| 摘要 |
PURPOSE:To stably obtain an anisotropic hydrophilic membrane various permselectivities and separation properties in good efficiency, by sulfonating a laminate consisting of two or more kinds of ethylenic copolymers. CONSTITUTION:Two or more kinds of ethylenic copolymers different in sulfone group content are laminated. After the surface of this laminate is converted to a microporous membrane if necessary, it is sulfonated to obtain an anisotropic hydrophilic membrane having two or more cation exchange resin layers different in sulfone group content. This membrane has a layer containing at least 0.1 miliequvalent/g of a sulfone group and has electric resistance of 0.01-20OMEGA.cm<2> in alkali. This anisotropic hydrophilic membrane is excellent in heat resistance, solvent resistance and hydrophilicity and can be effectively used as a separation membrane of a water-org. compound solution mixture.
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