Presensitised lithographic plate of silver halide polymerisation type

摘要

A light-sensitive material comprises, in sequence, (a) a plastics base, (b) a hardening layer and (c) a light-sensitive layer, in which (b) contains an ethylenically unsatd. polymerisable cpd. or crosslinked polymer, (c) contains Ag halide (AgX) and (b) or (c) also contains a reducing agent. The novelty is that, between (a) and (b), the material has (d) a hydrophilic subbing layer of solid particles (I) with an average particle size of 0.1-10 mu , dispersed in a hydrophilic binder (II). Also claimed is a method for making a lithographic printing plate from the material. Pref. (I) consist of crystals of an inorganic substance, esp. TiO2, ZrO2 or more esp. SiO2. (II) is gelatin and esp. is crosslinked by adding a hardener. The (I):(II) wt. ratio is 0.1-10; and layer (d) is 0.1-5 mu thick. The material may also have an intermediate coat contg. (II) and opt. (I), having an average particle size of 0.1-5 mu , between layers (d) and (b); and an overcoat contg. a base precursor on layer (c).