US3676124A - Photographic negative material for color diffusion transfer process - Google Patents

Abstract

PHOTOGRAPHIC DIFFUSION TRANSFER ELEMENT WITH A SILVER HALIDE EMULSION CONTAINING A COLOR DEVELOPING AGENT AND COUPLER DISSOLVED IN A HIGH TEMPERATURE BOILING ORGANIC SOLVENT WHICH IS IMMISCIBLE WITH WATER, BUT MISCIBLE UPON CONTACT WITH AN ALKALINE MEDIUM. A COLOR DIFFUSION TRANSFER PROCESS USING THE ABOVE ELEMENT AS A NEGATIVE INVOLVES EXPOSING THE ELEMENT AND THEN, BY ALKALINE PROCESSING, FREEING THE SOLVENT TO THEREBY PERMIT TRANSFER TO A POSITIVE ELEMENT AND YIELD A POSITIVE ELEMENT. CONVENTIONAL DIFFUSION TRANSFER STEPS ARE ALSO PRACTICAL.

Description

United States Patent O1 3,676,124 Patented July 11, 1972 lice PHOTOGRAPHIC NEGATIVE MATERIAL FOR COLOR DIFFUSION TRANSFER PROCESS Kinji Ohkubo, Katsumi Hayashi, and Kazuya Sano, Kanagawa, Japan, assignors to Fuji Photo Film Co., Ltd., Ashigara-Kamigun, Kanagawa, Japan No Drawing. Filed Oct. 13, 1969, Ser. No. 866,022 Claims priority, application Japan, Oct. 12, 1968, 43/74,386 Int. Cl. G03c 1/40, 5/54 US. Cl. 96-290 12 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION Field of the invention The present invention relates to a diffusion transfer process and more particularly to a color photographic diffusion transfer process and a transfer material therefor.

Description of the prior art Photographic color diffusion processes are described in many publications and patents known to the prior art. For instance, reference can be made to US. Pat. No. 3,020,- 155 British Pat. No. 1,013,343; and British Pat. No. 1,027,742.

In this type of process, a light-sensitive silver halide emulsion layer on a negative is exposed, and generally contacted with a receiving or positive material in the presence of a developer.

Typically, transfer then occurs from the exposed negative to the unexposed positive whereby the final image desired results. One of the basic problems of the prir r art has been the necessity to utilize special organic coloring materials, for instance, in US. Pat. No. 3,020,155, it is necessary to utilize alkali-soluble acid-insoluble carboxylated cellulose derivatives to replace gelatin.

In British Pat. No. 1,013,343, development nuclei are provided to promote development, these nuclei being material such as the sulphides of the heavy metals, fogged silver halides, etc.

The present invention provides a process involving the same general area of the art as the abovediscussed references, but which provides a unique combination for liberating reactive materials during processing.

Hitherto, various methods or materials have been proposed as useful for color photographic diffusion transfer processes. The material of the present invention is novel and utterly different from conventionally used materials.

SUMMARY OF THE INVENTION The present invention provides a novel photographic negative element for use in a diffusion transfer process which comprises a support having thereon a silver halide emulsion layer containing a coupler dissolved in a high boiling organic solvent and a color developing agent, said coupler being insoluble in water but soluble in an alkaline medium and said organic solvent being immiscible with water but miscible with an alkaline medium. Thus, oily packets are not required.

Further provided is a novel color diffusion process comprising exposing a photographic negative material having a silver halide emulsion layer containing a coupler dissolved in a high boiling organic solvent and a color developing agent, said coupler being insoluble in water but soluble in an alkaline medium, said organic solvent being immiscible with water but miscible with an alkaline medium; processing, in an alkaline processing solution, said negative material being in close contact with a photographic positive material having an image-receiving layer containing an oxidizing agent, said developing agent being thereby consumed by the reaction with silver halide in the exposed areas of said emulsion layer, whereas silver halide, coupler and developing agent in the non-exposed areas thereof are diffusion-transferred to said image-receiving layer by the action of said processing solution to form a color image in said image-receiving layer, and thereafter removing said positive material from said negative material.

One object of the present invention is to provide a novel transfer material useful in the color photographic diffusion transfer process.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS .The negative material used in the present invention is composed of a support having thereon an emulsion layer containing light-sensitive silver halide grains, a color developing agent and a specific coupler (which Will be described below in detail) dispersed in a high boiling organic solvent (which will also be explained below).

The positive material used in the present invention is composed of a support having thereon an image receiving layer containing an oxidizing agent, such as a fogged silver halide emulsion, chloranil or an active clay.

