US3660092A

US3660092A - Colorphotographic material

Info

Publication number: US3660092A
Application number: US690105A
Authority: US
Inventors: Karl Frank; Jan Jaeken
Original assignee: Agfa Gevaert AG
Current assignee: Agfa Gevaert AG
Priority date: 1966-12-20
Filing date: 1967-12-13
Publication date: 1972-05-02
Anticipated expiration: 1989-05-02
Also published as: GB1200065A; DE1522418A1; BE708245A; NL6717399A; CH493862A

Abstract

Photographic color images having extremely good light-fastness are formed by converting a silver halide image to an image of a salt of a heavy metal that complexes with an organic complexing agent to make a strongly colored diffusion-resistant complex more light-fast than color coupler dyes. The heavy metal can be copper, chromium, manganese, iron, cobalt, nickel, palladium or platinum, or the like, and the organic complexing agent can have two different locations in its molecule for coordination with the metal. The silver halide is converted to the salt of the complexing heavy metal by applying to the silver halide image a differently colored or uncolored reactive complex of that metal having a disassociation constant larger than the corresponding complex of silver, so that the silver of the silver halide becomes bound by the reactive complex and liberates the heavy metal. It is also possible to go through two such reactive complex treatments to first convert the silver halide image to a mercury salt image, for example, and then convert the mercury salt image to an iron salt image, before the strongly colored light-fast final complex is formed. The organic complexing agent can be uniformly distributed in a light-sensitive silver halide emulsion, or it can be uniformly distributed in a layer adjacent that emulsion. After light-fast complex is formed, the unused complexing agent in such a layer can be complexed with a different metal ion to form a different color suitable for masking.

Description

United States Patent Frank et al.

[ 1 May 2,1972

[54] COLORPHOTOGRAPHIC MATERIAL AGFA-Gevaert Aktiengesellschaft, Leverkusen, Germany [22] Filed: Dec. 13,1967

[21] Appl.No.: 690,105

[73] Assignee:

[30] Foreign Application Priority Data Dec. 20, 1966 Germany 54426 [52] US. Cl ..96/54, 96/21, 96/72, 96/96 [51 Int. Cl "G031: 7/00 [58] Field of Search ..96/54, 90, 9, 7, 8, 95, 96, 96/55, 57, 72

[56] References Cited UNITED STATES PATENTS 3,196,014 7/1965 Rogers ..96/57 3,081,167 3/1963 Goulston et al ..96/57 2,013,159 9/1935 Lierg ..96/57 2,333,359 11/1943 Bunting .....96/57 2,415,626 2/1947 Coote ..96/57 2,533,181 12/1950 Sargent.... .....96/57 2,533,182 12/1900 Sargent... .....96/57 2,308,023 1/1943 Peterson ..96/54 2,333,126 11/1943 Schwarc ..96/54 3,243,296 3/1966 Nasu et al. ..96/61 3,445,230 5/1969 Francis ..96/90 Primary Examiner-William D. Martin Assistant Examiner-M. Sofocleous AttorneyConnolly and Hut:

[5 7] ABSTRACT Photographic color images having extremely good light-fastness are formed by converting a silver halide image to an image of a salt of a heavy metal that complexes with an organic complexing agent to make a strongly colored diffusionresistant complex more light-fast than color coupler dyes. The heavy metal can be copper, chromium, manganese, iron, cobalt, nickel, palladium or platinum, or the like, and the organic complexing agent can have two different locations in its molecule for coordination with the metal. The silver halide is converted to the salt of the complexing heavy metal by applying to the silver halide image a differently colored or uncolored reactive complex of that metal having a disassociation constant larger than the corresponding complex of silver, so that the silver of the silver halide becomes bound by the reactive complex and liberates the heavy metal. It is also possible to go through two such reactive complex treatments to first convert the silver halide image to a mercury salt image, for example, and then convert the mercury salt image to an iron salt image, before the strongly colored light-fast final complex is formed. The organic complexing agent can be uniformly distributed in a light-sensitive silver halide emulsion, or it can be uniformly distributed in a layer adjacent that emulsion. After light-fast complex is formed, the unused complexing agent in such a layer can be complexed with a different metal ion to form a different color suitable for masking.

