Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C8/00—Diffusion transfer processes or agents therefor; Photosensitive materials for such processes
  • G03C8/02—Photosensitive materials characterised by the image-forming section
  • G03C8/04—Photosensitive materials characterised by the image-forming section the substances transferred by diffusion consisting of inorganic or organo-metallic compounds derived from photosensitive noble metals
  • G03C8/06—Silver salt diffusion transfer

Definitions

• Knapp ABSTRACT Photographic developing agents which are lactone derivatives, such as coumarin derivatives, and especially 6-hydroxy coumarin and/0r 6-amino coumarin derivatives, and, which have the property of forming a lactone developing agent precursor under neutral, slightly alkaline and acid conditions, provide less stain without loss of desired sensitometric properties in diffusion transfer systems. These are especially suitable in combination with other photographic developing agents. Corresponding developing agent precursors are also suitable in diffusion transfer systems. Stabilization processing systems can also employ these developing agents and/or developing agent precursors BACKGROUND OF THE INVENTION 1.
• This invention relates to photographic developing agents and developing agent precursors and to photographic processingcompositions, especially developer compositions, elements and to processes utilizing such agents and' precursors.
• the invention relates to lactone derivative silver halide developing agents, such as hydroxy cinnamic acid and amino cinnamic acid compounds as photographic silver salt developing agents in developer compositions, processes and/or incorporated in photographic elements, especially those employed in diffusion transfer systems.
• the invention is directed to photographic developing agent precursors which are lactones, s,uch as hydroxy coumarins and amino coumarins in developer compositions and/or incorporated in photographic elements.
• a further aspect of the invention relates to photographic developer compositions such as viscous compositions designed for diffusion transfer processes containing such developing agents and/or developing agent precursors, e.g., amino cinnamic acid and/or hydroxy cinnamic acid silver ha- "lide developing agents, and/or hydroxy coumarin and/or amino'coumarin developing agent precursors, and to photographic diffusion transfer units comprising such developing agents and/or precursors.
• developing agents and/or developing agent precursors e.g., amino cinnamic acid and/or hydroxy cinnamic acid silver ha- "lide developing agents, and/or hydroxy coumarin and/or amino'coumarin developing agent precursors
• the diffusion transfer process is characterized by the use of a photographic emulsion layer and an image receiver or silver precipitating layer next to each other. After exposure of the photographic layer, typically a developer composition is applied between the exposed photographic layer and the silver precipitating layer.
• the developer composition usually contains a silver halide solvent, such as sodium thiosulfate, which causes the unexposed silver salts, usually silver halides, to dissolve forming a silver complex which diffuses to the image receiver or silver precipitating layer where development nuclei or a precipitating agent within that layer causes the silver to be precipitated from the silver complex.
• Development nuclei 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 are well known and are described, for example, in U.S. Pat. Nos. 2,698,237 of Land issued Dec. 28, 1954; 2,647,056 of Land issued July 28, 1953; 3,108,001 of Green issued Oct. 22, 1963; and 3,345,166 ofLand issued Oct. 3, 1967.
• the processing composition used in diffusion transfer processes normally contains the developing agent and is usually applied as a viscous fluid layer and spread between the photosensitive layer and the image receiving layer.
• diffusion transfer developing agents are very stringent and only relatively few of the developing agents which are satisfactory for general silver halide developin g processes will be satisfactory or active enough for diffusion transfer processes.
• One of the diffusion transfer developing agents used more successfully is 2,4-diaminophenol salts, and in particular 2,4-diaminophenol dihydrochloride, also known as Amidol.
• 2,4-diaminophenol salts and in particular 2,4-diaminophenol dihydrochloride, also known as Amidol.
• Amidol 2,4-diaminophenol dihydrochloride
• developing agents and/r developing agent precursors which are so-called acid quenchable include such compounds which have the property of providing desired developing action in the presence of a development activator and, when the desired degree of development is reached, such developing action can be stopped by lowering the pH and thus quenching the developing action by converting the developing agent to a developing agent precursor form.
• Developing agents whichare acid quenchable and which have a ring closure mechanism to form a developing agent precursor have not been previously known.
• coumarin compounds have been employed in photographic emulsions as sensitizers such as disclosed in French Pat. No. 1,349,658. However, such compounds are not developing agents or developing agent precursors.
• a developing component which'is a lactone derivative silver halide developing agent which has the property of forming a lactone developing agent precursor under neutral, slightly alkaline and acid conditions, e.g., a pH about 9 or below and/or a lactone silver halide developing agent precursor which has the property of forming a lactone derivative silver halide developing agent in the presence of an alkaline development activator.
• lactone derivative silver halide developing agents which have the property of forming a lactone silver halide developing agent precursor under neutral and acid conditions can be employed according to the invention. These include any lactone derivatives which 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 mechanism involved is believed to be the opening and closing of an anhydro ring in lactone compounds depending on pH conditions.
• anhydro ring in lactone compounds depending on pH conditions.
• the anhydro ring of such a lactone under alkaline conditions such as at a pH of about to about 14, the anhydro ring of such a lactone is believed to open forming a cinnamic acid developing agent, i.e., a coumarin derivative developing agent.
