MICROPOROUS POLYOLEFIN FILM WITH THERMALLY STABLE POROUS LAYER AT HIGH TEMPERATURE

摘要

Provided is a microporous film for a secondary battery, and more particularly, to a microporous film for a secondary battery with excellent quality stability and heat resistance, the microporous film that is a 3 layer microporous film, including: an inner layer that includes polypropylene of 20-80 wt% having a melting temperature of 15O0C or higher and a filler of 80-20 wt% having a melting temperature of 14O0C or higher, wherein a gross content of the filler and polypropylene in the inner layer is 60wt% or more, and both surface layers which include polyethylene, wherein at least one layer of the both surface layers including polyethylene of 70wt% or more.