6 Claims, No Drawings COLORPHOTOGRAPHIC MATERIAL This invention relates to a process for the production of color photographic images in which the image dye consists of an organic metal complex compound which is particularly fast to light, and also relates to light-sensitive photographic materials for carrying out this process.

By the term toning process" in this specification .is meant any process in which a silver image can be converted into a dye image of any desired color. The silver images may represent color separation records, simply termed blue, green and red separation records, and after conversion of the blue separation record into a yellow image, the green separation record into a magenta image and the red separation record into a cyan image, copies of the original in true colors are obtained if the the layers are brought into register. According to one toning process the silver images of the separation records are treated with potassium ferricyanide to convert the metallic silver image into a silver ferrocyanide image. Thereafter, the blue separation record may be treated with a solution of a lead salt, whereby the silver ferrocyanide is converted into insoluble lead ferrocyanide which, on further treatment with a chromate solution, is converted into yellow lead chromate which is very fast to light. The green separation record can be treated with a nickel salt, whereby nickel ferrocyanide is produced silver images of the three color separation records are first converted into silver ferrocyanide by means of potassium ferricyanide. Treatment with a nickel salt leads to imagewise formation of nickel ferrocyanide in all separation records. The blue separation record is then treated with dicyandiamidine sulfate, a yellow nickel complex being formed. The green separation record is treated in known manner with dimethylglyoxime, a red nickel complex being formed, and the red separation record is treated with 1,2-diaminoanthraquinone- 3-sulfonic acid, a blue nickel complex being formed. In all cases, the nickel salt image of each individual separation record must be reacted separately with the dye-forming agent, in this case with a solution of an organic complex forming agent. Although these processes have advantages in that the dye images are considerably superior in their light-fastness to conventional color photographic images which contain azomethine dyes produced by means of color forming developers, they have hitherto not come into general use owing to the complicated procedure for making the colored images. The main drawback is that a process of that kind was hitherto not suitable to produce a dye image in true colors in a multilayer photographic material which contains all partial images.

It is among the objects of the invention to provide novel processes based on the above toning processes which allow a simple processing and production of dye images in three-layer photographic materials.

We now have found that dye images which are very fast to light, and which consist of colored heavy metal complex compounds can be produced in simple manner. This is achieved by reacting silver halide which is imagewise distributed in a photographic emulsion layer with a solution of a first complex compound of a heavy metal of the auxiliary groups of the periodic system of elements, excepting silver, with complex forming agents (ligands). The dissociation constant of this first complex compound is greater than that of the corresponding complex compound of the same ligands with silver. In other words, these ligands form a more stable complex compound with silver ions than with the heavy metal ions of the first complex. Free heavy metal ions are liberated imagewise from the first complex compound by reaction with the imagewise distributed silver halide. These free heavy metal ions are capable of forming a colored complex compound with organic complex forming compounds. Therefore, the photographic materia] of the instant invention contains in addition to the imagewise distributed silver halide such an organic complex forming compound which is uniformly distributed and diffusion-fast incorporated in the silver halide layer or another layer adjacent thereto and which is incapable of reacting with silver halide. The colored heavy metal complex compound of the final image is formed only at those areas of the layer, which correspond to the silver halide image, i.e., at those areas where free heavy metal ions have been liberated. No reaction must occur between the organic complex-forming compound in the layer and the first complex compound which contains the heavy metal in complexed form. Therefore it is an important requirement that the dissociation constant of the colored heavy metal complex compound of the final image is greater than that of the first soluble heavy metal complex compound.

The process according to the invention requires a photographic layer which contains silver halide in imagewise distribution. Such a layer can be produced in various ways depending on whether a positive or negative image of the original is required. In the former case, an exposed silver halide emulsion layer is developed in the usual manner, a negative silver image of the original being obtained. The silver halide remaining in the layer then forms a positive, invisible silver halide image of the original.

Ifone has to start with a negative silver halide image, exposure and development are first carried out in the usual manner as described above, the silver halide remaining in the layer is then removed by fixing, and lastly the silver image is converted into silver halide.

