US3537850A

US3537850A - Color transfer image-forming process utilizing coupler-developers whose oxidation products can couple intermolecularly

Info

Publication number: US3537850A
Application number: US869443A
Authority: US
Inventors: Myron S Simon
Original assignee: Polaroid Corp
Current assignee: Polaroid Corp
Priority date: 1966-12-02
Filing date: 1969-10-13
Publication date: 1970-11-03
Anticipated expiration: 1987-11-03
Also published as: US3711546A

Abstract

Novel coupler developers for preparing color transfer images. Essentially the coupler developers contain a coupling moiety linked to a silver halide developing moiety.

Description

, M'. s. SIMON 3,537,850 COLOR TRANSFER IMAGE-FORMING PROCESS UTILIZING COUPLER-DEVELOPERS wnosm OXIDATION PRODUCTS CAN COUPLE INTERMOLECULARLY Original Filed Dec. 2, 1966 y SUPPORT L-COUPLER-DEVELOPER vSILVER HALIDE EMULSION b-PROC ESSING COMPOSITION v lMAGE-RECEIVING LAYER SUPPORT INVENTOR M72011. J xiiwmz and ATTORNEYS United States Patent 3,537,850 Patented Nov. 3, 1970 are heretofore known to provide an oxidation product which may couple with color couplers of the foregoing Polaroid Corporation, Cambridge, Mass., a corporation of Delaware Continuation of application Ser. No. 598,870, Dec. 2, 1966. This application Oct. 13, 1969, Ser. No. 869,443 Int. Cl. G03c 5/54, 1/40 US. C]. 96-29 1 ABSTRACT OF THE DISCLOSURE Photographic processes for forming color images employing a coupler-developer, said coupler-developer being a compound which is both a color coupler and a silver halide developing agent and whichis capable of providing an oxidation product that can couple intermolec ularly but that cannot couple intramolecularly.

This application is a continuation of the copending application of Myron S. Simon, Ser. No. 598,870, filed Dec. 2, 1966.

This invention relates to photography and, more particularly, to novel processes and products for preparing color transfer images.

A primary object of this invention, therefore, is to provide novel processes and products for preparing color images by diffusion transfer.

Another object is to provide novel photographic systems wherein .an exposed light-sensitive silver halide emulsion is developed in the presence of a compound which is both a color developer and a coupler, the developer moiety is selectively oxidized as a function of development, the oxidized compound couples intermolecularly to form a nondiffusible reaction product of substantially higher molecular weight, while the unreacted compound is free to transfer by imbibition to a superposed layer or stratum where it is oxidized and then couples intermolecularly to form a positive dye transfer image.

Still another object is to provide novel compounds for use in the aforementioned systems.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the several steps and the relation and order of one or more of such steps with respect to each of the others, and the products possessing the features, properties, and the relation of elements which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be-had to the following detailed description taken in conjunction with the accompanying drawing wherein:

The figure is a partially schematic, partially enlarged fragmentary sectional view illustrating a previously exposed photographic product of this invention during processing thereof.

The objectives of this invention are accomplished by providing novel processes and products utilizing a novel class of compounds which contain both a coupling moiety and a silver halide developing moiety, hereinafter referred to as coupler-developers. The coupling moiety is selected from the class of color couplers heretofore known to couple with oxidized color developer, e.g., phenol, naphthol, aniline, naphthylamine or active methylene color couplers, etc., and the developer moiety in turn is selected from theclass of color developers which 25 Claims description to form a dye, e.g., an indoaniline, indophenol, or an azomethine dye. The coupler and developer moieties are so positioned in the molecule with respect to one another so as to preclude self-coupling or intramolecular coupling between the coupler moiety and oxidized developer moiety.

