EP0078959B1 - Colour-photographic recording material with non-diffusing electron donor precursor compounds - Google Patents

Description

The invention relates to a color photographic recording material having at least one light-sensitive silver halide emulsion layer which contains non-diffusing electron donor precursor compounds from which strong reducing agents are formed under the conditions of alkaline development. In particular, the invention relates to a recording material in which the electron donor precursor compounds mentioned are used in combination with non-diffusing reducible coloring compounds which, in the reduced state under the conditions of alkaline development, release diffusible dyes, which as such or after conversion into their metal complexes for image formation serve.

DE-OS 2 809 716 describes coloring compounds with an electron-accepting nucleophilic precursor group, which in the reduced state are subject to an intramolecular nucleophilic displacement reaction under the conditions of alkaline development with the release of a diffusible dye.

The reduction is brought about by so-called electron donor compounds (ED compounds). which are present in the layers in addition to the coloring compounds and which are oxidized imagewise during development and are therefore consumed.

The remaining imagewise distribution (positive residual image) of the ED compounds reacts with the coloring compound and triggers the imagewise release of diffusible dyes. The ED compounds described there are, for example, derivatives of benzisoxazolone. of hydroquinone, p-aminophenol and ascorbic acid. In order to enable the generation of high-quality images by the process described in DE-OS 2 809 716, the ED compounds must not only be able to be oxidized by exposed silver halide or by silver halide developer oxidation products, but must also be able to use the coloring compounds themselves to reduce. In addition, the respective rates of oxidation or reduction reaction must be optimally adjusted to one another in such a way that the ED compound is already oxidized to a remarkable extent in the course of development before it can in turn reduce the coloring compound. The known ED connections do not meet these requirements in every respect, which manifests itself, for example, in an inadequate color density and / or in an unacceptable color haze of the color transmission images produced.

The high reduction capacity of suitable ED compounds also results in a high sensitivity to oxidation, which manifests itself in premature, non-imagewise consumption of the ED compounds due to oxidation when the photographic recording material is stored for a prolonged period, and this results in deteriorated image properties of the transfer image, which consist particularly in an inadequate color density. From DE-OS2809716 it is also known to use ED compounds not as such, but in the form of a less oxidation-sensitive precursor compound, from which the actual ED compound is only formed under the conditions of alkaline development. Examples of this are the ED connections ED-8, ED-9 and ED-10 of the aforementioned German published application. With the known ED precursor compounds, however, only an inadequate density of the color transfer image is obtained within an acceptable development time, which may be due to the fact that the actual ED compound either does not form quickly enough from its precursor compound or has an insufficient reduction capacity. Research Disclosure 19429 (June 1980) describes ED precursor compounds which are derived from α-hydroxyketones and which carry an electron-withdrawing group Z on the carbon atom.

The invention is based on the object of specifying new oxidation-stable ED precursor compounds which have good storage stability of the photographic material at elevated temperature and / or moisture and from which ED compounds with a high reducing capacity are only formed under the conditions of alkaline development. In particular in the color diffusion transfer process, they are intended to enable the generation of color transfer images with improved color density if they are used in combination with non-diffusing, reducible coloring compounds.

worin bedeuten :

• R' eine carbocyclische oder heterocyclische aromatische Gruppe ; und
• R² Wasserstoff, Alkyl, Alkenyl, Aryl oder Acyl ;

wobei wenigstens einer der Reste R' und R² einen Ballastrest enthält.The invention relates to a color photographic recording material having at least one light-sensitive silver halide emulsion layer and an associated non-diffusing coloring compound which contains in at least one light-sensitive silver halide emulsion layer or a non-light-sensitive binder layer a non-diffusing electron donor precursor compound (ED precursor compound) from which one does not exist under alkaline development conditions diffusing ED compound is formed, characterized in that the ED precursor compound corresponds to the following formula I:

in which mean:

• R 'is a carbocyclic or heterocyclic aromatic group; and
• R ^{2 is} hydrogen, alkyl, alkenyl, aryl or acyl;

wherein at least one of the radicals R 'and R ² contains a ballast radical.

The ED precursor compounds according to the invention are suitable for use in color photographic recording materials wherever it is a question of introducing strong reducing agents into the layers in a capped form, be it as a capped developing agent for silver halide or as a capped reducing agent to prevent the undesired diffusion of oxidation products, resulting from the development of silver halide. It is irrelevant what kind of coloring compounds are used for color image generation. These can be color couplers or coloring compounds that release diffusible dyes as a result of the development (color releasers). However, the preferred use of the ED precursor compounds according to the invention is in combination with non-diffusing, reducible coloring compounds. to see that release dyes that are diffusible in reduced form under the conditions of alkaline development.

