US3649265A - Diffusion transfer system comprising dye developers, a pyrazolone and an onium compound - Google Patents

Abstract

Improved color separation is achieved in color diffusion transfer systems such as multicolor dye developer systems by processing exposed photosensitive elements in the presence of a 5-pyrazolone unsubstituted in the 4-position in combination with an onium compound.

Description

O Umted States Patent [151 3,649,265 Stewart Mar. 14, 1972 [54] DIFFUSION TRANSFER SYSTEM [56] References Cited COMPRISING DYE DEVELOPERS, A

UNITED STATES PATENTS PYRAZOLONE AND AN ONIUM 3 2 3 2 96 B arr COMPOUND 3,312,549 4/1967 Salminen ..96/29 1) [72] Inventor: Paul Harold Stewart, Rochester, NY. 3,173,786 3/ 1965 Green et al. ..96/3 [73] Assigneez fiaztman Kodak Company, Rochester, Primary Emmmer Nrman G. Torch! Assistant Examiner-Alfonso T. Suro Pico Filtid! y 1970 Attorney-W. H. J. Kline, J. R. Frederick and H. E. Cole 211 App]. No.2 35,290 [57] ABSTRACT 52 U.S. c1. ..96/3 96/29 D 96166.3 SeParation is achieved in 51 1m. 01 ..G03C 7/00, 003 6 5/54 G036 5/30 "ansfer Systems as dye devebp" Systems 58 1 Field Of Search ..96/3, 29 D, 66.5, 66, 66.3 Processing e'emems the Presence a S-pyrazolone unsubstituted in the 4-position in combination with an onium compound.

18 Claims, No Drawings DIFFUSION TRANSFER SYSTEM COMPRISING DYE DEVELOPERS, A PYRAZOLONE AND AN ONIUM COMPOUND This invention relates to the art of photography and more particularly to a multicolor diffusion transfer process in photography and materials adapted for use in the process.

A diffusion transfer color process has been described in a number ofpatents, including US. Pat. No. 2,983,606, wherein photographic elements containing silver halide emulsion layers and layers containing difiusible dye developers (dyes having a silver halide developing function) are exposed to record the latent image in the silver halide and then treated with an alkaline processing composition which permeates the emulsion layers and layers containing the dye developers which then develop the latent images to silver images. At the same time, oxidation products of the dye developers are formed in situ with the silver images and which are relatively nondiffusing in the colloid vehicle of the layers.

The nondiffusing character of the oxidized dye developers is apparently due at least in part to a decrease in solubility in the alkaline processing liquid, and may also be due to a hardening effect of the oxidized developer upon the colloid vehicles of the layers which retards the diffusion of the oxidized dye developers. The residual unoxidized dye developers remaining in the layers in imagewise distribution are transferred by diffusion to a superposed reception element substantially to the exclusion of the silver image and oxidized dye developer to provide a positive dye image.

When an element containing differentially sensitized silver halide emulsion layers is used and substractively colored dye developers are present in or contiguous to the respective emulsion layers, upon treatment with the processing liquid the dye developers are oxidized and rendered nondiffusing in the developed regions of the layers and the residual dye developer images in the positive regions are transferred by diffusion and in register to the reception element to provide a multicolor reproduction.

It has been proposed in US. Pat. No. 3,173,786 to employ onium compounds as development accelerators for the processing of dye developer negatives. Thus, the onium compounds coact with the dye developers to increase the transfer of the dye developers from unexposed areas of the negativev The onium compounds act to inhibit the transfer of the dye developers from exposed areas thereby improving the highlights. This improvement in highlights is apparently due, at least in part, to the ability of the oniums through salt formation with'the dye developers to control the diffusibility of the dye developers, especially in exposed areas.

Broadly, the proposed onium compounds include quatemary ammonium, quaternary phosphonium, and tertiary sulfonium compounds. The quaternary ammonium compounds are indicated as yielding especially useful results. Likewise, it is taught that those onium compounds which contain a reactive methyl group, i.e., a methyl group which is capable of forming a methylene base in alkali, provide improved color separation. Thus, the employment of an onium compound having a'reactive methyl group, e.g., l-benzyl-Z-picolinium bromide, results in the transfer of the dye developer being more closely controlled by the silver halide emulsion with which each dye developer is associated. On the other hand, onium compounds, such as l-phenethyl pyridinium bromide, which do not form methylene bases in alkali solutions are indicated to be less useful. It would be highly desirable to provide a transfer system in which onium compounds which do not pos sess a reactive methyl group could be rendered more useful.

It is therefore an object of the invention to provide a novel color diffusion transfer system in which good print quality can be obtained with onium compounds including those having no reactive methyl group.

A further object of the invention is to provide a novel process for the production of a multicolor diffusion transfer image having better color separation than heretofore obtainable employing onium compounds having no reactive methyl group.

These and other objects are achieved in accordance with the present invention whereby color diffusion transfer processes are conducted in the presence of a S-pyrazolone unsubstituted in the 4-position in combination with an onium compound.

As will be hereinafter demonstrated, it has been discovered that prints having good color separation are obtainable with onium compounds including those having no reactive methyl group, e.g., l-phenethyl pyridinium bromide, when the onium compound is used in combination with a 5-pyrazolone unsubstituted in the 4-position.

In accordance with the present invention, a photographic film unit is provided which is adapted to be processed by passing the unit between a pair of juxtaposed pressure-applying members. The film unit comprises:

a. a photosensitive element comprising a support coated with at least one photosensitive silver halide emulsion layer, each silver halide emulsion layer having associated therewith a dye image-providing material;

a dye image-receiving layer; and

c. a rupturable container containing an alkaline processing composition; said film unit containing a 5-pyrazolone unsubstituted in the 4-position and an onium compound, said rupturable container being adapted to be positioned during processing of said film unit so that a compressive force applied to said container by said pressure-applying members will effect a discharge of the container's contents within said film unit.

Development of the exposed silver halide emulsion layers of the above-described film unit is conducted in the presence of at least one onium compound and especially in the presence of at least one onium compound possessing no reactive methyl group. The onium compounds are preferably selected from the group consisting of quaternary ammonium, quaternary phosphonium, and tertiary sulfonium compounds.

Especially useful results have been obtained through the use of quaternary ammonium compounds. As is known, quaternary ammonium compounds are organic compounds containing a pentavalent nitrogen atom. Generally, they can be considered as derivatives of ammonium compounds wherein the four valences usually occupied by the hydrogen atoms are occupied by organic radicals. Generally, the organic radicals are joined directly to the pentavalent nitrogen through a single or double carbon-to-nitrogen bond. The term quaternary ammonium, as used herein, is intended to cover compounds wherein the pentavalent nitrogen is one of the nuclear atoms in a heterocyclic ring as well as those wherein each of the four valences is attached to separate organic radicals, e.g., tetraalkyl quaternary ammonium compounds. As illustrations of quaternary ammonium compounds, mention may be made of those represented by the following formulae:

wherein each R is an organic radical, Y is an anion, e.g., hydroxy, bromide, chloride, toluene sulfonate, etc., and Z represents the atoms necessary to complete a heterocyclic ring. As examples of compounds within Formulae l, 2, and 3, mention may be made of tetraethylammonium bromide, N- ethylpyridinium bromide and N,N-diethylpiperidinium bromide.

The tertiary sulfonium and quaternary phosphonium compounds may be represented by the Formulae:

(R) S X {4| and M X (5) wherein each R is an organic radical, e.g., alkyl, aralkyl, aryl, etc. groups, and X is an anion, e.g., hydroxy, bromide. chloride, toluene sulfonate, etc. As examples of tertiary sulfonium and quaternary phosphonium compounds, mention may be made of lauryldimethylsulfonium p-toluene sulfonate, nonyl-dimethylsulfonium p-toluene sulfonate. butyldimethylsulfonium bromide, triethylsulfonium bromide, tetraethylphosphonium bromide, etc.

The onium compounds can be used as the free base or as the salt. When the onium compounds are used as the salt, the anion may be a derivative of any acid. However, it should be noted that when the anion is iodide, such iodide may have deleterious effects on the emulsion and suitable precautions should be taken. Especially good results are obtained when the onium compounds are employed as the bromide. When using onium compounds, which have an anion other than bromide, it has been found advantageous in certain instances to add a small amount of potassium bromide. Additional onium compounds are disclosed in U.S. Pat. No. 3,260,597 to Weyerts et al. the disclosure of which is hereby incorporated by reference.

Especially preferred onium compounds of the present invention are the pyridinium salts which do not form methylene bases in alkali solutions including:

l-phenethyl pyridinium bromide l-ethyl pyridinium bromide l-phenethyl-3-picolinium bromide l-n-nonylpyridinium p-toluenesulfonate, and the like.

The S-pyrazolone compounds useful in the present invention are distinguished from other pyrazolones in that the 4- position is always unsubstituted, i.e., an active methylene group is always present at the 4-position. This may be illustrated by the following formula:

II( 1-CR I ll /C@@N 1% wherein R is hydrogen, aryl or alkyl including substituting aryl and alkyl. Examples of such compounds include 1-phenyl-3- methyl-S-pyrazolone, l-p-nitrophenyl-3-methyl-5-pyrazolone, 1-a-naththyl-3-methyl-5-pyrazolone, l-p-bromophenyl-3- methyl-S-pyrazolone, 1-phenyl-3-ethoxy-5-pyrazolone, 1- phenyl-3-butoxy-5-pyrazolone, l-p-nitrophenyl-Ii-ethoxy-S- pyrazolone, l(p-sulfamylphenyl)-3-ethoxy-5-pyrazolone, l phenyl-3-acetylamino-5-pyrazolone, l-phenyl-3- propionylamino-S-pyrazolone, the compounds disclosed on pages 2, 3 and 4 of U.S. Pat. No. 2,369,489 of Porter et a1. issued Feb. 13, 1945, etc.

The onium compound and the S-pyrazolone unsubstituted in the 4-position can be provided in any suitable manner in the photographic film unit so long as they are present during development of the exposed silver halide emulsion layers of the film unit. Thus, for example, the onium and the 5- pyrazolone unsubstituted in the 4-position may be present in either or both the alkaline processing composition, in the reception sheet or in the photosensitive element.

The concentration of the onium compound can be varied over a wide range depending upon particular needs. Thus, for example, between about 1 and about percent, preferably between about 2 and about 4 percent by weight of the processing composition can comprise the onium compound. Likewise, the 5-pyrazolone unsubstituted in the 4-position can be present in an amount, for example, of between about 0.5 and about 5.0 percent, preferably between about 1 and 4.0 percent by weight of the processing composition.

