US3019104A - Photographic products, processes, and compositions - Google Patents
Photographic products, processes, and compositions Download PDFInfo
- Publication number
- US3019104A US3019104A US701991A US70199157A US3019104A US 3019104 A US3019104 A US 3019104A US 701991 A US701991 A US 701991A US 70199157 A US70199157 A US 70199157A US 3019104 A US3019104 A US 3019104A
- Authority
- US
- United States
- Prior art keywords
- silver halide
- processes
- image
- vinyl monomer
- development
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000000034 method Methods 0.000 title claims description 36
- 230000008569 process Effects 0.000 title claims description 36
- 239000000203 mixture Substances 0.000 title description 3
- 239000000178 monomer Substances 0.000 claims description 47
- 229910052709 silver Inorganic materials 0.000 claims description 41
- 239000004332 silver Substances 0.000 claims description 41
- -1 SILVER HALIDE Chemical class 0.000 claims description 35
- 229920002554 vinyl polymer Polymers 0.000 claims description 31
- 239000000839 emulsion Substances 0.000 claims description 23
- 238000011161 development Methods 0.000 claims description 22
- 150000003254 radicals Chemical class 0.000 claims description 21
- 230000000379 polymerizing effect Effects 0.000 claims description 5
- ORGHESHFQPYLAO-UHFFFAOYSA-N vinyl radical Chemical class C=[CH] ORGHESHFQPYLAO-UHFFFAOYSA-N 0.000 claims 2
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 30
- 239000000243 solution Substances 0.000 description 12
- 239000003795 chemical substances by application Substances 0.000 description 10
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 9
- PLIKAWJENQZMHA-UHFFFAOYSA-N 4-aminophenol Chemical compound NC1=CC=C(O)C=C1 PLIKAWJENQZMHA-UHFFFAOYSA-N 0.000 description 8
- 239000002904 solvent Substances 0.000 description 7
- 229920000642 polymer Polymers 0.000 description 6
- 239000000047 product Substances 0.000 description 6
- TXTCTCUXLQYGLA-UHFFFAOYSA-L calcium;prop-2-enoate Chemical compound [Ca+2].[O-]C(=O)C=C.[O-]C(=O)C=C TXTCTCUXLQYGLA-UHFFFAOYSA-L 0.000 description 5
- 238000006116 polymerization reaction Methods 0.000 description 5
- 125000003118 aryl group Chemical group 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 108010010803 Gelatin Proteins 0.000 description 3
- 229920000159 gelatin Polymers 0.000 description 3
- 239000008273 gelatin Substances 0.000 description 3
- 235000019322 gelatine Nutrition 0.000 description 3
- 235000011852 gelatine desserts Nutrition 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- 239000000725 suspension Substances 0.000 description 3
- RVGOBWDGAVAVPJ-UHFFFAOYSA-N (4-hydroxyphenyl)azanium;chloride Chemical compound Cl.NC1=CC=C(O)C=C1 RVGOBWDGAVAVPJ-UHFFFAOYSA-N 0.000 description 2
- MYRTYDVEIRVNKP-UHFFFAOYSA-N 1,2-Divinylbenzene Chemical compound C=CC1=CC=CC=C1C=C MYRTYDVEIRVNKP-UHFFFAOYSA-N 0.000 description 2
- HGINCPLSRVDWNT-UHFFFAOYSA-N Acrolein Chemical compound C=CC=O HGINCPLSRVDWNT-UHFFFAOYSA-N 0.000 description 2
- KAKZBPTYRLMSJV-UHFFFAOYSA-N Butadiene Chemical group C=CC=C KAKZBPTYRLMSJV-UHFFFAOYSA-N 0.000 description 2
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 2
- 239000012670 alkaline solution Substances 0.000 description 2
- 125000000217 alkyl group Chemical group 0.000 description 2
- 125000003277 amino group Chemical group 0.000 description 2
- 230000004888 barrier function Effects 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 230000035699 permeability Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- ADZWSOLPGZMUMY-UHFFFAOYSA-M silver bromide Chemical compound [Ag]Br ADZWSOLPGZMUMY-UHFFFAOYSA-M 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- FDBQTRARWCKEJY-UHFFFAOYSA-N (4-hydroxynaphthalen-1-yl)azanium;chloride Chemical compound [Cl-].C1=CC=C2C([NH3+])=CC=C(O)C2=C1 FDBQTRARWCKEJY-UHFFFAOYSA-N 0.000 description 1
- KJPRLNWUNMBNBZ-QPJJXVBHSA-N (E)-cinnamaldehyde Chemical compound O=C\C=C\C1=CC=CC=C1 KJPRLNWUNMBNBZ-QPJJXVBHSA-N 0.000 description 1
- OOCCDEMITAIZTP-QPJJXVBHSA-N (E)-cinnamyl alcohol Chemical compound OC\C=C\C1=CC=CC=C1 OOCCDEMITAIZTP-QPJJXVBHSA-N 0.000 description 1
- WBYWAXJHAXSJNI-VOTSOKGWSA-M .beta-Phenylacrylic acid Natural products [O-]C(=O)\C=C\C1=CC=CC=C1 WBYWAXJHAXSJNI-VOTSOKGWSA-M 0.000 description 1
- CBCKQZAAMUWICA-UHFFFAOYSA-N 1,4-phenylenediamine Chemical compound NC1=CC=C(N)C=C1 CBCKQZAAMUWICA-UHFFFAOYSA-N 0.000 description 1
- PQUXFUBNSYCQAL-UHFFFAOYSA-N 1-(2,3-difluorophenyl)ethanone Chemical compound CC(=O)C1=CC=CC(F)=C1F PQUXFUBNSYCQAL-UHFFFAOYSA-N 0.000 description 1
