Abstract: Catalyst systems for polymerization of mixtures comprising an olefin include a selectivity control agent comprising at least one silicon-containing compound containing at least one C1-C10 alkoxy group bonded to a silicon atom and an amount of one or more agent compounds. The agent compound comprises C2-C13 mono- or polycarboxylic esters of aliphatic C2-C7 carboxylic acids and inertly substituted derivatives thereof. One or more polymerization catalysts may also be present. A polymerization process includes contacting an olefin or a mixture of the olefin and one or more copolymerizable comonomers under polymerization conditions with the catalyst composition.

Abstract: A liquid cyclopentene ring-opened polymer having a weight average molecular weight (Mw) of 1,000 to 50,000 and a cis double content of 55% or more in repeating units.

Abstract: A liquid cyclopentene ring-opened polymer having a weight average molecular weight (Mw) of 1,000 to 50,000 and a cis double content of 55% or more in repeating units.

Abstract: A Ziegler-Natta catalyzed ethylene copolymer having a novel composition distribution in which comonomers are incorporated into the high molecular weight polymer molecules and distributed evenly among the entire polyethylene chains, and a method for making the same are provided. The resins having a novel composition distribution have controlled molecular weight distribution which is narrower than conventional ZN-ethylene copolymers but broader than single-site catalyzed ethylene copolymers. The resins having a novel composition distribution exhibit a superior tear strength and impact strength.

Abstract: Regular shaped magnesium particles containing attrition resistant precursors and procatalysts thereof and processes for their synthesis and their use in the manufacture of polyolefins are described. A process for the synthesis of precursor particles which give highly active and improved surface area procatalysts for producing high bulk density polyolefin resins containing low fines and capable of incorporating high rubber content are described. A process for the synthesis of an attrition resistant precursors to prepare an attrition resistant Zeigler Natta procatalysts synthesized by using the precursors and to the polyolefin resin synthesized using the procatalysts is also described.

Abstract: The present invention relates to a multi-component catalytic system that can be used for the cis-1,4 stereospecific polymerization of conjugated dienes. The system is based on: (i) a rare-earth complex of Formula (II) Ln(A)3(B)n, Ln being a rare-earth metal, A a ligand, B a Lewis base or a solvent molecule and n a number from 0 to 3; (ii) an alkylating agent; (iii) a compound based on an aromatic ring and having at least two heteroatoms chosen from the elements O, N, S, P, and corresponding to the Formula (III): in which the R groups each denote hydrogen, an alkyl radical optionally comprising one or more heteroatoms (N, O, P, S, Si) or one or more halogen atoms, a halogen atom, a group based on one or more heteroatoms (N, O, P, S, Si); x and y are integers from 0 to 6; D is a group having a chemical function, one of the atoms of which has a non-bonding pair; L being an atom from column 1 of the Periodic Table.

Abstract: An interpolymer of ethylene and at least one alpha-olefin is claimed, wherein the ethylene interpolymer is characterized as having an average Mv and a valley temperature between the interpolymer and high crystalline fraction, Thc, such that the average Mv for a fraction above Thc from ATREF divided by average Mv of the whole polymer from ATREF (Mhc/Mp) is less then about 1.95 and wherein the interpolymer has a CDBI of less than 60%. The interpolymer of ethylene and at least one alpha-olefin can also be characterized as having a high density (HD) fraction and an overall density such that % HD fraction<?2733.3+2988.7x+144111.5 (x?0.92325)2 where x is the density in grams/cubic centimeter. Fabricated articles comprising the novel interpolymers are also disclosed.

Abstract: Regular shaped magnesium particles containing attrition resistant precursors and procatalysts thereof and processes for their synthesis and their use in the manufacture of polyolefins are described. A process for the synthesis of precursor particles which give highly active and improved surface area procatalysts for producing high bulk density polyolefin resins containing low fines and capable of incorporating high rubber content are described. A process for the synthesis of an attrition resistant precursors to prepare an attrition resistant Zeigler Natta procatalysts synthesized by using the precursors and to the polyolefin resin synthesized using the procatalysts is also described.

Abstract: A conjugated diene polymer comprising a constitutional unit based on a conjugated diene and a constitutional unit based on a compound represented by Formula (1) below, R1Si(OR2)mR3nR4(3-m-n)??(1) wherein m represents 1 or 2; n represents 1 or 2; m+n=2 or 3; R1 represents a hydrocarbyl group having a polymerizable carbon-carbon double bond; R2 represents a hydrocarbyl group, and, when there are plural R2s, R2s each may be the same or different; R3 represents an aryl group that may have an oxygen-containing substituent, and, when there are plural R3s, R3s each may be the same or different; and R4 represents an alkyl group or a substituted amino group.

