US3239339A

US3239339A - Novel photographic products, compositions and processes

Info

Publication number: US3239339A
Application number: US107900A
Authority: US
Inventors: Dershowitz Samuel
Original assignee: Polaroid Corp
Current assignee: Polaroid Corp
Priority date: 1961-05-05
Filing date: 1961-05-05
Publication date: 1966-03-08
Anticipated expiration: 1983-03-08

Description

United States Patent Delaware No Drawing. Filed May 5, 1961, Bar. No. 107,900 20 Claims. (Cl. 96-29) This invention relates to photography and more particularly to products, compositions and processes for the development of photosensitive silver halide elements.

It is one object of the present invention to provide novel processes and compositions for the development of silver halide emulsions, in which colored developing agents are used to develop a latent image.

Another object is to provide novel processes and compositions for the development of silver halide emulsions, in which the novel developing agent is capable of developing a latent image and imparting a reversed or positive colored image of said latent image to a superposed image-receiving material.

Still another object is to provide novel products, processes and compositions suitable for use in preparing monochromatic and multichromatic photographic images.

A further object is to provide novel compounds which are useful as photographic color-providing materials.

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

The invention accordingly comprises the processes involving 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 and compositions 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.

The novel photographic developing agents employed in this invention possess the properties of both dye and a developing agent; thus they may be referred to as dye developers. The nature of these dye developers Will be described hereinafter.

The photographic processes and compositions disclosed herein are particularly useful in the development of an exposed sliver halide emulsion, whereby a dye transfer image may be imparted to an image-carrying or image-receiving layer.

The copendin-g application of Howard G. Rogers, Serial No. 748,421, filed July 14, 1958, now US. Patent No. 2,983,606, issued May 9, 1961, discloses diffusion-transfer processes wherein a photographic negative material such as a photographic element comprising an exposed silver halide emulsion layer is processed to impart to an imagereceiving element a positive dye image of said latent image by permeating into said emulsion layer a suitable liquid processing composition and bringing said emulsion layer into superposed relationship with an appropriate imagereceiving layer. It is an object of this invention to provide additional dye developers suitable for use in such processes.

In carrying out the processof this invention, a photosensitive element containing a silver halide emulsion is exposed and wetted with a liquid processing composition, for example, by immersing, coating, spraying, flowing, etc., in the dark, and the photosensitive element superposed, prior to, during or after wetting, on a sheetlike support element, which may be utilized as an imagereceiving element. In a preferred embodiment, the photosensitive element contains a layer of dye developer, and the liquid processing composition is applied to the photosensitive element in a uniform layer as the photosensi- Patented Mar. 8, 1966 tive element is brought into superposed position with an image-receiving element. It is also within the scope of this invention to apply the liquid processing composition prior to exposure, in accordance with the disclosure in the copending application of Edwin H. Land, Serial No. 498,672, filed April 1, 1955 (now US. Patent No. 3,087,- 816, granted April 30, 1963). The liquid processing composition permeates the emulsion to provide a solution of dye developer substantially uniformly distributed therein. As the exposed silver halide emulsion is developed, the oxidation product of the dye developer is immobilized or precipitated in situ with the developed silver, thereby providing an imagewise distribution of unoxidized dye developer dissolved in the liquid processing conmposition. This immobilization is apparently, at least in part, due to a change in the solubility characteristics of the dye developer upon oxidation, and especially as regards its solubility in alkaline solutions. It may also be due, in part, to a tanning effect on the emulsion by the oxidized dye developer and to localized exhaustion of alkali due to development. At least part of this imagewise distribution of unoxidized dye developer is transferred, by imbibition, to a superposed image-receiving lay-er or element. Under certain circumstances, the layer of the liquid processing composition may be utilized as the image-receiving layer. The latter element receives a depthwise diffusion, from the emulsion, of unoxidized dye developer without appreciably disturbing the imagewise distribution thereof to provide a positive dye transfer image. The image-receiving element may contain agents adapted to mordant or otherwise fix the diffused, unoxidized dye developer. If the color of the diffused dye developer is affected by changes in the pH of the image-receiving element, this pH may be adjusted in accordance with well-known techniques to provide a pH affording the desired color. Imbibition periods of approximately one minute have been found to give good results, but this contact period may be adjusted where necessary to compensate for variations in temperature or other conditions. The desired positive image is revealed by stripping the image-receiving elements from the photosensitive element at the end of the imbibition period.

