| 摘要 |
PURPOSE:To make better dimensional stability and storability by forming a separator with a grafted polymer obtained by grafting and acid-dissociative vinyl monomer on body polymer film whose acid dissociative groups are of di- or tri-valent metal salt type. CONSTITUTION:The separator is formed from a grafted polymer obtained by grafting an acid-dissociative vinyl monomer on a synthetic resin film of polyethylene, etc., as a body polymer, whose acid dissociative groups are of di- or tri-valent metal salt type. Usually, the substitution is made by dipping the acid or alkali metal salt type grafted film of body polymer in an aqueous solution containing an inorganic salt of a metal not harmful to cell, e.g., zinc sulfate, magnesium chloride, etc. Thus, the water absorbability and carbon dioxide absorbability of the separator can be suppressed or prevented, making its dimensional stability and storability better. |
