Method of recovering characteristics of deteriorated cation exchange membrane

摘要

Characteristics of a cation exchange membrane used for an electrolysis of an alkali metal chloride are recovered by immersing the perfluorocarbon type cation exchange membrane in an organic solvent having a water miscibility and a boiling point of higher than 120° C. in 760 mmHg; holding the immersed membrane between a pair of smooth plates and heating at 40° C. to 180° C.; treating the heat- treated membrane in hydrochloric acid and then, immersing it in an aqueous solution of sodium hydroxide and the organic solvent is preferably ethyleneglycol, propyleneglycol, isopropyleneglycol butanediol, pentanediol, hexanediol, glycerin or polyethyleneglycol.