Abstract: Provided is catalyst composition including a transition metal complex precatalyst represented by Formula 1; a first cocatalyst represented by Formula 2 which is an alkylaluminum compound; and a second cocatalyst represented by Formula 3 which is a salt compound comprising a Bronsted acid cation and a noncoordinating, compatible anion. Here, R1, R2, R3, R4, E, Q1, Q2 and M are defined in the specification. Al(R6)3 Formula 2 Here, R6 is defined in the specification. [L-H]+[ZA4]? Here, L, [L-H]+, Z and A are defined in the specification. A catalyst composition including binuclear transition metal complexes, an alkylaluminum compound, and a salt compound including a Bronsted acid cation, and a noncoordinating, compatible anion, and a method of preparing the catalyst composition are provided. The activity of the catalyst composition has been improved.

Abstract: Disclosed is a process for producing branched polymers including at least 50 mol % C3–C40 olefins. The process may include: (1) feeding a first catalyst, an activator, and one or more C2–C40 olefins into a first reaction zone at a temperature of greater than 70° C. and a residence time of 120 minutes or less to produce a product; (2) feeding the product a second catalyst, and an activator into a second reaction zone at a temperature of greater than 70° C., and a residence time of 120 minutes or less. One of the catalysts should be chosen to produce a polymer having a weight average molecular weight of 100,000 or less and a crystallinity of 20% or less. The other catalyst should be chosen to producing a polymer having a weight average molecular weight of 100,000 or less and a crystallinity of 20% or more.

Abstract: A crystalline higher ?-olefin polymer which is obtained from a C10 or more ?-olefin and satisfies either (1) the melting point (Tm) as measured with a differential scanning calorimeter (DSC) is 20 to 100° C. or (2) in an examination of spin-lattice relaxation time (T1) by solid NMR analysis, a single T1 is observed at the temperatures not lower than the melting point; and a process for producing the ?-olefin polymer with a specific metallocene catalyst. The crystalline higher ?-olefin polymer is excellent in low-temperature characteristics, rigidity, heat resistance, compatibility with lubricating oils, mixability with inorganic fillers, and secondary processability.

Abstract: An ethylene-based polymer which is an ethylene/C4 to C10 ?-olefin copolymer and satisfies the following requirements [k1] to [k3]: [k1] melt flow rate (MFR) under a loading of 2.16 kg at 190° C. is in the range of 1.0 to 50 g/10 minutes; [k2] LNR defined as a scale of neck-in upon film molding is in the range of 0.6 to 1.4; and [k3] take-up speed at break [DS (m/min)] at 160° C. and melt flow rate (MFR) satisfy the following relationship (Eq-1): 12×MFR0.577?DS?165×MFR0.577 (Eq-1), and a thermoplastic resin composition containing the ethylene-based polymer, provide a molded product, preferably a film, excellent in moldability and mechanical strength.

Abstract: Disclosed is a method of producing a polyolefin composition comprising contacting a metallocene pre-catalyst with a substoichiometric amount of a co-catalyst; adding a first olefin monomer; and polymerizing the first monomer for a time sufficient to form the polyolefin. The method allows for the use of a minimum amount of activating co-catalyst, and allows for the production of stereoregular and non-stereoregular polyolefins. The use of configurationally stable metallocene pre-catalysts allows for the production of monomodal isotactic polyolefins having narrow polydispersity. The use of configurationally unstable metallocene pre-catalysts allows for the production of monomodal atactic polyolefins having narrow polydispersity. The method of the present invention optionally further comprises contacting the polyolefin with a second amount of said co-catalyst; adding a second olefin monomer; polymerizing said second olefin monomer to form a block-polyolefin composition.

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: One or more oligomers of an olefin are prepared in the presence of a single-site catalyst. Preferably, the olefin is an ?-olefin, and the oligomers are a poly-alpha-olefin (PAO). The PAO so prepared is completely or substantially free of tertiary hydrogen resulting from isomerization. Consequently, the PAO possesses improved biodegradability, improved oxidation resistance, and/or a relatively higher viscosity index. The PAO has many useful applications, such as a component of a lubricant.

