Verfahren zur Herstellung eines Farbdiffusions-Übertragungsbilds

1,071,088. Diffusion transfer processes. INTERNATIONAL POLAROID CORPORATION. Oct. 18, 1963 [Nov. 1, 1962], No.1536/67. Divided out of 1, 71, 086. Heading G2C. In a process in which colour diffusion transfer images are formed by developing an exposed silver halide emulsion in the presence of a diffusible colour image-forming substance e. g. a dye developer which provides an imagewise distribution of diffusible colour image-forming substance and transferring at least a part of said substance from the undeveloped areas to an image receiving layer by means of an alkaline processing composition, there is used as image receiving layer an alkali permeable dyeable layer containing a mordant, and a polymeric acid layer separated by a spacer layer. Specified polymeric acids are cellulose acetate hydrogen phthalate/glutarate/ succinate, ethyl cellulose hydrogen succinate, ethyl cellulose acetate hydrogen succinate, cellulose acetate hydrogen succinate hydrogen phthalate, ether and ester derivatives of cellulose modified with sulphoanhydrides, polystyrene - sulphoric acid, carboxy methyl cellulose polyvinyl hydrogen phthalate, polyvinyl acetate hydrogen phthalate, polyacrylic acid, acetals of polyvinyl alcohol with carboxy or sulpho-substituted aldehydes and partial esters of ethylene/maleic anhydride or methyl vinyl ether/maleic anhydride copolymers. The polymeric acid layer may contain a cellulose ester e.g. cellulose acetate. The spacer layer e.g. gelatine, polyvinyl alcohol or partial acetals of polyvinyl alcohol is provided between the polymeric acid layer and the dyeable layer. Specified alkali permeable dyeable layers are polyvinyl alcohol and gelatine. Said dyeable layers contain a mordant e.g. poly-4-vinyl pyridine, and may contain 1-phenyl-5-mercapto-tetrazole. The whole may be carried on a support e.g. baryta paper or glass. The polymeric acid layer may contain titanium dioxide, imidazole or arbutin.