Patent ID: 6455229
Filing Date: 2002-09-24
Classification: B41C,B41N,Y10S

Abstract:
A method for the preparation of a lithographic printing plate comprisingexposing with IR light an imaging element comprising on a lithographic base with a hydrophilic surface a first layer including a polymer, soluble in an aqueous alkaline solution and a top layer on the same side of the lithographic base as the first layer which top layer is IR-sensitive and unpenetrable for or insoluble in an alkaline developer wherein said first layer and said top layer may be one and the same layer, said imaging element comprising a polysiloxane surfactant but not comprising a quinone diazide or a diazo compound; developing said exposed imaging element with an alkaline solution; gumming said developed imaging element with a baking gum solution; subjecting said gummed imaging element to a thermal treatment at a temperature above 50Â° C.; wherein said baking gum solution contains at least one surfactant making the contact angle between the baking gum solution and the surface of the plate less than 68Â° and/or at least one viscosity-regulating polymer making the viscosity of the baking gum solution between 1.7 cP and 5.0 cP.