Abstract:
Propylene terpolymers are prepared by polymerizing propylene, ethylene and an alpha-olefin selected from the group of C4-C8 alpha-olefins in the presence of a catalyst system obtained by contacting a solid catalyst component 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 40 to 90% by mol with respect to the total amount of donors and selected from succinates and the other selected from 1,3 diethers, an aluminum hydrocarbyl compound, and optionally an external electron donor compound.
Abstract:
A propylene composition comprising (percent by weight): A) 70%-95%, 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 MFR L (Melt Flow Rate according to ISO 1133, condition L, i.e. 230°C and 2.16 kg load) from 60 to 120 g/10 min; B) 5%-30%, of a copolymer of propylene containing from 34.5% to 30.0% extremes included of ethylene derived units; the composition having an intrinsic viscosity of the fraction soluble in xylene at 25 °C comprised between 3 and 5 dl/g.
Abstract:
A process for the gas-phase polymerization of one or more alpha-olefms in the presence of a polymerization catalyst, the process comprising: - at least a polymerization step wherein the polymer particles flow downward in densified form under the action of gravity so as to form a densified polymer bed; - metering an anti-fouling agent in said polymerization step by means of at least N feeding lines placed at different heights of said densified polymer bed, N being the integer number satisfying the equation N> (1+0.08 % H), where H is the height (expressed in meters) of the polymer bed.
Abstract:
A 1-butene propylene ethylene terpolymer having a content of propylene derived units ranging from 0.1-10 % by weight and an ethylene derived units content ranging from 0.1 to 3 % by weight having the following properties: a) distribution of molecular weight Mw/Mn measured by GPC lower than 3.5; b) melting point (DSC) comprised between 60°C and 120°C; c) Content of 1-butene units in the form of isotactic pentads (mmmm) higher than 95%.
Abstract:
1. A polyolefin composition comprising: A) from 65 wt% to 85 wt%, of a propylene/ethylene/ 1-butene terpolymer wherein: i) the content of ethylene derived units ranges from 0.6 wt% to 2.5 wt; ii) the content of 1-butene derived units ranges from 6 wt% to 12 wt%; iii) the fraction soluble in xylene at 25 °C ranges from 3.5 wt% to 20 wt%; B) from 15 wt% to 35 wt% of a propylene/ethylene copolymer having a content of ethylene derived units ranging from 10 wt% to 40 wt%; the copolymer optionally can contains 1-butene derived units in an amount less than 1 wt%; the sum A) + B) being 100.
Abstract:
A terpolymer containing propylene, ethylene and 1-hexene wherein: (i) the content of 1-hexene derived units ranges from 1 wt% to 2.6 wt%; (ii) the content of ethylene derived units is higher than 0.7 wt% and fulfils the following relation (1): C2
Abstract:
A polyolefin composition comprising (percent by weight): A) from 65% to 75% of a propylene homopolymer or a propylene copolymer containing from 0.1% to 5.0% of ethylene derived units having a fraction soluble in Xylene at 25°C lower than 3wt%; B) from 25 % to 35% of an ethylene copolymer containing from 3% to 12 % of propylene derived units; said composition having a melt flow rate (MFR) determined according to ISO method 133(230° C and 2.16 kg)comprised between 11 g/10 min and 50 g/10 min; the xylene soluble fraction ranging from 3% to 15% and the intrinsic viscosity (IV) of the xylene soluble fraction ranging from 0.8 dl/g to 2 dl/g.
Abstract:
A propylene composition comprising (percent by weight): A) 70%-95%, 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 MFR L (Melt Flow Rate according to ISO 1133, condition L, i.e. 230°C and 2.16 kg load) from 47 to 90 g/10 min; B) 5%-30%, of a copolymer of propylene containing from 40% to 34.5% extremes included of ethylene derived units; the composition having an intrinsic viscosity of the fraction soluble in xylene at 25 °C comprised between 3 and 5 dl/g.
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:
A process for the polymerisation of olefins in the presence of a solid catalyst component and a catalyst activator, the process being performed in a gas-phase reactor having interconnected polymerization zones, where the growing polymer particles flow upward through a first polymerization zone (riser) under fast fluidization conditions, leave said riser and enter a second polymerization zone (downcomer) through which they flow downward under the action of gravity, leave said downcomer and are reintroduced into the riser, thus establishing a polymer circulation between said riser and said downcomer, the process being characterized in that said solid catalyst component has an average size P50 ranging from 20 μm to 65 μm and the gas flows upward in said first polymerization zone at a velocity ranging from 0.8 to 2.0 m/s.