Process for the production of heterophasic polymer compositions, and compositions so obtained.

摘要

Process for the preparation of a heterophasic polyolefin compo- sition comprising i) a stage where take place, in any given order, a) the polymerization of propylene to form a crystalline propylene polymer at least 80% by weight insoluble in xylene at ambient temperature, or propylene with ethylene and / or a-olefin C4-C10 to form a crystalline propylene copolymer containing more than 85% by weight of propylene, or the polymerization of ethylene to form an ethylene homopolymer or ethylene a-olefin C3-C12 to form an ethylene copolymer containing up to 20 mol% of a-olefin C3-C12, and b) the copolymerization of ethylene and an a-olefin C3-C10, and optionally a diene, to form an elastomeric copolymer partially soluble in xylene at ambient temperature, containing up to 70% by weight of ethylene in the fraction soluble in xylene at room temperature; said step being carried out in the presence of a catalizadorZiegler-Natta.