After exposing the negative material to active radiation, the negative material is placed on the positive material so that the exposed emulsion layer of the negative material faces the image-receiving layer of the positive material. This is then immersed in aqueous alkali (as in the conventional silver salt diffusion transfer process), or else, aqueous alkali is inserted between the emulsion layer of the negative material and the image-receiving layer of the positive material by some other suitable manner, such as by using a commercially available processer for the silver salt diffusion transfer process, whereby the aqueous alkali* diffuses into the negative emulsion layer to dissolve the high boiling organic sol-vent. The coupler dispersed in the high boiling organic solvent thus becomes ready to react.

At the exposed portion of the emulsion layer, the color developing agent develops the exposed silver halide grains and suffers oxidation. The oxidation products of the color developing agents which are thus formed give rise to the coupling reaction (color formation) with the couplers in the layer, and a non-difiusible dye deposits in situ.

On the other hand, color developing agent and the coupler at the unexposed portions of the negative emulsion layer diffuse into the image-receiving layer where the color developing agent is oxidized by the oxidizing agent present and reacts with the coupler which also has diffused into this layer. Non-diffusible dyes are thereby deposited in situ. Thus, positive dye images are formed in the imagereceiving layer.

By proper matching of the spectral sensitivity of the silver halide photographic emulsion and the color hue of the formed dyes, a color print can be obtained.

*Preferred pH 29.

As described above, the invention has merits such as the negative material has good preservability or stability since the coupler is protected in an oily packet in the negative emulsion layer. Also, the transfer process can be readily conducted.

Now, the materials used in the present invention will be described below in detail.

The coupler used in this invention is not diffusible in a neutral aqueous solution and becomes diffusible only in alkaline media. It is, however, soluble in the organic solvents later discussed. Moreover, the coupler used in this invention can react with the oxidation product of the color developing agent to form a dye. Typical examples of the couplers used in the present invention are as follows:

1. N-hcptyl-1-hydroxy-2-naphthamide:

C N H C 71115 2. N -(2-ethylhexyl) -1-hydroxy-2-naphthamide:

4. l-phenyl-3-nonyl-5-pyrazo1one:

C s ts-('3 H:

5. 2-butoxy-henzoylacetanl1ide:

As will be inferred from the examples of couplers illustrated above, a coupler containing a chromogenic nucleus such as phenol, naphthol, pyrazolone, and fi-keto acid anilide can be used. These are used in conventional color photography in the substractive color process, and each has a preferred non-difiusibility at a low pH and preferred high diffusibility in a high pH region. The five compounds illustrated above are all novel compounds and the procedures for preparing them will later be explained in detail.

As the color developing agent used in the present invention, there can be given, as illustrative, N,N-dialkyl-pphenylenediamine derivatives which are usually used in color photographic process.

For example, the following well-known compounds can be used as the color developing agent in the present invention:

6. N, N-diethyl-p-phenyleuediamine:

mmnmQaun 7. 3-methyl-4a1nino-N, N-diethylanliine:

NH3 C Has OzNHCHaCHz These developing agents are incorporated in a silver halide emulsion in the form of a free base or as an inorganic acid salt, such as a sulfate or hydrochloride, or as an organic acid salt such as p-toluenesulfonate. Furthermore, to increase the development rate, a developing accelerator such as 1-phenyl3-pyrazolidone may also be incorporated in the emulsion.

The aforesaid components may either be added directly to the silver halide emulsion or be dissolved in the coupled solvent together with the coupler and then dispersed as fine particles in the silver halide emulsion.

When the coupler is incorporated in a silver halide photographic emulsion according to conventional preparation processes for color photographic light-sensitive materials, c.g., by dissolving the coupler in a high 'boiling solvent such as dibutyl phthalate or tricresyl phosphate and dispersing the solution in a silver halide emulsion, the expected color density cannot be obtained. The reason is 'believed to be that since the coupler is present in the oil droplet, the coupler cannot be brought sufliciently into contact with the aqueous alkaline phase during processing. On the other hand, in the present invention, a non volatile solvent which is poorly soluble in water but which becomes soluble in an aqueous alkaline medium is employed as the coupler solvent. Thus, the coupler can easily be dissolved out and diffused into the image-receiving layer to provide therein a transferred image having sufficient color density.

The most preferred solvents used in the present invention for dispersing the coupler in a silver halide emulsion are shown below, although the invention is not limited to them.