A preferred subject of the invention is therefore a color photographic recording material with at least one light-sensitive silver halide emulsion layer and a combination of a non-diffusing, reducible coloring compound which is capable of releasing a diffusible dye in the reduced state under the alkaline development conditions, and a non-diffusing electron donor precursor compound ( ED precursor compound), from which a non-diffusing electron donor compound (ED compound) is formed under the alkaline development conditions, which is able to reduce the non-diffusing coloring compound under the alkaline development conditions, characterized in that the recording material is a compound of the ED precursor compound contains general formula I.

The aromatic group represented by R 'in formula I may be a carbocyclic group, e.g. B. a phenyl, naphthyl or anthracenyl group or a 5- or 6-membered heterocyclic group with at least one of the heteroatoms N, 0, S as a ring member, for. B. a furyl, thienyl, pyrryl or pyridyl group. The carbocyclic and heterocyclic aromatic groups can be unsubstituted or mono- or polysubstituted and contain fused carbocyclic or heterocyclic rings, which in this case need not be aromatic.

The aryl group represented by R ² in formula I is in particular a phenyl group, which can also be mono- or polysubstituted.

The acyl group represented by R ² in formula I is derived from aliphatic or aromatic carboxylic acids of the formula R-COOH, in which R represents alkyl, alkenyl, aryl or a heterocyclic group, or is, for example, a carbamoyl radical.

Examples of suitable substituents on the aromatic groups represented by R 'and on the aryl group represented by R ² are: halogen such as fluorine, chlorine, bromine or iodine, hydroxy, sulfo, sulfamoyl, trifluoromethyl, trifluoromethylsulfonyl, amino, nitro, cyano, carboxy , Carbamoyl, alkoxycarbonyl, alkyl, alkenyl, cycloalkyl, in particular cyclohexyl or cyclopentyl, aryl, in particular phenyl, or heterocyclic groups, where the last-mentioned groups (alkyl, alkenyl, cycloalkyl, aryl and heterocyclic groups) may contain further substituents, for. B. those of the aforementioned type and wherein said alkyl, alkenyl, cycloalkyl, aryl or heterocyclic groups are linked either directly or via one of the following divalent connecting members: -0-, -S-, -S0 ₂ -, -S0 ₂ -NR-, -NR-S0 ₂ -, -CO-, ―NR ― CO― -CO-NR-, -NR-COO-, ―0 ― CO ― NR―, -NR-CO-NR- (R = hydrogen or alkyl).

The alkyl or alkenyl groups represented by R ² or present in R 'and R ² as a substituent can be straight or branched and contain 1-22 C atoms, as well as optionally further substituted, for. B. by halogen (such as fluorine, chlorine or bromine), hydroxy, amino, alkoxy, aroxy, alkylthio, arylthio, a heterocyclic thioether group, alkylsulfonyl, arylsulfonyl or a heterocyclic group, such as a 5- or 6-membered bonded via a ring nitrogen atom heterocyclic ring.

In preferred embodiments of the invention, R 'is an optionally substituted phenyl group and R ² is, in preferred embodiments, an alkyl radical having 1 to 3 carbon atoms, which may optionally be substituted by halogen, alkoxy, aroxy or hydroxyl.

According to the invention, all of the substituents present in the ED precursor compound are such that the ED precursor compound cannot be diffusively incorporated into photographic layers. For this purpose, at least one of the radicals R 'and R ^{2 contains} a ballast radical. The radical R ¹ is preferably such that even after the acyl radical -COR2 has been split off under the influence of alkali, the residual molecule remains diffusion-resistant or has only a limited diffusion capacity. A diffusion-resistant storage of the ED precursor compound is particularly desirable because these compounds are used in a precise localization in a specific layer or in a specific quantity relation to assigned non-diffusing, reducible coloring compounds, which are also possible during long storage of the photograph the recording material should not change significantly.

Such residues are to be regarded as ballast residues, which make it possible to incorporate the compounds according to the invention in a diffusion-resistant manner in the hydrophilic colloids usually used in photographic materials. Organic radicals which generally contain straight-chain or branched aliphatic groups with generally 8 to 22 C atoms and optionally also carbocyclic or heterocyclic aromatic groups are preferably suitable for this purpose. With the rest of the molecule, these residues are either directly or indirectly, e.g. B. connected via one of the following groups; -NHCO-, -NHS0 ₂ -, -NR-, where R is hydrogen or alkyl, -0- or -S-. In addition, the diffusion-proofing residue may also contain water-solubilizing groups, such as. B. sulfo groups or carboxyl groups, which may also be present in anionic form in certain cases. Since the diffusion properties depend on the molecular size of the total compound used, it is sufficient in certain cases, e.g. B. if the total molecule used is large enough, or if the ED precursor compounds are incorporated into the layers using so-called oil formers or high-boiling coupler solvents in emulsified form, as ballast residues also shorter-chain residues, e.g. B. isoamyl or tert-butyl radicals to use.

