EP0095650B1 - Image receiving element for the colour diffusion transfer process - Google Patents

Description

The invention relates to an image receiving element for the production of 'color photographic images according to the color diffusion transfer process, wherein predominantly post-metallizable diffusible dyes are used for the production of the color image. According to the invention, the image-receiving element has a layer combination arranged on a layer support, consisting of a layer which can be colored by diffusible organic dyes and an adjacent hydrophilic binder layer which contains a metallizing agent in the form of a dispersion of a water-insoluble organic copper (II) or nickel complex.

The use of polyvalent, in particular complex-forming, metal cations is of particular interest in image-receiving layers for the photographic color diffusion transfer process. As is known, a light-sensitive recording material with several silver halide emulsion layers of different spectral sensitivity and color compounds associated therewith is used in the color diffusion transfer method, which is particularly important for color immediate image photography. So-called dye developers, for example, are suitable as coloring compounds, which are compounds which are originally diffusible and have a chromophoric residue and a developer function by means of which the compounds are immobilized during development, or non-diffusing coloring compounds with a chromophoric residue, which is released during development as a diffusible dye or dye precursor (color releaser). If the chromophoric rest of the dye developer or the dye releaser contains special substituents that are suitable as ligands for complex formation with polyvalent metal cations, it is possible to use the complex formation to improve the light stability, to influence the color tone and to fix the image dyes transferred into the image-receiving layer. The complexation is expediently carried out only after the color transfer has taken place, for which purpose either the image-receiving material with a solution of the complex-forming polyvalent metal cations, for. B. in the form of a solution of the corresponding salts, is treated or in that the polyvalent metal cations are embedded in one or more layers of the image-receiving material so that they can react immediately during the development process with the diffusing dyes to form a complex.

Research Disclosure No. 18,534 (September 1979) describes polymers containing complex-bound polyvalent metal cations and their use in image-receiving layers of color photographic materials for the color diffusion transfer process. However, the absorption capacity of the polymers mentioned there for polyvalent metal cations is limited.

From EP-A 0009 411 it is known that the cationic nickel or copper (II) complexes of polyvinylpyridine or polyvinylimidazole can be used as metallizing agents for post-complexable image dyes. Although these complexes show little intrinsic coloration at neutral pH, they quickly take on a dark coloration at the pH value of an alkaline processing medium, which decomposes very slowly, if at all, and makes the image unsightly during this time.

From the European patent application mentioned it is also known that metal complexes of polymers with iminodiacetic acid units can be used as the metallizing agent. These metallization agents are difficult to handle polymer-chemically and - particularly in the case of latex polymers - are prone to agglomeration.

US-A4282305 describes an image-receiving element with a double-layer structure, consisting of a metal donor layer containing a metallizing agent in a hydrophilic binder and a dyeable layer arranged above it. Aqueous solutions of metal salts, e.g. B. mentioned nickel sulfate. The dyeable layer contains a polymeric mordant with heterocyclic tertiary amino groups, e.g. B. polyvinylimidazole. Even with this double-layer arrangement, casting problems arise during the production due to the reaction of copper (II) or nickel ions with polyvinylimidazole. In addition, such an image-receiving element is unusable if copper salts are used as the metallizing agent, since even proportions of 5 mmol / m ² or less then cause an undesirable prohibitive coloring of the image whites.

The object of the invention is to design an image receiving element for color photographic images according to the color diffusion transfer process, in which the metallizing agent and polymeric mordant are contained in separate but adjacent layers, in such a way that the nickel or copper (II) ions serving as the metallizing agent are bound diffusion-resistant, do not agglomerate with cationic pickling agents and have no disadvantages for the resulting image, in particular no disruptive intrinsic coloration.

It has been found that a double-layer image-receiving element which meets the requirements described can be produced if water-insoluble organic nickel or copper (II) complexes are used as the metallizing agent and these in the form of aqueous dispersions, optionally with the use of oil formers in the casting solution for the neighboring hydrophilic binder layer.

The invention relates to an image-receiving element for the color diffusion transfer process, with a layer arranged on a layer support which can be colored by diffusible organic dyes and an adjacent hydrophilic binder layer containing a metallizing agent for post-metallizable dyes, characterized in that the adjacent hydrophilic binder layer forms the metallizing agent in the form an optionally oil-containing dispersion of a water-insoluble organic copper (II) or nickel complex of a compound of one of the following formulas I to VI.

Nickel complexes and copper (II) complexes of iminobismethylenephosphinic or phosphonic acids (formula I) or of iminodiacetic acids (formula II)

Nickel complexes of 2,2'-thiobisphenols, 2,2'-sulfinylbisphenols or 2,2'-sulfonylbisphenols (formulas III and IV)

Nickel complexes and copper (II) complexes of enolizable 1,3-dicarbonyl compounds, e.g. B. 1,3-diketones (formula V) or β-ketocarboxylic acid esters (formula VI)

• R¹ einen gegebenenfalls durch ―O― unterbrochenen, Kohlenwasserstoffrest mit, bis zu 30 C-Atomen ;
• R², R^2' Wasserstoff, Alkyl mit bis zu 5 C-Atomen, Cycloalkyl, Aralkyl oder Aryl mit 6 bis 10 C-Atomen,
• R³, R³' Alkyl oder Alkoxy mit 1 bis 4 C-Atomen, Aralkyl oder OH ; x
  
• R⁴ einen Kohlenwasserstoffrest mit bis zu 18 C-Atomen, der entweder direkt oder über -0- angeknüpft ist, Halogen oder eine Gruppe R⁶ ;
• R⁵ Wasserstoff, Halogen, Alkyl oder Alkoxy mit bis zu 18 C-Atomen, Alkenyl, einen Rest zur Vervollständigung eines ankondensierten Benzolringes, oder eine Gruppe R⁶, falls nicht R⁴ eine Gruppe R⁶ bedeutet ; _R ⁶
  
• ―NH―CO―R¹¹ oder ―NH―SO₂-R¹² ;
• R⁷, R⁷Alkyl, Aryl oder eine heterocyclische Gruppe ;
• R⁸ Wasserstoff oder eine Gruppe R7; oder R⁷ und R⁸ bedeuten zusammen einen Rest zur Vervollständigung eines carbocyclischen oder heterocyclischen Ringes ;
• R⁹ Alkyl, Aralkyl oder Cycloalkyl mit bis zu 8 C-Atomen ;
• R¹⁰, R^10' Reste wie R² und R²' oder beide zusammen einen Rest zur Vervollständigung einer 5-, 6-oder 7-gliedrigen cyclischen Aminogruppe (Pyrrolidin, Piperidin, Perhydroazepin, Morpholin) ;
• R¹¹ Alkyl, Aralkyl, Aryl, ―OR⁹ oder
  
