METHOD FOR MAKING WATERLESS PLANOGRAPHIC LITHOGRAPHIC PRINTING PLATE

• Main Authors: ASANO MASAYA, TSUDA MIKIO, ABIKO SHIGEO
• Format: Patent
• Language: English
• Published: 07.09.1988
• Subjects: APPARATUS SPECIALLY ADAPTED THEREFOR; CINEMATOGRAPHY; ELECTROGRAPHY; HOLOGRAPHY; MATERIALS THEREFOR; ORIGINALS THEREFOR; PHOTOGRAPHY; PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES,e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTORDEVICES; PHYSICS

PURPOSE:To decolor a discolored part without degrading printing resistance by subjecting a waterless planographic printing plate formed by coating a photosensitive layer consisting of a material contg. quinone diazide structure as its constituting component and silicone rubber layer on a base to image exposure, then subjecting the plate to a base treatment simultaneously with or before or after development then processing the plate with a processing liquid contg. an org. acid. CONSTITUTION:For example, the ester of benzoquinone-1,2-diazide-4- or -5- sulphonic acid and polyhydroxyphenyl or the like is used as the quinone diazides. The silicone rubber layer essentially consisting of linear org. polysiloxane having the repeating unit such as the unit expressed by the formula I and having several thousands - several ten thousands mol.wt. is preferably used as the silicone rubber layer. In the formula, n: >=2 integer, R, R': an alkyl group of 1-10C, alkenyl group or phenyl group, >=60% of R, R' are preferably the methyl group. The printing plate is subjected to the basic treatment and the processing by the processing liquid contg. the org. acid after the image exposure or simultaneously therewith or before the image exposure.