Patent ID: 7300744
Filing Date: 2007-11-27
Classification: G03F,Y10S

Abstract:
1. A method of processing a light sensitive planographic printing plate material comprising an aluminum support, and provided thereon, a photopolymerizable light sensitive layer containing a polymerizable ethylenically unsaturated compound, a photopolymerization initiator, and a polymer binder, the method comprising: imagewise exposing the light sensitive planographic printing plate material; developing the exposed light sensitive planographic printing plate material with a developer to obtain a planographic printing plate, the developer containing no silicate or containing a silicate in amount of not more than 0.1% by weight in terms of SiO plate processing the resulting planographic printing plate with a plate protecting solution containing two or more phosphonic acid compounds having different molecular weights at a temperature of from 40 to 90° C., wherein the two or more phosphonic acid compounds are selected from a group consisting of a polyvinyl phosphonic acid, a phospnonic acid-modified starch in which a hydroxyl group in a glucose unit of the starch is reacted with phosphonic acid or its derivative to form an ester, and mixtures thereof.