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
  • G03C1/00—Photosensitive materials
  • G03C1/005—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein
  • G03C1/49—Print-out and photodevelopable emulsions
• • 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
  • G03C5/00—Photographic processes or agents therefor; Regeneration of such processing agents
  • G03C5/26—Processes using silver-salt-containing photosensitive materials or agents therefor
  • G03C5/263—Processes using silver-salt-containing photosensitive materials or agents therefor with an exterior influence, e.g. ultrasonics, electrical or thermal means

Definitions

• This invention relates to the preparation of photodeveloped images on silver halide sensitized photographic materials and particularly to a method of producing such images on normally nonphotodevelopable print-out materials.
• a recent development has been the direct print process in which a much lower image exposure than that required for the conventional print-out process, is used to generate a latent image which is made visible by a subsequent uniform light exposure.
• High intensity light of short duration is used to make the image exposure, and light of lower intensity and longer duration is used for the second exposure which is termed the latent image intensifying (latensifying) or photodeveloping exposure.
• the efliciency of latensification or photodevelopment in the direct print process can be improved in a number of ways, particularly by lowering the intensity of the light employed. This unfortunately results in prolonged photodevelopment times.
• Such photodeveloped images like print-out images, are not stable to prolonged exposure to further viewing light and the density difference between background and image decreases as further exposure occurs.
• a silver halide printout material is imagewise exposed to form a latent image, the exposed silver halide heated to at least about 300 F., and thereafter the heated silver halide is uniformly exposed to light for a sufficient time to produce a visible image.
• a print-out material that normally would uniformly fog if uniformly exposed to light after an imagewise exposure can be used to prepare light-stable visible silver images by heating to temperatures of at least about 300 F. prior to the photodevelopment or photolysis step.
• the heating step in the present process represses the usual printing out of unexposed or non-image areas (D the original recording sensitivity of the silver halide beinginactivated by such heating.
• D the original recording sensitivity of the silver halide beinginactivated by such heating.
• the optimum temperature and time interval to which the silver halide print-out material is heated in accordance with the present process can be readily ascertamed by one of ordinary skill in the art by simply moditying such variables until an image having optimum or desirable discrimination density is obtained after photodevelopment. Temperatures of at least about 300 F.
• heating conditions utilized in the present process can also be readily ascertained by one of ordinary skill in the art, such factors as the breaking down or charring of the support of the photographic element or the vehicle for the silver halide being practical considerations.
• the initial imagewise exposure is to light in the spectrum range in which the silver halide is sensitive sufiicient to form a latent image (invisible image) in the silver halide material, but insutficient to cause the silver halide to print out.
• a latent image invisible image
• Such an image exposure can be effected with high or low intensity light.
• Such exposure conditions can be readily ascertained and vary widely with the type of silver halide material utilized.
• the latent image so formed is capable of being chemically developed to a visible silver image with known photographic developing compositions.
• the final step in the present process is a uniform or over-all exposure of the image-exposed and heated silver halide material to light in the spectrum range in which the silver halide was initially sensitive (typically about 2500-5700 Angstrom units such as ordinary daylight, tungsten light, fiuoroescent light, etc.).
• This step is a photodevelopment or photolysis step and is utilized to develop the latent image formed in the initial imagewise exposure to a visible silver image of substantial discrimination.
• photodevelopment can be carried out during or after the heat treatment step.
• the development of the unexposed or non-image areas is repressed by the aforedescribed heating step.
• Light-developable directprint silver halide systems of the type typically exposed to a short duration, high-intensity light source to form a latent image and thereafter photodeveloped by exposure to a light source of longer duration and lower intensity than the imagewise exposure are not utilized in the present process.
• the present silver halide print-out systems are composed of fine-grain silver halide more typically having an average silver halide grain size of less than about .2 micron and generally ranging from about .01 to .2 micron.
