US3141772A

US3141772A - Photographic products, processes and compositions employing azo dye developers

Info

Publication number: US3141772A
Application number: US301181A
Authority: US
Inventors: Green Milton
Original assignee: Polaroid Corp
Current assignee: Polaroid Corp
Priority date: 1963-08-09
Filing date: 1963-08-09
Publication date: 1964-07-21
Anticipated expiration: 1981-07-21

Description

United States, Patent Delaware No Drawing. Filed Aug. 9, 1963, Ser. No. 301,131 18 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.

This application is a continuation-impart of my copending applications Serial No. 130,468, filed AugustlO, 1961 (now abandoned), Serial No. 130,498, filed August 10, 1961 (now abandoned) and Serial No. 268,451, filed March 23, 1963.

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 imagereceiving material.

A further object is to provide novel products, processes and compositions suitable for use in preparing mono chromatic and multi-chromatic photographic images.

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. a

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description.

The novel photographic developing agents employed in this invention possess the properties of both a 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 an exposed silver halide emulsion, whereby a positive dye image may be imparted to another element, herein referred to as an image-carrying or image-receiving element.

US. Patent No. 2,983,606, issued May 9, 1961 to Howard G. Rogers, discloses diffusion transfer processes wherein a photographic negative material, such as a photo graphic element comprising an exposed silver halide emulsion is developed in the presence of a dye developer to impart to an image-receiving layer a reversed or positive dye image of the developed 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 an image-re- Patented July 21, 1964? 1 ceiving element. In a preferred embodiment, the photo sensitive element contains a layer of dye developer, and the liquid processing composition is applied to the photosensitive element in a uniform layer as the photosensitive element is brought into superposed position with an image-receiving element. 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 oxi-' dation 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 also may be due, in part, to a tanning etfect on the emulsion by the oxidized developing agent. At least part of this imagewise distribution of unoxidized dye developer is transferred, by imbibition, to a superposed image-receiving layer. Under certain circumstances, the layer of the liquid processing composition may be utilized as the image-receiving layer. The image-receiving layer 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.

7 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 em bodiment, has the advantage of providing increased contrast in the positive image, and also minimizes any lightfiltering 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. Similar concentrations may be used if the dye developer is utilized as a component of the liquid processing composition. In an especially useful mode of dispersing the dye developers in the photosensitive elements, the dye developer is dissolved in a water-immiscible solvent and then dispersed in a gelatin coating solution.

The liquid processing composition above referred to comprises at least an aqueous solution of an alkaline com if) layer, it may also include a viscosity-increasing compound constituting the 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-forming 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 dye developers of this invention may be represented by the formula:

wherein R is a lower alkoxy, halogen, lower alkyl, trifiuorornethyl or sulfonarnido radical, p is an integer from to 4, inclusive, X is a hydrogen, lower alkoxy, halogen, lower alkyl, trifluoromethyl or sulfonamido radical, said X being located ortho to said N=N group, R is a phenyl or naphthyl radical, Ar is a phenylene radical; M is a lower alkylene radical, n is an integer from 0 to 1, inclusive, Y is an orthoor para-dihydroxyphenyl radical, and alkyl and halogen derivatives thereof, and Q is a radical wherein 'Z is a lower alkyl radical, and each R and R is hydrogen or an alkyl radical and R and R together may be a divalent aliphatic radical, e.g., a pentamethylene radical completing, with the nitrogen atom, a piperidine ring. Preferably, R and R contain no more than to 12 canbons. It should also be understood that the term alkyl, as represented by R and R is intended to include substituted alkyl radicals, e.g., hydroxyalkyl radicals.

In a preferred embodiment, Ar is a phenylene radical, R is a phenyl radical, n is 1 and Y is a para-dihydroxyphenyl radical. Such dye developers may be represented by the formula:

wherein R p, X, Q and M have the same meaning as above.

As examples of alkylene radicals comprehended by the radical M, mention may be made of radicals such as -CH --CH CHQ-CH OHZ and CH CH CH In the preferred embodiment, M is a lower alkylene group, e.g., less than 6 carbons, and more preferably an ethylene or propylene It should be understood that the substituents R and X and the specific position of said substituents on the ring may be selected by one skilled in the art guided by the teachings of the present invention and with due regard to the substituents effect on color, solubility and light stability of the compound.

The dye developers of this invention wherein Q is O -L-o-z compared with yellow pyrazolone azo dye developers described in the copending application of Elkan R. Blout, Milton Green and Howard G. Rogers, Serial No. 144,816, filed October 18, 1961 as a continuation-in-part of Serial No. 612,045, filed September 25, 1956 (now abandoned), have improved silver halide developing properties and increased light stability characteristics. Thus, for example, it has been found that compounds 4 and 6, infra, develop approximately 3 to 4 times as much silver (as measured by optical silver density) than 1-phenyl-3-N-n-hexyl-carboxamido 4 [p 3 hydroquinonylethyl) phenylazo]-5-pyrazolone in one minute under the same conditions, and in the absence of any other silver halide developing agent. In addition, any tendency toward fading of these novel yellow dye developers is not accompanied by a browning of the yellow dye developer. It has also been found that the above enumerated superior photographic properties, particularly the light stability, of these dye developers may be further enhanced when the ortho substituent X is other than hydrogen, that is, a halogen, trifluoromethyl, alkyl, or alkoxy radical.