Abstract: A process is disclosed for the preparation of a poly(?-olefin) polymer wherein the process comprises polymerizing at least one ?-olefin in the presence of hydrogen and a catalytically effective amount of catalyst comprising the product obtained by combining a metallocene catalyst with a cocatalyst, the metallocene catalyst being at least one meso compound of general formula: wherein: A1 and A2 are independently selected from the group consisting of mononuclear and polynuclear hydrocarbons; M1 is a metal from group IVb, Vb, or VIb of the Periodic Table; R1 and R2 are independently selected from the group consisting of hydrogen, C1–C10 alkyl, C1–C10-alkoxy, C6–C10 aryl, C6–C10 aryloxy, C2–C10 alkenyl, C7–C40 arylalkyl, C7–C40 alkylaryl, C8–C40 arylalkenyl and halogen; R7 is selected from the group consisting of: ?BR11, ?AlR11, —Ge—, —Sn—, —O—, —S—, ?SO, ?SO2, ?NR11, ?CO, ?PR11 and ?P(O)R11, where R11, R12, and R13 are independently selected from the group consisting of hydrogen, halogen, C1–C10 alky

Abstract: The invention provides an ethylene-?-olefin copolymer which is superior in extrusion molding processability. The present invention is to provide a copolymer of ethylene and ?-olefin of from 4 to 20 carbon atoms, having melt flow rate of from 1 to 100 g/10 min, an activation energy for melt flow of 60 kJ/mol or more, melt tension at 190° C. (MT), intrinsic viscosity ([?]) and a chain length A which satisfy the formula (1) to (3), wherein the chain length A is a chain length at peak position of a logarithm normal distribution curve of a component having the highest molecular weight among logarithm normal distribution curves obtained by dividing a chain length distribution curve obtained by gel permeation chromatography measurement into at least two logarithm normal distribution curves.

Abstract: The present invention provides a novel olefin polymerization catalyst having excellent olefin polymerization activity and, in polymerization with the catalyst comprising a transition metal compound, a polymerization process for preparing a polymer having a low molecular weight with high polymerization activity. The process comprises polymerizing olefin in the presence of an olefin polymerization catalyst comprising (A) a transition metal compound represented by the following [M: a Group 4 or 5 transition metal atom in the Periodic Table, m: 1–4, R1: H, a C1–C5 linear hydrocarbon group, 3- to 5-membered alicyclic hydrocarbon group, bicycloaliphatic hydrocarbon group wherein two alicyclic rings share one or more carbon atoms, R2 to R6: H, a halogen atom, hydrocarbon group etc, X: H, a halogen atom etc, and n is a valence of M], and (B) at least one compound selected from (B-1) an organometallic compound, (B-2) an organoaluminum oxy compound and (B-3) an ionizing ionic compound.

Abstract: The present invention provides a crystalline higher ?-olefin copolymer obtained by copolymerizing at least two higher ?-olefins having 10 or more carbon atoms or at least one higher ?-olefin having 10 or more carbon atoms with at least one other olefin, wherein it satisfies certain conditions.

Abstract: The present invention provides a crystalline higher ?-olefin copolymer obtained by copolymerizing at least two higher ?-olefins having 10 or more carbon atoms or at least one higher ?-olefin having 10 or more carbon atoms with at least one other olefin, wherein it satisfies certain conditions.

Abstract: Apparatus for olefin polymerization includes one or more shell and tube olefin polymerization reactors, each of which has an olefin polymerization reaction mixture inlet connection and a crude polyolefin product outlet connection. Each reactor is equipped with a recirculation system including a pump arranged to circulate a reaction mixture through the tube side of the reactor independently of the introduction of olefin polymerization reaction mixture into the reactor. The apparatus may also include an inlet reaction mixture distribution manifold and an outlet polymerization reaction mixture collection manifold interconnecting the reactors for operation in parallel. The apparatus also includes catalyst composition and catalyst modifier inlets for each reactor arranged such that a catalyst modifier to may be introduced into each reactor at a rate which is independent of the introduction of catalyst composition.

Abstract: The present invention relates to a process for polymerizing monomer and comonomer(s) utilizing a bulky ligand transition metal metallocene-type catalyst or catalyst system, where the process is operated in the absence of or with a low amount of any of the isomers of the comonomer(s). The level of these isomers in the process of the invention are eliminated or maintained below a threshold level. It has been discovered that removal of certain isomers of the comonomer used in a polymerization process using metallocene-type catalysts results in an improved process.

