US3672891A - Photographic element and process comprising a pyrimidine silver halide developing agent - Google Patents

Abstract

PHOTOGRAPHIC DEVELOPING AGENTS WHICH ARE PYRIMIDINE COMPOUNDS SUCH AS 5-HYDROXY AND/OR 5-AMINO-PYRIMIDINE DEVELOPING AGENTS PROVIDE REDUCED STAIN WITHOUT LOSS OF DESIRED SENSITOMETRIC PROPERTIES IN A DIFFUSION TRANSFER SYSTEM. THESE CAN BE USED IN COMBINATION WITH OTHER PHOTOGRAPHIC DEVELOPING AGENTS, SUCH AS REDUCTONE DEVELOPING AGENTS, AMINOMETHYL HYDROQUINONE DEVELOPING AGENTS, CINNAMIC ACID DEVELOPING AGENTS, LACTONE DEVELOPING AGENTS, OR DEVELOPING AGENT PRECURSORS E.G. COUMARIN DEVELOPING AGENTS OR DEVELOPING AGENT PRECURSORS. THEY ARE ESPECIALLY USEFUL IN A BLACK-AND-WHITE SILVER SALT DIFFUSION TRANSFER PROCESS.

Description

United States Patent Oflice 3,672,891 Patented June 27, 1972 PHOTOGRAPHIC ELEMENT AND PROCESS COM- PRISING A PYRIMIDINE SILVER HALIDE DE- VELOPING AGENT Edwin B. Wyand and William C. Farley, Rochester, N. assignors to Eastman Kodak Company, Rochester, N.Y.

No Drawing. Filed Oct. 2, 1969, Ser. No. 863,340 Int. Cl. G03c 1/48, 5/30, 5/54 US. Cl. 96-29 R 16 Claims ABSTRACT OF THE DISCLOSURE Photographic developing agents which are pyrimidine compounds such as S-hydroxy and/ or S-amino-pyrimidine developing agents provide reduced stain without loss of desired sensitometric properties in a difiusion transfer system. These can be used in combination with other photographic developing agents, such as reductone developing agents, aminomethyl hydroquinone developing agents, cinnamic acid developing agents, lactone developing agents, or developing agent precursorseg. coumarin developing agents or developing agent precursors. They are especially useful in a black-and-white silver salt diffusion transfer process. r

BACKGROUND OF THE'INVENTION Field of the invention This invention relates to photographic developing agents and to photographic elements, processing compositions,

especially developer compositions and to processes employing such developing agents. In one of its aspects, the invention relates to pyrimidine silver halide developing agents, such as S-hydroxy and/or S-amino-Pyrimidine developing agents and photographic elements, processes and/ or processing compositions, especially those employed by the use of a photographic emulsion layer and an image 7 receiver or precipitating layer contiguous to the emulsion 1 layer; After exposure of the photographic emulsion'layer, typically a processing composition, e.g. a developer composition, is applied between the exposed photographic emulsion layer and the image receiver or. precipitating layer. The processing composition usually contains a silver halide solvent, such as sodium thio'sulfaterwhich causes the unexposed silver salts,usually silver fhalides, to dissolve forming a silver complex which diffuses to the image receiver or precipitating layer where development nuclei or an image precipitating agent in that layer causes the silver to be precipitated from the silver complex imagewise. Development nuclei or precipitating agents can be present in the image receiving layer before contact with the complexed silver or the nuclei can be formed in situ. Diffusion transfer photographic processes, elements and compositions for such processes are well known and described, e.g. in US. Pat. 2,698,237 of Land issued Dec. 28, 1954; US. Pat. 2,647,056 of Land issued July 28, 1953; US. Pat. 3,108,001 of Green issued Oct. 22, 1963; and US. Pat. 3,345,166 of Land issued Oct. 3, 1957.

A processing composition employed in difiiusion transfer processes normally contains a developing agent and is usually applied as a viscous fluid layer spread between the photographic layer and the image receiving layer.

The requirements for developing agents for diffusion transfer systems are very stringent and relatively few of the developing agents which are satisfactory for general silver halide developing processes are satisfactory or active for diflfusion transfer systems. One of the dilfusion transfer developing agents used more successfully is a 2,4 diamino phenol, e.g. 2,4-diamino phenol dihydrochloride, also known as Amidol. However, although such developing agents will produce, a positive image, they are subject to rapid oxidation which results in an unsightly and objectionable dark oxidation product which stains the positive print.

Surprisingly developing agents which have been .employed successfully in developing silver halide emulsions in general photographic processing have not provided the desired reduction in stain. is illustrated in the following Examples 2, 3, and 4 in which it is demonstrated that hydroquinone, t-butyl hydroquinone and 6-methoxy-2 ,4- diamino phenol do not provide a desired reduction in stain.

Thus there has been a need for developing agents which provide desired sensitometric properties and developing action without objectionable stain or oxidation product.

Accordingly, it is an object of the invention to provide improved photographic elements, compositions and processes especially diffusion transfer processes and photographic elements and compositions therefor employing the described developing agents which provide reduced stain without loss of desired sensitometric properties.

SUMMARY OF THE INVENTION .cinnamic acid developing agents and coumarin developing agents or developing agent precursors are especially suitable according to the invention.

-- DESCRIPTION OF THE PREFERRED EMBODIMENTS lAiwide range of pyrimidine silver halide developing agents which provide reduced stain without loss of desired sensitometric properties can be employed according to [the invention. These include any pyrimidine silver halide developing agents which provide desired developing activity and reduction of stain without adversely affecting desired maximum density, minimum density, photographic speed, gamma and other desired sensitometric properties.