As examples of dye developers within the scope of the present invention wherein Q:

ll -o-o-z mention may be made of:

(1) 1-(4"-hydroquinony1ethy1pl1en l)-3-carbethox 4- 2',6-

dimethylphenylazo)-5-pyrazal0ne y N HO (2) 1-(4"-hydroquinonylethylphenyl)-3-carbethoxy-4-(etmethylphenylazo) -5-pyrazo1one HgCHg- 1 (B [4 chloro 2,5' dihydroxypheuyl] ethyl) pheuyl] 3 carbethoxy 4 (2,4,6-' tnmethylpheuylazo) -5-pyrazolone 0 t CH N=Nn OCzH5 N 231-1 HO LN HzCHg- CH3 (28) 1 [4 (18 [3",4" dimethyl 2",5 dihydroxyphenyl] ethyl) phenyl] 3 carbethoxy at (2',4r,6'- itrimethylphenylazo) -5pyrazol0ne CH HO ethyl) pheuyl] 3 carbethoxy 4 (2,4, 6trimethylphenylazo) -5-pyraz0l0ne (31) 1 [4 (B [2 methyl yl] ethyl) phenyl] 3 carbethoxy ylphenylazo) -5-pyrazo10ne The dye developers of this invention wherein Q is a radical have been found to be susceptible to hydrolysis, during synthesis, of the radical in the 3 position of the pyrazolone ring. The corresponding free acid is diflicult to separate from the corresponding ester, and the presence of the free acid may detract from the usefulness of such dye developers in some (but not all) photographic applications, e.g., by giving undesired transfer in diifusion transfer applications because of the greater solubility and mobility of the free acid than of the corresponding ester.

It has been found that replacement of the carboxylate radical by a carboxamido radical can be readily accomplished and provides dye developers wherein Q is a which retain many of the desirable properties of said dye developers but without the susceptibility to hydrolysis. The dye developers of this invention, wherein Q is a radical, do not exhibit hydrolysis of the 3-carbamyl group during synthesis, e.g., during hydrolysis of the acylated Y radical during synthesis, or under the condition present during imbibition. By the replacement of the ester group by an amide group many advantages of the dye developers of this invention wherein Q is a group, e.g., improved silver halide developing properties and increased light stability characteristics, have been retained while a serious disadvantage, i.e., the tendency of the ester group, particularly a S-carbethoxy group, to undergo hydrolysis during synthesis, has been eliminated.

(74) 1 [4 (B [3,4" dimethyl 2,5 dihydroxyphenyl] ethyl) phenyl] 3 (N hydroxypropyl) car- :bamyl-et- (2,4,6 -trimethylpheny1azo) -5-pyr"azolone (75) 1 [4 3 [3',4" dihydroxyphenyl] ethyl)- Pphenyl] 3 (N hydroxypropyl) carbamyl 4: (2,4',6- trimethylphenylazo) -5-pyraz0l0ne E on,- -N=Nu b-Nnon2omomon on, no-l :1 orrrcrn- -on (76) 1 [4 (13 [2 cllloro 3,4 dillydroxyphenyll ethyl) phenyl] 3 (N hydroxypropyl) carbamyl 4- (2,4 ,6-trimethylphenylazo) -5-pyrazolone (77) 1 [4" (B [2" methyl 3,4 dihydroxyphenyflethyl) phenyl] 3 (N hydroxypropyl) carbamyl 4- J (2 ,4 ,6-trimetl1ylphenylazo) -5-pyrazol0ne 22 The dye developers of this invention may be prepared from a novel coupler of the formula:

wherein Z, Ar, M and n have the same meaning as above and Y is the protected derivative of an orthoor paradihydroxyphenyl radical, preferably the 0,0-diacyloxy derivative, and more preferably the diacetoxy derivative. The term acyloxy is intended to signify the grouping wherein D is an aryl, alkyl, aryloxy, or alkoxy group. The terms alkyl and aryl as employed herein are intended to include the substituted aryl and alkyl groups, for example aralkyl and alkaryl groups.

The compounds within Formula C may be prepared by diazotizing a compound of the formula:

wherein Y M, n and Ar have the same meaning as above; and reacting said diazonium derivative with a substituted ester of succinic acid.

Suitable substituted esters of succinic acid may be prepared according to the method set out in Org. Syntheses, Coll. Vol. II, p. 262.

Compounds within Formula D, when n: 1, that may be used in this invention are disclosed in US. Patent No. 3,019,254, issued January 30, 1962, to Milton Green and Helen P. Husek, and in the copending application of Elkan R. Blout, Milton Green and Howard G. Rogers, Serial No. 144,816, filed October 18, 1961, as a continuation-in-part of Serial No. 612,045, filed September 25, 1956 (now abandoned). Examples of additional com pounds which may be o-acylated to form compounds within Formula D are disclosed and claimed in the copending application of Elkan R. Blout, Milton Green, Myron S. Simon, Howard G. Rogers and Robert B. Woodward, Serial No. 98,287, filed March 27, 1961. Compounds within Formula D, when n=0, that may be used in this invention are disclosed in the copending application of Myron S. Simon, Serial No. 196,523, filed May 21, 1962, as a continuation-in-part of Serial No. 612,053, filed September 25, 1956 (now abandoned). It has also been found convenient to use the hydrohalide salt of compounds within Formula D, in the preparation of compounds of this invention.

The compounds Within Formula C are disclosed and claimed in the copending application of Milton Green and Phylis T. Moore, Serial No. 130,489, filed August 10, 1961.

The dye developers of Formula A'Wherein Q is a radical may be prepared by diazotizing a compound of the formula:

wherein R p, X and R have the same meaning as above, and coupling the diazotized compound into a compound within Formula C and removing the protective groups of Y The protecting groups are removed prior to photographic utilization of the dyes, for example, the acyloxy protective groups are removed to generate thereby hydroxyl groups, the removal being accomplished, for example, by hydrolysis in the presence of alkali.