The dye image-receiving layer of the film unit can be located on a separate support adapted to be superposed on the photosensitive element afier exposure thereof. Such imagereceiving elements are disclosed, for example, in U.S. Pat. No. 3,362,819. The rupturable container is usually positioned during processing of said film unit so that a compressive force applied to the container by pressure-applying members in a camera will effect a discharge of the containers contents between the image-receiving element and the outermost layer of the photosensitive element. The dye image-receiving layer can also be located integral with the photosensitive element between the support and the lowermost photosensitive silver halide emulsion layer. Such integral receiver-negative photosensitive elements are disclosed, for example, in U.S. Pat. No. 3,415,644 and useful in camera apparatus of the type disclosed in Belgian Pat. Nos. 7l8,553 and 718.554. Another embodiment of an integral receiver-negative photosensitive element in which the instant invention may be employed is described in U.S. Pat. No. 2,983,606, column 14, lines 27-55.

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

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

Any dye image-providing material can be employed in the present film unit, provided that an imagewise distribution of the material will be formed after development as a function of the imagewise exposure of the silver halide emulsion to which the dye image-providing material is associated. Particularly good results are obtained when the dye image-providing materials are dye developers, i.e., compounds which contain in the same molecule both the chromophoric system of a dye and also a silver halide developing function. A preferred silver halide developing moiety in such dye developers is a hydroquinonyl group. Dye developers and their functioning in color diffusion transfer systems are well known in the art as shown, for example, by U.S. Pat. Nos. 2,983,606; 2,992,106; 3,047,386; 3,076,808; 3,076,820; 3,077,402; 3,126,280; 3,131,061; 3,134,762; 3,134,765; 3,135,604; 3,135,605; 3,135,606; 3,135,734; 3,141,772; and 3,142,565.

When dye developers are employed as the dye imageproviding materials in the film assembly of this invention, an alkaline processing or activating composition is conveniently employed in the rupturable container or pod. After exposure of the element, the alkaline processing composition is released from the pod to permeate the emulsion layers and initiate development of the latent images contained therein. The dye developers are immobilized in exposed areas as a consequence of the development of the latent images. This immobilization is due at least in part, to a change in the solubility characteristics of the dye developers upon oxidation.

In unexposed areas of the emulsion layers, the due developers remain diffusible and thus provide imagewise distributions of unoxidized dye developer dissolved in the liquid processing composition as a function of the point-to-point degree of exposure of the silver halide emulsion layers. At least part of these imagewise distributions of unoxidized dye developer are transferred, by diffusion, to the image-receiving layer. The image-receiving layer contains materials adapted to mordant or otherwise fix the diffused, unoxidized dye developers.

Good results are obtained when dye developers are employed in separate layers contiguous to each silver halide emulsion layer. Such layers can be applied by using coating solutions containing about 0.5 to about 8 percent, by weight, of the dye developer distributed in a hydrophilic film-forming natural material or synthetic polymer such as gelatin, polyvinyl alcohol, etc., which is adapted to be permeated by aqueous alkaline processing composition.

In addition to conventional techniques for the direct dispersion of a particulate solid material in a polymeric or colloidal matrix such as ball-milling and the like techniques, the preparation ofa dye developer dispersion can also be obtained by dissolving the dye developer in an appropriate solvent or mixture of solvents, dispersing the resultant solution in the polymeric binder, with optional subsequent removal of the solvent or solvents employed. Further details concerning these dispersing techniques and the solvents employed are found, for example, in U.S. Pat. Nos. 2,269,158; 2,322,027; 2,304,939; 2,304,940; 2,801,171; etc.

Other dye image-providing materials which can be employed in this invention include coupling dyes as disclosed, for example, in U.S. Pat. No. 3,087,817, shifted or colorless dye developers as disclosed, for example, in U.S. Pat. No. 3,230,085, dye developer-precursors, dye-precursor developers, metal-dye complexes as disclosed, for example, in U.S. Pat. No. 3,185,567 and U.S. Pat. No. 3,453,107, nondiffusible couplers as disclosed in U.S. Pat. Nos. 3,227,550 and 3,227,551, couplers requiring an oxidizing agent in the imagereceiving layer in order to form colors, ring-closing dye developers as disclosed in U.S. Pat. No. 3,443,943, colorproviding materials as disclosed in U.S. Pat. Nos. 3,443,940 and 3,443,941, etc. These dye image-providing materials can be incorporated into the photosensitive element in the same manner listed above for dye developers.

In a color film unit according to the present invention, each silver halide emulsion layer containing a dye image-providing material or having the dye image-providing material present in a contiguous layer can be separated from the other silver halide emulsion layers in the film unit by materials including gelatin, calcium alginate, or any of those disclosed in U.S. Pat. No. 3,384,483, polymeric materials such as polyvinylamides as disclosed in U.S. Pat. No. 3,421,892, or any of those disclosed in U.S. Pat. Nos. 2,992,104; 3,043,692; 3,044,873; 3,061,428; 3,069,263; 3,069,264; 3,121,01 1;and 3,427,158.

Generally speaking, except where noted otherwise, the silver halide emulsion layers of the invention comprise photosensitive silver halide dispersed in gelatin and are about 0.6 to 6 microns in thickness; the dye image-providing materials are dispersed in an aqueous alkaline solution-permeable polymeric binder, such as gelatin, as a separate layer about 1 to 7 microns in thickness; and the alkaline solution-permeable polymeric interlayers, e.g., gelatin, are about 1 to 5 microns in thickness. Of course, these thicknesses are approximate only and can be modified according to the product desired.

