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
  • G03C5/00—Photographic processes or agents therefor; Regeneration of such processing agents
  • G03C5/26—Processes using silver-salt-containing photosensitive materials or agents therefor
  • G03C5/29—Development processes or agents therefor
  • G03C5/305—Additives other than 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
  • 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

Definitions

• the present invention relates to the use of anti-fogging and stabilizing agents for photographic silver halide emulsions and, more particularly, to the employment of certain benzoquinone derivatives for such purposes.
• lightsensitive emulsions such as gelatino-silver halide emulsions exhibit a marked tendency to fog.
• the fog may be attributable to a number of influences such as excessive ripening of the emulsion by prolonged storage of the film and especially under elevated conditions of temperature and/or humidity and by prolonged development of the exposed emulsion.
• a primary object of the present invention resides in the provision of improved anti-fogging compounds in which the above disadvantages are eliminated or at least mitigated to a substantial degree.
• a further object of the present invention resides in the provision of light-sensitive emulsions containing a compound which stabilizes the emulsion against fogging while exhibiting little tendency to reduce the speed and/or contrast of the emulsion.
• a still further object of the present invention resides in the provision of light-sensitive emulsions containing a compound which stabilizes the emulsion against fogging while exhibiting little tendency to reduce the sensitivity of the emulsion to light of longer wave length affected by the presence of one or more sensitizing dyes.
• Another object of the present invention resides in the provision of improved silver halide developing compositions containing an antifogging compound whereby there is obtained reduced fog, improved contrast, speed, and stability of photographic emulsions developed therewith.
• X represents halogen e.g., chlorine, bromine, etc.
• R and R represent hydrogen, or a salt-forming cation such as sodium, potassium, barium, lanthanum, silver,
• the compounds encompassed by the above formula maybe prepared for example by treating 2,5-dihydroxy- 3,6-dimethoxy acetophenone with halogen e.g., bromine or chlorine, in acetic acid solution to form the corresponding 3,5-dihalo-2,5 dihydroxybenzoquinone derivative.
• halogen e.g., bromine or chlorine
• the compound produced by the above method may be readily converted to its salt by reaction with a compound containing the desired cation such as sodium carbonate, potassium carbonate, silver nitrate, ammonium carbonate or the like.
• Ripening finals are added during the ripening or the sensitivity increasing stage of the emulsion making process.
• Such additions may be made before, during or after the decomposition of the soluble silver salt such as silver nitrate by means of a soluble halide such as potassium, bromide, sodium chloride or the like in the presence of a colloidal carrier such as gelatin, PVA, solubilized casein, albumen or the like.
• Coating finals are added to the emulsion just prior to coating on a suitable support such as glass, paper or film at a time when the emulsion has nearly attained its maximum sensitivity.
• the antifoggings When used as ripening finals, the antifoggings are best employed in a concentration of 5 to 40 mg. per .6 mole of silver halide and when used as coating finals in a concentration of to 500 mg. per .6 mole of silver halide.
• concentration used depends on the type of emulsion employed and it is advisable to determine the optimum concentration from case to case.
• the :desired result may be procured by addition of the antifoggant and stabilizer to one or several processing baths such as developer, fixer or the like.
• the antifoggants of the present invention may be employed in concentrations ranging from 0.5 gram to 1 gram per liter, e.g. per liter of developer composition with a range of 0.2 gram to 0.5 gram being particularly preferred.
• antifoggants and stabilizers may be utilized in connection with any type of photographic emulsion, e.g., non-sensitized, orthochromatic, panchromatic, X-ray emulsions, paper emulsions, color emulsions or the like. They may be employed in combination with other known antifoggants and stabilizers, reductionand nietaland noble metal sensitizers, or in combination with hydroxypolyethanoxy derivatives, i.e., those obtained by reacting ethylene oxide with an alcohol, phenol, amine or the like (see US. Patent 1,970,578).
• Example I illustrates the improvements provided by the present invention when the antifoggant is added directly to a silver halide emulsion.
• Example I A silver halide emulsion in gelatin containing 2% silver iodide and 98% silver bromide was prepared in a conventional manner and brought up to its maximum light sensitivity. -It was then readied for coating; finals were position:
• the antifoggant was prepared as follows: 0.5 g. of 2,5-dihydroxy-3,6-dimethoxyacetophenone in 8 cc. of acetic acid was treated with chlorine (0.6 g.) in acetic acid (2 cc.). The mixture was heated on a steam bath for approximately 1 hr. and allowed to cool. A yellow precipitate formed which was removed and crystallized from acetic acid. The product, 2,5-dichloro-3,G-dihydroxyp-benzoquinone formed yellow needles and dried to a red powder. (Reference: J. Amer. Chem. See, p. 1395, (1953).)