• a particularly useful photographic system that can be utilized in the process of the invention is a radiationsensitive silver halide print-out system containing unfogged silver halide grains formed in the presence of a trivalent metal ion in an acidic media, such silver halide system preferably having contiguous to the trivalent metalcontaining silver halide grains a halogen acceptor.
• trivalent metal ions are used in the precipitation or formation of the silver halide.
• Silver halide crystals are formed with trivalent ions on the inside of the crystals, i.e., silver halide crystals with trivalent ions occluded therein.
• suitable trivalent metal ions include those of bismuth, iridium, rhodium and the like. Bismuth ions are particularly useful.
• the trivalent metal ion can be suitably added with the water-soluble silver salt (e.g., silver nitrate) or the water-soluble halide (e.g., sodium or potassium iodide, bromide or chloride) that are conventionally reacted to prepare or precipitate photographic silver halide.
• the trivalent ions can be introduced into the silver halide precipitation vessel with a hydrophilic colloid such as gelatin.
• the trivalent metal ions can be added to the system as water-soluble inorganic salts, as organo-metallic materials, as complexes, or any other form of material that results in the availability of trivalent metal ions during the formation of silver halide.
• the amount of trivalent metal utilized can be widely varied, although at least about 1x10 and more generally 1 10- to 2, mole percent based on the silver halide is used.
• the water-soluble silver salt and the watersoluble halide are reacted to precipitate the silver halide under acidic conditions.
• the pH of the silver halide precipitation is typically less than 6 and preferably less than 5.
• Such acids as phosphoric, trifluoracetic, hydrobromic, hydrochloric, sulfuric and nitric are typically utilized in the silver halide precipitating media to maintain acidic conditions.
• Suitable silver halides used in preparing the photographic elements processed in accordance with the invention include silver chloride, silver bromide, silver bromoiodide, silver chloroiodide, and silver chlorobromiodide.
• the silver halide preferably contains at least 50% bromide, less than 10% iodide and less than 50% chloride on a molar basis.
• Both silver halide that forms latent images predominantly on the surface of the silver halide crystal or those that form latent images predominantly inside the silver halide crystal, such as those described in Davey and 4 Knott, US. Patent 2,592,250 issued Apr. 8, 1952, can be used in the materials of the present invention.
• the silver halide used in preparing the photographic elements processed in accordance with the invention is typically utilized in an emulsion or dispersion containing a colloidal material.
• Gelatin is preferably used as the colloidal material, although other colloidal materials such as colloidal albumin, cellulose derivatives or synthetic resins, for instance, polyvinyl compounds can also be used.
• Mixtures of such dispersing agents in a wide range of proportions can be utilized,'typical of such mixtures being mixtures of gelatin and an acrylate-acrylic acid copolymer.
• Such emulsions can contain conventional addenda such as coating aids, plasticizers, sensitizing dyes, hardeners, etc.
• vacuum deposited photographic silver halide substantially free of conventional vehicles, binders or dispersing agents can be processed in accordance with the invention.
• Such vacuum deposited silver halide can be utilized in accordance with the invention by incorporating the halogen acceptors in a coating or layer contiguous to the vacuum deposited light-sensitive material.
• the silver halide utilized in the present instance is unfogged. Such silver halide contains no visible or developable latent image.
• the silver halide is sensitive to electromagnetic radiation such as light and x-ray.
• halogen acceptors can be utilized in the silver halide systems processed in accordance with the invention. Such materials are well known to those skilled in the photographic art and are conventionally added to light-developable, direct print silver halide emul- SlOIlS.
• Nitrogen-containing halogen acceptors are particularly useful in preparing the silver halide systems processed in accordance with the invention. Suitable nitrogen-containing halogen acceptors used can be represented -by the formulas,
• R, R and R can each be hydrogen atoms, alkyl radicals, aryl radicals, including substituted alkyl and aryl radicals, or acyl radicals (e.g.,
• R is a hydrogen atom, an alkyl radical or an aryl radical
• ⁇ R can be a nitrogen-containing radical such as an amino radical or a thiocarbamyl radical, including substituted amino and thiocarbamyl radicals
• D represents the necessary atoms to complete a heterocyclic nucleus generally having 5 or 6 atoms including at least two nitrogen atoms and at least one divalent radical having the formula
• a nitrogen atom comprising D or R is attached directly to the nitrogen atoms of the above formulas, at least one hyrogen atom is attached to at least one of such nitrogen atoms of the halogen acceptor.
