US3923511A

US3923511A - Photographic process and composition employing CO(III) complexes and silver halide solvents

Info

Publication number: US3923511A
Application number: US402432A
Authority: US
Inventors: Vernon Leon Bissonette
Original assignee: Eastman Kodak Co
Current assignee: Eastman Kodak Co
Priority date: 1971-10-14
Filing date: 1973-10-01
Publication date: 1975-12-02
Anticipated expiration: 1992-12-02

Abstract

A photographic process is provided wherein a photographic element comprising a support having thereon imagewise-exposed photosensitive metal salt is contacted with an alkaline processing solution to form a first image comprising metal, a second photographic image is formed, and the metal image and the photosensitive metal salt are bleached and fixed, while the element is contacted with said alkaline processing solution, with the combination of (1) a cobalt(III) complex and (2) a solvent for said photosensitive metal salt. In another aspect of the invention, metallic images are amplified by treatment with an alkaline processing solution to contact the metallic image with color-developing agent and cobalt(III) complex to produce oxidized color-developing agent, reacting the color-developing agent with a photographic color coupler to form dye, and adding to the combination of developing agent and cobalt(III) complex sufficient silver halide solvent to bleach and fix the element after the metallic image has been amplified by the dye. Novel processing solutions are also provided which comprise aromatic primary amino color-developing agent, a silver halide solvent and a cobalt(III) complex.

Description

United States Patent [191 Bissonette Dec.2,1975

[ 1 PHOTOGRAPI-IIC PROCESS AND COMPOSITION EMPLOYING CO(III) COMPLEXES AND SILVER HALIDE [73] Assignee: Eastman Kodak Company,

Rochester, NY

[22] Filed: Oct. 1, 1973 [21] Appl. No.: 402,432

Related US. Application Data [63] Continuation-impart of Ser. No. 189,289, Oct. 14, 1971, abandoned, and a continuation-in-part of Ser. No. 312,168, Dec. 4, 1972, abandoned.

[5 6] References Cited UNITED STATES PATENTS 2,839,405 6/1958 Jones 96/107 3,615,508 10/1971 Stephen et a1. 96/60 B F 3,655,383 4/1972 Shepard et a1 96/64 3,748,138 7/1973 Bissonette 96/66.3 3,765,891 10/1973 Travis 96/55 Primary Examiner-Charles L. Bowers, Jr. Assistant ExaminerRichard L. Schilling Attorney, Agent, or FirmG, E. Battist [5 7] ABSTRACT A photographic process is provided wherein a photographic element comprising a support having thereon imagewise-exposed photosensitive metal salt is contacted with an alkaline processing solution to form a first image comprising metal, a second photographic image is formed, and the metal image and the photosensitive metal salt are bleached and fixed, while the element is contacted with said alkaline processing solution, with the combination of (1) a cobalt(lll) complex and (2') a solvent for said photosensitive metal salt. 1n another aspect of the invention, metallic images are amplified by treatment with an alkaline processing solution to contact the metallic image with color-developing agent and cobalt(ll1) complex to produce oxidized color-developing agent, reacting the color-developing agent with a photographic color coupler to form dye, and adding to the combination of developing agent and cobalt(lll) complex sufficient silver halide solvent to bleach and fix the element after the metallic image has been amplified by the dye. Novel processing solutions are also provided which comprise aromatic primary amino color-developing agent, a silver halide solvent and a cobalt(l1l) complex.

23 Claims, No Drawings PHOTOGRAPHIC PROCESS AND COMPOSITION EMPLOYING CO(I11) COMPLEXES AND SILVER HALIDE SOLVENTS This application is a continuation-in-pait of Bissonette, U.S. Pat. application Ser. No. 189,289 filed Oct. 14, 1971 now abandoned, and a continuation-in-part of Bissonette, U.S. Pat. application Ser. No. 312,168 filed Dec. 4, 1972 now abandoned.

This invention relates to new photographic processing compositions and novel photographic processes.

Photographic processes are well-known in which a photographic element comprising a support having thereon an imagewise-exposed photosensitive salt is contacted with an alkaline processing solution to form a first image comprising metal, a second image such as a dye image is formed, and the metal image and the unused photosensitive metal salts are bleached and fixed. For example, the processing of exposed photographic silver halide emulsions containing photographic complexes typically includes a color-development step and a separate bleach-fix step. During color-development, the color-developing agent reduces exposed silver ha1- ide to metallic silver and the oxidized color-developing agent reacts with the color coupler to form a dye. In a separate step or steps, the metallic silver image and the unused silver halide are converted to soluble salts. These steps are known as bleaching and fixing. It would be highly desirable if the image-forming steps (e.g., color development) and the bleaching and fixing steps could all be accomplished with one processing solution.

Bleach-fix compositions comprising a cobalt(lll) complex and a metal salt solvent are described in Stephen et al, U.S. Pat. No. 3,615,508 issued Oct. 26, 1971, and British Pat. 777,635 published June 26, 1957. However, neither of these patents suggests that the bleach-fix compositions therein could be used in processing solutions or processes to provide image formation and bleaching and fixing during treatment with one processing solution.

Monobath processes and compositions are wellknown in the black-and-white photographic art. See, for example, Haist, Monobath Manual, The Fountain Press, London, 1966. In the monobath processes generally known in the art, silver images are generally produced in an exposed photographic element and the undeveloped silver halide is fixed to prevent further image recording by light. Generally, the monobath processes have been somewhat limited in application since the image silver remains in the image record processed in a monobath. The remaining silver interferes with reproduction of color images and is not recoverable.

One object of this invention is to provide photographic processes in which the image-forming steps and the bleaching and fixing steps are accomplished with one processing solution. Another object of this invention is to provide monobath processes in which a metal image is formed by the reduction of a light-sensitive metal salt, the metal image is amplified by a second image, and the metal image and the unused light-sensitive metal salt are bleached and fixed. Still other objects of this invention will be apparent from this disclosure and the appended claims.

1 have now found new compositions and processes for providing image records in a metal salt-containing photographic element whereby an image record is formed and the metal and metal salt can be bleached and fixed-out in a one-step processing cycle, i.e., a

monobath. In one aspect, the process according to this invention comprises developing an imagewise-exposed photographic element comprising a support having thereon at least one layer containing a photographic metal salt in the presence of a reducing agent for said metal salt, a cobalt complex, and a solvent for said metal salt. At least a substantial portion of the developable metal salt is reduced to form a first image before the solvent and the cobalt complex bleach the image metal and fix the metal salt. A second image can be formed by any of the products of the development reaction or bleaching action in the above process. For example, when the reducing agent is a color-developing agent such as an aromatic primary amino silver halide developing agent, the oxidized developer can react with a color coupler to produce an image dye; when the cobalt complex contains amine ligands, the released ammonia can react with an image-forming substance to form a dye such as an azo dye by the amine-induced interaction between a diazonium salt and an appropriate coupler; when the cobalt complex in its reduced form is a crosslinking agent, it can be used to harden imagewise a hydrophilic colloid binder; or the reduced cobalt complex can react with a reactive species, such as 8- hydroxyquinoline or 2,4diaminophenol, to produce a colored compound.

While I do not want to be bound by any theoretical explanation for the mechanism of my invention, it appears that the reactions take place as follows:

1. (cobalt) reducing agent exposed metal salt (cobalt) oxidized reducing agent 2. (cobalt) reducing agent fixing'a'gent metal (cobalt) reducing agent (metal g The first reaction proceeds as shown, producing oxidized reducing agent and the reduced cobalt complex.

At some point, perhaps when sufficient fixing agent reaches the reaction site, the potentials appear to favor oxidation of the metal catalyst by the cobalt complex- In accordance with one embodiment of this invention, an improvement is provided in photographic processes which comprise contacting a photographic element comprising a support having thereon an imagewise-exposed photosensitive metal'salt with an alkaline processing solution to form a first image comprising metal, forming a second photographic image in the element, and bleaching and fixing the metal image and the photosensitive metal salt with the combination of l a cobalt(1ll) complex and (2)-a solvent for said photosensitive metal salt. The improvement comprises com bining in the element the solvent for the photosensitive metal salt and the cobalt(lll) complex to bleach and fix the metal image and the photosensitive metal salt while the alkaline processing solution is in contact with the element. In accordance with this invention, the metal image is bleached and the metal salts are fixed while contactin g the photographic element with a single alkaline solution. The bleaching and fixing can occur after the second photographic image has been formed, or the second photographic image can be generated later', e.g., as a function of the bleaching and fixing step, such as by (l) imagewise hardening the gelatin by the cobalt(ll) which is formed during the bleaching operation by cobalt(lll), (2) releasing a ligand, such as ammine, to produce a colored material, such as an azo dye, or (3) reacting cobalt(l1) with an active species to form a colored material.