9. 2-1nethy1-3,- (N-n-octylacetamldo)-propi0nic acid ns n NOH2CHC O OH CHaCO CH;

10. 2methyl- -[N-(2ethylhexyl)butyramido1-proplonie acid:

C4H9CHCH3 2H5 NOHZOHOOOH n-O H C 0 CH3 11. [N- (2-ethylhexy1) acetamido1-propionie acid:

n-O-iHo CHCHi CZHE NCHzOHzCOOII O ilC Other examples of the solvents useful in the present invention and their procedures for their preparation are described in detail in the specification of Japanese patent application No. 84,02/2/66, U.S. Ser. No. 692,707, filed Dec. 22, 1967, now US. Pat. 3,594,171, filed by one of the inventors of the present application (Kazuya Sano).

The solvents disclosed in said application have the following general formula:

R100 X wherein X represents hydrogen or a methyl group, R and R each represent an unsubstituted or a substituted alkyl group, the sum of the number of carbon atoms in groups R and R being an integer from 7 to 11. Specific examples of such solvents are as follows:

H-CtHq N-CHz-CHr-C OOH n-C H O O Examples of the preparation of the cited solvents are described below:

Preparation of Compound 9: 2-methyl-3-(N-n-octylamido)-propionic acid A mixture of 100 g. of n-octylamine and 65 g. of methyl methacrylate was mixed with 1 g. of sodium methylate and the resulting mixture was allowed to stand for two days on a water bath at about 70 C. The product was then subjected to distillation under reduced pressure, and 95 g. of the adduct was collected as a fraction at 107 C./ 1 mm. Hg.

To all of the product obtained there was added (dropwise) 8 g. of freshly distilled acetic anhydride over a fifteen minute period. The mixture was then heated for 30 minutes on a steam bath and distilled under reduced pressure to provide 94 g. of Compound 9 as a fraction at 142-145" C./1 mm. Hg. When this product was mixed with 250 ml. of an aqueous 2 N sodium hydroxide solution containing 30 ml. of methanol, and the mixture was shaken at room temperature, the system generated heat after a short time, and the liquid became clear. After further shaking the system for a while, the system was then cooled and acidified with concentrated hydrochloric acid to separate an oily substance. The separated layer was extracted with ether, Washed with water, dried with sodium sulfate, and solvent was removed by vacuum evaporation to provide 78 g. of pure Compound 9. The elemental analysis: was Found: N, 5.29%, Calculated: N, 5.45%.

Preparation of Compound 2-methyl-3-[N-(2- ethylhexyl)butyramido]-propionic acid A mixture of 100 g. of Z-ethylhexylamine and 65 g. of methyl methacrylate was mixed with 1 g. of sodium methylate and the resulting mixture was allowed to react for two days at about 70 C. on a water bath. The product was then filtered and the filtrate was distilled under reduced pressure to provide 90 g. of an adduct having a boiling point of 103-109 C. The total amount of the product obtained was dissolved in 1 liter of dehydrated ether and, after the addition of 55 g. of triethylamine, 53 g. of butyryl chloride was added dropwise (with stirring) to the mixture with ice-cooling. Thereafter, the system was stirred for 1 hour and triethylamine hydrochloride, which precipitated was removed 'by filtration and the filtrate washed with water, dried and distilled under reduced pressure to provide 97 g. of Compound 10 as a fraction at 158 C./1 mm. Hg. The product was further processed as in the case of preparing Compound 9 to provide 8 g. of pure product.

Analysis for nitrogen: Found: 4.57%; Calculated: 4.92%.

Preparation of Compound 11: 3-[N-(2-ethylhexyl)- acetamidol-propionic acid To 129 g. of 2-ethylhexylamine was added dropwise, while stirring and cooling the system to a temperature lower than 30 C., 86 g. of methylacrylate.

Thereafter, the mixture was heated for one hour on a hot water bath and then distilled under reduced pressure to provide 170 g. of a fraction at 91 C./1 mm. Hg. The fraction was reacted with 92 g. of freshly distilled acetic anhydride as in the case of preparing Compound 9 and the product was again distilled under reduced pressure to provide 180 'g. of a fraction at -145 C./1 mm. Hg. The product was then mixed with 500 ml. of an aqueous 2 N sodium hydroxide solution containing 50 ml. of methanol and subjected to hydrolysis by shaking the mixture, whereby the liquid became transparent. The solution was then acidified with hydrochloric acid and the oily material that separated was extracted with ether, washed with water, dried, and freed from the solvent by evaporation in vacuo to provide g. of Compound 11.

Analysis for nitrogen: Found: 5.63%; Calculated: 5.76%.

In the practice of the present invention, it is also possible (as shown in Example 5) to transfer multiple-color copy by using a multi-layer color photographic lightsensitive material having photographic emulsion layers which each contains a coupler providing a different color hue and which each have a different spectral sensitivity.