- SRYYOKKLTBRLHT-UHFFFAOYSA-N 4-(benzylamino)phenol Chemical compound C1=CC(O)=CC=C1NCC1=CC=CC=C1 SRYYOKKLTBRLHT-UHFFFAOYSA-N 0.000 description 1
- JSWVCUXQICMATE-UHFFFAOYSA-N 4-amino-2,5-dimethylphenol Chemical compound CC1=CC(O)=C(C)C=C1N JSWVCUXQICMATE-UHFFFAOYSA-N 0.000 description 1
- OMVFXCQLSCPJNR-UHFFFAOYSA-N 4-amino-2,6-dimethylphenol Chemical compound CC1=CC(N)=CC(C)=C1O OMVFXCQLSCPJNR-UHFFFAOYSA-N 0.000 description 1
- MCNBYOWWTITHIG-UHFFFAOYSA-N 4-amino-2-methoxyphenol Chemical compound COC1=CC(N)=CC=C1O MCNBYOWWTITHIG-UHFFFAOYSA-N 0.000 description 1
- JTTMYKSFKOOQLP-UHFFFAOYSA-N 4-hydroxydiphenylamine Chemical compound C1=CC(O)=CC=C1NC1=CC=CC=C1 JTTMYKSFKOOQLP-UHFFFAOYSA-N 0.000 description 1
- ZVNPWFOVUDMGRP-UHFFFAOYSA-N 4-methylaminophenol sulfate Chemical compound OS(O)(=O)=O.CNC1=CC=C(O)C=C1.CNC1=CC=C(O)C=C1 ZVNPWFOVUDMGRP-UHFFFAOYSA-N 0.000 description 1
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 description 1
- WBYWAXJHAXSJNI-SREVYHEPSA-N Cinnamic acid Chemical compound OC(=O)\C=C/C1=CC=CC=C1 WBYWAXJHAXSJNI-SREVYHEPSA-N 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 1
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 description 1
- ZLHRQERTTJVJSJ-UHFFFAOYSA-N acetic acid;benzene-1,4-diol Chemical compound CC(O)=O.CC(O)=O.OC1=CC=C(O)C=C1 ZLHRQERTTJVJSJ-UHFFFAOYSA-N 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 238000004220 aggregation Methods 0.000 description 1
- 125000003545 alkoxy group Chemical group 0.000 description 1
- 125000005250 alkyl acrylate group Chemical group 0.000 description 1
- OOCCDEMITAIZTP-UHFFFAOYSA-N allylic benzylic alcohol Natural products OCC=CC1=CC=CC=C1 OOCCDEMITAIZTP-UHFFFAOYSA-N 0.000 description 1
- 238000000149 argon plasma sintering Methods 0.000 description 1
- 239000012876 carrier material Substances 0.000 description 1
- 229930016911 cinnamic acid Natural products 0.000 description 1
- 235000013985 cinnamic acid Nutrition 0.000 description 1
- KJPRLNWUNMBNBZ-UHFFFAOYSA-N cinnamic aldehyde Natural products O=CC=CC1=CC=CC=C1 KJPRLNWUNMBNBZ-UHFFFAOYSA-N 0.000 description 1
- 229940117916 cinnamic aldehyde Drugs 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 229920006037 cross link polymer Polymers 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000001804 emulsifying effect Effects 0.000 description 1
- LYCAIKOWRPUZTN-UHFFFAOYSA-N ethylene glycol Natural products OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 1
- 239000003292 glue Substances 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- WBYWAXJHAXSJNI-UHFFFAOYSA-N methyl p-hydroxycinnamate Natural products OC(=O)C=CC1=CC=CC=C1 WBYWAXJHAXSJNI-UHFFFAOYSA-N 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 230000001376 precipitating effect Effects 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 229940047670 sodium acrylate Drugs 0.000 description 1
- AKHNMLFCWUSKQB-UHFFFAOYSA-L sodium thiosulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=S AKHNMLFCWUSKQB-UHFFFAOYSA-L 0.000 description 1
- 235000019345 sodium thiosulphate Nutrition 0.000 description 1
- SONHXMAHPHADTF-UHFFFAOYSA-M sodium;2-methylprop-2-enoate Chemical compound [Na+].CC(=C)C([O-])=O SONHXMAHPHADTF-UHFFFAOYSA-M 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
- 238000010186 staining Methods 0.000 description 1
- 125000001424 substituent group Chemical group 0.000 description 1
- CNHDIAIOKMXOLK-UHFFFAOYSA-N toluquinol Chemical compound CC1=CC(O)=CC=C1O CNHDIAIOKMXOLK-UHFFFAOYSA-N 0.000 description 1
- 229940117958 vinyl acetate Drugs 0.000 description 1
- 238000010792 warming Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
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
- G03C8/32—Development processes or agents therefor
- G03C8/36—Developers
-
- 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
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/004—Photosensitive materials
- G03F7/027—Non-macromolecular photopolymerisable compounds having carbon-to-carbon double bonds, e.g. ethylenic compounds
- G03F7/028—Non-macromolecular photopolymerisable compounds having carbon-to-carbon double bonds, e.g. ethylenic compounds with photosensitivity-increasing substances, e.g. photoinitiators
- G03F7/0285—Silver salts, e.g. a latent silver salt image
-
- 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
- G03C2200/00—Details
- G03C2200/47—Polymer
Definitions
- One object of this invention is to provide processes for producing photographic images having increased density.
