US3779756A

US3779756A - Color developer scavenger layer for diffusion transfer dye image-receiving elements and systems

Info

Publication number: US3779756A
Application number: US00088215A
Authority: US
Inventors: C Farran; E Wolfarth
Original assignee: Eastman Kodak Co
Current assignee: Eastman Kodak Co
Priority date: 1970-11-09
Filing date: 1970-11-09
Publication date: 1973-12-18
Anticipated expiration: 1990-12-18
Also published as: CH541820A; AU457845B2; IT940477B; GB1360514A; BE775064A; CA982393A; FR2113597A5; AU3546571A

Abstract

A color developer scavenger layer comprising a photosensitive silver halide emulsion layer containing a nondiffusible coupler which is capable of forming an immobile product upon reaction with oxidized color developer is useful for reducing background stain in a dye image-receiving element of a color diffusion transfer system utilizing immobile couplers which form diffusible dyes. Various timing mechanisms are described for making the scavenger layer operative only after substantial development of the photosensitive element.

Description

United States Patent [191 Farran et a1.

[ Dec. 18, 1973 [73] Assignee: Eastman Kodak Company,

Rochester, NY.

22 Filed: Nov. 9, 1970 211 Appl. No.: 88,215

[52] US. Cl. 96/29 D, 96/76 R [51] Int. Cl G03c 5/54 [58] Field of Search 96/29 D, 3

[56] References Cited UNITED STATES PATENTS 3,573,042 3/1971 Milligan et al 96/3 3,445,228 5/1969 Beavers et al. 96/3 3,418,117 12/1968 Becker 96/29 D 3,585,028 6/1971 Stephens... 96/3 3,364,022 1/1968 Barr 96/56.1

Primary Examiner-Norman G. Torchin Assistant ExaminerJohn L. Goodrow Att0rney-W. H. J. Kline, J. R. Frederick and H. E.

Cole

[5 7] ABSTRACT A color developer scavenger layer comprising a photosensitive silver halide emulsion layer containing a nondiffusible coupler which is capable of forming an immobile product upon reaction with oxidized color developer is useful for reducing background stain in a dye image-receiving element of a color diffusion transfer system utilizing immobile couplers which form diffusible dyes. Various timing mechanisms are described for making the scavenger layer operative only after substantial development of the photosensitive element.

22 Claims, No Drawings COLOR DEVELOPER SCAVENGER LAYER FOR DIFFUSION TRANSFER DYE IMAGE-RECEIVING ELEMENTS AND SYSTEMS This invention relates to the art of photography, and more particularly to color diffusion transfer film units, dye image-receiving elements and methods for obtaining positive, right-reading diffusion transfer dye images with reduced color developer stain.

US. Pat. No. 3,445,228 of Beavers et al., issued May 20, 1969, describes a receiving sheet for use in a dye diffusion transfer process utilizing aromatic primary amino color developing agents. The receiving sheet comprises a support having thereon a nondiffusible acid material, an interlayer containing finely divided white pigment and a mordant layer. The acid layer terminates development by lowering the pH of the alkaline developer composition and apparently also functions to salt out residual color developer.

It is an object of this invention to provide a novel dye image-receiving element wherein a developer scavenger layer is employed which effectively destroys any residual color developer by a dye-forming coupler reaction.

Another object of this invention is to provide timing means in connection with the developer scavenger layer so that development in the photosensitive element is substantially complete before the developer scavenger layer becomes operative.

It is another object of this invention to prevent formation of yellowish-brown stain which appears on image transfer receiver sheets due to aerial oxidation of color developer present on the sheet.

Still another object of this invention is to provide novel color transfer film units and methods for processing same.

These and other objects are achieved by a photographic film unit according to our invention, which is adapted to be processed by passing the unit between a pair of juxtaposed pressure-applying members, such as would be found in a camera designed for in-camera processing, comprising:

a. a photosensitive element comprising a support having thereon at least one, and preferably three, photo-sensitive silver halide emulsion layers, each silver halide emulsion layer having associated therewith a dye image-providing material comprising a nondiffusible coupler capable of reacting with oxidized arorna'tic primary amino color developing agent to produce a diffusible dye;

.b. a dye image-receiving element comprising a support having thereon:

l. a developer scavenging layer comprising a silver ble of reacting with oxidized aromatic primary amino color developing agent to form an immobile product; I 21a light-reflective layer; and

3. a dye image-receiving layer; and "c. a rupturable container containing an alkaline processing composition and which is adapted to be positioned between the photosensitive element and the dye irriage-receiving element during processing of the film unit so that a compressive force applied to the container by pressure-applying members in a camera will effect a discharge of the containers contents between the image'receiving element and the outermost layer of halide emulsion and an immobilizing coupler capathe photosensitive element, the film unit containing an aromatic, primary amino color developing agent, preferably in the rupturable container.

The dye image-receiving layer of our film unit is located on a separate support which is adapted to be superposed on the photosensitive element after exposure thereof. Upon rupturing the pod, the processing composition diffuses through the film unit thereby initiating imagewise development of the silver halide emulsion layers. Dye images formed as a result of the reaction of oxidized developer with nondiffusible couplers contained in each silver halide emulsion layer or in a layer contiguous thereto, are formed as a function of the imagewise exposure of each said silver halide emulsion layer. At least a portion of the image-wise distributions of diffusible dye diffuses to the image-receiving layer. A positive dye image is viewable upon separation of the image-receiving element from the negative element. Unused color developer, however, also diffuses into the receiving element and reaches a finite concentration throughout. In the absence of our invention, rapid air oxidation and self-coupling of the unused developer would occur when the receiver is separated from the negative, thereby producing a yellow stain which would become progressively worse until all of the developer is exhausted.

Receiver stain is avoided, however, by use of the novel receiving elements of our invention as mentioned above in the description of our photographic film units. Upon removal of the exposed film unit from the camera and subsequent stripping away of the negative element, the unused color developer present in the receiving element develops the silver halide thus becoming oxidized, and the oxidized developer then couples with the immobilizing coupler to form an immobile product, usually a dye. This reaction product is masked from the viewer by the light-reflective layer. During the ensuing coupling reaction, the pH of the receiving element is also lowered due to the depletion of hydroxyl ions necessary for the coupling reaction between the oxidized developer and the immobile color coupler, thereby contributing to the stability of the transferred dyes in the receiver.

The developer scavenger layer can comprise a nondiffusible coupler capable of reacting with oxidized color developing agent to form an immobile product and a silver halide emulsion, e.g., an unsensitized silver halide emulsion, a panchromatically sensitized silver halide emulsion, a spontaneously developable silver halide emulsion, e.g., an emulsion prefogged chemically or with light or a silver halide emulsion containing a fogging agent, e.g., physical development nuclei, reducing agents such as hydrazines or hydrazine derivatives which fog during the development step, etc.

It is desirable to have the developer scavenger layer develop after the image-recording layers in the photosensitive element so as not to interfere with proper image formation. This can be accomplished in many ways. For example, when a panchromatically sensitized silver halide emulsion is employed in the developer scavenger layer, its exposure can be delayed until after separation of the image-receiving element from the negative element. At that time the silver halide emulsion layer can be exposed either through the top layers since the dye image-receiving layer and light-reflective layer are not completely opaque or through the support if it is transparent (in which case the film unit is dark processed or else a temporary opaque backing is removed).