Typically, pyrimidine developing agents are employed which are 5 -hydroxy and/or S-amino pyrimidine developing agents.

A wide variety of pyrimidine silver halide developing agents can be employed according to the invention. Suitable pyrimidine developing agents include, for example, compounds of the formula:

the

practiee of the invention in a range of physical locacontaining I-S carbonatoms, such-as-methy1',=ethyl,=pro:-" tions in a diifusion transfer photographic system. They pyl, butyl and pentyl; hydroxyl; aryl, especially aryl containing 6 to 12 carbon atoms, such as phenyl, tolyl and xylyl; aheterocycliegroup, especially a'heterocyclic group containing 215 0116 atom nucleus, such as pyridyl morpho- -lino, piperidino and pyrollino; amino, especially --"-NH R, wherein R R and R are each alkyl, especially alkyl containing 1-5 carbon atoms, or R and R taken together represent atoms completing a heterocyclic nucleus containing a nitrogen atom, preferably containing five to six carbonatoms in the nucleus, including for example, a second nitrogenor an oxygen atom, e.g. morpho1ino,-.piperably at least R being hydroxy or amino, as described. f'

1 Suitable pyrimidine silver halide developing agents in- These compounds can be prepared by methods known in the art. Some of these compounds tautomerize to correcluded for purposes of the invention. f 1

Pyrimidine silver halide developing agents are'described, for example, in an article by R. W. Henn and S. V. Carpenter, Photographic Science and Engineering, No. 3, May-June, 1959, pp. 135-139. Pyrimidine silver reacting the parent pyrimidine compound with a p'ersulfate compound such as ammonium persulfat'e, to produce a S-pyrimidyl hydrogen sulfate compound which can b'e azino, pyrollino, pyridino, pipe'ridino, and the like, prefersponding keto compounds. The tautomeric form is in- Lhalide developing agents can be prepared, for example, by

hydrolyzed with acid, such as concentratedhydrochloric The described pyrimidine silver halide developing agents e.g. S-hydroxypyrimidines- A typical preparation is' tlie preparation 2-amino-4,5-dihydroxy-fi-methylpyrimidine. This comprises heating 2-amino-4hydroxy-6-methyl-5- 'pyrirnidyl hydrogen sulfate under reflux in 5 normal hydrochloric acid for about 30 min. The resulting solution is cooled and the desired 5-hydroxy pyrimidine hy'drochloride collected and made into a slurry'with sodium hydrogen carbonate solution. The mixture is refiltered to provide the desired product. i

The described pyrimidine silver halide developing agents are typically in the Iorrn of an acid salt such as a hydrochloride, chloride, sulfate, or the like salt. A pyrimidine silver halide developing agent as employed herein includes such compounds either in salt form or in their non-salt form.

The described developing agents can be employed in can be employed in one or more layers of the photographic element and/ or in a processing composition if desired. The optimum location will dependzupon the desired image processing conditions and the like. For example, the described developing agents can be employed infa processing, composition, such as aqueous al aline developer solution, or theylcan be incorporated into one or more layers era photographic element, such as a photographic sil- -ver halide emulsion layer, a layer between the support and the silver halide emulsion layer and/or an overcoat layer. Suitable difiusion transfer systems, processes, processing compositions and elements therefor which can be employed in the practice of the invention are described ,for example, in US. Pat. 2,352,014 of Rott issued June 20, .1944; US. Pat. 2,452,181 of Land issued Feb. 27, 19.51; and US. Pat. 3,337,342 of Green issued Aug. 2 7 1967. {They can be used in so-called high-speed diifusion transfer processes and compositions therefor as described for example in U. S. Pat. 3,326,683 ofLand etal. issued June 20,, 19 67; or.in other types of diffusion transfer systems,

processes and compositionstherefor such as described in U. S.. .Pat.'2,8'57,274 of Land et al. issued Oct. 21, 1958; UlS Pat. 3,020,155.01? Yackel etal. issued Feb. 6, 1962; LES.- Pat. 2,584,030bf Land issued Jan. 29, 19,52; and U.SI Pat. 2,923,623 of Land issued Feb. 2, 1960. These references also describe typical photographic products suitable for diffusion transfer systems comprising in combination (a) a photographic element comprising a photographic silver salt layer e.g. a photographic silver halide layer, (b) a processing composition containing a silver halidesolvent and, typically, a silver halide developing agent, usually in a rupturable container, and (c) an image receiving layer. I

. Accordingly, one embodiment of the invention comprises in a photographic product comprising in combination (a) a photographic element comprising a photographic silver salt, typically photographic silverhalide,

, (b) a processingcomposition containing a silver halide solvent, suitably in a rupturable container, and (c) an ima e receiving layer, the improvement-comprising a pyrimidine silver halide developing agent. The described pyrimidine developing agent can be employed as described in any suitable physical location such as, in the photo: graphic element, in the processing composition, and/or in the image receiving layer or a layer contiguous thereto.

