Patent GB-503825-A (GB)
Title: Process and materials for colour photography
IPC: G03C7/30
Filed: 1937-07-07
Abstract: 503,825. Colour photography. KODAK, Ltd. July 7, 1937, No. 7054/39. Convention date, July 7, 1936. Divided out of 503,752. [Class 98 (ii)] Multilayer photographic elements are processed tocolour by development (primary, reversal or redevelopment) with an alkaline coupling developer in the presence of a coupling component which possesses several coupling functions of different types, whereby the oxidation products of the developing agent couple with the said coupling component to give a dye image. The coupling component is relatively insoluble in the alkali used in the developer. The coupling function are defined in the Specifications as " phenolic," " amine," " open chain reactive methylene," " intracyclic reactive methylene and " sulphonarylamide." The coupling component may, for example, have a phenolic group and an aceto-acetic group in the same molecule ; or a phenolic group and a pyrazolone group ; or a pyrazolone group and an aceto-acetic group, the molecule being in the form of a metal salt. The product obtained by reacting the 4-sulphonic acid chloride of alpha-naphthol with aromatic amines contains a phenolic and sulphonarylamido coupling functions. Another example is the product obtained by condensing two mols. alpha-naphthylamine with one molecule of alpha-naphthol-3 : 6- disulphonic acid chloride. Other coupling components specified are (a) the ketonimines of o-aceto-acetyl phenol, (b) compounds obtained by condensing amino alpha-naphthol with 3-methyl- 1-phenol-pyrazolone carboxylic acid chloride or 3-methyl-1-phenyl pyrazolone sulphonic acid chloride or hydroxy - # - naphthyl - pyrazolone monosulphonic acid chloride, (c) compounds obtained by condensing aceto-acetic ester or its homologues with amino alpha-naphthol or aminopyrazolones or o-aceto-acetyl phenols and (d) insoluble metal salts or ketonimines from the o-aceto-acetyl phenolic coupling components mentioned in (c), e.g. amino derivatives of o-aceto-acetyl phenol or 2-(#-amino crotonyl) 1-naphthol. The invention is described as applied to the multi-layer and mixed particle emulsion materials described in Specification 500,826 (as open to inspection under Sect. 91), and each emulsion may contain a coupling component which is insoluble and preferably of high molecular weight. One or more of the emulsions may contain no coupling component and be developed with a developing agent which either oxidizes directly to a dyestuff or its oxidized product couples with unoxidized developing agent ; or a coupling component may be dissolved in the developer. The coupling components may be added in amounts of 3 to 20 grams per litre of gelatino-silver bromide emulsion, the components being first dispersed in a 10 per cent gelatine solution. The components are deposited on or absorbed by the silver halide grams as described in Specification 376,794. The coupling components can be formed within the emulsion of low gelatine content, preferably after ripening or in centrifuged silver bromide emulsion. The coupling components are dissolved in alcoholic alkali, added to the emulsion, the coupling components precipitated by acid, and the emulsion set, shredded and washed. The element may carry a sound record in the layer nearest the support or in a separate layer. Specifications 376,746, 376,794, 376,795, 377,299, 440,032, 440,089, 447,092, 458,664, 475,784, 475,786, 498,869, 498,870, 498,871, 498,875, 499,185, 503,752, 503,816, 503,817, 503,818, 503,819, 503,820, 503,821, 503,823, 503,824, 503,826, 503,827, 503,940, and 503,941 also are referred to.