Patent ID: 7736779

Claim:
A proton-conducting polymer membrane which comprises polyazole blend and is obtained by a process (1) or (2) wherein process (1) comprises the steps A1) preparation of a mixture comprising polyphosphoric acid, at least one polyazole (polymer A) and/or one or more compounds which are suitable for forming polyazoles under the action of heat according to step B1), B1) heating of the mixture obtained according to step A1) under inert gas to temperatures of up to 400° C., C1) application of a layer using the mixture step B1) to a support to form a sheet-like structure, D1) treating said sheet-like structure formed in step C1) with hydrolysis until it is self-supporting, or wherein process (2) comprises the steps A2) preparing a mixture comprising polyphosphoric acid, at least one polyazole (polymer A) and/or one or more compounds which are suitable for forming polyazoles under the action of heat according to step C2), B2) applying a layer using the mixture from step A2) to a support to form a sheet-like structure, C2) heating of the sheet-like material obtained according to step B2) under inert gas to temperatures of up to 400° C., D2) treating the sheet-like structure in step C2) with hydrolysis until it is self-supporting, wherein at least one further polymer (polymer B) which is not a polyazole is added to the composition obtained according to step A1) or A2) and the weight ratio of polyazole to polymer B is in the range from 0.1 to 50.