- Another object of this invention is to provide novel photographic products embodying the means for increasing the density of a photographic image.
- the invention accordingly comprises the several steps and the relation and order of one or more of such steps with respect to each of the others, and the product possessing the features, properties and the relation of elements which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.
- the grains of silver halide in the exposed areas are rendered developable and, upon development, are reduced to metallic silver.
- the density of the resulting images in general, is dependent upon the number of grains of silver produced, the size of the grains, and the interspatial distance between said grains.
- photographic images having increased density, may be produced by carrying out the development in the presence of a polymerizable vinyl monomer and causing said monomer to be polymerized during the development step.
- the polymer, produced serves to bind the exposed and developed crystals which thereby exhibit a very dense image since light scattering per unit weight of developed silver is considerably decreased on aggregation of the grains.
- a latent silver halide image is developed with a developing agent which, upon oxidation, passes through a free radical state.
- the free radicals produced a intermediate oxidation products of the developing agent during the development, are used to initiate and propagate the polymerization of the vinyl monomer.
- the areas of polymerization will be substantially coextensive with the areas in which reduction of silver halide and oxidation of the developing agent are taking place (i.e., the exposed areas) and little, if any, polymer will be produced in unexposed areas.
- a group of developers, which pass through a free radical state upon being oxidized and which are especially useful in carrying out the processes of this invention, are those of the benzenoid class.
- developing agents of this class contain an aryl nucleus substituted in the ortho and para positions, with respect to each other, by hydroxyl and/ or amino groups, including alkyl and aryl substituted amino groups.
- the aryl nucleus in such developers may also be further substituted by other substituents such, for example, as alkyl, aryl, alkoxy, etc., groups.
- benzenoid developing agents which are useful in carrying out the processes of this invention, mention may be made of p-aminophenol hydrochloride, 2-a1nino-5-diethylaminotoluene hydrochloride, p-toluhydroquinone, p-methylaminophenol sulfate, hydroquinone diacetic acid, 3,5 -'dimethyl-4-aminophenol, p-benzylaminophenol, 2,6-dimethyl-4 aminophenol, 4-amino-1-naphthol hydrochloride, 2,5-dimethyl-4-aminophenol, 4-anilinophenol, 4-amino-2-methoxy-phenol and p-phenylene diamine.
- the vinyl monomer Since the life cycle of the free radicals, produced during development, is generally of short duration, the vinyl monomer must be present at the time of development. It has been found that no increase in density or polymerization will occur if the monomer is added after development.
- the vinyl monomer is incorporated in the photosensitive emulsion prior to exposure. This may be readily accomplished, for example, by dissolving or emulsifying the monomer in the silver halide: emulsion coating solution prior to its application to a suitable support. In certain instances the developing agent may be incorporated along with the vinyl monomer into the photosensitive element prior to exposure.
- the developing agent may be rendered operative after exposure by permeating the photosensitive element with an aqueous alkaline solution.
- the monomer is incorporated in the developing solution and imbibed on the photosensitive emulsion along with the developing agent.
- Monomers suitable for use in the processes herein disclosed may be selected from any of the polymerizable vinyl monomers available. It will be understood that the especially useful monomers are those which are readily dissolved or emulsified in the photosensitive emulsion or developing solution. A preferred class of monomers are the salts of vinyl acids. Such monomers have low vapor pressures, and thus the photosensitive elements in which they are incorporated will have considerably longer shelf lives. The amount of vinyl monomer incorporated will depend upon the amount of intensification desired. Photosensitive emulsions wherein the monomer constitutes about 20% of the carrier material (for example, gelatin) have been found to be especially useful.
- the carrier material for example, gelatin
- vinyl monomers contemplated to be useful in the processes herein disclosed mention may be made of calcium acrylate, sodium acrylate, sodium methacrylate, alkyl methacrylates, alkyl acrylates, vinylacetate, cinnamaldehyde, cinnamic acid, cinnamic alcohol, acrolein, acrylonitrile, styrene, etc.
- vinyl monomer is intended to include divinyl monomers such, for example, as divinylbenzene, glycol diacrylates, etc., which will produce a crosslinked polymer. It should be further understood that more than one monomer may be used, and thus a copolymer will be produced upon polymerization.
- the developing step is carried out under conditions which promote the production of free radicals with a sufiicient lifespan to initiate polymerization, such as the conditions conducive to color coupling. Excessively high pHs which are generally detrimental to the stability of most free radicals should be avoided.
- Example 1 A suspension of silver bromide crystals (average size about one micron) was made up in Water using a trace of glue a the stabilizer. The suspension was exposed to blue light and divided into two parts. One part was developed with a N p-aminophenol hydrochloride solution buffered at pH 8 and the other was developed with another portion of the same solution to which was added 20%, by weight, of calcium acrylate. After about fifteen minutes the sample which contained monomer turned an intense black and a large precipitate finally settled out. The sample without monomer turned into a murky brown stable suspension.
- Example 2 Two silver bromide gelatin emulsion plates were made up and exposed to feeble light. One plate was developed by conventional means with p-aminophenol and a barely perceptible image was obtained. The other element was developed with p-aminophenol in the presence of calcium acrylate, with a short warming at 35 C., and an intense black-and-white image was obtained.
