| 摘要 |
PURPOSE:To obtain the titled exchange membrane which retains excellent specific selective permeability for a long time, can be easily regenerated and does not decrease in current efficiency, by imparting selectivity to a specified anion exchange membrane by contacting it with a polymeric substance having cation exchange groups. CONSTITUTION:An anion exchange membrane is swollen by impregnating it with a liquid mixture of water and an organic substance which are soluble in water (solubility >=1,000ppm at the temperature of treatment), contains no cation and anion exchange group and has a MW <=500 (e.g., dimethylsulfoxide). The swollen ion exchange membrane is given selectivity by contacting it with the above liquid mixture in which 0.1-50g/l of a low-crosslinking degree, cation exchange group-containing polymeric substance having an exchange capacity >=0.5meq/g (dry) and a particle diameter <=100mu (e.g., ligninsulfonate) is dissolved or suspended.
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