US3655380A

US3655380A - Diffusion transfer product and process containing 5-seleno-1,2,3,4-tetrazole

Info

Publication number: US3655380A
Application number: US2964A
Authority: US
Inventors: Timothy F Parsons
Original assignee: Eastman Kodak Co
Current assignee: Eastman Kodak Co
Priority date: 1970-01-14
Filing date: 1970-01-14
Publication date: 1972-04-11
Anticipated expiration: 1989-04-11
Also published as: BE761557A; DE2101408A1; CA945000A; FR2090476A5; GB1318852A; NL7019084A

Abstract

Seleno tetrazoles such as 1-phenyl-5-seleno-1,2,3,4-tetrazole, 1-allyl-5-seleno-1,2,3,4-tetrazole, etc. are used as toners in a diffusion transfer process. The toner can be incorporated in the receiving sheet or in a processing solution. These toners are particularly useful when employed in a diffusion transfer process to improve the stability of the toned image.

Description

United States Patent Parsons {451 Apr. 11, 1972 [54] DIFFUSION TRANSFER PRODUCT AND [56] References Cited PROCESS CONTAINING S-SELENO- UNITED STATES PATENTS l,2,3,4-TETRAZOLE 2,699,393 l/l955 Weyde ..96/58 Inventor: Tlmothy Parsons, Hilton, NY. 3,305,362 2/1967 Riester et al. ..96/61 M [73] Assignee: gaztman Kodak Company, Rochester, Primary Examiner Norman G- Torchin Assistant Examiner.lohn L. Goodrow [22] Filed: Jan. 14, 1970 AttorneyW H. J. Kline, B. D. Wiese and Henry E. Byers [21] App]. No.: 2,964 57 ABSTRACT Seleno tetrazoles such as l-phenyl-S-seleno-l ,2,3,4-tetrazole, U-S. w u96/29, l al]yl 5 seleno l z 3 4 tetrazole etc are used as toners in a [51] Int. Cl ..G03C 5/54 diffusio transfer process, The toner can be incorporated in [58] Field of Search ..96/29, 52, 58 the receiving sheet or in a processing solution. These toners are particularly useful when employed in a diffusion transfer process to improve the stability of the toned image.

14 Claims, No Drawings BACKGROUND OF THE INVENTION This invention relates to receiving layers employing seleno tetrazoles and to diffusion transfer processes employing these receiving layers and also employing seleno tetrazoles to improve the tone of images obtained by a diffusion transfer process.

Diffusion transfer processes are well known. For example, Rott, U.S. Pat. No. 2,352,014 describes such a process wherein undeveloped silver halide of an exposed photographic emulsion layer is transferred in a silver complex imagewise by imbibition to a silver precipitating or nucleating layer, generally to form a positive image therein. The silver precipitating or nucleating layer generally comprises a binder containing nuclei such as nickel sulfide, colloidal metal or the like.

In carrying out the diffusion transfer process, there have been many problems involved in obtaining a satisfactory image. For instance, many of the prints have a brownish image, lack stability, etc. Therefore, various methods have been proposed to improve the process such as incorporation of toning agents in the processing solution, substitution of various silver precipitants, incorporation of quaternary salts, etc.

In order to improve the tone of diffusion transfer images, it is known to use phenyl mercapto tetrazoles such as those disclosed in U.S. Pat. No. 2,699,393. However, there have been problems involved with the stability of the prints obtained using these particular tetrazoles. Moreover, there has been a problem of obtaining satisfactory tone with certain binding materials used for coating the receiving sheet in which are dispersed a silver precipitant such as silver precipitating nuclei. For instance, proteinaceous colloids such as gelatin have been recognized as particularly useful binders for these silver precipitants. However, using gelatin as a vehicle for silver precipitants such as nuclei, and special types of nuclei such as colloidal silver, results in prints having a yellow to light brown color.

The problem of obtaining a desirable tone using a proteinaceous colloid such as gelatin has been recognized in the art and various attempts have been made to overcome this problem, as can be seen by Land et al. U.S. Pat. No. 2,774,667, issued Dec. 18, 1956, which describes the use ofa silica matrix for silver precipitating nuclei such as colloidal silver to avoid having the prints result in a yellow or light brown color.

