| 摘要 |
PURPOSE:To raise the holdability of electrolyte as well as maintain durability of separator by using a non-woven fabric, etc., made of a fiber of a copolymer with sulfon group from ethylene or propylene and acrylic acid monomer, etc. CONSTITUTION:A non-woven or woven fabric of polypropylene or polyethylene fiber is exposed to a radiation, electron rays, etc., and then subjected to a graft polymerization using acrylic acid, methacrylic acid, or its methylester or ethylester. Then, the fabric thus treated is passed through a fuming sulfuric acid for sulfonation, for example. In this way, sulfone group are introduced into (the carboxyle group of) non-woven or woven fabric. Preferably, the graft polymerization rate or acrylic acid or methacrylic acid is 1-5mol%, and the amount of sulfone group introduced is 0.05-2 mill equivalent/g. |
