Patent ID: 8207271

Claim:
Process for the manufacture of heterophasic propylene copolymer compositions comprising the steps of (a) in a first stage, forming a propylene polymer matrix in at least one slurry reactor and optionally in at least one gas phase reactor, (b) in a second stage, forming in at least one gas phase reactor an elastomeric propylene copolymer by copolymerizing propylene with ethylene and/or with another a-olefin in the presence of said matrix, wherein the polymerization at least in the first stage is carried out in the presence of a catalyst system comprising a catalyst in form of solid particles, said particles (i) have a surface area of less than 20 m 2 /g (ii) comprise a transition metal compound which is selected from one of the groups 4 to 10 of the periodic table (IUPAC) or a compound of actinide or lanthanide, (iii) comprise a metal compound which is selected from one of the groups 1 to 3 of the periodic table (IUPAC), and (iv) comprise inclusions not comprising catalytically active sites.