Patent ID: 6723829
Filing Date: 2004-04-20
Classification: C08F,C08L

Abstract:
A method of preparing a polypropylene heterophasic copolymer with good flow and impact properties, which involves visbreaking a starting polypropylene heterophasic copolymer of which the amorphous rubber, measured as xylene solubles fraction (XS) at room temperature, has an ethylene content, determined as the ethylene content of the acetone precipitated amorphous rubber fraction of the xylene soluble fraction, C2 of AM, from 20 wt-% to 45 wt-%, and an intrinsic viscosity, determined as the intrinsic viscosity of the acetone precipitated amorphous rubber fraction of the xylene soluble fraction, IV of AM, of 2 dl/g or more.