PERVAPORATION SEPARATION MEMBRANE

PURPOSE:To obtain a separation membrane excellent in mechanical strength, high in selectivity, furthemore having a high amt. of permeation soln. and suitable for a pervaporation method by laying a thin film having anion exchange groups on the surface of a cation exchange film. CONSTITUTION:As a cation exchange film, the one in which cation exchange groups such as sulfonic groups and carboxylic groups are bonded to a supporter film, particularly a acid-type cation exchange film is used. Then, a thin film having anion exchange groups such as a primary amine and a quaternary ammonium base is formed on at least either surface of the above cation exchange film. The composite ion exchange film obtd. in the above mentioned manner is excellent in mechanical strength, having a high amt. of permeation soln. and separation factor and suitable for a pervaporation method.