FORMATION OF DAMPENING WATER FREE PLANOGRAPHIC PRINTING PLATE

摘要

PROBLEM TO BE SOLVED: To enable laser recording and to satisfy the removing capacity and printability of the ink repelling layer of an exposure part by providing a first rubbing process for removing a part of the ink repelling layer and a second rubbing process for rubbing the surface of the ink repelling layer by using a liquid. SOLUTION: A support being an ink receiving part is exposed by utilizing the lowering of the close adhesiveness between the support and ink repelling layer of a laser exposure part to selectively remove the ink repelling layer of the laser exposure part to form a waterless flat plate. The removal of the ink repelling layer of the laser exposure part is achieved by two processes, that is, a first rubbing process for rubbing the ink repelling layer without using a liquid and a second rubbing process for rubbing the ink repelling layer by using the liquid. The second rubbing process can be performed by a known method wherein a plate surface is rubbed with a developing pad containing a liquid or a liquid is poured on the plate surface to rub the same with a brush. The temp. of a liquid to be used is arbitrary but pref. 10-50 deg.C.