The developing agents described can be employed for developing an' image in a widefrange of photographic emulsions; They can be employedin such emulsions if desired. The photographic emulsions employed in the practiceof the invention can be X-ray or other non-spectrally sensitized emulsions or they can contain spectral sensitizing dyes such as described in US. Pat. 2,526,632 of Brooker et a1. issued Oct. 24, 1950 and 2,503,776 of Sprague issued Apr. 11, 1960. Spectral sensitizers which can be used include e.g. eyanines, merocyanines, complex( trinuclear) cyanines, complex (trinuclear) merocyanines, styryls hernicyanines. I

Various photographic silver salts can be'used in the practice of the invention. These include photographic silver halides such as silver bromide, silver'chloride, as well as mixed"halidessuch as silver bromoiodide, silver chloroiodideand the'like. Photographic silver salts which are i ot silver halides can also be employed such' as silversalts of certain' organic acids; i

The photosensitive layers and/ or image receiving layers which are employed in the practice of the invention can 'be' coated on a wide variety of supports. Suitable supports include, for example, those generally employed for photographic-elements,- such as cellulose nitrate film, cellulose 'e'sterfilm," poly(vihyl acetal)film, polystyrene film, poly. (ethylene terephthalate)film, and related films or resinous materials, as 'well as papers such as paper supports coated with resinous materials-e.g. paper coated with alphaole fin polymers, particularly polymers of alpha-olefins containing 2 to 4 carbon atoms as exemplified by polyethylene, polypropylene, ethylene-butene copolymers orthe like; as well as glass, metal and the like. The supports or layerscoated on them, typically paper supports can contain fluorescent brightening agents, such as stilbenes, benzothiazoles, and benzoxazoles.

- The photographic elements and image receiver layers employed in the practice of the invention typically contain binding materials suitable for photographic purposes. These include natural and synthetic binding materials generally employed for this purpose, e.g. gelatin, colloidal albumin, water-soluble vinyl polymers, such as mono and polysaccharides, cellulose derivatives, acrylamide polymers, polyvinyl pyrrolidone and the like. Mixtures of binding agents can also be used. The binding agents for an emulsion layer of a photographic element as described can also contain other dispersed polymerized vinyl compounds. Such compounds are described for example in U.S. Pat. 3,142,568 of Nottorf issued July 28, 1964; U.S.

Pat. 3,193,383 of White issued July 6, 1965; U.S. Pat. 3,062,674 of Houck, Smith and Yudelson issued Nov. 6, 1962; and U.S. Pat. 3,220,844 of Houck, Smith and Yudelson issued Nov. 30, 1 965 and include the water-insoluble polymers of alkyl acrylates, and methacrylates, acrylic acid, sulfoalkyl acrylates or methacrylates and thelike. The described elements can also contain stripping layers and/or antistatic layers,'i.e. conducting layers.

Photographic emulsions employed in the practice of the invention can also contain speed increasing compound such as quaternary ammonium compounds, polyethylene glycols or thioethers. Frequently, useful effects can be obtained by adding the described speed increasing compounds to the processing solutions instead of, or in addition to, the photographic emulsions.

Photographic silver halide emulsions employed in the practice of the invention can be chemically sensitized using any of the well-known techniques in emulsion making, e.g. by digesting with naturally active gelatin or various sulfur, selenium, tellurium and/or noble metal sensitizers and/or reduction sensitizers. Combinations of sensitizers can be employed such as described in U.S. Pat. 3,297,446 of Dunn issued Ian; 10, 1967*and U.S. Pat. 3,408,196 of McVeigh issued Oct. 29, 1968.

The described developing agents employed in the practice of the invention can be employed in combination with addenda known in the art to be useful in processing photographic elements, especially those employed in photographic difiusion transfer systems. Various suitable addenda include hardeners, e.g. those set out in British 974,317; buffers which maintain desired developing activity and/or pH level; coating aids; plasticizers; and stabilizing agents, such as sodium sulfite. The described developing agents employed in the prac- 'tice of the invention can be used in colloid transfer processes and elements such as described in U.S. Pat. 2,596,- 752 of Williams issued May 13, 1952. They can also be used in photographic elements and/ or in processing compositions intended for use in monobath processing such as described in U.S. Pat. 2,875,048 of Haist et al. issued Feb. 24,-1959 and British 1,063,844 of Beavers et 'al. published Mar. 30, 1967. They can also be used in socalled web type processing such as described in U .S. Pat, 3,179,517 of Tregillus et al. issued Apr. 20, 1965.

The described developing agents employed in the practice of the invention can also be used to advantage in multilayer, single element diffusion transfer systems which utilize undeveloped silver halide in non-image areas of a negative to form a positive by physical development of this silver onto a nuclei containing, contiguous, image receiving layer after which the upper layer is removed by scrubbing, washing, stripping or other suitable method. Processes of this type are described, for instance, in U.S. Pat. 3,020,155 of Yackel et al. issued Feb. 6, 1962.

Good results, evidenced by improved tone and desirable contrast are obtained in elements of this type when they are processed by use of a so-called external processing web containing the described developers ofthe invention in combination with a silver halide solvent and other processing or coating components dispersed in a vehicle and coated on a suitable support. Processing webs of this type are described for example in U.S. Pat. 3,179,- 517 of Tregillus et al. issued Apr. 20, 1965.

The developing agents employed in the practice of the invention can be employed if desired in photographic elements designed for stabilization type processing. For instance, they can be incorporated in one or more layers of a photographic element which is exposed and then processed by contact with an alkaline development activator and followed by stabilization with a suitable stabilizer, such as with a thiocyanate or thiosulfate stabilizer e.g. by contact with a thiocyanate or thiosulfate solution containing ammonium thiocyanate or sodium thiosulfate. They can be incorporated in the alkaline activator if desired. Such processes are described for example in U.S. Pat. 3,326,684 of Nishio et al. issued June 20, 1967; British 1,004,302 of Ilford published Sept. 15, :1965; French 1,516,556 of Fassbender; and in an article by H. -D. Russell -et al. in PSA Journal, volume 8, No. 50, pp. 59-62 entitled Stabilization Processing of Films and Papers.

