CATION EXCHANGE MEMBRANE AND PROCESS FOR PRODUCING THE SAME

摘要

A cation exchange membrane having a fluorovinyl sulfonic acid monomer represented by the following formulae: (1) < IMG > or (2) < IMG > or (3) < IMG > (4) < IMG > (wherein R2 is fluorine or a perfluoroalkyl group having 1 to 5 carbon atoms, R3 is fluorine or CH3, R4 is fluorine or a perfluroalkyl group having 1 to 10 carbon atoms; R5 is fluorine or CH3 and R6 is fluorine or a perfluoroalkyl group having 1 to 10 carbon atoms; n is 2, ? is an integer of 1 to 3 and k is an integer of 1 to 3; Z is fluorine, hydroxyl group, NH2, ONH4 or OM, M being an alkali metal) grafted onto a high-molecular substrate film comprising a monomer of the formula: < IMG > (wherein X is hydrogen, fluorine or CH3 , and Y is hydrogen or fluorine) as a monomer unit and the process for preparing the same are disclosed. In producing the membrane the substrate olefinic polymer film is exposed to ionizing radiation and then brought into contact with a solution of fluorovinyl sulfonic acid monomer.