The dye developers of this invention may be utilized in the photosensitive element, for example in, on or behind the silver halide emulsion, or they may be utilized in the image-receiving element or in the liquid processing composition. In a preferred embodiment, a coating or layer of the dye developer is placed behind the silver halide emulsion, ".e., on the side of the emulsion adapted to be located most distant from the photographed subject when the emulsion is exposed and preferably also adapted to be most distant from the image-receiving element when in superposed relationship therewith. Placing the dye developer behind the emulsion layer, as in the preferred embodiment, has the advantage of providing increased contrast in the positive image, and also minimizes any light-filtering action by the colored dye developer. In this preferred embodiment, the layer of dye developer may be applied by using a coating solution containing about 0.5 to 8%, by weight, of the dye developer. Sim-ilar concentrations may be used if the dye developer is utilized as a component of the liquid processing composition, concentrations as low as 0.2% in the liquid processing composition being suitable in certain instances.

The liquid processing composition above referred to comprises at least an aqueous solution of an alkaline compound, for example, diethylamine, sodium hydroxide or sodium carbonate, and may contain the dye developer. In some instances, it may contain an auxiliary or accelerating silver halide developing agent. If the liquid processing composition is to be applied to the emulsion by being ice spread thereon, preferably in a relatively thin, uniform layer, it may also include a viscosity-increasing compound comprising a film-forming material of the type which, when said composition is spread and dried, will form a relatively firm and relatively stable film. A preferred film-formin g material is a high molecular weight polymer such as a polymeric, water-soluble ether inert to an alkali solution as, for example, a hydroxyethyl cellulose or sodium carboxymethyl cellulose. Other filmforming materials or thickening agents whose ability to increase viscosity is substantially unaffected when left in solution for a long period of time may also be used.

The novel dye developers herein contemplated contain an anthrapyrimidone nucleus to which is attached at least one and preferably not more than two organic groups capable of functioning as silver halide developing groups. The essence of the invention is thus the substitution in the anthrapyrimidone nucleus of at least one and preferably not more than two groups, such as hydroquinonyl groups, capable of functioning as silver halide developing groups. The presence of other substituents in the anthrapyrimidone nucleus, such as those set forth with more particularity below, does not prevent the function of the compound as a dye developer and the presence of such substituents is therefore within the scope of this invention. For example, the presence in the anthraquinonyl nucleus of various substituents such as aryl, alkyl or aralkyl radicals, halogen, or amino, cyano, acyl nitro, carboalkoxy, carboxyl, sulfo, alkoxy, hydroxyl, or carboxamido groups, is permissible. As indicated above, it is essential only that the anthrapyrimidone nucleus have attached thereto at least one organic group capable of functioning as a silver halide developing group.

The novel dye developers of the present invention accordingly comprise anthrapyrimidone dyes characterized in that they contain at least one group of the formula:

wherein Y is a covalent bond or a divalent radical and Z is an aryl nucleus selected from the group consisting of benzene and naphthalene nuclei substituted by at least two groups selected from the group consisting of hydroxyl and amino groups, at least one of said groups being ortho or para to another of said groups, so as to be capable of developing an exposed silver halide emulsion.