The developing agents employed according to the invention can also be present in one or more layers of a photographic element designed for recording color images. For example, these compounds can be employed in one or more layers of a photographic element containing a photographic layer sensitive to the blue region of the spectrum, a photographic layer sensitive to the green region of the spectrum, and a photographic layer sensitive to the red region of the spectrum. layers sensitive to the blue, green and red regions of the spectrum can contain any suitable sensitizing dyes. Photographic elements designed for recording color images in which the developing agents of the invention can be used are described for example in Mees, The Theory of the Photographic Process, 3rd ed. 1966, pp. 382-396.

The developing agents employed in the practice of the invention can be employed in an element containing development nuclei or silver precipitating nuclei, e.g. an image receiver. As described, they can also be employed in photographic elements and/ or processing compositions designed for use with an image receiver.

Development nuclei or silver precipitating agents which can be employed in diffusion transfer systems as described can be physical development nuclei or chemical precipitants including, for example: (a) heavy metals in colloidal form and salts of these metals, (b) salts of amines which form silver salts and/or (c) non-diffusing polymeric materials with functional groups capable of combining with silver amines.

Suitable development nuclei and/or silver image precipitating agents within the described classes include metal sulfides, selenides, polysulfides, polyselenides, thiourea and its derivatives, stannous halides, silver, gold, platinum, palladium, and mercury, colloidal sulfur, aminoguanidine sulfate, aminoguanidine carbonate, arsenious oxide, sodium stannite, hydrazines, xanthates, and

' similar agents disclosed, for example, in U.S. Pat. 3,020,-

square foot of the layer containing the precipitants or development nuclei. 7 p

The developing agents employed in the practice of the inventioncan be employed in combination with any silver halide developing agent. The developing agents employed in the practice of the invention can be employed in such combinations as auxiliary developing agents or as the main component of the developing combination. Suitable silver halide developing agents which can be employed in combination with the described pyrimidine developing agents include, for example, polyhydroxybenz enes such as hydroquinone developing agents, e.g. hydroquinone,.a1kyl substituted hydroquinones as exemplified by tertiary butyl hydroquinone,fmethyl hydroquinone and 2,5-dimethyl hydroquinone; catechol and pyrogallol; chloro substituted hydroquinone such as chlorohydroquinone or dichlorohydroquinone;-,alkoxy substituted hydroquinone such as methoxyhydroquinone or ethoxyhydroquinone; amino phenol developing agents, such as 2,4-diaminophenols" and methylaminbphehols; ascorbic acid developing agents such as ascorbic acid, ascorbic. 'acid ketals, and ascorbicacidv derivativ'es such as those described in US. ,Patent.2 ,337,342 of Green issued Aug. 22, 1967; hydroxyamine developing agents. such, as. N,N-di(2-ethoxyethyl)hydroxylamine; 3.-pyrazolidone developing agents such as 1-phenyl-3-pyrazolidone and l-phenyl-4-methyl-4-hydroxymethyl-3-pyrazolidone including those described in British 930,572, published July 3, 1963; and acyl derivatives of para aminophenol such as described in British 1,045,303, published Oct. 12, 1966. Such developing agents can be used alone or in combination. It is usually desirable to use other developing agents than hydroquinone compounds and aminophenol compounds because of the tendency of these compounds to cause stain.

The developing agents employed in the practice of the invention can be used in combination, for example, with the following compounds; l-phenyl-B-pyrazolidone hydroquinone methyl hydroquinone 2,5-dimethyl hydroquinone 2,6-dimethyl hydroquinone tertiary butyl hydroquinone 3,6-dihydroxy benzonorbornane 2,4-diamino-6-methyl phenol dihydrochloride 4-phenyl catechol tertiary butyl pyrocatechol 2,4-diaminophenol dihydrochloride ascorbic acid N-methyl-p-aminophenol sulfate I N,N-ethylene di(oxymethyl)pyridinium perchlorate 2-(3-sulfopropyl)-2-thiopseudo urea 7,14-diazo-6,IS-dioxoeicosane-1,2l-bis(pyridinium perchlorate) The described compounds can, for instance, be incorporated in a photographic element employed in a difinsion transfer system as described which after exposure can be developed employing a processing composition containing a developing agent of the invention. One or more of the described combination of compounds can be in a photographic element and/ or processing composition, eg. a developer composition employed in the practice of the invention. For example, a photographic element can contain a 3-pyrazolidone developing agent and/or a 2,4-diaminophenol developing agent and/or other described addenda and be developed employing a processing composition containing a developing agent of the invention, Le. a pyrimidine developing agent.

The developing agent employed in the practice .ofthe invention can be employed in a photographic'silver salt emulsion designed for diffusion transfer processing and/ This composition is typically employed in a combination of (a a photographic element comprising a photographic silver salt layer, -(b) a viscous processing.composition comprising: a a

(1) a silver halide solvent, I .(2) analkaline development activatonand (3') apyrimidine silver halide developing' agent, (c):'a n image receiving layer comprisin'gdevelopment nuclei, especially palladium development nuclei; dispersed in a polymeric binder. I I A processingcomposition employed in the practice of the invention is t'ypically'a viscous processing composition. A wide range of suitable viscosity canfbe employed. The viscosity is usually about 20 to about 100,000 centipoise. Various 'thickening"agents are suitable in the described processing compositions and processes of the invention. Any of those commonly employed in-diifusion'transfer photographic systems can be employed 'as well asthose employed in viscousmonobaths'JThese include those described inU.S. Pat. 3,120,795 of'Land et al., issued Feb. 11, 1964, such-as hydroxyethylcellulose and carboxymethylcellulose.- Y Y a p Suitable viscous monobaths in which-the described pyrimidine silver halide" developing agents can be employed are described, for example, in'the Monobath-Manual' by Grant. M. -Haist (1966) and U.S. Patent-3,392,0l9-of Barnes of et al.,-issued July9, 1968. I Y r A wide range of silver halide solvents cahbe' employed in the practice ofv the invention, Usually the silver "halide solvent is sodium thiosulfate, however various iorganic silver-halide complexing agents, such as those described in Haist et al., Photographic Science and Engineering, vol. '5, p. 198 (1961) anddescribed;. in, French 1,312,687, issued Nov. 12, 1962, and-Belgian 606,559 of Ulrich -et al., issued July 26, 1960, and similar agents, can also be; used. Another embodiment of the invention comprises in a photographic diffusion; transfer process comprising -developing a latentimagein-a photographic silver salt layer and precipitating an image in an image receiver layer the improvement comprising developing said latent image with various addenda employed in the. processing composition,

