Patent ID: 9287543
Filing Date: 2016-03-15
CPC Classification: B29C,B29K,C08J,H01M,Y02E

Claim Text:
1. A porous film having through-pores, containing: a polyolefin-based resin is a polypropylene resin having a melt flow rate of 4 to 30 g/10 min; and 70% to 99% by mass of the polypropylene resin having the melt flow rate of 4 to 30 g/10 min and 1% to 30% by mass of a propylene-ethylene copolymer having a melt flow rate of 0.1 to less than 4 g/10 min; or 80% to 99% by mass of the polypropylene resin having the melt flow rate of 4 to 30 g/10 min and 1% to 20% by mass of an elastomer containing at least propylene or butane as a constituent unit, wherein, when thickness of a circular region having a diameter of 10 mm as an initial thickness t0 after a load of 50 g is applied onto the circular region for 10 seconds, as a thickness t after a load of 500 g is subsequently applied onto the same region for 10 seconds, and as the thickness t