Another method of timing the developer scanvenging function is to employ a polymeric timing layer, e.g., gelatin, partial polyvinyl formal, partial polyvinyl acetate, partial polyvinyl propional, hydroxypropyl cellulose, or any of those spacer layers described in U.S. Pat. No. 3,455,686 issued July 15, 1969. Another timing mechanism which can be employed to increase the developer scavenging induction period is to employ in the developer scavenger layer a silver halide emulsion having a high iodide content which develops at a slow rate, thereby delaying the development of the developer scavenging layer until after substantial development of the image-recording layers.

Another timing mechanism which can be employed is the use of development restrainers, e.g., mercaptans and azoles such as 1-phenyl-5-mercaptotetrazole, benzotriazole, S-methylbenzotriazole, 6- nitrobenzimidazole, S-nitroindazole, etc. in the developer scavenger layer to delay scavenging action until after substantial development in the image-recording layers.

.Yet still another timing mechanism which can be employed is to packet the silver halide in the developer scavenger layer in capsules having a coating which retards penetration of the developing agent, e.g., an emulsion containing a silver chlorobromide core and a silver iodide shell.

The film assembly of our invention can be used to produce positive images in single'or multicolors. In a three-color system, each silver halide emulsion layer of the film assembly of our invention will have associated therewith a dye image-providing material possessing a spectral absorption range substantially complementary to, the predominant sensitivity range of its associated emulsion, i.e., the blue-sensitive silver halide emulsion layer will have a yellow dye image-providing material associated therewith, the green-sensitive silver halide emulsion layer will have a magenta dye imageproviding material associated therewith, and the redsensitive silver halide emulsion layer will have a cyan dye image-providing material associated therewith. The dye image-providing material associated with each silver halide emulsion layer can be contained either in the silver halide emulsion layer itself or in a layer contiguous to the silver halide emulsion layer.

Spectral sensitizing dyes can be used conveniently to confer additional sensitivity to the light sensitive silver halide emulsion of the multilayer photographic elements of the invention. For instance, additional spectral sensitization can be obtained by treating the emulsion with a solution of a sensitizing dye in an organic solvent or the dye may be added in the form ofa dispersion as described in Owens et a1 British Pat. No. 1,154,781. For optimum results, the dye can either be added to the emulsion as a final step or at some earlier stage.

Sensitizing dyes useful in sensitizing such emulsions are described, for example, in Brooker et a1 U.S. Pat. No. 2,526,632, issued Oct. 24, 1950; Sprague U.S. Pat. No. 2,503,776, issued Apr. 11, 1950; Brooker et al. U.S. Pat. No. 2,493,748; and Taber et al. U.S. Pat. No. 3,384,486. Spectral sensitizers which can be used include the cyanines, merocyanines, complex (tri or tetranuclear) merocyanines, complex (tri or tetranuclear) cyanines, holopolar cyanines, styryls, hemicyanines (e.g., enamine hemicyanines), oxonols and hemioxonols. Dyes of the cyanine classes can contain such basic nuclei as the thiazolines, oxazolines, pyrrolines, pyridines, orazoles, thiazoles, selenazoles and imidazoles. Such nuclei can contain alkyl, alkylene, hydroxyalkyl, sulfoalkyl, carboxyalkyl, aminoalkyl and enamine groups and can be fused to carbocylic or heterocyclic ring systems either unsubstituted or substituted with halogen, phenyl, alkyl, halo-alkyl, cyano, or alkoxy groups. The dyes can be symmetrical or unsymmetrical and can contain alkyl, phenyl, enamine or heter0 cyclic substitutents on the methine or polymethine chain. The merocyanine dyes can contain the basic nuclei mentioned above as well as acid nuclei such as thiohydantoins, rhodanines, oxazolidenediones, thiazolidenediones, barbituric acids, thiazolineones, and malononitrile. These acid nuclei can be substituted with alkyl, alkylene, phenyl, carboxyalkyl, sulfoalkyl, hydroxyalkyl, alkoxyalkyl, alkylamino groups, or heterocyclic nuclei. Combinations of these dyes can be used, if desired. In addition, supersensitizing addenda which do not absorb visible light can be included, for instance, ascorbic acid derivatives, azaindenes, cadmium salts, and organic sulfonic acids as described in McFall et al. U.S. Pat. 2,933,390 and Jones et al. U.S. Pat. No. 2,937,089.

The various silver halide emulsion layers of a color film assembly of the invention can be disposed in the usual order, i.e., the blue-sensitive silver halide emulsion layer first with respect to the exposure side, followed by the green-sensitive and red-sensitive silver halide emulsion layers. If desired, a yellow dye layer or a Carey Lea silver layer can be present between the blue-sensitive and green-sensitive silver halide emulsion layers for absorbing or filtering blue radiation that may be transmitted through the blue-sensitive layer. If desired, the selectively sensitized silver halide emulsion layers can be disposed in a different order, e.g., the blue-sensitive layer first with respect to the exposure side, followed by the red-sensitive and green-sensitive layers.

The silver halide emulsions used in this invention can comprise, for example, silver chloride, silver bromide, silver chlorobromide, silver bromoiodide, silver chlorobromoiodide or mixtures thereof. The emulsions can be coarse or fine grain and can be prepared by any of the well-known procedures, e.g., single jet emulsions, double jet emulsions, such as Lippmann emulsions, ammoniacal emulsions, thiocyanate or thioether ripened emulsions such as those described in Nietz et al. U.S. Pat. No. 2,222,264; lllingsworth U.S. Pat. No. 3,320,069; and McBride U.S. Pat. No. 3,271,157. Emulsions that contain silver halide grains having substantial surface sensitivity can be used, and emulsions that contain silver halide grains having substantial sensitivity inside the grains can be used such as those described in Davey et al. U.S. Pat. No. 2,592,250; Porter et a1. U.S. Pat. No. 3,206,313; and Bacon et al. U.S. Pat. No. 3,447,927. The emulsions can be regular grain emulsions such as the type described in Klein and Moisar, J. Phot. Sci., Vol. 12, No. 5, Sept./Oct., 1964, pp. 242-251. Negative-type emulsions can be used or direct positive emulsions can be used such as those described in Leermakers U.S. Pat. No. 2,184,013; Kendall et al. U.S. Pat. No. 2,541,472; Berriman U.S. Pat. No. 3,367,778; Schouwenaars British Pat. No. 723,019; lllingsworth et al. French Pat. No. 1,520,821;

Ives U.S. Pat. No. 2,563,785; Knott et al. U.S. Pat. No 2,456,953 and Land U.S. Pat. No. 2,861,885.

The emulsions used in this invention can be sensitized with chemical sensitizers, such as with reducing agents; sulfur, selenium or tellurium compounds; gold, platinum or palladium compounds; or combinations of these. Suitable procedures are described in Sheppard et al. U.S. Pat. No. 1,623,499; Waller et al. U.S. Pat. No. 2,399,083; McVeigh U.S. Pat. No. 3,297,447; and Dunn U.S. Pat. No. 3,297,446.

