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
  • G03C7/00—Multicolour photographic processes or agents therefor; Regeneration of such processing agents; Photosensitive materials for multicolour processes
  • G03C7/30—Colour processes using colour-coupling substances; Materials therefor; Preparing or processing such materials
  • G03C7/392—Additives
  • G03C7/39208—Organic compounds
  • G03C7/39212—Carbocyclic
  • G03C7/39216—Carbocyclic with OH groups

Definitions

• This invention relates to color photography'and par. ticularly to a method for preventing the formationi of color fog or stain in photographic emulsions.
• a difficulty frequently encountered in these processes is the formation of color fog or stain.
• dye fog is frequently formed'in the emulsion layer. Thisis Because the developing agent has been oxidizedvto-some,
• antistain agents which are non-difiusing in the photographic layer and which are strong enough reducing agents to react rapidly with oxidized 'color developer.
• a further object is-to provide antistain agents T which do not form highly colored oxidation products V formula: I
• an emulsion layer or other layer of a photographic material especially a silver halide emulsion layer in which a colored image is formed -by development in a color-forming developer, of a normal alkyl hydroquinone having the where 'R is a normal alkyl group having from 5 to 18 carbon atoms, e. g., amyl, hexyl, heptyl, octyl, octadecyl, etc., and R- is hydrogen or the same as R, and is attached to the hydroquinone in the 5 or 6 position.
• V 7 (
• dialkyl hydroqu'inones availa.-- on able at that time were the di-secondary and di tertiary hydroquinones.
• the flask was heated on a steam bath for 5-6 hours. After a short time, the mixture, which sets to an orange-yellow mush overnight, formed a deep, orange-red solution and drops of water were ap-- parent in the upper part of the flask. At the end of the heating period the mixture was cooled to room temperature with a stream of cold water. It was then poured, with mechanical stirring, into a room-temperature solution of 615 g. (7.5 moles) of sodium acetate in 3100 ml. of water in a 5-liter, 3-neck flask. An additional 100 ml. of tetrachloroethane was used for rinsing the reaction flask. The mixture was'then stirred at room temperature for 30-40 minutes to complete the hydrolysis.
• the organic layer was allowed to settle and the supernatant aqueous-layer removed as completely as possible by decantation with suction.
• the tetrachloroethane solution was washed twice with'2-3 liters of water, by
• the crude product formed yellow crystals, M. P. 84-86 C., with. preliminary softening at about 75 C.
• the crude yield was 361 g. (76.5%).
• the material was recrystallized from a mixture of 4 volumes of methanol and 1 volume ofwater, using 5 ml. per gram, with the addition of Darco (absorbent carbon).
• the recovery was 327 g. of bright yellow crystals, M. P. 845-86 C., withv some softening at about 80 C. This amounts to a yield of 69% of the theoretical 472 g.
• the stirrer was started and hydrogen gas from a cylinder was passed into the reaction mixture at such a rate that the 'full pressure determined by the depth of the outlet tube in the cylinder of water was maintained in the flask. (A very slo'w streamof bubbles in the water cylinder indicates a safe rate.
• the speed of reduction may be estimated by shutting off the hydrogen at the inlet and observing ft'he rate at which the water rises in the exit tube due to the absorption of the hydrogen in the flask.
• Thecatalyst was removed by gravity filtration, and the flask and filter rinsed with 25 ml. of glacial acetic acid.
• the light-yellow filtrate was heated to boiling and treated with sma'll portions of zinc dust until no further 'decolori'z'atio'n occurred Z- 3 g.).
• the zinc dust was filtered oii and washed with 25 ml. of hot glacial acetic acid.
• the almost colorless (very light yellow) filtrate and washings were treated with 250 ml. of hot Water, mixed thoroughly, and cooled to 0 C.
• the atflrst oily precipitate soon crystallizes to a white solid.
• the 2-n-octylhydroquinone formed a slightly oft-white crystalline powder, M. P. 96.598 C., with some prespasms
• Compound 4.2-caprylyl-5-nbctylhydroziuizipna CHM/ Hmon A one-liter, ,3-necked flask was charged with a mixture of 111 g. (0.5 mole) of 2-n-octylhydroquinone, 108 g. (0.75 mole) of n-caprylic acid and 250 ml. of s-tetrachloroethane.
• the flask was fitted with a gas inlet tube extending to the bottom of the flask, a thermometer, and gas outlet tube to the hood.
• the whole apparatus was counterpoised on a balance pan. Boron trifluoride from a cylinder is passed directly into the slurry at such a rate that the temperature was maintained at 40-45 C. -Considerable heat was evolved and the n-octylhydroquinone slowly dissolved to form a dark, yellow-brown solution: When about 62 g.
