Abstract: Single step process for the preparation of lower ?-alkene polymerisation heterogeneous solid catalyst, wherein the procatalyst is obtained by reacting organomagnesium precursor and titanium tetrahalide or titanium haloalkoxo species of the formula Ti(OR)m Xn, with a hydrocarbon or halohydrocarbon solvent and internal electron donor and optionally an acid halide under microwave irradiation of 300 to 1200 W. The mole ratio of the organomagnesium precursor to the titanium tetrachloride or titanium haloalko species is 1:6 to 1:20 and the mole ratios of the electron donor and acid halide to titanium is 0.3 to 1.5 and 0.02 to 0.2, respectively.

Abstract: The present invention includes a bimodal polyethylene polymerization process wherein metallocene catalyst to is used to adjust the hydrogen response of a Ziegler-Natta catalyst. The polymerization may be carried out in a single reactor or in two or more reactors in series, preferably two or more continuously stirred tank reactors in series. In an embodiment having two or more reactors, the Zeigler-Natta catalyst is added to a first reactor and the metallocene catalyst is added to a downstream reactor. In another embodiment having two or more reactors, the Zeigler-Natta catalyst and metallocene catalyst are added to the same reactor, preferably an upstream reactor. A preferred Zeigler-Natta catalyst comprises TiCl4, and a preferred metallocene catalyst comprises bis(cyclopentadienyl) titanium dichloride.

Abstract: A process for producing a Gp 2/transition metal olefin polymerisation catalyst component, in which a Gp 2 complex is reacted with a transition metal compound so as to produce an oil-in-oil emulsion, the disperse phase containing the preponderance of the Gp 2 metal being selectively sorbed on a carrier to provide a catalyst component of excellent morphology. Polymerisation of olefins using a catalyst containing such a component is also disclosed.

Abstract: Methods of controlling the flow index and/or molecular weight split of a polymer composition are disclosed. The method of producing a polymer composition in one embodiment comprises incorporating a high molecular weight polymer into a low molecular weight polymer to form the polymer composition in a single polymerization reactor in the presence of polymerizable monomers, a bimetallic catalyst composition and at least one control agent; wherein the control agent is added in an amount sufficient to control the level of incorporation of the high molecular weight polymer, the level of low molecular weight polymer, or both. Examples of control agents include alcohols, ethers, amines and oxygen.

Abstract: Disclosed are compounds of formula (I) which compounds are useful as cocatalysts in olefinic polymerisation reactions, e.g., as Ziegler-Natta catalysts.

Abstract: The invention provides a process for producing an olefin polymerization catalyst comprising a catalyst component formed by contacting at least (a) a compound of Group 1 to 3 of the Periodic Table (IUPAC) with (b) a transition metal compound of Group 4 to 10 of the Periodic Table (IUPAC) or a compound of an actinide or lanthanide, in the form of solid catalyst particles, said process comprising: (1) preparing a solution from said compounds; (2) dispersing said solution to a solvent immiscible therewith and inert in relation to said compounds, to obtain an emulsion in which said solution forms the dispersed phase; and (3) solidifying the catalyst component in the dispersed droplets.

Abstract: The present invention relates to a new solid catalytic component, which can be used in combination with an aluminum compound as co-catalyst and optionally an external electron donor as additional co-catalyst to form a catalytic system of the Ziegler-Natta-catalyst-type. The solid catalytic system comprises titanium or vanadium compound, a compound of magnesium containing at least one halogen, a particulate porous support, and optionally an internal electron donor.

Abstract: An internal electron-donor compound selected from the 1,3-diethers of formula (I) in which R is a C1–C10 alkyl group, R1 is a linear or branched primary alkyl radical having at least three carbon atoms, optionally containing a heteroatom, and R2 is a secondary alkyl or cycloalkyl radicals different from i-propyl, optionally containing a heteroatom.

Abstract: Catalyst components for the polymerization of olefins CH2?CHR, wherein R is hydrogen or a hydrocarbon radical having 1–12 carbon atoms, comprising Mg, Ti, Cl, OR groups, where R is a C1–C10 alkyl group optionally containing heteroatoms, and an ether having two or more ether groups, characterized by the fact that the Mg/Ti weight ratio is lower than 3 from 2 to 6.5 the Cl/Ti weight ratio is from 1.5 to 6, the OR/Ti weight ratio is from 0.5 to 3.5 and at least 50% of the Titanium atoms are in a valence state lower than 4. The said catalyst components allow the preparation of ethylene copolymers with a low content of xylene soluble fractions.