The silver halide emulsions used in this invention may contain speed increasing compounds such as polyalkylene glycols, cationic surface active'agents and I thioethers or combinations of these as described in Piper U.S. Pat. No. 2,886,437; Dann et al. U.S. Pat. No. 3,046,134; Carroll et al. U.S. Pat. No. 2,944,900; and Goffe U.S. Pat. No. 3,294,540.

The silver halide emulsions used in the practice of this invention can be protected against the production of fog and can be stabilized against loss of sensitivity during keeping. Suitable antifoggants and stabilizers each used alone or in combination includev thiazolium salts described in Brooker et al. U.S. Pat. No. 2,131,038 and Allen et al. U.S. Pat. No. 2,694,716; the azaindenes described in Piper U.S. Pat. No. 2,886,437 and Heimbach et al U.S. Pat. No. 2,444,605; the mercury salts as described in Allen et a1 U.S. Pat. No. 2,728,663; the urazoles described in Anderson et al U.S. Pat. No. 3,287,135; the sulfo-catechols described in Kennard et al U.S. Pat. No. 3,236,652; the oximes described in Carroll et al. British Pat. No. 623,448; nitron; nitroindazoles; the mercaptotetrazoles described vin Kendall et al. U.S. Pat. No. 2,403,927; Kennard et al. U.S. Pat. No. 3,266,897 and Luckey et al. U.S. Pat. No. 3,397,987; the polyvalent metal salts described in Jones U.S. Pat. No. 2,839,405; the thiuronium salts described in Herz et al U.S. Pat. No. 3,220,839; and the palladium, platinum and gold salts described in Trivelli et al. U.S. Pat. No. 2,566,263 and Yutzy et al. U.S. Pat. No. 2,597,915.

The nondiffusible couplers employed in this invention include those having the formulas:

DYE LINK (COUP BALL and BALL LINK (COUP SOL),

wherein 1. DYE is a dye radical exhibiting selective absorption in the visible spectrum and containing an acidic solubilizing radical;

2. LINK is a connecting radical such as an azo radical, a mercuri radical, an oxy radical, an alkylidene radical, a thio radical, a dithio radical or an azoxy radical;

3. COUP is a coupler radical such as a 5-pyrazolone coupler radical, a pyrazolotriazole coupler radical, a phenolic coupler radical or an open-chain ketomethylene coupler radical, COUP being substituted in the coupling position with LINK;

4. BALL is a photographically inert organic ballasting radical of such molecular size and configuration as to render such coupler nondiffusible during development in the alkaline processing composition;

5. SOL is a hydrogen atom or an acidic solubilizing group when the color developing agent contains an acidic solubilizing group, and SOL is an acidic solubilizing group when the color developing agent is free of an acidic solubilizing group; and

6. n is an integer of 1 to 2 when LINK is an alkylidene radical, and n is 1 when LINK is an azo radical, a mercuri radical, an oxy radical, a thio radical, a dithio radical or an azoxy radical.

The acidic solubilizing radicals attached to the diffusible dye producing couplers described above can be solubilizing radicals which when attached to the cou' pler or developer moieties of the dyes, render the dyes diffusible in alkaline processing compositions. Typical of such radicals are carboxylic, sulfonic, ionizable sulfonamide, and hydroxy-substituted groups that lend to dyes negative charges.

The nature of the ballast groups in the diffusible dyeproducing coupler compounds described above (BALL is not critical as long as they confer nondiffusibility to the coupler compounds. Typical ballast groups include long chain alkyl radicals linked directly or indirectly to the coupler molecules as well as aromatic radicals of the benzene and naphthalene series, etc., linked directly or indirectly to the coupler molecules by a splittable linkage, or by a removable or irremovable but otherwise nonfunctional linkage depending upon the nature of the coupler compound. Useful ballast groups have at least 8 carbon atoms.

Typical dye radical substitutents (DYE include azo, azomethine, indoaniline, indophenol, anthraquinone and related dye radicals well known in the art that exhibit selective absorption in the visible spectrum. The dye radicals contain acidic solubilizing moieties.

With regard to the above-described coupler radicals (COUP the coupling position is well known to those skilled in the photographic art. The 5-pyrazolone coupler radicals couple at the carbon atom in the 4- position, the phenolic coupler radicals, including a-naphthols, couple at the carbon atom in the 4- position and the openchain ketomethylene coupler radicals couple to the carbon atom forming the methylene moiety (e.g.,

l l CCH C *denoting the coupling position). Pyrazolotriazole couplers and their coupling position are described, for example, in U.S. Pat. No. 3,061,432 and U.S. application Ser. No. 778,329 of Bailey et al, filed Nov. 22, 1968.

Particularly good results are obtained when the cyanproducing coupler has the formula BALL-O-CYAN- COUP, the magenta-producing coupler has the formula BALL-N=NMAGCOUP and the yellow-producing coupler has the formula BALL-O-YELLCOUP wherein:

a. BALL is a photographically inert organic ballasting radical having at least eight carbon atoms and of such molecular size and configuration as to render the coupler nondiffusible during development in an alkaline processing composition;

b. CYANCOUP is a phenolic coupler radical substituted in the 2-position with a fully substituted amido group and attached to the O- moiety of the cyanproducing coupler in the coupling position;

c. MAGCOUP is a 5-pyrazolone coupler radical joined to the N=N moiety of the magentaproducing coupler in the coupling position; and

d. YELLCOUP is an open-chain ketomethylene coupler radical attached to the -O moiety of the yellowproducing coupler in the coupling position;

The term nondiffusing used herein as applied to the 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 organic colloid layers, such as gelatin, comprising the sensitive elements of the invention. The same meaning is to be attached to the term immobile.

The term diffusible" as applied to the dyes formed from the nondiffusing couplers in this invention has the converse meaning and denotes materials having the property of diffusing effectively through the colloid layers of the sensitive elements in the presence of the nondiffusing materials from which they are derived. Mobile has the same meaning.

When the couplers having the formula DYE LINK (COUP BALL) as described above are reacted with oxidized color developing agent, the connecting radical (LINK) is split and a difi'usible preformed dye (DYE) is released which diffuses imagewise to a reception layer. An acidic solubilizing group on the preformed dye lends diffusibility to the dye molecule. The coupling portion of the coupler (COUP) couples with the color developing agent oxidation product to form a dye that is non-diffusible because of the attached ballasting group (BALL) in a noncoupling position. In this type of coupler, the color of the diffusible dye is determined by the color of the preformed dye moiety (DYE), the color of the reaction product of color developer oxidation product and the coupler moiety (COUP) being unimportant to the color of the diffusible image.

When couplers having the formula BALL LINK (COUP SOL), as described above are reacted with oxidized color developing agent, the connecting radical (LINK) is split and a diffusible dye is formed with the color developing agent oxidation product and the coupling portion (COUP) of the coupler which diffuses imagewise to a reception layer. Diffusibility is imparted to the dye by an acidic solubilizing group attached to a noncoupling position of the coupling portion (COUP) of the coupler or to the color developing agent. The ballasting portion of the coupler remains immobile. In this type of coupler, the color of the diffusible dye is determined by the color of the reaction product of color developer oxidation product and the coupler moiety (COUP).