The coupler-developers of this invention may be represented by the following formula: (n.-1) wherein:

X represents a color coupler, e.g., a hydroxyphenyl, a-

hydroxynaphthyl, aminophenyl, a aminonaphthyl or methylene color coupler such as described, for example, in Mees, The Theory of the Photographic Process, revised edition, 1954, pp. 594-604;

D represents an aromatic primary amino color developer moiety, e.g., of the p-aminophenol and p-phenylenediamine series;

L is a divalent linking group linking the developer moiety,

D, to the coupler moiety, X; and

n is a positive integer from 1 to 2, the developer moiety, D, being positioned in the molecule with respect to the coupler moiety, X, so as to preclude self-coupling.

This may be effected in the following manner:

(1) Having the primary amino substituent of the developer moiety separated from the coupling position of the coupler moiety by more than four or less than three other atoms so as to preclude self-coupling to form a 5- or 6-membered ring; or

(2) In instances where the amino substituent is separated from the coupling position by four atoms, the developer moiety is not linked to the coupler in a position ortho-, or in the case of naphthyl couplers, perito the coupling position.

- While the developer moiety may be the radical of a paminophenol color developer, e.g.,

examples of useful color developers of this class, mention may be made of:

N,N-diethyl-p-phenylenediamine,

link a developing moiety to a dye moiety to provide a dye developer, i.e., a dye which is also a silver halide developing agent. Dye developers and the use thereof are described and claimed, for example, in U.S. Pat. No. 2,983,606, issued to Howard G. Rogers. Useful linking groups are disclosed in this patent and in particular are described and claimed in U.S. Pat. No. 3,255,001, issued June 7, 1966 to Elkan R. Blout and Howard G. Rogers, as well as in other issued patents. Such linking groups include, by way of example, alkylene, phenylene, alkylphenyl, CO, CONH-alkyl, etc.

As was mentioned previously, the coupling moiety may be selected from any of the known couplers such as are described, for example, in the aforementioned Mees text. The preferred couplers are taken from the classes of anaphthol, phenol, aniline and a-naphthylamine couplers, including substituted derivatives thereof. This preferred class may be represented by the formula:

wherein:

L, n and D have the meanings heretofore noted;

Y is hydroxy or amino, e.g., a primary, secondary or tertiary amino substituent of the formula wherein each R may be hydrogen, a hydrocarbon radical, e.g., alkyl, such as methyl, ethyl, butyl, dodecyl, etc., aryl such as phenyl or naphthyl attached through a carbon atom thereof to the nitrogen atom, a cyclic alkyl such as cyclopentyl or cyclohexyl, i.e., where both Rs are alkylene comprising together with the nitrogen atom a heterocyclic ring, a substituted alkyl, such as hydroxyethyl, methoxyethoxyethyl, polyglycoloxyethyl, carboxymethyl, carboxyethyl, ethlcarboxymethyl, benzyl, phenylethyl, sulfo-phenylethyl, acetylaminophenylethyl, succinylamino, phenylethyl, furanemethyl, or a substituted aryl such as methylphenyl, ethylphenyl, etc., couplers containing such substituents being disclosed, for example, in U.S. Pat. No. 3,245,795, compounds wherein Y is hydroxy being the most preferred; Z represents a coupling position para to the Y substituent and may be hydrogen or any of the substituents heretofore known in the art (such as disclosed in the aforementioned Mees text) which are replacable by oxidized aromatic amino color developer in so-called elimination-coupling reactions, e.g., chloro, bromo, carboxy, sulfo, hydroxy, alkoxy, hydroxyalkyl, etc.; and A represents the atoms necessary to complete an aromatic ring of the benzene or naphthalene series, which ring may be further substituted. As in the coupled-developers of Formula A, the developer moiety is positioned so as to preclude intramolecular coupling of the oxidation product.

