| 摘要 |
1523047 Cation exchange membranes for brine electrolysis cells ASAHI KASEI KOGYO KK 2 July 1976 [9 July 1975(2) 31 March 1976] 27654/76 Heading C7B [Also in Divisions B5 and C3] Electrolytic cells, especially for brine, have the anode and cathode compartments separated by a cation exchange membrane comprising a fluorocarbon polymer containing pendant carboxylic groups of formula -OCF2COOM, where M is hydrogen, ammonium, quaternary ammonium or metal. The said groups are obtained by reduction of -OCF 2 CF 2 SO 3 X groups (see Division C3), and the membrane may contain residual groups of this type. Preferred membranes contain -OCF 2 COOM groups on one surface, which faces the cathode, and -OCF 2 CF 2 SO 3 M groups on the opposite surface. The membrane may be formed from a single film, or may be a composite of two polymeric films, and in either case it may further include a reinforcing layer, e.g. a fabric formed from PTFE fibres. The 27 specific examples describe a variety of such membranes and their application in the electrolysis of brine, the starting copolymers being of tetrafluoroethylene and perfluoro (3, 6-dioxa- 4-methyl-7-octene sulphonyl fluoride, in some cases with a further monomer which is hexafluoropropene, perfluoropropyl vinyl ether or perfluoro- 3, 6-dioxa-5-methyl-nonene-1. |
