Abstract: The present method is directed to techniques for estimating and periodically controlling the reactor split of alpha-olefin polymerizations using multiple catalysts that selectively incorporate monomers and other reactants into polymer compositions. The method provides for the rapid determination of instantaneous reactor split and cumulative split in polymerization reactors by the use of a novel linear relationship between Incorporation and Reactor Split.

Abstract: Multimodal polyolefin polymers may be prepared in series-connected polymerization reactors where a prior reactor is a slurry reactor employing light solvent as the slurry medium and hydrogen to limit polymer molecular weight, the polymer product from the prior reactor being substantially freed of hydrogen prior to entry into a subsequent polymerization reactor operating at low hydrogen pressure to produce a high molecular weight olefin. The economics and operating performance of such a series slurry reactor polyethylene process can be significantly improved through the use of an intermediate slurry transfer system and hydrogen removal apparatus that employs flash drums in series in conjunction with a warm recycle solvent slurry diluent.

Abstract: The invention relates to a process for the preparation of an olefin polymer comprising at least two polymerization stage in the presence of an olefin polymerization catalyst material, an olefin polymer produced by such process, and the use of such polymers for the production of fibres, pipes, films, moulded products and products for wire and cable applications.

Abstract: A process for preparing and controlling the density of high density polyethylene in the gas phase comprising contacting ethylene or a mixture of ethylene and one or more alpha-olefins with a chromium oxide catalyst supported on a granular or microspherical refractory oxide in a fluidized bed reactor in the presence of oxygen.

Abstract: An ethylene copolymer is provided which is a copolymer of ethylene and an ?-olefin of 3 to 20 carbon atoms and has the following properties: (a) the melt index (MI2) at 190° C. under a load of 2.16 kg is in the range of 0.0001 to 1000 g/10 min, (b) the density is not more than 0.899 g/cm3, (c) the relationship between a vinyl group amount and MI2 of the polymer satisfies the following expression: (vinyl group amount: number of vinyl groups/1000 carbon atoms)?0.004509+0.000815×log(MI2), and (d) the relationship between a vinylidene group amount and MI2 of the polymer satisfies the following expression: (vinylidene group amount: number of vinylidene groups/1000 carbon atoms)?0.013528+0.002445×log(MI2).

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: A multimodal polymer composition for pipes is disclosed. The polymer is a multimodal polyethylene with a density of 0.930-0.965 g/cm3, an MFR5 of 0.2-1.2 g/10 min, an Mn of 8000-15000, an Mw of 180-330×103, and an Mw/Mn of 20-35, said multimodal polyethylene comprising a low molecular weight (LMW) ethylene homopolymer fraction and a high molecular weight (HMW) ethylene copolymer fraction, said HMW fraction having a lower molecular weight limit of 3500, and a weight ratio of the LMW fraction to the HMW fraction of (35-55):(65:45).

Abstract: The present invention concerns a high melt strength propylene polymer or copolymer suitable for manufacturing foams and thermoformed product exhibiting a melt strength of at least 3 g and comprising a high molar mass portion and a low or medium molar mass portion. The polymers are produced by subjecting propylene and optionally other olefins to polymerization in a plurality of polymerization reactors connected in series, employing different amounts of hydrogen as a molar mass modifier in at least two of the reactors, and carrying out the polymerization reaction in the presence of a catalyst system capable of catalyzing the formation of a high molar mass polymerization product having a MFR2 of less than 0.1 g/l0 min and a low or medium molar mass polymerization product having a MFR2 of more than 0.5 g/10 min.

Abstract: A process for preparing syndiotactic polymers of vinylaromatic monomers having improved melt flowability comprising contacting one or more vinylaromatic monomers with a catalyst system comprising a titanium coordination complex capable of preparing syndiotactic vinylaromatic polymers under addition polymerization conditions in the presence of hydrogen gas at a hydrogen partial pressure from 0.1 to less than 10 kPa.

Abstract: Complexes of the formulae Ia and Ib where M=Ti, Zr, Hf, V, Nb, Ta, Cr, Ni, Pd, can be used for the polymerization and copolymerization of olefins, for example in suspension polymerization processes, gas-phase polymerization processes and bulk polymerization processes.