23 It will be understood that suitable precautions should be taken during the hydrolysis step to avoid hydrolysis also of the group in the 3-position. The acyloxy protective groups of Y are less stable to hydrolysis than the ester group in the 3-position and may be removed, therefore, with relatively mild hydrolysis reaction conditions which will leave said ester group in the 3-position unaffected.

The dye developers of this invention wherein Q is a I? i CNR3 radical may be prepared by reacting a compound of Formula A wherein Q is a radical with an excess of an amine. This method of preparing dye developers utilizes the increased reactivity of the 3-carboxylate group by treating the corresponding azopyrazolone 3-carboxylate dye with the appropriate nucleophile, preferably an amine function, to convert the carboxylate group to a carbamyl group by a replacement reaction. The thus-formed 3-carbamyl dye is relatively difficult to hydrolyze unlike the 3-carboxylate dyes which possess a susceptibility to hydrolysis.

It should be noted that the novel dye developers of the present invention wherein Q is a radical may also be prepared by reacting compounds of Formula C and E as above and then treating the thusformed product with an excess of an amine before removing the protective groups. In such a process the protective groups are removed at the same time the 3-ester group is replaced by the amide.

As examples of amines suitable for use in the present invention, mention may be made of alcoholic ammonia, primary amines, such as ethylamine, secondary amines, such as diethylamine, heterocyclic amines such as piperidine, hydrazines, hydroxylamines, and guanidine.

The dye developers of the present invention wherein R is a sulfonamido radical and the o H ll l,

alkylene OH radical have been found, unexpectedly, to possess advantageous properties over corresponding dye developers which do not possess such a sulfonamido radical. The above-mentioned sulfonamido-containing dye developers have been found to exhibit a still greater degree of control, contrast and stability than that possessed by dye developers which do not contain such a sulfonamido radical, such as the yellow dye developers of the above-mentioned copending application, Serial No. 130,- 468, and other prior art yellow dye developers such as, for example, l-phenyl-3-N-n-hexylcarbamyl-4-[p-(2,5'- dihydroxyphenethyl) -phenylazo] -5-pyrazolone.

The following non-limiting examples illustrate the preparation of dye developers Within the scope of this invention wherein Q is a Example 1 radical A solution of 2 grams of 2,4-dimethylaniline, 2.7 ml. of

concentrated hydrochloric acid and ml. of water was prepared and cooled to 0.5 C. A solution of 0.76 gram of sodium nitrate in 5 ml. of water was added with stirring. Stirring was continued 10 minutes and then a solution of 3 grams of l-(p-[2,5'-diacetoxyphenethyl]phenyl)-3-carbethoxy-5-pyrazolone, 10 grams of sodium bicarbonate, 200 ml. of acetone and 100 ml. of Water was added dropwise, with the temperature maintained at 510 C., until a spot test with resorcinol showed a slight excess. After stirring for an hour, the mixture was acidified, with hydrochloric acid, filtered, washed with water and dried with suction. The solid dye was then added to 500 ml. of methyl cellosolve in a 1 liter 3-necked flask. Nitrogen was allowed to bubble through the mixture for 20 minutes at room temperature. An oxygen-free solution of 0.65 gram of sodium hydroxide in 25 ml. of water was added to the mixture and nitrogen again allowed to bubble through the mixture for 90 minutes. 10 ml. of concentrated hydrochloric acid was then added to the mixture. The product was then precipitated by the addition of water and separated. The resulting product, 1-(4"-hydroquinonylethylphenyl) 3 carbethoxy-4-(2,4'-dimethylphenylazo)-5-pyrazolone, melted at 96101 C.

Example 2 2,6-dimethylaniline was diazotized and coupled into l-(p-[2,5'-diacetoxyphenethyl]-phenyl 3 carbethoxy- S-pyrazolone according to the procedure of Example 1. The resulting product, 1-(4"-hydroquinonylethylphenyl)- 3-carbethoxy-4-(2,6' dimethylphenylazo)-5-pyrazolone, melted at -175 C.

Example 3 p-Toluidine was diazotized and coupled into 1-(p-[2, 5'-diacetoxyphenethyl] -phenyl) 3 carbethoxy-S-pyrazolone according to the procedure of Example 1. The resulting product, 1-(4"-hydroquinonylethylphenyl-3-car bethoxy-4-(4'-methylphenylazo)-5-pyrazolone, melted at 207211 C. with decomposition.

Example 4 4-N-diethylsulfonamidoaniline was diazotized and coupled into 1- (p- [2,5 '-diacetoxyphenethyl] -phenyl -3 -carbethoxy-S-pyrazoline according to the procedure of Example 1. The resulting product, 1-(4"-hydroquinonylethylphenyl) 3 carbethoxy 4 (4' N,N diethylsulfonamidophenylazo)-5-pyrazolone, melted at 242- 245 C. with decomposition.

Example 5 .2,3-dimethylaniline was diazotized and coupled into 1-(p-[2,5' diacetoxyphenethyl] phenyl) 3 carbethoxy-S-pyrazolone according to the procedure of Example 1. The resulting product, 1-(4-hydroquinony1ethylphenyl) 3 carbethoxy-4-(2,3'-dimethylphenylazo)-5- pyrazolone, melted at 115-122 C. with decomposition.

Example 6 2,4-dimethylaniline was diazotized and coupled into 1-(p-[2,5'-diacetoxyphenylpropyl]-phenyl) 3 carbethoxy-S-pyrazolone according to the procedure of Example 2. The resulting product, 1-(4"-hydroquinonylpropylphenyl) 3 carbethoxy-4-(2',4'-dimethylphenylazo)-5- pyrazolone, melted at 100-105 C.