As examples of useful compounds within the scope of Formulae A and/or B, mention may be made of:

In general, the novel compounds of this invention, that is, the compounds of Formulae A and B, may be readily synthesized by appropriate replacement or substitution reactions between a compound providing the coupling moiety and a compound providing the color developer moiety. In some instances wherein the coupling moiety is a phenol or naphthol, it may be desirable for the hydroxy substituent to be protected during this reaction, e.g., by acylation. Following reaction, the protective group may be removed in known manner by hydrolysis. Since the general reactions by which the present compounds may be prepared are in general analogous to the preparation of dye developers such as disclosed in the aforementioned patents and elsewhere in the patent literature, the preparation of the present compounds will be readily apparent to those skilled in the art in the light of the present description, as exemplified by the following examples.

EXAMPLE 1 A mixture of 162.0 g. (1.34 M) of N-ethylaniline and 137.0 g. (0.67 M) of ,B-bromoethylamine hydrobromide was stirred for 105 minutes while the temperature was slowly raised to 145 C. [At about 105-110 C. there was some heat of reaction which sent the temperature briefly to 140 C.] The mixture was then maintained at 145 C. with stirring for an additional two hours, after which it was cooled overnight and then poured into 400 ml. of sodium hydroxide. It was then heated on a steambath, cooled, and the resulting mixture was extracted with ether. The ethereal solution was dried over sodium hydroxide pellets, filtered, the ether evaporated, and then distilled to yield 59.8 g. (54.5% yield) of:

(I) amply-0112011281112 COOH 1-aeetoxy-2-naphthoic acid in 175 ml. of acetone, 11.8 ml. (0.84 M) of triethylamine were added. The mixture was cooled to 5 C. and 11.5 g. (0.84 M) of isobutylchloroformate were added. After stirring for about 25 minutes at 5 C., a solution of 14.5 g. (.0885 M) of N-ethyl-N-fi-aminoethyl-aniline (I) in ml. of acetone was added. The resulting mixture was removed from the cold bath and stirred overnight at room temperature while protecting from moisture. The acetone .was then evaporated in vacuo and the residue was treated with ice-water to yield a precipitate which was filtered, triturated with sodium bicarbonate solution, filtered, and then dried in vacuo over phosphorous pentoxide to yield a sticky solid. This solid was then triturated with hexane and filtered to provide 23.5 g. of a soupy while solid, M.P. l02110 C. dec. This solid was crystallized from 300 ml. of toluene to yield 13 g. (40% yield) of a gelatinous white precipitate, M.P. 129-131 C.,.of the formula:

OCOCHs A solution of 5.82 g. (.0252 M) of sodium sulfanilate dihydrate in 30 ml. of water was cooled to 15 C. A solution of 1.76 g. (.0252 M) of sodium nitrite in water was added and the resulting mixture was immediately poured into 5.1 ml. of concentrated HCl in 30 g. of ice. After allowing 'itto stand for about minutes, the mixture was then poured into a chilled solution containing 9 g. (.024 M) of the amide (III) in 60 ml. of methyl Cellosolve plus 60 ml. of 3 N HCl. The resulting pink mixture was stirred in the cold for two and a half hours and refrigerated overnight. It was then deaerated with a stream of nitrogen and kept under a blanket of nitrogen while 125 ml. of 3 N sodium hydroxide were added. The reaction solution was then stirred at room temperature for 30 minutes, after which period it was neutralized with ml. of acetic acid. HCl was added and the resulting dark gum was filtered off and dried in vacuo over phosphorous pentoxide and potassium hydroxide to yield 12 g. of a dark solid. This solid was 6 further purified by dissolution in 500 ml. of hot water, filtering, and acidifying with dilute HCl to yield a precipitate which was filtered and dried to yield 9.2 g. of a maroon solid, M.P. 200 C. dec. with prior sintering. For further purification, 7.4 g. of the solid were stirred with 50 ml. of 3 N sodium bicarbonate and 50 ml. of water for 30 minutes, filtered and acidified with 55 ml. of 3 N HCl to yield a precipitate which was filtered and dried in vacuo over phosphorous pentoxide to yield 7.3 g. of a red azo dye, M.P. 200-205" C., of the formula:

