Patent ID: 9748545
Date: 2017-08-29
CPC Classifications: B29C,B29K,B29L,C08J,H01M,Y02E

Claim:
1. A propylene-based resin microporous film having micropores, comprising a propylene-based resin having a weight average molecular weight of 250,000 to 500,000, a melting point of 160 to 170° C., and a pentad fraction of 96% or more, and having a surface aperture ratio of 27 to 42%, a ratio of a surface aperture ratio to a porosity of 0.6 or less, a degree of gas permeability of 50 to 400 s/100 mL, and an electrolyte solution retention amount of 0.90 g/cm 3 to 1.5 g/cm 3 .