Patent ID: 6358450
Filing Date: 2002-03-19
Classification: C08J,C08K

Abstract:
A process for making a mono-axially oriented polypropylene film comprising:1) Blending sodium benzoate at a level up to 1000 ppm into polypropylene; 2) plasticating the polypropylene-sodium benzoate mix in an extruder, 3) extruding the polypropylene-sodium benzoate mix through a flat sheet die to produce a polypropylene sheet, 4) contacting the polypropylene sheet with a cooling cylinder or a water quenched bath, 5) drawing the polypropylene sheet longitudinally with respect to the direction of extrusion at a temperature below the melting point of the polypropylene and at a draw ratio in the longitudinal direction of at least about 4:1.