| 摘要 |
946,538. Lithographic silver salt diffusion processes. GEVAERT PHOTO-PRODUCTEN N. V. Jan. 19, 1960 [Jan. 19, 1959], No. 1932/59. Headings G2C and G2M. Processes for the production of printing plates by silver halide diffusion transfer on to an aluminium plate, the metal of which plays an active part in the electrolytic reduction of the transferred silver salt, are conducted with a cadmium and/or zinc salt present during the step of pressing the silver halide emulsion layer into contact with the plate to improve the adherence of the image. The salt may be in the emulsion, combined with the surface of the plate or in the developer, in which case a wetting agent such as an aliphatic alcohol may also be present. Specified salts are cadmium and zinc chlorides, nitrates, sulphates and thiosulphates and zinc acetate, oxalate and tartrate. Generally applicable features of the process are as described in Specification 913, 591 through the present Specification contains a more exhaustive list of suitable ingredients for lithographic preparations suitable for aftertreatment to improve ink-receptivity than is given therein. Specification 821, 251 also is referred to. |