Abstract: The invention provides for polymerization catalyst compositions, and for methods for introducing the catalyst compositions into a polymerization reactor. More particularly, the method combines a catalyst component containing slurry and a catalyst component containing solution to form the completed catalyst composition for introduction into the polymerization reactor. The invention is also directed to methods of preparing the catalyst component slurry, the catalyst component solution and the catalyst compositions, to methods of controlling the properties of polymer products utilizing the catalyst compositions, and to polymers produced therefrom.

Abstract: The invention relates to olefin branched macromonomers, olefin graft copolymers and olefin resin compositions having the advantage of good compatibility with polyolefin resins and good moldability and workability. The olefin branched macromonomer satisfies the following (a) and (b): (a) its weight-average molecular weight (Mw) measured through gel permeation chromatography (GPC) falls between 400 and 200000; (b) its vinyl content is at least 70 mol % of all the unsaturated groups in the macromonomer.

Abstract: A process for producing a polyolefin according to the present invention comprises (co) polymerizing one or two or more ?-olefins in a vapor phase in a fluidized-bed reactor, wherein the concentration of (A) a saturated aliphatic hydrocarbon in the fluidized bed reactor is 1 mol % or more and at least one compound selected from (B) an aliphatic amide and (C) a nonionic surfactant constituted only of carbon, oxygen and hydrogen atoms is made to exist in the reactor. The present invention can provide a process for producing a polyolefin, the process ensuring that the prevention of clogging caused by the generation of sheet or block polymers and a high efficiency of the production of a polyolefin due to good catalytic activity can be accomplished at the same time and also having superb continuous productivity.

Abstract: The present invention relates to polyolefins and in particular to polyolefins comprising C3-C20 monomers and having a molecular weight of at least 700 kg/mol preferably 1000 kg/mol. The present invention further relates to a hafnium based metallocene catalyst and a process for making such polyolefins.

Abstract: An ethylene-based polymer resin which is obtained by copolymerizing ethylene with an ?-olefin having 5 to 20 carbon atoms, and has a melt flow rate (MFR) measured at 190° C. under a load of 21.18 N according to JIS K7210-1995, of not less than 0.01 g/10 min. and less than 1 g/10 min., wherein the melt flow rate and a melt tension(MT) at 190° C. (unit: cN) of the resin satisfy a relation of the following expression (1) and an intrinsic viscosity [?] (unit: dL/g) and the melt flow rate of the resin satisfy a relation of the following expression (2): 2×MFR?0.59<MT<3.6×MFR?0.66??(1) 1.02×MFR?0.094<[?]<1.50×MFR?0.156??(2).

Abstract: The process for producing an olefinic polymer comprises introducing a saturated aliphatic hydrocarbon in a liquid phase state and in a vapor phase state into the aforementioned fluidized-bed and (co)polymerizing in the condition that when the inside radius of the cylinder section of the fluidized-bed reactor is defined as a distance of 1, the relationship between the concentration (C1) of the saturated aliphatic hydrocarbon put in a liquid state in the peripheral portion of the cylinder section at a relative distance of 0.7 to 1.0 from the center of the cylinder section as a start point and the concentration (C2) of the saturated aliphatic hydrocarbon put in a liquid state in the center portion of the cylinder section at a relative distance less than 0.7 from the center fulfills the following equation: C1>C2 at a place close to the upstream section of said gas distributing plate.

Abstract: The invention provides for polymerization catalyst compositions, and for methods for introducing the catalyst compositions into a polymerization reactor. More particularly, the method combines a catalyst component containing slurry and a catalyst component containing solution to form the completed catalyst composition for introduction into the polymerization reactor. The invention is also directed to methods of preparing the catalyst component slurry, the catalyst component solution and the catalyst compositions, to methods of controlling the properties of polymer products utilizing the catalyst compositions, and to polymers produced therefrom.

Abstract: The subject invention pertains to branched polyolefin materials that exhibit temperature-sensitive permeability. The subject invention also concerns a package including a polymer material that exhibits temperature-sensitive permeability and separates a respiring article from the surrounding atmosphere. Methods of the subject invention involve placing a respiring article within a container comprising a polymer material exhibiting temperature-sensitive permeability.

