Patent ID: 8277605

Claim:
A thermosetting solution composition comprising a biphenyltetracarboxylic acid compound containing at least 15 mol % of a partial lower aliphatic alkyl ester of 2,3,3′,4′-biphenyltetracarboxylic acid and/or a partial lower aliphatic alkyl ester of 2,2′,3,3′-biphenyltetracarboxylic acid, an aromatic diamine compound in a molar amount larger than a molar amount of the biphenyltetracarboxylic acid compound, said aromatic diamine compound being selected from the group consisting of p-phenylenediamine, m-phenylenediamine, 1,3-bis(4-aminophenoxy)benzene and a mixture thereof, and a partial lower aliphatic alkyl ester of 4-(2-phenylethynyl)phthalic acid compound in a molar amount as much as 1.8-2.2 times a molar amount corresponding to a difference between the molar amount of the aromatic diamine compound and the molar amount of the biphenyltetracarboxylic acid compound dissolved in an organic solvent consisting of methanol, ethanol, or a mixture of methanol and ethanol.