LITHOGRAPHIC PRINTING PLATES AND METHOD FOR THEIR PREPARATION

摘要

A method for the preparation of a lithographic printing plate comprises forming an oleophilic image on the surface of a hydrophilic support by depositing, preferably by ink-jetting, the desired image on the surface using an aqueous emulsion of an organic film-forming polymer which has been prepared by emulsion polymerisation, whereby the polymer adheres to the surface of the printing plate forming an oleophilic film. The polymer preferably has functional groups such as sulphonate that bind the polymer to the hydrophilic surface. Preferably the polymer has a glass transition temperature of not greater than about 105 DEG C and where the glass transition temperature is above 5 DEG C the polymer, after deposition on the plate, is preferably subjected to a heat treatment to assist in film formation.