A solution was made under nitrogen, of 7.2 g. of this dye (IV), ml. of water and 30 ml. of 3 N sodium hydroxide. This solution was introduced into a Parr hydrogenator and reduced with hydrogen over 2 g. of palladium/barium sulfate. Hydrogen uptake was complete in 25 minutes to yield a colorless solution which was acidified with 50 ml. of 3 N HCl, and catalyst and occluded s'ulfanilic acid were filtered off. The filtrate was treated with aqueous acetic acid to a pH of about 4 to cause precipitation. Filtration, followed by drying in vacuo over phosphorous pentoxide yielded a yellow solid. Isolation was etfected by solution in 15 ml. of warm acetic acid and filtration followed by addition of 15 ml. of acetic acid saturated with HCl, then 150 ml. of dry ether, to yield a light-colored precipitate. This precipitate was filtered through a sintered glass filter and then transferred quickly to a desiccator where it was dried in vacuo over phosphorous pentoxide to yield 2.5 g. of the amino hydrochloride of the coupler-developer of Formula I, a light colored solid, M.P. l00150 C., dec.

EXAMPLE 2 A mixture of 10.4 g. of acetylsalicyclic acid in 122 cc. of acetone and 8.14 cc. of triethylamine was cooled with stirring to 5 C. 7.94 g. of isobutylchloroformate were then added to yield a white precipitate. After stirring at 5 C. for about 25 minutes, a solution of 10 g. of N-ethyl-N-fiaminoethyl-aniline (I) in 10 cc. of acetone was added. The reaction mixture was then removed from the cold bath, stirred overnight at room temperature, the acetone evaporated in vacuo, and cold water was added tothe residue. The liquid phase was then decanted to provide a pasty product. This was purified by trituration with a small amount of ether, with water, and with sodium bicarbonate solution, washed with water and then dried in vacuo over phosphorous pentoxide to yield a white solid, M.P. about 70 C. This white solid was recrystallized from 250 cc. to ligroin and 50 cc. of toluene to yield 10 g. (50.3% yield) of a white crystal amide, M.P. 89-91" C., having the following formula:

(V) OCOGH:

3.24 g. of 2,5-dichloroanalinc were dissolved in a boiling solution of 8 cc. of cone. HCl and 35 cc. of water. The solution was cooled in an ice bath to about 10 C. at which temperature crystallization occurred. A cold solution of 1.39 g. of sodium nitrite in 3 cc. of water was added dropwise. The mixture was stirred for 10 minutes and filtered in the cold to provide a pale yellow solution. The

solution was added slowly in the cold to a stirred solution of 6.52 g. of the amide (V) in 42 cc. of 3 N HCl. The resulting mixture turned deep red and a precipitate started to form. The mixture was stirred at to C. for about two and a half hours and then filtered. Overnight more solid precipitated from the mother liquor and the solids were combined, the combined solids being:

The acetylated azo dye (VI) was added to 100 cc. of previously deaerated 3. N sodium hydroxide solution. After stirring for two hours until almost complete solution occurred, 100 cc. of 3 N HCl were added dropwise while stirring vigorously to yield an orange precipitate which was filtered, washed with water, dried in air and recrystallized from about 100 cc. of benzene and 25 cc. of hexane to yield a product, M.P. 143l46 C. This product was recrystallized once more from ethanol to yield 8.0 g. (86.6% yield) of the azo dye, M.P. l49l5l 0., having the formula:

(VII) on 7.5 g. of the azo dye (VII) were dissolved in about 150 cc. of boiling ethanol, the solution cooled to about 4045 C. (some of the dye crystallized out) and l g. of palladium/barium sulfate was added, then 1.37 cc. of cone. HCl. The dye was reduced in a Parr hydrogenator for about one hour and the catalyst was then filtered off. The ethanol was evaporated to about cc. and a large excess of ether was added. The ether was stirred with a glass rod while heating on a steambath to yield a fine beige powder. This powder was dissolved in about 60 cc. of methanol on a steambath, filtered and rapidly reprecipitated with ether. It was then left in a refrigerator for about two hours and filtered to yield 1.2 g. of the coupler-developer of Formula II, as the dihydrochloride, a light beige powder, M.P. 229-231 C.