Abstract: The invention relates to a method to safely produce, handle and transport packaged organic peroxide formulations comprising a reactive phlegmatiser and to the use of such packaged material in polymerisation and polymer modification processes, particularly the high-pressure (co)polymerisation process of ethylene and/or the suspension (co)polymerisation process of styrene.

Abstract: The invention comprises an olefin polymerization process comprising contacting ethylene alone or with one or more olefinically unsaturated comonomers with a Group 3-6 metallocene catalyst compound comprising one &pgr;-bonded ring having a C3 or greater hydrocarbyl, hydrocarbylsilyl or hydrocarbylgermyl substituent said substituent bonded to the ring through a primary carbon atom; and, where the compound contains two &pgr;-bonded rings, the total number of substituents on the rings is equal to a number from 3 to 10, said rings being asymmetrically substituted where the number of substituents is 3 or 4. The invention process is particularly suitable for preparing ethylene copolymers having an MIR less than about 35, while retaining narrow CD even at high comonomer incorporation rates, and with certain embodiments providing ethylene copolymers having improved melt strength with the low MIR.

Abstract: Long-chain, branched, propylene-based polymers, of which the melt index and the molecular weight distribution and the melt tension and the limiting viscosity both satisfy specific requirements, have good physical properties that are comparable to or better than those of conventional propylene-based polymers. They have good melt workability and are favorable to large-size blow molding and extrusion foaming. They are favorably used as miscibility improvers for propylene homopolymers and propylene-based copolymers.

Abstract: This invention is related to extruded pipe resins comprising polyethylene.

Abstract: A disengagement vessel employing a lock hopper effectively reduces concentration of non-polymer-associated components in the polymer product slurry of a first olefin slurry polymerization reactor, allowing cascading of a second slurry polymerization reactor operating at lesser concentration of comonomers, hydrogen, and other components to produce multicompositional polyolefin polymers and/or polymers having a multimodal monomer distribution, e.g. diblock polymers having substantially non-overlapping comonomer contents between the blocks.

Abstract: Disclosed is a method of producing a polyolefin composition comprising contacting a metallocene pre-catalyst with a substoichiometric amount of a co-catalyst; adding a first olefin monomer; and polymerizing the first monomer for a time sufficient to form the polyolefin. The method allows for the use of a minimum amount of activating co-catalyst, and allows for the production of stereoregular and non-stereoregular polyolefins. The use of configurationally stable metallocene pre-catalysts allows for the production of monomodal isotactic polyolefins having narrow polydispersity. The use of configurationally unstable metallocene pre-catalysts allows for the production of monomodal atactic polyolefins having narrow polydispersity. The method of the present invention optionally further comprises contacting the polyolefin with a second amount of said co-catalyst; adding a second olefin monomer; polymerizing said second olefin monomer to form a block-polyolefin composition.

Abstract: The invention refers to a linear, isotactic polymer which has a structure of one or several C2 to C20 olefins, of which the isotacticity, due to a statistic distribution of stereoscopic errors in the polymer chain, is within the range of from 25 to 60% of [mmmm] pentad concentration with the proviso that an arbitrary or rather regular sequence of isotactic and atactic blocks is excluded, the polymer having a mean molecular weight Mw within the range of from 100,000 to 800,000 gms/mol and a TG of from −50 to +30.

Abstract: Low color, aromatic modified C5 hydrocarbon resins are disclosed. The resins are predominantly an aromatic modified piperylene resin. The resins are useful as tackifies in hot melt adhesives and hot melt pressure sensitive adhesives.

Abstract: The present invention provides a polymer that can be used as an anti-reflective coating (ARC) polymer, an ARC composition comprising the same, methods for producing the same, and methods for using the same. The polymer of the present invention is particularly useful in a submicrolithographic process, for example, using KrF (248 nm) or ArF (193 nm) lasers as a light source. The polymer of the present invention comprises a chromophore that is capable of absorbing light at the wavelengths used in a submicrolithographic process. Thus, the ARC of the present invention significantly reduces or prevents back reflection of light and the problem of the CD alteration caused by the diffracted and/or reflected light. The ARC of the present invention also significantly reduces or eliminates the standing wave effect and reflective notching.