Some examples of the non-diffusing ED precursor compounds used according to the invention are listed below:

The ED compounds according to the invention are a-substituted malonic acid diamides. For their preparation, it is expedient to start from aromatic amines of the formula R'-NH ₂ , which are condensed with diethyl malonate with the liberation of ethanol. The a-bromo compound is prepared from the malonic acid diamide obtained by known methods. The bromine atom is then exchanged for the remainder ―0 ― CO ― R ² . The production process is explained below using the example of compound 2.

Establishing connection 2

a) 15.1 g of 3-amino-4-methylbenzoic acid in 150 ml of dimethylformamide were mixed with 13.8 g of potassium carbonate and 30.5 g of hexadecyl bromide and heated with stirring on the boiling water bath for 2 hours. After cooling to room temperature, the reaction mixture was stirred in a mixture of 300 ml of methanol and 30 ml of water. The resulting precipitate was filtered off and stirred in succession in 200 ml of water and 300 ml of methanol, suctioned off again and air-dried.

Yield: 29 g.

b) 30 g of the compound obtained and 6.4 g of diethyl malonate were gradually heated to 220 ° C. while distilling off the ethanol which had been split off and kept at this temperature for 2 h. The reaction mixture was stirred with 50 ml of methanol and suction filtered. After stirring again with 50 ml of cyclohexane, 11 g of malonic acid anilide were obtained.

c) 6.5 g of the compound obtained under b) were mixed with 0.41 ml of bromine in a suspension in 50 ml of glacial acetic acid. The mixture was 15 min. heated to 60 ° C. After cooling to room temperature and adding 50 ml of methanol, the precipitate formed was suction filtered and washed with methanol.

Yield: 5.8 g.

Connection 2

2.4 g of ethoxyacetic acid and 2.1 g of potassium carbonate were successively added to 13.5 g of the compound obtained in c) in 120 ml of dimethylacetamide and the reaction mixture was stirred at room temperature for 3 h. The reaction mixture was then poured into a mixture of 300 ml of methanol, 30 ml of water and 10 ml of glacial acetic acid at 10 ° C. The resulting precipitate was filtered off and stirred in succession with 200 ml of water and 200 ml of methanol, suction filtered, washed with 50 ml of methanol and air-dried.

Yield: 11 g.

The ED precursor compounds according to the invention are the known ED compounds, e.g. As ascorbyl palmitate, as well as the known ED precursor compounds in that they can produce higher maximum color densities with lower minimum color densities (veils) within a given development time. It remains to be seen whether the higher maximum color densities obtained can be attributed to a slight cleavage (hydrolysis) of the acyl residue and thus to a faster availability of the actual ED compounds or to their higher reducibility or both.

Another advantage of the ED precursor compounds according to the invention is that they are present in an oxidation-insensitive form and are only converted into the ordinary ED compounds during development by treatment with aqueous alkali (hydrolytic elimination of the acyl group).

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 ;
• R⁴ 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 Aralkylenrest bedeutet und wobei die beiden Reste R die gleiche Bedeutung oder voneinander verschiedene Bedeutungen haben können ;
• L -0-, -CO-, ―CONR⁶―, ―SO₂NR⁶―, ―0―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.The reducible color releasers used in combination with the ED precursor compounds according to the invention release a diffusible dye under alkaline development conditions by reduction or as a result of a reduction. Reducible color releasers are described in DE-OS 2 809 716, in DE-OS 3 008 588, DE-OS 3 014 669, in EP-A 0 004 399 and in GB-A8012242. Reducible color releasers particularly preferably used according to the invention correspond to the following formula II:

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―, where R is an alkylene radical with 1-6 C atoms or an optionally substituted arylene or aralkylene radical and where the two radicals R have the same meaning or can have different meanings from each other;
• L -0-, -CO-, ―CONR ⁶ -, ―SO ₂ NR ⁶ -, ―0 ― 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 ¹ , R ² , R ³ and R ⁵ in formula 11 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 said radicals R ', R ² and R ³ are, for example, phenyl groups which may be substituted, for. B. 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 condensed rings completed by R ² and R ³ are preferably carbocyclic rings, e.g. B. fused 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 include 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 together contain in a quinoid carrier radical not 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 ^{1 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.

« Carquin » worin R', R², R³, R⁴, R⁵ die bereits angegebenen Bedeutungen haben.The preferably used reducible dye releasers contain, per dye residue A, a diffusion-releasable quinoid carrier residue of the formula

"Carquin" wherein R ', R ² , R ³ , R ⁴ , R ^{5 have} the meanings already given.

In principle, the residues of dyes of all classes of dyes are suitable as dye residues insofar as they are sufficiently diffusible to be able to diffuse through the layers of the light-sensitive material into the 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 may already have been pre-formed in the dye releasers used according to the invention or may only result from the cleavage of the dye residue from the carrier residue which contains ballast groups. The following are mentioned as dyes which are particularly suitable for the process according to the invention: azo dyes, azomethine dyes, anthraquinone dyes, phthalocyanine dyes, indigo dyes, triphenylmethane dyes, including those dyes which 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, are subject to customary or additional processing steps, either by oxidation, by coupling, by complex formation or by exposure of an auxochromic group in a chromophoric system, for example by Saponification to 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.

