Patent ID: 7279244

Claim:
A process for producing an electrode assembly having an electrode catalyst formed therein which comprises a step of applying a coating of electrode paste for a fuel cell on a principal plane of a polymer electrolyte membrane of polyarylene type wherein sulfonic acid groups are bonded to aromatic rings via alkylene ether linkages, followed by drying, wherein: the electrode paste comprises carbon particles carrying a metal catalyst dispersed in a solution for electrode catalyst coating, the solution comprises an ion exchange resin dissolved in a solvent, and said ion exchange resin comprises an arylene copolymer having at least two repeating structural units represented by the following formulas (I), (II) and (III): wherein Ar is at least one of the following linked structures represented by the following formulas (IV), (V) and (VI): R 1 -R 6 are each a group independently selected from the group of alkyl groups having 1-6 carbon atoms, and Z is hydrogen or the methyl group.