Abstract: An olefin polymerization catalyst comprising: (A1) a solid catalyst component prepared by contacting (a1) a dialkoxymagnesium, (b1) a tetravalent titanium halide, (c1) an electron compound, and (d1) a polysiloxane, (B) an organoaluminum compound of the formula R1pAlQ3-p, and (C) an aminosilane compound of the formula (R2R3N)Si(OR4)3 has a high activity to hydrogen as compared with conventional catalysts and maintains the capability of producing polymers with a high stereoregularity at a high yield.

Abstract: A process for polymerizing olefins is disclosed. The process uses a hydrosilane in a polymerization catalyzed by an open architecture, bridged indenoindolyl organometallic complex and an activator. Polyolefins from the process have increased molecular weight.

Abstract: The invention relates to coordination compounds of the general formulae (Ia) to (Ib), wherein M=Ti, Zr, Hf, V, Nb or Ta. The invention also relates to a method for producing the metal complexes and to the use of the complexes so obtained for the polymerization and copolymerization of olefins.

Abstract: Novel waterborne vinyl copolymer dispersions useful as a fabric coating or treatment to improve the performance properties of textile products are disclosed and claimed. The compositions contain vinyl monomers, a vinyl silane and hydroxy fatty acid ester compounds having at least one double bond in their backbone featuring internally plasticizable and crosslinkable properties.

Abstract: Ethylene and optional comonomers are polymerized using a supported metallocene catalyst, an alumoxane activator, and triisobutylaluminum (TIBAL). A silica support is first pretreated with a silane compound and then with an organoboron compound. The treated silica is then combined with a Group 4 metallocene complex and an alumoxane to generate a supported, activated catalyst. While it was previously thought that the particular support treatment technique used herein provided benefits only for polymerizations catalyzed by non-metallocene single-site complexes, it has now been found that similar benefits can be realized even with conventional metallocenes if TIBAL is selected as the scavenger.

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: Olefin polymerization in the presence of heterogeneous supported catalysts is improved by incorporating into the supported catalyst a unifunctional hydrophobic tether comprising a hydrophobic portion containing no basic nitrogen and a univalent reactive group. The unifunctional hydrophobic tether reduces fouling and sheeting in gas phase polymerization processes and improves polymer morphology and bulk density in slurry polymerization processes, while substantially maintaining or enhancing catalyst polymerization activity.

Abstract: In a method of adding catalysts for the polymerization of C2-C20-olefins, the catalyst is firstly introduced into a container A and the cocatalysts used are subsequently mixed with an inert solvent in a container B, and the contents of the container B are introduced into the container A and mixed with the catalyst there and the mixture is introduced from there into the actual polymerization reactor.

Abstract: This invention provides catalyst compositions that are useful for polymerizing at least one monomer to produce a polymer. This invention also provides catalyst compositions that are useful for polymerizing at least one monomer to produce a polymer, wherein said catalyst composition comprises a post-contacted organometal compound, a post-contacted organoaluminum compound, and a post-contacted treated solid oxide compound.

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: Processes for utilizing various emulsion polymerization procedures for preparing aqueous nanocomposite dispersions are disclosed. The disclosed processes include both in-situ polymerizations in the presence of at least partially exfoliated unmodified clays as well as admixtures of polymer dispersions with at least partially exfoliated unmodified clay dispersions. The disclosed nanocomposite dispersions are useful for preparing a variety of materials, such as coatings, adhesives, caulks, sealants, plastics additives, and thermoplastic resins. Processes for preparing polymer clay nanocomposite powders and use of these powders as plastic resin and plastics additives are also disclosed.

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: The present invention provides a method of forming a polyolefin resin having a relatively high densities and a long chain branch index (“LCB”) greater than about 1. The method of the invention comprises forming a reaction mixture by combining molecular hydrogen, a first olefin, an optional second olefin, a diluent, and a vanadium-containing catalyst system at a sufficient temperature to allow formation of the polyolefin resin and initiating polymerization of the reaction mixture.

Abstract: The present invention relates to a method for producing a polymer and copolymer of ethylene, and more particularly to a method for producing an ethylene polymer and copolymer by reacting a compound of an organic metal of Group 2, 12, or 13 on the periodic table of elements with an alkoxy silane compound in the presence of a titanium catalyst, the said titanium catalyst being produced by a process of preparing a magnesium compound by contact-reacting a halogenated magnesium compound and alcohol, of reacting the said solution with an ester compound which contains at least one hydroxy group and a silicon compound containing an alkoxy group, and also of reacting it with a solid matter obtained by reaction of a mixture of a titanium compound and a silicon compound with a titanium compound.

