PROPYLENE-BASED RESIN MICROPOROUS FILM, SEPARATOR FOR BATTERY, BATTERY, AND METHOD FOR PRODUCING PROPYLENE-BASED RESIN MICROPOROUS FILM

摘要

The present invention provides a propylene-based resin microporous film which has excellent electrolyte solution retention property, and can provide a lithium ion battery in which a decrease in discharge capacity is highly reduced even after repeated charge and discharge.;The propylene-based resin microporous film is a propylene-based resin microporous film having micropores, wherein 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 is contained, the surface aperture ratio is 27 to 42%, the ratio of a surface aperture ratio to a porosity is 0.6 or less, and the degree of gas permeability is 50 to 400 s/100 mL.

主权项

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, and a degree of gas permeability of 50 to 400 s/100 mL.