| abstract |
The polyamic acid according to the present invention, which is produced by a polyaddition reaction between a diamine and tetracarboxylic dianhydrides, contains 2,2'-bistrifluoromethylbenzidine as a diamine component and 3,3',4,4'-biphenyltetracarboxylic dianhydride and 9,9'-(3,4'-dicarboxyphenyl)fluorenic dianhydride as tetracarboxylic dianhydride components. Preferably, the amount of 9,9'-(3,4'-dicarboxyphenyl)fluorenic dianhydride is 0.5-10 mol% inclusive relative to the total amount of the tetracarboxylic anhydrides. |