It is recognized that a toning agent resulting in a neutral or black image which would be operative with a proteinaceous binder would be very useful in diffusion transfer processes. It is also recognized that it would be desirable to have a toner which could be applied either in the developing agent or which could be incorporated satisfactorily in the receiving sheet itself.

SUMMARY OF THE INVENTION In accordance with this invention, it has been found that a receiving element for use in the diffusion transfer process comprises a seleno tetrazole toning agent. The seleno tetrazole toning agent may be present in a developer or activator solution when the diffusion transfer process is carried out or in the silver halide emulsion provided the seleno tetrazole is present at the time of formation of the image in the receiving sheet. The seleno tetrazole is used in amounts of about 0.01 to about 1.0 g. per liter of developing or activating solution, about 0.01 mg. to about 0.5 g. per ft in the reception layer.

The following seleno tetrazoles are included among those found to be suitable for the purpose defined above; seleno tetrazoles substituted by aliphatic residues, as for example, 1- all'yl5-seleno-l,2,3,4-tetrazole, seleno tetrazoles substituted by aromatic or heterocyclic residues having 1 to 12 carbon atoms' as for example, l phenyl--seleno-l,2,3,4-tetrazgle.

The following formula illustrates suitable 5-seleno-l,2,3,4- tetrazoles:

R represents alkyl having one to 10 carbon atoms such as, for example, methyl, ethyl, propyl, butyl, etc., aralkyl (one to 10 carbon atoms) such as benzyl, etc., alkenyl (one to 10 carbon atoms) such as, for example, allyl, etc., aryl such as, for example, phenyl, tolyl, etc.

Additional advantages may be obtained by incorporating in the receiving sheet other materials such as a polyvinyl quaternary salt, an iodide, other toners, or a silver salt such as e.g. silver nitrate.

A receiving element described above is used advantageously to provide a photographic print having an image in a receiving layer on a support by a photographic silver salt diffusion transfer process.

DESCRIPTION OF PREFERRED EMBODIMENTS In one embodiment of this invention, colloidal noble metal nuclei are dispersed in a proteinaceous binder such as gelatin containing a polyvinyl quaternary salt such as poly( l-methyl- 4-vinyl pyridinium methylsulfate), potassium iodide and lphenyl-S-seleno-l,2,3,4-tetrazole, after which the mixture is coated on a suitable support such as paper. After drying, the receiving sheet can then be used in a diffusion transfer process and results in an image of good tone and density.

In another embodiment of this invention, colloidal nuclei are dispersed in a binder as described in the above embodiment and the composition coated on a suitable support such as paper. After drying, an unhardened silver halide emulsion is coated over the receiving layer. Particularly useful emulsions are described in Yackel et al. U.S. Pat. No. 3,020,155. The exposed photographic element is processed using a silver halide developing solution containing a silver halide solvent such as sodium thiosulfate. The undeveloped silver halide, complexed with thiosulfate, diffuses to the nucleated underlayer where an image is formed in the silver halide emulsion. Unhardened silver halide emulsion is then removed by washing with warm water.

The binder for the silver precipitant can be substantially protein and typically at least 50 percent, by weight, of a protein as described herein. Gelatin is a particularly useful binder, but other proteins such as casein, zein, albumin, etc., may be used.

In another embodiment, a reduced level of process stain is obtained by reducing the amount of the colloid binder such as gelatin or some other protein so that not more than 15 mgs./ft is coated on the support. This result in a coating of about 0. 10 to about 0.20 micron in thickness.

Gelatin and other proteins may also be admixed with compatible polymers. Polymers which are particularly useful include terpoly(ethylacrylate-acrylic acid-Z-acetoxyoxyethyl methacrylate), etc.

Polymers particularly useful as water-soluble polyvinyl quaternary salts are described in VanHoof et al., U.S. Pat. No. 3,174,858 issued Mar. 23, 1965. These water-soluble basic polymeric quaternary salts have a polyvinyl chain having two to 10,000 monomeric units, at least monomeric unit monomerinuit of which is linked to a five or six membered heterocyclic nucleus containing a hetero-quaternary nitrogen atom.

In one embodiment, the polymer has the following structure:

l l Ton CHZI N r R e in which n is an integer from two to 10,000 and X is any suitable anion such as CH SO e, para toluene sulfonatee, iodide, etc. R represents H, an alkyl group having one to 10 carbon atoms such as, for example, methyl, ethyl, propyl, butyl, etc., halogen, N NH a, aralkyl, aryl, etc. R is selected from the same group as R, but can be a different group than R. It will be appreciated, of course, that the heterocyclic nucleus can contain additional hetero atoms and that the ring may be substituted with other groups as R above. The substituents can be the same or different.