• This cinnamic acid developing agent has good developing properties and forms oxidation products which provide very little or no stain.
• Suitable hydroxy cinnamic acid and/or amino cinnamic acid developing agents can be employed according to the invention.
• Suitable hydroxy cinnamic acid or amino cin namic acid developing agents include any such compounds which cause reduction cause a photographic silver salt in exposed areas ofa layer containing such photographic silver salt without adversely afiecting the unexposed areas of the photosensitive silver salt.
• Especially suitable developing agents are derivatives of 6-hydroxy coumarins, 6-amino coumarins, mixtures thereof and their salt, e.g. water soluble salts.
• Suitable cinnamic acid developing agents of the invention include compounds of the formula:
• R and R are individually hydrogen, halogen, e.g., chlorine, bromine or iodine, or alkyl, e.g., alkyl containing one to five carbon atoms such as methyl, ethyl, propyl, butyl and pentyl;
• R are individually hydrogen, alkyl, e.g., alkyl containing one to eight carbon atoms such as methyl, ethyl, propyl, butyl and pentyl, alkoxy, e.g., alkoxy containing one to five carbon atoms such as methoxy, ethoxy, propoxy, butoxy and pentoxy, halogen, as described, and aryl, e.g., aryl containing up to carbon atoms, such as phenyl, tolyl and xylyl;
• R and R are individually hydroxy, hydrogen, amino, i.e., NH NHR or NRR wherein R and R are alkyl containing one to five carbon atoms, such as methyl, ethyl, butyl and pentyl; alkyl containing one to five carbon atoms, as described alkoxy containing one to five carbon atoms, as described, described, e.g., aryl containing up to 20 carbon atoms such as phenyl, tolyl, xylyl, mixtures thereof, and their salts, e.g., acid salts such as chloride, hydrochloride and sulfate salts and alkali metal salts such as potassium and sodium salts. Water soluble salts are suitable, as described.
• Esters such as alkyl esters containing one to five carbon atoms, typically a methyl ester, ethyl ester, propyl ester, or butyl ester of the described cinnamic acid compounds, e.g., those within struct ire l ire also developirgagents.
• an ester of a compound of structure I this can hinder or prevent the formation ofa developing agent precursor as described. Accordingly, in some cases it can be undesirable to include compounds in a photographic element, composition or process according t6 the invention which cause formation of esters, typically alkyl esters of the described cinnamic acid developing agents.
• Suitable cinnamic acid developing agents include:
• Beta,4-dimethyl-2-hydroxy-5-amino cinnamic acid
• lactone developing agent precursors which are derivatives of lactones containing a S-membered anhydro ring rather than a 6-membered anhydro ring as in coumarins.
• These include, for example, derivatives which are developing agents of the formula:
• R, R R R R R and R are as described for structure Also included are compounds which are derivatives of 3,4- dihydrocoumarins. These include compounds of the formula:
• lactone silver halide developing agent precursors can be employed which have the property of forming a lactone derivative silver halide developing agent in the presence of an alkaline development activator, e.g., under alkaline conditions including a pH of about to 14, typically a pH of about 12-14,.
• Suitable lactone developing agent precursors include any lactones which in the presence of an alkaline development activator have the property of forming a lactone derivative silver halide developing agent, typically, it is believed, by opening of the anhydro ring of the lactone, and in the presence of such a development activator provide desired developing activity and reduction of stain without adversely affecting desired maximum density, minimum density, photographic speed and other desired sensitometric properties.
• Suitable hydroxy coumarins and amino coumarins which are developing agent precursors according to the invention include developing agent precursors of the formula:
• R4 1 (IV) wherein R R R R R and R are as described for structure 1.
• Suitable amino coumarins and/or hydroxy coumarins which, for example, can be employed according to the invention include:
• lactone silver halide developing agent precursors include those containing a S-membered anhydro ring. These include, for example, lactones which are developing agent precursors of thgf o rmula:
• R can also be aryl, as described, espe- 6 cially phenyl, tolyl or xylyl.
• developing agent precursors within structure lV-in include:
• lactone developing agents include 3,4-dihydrocoumarin developing agent precursors corresponding to the coumarindeveloping agent precursors of structure IV.
• 3,4-dihydrocoumarin developing agent precursors include:
• the developing agents and/or developing agent precursors of the invention are suitable in a range of physical locations in a diffusion transfer photographic system. They can be employed in one or more layers ofa photographic element and/or in a processing composition if desired. For example, they can be employed in a developer composition, such as an aqueous alkaline developer solution,or they can be incorporated into a layer of a photographic element, such as a silver halide emulsion layer, or overcoat layer. They can be employed in one or more layers ofa photographic element and/or developer composition intended for use in a diffusion transfer system. Suitable diffusion transfer systems, processes, developer compositions and elements therefor are described, for example,in U.S. Pat. Nos.
• Typical photographic products suitable for diffusion transfer systems comprising in combination (a) a photographic element comprising a photographic silver salt layer, (b) a rupturable container containing a processing composition containing a silver halide solvent and, typically, a silver halide developing agent, and (c) an image receiving layer.
• the lactone derivative developing agent is typically selected from coumarin derivatives, mixtures thereof,.and their salts, e.g., cinnamic acid developing agents within structure I, especially derivatives of 6-hydroxy coumarins, 6-amino coumarins, mixtures thereof, and their salts.
