US3236864A - Anthraquinone derivatives containing the hydroquinonylcarbamylmethylamino substituent - Google Patents

Description

United States Patent ANTHRAQUINONE DERIVATIVES CONTAINING THE HYDROQUINONYLCARBAMYLMETHYL- AMINO SUBSTITUENT Elkan R. Blout, Belmont, and Richard S. Corley, Wellesley, Mass., assignors to Polaroid Corporation, Cambridge, Mass., a corporation of Delaware No Drawing. Filed May 8, 1962, Ser. No. 193,320

4 Claims. (Cl. 260-372) 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 treatment of a latent image present in a photosensitive element, such as an exposed silver halide emulsion, whereby a positive dye image thereof may be imparted to another element, herein referred to as an image-carrying or image-receiving element.

U.S. Patent No. 2,983,606, issued May 9, 1961, discloses diffusion-transfer reversal processes wherein a photographic negative material such as a photographic element comprising an exposed silver halide emulsion layer containing a latent image, is processed to impart to an image-receiving element a reversed or 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 image-receiving layer. It is an object of this invention to provide additional dye developers suitable for use in such processes.

In carrying out the process of 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 3,236,864 Patented Feb. 22, 1966 photosensitive element in a uniform layer as the photosensitive 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. The liquid processing composition permeates the emulsion to provide a solution of dye developer substantially uniformly distributed therein. As the latent image 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 composition. 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 developing agent 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 layer or element, said transfer substantially excluding silver or oxidized dye developer. 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 reversed or positive, colored image of the developed 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 element 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, i.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 develop-er may be applied by using a coating solution containing about 0.5 to 8%, by weight, of the dye developer. Similar 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 process- :ing 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 developing agent. If the liquid processing composition is to be applied to the emulsion by being 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 filmforming 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 film-forming 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-compounds of the present invention comprises anthraquinone dyes characterized in that they contain, as nuclear substituents, not less than one and not more than two groups of the formula:

wherein X represents an arylene group such as a phenylene, or a lower alkylene group, preferably comprising from 1 to carbon atoms, inclusive, such as methylene, ethylene, propylene, etc.; each of R, R and R may be the same or different and represents a hydrogen or an alkyl group, preferably a lower alkyl group comprising from 1 to 5 carbon atoms, inclusive such as methyl, ethyl, propyl, etc.; in and 11 each may be the same or different and represent the positive integers 1 or 2; Y represents a divalent organic linking radical; and Z represents a henzenoid silver halide developing radical and preferably comprises a monovalent aryl group of the benzene or naphthalene series so substtituted by at least two amino and/or hydroxyl groups as to be capable of developing an exposed silver halide photographic emulsion.

The preferred compounds of the instant invention comprises anthraquinone dyes containing not more than one anthraquinone nucleus which is nuclear substituted by not less than one and not more than two groups of the formula:

R R o R wherein Z represents a p-dihydroxyphenyl or an o-dihydroxyphenyl group, Y represents a phenylene, an alkylene or a phenalkylene group, wherein the alkylene radicals comprise lower alkylene groups; X represents a phenylene group or a lower alkylene group; and each of m, n, R, R and R have the same significance as previously denoted.

As examples of divalent radicals, signified by the term Y in Formula A and suitable for use in the practice of the present invention, mention may be made of: preferred divalent hydrocarbon radicals such as alkylene radicals, preferably lower alkylene radicals comprising from 1 to 5 carbon atoms, inclusive, such as ethylene, isopropylene, etc.; arylene radicals such as phenylene, etc.; aralkylene radicals such as phenethylene, etc.; acyl radicals such as and divalent organic radicals which contain both hetero and carbon atoms as constituent components, as for example etc., radicals.

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 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, that is, benzene and naphthalene nuclei substituted by at least two hydroxyl and/or amino groups, one of said groups substituted in one of ortho and para positions with respect to one other of said groups. The preferred silver halide developing groups comprise dihydroxyphenyl groups, and specifically p-dihydroxyphenyl and o-dihydroxyphenyl groups and the substituted derivatives of such groups as, for example, nuclear substituted alkyl and halogen derivatives. Other suitable developing groups include orthoand para-amino-substituted hydroxyphenyl groups. In general, the developing group comprises a benzenoid developing configuration, that is, an aromatic developing group which forms quinonoid or quinone products upon oxidation.

The novel dye developers of this invention may be prepared by reacting an anthraquinone dye having not less than one and preferably not more than two reactive nuclear substituted groups of the formula:

o 1 I -x)m-11 IH wherein R, X, m and R have the same significance as previously set forth, or

i i (D) HalCHzO-N(-Y)n-1Z wherein Z, Y, n, and R have the same significance as previously set forth, and Hal indicates a halogen atom, preferably a chlorine atom. However, where an anthraquinone dye has more than two available reactive groups of Formula C, reaction may occur at two or more of such groups, dependent upon the mole ratios of the respective reactants.