Abstract: The present invention provides to a catalytic system, its method for preparation, and a method for preparation of a copolymer of ethylene and a conjugated diene, which uses this catalytic system. A catalytic system according to the invention comprises: an organometallic complex compound, which is represented by one formula A or B: in which Ln represents a metal of a lanthanide, the atomic number of which is between 57 and 71; X represents a halogen, which can be chlorine, fluorine, bromine or iodine; and Cp1 and Cp2 each comprise a cyclopentadienyl or fluorenyl group, which is or is not substituted, and P is a bridge corresponding to the formula MR2, in which M is an element of column IVA of Mendeleev's periodic classification, and R is an alkyl group comprising from 1 to 20 atoms of carbon; and a co-catalyst selected from among a magnesium alkyl, a lithium alkyl, an aluminium alkyl, or a Grignard's reagent, and mixtures thereof.

Abstract: A polymerization catalyst system and process, which utilizes a Group 14 and Group 16 containing non-crystalline compound to solubilize or emulsify polymerization catalyst components, is disclosed.

Abstract: The invention relates to new compounds having an element of group 12 and having a tridentate ligand, a process for their preparation and their use in particular as a polymerization catalyst.

Abstract: The present invention describes catalysts for atom transfer radical polymerization processes. Specifically, a hybrid catalyst system comprising transition metal complexes held in close conjunction with a solid support and of a soluble ligand, or soluble transition metal complex or desorbed catalyst. The hybrid catalyst system may be used in a controlled polymerization process of radically (co)polymerizable monomers in the presence of a system comprising an initiator comprising one or more radically transferable atom(s) or group(s). The catalyst may include a transition metal, one or more counterions, a ligand attached to a solid support, and a soluble ligand. The hybrid catalyst may also be comprised of an attached transition metal complex, and a soluble transition metal complex.

Abstract: Disclosed are catalysts for the polymerization of alpha-olefins which comprise the reaction product of: (a) an Al-alkyl compound; (b) a silicon compound containing at least one Si—OR or Si—OCOR or Si—NR2 bond, R being a hydrocarbyl radical; (c) a solid comprising, as essential support, a Mg dihalide in active form and, supported thereon, a Ti halide or a halo-Ti-alcoholate and a particular type of electron donor compound. The present invention refers to new supported components of catalysts for the polymerization of CH2═CHR olefins wherein R is an alkyl radical with 1 to 4 carbon atoms, or an aryl radical, and mixtures of said olefins with ethylene and the catalysts obtained from said components.

Abstract: Industrial polyolefin piping system with improved stiffness, impact strength for use at high service temperature, comprising single or multilayer pipes, fitting, chambers, valves and vessels, consisting of &bgr;-nucleated propylene homopolymers with an IR&tgr;≧0.98 having a tensile modulus ≧1500 MPa, a Charpy impact strength, notched, at +23° C.≧30 kJ/m2 and a Vicat B temperature >90° C. and a Heat Distortion Temperature >100° C. The industrial polyolefin piping system is suitable for chemical plant constructions comprising single or multilayer pipes, fittings, chambers, valves and vessels with improved stiffness, impact strength and high service temperature, preferred for conveyance of natural gas, dangerous liquids and/or toxic liquids.

Abstract: The present invention is directed to, in part, polymer clay nanocomposites having an acid containing monomer and clay. In one embodiment, there is provided a process for preparing an aqueous polymer clay nanocomposite dispersion, wherein the process comprises: providing an aqueous dispersion comprising at least one clay, optionally at least one ethylenically unsaturated monomer, and optionally at least one surfactant; providing a monomer mixture comprising at least 10% by weight of an acid containing monomer within the monomer mixture and optionally a surfactant; mixing the aqueous dispersion and the monomer mixture; and polymerizing the monomer to form the nanocomposite dispersion wherein the clay is at least partially exfoliated within the nanocomposite dispersion. The present invention also relates to the use of these compositions such as thickeners, dispersants, plastics additives, adhesives, coatings, flexographic inks, overprint varnishes, and dry cement powder modifiers.

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.

