Patent ID: 6649103
Filing Date: 2003-11-18
Classification: C08J,C08L

Abstract:
A process for making a multiphase polymeric film having a lamellar structure with controlled permeability, comprising the steps of:preparing a molten blend comprising: a first polymer phase dispersed in a second polymer phase which is a matrix polymer phase incompatible with the said first phase, and a compatibilizer selected from the group consisting of DEM, DEM-g-SEBS and DEM-g-PP; extruding the molten blend through a flat die provided with an exit; stretching the so-extruded blend downstream of said exit at a preselected stretching ratio to produce the said multiphase polymeric film; and solidifying the extruded film sufficiently rapidly to preserve the lamellar structure; wherein a permeability of the polymeric film to oxygen gas under an O2/N2 relative humidity of 31%/dry is 2.7 mm*cm3/(m2*day*atm) or less.