• the lactone ring of the described coumarin compounds opens to yield a hydroxy group ,and thus a strong developer.
• the developing action can be stopped, or returned to its initial precursor form, which in some cases can .possess a weak developing paaf fF returning the dzveloping agent .form to the developing agent precursor .form by treatment with an acid, e.g., usually a mild acidic solution, such as an aqueous acetic acid, carbonic acid, hydrochloric acid, boric acid or nitric acid solution.
• an acid e.g., usually a mild acidic solution, such as an aqueous acetic acid, carbonic acid, hydrochloric acid, boric acid or nitric acid solution.
• This property is referred to as acid quenching and is especially useful in photographic processes 0 where residual oxidation or developer activity is undesirable.
• Clunamlcacld form coumarin form form the coumarin preferably has a hydroxy group or an amino group or a derivative of these groups which is in'the 6 position (i.e., R and/or 8 position (i.e., R i.e., located para or ortho, in the cinnamic form, to the unblocked hydroxy group.
• one of the embodiments of the invention is in a photographic product comprising in combination (a) a photographic element comprising a photographic silver salt layer, (b) a rupturable container containing a processing composition containing a silver halide solvent, and typically, a silver halide developing agent, and (c) an image receiving layer the improvement comprising a lactone silver halide I developing agent which has the property of forming a lactone developing agent precursor under neutral, slightly alkaline and acid conditions.
• a photographic product is especially suitable wherein the lactone derivative is selected from the group consisting of coumarin derivatives, mixtures thereof, and their salts.
• a suitable photographic element according to the invention comprises a layer containing a silver halide developing agent and/or precursor as described.
• Part of the described developing agents and/or precursor can be present in the photographic element and part present in a photographic processing composition, e.g., an otherwise conventional photographic developer composition employed in diffusion transfer systems.
• a photographic processing composition e.g., an otherwise conventional photographic developer composition employed in diffusion transfer systems.
• lactone derivative silver halide developing agents and lactone developing agent precursors e.g., coumarin or coumarin derivatives used in the practice of the invention can be prepared by conventional methods well known to the art or by obvious modifications of such methods to obtain derivative or substituted products.
• Various methods for preparing a given coumarin, as described, can, for example, be obtained from the following sources:
• hydroxy cinnamic acids and/or amino cinnamic acids and their salts can be prepared by known processes or, as in the practice of the invention, by the alkalation of the respective coumarin.
• the described developing agents and developing agent precursors according to the invention can be employed directly in the photographic element in any of a wide variety of photographic emulsions and/or in other layers of a photographic element.
• these compounds can be employed in a silver salt emulsion layer, an overcoat layer, a layer under the emulsion layer, a baryta layer, an antihalation layer, or virtually any later contiguous to the silver salt to be developed.
• the developing agents and/or developing a g eEprecursors of the invention can be employed in a photographic element having a layer containing:
• a silver halide developing agent which is a hydroxy cinnamic acid or an amino cinnamic acid
• a silver halide developing agent precursor which is a hydroxy coumarin or an amino coumarin and a silver halide emulsion layer.
• the developing agents and/or developing agent precursors described can be employed for developing an image in a wide range of photographic emulsions. They can be employed in such emulsions if desired.
• the photographic emulsions employed according to the invention can be X-ray or other nonspectrally 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, 1950 and 2,503,776of Sprague issued Apr. 11, 1950. Spectral sensitizers which can and Mavani,
• cyanines include cyanines, merocyanines, styryls and hemicyanines.
• 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 and the like. Photographic silver slats which are not silver halides can also be employed such as silver salts of certain organic acids such as silver behenate.
• the photosensitive coatings or receiving layers which are processed with the developing agents of the invention and/or contain the developing agents and/or developing agent precursors of the invention can be coated on a wide variety of supports.
• Suitable supports include those generally employed for photographic elements, such as, for example, cellulose acetate films, cellulose nitrate films, polyethylene terephthalate films, or other polyester films, polycarbonate films and related films or resinous materials; as well as papers, such as paper supports coated with resinous materials, e.g., coated with polyethylene, polypropylene and/or ethylene-butene copolymers; glass; metal, and the like.
• the supports or layers coated on them can contain fluorescent brightening agents, such as stilbenes, benzothiazoles, and benzoxazoles. Some of the coumarin compounds described can act as brightening agents.
• the photographic elements processed according to the invention typically contain an emulsion layer comprising any of the known binding materials suitable for photographic purposes.
• 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, such as 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 stripping layers and/or antistatic layers (i.e., conducting layers).
• the developing agents and/or developing agent precursors of the invention can be employed in combinations with addenda known in the art to be useful in and/or for processing photographic elements.
• the photographic emulsions and compositions of the invention can contain various photographic addenda, particularly those known to be beneficial in photographic compositions.
• the 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.
• the photographic silver salt emulsions of the invention can also be chemically sensitized with compounds of the sulfur group such as sulfur, selenium and teelurium sensitizers, noble metal salts such as gold, or reduction sensitized with reducing agents or combinations of such materials.