Abstract: Functional polymers containing hydroxyl groups as supports for use with catalysts can increase the activity of these catalysts which results in improved ethylene polymerization. The present invention seeks to provide catalysts with improved activity by incorporating 2-hydroxyethyl methacrylate (HEMA) into the support of the catalyst.

Abstract: The present invention concerns high-stiffness polymer composition and a process for producing a polymer composition by nucleated with a polymeric nucleating agent containing vinyl compound units. The method comprises modifying a catalyst by polymerizing a vinyl compound in the presence of said catalyst and a strongly coordinating donor in a medium, which does not essentially dissolve the polymerized vinyl compound, and by continuing the polymerization of the vinyl compound until the concentration of unreacted vinyl compounds is less than about 0.5 wt-%. The thus obtained modified catalyst composition is used for polymerizing propylene optionally together with comonomers in the presence of said modified catalyst composition. Modification of the catalyst according to the present invention will reduce production costs and provide highly reliable catalyst activity and polymers of high stiffness.

Abstract: The invention concerns a method for producing ethylene homopolymers or copolymers comprising at least 90 mol % of units derived from ethylene which consists in: contacting in polymerising conditions, the monomers with a catalytic system including: (a) a catalytic solid comprising a metallocene of a transition metal of groups 4 to 6 of the periodic table containing at least a cyclopentadiene ligand capable of being substituted and a support, (b) at least an organoaluminium compound selected among compounds of general formula (1): AlTx(Y′)yX′z wherein: T is a hydrocarbon group containing 1 to 30 carbon atoms; Y′ is a group selected among —OR′, —SR′ and NR′R″ with R′ and R″ independently representing a hydrocarbon group containing 1 to 30 carbons atoms; X′ is a halogen atom: x verifies the relationship 0<x≦3; y verifies the relationship 0≦y<3; z verifies the relationship 0≦2<3, and x+y+z=3, and (c) at least

Abstract: Catalyst systems of the Ziegler-Natta type, which are suitable for the polymerization of olefins are prepared by: A) bringing an inorganic metal oxide on which a magnesium compound has been deposited into contact with a tetravalent titanium compound, B) if desired, bringing the intermediate obtained in this way into contact with an electron donor compound and C) bringing the intermediate obtained in step A) or B) into contact with a polysiloxane.

Abstract: Olefin polymers with a broad molecular weight distribution can be obtained while maintaining the high stereoregularity of the polymers by polymerizing olefins using a catalyst comprising (A) a solid catalyst component prepared by contacting (a) a dialkoxymagnesium, (b) a tetravalent titanium halide compound, and (c) an electron donor compound one another, (B) an organoaluminum compound of the formula R1pAlQ3-p, and (C) an aminosilane compound of the formula R2R3Si(OR4)2.

Abstract: The present invention provides a method for producing homo- and co-polymers of ethylene, or more particularly a method for producing homo- and co-polymers 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) a cyclic nitrogen compound. The catalyst for homo- and co-polymerization of ethylene, produced according to the present invention, exhibits high activity, and the polymers produced by the method of the present invention by using said catalyst have the advantages of exhibiting high bulk densities and narrow molecular weight distributions.

Abstract: The present invention provides an ethylene copolymer resin that has unique melt elastic properties not observed in ethylene copolymers heretofore known. Specifically, the ethylene copolymer resin of the present invention when in pelletized form has a reduction in melt elasticity (ER) of 10% or more to a final value of 1.0 or less upon rheometric low shear modification or solution dissolution. Moreover, the resin of the present invention when in reactor-made form exhibits at least a partially reversible increase of 10% or more in ER when pelletizing the same. An ethylene polymerization catalyst, a process of preparing the ethylene copolymer resin and a high-impact film are also provided herein.

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: A process (I) for producing an &agr;-olefin polymerization catalyst whereby (1) a titanium compound is reduced by an organomagnesium compound in the presence of an organosilicon compound to produce a reduction solid, (2) the reduction solid is aged to produce a solid product, (3) the solid product is contacted with an ether compound, titanium tetrachloride and an organic acid halide compound, to produce an organic acid halide-treated solid, (4) the organic acid halide-treated solid is contacted with a mixture of an ether compound, titanium tetrachloride and an ester compound, or with a mixture of an ether compound and titanium tetrachloride to produce a solid catalyst component containing a titanium compound, and (5) the solid catalyst component is contacted with an aluminum compound and an electron donor compound to produce a catalyst for &agr;-olefin polymerization. A process (II) for producing an &agr;-olefin polymer using a catalyst produced by process (I).

