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: 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 is provided for the preparation of a solid catalyst component for the polymerization of olefins, comprising continuously feeding a liquid containing a titanium compound having at least one titanium-halogen bond into a vessel containing a solid comprising a magnesium halide and continuously discharging liquid from the vessel, whereby the concentration of the solid is maintained within the range of between 80 and 300 g/l, and the product between the average residence time of the liquid in the vessel and the concentration of the solid is maintained below 10,000 min*g/l. An advantage of the process is the reduced time and reactor volume necessary to prepare the catalysts, which show good activity and stereospecificity.

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: A process is provided for the preparation of a solid catalyst component for the polymerization of olefins, comprising continuously feeding a liquid containing a titanium compound having at least one titanium-halogen bond into a vessel containing a solid comprising a magnesium halide and continuously discharging liquid from the vessel, whereby the concentration of the solid is maintained within the range of between 80 and 300 g/l, and the product between the average residence time of the liquid in the vessel and the concentration of the solid is maintained below 10,000 min*g/l. An advantage of the process is the reduced time and reactor volume necessary to prepare the catalysts, which show good activity and stereospecificity.

Abstract: Polyethylene composition comprising (percentages by weight): A) from 60 to 95% of an LLDPE copolymer having a density from 0.905 to 0.9 g/cm3, Mw/Mn values less than 4 and F/E ratio values greater than 20; B) from 5 to 40% of one or more crystalline copolymers of propylene selected from among defined copolymers of propylene with ethylene and/or higher alpha-olefins.

Abstract: Polyethylene composition comprising (percentages by weight): A) from 60 to 95% of an LLDPE copolymer having a density from 0.905 to 0.935 g/cm3, {overscore (M)}w/{overscore (M)}n values less than 4 and F/E ratio values from 10 to 20; B) from 5 to 40% of one or more crystalline copolymers of propylene selected among defined copolymers of propylene with ethylene and/or higher alpha-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: 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 polybutene-1 homopolymers, or copolymers containing up to 20% by weight of alpha olefins having from 2 to 10 carbon atoms other than butene-1, characterized by the following properties: (i) an isotactic index (mmmm %), measured by NMR analysis according to the method specified below, of higher than 93; (ii) a Molecular Weight Distribution (MWD) in terms of Mw/Mn, measured by GPC analysis according to the method specified below, of higher than 6; and (iii) a content of catalytic residues expressed in terms of Ti ppm of lower than 50. Said polymers are very suitable for the preparation of articles, in particular pipes, having improved creep and burst stress resistance.

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: Process for the gas-phase polymerization of ethylene and ethylene mixtures with .alpha.-olefins CH.sub.2 .dbd.CHR in the presence of a high activity catalyst comprising a titanium compound containing at least one Ti-halogen bond, supported on magnesium dichloride in active form said process comprising the steps of: (a) contacting the catalyst component; (b) prepolymerizing ethylene or ethylene mixtures with .alpha.-olefins in order to produce a polymer amount of from approximately 5 g per g of solid component, up to an amount corresponding to about 10% of the final catalyst yield; (c) polymerizing ethylene or ethylene mixtures with .alpha.-olefins in the gas-phase, in the presence of the prepolymer-catalyst system obtained in (b), while maintaining in the gas phase a molar concentration concentration of the alkane comprised between 20 and 90% with respect to the total gases.

Abstract: Gas-phase process for the preparation of polymers and copolymers of olefins CH.sub.2 .dbd.CHR, carried out in at least 2 fluidized or mechanically agitated bed gas-phase reactors operating under different reaction conditions so as to obtain different polymers in the different reactors; the process is characterized in that the polymer is at least partially recycled among the different reactors by using ratios of the flow rate of circulation among the different reactors to the discharge flow rate comprised between 2 and 6.

Abstract: Process for gas-phase polymerization carried out in two interconnected polymerization zones, to which one or more .alpha.-olefins CH.sub.2 .dbd.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: Polymeric compositions based on Linear Low Density Polyethylene (LLDPE) comprising: (A) from 75 to 95% by weight of an ethylene copolymer with an .alpha.-olefin CH.sub.2 =CHR, wherein R is an alkyl radical having from 1 to 10 carbon atoms, and (B) from 5 to 25% by weight of a copolymer of propylene with ethylene and an .alpha.-olefin CH.sub.2 =CHR.sup.I, wherein R.sup.I is an alkyl radical having from 2 to 10 carbon atoms. Copolymer (B) is characterised by a relatively high insolubility in xylene. The polymeric compositions of the invention are endowed with improved processability and improved mechanical properties with respect to the LLDPE of the conventional type.

Abstract: Process for the preparation of LLDPE with improved processability by gas phase polymerization performed in two or more reactors, wherein, whatever the order, in one of the reactors a mixture of ethylene and an alpha-olefin CH.sub.2 .dbd.CHR, where R is an alkyl having 1-10 carbon atoms, is polymerized to yield a copolymer containing up to about 20% by mole of the alpha-olefin, and in another reactor a mixture of propylene and an alpha-olefin CH.sub.2 .dbd.CHR', where R' is an alkyl radical having 2-10 carbon atoms, is polymerized to yield a copolymer containing from 5 to 40% by weight of said olefin, in an amount of 5-30% with respect to the total polymer weight and the polymer-catalyst system obtained in the first reactor is fed to the other reactors.

Abstract: Discosed are compositions of crystalline propylene polymers comprising (by weight):A) 30-65% of a copolymer of propylene with a C.sub.4 -C.sub.8 .alpha.-olefin, containing from 98 to 80% propylene;B) 35-70% of a copolymer of propylene with ethylene and optionally from 2 to 10% of a C.sub.4 -C.sub.8 .alpha.-olefin, said copolymer containing 2 to 10% ethylene when the C.sub.4 -C.sub.8 .alpha.-olefin is not present, and 0.5 to 5% ethylene when the C.sub.4 -C.sub.8 .alpha.-olefin is present.