Example 7 2,4,6-trimethylaniline was diazotized and coupled into 1-(p-[2',5' diacetoxyphenethyl] phenyl) 3 carbethoxy-5-pyrazolone according to the procedure of Example 1. The resulting product, 1-(4"-hydroquinonylethylphenyl) 3 carbethoxy 4 (2,4',6 trimethylphenylazo)-5-pyrazolone, melted at -188 C.

Example 8 l-naphthylamine was diazotized and coupled into 1-(p 25 [2,5' diacetoxyphenethyl] phenyl) 3 carbethoxy-5- pyrazolone according to the procedure of Example 1. The resulting product, 1-(4"-hydroquinonylethylphenyl)- 3-carbethoxy-4-(1-naphthylazo)-5-pyrazolone, melted at 134-140 C.

Example 9 2-methoxyaniline was diazotized and coupled into 1-(p-[2,5' diacetoxyphenethyl] phenyl) 3 carbethoxy-S-pyrazolone according to the procedure of Example 1. The resulting product, 1-(4-hydroquinonylethylphenyl) 3 carbethoxy 4 (2'-methoxyphenylazo)-5- pyrazolone, melted at 228-232 C.

Example 10 2-chloro-4-methylaniline was diazotized and coupled into 1-(p-[2',5-diacetoxyphenethyl] phenyl)-3-carbethoxy-5-pyrazolone according to the procedure of Example 1. The resulting product, 1-(4"-hydroquinonylethylphenyl) 3 carbethoxy 4 (2.-chloro-4'-methylphenylazo)-5-pyrazolone, melted at 106-113 C.

Example 13 2-methyl-4-chloroaniline was diazotized and coupled into l-(p-[2',5'-diacetoxyphenethyl] phenyl)-3-carbethoxy-5-pyrazolone according to the procedure of Example 1. The resulting product, 1-(4-hydroquinonylethylphenyl) 3 carbethoxy 4 (2-methyl-4'-chloropheny1- azo)-5-pyrazolone, melted at 143149 C.

Example 14 2,4-metl1ylaniline was diazotized and coupled into 1-(p-[2,5' diacetoxyphenyl] phenyl) 3 carbethoxy- 5-pyrazolone according to the procedure of Example 1. The resulting product, l-(4"-hydroquinonylphenyl)-3- carbethoxy 4 (2,4'-dimethylphenylazo)-8-pyrazolone, melted at 12813=0 C.

Example 15 2,4-dimethylaniline acetate was diazotized and coupled into 1-(p-[2',5'-diacetoxyphenylpropyl] phenyl)-3-carbethoxy-S-pyrazolone according to the procedure of Example 1. The resulting solid was hydrolyzed with sodium hydroxide in a nitrogen atmosphere. The product, 1-(4" hydroquinonylpropylphenyl) 3 carbethoxy-4- (2',4'-dimethylphenylazo)-5-pyrazolone, melted at 100- 105 C.

Example 16 O-arninobenzotrifluoride was diazotized and coupled into 1-(p-[2',5'-diacetoxyphenethyl] phenyl)-3-carbethoxy-S-pyrazolone according to the procedure of Example 1. The resulting product, 1-(4"-hydroquinonylethylphenyl) 3 carbethoxy 4 (2-trifluoromethylphenylazo)-5-pyrazolone melted at 110-418 C.

The following nonlimiting examples illustrate the prep aration of dye developers within the scope of this invention wherein Q is a radical.

26 Example 17 A 100 ml. stainless steel bomb containing 5.84 g. (0.01 M) of 1-(4"-hydroquinonylphenethyl)-3-carbethoxy-4 (4'-methylphenylazo)-5-pyrazolone was chilled in a Dry Ice bath and flushed with nitrogen. 30 ml. of ethylamine was then added and the bomb was sealed and heated on the steam bath overnight. The bomb was then cooled to below room temperature and opened. The excess ethylarnine was removed by passing a stream of nitrogen through the reaction mixture. The temperature of the bomb was maintained at room temperature and deaerated dilute hydrochloric acid was added. The resulting solid was filtered, washed with more dilute hydrochloric acid and dried with suction. The product 1-(4" hydroquinonylethylphenyl) 3 N ethyl carbamyl 4- (2',4'-dimethylphenylazo)-5-pyrazolone, melted at 245 C. with decomposition and showed the following analysis calculated for C H N O C H N Calculated 67. 4 5. 7 14. 0 Found 67. 2 5. 9 13. 6

Example 18 100 ml. of 40% methylamine were placed in a 250* m1. round bottom flask, flushed with nitrogen for 5 minutes. 5.51 g. (0.01 M) of 1-(4"-hydroquinonylethylphenyl)-3- carbethoxy 4 (2',4',6 trimethylphenylazo)-5-pyrazolone were added to the flask. The flask was fitted with a condenser, and an adapter and a balloon were fitted to the open end of the condenser. The mixture was left standing overnight. The excess methylamine was then boiled oil on the steam bath. Deaerated dilute hydrochloric acid was added to the reaction mixture and the resulting solid was filtered, Washed with dilute hydrochloric acid and sucked dry. The product, 1-(4"-hydroquinonylethylphenyl) 3 N methyl carbamyl-4-(2, 4',6'-trimethylpheny1azo)-5-pyrazolone, melted at 206-7 C. with decomposition. The spectral absorption curve exhibited a k at 438 mp; e=18,100.

Example 1 9 1-(4"-hydroquinonylethylphenyl) 3 carbethoxy 4- (2',4,6'-trimethylphenylazo) 5 pyrazolone was treated with an excess of dimethylamine for 16 hours at -100 C. The resulting product, 1 (4" hydroquinonylethylphenyl)-3 N,N dimethylcarbamyl-4-(2',4,6-trimethylphenylazo)-5-pyrazolone melted at 21011 C., with decomposition. The spectral absorption curve showed a xmax, at 415 m e=18,800.