Abstract: The present invention relates to catalysts particularly suitable for the sterospecific polymermerization of olefins, comprising Ti, Mg, halogen and an electron donor compound selected from heteroatoms containing esters of malonic acids. Polymers produced by the catalysts have high isotactic index expressed in terms of high xylene insolubility.

Abstract: An &agr;-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 &agr;-olefin polymer which comprises homopolymerizing an &agr;-olefin or copolymerizing two or more &agr;-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: The present invention provides a catalyst for bulk or vapor-phase polymerization having high polymerization activity during bulk or vapor-phase polymerization and providing an olefin polymer having excellent properties in melt flow rate and stereoregularity by adding a small amount of hydrogen. The catalyst for bulk or vapor-phase polymerization of an &agr;-olefin compound under a presence of hydrogen, the catalyst is made by contacting the following ingredients (A) to (C). (A) a solid catalyst ingredient, comprising: (a) a magnesium compound, (b) titanium tetrachloride, and (c) dialkyl phthalate (Each of the alkyl group denotes a straight-chain or branched-chain hydrocarbon group having a carbon number of 3 to 20.); (B) an organoaluminum compound; and (C) an organosilicon compound, which is expressed by the following general chemical formula (1).

Abstract: The present invention relates to a process for the polymerization of olefins using catalyst components and catalysts obtained therefrom comprising Ti, Mg, halogen and an electron donor compound selected from heteroatoms containing esters of malonic acids. The catalysts are particularly suitable for the sterospecific polymermerization of olefins having high isotactic index expressed in terms of high xylene insolubility.

Abstract: The present invention provides a catalyst system that exhibits unexpected control of desired properties in polyolefin products. The catalyst system includes a titanium-supported catalyst in combination with a mixture of tetraethoxysilane (TEOS) and dicyclopentyldimethoxy-silane (DCPMS). This catalyst system has been found to be effective in making polypropylene and polypropylene copolymers having relatively high melt flow rates and moderately broad molecular weight distribution.

Abstract: There are provided (1) a process for producing a solid product, which comprises the step of reducing a titanium compound represented by the following formula [I] with an organomagnesium compound in the presence of an organosilicon compound having an Si—O bond, an inorganic fine particle and optionally an ester compound, (2) a process for producing a solid catalyst component, which comprises the step of contacting the solid product obtained by the above process, a halogenation ability-carrying halogeno compound, and an inner electron donor compound, (3) a process for producing a catalyst, which comprises the step of contacting the solid catalyst component obtained by the above process, an organoaluminum compound, and an outer electron donor compound, and (4) a process for producing an olefin polymer, which comprises the step of polymerizing an olefin in the presence of the catalyst obtained by the above process.

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 maleates of a particular formula. Said catalyst components when used in the polymerization of olefins, and in particular of propylene, are capable to give polymers in high yields and with high isotactic index expressed in terms of high xylene insolubility.

Abstract: This invention relates to metallocene catalyst compositions which are highly active for the polymerization of olefins, particularly prochiral &agr;-olefins. The catalyst compositions contain at least one metallocene, and least one activator and a support that has been fluorided using a fluoride containing compound.

Abstract: Processes for the formulation of Ziegler-type catalysts from a plurality of catalyst components including transition metal, organosilicon electron donor, and organoaluminum co-catalyst components. The components are mixed together in the course of formulating the Ziegler-type catalyst to be charged to an olefin polymerization reactor. Several orders of addition of the catalyst components can be used in formulating the Ziegler catalyst. One involves mixing of the transition metal component with the organoaluminum co-catalyst to formulate a mixture having an aluminum/transition metal mole ratio of at least 200. This mixture is combined with the organosilicon electron donor component to produce a Ziegler-type catalyst formulation having an aluminum/silicon mole ratio of no more than 50. There may be an initial pre-polymerization of the catalyst prior to introducing the catalyst into an olefin polymerization reactor.