• _R ¹² Alkyl, Aryl oder
  

In formulas I to VI:

• R ^{1 is} a hydrocarbon radical with up to 30 C atoms which may be interrupted by ―O―;
• R ² , R ^{2 'are} hydrogen, alkyl having up to 5 carbon atoms, cycloalkyl, aralkyl or aryl having 6 to 10 carbon atoms,
• R ³ , R ³ 'alkyl or alkoxy having 1 to 4 carbon atoms, aralkyl or OH; x
  
• R ^{4 is} a hydrocarbon radical with up to 18 C atoms, which is either directly or via -0-, halogen or a group R ⁶ ;
• R ^{5 is} hydrogen, halogen, alkyl or alkoxy having up to 18 carbon atoms, alkenyl, a radical to complete a fused-on benzene ring, or a group R ⁶ if R ^{4 is} not a group R ⁶ ; _R ⁶
  
• ―NH ― CO ― R ¹¹ or ―NH ― SO ₂ -R ¹² ;
• R ⁷ , R ^{7 are} alkyl, aryl or a heterocyclic group;
• R ^{8 is} hydrogen or a group R7; or R ⁷ and R ⁸ together represent a radical to complete a carbocyclic or heterocyclic ring;
• R ^{9 is} alkyl, aralkyl or cycloalkyl having up to 8 carbon atoms;
• R ¹⁰ , R ^{10 '} radicals such as R ² and R ² ' or both together a radical to complete a 5-, 6- or 7-membered cyclic amino group (pyrrolidine, piperidine, perhydroazepine, morpholine);
• R ¹¹ alkyl, aralkyl, aryl, ―OR ⁹ or
  
• _R ^{12 is} alkyl, aryl or
  

The radicals R ¹ to R ⁸ shown in the formulas I to VI have, inter alia, the function of ballast radicals, ie the size of all the radicals present in a compound is such that diffusion-resistant incorporation of the nickel or Copper (II) complexes in photographic layers is guaranteed.

Examples of possible hydrocarbon radicals represented by R ¹ and R ⁴ are: alkyl, aralkyl, cycloalkyl or aryl. Particular examples are ethyl, n-butyl, 2-ethylhexyl, n-dodecyl, n-octadecyl, benzyl, phenylethyl, phenyl, 4-dodecylphenyl, cyclohexyl. A hydrocarbon radical interrupted by -0- is, for example, an alkoxyalkyl radical or an aroxyalkyl radical; an example of this would be a 4- (2,4-bis-tert-amylphenoxy) butyl group.

An alkyl group represented by R ² , R ³ , R ⁵ , R ⁷ , R ⁹ , R ¹¹ or R ¹² is, for example, methyl, ethyl, n-propyl, n-butyl, isobutyl or n-heptadecyl.

Examples of aryl groups represented by R ² , R ⁷ , R ¹¹ or R ¹² are phenyl and naphthyl, which may optionally be further substituted, e.g. B. by hydroxy, methoxy, t-butyl or a group with ballast character, such as an n-dodecylthio or n-hexadecyloxy group.

worin

• R¹³ für eine Gruppe R⁷ und R¹⁴ für Alkyl steht und
• R⁷ und R^7' die bereits angegebene Bedeutung haben.

A carbocyclic ring completed by R ⁷ and R ⁸ is, for example, a cyclohexadienone ring. Examples of 1,3-dicarbonyl compounds in which R ⁷ and R ⁸ together complete a heterocyclic ring are approximately 4-acylpyrazolinones of the following formula VII

wherein

• R ^{13 represents} a group R ⁷ and R ^{14 represents} alkyl and
• R ⁷ and R ^{7 'have} the meaning already given.

Examples of compounds of the general formulas I to VI are given below.

The iminobismethylenephosphonic or phosphinic acids (formula I) used to produce suitable nickel or copper (II) chelates are known in principle. Their production is described, for example, in Houben-Weyl, Methods of Organic Chemistry, Volume XII / 1, pages 486-488 and in the articles by Petrov Makljaev and Bliznjuk in Chem. Abstr. 54, 260 (1960) and G.M. Kosolapoff in J. Amer. Chem. Soc. 67.1 180 (1945); further in US Pat. No. 2,470,190. It is carried out in a favorable manner by reacting 1 mole of primary amine with two moles of carbonyl compound, preferably formaldehyde or benzaldehyde and two moles of dialkyl phosphate or dialkyl phosphonate. The N-substituted iminobismethylenephosphonic diester or iminobismethylenephosphinic acid ester formed can be easily saponified with mineral acids, in particular with hydrobromic or hydroiodic acid.

If in formula IR ³ and R ^{3 'stands} for an alkoxy radical, then depending on the hydrolysis conditions used, either a dibasic phosphonic acid group or a monobasic phosphinic acid monoester group results at the end of the synthesis.

The starting materials for the iminobismethylenephosphonic acids and phosphinic acids according to the invention are all known and technically easily accessible compounds. So z. B. the alkanephosphonous monoalkyl from the easily accessible dialkyl esters by acidic saponification in a simple manner and in high yields. In this context, reference is made to the article by K. Sasse in Houben-Weyl, Volume XII / 1 Pages 294-331. Detailed information on individual syntheses can be found in M. Sander, Chem. Ber. 93, 1220 (1960) and K.A. Petrov, Zhnr. obszh. Khim. 31, 179 (1961).

The preparation of compound 1 is described below as an example of the synthetic processes used.

Connection 1 a) Diisobutyl N-octadecyliminobismethylenephosphinate

100 g of 30% formaldehyde solution were added dropwise at 20 ° C. to 134.5 g (0.5 mol) of n-octadecylamine and 122 g (1.0 mol) of monoisobutyl methanephosphorate. The mixture was stirred for a further 2 hours on a steam bath and then concentrated under reduced pressure. The product is obtained as a slightly yellowish oil.

b) N-octadecyliminobismethylenephosphinic acid (compound 1)

The crude product from the reaction described above was taken up in 600 ml of acetic acid, warmed to 80 ° C. and mixed with 170 g of 48% hydrobromic acid. The mixture is kept under reflux for 6 h and then cooled to room temperature. The reaction mixture was partitioned between 800 ml dichloromethane and 300 ml water. The dichloromethane phase was separated and evaporated. The mass crystallized when digested with acetonitrile. Yield 162 g = 72% of theory.

