Abstract: A process for introducing a catalyst powder based on a titanium compound supported on magnesium halide into a gas-phase olefin polymerization reactor, characterized in that it comprises: (a) storing the catalyst powder under an atmosphere of a liquid C3-C12 alkane; (b) withdrawing from step (a) a measured amount of said catalyst powder by means of a rotary valve; (c) transferring said metered amount of catalyst powder to a catalyst activation section by a continuous pick-up flow of a liquid C3-C12 alkane; (d) contacting the catalyst powder with a liquid phase comprising an organo-aluminum compound and optionally an external donor compound, at a temperature ranging from ?20° C. to 60° C.; (e) introducing the activated catalyst powder in one or more gas-phase olefin polymerization reactors, where a gaseous mixture comprising at least one alpha-olefin is subjected to polymerization.

Abstract: Catalyst component comprising Mg, Ti, and halogen atoms, and is characterized in that (a) the Ti atoms are present in an amount higher than 4% based on the total weight of the said catalyst component, (b) the amount of Mg and Ti atoms is such that the Mg/Ti molar ratio is higher than 2 and (c) by a X-ray diffraction spectrum, in which, in the range of 2? diffraction angles between 47° and 52°, at least two diffraction lines are present at diffraction angles 2? of 48.3±0.2°, and 50.0±0.2°, the most intense diffraction lines being the one at 2? of 50.0±0.2°, the intensity of the other diffraction line being equal to or lower than the intensity of the most intense diffraction line.

Abstract: A process for introducing a catalyst powder based on a titanium compound supported on magnesium halide into a gas-phase olefin polymerization reactor, characterized in that it comprises: (a) storing the catalyst powder under an atmosphere of a liquid C3-C12 alkane; (b) withdrawing from step (a) a measured amount of said catalyst powder by means of a rotary valve; (c) transferring said metered amount of catalyst powder to a catalyst activation section by a continuous pick-up flow of a liquid C3-C12 alkane; (d) contacting the catalyst powder with a liquid phase comprising an organo-aluminum compound and optionally an external donor compound, at a temperature ranging from ?20° C. to 60° C.; (e) introducing the activated catalyst powder in one or more gas-phase olefin polymerization reactors, where a gaseous mixture comprising at least one alpha-olefin is subjected to polymerization.

Abstract: The present invention relates to butene-1 copolymers containing up to 40% by mol of ethylene and/or propylene derived units characterized by the following properties: d) Product of the reactivity ratios r1·r2?2; e) Content of butene-1 units in form of isotactic pentads (mmmm)>98%; and f) absence of 4,1 insertions of butene units.

Abstract: The present invention relates to butene-1 copolymers containing up to 40% by mol of ethylene and/or propylene derived characterized by the following properties: d) Product of the reactivity ratios r1·r2?2; e) Content of butene-1 units in form of isotactic pentads (mmmm)>98%; and f) absence of 4,1 insertions of butene units.

Abstract: A process to perform the finishing of polyolefins produced by gas-phase catalytic polymerization of one or more ?-olefins in the presence of a polymerization diluent selected from a C3-C5 alkane, wherein the polyolefin granules discharged from the gas-phase reactor are subjected to: (1) a first degassing step in which said polyolefin is counter-currently contacted with a gaseous stream containing at least 85% by mol of a stripping agent selected from a C3-C5 alkane, said gaseous stream being continuously derived from the monomer recovery section of the polymerization plant; (2) a second degassing step in which said polyolefin is counter-currently contacted with steam, the amount of steam being from 10 to 200 Kg per 1000 kg of polyolefin.

Abstract: A process for the gas-phase polymerization of ?-olefÊns CH2?CHR, where R is hydrogen or a hydrocarbon radical having 1-12 carbon atoms, carried out in a first and a second interconnected polymerization zones, wherein the growing polymer particles flow through the first of said polymerization zones (riser) under fast fluidization conditions, leave said riser and enter the second of said polymerization zones (downcomer) through which they flow downward in a densified form, leave said downcomer and are reintroduced into said riser, in which process: (a) the gas mixture present in the riser is totally or partially prevented from entering the downcomer, and (b) the gaseous composition inside a portion of the downcomer is maintained substantially similar to the gaseous composition reacting in the riser.

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 to perform the finishing of polyolefins produced by gas-phase catalytic polymerization of one or more ?-olefins in the presence of a polymerization diluent selected from a C3-C5 alkane, wherein the polyolefin granules discharged from the gas-phase reactor are subjected to: (1) a first degassing step in which said polyolefin is counter-currently contacted with a gaseous stream containing at least 85% by mol of a stripping agent selected from a C3-C5 alkane, said gaseous stream being continuously derived from the monomer recovery section of the polymerization plant; (2) a second degassing step in which said polyolefin is counter-currently contacted with steam, the amount of steam being from 10 to 200 Kg per 1000 kg of polyolefin.

Abstract: A process for the gas-phase polymerization of one or more alpha-olefins in the presence of a polymerization catalyst system, the process comprising: a) contacting in a continuous way a gas comprising one or more of said alpha-olefins with said catalyst system in a gas-phase tubular reactor at a temperature from 30° C. to 130° C. in order to obtain a polymerization degree up to 500 grams per gram of catalyst system; b) feeding in continuous the prepolymer from step a) to a successive gas-phase polymerization reactor; wherein said gas-phase tubular reactor has a length/diameter ratio higher than 100.

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: A process for the gas-phase polymerization of ?-olefÊns CH2?CHR, where R is hydrogen or a hydrocarbon radical having 1-12 carbon atoms, carried out in a first and a second interconnected polymerization zones, wherein the growing polymer particles flow through the first of said polymerization zones (riser) under fast fluidization conditions, leave said riser and enter the second of said polymerization zones (downcomer) through which they flow downward in a densified form, leave said downcomer and are reintroduced into said riser, in which process: (a) the gas mixture present in the riser is totally or partially prevented from entering the downcomer, and (b) the gaseous composition inside a portion of the downcomer is maintained substantially similar to the gaseous composition reacting in the riser.

Abstract: A solution process for polymerizing one or more ?-olefins of the formula CH2?CHR, where R is H or an alkyl radical C1-C18, to produce a polymer that is soluble in the reaction medium, comprising the steps of: continuously polymerizing in a liquid phase the ?-olefin in the presence of a catalyst system based on a transition metal compound to obtain a solution of polymer in the reaction medium; the polymeric solution obtained from step a) is then mixed in one or more mixing stages with an aqueous mixture comprising one or more organic compounds having at least a hydroxy or epoxy group, said aqueous mixture having a dynamic viscosity at 30° C. higher than 50 cP (centiPoise).

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 solution process for polymerizing one or more ?-olefins of the formula CH2?CHR, where R is H or an alkyl radical C1-C18, to produce a polymer that is soluble in the reaction medium, comprising the steps of: continuously polymerizing in a liquid phase the ?-olefin in the presence of a catalyst system based on a transition metal compound to obtain a solution of polymer in the reaction medium; the polymeric solution obtained from step a) is then mixed in one or more mixing stages with an aqueous mixture comprising one or more organic compounds having at least a hydroxy or epoxy group, said aqueous mixture having a dynamic viscosity at 30° C. higher than 50 cP (centiPoise).

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: The present invention relates to butene-1 copolymers containing up to 40% by mol of ethylene and/or propylene derived characterized by the following properties: d) Product of the reactivity ratios r1·r2?; e) Content of butene-1 units in form of isotactic pentads (mmmm)>98%; and f) absence of 4,1 insertions of butene units.

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.