| abstract |
An ion conductive binder that is economical, environmentally friendly, excellent in moldability and oxidation stability, and uses thereof. Ion conductivity used for a membrane-electrode assembly for a polymer electrolyte fuel cell, comprising a polymer electrolyte membrane and two gas diffusion electrodes joined to the electrolyte membrane with the membrane sandwiched therebetween. A block copolymer comprising a polymer block (A) and a flexible polymer block (B), which is a binder, the main repeating unit of which is an aromatic vinyl compound whose α-carbon is a quaternary carbon. And the polymer block (A) has a monovalent anion conductive group, or the polyvalent anion conductive group is bonded in a form of cross-linking the polymer blocks (A), and And / or a solution or suspension of the ion-conductive binder in which a polyvalent anion-conducting group is bonded in a form of cross-linking aromatic vinyl compound units in the polymer block (A), and a membrane Electrode assembly and a polymer electrolyte fuel cell. |