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
  • G03C1/06—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein with non-macromolecular additives
  • G03C1/34—Fog-inhibitors; Stabilisers; Agents inhibiting latent image regression
• • 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
  • G03C1/04—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein with macromolecular additives; with layer-forming substances
  • G03C1/053—Polymers obtained by reactions involving only carbon-to-carbon unsaturated bonds, e.g. vinyl polymers

Definitions

• This invention relates to improved gelatin silver halide emulsions containing a poly-N-vinyllactam having 4 or 5 carbon atoms in the heterocyclic ring and fog inhibiting amounts of a monohydric or dihydric phenol anti-fogging agent.
• An object of this invention is to provide a simple and effective process for reducing the fogging tendencies of gelatino silver halide photographic emulsions containing poly-N-vinyllactams having 4 to 5 carbon atoms in the heterocyclic ring. Another object is to provide such a process which uses available chemical compounds of simple structure. Yet another object is to provide such a process which involves simple mixing procedures. A further object is to provide photographic gelatino silver halide emulsions containing substantial amounts of poly- N-vinyllactams which have enhanced covering power and contrast characteristics and which do not evidence any substantial increase in fog or loss in speed under high temperature or humidity conditions during storage. Still further objects will be apparent from the following description of the invention.
• photographic gelatino silver halide emulsions containing 8 to 50% by weight based on the weight of total solids in the emulsion of a water-soluble N-vinyllactam polymer containing 4 to 5 carbon atoms in the heterocyclic ring having an average molecular weight of at least 20,000 up to 200,000 or more, enhanced covering power and contrast and being stabilized against fog can be made by admixing with the emulsion small amounts from 5 to 50 millimoles per mole of silver halide of a phenol' antifoggantn
• the mono or dihydric phenol antifogging agents can be added to the aqueous gelatin/poly-N-vinyllactam silver halide emulsion or dispersion at any time but are preferably added to the aqueous molten or liquefied emulsion after it has been brought to its maximum sensitivity and just prior to coating onto a suitable support to form a photographic film
• the phenol antifogging agents can be added from ethanol solution (e.g., 2% by weight) or in some cases can be added to the emulsions described above.
• a particularly useful class of monohydric phenols wherein the amass)? Patented July 10, 1962 ice hydroxyl group is attached to a benzene nucleus can contain a hydrocarbon substituent in the para-position to the hydroXyl group and have one, two or three of the remaining nuclear hydrogen atoms substituted by hydrocarbon groups.
• hydrocarbon substituents which may be present in -the para-position and in the other positions of the benzene ring are alkyl radicals of 1 to 18 carbon atoms, e.g., methyl, ethyl, n-propyl, isopropyl, t-butyl, sec-amyl, t-amyl, t-octyl, n-nonyl and n-dodecyl; aryl, e.g., phenyl, naphthyl and biphenyl; aralkyl, e.g., benzyl, u-cumyl and naphthylmethyl, and cycloalkyl, e.g., cyclopentyl and cyclohexyl.
• Specific compounds of this type are described below and in as-. signees Smith application Serial No. 656,195, filed May 1, 1957, U.S. Patent 2,955,037, Oct. 4, 1960.
• phenol antifogging agents which are particularly useful in accordance with the present invention are the hydrocarbon-substituted mono nuclear monohydric phenols of at least 10 carbons wherein the hydrocarbon substituent is in one of the-positions ortho and metato the hydroxyl group and theother positions of the benzene ring are unsubstituted.
• These phenols have the general formula:
• the hydrocarbon radicals may be alkyl, cycloalkyl, aryl and aralkyl.
• the alkyl radicals may contain 4 to 12 or more carbon atoms and suitable alkyl radicals are t-butyl, sec-amyl, t-amyl and t-octyl, n-nonyl and n-dodecyl; Suitable cycloalkyl radicals are cyclopentyl and cyclohexyl.
• Useful aryl radicals include phenyl, naphthyl and biphenyl.
• Suitable aralkyl radicals include benzyl, u-cumyl and naphthylmethyl. Suitable specific compounds of this type are described below and in assignees copendingSmith application Serial No. 656,181, filed May 1, 1957 abandoned but refiled as continuationin-part US. application Ser. No. 859,108, Patent 2,965, 487, Dec. 20, 1960.
• Suitable phenols having anti-fogging properties are the bisphenols of the general formula Where Q is a direct carbon-to-carbon linkage S-- O-, (---CH,,--) where n is 1 to 10, or
• aryl, and the hydroxyl groups preferably are in the oor ,p-position to the radical Q.
• suitable alkyl radicals include methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl, pentyl, n-hexyl, n-octyl and t-octyl.
• Useful aryl radicals include phenyl and naphthyl, and suitable cycloalkyl radicals are cyclopentyl and cyclohexyl.
• the invention is not limited to any particular type of light-sensitive silver halide as it is useful with silver chloride, silver bromide, silver iodobromide, silver chlorobromide, silver iodide, etc., emulsions and mixed emulsions of these types. It is particularly efficacious in silver iodobromide emulsions containing about 2 mole percent iodide and the rest bromide. These emulsions may be sensitized by means of chemical sensitizing agents, e.g.
• noble metal sensitizers e.g., gold salts, e.g., chlorauric acid and auric trichloride
• sulfur sensitizers e.g., sodium sulfite, thiosinarnine, allylthiourea, sodium thiosulfate, allyl thio- 'carbamate, alkali metal thiocyanates and sodium sulfide,
