Patent ID: 7785726

Claim:
A process for producing a hybrid ion-exchange membrane comprising functional inorganics and a graft polymer, the process comprising: adding at least one inorganic fine powder selected from the group consisting of fine particulate amorphous silica (SiO 2 ), H + form mordenite ((Ca, Na 2 , K 2 )Al 2 Si 10 O 24 .7H 2 O), alumina (Al 2 O 3 ), and zirconium oxide (ZrO 2 ) to an ethylene-tetrafluoroethylene copolymer as a thermoplastic polymer in an amount ranging from 1 wt % to 20 wt % of the polymer, mixing the ingredients uniformly, shaping the mixture to form a functional inorganics/polymer membrane, exposing the functional inorganics/polymer membrane to an ionizing radiation for a total dose ranging from 10 kGy to 1 MGy, then bringing the membrane into contact with the oxygen-free polymerizable monomer styrene so that the styrene is grafted to the functional inorganics/polymer membrane to prepare a functional inorganics/graft polymer membrane, and reacting the functional inorganics/graft polymer membrane with chlorosulfonic acid to introduce sulfonic acid groups into the phenyl groups in the graft chains.