Abstract: Process for the gas-phase catalytic polymerization of olefins carried out in a plurality of interconnected polymerization zones, the process comprising feeding one or more monomers to said polymerization zones in the presence of a catalyst under reaction conditions and collecting the polymer product from said polymerization zones, in which process the polymer particles grow within a first polymerization zone where a fluidized bed is formed, at least a part of said polymer particles leave said first polymerization zone to enter a second polymerization zone through which they flow downward, leave said second polymerization zone and enter a third polymerization zone through which they flow upward under fast fluidization or transport conditions, leave said third polymerization zone and are reintroduced into the first polymerization zone, thus establishing a circulation of polymer between the different polymerization zones.

Abstract: A method for controlling the flowability of polymer particles flowing downward in a densified form inside a polymerization reactor, in which one or more monomers are gas-phase polymerized in the presence of a polymerization catalyst, the density of solid (Kg of polymer per m3 of reactor occupied by the polymer) being higher than 80% of the “poured bulk density” of the polymer, the method being characterized in that a liquid stream is continuously fed into the polymerization reactor at a mass flow rate per unity of reactor surface higher than 30 Kg/h m2.

Abstract: A propylene polymer composition having a melt flow rate (MFR) value from 3 to 30 g/10 min, comprising (percent by weight): A) 50-90% of one or more propylene copolymer(s) having a content of xylene-insoluble mojety at room temperature of not less than 85%, selected from the group consisting of propylene-ethylene random copolymers containing from 1 to 7%, of ethylene; propylene-C4-C8 ?-olefin copolymers containing 2-10% of the C4-C8 alpha-olefins; and propylene-ethylene-C4-C8 ?-olefin copolymers containing 0.5-5% of ethylene and 2-6% Of C4-C8 ?-olefins; and B) 10-50% of a copolymer of propylene containing from 8 to 40% of ethylene and optionally 1-10% of a C4-C8 alpha-olefin; the said MFR value (MFR (2)) being obtained by subjecting to degradation a precursor composition comprising the same components A) and B) in the above said proportions, but having the MFR value (MER (1)) from 0.1 to 5 g/10 min with a ratio MFR (2) to MFR (1) of from 1.5 to 20.

Abstract: A method for controlling the flowability of polymer particles flowing downward in a densified form inside a polymerization reactor, in which one or more monomers are gas-phase polymerized in the presence of a polymerization catalyst, the density of solid (Kg of polymer per m3 of reactor occupied by the polymer) being higher than 80% of the “poured bulk density” of the polymer, the method being characterized in that a liquid stream is continuously fed into the polymerization reactor at a mass flow rate per unity of reactor surface higher than 30 Kg/h m2.

Abstract: A process for preparing a broad molecular weight polyethylene carried out in the presence of a catalyst system comprising (i) a solid catalyst component comprising Mg, Ti, halogen, and optionally an internal electron donor compound, and (ii) an Al-alkyl cocatalyst said process comprising at least two step of polymerization (a) and (b), in which: in a first step (a) ethylene is polymerized in the presence of a molecular weight regulator in order to produce a ethylene (co)polymer, and in a further step (b), which is carried out in the presence of an external electron donor compound added to this polymerization step as a fresh reactant, ethylene is copolymerized with an alpha olefin of formula CH2?CHR, in which R is a C1-C20 hydrocarbon group, to produce an ethylene copolymer having a molecular weight higher than that of the copolymer produced in step (b).

Abstract: A process for preparing heterophasic propylene copolymers by polymerizing propylene in the presence of a polymerization catalyst and hydrogen as a molecular weight regulator, the process comprising the following steps: a) polymerizing in gas- or liquid-phase propylene to prepare a crystalline polymer fraction; b) copolymerizing ethylene with propylene and/or 1-butene, and optionally one or more alpha-olefin comonomers C5-C12, in a gas-phase reactor having interconnected polymerization zones, wherein the growing polymer particles flow upward through a first polymerization zone (riser) under fast fluidization or transport conditions, leave said riser and enter a second polymerization zone (downcomer) through which they flow downward under the action of gravity.