In a preferred embodiment of the present invention, the color photographic recording material in monochromatic processes contains at least one, in processes for producing multicolored images usually at least three image-forming layer units, each of which has at least one light-sensitive silver halide emulsion layer and a combination of a non-diffusing reducible coloring compound associated therewith and contains an electron donor compound, an ED precursor compound according to the invention being used in at least one layer unit. As a rule, one of the layer units is predominantly sensitive to blue light, another one to green light and a third one to red light, the assigned coloring compounds each providing complement-colored image dyes.

The term “assignment and” assigned means that the mutual arrangement of silver halide emulsions, ED compound or ED precursor compound and color releaser is of such a type that an interaction between them is possible, an imagewise correspondence between the silver image formed and the consumption of ED compound on the one hand and between the unused ED compound and paint releaser on the other hand, so that an imagewise distribution of diffusible dye is produced in accordance with the non-nickel silver halide. For this purpose, light-sensitive silver halide and a combination of color releaser and ED compound need not necessarily be present in the same layer; they can also be accommodated in mutually adjacent layers, each belonging to the same layer unit.

In order to ensure a sufficient interaction between the dye releasing agent and the assigned ED precursor compound, it is advisable to place these two compounds in a combination in the same layer, which does not, however, have to be identical to the assigned silver halide emulsion layer. The fact that the ED precursor compounds according to the invention are hydrolysis-stable under neutral conditions and thus also insensitive to oxidation makes these compounds particularly suitable for use in a common emulsifier (together with the color releaser), whereas conventional ED compounds are too sensitive to oxidation under comparable conditions have, so that they can not be used with the paint releasers in the same emulsifier.

For the incorporation of the ED precursor compounds according to the invention, all methods are suitable by which hydrophobic compounds are usually incorporated into photographic layers, i.e. H. the usual emulsification techniques come into question, e.g. B. Methods by which photographic auxiliaries are added to the casting solutions in the form of emulsifiers using so-called oil formers. It is advisable to avoid all methods in which the use of alkali is unavoidable.

The reducible color releaser is usually used in such a quantity in one layer, which is sufficient to produce a color image with the highest possible maximum color density, for example in an amount of 1-20 _'10 -4 mol / m ^2. The amount of the ED precursor compound according to the invention is matched to that of the color releasing agent. It should be large enough to achieve the highest possible maximum color density, ie in order to be able to reduce the color splitting as completely as possible. On the other hand, it should not be significantly higher than is necessary for this, so that the resulting reducing agent at the exposed areas can be used as completely as possible through the development of the exposed silver halide. The most favorable quantitative ratios between silver halide, ED precursor compound and color releaser are expediently determined on the basis of routine tests. Useful results can be obtained, for example, if the ED precursor compound is present in 0.5-5 times the molar amount, based on the color releasing agent. The suitable quantitative ratio between silver halide and assigned color releaser is approximately in the range of 2-20 moles of silver halide per mole of color releaser.

Separating layers are expediently present between different layer units, which can contain compounds which react with diffusing development products and are able to prevent their diffusion from one layer unit into another. This helps to ensure that the assignment is always limited to one shift unit. Such compounds are known, for example non-diffusing hydroquinone derivatives and, for example, those described in the publication “Research Disclosure No. 17842 (February 1979) described “scavenger compounds •. Last but not least, the ED precursor compounds according to the invention can also perform this function, regardless of the type of coloring compound used (color coupler, color releaser), if the ED precursor compounds according to the invention are incorporated as so-called scavengers in a separating layer between different layer units.

The interaction between the exposed silver halide and the ED compound is generally accomplished by the oxidized form of the silver halide developer used. The latter is oxidized imagewise during development and the oxidation product is in turn able to oxidize the ED compound and thus to avoid the reaction with the color releaser.