For the sake of better understanding, the principle of the inventive process will be explained in the following by means of a specific example. A layer which contains silver halide in imagewise distribution and contains uniformly distributed in diffusion-resistant form an organic compound, which forms a dye with free nickel ions, is first reacted with a solution of Ni(CN) complex compound. Since the dissociation constant of the complex compound is greater than that of the corresponding silver cyanide complex compound, the nickel complex compound is destroyed in those areas where silver halide is present, and nickel ions are liberated in these image areas. The organic complex forming agent referred to above now reacts with the free nickel ions to form the image dye in these areas. This dye image is exactly proportional in its density to the silver image. This is due to the fact that on formation of the silver cyan complex compound, the stoichiometric quantity of nickel ions is liberated.

As already explained above, the relationship between the dissociation constants of the first heavy metal complex agent, the corresponding silver complex agent and the colored heavy metal complex agent of the final image is important in the process according to the invention. The required relation between the dissociation constants of the complexes can easily be adjusted by suitable choice of heavy metal ions, the ligands of the first heavy metal complex, and the organic complex forming agents which yield with the liberated heavy metal ions the final image dye. Since innumerable heavy metal complexes with inorganic and organic ligands are described in the literature, a person skilled in the art can easily find combinations which meet the required conditions.

The three components essential for the process according to the invention are as follows:

1. Heavy metals: suitable are auxiliary group elements of the periodic system of elements, especially of the first, sixth, seventh and eighth auxiliary group; e.g., copper, chromium, manganese, iron, cobalt, nickel, palladium and platinum. Copper, iron, cobalt and nickel are especially suitable for reasons of cost and owing to suitable color tones of their complex compounds.

2. Suitable ligands for the original heavy metal complex compounds include cyano-, thiocyanato or thiosulfate ions, aliphatic and heterocyclic amines or polyamines, complex forming amino-carboxylic acids such as ethylenediaminotetraacetic acid or nitrilotriacetic acid. By the term ligands is meant groups which are attached directly to the heavy metal central atom.

3. Complex forming agents or ligands for the complex which forms the final image dye, are shown in the following tables: 5

TABLE 1 Nickel-(Il)ion Organic complex forming agent Color -yor syn form of dioximes of l,2-diketones yellow -y-benzil dioxime yellow 'y-methyldecylglyoxime yellow Dlisonitroacetone and derivatives thereof yellow Mercaptobenzothiazole and its derivatives dark yellow Dicyandiamidine and derivatives thereof yellow Dimethylglyoxime magenta Cyclohexandiondioxime magenta a-or anti-benzildioxime magenta a-furildioxime magenta Nitrosoguanidine magenta Bis-( diacetylmonoxime-imino )-propane-l ,3 magenta Bis-( diacetylmonoxime-imino )-ethane-1 ,2 magenta Diphenylcarbazide magenta to blue-violet l,2-diamino-3 -sulfo-anthraquinone dark blue Triethanolamine blue o-aminobenzoic acid green S-chlorosalicylicaldoxime green Acetaldoxime cyan Benzaldoxime V cyan Phenylthiosemicarbazide dark green o-hydroxyacetophenonoxime green TABLE 2 lron-(II)-ion rgamc complex forming agent Color Pyridine-Z-carboxylic acid yellow a,ct-dipyridyl red Dimethylglyoxime red Thioglycolic acid red-violet Quinoline-8-carboxylic acid red Nitrosoguanidine magenta 2-nitroso-l-naphthol-4-sulfonic acid green Triethanolarnine green Phenanthrenequinonemonoxime blue-green 5 5 lsonitroacetylacetone blue 4-isonitroso- 1 -phenyl-3 -methyl-pyra.zolone-5 blue a-nitroso-fl-naphthol green TABLE 3 0 lron--(Il'l)ion Organic complex forming agent Color Kojic acid yellow-orange Acetylacetone red l-(thenoyl-[a )-3,3,3-trifluoracetone H COCH COCF red s 7 V 7 V ,7 4-dimethylamino-1-phenyl-2 ,3- dimethylphrazolone:(5) blue TABLE 4 Copper-(D-ion Color Zinc diethyldithiocarbamate brown-yellow 2,2'-diquinolyl magenta l l0-phenanthroline blue TABLE 5 Copper-(Il)ion Organic complex forming agent Color Antipyrine lemon yellow Salicylicaldoxime yellowish Schloro-salicylicaldoxime yellow-brown Mercaptobenzothiazol pale orangeyellow Sodium diethyldithiocarbaminate yellow Diethylaminodiethyldithiocarbaminate orange Dicyandiamidine red Monoethylphthalate cyan Glycine blue Diethanolamine blue Triethanolamine blue Phenylthiosemicarbazide deep blue Quinoline indigo blue a-benzoinoxime green Diisonitrosoacetone dark green Acetaldoxime luminous blue Acetone Dicarboxylic acid oxirne green 1,2-diaminoanthraquinone-3-sulfonic acid blue Quinaldic acid cyan Phenylglyoxalic acid oxime luminous green TABLE 6 Cobalt--(ll)-ion Organic complex forming compound Color l-(thenoyl[a']-3,3,3-trifluoroacetone orange 2-nitroso-I-naphthol-4-sulfonic acid red a-benzilmonoxime red Diisonitrosoacetone red Phenylglyoxalic acid oxime red l,Z-diamino-anthraquinone-3-sulfonic acid green-blue quinoline blue S-nitrosalicylicaldoxime green Acetonedicarboxylic acid oxime green Acetone oxirne cornflower blue Mercaptobenzothiazol green phenylthiosemicarbazide green l-( 2-pyridyl-azo )-2-naphthol cyan TABLE 7 Platinum Organic complex fonning agent Color Z-mercaptobenzothiazole canary yellow Thionalide yellow Dithiooxarnide Benzidine magenta green Dimethylglyoxime Cyclohexanedionedioxime orange-yellow Orange-yellow a-nitroso-fi-naphthol violet p dimethylaminobenzylidene thioxyanate red-violet suitably substituted formazanes cyan The process of the invention is characterized by applying a photographic material comprising at least one layer which contains silver halide in imagewise distribution and which further contains uniformly distributed in the silver halide or another layer adjacent to the said silver halide layer the organic complex forming agent fast to difl'usion.

