MICROPOROUS MEMBRANE, METHOD FOR PRODUCING SAME, AND BATTERY SEPARATOR USING SAME

摘要

The present invention is a microporous membrane which contains (a) a polymethyl pentene, (b) a polyethylene and (c) a polypropylene and which has a meltdown temperature of 180°C or more, a TD thermal shrinkage at 170°C of 35% or less, and a thickness variation rate per membrane thickness of 10% or less. The purpose of the present invention is to provide a microporous membrane that has high meltdown temperature, low shutdown temperature and resistance to thermal shrinkage at high temperatures, which have not been achieved by conventional technology.