The iminodicarboxylic acids (formula II) used to produce suitable nickel or copper (II) chelates are also known in principle. Their manufacture is described for example in Houben-Weyl, volume XI / 2 pages 404-416 and in the article by Stein, Gregor and Spoerri in J. Amer. Chem. Soc. 77, 191 (1955).

It is carried out in a favorable way by reacting 1 mol of primary amine with 1 mol of an a-chlorocarboxylic acid ester. The N-substituted aminocarboxylic acid ester formed is particularly easy to saponify with sodium hydroxide solution. The disodium salt of an iminodicarboxylic acid is obtained by further reaction with 1 mol of sodium a-chlorocarboxylic acid. The preparation of compound 3 is described below as an example of the synthetic methods used.

Connection 3 N-octadecyliminodiacetic acid

53.8 g (0.2 mol) of n-octadecylamine and 34.0 g (0.22 mol) of methyl chloroacetate were heated in 400 ml of ethanol for 3 hours on a steam bath. 25 g of sodium hydroxide in 150 ml of water were added to the solution and the mixture was stirred on the steam bath for a further 2 h. 35.7 g (0.22 mol) of sodium chloroacetic acid and 10 g (0.25 mol) of sodium hydroxide in 200 ml of ethanol and 200 ml of water were added and the mixture was heated on the steam bath for a further 4 h. After cooling, the precipitate was filtered off and air-dried.

Yield: 72.6 g, 87% of theory; colorless crystal powder.

The preparation of the 2,2'-thiobisphenols (formula 111) is known in principle and z. B. in GB-A 858 890 and described in DE-A 29 37 294. All of the 2,2'-thiobisphenols listed were prepared by reacting the corresponding phenol with the 0.5 molar amount of sulfur dichloride in the presence of a little ZnCl _{2 by the} process indicated there. If the phenol used has two unsubstituted o-positions to the phenolic hydroxyl group and sulfur dichloride is used in excess, reaction products are obtained which, in addition to the thiobisphenols, contain higher molecular weight compounds with 2, 3 or more radicals. The sulfoxides and sulfones can be prepared from the thiobisphenols by mild oxidation with H ₂ 0 ₂ in glacial acetic acid or in dimethylformamide in the presence of tungstic acid. They are more soluble in methanol than the thiobisphenols.

1,3-diketones (formula V) and α-keto esters (formula VI) are known in principle and z. B. in Houben-Weyl, Volume VII / 2d, page 525 ff., Volume VIII, page 567 ff and Volume VI / ld, page 41 to 45 and page 68 ff. They are produced cheaply by reacting 1 mol of ketone and 1 mol of carboxylic acid ester or carbonic acid ester with a base (eg NaH) in toluene as the solvent. The preparation of compound 6 is described below as an example of the synthetic methods used.

Connection 6

96.0 g (0.3 mol) of p-dodecylthioacetophenone and 9.0 g (0.3 mol) of 80% NaH dispersion in white oil were boiled with 54.0 g of ethyl acetate in 400 ml of toluene. The mixture was stirred at 120 ° C for 2 h. After the solution had cooled, 120 ml of isopropanol and then 200 ml of 2N hydrochloric acid were added. The organic phase was separated off and concentrated. The solid residue was recrystallized from acetonitrile. Yield 97.6 g = 90% of theory; colorless crystals.

4-acylpyrazolones (formula VII) are also known in principle and z. B. in BE-A 817 382, DE-A 24 10 370 and US-A4146540. The preparation of compound 9 is described below as an example of the synthetic methods used.

Connection 9

134.5 g (0.77 mol) of 1-phenyl-3-methyl-5-pyrazolone, 50.0 g (0.89 mol) of calcium oxide and 250 ml of dioxane were heated to 75 ° C. 228 g (0.77 mol) of octadecanoic acid chloride were added dropwise over 45 min. After the addition, the mixture was stirred at 80 ° C. for 1 h, then cooled to room temperature. 400 ml of methanol and 100 ml of concentrated hydrochloric acid were added and the mixture was stirred for 30 minutes. After standing overnight, the mixture was filtered and recrystallized from methanol. Yield 71.6 g = 21% of theory.

The preparation of the nickel and copper II chelates is explained below.

Chelation 1 (Cu (II) chelate of compound 1)

• Ausbeute 80 g 60 % der Theorie
• Cu berechnet auf Monohydrat 11,9%
• Cu gefunden 11,4%

113 g of compound 1 were refluxed with 50 g of copper acetate hydrate in 800 ml of absolute ethanol for 6 hours. The solution was introduced into a mixture of 500 ml of dichloromethane and 500 ml of water, the dichloromethane phase was separated off and stirred into 1 l of acetonitrile. The green precipitate was filtered off and washed with acetonitrile.

• Yield 80 g 60% of theory
• Cu calculated on monohydrate 11.9%
• Cu found 11.4%

Chelation 2 (Ni chelate of compound 1)

45.5 g (0.1 mol) of compound 1 were boiled with 25 g (0.1 mol) of nickel acetate tetrahydrate and 15 g of ethyldiisopropylamine in 200 ml of ethanol and kept under reflux for 4 h. After evaporation under reduced pressure, the residue was partitioned between 300 ml of dichloromethane and 200 ml of water, the dichloromethane phase was separated off, dried with NaCl and evaporated.

Yield: 50 g of pale green powder.

Both the Cu (II) chelate and the Ni chelate are readily soluble in ethyl acetate.

Chelate 1 probably corresponds to the formula

Chelate 2 probably corresponds to the formula

Chelation 3 (Ni chelate of compound 3)

41.6 g (0.1 mol) of compound 3 were reacted with 25 g (0.1 mol) of nickel acetate tetrahydrate and 15 g of ethyldiisopropylamine according to the instructions for chelate 2.

Yield: 42 g of pale green powder

Chelation 4 (Cu (II) chelate of compound 3)

41.6 g (0.1 mol) of compound 3 were reacted with 20 g (0.1 mol) of copper acetate hydrate analogously to the instructions for chelate 1.

Yield: 40 g of green powder

Chelate 3 probably corresponds to the formula

Chelate 4 probably corresponds to the formula

The water-insoluble Ni chelates of 2,2'-thiobisphenols, 2,2'-sulfinyl bisphenols and 2,2'-sulfonyl bisphenols contain 0.5-1.5 moles of nickel per mole of bisphenol (III, IV); in the case of bisphenols III they correspond, for example, to the general formulas VIII, IX, X or XI, in which the radicals given have the meaning described above and L, L 'are non-colored neutral (L) or anionic (L') foreign ligands which be included in the production of the complexes.