In accordance with another embodiment of this invention, an improvement is provided in a process for forming dye images in a photographic element comprising at least one image dye-providing unit containing an imagewise-exposed silver halide emulsion, which process comprises contacting the element with an alkaline processing solution in the presence of:

1. an aromatic primary amino color-developing agent;

2. a photographic color coupler; and

3. a cobalt(IlI) complex capable of bleaching and fixing metallic silver in the presence of a silver halide solvent; I 5 thereby:

a. developing a metallic silver image in the element; b. oxidizing the aromatic primary amino colordeveloping agent in the area of said metallic silver image; and v c. reacting said oxidized aromatic primary amino color-developing agent with said color coupler to form a dye image. The improvement in accordance with this aspect of the invention features combining a silver halide solvent with said cobalt(IlI) complex, while said element is being contacted with said alkaline processing solution, to bleach and fix the element after formation of the dye image.

In another embodiment of this invention, an improvement is provided in photographic processes wherein a metallic image (e.g., a silver image) in a photographic element is replaced by a dye image, which processes comprise treating the photographic element with an alkaline processing solution to contact the metallic silver image with the combination of an aromatic primary amino color-developing agent and a cobalt(III) complex to produce oxidized color-developing agent, and reacting said oxidized color-developing agent with a photographic color coupler to form a dye, the cobalt- (lll) complex being so chosen that it undergoes redox reaction with the color-developing agent essentially only in the presence of the metallic image. The improvement in accordance with this aspect of the invention comprises combining a silver halide solvent with the cobalt(III) complex while the element is being treated with the alkaline processing solution, the silver halide solvent and the cobalt(III) complex bleaching and fixing the element after the metal image has been amplified by the dye. The metallic image can be formed in any convenient manner, such as photolytically or by chemical or physical development. Prior to treatment in accordance with this invention, the light-sensitive silver salts can optionally be fixedand washed out of the element. I

In accordancewith another embodiment of this invention, an improvement is provided in photographic processing solutions containing an aromatic primary amino color-developing agent capable of developing silver and dyeimages in an imagewise-exposed photographic element containing a silver halide emulsion and having associated therewith a photographic color coupler. The improvement in accordance with this aspect of the invention features incorporating in the processing solution a bleach-fix combination of a silver halide solvent and a cobalt(lll) complex.

As used herein and in the claims, the terms solvents for photosensitive metal salt and silver halide solvents refer to compounds and concentration levels of those compounds which, when employed in an aqueous solution (60 C), are capable of dissolving more than 4 ten times the amount (by weight) of the metal salt (silver chloride in the case of silver halide solvents) than that which can be dissolved by water at 60 C.

The concentration of a solvent necessary to fix a silver halide layer is understood to mean that concentration of solvent in a liquid bath which will remove substantially all silver bromide from a photographic element containing a single silver bromide gelatin emulsion layer coated at 30 mg. silver/ft. in 1 /2 min. at 40 C. maintained at a pH range within 4.0l2.0.

The amount of. silver halide solvent required to fix a particular silver halide layer will depend on a number of variables, such as (l) the thickness and composition of any overcoat, (2) the coverage of the silver halide, (3) composition of the silver halide, (4) the activity of the developing agent and whether all or part of the developing agent is incorporated in the photographic element, (5) the pH of the processing composition, (6) the temperature of the process and (7) agitation. Further, silver halide solvents vary in reactivity, and the optimum amount must be determined for any given silver halide solvent in the particular process and element being used. Generally, about .5 to 250 g. of sodium thiosulfate can be used per liter of alkaline processing solution; with most developing agents and elements, about 2 to 50 g. sodium thiosulfate/liter of alkaline processing solution can be used. a

Certain silver halide solvents, e.g., isothiuronium, thiuronium compounds, bis-isothiuronium compounds and 3-S-thiuronium salts, can be incorporated in photographic elements. Solvents of this type are described in US. Pat. Nos. 3,506,444 issued Apr. 14, 1970, and 3,669,670 issued June 13, 1972, both by I-Iaist et al, and 3,301,678 by Humphlett et al issued Jan. 31, 1967. Such elements can be processed in accordance with this invention without requiring any additional silver halide solvent in the alkaline processing solution.

Any silver halide solvent can be used in this invention which, in combination with' the cobalt complex used, will bleach silver and fix bleached silver and silver halide. Typical useful solvents include water-soluble thiosulfates (e.g., sodium thiosulfate, potassium thiosulfate, ammonium thiosulfate, etc.), thiourea, ethylenethiourea, a water-soluble thiocyanate (e.g., sodium thio included in compounds having the formula; I-IO(- ,(CI-I CH X), ,(CH CH X) .,-CH CI-I OH, wherein X and X represent oxygen or sulfur, such that when X represents oxygen, X represents sulfur, and when X represents sulfur, X represents oxygen; and each of c,

d, e, f and g represents an integer of from I to 15, such that the sum of c+d+ef+g represents an integer of from 6 to 19, and such that at least one third of the total of all the Xs plus all the Xs represents sulfur atoms and at least two consecutive Xs and/or X s in the structure of the compound are sulfur atoms.

Typical diols include the following:

1. 3.6-dithia-1,8-octzmediol nocu cmscn cu scn cu ou 2. 3,6,9-trithia-l ,l l-undecanediol l-lOCl-l CH SCl-l Cl-l SCl-l Cl-l SCl-l Cl-l OH 3. 3,6,9, 1 Z-tetrathial l 4-tetradecanediol HO(CH CH S) CH CH OH 4. 9-oxo-3 ,6,9, l 2, l S-tetrathial l 7-heptadecanediol HO(CH CH S) Cl-l CH O(Cl-l Cl-l S) Cl-l CH Ol-l 5. 9,1 2-dioxa-3,6, l 5, l 8-tetrathia-l ,ZO-eicosanediol HO(CH CHS) (CH CH O) (CH Cl-l S) CH OH 6. 3,6-dioxa-9, l 2-dithial l4-tetradecanediol HO(CH CH O) (CH Cl-l S) Cl-l Cl-l Ol-l 7. 3, 1 2-dioxa-6,9-dithial l4-tetradecanediol HOCl-l Cl-l O(CH Cl-l S) CH CH OCH CH OH 8. 3, l 8-dioxa-6,9, l 2, l S-tetrathia- 1 ,ZO-eicosanediol HOCl-l CH O(Cl-l CH S) Cl-l Cl-l OCl-l Cl-l OH 9. 12, l 8-dioxa-3,6,9, 15,21 ,24,27-heptathia-l,29-

nonacosanediol l0. 6,9,1 5, 1 8-tetrathia-3, l 2,2 l-trioxal ,23-

tricosanediol Water-soluble sulfur-containing dibasic acids which can be used include those having the formula: HOOCCH (SCH CH SCH COOH, in which q represents an integer of from 1 to, and including, 3 and the alkali metal and ammonium salts of said acids. Typical illustrative examples include:

1. ethylene-bis-thioglycolic acid HOOCCH SCH CH SCH COOH 2. 3,6,9-trithiahendecane dioic acid HOOCCH (SCH CH SCH COOH 3. 3,6,9, 1 Z-tetrathiatetradecanedioic acid 4. ethylene-bis-thioglycolic acid disodium salt 5. ethylene-bis-thioglycolic acid dipotassium salt 6. ethylene-bis-thioglycolic acid diammonium salt 7. 3,6,9-trithiahendecane dioic acid disodium salt 8. 3,6,9,l2-tetrathiatetradecanedioic acid disodium salt In accordance with the invention, the element is bleached by the combination of the cobalt complex and the silver halide solvent. ln embodiments of the invention where it is desirable to form metal images, or where it is desirable to amplify a preformed metal image with a dye image, the bleach-fix reaction should be delayed for a predetermined period until sufficient metal or dye image has been generated. The desired delay in the bleach-fix reaction can he achieved by several means, for example, by using silver halide solvents which diffuse slowly through hydrophilic colloid layers, incorporating developing agent in the element, incorhalide solvent in the element using means to delay release of the silver halide solvent, and using silver halide layers, such as Lippmann emulsion layers, over the layers which are to be bleached and fixed.

Any cobalt(III) complex can be used in the practice of this invention which bleaches metallic silver images in the presence of the silver halide solvent selected, such as sodium or potassium thiosulfate. Preferably, the cobalt(lll) complex is one which will undergo a redox reaction with aromatic primary amino colordeveloping agents in the presence of metallic silver. Such complexes feature a molecule having a cobalt atom or ion. This cobalt atom or ion is surrounded by a group of atoms, ions or other molecules which are generically referred to as ligands. The cobalt atom or ion in the center of these complexes is a Lewis acid; the ligands are Lewis bases. Werner complexes are wellknown examples of such complexes. The useful cobalt complexes are typically capable of existing in at least two valent states. In a preferred aspect of the invention, the cobalt complexes are those referred to by American chemists as inert" and by European chemists as robust, Particularly useful are complexes of a cobalt ion with a ligand which, when a test sample thereof is dissolved at .1 molar concentration at 20 C. in an inert solvent solution also containing .1 molar concentration of a tagged ligand of the same species which is uncoordinated, exhibits essentially no exchange of uncoordinated and coordinated ligands for at least 1 min., and preferably for at least several hours, such as up to 5 hr. or more. This test is advantageously conducted under the pH conditions which will be utilized in the practice of the invention. In silver halide photography, this generally will be a pH of over about 8. Many cobalt complexes useful in this invention show essentially no exchange of uncoordinated and coordinated ligands for several days. The definition of inert cobalt complexes and the method of measuring ligand exchange using radioactive isotopes to tag ligands are well-known in the art; see, for example, Taube, Chem. Rev., Vol. 50, p. 69 (1952), and Basolo and Pearson, Mechanisms of Inorganic Reactions, a Study of Metal Complexes and Solutions, 2nd Edition, 1967, published by John Wiley and Sons, p. 141. Further details on measurement of ligand exchange appear in articles by Adamson et al, J. Am. Chem. Soc., Vol. 73, p. 4789 (1951). The inert cobalt complexes should be contrasted with labile complexes which, when tested by the method described above, have a reaction half-life of generally less than 1 min. Cobalt chelates are a special type of cobalt complex in which the same ligand (or molecule) is attached to the central cobalt ion at two or more different points. The cobalt chelates generally exhibit somewhat slower ligand exchange than nonchelated complexes. Labile-type chelates may have a half-life of several seconds, or perhaps slightly longer. Preferred cobalt complexes in accordance with this process have coordination numbers of 6 and are known as octahedral complexes.

