Composite membrane
 A composite membrane excelling in organic solvent resistance, heat resistance and organic vapor resistance is disclosed. The composite membrane of the present invention comprises a porous membrane including as a major constituent a polymer having a repeating unit represented by the formula (I) EQU --Ph--S--Ph--SO.sub.2).sub.n (I) (wherein Ph represents phenyl group, n represents a natural number) and an active layer formed on said porous membrane. The composite membrane of the present invention may be used as a composite membrane for pervaporation, gas separation membrane and as a reverse osmosis membrane. 
Toray Industries, Inc.
B B B
B01D B01D B01D
inventional inventional inventional
Masaru Shinichi Tadahiro Yoshio Tetsuo Kuniyasu
Kurihara Yamada Uemura Himeshima Watanabe Shiro