| 摘要 |
PROBLEM TO BE SOLVED: To obtain a solution of aromatic polyamic acid, controlled in property deterioration resulting from hydrolysis, convertible into the corresponding imide virtually completely, notably high in mechanical stability and resistance to heat, and useful for the production of aromatic polyimide. SOLUTION: This solution is obtained by dissolving a polyamic acid, as a product of polymerization of 3,4,3',4'-biphenyltetracarboxylic acid dihydrate with p-phenylenediamine, in a mixed solution of an organic polar solvent and imidazole or benzimidazole which optionally has a substituent at 0.02 to 0.5 equivalents per equivalent of the amic acid unit of the polyamic acid. |
