Separator material for storage batteries and method for making the same.

摘要

Conjugate fibers using, as a surface component,[11] ethylene copolymer containing a unit represented by a formula -CH<2> -CH(COOH)-, and using, as a core component, [12] polypropylene or like polyolefin fibers, are used to obtain thermally bonded non-woven fabric sheet to be treated with concentrated sulfuric acid or the like. By so doing, it is possible to readily introduce sulfo groups to replace tertiary carbon atoms and thus impart the fibers with hydrophilicity. By using thus sulfonated thermal bonded non-woven fabric sheet as alkalin storage battery separators, it is possible to maintain high discharge capacity retention.