This coupler-developer was also prepared from the acetylated amide (VI) by nitrosation and reduction of the nitroso group.

As was stated previously, the coupler-developers of this invention provide an oxidation product which can couple intermolecularly, but which will not self-couple or couple intramolecularly. When two molecules so couple, a dye of substantially higher molecular weight is formed. It will be apparent that three or more molecules of oxidized coupler-developer may couple to provide a polymeric dye of still higher molecular weight. In any event, the coupling of two or more molecules provides a dye which is relatively nondiffusible in the processing fluid.

With reference to the coupler-developer of Formula I,

the reaction mechanism upon which nondiffusible dye formation is predicated may be illustrated as follows:

I I Following oxidation, e.g., by development of an exposed silver halide emulsion, the nitrogen atom [bearing the free valence] of one molecule of oxidized couplerdeveloper couples para to the naphtholic hydroxyl group of another molecule to form a dye. Further intermolecular coupling of other molecules of oxidized coupler-developer may occur to provide a polymeric dye of greater molecular weight.

The novel coupler-developer of this invention may be employed in various photographic systems wherein color transfer image is predicated upon an imagewise differential in mobility or diffusibility obtained as a function of developing an exposed light-sensitive silver halid emulsion. Such a system is illustrated in the drawing.

As shown therein, a photosensitive element comprising a support 10 having a layer 12 of coupler-developer and a light-sensitive silver halide emulsion layer 14 which has been previously exposed to contain a developable image, is developed by spreading an aqueous alkaline processing composition 16 between the thus exposed element and a superposed image-receiving element comprising an imagereceiving layer or dyeable stratum 18 on a suitable support 20. The processing composition permeates emulsion layer 14 to layer 12 where at least a portion of the coupler-developer in layer 12 is dissolved in the processing medium. (If the particular coupler-developer employed is not readily soluble in water, at least at the processing temperature employed, a suitable water-miscible organic solvent therefor may be contained in the processing composition.) The processing composition containing coupler-developer thus formed thereafter contacts the emulsion layer where the developing moiety reduces exposed silver halide to image silver and as a function thereof is in turn oxidized. This oxidized developer then couples intermolecularly in the manner previously described to form a dye in terms of exposed areas. This dye is relatively nondiifusible in the processing medium and hence remains in the photosensitive element. In unexposed areas, an imagewise distribution of unoxidized and dilfusible coupler-developer remains. This latter -imagewise distribution is transferred at least in part, by

imbibition, to the superposed image-receiving layer or dyeable stratum to form thereon in terms of unexposed areas of the emulsion an imagewise distribution of coupler-developer. This imagewise distribution of unoxidized coupler-developer may then be oxidized to form a positive dye transfer image. The oxidation may be effected simply by exposure to air, e.g., upon separation of the respective elements following development, or, if desired, the receiving layer may contain an oxidizing agent to facilitate oxidation and subsequent dye formation.

In the color transfer process just described, it will be appreciated that a negative color image is formed in the photosensitive element. If desired the photosensitive element may be treated for removal of silver in conventional manner, e.g., by bleaching and subsequent fixation to provide a useful negative image. Any residual couplerdeveloper remaining in unexposed areas may also be removed by conventional techniques to provide clean highlight areas in the negative image. This aspect of the invention may be employed, for example, as a system for making positive reproductions from a negative, e.g., from a negative or reversed color transparency. Hence, as used herein, the terms positive and negative are given their ordinary meaning in the art and are intended to connote whether or not the image is a reverse image of the subject matter to which the novel film unit of this invention is exposed.