- the processes of this invention are equally useful in silver transfer processes such, for example, as those disclosed in US. Patent No. 2,662,822.
- a sheet of photosensitive material preferably a silver halide
- actinic light to create therein a latent negative image.
- This latent image is developed and a positive image thereof is formed on a superposed image-receiving layer, preferably by creating between the superposed layers a uniform film of a viscous alkaline developer solution containing a substance capable of forming positive image-forming components.
- This latter substance in a preferred form of the invention, comprises a silver halide solvent such as sodium thiosulfate.
- the developer therein develops the exposed photosensitive material and the silver halide solvent forms soluble complex ions with the unexposed photosensitive material.
- These complex ions are transferred and imbibed on the image-carrying layer (which may contain silver Precipitating agents) where they are reacted to form a positive image of the latent negative image.
- the processes of the present invention may be used to prevent staining in the highlights of the transferred positive image.
- This object may be accomplished by having polymerizable vinyl monomers present during the development of the latent negative image and using the resulting polymer to at least assist in preventing the transfer of undeveloped silver halide from such areas.
- the vinyl monomer may be incorporated in the photosensitive element or in the developer solution.
- the processesof this invention may also be used in silver transfer processes to intensify the transferred positive image.
- This intensification may be accomplished by carrying out the reduction of the transferred silver ions in the presence of a polymerizable vinyl monomer.
- the vinyl monomer may be disposed in the image-receiving element prior to processing, or it may be imbibed from the processing solution.
- unreacted monomer from said photosensitive element may be transferred to the image-receiving element and used to intensify the positive image.
- the resulting increased density is apparently attributable, as in conventional photography, to the aggrgating effect of the polymer produced.
- the processes of the present invention are further useful in color diffusion transfer processes. They are especially useful in processes wherein a complete dye, soluble in aqueous alkaline solutions, is incorporated in or behind a silver halide emulsion and its transfer to a superposed image-receiving element is controlled by reducing the permeability of the emulsion in exposed areas.
- the processes of the present invention enable one to control the transfer of the dye by creating in the exposed areas polymeric barriers having reduced permeability to the dye. These barriers may be created by carrying out the development of the latent image in the presence of a suitable vinyl monomer.
- the processes of this invention are still further useful in the preparation of relief images.
- Such images may be made, for example, by developing a silver halide gelatin emulsion in the presence of a suitable polymerizable vinyl monomer and, after development, washing the resulting image with a material which is a solvent for the emulsion and the monomer, but not for the resulting polymer.
- the relief images may be used as printing plates in conventional mechanical printing processes.
- Colored polymeric images can be produced by the processes of this invention by using a primary aromatic amino silver halide developer (i.e., a color developer) as the developing agent and carrying out the development in the presence of a color coupler in addition to the vinyl monomer.
- a primary aromatic amino silver halide developer i.e., a color developer
- a red polymeric image is produced by developing exposed silver halide with a solution comprising equimolar amounts of p-aminophenol hy-- drochloride and l-(2-chloro-5-sulfophenyl)-3-methyl-5-- pyrazolone coupler and 20%, by weight, of calcium acrylate, buffered at pH 8.
- a photographic process comprising the steps of permeating a photosensitive element including an exposed silver halide emulsion layer with a free radical polymerizable vinyl monomer, developing the exposed silver halide emulsion with a benzenoid silver halide developer, which developer forms free radicals upon being oxidized as a function of development and polymerizing said polymerizable vinyl monomer with said free radicals in the exposed and developed areas.
- a photographic process comprising the steps of developing a photosensitive element including an exposed silver halide emulsion in the presence of a free radical polymerizable vinyl monomer which i in the emulsion at the time of development, with a benzenoid silver halide developer, which developer forms free radicals upon being oxidized as a function of development, polymerizing said vinyl monomer with said free radicals in the exposed and developed areas and subsequent to development washing said photosensitive element with a solvent in which the emulsion is soluble and the resulting polymer is insoluble to produce a relief image.
- a photographic process comprising the Steps of developing a photosensitive element, including an exposed silver halide emulsion layer, which has therein at the time of development a free radical polymerizable vinyl monomer, a silver halide solvent and a benzenoid silver halide developer, which developer forms free radicals upon being oxidized as a function of development, polymerizing said vinyl monomer with said free radicals in exposed and developed areas, forming a soluble complex between said silver halide solvent and undeveloped silver halide and transferring said complex to a superposed image-receiving element to produce a transfer image on said image-receiving element.
- a photographic process as defined in claim 1 where- UNITED STATES PATENTS in said silver halide developer is a primary aromatic amino 0 2,380,280 Weyerts July 10, 1945 silver hahde developer and the development of said ex- 2,647,056 Land July 28, 1953 posed silver hallde emulsion 1s carrled out in the pres- 2 701766 Hensley Feb 8 1955 ence of a color coupler in addition to said polymerizable 2,76O:363 palmbeck Aug 28 95 vinyl monomer to produce a colored polymeric image, 10 2,891,985 Roth Aug. 6, 1957
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Photosensitive Polymer And Photoresist Processing (AREA)
- Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)
- Silver Salt Photography Or Processing Solution Therefor (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
Description
United States Patent 3,019,104 PHOTOGRAPHIC PRODUCTS, PROCESSES, AND COMPOSITIONS Gerald Oster, Brooklyn, N.Y., assignor to Polaroid Corporation, Cambridge, Mass, a corporation of Delaware No Drawing. Filed Dec. 11, 1957, Ser. No. 701,991 9 Claims. (Cl. 96-29) The present invention is concerned with photography and more particularly with photographic products and processes for producing photographic images having increased density.
