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
  • G03C1/346—Organic derivatives of bivalent sulfur, selenium or tellurium

Definitions

• This invention relates to fog inhibiting agents for photographic emulsions and to photographic emulsions containing them.
• Photographic emulsions particularly ultrasensitive emulsions are those containing color sensitizers exhibiting a tendency to tog.
• This fog manii'ests.itself as a uniform deposit of silver extending over ihe emulsion, It may be caused by exposing the emulsion in a room which is not completely dark or by development oi the him for protracted periods or at temperatures above normal.
• Highly sensitive emulsions are more likely to 05 than those of lower sensitivity owing to the small amount of energy required to make the silver halide grains developable.
• 2-mercapto-py-- lio'iiclines having an amino suhstituent in the 4 position or fl-positlon or both of the pyrimidine rim; are valuable to: inhibitors.
• the amino group may be a primary amino group or may be substituted with other uroups.
• Amino derivatives of this compound which we have round suitable as antifogganta are as follows:
• the tog inhibiting agent was made up in a suitable solvent such as water or 56 alcohol and this solution mixed with the emulelon.
• a suitable solvent such as water or 56 alcohol
• a high speed negative emulsion containing no sensitizing dyes or coating doctors and having a pH o! 1.1 was used.
• Stock solutions of the fog inhibiting oomlil pounds were made and these were added to the emulsion in varying amounts.
• the emulsions were coated on glass plates, dried and incubated to obtain a. substantial log on the control plate containing no fog inhibitor. Incubation was carried out at 48% C. for a period of time willcient to produce an appreciable amount of fog on the control plate. All of the plates were incubated for the same period of time.
• the amount of fog inhibiting agent added to the emulsion is of importance since 11' too much of the fog inhibiting compound is added it may desensitise the emulsion.
• the exact amount that must be used varies without particular fog inhibiting compounds selected and with the type of emulsion used as regards Ira-in sine and alkalinity of the emulsion and ratio of the Ielatin to silver halide.
• the amotmt of anti-foggant will generally vary between about .001 gram and 1 gram of antifoggant per 1000 cc. of emulsion.
• the fog inhibiting agents which we have found to be satisfactory may be used in various kinds of photographic emulsions. In addition to being useful in ordinary non-color-sensitized emulsions, they may also be used in ortho-chromatic or panchromatic emulsions or in X-ray emulalone. They can be used with or without sensitiming dyes and ii: used with sensitizing dyes may be added to the emulsion beiore or after such dyes.
• a photographic emulsion comprising a colloidal material having a sensitive silver salt dispersed therein and containing a Z-mercapto pyrimidine having an amino group in at least one of the positions in the pyrimidine ring. selected from the 4-position and the 6-position, in fog-inhibiting amount.
• a photographic emulsion comprising a colloidal material having a sensitive silver salt dispersed therein and containing a Z-mercapto pyrimidine having a primary amino group in at least one of the positions in the pyrimidine ring. selected from the 4-position and the 6-position, in fog-inhibiting amount.
• a photographic emulsion comprising a gel. atino-silver halide emulsion containing a 2-mercapto-6amino-pyrimidine in fog-inhibiting amount.
• a photographic emulsion comprising a gelatino-silver halide emulsion containing a fi-mercaptoi -amino-pyrimidine in fog-inhibiting amount.
• a photographic emulsion comprising a gelatino-silver halide emulsion containing a 2-mercapto-4,8-diami.no-pyrimidine in fog-inhibiflng amount.
• a photographic emulsion comprising a gelatino-silver halide emulsion containing from about 0.001 gram to about 1 gram per liter oi emulsion of a il-mercapto-B-amino-pyrimidine.
• a photographic emulsion comprising a gelatino-silver halide emulsion containing from about 0.001 gram to about 1 gram per liter of emulsion of a Z-mercapto-t-amino-pyrimidine.
• a photographic emulsion comprising a gelatino-silver halide emulsion containing from about 0.001 gram to about 1 gram per liter of emulsion of a 2-mercapto-4,8-amino-pyrimidine.

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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)
• Silver Salt Photography Or Processing Solution Therefor (AREA)

Priority Applications (2)

Applications Claiming Priority (1)

Publications (1)

Family

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Family Applications (1)

Country Status (2)

Cited By (5)

• 0
  • FR FR956699D patent/FR956699A/fr not_active Expired
• 1941
  • 1941-10-09 US US414284A patent/US2304962A/en not_active Expired - Lifetime

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