| 摘要 |
PURPOSE:To obtain a bipolar film, by covering one side of a high polymer film having a functional group capable of introducing ion exchange groups with a layer, by sulfonating the other side of the film to introduce a cation, followed by releasing the covering layer to produce the untreated side, to which an anion is introduced. CONSTITUTION:A covering layer is placed on one side of a high polymer film having a functional group suitable to introduce ion exchange groups to make a composite so that the surface is inactive in sulfonation. The other side of the film is sulfonated so that a cation exchange group is introduced. The covering layer is separated and an anion exchange group is introduced into the released surface. Polypropylene, etc., capable of not being corroded by a sulfonating liquid, may be used as the covering layer. Sulfonating reaction, done by sulfuric acid, etc., forms a layer made of sulfonic group to a thickness of 1/10-9/10 of the cross-sectional area of the film on the one side of the film. The introduction of the anion exchange group can be carried out by any conventional method. |
