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
  • G03C1/08—Sensitivity-increasing substances
  • G03C1/10—Organic substances
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
  • C07C45/61—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups
  • C07C45/65—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups by splitting-off hydrogen atoms or functional groups; by hydrogenolysis of functional groups
  • C07C45/66—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups by splitting-off hydrogen atoms or functional groups; by hydrogenolysis of functional groups by dehydration
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C49/00—Ketones; Ketenes; Dimeric ketenes; Ketonic chelates
  • C07C49/385—Saturated compounds containing a keto group being part of a ring
  • C07C49/487—Saturated compounds containing a keto group being part of a ring containing hydroxy groups
  • C07C49/497—Saturated compounds containing a keto group being part of a ring containing hydroxy groups a keto group being part of a six-membered ring
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C49/00—Ketones; Ketenes; Dimeric ketenes; Ketonic chelates
  • C07C49/587—Unsaturated compounds containing a keto groups being part of a ring
  • C07C49/603—Unsaturated compounds containing a keto groups being part of a ring of a six-membered ring

Definitions

• This' invention concerns photographic silver halide emulsions, and more particularly, photographic silver halide emulsions containing a novel sensitizing material.
• silver halide emulsions can be chemically sensitized with a variety of materials in order to increase the speed thereof. Certain chemical sensitizers are believed to react with the silver halide to form on the surface of the silver halide minute amounts of silver sulfide, silver, or other noble metals. In addition, other classes of compounds can be utilized to increase the sensitivity of photographic silver halide emulsions that apparently do not enter into chemical combination with the silver halide.
• ketonic sensitizers of the invention are 3-alkyl-3- hydroxycyclohexanones and 3-alkyl-2-cyclohexenones having at least one carbonyl radical attached to the cyclic nucleus, the 4 and 6 positions on the cyclic nucleus being points of attachment for the carbonyl radicals.
• substituents can also be attached to the 5 position on the cyclic nucleus including alkyl, acyl, alkoxy carbonyl, alkoxy, pyridyl etc.
• Preferred ketonic sensitizers of the invention have the formulas R' R B R R R R -O wherein R and R are alkyl radicals having 1 to 6 carbon atoms and wherein R R R and R are hydrogen atoms or carbonyl radicals having the formulas wherein R and R are alkyl radicals having 1 to 6 carbon atoms. At least one of the substituents in the group R and R or R and R is a carbonyl radical.
• Typical alkyl radicals include methyl, ethyl, n-propyl, isopropyl, nbutyl, tert.-butyl, n-phenyl, n-hexyl and the like.
• ketonic addenda of the invention can be added to photographic silver halide emulsions for the purpose of increasing the sensitivity or speed thereof.
• the preparation of photographic silver halide emulsions such as are suitably sensitized with the addenda ofthe invention typically involves three separate operations: (1) emulsification and digestion of silver halide, (2) the freeing of the emulsion of excess water-soluble salts, suitably by washing with water, and (3) the second digestion or after-ripening to obtain increased emulsion speed or sensitivity.
• the sensitizers of our invention can be added to the emulsion before the final digestion or afterripening, or they can be added immediately 'prior to the coating.
• the particular quantity of the present ketonic sensitizers used in a given emulsion ⁇ can vary, depending upon the effects desired, degree of ripening, silver content of the emulsion, etc.
• the amount used is also dependent upon the particular stage at which the sensitizer is added during the preparation of the emulsion. I have found that generally from about .1 to 10 grams per mole of silver halide are quite adequate to accomplish the desired sensitization. Exposure of the treated emulsion in conventional photographic testing apparatus, such as an intensity scale sensitometer, will reveal the most advantageous concentrations for the present ketonic sensitizers in that particular emulsion. Such techniques are well understood by those skilled in the art.
• the sensitizer addenda of the invention can be added to photographic emulsions using any of the well-known techniques in emulsion making.
• the subject sensitizers can be dissolved in a suitable solvent and added to the silver halide emulsion, or they can be added to the emulsion in the form of a dispersion similar'to the technique used to incorporate certain types of color-forming compounds (couplers) in a photographic emulsion.
• Couplers color-forming compounds
• the solvent should be selected so that it has no harmful effect upon the emulsion in accordance with usual practice, and generally solvents or diluents which are miscible with water are to be preferred.
• Water alone is a dispersing medium for some of the sensitizers of the invention.
• the subject sensitizers can be dissolved in solvents, such as ethanol, acetone, pyridine, N,N-dimethylformamide, etc., and added to the emulsion in this form.
• the ketonic sensitizer addenda which have been described can be used in various kinds of photographic emulsions. In addition to being useful in orthochromatic, panchromatic, and infrared sensitive emulsions, they are also useful in X-ray and other nonoptically sensitized emulsions. They can be added to the emulsion before or after any sensitizing dyes which are used.
