Patent ID: 7682776
Filing Date: 2010-03-23
Classification: B41C,B41N,G03F

Abstract:
1. A method of processing a lithographic printing plate comprising in order: (a) providing a lithographic printing plate comprising (i) an aluminum substrate; (ii) a photosensitive layer comprising a polymeric binder, a urethane (meth)acrylate monomer having at least 6 (meth)acrylate groups, a non-urethane (meth)acrylate monomer having at least 4 (meth)acrylate groups, a free-radical initiator, and an infrared absorbing dye; and (iii) a water soluble or dispersible overcoat; wherein said aluminum substrate is electrochemically grained, anodized, and further treated with a hydrophilic material, and has a reflection optical density of at least 0.30; (b) exposing said plate with an infrared laser having a wavelength of from 750 to 1200 nm according to digital imaging information to cause hardening of the photosensitive layer in the exposed areas; and (c) developing said plate on a lithographic press with ink and/or fountain solution.