One object of this invention is to provide processes for producing photographic images having increased density.
Another object of this invention is to provide novel photographic products embodying the means for increasing the density of a photographic image.
Other objects of the invention will in part be obvious and will in part appear hereinafter.
The invention accordingly comprises the several steps and the relation and order of one or more of such steps with respect to each of the others, and the product possessing the features, properties and the relation of elements which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.
For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description.
When a photographic emulsion is exposed to light, or other form of radiant energy, the grains of silver halide in the exposed areas are rendered developable and, upon development, are reduced to metallic silver. The density of the resulting images, in general, is dependent upon the number of grains of silver produced, the size of the grains, and the interspatial distance between said grains.
I have discovered that photographic images, having increased density, may be produced by carrying out the development in the presence of a polymerizable vinyl monomer and causing said monomer to be polymerized during the development step. Apparently, the polymer, produced, serves to bind the exposed and developed crystals which thereby exhibit a very dense image since light scattering per unit weight of developed silver is considerably decreased on aggregation of the grains.
In carrying out the processes of this invention a latent silver halide image is developed with a developing agent which, upon oxidation, passes through a free radical state. The free radicals, produced a intermediate oxidation products of the developing agent during the development, are used to initiate and propagate the polymerization of the vinyl monomer. The areas of polymerization will be substantially coextensive with the areas in which reduction of silver halide and oxidation of the developing agent are taking place (i.e., the exposed areas) and little, if any, polymer will be produced in unexposed areas. A group of developers, which pass through a free radical state upon being oxidized and which are especially useful in carrying out the processes of this invention, are those of the benzenoid class. In general, developing agents of this class contain an aryl nucleus substituted in the ortho and para positions, with respect to each other, by hydroxyl and/ or amino groups, including alkyl and aryl substituted amino groups. The aryl nucleus in such developers may also be further substituted by other substituents such, for example, as alkyl, aryl, alkoxy, etc., groups. As examples of benzenoid developing agents which are useful in carrying out the processes of this invention, mention may be made of p-aminophenol hydrochloride, 2-a1nino-5-diethylaminotoluene hydrochloride, p-toluhydroquinone, p-methylaminophenol sulfate, hydroquinone diacetic acid, 3,5 -'dimethyl-4-aminophenol, p-benzylaminophenol, 2,6-dimethyl-4 aminophenol, 4-amino-1-naphthol hydrochloride, 2,5-dimethyl-4-aminophenol, 4-anilinophenol, 4-amino-2-methoxy-phenol and p-phenylene diamine.
Since the life cycle of the free radicals, produced during development, is generally of short duration, the vinyl monomer must be present at the time of development. It has been found that no increase in density or polymerization will occur if the monomer is added after development. In a preferred mode of carrying out the processes of this invention, the vinyl monomer is incorporated in the photosensitive emulsion prior to exposure. This may be readily accomplished, for example, by dissolving or emulsifying the monomer in the silver halide: emulsion coating solution prior to its application to a suitable support. In certain instances the developing agent may be incorporated along with the vinyl monomer into the photosensitive element prior to exposure. In such an embodiment the developing agent may be rendered operative after exposure by permeating the photosensitive element with an aqueous alkaline solution. In another useful mode of carrying out the invention, the monomer is incorporated in the developing solution and imbibed on the photosensitive emulsion along with the developing agent.
Monomers suitable for use in the processes herein disclosed may be selected from any of the polymerizable vinyl monomers available. It will be understood that the especially useful monomers are those which are readily dissolved or emulsified in the photosensitive emulsion or developing solution. A preferred class of monomers are the salts of vinyl acids. Such monomers have low vapor pressures, and thus the photosensitive elements in which they are incorporated will have considerably longer shelf lives. The amount of vinyl monomer incorporated will depend upon the amount of intensification desired. Photosensitive emulsions wherein the monomer constitutes about 20% of the carrier material (for example, gelatin) have been found to be especially useful. A examples of vinyl monomers contemplated to be useful in the processes herein disclosed, mention may be made of calcium acrylate, sodium acrylate, sodium methacrylate, alkyl methacrylates, alkyl acrylates, vinylacetate, cinnamaldehyde, cinnamic acid, cinnamic alcohol, acrolein, acrylonitrile, styrene, etc. It should be understood that the term vinyl monomer is intended to include divinyl monomers such, for example, as divinylbenzene, glycol diacrylates, etc., which will produce a crosslinked polymer. It should be further understood that more than one monomer may be used, and thus a copolymer will be produced upon polymerization.
The developing step is carried out under conditions which promote the production of free radicals with a sufiicient lifespan to initiate polymerization, such as the conditions conducive to color coupling. Excessively high pHs which are generally detrimental to the stability of most free radicals should be avoided.
The following nonlimiting examples illustrate the processes of this invention.
Example 1 A suspension of silver bromide crystals (average size about one micron) was made up in Water using a trace of glue a the stabilizer. The suspension was exposed to blue light and divided into two parts. One part was developed with a N p-aminophenol hydrochloride solution buffered at pH 8 and the other was developed with another portion of the same solution to which was added 20%, by weight, of calcium acrylate. After about fifteen minutes the sample which contained monomer turned an intense black and a large precipitate finally settled out. The sample without monomer turned into a murky brown stable suspension.