Abstract: An olefin polymerization catalyst system, comprising a catalyst represented by the general formula CrR4, wherein each R is independently a hydrocarbyl or substituted hydrocarbyl, with the proviso that R may not be a cyclopentadienyl group, an activator represented by the general formula, MQ2, where M is a Group II metal, where each Q is independently an alkyl, or substituted alkyl; and a support. The support may be organic or inorganic. Ethylene and one or more olefins may be polymerized by the catalyst system.

Abstract: A polyolefin product is provided which comprises a branched olefin copolymer having an syndiotactic polypropylene backbone, polyethylene branches and, optionally, one or more comonomers. The total comonomer content of the branched olefin copolymer is from 0 to 20 mole percent. Also, the mass ratio of the syndiotactic polypropylene to the polyethylene ranges from 99.9:0.1 to 50:50.

Abstract: A complex of transition metal Ti, Fe, Co, Ni, Cr, Mn, Ta, Rh, Y, Sc, Ru, Pd, Zr, Hf, V or Nb and a mono-, bi-, tri-, or tetra-dentate ligand, wherein at least one of the donor atoms of the ligand is a nitrogen atom N with a 5-membered heterocyclic substituent joined to the N by a carbon atom. The complex is preferably formula (I) wherein R5—N-G-X1 is a bi-, tri.

Abstract: This invention relates to a process to polymerize olefins comprising contacting, in a polymerization system, olefins having three or more carbon atoms with a catalyst compound, activator, optionally comonomer, and optionally diluent or solvent, at a temperature above the cloud point temperature of the polymerization system and a pressure no lower than 10 MPa below the cloud point pressure of the polymerization system, where the polymerization system comprises any comonomer present, any diluent or solvent present, the polymer product, where the olefins having three or more carbon atoms are present at 40 weight % or more.

Abstract: This invention relates to a process to produce propylene polymers comprising contacting a metallocene catalyst compound and an activator in a reaction medium comprising propylene, from 0 to 30 volume % of one or more solvents and from 0 to 30 mole % of one or more comonomers, under temperature and pressure conditions below the melting point of the propylene polymer and where:

Abstract: Methods for controlling the temperature of an olefin polymerization reactor (e.g., a polyethylene reactor) system are disclosed herein. The olefin polymerization reactor system includes a polymerization reactor and a cooling jacket in thermal contact with the reactor. An aqueous froth is present in the jacket, and the pressure therein is maintained below atmospheric pressure. Control of the pressure in the jacket controls the boiling temperature of the jacket fluid, and thus, controls the rate of heat transfer from the reactor to the fluid in the jacket. This provides an efficient and simple means for controlling the reactor temperature.

Abstract: An adhesive blend is described that can include a semi-crystalline copolymer of propylene and at least one comonomer selected from the group consisting of ethylene and at least one C4 to C20 &agr;-olefin, the copolymer having a weight average molecular weight (Mw) from about 15,000 to about 200,000; an melt index (MI) from about 7 dg/min to about 3000 dg/min as measured by ASTM D 1238(B), and a (Mw/Mn) of approximately 2. Various production processes are also described. Also described are adhesive compositions and methods for making adhesive compositions having polymers or polymer blends with melt flow rates (MFRs) equal to and above 250 dg/min. at 230NC. Certain specific embodiments of the invention involve the use of a free radical initiator, e.g., a peroxide.

Abstract: A method of making a sterile adhesive composition includes placing a mixture of a polymerizable adhesive monomer and a thickening agent in a container, sealing the container, and sterilizing the mixture and the container. The method provides superior viscosity for the monomer composition. An adhesive composition includes 2-octyl cyanoacrylate and at least one thickener. The sterile adhesive composition is particularly useful as a medical adhesive and can comprise 1,1-disubstituted ethylene monomers, such as &agr;-cyanoacrylates.

Abstract: Ethylene based polymers having high molecular weights can be obtained in high yields at temperatures of industrial interest, by carrying out the polymerization reaction in the presence of catalysts comprising silicon bridged metallocenes having a particular ligand system containing a heteroatom.

Abstract: A method of lowering MFR response of a high melt flow rate polymer producing metallocene catalyst is provided. The method includes contacting the metallocene catalyst with a sufficient quantity of &agr;,&ohgr;-diene monomer such that when the catalyst composition is contacted with polymerizable reactants under suitable polymerization conditions, the resulting polymer has an MFR rate in the range of 0.1 to 19. Hydrogen and ethylene may also be present in the polymerization. Additionally a catalyst composition is provided which includes a high melt flow rate polymer producing metallocene catalyst and a sufficient quantity of &agr;,&ohgr;-diene monomers such that when the catalyst composition is contacted with a monomer under polymerization conditions, the resulting polymer has an MFR rate in the range of 0.1 to 19.

