GB482652A - Photographic production of colour pictures - Google Patents

Abstract

482,652. Colour photography. I. G. FARBENINDUSTRIE AKT.-GES. Aug. 26, 1936, No. 23428. Convention date, Aug. 30, 1935. [Class 98 (ii)] In a process for producing colour pictures by the use of a photographic material having several superimposed silver halide emulsion layers arranged on one or both sides of the support, some of the emulsion layers contain colour formers and are converted into colour images by colour development and the other emulsion laver or layers are converted into residual colour images by means of a developing substance present in the layer and capable itself of forming a colour image by virtue of its developing action. Developing substances for producing the residual image include the compounds obtained by introducing into pyrocatechol, o-methylaminophenol or 4-aminomethylphenylpyrazolone residues imparting a substantive character thereto, such as those of diphenyl, stilbene, azoxybenzene, 2 : 3-oxynaphthoic acid, diarylureas, benzthiazole, oxyanthracenecarboxylic acids and oxycarbazolecarboxylic acids. The residues of stearic and oleic acids may be introduced into the compounds to diminish solubility. Derivatives of 1 : 4 - oxynaphthalenemonomethylether containing substantive groups give a blue residual image and derivatives of methylaminophenol containing substantive groups produce red and yellow residual images. A three-layer film comprises a top non-colour-sensitized silver halide layer containing 1-(p-aminophenyl)-3- methyl-4-amino-5-pyraxolone containing a substantive group, an orthochromatically sensitized layer containing 1-p-(2-oxy-3-naphthoylamino)phenyl-3-methyl-5-pyrazolone, and a redsensitized layer containing 3 : 5-di(phenylamino) phenol. On development with p-dimethylamino-aniline in absence of sulphite, red and blue images are produced in the two lower layers, while the alkalinity of the developing solution causes the developing substance in the top layer to produce a yellow residual image. The use of 1-p-stearylaminophenyl- 3-methyl-4-amino-5-pyrazolone as a developer for producing a yellow residual image is referred to. Specification 458,400 is referred to.