Abstract:
A microporous polyolefin membrane comprising a polyethylene, and polypropylene having a weight-average molecular weight of 6 x 10 5 or more and a heat of fusion of 90 J/g or more (measured by a differential scanning calorimeter), a fraction having a molecular weight of 5 x 10 4 or less being 5% or less by mass of the polypropylene.
Abstract:
A microporous polyolefin membrane comprising a polyethylene resin, and polypropylene having a weight-average molecular weight of 6 x 10 5 or more and a heat of fusion of 90 J/g or more (measured by a differential scanning calorimeter), a fraction having a molecular weight of 1.8 x 10 6 or more being 10% or more by mass of the polypropylene.