Patent ID: 6802258
Filing Date: 2004-10-12
Classification: B41C

Abstract:
Direct-to-plate method of lithographic printing with a reusable substrate having a hydrophilic surface comprising the steps of:(a) making a negative-working imaging layer by coating on the hydrophilic surface a solution comprising hydrophobic thermoplastic particles; (b) making a printing master having ink-accepting areas by image-wise exposing the imaging layer to heat or light; (c) applying ink and fountain solution to the printing master; (d) removing the ink-accepting areas from the printing master by supplying a cleaning liquid to the imaging layer thereby obtaining a recycled substrate, wherein the cleaning liquid comprises an aqueous emulsion of an alcohol and a cyclic compound having at least one double bond, and (e) treating the recycled substrate by supplying a refreshing liquid consisting of an aqueous solution having a pH<7.