• Various silver salts can be used as the sensitive salt such as silver bromide, silver iodide, silver chloride, or mixed silver halides such as silver chlorobromide or silver bromoiodide.
• the subject addenda can be used in emulsions intended for color photography, for example, emulsions containing colorforming couplers or emulsions to be developed by solutions containing couplers or other color-generating materials, emulsion of the mixed-packet type, such as described in Godowsky US. Patent 2,698,794, issued January 4, 1955, or emulsions of the mixed-grain type, such as described in Carroll and Hanson US. Patent 2,592,243, issued April 8, 1952.
• ketonic sensitizers can also be used in emulsions which form latent images predominantly on the surface of the silver halide crystals or in emulsions ployed for preparing silver halideemulsions, there can.
• colloids which can be used are polyvinyl alcohol or a hydrolyzed polyvinyl acetate as described in Lowe US. Patent [2,286,215, issued June 16, 1942; a far hydrolyzed cellulose ester such as cellulose acetate hydrolyzed to an acetyl content of 19-26% as described in U.S. Patent 2,327,808, of Lowe and. Clark, issued August 24, 1943; a water-soluble ethanolamine cellulose acetate as described in Yutzy US.
• Patent 2,768,154 issued October 23, 1956; or containing cyano-acetyl groups such asthe vinyl alcohol-vinyl cyano acetate copolymer as described in Unruh, Smith and Priest US. Patent 2,808,331, issued October 1, 1957; or a polymeric material which results from polymerizing a protein or a saturated acylated protein with a monomer having a'vinyl group as described in Illingsworth, Dann and Gates US. Patent 2,852,382, issued September 19, 1958. If desired, compatible mixtures of two or more of these colloids can be employed for dispersing the silver halide in its preparation. of the invention can be coated on a wide variety of supports in accordance with usual practice.
• Typical supports for photographic elements of the invention include cellulose nitrate film, cellulose acetate film, polyvinyl acetal film, polystyrene film, polyethyleneterephthalate film and related films of resinous materials, as well as glass, paper,
• a high speed gelatino-silver halide emulsion panchrorm atically sensitized With a cyanine dye was prepared. The.
• silver halide was composed of 6 molepercent of silver iodide and 94 mole percent of silver bromide.
• the emulsion comprised 245 g. of gelatin per mole of silver halide.
• Several typical ketonic sensitizers of the invention were incorporated in varying amounts in the prepared photographic emulsion.
• the emulsion containing the various sensitizers and control emulsions containing no sensitizer were coated on a cellulose acetate film support at a coverage of 430 mg. ofsilver per square foot.
• Samples The above-described emulsions The results of the sensitomctric tests are summarized by the data set out in the table below.
• the amount of addenda is set out as grams of addenda per mole of silver halide.
• the developer had the following formula:
• the 4,6 diacetyl -'3 hydroxy-3-methylcyclohexanone sensitizer employed in Example 1 was prepared'by the procedure of Knoevnagel disclosed in Chem. Ber., 36, 2136 1903 r r
• the 4,6 diacetyl 3-methyl-2-cyclohexenone sensitizer employed in Example 2 was prepared by dehydrating the sensitizer utilized in Example 1. Thedehydration was effected by passing hydrogen chloride gas into 4,6-diacetyl- 3 -hydroxy-3-methylcyclohexanone in a;reaction vessel in an ice bath until turbidity was observed, and thereafter the reaction mixture was poured into a sodium carbonate.
• V 1 6-acetyl-3-methyl-2-cyclohexenone sensitizer i employed in Example 3, was prepared by the procedure of This sensitizer boiled 7172 C./0.6 mm. and. had an index of refraction of 1.52 71.
• Example 4 employed in Example 4 was prepared by the pyrolytic distillation' of 4,6-dicarbethoxy -3-hydroxy-3-methycyclohexanone which was described by Rabe in Annalen, 332, 1 (1904). This'sensitizer was a pale yellow oil boiling 72 C./0.04 mm., having an index of refraction of n 1.4854 and a carbon and'hydrogen analysis calculated for C10H1403 of: I
• the present invention thus provides newand' useful photographic emulsions, and more particularly, photographicsilver halide emulsions sensitized with a novel class of sensitizers.
• a photographic silver halide emulsion containing a sensitizing amount of a cyclic sensitizing compound having a formula selected from the group-consisting of R1 R2 R R7 and R ' O EL- 0 0e wherein and R arealkyl radicals having 1m 6 car bon atoms, and R R R and R are selected from the group consisting of a hydrogen atom and a carbonyl radical having a formula selected from the group consisting of l u (

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Physics & Mathematics (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• General Physics & Mathematics (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Silver Salt Photography Or Processing Solution Therefor (AREA)

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Citations (3)

• 0
  • BE BE618139D patent/BE618139A/xx unknown
• 1961
  • 1961-05-29 US US113065A patent/US3165410A/en not_active Expired - Lifetime
• 1962
  • 1962-05-28 GB GB20378/62A patent/GB986205A/en not_active Expired

Patent Citations (3)

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