GB464398A - Process for the production of coloured photographic pictures - Google Patents

Abstract

464,398. Colour photography. GROVES, W. W. (I. G. Farbenindustrie Akt.-Ges.) Sept. 13, 1935, No. 25468. [Class 98 (ii)] In photographic material having several silver-halide emulsion layers arranged on one or both sides of a support, one or more colour - component pictures are formed by colour development and another or other colour-component pictures are formed by the silver anti-diazotate method. Colour developers specified are diethyl-p-phenylenediamine, p-phenylenediamine; o-toluylenediamine, amino-p-phenylenediamine, chlor-pphenylenediamine, mono -ethyl-p-phenylenediamine, dimethyl-p-phenylenediamine, dibromamino phenol, and dichloraminophenol. Colourforming components having substantive properties in respect of the binding agent of the layer, such as are described in Specification 458,400, are particularly suitable. A threelayer film comprises a non-colour sensitized layer-containing terephthaloyl-bis-acetanilide or benzoyl-acetanilide, an orthochromatic layer containing diphenyl - 4 - 41 - di(carboylamino - phenyl-3-carbethoxy-5-pyrazolone), and a red sensitized layer containing di-(2 - 8-dioxy-3- naphthoic acid)-benzidide. Colour development with dimethylaniline produces a yellow picture in the first layer, a red picture in the second, and a blue picture in the third. The latent image may be developed with dimethylamine-aniline, and the silver picture converted to a silver salt, which is converted into a silver anti-diazotate by treatment with diphenyl di-anti-diazotate. In a weakly acid bath the liberated diazonium compound couples with the unconverted portion of the colourforming component. The film may also be first developed with an ordinary developer, fixed, bleached, re-developed with dimethylamino-aniline, rebleached, and caused to react with an anti-diazotate. Alternatively, the silver produced by the ordinary developer is dissolved, a second exposure is given, and the film re-developed with dimethylaminoaniline. The silver produced is bleached and caused to react with an anti-diazotate. In a modification a film comprising a non-colour sensitized layer containing salicyclic acid benzidide, an ortho chromatically sensitized layer containing 1-(diphenyl)-3-methyl-5-pyrazolone, and a red-sensitized layer containing 1 : 2-oxynaphthoic acid benzidide is developed with dimethylaminoaniline and fixed, the silver in the first layer bleached and transformed into silver diphenyl-di-anti-diazotate and caused to couple with the salicylic acid benzidide by treatment with a weakly acid solution. Specification 387,197 also is referred to.