The silver halide emulsions used with this invention can comprise silver chloride, silver bromide, silver bromoiodide, silver chlorobromoiodide or mixtures thereof. The emulsions can be coarse or fine grain and can be prepared by any of the well-known procedures, e.g., single jet emulsions, double jet emulsions, such as Lippmann emulsions, ammoniacal emulsions, thiocyanate or thioether ripened emulsions such as those described in Nietz et al. U.S. Pat. No. 2,222,264; lllingsworth U.S. Pat. No. 3,320,069; and McBride U.S. Pat. No. 3,271,157. Surface image emulsions can be used or internal image emulsions can be used such as those described in Davey et al. U.S. Pat. No. 2,592,250; Porter et al. U.S. Pat. No. 3,206,313 and Bacon et al. U.S. Pat. No. 3,447,927. The emulsions may be regular grain emulsions such as the type described in Klein and Moisar, J. Phot. Sci., Vol. 12, No. 5, Sept./Oct., 1964, pp. 242-251. If desired, mixtures of surface and internal image emulsions can be used as described in Luckey et al. U.S. Pat. No. 2,996,382. Negative-type emulsions can be used or direct positive emulsions can be used such as those described in Leermakers U.S. Pat. No. 2,184,013; Kendall et al. U.S. Pat. No. 2,541,472; Berriman U.S. Pat. No. 3,367,778; Schouwenaars British Pat. No. 723,019; lllingsworth et al. French Pat. No. 1,520,821; lves U.S. Pat. No. 2,563,785; Knott et al. U.S. Pat. No. 2,456,953 and Land U.S. Pat. No. 2,861,885.

The silver halide emulsions can be unwashed or washed to remove soluble salts. 1n the latter case the soluble salts may be removed by chill-setting and leaching or the emulsion may be coagulation washed, e.g., by the procedures described in Hewitson et al. U.S. Pat. No. 2,618,556; Yutzy et al. U.S. Pat. No. 2,614,928; Yackel U.S. Pat. No. 2,565,418; Hart et al. US. Pat. No. 3,241,969; and Waller et al. U.S. Pat. No. 2,489,341.

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

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

Any material can be employed as the image-receiving layer in this invention as long as the described function of mordanting or otherwise fixing the dye images will be obtained. The particular material chosen will, of course, depend upon the dye image to be mordanted. 1f acid dyes are to be mordanted, the image-receiving layer can contain basic mordants such as polymers of amino guanidine derivatives of vinyl methyl ketone such as described in the Minsk U.S. Pat. No. 2,882,156 granted Apr. 14, 1959. Other mordants useful in the present invention include the 2-vinyl pyridine polymer metho-ptoluene sulfonate and similar compounds described in Sprague et a1. U.S. Pat. No. 2,484,430 granted Oct. 1 1, 1949, and cetyl trimethylammonium bromide, etc. Effective mordanting compositions are also described in Whitmore U.S. Pat. No. 3,271,148 and Bush U.S. Pat. No. 3,271,147. Furthermore, the image-receiving layer can be sufficient by itself to mordant the due as in the case of use of an alkaline solution-permeable polymeric layer such as N-methoxymethyl polyhexylmethylene adipamide; partially hydrolyzed polyvinyl acetate; polyvinyl alcohol with or without plasticizers; cellulose acetate; gelatin; and other materials of a similar nature.

Polyvinyl alcohol or gelatin containing a dye mordant such as poly-4-vinyl-pyridine as disclosed in U.S. Pat. No. 3,148,061 can also be employed in the invention for mordanting dye developers. Generally, good results are obtained when the image-receiving layer is from about 0.25 to about 0.04 mil in thickness. This thickness, of course, may be modified depending upon the result desired. The image-receiving layer may also contain ultraviolet absorbing materials to protect the mordanted dye images from fading due to ultraviolet light.

Use of a polymeric acid layer, as disclosed in U.S. Pat. No. 3,362,819, in the film unit of the invention will enhance the results obtained. Generally, the polymeric acid layer will effeet a reduction in the pH of the image layer from about 13 or 14 to at least 1 1 and preferably 8 within a short time after inhibition. Such polymeric acids reduce the pH of the film unit after development to terminate further dye transfer and thus stabilize the dye image. Such polymeric acids comprise polymers containing acid groups, such as carboxylic acid and sulfonic acid groups, which are capable of forming salts with alkali metals, such as sodium or potassium or with organic bases particularly quaternary ammonium bases. such as tetramethyl ammonium hydroxide. The polymers can also contain potentially acid-yielding groups such as anhydrides or lactones or other groups which are capable of reacting with bases to capture and retain them. Generally the most useful polymeric acids contain free carboxyl groups, being insoluble in water in the free acid form and which form water-soluble sodium and/or potassium salts.

The polymeric acid layer is usually about 0.3 to about 1.5 mils in thickness. Although the polymeric acid layer is usually located in the receiver portion of the film unit between the support and the image-receiving layer, it can also be located in the negative portion of the film unit, as disclosed in U.S. Pat. No. 3,362,821.

An inert timing or spacer layer coated over the polymeric acid layer may also be used to "time" or control the pH reduction of the film unit as a function of the rate at which the alkali diffuses through the inert spacer layer. Examples of such timing layers include gelatin, polyvinyl alcohol or any of these disclosed in U.S. Pat. No. 3,455,686. The timing layer is also effective in evening out the various reaction rates over a wide range of temperatures, e.g., premature pl-l reduction is prevented when imbibition is effected at temperatures above room temperature, for example, at 95 to 100 F. The timing layer is usually about 0.1 to about 0.7 mil in thickness.