Abstract: It has been discovered that using n-butylmethyldimethoxysilane (BMDS) as an external electron donor for Ziegler-Natta catalysts can provide a catalyst system that may prepare polypropylene films with improved properties. The catalyst systems of the invention provide for controlled chain defects/defect distribution and thus a regulated microtacticity. Consequently, the curve of storage modulus (G?) v. temperature is shifted such that the film achieves the same storage modulus at a lower temperature enabling faster throughput of polypropylene film through a high-speed tenter.

Abstract: The present invention relates to a solid catalyst component for the polymerization of olefins CH2?CHR in which R is hydrogen or a hydrocarbon radical with 1–12 carbon atoms, comprising Mg, Ti, halogen and an electron donor selected from succinates, said catalyst component being obtainable by a process comprising the following steps: (a) dissolving a halide of magnesium in a solvent system comprising an organic epoxy compound or an organic phosphorus compound and optionally an inert diluent to form a solution; (b) mixing the obtained solution with a titanium compound to form a mixture; (c) precipitating a solid from the mixture obtained in step (b) in the presence of a succinate and/or an auxiliary precipitant; (d) if a succinate is not used in step (c), contacting the solid obtained in (c) with a succinate, and (e) treating the solid obtained in (c) or (d) with a titanium compound optionally in the presence of an inert diluent.

Abstract: The invention provides ethylene/?-olefin copolymers exhibiting improved environmental stress cracking resistance properties, and methods for the production of the copolymers in a single reactor by means of a bimetallic catalyst including a Ziegler component and a metallocene component.

Abstract: The invention relates to a modified Ziegler catalyst for preparing a poly-1-olefin in suspension, in solution or in the gas phase, which catalyst comprises the reaction product of a magnesium alkoxide (component a) with a transition metal compound (component b) and an organometallic compound (component c) together with an additional component (d) comprising a compound of the chemical formula M?Rx where M is an element of main group IV of the Periodic Table, R is halogen or an organic radical such as alkyl having from 1 to 10 carbon atoms, oxyalkyl having from 1 to 10 carbon atoms, cycloalkyl having from 4 to 8 carbon atoms in the ring and, if desired, from 1 to 6 substituents R? on the ring, aryl having from 6 to 10 carbon atoms in the aromatic and, if desired, from 1 to 6 substituents R? on the aromatic, where R? is a halogen or an alkyl radical having from 1 to 4 carbon atoms or an OH group or an NO2 group or an oxyalkyl radical having from 1 to 4 carbon atoms, and x is an integer from 1 to 4.

Abstract: A pre-catalyst is formed by reacting butylethylmagnesium with an alcohol to form a magnesium alkoxide compound, followed by contacting the magnesium alkoxide compound with a phosphorous compound to form a magnesium alkoxide phosphorous compound mixture. The magnesium alkoxide phosphorous compound mixture is subsequently reacted with TiCl4 to form a MgCl2 support. The MgCl2 support is then contacted with an internal donor while being heated to form a first catalyst slurry, which is then contacted with TiCl4 while being heated to form a second catalyst slurry. The second catalyst slurry is next contacted with TiCl4 while being heated to form a third catalyst slurry, which is washed and dried, resulting in a highly active pre-catalyst with controlled morphology. The pre-catalyst may be combined with one or more co-catalysts and optionally one or more external electron donors to form an active catalyst system, which may be used for the polymerization of olefins.

Abstract: The present invention relates to propylene polymers made by using catalyst components for the polymerization of olefins comprising Mg, Ti, halogen and at least two electron donor compounds, said catalyst component being characterized by the fact that at least one of the electron donor compounds, present in an amount from 20 to 50% by mol with respect to the total amount of donors, is selected from esters of succinic acids which are not extractable, under the conditions described below, for more than 25% by mol and at least another electron donor compound which is extractable, under the same conditions, for more than 35%. The said catalyst component are capable to give polymers with high xylene insolubility, high stereoblock content and broad MWD suitable for making the polymers usable in the BOPP sector.

Abstract: It has been discovered that using di-sec-butyldialkoxysilanes, such as di-sec-butyldimethoxysilane (DSBDMS), as external electron donors for Ziegler-Natta catalysts can provide a catalyst system that may prepare polypropylene films with improved properties and processing. The catalyst systems of the invention provide high activity, high bulk density, moderate hydrogen response, moderate donor response and high polydispersity (MWD). Suitable di-sec-butyldialkoxysilanes have the formula (sBu)2Si(OR?)2, where R? is independently a straight or branched alkyl group of 1–5 carbon atoms.

