Patent ID: 6638687
Filing Date: 2003-10-28
Classification: G03F

Abstract:
A method for preparing a lithographic printing plate comprising the steps of subjecting, to imagewise exposure, a presensitized plate for use in making a lithographic printing plate comprising an aluminum substrate provided thereon with a light-sensitive layer formed from a photopolymerizable light-sensitive composition, which comprises a compound having an ethylenically unsaturated double bond, a photopolymerization initiator and a polyurethane resin binder and then developing the imagewise exposed plate with a developer containing an inorganic alkaline agent and a nonionic surfactant, carrying a polyoxyalkylene ether group, and having a pH value ranging from 10.0 to 12.5 and an electrical conductivity ranging from 3 to 30 mS/cm.