The photographic elements used with this invention can contain antistatic or conducting layers, such layers may comprise soluble salts, e.g., chlorides, nitrates, etc., evaporated metal layers, ionic polymers such as those described in Minsk U.S. Pat. No. 2,861,056 and Sterman et a1. U.S. Pat. No. 3,206,312 or insoluble inorganic salts such as those described in Trevoy U.S. Pat. No, 3,428,451.

The liquid-processing composition employed in this invention is the conventional aqueous solution of an alkaline material, e.g., sodium hydroxide, sodium carbonate or an amine such as diethylamine, preferably possessing a pH in excess of 12. The composition also preferably contains a viscosity-increasing compound such as a high molecular weight polymer, e.g., a water-soluble ether inert to alkaline solutions such as hydroxyethyl cellulose or alkali metal salts of carboxymethyl cellulose such as sodium carboxymethyl cellulose. A concentration of viscosity-increasing compound of about 1 to about 5 percent by weight of the processing composition is preferred which will impart thereto a viscosity of about 100 c.p.s. to about 200,000 c.p.s.

The layers of the photographic element employed and described herein can be coated on a wide variety of supports. Typical supports include cellulose nitrate film, cellulose ester film, poly(vinyl acetal) film, polystyrene film, poly(ethylene terephthalate) film, polycarbonate film and related films or resinous materials, as well as glass, paper, metal and the like. Typically, a flexible support is employed, especially a paper support, which can be partially acetylated or coated with baryta and/or an alpha-olefin polymer, particularly a polymer of an alpha-olefin containing 2-10 carbon atoms such as polyethylene, polypropylene, ethylene-butane copolymers and the like.

The photographic elements of this invention can contain incorporated developing agents such as hydroquinones, catechols, aminophenols, 3-pyrazo1idones, ascorbic acid and its derivatives, reductones and phenylenediamines. Combinations of developing agents can be employed in the practice of the invention. The developing agents can be in a silver halide emulsion and/or in another suitable location the photographic element. Especially useful auxiliary developing agents are colorless hydroquinone derivatives such as those listed in column 6 of U.S. Pat. No. 3,253,915 of Weyerts et a1. issued May 31, 1966.

The photographic emulsions and elements described in the practice of this invention can contain various colloids alone or in combination as vehicles, binding agents and various layers. Suitable hydrophilic materials include both naturally occurring substances such as proteins, for example, gelatin, gelatin derivatives, cellulose derivatives, polysaccharides such as dextran, gum arabic and the like; and synthetic polymeric substances such as water-soluble polyvinyl compounds like poly(vinylpyrrolidone acrylamide polymers and the like.

The described photographic emulsion layers and other layers of a photographic element employed in the practice of this invention can also contain alone or in combination with hydrophilic, water-permeable colloids, other synthetic polymeric compounds such as dispersed vinyl compounds such as in latex form and particularly those which increase the dimensional stability of the photographic materials. Suitable synthetic polymers include those described, for example, in Nottorf U.Sv Pat. No. 3,142,568, issued July 28, 1964; White U.S. Pat. No. 3,193,386, issued July 6,1965;Houck et a1. U.S. Pat. No. 3,062,674, issued Nov. 6, 1962; Houck et al. US Pat. No. 3,220,844 issued Nov. 30, 1965; Ream et al. US. Pat. No. 3,287,289, issued Nov. 22, 1966; and Dykstra U.S. Pat. No. 3,411,911, issued Nov. 19, 1968. Particularly effective are those water-insoluble polymers of alkyl acrylates and methacrylates, acrylic acid, sulfoalkyl acrylates or methacrylates, those which have cross-linking sites which facilitate hardening or curing and those having recurring sulfobetaine units as described in Dykstra Canadian Pat. No. 744,054.

The various photographic layers may contain plasticizers and lubricants such as polyalcohols, e.g., glycerin and diols of the type described in Milton et al, U.S. Pat. No. 2,960,404; fatty acids or esters such as those described in Robijns U.S. Pat. No. 2,588,765 and Duane US. Pat. No. 3,121,060; and silicone resins such as those described in DuPont British Pat. No. 955,061.

The photographic layers used in the practice of this invention may be coated by various coating procedures including dip coating, air knife coating, curtain coating, or extrusion coating using hoppers of the type described in Belguin U.S. Pat. No. 2,681,294. If desired, two or more layers may be coated simultaneously by the procedures described in Russell U.S. Pat, No. 2,761,791 and Wynn British Pat. No. 837,095. This invention also can be used for silver halide layers coated by vacuum evaporation as described in British Pat. No, 968,453 and LuValle et a1. U.S. Pat. No. 3,219,451.

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

The following nonlimiting example illustrates processes and products within the scope of the present invention:

EXAMPLE A photosensitive element is prepared by coating a subbed film support comprising cellulose acetate with suitably hardened gelatin layers sequentially coated as follows:

1. Cyan Dye Developer Layer The cyan dye developer 5,8-dihydroxy-l,4-bis[(fihydroquinonyl-a-methyl)ethylamino]anthraquinone is dissolved in a mixture of N-n-butylacetanilide and 4-methyl cyclohexanone and dispersed in an aqueous gelatin solution with a sodium diisopropylnaphthalene sulfonate dispersing agent. The mixture is passed through a colloid mill several times, coated on the subbed support and dried so as to volatilize the 4-methyl cyclohexanone.

