Patent ID: 9748542
Date: 2017-08-29
CPC Classifications: B32B,C08J,H01M,Y02E

Claim:
1. A composite porous film comprising a heat-resistant layer formed of an inorganic filler and a binder, and a microporous membrane formed of a polyolefin resin, wherein the heat-resistant layer is laminated on the microporous membrane, a primary particle size of the inorganic filler is 5 nanometers to 100 nanometers, a weight average molecular weight (Mw) of the binder is 300,000 to 1,000,000, a molecular weight distribution (Mw/Mn) of the binder is 2.0 or less, and the microporous membrane has a film thickness of 10-30 micrometers and a porosity of 40 to 60%.