Examples of suitable silver halide developing agents are hydroquinone and its derivatives, pyrocatechol and its derivatives, p-phenylenediamine derivatives and 3-pyrazolidone compounds, in particular 1-phenyl-3-pyrazolidone, 1-phenyl-4,4-dimethyl-3-pyrazolidone, 4 -Hydroxymethy-1-4-methyl-1-phenyl-3-pyrazolidone, 1-phenyl-4-methyl-3-pyrazolidone, 1-phenyl-5-methyl-3-pyrazolidone, 1-phenyl-4,4-bis - (hydroxymethyl) -3-pyrazolidone, 1,4-dimethyl-3-pyrazolidone, 4-methyl-3-pyrazolidone, 4,4-dimethyl-3-pyrazolidone, 1- (3-chlorophenyl) -4-methyl-3-pyrazolidone , 1- (4-chlorophenyl) -4-methyl-3-pyrazolidone, 1- (3-chlorophenyl) -3-pyrazolidone, 1- (4-chlorophenyl) -3-pyrazolidone, 1- (4-tolyl) -4-methyl-3-pyrazolidone, 1- (4-tolyl) -4-hydroxymethyl-4-methyl-3-pyrazolidone, 1- (3-tolyl) -3-pyrazolidone, 1- (3-tolyi) -4,4-dimethyl-3-pyrazolidone, 1- (2-trifluoroethyl) -4,4-dimethyl-3-pyrazolidone and 5-methyl-3-pyrazolidone, including those derivatives of 3-pyrazolidone that are in capped form , for example ace tylated phenidone derivatives.

A combination of different silver halide developing agents can also be used. The silver halide developing agents can be contained in an alkaline developer preparation or else in whole or in part in one or more layers of the color photographic recording material to be processed.

In order to carry out the color diffusion transfer method according to the present invention, a light-sensitive element is generally used which contains one or more silver halide emulsion layer units and the reducible color releasers and ED compounds or their precursors associated therewith, and an image receiving element in which the released by image transfer Dyes the desired color image is generated. This requires that there be firm contact between the photosensitive member and the image-receiving member for at least a finite period within the development time, so that the imagewise distribution of diffusing dyes generated in the photosensitive member as a result of development can be transferred to the image-receiving member. The contact can be made after development has started or it can have been made before development begins. The latter is the case, for example, if a so-called integral recording material is used to carry out the color diffusion transfer process, in which the light-sensitive element and the image-receiving element form an integral unit, also referred to below as mono-sheet material, which can continue to exist even after the development process has ended, if a separation of the photosensitive element from the image receiving element is not provided even after color transfer. Such an embodiment is described for example in DE-OS 2 019 430.

The image receiving element can therefore be part of the color photographic recording material, for. B. in the form of an image-receiving layer, which is arranged below the light-sensitive element on a transparent support, wherein there is advantageously an opaque, preferably light-reflecting binder layer between the image-receiving layer and the light-sensitive element. The image-receiving layer, which in a different embodiment of the color transfer method but also a different embodiment of the color transfer method can also be arranged on a separate carrier (image-receiving sheet), as a rule contains, in a known manner, a basic mordant for diffusing anionic (acidic) dyes.

Long-chain quaternary ammonium or phosphonium compounds or tertiary sulfonium compounds, e.g. B. those as described in US 3,271,147 and US 3,271,148. Furthermore, certain metal salts and their hydroxides, which form poorly soluble compounds with the acid dyes, can also be used. The dye mordants are dispersed in the receiving layer in one of the usual hydrophilic binders, e.g. B. in gelatin, polyvinyl pyrrolidone, completely or partially hydrolyzed cellulose esters. Of course, some binders can also act as mordants, e.g. B. copolymers or polymer mixtures of vinyl alcohol and N-vinylpyrrolidone, as described for example in DE-AS 1 130 284, furthermore those which are polymers of nitrogen-containing quaternary bases, for. B. Polymers of N-methyl-2-vinylpyridine, as described, for example, in US Pat. No. 2,484,430. Further pickling binders which can be used are, for example, guanylhydrazone derivatives of alkylvinyl ketone polymers, as described in US Pat. No. 2,882,156, or guanylhydrazone derivatives of acylstyrene polymers, as described, for example, in DE- OS 2 009 498.

In general, however, other binders, e.g. B. add gelatin. Further polymeric mordants are described, for example, in US Pat. No. 3,709,690, DE-OS 2,315,304, DE-OS 2,445,782, DE-OS 2,551,786 and DE-OS 2,631,521.

The color photographic recording material according to the invention can also contain acidic layers and so-called braking or retarding layers, which together form a so-called integral neutralization system. Such an integral neutralization system can be arranged in a known manner between the layer support and the image-receiving layer arranged thereon or at another location in the layer structure, e.g. B. above the photosensitive layers, d. H. beyond these light-sensitive layers, viewed from the image-receiving layer. The neutralization system is usually oriented so that the braking or retarding layer is between the acid layer and the point at which an alkaline developing liquid or paste is exposed. Such acid layers, brake layers, etc. from both existing neutralization systems are known, for example, from US 2,584,030, US 2,983,606, US 3,362,819, US 3,362,821, DE-OS 2,455,762, DE-OS 2,601,653, DE- OS 2 716 505, DE-OS 2816878. Such a neutralization system can also contain two or more brake layers in a known manner.

