Abstract: An apparatus for gas-phase catalytic polymerization comprising a first vertical reactor (1), a second vertical reactor (2), the upper region of said reactor (1) being connected by a connecting part (3) to a solid as separator (4), which is in turn connected to the upper region of second reactor (2), the lower region of second reactor (2) being connected to the lower region of first reactor (1) by a connecting part (5), the solid/gas separator (4) being connected through a recycle line (6) to one or more points of reintroduction into connecting part (5) or into reactor (1), the apparatus having a line (12) for feeding catalyst into reactor (1), a polymer discharge system (11) from reactor (2), a line (13) for feeding monomers, the apparatus being further characterized in that it comprises a line (15) for feeding gas or liquid into reactor (2).

Abstract: A process for the gas-phase catalytic polymerisation carried out in two interconnected polymerisation zones, to which one or more monomers are fed in the presence of a catalyst under polymerisation conditions and from which the produced polymer is discharged. The growing polymer particles flow through a first polymerisation zone under fast fluidisation conditions, leave said first zone and enter a second polymerisation zone through which they flow in a densified form under the action of gravity, leave said second zone and are reintroduced into the first polymerisation zone, thus establishing a circulation of polymer between the two polymerisation zones. The present invention is characterised in that a gas of composition different from that present in the first polymerisation zone is introduced into the second polymerisation zone and it is avoided that the gases present in the first polymerisation zone are introduced into the second polymerisation zone.

Abstract: A process for the gas-phase catalytic polymerisation carried out in two interconnected polymerisation zones, to which one or more monomers are fed in the presence of a catalyst under polymerisation conditions and from which the produced polymer is discharged. The growing polymer particles flow through a first poly-merisation zone under fast fluidisation conditions, leave said first zone and enter a second polymerisation zone through which they flow in a densified form under the action of gravity, leave said second zone and are reintroduced into the first polymerisation zone, thus establishing a circulation of polymer between the two polymerisation zones. The present invention is characterised in that a gas of composition different from that present in the first polymerisation zone is introduced into the second polymerisation zone and it is avoided that the gases present in the first polymerisation zone are introduced into the second polymerisation zone.

Abstract: The present invention relates to MgCl2.mROH.nH2O adducts, where R is a C1-C10 alkyl, 2≦m≦4.2, 0≦n≦0.7, characterized by an X-ray diffraction spectrum in which, in the range of 2&thgr; diffraction angles between 5° and 15°, the three main diffraction lines are present at diffraction angles 2&thgr; of 8.8±0.2°, 9.4±0.2° and 9.8±0.2°, the most intense diffraction lines being the one at 2&thgr;=8.8±0.2°, the intensity of the other two diffraction lines being at least 0.2 times the intensity of the most intense diffraction line. Catalyst components obtained from the adducts of the present invention are capable to give catalysts for the polymerization of olefins characterized by enhanced activity and stereospecificity with respect to the catalysts prepared from the adducts of the prior art.

Abstract: The invention provides new prepolymerized catalyst components for the (co)polymerization of olefins CH2═CHR, wherein R is hydrogen or a C1-C12 alkyl group, characterized by comprising a solid catalyst component, comprising Ti, Mg, halogen and an electron donor compound, being capable of yielding, under standard polymerization conditions, a propylene homopolymer having an insolubility in xylene at 25° C. higher than 90%, which is prepolymerized with ethylene to such an extent that the amount of the ethylene prepolymer is up to 100 g per g of said solid catalyst component. These solid catalyst components display to obtain a high catalyst activity, a high isotactic index, and are not affected by aging.

Abstract: The present invention relates to MgCl2.mROH.nH2O adducts, where R is a C1-C10 alkyl, 2≦m≦4.2, 0≦n≦0.7 , characterized by an X-ray diffraction spectrum in which, in the range of 2&thgr; diffraction angles between 5° and 15°, the three main diffraction lines are present at diffraction angles 2&thgr; of 8.8±0.2°, 9.4±0.2° and 9.8±0.2°, the most intense diffraction lines being the one at 2&thgr;=8.8±0.2°, the intensity of the other two diffraction lines being at least 0.2 times the intensity of the most intense diffraction line. Catalyst components obtained from the adducts of the present invention are capable to give catalysts for the polymerization of olefins characterized by enhanced activity and stereospecificity.

