| 摘要 |
PURPOSE:To carry out electrolysis of alkali chlorides at a high current efficiency, by disposing a film of a fluorocarbon copolymer with a specified ion exchange capacity to face a cathode side, and a film that has been obtained by converting the exchange groups into specified substituents to face an anode side. CONSTITUTION:Substituents -O(CF2)nI derived from ion exchange groups (a) -O(CF2)nCOOM present in the film of a fluorocarbon copolymer having an ion exchange capacity of 1.1-2.0mg equivalent/g of dried resin are converted to ion exchange groups (b) -O(CF2)nSO3M. The ratio of the thicknesses of the layers with the side chains (a) and (b) is[the layer having the structure (b)]/[the layer having the structure (a)]+[the layer having the structure (b)]=0.2-0.9. Use is made of these two fluorocarbon cation-exchange mebranes with the layer having the structure (b) at an anode side. M in the exchange group is H, an alkali metal or an ammonium group, and n=2-5. |