The organic complex forming agent is added in a diffusionresistant form to the silver halide emulsion layer, or to an adjacent layer, in a manner well known in the art. This can be accomplished in the same way as the diffusion'fast incorporation of color couplers in conventional color photography. The organic complex forming agent may either be substituted by long chained alkyl radicals having about 12 to 18 carbon atoms and a solubilizing group such as sulfo groups, or it may be dissolved in an organic solvent and emulsified in the photographic layer. In the latter process, high boiling solvents, socalled oil forming agents, may be added in known manner.

The present invention is preferably used for producing multi-layered materials according to the subtractive color principle. These materials are similar in structure to the known color photographic multi-layer materials except that the conventional color forming system consisting of color couplers capable of reacting with the oxidation products of color-forming developers is replaced by the system according to the invention which consists of the solution of the heavy metal complex and the diffusion resistant organic complex forming agent in the photographic layer.

A photographic material which is operative in the process of the present invention consists of a blue-sensitive silver halide emulsion layer which contains an organic complex forming agent in a diffusion-fast form which yields a yellow dye with a heavy metal ion, a green-sensitive silver halide emulsion layer which contains an organic complex forming agent in a diffusion-fast form capable of forming a magenta dye with the heavy metal ion, and lastly, a red-sensitive silver halide emulsion layer which contains an organic complex forming agent in diffusion-fast form capable of forming a cyan dye with the heavy metal ion.

The above mentioned organic complex forming agents, especially those which yield a magenta or cyan dye, include some which have a yellow to red color of their own. These complex forming agents are of special importance in that they act as integral masks for eliminating undesired side-absorptions of magenta or cyan dyes. The principle of masking is well known in the art of color photography.

