| 摘要 |
PURPOSE:To improve developability by using a polyurethane resin having the constituting unit derived from a compd. obtd. by ring opening of tetracarboxylic dianhydride with a diol compd. CONSTITUTION:The polyurethane resin is the polyurethane resin having at least 1mol% constituting unit derived from the compd. obtd. by ring opening of the tetracarboxylic dianhydride with the diol compd. The preferable tetracarboxylic dianhydride is exemplified by pyromellitic dianhydride, etc., and the diol compd. to be used is exemplified by ethylene glycol, etc. The method of introducing the constituting unit derived from the compd. obtd. by ring opening of the tetracarboxylic dianhydride with the diol compd. into the polyurethane resin includes a method of bringing the compd. of the alcohol terminal obtd. by ring opening of the tetracarboxylic dianhydride and the diol compd. and a diisocyanate compd. into reaction, etc. The excellent developability to an aq. alkaline developing soln. is thereby obtd. and the planographic printing plate obtd. by using said compsn. has high printing resistance. |