Typical polymeric materials include poly(l,2-dimethyl-- vinylpyridinium methylsulfate poly( 1 -methyl-2-vinylpyridinium iodide), poly( l-methyl-2-vinylpyridinium methylsulfate), poly)l -methyl-4-vinylpyridinium iodide), poly( l methyl-4-vinylpyridinium methylsulfate), poly(l-vinyl-3- methyl imidazolium iodide) and poly( l-vinyl-3-methyl imidazolium methylsulfate).

In another embodiment, in which the polyvinyl chain has attached thereto at least one monomeric unit linked to a hetero cyclic nucleus containing a hetero-quaternary nitrogen atom, the chain can contain attached thereto at least one linear group. In preparing a typical polyvinyl quaternary salt, the polymerization mixture can contain a linear compound such as N-cyanoacetyl-N-methacrylylhydra2ine (described in US. Pat. No. 2,940,956),

2-acetoacetoxyethyl methacrylate, described in US. Pat. Application Ser. No. 525,272 filed Dec. 20, 1965 in the name of Donald A. Smith, entitled Photographic Materials, issued as Belgian Pat. No. 691,446.

In a particularly useful receiving layer, we employ from 0.1 to 80 mg,/ft preferably 0.2 to about 5 mg./ft In a typical embodiment, 30 mg. of the polyvinyl polymer are used for l g. of gelatin in the receiving layer.

In addition to binder combinations which include a proteinaceous material combined with a synthetic polymer, we can use a substantially protein free receiving layer, comprising a colloid binder and a silver precipitant. In one embodiment a colloid binder comprises at least 90 percent by weight of a copolymer (1) about 90 percent to about 98 percent by weight, of at least one haloalkyl methacrylate in which the haloalkyl group contains one to carbon atoms with (2) about 2 percent to about 10 percent by weight, of an unsaturated polymerizable organic acid having three to six carbon atoms.

In the event that an integral diffusion transfer element is desired in which a silver halide emulsion is coated over a receiving layer on a support, it is particularly useful to employ a polymeric binder such as a latex binder for the nuclei. For example, a styrene-butadiene latex may be used such as one having a 65/35 molar composition at a concentration of 50 percent by weight solids. Various other latices of vinyl or acrylic homoor copolymer may be used. After the latex coating containing a silver precipitant has been prepared in a suitable support, it can then be overcoated with an unhardened gelatin silver halide emulsion which, after exposure and processing to obtain an image in the receiving layer, can then be removed by washing with warm water or similar means.

In still another polymeric binder type of receiving layer, alkyl acrylate-sulfo alkyl polymers are used. Polymers of this type are described in US. Pat. Application Ser. No. 525,272 in the name of D. A. Smith issued as Belgian Pat. No. 691,446. Typical polymers include copoly(butyl acrylate-sulfopropyl acryIate-Z-acetoxyethyl methacrylate), copoly(butylacrylatesulfopropyl acrylate etc.

An alkaline iodide, such as, e.g., ammonium, guanidine, sodium, potassium, lithium iodide, etc., can be present in the receiver in an amount of about 0.1 to about 20 mgJft, preferably 0.5 to about 10 mgJft". The effect of incorporation in certain receiving layers of iodide is particularly unexpected, since the tone is improved.

The addition of a silver salt or complex such as, e.g., silver nitrate, to certain receiving sheets improves the quality of the transfer, e.g., the image density. Any silver salt or complex can be used, including both organic and inorganic silver compounds. A typical organic silver complex is, for example, silver dipyridyl nitrate. Other silver salts and complexes which are included are described in Gilman et al., US Pat. No. 3,446,619. Still other silver salts of mercaptotetrazole and mercaptotriazles and related heterocyclic mercapto compounds are described in U.S. Pat. No. 2,432,864. However, silver nitrate is preferred. The silver compound can be used in an amount of about 0.01 to about 10 mgjft preferably 0.05 to about 5 mg./ft

Coating solutions which contain addenda other than a silver precipitant are also useful in preparing receiving layers. In addition to various components contained in the coating composition according to this invention, surfactants, coating aids, developing agents, release agents, silver halide solvents, etc, may be added to improve the image quality in the receiving sheet.

