Method of manufacturing the microporous polyolefin composite film with a thermally stable layer at high temperature

Abstract

Provided is a method of manufacturing a microporous polyolefin composite film with a thermally stable porous layer at high temperature, particularly, to a method of manufacturing a microporous polyolefin composite film with a thermally stable porous layer at high temperature, comprising preparing a polyolefin microporous film using a composition containing a polyolefin resin; coating a solution, in which a high heat-resistant resin is dissolved in a solvent, on one surface or both surfaces of the polyolefin microporous film; phase-separating the polyolefin microporous film coated with the solution by contacting with a nonsolvent after the coating; and drying the polyolefin microporous film so as to remove the solvent and nonsolvent remained after the phase-separating, and thus forming the thermally stable layer at high temperature.

Dependencies are inferred from the claim text.