| 摘要 |
PURPOSE:To improve developability with an aq. alkaline developing soln. and printing resistance by specifying the acid value of a polyurethane resin and the structural units to be provided thereto. CONSTITUTION:The acid value of the polyurethane resin is specified to a 0.4-2.0meq/g range and at least one kind of the structural unit selected from the structural units (group A) expressed by the formulas I, II and at least one kind of the structural unit selected from the structural units (group B) expressed by the formulas III-VI are respectively provided in combination to said resin. In the formula I, II, R<1> denotes a hydrogen atom or methyl group; R<2>, R<3> may be respectively the same or different and denote an alkyl group of <=4C; l, m, n respectively denote 2-8 integer. The ratio of the structural unit selected from the group A and the structural unit selected from the group B is preferably 0.1-10 molar ratio. The developability with the aq. alkaline developing soln. and printing resistance are thereby improved. |