The invention, in the form described earlier using nickel as heavy metal ion is based on the fact that the stability of the silver cyanide complex is higher, or in other words the dissociation constant is lower than that of the nickel cyanide complex. Silver halides are, therefore, capable of displacing nickel ions from the cyanide complex. Numerous combinations of heavy metal ions, inorganic and organic complex forming agents are already known which would be suitable as regards the dye formed, but these cannot be used in the described simplified form of the process according to the invention because the dissolved inorganic or organic heavy metal complex is more stable than the corresponding silver complex. In such a situation the silver would not be capable of displacing the heavy metal ions from the soluble complex compound. This applies, for example, to the iron cyanide complex compounds which have a higher stability than the silver cyanide complex. Silver halide is, therefore, not capable of liberating iron ions from the cyanide complex at room temperature. However, since iron ions would themselves be suitable, especially since numerous organic complex forming agents are known which react with iron ions to yield dyes of subtractive colors, yellow, magenta or cyan, the use of these heavy metal ions is very desirable. This system can, in fact, be used by slightly modifying the process according to the invention. In the modified process, the silver halide image is converted into a mercury salt image in a manner which is well known in the art. Since the mercury cyanide complex has a much lower dissociation constant than the iron cyanide complex, the process can now be carried out in the manner described.

The direct use of suitable heavy metal complexes is only possible if the complex forming agent (ligand of the first soluble complex) is so chosen that the silver ion is capable of displacing the heavy metal from the complex compound.

In general, any heavy metal ion that yields the color triplet yellow, magenta and cyan with suitably selected organic complex forming agents, may be used in the process of the present invention. The heavy metal ions must first form a first complex compound which is sufiiciently stable so as not to react with the organic complex fonning agent in the layer. It is only after liberation of the heavy metal ion by a second metal ion, preferably silver, which has a greater tendency to fonn a complex compound with the ligands of the first complex that the desired colored heavy metal complex agent of the final image is formed. A few figures may serve as examples. The dissociation constant of the mercury cyanide complex is 4 X 10", that of the ferrocyanide complex is l0' Mercuric chloride, therefore, displaces ferrous ions from the ferrocyanide complex. The ferrous ions liberated can react with the organic complex forming compounds to yield the appropriate dyes.

The dissociation constants of the colored heavy metal complexes of the final image are substantially higher and are probably of the order of 10" to l0". For example, in the simplest case, namely the displacement of nickel ions from the nickel cyanide complex by silver ions, the dissociation constants of the different silver cyanide complexes are of the order of 10 to 10', whilst the nickel cyanide complex has a dissociation constant of about 10' so that the silver salt can displace nickel ions from its cyanide complex compound. The free nickel ions then react with the organic complex forming agent, and the dissociation constant of the complex compounds thus formed being presumably in the region of 10' to 10 The main advantage of the process described above is the high fastness to light of the complex compounds forming the final image. Light-fastness values are achieved which are multiples of those obtained by azomethine dyes of the conventional color photographic processes. The process is suitable for a negative process as well as a positive or reversal process. Furthermore, automatically masked colored negatives can be obtained by applying originally colored organic complex fonning agents.

In another variation which may be employed for obtaining masked negatives, the organic complex forming agents at the areas which in the original silver halide image were free from silver halide and which accordingly have not undergone reaction with heavy metal ions are reacted with a suitable heavy metal salt solution wherein the heavy metal is different from that of the first heavy metal complex to form the masking dye. For example, a dicyandiamidine derivative incorporated in a difl'usion-fast manner reacts with copper to form a magenta image dye, and after treatment with a nickel salt solution the complex forming agent that has not been usedup yields a yellow masking dye in the areas that have not been exposed to light.

The concentration of organic complex forming agent in the silver halide emulsion layer may vary within, wide limits according to the requirements of the reproduction process and the properties of the photographic material. A ratio of concentrations of the organic complex forming agents to the silver present of about 1 mol to 1 mol has generally proved suitable. The valency of the heavy metal cation is of little influence in this respect since monovalent cations are usually in twofold coordination, bivalent cations are usually in four-fold coordination and trivalent cations are usually in sixfold coordination, provided, of course, that the organic complex forming agent has two positions for coordination on the metal, which is practically always the case.

The silver content of the emulsion layers depends to a certain extent on the valency of the cation used for production of the image dyes. Thus 2 mols of silver are required for liberating a bivalent cation, 3 mols of silver for liberating a trivalent cation etc. In general quantities of between 0.5 to 10 g. silver in the form of silver halide per square meter per layer have proved sufficient.

Example 1 Production of a negative magenta image:

20 g. of -y-benzildioxime are dissolved in 300 ml. of

per liter of solution ready p-methylaminophenol l g. anhydrous sodium sulfite 13 g. hydroquinone 3 g. borax 20 g. potassium bromide l g.

