Patent ID: 10022716

Abstract:
To provide a simple method whereby an ionic polymer membrane having a high ion exchange capacity and a low water uptake can be produced by converting a —SO2F group in a polymer to a pendant group having multiple ion exchange groups, while preventing a cross-linking reaction.At the time of obtaining an ionic polymer membrane by converting —SO2F (group (1)) in a polymer sequentially to —SO2NZ1Z2 (group (2)), —SO2N−(Mα+)SO2(CF2)2SO2F (group (3)), —SO2N−(H+)SO2(CF2)2SO2F (group (4)) and —SO2N−(Mβ+)SO2(CF2)2SO3−Mβ+ (group (5)), the polymer is formed into a polymer membrane in the state of any one of the groups (1) to (4), and the polymer membrane is thermally treated in the state of group (4). Here, Z1 and Z2 are hydrogen atoms, etc., Mα+ is a monovalent cation, and Mβ+ is a hydrogen ion or a monovalent cation.