Abstract: The present invention relates to MgCl2.mROH.nH2O adducts, where R is a C1-C10 alkyl, 2≦m≦4.2, 0≦n≦0.7 , characterized by an X-ray diffraction spectrum in which, in the range of 2&thgr; diffraction angles between 5° and 15°, the three main diffraction lines are present at diffraction angles 2&thgr; of 8.8±0.2°, 9.4±0.2° and 9.8±0.2°, the most intense diffraction lines being the one at 2&thgr;=8.8±0.2°, the intensity of the other two diffraction lines being at least 0.2 times the intensity of the most intense diffraction line.

Abstract: Process for gas-phase polymerization carried out in two interconnected polymerization zones, to which one or more &agr;-olefins CH2═CHR are fed in the presence of catalyst under reaction conditions and from which the polymer product is discharged. The process is characterized in that the growing polymer flows through a first polymerization zone under fast fluidization conditions, leaves said first zone and enters a second polymerization zone through which it flows in a densified form under the action of gravity, leaves said second zone and is reintroduced into the first polymerization zone, thus establishing a circulation of polymer around the two polymerization zones. The novel process allows olefins to be polymerized in the gas phase with high productivity per unit volume of the reactor without incurring the problems of the fluidized-bed technologies of the known state of the art.

Abstract: The present invention relates to MgCl2.mROH.nH2O adducts, where R is a C1-C10 alkyl, 2≦m≦4.2, and 0≦n≦0.7, characterized by a differential scanning calorimetry (DSC) profile in which no peaks are present at temperatures below 90° C. or, if peaks are present below said temperature, the fusion enthalpy associated with said peaks is less than 30% of the total fusion enthalpy. Catalyst components obtained from the adducts of the present invention are capable to give catalysts for the polymerization of olefins characterized by enhanced activity and stereospecificity with respect to the catalysts prepared from the adducts of the prior art.

Abstract: The present invention relates to components of catalysts for the polymerization of olefins comprising a metallocene compound and a magnesium halide which have particular values of porosity and surface area. Group 4 and vanadium metallocenes are useful metallocenes and the components typically include an electron donor such as an ether, ester or ketone. In particular the components of the invention have surface area (BET) greater than about 50 m2/g, porosity (BET) greater than about 0.15 cm3/g and porosity (Hg) greater than 0.3 cm3/g, with the proviso that when the surface area is less than about 150 m2g, the porosity (Hg) is less than about 1.5 cm3/g. The magnesium halide is complexed by an ether, ester, or ketone electro donor. The components of the invention are particularly suitable for the preparation of catalysts for the gas-phase polymerization of &agr;-olefins.

Abstract: Process for gas-phase polymerization carried out in two interconnected polymerization zones, to which one or more &agr;-olefins CH2=CHR are fed in the presence of catalyst under reaction conditions and from which the polymer product is discharged. The process is characterized in that the growing polymer flows through a first polymerization zone under fast fluidization conditions, leaves said first zone and enters a second polymerization zone through which it flows in a densified form under the action of gravity, leaves said second zone and is reintroduced into the first polymerization zone, thus establishing a circulation of polymer around the two polymerization zones. The novel process allows olefins to be polymerized in the gas phase with high productivity per unit volume of the reactor without incurring the problems of the fluidized-bed technologies of the known state of the art.

Abstract: A process for the preparation of heterophasic polyolefin compositions by (i) polymerizing to form (a) a crystalline propylene or ethylene polymer, and (b) an elastomeric copolymer of ethylene and a C3-C10 &agr;-olefin, wherein the polymerizations are carried out in the presence of a Ziegler-Natta catalyst, (ii) contacting the polymer obtained in (i) with: (a) a compound capable of deactivating the catalyst present in (i), and (b) a catalyst (2) obtained by contacting (I) a compound containing a transition metal M, and at least one ligand coordinated with the metal M by a &pgr; bond, and (II) a cocatalyst, and (iii) copolymerizing ethylene and a C3-C10 &agr;-olefin in the presence of the polymer treated as in (ii), and the catalyst (2).

