| 摘要 |
PURPOSE:To improve printing resistance by incorporating fine powder specified in particle diameter in the undercoat layer and the emulsion layers of a lithographic plate using the silver complex salt diffusion transfer process. CONSTITUTION:The undercoat layer of a lithographic plate obtained by successively forming the undercoat layer, a silver halide emulsion layer, and a physical development nucleus layer on a support contains fine powder having 2-10mum particle diameter and an average particle diameter equal to or more than the thickness of the undercoat layer in an amt. of about 80wt% of the total fine powder contained in the constituent layers, and said emulsion layer contains fine powder having an average particle diameter up to twice the thickness of the emulsion layer and, preferably, smaller than that of the undercoat layer. Dots having, for instance, >=175 lines per inch can be printed by exposing said plate to high illumination flash light in a short time by the scanning type flash exposure process to execute direct plate making, and further, peeling of transferred silver can be prevented in making a large number of prints. |
