| 摘要 |
PURPOSE:To obtain a lithographic printing plate having exellent processability and visible image characteristic by providing an undercoating layer contg. a specific content of a water soluble polymer compd. as a binder, layer having physical developing nuclei and a silver halide emulsion layer on one or both sides of a substrate. CONSTITUTION:A water soluble polymer compd. (e.g.; gelatin) is coated as a binder on one or both surfaces of a substrate so as to be contained at 2- 200mg/100cm<2> whereby an undercoating layer is provided. A layer coated with physical developing nuclei (e.g.; gold colloid) so as to be contained at 0.001- 0.1mg/100cm<2> and a photosensitive silver halide emulsion layer are coated thereon, whereby a material for printing plates is obtained. After such material for printing plates is exposed and is subjected to diffusion transfer development, the silver halide emulsion layer is removed, and silver picture images are formed on the physical developing nuclei, whereby the lithographic printing plate which utilizes the silver picture images as lipophilic ink receptive parts and has excellent printing resistance and ink receptivity is obtained. |