In the above formula, Y does not contribute a colorproducing group to the molecule but acts to prevent or interrupt any system of conjugation or resonance extending from the anthrapyrimidone dye nucleus to the developer nucleus Z. Thus the developer unit is in fact insulated from the dye unit, and the color is determined substantially entirely by the chromophoric system of the dye unit. In other words, it may be said that the shape of the visible spectral absorption curve of the dye developer and the absorption peaks do not differ substantially from those of the parent dye.

In addition to the substituents which provide the silver halide developing function, Z may be substituted by halogen, alkoxy, alkyl, etc., radicals. The term amino as used herein is intended to include amino groups so substituted as not to impair their respective silver halide developing functions, for example, suitably substituted alkylamino and arylamino groups.

The novel compounds of this invention, as noted above, are anthrapyrimidone dye developers which contain an aryl nucleus selected from the group consisting of benzene and naphthalene nuclei so substituted by at least two groups selected from the group consisting of hydroxyl and amino groups as to be capable of developing an exposed silver halide emulsion. A preferred silver halide developing group comprises a hydroquinonyl group. Other suitable developing groups include ortho-dihydroxyphenyl and orthoand para-amino substituted hydroxyphenyl groups. In general, the developing group comprises a benzenoid developing configuration, that is, an

4 aromatic developing group which forms quinonoid or quinone products upon oxidation.

As examples of divalent radicals, signified by the term Y and suitable for use in the practice of the present invention, mention may be made of: divalent organic radicals such as alkylene radicals, preferably lower alkylene radicals such as ethylene, isopropylene, etc.; sulfonamido; sulfamyl; carboxamido; carbamyl; amino radicals such as NHalkylene-; arylene radicals such as phenylene, etc.; aralkylene radicals such as phenethyl, etc.; acyl radicals such as etc.; divalent radicals which contain hetero and carbon atoms as constituent components, as for example etc.; and suitable combinations thereof.

One preferred group of anthrapyrimidone dye developers may be represented by the formula:

a i la wherein: each of R R R R R R, R and R may be YZ, hydrogen, aryl, alkyl and preferably lower alkyl, halogen, amino, cyano, acyl, nitro, carboalkoxy, carboxyl, sulfo, alkoxy, hydroxyl, carboxamido, or aralkyl; and at least one of R and R is --Y-Z; YZ has the same significance as previously noted; and where more than one developing group YZ is present, each such group YZ may be the same or different.

As used herein, the terms amino, alkyl, aryl, etc., are intended to include the corresponding substituted groups. Thus, amino is intended to include groups such as methylamino and anilino, alkyl is intended to include groups such as aminomethyl and B-hydroxyethyl, etc.

The anthrapyrimidone dye developers of this invention may be prepared by introducing the desired developer group or groups prior to formation of the anthrapyrimidone nucleus. The novel dye developers of this invention may therefore be prepared by condensing, with urea in hot acetic acid or phenol, an anthraquinone dye of the formula:

(11) R (H) NEE-R l l R 0 R wherein: R have the meaning heretofore given to R in Formula I; where at least one of R and R is YZ; and YZ has the meaning previously given.

The anthrapyrimidone dye developers of this invention may also be prepared by introducing the desired developer group YZ subsequent to the formation of the anthrapyrimidone nucleus.

A preferred method of introducing the desired developer group subsequent to formation of the anthrapyrimidone nucleus comprises reacting an anthrapyrimidone dye El U1 having a nitro group or halogen group substituted in position 6 with a compound of the formula:

X-Y-Z Amino-ethyl-hydroquinone, the preparation of which is disclosed in the copending US. application of Milton Green, Serial No. 514,095, filed June 8, 1955 (now US. Patent No. 3,062,884, granted November 6, 1962);

Amino-phenethyl-hydroquinone, the preparation of which is disclosed in the copending U.S. application of Elkan R. Blout, Milton Green, Howard G. Rogers, Myron S. Simon and Robert B. Woodward, Serial No. 612,051, filed September 25, 1956 (now US. Patent N0. 3,019,- 107, granted January 30, 1962), and in a continuation in-part thereof, Serial No. 98,287, filed March 27, 1961;