The water-insoluble nickel complexes of compounds of the formulas 111 and IV can be prepared in various ways. Those processes are preferred in which the bisphenol and optionally an additional ligand are present in a low-boiling, water-immiscible solvent and the nickel salt is introduced via an aqueous or at least partially aqueous phase. The reaction is generally carried out with vigorous stirring and continued until nickel is no longer taken up from the aqueous phase. To accelerate the reaction, the mixture can be heated or part of the solvent can be distilled off. When the reaction has ended, the aqueous phase, which may contain excess nickel salt, is separated off.

The reaction is preferably carried out at pH values above 7, based on the aqueous phase. An alkali hydroxide, an alkali alcoholate, an amine or amidine, an alkali phenolate, a water-soluble carbonate or a water-soluble salt of a carboxylic acid can be used as the base.

As a foreign ligand L, which is optionally incorporated in the nickel chelate, for example: a preferably tertiary mono- or diamine or amidine, e.g. B. ethyldiisopropylamine, bis-2-hydroxyethylcyclohexylamine, pyridine, diazabicyclo [2,2,2] octane, 1,8-diazabicyclo [5,4,0] -undecene, 1,5-diazabicyclo [4,3,0] -non-5-en, a di- or triester of phosphorous acid, e.g. B. tributyl phosphite, an aliphatic, cycloaliphatic or araliphatic alcohol, a glycol monohydrate, or the corresponding anion.

Chelation 5 (Ni chelate of compound 4)

According to DE-A 1 768 258, the preparation is carried out by boiling the starting compounds (compound 4 and nickel acetate in a molar ratio of 1: 2) in methanol in the presence of calculated amount of namethylate. The complex is colored pale green and is readily soluble in toluene or ethyl acetate.

Chelation 6 (Ni chelate of compound 4)

11.8 g (26 mmol) of compound 4 (prepared as described in GB-A 858 890, FP: 134-135 ° C.), 18.4 ml (108 mmol) of ethyldiisopropylamine, 80 ml of toluene and a solution of 12, 4 g (54 mmol) of nickel chloride in 20 ml of water were stirred for 24 hours on a steam bath after the addition of 2.4 g of NaOH in 10 ml of water. The organic phase (toluene) was decanted from the water phase and evaporated. Yield 11.1 g (80% of theory)

Chelation 7 (Ni chelate of compound 4)

To a suspension of the [2,2'-thiobis (4-t-octylphenolate)] - aquonickel (II) chelate described in Example 1 of DE-A 2 042 652 (prepared from 11.8 g of compounds 1 and 6 , 2 g of nickel chloride) in 120 ml of toluene, 1.5 g of diazabicyclo [2.2.2] octane were added. After heating under reflux for 2 h, the clear solution formed was evaporated under reduced pressure. 12.7 g (95% of theory) of pale green crystals which were completely soluble in ethyl acetate were obtained.

Chelate 8 (Cu (II) chelate of compound 6)

36.2 g (0.1 mol) of compound 6 were refluxed with 5.5 g of copper acetate hydrate in 300 ml of absolute ethanol for 6 hours. The solution was introduced into a mixture of 400 ml of dichloromethane and 500 ml of water, the dichloromethane phase was separated off and concentrated. The solid residue was recrystallized from methanol. Yield 25.0 g, 64% of theory; Pale green powder.

Chelation 9 (Ni chelate of compound 6)

36.2 g (0.1 mol) of compound 6 were mixed with 6.6 g of nickel acetate tetrahydrate in 300 ml of absolute ethanol analogous to chelate 8.

Yield 25.9 g, 66% of theory; Pale green powder.

Chelate 8 probably corresponds to the formula

Chelate 9 probably corresponds to the formula

Chelate 10 (Nickel chelate of compound 9)

22.1 g (0.05 mol) of compound 9 and 6.25 g (0.025 mol) of nickel acetate tetrahydrate were heated in 200 ml of absolute methanol on a steam bath for 2 hours. After cooling, the mixture was filtered and washed with cold methanol.

Yield 14.5 g = 62% of theory; Pale green powder.

Chelate 11 (Copper (II) chelate of compound 9)

22.1 g (0.05 mol) of compound 9 and 5.0 g (0.025 mol) of copper acetate hydrate were reacted in 300 ml of absolute methanol analogously to chelate 10.

Yield 15.7 g = 68% of theory; Pale yellow-green powder;

Chelate 10 is believed to have the structure

Chelate 11 probably has the structure

In contrast to the water-soluble metal salts used according to US Pat. No. A4282305, the metallizing agents used in accordance with the present invention are more or less water-insoluble compounds which are added to the respective layer in dispersed form, in which they are separated because of their water-insolubility Train phase. Incorporation into a hydrophilic binder layer usually takes place in such a way that the water-insoluble Cu (II) or Ni complexes are dispersed as a solution in a low-boiling solvent such as diethyl carbonate or ethyl acetate in the casting composition for a hydrophilic binder layer, expediently with simultaneous use an oil producer.

The oil formers are substances which generally boil above 180 ° C. and have good solubility for the water-insoluble organic copper (II) or nickel complexes to be dispersed. Among these, the esters of glutaric acid, adipic acid, phthalic acid, sebacic acid, succinic acid, maleic acid, fumaric acid, isophthalic acid, terephthalic acid and phosphoric acid or the esters of glycerol, as well as paraffin and fluorinated paraffin are preferably used because these compounds are chemically stable and very easily accessible, very much can be handled easily and have no adverse effect on the photosensitive materials when the dispersions are used for photographic purposes. The following are particularly preferably used as oil formers according to the invention: tricresyl phosphate, triphenyl phosphate, dibutyl phthalate, di-n-octyl phthalate, di-2-ethylhexyl phthalate, glycerol tributyrate, glycerol tripropionate, dioctyl sebacate, paraffin and fluorinated paraffin. Monoesters of long-chain alkylated succinic acids have also proven to be suitable oil formers. Such compounds are described in US-A 3,689,271.

The content of oil-forming agent is preferably between 10 and 200%, based on the amount by weight of the Cu (II) or Ni chelate used.

According to the invention, the water-insoluble Cu (II) or Ni complexes are incorporated as metallizing agents in a hydrophilic binder layer of an image-receiving element, which is adjacent to a hydrophilic binder layer that can be colored by diffusible dyes. This addresses a spatial relationship which ensures that the metallizing agents do not give rise to any disturbances in the dyeable layer, e.g. B. in the form of an undesirable staining, but on the other hand, with a certain delay allow diffusion of the corresponding metal ions into the dyeable layer, so that complexation of the image dye can take place if the latter contains chelatable groups. The metallization agent is expediently contained in a layer of the image-receiving element which is arranged on the side of the dyeable layer facing away from the photosensitive element, i. H. between the layer support of the image receiving element and the dyeable layer.