In using both types of couplers in the invention, the production of diffusible dye images is a function of the reduction of developable silver halide images which may involve direct or reversal development of the silver halide emulsions with an aromatic primary amino developing agent. If the silver halide emulsion employed is a direct positive silver halide emulsion, such as an internal image emulsion or a solarizing emulsion, which is developable in unexposed areas, a positive image can be obtained in the receiver portion of the film unit. In this embodiment, the nondiffusible coupler can be located in the silver halide emulsion itself. After exposure of the film unit, the alkaline processing composition permeates the various layers to initiate development of the exposed photosensitive silver halide emulsion layers. The aromatic primary amino color developing agent present in the film unit develops each of the silver halide emulsion layers in the unexposed areas (since the silver halide emulsions are direct positive ones), thus causing the developing agent to become oxidized imagewise corresponding to the unexposed areas of the direct positive silver halide emulsion layers. The oxidized developing agent then reacts with the nondiffusible coupler present in each silver halide emulsion layer to form imagewise distributions, respectively, of diffusible cyan, magenta and yellow dye as a function of the imagewise exposure of each of the silver halide emulsion layers. At least a portion of the imagewise distributions of diffusible cyan, magenta and yellow dye diffuse to the image-receiving layer to provide a positive dye image upon separation of the receiver from the negative. Specific examples of such nondiffusing couplers and other details concerning this type of photographic chemistry are found in U.S. Pat. Nos. 3,227,550 and 3,227,552.

Internal image silver halide emulsions useful in the above-described embodiment are direct positive emulsions that form latent images predominantly inside the silver halide grains, as distinguished from silver halide grains that form latent images predominantly on the surface thereof. Such internal image emulsions were described by Davey et al. in U.S. Pat. No. 2,592,250 issued Apr. 8, 1952, and elsewhere in the literature. Internal image silver halide emulsions can be defined in terms of the increased maximum density obtained when developed with internal-type developers over that obtained when developed with surface-type developers. Suitable internal image emulsions are those which, when measured according to normal photographic techniques by coating a test portion of the silver halide emulsion on a transparent support, exposing to a light intensity scale having a fixed time between 0.01 and 1 second, and developing for 3 minutes at 20C in Developer A below (intemal-type developer), have a maximum density at least five times the maximum density obtained when an equally exposed silver halide emulsion is developed for 4 minutes at 20C in Developer B described below (surface-type developer).

DEVELOPER A Hydroquinone l5 g. MonomethyI-p-aminophenol sulfate l5 g. Sodium sulfite (desiccated) g. Potassium bromide l0 g. Sodium hydroxide 25 g. Sodium thiosulfate 20 g. Water to make I liter.

DEVELOPER B P-hydroxyphenylglycine l0 g. Sodium carbonate I00 g.

Water to make 1 liter The solarizing direct positive silver halide emulsions useful in the above-described embodiment are well known silver halide emulsions which have been effectively fogged either chemically or by radiation to a point which corresponds approximately to the maximum density of the reversal curve as shown by Mees, The Theory of the Photographic Process, published by .the Macmillan Co., New York, N.Y., 1942, pages 26 l297. Typical methods for the preparation of solarizing emulsions are shown by Groves British Pat. No. 443,245, Feb. 25, 1936, who subjected emulsions to Roentgen rays until an emulsion layer formed therefrom, when developed without preliminary exposure, is

blackened up to the apex of its graduation curve; Szaz British Pat. No. 462,730, Mar. 15, 1937, the use of either light or chemicals such as silver nitrate, organic sulfur compounds and dyes to convert ordinary silver halide emulsions to solarizing direct positive emulsions; and Arens U.S. Pat. No. 2,005,837, June 25, 1935, the use of silver nitrate and other compounds in conjunction with heat to effect solarization. Kendall and Hill U.S. Pat. No. 2,541,472, Feb. 13, 1951, shows useful solarized emulsions particularly susceptible to exposure with long wavelength light and initial development to produce the Herschel effect described by Mees above, produced by adding benzothiazoles and other compounds to the emulsions which are fogged either chemically or with white light. In using the emulsions a sufficient reversal image exposure is employed using minus blue light of from about 500-700m wavelength preferably 520554m,u., to substantially destroy the latent image in the silver halide grains in the region of the image exposure. Particularly useful are the fogged direct positive emulsions of Berriman U.S. Pat. No. 3,367,778 and French Pat. No. 1,520,821.

Internal image silver halide emulsions which contain or which are processed in the presence of fogging or nucleating agents are particularly useful in the abovedescribed embodiment employing nondiffusible couplers since the use of fogging agents is a convenient way to inject electrons into the silver halide grains. Suitable fogging agents include the hydrazines disclosed in Ives U.S. Pat. No. 2,588,982 issued Mar. 11, 1952 and U.S. Pat. No. 2,563,785 issued Aug. 7, 1951; the hydrazides and hydrazones disclosed in Whitmore U.S. Pat. No. 3,227,552 issued Jan. 4, 1966; hydrazone quaternary salts described in Lincoln and Heseltine application Ser. No. 828,064 filed Apr. 28, 1969; or mixtures thereof. The quantity of fogging agent employed can be widely varied depending upon the results desired. Generally, the concentration of fogging agent is from about 1 to about mg. per square foot of photosensitive layer in the photosensitive element or from about 0.1 to about 2 grams per liter of developer if it is located in the developer.

Other embodiments of our invention employ the photosensitive elements described in the above-mentioned U.S. Pat. Nos. 3,227,550; 3,227,551 and 3,227,552 and in British Pat. No. 904,364, page 19, lines 141. These embodiments all employ the nondiffusible couplers described above.

The immobilizing cou'pler employed in our invention can be any coupler with a ballast group, as defined above, which is capable of reacting with oxidized color developing agent to form an immobile product. Such compounds are well known to those skilled in the art.

In the above-described embodiments employing nondiffusible couplers, interlayers are generally employed between the various photosensitive color-forming units to scavenge oxidized developing agent and prevent it from forming an unwanted dye in another colorforming unit. Such interlayers would generally comprise a hydrophilic polymer such as gelatin and an immobilizing coupler, as described above, which is capable of reacting with oxidized aromatic primary amino color developing agent to form an immobile product.

As previously mentioned, the aromatic primary amino color developing agent employed in the abovedescribed embodiments is is preferably present in the alkaline processing composition in the rupturable pod.