Amino-phenethyl-thio-hydroquinone, the preparation of which is disclosed in the copending US. application of Milton Green and Howard G. Rogers, Serial No. 663,- 876, filed June 6, 1957 (now US. Patent No. 3,009,958, granted November 21, 1961);

Amino-phenoxy-hydroquinone, the preparation of which is disclosed in the copending US. application of Milton Green and Warren E. Solodar, Serial No. 680,406, filed August 26, 1957 (now US. Patent No. 3,061,434, granted October 30, 1962);

Amino-propyl-amino-hydroquinone, the preparation of which is disclosed in the copending US. application of Milton Green and Myron S. Simon, Serial No. 711,812, filed January 29, 1958 (now US. Patent No. 3,002,997, granted October 3, 1961); and

Amino-hydroquinone, amino-phenyl-hydroquinone, and amino-phenyl-sulfonyl-hydroquinone, etc., which may be prepared by known chemical reactions.

In addition, the aforementioned anthrapyrimidone dye developers may be prepared by effecting a condensation reaction between an anthrapyrimidone dye having substituted thereon one or more primary and/or secondary amino groups and a compound of the formula:

wherein: Y and Z have the same significance as previously noted and W represents an acid chloride or sulfonyl chloride group.

The enumeration and preparation of compounds within the last-mentioned formula are set forth in the following copending US. applications:

Serial No. 471,542, filed November 26, 1954; in the names of Elkan R. Blout, Saul G. Cohen, Milton Green, Howard C. Rogers, Myron S. Simon, and Robert B. Woodward (now abandoned and replaced by Serial No. 1,442, filed January 11, 1960 (now abandoned and the subject matter of which is incorporated in continuation-in-part application Serial No. 401,714, filed October 5, 1964); and Serial No. 771,718, filed November 4, 1958, in the names of Elkan R. Blout and Richard S. Corley (now abandoned).

It may be desirable to protect the hydroxyl and/or amino groups of the developing function, during the above-mentioned reactions, to avoid undesirable side reactions, that is, to employ a protected derivative of Z. The protected derivatives of Z set forth in formula XY--Z may be prepared by the selective acylation of Z according to the procedure disclosed in the copending US. application of Milton Green and Helen P. Husek, Serial No. 805,673, filed April 13, 1959 (now US. Patent No. 3,019,254, granted January 30, 1962), as a continuation-in-part of Serial No. 612,063, filed September 25, 1956 (now abandoned). The protected derivatives of Z set forth in formula WY-Z may be prepared by conventional acylation of Z according to the procedures well known to the art. After reaction and prior to use as a photographic dye developer, the acyloxy groups may be removed by deesterification as, for example, by hydrolysis in the presence of alkali.

The following examples serve by way of illustration and not by limitation to show the preparation and use of the novel dye developers of this invention.

Example 1 242 gm. of 1,4 bis-[u-methyI'B-(Z',5-dihydroxyphenyl)-ethylamino]-anthraquinone and 240 gm. of urea in 1.4 liter of glacial acetic acid were refluxed for 17 hours at approximately the boiling point of acetic acid (118 C.). The reaction mixture was poured into 2 /2 liters of water and the resulting precipitate collected by filtration. The weight of this precipitate was 260 gm. It was 3-11- methyl l8 (2',5' dihydroxyphenyl)-ethyl-6-a-methyl-fi- (2,5 dihydroxyphenyl)-ethylaminoanthrapyrimidone of the structure:

l C Ha terial is a powder, insoluble in water but soluble in ethyl acetate, acetic acid, acetone and similar organic solvents.

