Process for electrochemically roughening a surface of a metal web

摘要

A process for roughening a surface of a support for a lithographic printing plate in which an electric current is supplied between a metal web and an electrode facing the metal web in an electrolyte containing metal ions so that the metal web is subjected to electrochemical processing continuously, 1-20 pause sections are provided in the electrochemical processing and the time taken for passage through once processing pause section in the electrochemical processing is set to 1-30 seconds. With the process, the grain shape can be controlled with no troublesome condition setting to improve a scumming resistance without deteriorating a printing durability and a fill-in reduction so that the plate has superior performance.