• the developing agents and developing agent precursors of the invention can be used in colloid transfer processes and elements such as described in U.S. Pat. No. 2,596,752 of Williams issued May 13, 1952. They can also be used in layers of photographic elements or in processing solutions intended for use in monobath processing such as described in U.S. Pat. No. 2,875,048 of l-laist et al. issued Feb. 24, l959, and British Pat. No. 1,063,844 of Beavers et al. published Mar. 30, 1967, and in web type processing, such as described in U.S. Pat. No. 3,179,517 ofTregillus et al. issued Apr. 20, 1965.
• the developing agents and developing precursor agents of this invention are also used to advantage in multilayer, single element diffusion transfer processes which utilize the undeveloped silver halide in nonimage areas of the negative to form a positive by physical development of this silver onto a nuclei-containing lower layer after which the upper layer is removed by scrubbing, washing or stripping. Processes of this type are described, for example, in U.S. Pat. No. 3,020,155 of Yackel et al. issued Feb. 6, 1962.
• the developing agents and developing agent precursors of the invention can be employed in photographic elements designed for processing in stabilization type processing. For example, they can be incorporated in one or more layers of a photographic element which is exposed, activated by contact with alkaline activator, and then contacted with a thiocyanate or thiosulfate solution, such as an ammonium thiocyanate or they can be incorporated in the alkaline activator.
• a thiocyanate or thiosulfate solution such as an ammonium thiocyanate or they can be incorporated in the alkaline activator.
• Such processes are described, for example, in U.S. Pat. No. 3,326,684 of Nishio et a1. issued June 20, 1967; British Pat. No. 1,004,302 of llford published Sept. 15, 1965; French Pat. No. 1,516,556 of Fassbender; and in an article by H. D. Russell et al. in the P.S.A. JOURNAL, Aug
• the developing agents and developing agent precursors employed according to the invention also be present in one or more layers of a photographic element designed for recording color images.
• these compounds can be employed in one or more layers ofa 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.
• the 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 and developing agent precursors of the invention are useful are described, for example, in Mees, The Theory of the Photographic process, 3rd Edition, Pages 382-396.
• the developing agents and developing agent precursors of the invention can be employed in an element containing silver precipitating nuclei or development nuclei, e.g., an image receiver. As described, they can also be employed in photographic elements or processing compositions designed for use with an image receiver, e.g., a reception layer or receiving sheet which contains silver precipitating nuclei.
• Silver precipitating or development nuclei or agents which can be employed in diffusion transfer systems as described can be physical development nuclei or chemical precipitants including:
• Suitable sifir precipitating agents and/or nuclei within the above classes include metal sulfides, selenides, polysulfides, polyselenides, thiourea derivatives, stannous, hydroxy, silver, gold, platinum, palladium, and mercury, colloidal silver and similar agents disclosed, for example, in U.S. Pat. No. 3,020,155 of Yackel et al. issued Feb. 6, 1962. A wide range of concentrations of the silver precipitating agents and nuclei can be employed.
• the concentration of silver precipitant or nuclei in the receiving layer or receiving sheet must be at least sufficient to ensure a positive and sufficient removal of undeveloped silver salt from the light-sensitive layer to be processed.
• concentration of developing agent and/or precursor described is about 3 to about 320 milligrams per square foot of the layer containing the precipitants or nuclei. 1
• the developing agents and/or developing agent precursor of the invention can be employed in combination with any silver halide developing agent.
• the developing agents and/or developing agent precursors of the invention can be employed in such combinations as auxiliary developing agents or as the main components of the developing combination or developing precursor combination.
• Suitable silver halide developing agents which can be employed with the developing agent or developing agent precursor of the invention include, for example, polyhydroxybenzenes, such as hydroquinone developing agents, e.g., hydroquinone, alkyl substituted hydroquinones, as exemplified by t-butyl hydroquinone, methyl hydroquinone and 2,S-dimethylhydroquinone, catechol and pyrogallol; chloro substituted hyydroquinones such as chlorohydroquinone or dichlorohydroquinone; alkoxy substituted hydroquinones such as methoxy hydroquine; or ethoxy hydroquinone; aminophenol developing agents, such as 2,4-diaminopheuds and methylaminophenols; ascorbic acid, ascorbic acid ketals, such as those described in U.S.
• polyhydroxybenzenes such as hydroquinone developing agents, e.g., hydroquinone, alkyl substituted hydro
• the developing agents and/or developing agent precursors of the invention can be used in combination, for example, with the following compounds:
• a photographic element can contain a 3-pyrazolidone developing agent, such as l-phenyl-S-pyrazolidone and/or a 2,4-diaminopheno1 developing agent, such as 2,4-diamino-6- riiEFQifififiJfand/or 2,4-cHaminF6-methoxyphenol, and be developed employing a developer composition containing a developing agent and/or developing agent precursor of the invention, e.g., a 6-amino coumarin and/or 6-hydroxy coumarin, as described, such as 4,7-dimethyl-6-hydroxy coumarin.
• a developing agent and/or developing agent precursor of the invention e.g., a 6-amino coumarin and/or 6-hydroxy coumarin, as described, such as 4,7-dimethyl-6-hydroxy coumarin.
• the developing agents and/or developing agent precursors can be employed in a photographic silver salt emulsion designed for diffusion transfer processing and/or in a developer composition designed for developing and stabilizing the element.
