 and the package emulsions described in Example 5, photographic recording materials (materials 2 to 10) were produced as follows.

A coating solution was applied as the fourth layer, which was prepared from one of the package emulsions PE-1 to PE-9 described in Example 5 by homogenizing each of the package emulsions with 100 ml of water for 10 minutes and with 40 ml of a 10% guanidine trichloroacetate solution, 4 ml of Triton X® wetting agent, 4 Xig, 18.4 g of dispersant 5 (auxiliary developer) and a solution of 19 g of gelatin in 170 ml of water were added. The casting solutions thus obtained were applied as a fourth layer with a wet layer thickness of 100 µm. In the case of materials 8, 9 and 10, 64 mg of 1-phenyl-5-mercaptotetrazole in methanolic solution had additionally been added to the casting solution per 100 g of AgNO ₃ .

A gelatin protective layer (1 g / m ² ) was applied as the fifth layer. It was then cured and dried.

Aus Tabelle 1 ist ersichtlich, daß unabhängig von dem gewählten speziellen Emulsionstyp ein gutes Verhältnis zwischen Dmin und Dmax erzielt wurde. Nach vierwöchiger Lagerung waren die erhaltenen Dmin- und Dmax-Werte nur geringfügig angestiegen.A sample of each of the materials 2 to 10 thus produced was exposed to red, green or blue light by filter exposure in accordance with the respective spectral sensitization behind a gray wedge. The subsequent processing (heat treatment) was carried out as in Example 7 described. Visible color wedges with the Dmin and Dmax values shown in Table 1 were obtained through the transparent layer support. A further sample of materials 2 to 10 was initially stored at room temperature for 4 weeks and only then exposed and processed. The values obtained are given in brackets in Table 1.

It can be seen from Table 1 that a good ratio between Dmin and Dmax was achieved regardless of the particular emulsion type chosen. After four weeks of storage, the Dmin and Dmax values obtained had risen only slightly.

Example 9

• 4. Schicht: Abmischung der in Beispiel 6 beschriebenen Gießlösungen für die vierte Schicht der Materialien 2 und 3 mit den Paketemulsionen PE-1 und PE-2, Naßauftrag 200 µm.
• 5. Schicht: Gelbfilterschicht mit 1 g Gelatine pro m² und einem Gelbfilterfarbstoff; Dichte ca. 2,0.
• 6. Schicht: Die in Beispiel 6 beschriebene Gießlösung für die vierte Schicht des Materials 4 mit der Paketemulsion PE-3, Naßauftrag 100 um.
• 7. Schicht: Schutzschicht mit 1 g Gelatine pro m².
• 8. Schicht: Härtungsschicht.

Using the coating substrates described in Example 6 with layers 1, 2 and 3, the following further layers were applied in succession (material 11):

• 4th layer: Mixing of the casting solutions described in Example 6 for the fourth layer of materials 2 and 3 with the packet emulsions PE-1 and PE-2, wet application 200 μm.
• 5th layer: yellow filter layer with 1 g gelatin per m ² and a yellow filter dye; Density approx.2.0.
• 6th layer: The casting solution described in Example 6 for the fourth layer of material 4 with the packet emulsion PE-3, wet application 100 .mu.m.
• 7th layer: protective layer with 1 g gelatin per m ² .
• 8th layer: hardening layer.

Example 10

• 4. Schicht: Abmischung der in Beispiel 8 beschriebenen Gießlösung für die vierte Schicht der Materialien 2, 3 und 4 mit den Paketemulsionen PE-1, PE-2 und PE-3, Naßauftrag 300 µm.
• 5. Schicht: Schutzschicht mit 1 g Gelatine pro m².
• 6. Schicht: Härtungsschicht.