emulsion and image receiver, processing conditionsarid the like. Any development activatorcan,be employed which provides the desired pH. Typical developmentl activators,.w'hich can be ernployed 'are alkali metal hydroxides such as sodium hydroxide, potassiumhydroxide or lithium hydroxide as well as organicdevelopment activatorsw such as amines, e.-g 29aminoethanol, l 2-methylarninoethanol, 2-dimethylaminoethanol, 2 ethylaminoeth- 'anol, 2-dietlhylaminoethanol, 2,2'-di iminodiethanol, ,Sdi-

'ethylamino-2-pentenol, and the like, i p A photographic process according to the ,invention accordingly can comprise the steps of exposing-aphotographic element comprisinga photographic. silversalt layer to form a latent image therein,-developing the resulting latent image with a processingcomposition as described at a pH of about 12 to about 14 comprising a pyrimidine silver halide developing agent, contacting undeveloped silver salts in the photographic silver salt layer with a silver halide solvent to form an imagewise distribution of a silver complex in the unexposed areas of the photographic silver salt layer, transferring at least part of the silver complex to an image receiver layer contiguous to the photographic silver complex in the presence of development nuclei, to form a visible image in the receiver layer.

Processing conditions, time of development and the like can vary depending on several factors such as the desired image, the particular components of the described photographic element, processing composition and image receiver. Typical processing is carried out under normal atmospheric conditions and is completed within about 60 seconds, e.g. within about 10 seconds. Processing temperatures are typically about 20 C. to about 30 C. but elevated temperatures can'be employed if desired, such as temperatures up to about 50 C.

The described photographic element, receiving element and/or processing composition can also contain toning agents. Typical toning agents which can be employed include, for example, polyvalent inorganic salts as described in U.S. Patent 2,698,236 of Land issued Dec. 28, 1954; silica as described in U.S. Patent 2,698,237 of Land issued Dec. 28, 1954; and heterocyclic mercaptans such as mercaptoazoles, e.g. mercaptodiazoles, mercaptotriazoles, and mercaptotetrazoles.

The concentrations of developing agents used in the practice of the invention can vary over wide ranges depending on the particular photographic and physical variables present in the system. For example, the location of the developing agent in the system and the photographic element, processing composition, the desired image, processing conditions and the like will determine a suitable range. Suitable concentrations also depend on the particular addenda present in the photographic element to be processed and/or in the processing compositions. Typically when a developing agent according to the invention is employed in a photographic element, it is employed in the concentration of about 0.01 to aboutS mols of developing agent per mol of silver present in the photographic element. When a developing agent as described is employed in a processing composition, the total concentration of developing agents in the system is typically about 0.01% to about'10%, preferably 1% to about 5% by weight of the total developer composition. i

' It is often advantageous to have an antifoggant present 7 in the processing compositions and/or photographic elements processed according to the invention. Suitable antifoggants include organic antifoggants, such as benzotriazole, benzimidazole, 2 mercaptobenzimidazole, nitroinda zole and mercaptotetrazole antifoggants. The developercompositions of the invention can contain inorganic antifoggants such as potassium bromide, potassium iodide and/or sodium bromide. The concentration of antifoggant in either the processing composition or photographic element can vary depending upon the desired image or the components present, processing conditions and the like. The processing composition typically contains less than about 2% by weight of the antifoggant and the antifoggant is usually in the range of about 0.01 .to 2% by weight of the total processing composition.

Especially good results can be obtained in the practice of the invention when the described pyrimidine silver halide developing agents are employed in combination with reductone silver halide developing agents and/or hydroxy cinnamic acid silver halide developing agents and/ or more layers of a photographic element and/or processing composition and/or in an image receiver. For example, ore or more of the described developing agents can be employed in the processing composition such as an aqueone or more of the described developing agents can be incorporated in a layer of a photographic element such as in a silver salt emulsion layer, an overcoat layer, a layer between the emulsion layer and the support and/or some other layer contiguous to the silver salt to be developed. The described developing agents can be employed in such combinations as auxiliary developing agents or one or more can be used as the main components of the developing combination or developing precursor combination.

