| 摘要 |
PURPOSE:To obtain a cation exchange membrane which is durable and highly preventive against anion permeability by a method wherein a membrane having exchangeable gp. whose acidity is weaker than sulfonic gp. is partially substituted with carboxyl gp, then swelled and heat-treated. CONSTITUTION:A cation exchange membrane A having as cation exchange gp. at least one of exchangeable gp. such as carboxylic acid whose acidity is weaker than that of sulfonic gp. and phosphoric acid is impregnated with carboxyl gp. or a diene derivative, etc. and partially polymerized. Then, the membrane is swelled with organic solvent such as ethylene glycol and glycerol, and heat-treated. When diene derivative has been used, the membrane is transformed into carboxylic acid by hydrolysis. The so obtained cation exchange membrane B is excellent as electrolytic diaphragm, providing durability and property to prevent anions including durability and property to prevent anions including hydroxyl ions from passing through the membrane. |
