Patent ID: 9325025
Filing Date: 2016-04-26
CPC Classification: B01D,C08G,C08K,C08L,H01M,Y02E

Claim Text:
1. A proton-conducting polymer membrane based on polyoxazoles, obtained by a process comprising the steps of (i) mixing (a) one or more aromatic diamino dihydroxy compounds with (b) one or more aromatic carboxylic acids or esters thereof comprising at least two acid groups per carboxylic acid monomer, (ii) heating the mixture from step (i), to temperatures in the range from 120° C. up to 300° C. to form polybenzoxazole polymer, (iii) applying a layer using the mixture from step ii) to a support or to an electrode, (iv) at least partially hydrolyzing the polyphosphoric acid present in the layer from step (iii) by contacting with water and/or aqueous media, (v) detaching the self-supporting membrane formed from the support and wherein the membrane has a proton conductivity, measured at 160° C. and without additional moistening of the gases required, of at least 0.1 S/cm and the content of polyoxazoles is between 2 and 15% by weight and the content of phosphoric acid between 40 and 70% by weight, and the remaining amount is water.