• the amino radical for substituent R can be represented by the formula,
• R and R can each typically be such substituents as hydrogen atoms, alkyl radicals, aryl radicals or acyl radicals as described above for R and R
• the thiocarbamyl radical for substituent R can be represented by the formula,
• R and R can be the same substituents as R and R or amino radicals.
• R R R R R R R R R R and R can each be hydrogen atoms, al'kyl radicals, aryl radicals or acyl radicals as described above for R, R and R E can be a sulfur atom, an oxygen atom, a selenium atom or an imino radical; and Q and Z can be the necessary atoms to complete a heterocyclic nucleus generally having 5 or 6 members.
• Q and Z typically are the ,necessary atoms to complete such moieties as a triazole-thiol, a mercaptoimidazole, an imidazolidine-thione, a triazinethiol, a thiobarbituric acid, a thiouracil, a urazole including a thiourazole and the like heterocyclic moieties.
• the aryl radical substituents are those of the naphthyl and phenyl series, and include such common substituents as alkyl groups, halogen atoms, acyl radicals and the like;
• the alkyl radical substituents typically can contain 1 to 20 carbon atoms and more generally 1 to 8 carbon atoms, and can be substituted with such radicals as aryl radicals, halogen atoms, acyl radicals and the like.
• Typical halogen acceptors of the thiourea type represented by Formula A and Formula B are disclosed in copending Kitze application, now US. Patent No. 3,241,- 971 issued Mar. 22, 1966; and in copending Fix application, now US. Patent No. 3,326,689.
• Typical halogen acceptors of the hydrazine type represented by Formula C are disclosed in Ives, US. Patent 2,588,982, issued Mar. 11, 1952.
• Typical halogen acceptors of the type represented by Formula D are the urazole and thiourazole halogen acceptors disclosed in Bacon and Illing'swo'rth application, U.S. Ser. No. 406,186 filed Oct. 23, 1964.
• halogen acceptors that can be used in the invention include stannous salts such as stannous chloride as disclosed in Hunt, US. Patent 3,033,678 issued May 8, 1962; aromatic mercaptans such as thiosalicylic acid; hydroquinones such as hydroquinone, chlorohydroquinone, gentistic acid and t-butylhydroquinone; catechols such as phenyl catechol and t-butylcatechol; paminophenols such as N-methyl-p-aminophenol sulfate; 3-pyrazolidones such as 1-phenyl-3pyrazolidone, 4-methyl-l-phenyl-B-pyrazolidone and 1-phenyl-4,4-dimethyl-3- pyrazolidone; phenylenediamines; nitriles; phenols; glycine; sodium sulfite; alkaline materials such as borax, alkali metal hydroxide, etc.; and the like halogen acceptors
• concentration of halogen acceptor utilized in the emulsions of the invention can be widely varied in accordance with usual practice. Usually, about .01 to mole percent, and more generally about .1 to 25 mole percent, based on the silver halide in the emulsion is utilized.
• halogen acceptors are utilized contiguous to the silver halide in the present photographic system.
• Such halogen acceptors can be incorporated in the same photographic layer as the silver halide such as in the same emulsion layer, or in a layer adjacent to the silver halide.
• the photographic silver halide system of the inven tion can comprise layers coated on a wide variety of supports in accordance with usual practice.
• suitable supports include paper, polyethylene-coated paper, polypropylene-coated paper, cellulose acetate film, polyvinyl acetal film, polystyrene film, polyethylene terephthalate film, and related films of resinous materials, as well as glass, metals and others.