The color developing agent can also be incorporated into the negative portion of the film unit as a separate layer, e.g., by employing a Schiff base derivative of an aromatic primary amino color developing agent such as that formed by reacting o-sulfobenzaldehyde and N,N- diethy1-3-methyl-4-amino-aniline. Such incorporated developing agent will be activated by the alkaline processing composition. While the incorporated developing agent can be positioned in any layer of the photosensitive element from which it can be readily made available for development upon activation with alkaline processing composition, it is generally either incorporated in the light-sensitive silver halide emulsion layers or in layers contiguous thereto. As mentioned above, aromatic primary amino color developing agents employed in this invention are preferably pphenylenediamine developing agents. These developing agents are well known to those skilled in the art and include 4-amino-N,N-diethyl-3-methyl aniline hydrochloride, N,N-diethyl-p-phenylenediamine, 2-amino-5- diethylamino toluene, N-ethyl-B-methanesulfonamido-ethyl-3-methyl-4-aminoaniline, 4-amino- N-ethyl-3-methyl-N-(B-sulfoethyl)aniline, 4-amino-N- ethyl-3-methoxy-N-(B-sulfoethyl)aniline, 4-amino-N- ethyl-N-(B-hydroxyethyl)aniline, 4-amino-N,N- diethyl-3-hydroxy-methyl aniline, 4-amino-N-methyl- N-(B-carboxyethyl)aniline, 4-amino-N,N-bis(B- hydroxyethyl)aniline, 4-amino-N,N bis(B-hydroxyethyl)-3-methyl aniline, 3-acetamido-4-amino-N,N,- bis(B-hydroxy-ethyl)aniline, 4-amino-N-ethyl-N- (2,3,dihydroxypropyl)-3-methy1 aniline sulfate salt, 4- amino-N,N-diethyl-3-(3-hydroxypropoxy)-aniline, and the like.

The rupturable container employed in this invention can be of the type disclosed in U.S. Pat. Nos. 2,543,181; 2,634,886; 2,653,732; 2,723,051; 3,056,492; 3,056,491 and 3,152,515. In general, such containers comprise a rectangular sheet of fluid and air-impervious material folded longitudinally upon itself to form two walls which are sealed to one another along their longitudinal and end margins to form a cavity in which the processing composition is contained.

In a color film unit according to the invention, each silver halide emulsion layer containing a dye imageproviding material or having the dye image-providing material present in a contiguous layer may be separated from the other silver halide emulsion layers in the negative portion of the film unit by materials in addition to those described above, including gelatin, calcium alginate, or any of those disclosed in U.S. Pat. No. 3,384,483, polymeric materials such as polyvinylamides as disclosed in U.S. Pat. No. 3,421,892, or any of those disclosed in U.S. Pat. Nos. 2,992,104; 3,043,692; 3,044,873; 3,061,428; 3,069,263; 3,069,264; 3,121,011; and 3,427,158.

Generally speaking, except where noted otherwise, the silver halide emulsion layers in the invention comprise photosensitive silver halide dispersed in gelatin and are about 0.6 to 6 microns in thickness; the dye image-providing materials are dispersed in an aqueous alkaline solution-permeable polymeric binder, such as gelatin, as a separate layer about 1 to 7 microns in thickness; and the alkaline solution-permeable polymeric interlayers, e.g., gelatin, are about 1 to 5 microns in thickness. Of course, these thicknesses are approximate only and can be modified according to the product desired. In addition to gelatin, other suitable hydrophilic materials include both naturally occurring substances such as proteins, cellulose derivatives, polysaccharides such as dextran, gum arabic and the like; and synthetic polymeric substances such as water soluble polyvinyl compounds like poly(vinylpyrrolidone), acrylamide polymers and the like.

The photographic emulsion layers and other layers of a photographic element employed in the practice of this invention can also contain alone or in combination with hydrophilic, water-permeable colloids, other synthetic polymeric compounds such as dispersed vinyl compounds such as in latex form and particularly those which increase the dimensional stability of the photographic materials. Suitable synthetic polymers include those described, for example, in Nottorf U.S. Pat. No. 3,142,568, issued July 28, 1964; White U.S. Pat. No. 3,193,386, issued July 6, 1965; Houck et al. U.S. Pat. No. 3,062,674, issued Nov. 6, 1962; Houck et al. U.S. Pat. No. 3,220,844, issued Nov. 30, 1965; Ream et al. U.S. Pat. No. 3,287,289, issued Nov. 22, 1966; and Dykstra U.S. Pat. No. 3,41 1,91 1, issued Nov. 19, 1968. Particularly effective are water-insoluble polymers of alkyl acrylates and methacrylates, acrylic acid, sulfoalkyl acrylates or methacrylates, those which have crosslinking sites which facilitate hardening or curing, and those having recurring sulfobetaine units as described in Dykstra Canadian Pat. No. 774,054.

Any material can be employed as the image-receiving layer in this invention as long as the desired function of mordanting or otherwise fixing the dye images will be obtained. The particular material chosen will, of course, depend upon the dye image to be mordanted. If acid dyes are to be mordanted, the image-receiving layer can contain mordants such as polymers of amino guanidine derivatives of vinyl methyl ketone such as described in the Minsk U.S. Pat. No. 2,882,156 granted Apr. 14, 1959. Other mordants useful in our invention include the 2-vinyl pyridine polymer metho-p-toluene sulfonate and similar compounds described in Sprague et al. U.S. Pat. No. 2,484,430 granted Oct. 11, 1949, and cetyl trimethylammonium bromide, etc. Effective mordanting compositions are also described in Whitmore U.S. Pat. No. 3,271,148 and Bush U.S. Pat. No. 3,271,147. Furthermore, the image-receiving layer can be sufficient by itself to mordant the dye as in the case of use of an alkaline solution-permeable polymeric layer such as N-methoxy-methyl polyhexylmethylene adipamide; partially hydrolyzed poly-vinyl acetate; polyvinyl alcohol with or without plasticizers; cellulose acetate; gelatin; and other materials ofa similar nature. Generally, good results are obtained when the imagereceiving layer, preferably alkaline solution-permeable, is transparent and about 0.25 to about 0,04 mil in thickness. This thickness, of course, can be modified depending upon the result desired. The imagereceiving layer can also contain ultraviolet absorbing materials to protect the mordanted dye images from fading due to ultraviolet light and/or brightening agents such as the silbenes, coumarins, triazines, oxazoles, etc.

The alkaline processing composition employed in this invention is the conventional aqueous solution of an alkaline material, e.g., sodium hydroxide, sodium carbonate or an amine such as diethylamine, preferably possessing a pH in excess of 12. The solution also preferably contains a viscosity-increasing compound such as a high molecular weight polymer, e.g., a watersoluble ether inert to alkaline solutions such as hydroxyethyl cellulose or alkali metal salts of carboxymethyl cellulose such as sodium carboxymethyl cellulose. A concentration of viscosity-increasing compound of about 1 to about 5 percent by weight of the processing solution is preferred which will impart thereto a viscosity of about cps. to about 200,000 cps.

While the alkaline processing composition used in this invention can be employed in a rupturable container, as described previously, other methods of applying processing composition could also be employed, e.g., bathing the photosensitive element in a processing bath.

While the film units of our invention can be modified so as to be employed in roll form, they are preferably used in cartridges similar to those described in U.S. Pat. Nos. 3,079,849; 3,080,805; 3,161,] 18; and 3,161,122; said patents also illustrating typical cameras for performing color diffusion transfer processes of our invention.