Example 2 1.8 gm. of 1,4-bis-[rx-ethyl-B-(2',5'-dihydroxyphenyl)- ethylaminoJ-anthraquinone and 2 gm. of urea in 40 ml. of glacial acetic acid were refluxed for 15 hours. 2 gm. of additional urea were then added and the reflux continued for 5 hours. Subsequently, another 2 gm. of urea were added and the refluxing was continued for an additional 15 hours. The reaction mixture was then cooled and poured into 500 ml. of water and the resulting precipitate was collected by filtration. The weight of this precipitate was 1.7 gm. It was 3-a-ethyl- 5-(2,5'-dihydroxyphenyl)ethyl-6-a-ethyl-,B-(2,5 dihydroxyphenyl)- ethylamino-anthrapyrimidone of the structure:

A pure sample was obtained by an ethyl acetate ex traction in the manner described in Example 1 and the pure material exhibited the same solubility characteristics as the compound prepared in Example 1.

The following example will illustrate the photographic use of the dye developers of this invention.

Example 3 A photosensitive element was prepared by coating 21 gelatin-subcoated cellulose acetate film base with a solution comprising 4.1% 3-B-(2',5'-dihydroxyphenyl)-isopropyl-6,B-(2,5-dihydroxyphenyl) isopropylamino-anthrapyrimidone and 2.0% cellulose acetate hydrogen phthalate in a 50:50 mixture, by volume, of acetone and tetrahydrofuran. After this coating had dried, a greensensitive silver iodobromide emulsion was applied. The resulting photosensitive element was exposed and then processed by spreading a thin layer of an aqueous processing composition comprising:

Percent Sodium hydroxide 1.0 Hydroxyethyl cellulose (high viscosity) (sold by Hercules Powder Co., Wilmington, Delaware,

under the trade name Natrasol 250) 3.5 l-phenyl-4,4-dimethyl-3-pyrazolidone 0.6 Xylohydroquinone 0.4 S-nitrobenzimidazole 0.0

between the exposed photosensitive element and an imagereceiving element as said elements were brought into superposed relationship. The image-receiving element comprises a nylon image-receiving layer, i.e., N-methoxymethyl polyhexamethylene adipamide, carried on a cellulose acetate-subcoated baryta paper. After an imbibition period of approximately 1 minute, the image-receiving element was separated and contained a magenta positive dye image.

Instead of the nylon image-receiving layer employed in the above example, one may employ a stratum of other materials dyeable from an alkaline solution, e.g., gelatin, polyvinyl alcohol, gelatin or polyvinyl alcohol containing a polymeric mordant, e.g., poly-4-vinylpyridine, and the image-receiving layer may be coated on a transparent or opaque support.

The vehicle from which the anthrapyrimidone dye developer is applied to form the dye developer layer in the photosensitive element may also be prepared by forming a solution of the dye developer in a water-immiscible organic solvent and dispersing this solution in gelatin.

The anthrapyrimidone dye developers of this invention have been found to be more stable to fading by light than similar dye developers containing an anthrapyridone nucleus. In some instances, an anthrapyrimidone dye developer has been found to have a desensitizing action on a silver halide emulsion coated over the dye developer layer, thereby reducing the film speed and/ or color sensitivity of the silver halide emulsion. It is not known if this desensitizing effect was due to a displacement, in part, of the sensitizing dye, or to the presence of an unidentified impurity. In any event, this desensitizing effect does not occur if the anthrapyrimidone dye developer is initially present in the processing solution and thus contacts the silver halide emulsion only after exposure thereof. Suitable precautions therefore should be observed, and practices known in the art to restrain desensitization may be utilized in the event such desensitization is observed with particular dye developers of this invention.

