LAMINATED POROUS POLYOLEFIN FILM, CELL SEPARATOR USING SAME, AND METHOD FOR MANUFACTURING LAMINATED POROUS POLYOLEFIN FILM

摘要

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°C, a rate of increase in air permeation resistance from 30°C to 105°C scaled to 20 µm thickness less than 1.5 sec/100 cc Air/°C, and a thickness not more than 20 µm.