Patent ID: 7399507

Claim:
A method of preparing a lithographic printing plate suitable for use with inkjet printers as image forming devices, said inkjet printers using a pigment based ink, said method comprising the steps of: a) selecting a substrate which is a synthetic polymeric sheet having a tensile strength of 400 to 3000 kg/cm 2 and a thickness of 75 to 250 microns; b) shrinking said substrate to have shrinkage in the range of 0.2 to 2.0% by exposing the substrate to temperatures ranging from 140 to 180° C. for 8 to 12 minutes; c) treating the surface to alter the surface energy of the substrate, and d) forming at least one layer of a hydrophilic lithographic coating obtained by reacting a hydrophilic binder, a cross linking agent, a catalyst, an accelerator, at least one pigment, at least one nonionic surfactant and particulate silica having particle size between 1 to 5 microns and pore volume between 0.2 to 1.8 ml/gm, wherein the ratio of catalyst to accelerator is 1:1, ratio of catalyst to cross linking agent is 8:15, ratio of catalyst to hydrophilic binder is 8:300, ratio of catalyst to pigment is 8:770, ratio of catalyst to surfactant is 8:5 and ratio of catalyst to particulate silica is 8:260.