HEAT SENSITIVE PLATE PRECURSORS

摘要

A lithographic printing plate precursor comprises a grained and anodised aluminium substrate coated with a layer of metallic silver on top of which is applied a composition comprising an oleophilising agent and a proteolytic enzyme. Imagewise exposure of the precursor by means of a high intensity laser beam allows for the direct provision of press ready plates showing excellent start-up and clean-up properties on press and providing high image quality and high printing durability without the requirement for the use of intermediate film and developer chemistry. On exposure of the plate precursor, removal of the metallic layer occurs in the exposed areas.