• the silver halide emulsions may contain one or more optical sensitizing agents, e.g., cyanine, carbocyanine, merocyanine, pseudocyanine, cyazine, etc., dyes.
• optical sensitizing agents e.g., cyanine, carbocyanine, merocyanine, pseudocyanine, cyazine, etc., dyes.
• the finished emulsions will contain on a dry basis, by weight, 8 to 50% poly-N-vinyllactam, 30 to 70% silver halide and to 60% gelatin and 5 to 50 millimoles per mole of silver halide of the phenol antifogging agent.
• Example 1 A high speed gelatino-silver iodobromide (about 2 mole percent iodide, 98% bromide) was digested with an organic sulphur sensitizing compound and gold chloride. After digestion the emulsion was divided into three parts. One part was treated with 45.5 grams of poly-N- vinyl-Z-pyrrolidone having an average molecular weight of approximately 45,000 per mole of silver halide. To a second part of emulsion were added 45.5 grams of poly- N-vinyl-2-pyrrolidone and 18 millimoles of resorcinol per mole of silver halide. The third part containing neither of the above additions was used as a control.
• the emulsions were coated on cellulose acetate film base and were exposedto X-rays in the presence of an intensifying screen at two difierentintensity levels through an aluminum /2 step wedge.
• the exposure of greater intensity has been designated as No. 2 and that of lower intensity and longer time as No. 1.
• the coatings were developed for 5 minutes in a developer of the following composition:
• Example 3 Example 5 1 1 s t g i gg sfi gg 2 3. 2: 5 2 3: 10 A gelatino-silver iodobromide emulsion digested with if. t 11S i at with sulphur and gold sensitizing compounds was divided into Z i z j i g three parts. One part was treated with 45.5 grams of 1 e p f Signer g g 5 a Second the poly-N-vinyl-Z-pyrrolidone described in Example 1 E g: e 5 ms of the 15 per mole of silver halide.
• Control 750 3. 22 390 2. 45 05 800 3. 55 440 2. 03 14 E a l 7 I plus phenol 770 3. 47 440 2. 70 .08
• a gelatino-silver iodobromide emulsion digested with sulphur and gold sensitizing compounds was divided into ONE WEEK AT 120 F. AND 55% EH.
• Example 8 A gelatino-silver iodobromide emulsion digested with 5 ONE WEEK AT R AND sulphur and gold sensitizing compounds was divided into three parts. One part was treated with 45 .5 grams of the Fog poly-N-viny-l-Z-pyrrolidone described in Example 1 per mole of silver halide.
• Example 10 A gelatinO-silver iodobromide emulsion digested with sulphur and gold sensitizing compounds was divided into three parts. One part was treated with 45.5 gramsof the poly-N-vinyl-Z-pyrrolidone described in Example 1 per mole of silver halide.
• a gelatino-silver iodobromide emulsion digested with sulphur and gold sensitizing compounds was divided into three parts. One part was treated with 45.5 grams of the poly-N-vinyl-Z-pyrrolidone described in Example 1 per mole of silver halide. To a second part of the emulsion were added 45.5 grams of the polymer and 20 millimoles of 2,2-methylene-bis '(4-t-butyl-6-methylphenol) per mole of silver halide. Neither of these additions was made to a third part of the emulsion.
• the invention is not limited to the use of the specific copolymers and homopolymers of the examples as various other such polymers can be used, e.g., poly-N-vinylcaprolac- 10 tam, poly-N-vinylvalerolactam and poly-N-vinyl-S-methyl-Z-pyrrolidone and copolymers of two or more of the corresponding monomers.
• copolymers of the latter with vinyl salicylate, vinyl acetate, vinyl alcohol, vinyl oxazolidone, methyl acrylate, acrylamide, methacrylamide, acrylonitrile, vinyl chloride, vinylidene chloride, and styrene containing at least by Weight of the poly-N- vinyllactam can be prepared by the method described in J. Org. Chem.'22, 849 (1957).
• An advantage of this invention is that it provides a simple and effective way of improving the stability and aging characteristics of gelatino silver halide photographic emulsions containing substantial amounts of poly- N-vinyllactams. It enables one to obtain the advantages of the covering power of such emulsions and overcomes their tendency to fog during normal or tropical storage conditions.
• the invention does not require expensive chemicals or involved procedures and can be carried out by the ordinary technician. Still further advantages will be apparent from the above.
• a photographic silver halide emulsion comprising on a dry-weight basis 30% to 70% silver halide, 10% to 60% gelatin, 8% to 50% of an organic Water-soluble addition polymer taken from the group consisting of homopolymers of at least one N-vinyllactam containing 4 to 5 carbon atoms in the heterocyclic ring and copolymers of such an N-vinyllactam with an ethylenically unsaturated compound taken from the group consisting of vinyl salicylate, vinyl acetate, vinyl oxazolidone, methyl acrylate, acrylamide, methacrylarnide, acrylonitrile, vinyl chloride, vinylidene chloride and styrene containing at least 80% by weight of said N-vinyllactam, and 5 to 50 millimoles per mole of silver halide of a phenol antifogging agent taken from the group'consisting of (a) a hydrocarbon-substituted monohydric phenol of at least 10 carbon

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• Chemical & Material Sciences (AREA)
• Physics & Mathematics (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• General Physics & Mathematics (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)

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Citations (9)

• 0
  • BE BE581611D patent/BE581611A/xx unknown
• 1958
  • 1958-08-27 US US757460A patent/US3043697A/en not_active Expired - Lifetime
• 1959
  • 1959-07-07 GB GB23368/59A patent/GB867900A/en not_active Expired
  • 1959-08-17 DE DEP23369A patent/DE1120272B/de active Pending
  • 1959-08-18 FR FR803081A patent/FR1233875A/fr not_active Expired

Patent Citations (9)

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