Patent ID: 8262973
Filing Date: 2012-09-11
Classification: B29C,B29K,C08J,H01M,Y02E,Y10T

Abstract:
1. A method of manufacturing microporous polyolefin films having a puncture strength greater than 0.14 N/μm, a Darcy's permeability constant greater than 1.5×10 −5 Darcy, a shut-down temperature lower than 140° C., and a melt-down temperature higher than 160° C. comprising the steps of: melt-extruding a composition comprising 20-50 weight % of a resin composition and 80-50 weight % of a diluent (Component III) to mold in the form of sheets, wherein the resin composition comprises a blend of: stretching said sheets to mold in the form of films; extracting said diluent from said films; and heat-setting said films.