• Example 1 A radiation-sensitive gelatino silver chlorobromide (5 mole percent chloride and 95 mole percent bromide) photographic emulsion having an average grain size of about .06 micron was prepared by slowly adding simultaneously an aqueous solution of silver nitrate and an aqueous solution of alkali metal halides to an agitated aqueous gelatin solution containing 122 mg. of bismuth nitrate pentahydrate per silver mole at 60 C. at a pH of about 2.0 adjusted with nitric acid. About 5.0 mole percent of the halogen acceptor dithiourazole hydrazine salt, based on the silver, was added to the emulsion and thereafter the emulsion was coated on a photographic paper support. The resulting prepared photographic element was a print-out paper that can be utilized to prepare visible images without a photodevelopment or chemical development step by exposure to suflicient light.
• the area receiving no latent image exposure was darkened only slightly by the exposure of 400,000 foot-candle seconds, the reflection density being 0.33.
• the image discrimination of this photographic element was 0.92 density units (1.250.33).
• Example 2 Two photographic elements of the type described in Example 1 and treated as described in Example 1A and Example 1B were prepared and designated Element A and Element B in Table I below.
• Both Element A and Element B were exposed for 2 minutes to 1600 foot-candles of illumination from a white flame arc lamp.
• the reflection densities of exposed and unexposed areas (image and non-image areas) were measured before and after the arc lamp exposure.
• Table I illustrates the improved light stability of images processed in accordance with the invention with a print-out photographic system.
• Example 1B The various emulsions were coated on photographic paper supports, image exposed, heated and thereafter photodeveloped to form visible images in the areas of exposure as described in Example 1B.
• the present invention thus provides a process for utilizing normally nonlatensifiable silver halide print-out materials for preparing photodeveloped images having high stability.
• a photodevelopment process for preparing visible silver photographic images in a fine-grain silver halide photographic print-out material comprising silver halide grains which have trivalent metal ions occluded therein, said grains having been formed in an acidic media, and wherein said silver halide grains have a halogen acceptor contiguous thereto; said process comprising imagewise exposing said silver halide to form a latent image, heating said exposed silver halide to at least about 300 F. to repress printing out of unexposed areas of said silver halide and thereafter uniformly exposing said heated silver halide to light to produce a visible silver image.
• trivalent metal ions are selected from the group consisting of bismuth, iridium and rhodium.
• said silver halide print-out material is a gelatino silver chlorobromide emulsion in which said silver chlorobromide has an average grain size of less than about .2 micron.
• a photodevelopment process for preparing visible silver photographic images in a fine-grain silver halide photographic print-out material comprising trivalent metal ion-containing silver halide grains, said grains having been formed in an acidic media, and wherein said silver halide grains have a halogen acceptor contiguous thereto; said process comprising imagewise exposing said silver halide to form a latent image, heating said exposed silver halide to at least about 300 F to repress printing out of unexposed areas of said silver halide and thereafter uniformly exposing said heated silver halide to light to produce a visible silver image.
• a photodevelopment process for preparing visible silver photographic images in a silver halide photographic print-out emulsion comprising silver halide grains having an average size of less than about .2 micron and having 4 occluded bismuth ions therein, wherein said grains are formed in an acidic media, and wherein said grains have a halogen acceptor contiguous thereto; said process comprising imagewise exposing said silver halide to form a latent image, heating said exposed silver halide to at least about 300 F. to repress printing out of unexposed areas of said emulsion and thereafter exposing said heated silver halide to light to produce a visible silver image.
• halogen acceptor is a nitrogen-containing halogen acceptor.
• a process as described in claim 10 wherein said halogen acceptor is dithiourazole hydrazine salt.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)

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Citations (8)

• 1965
  • 1965-08-23 US US481918A patent/US3418122A/en not_active Expired - Lifetime
• 1966
  • 1966-08-16 BE BE685580D patent/BE685580A/xx unknown
  • 1966-08-19 GB GB37235/66A patent/GB1158635A/en not_active Expired
  • 1966-08-22 DE DE1547726A patent/DE1547726C3/de not_active Expired

Patent Citations (8)

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