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 spray-dried composition comprising the reaction product of a magnesium halide, a solvent, an electron donor compound, and a transition metal compound and an inert filler comprising substantially spherical particles having an average particle size ranging from about 1 ?m to about 12 ?m, and a polymerization process using the same.

Abstract: A process for preparing olefin homopolymers or copolymers by polymerization of at least one olefin in a hydrocarbon (mixture) in the presence of a molar mass regulator, a mixed catalyst and a substance which increases the electrical conductivity of the hydrocarbon (mixture) and is soluble in the hydrocarbon or the mixture of hydrocarbons or which reacts with components of the mixed catalyst, wherein the mixed catalyst is obtainable by reaction of a magnesium alkoxide with titanium(IV) halide and comprises titanium in the oxidation states four and three and also an organic aluminum compound, where the molar ratio of Ti(IV) to Ti(III) is from 100:1 to 1:100. The process makes it possible to prepare, in particular, polyethylenes having an ultrahigh molecular weight. The formation of deposits on the walls during the polymerization is significantly reduced.

Abstract: The present invention provides a catalyst component for ethylene polymerization, a process for preparing the same, a catalyst comprising the same, and a process for polymerizing ethylene using the catalyst. The catalyst component comprises a reaction product, supported on an inorganic oxide support, of a magnesium complex, a titanium compound, an alcohol compound, and an organoaluminum compound, wherein said magnesium complex is formed by dissolving a magnesium halide in a solvent system comprising an organic epoxy compound and an organo phosphorus compound. The catalyst according to the invention is especially suitable for slurry phase polymerization of ethylene. The catalyst according to the present invention has high catalytic activity, and a good hydrogen response, with the resultant polymer having a more uniform particle size diameter and a narrow particle size distribution.

Abstract: An improved two-step polymerization process wherein ethylene homopolymer is produced in a first reactor and ethylene copolymer having narrowed short-chain branching distribution is prepared in a second reactor. Narrowed short-chain branching distribution of the copolymer is achieved by including specific silane modifiers in the second reactor.

Abstract: A catalyst for olefin polymerization comprising (A) a solid catalyst component which is prepared by causing (a) a magnesium compound, (b) a tetravalent titanium halide compound, and (c) an electron donor compound to come in contact with each other, (B) an organoaluminum compound of the formula R1pAlQ3-p, and (C) an organosilicon compound of the formula SiR2R3(OR4)(OR5), and (D) an organosilicon compound of the formula R6xSi(OR7)4-x exhibits a higher hydrogen activity than conventional catalysts.

Abstract: A process for the trimerization of olefins is disclosed, comprising contacting a monomeric olefin or mixture of olefins under trimerization conditions with a catalyst which comprises (a) a source of chromium, molybdenum or tungsten (b) a ligand containing at least one phosphorus, arsenic or antimony atom bound to at least one hydrocarbyl or heterohydrocarbyl group having a polar substituent, but excluding the case where all such polar substituents are phosphane, arsane or stibana groups; and optionally (c) an activator.

Abstract: A catalyst composition for the polymerization of olefins and process for the use thereof, comprising the combination of one or more Ziegler-Natta catalysts, comprising one or more transition metal compounds, one or more aluminum containing cocatalyts, and a mixture of different selectivity control agents, including in said mixture of selectivity control agents at least one normally dominating selectivity control agent and one normally dominated selectivity control agent, characterized in that the individual selectivity control agents are present in the mixture in relative amounts to each other and relative to the one or more transition metal compounds, such that the effect of the selectivity control agents on the resulting polymer properties is not determined solely or substantially solely by the normally dominating selectivity control agent.

Abstract: Disclosed are catalyst systems and methods of making the catalyst systems/supports for the polymerization of an olefin containing a solid titanium catalyst component having a substantially spherical shape and containing an internal electron donor, a support made from a magnesium compound, an alcohol, an ether, a surfactant, and an alkyl silicate. The catalyst system may further contain an organoaluminum compound and an organosilicon compound. Also disclosed are methods of making an impact copolymer involving polymerizing an olefin to provide a polyolefin matrix and polymerizing a polyolefin rubber using a catalyst component containing a support made from a magnesium compound, an alcohol, an ether, a surfactant, and an alkyl silicate.

