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
  • G03C7/32—Colour coupling substances
  • G03C7/36—Couplers containing compounds with active methylene groups
  • G03C7/362—Benzoyl-acetanilide couplers

Definitions

• a phenol or phenolic type of compound such as a naphthol.
• pyrazolones are frequently employed, whereas the yellow image is formed from an a-arylacetanilide structure. It is this latter representative of color formers with which the present invention is concerned.
• Yellow color forming components of the type derived from an c-arylacetanilide can be formulistically depicted as follows:
• couplers of this type embody a reactive methylene grouping, i.e., a structure characterized by the presence of a methylene bridge linked to various negative groupings which, in the above formula, are keto functions located on either side of the methylene bridge. It is the methylene portion of the coupler, the hydrogen atoms of which are acidic by virtue of the electron-attracting keto functions, which couples with the oxidized primary aromatic amino developing agent to produce the colored dye images.
• R is a higher alkyl group having from 8 to 20 carbon atoms, the purpose of which is to prevent wandering or difiusion of the color forming compounds throughout the emulsion layer with concomitant color degradation.
• Suitable alkyl moieties for this purpose include alkyl groups such as octyl, nonyl, decyl, undecyl, tetradecyl, octadecyl, eicosyl and the like; M and M which may be alike or different can be hydrogen or a carboxylic acid salt such as an ammonium salt including amine salts, alkali metal salts, i.e., lithium, potassium, sodium, etc.
• the designation of M and M will depend to some extent on the pH of the emulsion in which the coupler is incorporated.
• the coupler may be added in the form of its alkali metal salt to the emulsion which, after the coating operation, may be subjected to conditions of lower pH causing the coupler to be converted to its acid form. It is to be understood, therefore, that the coupler structures as herein described are not limited to any particular salt or free acid form.
• a novel feature of the couplers as described herein for producing yellow dye images on color development is the presence of a carboxylic acid function on the para-position of the benzoyl grouping. That this particular structural modification has heretofore been unknown to the art is indeed not surprising. Normally such structures would be synthesized by reacting a p-carboxylbenzoyl acetic ester with an aniline to form a benzoyl acetanilide. However, because of the unavailability of p-carboxylbenzoyl acetic ester, this reaction is not suited for producing color former structures of the benzoyl acetanilide type wherein the benzoyl grouping contains a carboxylic acid function particularly in the para-position thereof.
• the ethyl-4-cyanobenzoy1 acetate was prepared by reacting 4-cyanobenzoyl chloride with acetoacetic ester in the presence of sodium methylate. Hydrolysis of the resulting ester complex with a mixture of ammonium chlo ride and ammonium hydroxide yielded the ethyl-4-cyanobenzoyl acetate. After one crystallization from alcohol, the purified product melted at 836 C.
• the preparation of benzoylacetic esters as described herein is patterned after the method published by Thorp and Brunskill in J.A.C.S. 37, 1261.
• the 4-cyanobenzoyl chloride-M.P. 73 C.-- was obtained by acylating the free acid with phosphorous pen tachloride utilizing the method of Scholl and Neuberger M, 33, 517.
• the 4-cyanobenzoic acid was produced by the diazotization of p-aminobenzoic acid followed by treating the resulting diazonium salt with cuprous cyanide (Sandmeyer reaction). The preparation was modeled after the method disclosed by Valby and Lucas in J.A.C.S., 51, 2719 (1929).
• this yellow coupler was patterned after the procedure used in the first example except that the 3-amino-4-tetradecoxybenzoic acid of the earlier example was replaced by the corresponding octadecoxy derivative.
• the color couplers contemplated in the instant invention can be incorporated in a photographic light sensitive silver halide emulsion in the manner well known to the art.
• the coupler can be dissolved in an aqueous alkaline solution which is then blended with the silver halide emulsion and the mixture then coated on a suitable photographic support or base.
• the coupler can be dissolved in any suitable alkaline solution capable of forming soluble salts with the carboxylic functions of the coupler.
• aqueous or alcoholic solutions of organic bases including ammonium hydroxide, alkali metals are especially suitable for this purpose.
• Example 1 Typically, one gram of the color former of Example 1 was dissolved in about 20 milliliters of water containing sufficient sodium hydroxide to impart the solution a pH at about 7.5. The solution was combined with a silver bromide emulsion and the mixture coated on a suitable base such as triacetate filmbase. Upon exposure and development in a color developer containing as the active principal N-ethyl-N-hydroxyethyl-p-aminoaniline there was obtained a brilliant yellow dye image having an absorption maximum at 428 mu.
• M and M are each selected from the class consisting of hydrogen and ammonium group and the alkali metals and R is a higher alkyl group of from 8 to 20 carbon atoms.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Silver Salt Photography Or Processing Solution Therefor (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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Citations (4)

• 0
  • BE BE613367D patent/BE613367A/xx unknown
• 1961
  • 1961-02-01 US US86281A patent/US3056674A/en not_active Expired - Lifetime
• 1962
  • 1962-01-25 GB GB2851/62A patent/GB934017A/en not_active Expired
  • 1962-01-30 DE DEG34149A patent/DE1157483B/de active Pending
  • 1962-02-01 CH CH124062A patent/CH424477A/de unknown

Patent Citations (4)

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