The described reductone silver halide developing agents which can be employed in the practice of the invention are typically amino reductones such as amino hexose reductones and anhydro amino hexose reductones or dihydro anhydro amino hexose reductones. Such compounds are typically prepared from sugars especially D-glucose although other reducing sugars such as D-galactose, D-manose, D-fructose, L-sorbose or the like can be used. A typical method of preparing the described reductone compounds is set out in U.S. Pat. 2,936,308 of Hodges issued May 10, 1960. The amino moiety in the described reductone silver halide developing agents can be -NH --NHR or a wherein R R and R are each alkyl, especially alkyl containing 1 to 5 carbon atoms or R and R taken together represent atoms completing a heterocyclic nucleus containing a nitrogen atom, preferably containing five to six carbon atoms in the nucleus, including for example a second nitrogen or an oxygen atom, e.g. morpholino, piperazino, pyrollino, pyridino, piperidino and the like. Suitable reductone silver halide developing agents include:

dimethylamino hexose reductone diallylamino hexose reductone di-n-butylamino hexose reductone di-n-hexylamino hexose reductone morpholino hexose reductone piperazino hexose reductone pyrrolino hexose reductone piperidino hexose reductone anhydro dimethylamino hexose reductone anhydro diallylamino hexose reductone anhydro di-n-hexylamino reductone anhydro morpholino hexose reductone anhydro piperazino hexose reductone anhydro pyrrolino hexose reductone anhydro piperidino hexose reductone 4-methyl piperidino hexose reductone 2,6-dimethylmorpholino hexose reductone N-benzyl-N-methylamino hexose reductone anhydro-4-rnethyl piperidino hexose reductone anhydro-2,G-dimethylmorpholino hexose reductone anhydro-N-benzyl-N-methylamino hexose reductone Other suitable reductone compounds include the corresponding dihydro hexose reductones.

A variety of hydroxycinnamic acid and/or aminocinnamic acid developing agents can be employed in combination with the described pyrimidine silver halide developing agents in the practice of the invention. Suitable cinnamicacid developing agents include, for example:

Beta-4-dimethyl-2,S-dihydroxy cinnamic acid 4-methyl-2,5-dihydroxy cinnamic acid 6-bromo-4-methyl-2,S-dihydroxy cinnamic acid 2-hydroxy-5-amino cinnamic acid Beta-methyl-2-hydroxy-4-methoxy-5-amino cinnamic acid Beta-4-dirnethyl-2-hydroxy-S-amino cinnamic acid Beta-methyl-2,5-dihydroxy-4-methoxy cinnamic acid in the practice of the invention include,

- 1 I 2-hydroxy-5-methylamino cinnamic acid 4- t.-butyl-2,5-dihydroxy cinnamicacid 2,5-dihydroxy cinnamic acid 2,5-dihydroxy-3,4,6trimethyl cinnamic acid 2,3-dihydroxy cinnamicacid Cinnamic acid silver'halide developing agents in a diffusion transfer system are described, for example in US. application Ser. No. 764,301 of Oftedahl filed Oct. 1, 1968;

Typically, the described cinnamic acid silver halide developing agents HI'QdEI'iVCd from corresponding hydroxy coumarin and/or amino coumarin developing agent precursors. Suitable amino coumarin and/or hydroxy coumarin compoundswhich can be employed inthe practice 'of the invention include, for example:

one compounds which are developing agent precursors can also be employed. Lactone developing agent precursors, such as hydroxy coumarin and/or amino coumarin developing agent precursors are set out in US. application Ser. No. 764,301 of Oftedahl filed Oct. 1,1968.-

A wide variety of aminoalkyl hydroquinone. and/or aminoalkyl catechol silver halide developing agents. can be used in the practice of the invention. Aminoalkyl hydroquinone silver halide developing agents which are suitable for example, "compounds of the formula: V

Rns wherein R R R and R are each hydrogen; alkoxy, especially alkoxy containing 1 to 5 carbon atoms, such as methoxy, ethoxy, propoxy, butoxy or pentoxy; alkyl, especially alkyl containing 1 to 5 carbon atoms, e.g. methyl, ethyl, propyl, butyl and pentyl; aminomethyl, i.e.

wherein R and R are each hydrogen, alkyl, especially alkyl containing 1 to 5 carbon atoms as described, aryl containing up to 20 carbon atoms, especially phenyl, tolyl and xylyl, or together are atoms completing a heterocyclic nucleus, especially a5 or 6 atom heterocyclic'nucleus, in-

cluding a second nitrogen atom or oxygen atom, such as morpholino, piperazino, pyrrolino, pyridino or pyrimidine; at least one of R R R and R being aminomethyl as described. Suitable aminomethyl hydroquinone developing agents which can vbe employed include, for example:

12 2-morph0linomethyl hydroquinone 2-piperazinomethyl hydroquinone Z-pyrrolinomethyl hydroquinone. Z-pyridinomethyl hydroquinone Z-pyrimidinomethyl hydroquinone 2,5-dimorpholinomethyl hydroquinone -2,5-dipiperazinomethyl hydroquinone 2,5-dipiperidinomethyl hydroquinone Z-methyl-5-morpholinomethyl hydroquinone 2-methyl-5-piperidinomethyl hydroquinone 2-methyl-5-pyrrolidinomethyl hydroquinone 2-methoxy-S-morpholinomethyl hydroquinone Z-methyl-S -bis(hydroxyethyl) aminomethyl hydroquirione 2-t-butyl-5-morpholinomethyl hydroquinone Corresponding aminomethyl-catechol silverhalid'e developing agents can also be employed.

These are typically in the form of their acid salts,'e;-g. sodium or potassium salts.

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

. EXAMPLE 1 F This illustrates a pyrimidine .silver halidedeveloping agent in a diffusion transfer system according to the invention. 1

A processing composition is prepared by mixing the following components: 1

Water, 850 ml.

Potassium sulfiite, 50 g.

Sodium thiosulfate pentahydrate, 40 g.

Potassium iodide, 1.6 g.

Potassium hydroxide, 16.7 g.

Sodium hydroxide, 17.5 g.

4-amino-5,6-dihydroxy-Z-methylpyrimidine, 30.0 g.-

Hydroxyethyl cellulose (Natrasol 250H, sold by The cules Powder Company, U.S.A.),. 30.0 g.

The resulting processing solution is a viscous liquid.

