| abstract |
The present invention is obtained by melting and kneading a polyolefin resin, an inorganic particle and a plasticizer into a sheet, followed by biaxial stretching having a plane magnification of 20 times or more and less than 100 times, extracting a plasticizer, and having an inorganic particle content of 20 mass. It is related with the microporous membrane which is 20% or more and 60 mass% or less, and puncture strength is 3.0 N / 20 micrometers or more.n n n Microporous membrane, polyolefin, inorganic particles, plasticizer, puncture strength |