Abstract: A process for preparing polypropylene-b-poly(ethylene-co-propylene) by the use of a tubular continuous polymerizer in the presence of an olefin-polymerizing catalyst comprising a solid catalyst component (1) composed of titanium and halogen; an organosilicon compound (2); and, if necessary, at least one electron-donating compound (3) selected from the group consisting of organosilicon compounds represented by the general formula: RnSi(OR′)4−n (wherein R and R′ are each independently a C1-C10 hydrocarbon group; and n is an integer of 1 to 3) and nitrogenous heterocyclic compounds, wherein the solid catalyst component (1) is preliminarily brought into contact with the organosilicon compound (2) in the presence of the electron-donating compound (3), and then a polypropylene segment is formed through polymerization, followed by formation of a poly(ethylene-co-propylene) segment at the end of the polypropylene segment through polymerization.

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: This invention provides catalyst compositions that are useful for polymerizing at least one monomer to produce a polymer. This invention also provides catalyst compositions that are useful for polymerizing at least one monomer to produce a polymer, wherein said catalyst composition comprises a post-contacted organometal compound, a post-contacted organoaluminum compound, and a post-contacted fluorided solid oxide compound.

Abstract: Use of a catalyst system comprising a metallocene catalyst component of general formula R″ (CpRn)(Cp′R′n)MQ2 supported on an inert support in the slurry phase production of linear low density polyolefin, wherein Cp is a cyclopentadienyl moiety, Cp′ is a substituted or unsubstituted fluorenyl ring: R″ is a structural bridge imparting stereorigidity to the component; each R is independently hydrogen or hydrocarbyl having 1 to 20 carbon atoms in which 0≦m≦4; each R′ is independently hydrocarbyl having 1 to 20 carbon atoms in which 0≦n≦8; M is a Group IVB transition metal or vanadium; and each Q is hydrocarbyl having 1 to 20 carbon atoms or halogen; the metallocene having a centroid-M-centroid angle in the range 105° to 125°.

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 process for the polymerization of olefins is disclosed. A boraaryl catalyst precursor and an activator are used in the presence of a silane modifier. A low level of silane modifier enhances the activity of the catalyst.

Abstract: Functional polymers containing hydroxyl groups as supports for use with catalysts can increase the activity of these catalysts which results in improved ethylene polymerization. The present invention seeks to provide catalysts with improved activity by incorporating 2-hydroxyethyl methacrylate (HEMA) into the support of the catalyst.

Abstract: The present invention provides polypropylene having xylene solubles from 0.6 to 1.5 weight percent and isotacticity equal to or greater than about 98.0 percent. The polypropylene is obtained by contacting propylene monomer under suitable polymerization conditions with (a) a Ziegler-Natta catalyst, (b) a co-catalyst, and (c) an electron donor.

Abstract: A class of metallocene compounds is disclosed having general formula (I) wherein Y is a moiety of formula (II) wherein A, B, and D, same or different from each other, are selected from an element of the groups 14 to 16 of the Periodic Table of the Elements (new IUPAC version), with the exclusion of nitrogen and oxygen; R1, R2, R3, R4 and R5 are hydrogen or hydrocarbon groups, Z is selected from a moiety of formula (II) as described above and from a moiety of formula (III) wherein R6, R7, R8 and R9, are hydrogen or hydrocarbon groups; L is a divalent bridging group; M is an atom of a transition metal selected from those belonging to group 3, 4, 5, 6 or to the lanthanide or actinide groups in the Periodic Table of the Elements (new IUPAC version), X, same or different, is hydrogen, a halogen, a R10, OR10, OSO2CF3, OCOR10, SR10, NR102 or PR102 group, wherein the substituents R10 are hydrogen or alkyl groups; p is an integer of from 1 to 3, being equal to the oxidation state of the metal M minus 2.

Abstract: Use of a catalyst system comprising a metallocene catalyst component of general formula R″(CpRm) (Cp′R′n)MQ2 supported on an inert support in the slurry phase production of linear low density polyolefin, wherein Cp is a cyclopentadienyl moiety, Cp′ is a substituted or unsubstituted fluorenyl ring; R″ is a structural bridge imparting stereorigidity to the component; each R is independently hydrogen or hydrocarbyl having 1 to 20 carbon atoms in which 0≦m≦4; each R′ is independently hydrocarbyl having 1 to 20 carbon atoms in which 0≦n≦B; M is a Group IVB transition metal or vanadium; and each Q is hydrocarbyl having 1 to 20 carbon atoms or halogen; the metallocene having a centroid-M-centroid angle in the range 105° to 125°.