Abstract: A method for manufacturing a styrene polymer having a low number average molecular weight and a low polydispersity index, wherein the polymer has a number average molecular weight of 2000 or less and a polydispersity index of 1.01 to 1.10. For this purpose, the method includes polymerizing a styrene monomer in a solvent comprising an ether group-containing solvent in the presence of a polymerization initiator represented by formula [II], an organometallic compound represented by formula [III], and an organic potassium compound, at a temperature between ?10° C. or higher and a boiling point of the solvent or lower.

Abstract: Process for polymerization of ethylene using a catalyst system including (i) a solid catalyst of Ti, Mg and halogen, (ii) a first activator which is at least one trialkylaluminium compound of the formula AlR3, where each R is independently a C2 to C20 alkyl radical, and (iii) a second activator which is at least one alkylaluminium chloride of the formula AlR?2Cl, where each R? is independently a C2 to C20 alkyl radical. The second activator is introduced directly into the polymerization reactor, without precontact with the solid catalyst, continuously or semi-continuously, and at a maximum rate of introduction at any time corresponding to less than 10 ppm by weight of chlorine relative to the rate of polyethylene production.

Abstract: Homogeneous catalyst based on titanium compounds of the type (R1Cp)(R2Cp)Ti(PhOR3)2, where Cp is a cyclopentadienyl group, R1 and R2 are identical or different alkyl radicals (C3-C10), Ph is a phenyl group and OR3 is an alkoxyl group. Moreover, the invention relates to the use of said catalyst in a method for the hydrogenation of double bonds in unsaturated compounds, preferably polymers and/or copolymers of conjugated dienes, under mild reaction conditions.

Abstract: The present invention relates to an ultrahigh-molecular-weight ethylene copolymer powder having an intrinsic viscosity (?) of 10 dl/g to 34 dl/g, obtainable by copolymerizing ethylene and at least one olefin selected from the group consisting of ?-olefins having 3 to 20 carbon atoms, cyclic olefins having 3 to 20 carbon atoms, compounds represented by the formula CH2?CHR1 wherein R1 is an aryl group having 6 to 20 carbon atoms, and linear, branched or cyclic dienes having 4 to 20 carbon atoms, wherein (1) a molded article of the copolymer powder has a haze of from 30% to 80% and (2) the copolymer powder has a bulk density of from 0.35 g/cm3 to 0.6 g/cm3.

Abstract: A solid, hydrocarbon-insoluble, catalyst component useful in polymerizing olefins, said catalyst component containing magnesium, titanium, and halogen, and further containing an internal electron donor having a structure: [R1—O—C(O)—O—]xR2 wherein R1 is independently at each occurrence, an aliphatic or aromatic hydrocarbon, or substituted hydrocarbon group containing from 1 to 20 carbon atoms; x is 2-4; and R2 is an aliphatic or aromatic hydrocarbon, or substituted hydrocarbon group containing from 1 to 20 carbon atoms, provided that there are 2 atoms in the shortest chain connecting a first R1—O—C(O)—O— group and a second R1—O—C(O)—O— group.

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.

Abstract: A catalyst composition and a method for hydrogenating a polymer having a conjugated diene are provided. The catalyst composition includes (a) a first composition having one of a bis(cyclopendienyl, fluorenyl, indenyl and derivatives thereof) titanium compound and a mixture thereof; (b) a second composition having one selected from the group consisting of a first compound of a formula (II), a second compound of a formula (III) and a mixture thereof: wherein the formula (II) has a chain structure, the formula (III) has a cyclic structure, the R is C1˜C12 alkyl, the X1 and X2 are ones selected from the group consisting of C1˜C12 alkyl, C1˜C12 cycloalkoxy, aryl, C1˜C12 alkyl aryl and carbonyl, and n>1 and m>2; and (c) a third composition having an organic metallic compound.

Abstract: An optical resin lens characterized in comprising a polymer prepared employing a production method including a process which polymerizes olefin employing titanium halide and a catalyst comprised of the organic aluminum represented by Formula RnAlX3-n (wherein 1<n?2, R represents a hydrocarbon group, and X represents a halogen atom).