• Einerseits kann hierdurch der unerwünschte Zutritt von Licht zu lichtempfindlichen Schichten unterbunden werden und andererseits kann eine solche Pigmentschicht - insbesondere, wenn ein helles oder weißes Pigment, z. B. Ti0₂ verwendet wird - für das erzeugte Farbbild einen ästhetisch angenehmen Hintergrund bilden. Integrale farbfotografische Aufzeichnungsmaterialien mit einer solchen Pigmentschicht sind bekannt, z. B. aus US 2 543 181 und DE-AS 1 924 430. Anstelle einer vorgebildeten opaken Schicht können auch Mittel vorgesehen sein, um solche Schicht erst im Verlauf des Entwicklungsverfahrens zu erzeugen. Entsprechend den beiden erwähnten Funktionen können derartige Pigmentschichten aus zwei oder mehreren Teilschichten aufgebaut sein, von denen eine beispielsweise ein weißes Pigment und die andere beispielsweise ein dunkles, lichtabsorbierendes Pigment, z. B. Ruß, enthält.

In a special embodiment, the recording material according to the invention can furthermore contain one or more pigment-containing opaque layers which are permeable to aqueous liquids. These can perform two functions:

• On the one hand, this can prevent the undesired access of light to light-sensitive layers, and on the other hand, such a pigment layer - especially if a light or white pigment, e.g. B. Ti0 ₂ is used - form an aesthetically pleasing background for the color image generated. Integral color photographic recording materials with such a pigment layer are known, e.g. B. from US 2 543 181 and DE-AS 1 924 430. Instead of a pre-formed opaque layer, means can also be provided to produce such a layer only in the course of the development process. According to the two functions mentioned, such pigment layers can be constructed from two or more partial layers, one of which, for example, a white pigment and the other, for example, a dark, light-absorbing pigment, e.g. B. carbon black.

• 1) einen transparenten Schichtträger
• 2) eine Bildempfangsschicht
• 3) eine lichtreflektierende Schicht
• 4) ein lichtempfindliches Element mit mindestens einer lichtempfindlichen Silberhalogenidemulsionsschicht und einer dieser zugeordneten Kombination aus reduzierbarem Farbabspalter und ED-Vorläuferverbindung
• 5) eine Verzögerungsschicht
• 6) eine saure Polymerschicht
• 7) einen transparenten Schichtträger.

In a particularly preferred embodiment of the invention, the photographic material is an integral color photographic marking material for carrying out the color diffusion transfer process and has, for example, the following layer elements:

• 1) a transparent substrate
• 2) an image receiving layer
• 3) a light reflecting layer
• 4) a light-sensitive element with at least one light-sensitive silver halide emulsion layer and a combination of a reducible color releaser and ED precursor compound assigned to this
• 5) a retardation layer
• 6) an acidic polymer layer
• 7) a transparent substrate.

The mono-sheet material can be composed in such a way that two different parts are produced separately from one another, namely the light-sensitive part (layer elements 1-4) and the cover sheet (layer elements 5-7), which are then placed on top of one another on the layer side and connected to one another, optionally under Use of spacer strips so that a space is formed between the two parts for receiving a precisely measured amount of a developer preparation. The layer elements 5 and 6, which together form the neutralization system, can also be arranged, albeit in the opposite order, between the layer support and the image-receiving layer of the light-sensitive part.

Means can also be provided to insert a developer preparation between the light bulbs introduce sensitive part and the cover sheet, e.g. B. in the form of a laterally arranged, splitable container that pours its contents between two adjacent layers of mono-sheet material when subjected to mechanical forces.

In addition to the aqueous alkali, the developer preparation can also contain developer compounds which, however, have to be matched to the type of color-providing compounds. Other possible components of the developer preparation are thickeners to increase the viscosity, for. B. hydroxyethyl cellulose, silver halide solvent, e.g. As sodium thiosulfate, or one of the bis-suifonylalkane compounds described in DE-OS 2 126 661, opacifiers for producing opaque layers, for. B. pigments of Ti0 ₂ , ZnO, barium sulfate, barium stearate or kaolin. Alternatively or additionally, some of these components can also be embedded in one or more layers of the color photographic recording material according to the invention.

example 1 Photosensitive element

• 1. Eine rotsensibilisierte Silberbromidiodidemulsionsschicht aus 0,5 g AgN0₃ mit 0,3 g des Farbabspalters A (= Verbindung 2 aus DE-OS 2 854 946), 0,16 g ED-Verbindung 2, 0,46 g palmitinsäure- diethylamid (gemeinsamer Ölbildner für A und ED-Verbindung) und 1,15 g Gelatine.
• 2. Eine Schutzschicht mit 0,6 g Monoacetylierungsprodukt von 4-Methyl-1-phenyl-3-pyrazolidon. 0,12 g 2-Isooctadecyl-5-sulfohydrochinon und 0,6 g Gelatine.
• 3. Eine Härtungsschicht mit 0,1 g Gelatine und 0,12 g Härtungsmittel D.

The following layers were applied in succession to a paper support coated on both sides with polyethylene. All data refer to 1 m ² .

