Patent ID: 8765830

Claim:
A polyimide foam made of an aromatic polyimide having a repeating unit represented by chemical formula (1) shown below: wherein, 40 to 70% by mole of A in the chemical formula (1) is a tetravalent unit based on a biphenyltetracarboxylic acid structure represented by chemical formula (2) shown below, and 60 to 30% by mole of A is a combination of a tetravalent unit based on a benzophenone tetracarboxylic acid structure represented by chemical formula (3) shown below and a tetravalent unit based on a biphenyltetracarboxylic acid structure represented by chemical formula (4) shown below: and 50 to 97% by mole of B in the chemical formula (1) is a divalent unit based on a m-phenylene structure represented by chemical formula (5) shown below, and 50 to 3% by mole of B is a divalent unit based on a diphenylmethane structure represented by chemical formula (6) shown below: