COMPOSITE ELECTROLYTIC MEMBRANE, CATALYTIC LAYER MEMBRANE ASSEMBLY, MEMBRANE ELECTRODE ASSEMBLY AND POLYMER ELECTROYTIC FUEL CELL

摘要

A polymer electrolytic membrane exhibiting excellent dimensional stability and mechanical strength in which the dimensions are not varied by the water containing state, positional shift and creasing are prevented when a polymer electrolytic fuel cell is manufactured, and breakage is prevented when the polymer electrolytic fuel cell is manufactured and operated. In a composite electrolytic membrane comprising a porous reinforcing layer composed of resin, and an electrolytic layer formed of polymer electrolyte and laid on at least one major surface of the reinforcing layer, the direction of giving a high modulus of tensile elasticity in the reinforcing layer is substantially matched to the direction of giving a high dimensional variation rate in the electrolytic layer.