Patent ID: 7816456
Filing Date: 2010-10-19
Classification: C08F,C08L,Y10S

Abstract:
1. A biaxially stretched film having a longitudinal stretching ratio of at least 1:3 and a transverse stretching ratio of at least 1:5 obtained by biaxially stretching a semicrystalline propylene polymer composition with a melting point T M of from 135 to 165° C., where the melting point T where the semicrystalline propylene polymer composition can be broken down into where the proportions of component A, B and C are determined by carrying out TREF (temperature rising elution fractionation) in which the polymers are firstly dissolved in boiling xylene and the solution is then cooled at a cooling rate of 10° C/h to 25° C., and then, as the temperature rises, that fraction of the propylene polymer composition which is soluble in xylene at (T where at least 50 mol % of the resultant monomer units stem from the polymerization of propylene, which process comprises polymerizing propylene, alone or together with ethylene and/or C