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
  • G03C1/35—Antiplumming agents, i.e. antibronzing agents; Toners
  • G03C1/355—Organic derivatives of bivalent sulfur, selenium or tellurium
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S430/00—Radiation imagery chemistry: process, composition, or product thereof
  • Y10S430/13—Antibronze agent or process

Definitions

• This invention relates to improvements in the production of photographic images, such as images on paper supports, prepared from silver halide emulsions. More particularly this invention relates to silver halide emulsions having associated therewith a novel antiplumming or antibronzing compound which prevents image degradation of an exposed silver halide emulsion during processmg.
• Silver halide emulsions after exposure often are subject to image degradation during processing, that is, during development, fixing, washing, toning, etc., and particularly When they encounter the moist heat to which they are subjected on drying as when prints are subjected to ferrotyping or hot glazing. This degradation of the image frequently manifests itself as plumming or bronzing.
• An object of the present invention is to provide a novel method of producing photographic images of superior quality. Another object is to provide a method for preventing image degradation of an exposed silver halide emulsion during processing. Still another object is to prevent plumming or bronzing of photographic prints during a hot glazing process. Another object of the invention is to provide compounds suitable for use as antiplumming agents in silver halide emulsions. Other objects will appear hereinafter.
• endothiophenyl thiadiazoline thiol and its potassium salt, are effective antiplumming agents when employed with silver halide photographic emulsions during processing of an exposed silver halide emulsion which term includes one or more of the operations of developing, fixing, washing and drying.
• Potassium endothiophenyl thiadiazoline thiol may be prepared by the method described in J. Prakt. Chem, 60, 206 (1899).
• Potassium ethyl xanthate was prepared by adding 30 g. of carbon bisulfide to a solution of 16 g. of potassium hydroxide in 50 m1. of ethanol. To the resulting slurry, a solution of 20 g. of freshly-distilled phenylhydrazine in 60 ml. of ethanol was added gradually. The mixture at first thinned out, and then set up again. It was heated with stirring, on the steam bath for four hours, then half of the solvent was distilled off, and the solution cooled in an ice bath. The white, crystalline potassium salt which separated was removed by filtration, washed with a little cold alcohol, and finally with ether.
• the free endothiphenylthiadiazolinethiol may be prepared by treating the potassium salt thereof with hydrochloric acid.
• these compounds may be added preferably to the emulsion layer or layers. They are also elfective if added to the developing solution, or to other layers carried on the I sensitive emulsion support such as the backing layer or supercoat. Alternately the sensitive layer may be bathed in a solution of theagent after exposure but prior to development. amounts between 0.1 and 4.0 grams per, molof silver halide in the emulsion.
• Example 1 An emulsion was prepared in accordance with Examples l of U. S. Patent 2,596,756. To separate portions .of this emulsion were added quantities of a 1:500 aqueous solution of potassium endothiophenyl thiadiazoline thiol equivalent to 0, 0.5, 1.0 .and 2.0 grams per mol of silver.
• An emulsion was prepared according to Example 1 of U. S. Patent 2,596,756. To portions of this emulsion were added quantities of a 1:200 solution of endothiophenylthiadiazoline thiol dissolved in equal parts of methanol and acetone, and equivalent to 0, 0.5 and 2.0 g./mol of silver. These emulsions were then coated on glossy baryta-coated single-weight paper at a rate of 650 ft. mol of silver. Two samples of each coating were exposed through a step wedge, developed, fixed and washed. One set of prints was dried without heat, and the other Patented Apr.
• the method'of preventing'image degradation of an exposed silver halide emulsion during drying which comprises performing at least one of the steps of developing,
• a photographic silver halide emulsion containing from 0.1 and 4.0 grams per mol of silver halide of a compound having the formula:

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• Physics & Mathematics (AREA)
• Chemical & Material Sciences (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• General Physics & Mathematics (AREA)
• Nitrogen- Or Sulfur-Containing Heterocyclic Ring Compounds With Rings Of Six Or More Members (AREA)
• Thiazole And Isothizaole Compounds (AREA)
• Plural Heterocyclic Compounds (AREA)

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Citations (2)

• 0
  • BE BE537818D patent/BE537818A/xx unknown
• 1954
  • 1954-05-03 US US427373A patent/US2743184A/en not_active Expired - Lifetime
• 1955
  • 1955-04-29 GB GB12401/55A patent/GB774618A/en not_active Expired
  • 1955-05-02 DE DEE10662A patent/DE1005839B/de active Pending
  • 1955-05-03 FR FR1123458D patent/FR1123458A/fr not_active Expired

Patent Citations (2)

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