A wide variety of ligands can be used with a cobalt ion to form suitable complexes. Nearly all Lewis bases (i.e., substances having an unshared pair of electrons) can be ligands in metal complexes. Some typical useful ligands include the halides, e.g., chloride, bromide, fluoride, nitrate, water, amino, etc, as well as such common ligands as those referred to on p. 44 of Basolo et al, supra. The lability of a complex is influenced by the nature of the ligands selected in forming said complex.

Particularly useful cobalt complexes have a coordination number of 6 and have a ligand selected from the group consisting of ethylenediamine(en), diethylenetriamine(dien), triethylenetetraamine(trien), ammine(Nl-l nitrate, nitrite, azide, chloride, thiocyanate, isothiocyanate, water, carbonate and propylenediamine(tn). Especially useful are the complexes comprising ammine ligands, such as cobalt hexamminesalts. Some specific highly useful cobalt complexes include those having one of the following formulae: [CO(Nl-l H O]X; [CO(NH CO ]X; [CO(NH Cl]X; and [CO(NH CO ]X; wherein X represents one or more anions determined by the charge neutralization rule and X preferably represents polyatomic organic anions.

With many complexes, such as cobalt hexammine, the anions selected can substantially effect the reducibility of the complex. The following ions are listed in the order of those which give increasing stability to cobalt hexammine complexes: bromide, chloride, nitrite, perchlorate, acetate, carbonate, sulfite and sulfate. Other ions will also effect the reducibility of the complex. These ions should, therefore, be chosen to provide complexes exhibiting the desired degree of reducibility. some other useful anions include chloride, nitrate, thiocyanate, dithionate and hydroxide. Neutral complexes such as [CO(dien)(SCN) Ol-l] are useful, but positively charged complexes are generally preferr'ed.

In certain highly preferred embodiments, the cobalt- (lll) ion complexes used in this invention either contain at least three amine (NI-l ligands and/or have a net positive charge which is preferably a net charge of +3. A cobalt(lll) ion with six (NI-l ligands has a net charge of +3.. A cobalt(lll) ion with five (NH- ligands and one chloro ligand has a net charge of +2. A cobalt- (lll) ion with two ethylenediamine(en) ligands and two (N azide ligands has a net charge of +1. Generally, the best results have occurred where the cobalt(III) complex has anet charge of +3 and/or where the cobalt(lll) complex comprises at least 3 and preferably at least 5 ammine ligands.

The cobalt(lll') complexes can be incorporated in the photographic element as water-insolubleion-pairs. The use of water-insoluble ion-pairs of cobalt( III) ion complexes is described inmore detail in Bissonette et al, U.S. Ser. No. 307,894 filed Nov. 20, 1972, which is incorporated herein by reference. Generally, these ionpairs 'comprisea cobalt(lll) ion, complex ion-paired with an anionic organic acid having an equivalent weight of at least 70 based on acid groups. Preferably, the acid groups are sulfonic acid groups.

The most useful concentration of cobalt complex in the processing solution depends on numerous variables and the optimum result must be determined from each element and solution. With cobalt hexammine chloride, good results are obtained with about .2 to 20, and preferably .4 to 10, g./liter of processing solution.

Any aromatic primary amino color-developing agent can be used in the process of this invention, such as paminophenols or p-phenylenediamines. Color-developing agents which can be used include 3-acetamido-4- amino-N,N-diethylaniline, 4-amino-N-ethyl-N-B- hydroxyethylaniline sulfate, N,N-diethyl-pphenylenediamine, 2-amino-5-diethylaminotoluene, N-ethyl-N-B-methanesulfonamidoethyl-3-methyl-4- aminoaniline, 4-amino-N-ethyl-3-methyl-N-(,B-sulfoethyl)aniline and the like. See Bent et al, JACS, Vol. 73, pp. 3100-3125 (1951), and Mees and James, The Theory 0f the Photographic Process, 3rd Edition, 1966, published by MacMillan Co., New York, pp. 27831 1, for further typical, useful developing agents. Aromatic primary amino color-developing agents which provide particularly good results in this invention are 4-amino- N,N-diethylaniline hydrochloride, 4-amino-3-methyl- N,N-diethylaniline hydrochloride, 4-amino-3-methyl- N-ethyl-NB-(methanesulfonamido)ethylaniline sulfate hydrate, 4-amino-3 -methyl-N-ethyl-N-B-hydroxyethylaniline sulfate, 4-amino-3-dimethylamino-N,N-diethylaniline sulfate hydrate, 4-amino-3-methoxy-N- ethyl-N-B-hydroxyethylaniline hydrochloride, 4- amino-3-B-(methanesulfonamido)ethyl-N,N-diethylaniline dihydrochloride and 4-amino-N-ethyl-N-(2- methoxyethyl)-m-toluidine di-p-toluene sulfonate.

A black-and-white developing agent can be used in combination with color-developing agent. The blackand-white developing agent can be incorporated in the processing solution or the photographic element, e.g., as described in Bissonette et al, US. Ser. No. 307,893 filed Nov. 20, 1972. During development of silver halide, the oxidized black-and-white developer can crossoxidize with the color-developing agent to generate oxidized color-developing agent which forms dye by reaction with color couplers. lf desired, the'color-develop- 'ing agent can be incorporated in the element.

The amount of color-developing agent used in the processing solution can vary over'a wide range such as about 1 to 20, and preferably 2 to 10, g./lite r, although more or less color-developing agent can also be used.

The photographic layers and other layers of a photographic element employed and described herein can be coated on a wide variety of supports. Typical supports include cellulose nitrate film, cellulose ester film, poly(vinyl acetal) film, polystyrene film, poly(ethylene terephthalate) film, polycarbonate film and related films or resinous materials, as well as glass, paper, metal and the like. Typically, a flexible support is em ployed, especially a paper support, which can be partially acetylated or coated with baryta and/or an a-olefin polymer, particularly a polymer of an a-olefin containing 2 to 10 carbon atoms such as polyethylene, polypropylene, ethylenebutene copolymers and the like. The color-providing layer units can be coated on the same side of the support or on opposite sides of the support where desired, such as when using a transparent film support. 7

The photographic elements which can be processed as described herein can comprise a support having thereon image dye-providing layer units. A multicolor photographic element comprises at least two of said image dye-providing layer units, each of which records light primarily in different regions of the light spectrum. The layer unit comprises a light-sensitive silver salt, which is generally spectrally sensitized to a specific region of the light spectrum, and has associated therewith a photographic color coupler. ln certain preferred embodiments, the color-providing layer units are continuous layers which are effectively isolated from other layer units by barrier layers, spacer layers, layers containing scavengers for oxidized developer and the like to prevent any substantial color contamination between the image dye-providing layer units. In other embodiments, the layer units are discontinuous layers comprising mixed packets which are effectively iso- 9 lated from each other, as disclosed in Godowsky, U.S. Pat. No. 2,698,794 issued Jan. 4, 1954. The effective isolation of the layer units is known in the art and is utilized to prevent contamination in many commercial color products.

Photographic elements processed by the monobaths of this invention can comp rise a support having thereon at least one image dye-providing layer unit containing a light-sensitive silver salt, preferably silver halide, having associated therewith a stoichiometric excess of coupler of at least 40% and at least preferably 70%. The equivalency of color couplers is known in the art; for example, a 4-equivalent coupler requires 4 moles of oxidized color developer, which in turn requires development of 4 moles of silver, to produce 1 mole of dye. Thus, for a stoichiometric reaction with silver halide, l-equivalent weight of this coupler will be 0.25 mole. In accordance with this invention, the color image-providing unit comprises at least a 40% excess of the equivalent weight of image dye-providing color coupler required to react on a stoichiometric basis with the developable silver and preferably a 70% excess of said coupler. In one highly preferred embodiment, at least a 110% excess of coupler is present in said dye imageproviding layers based on silver. Preferably, the coupler-to-silver ratio is based on effective silver. The ratio can also be defined as an equivalent excess with a coupler-to-silver ratio of at least 1.421, and preferably at least 1.7:1 (i.e., 2:1 being a 100% excess). In certain preferred embodiments, the photographic color couplers are employed in the image dye-providing layer units at a concentration of at least 3 times, such as from 3 to 20 times, the weight of the silver in the silver halide emulsion, and the silver is present in said emulsion layer at up to 30 mg. silver/ft? Weight ratios of coupler-to-silver coverage which are particularly useful are from 4 to 15 parts by weight coupler to 1 part by weight silver. Advantageously, the coupler is present in an amount sufficient to give a density of at least 1.7 and preferably at least 2.0. Preferably, the difference be tween the maximum density and the minimum density (which can comprise unbleached silver) is at least .6 and preferably at least 1.0.

