| 摘要 |
1,238,340. Photographic materials. INTERNATIONAL POLAROID CORP. Oct.15 1968 [Oct. 16, 1967], No. 48907/68. Addition to 1,149,921. Heading G2C. Image receiving elements for the silver salt diffusion transfer process are formed by (i) precipitating a silver precipitating agent in a solution of an alkali-impermeable polymer by adding soluble reagents thereto, (ii) forming a solid layer of said polymer containing the dispersed precipitating agent, and (iii) hydrolyzing at least a depthwise portion of said polymer to an alkalipermeable polymer. The precipitating agent may be a metal or a metallic sulphide or selenide. The solid layer may be coated over a layer of acidic polymer, may contain a toning agent and/or may be overcoated with a stripping layer, e. g. of dimethyl hydantoin formaldehyde, gum arabic or cellulose acetate hydrogen phthalate suitable alkaliimpermeable polymers are cellulose esters and polyvinyl esters and acetates. |
