METHOD FOR MANUFACTURING POLYMERIC ELECTROLYTE MEMBRANE

摘要

[Object] To provide a method for producing a polymer electrolyte membrane in which irregularity in thickness, wrinkles and unevenness hardly occur. [Constitution] A method for producing a polymer electrolyte membrane including (A) a membrane formation step of forming a membrane-form product of an ionic group-containing polymer electrolyte on a support, (B) an acid treatment step of exchanging the ionic group into an acid type by bringing the membrane into contact with an inorganic acid-containing acidic liquid, (C) an acid removal step of removing a free acid in the acid-treated membrane, and (D) a drying step of drying the acid-removed membrane, wherein the steps (B) to (D) are carried out without separating the membrane from the support. Preferably, the membrane formation step (A) includes (A 1 ) a casting step of casting a solvent solution of an ionic group-containing polymer electrolyte on a support to form a cast membrane, (A 2 ) a drying step of drying the cast membrane, and (A 3 ) a solvent-removing step of removing a solvent in the dried membrane with a liquid that is miscible with the solvent of the ionic group-containing polymer electrolyte.