Abstract: Methods of monitoring and controlling polymerization reactions are disclosed. The ratio of concentrations of two reactor components are determined in a gas stream of a reactor to obtain a leading indicator function L. The value of L or a function of L, such as a rescaled value or a reciprocal, is compared to a target value, and at least one reactor parameter is adjusted in response to a deviation between L or the function of L and the target value. Monitoring of the leading indicator permits rapid diagnosis of reactor problems, and rapid adjustments of reactor parameters, compared to laboratory analysis of samples of polymer properties.

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 process for polymerizing olefins uses a plurality of series-connected polymerization reactors in which at least one of second and subsequent reactors is a vapor-phase polymerization reactor containing a multicomponent gas. The process comprises the steps of: taking the multicomponent gas out of the vapor-phase polymerization reactor; mixing the multicomponent gas with an inert gas which is lighter than at least one component of the multicomponent gas, thereby obtaining a mixed gas; compressing and/or cooling the mixed gas to liquefy a part of the multicomponent gas; discharging at least a part of a gaseous mixture comprising the inert gas and an unliquefied multicomponent gas out of a reaction system; and returning a fluid comprising the remainder of the gaseous mixture and the liquefied multicomponent gas to the vapor-phase polymerization reactor.

Abstract: Processes, methods and apparatus relating to olefin polymerization include the use of Raman spectrometry to monitor the concentration of reactants, products or other chemical components. One or more polymerizaton conditions are adjusted in response to those monitored concentrations. The present processes, methods and apparatus are applicable with slurry olefin polymerization process, even though such slurry processes contain solid particles were are known to interfere with Raman spectrometry. Furthermore, the present processes, methods and apparatus are applicable where there is some degree of overlap between Raman spectral peaks. Methods of monitoring and controlling olefin polymerization processes, reactants and other components use Raman spectrometry.

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: A process for polymerizing olefins is disclosed. The process combines a bridged indenoindolyl organometallic complex and an activator with a support material in the presence of an aromatic solvent. The supported catalyst containing the aromatic solvent is used to polymerize an olefin in the presence of hydrogen. Polyolefins from the process have improved flow properties.

Abstract: In a process for the polymerization of ethylene and optionally further monomers in a high-pressure reactor at from 120 to 350° C. and pressures of from 1000 to 4000 bar, hydrogen is intermittently introduced into the reactor.

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: A poly(&agr;-olefin) copolymer obtained from the polymerization of at least one &agr;-olefin having from 2 to about 20 carbon atoms and at least one bulky olefin, the process comprising polymerizing the monomers in the presence of hydrogen and a catalytically effective amount of a catalyst comprising the product obtained by combining a metallocene procatalyst with a cocatalyst; lubricant compositions comprising such poly(&agr;-olefin) copolymer; and a method for improving the viscosity index of a lubricant composition using such poly(&agr;-olefin) copolymer.

Abstract: Shear-thinning ethylene/&agr;-olefin and ethylene/&agr;-olefin/diene monomer interpolymers that do not include a traditional branch-inducing monomer such as norbornadiene are prepared at an elevated temperature in an atmosphere that has little or no hydrogen using a constrained geometry complex catalyst and an activating cocatalyst.

Abstract: A gas phase polymerization process for producing a polyolefin composition is described, which includes passing a gaseous stream containing hydrogen gas and one or more monomers, including ethylene monomers, through a reactor that includes a fluidized bed, under reactive conditions, in the presence of a catalyst that includes metallocene, to provide a polyolefin composition, wherein in one embodiment the fluidized bulk density is 60% or more of the settled bulk density (or, a voidage of 40% or less); and wherein the voidage is controlled by a number of factors including, in certain embodiments, (a) the reactor temperature being maintained at 100° C. or below; (b) the molar ratio of hydrogen gas to ethylene introduced into the reactor being 0.015 or below.

Abstract: Improved Group 3-11 transition metal based catalysts and processes for the polymerization of olefins are described. Some of the ligands are characterized by a preferred substitution pattern which allows for higher productivities of highly branched olefins; substitution patterns which boost productivity or alter the polymer microstructure are also described.