Example 20 1 (4" hydroquinonylethylphenyl) 3 carbethoxy-4- (2',4,6-trimethylphenylazo) 5 pyrazolone was heated with an excess of piperidine for 16 hours at 90-100" C. The resulting product, 1-(4"-hydroquinonylethylphenyl)- 3-(N-pentamethylene)-carbamyl 4 (2','4,6-trimethylphenylazo)-5-pyrazolone melted at 219-21 C. The spectral absorption curved exhibited a A at 412 m e=19,000.

Example 21 1-(4'-hydroquinonylethylphenyl) 3 carbethoxy 4- (2,4',6-trimethylphenylazo) 5 pyrazolone was heated with alcoholic ammonia for 16 hours at 90-100 C. The resulting product, 1 (4" hydroquinonylethylphenyl)-3- carbarnyl 4(2',4',6' trimethylphenylazo)-5-pyrazolone melted at 201.5-202.5 C. The spectral absorption curve exhibited a A at 440 m e: 17,400.

Example 22 1-(4"-hydroquinonylethylphenyl) 3 N,N-diethylcarbamyl 4 (2',4,6-trirnethylphenylazo) 5 pyrazolone Was prepared by treating 1-(4"-hydroquinonylethylphenyl) 3 carbethoxy-4-(2',4,6'-trimethylphenyl-azo)- 2? S-pyrazolone with an excess of diethylamine for 16 hours at 90100 C.

Example 23 1 (p [2,5 diacetoxyphenylpropyl] -phenyl) 3 carbethoxy 4 (2.,4,6-trimethylphenylazo) 5 pyrazolone Was treated with methylaminoethanol in a nitrogen atmosphere to provide 1-(4"-hydroquinonylpropylphenyl)-3- (N-ethyl-N-hydroxyethyl-carbarnyl) 4 (2,4,6' trimethylphenylazo)-5-pyrazolone, melting at 201-24 C. with decomposition. a 1 Example 24 l-(p [2,5' diacetoxyphenylpropyl]-phenyl)-3-carbethoxy-4-(2',4',6-trimethylpheriylazo) 5 pyrazolone was treated with 3-amino-1-propanol at 90- 95 C. to provide 1 (4 hydroquinonylpropylphenyl) 3 (N hydroxypropyl) carbamyl 4 (2',4',6 trimethylphenylazo)-5-pyrazolone melting at 162164 C.

Example 25 l-(p-[2,5'-diacetoxyphenethyl] phenyl) 3 carbethoxy 4 (2',4,6'-trimethylphenylazo)-5-pyrazol0ne was heated with an excess of n-propylamine to provide 1-(4f'-' hydroquinonylethylphenyl) 3 N-n-propylcarbamyl-4- (2',4',6-trimethylphenylazo) 5 pyrazolone, melting at I Example 26 7 4 l-(p-[2,5-diacetoxyphenylpropyl]-phenyl) 3 carbethoxy 4 (2',4',6'-trimetl1ylphenylazo)-5-pyrazolone was heated in a nitrogen atmosphere with an excess of 2-amino-2-rnethyl-1,3-propanediol to provide 1-(4-hydro quinonylpropylphenyl) 3 (N-a,ot'-bishydroxymethyl)- ethylcarbamyl 4 (2,4',6'-trimethylphenylazo)-5-pyrazolone which melted at l35140 C.

Example 27 l-(p [2,5'-diacetoxyphenethyl]-phenyl)-3-carbethoxy- 4-(2',4,6-trimethylphenylazo)-5-pyrazolone was treated with 1-arnino-2-propanol to provide 1-(4"-hydroquinonylethylphenyl) 3 (2-hydroxypropyl)-carbaniyl-4-(2',4', 6-trimethylphenylazo)-5-pyrazolone, melting at 206 207 C.

The following non-limiting examples illustrate the photographic utilization of the dye developers of this invention:

.. Example 28 I A photosensitive element was prepared by coating a gelatin subcoated film base with a solution comprising 0.089 g. of 1-(4"-hydroquinonylethylphenyl) 3 canbethoxy-4-(2',4,6'-trimethylphenylazo) 5 pyrazolone dissolved in cc. of a solution of 2% cellulose acetate hydrogen phthalate in a 50:50 mixture, by volume, of tetrahydrofuran and acetone. After this coating dried, a bluesensitive silver iodobromide emulsion was applied and allowed to dry. This photosensitive element was exposed, and brought into superposed relationship with an imagereceiving element as an aqueous liquid composition comprising:

Water cc 100 NaOH g 5.17 Hydroxyethyl cellulose (high viscosity) [commercially available from Hercules Powder Cot, Wilmington 99, Delaware, under the trade name Natrosol 250] g 4.03 Sodium thiosulfate g 1.15 Benzotriazole g 2.3 N-bGI'lZYI-OL-PlCOliIllllfl'l bromide g 2.3

was spread between said elements. The image-receiving element comprised a 2:1 mixture, by weight, of polyvinyl alcohol and poly-4-vinylpyridine on a baryta paper sup port. After an imbibition period of approximately one minute, the image-receiving element was separated. and contained a yellow positive image.

Example 29 The procedure described in Example 28 was repeated,

except that the dye developer was dispersed in a layer of gelatin. The coating solution from which the dye developer layer was coated was prepared by adding 0.5 g. of the dye developer dissolved in 1.5 cc. of N-n-butylacetanilide to 5 g. of 10% gelatin solution, 1.67 cc. of water, and 0.67 cc. of Alkanol B. Emulsification was eifected by high speed agitation in a Waring Blendor. 5 cc. of the resulting dye dispersion was added to 10 cc. of Water containing small amounts of saponin and succinaldehyde, and then cooled on the gelatin subcoated cellulose acetate film base.

