Japan Vilene Company, Ltd.

Nobutoshi Tokutake

Masanao Tanaka

Koji Kimura

Hiroaki Yamazaki

Yoshihiko Kondo

Masaki Hirooka

An alkaline battery separator comprising a nonwoven fabric containing one or more mixture layers of entangled short fibers and entangled long fibers, wherein a fiber length of the short fibers is from 1 mm to less than 25 mm, a fiber length of the long fibers is 25 mm or more, and a total thickness of all of the mixture layers accounts for not less than one-third of a whole thickness of the nonwoven fabric is disclosed. The alkaline battery separator according to the present invention exhibits an excellent electrolyte-holding capacity, tensile strength, tear strength and bending resistance, and can be used to stably prepare a battery. Electrode flash rarely penetrate the separator, to thereby cause a short circuit between electrodes.

Alkaline battery separator and process for producing the same

An alkaline battery separator comprising a hydrophilic nonwoven fabric obtainable by heat-fusing and hydro-entangling (1) polyolefin dividable composite fibers having an average fiber length of 20 to 60 mm, (2) high-strength fibers having an average fiber length of 30 to 60 mm and a fiber strength of 5 g/denier or more, and (3) polyolefin heat-sensitive-adhesive fibers having an average fiber length of 30 to 60 mm, to obtain a heat-fused and hydro-entangled nonwoven fabric by a dry-laid method, and imparting a hydrophilic property to the resulting heat-fused and hydro-entangled nonwoven fabric; these high-strength fibers accounting for 20 to 45 mass % with respect to a total mass of the polyolefin dividable composite fibers, the high-strength fibers and the polyolefin heat-sensitive-adhesive fibers. The alkaline battery separator exhibits an excellent breaking strength, and has practical and sufficient tensile strength and electrolyte-holding capacity properties.

An alkaline battery separator comprising a hydrophilic nonwoven fabric obtainable from a fiber web prepared by a wet-laid method from (1) dividable composite fibers capable of producing polyolefin fine fibers, (2) high-strength fibers having a single-fiber strength of 5 g/denier or more, and (3) fusible fibers containing at least on a surface thereof a resin component having a melting point lower than a melting point of the dividable composite fibers and lower than a melting point of the high-strength fibers: by dividing the dividable composite fibers, entangling the fibers, and fusing the fusible fibers, to obtain a heat-fused and entangled nonwoven fabric, and imparting a hydrophilic property to the resulting heat-fused and entangled nonwoven fabric; wherein an average fiber length of the constituent fibers of the hydrophilic nonwoven fabric is 10 mm or more, is disclosed. The alkaline battery separator according to the present invention exhibits an excellent electrolyte-holding capacity, tensile strength, tear strength and bending resistance, and can be used to stably prepare a battery. An electrode flash rarely penetrates the separator to thereby cause a short circuit between electrodes.

A battery separator comprising a sheet material containing a polyvinyl alcohol cross-linked by a cross-linking group of the general formula (I): ##STR1## wherein A represents a group of --CH.dbd.CH--R.sub.1 or ##STR2## R.sub.1 represents an optionally substituted quaternary nitrogen-containing aromatic heterocyclic group, R.sub.2 and R.sub.3 independently represent a hydrogen atom or alkoxy group having 1 to 4 carbon atoms, m is o or 1, and n is an integer of 1 to 6, is disclosed. The separator exhibits a good resistance to electrolyte, electrolyte holding rate, and resistant to short-circuits.

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Ibaraki, Japan

Nobutoshi Tokutake