Abstract: Method for monitoring the velocity of growing polymer particles flowing in a two-phase stream during a polymerization process, said method comprising measuring the degree of attenuation in the propagation of light in said two-phase stream by means of a photometric instrument, said photometric instrument comprising: one or more transmitting optical waveguides connecting one or more light sources to said two-phase stream, one or more receiving optical waveguides connecting said two-phase stream to a light detector.

Abstract: Process for preparing a broad molecular weight polyethylene by polymerizing ethylene in the presence of a polymerization catalyst, the process comprising the following steps, in any mutual order: a) polymerizing ethylene, optionally together with one or more ?-olefinic comonomers having from 3 to 12 carbon atoms, in a gas-phase reactor in the presence of hydrogen, b) copolymerizing ethylene with one or more ?-olefinic comonomers having from 3 to 12 carbon atoms in another gas-phase reactor in the presence of an amount of hydrogen less than step a), where in at least one of said gas-phase reactors the growing polymer particles flow upward through a first polymerization zone under fast fluidization or transport conditions, leave said first polymerization zone and enter a second polymerization zone through which they flow downward under the action of gravity.

Abstract: Method for continuously removing the unreacted butene-1, and optionally other volatile components, from a polymeric solution obtained by liquid phase (co)polymerization of butene-1, the method comprising the steps of: subjecting the polymeric solution to heating and mixing conditions such that a mixture is formed consisting substantially of: (1) a polybutene melt containing entrapped butene-1 and (2) supercritical gaseous butene-1; subjecting the above mixture to a sequence of devolatilization steps operating at decreasing pressures.

Abstract: A liquid-phase process for polymerizing ?-olefins of the formula CH2?CHR, where R is H or an alkyl radical C1–C6, to produce a polymer that is soluble in the reaction medium, comprising the steps of: a) continuously polymerizing in liquid phase the ?-olefin in the presence of a catalyst system based on a transition metal compound; b) continuously withdrawing from step a) a solution of polymer in the liquid reaction medium; c) mixing in one or more mixing stages said solution of polymer in the reaction medium with an organic deactivator having: at least a hydroxy group, a boiling point higher than 150° C., and a ratio between the molecular weight (MW) and the number of hydroxy groups (OH) comprised between 20 and 100.

Abstract: A continuous process for the olefin polymerization in a fluidized bed reactor, said process comprising continuously passing a gaseous stream comprising one or more ?-olefin monomers through the fluidized bed in the presence of a polymerization catalyst under reactive conditions, withdrawing polymeric product and unreacted fluids from the reactor, cooling part of said unreacted fluids below the dew point to form a two-phase mixture of gas and condensed liquid and reintroducing said two-phase mixture into the reactor, the process being characterized in that said twophase mixture is reintroduced under the distribution plate of the reactor so that a part of condensed liquid is separated from the gas and is successively fed above the fluidized bed through an external pipe connecting the bottom of the reactor to a point situated above the upper limit of the fluidized bed of polymer particles.

Abstract: Process for the gas-phase catalytic polymerization of olefins carried out in a plurality of interconnected polymerization zones, the process comprising feeding one or more monomers to said polymerization zones in the presence of a catalyst under reaction conditions and collecting the polymer product from said polymerization zones, in which process the polymer particles grow within a first polymerization zone where a fluidized bed is formed, at least a part of said polymer particles leave said first polymerization zone to enter a second polymerization zone through which they flow downward, leave said second polymerization zone and enter a third polymerization zone through which they flow upward under fast fluidization or transport conditions, leave said third polymerization zone and are reintroduced into the first polymerization zone, thus establishing a circulation of polymer between the different polymerization zones.

Abstract: Biaxially oriented polypropylene films (BOPP) having at least one layer of a propylene polymer containing at least 0.8% by weight of ethylene and, optionally, one or more C4-C10 ?-olefins, or a propylene polymer composition containing at least 0.8% by weight of one or more comonomers selected from the group consisting of ethylene and C4-C10 ?-olefins, and having I) a melting temperature of 155° C. or higher; and II) a xylene soluble fraction at room temperature lower than 3% by weight, and a value of the ratio of the polymer fraction collected at the temperature range from 25° C. to 95° C. (by TREF) to the said xylene soluble fraction higher than 8.