It will be noted that the liquid processing composition may, and in the above examples does, contain at least one auxiliary or accelerating developing agent which is substantially colorless in at least its unoxidized form, such as p-methylaminophenol (Metol); 2,4-diaminophenol (Amidol); benzylaminophenol, or a 3-pyrazolidone, such as l-phenyl-3-pyrazolidone. Preferred auxiliary silver halide developing agents include l-phenyl-3- pyrazolidone, 2,5-bis-ethyleneimino-hydroquinone, xylohydroquinone, phenyl-hydroquinone, toluhydroquinone,

and 4'-methyl-phenyl-hydroquinone. This auxiliary developing agent serves to accelerate and possibly initiate the action of the dye developer; thus may be denoted as an accelerating developer. A portion of the dye developer may be oxidized by an energy transfer reaction with oxidized auxiliary developing agent.

The dye developer of this invention may be used also in conventional photographic processes, such as tray or tank development of conventional photosensitive films, plates or papers to obtain black-and-white, monochromatic or toned prints or negatives. By way of example, a developer composition suitable for such use may comprise an aqueous solution of approximately 1 to 2% of the dye developer, 1% sodium hydroxide, 2% sodium sulfite and 0.05% potassium bromide. After development is completed, any unreacted dye developer is washed out of the photosensitive element, preferably with an alkaline washing medium or other medium in which the unreacted dye developer is soluble. The expression toned is used to desiginate photographic images wherein the silver is retained with the precipitated dye, whereas monochromatic is intended to designate dye images free of silver.

It should be noted that the dye developers of this invention are self-sufficient to provide the desired color image and do not depend upon coupling reactions to produce the desired color. They thus provide a complete departure from conventional photographic color processes in which the color is produced by a coupling reaction involving the oxidized developing agent.

It should be noted that it is within the scope of this invention to use mixtures of dye developers to obtain a desired color.

It will be apparent that, by appropriate selection of the image-receiving element from among suitable known opaque and transparent materials, it is possible to obtain either a colored positive reflection print or a colored positive transparency. Likewise, the inventive concepts herein set forth are adaptable for multicolor work by the use of special photographic materials, for example, film materials of the type containing two or more photosensitized elements associated with an appropriate number of image-receiving elements and adapted to be treated with one or more liquid processing compositions, appropriate dye developers suitable to impart the desired subtractive colors being incorporated in the photosensitized elements or in the liquid processing compositions. Examples of such photographic materials are disclosed in US. Patent No. 2,647,049 to Edwin H. Land.

The inventive concepts herein set forth are also adaptable for the formation of colored images in accordance with the photographic products and processes described and claimed in US. Patent No. 2,968,554, issued to Edwin H. Land on January 17, 1961, and also the copending application of Edwin H. Land and Howard G. Rogers, Serial No. 565,135, filed February 13, 1956.

In the preceding portions of the specification the expression color has been frequently used. This expression is intended to include the use of a plurality of colors to obtain black, as well as the use of a single black dye developer.

Since certain changes may be made in the above products, compositions and processes without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A photographic developer composition comprising an aqueous alkaline solution containing at least one accelerating silver halide developing agent which is substantially colorless in at least its unoxidized form and an anthrapyrimidone dye, at least one of the 3 and 6 position nuclear carbon atoms of said anthrapyrimidone nucleus having linked thereto a group of the formula:

wherein: Z in an aryl nucleus selected from the group consisting of benzene and naphthalene nuclei substituted by at least two groups selected from the group consisting of hydroxyl and amino groups, at least one of said groups being substituted in one of the ortho and para positions with respect to the other of said groups, so as to be capable of developing an exposed silver halide emulsion; and Y is a lower alkylene radical.

2. A photographic developer composition comprising an aqueous alkaline solution containing at least one accelerating silver halide developing agent which is substantially colorless in at least its unoxidized form and an anthrapyrimidone dye of the formula:

O NH-R wherein: each of R and R is selected from the group consisting of hydrogen and Y-Z; Y is a lower alkylene radical; Z is a dihydroxyphenyl silver halide developing radical, and at least one of said R and R is -Y-Z.

