Presensitized plates for use in making lithographic printing plates not requiring dampening with water.

摘要

A presensitized plate for use in making lithographic printing plates not requiring dampening with water (dry PS plate) comprising a substrate provided thereon with a photopolymerizable light-sensitive layer and an ink-repellent layer in that order, wherein the light-sensitive layer contains at least one water-soluble compound and at least one water-insoluble polymer compound which compounds cause phase separation in the light-sensitive layer to form a layer rich in the water-soluble compound contiguous to the interface of the light-sensitive layer and the ink-repellent layer. The dry PS plate exhibits excellent developability of image area and can be stably developed with a safe developer, i.e., water or an aqueous solution of water-soluble organic solvents mainly composed of water.