The solvent used for dispersing the coupler in a silver halide emulsion in the present invention need not necessarily be of a single composition, but may be a mixture with a solubilizable amount of an alkali-insoluble solvent.

The oxidizing agent contained in the image-receiving layer of the positive material of the present invention is one which is capable of oxidizing the color developing agent to quinonediimine. Chloranil or active clay is dispersed in a medium such as gelatin or latex and the dispersion is applied to a support. A silver halide emulsion which has been fogged by chemicals or by light is partic ularly excellent with regard to color density. In this case, metallic silver is formed together with a dye image, and hence the former has to be removed in a bleach-fixing or a bleach-stabilizing bath.

By exposing the negative material, followed by bringing the emulsion layer into contact with the image-receiving layer of a positive material and passing the assembly through a processing bath containing an alkali, an image is obtained on the image-receiving layer. After processing, the alkaline solution used in the transfer process must have a concentration sufficient to dissolve the solvent and the coupler to such an extent that they diffuse into the image-receiving layer. A concentration of about 1 N gives best results. To increase the viscosity, sodium carboxymethyl cellulose can be added to the alkaline solution.

Furthermore, as shown in Example 4, by applying a silver halide emulsion layer which has not been fogged to the surface of the negative material, the formation of transfer fog on the image-receiving layer corresponding to the exposed portion of the negative material can be prev ented.

As mentioned above, the primary feature of the present invention is in that the couplers and the color developing agents in the unexposed portions of the negative material diffuse into the image-receiving layer of the positive material, where the coupler causes the coupling reaction with the aid of the oxidizing agents present in the imagereceiving layer. This purpose is achieved by dispersing the coupler which is insoluble in water but soluble in an alkaline solution in the silver halide emulsion for the negative material using a coupler solvent which is insoluble in water but soluble in an alkaline medium.

The invention is not, of course, to be limited to the various compounds heretofore illustrated.

As described above, the practical examples of the couplers shown are novel compounds, and hence procedures for their preparation will be explained by the following examples. It will be understood that other couplers than the ones shown can of course be employed in this invention if they satisfy the aforesaid conditions.

Preparation of compound 1: N-heptyl-l-hydroxy- Z-naphthamide' A mixture of 132 g. of phenyl-1-hydroxyl-2-naphthoate and 63 g. of n-heptylamine was heated to 100 C. for 20 minutes on an oil bath, and then, after raising the bath temperature to 150 C., the reaction was conducted for 20 minutes, whereby the phenol thus formed was removed by distillation. After one hour, the product was mixed with methanol and ice-cooled to form crystals, which were collected and recrystallized from methanol to provide 60 g. of Compound 1 melting at 36 C.

Preparation of Compound 2: N-(2-ethylhexyl)- 1-hydroxy-2-naphthamide A mixture of 132 .g. of phenyl-1-hydroxy-2-naphthoate and 65 g. of 2-ethylhexylarnine was caused to react as above and the reaction product was recrystallized three times from methanol to provide 50 g. of Compound 2 melting at 59 C.

Preparation of Compound 3: l-phenyl-3-pentyl- 5-pyrazolone A mixture of 56 g. of ethyl 3-oxocaprylate (cf. Spath Pikl, Ber. 62, 2250) and 32 g. of phenylhydrazine was mixed with 200 ml. of ethanol containing g. of sodium ethylate, and the resulting mixture was stirred for two hours on a water bath at 60 C. The product was dissolved in 300 ml. of water and neutralized with acetic acid to provide crystals, which were collected and recrystallized twice from methanol to provide 35 g. of Compound 3 melting at 98 C.

Preparation of Compound 4: l-phenyl- 3-nonyl-5-pyrazolone A mixture of ethyl 3-oxo1aurate (cf. Moureu Delange; Compt Read; 136, 754) and 22 g. of phenylhydrazine was treated in 200 ml. of ethanol containing 13 g. of so dium ethylate as in the formation of Compound 2, and 22 g. of Compound 4 melting at 70 C. was obtained by the same procedure as above.

Preparation of Compound 5 2-butoxybenzoylacetanilide In 50 ml. of ethanol were dissolved 139 g. of o-nitrophenol and 150 g. of butyl bromide. 40 g. of sodium hydroxide was dissolved in the smallest possible amount of water and the solution was added to this solution followed by three days refluxing. The mixture was poured in water and the organic layer was extracted with ether. The product was washed with a dilute alkali, dried with sodium sulfite, and distilled under reduced pressure to provide 98 g. of o-butoxynitrobenzene boiling at 106 C./ 1 mm. Hg. The nitro compound was reduced in an autoclave at 120 C., 70 atms. using Raney nickel catalyst to provide 67 g. of o-butoxyaniline boiling at 95 C./1 mm. Hg.