The dyeable layer of the image-receiving element according to the invention preferably contains, as a mordant for the diffusible image dyes, a polymer having structural units which have a heterocyclic amino function, preferably in quaternized or protonated form. A heterocyclic amino function is understood to mean a nitrogen atom which is a ring member of a heterocyclic ring and (in the form of the tertiary base) is exclusively connected to those carbon or heteroatoms which are also ring members of a heterocyclic ring, in particular the same heterocyclic ring.

worin bedeuten

• Z die zur Vervollständigung eines stickstoffhaltigen heterocyclischen Ringes, insbesondere eines Pyridin- oder Imidazolringes erforderlichen Atome ;
• L eine einfache chemische Bindung oder ein zweibindiges Bindeglied zwischen dem heterocyclischen Ring und dem C-Atom, das den Rest R^B trägt, z. B. -O-, Alkylen mit bis zu 6 C-Atomen, Arylen mit 6 bis 10 C-Atomen, Arylenalkylen mit 7 bis 12 C-Atomen, -COOR^D- oder -CONHR°-;
• R^A H, ―COOR^C oder ―CONHR^C ;
• R^B H oder Alkyl mit 1 bis 6 C-Atomen, z. B. Methyl ;
• R^C Wasserstoff, Alkyl, z. B. Methyl oder Hydroxyethyl, oder Aralkyl wie Benzyl ;
• R^D Alkylen mit bis zu 6 C-Atomen, Arylen mit 6 bis 10 C-Atomen oder Arylenalkylen mit 7 bis 12 C-Atomen.
• x^e ein ein- oder zweiwertiges Anion, z. B. Halogenid, Sulfat, Alkylsulfat, Acetat, oder Phosphat.

The structural units with a quaternized or protonated heterocyclic amino function, which are a feature of the mordants preferably used according to the invention, can be represented by the following general formula XII

in what mean

• Z the atoms required to complete a nitrogen-containing heterocyclic ring, in particular a pyridine or imidazole ring;
• L is a simple chemical bond or a double bond between the heterocyclic ring and the C atom which carries the radical R ^B , e.g. B. -O-, alkylene with up to 6 carbon atoms, arylene with 6 to 10 carbon atoms, arylene alkylene with 7 to 12 carbon atoms, -COOR ^D- or -CONHR ° -;
• R ^A H, ―COOR ^C or ―CONHR ^C ;
• R ^B H or alkyl having 1 to 6 carbon atoms, e.g. B. methyl;
• R ^{C is} hydrogen, alkyl, e.g. B. methyl or hydroxyethyl, or aralkyl such as benzyl;
• R ^D alkylene with up to 6 carbon atoms, arylene with 6 to 10 carbon atoms or arylene alkylene with 7 to 12 carbon atoms.
• x ^{e is} a mono- or divalent anion, e.g. B. halide, sulfate, alkyl sulfate, acetate, or phosphate.

The nitrogen-containing heterocyclic ring completed by Z can contain at least one further nitrogen atom in addition to the nitrogen atom represented in the formula XII and can accordingly be linked to the polymer chain, optionally with the inclusion of a link L, either via a ring C atom or a ring N atom. The ring can also be further substituted, e.g. B. by alkyl, especially methyl.

In addition to the structural units with quaternized or protonated heterocyclic amino function, the polymer used as binder can contain further structural units, in particular structural units which contain the heterocyclic amino function mentioned, but not in quaternized or protonated form, but in the form of the tertiary base, and optionally structural units, which are derived from comonomers without the heterocyclic amino function mentioned and which are copolymerizable with the monomers containing the heterocyclic amino function mentioned.

Examples of polymers suitable as mordants are listed below:

The (mixed) polymers can be prepared by methods of solution or precipitation polymerization known to those skilled in the art. The heterocyclic amino function can be introduced either by using appropriate monomers or by polymer-analogous reactions. Suitable monomers are, for example, 4-vinylpyridine, 2-methyl-5-vinylpyridine, N-vinylimidazole, 2-methyl-N-vinylimidazole, 1-methacrolyloxyethylimidazole and their quaternization products with alkylating agents, such as. B. described in J. Polymer Science, Polymer Letters Ed., 16, 393-399 (1978); Polymer, 14, 639 (1973); J. Polymer Science, Polymer Chemistry Ed .; 13, 161-170 (1975).

The polymer-analogous reactions are based on predetermined reactive polymers, which are then reacted with appropriately substituted heterocycles. One example is the reaction of polymeric maleic anhydrides with aminopropylimidazole.

As comonomers come a, ß-unsaturated compounds such as. B. vinyl aromatics (styrenes), vinyl esters, vinyl ethers, vinyl chloride, vinylidene chloride, N-vinyl pyrrolidone, acrylic acid esters, methacrylic acid esters, acrylamides, methacrylamides and maleic acid derivatives.

It is known that anionic image dyes can suffer a considerable loss in light fastness when fixed on cationic mordants. The loss of light fastness is strongly dependent on the structure and the form of storage of the cationic mordant and is also connected with the constitution of the specified image dye in a manner which is difficult to predict.

To improve the light fastness of image dyes fixed on cationic mordants, their subsequent metallization with transition metal ions has been proposed in DE-A 2740719. According to the invention, the metallization is carried out by means of Cu (II) or Ni ions, which are supplied by the so-called metal donor layer adjacent to the dyeable layer, in which these ions are dispersed in the form of water-insoluble organic complex compounds.

The use of nickel chelates to stabilize color photographic images has been described several times. DE-A 28 53 826 describes the use of nickel chelates from thioamides of the picolinic acid or quinaldic acid series for stabilizing dyes against light. The considerable intrinsic coloration of the nickel chelates described there would lead to a prohibitive coloring of the image whites even with proportions of 5 mmol / m ^{2 of the} image-receiving layer.

Only those copper or nickel complexes are suitable for use in image-receiving elements for the color diffusion transfer process which, even in proportions of 50 mmol / m ^2, do not cause the dyeable layer to be colored by densities of 0.07, measured behind a blue, green or red filter. to lead.