Example 30 Water cc NaOH g 5.17

Hydroxyethyl cellulose (high viscosity) [commercially available from Hercules Powder Co., Wilmington 99, Delaware, under the trade name Natrosol 250] g 4.03 Sodium thiosulfate g 1.15 Benzotriazole g 2.3 N-benzyl-a-picolinium bromide g 2.3

was spread between said elements. The image-receiving element comprised a 2:1 mixture, by weight, of polyvinyl alcohol and poly-4-vinylpyridine on a baryta paper support. After an irnbibition period of approximately 1 minute, the image-receiving element was separated and contained a yellow positive image. Example 31 The procedure described in Example 30 was repeated, except that the dye developer was dispersed in a layer of gelatin. The coating solution from which the dye developer layer was coated was prepared by adding 0.5 g. of the dye developer dissolved in 1 cc. of N-nbutylacetanilide and 0.5 cc. of cyclohexanone to 5 g. of 10% gelatin solution, 1.67 cc. of water, and 0.67 cc. of Alkanol B. Emulsification was effected by high speed agitation in a Waring Blendor. 5 cc. of the resulting dye dispersion were added to 10 cc. of water containing small amounts of saponin and succinaldehyde, and then coated on the gelatin-subcoated cellulose acetate film base.

Example 32 A photosensitive element was prepared by coating a gelatin subcoated film base with a solution comprising 0.089 g. of 1-(4'-hydroquinonylethylphenyl)-3-N-(3"- hydroxypropyl) carbarnyl 4 [(2" N,N diethylsulfonarnido)-phenylazo]-5-pyrazolone dissolved in 10 cc. of a solution of 2% cellulose acetate hydrogen phthalate in distilled tetrahydrofuran. After this coating dried, a blue-sensitive silver iodobromide emulsion was applied and allowed'to dry. This photosensitive element was exposed, and brought into superposed relationship with an 29 was spread between said elements. The image-receiving element comprised a 2:1 mixture, by weight, of polyvinyl alcohol and poly-4-vinylpyridine on a baryta paper support. After an imbibition period of approximately 1 minute, the image-receiving element was separated and contained a yellow positive image.

Example 33 The procedure described in Example 32 was repeated, except that the dye developer was dispersed in a layer of gelatin. The coating solution from which the dye developer layer was coated was prepared by adding 0.5 g. of the dye developer dissolved in 1 cc. of N-n-butylacetanilide and 0.5 cc. of cyclohexanone to '5 g. of 10% gelatin solution, 1.67 cc. of water, and 0.67 cc. of Alkanol B. Emulsification was effected by high speed agitation in a Waring Blendor. 5 cc. of the resulting dye dispersion was added to cc. of water containing small amounts of saponin and succinaldehyde, and then coated on the gelatin-subcoated cellulose acetate film base.

Substitution of the other dye developers described above in the procedures described in Examples 28 through 33 gave similar positive transfer images.

In order to illustrate the above-mentioned increased stability of the dye developers of this invention wherein R is a sulfonamido radical and the group is a I I-akylene- O H group, a comparison of results of an accelerated fading test was made.

The yellow positive image prepared by the process of Example 32 was exposed (over saturated NaCl) to a xenon are along with yellow positive images prepared according to the procedure of Example 32 but using (A) l phenyl 3 N n hexylcarbamyl 4 [p (2',5'- dihydroxyphenethyl)-phenylazo]-5-pyrazolone in one instance and (B) 1,3-N,N-diethylcarbamyl-4-(2,4',6'-trimethylphenylazo)5-pyrazolone in another instance. The positive image of Example 32 was designated (C). The table below sets forth the percent fading after swabbing the prints with a boric acid solution followed by exposure to the xenon are for 40 and 100 hours. The integral densities of the images were measured prior to the test and after exposure to the xenon are. From these values, the percent fading was calculated.

Percent Fading It should also be noted that the dye developers of this invention fade to a true yellow color. In other words, a color change is not involved as a result of the fading of the image, just a diminishing of the intensity of the same color.

The novel dye developers of this invention are also suitable for use with liquid processing compositions which contain cesium hydroxide, which are disclosed and claimed in the copending application of George H. Fernald, Jr., Serial No. 247,867, filed December 28, 1962, and compositions which contain potassium hydroxide, which are disclosed and claimed in the copending application of Dorothy C. Mendelsohn, Serial No. 247,863, filed December 28, 1962. e

The novel dye developers of this invention are also suitable for use with image-receiving elements containing a layer of a polymeric acid between the image-receiving 3%) layer and the support and prepared in accordance with the invention disclosed and claimed in the copending application of Edwin H. Land, Serial No. 234,864, filed November 1, 1962.

The dye developers of this invention are also useful in integral multilayer photosensitive elements for use in multicolor diffusion transfer processes. As an example of such photosensitive elements, mention may be made of the photosensitive elements disclosed and claimed in the copending U.S. application of Edwin H. Land and Howard G. Rogers, Serial No. 565,135, filed February 13, 1956, wherein at least two selectively sensitized photosensitive strata are superposed on a single support and are processed, simultaneously and without separation, with a single common image-receiving element. A suitable arrangement of this type comprises a support carrying a red-sensitive silver halide emulsion stratum, a greensensitive silver halide emulsion stratum and a blue-sensitive silver halide emulsion stratum, said emulsions having associated therewith, respectively, a cyan dye developer, a magenta dye developer and a yellow dye developer. In one of the preferred embodiments of photosensitive elements of this type, the dye developers are disposed in separate alkali-permeable layers behind the photosensitive silver halide emulsion stratum with which they are associated.

