CPC H01G 11/52 (2013.01) [H01M 10/0525 (2013.01); H01M 50/411 (2021.01); H01M 50/417 (2021.01); H01M 50/449 (2021.01); H01M 50/489 (2021.01)] | 7 Claims |
1. A polyolefin porous film, comprising a polyethylene-based resin and a polypropylene-based resin,
the polyolefin porous film has a pair of polypropylene-based resin layers comprising the polypropylene-based resin on both surfaces of a polyethylene-based resin layer comprising the polyethylene-based resin,
the polyolefin porous film has a film thickness of 8 to 40 μm,
a Gurley value of the polyolefin porous film is 65 to 230 seconds/100cc,
a ratio of the Gurley value of the polyethylene-based resin layer to the Gurley value of the polyolefin porous film is 20% or less,
wherein a weight average molecular weight of the polyethylene-based resin is 450,000 or less,
a molecular weight distribution of the polyethylene-based resin is 6 to 13,
a content of a high molecular weight component having a molecular weight of 1,000,000 or more in the polyethylene-based resin is in a range of 5 to 11% by mass,
a melt flow rate of the polyethylene-based resin is in a range of 0.1 to 10 g/10 minutes, and
a weight average molecular weight of the polypropylene-based resin is 500,000 to 1,000,000.
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