The copper or nickel complexes used according to the invention can be used in a wide variety of ways in order to store copper (II) or nickel ions diffusion-resistant in layers without losing their reactivity towards complex-forming dyes. The complexes can be mixed with binders such as gelatin, polyvinyl alcohol, cellulose derivatives, polyacrylamides and used in the form of these mixtures to produce transparent layers.

The Cu (II) or Ni complexes described are also suitable as metal donors for the insert tion in photographic layers in which a uniform or imagewise staining is to be produced by reaction of the complex-bound metal ions with other organic colorless or colored color-forming complexing agents. The generation of a uniform staining serves, for example, to make an undesired image which arises during the development of an integral recording material invisible after the image-wise exposure, e.g. B. a negative color image retained in the photosensitive member when a positive color image is formed in the image receiving layer. However, the complexes described according to the present invention are advantageously used in a so-called metal donor layer (“metal source”), which together with a dyeable layer and a layer support constitutes a so-called image-receiving element. Such an image receiving member may be an integral part of a multi-layer color photographic light-sensitive material, in which case it either remains attached to the original photosensitive member or is separated therefrom after development. The image-receiving element can, however, also initially be present as a separate, non-light-sensitive photographic material, which is only brought into contact with the light-sensitive recording material during processing and, if appropriate, subsequently separated again.

The image receiving element according to the present invention is distinguished by considerable advantages, especially with regard to the high level of light fastness and the clear color tone of the color transfers, in particular when image dyes with chelatable groups are used.

The image-receiving elements can be hardened in a conventional manner to improve their scratch resistance and to limit the absorption of liquid during processing with an alkaline medium.

The stability of the dispersed copper (II) or nickel chelates is high enough to prevent Cu (II) or NI ions from escaping into the hydrophilic binder phase during prolonged storage and possibly diffusing there as far as the incorporated color releaser. which would result in a loss of diffusibility and photographic sensitivity.

The image-receiving element according to the invention is therefore particularly suitable for producing integral mono-sheet or single-sheet materials in which the image-receiving element is present together with the layers of the letter-sensitive element in a closed layer structure and is optionally separated from those only by an opacifying layer which serves for optical separation.

The image-receiving element according to the invention with the hydrophilic binder layer containing the described chelates in the vicinity of the dyeable layer is suitable as an image-receiving material for any type of photographic color diffusion transfer process in which diffusing image dyes or diffusing color formers (image dye precursors) with chelating substituents are used and / or released in an imagewise manner can be transferred to an image receiving layer. After the transfer has taken place, such a photographic material in the image-receiving layer has an image-wise distribution of one or more such dyes in the form of the corresponding dye-metal complexes.

According to an advantageous embodiment of the invention, an integral photographic recording material, in addition to the image-receiving element according to the invention with the (hydrophobic) copper (II) or nickel complexes described, can have a layered photosensitive element which has at least one layer with a preferably acidic dye or a corresponding precursor compound and at least one contains a light-sensitive layer, in particular a light-sensitive silver halide emulsion layer. The dyes or dye precursor compounds mentioned are collectively referred to below as coloring compounds. Advantageously, such a recording material can also contain a plurality of light-sensitive silver halide emulsion layers of different spectral sensitivity, as well as further non-light-sensitive layers such as intermediate layers, cover layers and other layers of the most varied functions, as are customary in multi-layer color photographic recording materials.

Photographic materials which have an image receiving element with copper (II) or nickel complexes according to the invention, i. H. the image-receiving materials themselves and in particular also color-photographic recording materials which contain such an image-receiving material as an integral part may also contain acidic layers and so-called braking or deceleration layers, which together form a so-called combined neutralization system. Such a 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, for. 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 location where the alkaline developing liquid or paste is exposed. Such acid layers, brake layers or neutralization layers consisting of both are known, for example, from US Pat. No. 2,584,030, US Pat. No. 2,983,606, US Pat. No. 3,362,819, US Pat. No. 3,362,821, DE-A 2,455,762, DE -A 26 01 653, DE-A 26 52 464, DE-A 27 16 505, DE-A 28 16 878. Such a neutralization system can also contain two or more brake layers in a known manner.

In a special embodiment, the photographic material 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 can be used in particular if a light or white pigment, e.g. B. Ti0 _{2 were} used to 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-A 2543 181 and DE-A 1 924430.

Instead of a pre-formed opaque layer, means can also be provided in order 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, is a white pigment and the other is, for example, a dark, light-absorbing pigment, e.g. B. carbon black.

• 1) einen transparenten Schichtträger ;
• 2) eine hydrophile Bindemittelschicht mit einer Dispersion wasserunlöslicher organischer Ni- oder Cu-(lI)- Komplexe ;
• 3) eine anfärbbare Schicht ;
• 4) eine lichtundurchlässige Schicht (Pigmentschicht) ;
• 5) ein lichtempfindliches Element mit mindestens einer lichtempfindlichen Silberhalogenidemulsionsschicht und mindestens einer dieser zugeordneten farbgebenden Verbindung ;
• 6) eine Bremsschicht ;
• 7) eine saure Polymerschicht ;
• 8) einen transparenten Schichtträger.

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

• 1) a transparent substrate;
• 2) a hydrophilic binder layer with a dispersion of water-insoluble organic Ni or Cu (II) complexes;
• 3) a dyeable layer;
• 4) an opaque layer (pigment layer);
• 5) a light-sensitive element with at least one light-sensitive silver halide emulsion layer and at least one coloring compound assigned to it;
• 6) a brake layer;
• 7) an acidic polymer layer;
• 8) a transparent substrate.

This 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 to 5) and the cover sheet (layer elements 6 to 8), which are then placed on one another on the layer side and connected to one another, if appropriate using spacer strips so that a space for receiving a precisely measured amount of a developing liquid is formed between the two parts. The layer elements 6 and 7, 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 may be provided to introduce a developing liquid between two adjacent layers of the integral recording material, e.g. B. in the form of a laterally arranged, splitable container, which pours its contents under the action of mechanical forces between two adjacent layers of the recording material, in the present case between the photosensitive part and the cover sheet.

In the case of a single-dye transfer process, the photosensitive element contains a photosensitive silver halide emulsion layer and associated with this a coloring compound. The coloring compound can be in a layer adjacent to the silver halide emulsion layer or in the silver halide emulsion layer itself, in the latter case the color of the image dye is preferably selected so that the predominant absorption range of the coloring compound does not match the predominant sensitivity range of the silver halide emulsion layer. In order to produce multicolored transfer images in true-to-life colors, however, the light-sensitive element contains three such assignments of coloring compound and light-sensitive silver halide emulsion layer, the absorption range of the image dye resulting from the coloring compound generally matching the range of spectral sensitivity of the assigned silver halide emulsion layer substantially. However, it is beneficial for achieving the highest possible sensitivity if the color-providing compound is arranged in a separate binder layer (viewed in the direction of the light incident during the exposure) behind the silver halide emulsion layer or has an absorption which is different from that of the image dye ("Shifted image dyes" - US-A 3 854 945). A shift in the absorption generally results in the image-receiving layer as a result of complex formation with the copper (II) or nickel ions present therein if dyes with substituents capable of chelating are used.

