Patent ID: 7981566

Claim:
A membrane electrode assembly for a polymer electrolyte fuel cell, comprising: a pair of electrodes comprising a catalyst; and a polymer electrolyte membrane disposed between the electrodes, the polymer electrolyte membrane comprising: a polymer segment A having an ion conductive component; and a polymer segment B not having an ion conductive component, wherein the polymer segment A is a repeated constitutional unit shown in Chemical Formula 1 and the polymer segment B is a repeated constitutional unit shown in Chemical Formula 2; wherein A is a bivalent electron attracting group, B is a bivalent electron donating group or a covalent bonding, Ar is an aromatic group having a substituent shown as —SO 3 H, m is an integer from 0 to 10, n is an integer from 0 to 10, and k is an integer from 1 to 4; wherein groups from R 1 to R 8 are the same or different, the groups are at least one kind of atom or group selected from hydrogen atom, fluorine atom, alkyl group, fluorine substituted alkyl group, allyl group, aryl group, or nitrile group, W is a bivalent electron attracting group or single bond, T is a single bond or bivalent organic group, and p is 0 or a positive integer, wherein a water absorption efficiency (an amount of water absorbed in the polymer electrolyte membrane that has been immersed in water at 90° C. for 30 minutes) is in a range from 0.02 to 1.13 g per 1 g of the polymer electrolyte membrane at a thawing temperature of from −30 to 0° C., and wherein 1-methoxy-2-propanol and γ-butyrolactone are used as a solvent during production of the polymer electrolyte membrane.