Abstract: Processes, methods and apparatus relating to olefin polymerization include the use of Raman spectrometry to monitor the concentration of reactants, products or other chemical components. One or more polymerizaton conditions are adjusted in response to those monitored concentrations. The present processes, methods and apparatus are applicable with slurry olefin polymerization process, even though such slurry processes contain solid particles were are known to interfere with Raman spectrometry. Furthermore, the present processes, methods and apparatus are applicable where there is some degree of overlap between Raman spectral peaks. Methods of monitoring and controlling olefin polymerization processes, reactants and other components use Raman spectrometry.

Abstract: A process for producing high density polyethylene (HDPE) or linear low density polyethylene (LLDPE) in gas phase reactors, isolated or combined, using chromium or Ziegler-Natta catalysts, provided with on-line control of certain process variables as well as physical properties of the produced resin is described. Such process comprises the use of models for the inference of the physical properties and of the process variables that are not continuously measured as well as models which are relevant for the control of said properties and of the operating conditions of the process. The control of the process variables provides further the maximization of the production rate and of the catalyst productivity in the polymerization reaction.

Abstract: A polyacrylate pressure sensitive adhesive, having an average molecular weight Mw (weight average) of from 100 000 to 600 000 g/mol a polydispersity of not more than 3.0 copolymerized photoinitiator units, and a process for preparing a UV-crosslinkable polyacrylate pressure sensitive adhesive having a polydispersity of not more 3.0, comprising a radical polymerization process for preparing a polymer from a monomer mixture, the monomer mixture to be polymerized comprising copolymerizable photoinitiators, the polymerization process being regulated by the presence of at least one chemical compound comprising the unit in which X is S, O or N as polymerization regulator.

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 method for controlling resin properties during the production of polyolefins is provided. The method utilizes coordinated manipulation of reaction temperature in combination with a secondary process variable to control resin flow properties to rapidly respond to manufacturing upsets or specification changes to minimize off-grade or transition polymer material when moving from one polymer grade to another, or during a disturbance in a steady state production.

Abstract: An olefin polymerization process and apparatus produce, in a single reactor, a polymer with a broad molecular weight distribution and short chain branching concentrated in the high molecular weight portion of the polymer product. A molecular weight lever, such as hydrogen, is pulsed out of phase with a short chain branching lever, such as 1-hexene, to produce a polymer product having desirable toughness characteristics and improved processability.

Abstract: A gas phase polymerization process for producing a polyolefin composition is described, which includes passing a gaseous stream containing hydrogen gas and one or more monomers, including ethylene monomers, through a reactor that includes a fluidized bed, under reactive conditions, in the presence of a catalyst that includes metallocene, to provide a polyolefin composition, wherein in one embodiment the fluidized bulk density is 60% or more of the settled bulk density (or, a voidage of 40% or less); and wherein the voidage is controlled by a number of factors including, in certain embodiments, (a) the reactor temperature being maintained at 100° C. or below; (b) the molar ratio of hydrogen gas to ethylene introduced into the reactor being 0.015 or below.

Abstract: A process of producing a bimodal polyolefin composition is described, which includes in one embodiment contacting monomers with a supported bimetallic catalyst composition for a time sufficient to form a bimodal polyolefin composition that includes a high molecular weight polyolefin component and a low molecular weight polyolefin component; wherein the supported bimetallic catalyst includes a first catalyst component that is preferably non-metallocene, and a second catalyst component that includes a metallocene catalyst compound having at least one fluoride or fluorine containing leaving group, wherein the bimetallic catalyst is supported by an enhanced silica, dehydrated at a temperature of 800° C. or more in one embodiment.

Abstract: Shear-thinning ethylene/&agr;-olefin and ethylene/&agr;-olefin/diene monomer interpolymers that do not include a traditional branch-inducing monomer such as norbornadiene are prepared at an elevated temperature in an atmosphere that has little or no hydrogen using a constrained geometry complex catalyst and an activating cocatalyst.