The following further layers were applied using the coating base described in Example 6 (material 12):

• 4th layer: Mixing of the casting solution described in Example 8 for the fourth layer of materials 2, 3 and 4 with the packet emulsions PE-1, PE-2 and PE-3, wet application 300 μm.
• 5th layer: protective layer with 1 g gelatin per m ² .
• 6th layer: hardening layer.

Example 11

Bei Material 12 wird für alle drei Farben annähernd die gleiche hohe Maximaldichte erreicht. Dahingegen bleibt bei Material 11 die Gelbdichte aufgrund des längeren Diffusionsweges etwas zurück. Jedoch kann dies bis zu einem gewissen Grade durch erhöhte Naßaufträge der betreffenden Paketemulsionen ausgeglichen werden.The photographic materials described in Examples 9 and 10 were exposed to red, green and blue light through a combination filter and subjected to the heat treatment described in Example 5, the results obtained are shown in Table 2.

With material 12, approximately the same high maximum density is achieved for all three colors. In contrast, the yellow density in material 11 remains somewhat due to the longer diffusion path. However, this can be offset to a certain extent by increased wet orders for the package emulsions in question.

Example 12

When the photographic materials described in Examples 7, 8, 9 and 10 were exposed to red, green and blue light through a combination pull-out filter and subjected to the heat treatment described in Example 7 but in the absence of the auxiliary sheet according to the invention, no color transfer was obtained. This development or color transfer state corresponds, based on the amount of water available, to the state of equilibrium of the residual moisture of the recording material with its surroundings.

Claims (10)

1. Heat development process for producing colored images, in which an imagewise exposed color photographic recording material, consisting of a laminate arranged on a layer support of at least one image-receiving layer that can be colored by diffusible dyes and at least one binder layer, the light-sensitive silver halide, optionally in combination with an essentially non-light-sensitive one Contains silver salt and which is associated with a non-diffusing coloring compound which, as a result of the development, is able to release a diffusible dye, is developed by heat treatment in the presence of a thermal development and diffusion promoting agent, characterized in that the heat treatment is carried out while the color photographic recording material is in surface contact on the coating side with an applied auxiliary sheet which contains at least one th in a binder layer contains developmental and diffusion-promoting agents1 in dispersed form. 2. Heat development process according to claim 1, characterized in that an auxiliary sheet is used which contains a thermal development and diffusion promoting agent which is liquid under normal conditions in dispersed form. 3. Thermal development method according to claim 1 or 2, characterized in that an auxiliary sheet is used which, dispersed in a binder layer, contains a hydrophilic compound having at least one -CO-, -S0 ₂ -, -N → O or OH group, which at is liquid at a temperature above 80 ° C. 4. Heat development process according to claim 2, characterized by the use of an auxiliary sheet with microcapsules dispersed in a binder layer made of a polymeric organic material, which contain a thermal development and diffusion promoting agent which is liquid under normal conditions. 5. Heat development process according to claim 4, characterized in that water, ethylene glycol, propylene glycol, butylene glycol or glycerol or mixtures thereof are used in encapsulated form as a thermal development and diffusion promoting agent. 6. Heat development process according to claim 4, characterized in that polystyrene is used as the capsule material. 7. The heat development process according to claim 1, characterized by the use of a color photographic recording material which contains an image-receiving layer, an opaque, light-reflecting layer and one or more binder layers with the photosensitive silver halide contained therein and associated color-imparting compounds on a transparent support in the following order. 8. Auxiliary sheet for the heat development process according to claim 1, with a binder layer arranged on a support, which contains a thermal development and diffusion promoting agent in dispersed form. 9. auxiliary sheet according to claim 8, characterized in that the binder layer as a thermal development and diffusion promoting agent contains a hydrophilic compound with at least one -CO-, -S0 ₂ -, -N → O or OH group, which at a temperature above 80 ° C is liquid. 10 auxiliary sheet according to claim 8, characterized in that the binder layer as a thermal development and diffusion promoting agent contains a dispersion of a liquid under normal conditions development and diffusion promoting agent in microencapsulated form.