A photographic element is prepared by coating'a' gelatme high speed silver bromoiodide photographic emulsion of; a film support. An image receiver is prepared by coating a water-resistant paper support with' palladium development nuclei dispersed in a polymeric binder. The photographic element is sensitometrically exposed. The processing composition as described is then squeezed between the photographic element and the imagerccciverandthe'resulting so-called sandwich is pressed together by running it bewteen two rollers. After 30 seconds, the so-called sand- Herwich is peeled apart and the resultingimage on the image receiver is observed'for'oxidation stain. Employing this procedure a good positive image is produced on-Ethe receiver having a maximum density higher than 1.3 and a minimum density of 0.01. Theresulting positive image exhibits no oxidation stain and other sensitomet'ric properties are satisfactory. v A comparison of oxidation stain provided byother developing agents-compared to a developing agent employed in the practice of the invention in a'ditfusion transfer system is set outin Table 1 following Example 4.

EXAMPLE -2 r g This is a comparative example. I f

The procedure set out in Example 1 is repeated with the exception that 6-methoxy-2,4-diarninophenol"dihydrbchloride is employed in place of the-described pyrimidine silver halide developing agent, A positiveima g'e is'produced which has heavy 'yello'w or orange stain. W

EXAMPLE 3 This isacomparative example The procedure set outin Examplel is repeated' 'wi'th the exceptionthat hydroquinone is employed as" the developing agent in place of the described pyrimidine'silv'er halide developing agent ofExample 1'." A positive imageis produced which has heavy yellow or orange stain.

13 EXAMPLE 4 TABLE I Oxida- Example tron Number Compound stain a 1 4-amino-5,6d.ihydroxy-2-methyl pyrimidine (inveiib tio 2 G-methoxy-Zkdiaminophenol dihydroehlorlde (prior 3 art 3 Hydroquinone (prior art) 3 4 t-Butyl hydroquirione (prior art eontrol) 9 4 l Stain value is ratedby visual observation. a stain scale is assigned ranging from 0 for no stain to 4 for very heavy stain: 0=no stain; 1 =slight stain; 2=moderate stain; 3=heavy stain; 4=very heavy stain.

b No stain. I 2

Yellow or orange stain.

EXAMPLE 5 i This example illustrates the invention employing a combination of developing agents.

The procedure set out in Example 1 is repeated with the exception that the described photographic element contains 1-phenyl-4-methyl-4-hydroxymethyl-3-pyrazolidone as an auxiliary developing agent. This 3-pyrazolidone compound is applied to the described photographic element in an overcoat layer in a concentration of 0.5 mol of 3-pyrazolidone compound for each mol of silverpresent in the photographic element. s

The resulting positive image is free of stain and has a neutral tone.

EXAMPLE 6 I This illustrates the invention employing a; polyvinyl 7 alcohol binder in the image receiver.

The procedure set out in Example 5 is repeated with the exception that polyvinyl alcohol is employed as a binder in the described receiver of Example 1. Employing this procedure, a stain free very high speed brown tone positive image is obtained after 30 seconds.

EXAMPLE 7 This illustrates the invention employing a combination of developing agents in the processing composition. A processing composition is prepared by mixing the following components:

Water, 850 ml.

Potassium sulfite, 50 g.

Sodium thiosulfate pentahydrate, 40 g. 1

Potassium iodide, 1.6 g.

Potassium hydroxide, 16.7 g.

Sodium hydroxide, 17.5 g. r 1

4-amino-5,6-dihydroxy-2-methyl pyrimidine, 30.0 g.

2,5-bis morpholinomethyl hydroquinone, 30.0 g.

Hydroxyethyl cellulose (Natrasol ,250H, produced by Hercules Powder Company, U.S.A.).' 30.0 g. I

Employing this processing composition and the phov 14 EXAMPLE 8 This illustrates a "pyr'iinidinesilver'halide developing agent in a photographic element in a diffusion transfer system according to the iiiv'e'i'ition'l 'A A photographic element is prepared by coating a waterresistant paper support with a gelatin layer containing a developing agent at the rate of 240 mg. of gelatin per square foot and 50 mg. per square foot of 4-amino-5,6- dihydroxyQ-inethyl pyrimidine. Over this layer is coated a coarse grain silver bromoiodide gelatino emulsion containing 125 mg. of silver per square foot," 320 mg. of gelatin per square foot' and 200 mg.'of 'a copolymer of butyl acrylate with acrylic acid by weight butyl acrylate-- 10% by weight acrylic acid) per square foot.'A gelatin overcoat layer is then applied at the rate of mg. per square foot.

The resulting photographic element is sensitometrically exposed. A processing composition which is a development activator composition containing a'silver halide solvent is then squeezed between the resulting photographic element and an image receiver as described in Example 1. The processing composition contains:

Water, 850 ml. v, 7

Potassium sulfite, 50 g. v. I Sodium thiosulfate pentahydrate, 40 g. v Potassium iodide, 1.6 g. Potassium hydroxide, 16.7 g.

Sodium hydroxide, 17.5 g. Hydroxyetl yl cellulose (Natrasol 250H),"30.0 g.

The processingcomposition is squeezed between the photographic element and an image receiver and the resulting so-called sandwich is pressed together by running in between two rollers. After 30 seconds, the sandwich is peeled apart and the' resulting image on the image receiver is observed.

A positive image is produced having very slight stain.

EXAMPLE 9 The procedure described in Example 8 is repeated with the exception that, in addition, 50 mg. per square foot of 4-methyl 4 hydroxyme'thyl-l-phenyl-gi-pyrazolidone is employed in combination with the described pyrimidine silver halide developing agent.

The resulting positive image'has no undesired stain.

