EP0982785A1 — Separator for battery and alkali secondary battery using the same

USPTO Abstract

A separator for alkaline secondary batteries comprising a porous sheet comprising organic fiber 1, a binder resin 4, and ion-exchange fine powder 3, wherein the ion-exchange fine powder 4 is adhered to the porous sheet with the binder resin 3 that infiltrates and seals the fine voids 2 or slits provided on the surface of the organic fiber 1 of the porous sheet, and wherein the ion-exchange fine powders do not fall out, electrolyte retention is excellent, and ion-exchange performance can be exhibited for a long time; and an alkaline secondary battery using the above-mentioned separator. The surface of the olefin-based finer 1 is provided with fine voids 2 and slits on its surface. The fine voids 2 and slits are formed by etching the olefin-based fiber with an organic solvent. The binder resin 3 is adhered to the porous sheet in a manner in which the binder reins partially infiltrates the fine voids 2 or slits while projecting outwards. On the tip of the projecting part, the ion-exchange fine powder 4 is fixed. As the binder resin 3, styrene―ethylene― butylene―styrene (SEBS) thermoplastic copolymer is preferred.