Particularly useful surfactants and spreading agents in receiver coatings include saponin, lauryl alcohol sulfate, p-tert octyl phenoxy ethoxy ethyl sodium sulfonate, etc.

Suitable silver precipitants for use in the receiving layer include various silver precipitating agents known in the art. As examples of suitable silver precipitating agents and of imagereceiving elements containing such silver precipitating agents, reference may be made to US. Pat. No. 2,698,237, 2,698,238 and 2,698,245 issued to Edwin H. Land on Dec. 28, 1954, US Pat. No. 2,774,667 issued to Edwin H. Land and Meroe M. Morse on Dec. 18, 1956, US. Pat. No. 2,823,122 issued to Edwin H. Land on Feb. 11, 1958, US. Pat. No. 3,396,018 issued to Beavers et al. Aug. 6, 1968 and also US. Pat. No. 3,369,901 issued to Fogg et al. Feb. 20, 1968. The noble metals, silver, gold, platinum, palladium, etc., in the colloidal form are particularly useful.

Nobel metal nuclei are particularly active and useful when formed by reducing a noble metal salt using a borohydride or hypophosphite in the presence of a colloid as described in the Rasch US. Pat. Application Ser. No. 796,552 filed Feb. 4, 1969. The metal nuclei are prepared in the presence of a proteinaceous colloid, such as gelatin, and coated on the receiving sheet. The same or a different colloid may be added, if desired. It will be appreciated from the above that the coating composition generally contains not only nuclei, but also reaction products which are obtained from reducing the metal salt. Accordingly, it is within the scope of our invention to include in the receiving layer the reaction by-products which are obtained during the reducing operation.

The amount of colloid used in preparing the above active noble metal nuclei can be varied depending upon the particular colloid used, e.g., gelatin, reducing agent employed, e.g., borohydride, proportions of reagents, etc. Typically about 0.5 percent to about 20, percent by weight, based on the total reaction mixture of colloid is used, preferably from about 1 percent to about 10 percent.

In a particularly useful embodiment, 30 to ,ug/ft of ac tive palladium nuclei in 80 mg. of colloid (solids basis) is coated per square foot of support. The colloid binder is advantageously coated in a range of about 5 to about 500 mg./ft Suitable concentrations on the receiving sheets of active noble metal nuclei as disclosed above can be about 1 to about 500 ug/ft Other silver precipitants can be coated in a concentration of up to 5 mg./ft

The supports which can be used for coating with the receiving layer are any of those which are suitable and include paper, wood, glass, plastics, etc. A particularly useful support is paper, especially baryta coated paper. However, in a preferred embodiment, a polymeric material which acts as a moisture barrier, such as polyethylene or the like, which is pigmented to provide a white surface is used. Antistain agents, such as acids, etc., can be incorporated in the supports or supporting layers. Typical antistain agents are disclosed in Yungkurth et al., US. Pat, No. 3,250,619 and Yungkurth, US. Pat. No. 3,326,744. Other polymeric materials which may be used as coatings on paper or as self-supporting webs include polyesters, polyamides, polycarbonates, polyolefins, cellulose esters, polyacetals and the like.

In order to obtain adhesion or to improve adhesion to a receiving support, treatments of the support, e.g., photographic film base, may be carried out including subbing the support, electron bombardment, treating with peroxide and the like.

The receiving layers of our invention may also have therein particles such as silica, bentonite, diatomaceous earth such as Kieselguhr, powdered glass and fullers earth. In addition, colloids and colloidal particles of metal oxides such as titanium dioxide, colloidal alumina, coarse aluminum oxide, zirconium oxide and the like may be used with the nuclei in the receiving layers.

In carrying out the diffusion transfer process, conventionally a silver halide emulsion is exposed to a light image after which it is contacted with a silver halide developing agent containing a silver halide complexing agent. The exposed emulsion is developed in the light struck areas and the unexposed silver halide is complexed with the silver halide complexing agent after which the emulsion is contacted against a receiving sheet and the complexed silver halide diffuses imagewise to the receiving sheet containing a silver precipitant.