The developed material is treated for one-half minute in a 2 percent aqueous solution of acetic acid. The film is then fixed for 2 minutes in an acid fixing bath and thoroughly washed with water. Thereafter, the silver image is bleached for minutes in a bleaching bath which contains g. of potassium bromide and 50 g. of potassium hexacyanoferrate (lll) per liter, and it is thoroughly washed with water.

The image thus bleached and thoroughly washed is now immersed in a solution of 5 g. of potassium nickel cyanide in 500 ml. of water.

A few ml. of concentrated ammonia solution are advantageously added to the solution to accelerate the reaction. A magenta dye image is formed in the image areas that contain silver halide. After a treatment time of 10-15 minutes, the dye image does not undergo any further intensification. The paper is thoroughly washed with water and is again fixed with a fixing bath usually employed to remove unreacted silver halide. Finally the material is washed with water. An excellent negative magenta image of the step wedge is obtained.

If the 'y-benzildioxime is replaced with the equivalent amount of o-hydroxybenzophenone oxime and otherwise identical technique, a green image is obtained.

Example 2 Production of a positive yellow image:

200 mg. of an organic complex forming agent of the following formula:

are dissolved in 200 ml. of ethanol and ml. of N-sodium hydroxide. The solution is slowly added with vigorous stirring to 400 ml. of a 4 percent aqueous gelatin solution, containing 0.2 g. of saponine as wetting agent. An emulsion of the organic complex forming agent in the aqueous gelatin solution is obtained.

The above emulsion and 50 ml. of n-succinic acid are added to 800 ml. of a silver bromide iodide gelatin emulsion. The

' mixture is applied onto a support of cellulose triacetate.

The dried material is exposed behind a step wedge as described in Example 1, developed in the same developer solution and thoroughly rinsed. In this case it is not fixed but the remaining residual silver halide is converted into a yellow dye image by treatment with the same potassium nickel cyanide solution as in Example 1.

The remaining silver halide is thereby converted into a positive yellow dye image. After this treatment, the paper is thoroughly washed with water, and the silver formed on exposure and development is removed by bleaching in the beaching bath describedabove and the image is fixed. After a final washing with water, a positive yellow image is obtained.

The fastness to light of the resulting yellow dye is practically infinite compared with the light-fastness of azomethine dyes produced by colorforming development. After an exposure time which is five times as long as that required to destroy an azomethine dye image obtained by color-forming development, no change is detected with the yellow dye obtained according to the invention Example 3 Production of the organic complex forming agent:

A nitroso group is introduced into methylundecylketone by reaction with amyl nitrite with the addition of a small quantity of hydrochloric acid. The resulting Methyl-isonitrosoundecylketone is reacted with hydroxylaminein alcoholic solution to form methyldecyldiketodioxime. The resulting product has a melting point of 149 C. after recrystallization from methanol.

20 g. of the methyldecyldiketodioxime are dissolved in.300 cc. of methanol, and 300 cc. of a 4 percent aqueous gelatin solution containing 0.5 percent by weight of the oleylether of polyethyleneglycol as wetting agent, are slowly added with vigorous stirring. An emulsion of the organic complex forming compound in the gelatin solution is obtained.

The emulsion is added to a photographic silver bromide gelatin emulsion in such a proportion that the molar ratio of silver to complex forming agent obtained is 1:1. This solution which is ready for casting, is applied onto a barytacoated paper.

It is exposed behind a step wedge and processed as described in Example 1 or 2.

An aqueous solution of potassium nickel tetracyanide is used for forming the dye image. The solution contains 10 g. of potassium nickel tetracyanide per liter. Further treatment is carried out as described in Example 1 or Example 2. A negative or positive yellow dye image is produced.

The final dye image of the step wedge is exposed to daylight for a period of about 1 year without any noticeable bleaching. For comparison, several yellow azomethine dye images produced by conventional color photographic processes were subjected to the same exposure. The azomethine dye images were completely bleached after exposure for 1 year.