• 1. A red-sensitized silver bromide iodide emulsion layer from 0.5 g AgN0 ₃ with 0.3 g of the color releasing agent A (= compound 2 from DE-OS 2 854 946), 0.16 g ED compound 2, 0.46 g palmitic acid diethylamide ( common oil former for A and ED compound) and 1.15 g gelatin.
• 2. A protective layer with 0.6 g of monoacetylation product of 4-methyl-1-phenyl-3-pyrazolidone. 0.12 g 2-isooctadecyl-5-sulfohydroquinone and 0.6 g gelatin.
• 3. A hardening layer with 0.1 g gelatin and 0.12 g hardening agent D.

Image receiving sheet

• 1. Eine Beizschicht mit 6 g eines Polyurethans gemäß Beispiel 3 der DE-OS 2 631 521 und 5 g Gelatine.
• 2. Eine Härtungsschicht mit 0,1 g Gelatine und 0,15 g Härtungsmittel D.

The following layers were applied to a paper support coated on both sides with polyethylene. The data refer to 1 m ² .

• 1. A pickling layer with 6 g of a polyurethane according to Example 3 of DE-OS 2 631 521 and 5 g of gelatin.
• 2. A hardening layer with 0.1 g gelatin and 0.15 g hardening agent D.

The imagewise exposed photosensitive element and the image-receiving sheet were impregnated with a treatment solution of the composition given below and pressed together on the layer side:

After a contact time of 2 minutes, the sheets were separated from one another and the image-receiving sheet was washed for 30 seconds. After drying, the Dmin / Dmax values of the positive blue-green image were measured.

Examples 2 to 4

The procedure was as in Example 1, but instead of the photosensitive element described there, those were used which instead of the ED compound 2 contained further ED precursor compounds according to the invention in the same molar amount.

Beispiel 5 (nicht erfindungsgemäß)The results (Dmin / Dmax) are summarized in the following table:

Example 5 (not according to the invention)

• 1. Blausensibilisierte AgBr-Negativemulsion aus 0,5 g AgN0₃, mit 0,357 g Verbindung B (Gelbfarbstoff freisetzende Verbindung), 0,306 g Verbindung E (ED-Verbindung 4 aus DE-OS 3 006 268) 0,663 g Palmitinsäurediethylamid (Ölbildner) und 1,164 g Gelatine.
• 2. Gelbfilterschicht mit 0,16 g Gelbfarbstoff Solvent Yellow 29 (C.I. 21230), 0,07 g 2-iso-Octadecyl-5-sulfo-hydrochinon (Scavenger) und 1,0 g Gelatine.
• 3. Grünsensibilisierte AgBr-Negativemulsion aus 0,5 g AgN0₃, mit 0.314 g Verbindung C (Purpurfarbstoff freisetzende Verbindung), 0,223 g Verbindung E, 0,537 Diethyllauramid (Ölbildner) und 1,037 g Gelatine.
• 4. Zwischenschicht mit 0,4 g 2-iso-Octadecyl-5-sulfo-hydrochinon, 0,60 g Acetylierungsdprodukt von 4-Methyl-1-phenylpyrazolidon(3) (Entwickler) und 1,0 g Gelatine.
• 5. Rotsensibilisierte AgBr-Negativemulsion aus 0,5 g AgN0₃, mit 0,30 g Verbindung A (Blaugrünfarbstoff freisetzende Verbindung), 0,162 g Verbindung E, 0,462 g Palmitinsäure-diethylamid und 0,962 g Gelatine.
• 6. Schutzschicht mit 0,6 g Gelatine
• 7. Opake lichtreflektierende Schicht mit 18 g TiO_z und 2,57 g Gelatine.
• 8. Schutzschicht mit 4,0 g Gelatine.
• 9. Bildempfangsschicht mit 2,08 g eines polymeren Beizmittels aus 4,4'-Diphenylmethandiisocyanat und N-Ethyldiethanolamin, quaterniert mit Epichlorhydrin gemäß DE-OS 2 631 521, Beispiel 1, und 5,2 g Gelatine.
• 10. Schutz- und Härtungsschicht mit 1,2 g Verbindung D (Härtungsmittel) und 0,6 g Gelatine.

A light-sensitive element of a photographic material according to the invention was produced by successively applying the following layers on a transparent support made of polyethylene terephthalate. The quantities given relate in each case to 1 _M ² .