Thirty-three g. of the o-butoxyaniline prepared above and 38.4 g. of ethyl benzoylacetate were heated for two hours at 160 C. and after evaporating the liberated ethanol, the cooled product was mixed with hexane to separate crystals, which were collected and recrystallized from a mixture of benzene and hexane (1:1) to provide 12 g. of Compound 5 melting at 62 C.

The following examples, illustrate how this invention is practiced.

EXAMPLE 1 In 2.1 ml. of ethyl acetate were dissolved 0.9 g. of a cyan forming coupler, N-(Z-ethylhexyl)-1-hydroxy-2- naphthamide (Compound 2) and 2.1 g. of a color developing agent, 3 methyl 4 amino- [N-ethyl-N-(methanesulfonamido)ethyl]-aniline (Compound 8), and the resulting solution was uniformly mixed with 1.1 g. of 3-[N- (2 ethylhexyl)acetamido] propionic acid (Compound 11). The mixture was added to 52 ml. of a 10% gelatin solution containing a surface active agent with mechanical stirring to disperse it into the colloidal state.

To g. of a silver halide emulsion containing 3.0 g. of silver chlorobromide (30 mole percent silver bromide) and 9.0 g. of gelatin there was successively added this dispersion and suitable state of the art amounts of additives. The resultant emulsion was applied to a baryta paper to yield a coated emulsion layer containing 2.0 g. of the silver halide per 1 m? thereof, and dried.

The positive material was prepared by applying a composition consisting of 100 ml. of an aqueous 5% gelatin solution and 0.5 g. of chloranil to a paper followed by drying.

The negative material prepared above was exposed through a negative and immersed for 5 seconds at 25 C. in an activator of the following composition:

Sodium hydroxide: 40 g. Water to make 1 liter The emulsion layer of the negative material having the activator thereon was brought into close contact with the image-receiving layer of the positive material prepared above and they were squeezed together by passing them through a pair of rollers. After 20 seconds, the positive material was separated from the negative material to obtain a cyan color image at the portions of the image-receiving layer corresponding to the unexposed portions of the emulsion layer of the negative material.

EXAMPLE 2 In 5 ml. of methanol was dissolved 2.5 g. of a magenta coupler, 1 phenyl 3 nonyl 5 pyrazolone (Compound 4) and then the solution was mixed with 2.5 g. of a color developing agent, 3 methyl 4 amino- N,N-diethylaniline (Compound 7) and 2.6 g. of a dispersing solvent, 2 methyl 3 [N (2 ethylhexyl)- butyramido]-propionic acid (Compound 10). The resulting solution was colloidally dispersed in 50 ml. of an aqueous 10% gelatin solution with mechanical stirring.

The dispersion thus obtained was added to 100 g. of a silver halide photographic emulsion containing 2.9 g. of silver chloride and 7.45 g. of gelatin, and after adding suitable amounts of additives, the emulsion was applied to a baryta paper to yield a layer containing 1.7 g. of the silver halide per 1 m? of said layer, and dried.

A composition consisting of 100 ml. of an aqueous 0.1% gelatin solution and 10 g. of active clay was applied to a baryta paper to provide a positive material.

The negative material prepared above was exposed through a negative and immersed for 10 seconds in an activator of the following composition:

Sodium hydroxide: 32 g. Water to make 1 liter The emulsion layer of the negative material having the activator thereon was closely brought into contact with the image-receiving layer of the positive material and they were squeezed by passing them in the superposed state through a pair of rollers.

By stripping the positive material from the negative after 60 seconds, a magenta color image was obtained on the image-receiving layer of the positive material corresponding to the unexposed portions of the emulsion layer of the negative material.

EXAMPLE 3 The negative material prepared by the same procedure as m Example 1 was exposed through a negative, the emulslon layer of the negative material was brought into close contact with the image-receiving layer of a positive material which was prepared by applying a silver chloride emulsion, sufliciently fogged by light, to a support. The assembly was immersed in an activator of the following composition:

Sodium hydroxide: 40 g. Water to make 1 liter at 25 C. and thereafter squeezed by passing the superposed assembly through a pair of rollers.