2. Red-Sensitive Emulsion Layer A gelatino silver bromoiodide emulsion layer, which is sensitized to the red region of the spectrum, is coated upon the cyan dye developer layer.

3. Interlayer A gelatin interlayer is then coated on the red-sensitive emulsion layer. 4. Magenta Dye Developer Layer The magenta dye developer 2 [p-(2',5'-dihydroxyphenethyl)-phenylazo]-4-n-propoxy-l-naphthol is dissolved in a mixture of cyclohexanone and N-n-butylacetanilide and dispersed in an aqueous gelatin solution with a sodium alkylnaphthalene sulfonate dispersing agent. The mixture is passed through a colloid mill several times, coated on the interlayer and dried to volatilize the cyclohexanone. 5. Green-Sensitive Emulsion Layer A green-sensitive silver-bromoiodide emulsion is coated on the magenta dye developer layer. 6. lnterlayer A second gelatin interlayer is coated onto the green-sensitive emulsion layer. 7. Yellow Dye Developer Layer The yellow dye developer, l-phenyl-3-N-n-hexylcarboxamido-4-[p-(2',5-dihydroxyphenethyl)-phenylazo]-5- pyrazolone is dissolved in a mixture of ditetrahydrofurfuryl adipate and ethylene glycol monobenzyl ether and dispersed in an aqueous gelatin solution with a sodium diisopropylnaphthalene sulfonate dispersing agent. The mixture is passed through a colloid mill several times. The resulting dispersion is chilled to set it, washed to remove ethylene glycol monobenzyl ether followed by coating upon the second interlayer and dryin 8. Blue-Sensitive Emulsion Layer A blue-sensitive silver bromoiodide emulsion is coated onto the yellow dye developer layer. 9. Overcoat Layer A final gelatin overcoat layer is provided on the foregoing layers having dispersed therein an auxiliary developing agent 4-methylphenylhydroquinone.

Samples of the photosensitive element are exposed for 1/50 sec. on an Eastman 1b Sensitometer with a 500 w. tungsten light source through appropriately filtered step tables as shown in Table 111. Next, one of the samples is processed with a stock processing solution having the composition set forth in Table 1 below:

The stock activator is spread between the negative and a receiving sheet. The exposed film is processed at a gap of 0.004 inch between a pair of pressure rollers in order to spread the activator. The receiving sheet is a cellulose acetate butyrate subbed paper support carrying in the following order:

1. a polymeric acid layer for pH control,

2. a polyvinyl alcohol spacer layer,

3. a mordant layer comprising poly-4-vinyl pyridine and polyvinyl alcohol, and

4. a polyvinyl alcohol protective layer. After an inhibition period of approximately 1 minute, the receiver is separated from the negative and contains a positive trichrome image of the photographed subject. The foregoing procedure is repeated employing activators comprising the stock processing solution of Table 1 containing the added in- The integral red, green and blue densities of all the resulting transfer images are then measured by reflectance through red, green and blue filters, respectively. Theoretically, only cyan dye developer should transfer from the negatives exposed to green and blue light, only magenta dye developer should transfer from the negatives exposed to red and blue light, and only yellow dye developer should transfer from the negatives that are exposed to green and red light. Since reflected density of a particular color is being measured through a filter of the same color, the lower the value means that more of that light is being reflected. The results are set forth in Table 111 as follows:

TABLE III.REFLECTED PRINT DENSITY Exposure (Wratten filters) Max. density in Green and blue Blue and red Green and red unexposed area (W-44A) (two W-32) W-15 and W-25 Activator R G B R G B R G B R G B Stock 1 35 2. 87 2. 52 1. 03 1. 71 1. 35 0. 66 1. 64 1. 31 42 0. 99 1. 15 A 0. 87 1. 30 1. 62 0. 45 0. 46 0. 57 0. 24 0. 56 0. 59 19 0. 45 0. 84 B 1.51 2.97 2.58 1.39 1.96 1.69 1.01 1.97 1 68 .86 1.26 1.69 C 1. 26 1. 58 1. 86 1. 25 0. 73 0. 82 0. 51 1. 12 0 89 30 0. 51 1. 29

Neutral Red Green Blue (unfiltered) (W-29) (W-99) (W-47B) Activator R G B R G B R G B R G B The foregoing results illustrate that Activator C. which contains the S-pyrazolone unsubstituted in the 4-position in combination with the onium compound. viz. l-phenethyl pyridinium bromide. yields a print having decidedly more color separation than the print made with the Activator A. which contains an onium compound having no reactive methyl group (l-phenethyl pyridinium bromide). alone. ln addition. the print produced with Activator C has acceptable D... and rum- The photographic layers employed in the practice of this in vention can contain surfactants such as saponin'. anionic compounds such as the alkyl aryl sulfonates described in Baldsiefen US. Pat. No. 2.600.831; amphoteric compounds such as those described in Ben-Ezra US. Pat. No. 3.133.816. and water-soluble adducts of glycidol and an alkyl phenol such as those described in Olin Mathieson British Pat. No. 1,022,878. In addition. the photographic elements may contain matting agents such as starch. titanium dioxide. zinc oxide, silica, polymeric beads including beads of the type described in Jelley et alv US. Pat. No. 2,992,101 and Lynn US. Pat. No. 2,701,245.

