Patent ID: 9431642
Filing Date: 2016-08-30
CPC Classification: B01D,B29B,B29C,B29K,B29L,B32B,H01M,Y02E

Claim Text:
1. A multi-layer, microporous polyolefin membrane having at least three layers, which comprises first microporous layers comprising a polyethylene resin for constituting at least both surface layers, and at least one second microporous layer comprising a polyethylene resin and polypropylene and disposed between both surface layers, the polyethylene resin in the first and second microporous layers having a melting point of 130° C. to 140° C., the heat of fusion (ΔH m ) of the polypropylene measured by differential scanning calorimetry being 90 J/g or more, and the polypropylene content in the second microporous layer being 3 to 45% by mass based on 100% by mass of the total of the polyethylene resin and the polypropylene.