After seconds, the positive material was stripped from the negative material, immersed for 2 seconds in a stopping solution consisting of an aqueous 1.5% acetic acid solution, and processed for seconds at C. in a bleach-stabilizing solution of the following composition to provide a cyan color image on the positive material:

I-ron (ED-ethylenediamine tetraacetic acid complex: 35.0 g. Sodium carbonate monohydrate: 11.0 g. Boric acid: 45.0 g. Ammonium thiosulfate (aq. 69.9% solution): 39.9 ml. Thiourea: 5.0 g. Water to make 1 liter As the silver halide remaining in the positive material was converted into a light-stable silver complex salt by the stabilizing agent (ammonium thiosulfate) for the silver halide, the formation of stain caused by the photd decomposition of the silver halide was prevented without water washing.

EXAMPLE 4 In 1.5 ml. of cyclohexane there was dissolved a magenta coupler, l phenyl 3 pentyl 5 pyrazolone (Compound 3) and the resulting solution was well mixed with 6.3 g. of a dispersing solvent, 2 methyl 3 (N noctylacetamido)-propionic acid (Compound 9). The solution was dispersed in 50 ml. of an aqueous 10% gelatin solution containing a color developing agent, N,N-diethyl-p-phenylenediamine (Compound 6) with mechanical stirring.

The dispersion was added to 100 g. of a gelatino silver chlorobromide emulsion containing 50 mole percent silver bromide, and after adding suitable amounts of standard photographic additives, the resulting emulsion was applied to a baryta paper to yield a coated emulsion layer containing 1.5 g. of the silver chlorobromide per 1 m. of the layer. This was then dried. Onto the emulsion layer thus formed was applied a gelatino silver iodobromide emulsion containing 10 mole percent silver iodide and suitable amounts of additives such as a hardening agent, a wetting agent, etc., so that the layer contained 0.6 g. of the silver iodobromido per 1 m3 thereof.

The emulsion layer of the negative material prepared above was exposed through a negative and closely brought into contact with the image-receiving layer of a positive material prepared by applying a fogged gelatino silver chloride emulsion to a paper in an activator having the following composition:

Sodium hydroxide: 40 g. Water to make 1 liter The assembly in a superposed state was squeezed by passing it through a pair of rollers.

After 60 seconds, the positive material was stripped from the negative material, immersed for 5 seconds in a stopping solution consisting of aqueous 1.5% acetic acid, and then processed for 1 minute in a bleach-fixing solution of the following composition:

Disodium ethylenediamine tetraacetic acid: 45.0 g. Ferric chloride: 32.0 g.

Sodium carbonate monohydrate: 20.0 g.

Potassium bromide: 30.0 g.

Crystalline sodium thiosulfate: 220.0 g. Potassium thiocyanate: 8.5 g. Water to make 1 liter The image-receiving layer was then washed with running water for 30 minutes to provide a magenta color image on the image-receiving layer of the positive material corresponding to the unexposed areas of the emulsion layer of the negative material. Also, no transfer fogs were observed at the image-receiving layer corresponding to the exposed portion of the emulsion layer of the negative material.

EXAMPLE 5 The following composition, that is, Emulsion I, a gelatin solution, and Emulsion II were prepared and they were applied to a baryta paper in the following order.

Emulsion I (green-sensitive emulsion) In 1.5 ml. of ethyl acetate was dissolved a cyan forming coupler, N heptyl 1 hydroxy 2- naphthamide (Compound 1), and the resulting solution was well mixed with 1.0 g. of a dispersing solvent, 2 methyl 3 [N- (2 ethylhexyl)butyramido] propionic acid (Compound 10). The mixture was then dispersed in a colloidal state with mechanical stirring in 50 ml. of an aqueous 10% gelatin solution containing 3.0 g. of a color developing agent, N,N-diethyl-p-phenylenediamine (Compound 6) and a surface active agent.

This dispersion was then added to 1 00 g. of a gelatino silver chloride emulsion provided with a green sensitivity by a sensitizing dye with suitable amounts of additives to provide Emulsion I.

Gelatin solution (for filter layer) A mixture of 10 g. gelatin, 0.1 g. of a dye, Zapon Fast Yellow CGR (made by Farbwerk Hoechst A.G.; Color Index 2nd ed., C.I. Solvent Yellow 69), and suitable amounts of a hardening agent and a wetting agent were dissolved in 200 ml. of water. This comprised the filter layer material.

Emulsion II (blue-sensitive emulsion) In 2.4 ml. of ethyl acetate was dissolved 1.5 g. of a yellow forming coupler, 2-butoxy-benzoylacetanilide (Compound 5) and the resulting solution was well mixed with 2.0 g. of a dispersing solvent, 2-methyl-3-[N-(2- ethylhexyDbutyramido]propionic acid (Compound 10). The solution was dispersed with mechanical stirring in 50 ml. of an aqueous 10% gelatin solution containing 3.0 g. of a color developing agent, N,N-diethyl-p'-phenylenediamine (Compound 6), 0.3 g. of a developing accelerator, l-phenyl-3-pyrazolidone, and a surface active agent.