• a typical developer composition is disclosed in U.S. Pat. 3,120,795 ofLand et al. issued Feb. 11, 1964.
• Another embodiment of the invention is accordingly in combination (a) a photographic element comprising a photographic silver salt layer, (b) a rupturable container containing a viscous precessing composition comprising:
• an image receiving layer comprising development nuclei, especially palladium development nuclei, dispersed in a polymeric binder.
• the developing agents and/or developing agent precursors of the invention can be employed in processing compositions in any form suitable for developing an exposed photographic element.
• they can be employed as mixtures such as mixtures of the developing agents and/or developing agent precursors of the invention with auxiliary developing agents or they can be used as auxiliary developers with other developing agents.
• aqueous silver halide developer solution or liquid concentrate can be supplied as an aqueous silver halide developer solution or liquid concentrate; as a component of a solid particulate composition suitable for dissolving in a solvent such as an aqueous solvent; as a viscous composition containing various thickening agents; as a packaged component of a kit for mixing with various processing agents or as a component of a fusible solid such as a solid containing a homogeneous of an alkaline oxide polymer and a developing agent precursor of the invention which melts above about room temperature, and the like.
• a viscous liquid photographic developer composition comprising (a) a silver halide solvent, and (b) a silver halide developing component the improvement wherein said developing component is a lactone derivative silver halide developing agent which has the property of forming a lactone developing agent precursor under neutral and acid conditions.
• a viscous liquid photographic developer composition can contain a lactone derivative, as described, which is a coumarin derivative, especially a 6-hydroxy coumarin and/or 6-amino coumarin derivative, mixtures thereof and their salts.
• a preferred embodiment is such a viscous liquid photographic developer composition also containing a second silver halide developing agent, as described, especially a 3-pyrazolidone silver halide developing agent.
• the second silver halide developing agent can be present in a greater proportion, by weight, than the described lactone derivative silver halide developing agent.
• a viscous liquid photographic developer composition according to this embodiment can comprise a viscous monobath.
• Suitable viscous monobaths are described, for example, in the Monobath Manual, by Grant M. Haist (1966).
• a suitable developer composition according to the invention can comprise a viscous developer containing:
• a silver halide solvent such as sodium thiosulfate
• a diaminophenol developing agent such as 6-methoxy- 2,4-diaminophenol or 6-ethyl-2,4-diaminophenol or a 3-pyarzolidone developing agent, such as l-phenyl-3-pyrazolidone or l-phenyl-4,4-dimethyl-3-pyrazoldione,
• R C C-C OOH R5 OH I and/or a coumarin silver halide developing agent precursor of the formula:
• an alkaline development activator and e.g.,
• a thickening agent such as a cellulose derivative, e.g., hydroxy ethyl cellulose and/or carboxy methyl cellulose.
• viscosity is usually about 20 to about 1,000 cps.
• thickening agents are suitable in the described processing compositions and processes of the invention. Any of those commonly employed in diffusion transfer photographic systems can be employed. These include those described in the art, such as cellulose derivatives, e.g., hydroxy ethyl cellulose and/or carboxy methyl cellulose.
• a photographic silver salt developer composition typically can contain a hydroxy ethyl cellulose or carboxy methyl cellulose as the thickening agent, a silver halide developing agent, sodium hydroxide, potassium hydroxide or lithium hydroxide as the development activator and, for example, one or more cinnamic acid developing agents, i.e., coumarin derivatives selected from the following coumarins:
• a further embodiment of the invention is in a photographic diffusion transfer process comprising developing a latent image in a photographic silver salt layer and precipitating an image on an image receiver layer the improvement comprising developing said latent image with a lactone derivative silver halide developing agent which has the property of forming a lactone developing agent precursor under neutral and acid conditions.
• This process is typically carried out at a pH about 10, e.g., ofabout 12 to about 14.
• a photographic diffusion transfer process can also comprise lowering the pH of the lactone derivative silver halide developing agent to about 9 or lower, e.g., about 2 to about 9, after precipitating an image on the image receiver layer. This is believed to convert the lactone developing agent to its precursor from, as described.
• a photographic process according to the invention accordingly can comprise the steps of exposing a photographic element comprising a photographic silver salt layer to form a latent image therein, developing the latent image with a developer composition, at a pH of about 12 to about 14 comprising a 6-hydroxy coumarin or 6-amino coumarin derivative 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 said 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 or said receiver layer; and lowering the pH of the developer compositions below about 9 to form a stable developed image.
• Processing conditions, time of development, and the like can vary depending on the desired image, the particular components of the described element. processing composition. and image receiver. Typically processing is carried out under normal atmospheric conditions and is completed within about 60 seconds, e.g., within about 10 seconds.
• the process according to this embodiment can also employ a second silver halide developing agent, as described, in a layer of the photographic element processed and/or in the developer and/or developer precursor composition of the invention
• the silver halide solvent will be sodium thiosulfate, however, various organic silver halide complexing agents such s as those described'by l-laist et al., hoto. Sci. Eng, 198 (1961) and in Kodak French Pat. No. 1,312,687 issued NO ⁇ 12, 1962 and Belgian Pat. No. 606,559 of Ulrich et al. issued July 26, 1960, and similar agents can also be used.
