Patent ID: 8133927
Filing Date: 2012-03-13
Classification: B01D,C08J

Abstract:
1. A composite ionomeric membrane comprising a layer or film of a porous inert material on which a sulphonic fluorinated ionomer is deposited, the sulphonic fluorinated ionomer comprising side chains of formula: —O—CF wherein the sulphonic fluorinated ionomer has an equivalent weight from 380 to 1,700 g/eq, wherein said composite ionomeric membrane, after drying at 105° C. under vacuum for one hour and subsequent dipping in demineralized water at 100° C. for 30 minutes, has size variations lower than 25% in both the orthogonal directions of the xy plane, and wherein the composite ionomeric membrane is prepared by a process comprising the following steps: 1) preparing a liquid dispersion comprising a fluorinated ionomer in acid or salified form; 2) depositing the dispersion on a surface of a porous inert material and removing excess dispersion to obtain a film or layer of impregnated porous inert material; 3) applying a non-porous support that is inert under the process conditions to one side of the film or layer of impregnated porous inert material; 4) annealing the film or layer of impregnated porous inert material and applied to the non-porous support at temperatures from 130° to 280° C.; and 5) detaching the film or layer of impregnated porous inert material from the non-porous support.