The dispersion was added to g. of a gelatino silver chloride emulsion provided with blue sensitivity together with suitable amounts of a hardening agent and a wetting agent to provide Emulsion II.

The multilayer color negative material prepared by coating the above onto a support was exposed to a lamp through a blue filter (Kodak Wratten No. 34) and a green filter =(Koda'k Wratten No. 12).

Thereafter, the diffusion transfer was conducted by the procedure described in Example 4, and the positive material was bleach-fixed and water-washed.

On the portions of the positive material thus processed which corresponded to the areas of the negative layer exposed to the tungsten lamp through a blue filter and a green filter were obtained a cyan color image and a yellow color image, respectively. On the areas of the positive material corresponding to the unexposed areas of the negative material, there was obtained a green image. Again, no transfer fogs were observed.

What is claimed is:

1. A photographic negative material for use in a diffusion transfer process, which comprises:

(a) a support having thereon a silver halide emulsion layer comprising a coupler which contains a chromogenic nucleus selected from the group consisting of phenol, naphthol, pyrazolone and ,B-ketoacid anilide dissolved in a high boiling organic solvent having the formula:

N-CHz-CH-C OH R CO }[C wherein X represents a hydrogen atom or a methyl group, R and R each represents an unsubstituted or substituted alkyl group, the sum of the number of carbon atoms in groups R and R being an integer from 7 to 11, said organic solvent being immiscible with water, but miscible with an alkaline medium, and

(b) a N,N-dialkyl-p-phenylenediamine color developing agent, said coupler being insoluble in water but soluble in alkaline medium.

2. The photographic negative material of claim 1, wherein said coupler is a member selected from the group consisting of N-heptyl-1-hydroxyl-2-naphthamide, N-(2- ethylhexyl)-l-hydroxy-Z-naphthamide, 1-phenyl-3-pentyl- '5-pyrazolone, 1-phenyl-2-nonyl-5-pyrazolone, and 2'-bu toxy-benzoylacetanilide.

3. The photographic negative material of claim 1, wherein said organic solvent is a member selected from the group consisting of 2-methyl-3-(N-n-octylacetamido) propionic acid, 2-methyl-3- [N- (Q-ethylhexyl)butyramido] propionic acid, and 3-[N-(2-ethylhexyl)acetamido]-propionic acid.

4. The photographic negative material of claim 1, wherein said color developing agent is a member selected from the group consisting of N,N-diethyl-p-phenylenediamine, 3-methyl-4-amino-N,N-diethylaniline, and 3-methyl-4-amino-[N-ethyl-N-(2 (methanesulfoamido)ethyl]- aniline.

5. A photographic negative material for use in a diffusion transfer process, which comprises:

(a) a support having thereon, a silver halide emulsion layer comprising a coupler containing a chromogenic nucleus selected from the group consisting of phenol, naphthol, pyrazolone and fi keto acid anilide dissolved in a high boiling organic solvent which is a N-substituted propionic acid, and

(b) a N-,N-dialkyl -p-phenylenediamine color developing agent, said coupler being insoluble in water but soluble in an alkaline medium and said organic solvent b eingimmiscible in water but miscible with an alkaline medium,

said coupler being a member selected from the group consisting of N-heptyl-1-hydroxy-2-naphthamide, N- (2-ethylhexyl)-1-hydroxy-2-naphthamide, l-phenyl-3- pentyl-S-pyrazolone, l-phenyl-3-nonyl-S-pyrazolone, and 2-butoxy-benzoylacetanilide, said organic solvent being a member selected from the group consisting of Z-methyl-S-(N-n-octylacetamido)-propionic acid, 2-methyl-3- [N (2-ethylhexyl) butyramido] -pro pionic acid and 3-[N-(2-ethylhexyl)acetamido]propionic acid, and said color developing agent being a member selected from the group consisting of N,N- diethyl-p-phenylenediamine, 3-methyl-4-amino-N,N- diethylaniline, and 3-methyl-4-amino-[N-ethyl-N-(Z- (methanesulfoamido) ethyl] -aniline.