• the light-sensitive element, receiving element or processing composition can also contain toning agents such as. for exam ple, polyvalent inorganic salts of the type described in US. Pat. No. 2,698,236 of Land issued Dec 28, 1954. silica as described in US Pat. No. 2,698,237 of Land issued Dec 28, 1954, and heterocyclic mercaptans such as the mercapto azoles, e.g., mercapto diazoles. mercapto triazoles and mercapto tetrazoles.
• toning agents such as. for exam ple, polyvalent inorganic salts of the type described in US. Pat. No. 2,698,236 of Land issued Dec 28, 1954. silica as described in US Pat. No. 2,698,237 of Land issued Dec 28, 1954, and heterocyclic mercaptans such as the mercapto azoles, e.g., mercapto diazoles. mercapto triazoles and mercapto tetrazoles.
• one of the advantages of the developing agents of the invention is that the developing action. which takes place upon contact of the developing agent precursor with a suitable activator, can be stopped by merely lowering the pH in the vicinity of the developing agent and thus returning the developing agent to its precursor form.
• Suitable alkaline development activators which can be used include those described and especially those which yield a pH of about 10.0 or greater Further development or oxidation can then be stopped thus preventing or substantially reducing developerstain, by lowering the pH of the developer to about 9 or lower As described, the lowering of the pH causes the hydroxy cinnamic acid and/or amino cinnamic acid, for example, to form its respective coumarin form which has only weak and usually negligible, developing activity, if any
• the activating pH according to this process should range from about 10 to 14, and best results are obtained when the pH is above about 12.
• the quenching pH range should be about from 9 to 2.
• the optimum pH for any system will in many cases also be influenced by the photographic element. the desired image, the various addenda used in the developer, emulsion or layers, etc.
• the concentrations of the developing agents and/or developing agent precursors used in the practice of the invention can vary over wide ranges depending upon the particular photographic and physical variables present in the system for example, the position of the developing agent and/or developing agent precursors in the photographic element the developer composition, the desired image, CR. Suitable c-mcentrations are also dependent on processing conditions. addenda present in the photographic element to be processed and/or in the processing compositions Suitable optimum ton centrations can be easily determined by those skilled in the art through routine experimentation. Typically. when a develop ing agent according to the invention is employed in a photo graphic element. it is employed in the concentration of about 0.01 to about 5 moles of developing agent per mole of silver present in the photographic element.
• a developing agent precursor When a developing agent precursor is employed in a photographic element, it is typically employed in a concentration which provides about 0;0 l to about 5 moles of developing agent per mole of silver present in the photographic element upon activation Usually about 0.01 to about 5 moles of developing agent precursor per mole of silver present is SUfflCleltI
• a developing ageni and/or developing agent precursor composition as described. is employed to process a photographic element.
• the total con centration of developing agents and precursors is tvpicalh about 0.01 to about i0. eg I to pr'cent by, weight of the total developer composition
• the parnt ulai developing time required can an over a wide :igt neiween a few seconds up to an hour or more.
• Suitable antifoggants include organic antifoggants. such as benzotriazole, benzimidazole, 2-mercaptobenzimidazole, nitro indazole, and mercaptotetrazole antifoggants.
• the developer compositions of the invention can contain an inorganic antifoggant. such as potassium bromide, potassium iodide and/or sodium bromide.
• the concentration of antifoggant in either the developer composition or element can be varied depending upon the desired image, other components present, subsequent processing steps and the like.
• the developer typically contains less than about 2 percent by weight ot the antifoggant and usually in the range of about 0 01 to 2 percent by weight
• Copending L S Pat. application Ser No. 764,358, of Oftedahl, filed concurrently herewith, titled Photographic Compositions and Processes-A" sets-out use of developing agents and/or developing agent precursors, especially 6- hydroxy coumarins and 6-amino coumarins described herein. with photographic elements, compositions, and processes in general
• the disclosure in this application is incorporated herein by reference. It willbe appreciated that the requirements for developing agents and/or developing agent precursors in diffusion transfer systems set out in the present application are very stringent compared to photographic systems in general.
• a hydroxyethyl cellulose and t-butyl hydroguinone solution is prepared by dissolving 34 grams of hydroxyethyl in 700 ml. of water at C., cooling and purging the solution with nitrogen, and then admixing and dissolving 50 grams of sodium hydroxide and 20 grams of t-butylhydroquinone in the hydroxyethyl cellulose solution.
• a so-called hypohalide solution is prepared bydissolving 88 grams of sodium thiosulfate pentahydrate (NaSO '5H O), 1.0 gram of potassium iodide and 1.5 grams of sodium sulfite in 200 ml. of water and then purging the solution with nitrogen.
• hydroxyethyl cellulose-t-butyl hydroquinone solution and the so-called hypohalide solution are mixed together and the volume adjusted to 1 liter by the addition of water.
• 0.0015 mole of 6-hydroxy-4- methyl coumarin is added to 10 milliliters of the resulting solution to produce a developer composition ofthe invention. This is done by squeezing the coumarin compound and the solutions back and forth between two connected syringes.
