| 摘要 |
PURPOSE:To increase barrier performance to active material penetration by graft-copolymerizing a plastic film with vinyl acetate, and saponifying vinyl acetate polymer used as a branch polymer to form a separator. CONSTITUTION:Graft-copolymerization of a plastic film and vinyl acetate is carried out in such a way that, for example, the plastic film is brought into contact with vinyl acetate and activating ray such as radioactive rays are irradiated to them. The saponification of vinyl acetate polymer graft- copolymerized to the plastic film is carried out, for example, by immersing the graft-copolymer in a solution of sodium hydroxide or potassium hydroxide. The actual data of silver penetration rate and silver deposition amount vs grafting rate and saponification degree are shown in the tables. The data show this separator has excellent barrier performance to active material penetration. |
