Abstract: A process for the preparation of propylene polymer compositions comprising from 50 to 90% by weight of a propylene polymer fraction insoluble in xylene at 25° C., and from 10 to 50% by weight of an ethylene copolymer fraction soluble in xylene at 25° C., said process being carried out in the presence of a specific catalyst system, is also characterized by the following step: (i) contacting the catalyst components (a), (b) and optionally (c) for a period of time ranging from 0.1 to 120 minutes, at a temperature ranging from 0 to 90° C.; (ii) polymerizing propylene in the optional presence of ethylene and/or C4-C10 alpha olefins producing a propylene (co)polymer being for at least 85% by weight of insoluble in xylene at 25° C. and (iii) in a successive step, carried out in gas-phase, in the presence of the product coming from (ii), polymerizing mixtures of ethylene with a-olefins CH2?CHR in which R is a hydrocarbon radical having 1-10 carbon atoms, to produce an ethylene copolymer.

Abstract: A propylene composition comprising (percent by weight): A) 60%-95%, of a crystalline propylene copolymer containing from 2.0% to 10.0% of ethylene derived units having a melting point ranging from 148° C. to 160° C.; wherein the melting temperature Tm is measured by DSC on the as-reactor polymer; B) 40%-5%, of a copolymer of ethylene containing from 70% to 85%, of ethylene derived units intrinsic viscosity ranging from 0.8 to 3 dl/g.

Abstract: A propylene polymer composition comprising (percent by weight): A) 74%-84% of a propylene homopolymer having a Polydispersity Index (P.I.) value of from 4.6 to 10, a fraction insoluble in xylene at 25° C., higher than 90%, and a MFR L (Melt Flow Rate according to ISO 1133, condition L, i.e. 230° C. and 2.16 kg load) from 110 to 200 g/10 min; B) 16%-26%, of a copolymer of propylene with from 39% to 48%, of ethylene derived units; the composition having an intrinsic viscosity of the fraction soluble in xylene at 25° C. comprised between 2.7 and 4.0 dl/g; and a MFR L (Melt Flow Rate according to ISO 1133, condition L, i.e. 230° C. and 2.16 kg load) from 30 to 80 g/10 min.

Abstract: Polyolefin compositions particularly suitable for cast film, exhibiting heat sealability, retortability, low haze and stiffness, comprising: 1) 75-85% of a propylene homopolymer or copolymer of propylene with ethylene and/or one or more C4-C10 ?-olefin(s), the homopolymer or copolymer having melting temperature equal to or higher than 150° C., 2) 15-25% of a copolymer of ethylene with one or more C4-C10 ?-olefin(s) containing from 20 to 30% of said C4-C10 ?-olefin(s); said composition having MFR (at 230° C., 2.16 kg) of from 5-10 g/10 min, the total content of ethylene of from 10 to 20%, the total content of C4-C10 ?-olefin(s) of from 2 to 8%, the ratio XStot/XSm of the total fraction soluble in Xylene at room temperature to the fraction soluble in Xylene at room temperature of the matrix component (1) of from 5 to 15, and the value of the intrinsic viscosity of the total fraction soluble in Xylene at room temperature (XSIVtot) of 1.5 dl/g or less.

Abstract: A process for the preparation of propylene polymer compositions carried out in the presence of a catalyst system comprising (a) a solid catalyst component having average particle size ranging from 15 to 80 ?m comprising a magnesium halide, a titanium compound having at least a Ti-halogen bond and at least two electron donor compounds one of which being present in an amount from 50 to 90% by mol with respect to the total amount of donors and selected from succinates and the other being selected from 1,3 diethers, (b) an aluminum alkyl and optionally (c) an external electron donor compound, and comprising the following steps: (i) contacting the catalyst components (a), (b) and optionally (c); (ii) pre-polymerizing up to forming amounts of polymer from about 0.1 up to about 1000 g per gram of solid catalyst component (a); (iii) polymerizing propylene producing a propylene (co)polymer being for at least 85% by weight of insoluble in xylene at 25° C.

Abstract: A propylene composition comprising (percent by weight): A) 60%-90%, of a crystalline propylene copolymer containing from 3.5% to 10% of ethylene derived units; B) 10%-40%, of a copolymer of propylene containing from 18.5% to 23.5%, of ethylene derived units.

Abstract: Articles, particularly pressure pipes, having high strength as well as high stiffness and very good impact resistance even at low temperatures can be obtained by using a heterophasic polyolefin composition comprising (percent by weight) 70-90% of a random copolymer of propylene with 0.5-6% of 1-hexene, and 10-30% of a polymer of ethylene with a C3-C10 ?-olefin and optionally a diene, wherein the polymer of ethylene has an ethylene content higher than 45% and an intrinsic viscosity [?] value from 3 to 5 dl/g. A particular advantage of the present invention is that articles comprising the above heterophasic polyolefin composition show a low ductile to brittle transition temperature (DBTT).

Abstract: A polyolefin composition having good transparency and mechanical properties comprising, all percent amounts being by weight: A) from 70 to 98% of a propylene homopolymer or copolymer having haze of 25% or less and melting temperature of 130° C. or higher; and B) from 2 to 30% of a butene-1 copolymer containing from 0.5 to 30% of one or more comonomer(s).