The photosensitive elements within the scope of this invention may be used in roll film units which contain a plurality of photosensitive frames. The photosensitive elements of this invention are especially useful in composite roll film intended for use in a Polaroid Land Camera, sold by Polaroid Corporation, Cambridge 39, Massachusetts, or a similar camera structure such, for example, as the camera forming the subject matter of US. Patent No. 2,435,717, issued to Edwin H. Land on February 10, 1948. In general, such composite roll films comprise a photosensitive roll, a roll of image-receiving material and a plurality of pods containing an aqueous alkaline processing solution. The rolls and pods are so associated with each other that, upon processing, thephotosensitive element may be superposed on the imagereceiving element and the pods may be ruptured to spread the aqueous alkaline processing solution between the superposed elements. The nature and construction of the pods used in such units are well known to the art. See, for example, US. Patents Nos. 2,543,181 and 2,634,886, issued to Edwin H. Land.

It will be noted that the liquid processing composition may contain one or more auxiliary or accelerating silver halide developing agents, such as p-methylaminophenol (Metol); 2,4-diaminophenol (Amidol); benzylaminophenyl; hydroquinone; a substituted hydroquinone such as toluhydroquinone, phenylhydroquinone, or 4'- methylphenylhydroquinone; or a 3-pyrazolidone such as 1-phenyl-3-pyrazolidone. These silver halide developing agents are substantially colorless, at least in their unoxidized form. It is possible that some of the dye developer oxidized in exposed areas may be oxidized by an energy transfer reaction with oxidized auxiliary developing agent.

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 US. application of Milton Green and Howard G. Rogers, Serial No. 50,851, filed August 22, 1960.

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 12% 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 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 medium are self-sufiicient 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 between a color former or coupler and the oxidized developing agent, as well as so-called auto-coupling processes in which color is obtained by a reaction of the oxidized developing agent with unoxidized developing agent.

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.

As examples of useful image-receiving materials, mention may be made of nylon, e.g., N-methoxyrnethyl-polyhexamethylene adipamide, polyvinyl alcohol, and gela tin, particularly polyvinyl alcohol or gelatin containing a dye mordant such as poly-4-vinyl-pyridine. The imagereceiving element also may contain a development restrainer, e.g. 1-phenyl-5-mercaptotetrazole, as disclosed in the copending application of Howard G. Rogers and Harriet Y. Lutes, Serial No. 50,849, fiied August 22, 1960.

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.

The novel compounds herein disclosed are also suitable for use as dyes for textile fibres, such as nylon.

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.

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' process for forming a photographic image in color comprising developing an exposed silver halide emulsion by contacting said exposed silver halide emulsion with an aqueous alkaline solution comprising a dye wherein R is selected from the group consisting of lower alkoxy, halogen, lower alkyl, trifluoromethyl and sulfonamido radicals, p is an integer from to 4, inclusive, X is selected from the group consisting or hydrogen, lower alkoxy, halogen, lower alkyl, trifiuoromethyl, and sulfonamido radicals, said X being located ortho to said -H=N-radical, R is selected from the group consisting of phenyl and naphthyl radicals, Ar is a phenylene radical, M is a lower alkylene radical, n is an integer from 0 to 1, inclusive, Y is selected from the group consisting of orthoand para-dihydroxyphenyl radicals and alkyl and halogen derivatives thereof, Q is selected from the group consisting of -ii-o-z and NR radicals wherein Z is a lower alkyl radical and R and R each are selected from the group consisting of hydrogen and alkyl radicals and R and R taken together is a divalent aliphatic radical, to thereby provide a predetermined imagewise distribution of unoxidized dye developer, and transferring at least a part of said imagewise distribution of unoxidized dye developer by imbibition to an image-receiving layer in superposed relationship with said silver halide emulsion to impart a dye image to said image-receiving layer.

2. A process as defined in claim 1 wherein said dye developer is disposed, prior to exposure, in the photosensitive element comprising said exposed silver halide emulsion, and the solution containing said dye developer is formed by permeating said photosensitive element with an aqueous alkaline liquid capable of solubilizing said dye developer.

3. The process as defined in claim 2 whereby said liquid is introduced by being spread in a substantially uniform layer as said photosensitive element and imagereceiving layer are brought into superposed relationship.

4. The process as defined in claim 2 wherein said liquid contains a thickener for increasing viscosity and for facilitating the spreading thereof between said photosensitive element and said image-receiving layer.

5. A process as defined in claim 2 where in said aqueous alkaline solution also contains a silver halide developing agent which is substantially colorless in at least its unoxidized state.

6. A process as defined in claim 1 wherein said dye developer is 1 (4" hydroquinonylethylphenyl)-3-carbethoxy-4-2',6-dimethylphenylazo) -5-pyrazolone.

7. A process as defined in claim 1 wherein said dye developer is 1 (4" hydroquinonylethylphenyl)-3-carbethoxy-4-( 1'-naphthylazo) -5-pyrazolone.

8. A process as defined in claim 1 wherein said dye developer is 1-(4"-hydroquinonylethylphenyl)-3-N-ethylcarbamyl-4-(2,4-dimethylphenylazo-5-pyrazolone.

9. A process as defined in claim 1 wherein said dye developer is 1 (4" hydroquinonylethylphenyl)-3-(N- pentamethylene) carbamyl-4-(2,4',6 trimethylphenylazo)-5-pyrazolone.

10. A process as defined in claim 1 wherein said dye developer is 1-(4" hydroquinonylpropylphenyl) 3 N- (3'-hydroxypropyl carbamyl 4 [(2'-N,N-diethylsulfonamido) -phenylazo] -5-pyrazolone.

11. A photographic product comprising a support, a plurality of layers on said support, at least one silver halide emulsion layer on said support, at least one of said layers containing a dye developer of the formula:

wherein R is selected from the group consisting of lower alkoxy, halogen, lower alkyl, trifiuoromethyl and sulfonamido radicals, p is an integer from 0 to 4, inclusive, X is selected from the group consisting of hydrogen, lower alkoxy, halogen, lower alkyl, trifiuoromethyl, and

sulfonarnido radicals, said X being located ortho to said N:N- radical, R is selected from the group consisting of phenyl and naphthyl radicals, Ar is a phenylene radical, M is a lower alkylene radical, n is an integer from to 1, inclusive, Y is selected from the group consisting of orthoand para-dihydroxyphenyl radicals and alkyl and halogen derivatives thereof, Q is selected from the group consisting of radicals, wherein Z is a lower alkyl radical, and R and R each are selected from the group consisting of hydrogen and alkyl radicals and R and R taken together is a divalent aliphatic radical.

12. A product as defined in claim 11 wherein said dye developer is 1-(4"-hydroquinonylethylphenyl)-3-(N-hydroxypropyD-carbamyl 4 (2'-trifluoromethylphenylazo --pyrazolone.

13. A process as defined in claim 11 wherein said dye developer is 1- (4"-hydroquinonylpropylphenyl)-3-(N- hydroxypropyl)-carbarnyl 4 (3-trifluoromethylphenylazo) -5-pyrazolone.

14. A process as defined in claim 11 wherein said dye developer is 1-(4"-hydroquinonylethylphenyl)-3-(N-hydroxypropyD-carbarnyl 4 (3'-trifluoromethylphenylazo)-5-pyrazolone.

15. A process as defined in claim 11 wherein said dye developer is 1-(4"-hydroquinonylethylphenyl)-3-(N-hydroxypropyl)-carbamyl 4 (2,4,6' trimethylphenylazo) -5-pyrazolone.

16. A process as defined in claim 11 wherein said dye developer is 1-(4"-hydroquinonylpropylphenyl)-3-N-hydroxypropyD-carbamyl 4 (2',4',6' trimethylphenylazo) -5-pyrazolone.

17. A process of developing an exposed silver halide emulsion which comprises treating said emulsion with an aqueous alkaline solution comprising a compound of the formula:

HO- N/ lit-(M) n Y wherein R is selected from the group consisting of lower alkoxy, halogen, lower alkyl, trifluoromethyl and sulfonamido radicals, p is an integer from 0 to 4, inclusive,

34 X is selected from the group consisting of hydrogen, lower alkoxy,'halogen, lower alkyl, trifluoromethyl, and sulfonamido radicals, said X being located ortho to said -N=N- radical, R is selected from the group consisting of phenyl and naphthyl radicals, Ar is a phenylene radical, M is a lower alkylene radical, n is an integer from O to 1, inclusive, Y is selected from the group consisting of orthoand para-dihydroxyphenyl radicals and alkyl and halogen derivatives thereof, Q is selected from the group consisting of o 0 R i3oz and i 1 IR radicals, wherein Z is a lower alkyl radical, and R and R each are selected from the group consisting of hydrogen and alkyl radicals and R and R taken together is a divalent aliphatic radical.

18. A photographic developer composition comprising an aqueous alkaline solution of a colorless silver halide developing agent and a dye developer of the formula:

| v" l 'Q .z kr(M)nY wherein R is selected from the group consisting of lower alkoxy, halogen, lower alkyl, trifluoromethyl and sulfonamido radicals, p is an integer from 0 to 4, inclusive, X is selected from the group consisting of hydrogen, lower alkoxy, halogen, lower alkyl, trifluoromethyl, and sulfonamido radicals, said X being located ortho to said --N=N radical, R is selected from the group consisting of phenyl and naphthyl radicals, Ar is a phenylene radical, M is a lower alkylene radical, n is an integer from 0 to 1, inclusive, Y is selected from the group consisting of orthoand para-dihydroxyphenyl radicals and alkyl and halogen derivatives thereof, Q is selected from the group consisting of i1O-Z and J-1 IR radicals, wherein Z is a lower alkyl radical, and R and R each are selected from the group consisting of hydrogen and alkyl radicals and R and R taken together is a divalent aliphatic radical.

No references cited.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,141,772 July 2l 1964 Milton Green It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3, lines- 141 to 20 the lower portion of the formula reading:

Rr-(M) -Y read Ar(M) -Y column 8, lines 1 to 16, for that portion of the formula reading:

ll read N N I 1 column 10 lines '18 to 33 the formula should appear as shown helow instead of as in the patent:

column 13, lines 20 to 35, for that portion of the formula reading OH OH read column 14, line 37, for "(N-hydr0xypropy)" read (Nhydroxy propyl)- column 16, lines 40 to 54, for that portion of the formula reading: 0

C-NHCH -iH-CH read --CNHCH 3HCH H OH column 20, lines 40 to 54, for that portion of the formula reading CNHCH CH CH OH read -C -NHCd CH CI-l OH column 26, line 6, for "was", first occurrence, read were column 31, line 43, for "Harriet Y. Lutes" read Harriet W. Lutes column 32, line 1, for "or" read of line 4, for "H=N-" read -N=N line 45, for "4-2 6 read 4(2,6 line 58, for "(3hydroxypropyl" read (3hydroxypropyl)- Signed and sealed this 9th day of March 1965.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents

Claims

1. A PROCESS FOR FORMING A PHOTOGRAPHIC IMAGE IN COLOR COMPRISING DEVELOPING AN EXPOSED SILVER HALIDE EMULSION BY CONTACTING SAID EXPOSED SILVER HALIDE EMULSION WITH AN AQUEOUS ALKALINE SOLUTION COMPRISING A DYE DEVELOPER OF THE FORMULA: