| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a solution forming a colorless transparent polyimide coat by reacting an aromatic tetracarboxylic acid dianhydride with a p-substituted aromatic diamine in a polar solvent. SOLUTION: A polyamide acid solution is obtained by reacting an aromatic tetracarboxylic acid dianhydride (A) represented by formula I with a p- substituted aromatic diamine (B) represented by formula II or III in a molar ratio of component A/component B of 0.9-1.1/1.0 at not less than 80 deg.C in a polar solvent such as dimethylacetamide. The polyamide acid solution adjusted to a concentration of 10-30 wt.% is cast on a base, than after heat drying, a film is obtained by imidation at 200-250 deg.C. Component A includes 2,2-bis(3,4'- dicarboxyphenyl)hexafluoropropane dianhydride, or the like, and component B includes bis(4-aminophenyl)sulfone, or the like. In the formulae, X is -O-, CH2, or the like; and Y is O, SO2, CF2, CO, a direct bond, or the like.</p> |
