POLYOLEFIN MULTILAYER MICROPOROUS FILM, METHOD FOR PRODUCING SAME AND BATTERY SEPARATOR

摘要

Disclosed is a polyolefin multilayer microporous film wherein (1) a porous layer composed of a polyethylene resin and another porous layer containing polypropylene and a heat-resistant resin having a melting point or glass transition temperature of not less than 170°C are arranged, or (2) a porous layer composed of a polyethylene resin and another porous layer containing polypropylene and an inorganic filler having an aspect ratio of not less than 2 are arranged. This polyolefin multilayer microporous film has an excellent balance among permeability, mechanical strength, thermal shrinkage resistance, shutdown characteristics and meltdown characteristics.