SEPARATION MEMBRANE FOR ORGANIC LIQUID MIXTURE, ITS PRODUCTION METHOD, SEPARATION METHOD USING THE SAME SEPARATION MEMBRANE AND DEVICE THEREFOR

PROBLEM TO BE SOLVED: To provide a technique for membrane separation of an organic liquid mixture which is applicable to industrial use and has excellent efficiency. SOLUTION: This separation membrane is used in a membrane separation method in which the organic liquid mixture is fed to one side of the membrane and a part of the components in the organic liquid mixture is separated from the other side in a gas phase. The separation membrane of organic liquid mixture consists of a porous support membrane and sulfonic acid group-containing polyimide having silver ions as pair ions, and the membrane separation method uses this separation membrane for separating the organic liquid mixture.