Abstract: The present invention relates to a process for the polymerization and copolymerization of 1-olefins and to a catalyst to be used in said process wherein the catalyst comprises (1) a complex having formula (I) wherein M is Fe[II], Fe[III], Co[I], Co[II], Co[III], Mn[I], Mn[II], Mn[III], Mn[IV], Ru[II], Ru[III] or Ru[IV]; X represents an atom or group covalently or ionically bonded to the metal M; T is the oxidation state of the metal; b is the valency of the atom or group X; and R 1 to R 7 are each independently selected from hydrogen, halogen, hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl, substituted heterohydrocarbyl or SiR′ 3 where each R′ is independently selected from hydrogen, halogen, hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl, substituted heterohydrocarbyl; and when any two or more of R 1 to R 7 are hydrocarbyl, substituted hydrocarbyl, heterohydroc

Abstract: A hydrogenated nitrile rubber having lower molecular weights and narrower molecular weight distributions than those known in the art can be prepared by the olefin metathesis of nitrile butadiene rubber, followed by hydrogenation of the resulting metathesized NBR.

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

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: 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 stable continuous production of a propylene-based block copolymer can proceed for a long time without causing accumulation of particles having a small diameter by a process having the following steps: (1) polymerizing an &agr;-olefin containing liquid propylene as a main component in the presence of hydrogen and a stereoregular polymerization catalyst in one or more polymerization reactors to obtain a polymer slurry; (2) feeding the polymer slurry to a copolymerization reactor; and (3) copolymerizing propylene and an &agr;-olefin other than propylene substantially in a gaseous phase in the presence of the stereoregular polymerization catalyst, the polymer slurry and a deactivating compound in the copolymerization reactor to obtain a propylene-block copolymer powder.

Abstract: An active non-metallocene pre-catalyst featuring a diamine diphenolate complex and a corresponding method for catalytic polymerization, in general, and, tactic catalytic polymerization, in particular, of alpha-olefin monomers using the disclosed pre-catalyst.

Abstract: Multimodal polyolefin polymers may be prepared in series-connected polymerization reactors where a prior reactor is a slurry reactor employing light solvent as the slurry medium and hydrogen to limit polymer molecular weight, the polymer product from the prior reactor being substantially freed of hydrogen prior to entry into a subsequent polymerization reactor operating at low hydrogen pressure to produce a high molecular weight olefin. The economics and operating performance of such a series slurry reactor polyethylene process can be significantly improved through the use of an intermediate slurry transfer system and hydrogen removal apparatus that employs flash drums in series in conjunction with a warm recycle solvent slurry diluent.

Abstract: A method for producing an olefin homopolymer or an olefin copolymer from an olefin or an olefin and at least one comonomer copolymerizable therewith by continuous slurry polymerization or continuous gaseous phase polymerization in the presence of a metallocene catalyst, the method comprising transferring the catalyst to a polymerizer and introducing the catalyst into the polymerizer while continuously feeding the olefin or the olefin and the comonomer into the polymerizer, to thereby effect a homopolymerization of the olefin or a copolymerization of the olefin and the comonomer, wherein, said catalyst is subjected to hydrogen gas-treatment in which said catalyst is contacted with hydrogen gas.

Abstract: This invention relates to a process for the preparation of olefin polymers, preferably a multi-stage process, in which hydrogen is used to control the molecular weight of the olefin polymer produced in a continuous reactor, in particular a process wherein a metallocene or other single site catalyst is present in the polymerization reaction mixture, as well as to olefin polymers produced thereby.