The emulsions used in this invention can be sensitized with chemical sensitizers. such as with reducing agents; sulfur. selenium or tellurium compounds; gold. platinum or palladium compounds; or combination of these. Suitable procedures are described in Sheppard et al. US. Pat. No. l,623,499; Waller et al. US Pat. No. 2,399,083; McVeigh US Pat. No. 3,297,477; and Dunn US. Pat. No. 3,297,466.

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

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

The various layers, including the photographic layers, employed in the practice of this invention can contain light-absorbing materials and filter dyes such as those described in Sawdey US. Pat. No. 3,253,921; Gaspar US. Pat. No. 2,274,782; Silverstein et al. US. Pat. No. 2,527,583 and Van- Campen U.S. Pat. No. 2,956,879. If desired, the dyes can be mordanted. for example. as described in Jones et al. US Pat. No. 3.282.699.

The photographic elements used in this invention may contain brightening agents including stilbenes, triazines. oxazoles and coumarin brightening agents. Water-soluble brightening agents may be used such as those described in Albers et al. German Pat. No. 972.067 and Mel-all et al. U.5. Pat. No. 2.933.390 or dispersions of brighteners may be used such as those described in Jansen German Pat. No. l.l50.274, Oetiker et al. US. Pat. No. 3,406,070 and Heidke French Pat. No. 1,530,244.

The sensitizing dyes and other addenda used in the practice of this invention can be added from water solutions or suitable organic solvent solutions may be used. The compounds can be added using various procedures including those described in Collins et al. US. Pat. No. 2.912.343; McCrossen et al. U.S. Pat. No. 3,342,605; Audran US Pat. No. 2.996.287 and Johnson et al. US Pat. No. 3,425,835.

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

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

lclaim:

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

a. a photosensitive element comprising a support coated with at least one photosensitive silver halide emulsion layer, each said silver halide emulsion layer having associated therewith a dye developer;

b. a dye image-receiving layer; and

c. a rupturable container containing an alkaline processing composition;

said film unit containing a 5 pyrazolone unsubstituted in the 4- position and an onium compound comprising a quaternary ammonium, quaternary phosphonium or tertiary sulfonium compound; said rupturable container being adapted to be positioned during processing of said film unit so that a compressive force applied to said container by said pressure-applying members will effect a discharge of the containers contents within said film unit.

2. The film unit of claim 1 wherein said dye image-receiving layer is located in said photosensitive element between said support and the lowermost photosensitive silver halide emulsion layer.

3. The film unit of claim 1 wherein said dye image-receiving layer is coated on a separate support and is adapted to be superposed on said photosensitive element after exposure thereof.

4. The film unit of claim 3 wherein said rupturable container is so positioned during processing of said film unit that a compressive force applied to said container by said pressureapplying members will effect a discharge of the container's contents between said dye image-receiving layer and the outermost layer of said photosensitive element. halide 5. The film unit of claim 4 wherein said photosensitive element comprises a support coated with a cyan dye developer layer, a red-sensitive silver halide emulsion layer, a magenta dye developer layer, a green-sensitive silver halide emulsion layer. a yellow dye developer layer and a blue-sensitive silver halide emulsion layer.

6. The film unit of claim 5 wherein said S-pyrazolone unsubstituted in the 4-position and said onium compound are provided in said rupturable container.

7. The film unit of claim 6 wherein said onium compound possesses no active methyl group.

8. The film unit of claim 7 wherein said onium compound is a quaternary ammonium compound.

9. The film unit of claim 8 wherein said quaternary ammonium compound is l-phenethyl pyridinium bromide, l-ethyl pyridinium bromide, l-phenethyl-3-picolinium bromide, or 1- n-nonylpyridinium p-toluenesulfonate.

10. The film unit of claim 9 wherein said S-pyrazolone unsubstituted in the 4-position is l-phenyl-3-methyl-5- pyrazolone.

11, A photographic film unit which is adapted to be processed by passing said unit between a pair of juxtaposed pressure-applying members comprising:

a. a photosensitive element comprising a support coated with a cyan dye developer layer, a red-sensitive silver halide emulsion layer, a magenta dye developer layer, a green-sensitive silver halide emulsion layer, a yellow dye developer layer, and a blue-sensitive silver halide emul sion layer;

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

c. a rupturable container containing an alkaline processing composition which is adapted to be positioned during processing of said film unit so that a compressive force applied to said container by said pressure-applying members will effect a discharge of the container's contents between said dye image-receiving layer and said blue-sensitive silver halide emulsion layer of said photosensitive element, said rupturable container additionally containing a S-pyrazolone unsubstituted in the 4-position in an amount of from about 1 to about 4 percent by weight of said processing composition and an onium compound having no reactive methyl group in an amount of from about 1 to about 10 percent by weight of said processing composition.

12. A process for producing a photographic transfer image in color comprising:

a. imagewise exposing a photosensitive element comprising a support coated with at least one photosensitive silver halide emulsion layer, each silver halide emulsion layer having associated therewith a dye developer;

b. treating said photosensitive element with an alkaline processing composition;

c. effecting development of each of said exposed silver halide emulsion layers;

d. forming an imagewise distribution of diffusible dye developer as a function of said imagewise exposure of each of said silver halide emulsion layers; and

e. at least a portion of each of said imagewise distributions of diffusible dye developer diffusing to a dye imagereceiving layer;

said development being effected in the presence of a 5- pyrazolone unsubstituted in the 4-position and an onium compound comprising a quaternary ammonium, quaternary phosphonium or tertiary sulfonium compound.

