Solvent-resistant asymmetric hollow fiber gas separation membrane, and method for production thereof

Abstract

An asymmetric hollow fiber gas separation membrane obtained by subjecting an asymmetric hollow fiber polyimide membrane to a heat treatment having a maximum temperature of from 350 to 450° C., wherein the asymmetric hollow fiber polyimide membrane is formed with a polyimide essentially having a repeating unit represented by a general formula (1); is excellent in a solvent resistance and a thermal stability, and as well has such a mechanical strength that a tensile elongation at break is not less than 10% as a hollow fiber membrane. In the general formula (1), 20 to 80 mol % of A is a tetravalent unit based on a biphenyl structure represented by formula (2), 20 to 80 mol % of A is a tetravalent unit based on a diphenylhexafluoropropane structure represented by formula (3), and 0 to 30 mol % of A is a tetravalent unit based on a phenyl structure represented by formula (4); and in the general formula (1), 30 to 70 mol % of R is a divalent unit represented by formula (5) and/or formula (6), and 30 to 70 mol % of R is a divalent unit having one or two other aromatic rings than formula (5) or (6),