The light-sensitive silver salt layers used in elements processed in accordance with this invention are most preferably at silver coverages of up to about 30 mg. silver/ft. (325 mg./m. such as from 1 to 30 mg./ft. (-325 mg./m. and more preferably from about 1 to 25 mg. silver/ft. lO-27O mg./m. Especially good results are obtained with coverages on the order of from about 2 to mg./ft. of silver (l60 mg./m. for the greenand red-sensitive layers in typical multilayer color films.

It is realized that the density of the dye may vary with the developing agent combined with the respective coupler, and accordingly the quantity of coupler can be adjusted to provide the desired density. Preferably, each layer unit contains at least 1 X 10 5 moles/ft. of color coupler.

Advantageously, the photographic color couplers utilized are selected so that they will give a good neutral dye image. Preferably, the cyan dye formed has its major visible light absorption between about 600 and 700 nm., the magenta dye has its major absorption between about 500 and 600 nm., and the yellow between about 400 and500 nm. Particularly useful elements comprise a support having coated thereon red-, greenand blue-sensitive silver halide emulsion layers contain l0 ing, respectively, cyan, magenta and yellow photographic color couplers.

The light-sensitive silver salts are generally coated in the color-providing layer units in the same layer with the photographic color coupler. However, they can be coated in separate adjacent layers as long as the coupler is effectively associated with the respective silver halide emulsion layer to provide for immediate dyeproviding reactions to take place before substantial color-developer oxidation reaction products diffuse into adjacent color-providing layer units.

As used herein, the terms photographic color coupler and image dye-providing color coupler include any compound which reacts (or couples) with the oxidation products or primary aromatic amino developing agent on photographic development to form an image dye. The photographic couples can be incorporated in the alkaline processing solution or in the photographic element, e.g., as described and referred to in Product Licensing Index, Vol. 92, December, 1971, page 110, paragraph XXII. When they are incorporated in the element, they preferably are nondiffusible in a hydrophilic colloid binder (e.g., gelatin) useful for photographic silver halide and also those couplers which provide useful image dyes when reacted with oxidized primary aromatic amino developing agents such as by a coupler-release mechanism. The couplers can form diffusible or nondiffusible dyesv Typical preferred color couplers include phenolic, S-pyrazolone and openchain ketomethylene couplers. Specific cyan, magenta and yellow color couplers which can be employed in the practice of this invention are described in Graham et al, US. Pat. No. 3,046,129 issued Jan. 24, 1962, Column 15, line 45, through column 18, line 51, which disclosure is incorporated herein by reference. Such color couplers can be dispersed in any convenient manner, such as by using the solvents and the techniques described in US. Pat. Nos. 2,322,027 by .lelley et al issued June 15, 1943, or 2,801,171 by Fierke et al issued July 30, 1957. When coupler solvents are employed, the most useful weight ratios of color coupler to coupler solvent range from about 1:3 to 1:01. The useful couplers include Fischer-type incorporated couplers such as those described in Fischer, US. Pat. No. 1,055,155 issued Mar. 4, 1913, and particularly nondiffusible Fischer-type couplers containing branched carbon chains, e.g., those referred to in the references cited in Frohlich et al, US. Pat. No. 2,376,679 issued May 22, 1945, column 2, lines 50-60. Particularly useful in the practice of this invention are the nondiffusible color couplers which form nondiffusible dyes.

In certain preferred embodiments, the incorporated couplers in the layer units of this invention are waterinsoluble color couplers which are incorporated in a coupler solvent which is preferably a moderately polar solvent. Typical useful solvents include tri-o-cresyl phosphate, di-n-butyl phthalate, diethyl lauramide, 2,4- diarylphenol, liquid dye stabilizers as described in an article entitled Improved Photographic Dye Image Stabilizer-Solvent, Product Licensing Index, Vol. 83, pp. 26-29, Mar, 1971, and the like.

In certain highly preferred embodiments, the couplers are incorporated in the photographic elements by dispersing them in a water-miscible, low-boiling solvent having a boiling point of less than 175 C. and preferably less than C., such as, for example, the esters formed by aliphatic alcohols and acetic or propionic acids, i.e., ethyl acetate, etc. Typical methods for incor- 1 1 porating the couplers in photographic elements by this technique and the appropriate solvents are disclosed in U.S. Pat. Nos. 2,949,360, column 2, by Julien, 2,801,170 by Vittum et al, and 2,801,171 by Fierke et al.

The term nondiffusible used herein as applied to couplers and products derived from couplers has the meaning commonly applied to the term in color photography and denotes materials which for all practical purposes do not migrate or wander through photographic hydrophilic colloid layers, such as gelatin, particularly during processing in aqueous alkaline solutions. The same meaning is attached to the term immobile. The terms diffusible and mobile have the converse meaning.

This invention is also applicable to other photographic processes for forming multicolor images, such as color diffusion transfer processes of the type described in U.S. Pat. Nos. 2,983,606 by Rogers issued May 9, 1961, 3,146,102 by Weyerts issued Aug. 25, 1964, 3,087,817 by Rogers issued Apr. 30, 1963, 3,227,551 and 3,227,554, both by Barr et a1, issued Jan. 4, 1966, 3,243,294 by Barr issued Mar. 29, 1966, 2,337,550 by Whitmore et a1 issued Jan. 4, 1966, 2,75 6,142 by Yutzy issued July 24, 1956, 3,227,552 by Whitmore issued Aug. 27, 1964, 3,443,940 by Bloom et a1 and 3,443,943 by Rogers, both issued May 13, 1969, 3,415,644, 3,415,645 and 3,415,646 by Land, all issued Dec. 10, 1968, and U.S. Ser. No. 169,667 by Bush et al filed Aug. 6, 1971 now U.S. Pat. No. 3,765,886. The process of this invention is useful in generating diffusible dye images by the method described in U.S. Ser. No. 351,673 by Fleckenstein et a1 filed Apr. 16, 1973, or 308,869 by Lestina and Bush filed Nov. 22, 1972, which is a continuation-in-part of U.S. Ser. No. 206,836 filed Dec. 10, 1971, now abandoned. The processes of this invention are useful in color diffusion transfer systems, such as those wherein the dye-receiving sheet is separated from the photosensitive element after processing, such as the elements described in U.S. Pat. No. 3,362,819, and color diffusion transfer systems wherein the film unit and the dye image-receiving layer are integral, as described in Belgian Pat. Nos. 757,959 and 757,960, both issued Apr. 23, 1971.

This invention offers certain advantages in the above color transfer processes, in that the processes can be modified, using the bleach-fix monobath embodiments of this invention, to retain the desired dye image in the layers of the element that were imagewise-exposed, and diffusing any unused dyes, complexed silver salts, etc., to a separate sheet which (1) is capable of being stripped away from the image layer or (2) is separated from the image layer by a suitable masking layer. It is particularly desirable to retain the ultimate image in the layers initially exposed to avoid prior-art problems in unsharpness whi; h results in the diffusion of image dyes through hydrophilic colloids to a receiving sheet, when transparencies are being prepared, etc.

The processes and monobaths of this invention are useful with the emulsion types and with emulsions containing the development modifiers, antifoggants, stabilizers, developing agents, hardeners and spectral sensitizers described and referred to in Product Licensing Index, Vol. 92, Dec., 1971, publication 9232, pp. 107-1 10. The photographic elements that can be pro cessed in accordance with this invention can contain the vehicles, antistatic layers, support, plasticizers, lu-

12 bricants, coating aids, matting agents, brighteners, absorbing dyes and filter dyes described in the abovecited Product Licensing Index.

Example 1 illustrates the poor results obtained when conventional photographic elements are processed with a color-developing solution of the prior art, followed only by washing and drying.

EXAMPLE l-A color development 5 min. acid rinse 1 min. bleach 5 min. wash 2 min. fix 5 min. wash 5 min. dry

The composition of the color-development bath is as follows:

sodium polyphosphate 2 g N11 50:, 4 g 4-amino-3-methyl-N,N-diethylaniline 3 g Na Co H 0 20 g KBr 2 g water to 1 liter A second sample of the above exposed photographic element (Elememt l-B) is processed at a temperature of 38 C. in a color developer by the following sequence:

color developer 10 min. wash 5 min. dry

The color developer has the following composition:

N21 4amino-N-ethyl N-(2-methoxyethyl)-mtoluidine-di-p-toluene sulfonic acid Na CO 2 KBr o-mercaptobenzoic acid chlorohydroquinone Na S O H O to 1 liter a e- CONGO O0 enem we The example processed in the above monobath is then slit into two identical strips, and one of the strips (Element l-B) is bleached, fixed, washed and dried while the remaining portion (Element 1-C) receives no further treatment. The sensitometric results of the red records in Elements l-A and l-B are as follows:

EXAMPLE l-B Another exposed sample of the coating of Example l is processed in a monobath as follows:

monobath min. wash 5 min. dry

The monobath contains a cobalt complex and has the following composition:

4-amino-N-ethyl-N-( Z-methoxyethyl )-mtoluidine-di-p-toluene sulfonic acid Na CO,

KBr

o-mercaptobenzoic acid chlorohydroquinone l i alsl a H O to 1 liter The processed sample is slit into two strips and one of the samples (Element l-D) is bleached, fixed and washed while the other sample (Element l-E) receives no further treatment. The sensitometric densities of the red record for Elements H) and l-E are compared with Element l-A as follows:

Dmax Dmin Element 14) 2.3 0.3 Element l-A 3.2 1.0 (control) Element l-E is analyzed for silver and is found to have a silver Dmax of 0.08 and a silver Dmin of 0.04.

The above results demonstrate that a one-step monobath treatment produces a dye image essentially resembling that produced by a conventional color process as described in Example l-A for Element l-A, and that the developed silver is effectively removed without the requirement for additional bleach and fix treatments.

Results generally similar to those in Example l-B are obtained when the cobalt complex is incorporated in the photographic element, such as by the ion-pairing method described by Bissonette et a], supra, or by using other cobalt complexes or silver halide solvents, such as those referred to above.

Good results can be obtained when the photographic element is replaced with an element containing a redsensitive emulsion containing a cyan dye-forming coupler, a green-sensitive emulsion containing a magenta 14 dye coupler, and a blue-sensitive emulsion containing a yellow dye coupler. Such elements can have relatively low coverages of silver, and can contain incorporated black-and-white developing agents and an ion-paired cobalt complex.

EXAMPLE 2 A photographic element is prepared comprising a cellulose acetate support having coated thereon, in the following order:

1. a blue-sensitive silver bromoidide (about 6 mole percent of the halide being iodide) emulsion containing 16 mg. silver/ftF, mg. gelatin/ff, 16 mg. lft. 4-hydro xymethyl-4-methyll -phenyl-3 pyrazolidone, and 60 mg./ft. of a-[4-(4-benzyloxyphenylsulfonyl)phenoxy]-a-pivalyl-2-chloro-5-[Mt -(2,4-di-tert-amylphenoxy) butyramido]acetanilide dispersed in tricresyl phosphate;

2. an interlayer containing 100 mg. gelatin/ft. and 5 mg./ft. of dioctylhydroquinone;

3. a green-sensitive silver bromoiodide (6 mole percent iodide) emulsion containing 10 mg. silver/ft. mg. gelatin/11 and 25 rng./ft. of 1-(2,4,6-trichlorophenyl)-3-[2-chloro-5-(a-{ 4-hydroxy-3- tert.-butylphenoxy}tetradecanoamido)anilino]-5- pyrazolone dispersed in dibutyl phthalate;

4. an interlayer containing mg. gelatin/ft. and 5 mg./ft. of dioctylhydroquinone;

5. a red-sensitive silver bromoiodide (6 mole percent iodide) emulsion containing 6 mg. silver/ft. 90 mg. gelatin/ft. and 35 mg./ft. of Z-(a-diamylphenoxy-n-butyrylamino )4.,6-dichloro-5-methylphenol dispersed in dibutyl phthalate;

6. an overcoat containing 100 mg. gelatin/ft? The element is imagewise exposed and processed for 4 min. in the following monobath:

KOH

10 ml. Na sO 2 g. 4-amino-N-ethyl-N-(2-methoxyethyl)-m- 5 g. toluidine-di-p-toluene sulfonic acid Na C0 40 g. diaminopropanol tetraacetic acid 10 g. (sequestering agent) a)al a 2 8- NaS 0 l0 g. water to 1 liter pH l0.5

Thereafter, the element is washed for 5 min. Excellent color images are obtained and the element is satisfactorily bleached and fixed. A control, processed with similar solution without silver halide solvent, contains visible amounts of unbleached silver.

EXAMPLE 3 ELEMENT 3-A 4. layer containing a green-sensitive silver halide emulsion at mg. of silver/ft, gelatin at 132 mg./ft. and the color coupler 1-(2,4,6-trich1orophenyl 3-{ 5-[ a-( 3-tert-butyl-4-hydroxyphenoxy tetradecanamido -2-chloroanilino l-5 -pyrazolone at 25 mg./ft. dispersed in tricresyl phosphate at 12.5 mg./ft.

5. layer containing gelatin at 160 mg./ft.

6. layer containing a red-sensitive silver halide emulsion at 6 mg. of silver/ftF, gelatin at 90 mg./ft. and the color coupler 2-[a-(2,4-di-tert-amylphenoxy)- butyramido]-4,6-dichloro-5-methylphenol at 35 mg./ft. dispersed in di-n-butyl phthalate at 17.5 mg./ft.

7. layer containing gelatin at 100 mg./ft.

ELEMENT 3-B This element is prepared exactly the same as Element 3-A except the level of silver in layer 6 (red-sensitive layer) is raised to 24 mg./ft.

The respective samples are exposed through a multicolor graduated-density test object, treated in the monobath described below for 4 min. at a temperature of 35 C. and then washed and dried.

Monobath Composition benzyl alcohol 10.0 ml. Na SO 2.0 g. 4amino3-methyl-N-ethyl-N-B-(methane 10.0 sulfonamido)ethylaniline sulfate hydrate Na CO 20.0 g. diaminopropanol tetraacetic acid 10.0 g. Na s Q- 5 H O 11.25 g. [Co(Nl-l ]Cl 2.0 g.

H O to 1 liter; pH 12.5

The Dmax values from the H and D curves are as follows:

Red Green Blue Element 3-A .15 .28 1.12 Element 3-B .75 1.44 .58

The results indicate that an increased quantity of silver halide in the outermost emulsion layer relative to the quantity of silver halide in the other two emulsion layers apparently retards the rate of diffustion of the silver halide solvent (hypo) from the processing solution into the photographic element and significantly improves the image reproduction.

EXAMPLE 4 Dmax 1 Red Green Blue Element 3-B 1 .75 1.44 1.53

-continued Dmax Red Green Blue Element 4A 2.03 1.82 1.90

A comparison between the H and D curves indicates the further improvement in image reproduction attained by increasing the quantity of gelatin in the elements overcoat. The improvement apparently results from the retardation by the gelatin of the rate of diffusion of the silver halide solvent from the processing solution into the element.

EXAMPLE 5 This example demonstrates the further improvement attainable by the addition of an auxiliary black-andwhite developing agent in the blue-sensitive (i.e., yellow dye-forming) silver' halide emulsion layer of the Dmax Red Green Blue Element 4-A 2.03 1.82 1.90 Element 5-A 2.14 2.50 2.52

EXAMPLE 6 This example demonstrates the capability of the monobath to produce image dye at high density and to remove effectively the developed image silver. It demonstrates the functioning of the dye-forming reaction and the subsequently occurring bleach-fix reaction.

A sample (Sample 1) of Element 5-A is exposed and treated for 4 min. in a monobath solution as described in Example 3 except the monobath solution does not contain any [Co(Nl-l ]C1 The element is then washed and dried as in Example 3.

Another sample (Sample 2) of Element 5-A is exposed and treated for 4 min. in a monobath according to Example 3 which contains 2 g. of [Co(Nl-1 ]C1 liter of solution. The element is then washed and dried as in Example 3.

The density of the dye produced and of the silver retained in the respective layers in each sample is as follows:

*The dye density is read after subjecting the photographic element to a bleach-fix in a bath of the following composition:

Bleach-Fix Bath diaminopropanol tctraacetic acid 3.0 g. acetic acid 20.0 ml.

water to 1 liter; pH 4.5

EXAMPLE 7 A positive image record can be produced in the exposed photographic element with the monobath compositions of this invention.

A photographic element is prepared as follows:

ELEMENT 7-A 1. support;

2. layer containing 100 mg./ft. of a silver halide emulsion based on silver, 200 mg./ft. of gelatin, l mg./ft. of 4-hydroxymethyl-4-methyl-l-phenyl-3- pyrazolidone and 60 mg./ft. of Compound I dissolved in 90 mg./ft. of l,4-cyclohexanediol-di-(2- ethyl hexoate).

Compound I is as follows:

OH @CONHUJHEMOQ c H unso 5 11 11118 OQCH} Element 7-A is exposed through a graduated-density test object and treated for 30 sec. at room temperature in the following monobath composition.

ethanolamine 50 ml. Co[NH;,] Cl l g. Na S O 75 g. diaminopropanol tetraacetic acid 10 g H O to total of 1 liter pH adjusted to 13.0 with NaOH The element is then treated for 1 min. in a dye-stabilizing solution which is as follows:

ethanolamine 25 ml.

H O to total of 1 liter The element is then washed for .3 min. and dried.

The processed sample contains a positive magenta dye image of the photographed test object. It is apparent that a dye image can be produced by release of a 18 diffusible dye in proportion on to development with the remaining immobile dye serving as the image record; the silver and silver halide appear to be substantially removed by the monobath composition.

EXAMPLE 8 In certain embodiments, photographic elements processed in the monobath compositions of this invention produce improved image properties if the coupler is dispersed in a carrier by nonsolvent techniques.