The coloring compounds can be colored compounds which are themselves diffusible and which begin to diffuse when the layers are treated with an alkaline working liquid and are only determined by the development at the exposed areas. However, the coloring compounds can also be diffusion-resistant and release a diffusible dye in the course of development.

Color-imparting compounds which are a priori diffusible are known, for example, from German patents 1,036,640, 1,111,936 and 1,196,075. The so-called described there Dye developers contain in the same molecule a dye residue and a group that is able to develop exposed silver halide.

• US-A 3 227 550, US-A 3 443 939, US-A 3 443 940, DE-A 1 930 215, DE-A 2 242 762, DE-A 2 402 900, DE-A 2 406 664, DE-A 2 505 248, DE-A 2 543 902, DE-A 26 13 005, DE-A 26 45 656, DE-A 28 09 716, BE-A 861 241.

Among the processes known to date for producing color photographic images using the color diffusion transfer process, those based on the use of diffusion-resistant embedded coloring compounds, from which diffusible dyes or dye precursor products are cleaved during development and transferred to an image-receiving layer, have recently become increasingly important. Such non-diffusing coloring compounds (color releasers) are described, for example, in the following publications:

• US-A 3 227 550, US-A 3 443 939, US-A 3 443 940, DE-A 1 930 215, DE-A 2 242 762, DE-A 2 402 900, DE-A 2 406 664, DE -A 2 505 248, DE-A 2 543 902, DE-A 26 13 005, DE-A 26 45 656, DE-A 28 09 716, BE-A 861 241.

In the cited documents both those color releasers are described which produce negative color images when using conventional negative silver halide emulsions, and those which produce positive color images when using negative silver halide emulsions. In the former case, if positive color images are desired, either the use of directly positive silver halide emulsions or, if negative emulsions are used, the use of one of the known reversal methods, e.g. B. by the silver salt diffusion process (US-A 2 763 800) or by using compounds that release development inhibitors as a result of development.

When using the image-receiving elements according to the invention, color releasers are preferably used which contain substituents capable of complex formation in the dye residue. These include, in particular, azo dyes which, in addition to the azo bond, have chelating substituents such as -OH, -NHR or also ring nitrogen atoms. Coloring compounds with such dye residues are described, for example, in Research Disclosure Publications No. 17 334 (September 1978) and No. 18 022 (April 1979), as well as in US Pat. No. 3,081,167, DE-A 27 40 719, DE- A 31 07 540, DE-A 31 15648 and DE-A 31 17 243.

Surprisingly, however, a stabilizing effect is also achieved if color releasers are used which do not provide post-complexable dyes.

example 1

Image-receiving sheets according to the invention and image-receiving sheets not according to the invention were produced by successively applying the layers indicated below on a polyethylene-coated paper backing (amounts per m ² ):

Image receiving sheet 1

Image receiving sheet 2

The procedure was as for sheet 1, but with the difference that layer 1 had the following composition:

Image receiving sheet 3

The procedure was as for sheet 1, but with the difference that layer 1 had the following composition:

Image receiving sheet 4

The procedure was as for sheet 1, but with the difference that layer 1 had the following composition:

Image receiving sheet 5

The procedure was as for sheet 1, but with the difference that layer 1 had the following composition:

Image receiving sheet 6 (not according to the invention)

A prior art image-receiving sheet (US-A 3,282,305) was prepared by following the same procedure as for sheet 1, but with the difference that layer 1 had the following composition:

In the case of the image-receiving sheets 1 to 6, a weak green colored image-receiving layer with a smooth surface is obtained in each case. The optical density is no greater than 0.05 measured behind the red filter.

Image receiving sheet 7

The procedure was as for sheet 1, but with the difference that layer 1 had the following composition:

Image receiving sheet 8

The procedure was as for sheet 1, but with the difference that layer 1 had the following composition:

Image receiving sheet 9

The procedure was as for sheet 1, but with the difference that layer 1 had the following composition:

Image receiving sheet 10

The procedure was as for sheet 1, but with the difference that layer 1 had the following composition:

In the case of the image-receiving sheets 7 to 10, an image-receiving layer with a smooth surface is always obtained. The image receiving layer is faintly blue in the case of the image receiving sheets 7 and 8 and faintly yellow in the case of the image receiving sheets 9 and 10. The optical density measured behind the red filter or blue filter is in any case less than 0.05.

Image receiving sheet 11 (not according to the invention)

An image receiving sheet according to the prior art (US 4,282,305) was produced by following the same procedure as for sheet 1, but with the difference that layer 1 had the following composition:

A blue-colored image-receiving layer with a smooth surface is obtained. The density measured behind the red filter is 0.25. This image receiving sheet is unusable for practical purposes.

Image receiving sheet 12

The procedure was as for sheet 3 (chelate 5 - Ni), but with the difference that layer 2 had the following composition:

Image receiving sheet 13

The procedure was as for sheet 12, but with the difference that layer 1 had the following composition:

Image receiving sheet 14

The procedure was as for sheet 3 (chelate 5 - Ni), but with the difference that layer 2 had the following composition:

Image receiving sheet 15

The procedure was as for sheet 14, but with the difference that layer 1 had the following composition:

Image receiving sheets 12 to 15 with a smooth surface were obtained. Leaves 12 and 14 were pale green and leaves 13 and 15 were pale blue. The optical density measured behind the red filter was less than 0.05 in each case.

Image receiving sheet 16 (not according to the invention)

Like image receiving sheet 1, but without layer 1.

1 strip each of the image-receiving sheets 1 to 15 was immersed in a 4% NaOH solution for 2 minutes. Image-receiving sheets 1-5, 7-10 and 12-15 then appeared pale beige to pale blue when viewed in daylight, image-receiving sheet 6 clearly chamois and image-receiving sheet 11 stained clearly blue.

After a subsequent treatment bath with a 3% Na succinate buffer adjusted to pH = 6, the image-receiving sheets 1-5, 7-10 and 12-15 were decolored. Image receiving sheet 6, on the other hand, retained a brownish, image receiving sheet 11 a bluish tint; the latter were unsuitable for practical purposes.

