SEPARATING MEMBRANE FOR FUEL CELL

摘要

This invention provides a separating membrane for a fuel cell in which a polymer having a weight average molecular weight of 5,000 to 1,000,000 is adhered at a coverage of 0.0001 to 0.5 mg/cm² on at least one surface of a solid polymer electrolyte membrane formed of a crosslinking-type ion exchange resin, the polymer contains a charge group having polarity opposite to the ion exchange group contained in the ion exchange resin. Preferably, the polymer is adhered so that, when the separating membrane for a fuel cell is immersed in a 50 mass% aqueous methanol solution of 30°C, there is substantially no difference in coverage of the polymer before and after the immersion. There is also provided a separating membrane-electrode joined product for a fuel cell comprising the above separating membrane for a fuel cell and a catalyst electrode layer joined to the separating membrane, the catalyst electrode layer comprising an ion exchange resin, having the same polarity as the crosslinking-type ion exchange resin constituting the above solid polymer electrolyte membrane, and a catalyst material.