Patent ID: 9126450
Filing Date: 2015-09-08
Classification: B41M,G03B,Y10T

Abstract:
1. A lithographic printing method comprising: exposing an imaging surface layer of a printing plate to a first light expose source to render the surface layer uniformly hydrophilic; wherein the surface layer comprises a polymer film including a compound having reversible light controlled wettability whereby the surface layer is reversibly hydrophilic and hydrophobic upon exposure to different wavelengths of light; wherein the surface layer is disposed over a portion of the printing plate imaging surface; or wherein the surface layer is disposed over substantially all of the printing plate imaging surface; exposing the surface layer to a second light expose source in an image-wise fashion to render image areas of the surface layer hydrophobic; exposing the surface layer to a polar liquid wherein the polar liquid attracts to non-image hydrophilic areas; exposing the surface layer to a hydrophobic liquid colorant wherein the hydrophobic liquid colorant attracts to hydrophobic image areas; contacting the surface layer with an offset receiving member to transfer the image to the offset receiving member; contacting the offset receiving member with an image receiving substrate to transfer the image thereto; optionally, fixing the image; and optionally, treating the surface layer to remove residual hydrophobic liquid colorant.