Example 2 Two silver bromide gelatin emulsion plates were made up and exposed to feeble light. One plate was developed by conventional means with p-aminophenol and a barely perceptible image was obtained. The other element was developed with p-aminophenol in the presence of calcium acrylate, with a short warming at 35 C., and an intense black-and-white image was obtained.
In addition to conventional photographic processes, such as described above, the processes of this invention are equally useful in silver transfer processes such, for example, as those disclosed in US. Patent No. 2,662,822. In such processes a sheet of photosensitive material, preferably a silver halide, is exposed to actinic light to create therein a latent negative image. This latent image is developed and a positive image thereof is formed on a superposed image-receiving layer, preferably by creating between the superposed layers a uniform film of a viscous alkaline developer solution containing a substance capable of forming positive image-forming components. This latter substance, in a preferred form of the invention, comprises a silver halide solvent such as sodium thiosulfate. With such a film of liquid composition between the exposed photosensitive layer and the image-receiving layer, the developer therein develops the exposed photosensitive material and the silver halide solvent forms soluble complex ions with the unexposed photosensitive material. These complex ions are transferred and imbibed on the image-carrying layer (which may contain silver Precipitating agents) where they are reacted to form a positive image of the latent negative image.
In silver transfer processes, such as described above, the processes of the present invention may be used to prevent staining in the highlights of the transferred positive image. This object may be accomplished by having polymerizable vinyl monomers present during the development of the latent negative image and using the resulting polymer to at least assist in preventing the transfer of undeveloped silver halide from such areas. The vinyl monomer may be incorporated in the photosensitive element or in the developer solution.
The processesof this invention may also be used in silver transfer processes to intensify the transferred positive image. This intensification may be accomplished by carrying out the reduction of the transferred silver ions in the presence of a polymerizable vinyl monomer. The vinyl monomer may be disposed in the image-receiving element prior to processing, or it may be imbibed from the processing solution. When a vinyl monomer is used in the photosensitive emulsion and said monomer is soluble in the liquid processing solution, unreacted monomer from said photosensitive element may be transferred to the image-receiving element and used to intensify the positive image. The resulting increased density is apparently attributable, as in conventional photography, to the aggrgating effect of the polymer produced.
The processes of the present invention are further useful in color diffusion transfer processes. They are especially useful in processes wherein a complete dye, soluble in aqueous alkaline solutions, is incorporated in or behind a silver halide emulsion and its transfer to a superposed image-receiving element is controlled by reducing the permeability of the emulsion in exposed areas. The processes of the present invention enable one to control the transfer of the dye by creating in the exposed areas polymeric barriers having reduced permeability to the dye. These barriers may be created by carrying out the development of the latent image in the presence of a suitable vinyl monomer.
The processes of this invention are still further useful in the preparation of relief images. Such images may be made, for example, by developing a silver halide gelatin emulsion in the presence of a suitable polymerizable vinyl monomer and, after development, washing the resulting image with a material which is a solvent for the emulsion and the monomer, but not for the resulting polymer. In certain instances, the relief images may be used as printing plates in conventional mechanical printing processes.
Colored polymeric images can be produced by the processes of this invention by using a primary aromatic amino silver halide developer (i.e., a color developer) as the developing agent and carrying out the development in the presence of a color coupler in addition to the vinyl monomer. Thus, for example, a red polymeric image is produced by developing exposed silver halide with a solution comprising equimolar amounts of p-aminophenol hy-- drochloride and l-(2-chloro-5-sulfophenyl)-3-methyl-5-- pyrazolone coupler and 20%, by weight, of calcium acrylate, buffered at pH 8.
Since certain changes may be made in the above product and process without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.
What is claimed is:
1. A photographic process comprising the steps of permeating a photosensitive element including an exposed silver halide emulsion layer with a free radical polymerizable vinyl monomer, developing the exposed silver halide emulsion with a benzenoid silver halide developer, which developer forms free radicals upon being oxidized as a function of development and polymerizing said polymerizable vinyl monomer with said free radicals in the exposed and developed areas.
2. A photographic process as defined in claim 1 wherein said benzenoid silver halide developer is p-aminophenol.
3. A photographic process as defined in claim 1 wherein said polymerizable vinyl monomer is calcium acrylate.
4. A process as defined in claim 1 wherein said silver halide developer and said polymerizable vinyl monomer are applied to the photosensitive element from the same processing solution.
5. A photographic process comprising the steps of developing a photosensitive element including an exposed silver halide emulsion in the presence of a free radical polymerizable vinyl monomer which i in the emulsion at the time of development, with a benzenoid silver halide developer, which developer forms free radicals upon being oxidized as a function of development, polymerizing said vinyl monomer with said free radicals in the exposed and developed areas and subsequent to development washing said photosensitive element with a solvent in which the emulsion is soluble and the resulting polymer is insoluble to produce a relief image.
6. A photographic process comprising the Steps of developing a photosensitive element, including an exposed silver halide emulsion layer, which has therein at the time of development a free radical polymerizable vinyl monomer, a silver halide solvent and a benzenoid silver halide developer, which developer forms free radicals upon being oxidized as a function of development, polymerizing said vinyl monomer with said free radicals in exposed and developed areas, forming a soluble complex between said silver halide solvent and undeveloped silver halide and transferring said complex to a superposed image-receiving element to produce a transfer image on said image-receiving element.