Abstract: The present invention relates to a process for the preparation of MgCl2.pROH.qH2O adducts, where R is a C1-C10 alkyl, 1≦p≦6, and 0≦q≦1, comprising the steps of (a) dispersing magnesium dichloride in an inert liquid, (b)adding the alcohol in vapour phase and maintaining the temperature at values allowing the adduct to be melted, (c)emulsifying the molten adduct in a liquid medium immiscible with and chemically inert to said adduct and, (d) contacting the adduct with an inert cooling liquid.

Abstract: The present invention relates to components of catalysts for the polymerization of olefins comprising a metallocene compound and a magnesium halide which have particular values of porosity and surface area. In particular the components of the invention have surface area (BET) greater than about 50 m2/g, porosity (BET) greater than about 0.15 cm3/g and porosity (Hg) greater than 0.3 cm3/g, with the proviso that when the surface area is less than about 150 m2/g, the porosity (Hg) is less than about 1.5 cm3/g. The components of the invention are particularly suitable for the preparation of catalysts for the gas-phase polymerization of &agr;-olefins.

Abstract: Components of bimetallic catalysts for the polymerization of olefins comprising a compound of a transition metal M selected from Ti, V, Zr and Hf containing at least one M-&pgr; bond, a compound of Ti or V not containing metal-&pgr; bonds and a support comprising a magnesium halide. The catalysts obtained from the components of the invention are particularly suitable for gas-phase polymerization processes.

Abstract: Components of bimetallic catalysts for the polymerization of olefins comprising a compound of a transition metal M selected from Ti, V, Zr and Hf containing at least one M-&pgr;bond, a compound of Ti or V not containing metal-&pgr; bonds and a support comprising a magnesium halide. The catalysts obtained from the components of the invention are particularly suitable for gas-phase polymerization processes.

Abstract: Process for the gas-phase polymerization of olefins of the formula CH2═CHR where R is hydrogen or an alkyl or aryl radical with 1 to 8 carbon atoms carried out in one or more reactors having a fluidized or mechanically agitated bed, using a catalyst obtained by reaction of a titanium halide or haloalcoholate and optionally an electron-donor compound supported on an active Mg-dihalide with an Al-trialkyl compound and optionally an electron-donor compound, comprising the steps of: a) contacting the catalyst components in the absence of polymerizable olefin or optionally in the presence of said olefin in an amount to from up to 3 g per g of solid catalyst component; b) prepolymerizing propylene or mixtures of propylene with ethylene or an alpha-olefin to form a propylene polymer having an insolubility in xylene of at least 60% by weight, in an amount of from 5 g of polymer per g of solid catalyst component to 10% by weight of the final catalyst yield; and c) polymerizing one or more CH2═CHR olefins

Abstract: The present invention relates to MgCl.sub.2.mROH.nH.sub.2 O adducts, where R is a C.sub.1 -C.sub.10 alkyl, 2.ltoreq.m.ltoreq.4.2, 0.ltoreq.n.ltoreq.0.7, characterized by an X-ray diffraction spectrum in which, in the range of 2.theta. diffraction angles between 5.degree. and 15.degree., the three main diffraction lines are present at diffraction angles 2.theta. of 8.8.+-.0.2.degree., 9.4.+-.0.2.degree. and 9.8.+-.0.2.degree., the most intense diffraction lines being the one at 2.theta.=8.8.+-.0.2.degree., the intensity of the other two diffraction lines being at least 0.2 times the intensity of the most intense diffraction line. Catalyst components obtained from the adducts of the present invention are capable to give catalysts for the polymerization of olefins characterized by enhanced activity and stereospecificity with respect to the catalysts prepared from the adducts of the prior art.

Abstract: Components and catalysts for the polymerization of olefins comprising the product obtained by contacting a compound of a transition metal M, containing at least one M-.pi. bond, with an olefinic prepolymer obtained by polymerization of one or more olefins with a coordination catalyst comprising a compound of Ti or V supported on a magnesium halide.

Abstract: A method and apparatus for the classification of solid particles, in particular powdery catalytic components for the polymerization of olefins, which comprises sending solid particles suspended in a transporting gas flow through a screening device. Immediately upstream to the screening device there is an auxiliary fluidized bed classifier, in which the top of the bed is at the level of the lower part of the screening device.