• Example II Exposed samples of a photographic film were developed for '12 minutes at 65 F. in a standard metol-hydroquinone developer. Two tests are made, one with the normal developing solution and one with a developer containing 50 milligrams per liter of the antifoggant of Example I.
• Sensitometric strips developed in the normal developer (control) for 12 minutes showed of fog of .30, whereas those strips which were developed in the developer containing the antifoggant, had a fog of .20.
• the following example illustrates the improved results obtained when the antifoggant compound is included in an antiabrasion layer.
• Example III A silver halide emulsion in gelatin containing 2% silver iodide and 98% silver bromide was coated on filmbase in a manner known to the art. After the coating was applied, an aqueous gelatin solution containing grams of gelatin per 1 liter and 50 mg. of 2,5-dichloro-3,6-dihydroxy-p-benzoquinone, prepared in the manner described above, was coated thereon as an antiabrasion layer. After drying, film samples were exposed and processed as described in Example I. The samples exhibited a relative speed of 100 and a fog of .20 compared with a type coating of the above, but lacking the antifoggant, and having a speed of 100 and a fog of .30.
• Example IV Silver chlorobromide emulsions for enlarging paper are prepared according to the formulae described on p. 343 of Photographic Chemistry by Pierre Glafkides, a a Fountain Press Publication 1958.
• Emulsion Fresh Oven Variable Contrast Emulsion
• the developer composition may be any of those conventionally employed in the development of exposed silver halide emulsions and accordingly may be of the hydroquinone type, i.e., those which contain hydroquinone, potassium metabisulfite and potassium bromide, or they may be of the metol-hydroquinone type, i.e., those which contain p-methylaminophenol, sodium sulfite, sodium 'bisulfite, hydroquinone, sodium carbonate, and potassium bromide.
• the developer composition may be of the so-called borax type, i.e., those which contain p-methylaminophenol, sodium sulfite, hydroquinone, borax and potassium bromide.
• the improvement in the fog characteristic made possible by the antifoggants of the present invention does not entail any adverse etfects upon any of the other photographic properties of the silver halide emulsion such as D Max, contrast, speed and the like.
• a light-sensitive silver halide emulsion containing an antifoggant and stabilizer comprising a compound of the following general formula:
• X represents halogen and R and R are selected from the group consisting of hydrogen and a cation.
• a light-sensitive photographic material comprising a base and a light-sensitive silver halide emulsion, said light-sensitive material containing an antifoggant and stabilizer comprising a compound of the following general formula:
• RO/WX X L/OR ll wherein X represents halogen and R and R are selected from the group consisting of hydrogen and a cation.
• An aqueous developer solution containing a silver halide photographic developing agent and an antifoggant and stabilizer comprising a compound of the following general formula:
• X represents halogen and R and R are selected from the group consisting of hydrogen and a cation.
• said antifoggant comprises 2,5-dichloro-3,6-dihydroxy-p-benzoquinone.
• a process for the preparation of a photographic emulsion having a reduced tendency to fog which comprises forming the emulsion, ripening the emulsion and, during said ripening, adding thereto an antifoggant and stabilizer comprising a compound of the following general formula:
• X represents halogen and R and R are selected from the group consisting of hydrogen and a cation.
• a process for the preparation of a photographic emulsion having a reduced tendency to fog which comprises forming the emulsion, ripening the emulsion, coating said emulsion on a base and adding to said emulsion just prior to the coating thereof on the base an antifoggant and stabilizer comprising a compound of the following general formula:
• X represents halogen and R and R are Selected from the group consisting of hydrogen and a cation.
• Light-sensitive photographic material comprising a base, a light-sensitive silver halide emulsion layer, and an anti-abrasion layer containing an antifoggant and stabilizer comprising a compound of the following general formula:
• X represents halogen and R and R are selected from the group consisting of hydrogen and a cation.

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

Priority Applications (7)

Applications Claiming Priority (1)

Publications (1)

Family

ID=23854456

Family Applications (1)

Country Status (5)

Cited By (5)

• 0
  • NL NL134366D patent/NL134366C/xx active
• 1965
  • 1965-06-25 US US467123A patent/US3396022A/en not_active Expired - Lifetime
• 1966
  • 1966-06-14 GB GB26513/66A patent/GB1146719A/en not_active Expired
  • 1966-06-21 DE DE19661547910 patent/DE1547910A1/de active Pending
  • 1966-06-21 NL NL6608570A patent/NL6608570A/xx unknown
  • 1966-06-23 BE BE682993D patent/BE682993A/xx unknown

Non-Patent Citations (1)

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