Abstract: There are disclosed a process for producing a solid catalyst component and a catalyst for ?-olefin polymerization, and a process for producing an ?-olefin polymer, wherein the process for producing a solid catalyst component comprises the steps of: (1) reducing a specific titanium compound with an organomagnesium compound in the presence of an organosilicon compound having an Si—O bond (and an ester compound), thereby obtaining a solid product, and (2) contacting the solid product with a halogeno compound of the 14 group element, at least one member selected from the group consisting of an electron donor compound and an organic acid halide, and a compound having a Ti-halogen bond, thereby obtaining the solid catalyst component.

Abstract: The present invention provides a method for producing homo- and co-polymers of ethylene, or more particularly a method for producing homo- and copolymers of ethylene in the presence of (a) a solid titanium catalyst produced by preparing a magnesium solution by contact-reacting a halogenated magnesium compound with an alcohol; reacting thereto an ester compound having at least one hydroxyl group and a silicon compound having at least one alkoxy group; and adding a mixture of a titanium compound and a silicon compound; (b) organometallic compounds of Group II or III of the Periodic Table; and (c) an alkoxysilane compound and a haloalkne compound. The catalyst for homo- and co-polymerization of ethylene, produced according to the present invention, exhibits a high activity and the polymers produced by the method of the present invention using said catalyst have the advantages of exhibiting a high bulk density and a narrow molecular weight distribution.

Abstract: A catalyst system useful for polymerizing olefins is disclosed. The catalyst system comprises a cocatalyst and a supported transition metal prepared from a halogen-containing Group 4–6 transition metal compound and an organoaluminum-siloxane containing mixture. The latter mixture, which is prepared from an organoaluminum compound and an organomagnesium-siloxane reaction product, incorporates a chelating ligand. The invention includes a method for making the catalyst system and a process for polymerizing olefins using the catalyst system. The process is convenient and avoids expensive catalyst components used in known olefin polymerization processes.

Abstract: Propylene polymers having a content of isotactic pentads (mmmm) higher than 97%, molecular weight distribution, expressed by the formula (a) ratio, equal to or higher than 6 and a value of formula (b) ratio equal to or lower than 5.5. The said polymers are prepared in the presence of a particular combination of Ziegler-Natta solid catalyst components and highly stereoregulating electron-donor compounds. Laminated articles, in particular bi-axially oriented films and sheets, can be prepared with the said polymers {overscore (M)}w/{overscore (M)}n ??(a) {overscore (M)}z/{overscore (M)}w.

Abstract: It has been discovered that using n-butylmethyldimethoxysilane (BMDS) as an external electron donor for Ziegler-Natta catalysts can provide a catalyst system that may prepare polypropylene films with improved properties. The catalyst systems of the invention provide for controlled chain defects/defect distribution and thus a regulated microtacticity. Consequently, the curve of storage modulus (G?) v. temperature is shifted such that the film achieves the same storage modulus at a lower temperature enabling faster throughput of polypropylene film through a high-speed tenter.

Abstract: The present invention provides a prepolymerized olefin polymerization catalyst and olefin polymerization method using the same. More particularly, the present invention provides a prepolymerized catalyst that is encapsulated with macromonomers produced by polymerizing olefin monomers with a vinyl-terminated polysiloxane compound in the presence of a solid titanium catalyst for olefin polymerization having been previously surface treated with silane compounds containing two or more vinyl groups, and a method for producing polyolefin having a high melt strength using the catalyst.

Abstract: A process for the (co) polymerization of olefins of formula CH2?CHR wherein R is a hydrogen atom, a methyl or an ethyl radical, carried out in the presence of a system comprising (a) solid catalyst component comprising a compound of Ti or V not containing Metal-? bonds, Mg, halogen and optionally an electron donor compound; (b) an Al-alkyl compound; and (c) one or more non-polymerizing olefins in an amount up to 1.2% by mol with respect to the total olefins present in the reactor.

Abstract: A MgCl2·mEtOH·nH2O adducts, where 3.4<m?4.4, 0?n?0.7, characterized by an X-ray diffraction spectrum, taken under the condition set forth above, in which, in the range of 2? diffraction angles between 5° and 10°, at least two diffraction lines are present at diffraction angles 2? of 9.3±0.2°, and 9.9±0.2°, the most intense diffraction lines being the one at 2? of 9.3±0.2°, the intensity of the other diffraction line being less than 0.4 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/or porosity with respect to the catalysts prepared from the adducts of the prior art.