Abstract: The present invention discloses a polyethylene catalyst and a process for preparing the same, said catalyst being composed of a main component of catalyst and a cocatalyst, wherein the main component of catalyst is prepared by reacting: (1) a magnesium-alcohol complex, (2) an alkyl aluminum compound having a formula R3nAlCl3-n supported on silica, and (3) a titanium compound having a formula Ti(OR2)mCl4-m, and the cocatalyst is an organic aluminum compound. The catalyst of the present invention has advantages including high polymerization activity, less difference between the polymerization activities at low hydrogen level condition and at high hydrogen level condition, stable polymerization reaction, good particle morphology of catalyst, and less fine powder of polymer product.

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 a 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: Polyolefins may be prepared using a cocatalyst conforming to the formula: AIRz(Xz)nLzm wherein Rz is a linear or branched organic moiety having at least 5 carbons and Xz is a linear or branched organic moiety having at least 5 carbons or a heterocyclic moiety having at least 4 atoms and can be anionic or di-anionic. The aluminum complex may also be in the form of an adduct complex where Lz is a Lewis base and m=1-3. The cocatalyst Rz components are selected such that they do not react with water under polymerization conditions to form a species that is highly soluble in the polymerization diluent. Use of the specified cocatalyst reduces fouling during metallocene-catalyzed runs and “post-metallocene hangover” when the same production equipment is transitioned to non-metallocene catalyst runs using catalysts such as chromium.

Abstract: The invention relates to a magnesium compound effective in producing olefin polymers having an increased bulk density and a narrowed particle size distribution, not lowering the stereospecificity of the polymers produced and not lowering the polymerization activity in producing the polymers, to an olefin polymerization catalyst comprising the compound, and to a method for producing such olefin polymers. The olefin polymerization catalyst comprises (A) a solid catalyst component prepared by contacting a magnesium compound having a specific particle size distribution index (P), a titanium compound and an electron donor compound with each other, (B) an organometallic compound, and (C) an electron donor. The olefin polymerization method comprises polymerizing an olefin in the presence of the catalyst to give olefin polymers.

Abstract: A modified aluminum oxy compound (A) obtained by reacting an aluminum oxy compound (a), water (b) and a compound having a hydroxyl group (c); a polymerization catalyst component comprising the modified aluminum oxy compound; a polymerization catalyst obtained by contacting said modified aluminum oxy compound (A), a transition metal compound (B) and optionally an organoaluminum compound (C) and a specified boron compound; and a process for producing an olefin polymer or an alkenyl aromatic hydrocarbon polymer with the polymerization catalyst.

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: 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: 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 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: 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: 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: 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: 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: 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: 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 solid catalyst component for the polymerization of olefins, comprising: an inert porous support, Mg, Ti, halogen and an electron donor selected from succinates of formula (I) wherein the radicals R1 and R2 equal to or different form each other, are hydrocarbon groups, the radicals R3, R4, R5 and R6, equal to or different from each other, are hydrogen or hydrocarbon groups.

Abstract: The present invention relates to butene-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) a Molecular Weight Distribution (MWD) in terms of Mw/Mn, measured by GPC analysis according to the method specified, of lower than 6; and (ii) a melt strength (measured according to the method specified below) higher than 2.8.

Abstract: Atactic or amorphous poly-alpha-olefins containing 100%–65% propylene and optionally up to about 35% ethylene and/or up to about 15% of a C4–C8 alpha-olefin are prepared by polymerizing the monomer(s) at 180–450° F. and at a pressure sufficient to substantially maintain the monomer(s) in the liquid phase. The polymerization is carried out in the presence of catalyst system consisting of (a) a transition metal halide selected from the group consisting of (i) a titanium trihalide and an aluminum alkyl, (ii) a titanium halide on a comminuted magnesium halide support, and (iii) a titanium halide sandwich compound and (b) aluminum alkyl as a co-catalyst. No stereoregulator or only minor amounts of a stereoregulator are used.

Abstract: A clay-filled polyolefin composition and process for making it are disclosed. The process involves treatment of a non-acid-treated smectite clay with a Ziegler-Natta catalyst in the presence of a hydrocarbon and subsequent polymerization of an olefin in the presence of the treated clay and an organoaluminum cocatalyst. Results indicate that filled compositions produced by this process contain exfoliated clay.

Abstract: A modified aluminum oxy compound (A) obtained by reacting an aluminum oxy compound (a), water (b) and a compound having a hydroxyl group (c); a polymerization catalyst component comprising the modified aluminum oxy compound; a polymerization catalyst obtained by contacting said modified aluminum oxy compound (A), a transition metal compound (B) and optionally an organoaluminum compound (C) and a specified boron compound; and a process for producing an olefin polymer or an alkenyl aromatic hydrocarbon polymer with the polymerization catalyst.

