Patent ID: 9722226
Date: 2017-08-01
CPC Classifications: B01D,C08J,H01M,Y02E,Y02T

Claim:
1. A polyolefin microporous membrane, comprising a polyolefin resin and inorganic particles, wherein the microporous membrane has a puncture strength of 3 N/20 μm or more, a membrane thickness retention ratio in penetration creep of 23% or more and 48% or less, and a membrane thickness reduction rate in penetration creep of 10% or less, wherein a content of the inorganic particles is 20% by mass or more and less than 60% by mass, wherein a particle diameter of the inorganic particles is 1 nm or more and less than 100 nm, and wherein the polyolefin resin comprises a composition containing polypropylene contained in an amount of 20% by weight or more and 40% by weight or less in 100% by weight of polyolefin resin.