Abstract: The use of two or more light solvent boiling pool reactors in series allows polymerization of ethylene and comonomer(s) to cost effectively produce bimodal polyethylene copolymers having lower densities than are practically achievable with conventional stirred tank, slurry loop or gas phase reactor technologies. Introducing catalyst to only the first reactor, operating the first reactor at high hydrogen compositions, and using a plurality of series-connected flash drums to remove hydrogen from the first reactor polymer slurry product stream allows for the production of highly homogeneous high molecular weight bimodal polyethylene resins.

Abstract: A process for the preparation of a poly(&agr;-olefin) copolymer is disclosed wherein the process comprises polymerizing at least one &agr;-olefin, and at least one bulky olefin, in the presence of hydrogen and a catalytically effective amount of catalyst comprising the product obtained by combining a metallocene procatalyst with a cocatalyst, ligand (Cp2R2p) and bridging group R3 contains at least two bulky groups.

Abstract: Catalyst precursor compounds having both (i) a polydentate ligand which comprises a cyclic moiety as well as a heteroatom and (ii) a protected hydride/hydrocarbyl ligand bonded to a metal atom, as well as olefin polymerization catalyst systems based thereupon, polymerization processes using such catalyst systems and polymers produced thereby.

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: A method for making a solid catalyst component for use in a Ziegler-Natta catalyst includes combining a porous particulate support with a magnesium source in a hydrocarbon solvent to form a mixture, the magnesium source including a hydrocarbon soluble organomagnesium compound and a hydrocarbon insoluble anhydrous inorganic magnesium-halogen compound. The organomagnesium compound is halogenated and the mixture is reacted with a titanium compound or vanadium compound to form the solid catalyst component. The solid catalyst component is then recovered and combined with an organoaluminum cocatalyst to form a Ziegler-Natta catalyst which is advantageously used for the polymerization of olefins, particularly alk-1-enes such as ethylene, propylene, 1-butene, and the like. The catalyst can optionally include internal and external electron donors.

Abstract: An ethylene-based polymer resin which is obtained by copolymerizing ethylene with an &agr;-olefin having 5 to 20 carbon atoms, and has a melt flow rate (MFR) measured at 190° C. under a load of 21.18N according to JIS K7210-1995, of not more than 0.01 g/10 min. and less than 1 g/10 min., wherein the melt flow rate and a melt tension (MT) at 190° C.

Abstract: A method of continuously manufacturing a high viscosity polyalphaolefin product by introducing a monomer and an ionic liquid catalyst together into a reaction zone while simultaneously withdrawing from the reaction zone a reaction zone effluent that contains the high viscosity polyalphaolefin. The reaction zone is operated under reaction conditions suitable for producing the high viscosity polyalphaolefin product. The preferred high viscosity polyalphaolefin has a kinematic viscosity exceeding about 8 cSt and is the reaction product of the trimerization, oligomerization, or polymerization of an alpha olefin or a mixture of one or more product thereof. The high viscosity polyalphaolefins are useful as lubricants or lubricant additives.

Abstract: A copolymer of ethylene and a higher alpha olefin, preferably 1-hexene, can be produced using an activated chromium containing catalyst system and a cocatalyst selected from the group consisting of trialkylboron, trialkylsiloxyalutninum, and a combination of trialkylboron and thalkylaluminum compounds. The polymerization process must be carefully controlled to produce a copolymer resin having an exceptionally broad molecular weight distribution, extremely high PENT ESCR values, and a natural branch profile that impacts branching preferably into the high molecular weight portion of the polymer. The resulting copolymer resin is especially useful in high stiffness pipe applications.

Abstract: A process is disclosed for the preparation of a poly(&agr;-olefin) polymer wherein the process comprises polymerizing at least one &agr;-olefin in the presence of hydrogen and a catalytically effective amount of catalyst comprising the product obtained by combining a metallocene catalyst with a cocatalyst, the metallocene catalyst being at least one meso compound of general formula: 1