Separator material for storage batteries and method for making the same
AssigneesDaiwabo Create Co., Ltd., Kanai Juyo Kogyo Co., Ltd.
InventorsYousuke Takai, Toyohiko Sano, Isao Ikkanzaka
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Abstract
Conjugate fibers using, as a surface component, ethylene copolymer containing a unit represented by a formula --CH.sub.2 --CH(COOH)--, and using, as a core component, polypropylene or like polyolefin fibers, are used to obtain thermally bonded non-woven fabric sheet to the treated with concentrated sulfuric acid or the like. By so doing, it is possible to readily introduce sulfo groups to replace tertiary carbon and thus impart the fibers with hydrophilicity. By using thus sulfonated thermal bonded non-woven fabric sheet as alkaline storage battery separators, it is possible to maintain high discharge capacity retention.
Claims7
A separator material for storage batteries comprising a fabric sheet made of fibers, said fibers comprising sulfonated conjugate fibers comprising at least first and second components thermally bonded together, said first component occupying a surface layer, said second component occupying a core portion, said first component comprising an olefinic random copolymer containing at least a unit represented as --CH.sub.2 --C (SO.sub.3 H) (COOH)--, and said second component comprising a nonsulfonated polyolefin having a melting point no higher than 250.degree. C.
Dependencies are inferred from the claim text.