3. A photographic developer composition comprising an aqueous alkaline solution containing at least one accelerating silver halide developing agent which is substantially colorless in at least its unoxidized form and 3-a-methyl- ,B-(Z',5'-dihydroxyphenyl)-ethyldoc-methyl fi-(2',5 dihydroxyphenyl) -ethylamino-anthrapyrimidone.

4. A photographic developer composition comprising an aqueous alkaline solution containing at least one accelerating silver halide developing agent which is substantially colorless in at least its unoxidized form and 3-04- ethyl-fi-(2,5-dihydroxyphenyl)-ethyl-6-u-ethyl-fl (2,5- dihydroxyphenyl)-ethyl-6a-ethyl [i (2',5 dihydroxyphenyl -ethylamino-anthrapyrimidone. consisting of benzene and naphthalene nuclei substituted 5. A process for developing an exposed silver halide emulsion which comprises contacting said emulsion with an aqueous alkaline solution of an anthrapyrimidone dye, at least one of the 3 and 6 position nuclear carbon atoms of said anthrapyrimidone nucleus having linked thereto a group of the formula:

wherein: Z is an aryl nucleus selected from the group consisting of benzene and naphthalene nuclei substituted by at least two groups selected from the group consisting of hydroxyl and amino groups, at least one of said groups being substituted in one of the ortho and para positions with respect to the other of said groups, so as to be capable of developing an exposed silver halide emulsion; and Y is a lower alkylene radical.

6. A process for developing an exposed silver halide emulsion which comprises contacting said emulsion with an aqueous alkaline solution of an anthrapyrimidone dye of the formula:

wherein: each of R and R is selected from the group consisting of hydrogen and YZ; Y is a lower alkylene radical; Z is a dihydroxyphenyl silver halide developing radical, and at least one of said R and R is Y-Z.

7. A process as defined in claim 5 wherein said dye is disposed, prior to exposure, in a photosensitive element comprising said silver halide emulsion, and the solution containing said dye is formed by permeating said photosensitive element with an aqueous alkaline solution capable of solubilizing said dye.

8. A process of defined in claim 5 wherein said aqueous alkaline solution contains at least one accelerating silver halide developing agent which is substantially colorless in at least its unoxidized form.

-9. A process of developing an exposed silver halide emulsion which comprises contacting said emulsion with an aqueous alkaline solution of 3-u-methyl-B-(2,S-dihy droxyphenyl)-ethyl-6-u-methyl-B-(2',5'-dihydroxy phenyl)-ethylamino-anthrapyrirnidone.

10. A process of developing an exposed silver halide emulsion which comprises contacting said emulsion with an aqueous alkaline solution of 3-u-ethyl-fl-(2',5' dihydroxyphenyl) ethyl 6 a ethyl ,8 (2,5 dihydroxyphenyl -ethylaminc-anthrapyrimidone.

11. In a process of forming photographic images in color, the steps which comprise developing an exposed silver halide emulsion with an aqueous alkaline solution of an anthrapyrimidone dye, at least one of the 3 and 6 position nuclear carbon atoms of said anthrapyrimidone nucleus having linked thereto a group of the formula:

wherein: Z is an aryl nucleus selected from the group consisting of benzene and naplrth-alene nuclei substituted by at least two groups selected from the group consisting of hydroxyl and amino groups, at least one of said groups being substituted in one of the ortho and para positions with respect to the other of said groups, so as to be capable of developing an exposed silver halide emulsion; and Y is a lower alkylene radical; to thereby provide in said emulsion a predetermined distribution of unoxidized anthrapyrimidone dye, and transferring at least part of said distribution of unoxidized dye by irnbibition from said emulsion to an image-receiving element in superposed relationship with said emulsion to impart to said imagereceiving element a positive dye image of the developed image.

12. The process as defined in claim 11, wherein said anthrapyrimidone dye is disposed, prior to exposure, in a photosensitive element comprising said exposed silver halide emulsion, and the solution containing said dye is formed by permeating said photosensitive element with an aqueous alkaline solution capable of solubilizing said 13. The process as defined in claim 11, wherein said solution is introduced by being spread in a substantially uniform layer between said photosensitive element and said image-receiving element as said elements are brought into superposed relationship.

