DEVELOPMENT ON PRESS OF LITHOGRAPHIC PRINTING PLATE THAT HAS ALLYLDIAZOSULFONATE RESIN ON PHOTOSENSITIVE LAYER

摘要

PROBLEM TO BE SOLVED: To obtain a printing plate imparting excellent printing properties such as printing durability, the ink receptivity of an image region or the ink repellency of a non-image region by a simple and environmentally friendly method. SOLUTION: An image forming element obtained by providing a photosensitive layer containing a photosensitive polymer containing an aryldiazosulfonate unit on the hydrophilic surface of a planographic plate base is imagewise exposed. The imagewise exposed image forming element is attached to the printing cylinder of a printing press and an aq. damping liquid and/or ink is supplied to the photosensitive layer while the printing cylinder is rotated to develop the photosensitive layer. The printing plate produced by this method is used to obtain an excellent printing result. The planographic plate base can be constituted of anodic oxidized aluminum or a support provided with an ink repelling layer containing a crosslinked hydrophilic binder.