Two cyan-forming coupler dispersions are prepared as follows:

Two 20.0-g. portions of the cyan-forming coupler 2- (a-diamylphenoxy-n-butyrylamino)-4,6-dichloro-5- methylphenol (described in U.S. Pat. No. 2,801,171) are dissolved at 50 C. in either 1) 60 g. ethyl acetate or 2) 60 g. ethyl acetate 10.0 g. di-n-butyl phthalate. The coupler solutions are then added, with stirring at 50 C., to separate 208-ml. portions of an aqueous solution containing 0.8 g. of Alkanol XC (tri-isopropyl naphthalene sulfonic acid, sodium salt). The resulting mixture is then passed through a colloid mill 5 times; the ethyl acetate is then extracted by bubbling nitrogen gas through the dispersion for 2 hr.

The solvent ratios of the above-described coupler dispersions, after drying or washing to remove the ethyl acetate, are given below.

Dispersion CouplerzSolvent Protective Number Ratio Colloid 1 1:0 (N.S.) none 2 1 1 /2 (control) gelatin benzyl alcohol 10.0 ml. sodium sulfite 2.0 g.

4-amino-3-methyl-N-ethyl-N-B-(metlhane- 10.0 g.

sulfonamido)ethylaniline sodium carbonate 20.0 g.

diaminopropanol tetraacetic acid 10.0 g.

sodium thiosulfate 5.0 g.

cobalt hexammine trichloride 2.0 g.

distilled water to 1 liter pH 12.5

The following photographic results are obtained.

Coupler Coupler/Solvent Dispersion Ratio Dmax Dmin 2 1% (control) 1.84 0.08 1 1:0 (N.S.) 2.38 0.14

The results demonstrate that the use of elements wherein the coupler is dispersed with only low-boiling solvent provides much better cyan density than elements containing coupler dispersed in a high-boiling coupler solvent.

Although the invention has been described in considerable detail with particular reference to certain preferred embodiments thereof, variations and modifications can be effected within the spirit and scope of the invention.

1 claim:

1. In a photographic process which comprises:

a. contacting a photographic element comprising a support having thereon an imagewise-exposed photosensitive silver halide with an alkanline processing solution and a silver halide developing agent to form a first image comprising silver,

b. forming a second photographic image in the areas of said first image, and

c. bleaching and fixing said silver image and said photosensitive silver halide salt with the combination of a cobalt(lll) complex and a solvent for said photosensitive silver halide salt,

the improvement wherein said solvent for said photo sensitive silver halide salt and said cobalt(lll) complex are combined in said element to bleach and fix said element while said alkaline processing solution is in contact with said element.

2. In a photographic process wherein a photographic element comprising a support having thereon an imagewise-exposed photosensitive silver halide salt is contacted with an alkaline processing solution in the presence of a silver halide developing agent to form a first image comprising silver and forming a second photographic image in the areas of said first image, and said silver image and said photosensitive silver halide salt are bleached and fixed with the combination of a cobalt(lIl) complex and a solvent for said photosensitive silver halide salt, the improvement wherein:

a. said alkaline processing solution contains said solvent for said photosensitive silver halide salt and b. said cobalt(lll) complex is present in said alkaline processing solution or said photographic element,

said solvent for said photosensitive silver halide salt and said cobalt(IIl) complex bleaching and fixing said silver image and said photosensitive silver halide salt after formation of said second photographic image.

3. A photographic process as defined in claim 2 wherein (1) said silver halide solvent is sodium or potassium thiosulfate and (2) said cobalt(lll) complex is a cobalt hexamine complex.

4. A photographic monobath process wherein a photographic element comprising a support having thereon an imagewise-exposed photosensitive silver halide is contacted with an alkaline processing solution in the presence of a reducing agent for said metal salt to form a first image comprising silver and forming a second photographic image in the areas of said first image, and said silver image and said photosensitive silver halide are bleached and fixed with the combination of a cobalt(Ill) complex with a solvent for said photosensitive silver halide, said alkaline processing solution contain-' ing said solvent for said photosensitive silver halide, and said cobalt(lll) complex being present in said alkaline processing solution or said photographic element, said solvent for said photosensitive silver halide and said cobalt(lll) complex bleaching and fixing said silver image and said photosensitive silver halide after formation of said second photographic image.

5. A process for forming dye images in a photographic element which comprises at least one image dye-providing unit containing an imagewise-exposed silver halide emulsion having associated therewith a photographic color coupler, said process comprising effecting contact of said image dye-providing unit in said photographic element with an alkaline processing composition containing a fixing amount of a silver halide solvent, in the presence of a silver halide developing agent, thereby developing a metallic silver image in said image dye-providin g layer unit, providing primary aromatic amino color-developing agent and a cobalt- (lII) complex in the area of said metallic silver image to form oxidized color-developing agent and reacting said oxidized color-developing agent with said photographic color coupler to produce an image dye, and then bleaching and fixing said metallic silver image and said silver halide by the combination of a cobalt(lll) complex and said silver halide solvent.

6. A process according to claim 5 wherein said colordeveloping agent and said cobalt(Ill) complex are present in said element before contact with said alkaline processing solution.

7. In a process for forming dye images in a photographic element comprising at least one image dyeproviding unit containing an imagewise-exposed silver halide emulsion, which process comprises contacting said element with an alkaline processing solution in the presence of:

a. an aromatic primary amino color-developing agent,

b. a photographic color coupler, and

c. a cobalt( Ill) complex capable of bleaching metallic silver in the presence of a silver halide solvent; thereby:

1. developing a metallic silver image in said element,

2. oxidizing said aromatic primary amino colordeveloping agent in the area of said metallic silver image, and

3. reacting said oxidized aromatic primary amino color-developing agent with said color coupler to form a dye image; the improvement wherein a silver halide solvent is combined with said cobalt( III) complex, while the element is being contacted with said alkaline processing solution, to bleach and fix said element after formation of 'said dye image.

8. In a process for forming dye images in a photographic element comprising at least one image dyeproviding unit containing an imagewise-exposed silver halide emulsion having associated therewith a photographic color coupler, which process comprises contacting said element with an alkaline processing solution in the presence of:

a. an aromatic primary amino color-developing agent and b. a cobalt(lll) complex capable of bleaching metallic silver in the presence of a silver halide solvent; thereby:

1. developing a metallic silver image in said element, 2. oxidizing said aromatic primary amino colordeveloping agent in the area of said metallic silver image, and 3. reacting said oxidized aromatic primary amino color-developing agent with said color coupler to form a dye image; the improvement wherein a silver halide solvent is combined with said cobalt( Ill) complex, while the element is being contacted with said alkaline processing solution, to bleach and fix said element after formation of 21 said dye image.

9. In a process for forming dye images in a photographic element comprising at least one image dyeproviding unit containing an imagewise-exposed silver halide emulsion having associated-therewith a photographic color coupler, which process comprises contacting said element with an alkaline processing solution in the presence of:

a. an aromatic primary amino color-developing agent and b. a cobalt(lll) complex capable of (i) bleaching metallic silver in the presence of a silver halide solvent and (ii) undergoing a redox reaction with primary aromatic amino-color-developing agent in the presence of metallic silver to form oxidized colordeveloping agent; thereby:

1. developing a metallic silver image in said element, 2. redoxing said cobalt(lll) complex and said aromatic primary amino color-developing agent in the area of said metallic silver image to form oxidized aromatic primary amino color-developing agent, and 3. reacting said oxidized aromatic primary amino color-developing agent with said color coupler to form a dye image; the improvement wherein said processing solution con tains a silver halide solvent, said silver halide solvent and said cobalt(lll) complex bleaching and fixing said photographic element after formation of said dye image.

10. In a process for forming dye images in a photographic element comprising at least one image dyeproviding unitcontaining an imagewise-exposed silver halide emulsion having associated therewith a photographic color coupler, which process comprises contacting said element with an alkaline processing solution in the presence of:

a. an aromatic primary amino color-developing agent and b. a cobalt(III) complex capable of (i) bleaching metallic silver in the presence of a silver halide solvent and (ii) undergoing a redox reaction with primary aromatic amino color-developing agent in the presence of metallic silver to form oxidized colordeveloping agent, said cobalt(lll) complex having a coordination number of 6 and a positive net charge of 3; thereby:

1. developing a metallic silver image in said element, 2. redoxing said cobalt(lll) complex and said aromatic primary amino color-developing agent in the area of said metallic silver image to form oxidized aromatic primary amino color-developing agent, and 3. reacting said oxidized aromatic primary amino color-developing agent with said color coupler to form a dye image; the improvement wherein said processing solution contains a silver halide solvent, said silver halide solvent and said cobalt(lll) complex bleaching and fixing said photographic element after formation of said dye imll. In a process for forming dye images in a photographic element comprising a support having thereon red-, greenand blue-sensitive silver halide emulsion layers containing, respectively, cyan, magenta and yellow dye-forming photographic color couplers, which 22 process comprises contacting said element with an alkaline processing solution in the presence of:

a. an aromatic primary amino color-developing agent and b. a cobalt(lll) complex capable of (i) bleaching metallic silver in the presence of a silver halide solvent and (ii) undergoing a redox reaction with primary aromatic amino color-developing agent in the presence of metallic silver to form oxidized colordeveloping agent; thereby:

1. developing a metallic silver image in said element, 2. redoxing said cobalt(III) complex and said aromatic primary amino color-developing agent in they area of said metallic silver image to form oxidized aromatic primary amino color-developing agent, and

3. reacting said oxidized aromatic primary amino color-developing agent with said color coupler to form a dye image;

the improvement wherein said processing solution contains a silver halide solvent, said silver halide solvent and said cobalt(lll) complex bleaching and fixing said photographic element after formation of said dye image.