14. In a process out forming photographic images in color, the steps which comprise developing an exposed silver halide emulsion with an aqueous alkaline solution of anthrapyrimidone dye of the formula:

wherein: each of R and R in selected atrom the group consisting of hydrogen and Y-Z; Y is a lower alkylene radical; Z is a dihydroxyphenyl silver halide developing radical, and at least one of said R and R is Y--Z; to thereby provide in said emulsion a predetermined distribution or unoxidized anthrapyrimidone dye, and

transferring at least part of said distribution of unoxidized dye by imbibition from said emulsion to an imagereceiving element in superposed relationship with said emulsion to impart to said image-receiving element a positive dye image of the developed image.

15. A process of forming photographic images in color, the steps which comprise developing an exposed silver halide emulsion with an aqueous alkaline solution of 3- a-methyl-/3 (2,5-dihyd-r0xyphenyl) ethyl-6-a-methyl-fi- 2',5'-d.ihydroxyphenyl)-ethylamino-anthrapyrimidone; to thereby provide in said emulsion a predetermined distribution of unoxidized anthrapyrimidone dye and transferring at least part of said distribution of unoxidized dye by imbibition from said emulsion to an image-receiving element in superposed relationship with said emulsion to impart to said image-receiving element a positive dye image of the developed image.

16. A process of forming photographic images in color, the steps which comprise developing an exposed silver halide emulsion with an aqueous alkaline solution of '3- methyl- 3 (2',5'-di'hydroxyphenyl) ethyl-6-a-ethyl-B-(Q', 5'-dihydroxyphenyl) ethylamino anthrapyrirnidone; to thereby provide in said emulsion a predetermined distribution of unoxidized anthrapyrimidone dye and transferring at least part of said distribution of unoxidized dye by imbibition from said emulsion to an image-receiving element in superposed relationship with said emulsion to impart to said image-receiving element a reversed, positive dye image of the developed image.

17. A photographic product comprising a support, a silver halide emulsion located in a layer on said support, and a dye developer located in a layer on the same side of said support as said emulsion, said dye developer being an anthrapyrimidone dye, at least one of the 3 and 6 position nuclear carbon atoms of said anthrapyrimidone nucleus having linked thereto a group of the formula:

18. A photographic product comprising a support, a silver halide emulsion located in a layer on said support, and a dye developer located in a layer on the same side of said support as said emulsion, said dye developer being an anthrapyrimidone dye of the formula:

wherein: each of R and R is selected from the group consisting of hydrogen and YZ; Y is a lower alkylene radical; Z is a dihydiroxyphenyl silver halide developing radical, and at least one of said R and R is -Y-Z.

19. A photographic product comprising a support, a silver halide emulsion located on a layer on said support and 3-a-methyI- S (2,5 dihydroxyphenyl) ethyl-6w:- methyl-fl-(2',5'-dihydroxyphenyl) ethylamino-antbrapyrimidone located in a layer on the same side of said support as said emulsion.

20. A photographic product comprising a support, a silver halide emulsion located on a layer on said support and 3-a-ethyl-B-(2,5-dihydroxyphenyl) ethyl-6-a-ethylp-(2',5'-dihydroxyphenyl) ethyl-6-a-ethyl-fi-(2',5'-d=ihy droxyphenyl)ethylamino-anthrapyrimidone located in a layer on the same side of said support as said emulsion.

References Cited by the Examiner FOREIGN PATENTS 11/1958 Great Britain.

OTHER REFERENCES Venkatararnan: Synthetic Dyes, Academic Press, N.Y., pages 852-857;121012'27.

NORMAN G. TORCHIN', Primary Examiner.

HAROLD N. BURS'DEIN, Examiner.