In some instances it may be desirable to treat the receiving sheet in order to improve the stability of the sheet, particularly with regard to the silver image thereon. A simple stabilizing method merely involves washing the print in order to remove any processing chemicals which may remain thereon. However, the washing step does not protect the print from subsequent chemical reactions with oxygen, hydrogen sulfide, etc., in the atmosphere, which have an adverse effect on the stability of the silver image. For these reasons, it has been proposed to coat the print with a coating composition such as that disclosed in US. Pat. No. 2,979,477 comprising a mixture of vinylpyridine polymer and a hydantoin-formaldehyde condensation polymer.

Suitable print coating compositions may also employ a polymeric material such as methylmethacrylate-methacrylic acid copolymer or the combination of an acid group or sulfate group containing polymer such as copoly(methylmethacrylate-methacrylic acid) and a hydantoin-formaldehyde condensation polymer, such as that disclosed in French Pat. No. 1,493,188. A heavy metal salt, such as zinc acetate, may also advantageously be incorporated in the print coating composition. Further improvement is obtained by incorporating in the coating composition an acid, such as acetic acid, propionic acid or the like.

Silver halide developing agents used for initiating development of the exposed sensitive element can be conventional types used for developing films or papers with the exception that a silver halide solvent or complexing agent such as sodium thiosulfate, sodium thiocyanate, ammonia or the like is present in the quantity required to form a soluble silver complex which diffuses imagewise to the receiving support. Usually, the concentration of developing agent and/or developing agent precursor employed is about 3 to about 320 mg./ft of support.

Developing agents and/or developing agent precursors can be employed in a viscous processing composition containing a thickener such as carboxymethyl cellulose or hydroxyethyl cellulose. A typical developer composition is disclosed in US. Pat. No. 3,120,795 of Land et al. issued Feb. 11, 1964.2

Developing agents and/or developing agent precursors can be employed alone or in combination with each other, as well as with auxiliary developing agents. Suitable silver halide developing agents and developing agent precursors which can be employed include, for example, polyhydroxybenzenes, alkyl substituted hydroquinones, as exemplified by t-butyl hydroquinone, methyl hydroquinone and 2,5-dimethylhydroquinone, catechol and pyrogallol; chloro substituted hydroquinones such as chlorohydroquinone or dichlorohydroquinone; alkoxy substituted hydroquinones such as methoxy hydroquinone or ethoxy hydroquinone; aminophenol developing agents such as 2,4-diaminophenols and methylaminophenols. These include, for example, 2,4- diaminophenol developing agents which contain a group in the six position, and related amino developing agents, e.g.:

6-methyl-2,4-diaminophenol 6-methoxy-2,4-diaminophenol 6ethyl-2,4-diaminophenol 6-phenyl-2,4-diaminophenol 6-para tolyl-2,4-dirninophenol 6-chloro-2,4-diaminophenol 6-morpholinomethyl-Z,4-diaminophenol 6-piperidino-2,4-diaminophenol 3,6-dimethyl-2,4-diaminophenol 6-phenoxy-2,4-diaminophenol 2-methoxy-4-amino-5-methyl phenol 4-aminocatechol 4-aminoresorcinol 2,4-diaminoresorcinol methyl-3,4-diaminophenol methoxy-3,4-diaminophenol methyl-2,5-diaminophenol methoxy-2,S-diaminophenol methyl- 1 ,2,4-triamino benzene methoxy-l ,2,4triamino benzene p-hydroxyphenyl hydrazine p-hydroxyphenyl hydroxylamine The aminophenol developing agents can be employed as an acid salt, such as hydrochloride or sulfate salt.

Other silver halide developing agents include ascorbic acid, ascorbic acid derivatives, ascorbic acid ketals, such as those described in US Pat. No. 3,337,342 of Green issued Aug. 22, 1967; hydroxylamines such as N,N-di(2-ethoxyethyl)hydroxylamine; 3-pyrazolidone developing agents such as l-phenyl- 3-pyrazolidone, including those described in Kodak British Pat. No. 930,572 published July 3, 1963; and acyl derivatives of p-aminophenol such as described in Kodak British Pat. No. 1,045,303 published Oct. 12, 1966; pyrimidine developing agents, such as 4-amino-5,6-dihydroxy-2-methyl pyrimidine; and aminomethyl hydroquinone silver halide developing agents, such as 2-methyl-5-pyrrolidinomethyl hydroquinone, 2-methyl-5-morpholinomethyl hydroquinone, and 2-methyl-5- piperidinomethyl hydroquinone. The aminomethyl hydroquinone silver halide developing agents are especially suitable incorporated in the negative photographic element.