1 Similar results to those in Example 1 are obtained employing the combinations of developing agents in the described locations set out in the following Table II. In Table II the following designations are employed:

E=negative photographic element =processing composition in pod PM:4-amino-5,6-dihydroxy-2-methyl pyrimidine RD=dihydro anhydro piperidino hexose reductone CO=4,7-dimethyl-6-hydroxy coumarin HQ:2-methyl-5-morpholinomethyl hydroquinone PD: 1-phenyl-4-methyl-4-hydroxymethyl-3-pyrazolidone X=location of developing agent TABLE II Example 10 1i i2 1a 14 15 E and S. V. Carpenter, Photographic Science andaEngineering, vol. 3, No. -3, May-June, 1959, pp. 135-139).

EXAMPLE 53 2,4-dihydroxy-5,6-diamino pyrimidine.

- i :lar reference to preferred embodiments thereof, but it "v'vill be understood that; variations and modifications can be -eifect ed within the spirit andiscopeof the invention. "We claim: i

+1.6 EXA L 54 2,4,6-trihydroXy-5-amino pyrimidine.

- EXAMPLE 55* 2,4,5,6 -tetrahyd roXy 7 EXAMPLE 5 6 i methyl l amino-5,6 dihydroxy pyrimidine.

EXAMPLE 57 2amino-4,5-dihydroXy-6-methyl pyrimidine.

EXAMPLE 58 2,4,5-trihydroXy-6-methyl pyrimidine. EXAMPLE s9 2,4,5-triamino pyrimidine.

"In each-ofEXamples 46 59, results similar toExample 1 are obtained.

The invention'hasbeen described in detail with particu- 1. In a photographic product comprising in' combination (a) a photographic element comprising a photographic silver salt, (b) a processing composition containing a silver halide solvent and (c) an image-receiving layer, said product containing a silver halide developing agent, the improvement comprising a pyrimidine silver halide developing agent of the formula: V

. R wherein R R5, R and R are each selected from the :group consisting of alkyl containing 1 to 5 carbon atoms;

hydroxyl; aryl containing 6 to 12 carbon atoms, atoms selected from the group consisting of carbon, hydrogen, oxygen and nitrogen atoms forming a 5 or 6 memberheterocyclic group; and amino which is -NH ,'-NHR or 'L'ih wherein R ',"R and R are each' alkyl containing 1 to 5 carbon atoms.

2. A photographic'product 'as' in claim 1 wherein said pyrimidine silver halide developing agent is present in the photographic element. p

3. A photographic product as in claim 1 wherein said pyrimidine silver halide developing agent is present in the processing composition.

4. A photographic product as in claim IWherein-said pyrimidine silver halide developing agent is 4-amino-5',6- dihydroxy-Z-phenyl pyrimidine 5. A photographic product as in claim -1 wherein said pyrimidine silver halide developing agent is 4-amino-5,6- dihydroxy-Z-methyl pyrimidine. s

6. A: photographic'product-asin claim 1 comprising a reductone-silver halidedeveloping agent. v 7 A 'photographic product as in claim 1 comprising a dihydro reductonesilver agent.

8, A photographic productas in claim 1 comprising an liydroxy cinnamie acid silver 'halidedeveloping agent.

'19. Aiphp'tog raphic product as in claim 1 comprising a lactone silver halide developing agent precursor.

10. A photographic product as in claim l comprising anaininon'iethyl'polyhydroxybenzene silver halide developing agent.

11. A photographic product as in claim 1 comprising a 3-pyrazolidone silver halide developing agent.

12. In a photographic diffusion transfer process comprising developing a latent image in a photographic silver salt layer and precipitating an image in an image-receiver layer, the improvement comprising developing said latent image with a pyrimidine silver halide developing agent of the formula:

wherein R R R and R are each selected from the group consisting of alkyl containing 1 to 5 carbon atoms; hydroxyl; aryl containing 6 to 12 carbon atoms; atoms selected from the group consisting of carbon, hydrogen, oxygen and nitrogen atoms forming a 5 or 6 member heterocyclic group; and amino which is NH NHR or wherein R R and R are each alkyl containing 1 to 5 carbon atoms.

13. A photographic diffusion transfer process as in claim 12 wherein said process is a silver salt difiusion transfer process.

14. A photographic process as in claim 12 wherein said pyrimidine silver halide developing agent is 4-amin0-5,6- dihydroxy-Z-methyl pyrimidine.

15. A photographic process as in claim 12 wherein said pyrimidine silver halide developing agent is 4-amino-5,6- dihydroxy-Z-phenyl pyrimidine.

16. A photographic product comprising in combination (a) a photographic element comprising photographic silver salt, (b) a processing composition containing a silver halide solvent and (c) an image-receiving layer, said product containing a silver halide developing agent, the

improvement comprising a pyrimidine silver halide developing agent of the formula:

1", wherein R R R and R are each selected from the group consisting of alkyl containing 1 to 5 carbon atoms; hydroxyl; aryl containing 6 to 12 carbon atoms; a heterocyclic group which is pyridyl, morpholino, piperidino or pyrollino; and amino which is NH -NHR or wherein R R and R are each alkyl containing 1 to 5 carbon atoms.

References Cited UNITED STATES PATENTS OTHER REFERENCES Glafkides, Pierre: Photographic Chemistry, volume 1, Fountain Press, London, 1958, pp. 129-130.

Mason, L. F. A.: Photographic Processing Chemistry, The Focal Press, London and New York, 1966, pp. 15-29.

ROBERT F. BURNETT, Primary Examiner D. J. FRITSCH, Assistant Examiner US. Cl. X.R.

9661 M, 66 HD, 76 R