The light-reflective layer in the photographic film unit of our invention can generally comprise any opacifier dispersed in a binder as long as it has the desired properties. Particularly desirable are white lightreflective layers since they would be esthetically pleasing backgrounds on which to view a transferred dye image and would also possess the optical properties desired for reflection of incident radiation. Suitable opacifying agents include titanium dioxide, barium sulfate, zinc oxide, barium stearate, silver flake, silicates, alumina, zirconium oxide, zirconium acetyl acetate, sodium zirconium sulfate, kaolin, mica, or mixtures thereof in widely varying amounts depending upon the degree of opacity desired. The opacifying agents may be dispersed in any binder such as an alkaline solutionpermeable polymeric matrix such as, for example, gelatin, polyvinyl alcohol, and the like. Brightening agents such as the stilbenes, coumarins,-triazines, and oxazoles can also be added to the light-reflective layer, if desired. When it is desired to increase the opacifying capacity of the light-reflective layer, dark-colored opacifying agents may be added to it. e.g., carbon black, nigrosine dyes, etc. The light-reflective layer may also be combined with the developer scavenger layer if desired.

The supports for the photographic elements of this invention can be any material as long as it does not deleteriously effect the photographic properties of the film unit and is dimensionally stable. Typical materials include cellulose nitrate film, cellulose acetate film, poly(vinyl acetal) film, polystyrene film, poly(ethyleneterephthalate) film, polycarbonate film, poly-aolefins such as polyethylene and polypropylene film, and related films or resinous materials as well as glass.

While the invention has been described with reference to layers of silver halide emulsions and dye imageproviding materials, dotwise coating, such as would be obtained using a gravure printing technique, could also be employed. In this technique, small dots of blue, green and red-sensitive emulsions have associated therewith, respectively, dots of yellow, magenta and cyan color-providing substances. After development, the transferred dyes would tend to fuse together into a continuous tone.

The photographic layers employed in the practice of this invention can contain surfactants such as saponin, anionic compounds such as the alkyl aryl sulfonates described in Baldsiefen U.S. Pat. No. 2,600,831; amphoteric compounds such as those described in Ben-Ezra U.S. Pat. No. 3,133,816; and water soluble adducts of glycidol and an alkyl phenol such as those described in Olin Mathieson British Pat. No. 1,022,878.

The various layers, including the photographic layers, employed in the practice of this invention can contain light absorbing materials and filter dyes such as those described in Sawdey U.S. Pat. No. 3,253,921; Gaspar U.S. Pat. No. 2,274,782; Silverstein et al. U.S. Pat. No. 2,527,583 and VanCampen U.S. Pat. No. 2,956,879. If desired, the dyes can be mordanted, for example, as described in Milton et al. U.S. Pat. No. 3,282,699.

The sensitizing dyes and other addenda used in the practice of this invention can be added from water solutions or suitable organic solvent solutions can be used. The compounds can be added using various procedures including those described in Collins et al. U.S. Pat. No. 2,912,343; McCrossen et al. US. Pat. No. 3,342,605; Audran U.S. Pat. No. 2,996,287 and Johnson et al. U.S. Pat. No. 3,425,835.

The photographic layers used in the practice of this invention can be coated by various coating procedures including dip coating, air knife coating, curtain coating, or extrusion coating using hoppers of the type described in Beguin U.S. Pat. No. 2,681,294. If desired, two or more layers can be coated simultaneously by the procedures described in Russell U.S. Pat. No. 2,761,791 and Wynn British Pat. No. 837,095. This invention also can be used for silver halide layers coated by vacuum evaporation as described in British Pat. No. 968,453 and LuValle et al. U.S. Pat. No. 3,219,451.

The photographic and other hardenable layers used in the practice of this invention can be hardened by various organic or inorganic hardeners, alone or in combination, such as the aldehydes, and blocked aldehydes, ketones, carboxylic and carbonic acid derivatives, sulfonated esters, sulfonyl halides and vinyl sulfonyl ethers, active halogen compounds, epoxy compounds, aziridines, active olefins, isocyanates, carbodiimides, mixed function hardeners and polymeric hardeners such as oxidized polysaccharides like dialdehyde starch and oxyguargum and the like.

The following examples illustrate the invention:

EXAMPLE 1 A multilayer photosensitive element is prepared by coating the following layers in the order recited on a transparent cellulose acetate film support:

1. Red-sensitive gelatin-silver chlorobromide emulsion (120mg gelatin/ft and 100mg silverlft cyan image transfer coupler l-hydroxy-4- 4-[a-(3-pentadecylphenoxy)butyramido]-phenoxy :N-ethyl-3 ,5 dicarboxy-2-naphthanilide (75mg/ft and fogging agent formyl-4-methylphenylhydrazide 4. A scavenger and yellow filter layer comprising 1- hydroxy-N-[a-(2,4-di-tert-amylphenoxy)butyl]-2- naphthamide (45mg/ft tri-cresyl phosphate (22mg/ft yellow Carey Lea Silver (IOmg/ft and gelatin (65mg/ft 5. Blue-sensitive gelatin-silver chlorobromide emulsion (mg gelatin/ft and 100mg silverlft yellow image transfer coupler a-pivalyl-a-(3-noctadecylcarbamylphenylthio-4-sulfo-acetanilide, potassium salt (l20mg/ft and fogging agent formyl-4- methylphenylhydrazide (0.5g/mole of silver chlorobromide) 6. Overcoat of gelatin (50mg/ft A multilayer dye image-receiving element is prepared by coating the following layers in the order recited on a transparent cellulose acetate film support:

1. A developer scavenging layer comprising gelatin, fine-grained, silver bromide emulsion (l000mg gelatin/ft and 400mg silver/ft and nondiffusible coupler 1-hydroxy-N-[a-(2,4-di-tert-amylphenoxy)butyl]- Z-naphthamide (300mg/ft 2. Light-reflecting layer comprising (2O00mg/ft and gelatin (500mg/ft 3. Image-receiving layer of dodecylammoniump-toluenesulfonate N-n-hexadecyl-N-morpholinium (mg/ft and gelatin (535mg/ft The photosensitive element is exposed to a graduated-density multicolor test object. The following processing composition is employed in a pod and is spread between the exposed surface of the element and the superposed image-receiving element by passing the transfer sandwich between a pair of juxtaposed pressure rollers:

TiO

methyl-tri-n- (22mg/ft ethosulfate Benzyl alcohol 1.0 ml 4-Amino-N-ethyl-N-fl- 3.0 g Hydroxyethylaniline sulfate S-Nitrobenzimidazole 0.06 g Sodium hydroxide 2.5 g Hydroxyethylcellulose 2.0 g Water 100 ml After 1 minute in the dark at about 20C, the film unit is separated and the silver halide emulsion layer in the image-receiving element is flash-exposed through the support with a high intensity light source. There was no apparent stain in the multicolor image after a 4-week keeping period.

EXAMPLE 2- The procedure of Example 1 is repeated with the exception of employing the following developer scavenging layer for Layer 1 of the image-receiving element in Example 1: gelatin, fine-grained, silver bromide emulsion (500mg gelatin/ft and 200mg silver/ft) and nondiffusible couple'r l-hydroxy-N-[a-(2,4-di-tert amylphenoxy)butyl]-2-naphthamide (l50mg/ft Similar results are obtained.

