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

摘要

Provided are: a porous polypropylene film which has low separator resistance and high surface modulus of elasticity, thereby exhibiting excellent coatability for a functional layer such as a heat-resistant protective layer and excellent suitability for battery assembly processes; a separator for electricity storage devices; and an electricity storage device. A porous polypropylene film of the present invention is mainly composed of a polypropylene resin, and satisfies formula (1). (TMD + TTD)/R >= 450 formula (1) (In formula (1), TMD represents the modulus of elasticity (MPa) in the longitudinal direction; TTD represents the modulus of elasticity (MPa) in the transverse direction; and R represents the separator resistance (Omega) per a thickness of 25 mum.)