Abstract: A liquid-phase process for polymerizing ?-olefins of the formula CH2?CHR, where R is H or an alkyl radical C1-C6, to produce a polymer that is soluble in the reaction medium, comprising the steps of: a) continuously polymerizing in liquid phase the ?-olefin in the presence of a catalyst system based on a transition metal compound; b) continuously withdrawing from step a) a solution of polymer in the liquid reaction medium; c) mixing in one or more mixing stages said solution of polymer in the reaction medium with an organic deactivator having: at least a hydroxy group, a boiling point higher than 150° C., and a ratio between the molecular weight (MW) and the number of hydroxy groups (OH) comprised between 20 and 100.

Abstract: Method for continuously removing the unreacted butene-1, and optionally other volatile components, from a polymeric solution obtained by liquid phase (co)polymerization of butene-1, the method comprising the steps of: subjecting the polymeric solution to heating and mixing conditions such that a mixture is formed consisting substantially of: (1) a polybutene melt containing entrapped butene-1 and (2) supercritical gaseous butene-1; subjecting the above mixture to a sequence of devolatilization steps operating at decreasing pressures.

Abstract: A propylene polymer composition having a melt flow rate (MFR) value from 3 to 30 g/10 min, comprising (percent by weight): A) 50-90% of one or more propylene copolymer(s) having a content of xylene-insoluble mojety at room temperature of not less than 85%, selected from the group consisting of propylene-ethylene random copolymers containing from 1 to 7%, of ethylene; propylene-C4-C8 &agr;-olefin copolymers containing 2-10% of the C4-C8 alpha-olefins; and propylene-ethylene-C4-C8 a-olefin copolymers containing 0.5-5% of ethylene and 2-6% Of C4-C8 &agr;-olefins; and B) 10-50% of a copolymer of propylene containing from 8 to 40% of ethylene and optionally 1-10% of a C4-C8 alpha-olefin; the said MFR value (MFR (2)) being obtained by subjecting to degradation a precursor composition comprising the same components A) and B) in the above said proportions, but having the MFR value (MER (1)) from 0.1 to 5 g/10 min with a ratio MFR (2) to MFR (1) of from 1.5 to 20.

Abstract: Polypropylene sheet for thermoforming having at least one layer comprises a propylene polymer containing at least 0.8% by weight of ethylene and, optionally, one or more C4-C10 &agr;-olefins, or a propylene polymer composition containing at least 0.8% by weight of one or more comonomers selected from the group consisting of ethylene and C4-C10 &agr;-olefins, and having I) a melting temperature of 155° C. or higher; and II) a xylene soluble fraction at room temperature lower than 4% by weight, and a value of the ratio of the polymer fraction collected at 25° C. to 95° C. to the xylene soluble fraction higher than 8.

Abstract: Bioriented polypropylene films (BOPP) wherein at least one layer comprises a propylene polymer containing at least 0.8 % by weight of ethylene and optionally one or more (C4-C10&agr;-olefins, or a propylene polymer composition containing at least 0.8% by weight of one or more comonomers selected from ethylene and more C4-C10&agr;-olefins, and having the following Icatures: 1) a melting temperature of 155° C. or higher; 2) a content of fraction soluble in xylene at room temperature lower than 3% by weight and a value of the ratio of the polymer fraction collected at the temperature range from 25° C. to 95° C. (by TREF) to the said xylene soluble fraction higher than 8.

Abstract: Polypropylene sheet for thermoforming wherein at least one layer comprises a propylene polymer containing at least 0.8% by weight of ethylene and optionally one or more C4-C10 &agr;-olefins, or a propylene polymer composition containing at least 0.8% by weight of one or more comonomers selected from ethylene and C4-C10 &agr;-olefins, and having the following features: 1) a melting temperature of 155 ° C. or higher; 2) a content of fraction soluble in xylene at room temperature lower than 4% by weight, and a value of the ratio of the polymer fraction collected at the temperature range from 25° C. to 95° C. to the said xylene soluble fraction higher than 8.