Patent ID: 11031618

Abstract:
To provide a polymer capable of forming a polymer electrolyte membrane that is resistant to breakage even when being repeatedly subjected to humidification and drying or a catalyst layer that is resistant to formation of cracks; a polymer electrolyte membrane employing said polymer; and a membrane/electrode assembly for a polymer electrolyte fuel cell. A polymer comprising units (u1) having two ion-exchange groups and units (u2) of e.g. a perfluoro(alkyl vinyl ether), wherein the molar ratio (u2)/((u1)+(u2)) is more than 0.30 and at most 0.70. A membrane/electrode assembly 10 comprising an anode 13 having a catalyst layer 11 and a gas diffusion layer 12, a cathode 14 having a catalyst layer 11 and a gas diffusion layer 12, and a polymer electrolyte membrane 15 disposed between the anode 13 and the cathode 14 in a state of being contact with the catalyst layers 11, wherein either one or each of the catalyst layers 11 and the polymer electrolyte membrane 15 contains the aforementioned polymer.