Another suitable silver halide developing agent which can be used in the practice of the invention is a reductone silver halide developing agent, especially an anhydro dihydro amino hexose reductone silver halide developing agent, such as anhydro dihydro piperidino hexose reductone, anhydro dihydro pyrrolidino hexose reductone, and/or anhydro dihydro morpholino hexose reductone.

The described reductone silver halide developing agents can be prepared as described in US Pat. No. 2,936,308 of Hodge, issued May 10, 1960 and in an article by F. Weygand et al., Tetrahedron, Volume 6, pages 123-138 (1959). Typically the described anhydro dihydro amino hexose reductone compounds are prepared from the corresponding anhydro amino hexose reductones by hydrogenation in the presence of a suitable hydrogenation catalyst, such as Raney nickel catalyst. The reductone silver halide developing agent can be employed in various locations in the diffusion transfer system, but is especially suitable in the processing composition. These can be used alone or in combinations of developing agents. These developing agents provide little or no stain and improved stability.

Lactone derivative silver halide developing agents which have the property of forming a lactone silver halide developing agent precursor under neutral and acid conditions are particularly useful. Typical lactone derivatives are described in copending US. Applications Ser. Nos. 764,348 and 764,301 filed Oct. 1, 1968, both entitled Photographic Compositions and Processes in the name of Oftedahl. The particularly suitable lactone derivatives provide desired developing activity and reduction of stain without adversely affecting desired maximum density, minimum density, photographic speed and other desired sensitometric properties. Suitable lactone derivative developing agents include those which under neutral, slightly alkaline or acid conditions, i.e., when the pH is lowered to a level of about 9 or lower, i.e., about 2 to about 9, do not have significant developing activity, if any, due to formation of a developing agent precursor.

The developer solution and/or activator solution may contain additives such as toners, potassium iodide, or the like. For instance, a toner such as the toners described herein may be used.

Silver halide emulsions employed with receiving layers and elements of this invention can contain incorporated addenda, including chemical sensitizing and spectral sensitizing agents, coating agents, antifoggants and the like. They can also contain processing agents such as silver halide developing agents and/or developing agent precursors. Of course, the processing agents can be incorporated in a layer adjacent to the: silver halide emulsion if desired.

The photographic emulsions employed can also be x-ray or other non-spectrally sensitized emulsions or they can contain spectral sensitizing dyes such as described in U.S. Pat. Nos. 2,526,632 of Brooker et al. issued Oct. 24, i950 and 2,503,776 of Sprague issued Apr. 11, 1950. Spectral sensitizers which can be used include cyanines, merocyanines, styryls and hemicyanines.

The photographic emulsions can contain various photographic addenda, particularly those known to be beneficial in photographic compositions. Various addenda and concentrations to be employed can be determined by those skilled in the art. Suitable photographic addenda include hardeners, e.g., those set forth in British Pat. No. 974,317; buffers which maintain the desired developing activity and/or pH level; coating aids; plasticizers, speed increasing addenda, such as amines, quaternary ammonium salts, sulfonium salts and alkylene oxide polymers; and various stabilizing agents, such as sodium sulfrte. The photographic silver salt emulsions can be chemically sensitized with compounds of the sulfur group such as sulfur, selenium and tellurium sensitizers, noble metal salts such as gold, or reduction sensitized with reducing agents or combinations of such materials.

Various photographic silver salts can be used in the practice of the invention. These include photographic silver halides such as silver iodide, silver bromide, silver chloride, as well as mixed halides such as silver bromoiodide, silver chloroiodide, silver chlorobromide and silver bromochloroiodide. Photographic silver salts which are not silver halides can also be employed such as silver salts of certain organic acids, silver-dye salts or complexes, etc.

The photographic silver salts are typically contained in an emulsion layer comprising any binding materials suitable for photographic purposes. These include natural and synthetic binding materials generally employed for this purpose, for example, gelatin, colloidal albumin, water-soluble vinyl polymers, mono and polysaccharides, cellulose derivatives, proteins, water-soluble polyacrylamides, polyvinyl pyrrolidone and the like, as well as mixtures of such binding agents. The elements can also contain release layers and/or antistatic layers (i.e. conducting layers).