Either or both of supports 14 and 20 may be transparent or opaque, depending upon whether reflection prints or transparencies are contemplated. They may also be translucent or contain a translucent layer so that the resulting image may be viewed either by reflected or by transmitted light to provide a single image which is both a reflection print and a transparency. As examples of typical materials which may be employed for the respective supports, mention may be made of films of cellulose acetate, cellulose nitrate, polyvinyl acetal, polystyrene, polyethylene terephthalate, polyethylene, polypropylene, etc., paper, glass and others. As an example of a particularly useful material for preparing a translucent layer, mention may be made of titanium dioxide.

Layer 12 containing the coupler-developer may be prepared by applying to support 14 a coating containing the coupler-developer and a suitable polymeric matrix or carrier, e.g., cellulose acetate hydrogen phthalate, gelatin, etc.

Emulsion layer 14 may comprise any of the conventional silver halide emulsions, e.g., silver chloride, silver bromide, silver bromiodide, silver chlorobromide or silver chlorobromoiodide. The emulsion layer may also contain the various additives heretofore employed in such layers, e.g., optical sensitizers, antifoggants, hardeners, plasticizers, coating aids, speed-increasing materials, ultraviolet absorbers, etc. The dispersing agent or substrate for the silver halide may be gelatin or some other colloidal material.

Image-receiving layer 18 may be any of those heretofore known in the art, e.g., a copolymer of vinylacetate and vinyl alcohol, nylon, polyvinyl alcohol, gelatin, etc. and it may also include a suitable dye mordant such as poly-4-pyridine.

The developing composition comprises at least an aqueous solution of an alkaline material such as sodium or potassium hydroxide. As was mentioned previously, it may also contain a suitable water-miscible organic solvent for the coupler-developer, e.g., phenethyl alcohol. In addition, the processing composition may also contain other reagents performing specific desired functions, e.g., a viscous film-forming reagent such as hydroxy-ethyl cellulose, sodium carboxymethyl cellulose, etc. It is to be understood that any of these ingredients may be present initially in the film unit, in which case the processing composition containing the desired ingredients is formed during processing by contacting the film unit with the aqueous medium therefor. In any event, the processing composition may, if desired, be confined in a frangible container or pod such as described, for example, in US. Pat. Nos. 2,543,181 and 2,634,886, issued to Edwin H. Land.

While for purposes of illustration, the coupler-developer has been shown in the drawing as being in a separate layer in the photosensitive element, it may also be contained in the same layer as the silver halide emulsion. When present in the same layer, it may be advantageous to use forms that have substantial stability in photographic emulsions. For example, it may be desirable to have the primary amino developing moiety present in the emulsion as a Schiff base derivative. Such Schitf bases may be prepared by reacting primary amino developing agents with sulfonated, hydroxylated or carboxylated aromatic aldehydes of the benzene or naphthalene series. A typical Schiff base color developing agent can be prepared by reacting a color developer moiety, e.g., Z-amino- S-diethylaminotoluene, and o-sulfobenzaldehyde. As is known, the Schiif base derivatives are activated upon contact with the aqueous alkaline composition.

Other variations in procedure or in the arrangement of elements will be apparent in the light of the foregoing description.

The following example shows by way of illustration and not by way of limitation the practice of this invention.

EXAMPLE 3 A photosensitive element was prepared by coating a gelatin subcoated film base at a speed of 10 feet/minute with a solution comprising 0.125 g. of the coupler-developer of Formula I dissolved in 5 cc. of 4% cellulose acetate hydrogen phthalate in acetone. After this coating dried, a blue-sensitive silver iodobromide emulsion was coated on at a speed of 5 feet/minute and allowed to dry. This photosensitive element was exposed for two seconds and then developed by spreading between the thus exposed photosensitive element and a superposed imagereceiving element at a gap of 0.0026" an aqueous processing composition comprising the following proportions of ingredients:

Waterl00.0 cc. Hydroxyethyl cellulose4.5 g. Sodium hydroxide1.5 g. Sodium carbonate-5.0 g. Phenethyl alcoholll.5 cc.

The image-receiving element was comprised of a 50:50 copolymer of vinylacetate-vinyl alcohol containing 0.6% benzoyl peroxide on a nitrate-subcoated sheet. After an imbibition time of approximately one minute, the imagereceiving element was separated and contained a positive green-blue image.