7. A photographic process as defined in claim 6 wherein said polymerizable vinyl monomer is soluble in an aqueous alkaline processing solution.
8. In a photographic process comprising the steps of developing a photosensitive element including an exposed silver halide emulsion layer with a benzenoid silver halide developer, which developer forms free radicals upon being oxidized as a function of development, and a silver halide solvent, and superposing said photosensitive element on an image-receiving element to produce a transfer image on said image-receiving element, the improvement of having a free radical polymerizable vinyl monomer in 6 the image-receiving element and polymerizing said vinyl said coupler being in the silver halide emulsion at the time monomer with said free radicals in the developed areas of development. of said image-receiving element References Cited in the file of this patent 9. A photographic process as defined in claim 1 where- UNITED STATES PATENTS in said silver halide developer is a primary aromatic amino 0 2,380,280 Weyerts July 10, 1945 silver hahde developer and the development of said ex- 2,647,056 Land July 28, 1953 posed silver hallde emulsion 1s carrled out in the pres- 2 701766 Hensley Feb 8 1955 ence of a color coupler in addition to said polymerizable 2,76O:363 palmbeck Aug 28 95 vinyl monomer to produce a colored polymeric image, 10 2,891,985 Roth Aug. 6, 1957
Claims (1)
1. A PHOTOGRAPHIC PROCESS COMPRISING THE STEPS OF PERMEATING A PHOTOSENSITIVE ELEMENT INCLUDING AN EXPOSED SILVER HALIDE EMULSION LAYER WITH A FREE RADICAL POLYMERIZABLE VINYL MONOMER, DEVELOPMENT THE EXPOSED SILVER HALIDE EMULSION WITH A BENZENOID SILVER HALIDE DEVELOPER, WHICH DEVELOPER FORMS FREE RADICALS UPON BEING OXIDIZED AS A FUNCTION OF DEVELOPMENT AND POLYMERIZING SAID POLYMERIZABLE VINYL MONOMER WITH SAID FREE RADICALS IN THE EXPOSED AND DEVELOPED AREAS.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US701991A US3019104A (en) | 1957-12-11 | 1957-12-11 | Photographic products, processes, and compositions |
| GB11548/58A GB890508A (en) | 1957-12-11 | 1958-04-11 | Photographic transfer processes |
| DEI14767A DE1119120B (en) | 1957-12-11 | 1958-04-28 | Process for developing exposed silver halide emulsion layers |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US701991A US3019104A (en) | 1957-12-11 | 1957-12-11 | Photographic products, processes, and compositions |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3019104A true US3019104A (en) | 1962-01-30 |
Family
ID=24819460
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US701991A Expired - Lifetime US3019104A (en) | 1957-12-11 | 1957-12-11 | Photographic products, processes, and compositions |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US3019104A (en) |
| DE (1) | DE1119120B (en) |
| GB (1) | GB890508A (en) |
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3165407A (en) * | 1962-06-08 | 1965-01-12 | Eastman Kodak Co | Process for improving color developability of reversal photograph films |
| US3194661A (en) * | 1961-02-02 | 1965-07-13 | Du Pont | Silver image transfer polymerization process |
| US3236644A (en) * | 1962-08-06 | 1966-02-22 | Eastman Kodak Co | Process for silver development of photopolymerization prints and print forming element therefor |
| US3241962A (en) * | 1963-01-15 | 1966-03-22 | Du Pont | Photographic processes and elements |
| US3255002A (en) * | 1961-03-09 | 1966-06-07 | Polaroid Corp | Color photographic process and product |
| US3276873A (en) * | 1963-08-30 | 1966-10-04 | Polaroid Corp | Photographic processes |
| US3306744A (en) * | 1962-12-17 | 1967-02-28 | Polaroid Corp | Copying process using dithioxamides, heavy metal salts and photopolymerizable monomers and photocross linkable polymers |
| DE1720665B1 (en) * | 1966-06-06 | 1972-07-06 | Fuji Photo Film Co Ltd | Process for the production of vinyl polymer images |
| US3767400A (en) * | 1967-08-28 | 1973-10-23 | Y Hayakawa | Process for the formation of polymer images |
| US3790378A (en) * | 1968-11-02 | 1974-02-05 | Fuji Photo Film Co Ltd | Process for the formation of polymer images |
| US3874947A (en) * | 1968-08-20 | 1975-04-01 | Fuji Photo Film Co Ltd | Process for the production of polymer images |
| US4287290A (en) * | 1979-04-05 | 1981-09-01 | Asahi Kasei Kogyo Kabushiki Kaisha | Process for producing polymeric image by diffusion step |
| US4547450A (en) * | 1982-01-13 | 1985-10-15 | Fuji Photo Film Company | Silver halide sensor type polymerizable light-sensitive material |
| US4557997A (en) * | 1981-06-23 | 1985-12-10 | Fuji Photo Film Co., Ltd. | Photo-polymerizable process of image formation using unsaturated materials and silver halide |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2380280A (en) * | 1943-03-06 | 1945-07-10 | Eastman Kodak Co | Chemical sensitizing of emulsions |
| US2647056A (en) * | 1948-02-12 | 1953-07-28 | Polaroid Corp | One step photographic transfer process |
| US2701766A (en) * | 1952-06-14 | 1955-02-08 | Gen Aniline & Film Corp | Developers for and method of producing phenazonium dyestuff images with p-dialkylaminoaniline developing agents |
