Toray Industries, Inc.

Toray Battery Separator Film Co., Ltd.

Kosuke Harumoto

Naoki Mizuno

Masami Sugata

Koichi Matano

Hideto Mitsuoka

Yukiko Miura

A polyolefin multilayer microporous membrane is disclosed. The polyolefin multilayer microporous membrane has a low air permeability value, maintains high porosity and mechanical strength even when formed into a thin film. The polyolefin multilayer microporous membrane also has excellent impedance characteristics. The polyolefin multilayer microporous membrane has excellent battery characteristics when used as a battery separator.

Polyolefin multilayer microporous film, method for producing same, and cell separator

Considering that battery separators will require further thinner materials and lower costs in the future, a battery separator of the present invention, in which multi-layer polyolefin porous membrane with exceptionally high peel strength against a modified porous layer, suitable for high-speed processing during slit process and battery assembly process, and suitable for laminating on a multi-layer modified porous layer, and a multi-layer modified porous layer are laminated, is provided. A multi-layer polyolefin porous membrane comprising at least two or more layers, the multi-layer polyolefin porous membrane having a shut-down temperature in a range of 128 to 135&#xb0; C., a rate of increase in air permeation resistance from 30&#xb0; C. to 105&#xb0; C. scaled to 20 &#x3bc;m thickness less than 1.5 sec/100 cc Air/&#xb0; C., and a thickness not more than 20 &#x3bc;m.

Multi-layer polyolefin porous membrane, battery separator using same, and process for producing multi-layer polyolefin porous membrane

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Tochigi, Japan

Kosuke Harumoto