| 摘要 |
1485708 Cation exchange membranes DIAMOND SHAMROCK CORP 15 Oct 1975 [16 Oct 1974] 42310/75 Heading C3P [Also in Divisions B5 and C7] Cation exchange membranes for use in an electrolytic cell are obtained by surface treatment of a membrane comprising a fluorine-containing polymer having pendant sulphonyl groups with an ethylene diamine to convert the sulphonyl groups to a depth of 5-75 microns to the form on one side only, the remaining sulphonyl groups being converted to -SO 3 R where R is H, Na or K and R<SP>1</SP> is R or -SO 2 -. The membrane is preferably formed from a copolymer of tetrafluoroethylene and CF 2 = CFYfSO 2 F where Yf is a bivalent C 2 -C 8 perfluorinated radical. After treatment on one side with ethylene diamine, the membrane is further treated with alkali metal hydroxide to hydrolyse other -SO 2 F groups to -SO 3 R. The membrane is used in the electrolysis of brine with the treated surface facing the cathode.
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