LASER DIRECT PHOTOSENSITIVE PLANOGRAPHIC PRINTING ORIGINAL PLATE NEEDING NO DAMPENING WATER

摘要

PROBLEM TO BE SOLVED: To obtain a laser direct planographic printing original plate needing no dampening water, excellent in sensitivity to heat-mode laser exposure, handleable in a light room and using no developer in a photochemical process. SOLUTION: The laser direct photosensitive planographic printing original plate has at least a thin silver film layer and a silicone rubber layer on the substrate in this order. The thin silver film layer comprises particulate silver grains having 0.005-0.2μm grain size and is formed by a silver salt diffusion transfer process using a diffusion transfer developer containing an amine compound.