12. A photographic process as defined in claim 9 wherein said photographic element comprises a support having thereon at least two separate color-providing layer units, each of which contains a light-sensitive silver halide having associated therewith an image dyeproviding photographic coupler in at least a 40% stoichiometric excess based on effective silver.

13. A photographic process as defined in claim 12 wherein each of said color-providing layer units of said photographic element comprises said silver halide in a concentration of up to 30 mg. of silver/ft}.

14. A photographic process as defined in claim 11 wherein each of said silver halide emulsion layers comprises a silver halide emulsion at a silver concentration of from 1 to 30 mgjft. and said color coupler at a concentration of from 3 to 20 times the weight of said silver.

15. A photographic process as defined in claim 11 wherein at least one of said color couplers is incorporated in said element in a nonsolvent'dispersion.

16. A process as defined in claim 11 wherein said cobalt(III) complex has a coordination number of 6 and a net positive charge of 3 and said silver halide solvent is a water-soluble thiosulfate.

17. A process as defined in claim 11 wherein said cobalt(lll) complex is cobalt hexammine chloride and said silver halide solvent is sodium or potassium thiosulfate.

18. A photographic process as defined in claim 11 wherein said photographic element contains a hydrophilic colloid layer of sufficient thickness to retard the diffusion of said silver halide solvent into the element to provide a predetermined time for silver development or dye formation.

19. In a process for forming; dye images on a photo.- graphic element comprising a support having coated thereon, in the order given:

a. a blue-sensitive silver halide gelatin emulsion layer having associated therewith a yellow dye-fonning coupler,

b. a green-sensitive silver halide gelatin emulsion layer coated at a coverage of less than about 15 mg. of effective silver/ft having associated therewith 23 a magenta dye-forming coupler in at least a 40% stoichiometric excess based on effective silver, and c. a red-sensitive photographic silver halide gelatin emulsion layer coated at a coverage less than about mg. of effective silver/ft. having associated therewith a cyan dye-forming coupler in at least a 40% stoichiometric excess based on effective silver; which process comprises contacting said element with an alkaline processing solution in the pres; nce of:

1. an aromatic primary amino color-developing agent and 2. a cobalt(llI) complex capable of (i) bleaching metallic silver in the presence of a silver halide solvent and (ii) undergoing a redox reaction with primary aromatic amino color-developing agent in the presence of metallic silver to form oxidized colordeveloping agent; thereby:

a. developing a metallic silver image in said element, b. redoxing said cobalt(llI) complex and said aromatic primary amino color-developing agent in the area of said metallic silver image to form oxidized aromatic primary amino color-developing agent, and c. reacting said oxidized aromatic primary amino color-developing agent with said color coupler to form a dye image; the improvement wherein said processing solution contains a silver halide solvent, said silver halide solvent and said cobalt(llI) complex bleaching and fixing said photographic element after formation of said dye im- 24 of said silver image, the improvement which comprises combining a silver halide solvent with said cobalt( III) complex while said element is being treated with said processing solution to bleach and fix said element after said silver image has been amplified by said dye.

21. In a photographic processing solution capable of developing silver and dye images in an imagewiseexposed photographic element comprising a support having coated thereon at least one image dye-providing layer unit containing a silver halide emulsion and having associated therewith a photographic color coupler, said processing solution comprising an aromatic primary amino color-developing agent, the oxidized form of said color-developing agent being capable of reaction with said color coupler to form a dye, the improvement wherein said processing solution comprises a bleach-fix combination of a silver halide solvent and a cobalt(llI) complex.

22. In a photographic processing solution capable of developing silver and dye images in an imagewiseexposed photographic element comprising a support having coated thereon at least one image dye-providing layer unit containing a silver halide emulsion and having associated therewith a photographic color coupler, said processing solution comprising an aromatic primary amino color-developing agent, the oxidized form of said color-developing agent being capable of reaction with said color coupler to form a dye, the improvement wherein said processing solution comprises a bleach-fix combination of a water-soluble thiosulfate and cobalt hexammine chloride.

23. In a photographic film unit comprising:

a. a photosensitive element comprising a support having thereon at least one photosensitive silver halide emulsion layer, each said silver halide emulsion layer having associated therewith a dye imageproviding material;

b. a rupturable container containing an alkaline processing composition; and

c. a silver halide developing agent; the improvement wherein said film unit contains a cobalt(III) complex and a silver halide solvent capable of bleaching and fixing said element.

UNITED STATES PATENT AND TRADEMARK OFFICE QER'HHCATE OF CORRECTION PATENT NO. 3,923,511

DATED December 2, 1975 INVENTOMX) Vernon Leon Bissonette It is certified that error appears in the aboveidentified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 7, after "1971", should be inserted; line 9, after "1972" should be inserted. Column 3, lines 21-26, the sentence "The improvement .dye image. although a part of the paragraph commencing with line 1 of column 3, is not a part of subparagraph "0. and should begin flush with the left margin of the column. Column 7, line 29, that part of formr %a reading ECO" should regd -[Co. Column 9, line 58, "l X 10 should read --l X l0 5 line 65, after "yellow", -dye has its major absorptionshould be inserted. Column 11, line 30, after "1971", should be inserted; last line, "support" should read -supports Column 12, line 16, that part of formula reading "ditert" should read ditert. Column l t, line 17, that part of formula reading "kl" should read line 62, "couper" should read coupler-; lines 63-6 1, that part of formula reading "phenoXy-2" should read phenoXy-2--; line 6", that part of formula reading "A A should read -Y-. Column 15, line 5, that part of formula reading [2" should read --]2--; line 13, '01. 58" should read l.58-; line 49, "diffustion" should read diffusion; line 62. "Exaple should read -EXample-.

Column 19, line 12, "alkanline" should read alkaline-; line 58, "with a" should read and a-.

Signed and Scaled this twenty-fifth Day of May 1976 ESEAL] Arrest:

RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner of Parents and Trademarks

Claims

1. In a photographic process which comprises: a. contacting a photographic element comprising a support having thereon an imagewise-exposed photosensitive silver halide with an alkanline processing solution and a silver halide developing agent to form a first image comprising silver, b. forming a second photographic image in the areas of said first image, and c. bleaching and fixing said silver image and said photosensitive silver halide salt with the combination of a cobalt(III) complex and a solvent for said photosensitive silver halide salt, the improvement wherein said solvent for said photosensitive silver halide salt and said cobalt(III) complex are combined in said elemeNt to bleach and fix said element while said alkaline processing solution is in contact with said element.

1. developing a metallic silver image in said element,

1. developIng a metallic silver image in said element,

1. an aromatic primary amino color-developing agent and

2. a cobalt(III) complex capable of (i) bleaching metallic silver in the presence of a silver halide solvent and (ii) undergoing a redox reaction with primary aromatic amino color-developing agent in the presence of metallic silver to form oxidized color-developing agent; thereby: ; a. developing a metallic silver image in said element, b. redoxing said cobalt(III) complex and said aromatic primary amino color-developing agent in the area of said metallic silver image to form oxidized aromatic primary amino color-developing agent, and c. reacting said oxidized aromatic primary amino color-developing agent with said color coupler to form a dye image; the improvement wherein said processing solution contains a silver halide solvent, said silver halide solvent and said cobalt(III) complex bleaching and fixing said photographic element after formation of said dye image.

2. oxidizing said aromatic primary amino color-developing agent in the area of said metallic silver image, and

2. redoxing said cobalt(III) complex and said aromatic primary amino color-developing agent in the area of said metallic silver image to form oxidized aromatic primary amino color-developing agent, and

2. In a photographic process wherein a photographic element comprising a support having thereon an imagewise-exposed photosensitive silver halide salt is contacted with an alkaline processing solution in the presence of a silver halide developing agent to form a first image comprising silver and forming a second photographic image in the areas of said first image, and said silver image and said photosensitive silver halide salt are bleached and fixed with the combination of a cobalt(III) complex and a solvent for said photosensitive silver halide salt, the improvement wherein: a. said alkaline processing solution contains said solvent for said photosensitive silver halide salt and b. said cobalt(III) complex is present in said alkaline processing solution or said photographic element, said solvent for said photosensitive silver halide salt and said cobalt(III) complex bleaching and fixing said silver image and said photosensitive silver halide salt after formation of said second photographic image.

3. A photographic process as defined in claim 2 wherein (1) said silver halide solvent is sodium or potassium thiosulfate and (2) said cobalt(III) complex is a cobalt hexamine complex.

3. reacting said oxidized aromatic primary amino color-developing agent with said color coupler to form a dye image; the improvement wherein said processing solution contains a silver halide solvent, said silver halide solvent and said cobalt(III) complex bleaching and fixing said photographic element after formation of said dye image.