It is generally desirable to protect the hydroxyl and/or amino groups of the developing function, during reaction, to avoid undesirable side reactions, for example, to employ a protected derivative of Z, that is, a compound within the formula:

wherein Y, n, R and Hal have the same significance as previously stated and Z represents the protected derivatives of a benzenoid silver halide developing 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 as, for example, the ester derivatives thereof.

The compounds of Formula D may be prepared, for example, by reacting, in the presence of a suitable halogen acid acceptor, such as, for example, quinoline, anhydrous pyridine, etc., a compound of the formula:

wherein Z, Y and R have the same significance as previously noted; such as, for example:

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;

Amino-phenethyl-hydroquinone, the preparation of which is disclosed in US. Patent No. 3,019,107, issued January 30, 1962;

Amino-phenethyl-thio-hydroquinone, the preparation of which is disclosed in US. Patent No. 3,009,958, issued 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; and

Amino-hydroquinone, amino-phenyl-hydroquinone, and

amino-phenyl-sulfonyl-hydroquinone, the catechol analogues, and corresponding secondary amines wherein R is an alkyl group, etc., which may be prepared by known chemical reactions;

with a compound of the formula:

wherein n and Hal have the same significance as previously noted and W is a halogen atom or an group, such as phosgene, chloroacetic anhydride, etc.

The compounds of Formula E may be prepared, for example, by the esterification of the compounds of Formula D or F with conventional acylating agents according to 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.

As examples of anthraquinone dyes within Formula C which may be employed in preparing dye developers within Formula A, mention may be made of:

1,4-bis- (,B-aminoethylamino -anthraquinone;

1-amino-4- (p-aminoanilino -2-anthraquinonesulfonic acid;

1-amino-4-anilino-anthraquinone;

1,5 -diamino-4,8-dihydroxy-anthraquinone 1,4-bis- (.p-aminoanilino -anthraquinone;

1,-4-diamino-anthraquinone 1,4-bis- (p-aminobenzylamino -anthraquinone; etc.

As-examplesof preferred compounds within Formula A mention may be made of:

1,5-bis-hydroqulnonylcarbamylmethylamln'0-4,8-dihyt1roxyanthraquinone 1-amlnoethylamino-4-hydr0quinonylcarbamylmethylaminoethylaminonnthraqulnone o ia NHHPaNa 1 amino-4-(p-[N (hydroqulnonylcarbamylmethyl) amino]- phenylamlno) Z-anthraquinonesulfonic acid sodium salt 1,4-bis-hydr0quinonylcarbamylmethylamino-anthraquinone Example 1 A mixture of 3.00 g. of 1-amino-4-p-aminoanilino)- anthraquinone-Z-sodium sulfonate and 2.13 g. of chloroacetamidohydroquinone monobenzoate in 50 cc. of pyridine is refluxed overnight. The mixture is allowed to cool and is then filtered. The filtrate is evaporated in vacuo nearly to dryness. The residue is rinsed out, washed With water and dried to give 3.85 g. of reaction product melting at about to C. This product is hydrolyzed by boiling for two minutes in a mixture of 60 cc. of methanol and 50 cc. of 5% aqueous sodium hydroxide. The resulting solution is acidified with acetic acid to give 1.8 g. of tiny blue-black crystals. Recrystallization from aqueous methyl Cellosolve provides '1-amino-4-1(p-[N-(hydroquinonylcarbamylmethyl) amino] phenylamino) 2 anthraquinonesulfonic acid sodium salt, which melts about 310 0. Analysis of the product, based on the above formula, shows:

C H N y S The dye developer product is insoluble in cold Water,

7 soluble in hot alcohol, and very soluble in pyridine and methyl Cellosolve. The sodium salt is moderately soluble in hot water.

Example 2 A mixture of 6.25 g. of 1,4-bis-(fl-aminoethylamino)- anthraquinone and 4.40 g. of chloroacetamidohydroquinone monobenzoate in 200 cc. of ethanol is refluxed for six hours. The mixture is cooled, filtered, and the filtrate evaporated to dryness. The residue is triturated with aqueous sodium bicarbonate solution, washed with water, dried, triturated with ether and collected to give 7.75 g. (91% yield) of crude product. A pyridine solution of the crude product is chromatographed on an alumina column. The first band passing through the column is evaporated in vacuo to dryness to give 3.3 g. of a product melting at 160 to 165 C. Analysis of this product as a monobenzoate of the dye developer, l-aminoethylamino 4 hydroquinonylcarbamylmethylamino The monobenzoate derivative may be hydrolyzed to give the dye developer of the above formula by boiling for a minute, under nitrogen, in a 1:3 methanol/% aqueous potassium hydroxide solution, followed by acidification. The precipitate is crystallized from ethanol to give small, blue-black crystals melting at 259 to 263 C.