We claim:

1. A process for the production of colored photographic images whereby the final image dye consists of colored heavy metal complex compounds, said process including the steps of preparing a photographic material comprising at least one emulsion layer containing therein image distributed silver halide said material including a uniformly distributed diffusionresistant organic complex-forming compound in or adjacent to said silver halide layer said complex-forming compound being capable of forming colored complex compounds with ions of heavy metals selected from the group consisting of nickel, iron, copper, cobalt, platinum and palladium, and being incapable of reacting with silver halide, treating said photographic material with a solution of a first complex compound of the said heavy metals having a dissociation constant greater than the dissociation constant of the corresponding silver complex compound, the first complex compound thus being capable of reacting with the image distributed silver halide to form image distributed free ions of the said heavy metals, and forming the colored heavy metal complex compounds of the final image by reacting the imagewise formed free heavy metal ions with the uniformly distributed organic complex-forming compound, thereby producing in image distribution the colored complex compound, the dissociation constant of said colored complex compound being greater than that of the first soluble heavy metal complex.

2. The combination of claim 1 in which the organic complex-forming compound has a color different from that of the final heavy metal complex and acts as a mask.

3. The combination of claim 1 in which after the final heavy metal complex is formed the layer is treated with a different heavy metal that forms with the residual organic complexforrning compound a differently colored complex which acts as a mask.

4. In the process of claim 1 the step of first converting the silver halide image to a mercury salt image and then reacting said mercury salt image with said first complex compound to thereby form free heavy metal ions and a complex mercury compound, and finally reacting said free heavy metal ions with the uniformly distributed organic complex-forming compound.

5. Colorphotographic material having on a support at least one layer of light-sensitive silver halide emulsion in which the silver halide is in intimate contact with a uniformly distributed organic complex-forming compound selected from the group consisting of an oxime, an aminocarboxylic acid, an amino anthraquinone, mercaptobenzthiazone, diphenylcarbazide, phenyl-thiosemicarbazide, thioglycolic acid, kojic acid, monoethylphthalate, dipyridyl, diquinolyl, phenanthroline, dicyanodiamidine, triethanolamine, nitrosoguanidine, an 1,3- diketone, antipyrine, 4-dimethylaminol -phenyl-2,3- dimethylpyrazolone-(S), diethyldithiocarbamate, quinoline, thionalide, dithioxamide and benzidine capable of forming colored complex compounds with free heavy metal ions, the quantity of complex-forming compound being 1 mol per mol of silver halide present.

6. The combination of claim 5 in which the aminocarboxylic acid is glycine, o-aminobenzoic acid, pyridine-2-carboxylic acid, quinoline-8-carboxylic acid or quinaldic acid.

Claims

2. The combination of claim 1 in which the organic complex-forming compound has a color different from that of the final heavy metal complex and acts as a mask.
3. The combination of claim 1 in which after the final heavy metal complex is formed the layer is treated with a different heavy metal that forms with the residual organic complex-forming compound a differently colored complex which acts as a mask.
4. In the process of claim 1 the step of first converting the silver halide image to a mercury salt image and then reacting said mercury salt image with said first complex compound to thereby form free heavy metal ions and a complex mercury compound, and finally reacting said free heavy metal ions with the uniformly distributed organic complex-forming compound.
5. Colorphotographic material having on a support at least one layer of light-sensitive silver halide emulsion in which the silver halide is in intimate contact with a uniformly distributed organic complex-forming compound selected from the group consisting of an oxime, an aminocarboxylic acid, an amino anthraquinone, mercaptobenzthiazone, diphenylcarbazide, phenyl-thiosemicarbazide, thioglycolic acid, kojic acid, monoethylphthalate, dipyridyl, diquinolyl, phenanthroline, dicyanodiamidine, triethanolamine, nitrosoguanidine, an 1,3-diketone, antipyrine, 4-dimethylamino-1-phenyl-2,3-dimethylpyrazolone-(5), diethyldithiocarbamate, quinoline, thionalide, dithioxamide and benzidine capable of forming colored complex compounds with free heavy metal ions, the quantity of complex-forming compound being 1 mol per mol of silver halide present.
6. The combination of claim 5 in which the aminocarboxylic acid is glycine, o-aminobenzoic acid, pyridine-2-carboxylic acid, quinoline-8-carboxylic acid or quinaldic acid.