ASYMMETRISCHE GASTRENNMEMBRAN

摘要

A gas separating asymmetric membrane such as a gas separating asymmetric hollow fiber comprises an aromatic polyimide comprising recurring units of the formulae (I) and (II): (* CHEMICAL STRUCTURE *) (I) (* CHEMICAL STRUCTURE *) (II) wherein A1 is a tetravalent unit having a diphenylhexafluoropropane structure, A2 is a tetravalent unit having a benzene structure, and A3 is a divalent aromatic unit which is a unit derived from a sulfur atom-containing diamine such as diaminodibenzothiophene, diaminodiphenylenesulfone, diaminothioxanthene-5,5-dioxide or diaminothioxanthone-5,5-dioxide. The aromatic polyimide contains the recurring unit of the formula (I) in an amount of 40 to 90 molar % and the recurring unit of the formula (II) in an amount of 10 to 40 molar %. Further, a process for the preparation of the gas separating asymmetric hollow fiber membrane is also disclosed.