6. A color diffusion transfer process which comprises:

(a) exposing a photographic negative material having a silver halide emulsion layer comprising a coupler containing a chromogenic nucleus selected from the group consisting of phenol, naphthol, pyrazolone and B-keto acid anilide dissolved in a high boiling organic solvent having the formula:

wherein X represents a hydrogen atom or a methyl group, R and R each represents an unsubstituted or substituted alkyl group, the sum of the number of carbon atoms in groups R and R being an integer from 7 to 11, said organic solvent being immiscible with water but miscible with an alkaline medium, and a N,N-dialkyl-p-phenylenediamine color developing agent, said coupler being insoluble in water, but soluble in an alkaline medium,

(b) processing, in an alkaline processing solution, said negative material in close contact with a photographic positive material having an image-receiving layer containing an oxidizing agent, said developing agent being thereby consumed by the reaction with silver halide in the exposed areas of said emulsion layer, whereas the silver halide, coupler and developing agent in the non-exposed areas thereof are diffusiontransferred to said image-receiving layer through the action of said processing solution to form a color image in said image-receiving layer, and

(c) subsequently removing said positive material from said negative material.

7. The process of claim 6, wherein said coupler is a member selected from the group consisting of N-heptyl-1- hydroxy-Z-naphthamide, N-(Z ethylhexyD-l-hydroxy-2- naphthamide, 1-phenyl-3-pentyl-5-pyrazolone, l-phenyl- 3-nonyl-5-pyrazolone, and 2'-butoxy-benzoylacetanilide.

8. The process of claim 6, wherein said organic solvent is a member selected from the group consisting of 2- methyl-3-(N-n-octylacetamido)-propionic acid, Z-methyl- 3-[N-(Z-ethylhexyl)butyramido1-propionic acid, and 3- [N- (2-ethylhexyl) acetamido1-propionic acid.

9. The process of claim 6, wherein said color developing agent is a member selected from the group consisting of N,N-diethyl-p-phenylenecliamine, 3-methyl-4-amino- N,N-diethylaniline, and 3-methyl-4-amino-[N-ethyl-N-(Z- (methanesulfoamido)ethyl]-aniline.

10. The process of claim 6, wherein said alkaline medium is an aqueous solution of sodium hydroxide.

11. The process of claim 6, wherein said oxidizing agent incorporated in the image-receiving layer is a member selected from the group consisting of chloranil, acid clay and fog silver halide grains.

12. A color diffusion transfer process which comprises:

(a) exposing a photographic negative material having a silver halide emulsion layer comprising a coupler containing a chromogenic nucleus selected from the group consisting of phenol, naphthol, pyrazolone and fi-keto acid anilide dissolved in a high boiling organic solvent which is a N-substituted propionic acid and a N,N-dialkyl-p-phenylenediamine color developing agent, said coupler being insoluble in water but soluble in an alkaline medium, and said organic solvent being immiscible vw'th water but miscible with an alkaline medium,

(b) processing, in an alkaline processing solution, said negative material in close contact with a photographic positive material having an image-receiving layer containing an oxidizing agent, said developing agent being thereby consumed by the reaction with silver halide in the exposed areas of said emulsion layer, Whereas the silver halide, coupler and developing agent in the non-exposed areas thereof are diffusiontransferred to said image-receiving layer through the action of said processing solution to form a color image in said image-receiving layer, and

(c) subsequently removing said positive material from said negative material, and

(d) said coupler being a member selected from the group consisting of N-heptyl-l-hydroxy-Z-naphthamide, N-(2-ethylhexyl)-l-hydroxy-Z-naphthamide, l-phenyl-3-pentyl-5-pyrazolone, 1-phenyl-3-nonyl-5- pyrazolone, and 2'-butoxy-benzoylacetanilide, said organic solvent being a member selected from the group consisting of 2-methyl-3-'(N-n-octylacetamido)- 13 14 propionic acid, 2-methyl-3-[N-(Z-ethylhexyl)butyr- 2,304,940 12/1942 Mannes et a1. 96--100 amido]-propionic acid, and [N-(Z-ethylhexyDaceta- 2,322,027 6/1943 Jelley et a1. 96114.7 mido]-propionic acid and said color developing agent 2,407,210 9/ 1946 Weissberger et a1. 96.100 being a member selected from 'the group consisting 2,474,293 6/1949 Weissberger et al. 96100 of N,N-diethyl-p-phenylenediamine, 3-methyl-4-ami- 5 3,330,655 7/1967 Salminen 963 no-N,N-diethylaniline, and 3-methyl-4-amino-[N-eth- 3,409,439 11/1968 Yoshida et a1. 963 yl-N-(2-(methanesulfoamido)ethyl]-aniline.

JOHN T. GOOLKASIAN, Primary Examiner Refe'ences D. I. FRITSCH, Assistant Examiner UNITED STATES PATENTS 10 1,969,479 8/1934 Seymour 96---100 2,213,986 9/1940 Kendall a a1. 96100 76,