Platemaking process with heat developable silver salt diffusion transfer

摘要

A process for simply and rapidly producing a lithographic printing plate is disclosed, which comprises image-wise exposing a silver halide photosensitive material comprising a substantially water-insoluble basic metal compound and optionally having a physical-development nucleus layer on the external surface thereof, superposing the silver halide photosensitive material either after or simultaneously with the image-wise exposure on an image-receiving material which contains a complex-forming compound and has a physical-development nucleus layer on the external surface thereof or on a sheet which contains a complex-forming compound, in such a manner that the coating side of the photosensitive material is in contact with the coating side of the image-receiving material or the sheet, heating the superposed materials in the presence of a reducing agent and water, and subsequently separating both materials from each other to form a silver image as an ink-receptive area on the physical-development nucleus layer by means of silver salt diffusion transfer. The printing plate of the present invention has improved impression capacity.