Release agents can be used either on the surface of the silver halide emulsion layer, on the receiving layer containing the nuclei in the receiving layer containing the nuclei, or can be contained in the developing or processing solutions. When added to the processing solution in concentrations of about 3 percent to about 10 percent, by weight, the release agents prevent the processing solution from sticking to the receiver. Suitable release agents normally are used which have a composition different from the binder used in the silver halide emulsion.

Among the release agents which may be used are the following: materials represented by the following general formula normally used as the free acid or anhydride or converted to a convenient salt such as the sodium or ammonium:

flail r t i l Us. 35

may be used:

I 7 GH2--C w CHCH Q l (0:4. 0:0)

NH- :0 I O y H x n X n onht ln CHCH o N o o T x on on -CHT-(I'JH LOB-CH (l o o o o\ o 0 CH3 x OH \OH y n oin-0H) OH OH y n CHz-CH CH CH- o i OCHZCN x \OH ONa y 11 CHrCH- -oH cH l. l o o\ /o o o 0 y OH x n materials represented by the following general formula:

in which R is chosen from among H, and the lower alkyls such as CH C l-l C l-l x, y and n are whole integers.

R is chosen from among OH, O-alkyl, NH and NHR where R can be alkyl, substituted alkyl, phenyl, a fivemembered heterocyclic ring or a six-membered heterocyclic ring.

Particularly useful materials are the following:

i CHZCHQSCHZ y n Especially useful materials are resinous materials having molecular weights of about 10,000 to about 500,000 as described in US. Pat. Nos. 3,169,946; 3,007,901; 3,206,312; 3,260,706; 2,306,071; and 3,102,028. These materials are lactones of resinous heteropolymers of a vinyl or isopropenyl organic acid tester of an unsaturated aB-dicarboxylic acid reacted with a member selected from the group consisting of a monohydric alcohol and a mixture of a monohydric hydroxy acid and a monohydric alkanol.

Coatings of these agents are relatively thin, having a preferred coverage of about 6.0 mg./ft However, a useful range may be from 1.0 mg. to 1.0 g./ft It will also be understood that a release agent can be incorporated in the receiving layer along with the nuclei and/or binder used as a carrier for the nuclei.

The following examples are included for a further understanding of the invention:

EXAMPLE 1 A nuclei melt is prepared as follows:

1. 138 grams of 10 percent bone gelatin in 862 ml. of

distilled water.

2. heat to 50 C. and add 7 ml. of 1.24 percent PdCl solution (1 percent HCl).

3. Adjust pH to 6.0 with sodium hydroxide.

4. Add 30 ml. of 0.2 percent NaBH solution (60 mg.) to react with the PdCl to form colloidal palladium (pH should rise to 8.3 8.5).

5. Stir 10 minutes at 50 C. and adjust pH to 5.5 with 0.1 N

HCl.

6. Add 562 g. of 10 percent bone gelatin and 438 ml. of

distilled water.

7. Stir and chill set.

Coatings using this nuclei melt are as follows:

Coatings Efieet on Tone 1 2 3 4 5 Nuclei melt, m1 48 48 48 48 48 Distilled water. 250 252 252 250 252 1% Polymer 1""... 5 5 5 5 5 10% Formaldehyde 2. 5 2. 5 2. 5 2. 5 2. 5 15% Saponln 3 3 3 3 3 10% Potassium iodide"... 1.3 1.3 1,3 0.2% Silver nitrate 5 5 1% 1-phenyl-5-selen0-1,2,3,4-tetrazol 1.0 1 0 1.0 1.0

Sodium salt of carboxy butyl esterlactone of the interpolymer of maleic anhydroXide-vinyl acetate (11.27% by weight) 29 ml, Distilled water 500 ml. Methanol 2250 ml.

Each receiver sheet is tested by placing in contact with a silver bromoiodide emulsion coated on opaque support, exposed, and developed by means of rupture of a viscous pod of the following formulation:

gll

-methyl-Z.4-diaminophenol sulfate 5-10 ter-Butyl Hydroquinone 25 Na,S,O H,O 6O NaOl-l 20 KOH 20 Kl 0.6-1.6 Hydroxy ethyl cellulose 3-4.5 7r K 50 25-50 Results;

Coating Dmax. Tone l 1.60 Cold 2 1.36 Cold 3 1.48 Warm 4 1.12 Neutral 5 1.10 Neutral EXAMPLE 2 Receiver sheets are prepared as in Example I coating 1, except that instead of l-phenyl-S-seleno-l ,2,3,4-tetrazole, other tetrazoles are employed. After processing the receiving sheets according to Example l, the washed samples are placed in a sealed chamber for six days at l F 85 percent R.H., 1,800 foot candles of white light using fluorescent lamps. The following results are obtained:

The reference to toe steps concerns a conventional H and D characteristic curve for a silver halide emulsion having increments of 0. l 5 log E or an increment ofO. l 5 log E for one step.

