| 摘要 |
PURPOSE:To eliminate the generation of scumming in an image part and to obtain a lithographic printing plate having a high sensitization characteristic and printing resistance by coating an aq. soln. contg. a specific compd. on said plate prior to a burning process and using such plate. CONSTITUTION:The aq. soln. contg. at least one kind of compd. selected from the group consisting of sulfonic acid expressed by the formula I and the salt thereof is used as the processing liquid to be coated on the lithographic printing plate prior to the burning process. In the formula, A, B denote an alkyl group of 1-18C, alkenyl group of 1-18C, alkenyl group of unsubstitution or 1-18C, alkoxy group of 1-18C, arom. or aliphat. ring substd. by a halogens group, amino group or a hydroxyl group, X denotes a bivalent atom or group selected from S, CO, NH, SO, SO2, alkylene and substd. alkylene, Z1, Z2 denote hydrogen or -SO3M, M denotes a hydrogen, alkali metal, aluminum or amine. The scumming is thereby obviated and the lithographic printing plate having the excellent sensitization characteristic in the image part is thus obtd. |