• a photographic element 15 prepared by coating a high-speed silver bromoiodide photographic emulsion on 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 developer composition of the invention is then squeezed between the photographic element and the image receiver and the resulting so-called sandwich is pressed together by running it between two rollersv After 10 seconds, the sandwich is peeled apart and the resulting image on the image receiver is stabilized by applying a dilute aqueous hydrochloric acid solution to the image receiver to lower the pH to below about 9 A good positive image is produced with acceptable D min and D max values having low oxidation stain
• Table I in following example 4.
• hypolhalide solution is prepared as described in example 1, by dissolving 88 grams of sodium thiosulfate pentahydrate (N,,SO 5H 0),l.O gram of potassium iodide andl.5 grams of sodium sulfite in 200 ml. of water and then purging the solution with nitrogen.
• the hydroxyethyl cellulose and developing agent solution and the so-called hypohalide solution are mixed together and the volume adjusted to 1 liter by the addition of water. 5 grams of l-phenyl-3-pyrazolidone is added per liter of the resulting solution to produce a developer composition of the invention.
• the resulting developer is a viscous liquid and is stored under nitrogen.
• a photographic element and an image receiver are prepared as in example 1.
• the photographic element is sensitometrically exposed.
• the developer composition of the invention is then squeezed between the photographic element and the image receiver and the resulting so-called sandwich is pressed together by running it together between two rollers. After 10 seconds, the sandwich is separated.
• a positive image is produced on the image receiver. Background stain is determined by reading reflectance of the minimum density area. The resulting positiveimage has a 77 TABLE I Positive print relative to control of Example 8 Oxidation stain Example N0 Dmax. Dmin.
• E Exeellent, Dmin. less than 0.03.
• F Fair, Dmin. between 0.06 to 0.15.
• P Poor, Dmin. between 0.15 to 0.25.
• EXAMPLE 15 This example illustrates the invention.
• a hydroxyethyl cellulose and developing agent solution is prepared by dissolving 34 grams of hydroxyethyl cellulose in percent reflectance at 450 my" This illustrates that the coumarin derivatives of the invention can be employed as the main developing agent and a 3- pyrazolidone developing agent can be employed as a so-called auxiliary developing agent.
• EXAMPLE 16 This is a comparative example.
• a positive image is produced on the image receiver. Background stain is determined by reading percent reflectance of the minimum density area. The resulting positive image has a 72 percent reflectance at 450 mu.
• EXAMPLE 17 This is a comparative example.
• a positive image is produced on the image receiver. Background stain is determined by reading percent reflectance of the minimum density area. The resulting positive image has a 59 percent reflectance at 450 mu.
• a positive image is produced on the image receiver.
• EXAMPLE 22 This example illustrates the preparation of 7-methyl-6- hydroxy coumarin.
• the so-heated solution is then poured over ice to cause the 7- methyl--hydroxy coumarin to crystallize.
• the 7product is then collected, washed with water and then recrystallized from ethanol.
• EXAMPLE 23 This example illustrates the preparation of 4,7-dimethyl-6- hydroxy coumarin.
• EXAMPLE 24 This example illustrates the preparation of 5-bromo-7- methyl-o-hydroxy coumarin.
• EXAMPLE 25 6-amino coumarin is prepared by nitrating coumarin according to the method of G. Morgan, J. Chem. Soc., Transactions, 85, l233 (1904) and then reducing the reaction product'in ethanol using a palladium catalyst under 40 pounds of hydrogen.
• EXAMPLE 26 in this example 4-methyl-6-amino-7-methyl coumarin is prepared by reducing 4-methyl-6-nitro-7-methyl coumarin in ethanol under 40 pounds of hydrogen pressure using a palladium catalyst.
• EXAMPLE 27 in this example 4,7-dimethyl-6-amino coumarin is prepared by reducing 4,7-dimethyl-6-nitro coumarin in ethanol under 40 pounds of hydrogen pressure using a palladium catalyst.
• EXAMPLE 28 This is an example of the invention.
• a hydroxyethyl cellulose and developing agent solution is prepared by dissolving 34 grams of hydroxyethyl cellulose in 700 ml. of water at 60 Q, cooling and purging the solution with nitrogen and then admixing and dissolving 50 grams of sodium hydroxide and 25 grams of 8-hydroxy coumarin in the hydroxyethyl cellulose solution.
• a so-called hypo-halide solution is prepared as described in example l, by dissolving 88 grams of sodium thiosulfate pentahydrate, 1.0 gram of potassium iodide and l.5-grams of sodium sulfite in 200 ml. of water and then purging the solution with nitrogen.
• the hydroxyethyl cellulose solution and developing agent solution and the socalled hypo-halide solution are mixed together and the volume adjusted to 1 liter by the addition of water.
• the resulting developer is a viscous liquid.
• a photographic element and image receiver are prepared as in example i with the exceptions that the silver halide emulsion layer of the photographic element containing 50 mgJft. of 4-methyl-4-hydroxymethyl-3-pyraxolidone and the support is a water resistant paper.
• the photographic element is exposed sensitometrically.
• the developer composition is then squeezed between the photographic element and the image receiver from a pad, as described, for example, in the U.S. Pat. No. 2,698,237 of Land issued Dec. 28, 1954, and the resulting so-called sandwich pressed together. After 30 seconds the sandwich is separated.