EXAMPLE 3 Example l is repeated with l-allyl-S-seleno-l,2,3,4- tetrazole substituted in coating 5 for l-phenyl-S-selenol,2,3,4-tetrazole. A neutral tone is obtained.

EXAMPLE 4 5 Selenol ,2,3,4-tetrazoles having the structure t :N W 747 in which R is methyl, ethyl, butyl or decyl, phenyl, or tolyl are employed as toners in a diffusion transfer process as described in Example 1, coating 5. A neutral tone results in each instance.

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

I claim:

1. A receiving element comprising a support having thereon an alkali permeable organic colloid layer containing a silver precipitant and a S-selenol ,2,3,4-tetrazole.

2. A receiving element of claim 1 in which said organic colloid is elatin.

3. 1% receiving element of claim 1 in which said silver precipitant is a colloidal noble metal.

4. A receiving element of claim 1 which also contains a silver halide solvent.

5. A receiving element of claim 1 which also contains a silver halide developing agent.

6. A receiving element of claim 1 in which said tetrazole is l-phenyl-S-seleno-l ,2,3 ,4-tetrazole.

7. A receiving element of claim 1 in which said tetrazole is 1-allyl-5-seleno-1,2,3,4-tetrazole.

8. A photographic element of claim 1 which contains over said organic colloid layer a light-sensitive silver halide emulsion layer.

9. A receiving element of claim 1 in which said seleno tetrazole comprises about 0.01 mg. to about 0.5 g. per square foot.

10. In a process of obtaining an image from undeveloped areas of an exposed developing silver halide emulsion layer to a reception layer containing a silver precipitant, the improvement which comprises carrying out the development of the silver halide layer in the presence of a 5-seleno-l,2,3,4- tetrazole.

11. A photographic process according to claim 10 wherein the seleno tetrazole is a l-phenyl-S-selenol ,2,3,4-tetrazole.

12. A photographic process according to claim 10 in which the reception layer comprises a 5-seleno-l,2,3,4-tetrazole toning agent.

13. A process of claim 10 in which said silver precipitant is a noble metal.

14. A photographic element comprising a silver image in a proteinaceous receiving layer on a support, said image obtained by a diffusion transfer process, said receiving layer comprising a 5-seleno-1,2,3,4-tetrazole toning agent.

Claims

2. A receiving element of claim 1 in which said organic colloid is gelatin.
3. A receiving element of claim 1 in which said silver precipitant is a colloidal noble metal.
4. A receiving element of claim 1 which also contains a silver halide solvent.
5. A receiving element of claim 1 which also contains a silver halide developing agent.
6. A receiving element of claim 1 in which said tetrazole is 1-phenyl-5-seleno-1,2,3,4-tetrazole.
7. A receiving element of claim 1 in which said tetrazole is 1-allyl-5-seleno-1,2,3,4-tetrazole.
8. A photographic element of claim 1 which contains over said organic colloid layer a light-sensitive silver halide emulsion layer.
9. A receiving element of claim 1 in which said seleno tetrazole comprises about 0.01 mg. to about 0.5 g. per square foot.
10. In a process of obtaining an image from undeveloped areas of an exposed developing silver halide emulsion layer to a reception layer containing a silver precipitant, the improvement which comprises carrying out the development of the silver halide layer in the presence of a 5-seleno-1,2,3,4-tetrazole.
11. A photographic process according to claim 10 wherein the seleno tetrazole is a 1-phenyl-5-seleno-1,2,3,4-tetrazole.
12. A photographic process according to claim 10 in which the reception layer comprises a 5-seleno-1,2,3,4-tetrazole toning agent.
13. A process of claim 10 in which said silver precipitant is a noble metal.
14. A photographic element comprising a silver image in a proteinaceous receiving layer on a support, said image obtained by a diffusion transfer process, said receiving layer comprising a 5-seleno-1,2,3,4-tetrazole toning agent.