EXAMPLE 3 A multilayer dye image-receiving element is prepared by coating the following layers in the order recited on an opaque cellulose acetate film support:

1. A developer scavenging layer comprising a chemically prefogged gelatin fine-grained, silver bromide emulsion (427mg gelatin and 400 mg silver/ft and nondiffusible coupler l-hydroxy-N-[a-(2,4-di-tertamylphenoxy)butyl]-2-naphthamide (300mg/ft 2. Light-reflecting layer comprising (3O00mg/ft and gelatin (3OOmg/ft 3. Dye image-receiving layer of N-n-hexadecyl-N- morpholinium ethosulfate (l33mg/ft methyl-tri-ndodecylammonium p-toluenesulfonate (45mg/ft and gelatin (744mg/ft 4. Overcoat of gelatin (40mg/ft A photosensitive element is prepared as in Example I. The element is exposed and then processed with the above image-receiving element as described in Example 1. After '1 minute at about C, the imagereceiving element is separated from the photographic element. The multicolor positive image showed minimum developer strain after a 4-week keeping period.

The invention has been described with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.

We claim:

1. In a photographic film unit which is adapted to be processed by passing said unit between a pair of juxtaposed pressure-applying members 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 nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible dye;

b. a dye image-receiving layer coated on a support and adapted to be superposed on said photosensitive element after exposure thereof; and

c. a rupturable container containing an alkaline processing composition and which is adapted to be positioned between said photosensitive element and said dye image-receiving layer during processing of said film unit so that a compressive force applied to said container by said pressure-applying members will effect a discharge of the containers contents between the outermost layer of said photosensitive element and said dye image-receiving layer;

said film unit containing an aromatic primary amino color developing agent; the improvement comprising employing between said dye image-receiving layer and its said support a developing agent scavenger layer comprising a silver halide emulsion and an immobilizing coupler which is capable of reacting with oxidized aromatic primary amino color developing agent to form an immobile product, and employing a lightreflective layer between said dye image-receiving layer and said scavenger layer.

2. The photographic film unit of claim 1 wherein said photosensitive element comprises a support having thereon a red-sensitive silver halide emulsion layer having associated therewith a cyan dye image-providing material comprising a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible cyan dye, a green-sensitive silver halide emulsion layer having associated therewith a magenta dye image-providing material comprising a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible magenta dye, and a blue-sensitive silver halide emulsion layer having associated therewith a yellow dye image-providing material comprising a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible yellow dye.

3. The photographic film unit of claim 1 wherein said silver halide emulsion in said scavenger layer is panchromatically sensitized.

4. The photographic film unit of claim 3 wherein said light-reflective layer is titanium dioxide.

5. The photographic film unit of claim 4 wherein said developer scavenger layer is developable only after substantial development of said photosensitive element.

6. The photographic film unit of claim 1 wherein said silver halide emulsion in said scavenger layer is fogged.

7. The photographic film unit of claim 6 wherein said light-reflective layer is titanium dioxide.

8. The photographic film unit of claim 7 wherein said developer scavenger layer is developable only after substantial development of said photosensitive element.

9. The photographic film unit of claim 1 wherein said silver halide emulsion in said scavenger layer is spontaneously developable.

10. The photographic film unit of claim 9 wherein said light-reflective layer is titanium dioxide.

11. The photographic film unit of claim 10 wherein said developer scavenger layer is developable only after substantial development of said photosensitive element.

12. In a photographic film unit which is adapted to be processed by passing said unit between a pair of juxtaposed pressure-applying members comprising:

1) a photosensitive element comprising a support having thereon the following layers in a sequence:

a. a direct-positive, red sensitive silver halide emulsion layer containing a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible cyan dye;

an alkaline solution-permeable interlayer containing a compound capable of scavenging oxidized aromatic primary amino color developing agent;

0. a direct-positive, green-sensitive silver halide emulsion layer containing a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible magenta dye;

d. an alkaline solution-permeable interlayer containing a compound capable of scavenging oxidized aromatic primary amino color developing agent; and

e. a direct-positive, blue-sensitive silver halide emulsion layer containing a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible yellow ,dye;

each said nondiffusible coupler having the fonnula:

DYE LINK (COUP BALL),

BALL LINK (COUP SOL),

wherein:

l. DYE is a dye radical exhibiting selective absorption in the visible spectrum and containing an acidic solubilizing group;

2. LINK is a connecting radical selected from the group consisting of an azo radical, a mercuri radical, an oxy radical, an alkylidene radical, a thio radical, a dithio radical and an azoxy radical;

3. COUP is a coupler radical selected from the group consisting of a -pyrazolone coupler radical, a pyrazolotriazole coupler radical, a phenolic coupler radical and an open-chain ketomethylene coupler radical, said COUP being substituted in the coupling position with said LINK;

4. BALL is a photographically inert organic ballasting radical of such molecular size and configuration as to render said coupler nondiffusible during development in said alkaline processing composition;

5. SOL is selected from the group consisting of a hydrogen atom and an acidic solubilizing group when said color developing agent contains an acidic solubilizing group, and SOL is an acidic solubilizing group when said color developing agent is free of an acidic solubilizing group; and

6. n is an integer of l to 2 when said LINK is an alkylidene radical, and n is I when said LINK is a radical selected from the group consisting of an azo radical, a mercuri radical, an oxy radical, a thio radical, a dithio radical and an azoxy radical;

II. a dye image-receiving layer coated on a support and adapted to be superposed over said bluesensitive silver halide emulsion layer after exposure of said photosensitive element; and

III. a rupturable container containing an alkaline processing composition and which is adapted to be positioned during processing of said film unit so that a compressive force applied to said container by said pressure-applying members will effect a discharge of the containers contents between said dye image-receiving layer and said blue-sensitive silver halide emulsion layer of said photosensitive element; said film unit containing an aromatic primary amino color developing agent; the improvement comprising employing between said dye image-receiving layer and its said support a developing agent scavenger layer comprising a silver halide emulsion and an immobilizing coupler which is capable of reacting with oxidized aromatic primary amino color developing agent to form an immobile product, and employing a light-reflective layer between said dye image-receiving layer and said scavenger layer.

13. The photographic film unit of claim 12 wherein said silver halide emulsion in said scavenger layer is fogged.

14. The photographic film unit of claim 13 wherein said light-reflective layer is titanium dioxide.

15. The photographic film unit of claim 14 wherein said developer scavenger layer is developable only after substantial development of said photosensitive element.

16. The photographic film unit of claim 15 wherein each said direct-positive silver halide emulsion is an internal-image emulsion wherein the silver halide forms latent images predominantly inside the silver halide grains.

17. The photographic film unit of claim 12 wherein said silver halide emulsion in said scavenger layer is spontaneously developable.

18. The photographic film unit of claim 17 wherein said light-reflective layer is titanium dioxide.

19. The photographic film unit of claim 18 wherein said developer scavenger layer is developable only after substantial development of said photosensitive element.