Abstract: The present invention relates to a process for homopolymerization of ethylene or copolymerization of ethylene with alpha-olefins by contacting ethylene or ethylene and alpha-olefin with a catalyst composition comprising: (a) a solid catalyst precursor comprising at least one vanadium compound, at least one magnesium compound and a polymeric material or a solid catalyst precursor comprising at least one vanadium compound, at least one further transition metal compound and/or at least one alcohol, at least one magnesium compound and a polymeric material; and (b) a cocatalyst comprising an aluminum compound.

Abstract: A solid catalyst component for olefin polymerization comprising titanium, magnesium and a compound of the general formula (I) wherein R1 and R2 are independently a C3 straight or branched hydrocarbon group, R3 is hydrogen or a C1-4 straight hydrocarbon group, R4 is a C1-4 straight or branched hydrocarbon group or a C3-4 aliphatic cyclic hydrocarbon group when R3 is hydrogen, R4 is the same C1-4 straight hydrocarbon group as R3 when R3 is a C1-4 straight hydrocarbon group, and n is an integer of 1 to 10. A catalyst for olefin polymerization, containing this catalyst component, obtains a high activity with high stereospecificity.

Abstract: It has been discovered that using di-sec-butyldialkoxysilanes, such as di-sec-butyldimethoxysilane (DSBDMS), as external electron donors for Ziegler-Natta catalysts can provide a catalyst system that may prepare polypropylene films with improved properties and processing. The catalyst systems of the invention provide high activity, high bulk density, moderate hydrogen response, moderate donor response and high polydispersity (MWD). Suitable di-sec-butyldialkoxysilanes have the formula (SBu)2Si(OR?)2, where R? is independently a straight or branched alkyl group of 1–5 carbon atoms.

Abstract: Crystalline polymers and copolymers of propylene having total MIL values>2 g/10 minutes, total [?] values in tetrahydronaphthalene at 135° C.?2/8 dl/g, Mw/Mn values>20, a fraction insoluble in xylene at 25° C.?94, and including from 10 to 60% by weight of a fraction (A) having [?]?2.6, are prepared by way of sequential polymerization in at least two stages, in the presence of particular Ziegler-Natta catalysts supported on magnesium halides. These polymers have high melt strength, high mechanical properties, and are particularly adequate for the manufacture of articles by using various conversion technologies, such as for example extrusion in thin sheets to be subjected to thermoforming, as well as for injection molding, and blow molding.

Abstract: A method for making a Ziegler-Natta catalyst support includes the steps of contacting a fumed silica with a surface modifying agent such as a compound having the formula RMgX MgR?R? wherein R, R? and R? are each individually a moiety selected from an alkyl group, cycloalkyl, aryl or alkaryl group, and X is a halogen selected from the group consisting of chlorine, bromine and iodine, to provide a pretreated silica seeding agent. The pretreated silica seeding agent is then dispersed in a non-aqueous liquid magnesium halide/alkanol complex, and the magnesium halide is crystallized onto the silica particles to form catalyst support particles especially suitable for Ziegler-Natta catalysts.

Abstract: The present invention relates to a MgCl2.mEtOH adduct in which m is from 2.5 to 3.2 optionally containing water up to a maximum of 1% wt based on the total weight of the adduct, characterized by a DSC profile in which the highest melting Temperature (Tm) peak is over 109° C. and has an associated fusion enthalpy ( H) of 103 J/g or lower. Catalyst components obtained from the adducts of the present invention are capable to give catalysts for the polymerization of olefins characterized by enhanced activity with respect to the catalysts prepared from the adducts of the prior art.

Abstract: A method for polymerization and copolymerization of ethylene is disclosed. The polymerization is carried out in the presence of a preactivated titanium solid complex catalyst supported on a carrier containing magnesium. The resulting polymers have the advantage of high bulk density and broad molecular weight distribution.

Abstract: The present invention relates to propylene polymerization process in a bulk loop reactor, and particularly to propylene polymerization process for polymerizing commercial quantities of polypropylene in a bulk loop reactor by sequentially introducing Ziegler-Natta and metallocene catalyst systems into the bulk loop reactor.

Abstract: Cyclopolyenic 1,3-diethers wherein the carbon atom in position 2 belongs to a particular cyclic or polycyclic structure containing two or three unsaturations, solid catalyst components and catalysts therefrom, the catalysts comprising the reaction product of: i. a solid catalyst component containing an internal donor; ii. an Al-alkyl compound, and optionally iii. an external donor; the internal donor and/or the external donor being cyclopolyenic 1,3-diethers. The catalysts are useful for the polymerization of alpha-olefins.

