Method for preparing heterophase propylene resin

The present invention relates to a process for preparing a heterophasic polypropylene resin by a multi-stage polymerization process in the presence of a metallocene catalyst, the process comprising: (I) in a first polymerization step, polymerizing propylene and optionally at least one C2-10 alpha-olefin comonomer; and subsequently (II) in a second polymerization step, polymerizing propylene, ethylene and optionally at least one C3-10 alpha-olefin comonomer in the presence of a metallocene catalyst and the polymer obtained in step (I); wherein step (II) is carried out in at least one gas phase reactor, the reactor operating pressure being at least 26 bar. The invention also relates to a heterophasic polypropylene resin comprising a polypropylene matrix phase (A) and an ethylene-propylene copolymer phase (B) dispersed in the polypropylene matrix phase wherein the ethylene-propylene copolymer phase (B) is an amorphous ethylene-propylene copolymer having an intrinsic viscosity (iV) of at least 3.5 dl/g measured i