Patent ID: 7557164

Claim:
A melt extruded membrane consisting essentially of a melt blended mixture of (a) about 70 to about 95 wt % fluorinated ionomer in acid or salt form or precursor thereof and (b) about 30 to about 5 wt % of two melt-processible crystalline fluoropolymers that are substantially free of ion-exchange groups, and that differ from each other in melting point by at least about 5° C., wherein the first of said two other fluoropolymers that are substantially free of ion-exchange groups has a melting point within about 10° C. of the melting point of the fluorinated ionomer, and the second of said two other fluoropolymers that are substantially free of ion-exchange groups has a melting point at least about 15° C. higher than the melting point of the fluorinated ionomer.