Process for electrochemically roughening a surface of a metal web
AssigneeFuji Photo Film Co., Ltd.
InventorsAtsushi Matsuura, Akio Uesugi
Life of this patent
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Abstract
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.
Claims6
A process for roughening a surface of a metal web, comprising the steps of:
- alternating applying, from one terminal of a power source, a positive current and a negative current to a plurality of electrodes, each of said electrodes being spaced apart from adjacent electrodes by a pause section;
- subjecting the metal web to electrochemical processing in an electrolyte by an electric current formed between the metal web and the plurality of electrodes facing the metal web;
- and
- pausing the electrochemical processing at the pause section between two of said electrodes for 1 to 30 seconds.
Dependencies are inferred from the claim text.