POROUS POLYPROPYLENE FILM, SEPARATOR FOR ELECTRICITY STORAGE DEVICE, AND ELECTRICITY STORAGE DEVICE

摘要

Provided is a porous polypropylene film that is safe and has low air permeation resistance. A porous polypropylene film of the present invention includes a polypropylene resin and a ²-crystal nucleating agent, in which a temperature at which a heat shrinkage rate of a dimension in a width direction of the film is 5% is 130 to 200 °C, air permeation resistance is 50 to 500 sec/100 ml, porosity is 35 to 70%, and when porosity is µ and air permeation resistance is G, a relation of the both satisfies the following expression (1): G + 15 × µ ‰¤ 1 , 200