Abstract: There are provided a process for producing a catalyst for ?-olefin polymerization, which comprises the step of contacting (1) a solid catalyst component having Ti, Mg and a halogen as essential components, (2) an organoaluminum compound and (3) a compound having a —C—O—C—O—C— bond group in a closed ring structure with one another; and a process for producing an ?-olefin polymer, which comprises the step of homopolymerizing or copolymerizing an ?-olefin in the presence of a catalyst for ?-olefin polymerization produced by the above process.

Abstract: Supported catalysts include a solid support such as silica that is functionalized to have inorganic acid functional groups attached thereto. Active catalyst particles are supported on the functionalized support material. The acid functionalized support material is made by reacting a solid support with an inorganic acid containing agent such as sulfuric acid or para-toluene sulfonic acid. An organic anchoring agent is used to form and anchor catalyst nanoparticles to the acid functionalized support material. The supported catalyst can be sized and shaped for use in any type of reactor, including a fixed bed or fluidized bed reactor. The methods of the present invention also include a process for the direct synthesis of hydrogen peroxide using the supported catalyst.

Abstract: There is provided a process for the copolymerisation of propylene with at least one C4-20 ?-olefin or C4-20 diene in a reaction medium in the presence of a catalyst system at a temperature of greater that 80° C. or at a temperature and pressure above the critical temperature and pressure of the reaction medium. Under such conditions, comonmer incorporation is higher than under standard conditions.

Abstract: Process for the preparation of a particular olefin polymerisation catalyst component including magnesium dihalide, titanium tetrahalide and a carboxylic acid ester, in which the precursors of its constituents are reacted in solution from which the component is precipitated, this precipitation being accompanied by co-precipitation of one or more oligoesters of the carboxylic acid formed in a controlled manner.

Abstract: A process for the preparation of heterophasic elastomeric polymer comprising the step of polymerizing ethylene, an alpha-olefin CH2?CHL, where L is an alkyl, cycloalkyl or aryl radical with 1–10 carbon atoms and a non-conjugated diene in the presence of a catalyst system comprising a transition metal catalyst component supported on a porous alpha-olefin polymer, characterized in that at least part of the diene is impregnated on the porous alpha-olefin polymer.

Abstract: A monomer stream containing propylene is supplied to a polymerization reactor which is operated under temperature and pressure conditions effective for the production of a stereoregular propylene polymer fluff. A titanium-based supported Ziegler-Natta catalyst having a titanium content of at least 1.7 wt. % and incorporating an internal electron donor is incorporated into the monomer stream. A trialkylaluminum co-catalyst is supplied to the monomer stream in an amount to provide an aluminum/titanium molar ratio within the range of 50–500. A silicon-based external electron donor is also supplied to the monomer stream in an amount to provide an aluminum/silicon molar ratio within the range of 10–500. Polymer fluff recovered from the polymerization reactor has a melt flow rate of at least 200 grams/10 minutes, and a xylene soluble content of no more than 4 wt. %.

Abstract: A method of preparing ultra high melt flow polypropylene having reduced xylene solubles is provided. The method utilizes a diether internal donor-containing Ziegler-Natta catalyst system to polymerize propylene. The polypropylene produced is characterized by having a melt flow of at least about 300 g/10 min and a xylene solubles of not more than about 3.5% and no peroxide residue. The catalyst system may also include an internal phthalate donor. The method of the invention allows the amount of external donors to be reduced, or even eliminated, without significant increases in xylene solubles.

Abstract: A process for the (co)polymerization ethylene, optionally in mixtures with olefins CH?CHR in which R is hydrogen or a hydrocarbyl radical with 1–12 carbon atoms, carried out in the presence of a catalyst system comprising (A) a solid catalyst component which comprises Mg, halogen an electron donor selected form ethers, esters, or amines, and Ti atoms in an oxidation state such that the weight percentage ratio between Ti(red)/Ti(tot) ranges from about 0.05 to about 1; wherein Ti(red) is the weight percentage on the solid catalyst component of the Ti atoms having a valence less than 4 and Ti(tot) is the weight percentage on the solid catalyst component of all the Ti atoms and (B) an Al-alkyl compound. The said process is capable to produce ethylene polymers with a reduced oligomers content and/or improved mechanical characteristics.