• the flask was then heated on the steam bath for 6 hours. The mixture soon became turbid and drops of water-were apparentin the upper partof the flask. At the end of the heating period the mixture was cooled to room temperature and poured, with stirring, into a room temperature solution of 140 g. (1.7 moles) of sodium acetate in 1260 ml. of water. An additional 50 ml. of s-tetrachloroethane was used for rinsing out the reaction flask. The mixture was stirred at room temperature for about 30 minutes to complete the hydrolysis.
• the filtered solution was concentrated under reduced pressure on the steam bath to a volume of about 300 ml. 600 ml. of petroleum ether was added' and the mixture cooled to C.
• the precipitate was filtered off, washed free-of dark, oily material with petroleum ether, and dried in the air. -It formed yellow crystals, M. P. 82-83" C., with some preliminary softening at 79 C. Weight: 115 g.
• the catalys't wa's filtered off and the filtrate poured into a large volume of water.
• the organic material was extracted into ether, and 't'he ether layer was neutralized with sodium bicarbonate, washed with water, dried over sodium sulfate, and concentrated.
• the 4-rnethoxy-2- n-octylphenol wascollected at 187-190/ 10 mm. (yield 141 g3, 88%).
• the-reaction mixture When cool, the-reaction mixture was poured into at least twice its volume of water and chilled under running water for a few hours. The solid was filtered off and the sticky material was slurried carefully in thefunnel with ice-cold petroleum ether, most of the color and stickiness beingremoved by this proceduref
• the product was recrystallized from a mixture of approximatelyZlS cc. of ligroin (B. P. 90-l20) and 215 cc. of low boiling petroleum ether, giving 15.5 g. (64%).M. P. 81.5-82.5.
• Patent 2,423,730 when incorporated in this way, produce dyes upon color development which are prone to fading by the action of visible or ultraviolet light, when known antistain agents such as 2,5-di-tert. octyl hydroquinone are used in the emulsion layer. These are the yellow and cyan dyes.
• the magenta dyes such as those formed from couplers described inLoria, Weissberger and Vittum U. S. Patent 2,600,788 are relatively little affected by the known antistain agents upon the action of light.
• a quantity of the antistain agent was dissolved with 0.5 g. of coupler in 1.5 cc. of dibutylphthalate.
• the mixture was passed through a colloid mill three times, and to the resulting dispersion, 32 cc. of a gelatino-silver halide emulsion were added, and the mixture blended and coated on a film support so'that the anti-stain agent was equivalent to 5 mg. per sq. ft. of 2,5-di-tert.-octyl hydroquinone.
• Two check coatings were made: one containing no anti-stain agent, and one containing 5 mg. per sq. ft. of 2,5-di-tert. octyl hydroquinone.
• the film strips were exposed on a Ib sensitometer using a silver wedge varying in density from 0 to 3. They were then developed 10 minutes at 68 F. in the following developer:
• T he antistain agents of our invention may also be used in non-sensitive overcoating or filter layers, such as a colloidal silver interlayer of multilayer photographic material.
• the antistain agents of our invention are used in the emulsion or other layer in quantities ranging from 0.07 gram to 4.3 grams per liter of emulsion or gelatin solution. These values are, however, merely illustrative.
• a processing solution such as a prebath, first developer bath,.or color-forming developer used with color film which is developed with a primary aromatic aminodeveloping agent.
• Our materials are particularly useful with color-forming emulsions coated on paper supports where it is especially important to reduce the minimum or fog densities. This applies both to negative developed paper and to reversal paper as well as to transparency materials.
• a color-forming photographic emulsion having reduced fogging tendency comprising a silver halide emulsion having incorporated therein a non-diffusing coupler compound capable of coupling with the oxidation product of a primary aromatic amino developing agent and as an where R and R are normal alkyl groups of from 9 to 18 "carbon atoms, and R is attached to the hydroquinone nucleous in a position selected from the class consisting of 5 and 6 positions.

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• Physics & Mathematics (AREA)
• Spectroscopy & Molecular Physics (AREA)
• General Physics & Mathematics (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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Cited By (31)

Citations (1)

• 0
  • BE BE529273D patent/BE529273A/xx unknown
• 1953
  • 1953-06-03 US US359422A patent/US2728659A/en not_active Expired - Lifetime
• 1954
  • 1954-06-02 GB GB16319/54A patent/GB752146A/en not_active Expired
  • 1954-06-02 FR FR1105049D patent/FR1105049A/fr not_active Expired

Patent Citations (1)

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