Example 3 A mixture of 4.94 g. of chloroacetamidohydroquinone monobenzoate and 3.00 g. of 1,5-diamino-4,8-dihydroxyanthraquinonesulfonic acid sodium salt (color Index No. 1053) in 50 cc. of ethylene glycol is refluxed under nitrogen for four hours. Hydrogen chloride and sulfur dioxide gases are continuously removed during refluxing. The resultant solution is poured into excess water, collected, washed and dried to provide 4.60 g. of blue-black powder exhibiting a melting point at approximately 150 C. The powder is hydrolyzed by boiling in the absence of air for three minutes in a mixture of 100 cc. of 10:1 water alcohol containing 3% potassium hydroxide and filtered hot into dilute aqueous acetic acid. The product, 1.5 bis hydroquinonylcarbamylmethylamino- 4,8-dihydroxy-anthraquinone, precipitates in the dilute acetic acid to give 2.35 g. of a blue-black powder, M.P. over 260 C., moderately soluble in hot water and hot ethanol; slightly soluble in acetone, ethyl acetate, and dioxane; very slightly soluble in chloroform; and very soluble in an aqueous 3% sodium hydroxide solution.

The compounds of Formulae K and L were prepared by procedures substantially similar to the procedure of Example 3. V

The chloroacetamidohydroquinone monobenzoate used in the above examples may be prepared as follows:

Example 4 A solution of 53.0 g. of chloroacetic anhydride in 50 cc. of hot benzene is added to a suspension of 71.0 g. of Z-aminohydroquinone-4-monobenzoate in 700cc. of boiling benzene. The 2 aminohydroquinone 4 monobenzoate dissolves and the product separates out with the evolution of heat. The mixture is heated ten minutes more on a steam bath and allowed to cool. Filtration of the reaction mixture gives 94 g. (98% yield) of 2-chloroacetamidohydroquinone-4-monobenzoate. The product may be crystallized by dissolving in a liter of acetone and concentrating the solutionuntil crystallization begins; The recrystallized product melts at 210 to 212 C. with azrmsea 8 V decomposition, and is insoluble in Water but soluble in cold aqueous alkali with a gradual loss of chloride ion. Analysis of the recrystallized product discloses:

Calculated Found Example 5 A photosensitive element is prepared by coating a subcoated cellulose acetate film base with a 4% aqueous solution of gelatin followed by a coating of a solution containing 2.5 g. of the dye developer prepared in Example 1 above, in 100 cc. of a solution comprising:

Cellulose acetate hydrogen phthalate g 4 Methyl Cellosolve cc Methanol cc 20 After this coat has dried, a silver halide emulsion is applied. An image-receiving element is prepared by coating a polyvinyl butyral coated baryta paper with a solution comprising:

N-methoxymethyl polyhexamethylene adipamide g 4 Isopropanol c 80 Water cc 20 The photosensitive element is exposed, and then wetted with a liquid processing composition comprising:

Water cc Diethylamine g 10 Dimethyl formamide g 20 Metol g.. 0.2 Sodium carboxymethyl cellulose g.... 4.5 as the photosensitive element is brought into superposed relationship with the image-receiving element. After an imbibition period of approximately one minute, the imagereceiving element is separated and contains a cyan positive, dye image of the photographed subject.

It is also possible to employ a composite film unit comprising an image-receiving layer and a photosensitive emulsion layer so arranged that the liquid processing composition must permeate through the emulsion layer before reaching the image-receiving layer. In this embodiment, the liquid processing composition is applied to the emulsion layer as the composite film um't is brought into superposed relationship with a relatively impermeable, backing or spreading layer. The emulsion layer is so formed that it may be readily separated from the imagereceiving layer. Thus, for example, when the imagereceiving layer is separated upon the completion of the imbibition period, the emulsion layer adheres to and is retained with the spreading layer. An example of such a composite film unit is given in US. Patent No. 2,661,293, issued to Edwin H. Land on December 1, 1953. Note, in particular, FIGURE 7 of the drawing of said patent.

The following example is given to illustrate the use of the dye developer as a component of the liquid processing composition and also to illustrate the use of a composite film unit such as just described.

Example 6 An image-receiving layer is prepared by coating a polyvinyl butyral coated baryta base with a solution of- 4: g. of Nylon Type F8 in 80 cc. of isopropanol and 20 cc. of

water. After this nylon coating has dried, a silver halide emulsion is applied thereto. A liquid processing composition is prepared comprising:

Water a. cc.. 100

Sodium carboxymethyl cellulose g 4.5 Dye developer (as prepared in Example 2,

above) g 0.2 Metol g 0.2 Sodium hydroxide g 1.5 Sodium sulfite g 1.0 Sodium carbonate g 2.0

The composite image-receiving and emulsion-containing element is exposed, and the liquid processing composition applied thereto as this element is brought into superposed relationship with a spreading sheet or element. After an imbibition period of approximately one minute, the imagereceiving layer is separated and contains a slate blue positive dye image of the photographed subject.