Abstract: An olefinic copolymer having a cyclic structure is prepared by copolymerizing a) ethylene (M1) and b) dicyclopentadiene or tricyclopentadiene (M2), and, optionally c) a cyclic olefin (M3), in the presence of a catalyst which contains a metallocene compound (A) having formula [1]: H2C(R′mCp)(R″nCp)MX2[1], wherein M is zirconium or hafnium, Cp has a cyclopentadienyl skeleton, each of R′ and R″ is a hydrocarbon group having 1 to 10 carbon atoms, each of two X's which may be the same or different from each other, is a halogen, a hydrogen, a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group, an alkylamino group, an alkoxy group, an aryloxy group of the formula —O—Ar—Yp, a thioalkyl group, or a thioaryl group of the formula —S—Ar—Yp; wherein Ar is an aromatic ring, Y is a halogen, a hydrogen, a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group, an alkoxy group, an alkylamino

Abstract: A process for the polymerization of one or more alpha-olefins having at least 3 carbon atoms, which comprises contacting the monomer or monomers in a polar or non-polar solvent under polymerization conditions with a homogeneous catalyst system including (a) a cationic form of a racemic mixture of a chiral octahedral transition metal complex or of a non chiral octahedral transition metal complex, comprising 1, 2 or 3 bidentate chelating ligands and no cyclopentadienyl ligands and having C1, C2, or C3 symmetry; and (b) an anion of a Lewis acid or a Brönsted acid; and adjusting the pressure so as to obtain either a highly stereoregular polymer or copolymer or an elastomer.

Abstract: This invention relates to a method to start up an olefin polymerization process comprising: a. calculating a trajectory, from elements including catalyst deactivation rate constants (kd), for the rate of introduction of a catalyst system, into a reactor, said catalyst system comprising two different metal catalyst compounds (A and B) and at least one activator, wherein the ratio of the deactivation constants of the two different metal catalyst compounds kdA/kdB is not 1; and b. introducing olefin monomer, a catalyst system, optional co-monomer, and optional chain transfer or termination agents into a polymerization reactor in a manner such that the catalyst system introduction rate is manipulated to follow the trajectory until a desired production rate is achieved.

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 process is characterized by the use of catalyst systems consisting of a single metallocene catalyst activated with mixtures of at least 2 co-catalysts. The co-catalysts are aluminium alkyls, aluminoxanes or boron compounds. Different active centers are produced in the catalyst through the use of these mixed co-catalyst systems, each having different rates of initiation and completion of the polymerization reaction, which give rise to polyolefins with different molecular weights, resulting in products with broad bimodal or multimodal molecular weight distributions and the incorporation of co-monomer can be controlled by appropriate selection of the metallocene and use of combinations of different types of co-catalysts, as well as by varying the reactor pressure, the reaction temperature and the molar ratios between the various components of the catalyst system.

Abstract: Improved Group 8-10 transition metal based supported catalyst processes for the polymerization of olefins are described. Some of the improvements pertain to protocols for catalyst preparation and activation which improve the catalyst productivity in the presence of hydrogen as a molecular weight control agent.

Abstract: A semicrystalline propylene polymer composition with good suitability for producing biaxially oriented films and prepared by polymerizing propylene, ethylene and/or C4-C18-1-alkenes, where at least 50 mol % of the monomer units present arise from the polymerization of propylene. Also described is the use of the semicrystalline propylene polymer composition for producing films, fibers or moldings, the films, fibers and moldings made from these compositions, biaxially stretched films made from the semicrystalline propylene polymer compositions, and also a method for characterizing the semicrystalline propylene polymer compositions.

Abstract: The invention relates to a method of forming carbon monoxide-containing polymers from multi-component syngas feeds and at least one vinyl comonomer. Feeds useful in the practice of the invention comprise ethylene in an amount ranging from about 5 to about 40 mole %, carbon monoxide is an amount ranging from about 1 to about 40 mole %, hydrogen in an amount ranging from about 4 to about 55 mole %, carbon dioxide in an amount ranging from about 3 to about 10 mole %, and methane in an amount ranging from about 4 to about 85 mole %. The feed may also include acetylene in an amount ranging up to about 10 mole %. The feed may contain at least one free radical-polymerizable vinyl comonomer, or a cofeed containing such a comonomer can be used.

Abstract: A polyethylene having improved rheological properties is disclosed. The polyethylene has a melt index (MI2) from about 0.01 dg/min to about 50 dg/min and a melt strength (&eegr;) that satisfies MI2×&eegr;≧3.5. A process for making the polyethylene is also disclosed. The process uses an azaborolinyl-containing single-site catalyst in the presence of hydrogen, where the hydrogen consumption is controlled to be less than 30%.