Flat pressure plates precursor as well as a process for the preparation of a 'waterless' planographic printing plate

摘要

PROBLEM TO BE SOLVED: To provide a lithographic printing original plate in which writing with an infrared laser is possible and which has a protective layer and can improve productivity in plate making work, and to provide a plate making method therefor.;SOLUTION: The lithographic printing original plate is obtained by sequentially stacking on a support a photosensitive layer containing an infrared absorbent, a polymerization initiator, a polymerizable compound and a binder polymer, and a protective layer, wherein the protective layer contains a mica compound and at least one polyvinyl alcohol selected from the group consisting of polyvinyl alcohols having a saponification degree of ≤90 mol% and acid modified polyvinyl alcohols. In the plate making method for a lithographic printing plate, the lithographic printing original plate is exposed at a wavelength of 750-1,400 nm and then developed at a conveyance speed of ≥1.25 m/min without substantially passing through heat treatment and water washing treatment.;COPYRIGHT: (C)2006,JPO&NCIPI