Example 2

0.03 molar solutions were prepared from the following post-complexable image dyes and made alkaline with 1% NaOH.

Dye F (dye 13 of DE-A 31 07 540)

Dye G (dye 13 of German patent application DE-A 31 15 648)

1 strip of each of the image-receiving sheets 1-6, 12 and 14 was immersed in these solutions until a density of 1.5, measured behind a complementary color filter, was reached. The corresponding strips of image-receiving sheet 16 were immersed until after-treatment with a 2% nickel acetate solution for 30 s gave a density of 1.5.

The strips were then post-treated with a 2% sodium succinate solution adjusted to pH = 1 and dried for 1 min.

The evaluation shows that the desired color tones in the image-receiving sheets according to the invention are achieved essentially without delay compared to the prior art and that the nuances of the image-receiving sheets 1-5, 12 and 14 correspond to those obtained with image-receiving sheet 16 after treatment with Ni-acetate will. There are no brown discolourations. The complexation takes place immediately, a gradual color change cannot be seen. The nuances of image receiving sheet 6 are somewhat cloudy.

For the light fastness test, 1 strip with color transfers of the dyes A to G on the image-receiving sheets 3, 4 and 16 was subjected to a high-intensity exposure in the Xenotest device for 48 hours. The percentage loss in density, determined after exposure to 4.8 · 10 ⁶ Ixh, based on the initial density 1.5, are summarized in Table 1 below:
(See table 1 page 24 f.)

The results allow the conclusion that the light fastness of color transfers from post-complexable anionic image dyes can be improved by metallization with hydrophobic nickel chelates according to the invention.

Example 3

1 strip of each of the image-receiving sheets 7-11, 13 and 15 was immersed in the dye solutions until a density of 1.5, measured behind a complementary color filter, was reached. The corresponding strips of image-receiving sheet 16 were immersed until after-treatment with a 2% copper acetate solution for 30 s gave a density of 1.5.

The strips were then post-treated with a 2% sodium succinate solution adjusted to pH = 1 for 1 min and dried.

The evaluation shows that the desired color tones are achieved essentially without delay compared to the prior art and that the nuances of the image-receiving sheets 7-10, 13 and 15 correspond to those which are obtained with image-receiving sheet 16 after treatment with Cu acetate. There are no brown discolourations. The complexation takes place immediately, a gradual color change cannot be seen. With image receiving sheet 11, the nuances are cloudy and somewhat shorter.

For the light fastness test, 1 strip each with color transfers of the dyes A to G on the image-receiving sheets 7, 9 and 16 was subjected to a high-intensity exposure in the Xenotest device for 48 hours. The percentage density losses, determined after exposure to 4.8-108 Ixh, based on the initial density 1.5, are summarized in the following Table 2:

The results allow the conclusion that the light fastness of color transfers from post-complexable anionic image dyes can be improved by metallization with hydrophobic copper (II) chelates according to the invention.

Example 4

The procedure was as in Application Example 2, but using the following non-post-complexable image dyes:

For the light fastness test, 1 strip each with color transfers of the dyes H to K on the image-receiving sheets 3, 4 and 16 was subjected to a high-intensity exposure in the Xenotest device for 48 hours. The percentage density losses, determined after exposure to 4.8 × 10 ⁶ Ixh, based on the initial density 1.5, are summarized in Table 3 below:

The results allow the conclusion that the light fastness of color transfers from non-complexable anionic image dyes with hydrophobic nickel chelates according to the invention can also be improved.

Claims (5)

1. Image-receiving element for the dye diffusion transfer process, having a layer which is capable of being dyed by diffusible organic dyes and is arranged on a layer support and, adjacent to said layer, a hydrophilic binder layer containing a metallising agent for subsequently metallisable dyes, characterised in that the adjacent hydrophilic binder layer contains the metallising agent in the form of a dispersion, optionally containing oil-formers, of a water-insoluble organic copper(II) or nickel complex of a compound of one of the following formulae I to VI :

wherein

R¹ denotes a hydrocarbon radical which has up to 30 C atoms and is optionally interrupted by ―O―;

R² and R²' denote hydrogen, alkyl with up to 5 C atoms, cycloalkyl, aralkyl or aryl with 6 to 10 C atoms,

R³ and R³' denote alkyl or alkoxy with 1 to 4 C atoms, aralkyl or OH ;

X denotes

R⁴ denotes a hydrocarbon radical with up to 18 C atoms, which is attached either directly or via -0-, or halogen or a group R6;

R⁵ denotes hydrogen, halogen, alkyl or alkoxy with up to 18 C atoms, alkenyl, a radical to complete a fused-on benzene ring, or a group R⁶, if R⁴ does not denote a group R⁶ ;

R⁶ denotes

-NH-CO-R" or ―NH―SO₂―R¹² ;

R⁷ and R⁷' denote alkyl, aryl or a heterocyclic group ;

R⁸ denotes hydrogen or a group R⁷ ; or R⁷ and R⁸ together denote a radical to complete a carbocyclic or heterocyclic ring ;

R⁹ denotes alkyl, aralkyl or cycloalkyl with up to 8 C atoms ;

R¹⁰ and R¹⁰ denote radicals such as R² and R²' or both together denote a radical to complete a 5-, 6- or 7-membered cyclic amino group ;

R¹¹ denotes alkyl, aralkyl, aryl OR⁹ or

and

R¹² denotes alkyl, aryl or

2. Image-receiving element according to Claim 1, characterised in that the dyeable layer contains, as a mordant for diffusible organic image dyes, a polymer containing structural units which contain a heterocylic amino function.

3. Image-receiving element according to Claim 2, characterised in that the polymeric mordant contains structural units in which the heterocyclic amino function is present in a quaternised or protonated form.

4. Image-receiving element according to Claim 3, characterised in that the polymer contained as a mordant in the dyeable layer contains structural units of the following formula:

wherein

Z denotes the atoms required to complete a nitrogen-containing heterocyclic ring ;

L denotes a single chemical bond or a divalent linking member between the heterocyclic ring and the C atom which carries the radical R^B ;

R⁴ denotes hydrogen, -COOR^c or ―CONHR^c ;

R^B denotes hydrogen or alkyl with 1 to 6 C atoms ;

R^C denotes hydrogen, alkyl or aralkyl ; and

X⁸ denotes a mono- or divalent anion.

5. Image-receiving element according to one of Claims 1 to 4, characterised in that it is an integral constituent of a multi-layered light-sensitive colour-photographic recording material.