Patent ID: 6303271
Filing Date: 2001-10-16
Classification: B41C,Y10S

Abstract:
A method for preparing a printing form, the method comprising:coating a layer of a radiation sensitive ink on a lithographic support having a hydrophilic surface layer to form an ink coating,imaging the ink coating by digital laser means to form exposed areas and unexposed areas of the ink coating, andacting on the support with aqueous covered dampening rollers to remove the unexposed areas of the ink coating thereby revealing the hydrophilic surface of the support and leaving an oleophilic image formed from the exposed areas of the ink coating,in which:the digital laser means emits in the visible or infra-red region of the spectrum;the ink comprises a radiation absorbing compound;the radiation absorbing compound is a phthalocyanine pigment; andthe ink additionally comprises an infra-red absorbing dye.