Patent ID: 7745030
Filing Date: 2010-06-29
Classification: B01D,C08G,C08J,H01M,Y02E,Y02P

Abstract:
1. A proton-conducting polymer membrane which comprises polyazoles containing sulfonic acid groups and is obtainable by a process comprising the steps: A) mixing one or more aromatic or heteroaromatic tetraamino compounds with one or more aromatic or heteroaromatic carboxylic compounds in polyphosphoric acid to form a solution or dispersion, wherein the carboxylic compounds contain at least two carboxylic groups selected from acids, esters, acid halides or acid anhydrides, with at least part of the tetraamino compounds or the carboxylic compounds comprising at least one sulfonic acid group; or mixing one or more aromatic or heteroaromatic diaminocarboxylic compounds in polyphosphoric acid to form a solution or dispersion, wherein the diaminocarboxylic compounds contain a carboxylic group selected from acids and esters, wherein at least a part of said diaminocarboxylic compounds comprises sulfonic acid groups; B) heating the solution or dispersion obtained according to step A) under inert gas to temperatures of up to 325° C. to form polyazole polymers; and C) applying a layer using the mixture from step B) to a support, thus forming a membrane on the support; or D) applying the solution or dispersion from step A) to a support, thus forming a membrane on the support; and E) heating the membrane formed in step D) under inert gas to temperatures of up to 325° C. to form polyazole polymers; and F) partially hydrolyzing the polyphosphoric acid moieties of the membrane from step C) or step E) until the membrane is self-supporting, wherein the concentration of phosphoric acid in the membrane of step (F) is from 10 to 80 mols of phosphoric acid per mol of a repeating unit of the polyazole polymer.