Patent ID: 8802272
Filing Date: 2014-08-12
Classification: B01D,H01M,Y02E

Abstract:
1. A method of producing a polyolefin microporous membrane, said method comprising a first step, a second step and a third step; said first, second and third steps, if said polyolefin microporous membrane is of a kind having a single film layer, serving to obtain said single film layer and, if said polyolefin microporous membrane is of a kind having two or more laminated film layers, serving to obtain those of said film layers that are on both outsides; said first step being for melting polyolefin resin and mixing together at least melted polyolefin resin, organosiloxane particles and a plasticizer to obtain a mixture; said second step being for molding said mixture and biaxially stretching molded product to obtain a stretched film; said third step being for extracting and removing said plasticizer from said stretched film; said organosiloxane particles comprising a polysiloxane cross-linked structure and having a spherical or golfball shape with an average particle diameter of 0.01-10 μm; and said polysiloxane cross-linked structure comprising siloxane unit shown by formula R