• 1. Blue-sensitized AgBr negative emulsion from 0.5 g of AgN0 ₃ , with 0.357 g of compound B (yellow dye-releasing compound), 0.306 g of compound E (ED compound 4 from DE-OS 3 006 268), 0.663 g of palmitic acid diethylamide (oil former) and 1.164 g gelatin.
• 2. Yellow filter layer with 0.16 g of yellow dye Solvent Yellow 29 (CI 21230), 0.07 g of 2-iso-octadecyl-5-sulfo-hydroquinone (scavenger) and 1.0 g of gelatin.
• 3. Green-sensitized AgBr negative emulsion from 0.5 g AgN0 ₃ , with 0.314 g compound C (purple dye-releasing compound), 0.223 g compound E, 0.537 diethyl lauramide (oil former) and 1.037 g gelatin.
• 4. Interlayer with 0.4 g of 2-iso-octadecyl-5-sulfo-hydroquinone, 0.60 g of acetylation end product of 4-methyl-1-phenylpyrazolidone (3) (developer) and 1.0 g of gelatin.
• 5. Red-sensitized AgBr negative emulsion from 0.5 g AgN0 ₃ , with 0.30 g compound A (cyan dye releasing compound), 0.162 g compound E, 0.462 g palmitic acid diethylamide and 0.962 g gelatin.
• 6. Protective layer with 0.6 g gelatin
• 7. Opaque light reflecting layer with 18 g TiO _z and 2.57 g gelatin.
• 8. Protective layer with 4.0 g of gelatin.
• 9. Image-receiving layer with 2.08 g of a polymeric mordant from 4,4'-diphenylmethane diisocyanate and N-ethyldiethanolamine, quaternized with epichlorohydrin according to DE-OS 2 631 521, Example 1, and 5.2 g of gelatin.
• 10. Protective and hardening layer with 1.2 g compound D (hardening agent) and 0.6 g gelatin.

The recording material was exposed through the transparent support behind a conventional gray wedge and in an open dish at 22 ° C. for 2 min. developed with a bath of the following composition:

It was then washed and dried for 5 minutes.

Examples 6 and 7 (According to the Invention)

The procedure was as in Example 5, but instead of the photosensitive element described there, those were used which, as scavengers in layers 2 and 4, 1.5 g of one of the compounds 2 and 13 according to the invention and in each case 1.5 g of dibutyl phthalate Contained oil formers. Processing was carried out as in Example 5.

The recording materials obtained according to Examples 5, 6 and 7 provided transfer images of comparable good color separation.

If the recording materials were exposed to a climate of 60 ° C. (with uncontrolled humidity) for 3 d before development and then processed as described in Example 5, transfer images were obtained which showed the following percentage increase in fog in relation to the freshly developed samples (positive values mean Veil rise):

As can be seen from the table, the compounds according to the invention can also be used particularly advantageously as oxform scavengers in photographic layers because of the significantly lower tendency to fog.

Formula attached to the examples.

Claims (5)

1. Colour-photographic recording material having at least one light-sensitive silver halide emulsion layer and a non-diffusing colour-providing compound associated therewith, which material contains, in at least one light-sensitive silver halide emulsion layer or non-light-sensitive binder layer, a non-diffusing electron donor precursor compound (ED precursor compound), from which a non-diffusing ED compound is formed under alkaline development conditions, characterised in that the ED precursor compound corresponds to the following formula I :

wherein :

R' denotes a carbocyclic or heterocyclic aromatic group : and

R² denotes hydrogen, alkyl, alkenyl, aryl or acyl :

at least one of the radicals R' and R² containing a ballast radical.

2. Colour-photographic recording material having at least one light-sensitive silver halide emulsion layer and, associated therewith, a combination of a non-diffusing reducible colourproviding compound which, in the reduced state, is capable of releasing a diffusible dye under the alkaline development conditions, and a non-diffusing electron donor precursor compound (ED precursor compound), from which a non-diffusing electron donor compound (ED compound) is formed under the alkaline development conditions, which ED compound is capable of reducing the non-diffusing colour-providing compound under the alkaline development conditions, characterised in that the recording material contains, as the ED precursor compound, a compound of the following formula I :

wherein :

R' denotes a carbocyclic or heterocyclic aromatic group and

R² denotes hydrogen, alkyl, alkenyl or acyl,

at least one of the radicals R' and R² containing a ballast radical.

3. Recording material according to Claim 1 or 2, characterised in that R¹ denotes an optionally substituted phenyl group.

4. Recording material according to Claim 1 or 2, characterised in that R² is a carbamoyl radical or an acyl radical which is derived from an aliphatic or aromatic carboxylic acid.

5. Recording material according to Claim 2, characterised in that a compound of the following formula II

wherein

R¹ denotes alkyl or aryl,

R² denotes alkyl, aryl or a grouping which, together with R³, completes a fused-on ring ;

R³ denotes hydrogen, alkyl, aryl, hydroxyl, halogen, amino, alkylamino, dialkylamino including cyclic amino groups, acylamino, alkylthio, alkoxy, aroxy, sulpho, or a grouping which, together with R², completes a fused-on ring ;

R⁴ denotes alkyl ;

R^S denotes hydrogen ;

A denotes the radical of a diffusible dye or dye precursor ;

X denotes a bivalent binding link ; and

m denotes 0 or 1,

is used as the non-diffusing reducible colour-providing compound.