Abstract: A new synthesis of a Ziegler-Natta catalyst uses a multi-step preparation that includes treating a magnesium dialkoxide compound with halogenating/titanating agents, an organoaluminum preactivating agent, and a heat treatment. The catalyst may be used in the polymerization of olefins, particularly ethylene, to control the molecular weight distribution of the resulting polyolefins.

Abstract: The present invention relates to catalyst components for the polymerization of olefins comprising a titanium compound, having at least a Ti-halogen bond, and at least two electron donor compounds supported on a Mg dihalide, said catalyst component being characterized by the fact that at least one of the electron donor compounds is selected from ethers containing two or more ether groups which are further characterized by the formation of complexes with anhydrous magnesium dichloride in an amount less than 60 mmoles per 100 g of MgCl2 and by the failure of entering into substitution reactions with TiCl4 or by reacting in that way for less than 50% by moles, and at least another electron donor compound is selected from esters of mono or polycarboxylic acids. Said catalyst components are able to produce propylene polymers which, for high values of xylene insolubility, show a broad range of isotacticity.

Abstract: A supported titanium catalyst system comprising a titanium catalyst bound via at least one heteroatom, a functionalized support, said heteroatom being connected to said support via an organic group.

Abstract: An olefin polymerization catalyst is described which includes: (A) a solid catalyst component being prepared by copulverizing a magnesium compound, an aluminum compound, an electron donor and a titanium compound, and (B) an organoaluminum compound. The present invention is also directed to a process for preparing polyolefins using the aforesaid catalyst system to polymerize olefins.

Abstract: An olefin polymerization catalyst is provided which makes use of a modified methylaluminoxane and thus stably exhibits an activity equivalent to, or higher than, the activity achieved by polymethylaluminoxane. Specifically, the olefin polymerization catalyst is in the form of a modified methylaluminoxane preparation prepared from: an organoaluminum compound represented by the following general formula (I): R1mAlX3-m??(I) wherein R1 represents a straight-chained or branched hydrocarbon group selected from the group consisting of alkyl, alkenyl, and aryl groups having 2 to 20 carbon atoms; X represents a hydrogen atom, halogen atom, alkoxy group, or allyloxy group; and 0<m?3; and trimethyl aluminum, wherein the mole fraction of methyl group of the aluminoxane unit with respect to the total number of moles of the hydrocarbon group having 2 to 20 carbon atoms and methyl group present in the modified methylaluminoxane preparation is 65 mol % or greater.

Abstract: An ?-olefin polymer having extremely high stereoregularity, exhibiting excellent fluidity and containing a decreased amount of catalyst residues in the polymer can be obtained industrially advantageously in accordance with a process for producing an ?-olefin polymer which comprises homopolymerizing an ?-olefin or copolymerizing two or more ?-olefins in the presence of (A) a solid catalyst component comprising magnesium, titanium and a halogen, (B) an organoaluminum compound having a content of hydroaluminum compounds of 0.1% by weight or smaller and (C) an organozinc compound.

Abstract: By controlling the hold up times and temperatures for mixing the components of aluminum, titanium and magnesium based catalyst for solution polymerization it is possible to prepare a catalyst having a high activity, which prepares high molecular weight polyolefins. Generally, catalyst loses activity and produces lower molecular weight polymer at higher temperatures. The catalyst of the present invention permits comparable polymers to be produced at higher reaction temperatures.

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: Some properties such as dart impact strength, hexane extractables and resin stickiness of a polyethylene copolymer produced in a gas phase polymerization using a Ziegler-Natta catalyst are better controlled by regulating the ratio of aluminum from the co-catalyst to the polymer production rate. This enables one to improve properties such as dart impact strength and reduce hexane extractables by changing the amount of co-catalyst fed into the reactor.

Abstract: A process for polymerizing olefins using a catalyst system comprising a conventional Ziegler-Natta catalyst and an external election donor selected from the group consisting of diethers and combinations thereof. The catalyst system comprises a Ziegler-Natta catalyst having a transition metal compound generally represented by the formula: MR′x where M is a transition metal, R′ is a halogen or a hydrocarboxyl, and x is the valence of the transition metal. The transition metal compound can be TiCl4. The Ziegler-Natta catalyst may comprise an internal electron donor, such as phthalate. The catalyst system further includes an external electron donor selected from the group consisting of diethers and a co-catalyst selected from the group of organoaluminum compounds. In one embodiment, the external electron donor is 2,2-diisobutyl-1,3-dimethoxypropane, and the co-catalyst is triethylaluminum.

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.