• a positive image is produced on the image receiver.
• a photographic product comprising in combination (a) a photographic element comprising a photographic silver salt layer, (b) a rupturable container containing a processing composition containing a silver halide solvent and (c) an imagere DCimig layer, the improvement comprising a developing component in said processing composition comprising 2,5- dihydroxy cinnamic acid or 2-hydroxy amino cinnamic acid silver halide developing agent and a l-phenyl-3-pyrazolidone silver halide developing agent.
• a photographic product comprising in combination (a) a photographic element comprising a photographic silver salt layer, (b) a rupturable container containing a processing composition containing a silver halide solvent and (c) an imagereceiving layer, the improvement comprising a developing component which is a hydroxy or amino cinnamic acid silver halide developing agent of the formula:
• R and R are individually selected from the group consisting of hydrogen, alkyl containing one to five carbon atoms;
• R and R are individually selected from the group consisting of hydrogen, alkyl containing one to five carbon atoms, alkoxy containing one to five carbon atoms, halogen and aryl containing up to 20 carbon atoms; and
• R, and R are individually selected from the group consisting of hydroxy, amino, hydrogen, alkyl containing one to five carbon atoms, alkoxy containing one to five carbon atoms and aryl containing up to 20 carbon atoms; and mixtures thereof, and their salts; at least R is amino or hydroxy.
• a photographic product comprising in combination (a) a photographic element comprising a photographic silver salt layer, (b) a rupturable container containing a processing composition containing a silver halide solvent and (c) an image-' receiving layer, the improvement comprising a developing component which is 2, 5 dihydroxy cinnamic acid or 2- hydroxy-S-amino-cinnamic acid silver halide developing agent.
• a photographic product comprising in combination (a) a photographic element comprising a photographic silver salt layer, (b) a rupturable container containing a processing composition containing a silver halide solvent and (c) an imagereceiving layer, the improvement comprising a silver halide developing agent selected from the group consisting of:
• a viscous liquid photographic developer composition comprising (a) a silver halide solvent and (b) a silver halide developing component, wherein said developing component is a hydroxy or amino cinnamic acid silver halide developing agent of the formula: wherein:
• R and R are individually selected from the group consisting of hydrogen, halogen and alkyl containing one to five carbon atoms;
• R;, and R are individually selected from the group consisting of hydrogen, alkyl containing one to five carbon atoms, alkoxy containing one to five carbon atoms, halogen and aryl containing up to 20 carbon atoms; and
• R, and R are individually selected from the group consisting of hydroxy, amino, hydrogen, alkyl containing one to five carbon atoms, alkoxy containing one to five carbon atoms and aryl containing up to 20 carbon atoms; mixtures thereof, and their salts; at least R,, is amino or hydroxy.
• a viscous liquid photographic developer composition comprising (a) a silver halide solvent, (b) a silver halide developing component which comprises -2, S-dihydroxy cinnamic acid or Z-hydroxy-S-amino Lcinnamic acid silver halide developing agent and (c) an alkaline development activator.
• a viscous liquid photographic developer composition comprising (a) a silver halide solvent, (b) a silver halide developing component which comprises -2,5-dihydroxy cinnamic acid or Z-hydroxy-S-amino cinnamic acid silver halide developing agent and a l-phenyl-3-pyrazolidone silver halide developing agent and (c) an alkaline development activator.
• a viscous liquid photographic developer composition as in claim 9 which is a monobath.
• a photographic process which comprises the steps of exposing a photographic element comprising a photographic silver salt layer to form a latent image therein; developing the latent image with a developer composition at a pH of about 12 to about 14 comprising -2,5-dihydroxy cinnamic acid or 2- hydroxy-S-amino cinnamic acid or 6-amino coumarin derivative 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 said photographic silver salt layer; transferring at least part of the silver complex to an image receiver layer contiguous to the photographic silver salt layer; reducing the silver complexin the presence of development nuclei to form a visible image on said receiver layer; and lowering the pH of the developer composition to below about 8 to form a stable developed image.
• a process as in claim 11 also comprising developing said latent image with a 3-pyrazolidone developing agent or a diaminophenol developing agent.
• a photographic process which comprises the steps of exposing a photographic element comprising a photographic silver salt layer to form a latent image therein; developing the latent image with a developer composition at a pH of about 12 to about 14 comprising a photographic silver halide developing agent selected from the group consisting of:
• Beta-methyl-4-methoxy-2-hydroxy-5-amino cinnamic acid 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 said photographic silver salt layer; transferring at least part of the silver complex to an image-receiver layer contiguous to the photographic silver salt layer; reducing the silver complex in the presence of development nuclei to form a visible image on said receiver layer; and lowering the pH of the developer composition to below about 8 to form a stable developed image.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Silver Salt Photography Or Processing Solution Therefor (AREA)

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Cited By (2)

• 1968
  • 1968-10-01 US US764301A patent/US3615439A/en not_active Expired - Lifetime
• 1969
  • 1969-09-26 BR BR212789/69A patent/BR6912789D0/pt unknown
  • 1969-09-30 DE DE19691949403 patent/DE1949403A1/de active Pending

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