13. The process of claim 12 wherein said treatment step (b) is effected by:

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

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

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

14. The process of claim 13 wherein said onium compound possesses no reactive methyl group.

15. The process of claim 14 wherein said onium compound is a quaternary ammonium compound.

16. The process of claim 15 wherein said quaternary ammonium compound is l-phenethyl pyridinium bromide, lethyl pyridinium bromide, l-phenethyl-3-picolinium bromide, or l-n-nonylpyridinium p-toluenesulfonate.

17. The process of claim 16 wherein said S-pyrazolone unsubstituted in the 4-position is l-phenyl-3-methyl-5- pyrazolone.

18. The film unit of claim 5 wherein the photosensitive element contains an auxiliary developing agent.

Claims (17)

1. 2. The film unit of claim 1 wherein said dye image-receiving layer is located in said photosensitive element between said support and the lowermost photosensitive silver halide emulsioN layer.
2. 3. The film unit of claim 1 wherein said dye image-receiving layer is coated on a separate support and is adapted to be superposed on said photosensitive element after exposure thereof.
3. 4. The film unit of claim 3 wherein said rupturable container is so positioned during processing of said film unit that a compressive force applied to said container by said pressure-applying members will effect a discharge of the container''s contents between said dye image-receiving layer and the outermost layer of said photosensitive element.
4. 5. The film unit of claim 4 wherein said photosensitive element comprises a support coated with a cyan dye developer layer, a red-sensitive silver halide emulsion layer, a magenta dye developer layer, a green-sensitive silver halide emulsion layer, a yellow dye developer layer and a blue-sensitive silver halide emulsion layer.
5. 6. The film unit of claim 5 wherein said 5-pyrazolone unsubstituted in the 4-position and said onium compound are provided in said rupturable container.
6. 7. The film unit of claim 6 wherein said onium compound possesses no active methyl group.
7. 8. The film unit of claim 7 wherein said onium compound is a quaternary ammonium compound.
8. 9. The film unit of claim 8 wherein said quaternary ammonium compound is 1-phenethyl pyridinium bromide, 1-ethyl pyridinium bromide, 1-phenethyl-3-picolinium bromide, or 1-n-nonylpyridinium p-toluenesulfonate.
9. 10. The film unit of claim 9 wherein said 5-pyrazolone unsubstituted in the 4-position is 1-phenyl-3-methyl-5-pyrazolone.
10. 11. A photographic film unit which is adapted to be processed by passing said unit between a pair of juxtaposed pressure-applying members comprising: a. a photosensitive element comprising a support coated with a cyan dye developer layer, a red-sensitive silver halide emulsion layer, a magenta dye developer layer, a green-sensitive silver halide emulsion layer, a yellow dye developer layer, and a blue-sensitive silver halide emulsion layer; b. a dye image-receiving layer coated on a support and adapted to be superposed over said blue-sensitive silver halide emulsion layer after exposure of said photosensitive element; and c. a rupturable container containing an alkaline processing composition which is adapted to be positioned during processing of said film unit so that a compressive force applied to said container by said pressure-applying members will effect a discharge of the container''s contents between said dye image-receiving layer and said blue-sensitive silver halide emulsion layer of said photosensitive element, said rupturable container additionally containing a 5-pyrazolone unsubstituted in the 4-position in an amount of from about 1 to about 4 percent by weight of said processing composition and an onium compound having no reactive methyl group in an amount of from about 1 to about 10 percent by weight of said processing composition.
11. 12. A process for producing a photographic transfer image in color comprising: a. imagewise exposing a photosensitive element comprising a support coated with at least one photosensitive silver halide emulsion layer, each silver halide emulsion layer having associated therewith a dye developer; b. treating said photosensitive element with an alkaline processing composition; c. effecting development of each of said exposed silver halide emulsion layers; d. forming an imagewise distribution of diffusible dye developer as a function of said imagewise exposure of each of said silver halide emulsion layers; and e. at least a portion of each of said imagewise distributions of diffusible dye developer diffusing to a dye image-receiving layer; said development being effected in the presence of a 5-pyrazolone unsubstituted in the 4-position and an onium compound comprising a quaternary ammonium, quaternary phosphonium or tertiary sulfonium cOmpound.
12. 13. The process of claim 12 wherein said treatment step (b) is effected by: a. superposing over the layer outermost from the support of said photosensitive element said dye image-receiving layer coated on a support; b. positioning a rupturable container containing said alkaline processing composition between said exposed photosensitive element and said dye image-receiving layer; and c. applying a compressive force to said container to effect a discharge of the container''s contents between said outermost layer of said exposed photosensitive element and said dye image-receiving layer.
13. 14. The process of claim 13 wherein said onium compound possesses no reactive methyl group.
14. 15. The process of claim 14 wherein said onium compound is a quaternary ammonium compound.
15. 16. The process of claim 15 wherein said quaternary ammonium compound is 1-phenethyl pyridinium bromide, 1-ethyl pyridinium bromide, 1-phenethyl-3-picolinium bromide, or 1-n-nonylpyridinium p-toluenesulfonate.
16. 17. The process of claim 16 wherein said 5-pyrazolone unsubstituted in the 4-position is 1-phenyl-3-methyl-5-pyrazolone.
17. 18. The film unit of claim 5 wherein the photosensitive element contains an auxiliary developing agent.