Repetition of substantially the same procedure as set forth in Example using the dye developers of Formulae H, K and L, respectively, results in the formation, in the image-receiving layer, of a reversed positive cyan dye image of the photographed subject.

It will be noted that the liquid processing composition may, and in the above examples does, contain an auxiliary or accelerating developing agent, such as p-methylaminophenol, 2,4-diaminophenol, p-benzylaminophenol, hydroquinone, toluhydroquinone, phenylhydroquinone, 4'-methylphenylhydroquinone, etc. A preferred accelerating developing agent is a 3-pyrazolidone developing agent and preferably 1-phenyl-3-pyrazolidone. It is also contemplated to employ a plurality of auxiliary or accelerating developing agents, such as a S-pyrazo-lidone developing agent and a benzenoid developing agent, as disclosed and claimed in the copending application of Howard G. Rogers and Harriet W. Lutes, Serial No. 654,781, filed April 24, 1957, now U.S. Patent No. 3,039,869. As examples of suitable combinations of auxiliary developing agents, mention may be made of 1-phenyl-3-pyrazolidone in combination with p-benzylaminophenol and 1-phenyl-3- pyrazolidone in combination with 2,5-bis-ethylenimino hydroquinone. Such auxiliary developing agents may be employed in the liquid processing composition or they may be initially incorporated, at least in part, in the silver halide emulsion strata or the strata containing the dye developers. It may be noted that at least a portion of the dye developer oxidized during development may be oxidized and immobilized as a result of a reaction, e.g., an energy-transfer reaction, with the oxidation product of an oxidized auxiliary developing agent, the latter developing agent being oxidized by the development of exposed silver halide. Such a reaction of oxidized developing agent with unoxidized dye developer would regenerate the auxiliary developing agent for further reaction with the exposed silver halide.

In addition, development may be effected in the presence of an onium compound, particularly a quaternary ammonium compound, in accordance with the processes disclosed and claimed in the copending U.S. application of Milton Green and Howard G. Rogers, Serial No. 50,851, filed August 22, 1960, now U.S. Patent No. 3,173,786.

The dye developers 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 '10 unreacted dye developer is soluble. The expression toned is used to designate 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.

As examples of useful image-receiving materials, mention may be made of nylon such as N-methoxymethyl polyhexamethylene adipamide; partially hydrolyzed polyvinyl acetate; polyvinyl alcohol with or without plasticizers; baryta paper, Le, a support having a baryta coating thereon; cellulose acetate with filler as, for example, one-half cellulose acetate and one-half oleic acid; gelatin; and other materials of a similar nature, as is well known in the art. Preferred materials comprise polyvinyl alcohol or gelatin containing a dye mordant such as poly-4- vinylpyridine, as disclosed and claimed in the copending U.S. application of Howard C. Haas, Serial No. 50,848, filed August 22, 1960, now U.S. Patent No. 3,148,061.

The inventive concepts herein set forth are also 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 U.S. Patent No. 2,647,049 to Edwin H. Land.

The inventive concepts herein set forth are also adapt able for the formation of colored images in accordance with the photographic products and processes described in U.S. Patent No. 2,968,554, issued 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 expres sion 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.

This application is in part a continuation of our copending application, Serial No. 771,719, filed November 4, 1958, which application is a continuation-in-part of Serial No. 459,198, filed September 29, 1954, now abandoned.

Our copending U.S. application, Serial No. 828,445, filed July 21, 1959, now abandoned, claims the photographic utilization of the novel compounds of the present invention, especially in diffusion-transfer reversal processes.

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. An anthraquinone dye characterized in that it contains, as the sole substituents, attached to separate alpha a 11 carbon atoms of the anthraquinone nucleus, at least one and not more than four groups selected from the group consisting of OH, NH and a group of the formula:

0 -NHX NHCH2' JNH (Y 11-1-2 wherein Z is selected from the group consisting of a pdihydroxyphenyl and an o-dihydroxyphenyl group; n is one of the positive integers l and 2; Y is a divalent hydrocarbon radical selected from the group consisting of alkylene, phenylene and phenalkylene groups wherein the alkylene radicals are lower alkylene radicals and the phenylene group is directly attached to the nitrogen atom of said i CNH radical; X is selected from the group consisting of phenylene and lower alkylene groups; and wherein not less than one and not more than two of said nuclear substituents comprise groups of said formula.

No references cited.

LORRAINE A. WEINBERGER, Primary Examiner.

30 LEON ZITVER, Examiner.