Patent ID: 6242156
Filing Date: 2001-06-05
Classification: B41C,G03F

Abstract:
A lithographic printing plate, comprising:(a) a substrate with roughened surface on at least one side, said surface comprising, at least, peaks and valleys; and(b) a radiation-sensitive layer on said substrate, said radiation-sensitive layer being capable of hardening or solubilization upon exposure to an actinic radiation or capable of thermal ablation upon exposure to a laser radiation, and exhibiting an affinity or aversion substantially opposite to the affinity or aversion of said substrate to at least one printing liquid selected from the group consisting of ink and an abhesive fluid for ink; wherein said radiation-sensitive layer is substantially conformally coated on the substrate surface so that the surface of the radiation-sensitive layer has peaks and valleys substantially corresponding to the major peaks and valleys of the substrate microscopic surface; and said substrate has an average surface roughness Ra of about 0.2 to about 2.0 microns, the radiation-sensitive layer has a coverage of about 0.1 to about 2.0 g/m.sup.2, and the average height of the valleys on the radiation-sensitive layer surface is at least 0.1 microns below the average height of the peaks of radiation-sensitive layer surface.