The present invention makes it possible to obtain color transfer images of excellent quality and stability. The oxidative coupling in the photosensitive element as a function of development forms a nondiffusible reaction product so that transfer thereof is effectively precluded. This inability of unwanted dye to transfer makes it possible to obtain transfer images having minimal stain and exhibiting exceptionally clean highlight areas. Further, the polymeric nature of the dye makes it possible to obtain a dye image having exceptional stability to light, heat and other degradative forces.

While the preparation of a monochromatic image has been described in the illustrative example, it will be appreciated that the invention is adaptable to the preparation of multicolor images. Systems for preparing multicolor images would, for example, employ multilayer photosensitive elements comprising at least two appropriately sensitized emulsion layers each having a suitable couplerdeveloper associated therewith.

It is also contemplated that a mixture of coupler-developers may be employed in a single emulsion system to provide a useful black-and-white process. Hence, as used throughout the specification and claims, the term color is intended to include the use of a black dye or a mixture of dyes to provide a black image.

Since certain changes may be made in the above prodnet and process without departing from the scope of the invention herein involved, it is intended that all matter contain in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A process of forming images in color which comprise the steps of developing a photosensitive element comprising an exposed light-sensitive silver halide emulsion with a coupler-developer, said coupler-developer being a compound which is both a color coupler and a silver halide developing agent and which is capable of providing an oxidation product that can couple intermolecularly but that cannot couple intramolecularly, the silver halide developing agent portion of the coupler-developer molecule being a color developer moiety of the-paraaminophenol or para-phenylenediamine series; and as a function thereof, forming an imagewise distribution of oxidized coupler-developer, said oxidized coupler-developer coupling intermolecularly to form a negative color image on said photosensitive element.

2. A process of forming images in color which comprises the steps of:

(a) developing a photosensitive element comprising an exposed light-sensitive silver halide emulsion with a coupler-developer, said coupler-developer being a compound which is both a color coupler and a silver halide developing agent and which is capable of providing an oxidation product that can couple intermolecularly but that cannot couple intramolecularly, the silver halide developing agent portion of the coupler-developer molecule being a color developer moiety;

(b) and, as a function thereof, forming an imagewise distribution of oxidized coupler-developer, said oxidized coupler-developer coupling intermolecularly to provide a nondiifusible reaction product;

(c) forming an imagewise distribution of unoxidized coupler-developer in terms of undeveloped areas of said emulsion;

(d) transferring said imagewise distribution of unoxidixed coupler-developer, at least in part, by imbibition, to a superposed stratum; and

(e) oxidizing said imagewise distribution of transferred color coupler, whereby to provide an oxidation product which in turn couples intermolecularly to provide a dye transfer image in terms of areas of said transferred coupler-developer.

3. A process as defined in claim 2 wherein said lastnamed oxidation step is effected by separating said stratum from said emulsion and exposing said stratum containing said transferred coupler-developer to air.

4. A process as defined in claim 2 wherein said stratum includes an oxidating agent.

5. A process as defined in claim 2 wherein said coupler-developer is contained initially in a layer in said photosensitive element.

6. A process as defined in claim 5 wherein said coupler-developer and said light-sensitive emulsion are contained initially in the same layer in said photosensitive element.

'7. A process as defined in claim 2 wherein the developer moiety of said coupler-developer comprises an aromatic primary amino color developer function.

8. A process as defined in claim 2 wherein said developer moiety is a color developer of the p-phenylenediamine series.

9. A process as defined in claim 2 wherein said developer moiety is a para-aminophenol.

10. A process as defined in claim 2 including the step of forming a negative color image in said photosensitive element in terms of said nondiifusible reaction product.