20. In a process of forming a transfer image comprising:

a. imagewise exposing 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 nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible dye;

b. treating the layer outermost from the support of said photosensitive element with an alkaline pro cessing composition to effect development of each of said exposed silver halide emulsion layers with an aromatic primary amino color developing agent;

c. forming an imagewise distribution of diffusible dye image-providing material as a function of said imagewise exposure of each said silver halide emulsion layer; and

d. at least a portion of each said imagewise distribution of diffusible dye image-providing material diffusing to a dye image-receiving layer coated on a support;

the improvement comprising employing between said dye image-receiving layer and its said support a developing agent scavenger layer comprising a silver halide emulsion and an immobilizing coupler which is capable of reacting with oxidized aromatic primary amino color developing agent to form an immobile product, and employing a lightreflective layer between said dye image-receiving layer and said scavenger layer.

21. The process of claim 20 wherein said treatment step b is effected by:

a. superposing over the layer outermost from the support of said exposed photosensitive element said dye image-receiving layer coated on a support;

b. positioning a rupturable container containing said alkaline processing composition between said exposed photosensitive element and said dye imagereceiving layer; and

c. applying a compressive force to said container to effect a discharge of the containers contents between said outermost layer of said exposed photosensitive element and said dye image-receiving layer.

22. The process of claim 21 wherein said scavenger layer is operative only after substantial development of said photosensitive element.

Claims

2. The photographic film unit of claim 1 wherein said photosensitive element comprises a support having thereon a red-sensitive silver halide emulsion layer having associated therewith a cyan dye image-providing material comprising a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible cyan dye, a green-sensitive silver halide emulsion layer having associated therewith a magenta dye image-providing material comprising a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible magenta dye, and a blue-sensitive silver halide emulsion layer having associated therewith a yellow dye image-providing material comprising a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible yellow dye.
2. LINK is a connecting radical selected from the group consisting of an azo radical, a mercuri radical, an oxy radical, an alkylidene radical, a thio radical, a dithio radical and an azoxy radical;
3. COUP is a coupler radical selected from the group consisting of a 5-pyrazolone coupler radical, a pyrazolotriazole coupler radical, a phenolic coupler radical and an open-chain ketomethylene coupler radical, said COUP being substituted in the coupling position with said LINK;
3. The photographic film unit of claim 1 wherein said silver halide emulsion in said scavenger layer is panchromatically sensitized.
4. The photographic film unit of claim 3 wherein said light-reflective layer is titanium dioxide.
4. BALL is a photographically inert organic ballasting radical of such molecular size and configuration as to render said coupler non-diffusible during development in said alkaline processing composition;
5. The photographic film unit of claim 4 wherein said developer scavenger layer is developable only after substantial development of said photosensitive element.
5. SOL is selected from the group consisting of a hydrogen atom and an acidic solubilizing group when said color developing agent contains an acidic solubilizing group, and SOL is an acidic solubilizing group when said color developing agent is free of an acidic solubilizing group; and
6. n is an integer of 1 to 2 when said LINK is an alkylidene radical, and n is 1 when said LINK is a radical selected from the group consisting of an azo radical, a mercuri radical, an oxy radical, a thio radical, a dithio radical and an azoxy radical; II. a dye image-receiving layer coated on a support and adapted to be superposed over said blue-sensitive silver halide emulsion layer after exposure of said photosensitive element; and III. a rupturable container containing an alkaline processing composition and which is adapted to be positioned during processing of said film unit so that a compressive force applied to said container by said pressure-applying members will effect a discharge of the container''s contents between said dye image-receiving layer and said blue-sensitive silver halide emulsion layer of said photosensitive element; said film unit containing an aromatic primary amino color developing agent; the improvement comprising employing between said dye image-receiving layer and its said support a developing agent scavenger layer comprising a silver halide emulsion and an immobilizing coupler which is capable of reacting with oxidized aromatic primary amino color developing agent to form an immobile product, and employing a light-reflective layer between said dye image-receiving layer and said scavenger layer.
6. The photographic film unit of claim 1 wherein said silver halide emulsion in said scavenger layer is fogged.
7. The photographic film unit of claim 6 wherein said light-reflective layer is titanium dioxide.
8. The photographic film unit of claim 7 wherein said developer scavenger layer is developable only after substantial development of said photosensitive element.
9. The photographic film unit of claim 1 wherein said silver halide emulsion in said scavenger layer is spontaneously developable.
10. The photographic film unit of claim 9 wherein said light-reflective layer is titanium dioxide.
11. The photographic film unit of claim 10 wherein said developer scavenger layer is developable only after substantial development of said photosensitive element.
12. In a photographic film unit which is adapted to be processed by passing said unit between a pair of juxtaposed pressure-applying members comprising: I) a photosensitive element comprising a support having thereon the following layers in a sequence: a. a direct-positive, red-sensitive silver halide emulsion layer containing a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible cyan dye; B. an alkaline solution-permeable interlayer containing a compound capable of scavenging oxidized aromatic primary amino color developing agent; c. a direct-positive, green-sensitive silver halide emulsion layer containing a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible magenta dye; d. an alkaline solution-permeable interlayer containing a compound capable of scavenging oxidized aromatic primary amino color developing agent; and e. a direct-positive, blue-sensitive silver halide emulsion layer containing a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible yellow dye; each said nondiffusible coupler having the formula: DYE - LINK -(COUP - BALL)n or BALL - LINK - (COUP - SOL)n wherein:
13. The photographic film unit of claim 12 wherein said silver halide emulsion in said scavenger layer is fogged.
14. The photographic film unit of claim 13 wherein said light-reflective layer is titanium dioxide.
15. The photographic film unit of claim 14 wherein said developer scavenger layer is developable only after substantial development of said photosensitive element.
16. The photographic film unit of claim 15 wherein each said direct-positive silver halide emulsion is an internal-image emulsion wherein the silver halide forms latent images predominAntly inside the silver halide grains.
17. The photographic film unit of claim 12 wherein said silver halide emulsion in said scavenger layer is spontaneously developable.
18. The photographic film unit of claim 17 wherein said light-reflective layer is titanium dioxide.
19. The photographic film unit of claim 18 wherein said developer scavenger layer is developable only after substantial development of said photosensitive element.
20. In a process of forming a transfer image comprising: a. imagewise exposing 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 nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible dye; b. treating the layer outermost from the support of said photosensitive element with an alkaline processing composition to effect development of each of said exposed silver halide emulsion layers with an aromatic primary amino color developing agent; c. forming an imagewise distribution of diffusible dye image-providing material as a function of said imagewise exposure of each said silver halide emulsion layer; and d. at least a portion of each said imagewise distribution of diffusible dye image-providing material diffusing to a dye image-receiving layer coated on a support; the improvement comprising employing between said dye image-receiving layer and its said support a developing agent scavenger layer comprising a silver halide emulsion and an immobilizing coupler which is capable of reacting with oxidized aromatic primary amino color developing agent to form an immobile product, and employing a light-reflective layer between said dye image-receiving layer and said scavenger layer.
21. The process of claim 20 wherein said treatment step b is effected by: a. superposing over the layer outermost from the support of said exposed photosensitive element said dye image-receiving layer coated on a support; b. positioning a rupturable container containing said alkaline processing composition between said exposed photosensitive element and said dye image-receiving layer; and c. applying a compressive force to said container to effect a discharge of the container''s contents between said outermost layer of said exposed photosensitive element and said dye image-receiving layer.
22. The process of claim 21 wherein said scavenger layer is operative only after substantial development of said photosensitive element.