3. reacting said oxidized aromatic primary amino color-developing agent with said color coupler to form a dye image; the improvement wherein a silver halide solvent is combined with said cobalt(III) complex, while the element is being contacted with said alkaline processing solution, to bleach and fix said element after formation of said dye image.

4. A PHOTOGRAPHIC MONOBATH PROCESS WHEREIN A PHOTOGRAPHIC ELEMENT COMPRISING A SUPPORT HAVING THEREON AN IMAGEWISE-EXPOSED PHOTOSENSITIVE SILVER HALIDE IS CONTACTED WITH AN ALKALINE PROCESSING SOLUTION IN THE PRESENCE OF A REDUCING AGENT FOR SAID METAL SALT TO FORM A FIRST IMAGE COMPRISING SOLVE AND FORMING A SEDOND PHOTOGRAPHIC IMGAE IN THE AREAS OF SAID FIRST IMAGE, AND SAID SILVER IMAGE AND SAID PHOTOGRAPHIC IMAGE IN HALIDE ARE BLEACHED AND FIXED WITH THE COMBINATION OF A COBALT(III) COMPLEX WITH A SOLVENT FOR SAID PHOTOSENSITIVE SILVER HALIDE, SAID ALKALINE PROCESSING SOLUTION CONTAINING SAID SOLVENT FOR SAID PHOTOSENSITIVE SILVER HALIDE, AND SAID COBALT(III) COMPLEX BEING PRESENT IN SAID ALKALINE PROCESSING SOLUTION OR SAID PHOTOGRAPHIC ELEMENT, SAID SOLVENT FOR SAID PHOTOSENSITIVE SILVER HALIDE AND SAID COBALT(III) COMPLE BLEACHING AND FIXING SAID SILVER IMAGE AND SAID PHOTOSENSITIVE SILVER HALIDE AFTER FORMATION OF SAID SECOND PHOTOGRAPHIC IMAGE.

5. A process for forming dye images in a photographic element which comprises at least one image dye-providing unit containing an imagewise-exposed silver halide emulsion having associated therewith a photographic color coupler, said process comprising effecting contact of said image dye-providing unit in said photographic element with an alkaline processing composition containing a fixing amount of a silver halide solvent, in the presence of a silver halide developing agent, thereby developing a metallic silver image in said image dye-providing layer unit, providing primary aromatic amino color-developing agent and a cobalt(III) complex in the area of said metallic silver image to form oxidized color-developing agent and reacting said oxidized color-developing agent with said photographic color coupler to produce an image dye, and then bleaching and fixing said metallic silver image and said silver halide by the combination of a cobalt(III) complex and said silver halide solvent.

6. A process according to claim 5 wherein said color-developing agent and said cobalt(III) complex are present in said element before contact with said alkaline processing solution.

7. In a process for forming dye images in a photographic element comprising at least one image dye-providing unit containing an imagewise-exposed silver halide emulsion, which process comprises contacting said element with an alkaline processing solution in the presence of: a. an aromatic primary amino color-developing agent, b. a photographic color coupler, and c. a cobalt(III) complex capable of bleaching metallic silver in the presence of a silver halide solvent; thereby:

8. In a process for forming dye images in a photographic element comprising at least one image dye-providing unit containing an imagewise-exposed silver halide emulsion having associated therewith a photographic color coupler, which process comprises contacting said element with an alkaline processing solution in the presence of: a. an aromatic primary amino color-developing agent and b. a cobalt(III) complex capable of bleaching metallic silver in the presence of a silver halide solvent; thereby:

9. In a process for forming dye images in a photographic element comprising at least one image dye-providing unit containing an imagewise-exposed silver halide emulsion having associated therewith a photographic color coupler, which process comprises contacting said element with an alkaline processing solution in the presence of: a. an aromatic primary amino color-developing agent and b. a cobalt(III) complex capable of (i) bleaching metallic silver in the presence of a silver halide solvent and (ii) undergoing a redox reaction with primary aromatic amino color-developing agent in the presence of metallic silver to form oxidized color-developing agent; thereby:

10. In a process for forming dye images in a photographic element comprising at least one image dye-providing unit containing an imagewise-exposed silver halide emulsion having associated therewith a photographic color coupler, which process comprises contacting said element with an alkaline processing solution in the presence of: a. an aromatic primary amino color-developing agent and b. a cobalt(III) complex capable of (i) bleaching metallic silver in the presence of a silver halide solvent and (ii) undergoing a redox reaction with primary aromatic amino color-developing agent in the presence of metallic silver to form oxidized color-developing agent, said cobalt(III) complex having a coordination number of 6 and a positive net charge of 3; thereby:

11. In a process for forming dye images in a photographic element comprising a support having thereon red-, green- and blue-sensitive silver halide emulsion layers containing, respectively, cyan, magenta and yellow dye-forming photographic color couplers, which process comprises contacting said element with an alkaline processing solution in the presence of: a. an aromatic primary amino color-developing agent and b. a cobalt(III) complex capable of (i) bleaching metallic silver in the presence of a silver halide solvent and (ii) undergoing a redox reaction with primary aromatic amino color-developing agent in the presence of metallic silver to form oxidized color-developing agent; thereby:

12. A photographic process as defined in claim 9 wherein said photographic element comprises a support having thereon at least two separate color-providing layer units, each of which contains a light-sensitive silver halide having associated therewith an image dye-providing photographic coupler in at least a 40% stoichiometric excess based on effective silver.

13. A photographic process as defined in claim 12 wherein each of said color-providing layer units of said photographic element comprises said silver halide in a concentration of up to 30 mg. of silver/ft.2.

14. A photographic process as defined in claim 11 wherein each of said silver halide emulsion layers comprises a silver halide emulsion at a silver concentration of from 1 to 30 mg./ft.2 and said color coupler at a concentration of from 3 to 20 times the weight of said silver.

15. A photographic process as defined in claim 11 wherein at least one of said color couplers is incorporated in said element in a nonsolvent dispersion.

17. A process as defined in claim 11 wherein said cobalt(III) complex is cobalt hexammine chloride and said silver halide solvent is sodium or potassium thiosulfate.

19. In a process for forming dye images on a photographic element comprising a support having coated thereon, in the order given: a. a blue-sensitive silver halide gelatin emulsion layer having associated therewith a yellow dye-forming coupler, b. a green-sensitive silver halide gelatin emulsion layer coated at a coverage of less than about 15 mg. of effective silver/ft.2, having associated therewith a magenta dye-forming coupler in at least a 40% stoichiometric excess based on effective silver, and c. a red-sensitive photographic silver halide gelatin emulsion layer coated at a coverage less than aBout 15 mg. of effective silver/ft.2, having associated therewith a cyan dye-forming coupler in at least a 40% stoichiometric excess based on effective silver; which process comprises contacting said element with an alkaline processing solution in the presence of:

20. In a photographic process wherein a silver image in a photographic element is replaced by a dye image, which process comprises treating the photographic element with an alkaline processing solution to contact the silver image with the combination of an aromatic primary amino color-developing agent and a cobalt(III) complex to produce oxidized color-developing agent, and reacting said oxidized color-developing agent with a photographic color coupler to form a dye, said cobalt(III) complex undergoing redox reaction with said color-developing agent essentially only in the presence of said silver image, the improvement which comprises combining a silver halide solvent with said cobalt(III) complex while said element is being treated with said processing solution to bleach and fix said element after said silver image has been amplified by said dye.

21. In a photographic processing solution capable of developing silver and dye images in an imagewise-exposed photographic element comprising a support having coated thereon at least one image dye-providing layer unit containing a silver halide emulsion and having associated therewith a photographic color coupler, said processing solution comprising an aromatic primary amino color-developing agent, the oxidized form of said color-developing agent being capable of reaction with said color coupler to form a dye, the improvement wherein said processing solution comprises a bleach-fix combination of a silver halide solvent and a cobalt(III) complex.

22. In a photographic processing solution capable of developing silver and dye images in an imagewise-exposed photographic element comprising a support having coated thereon at least one image dye-providing layer unit containing a silver halide emulsion and having associated therewith a photographic color coupler, said processing solution comprising an aromatic primary amino color-developing agent, the oxidized form of said color-developing agent being capable of reaction with said color coupler to form a dye, the improvement wherein said processing solution comprises a bleach-fix combination of a water-soluble thiosulfate and cobalt hexammine chloride.

23. IN A PHOTOGRAPHIC FILM UNIT COMPRISING: A. A PHOTOSENSITIVE ELEMENT COMPRISING: THEREON AT LEAST ONE PHOTOSENSITIVE SILVER HALIDE EMULSION LAYER, EACH SAID SILVER HALIDE EMULSION LAYER HAVING ASOCIATED THEREWITH A DYE IMAGE-PROVIDING MATERIAL, B. A RUPTURABLE CONTAINER CONTAINING AN ALKALINE PROCESSING COMPOSITION, AND C. A SILVER HALIDE DEVELOPING AGENT, THE IMPROVEMENT WHEREIN SAID FILM UNIT CONTAINS A COBALT(III) COMPLEX AND A SILVER HALIDE SOLVENT CAPABLE OF BLEACING AND FIXING SAID ELEMENT.