| US2760863A (en) * | 1951-08-20 | 1956-08-28 | Du Pont | Photographic preparation of relief images |
| US2891985A (en) * | 1956-11-16 | 1959-06-23 | Us Rubber Co | Monomers for flame resistant resinous copolymers |
-
1957
- 1957-12-11 US US701991A patent/US3019104A/en not_active Expired - Lifetime
-
1958
- 1958-04-11 GB GB11548/58A patent/GB890508A/en not_active Expired
- 1958-04-28 DE DEI14767A patent/DE1119120B/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2380280A (en) * | 1943-03-06 | 1945-07-10 | Eastman Kodak Co | Chemical sensitizing of emulsions |
| US2647056A (en) * | 1948-02-12 | 1953-07-28 | Polaroid Corp | One step photographic transfer process |
| US2760863A (en) * | 1951-08-20 | 1956-08-28 | Du Pont | Photographic preparation of relief images |
| US2701766A (en) * | 1952-06-14 | 1955-02-08 | Gen Aniline & Film Corp | Developers for and method of producing phenazonium dyestuff images with p-dialkylaminoaniline developing agents |
| US2891985A (en) * | 1956-11-16 | 1959-06-23 | Us Rubber Co | Monomers for flame resistant resinous copolymers |
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3194661A (en) * | 1961-02-02 | 1965-07-13 | Du Pont | Silver image transfer polymerization process |
| US3255002A (en) * | 1961-03-09 | 1966-06-07 | Polaroid Corp | Color photographic process and product |
| US3165407A (en) * | 1962-06-08 | 1965-01-12 | Eastman Kodak Co | Process for improving color developability of reversal photograph films |
| US3236644A (en) * | 1962-08-06 | 1966-02-22 | Eastman Kodak Co | Process for silver development of photopolymerization prints and print forming element therefor |
| US3306744A (en) * | 1962-12-17 | 1967-02-28 | Polaroid Corp | Copying process using dithioxamides, heavy metal salts and photopolymerizable monomers and photocross linkable polymers |
| US3241962A (en) * | 1963-01-15 | 1966-03-22 | Du Pont | Photographic processes and elements |
| US3276873A (en) * | 1963-08-30 | 1966-10-04 | Polaroid Corp | Photographic processes |
| DE1720665B1 (en) * | 1966-06-06 | 1972-07-06 | Fuji Photo Film Co Ltd | Process for the production of vinyl polymer images |
| US3767400A (en) * | 1967-08-28 | 1973-10-23 | Y Hayakawa | Process for the formation of polymer images |
| US3874947A (en) * | 1968-08-20 | 1975-04-01 | Fuji Photo Film Co Ltd | Process for the production of polymer images |
| US3790378A (en) * | 1968-11-02 | 1974-02-05 | Fuji Photo Film Co Ltd | Process for the formation of polymer images |
| US4287290A (en) * | 1979-04-05 | 1981-09-01 | Asahi Kasei Kogyo Kabushiki Kaisha | Process for producing polymeric image by diffusion step |
| US4557997A (en) * | 1981-06-23 | 1985-12-10 | Fuji Photo Film Co., Ltd. | Photo-polymerizable process of image formation using unsaturated materials and silver halide |
| US4547450A (en) * | 1982-01-13 | 1985-10-15 | Fuji Photo Film Company | Silver halide sensor type polymerizable light-sensitive material |
Also Published As
| Publication number | Publication date |
|---|---|
| GB890508A (en) | 1962-02-28 |
| DE1119120B (en) | 1961-12-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3019104A (en) | Photographic products, processes, and compositions | |
| US3099558A (en) | Photopolymerization of vinyl monomers by means of a radiation absorbing component in the presence of a diazonium compound | |
| US4560637A (en) | Silver halide sensor type polymerizable light-sensitive material | |
| US3103437A (en) | Hardening | |
| JPS6057836A (en) | Photographic element | |
| US3518088A (en) | Developing agent dispersions | |
| US4145220A (en) | Silver halide element with polymeric mordanting agents for anionic compounds | |
| US4308335A (en) | Color diffusion transfer photographic elements | |
| US3436215A (en) | Photopolymerization initiated by electrolysis of a catalyst progenitor exposed through a photoconductive layer | |
| JPH0312307B2 (en) | ||
| US3770431A (en) | Photographic elements containing ballasted resorcinols | |
| US3746542A (en) | Process for the production of polymer images | |
| US3756820A (en) | Polymer image formation | |
| US3585030A (en) | Process for the production of colour images by polymerization | |
| US3711284A (en) | Photographic film with subbing layers | |
| US4080206A (en) | Photographic processing composition containing polyvinyl aminimide | |
| GB1221325A (en) | Dormation of dye images from photographic images | |
| US3687667A (en) | Process for forming polymer images | |
| US3568597A (en) | Lithographic printing plate and process | |
| US3885081A (en) | Sheet material | |
| JP2530828B2 (en) | Silver halide photographic light-sensitive material for semiconductor laser light source | |
| US2968558A (en) | Thermo-reversible gels and photographic emulsions prepared therewith | |
| US3788856A (en) | Plural coated sheet material containing photosensitive semiconductive particles | |
| JPH06509880A (en) | Polymer scavengers for oxidized developer agents and photographic elements containing the same | |
| US4220703A (en) | Photographic receiving layer with acid processed gelatin |