| 摘要 |
PURPOSE:To enhance inking characteristics (lipophilicness), solvent resistance, and printing resistance, and to enable development using an aqueous alkaline solution containing no organic solvent by incorporating a specified alkali-soluble copolymer and a diazo resin. CONSTITUTION:The alkali-soluble copolymer to be used is represented by formula in which R is H, methyl, or ethyl; each of R1-R4 is H or methyl: R5 is 1-12 C alkyl; and r is an integer of 1-6. This alkali-soluble copolymer is photocurable only by adding the diazo resin as the photosensitive agent, but since the copolymer has unsaturated double bonds on the terminals, it is allowed to copolymerize with an additionally copolymerizable compound by adding this compound and a photopolymerization initiator, resulting in forming a stronger and tougher resin. When this resin is applied to a planographic printing plate as a photosensitive composition, the inking characteristics and resistances to solvents and abrasion are enhanced and a printing plate high in printing resistance can be obtained even in the case of using a UV ink. |