11. A process as defined in claim 2 wherein said coupler-developer is a compound of the formula:

X represents a color coupler moiety;

D is an aromatic primary amino color developer moiety;

L is a divalent radilal linking said developer moiety,

D, to said coupler moiety, X; and

n is a positive integer from 1 to 2, said developer moicty, D, being positioned in said compound with respect to said coupler moiety, X, so as to preclude self- 12 coupling of the oxidation product of said compound. 12. A process as defined in claim 2 wherein said coupler moiety is selected from the group consisting of monovalent radicals of couplers of the u-naphthol, phenol, anaphthylamine and aniline series.

13. A process as defined in claim 12 wherein said coupler-developer is a compound of the formula:

wherein:

D is an aromatic primary amino color developer moiety; L is a divalent linking group; N is a positive integer from 1 to 2; Y is selected from the group consisting of hydroxy, and primary, secondary and tertiary amino groups; A represents the atoms necessary to complete an aromatic ring of the benzene or naphthalene series; and Z represents a coupling position para to said Y substituent,

said Z being selected from the group consisting of hydrogen and radicals replaceable by oxidized aromatic amino color developer in elimination-coupling reactions.

14. A photographic product comprising a support, a light-sensitive silver halide emulsion in a layer on said support, and a coupler-developer in a layer on the same side of said support as said emulsion, said coupler-developer being a compound which is both a color coupler and a silver halide developing agent and which is capable of providing an oxidation product that can couple intermolecularly, but that cannot couple intramolecularly, the silver halide developing agent portion of the couplerdeveloper molecule being a color developer moiety.

15. A product as defined in claim 14 wherein said emulsion and said coupler-developer are contained in the same layer.

16. A product as defined in claim 14 wherein the developer moiety of said coupler-developer comprises an aromatic primary amino color developer function.

17. A product as defined in claim 14 wherein said developer moiety is a color developer of the p-phenylenediamine series.

18. A product as defined in claim 16 wherein said coupler-developer is present as a Schifi. base derivative.

19. A product as defined in claim 14 including an imagereceiving element comprising a dyeable stratum, said image-receiving element being adapted for placement in superposition with said emulsion.

20. A product as defined in claim 19 wherein said image-receiving element includes an oxidizing agent.

21. A product as defined in claim 14 including means for applying a photographic processing composition to said emulsion.

22. A product as defined in claim 14 wherein said cou pler-developer is a compound of the formula:

X represents a color coupler moiety;

D is an aromatic primary amino color developer moiety;

L is a divalent radical linking said developer moiety,

D, to said coupler moiety, X; and

n is a positive integer from 1 to 2,

said developer moiety, D, being positioned in said compound with respect to said coupler moiety, X, so as to preclude self-coupling of the oxidation product of said compound.

23. A product as defined in claim 14 wherein said coupler moiety is selected from the group consisting of monol 13 14 valent radicals of couplers of the a-naphthol, phenol, w Z represents a coupling position para to said Y substitnaphthylamine and aniline series. uent, said Z being selected from the group consist- 24. A product as defined in claim 23 wherein said couing of hydrogen and radicals replaceable by oxidized pier-developer is a compound of the formula: aromatic amino color developer in elimination-cou- 5 pling reactions. r Y 25. A product as defined in claim 14 wherein said coupler-developer is selected from the group consisting of the V r 3 compounds identified in the specification as Formulae I {A through VII. v 10 References Cited UNITED STATES PATENTS h 3,079,259 2/1963 Rauch et al. 96-100 w j 3,278,306 muses Greenhalgh 96-100 D is an aromatic primary amino color developer moiety 15 3,293,032 55 liicken et 96100 of the pamino'phenol or p-phenylenediamine series; 3 3 7 at 96-100 L is a divalent linking group; n is a positive integer from 1 to NORMAN G. TORCHIN, Primary Examiner Y is selected from thegroup consisting of hydroxy, and A, T, SURO PICO, A i t t E i primary, secondary and tertiary amino groups; i

A represents the atoms necessary to complete an aro- U.S. Cl. X.R. matic ring of the benzene or naphthalene series; and 96--l00