Presensitized plate for making lithographic printing plate

Abstract

A presensitized plate useful for making a lithographic printing plates comprises an aluminum substrate provided thereon with a photopolymerizable light-sensitive layer, wherein the light-sensitive layer comprises an ethylenically unsaturated bond-containing compound having at least three methacryloyl or acryloyl groups alone or in any combination in the molecule and the substrate is Substrate A, which has, on the surface, grained structures comprising medium waved structure whose average pore size ranges from 0.5. to 5 μm and small waved structure whose average pore size ranges from 0.01 to 0.2 μm, which are superimposed; or Substrate B, which has, on the surface, grained structures comprising large waved structure whose average wavelength ranges from 5 to 100 μm, medium waved structure whose average pore size ranges from 0.5 to 5 μm and small waved structure whose average pore size ranges from 0.01 to 0.2 μm, which are superimposed. The presensitized plate permits the maintenance of the balance between the resistance to contamination and the printing durability of the resulting lithographic printing plate to a substantially high level, when forming a light-sensitive layer containing a methacryl or acryl compound having at least three functional groups on the substrate according to the present invention having a characteristic surface grained pattern.

Dependencies are inferred from the claim text.