Patent ID: 6022916
Filing Date: 2000-02-08
Classification: C08J,C08K,D01D,D01F

Abstract:
An extrusion process for making a polyolefin film said process comprising:forming a polyolefin composition comprising a polyolefin resin, an organic phosphite ester stabilizer, and a metal salt of a lactic acid, said phosphite stabilizer being selected from the group consisting of tetrakis(2,4-di-t-butyl-phenyl) 4,-4'-biphenylylene diphosphonite, tris(2,4-di-t-butylphenyl)-phosphite, trisnonylphenyl phosphite, bis(2,4-di-t-butylphenyl)pentaerythritol diphosphite, and bis(distearyl)pentaerythritol diphosphite, said metal salt being a bivalent salt of lactic acid, said polyolefin composition comprising from 90 to 99.5 weight percent polyolefin resin, from 0.001 to 5 weight percent phosphite stabilizer, and from 0.01 to about 5 weight percent of said metal salt,b) melt extruding said composition through a filtration system to produce a filtered polyolefin melt stream, said filtration system a plurality of filter screens,c) passing said filtered melt stream through an elongated die orifice to to form a polyolefin film.