Abstract: A new P—N—P ligand is useful in ethylene oligomerizations. In combination with i) a source of chromium and ii) an activator such as methylalumoxane; the ligand of this invention may be used to prepare an oligomer product that contains a mixture of hexenes and octenes. The hexenes and octenes produced with this ligand contain very low levels of internal olefins when produced under preferred reaction conditions.

Abstract: Methods for polymerization of an olefin monomer and polymers formed therefrom are described herein.

Abstract: The present invention relates to a method for determining activity of a catalyst in a polymerization process, said polymerization process comprising the steps of feeding a catalyst and a diluent into a storage vessel, to form a concentrated settled catalyst, feeding said concentrated settled catalyst into a mixing vessel equipped with mixing means and feeding hydrocarbon diluent into said mixing vessel, to form a diluted catalyst slurry, feeding said diluted catalyst slurry into a polymerization reactor via a volumetric pump, and feeding at least one monomer into said polymerization reactor to form a polymer.

Abstract: The present invention relates to a polymerization process for producing olefin polymers in a loop reactor comprising the steps of: introducing into the loop reactor one or more olefin reactants, polymerization catalysts and diluents, and while circulating said reactants, catalysts and diluents, polymerizing said one or more olefin reactants to produce a polymer slurry comprising essentially liquid diluent and solid olefin polymer particles, said process further comprising one or more cycles of: (a) allowing said polymer slurry to settle in one or more setting legs connected to said reactor, and (b) discharging from a setting leg a predetermined volume of polymer slurry substantially equal to the volume of polymer slurry settled in said settling leg since its previous discharge.

Abstract: The purpose of the present invention is to provide a process for producing an olefin polymer, which can produce an olefin polymer having a higher molecular weight by lowering hydrogen concentration efficiently in polymerizing an olefin in the presence of hydrogen by use of a gas phase reaction vessel. There is provided a process for producing an olefin polymer comprising the steps of: using a gas phase reaction vessel; polymerizing an olefin by use of a catalyst for olefin polymerization in the presence of hydrogen; and adding a hydrogenation catalyst to a bed portion in the gas phase reaction vessel.

Abstract: The present invention relates to a process for oligomerization/polymerization of ethylene and/or alpha-olefins, comprising the steps of oligomerizing/polymerizing ethylene and/or alpha-olefins to produce a reaction product which contains undesired reaction by-products, separating the reaction by-product from the reaction product as one or more reaction by-product fractions, and subjecting at least one of the reaction by-product fractions to steam cracking to produce a steam cracking product which comprises ethylene, which may be optionally purified and feed to the oligomerization/polymerization of ethylene and/or alpha olefins step.

Abstract: Polymerization processes of the present invention comprise low catalyst concentration. Embodiments include a polymerization process comprising polymerizing free radically (co)polymerizable monomers in a polymerization medium comprising one or more radically (co)polymerizable monomers, a transition metal catalyst complex capable of participating in a one electron redox reaction with an ATRP initiator; a free radical initiator; and an ATRP initiator; (wherein the concentration of transition metal catalyst complex in the polymerization medium is less than 100 ppm). Further embodiments include a polymerization process, comprising polymerizing one or more radically (co)polymerizable monomers in the presence of at least one transition metal catalyst complex; and an ATRP initiator; and a reducing agent; wherein the transition metal catalyst complex is present at less than 10?3 mole compared to the moles of radically transferable atoms or groups present on the ATRP initiator.

Abstract: The present disclosure provides a Ziegler-Natta catalyst composition comprising a procatalyst, a cocatalyst and a mixed external electron donor comprising a first selectivity control agent, a second selectivity control agent, and an activity limiting agent. A polymerization process incorporating the present catalyst composition produces a high-stiffness propylene-based polymer with a melt flow rate greater than about 50 g/10 min. The polymerization process occurs in a single reactor, utilizing standard hydrogen concentration with no visbreaking.

Abstract: Method of determining the melt mass flow rate of an ethylene polymer in the polymerization of ethylene or of ethylene with further comonomers, which is carried out at temperatures of from 140° C. to 350° C. and pressures of from 40 MPa to 350 MPa in a reactor to form the ethylene polymer and the ethylene polymer is subsequently cooled in a heat exchanger, which comprises: a) establishment of a correlation between the thermal conductivity of the ethylene polymer in the heat exchanger and the melt mass flow rate of the ethylene polymer, with the individual measurements each being carried out at an essentially constant melt mass flow rate, b) measurement of the thermal conductivity of an ethylene polymer in the heat exchanger c) calculation of the melt mass flow rate from the thermal conductivity measured in b) and the correlation established in a).

Abstract: A modified Ziegler-Natta catalyst system, a method for preparing the catalyst system, and a process for polymerizing an olefin in the presence of the catalyst system are disclosed. The catalyst system comprises a titanium or vanadium compound, an aluminum compound, and a 2-hydroxypyridine N-oxide. Improved properties such as increased molecular weight are obtained.

Abstract: The present invention relates to a process for the preparation of multimodal ethylene homo- or copolymers in at least two stages, the process comprising preparation of a first ethylene homo- or copolymer fraction in a loop reactor in slurry phase, preparation of a second ethylene homo- or copolymer fraction in a gas phase reactor, by using a catalyst not containing an inorganic oxide support, and operating the gas phase reactor in such conditions that at least part of the gas is recycled, and that at least a part of the recycled gas is condensed and the (partially) condensed gas is re-introduced into the gas phase reactor.

Abstract: This invention relates to an improved method for improving the tacticity of Ziegler-Natta catalyst systems and for controlling the behaviour of the active stereospecific sites.

Abstract: The invention discloses a metallocene catalysed slurry polymerisation process of ethylene in the presence of a low concentration of scavenger. This allows improving the anti-sheeting of the reactor during the polymerisation process.

Abstract: Process for preparing an antistatic for olefin polymerization by contacting an antistatically acting compound comprising at least one hydrogen atom bound to a nonmetallic heteroatom with at least one metal alkyl in an amount which is sufficient to react completely with the at least one hydrogen atom bound to a heteroatom, wherein the antistatically acting compound and the metal alkyl are each present in a concentration of at least 0.01% by weight during contacting.

Abstract: The invention provides an apparatus and a process for the high pressure polymerization of ethylene, optionally with one or more comonomers, in which unreacted monomer is separated from the polymer in a separation system having at least first, second and third separation vessels and in which off gas from the second vessel is recombined back into the product mixture upstream of the first separation vessel, preferably using a jet pump.

Abstract: A new P-N-P ligand is useful in ethylene oligomerizations. In combination with i) a source of chromium and ii) an activator such as methylalumoxane; the ligand of this invention may be used to prepare an oligomer product that contains a mixture of hexenes and octenes. The hexenes and octenes produced with this ligand contain very low levels of internal olefins when produced under preferred reaction conditions.

Abstract: Cyclic organosilicon compounds that may be employed as an electron donor for polymerization catalyst systems, polymerization catalyst systems employing the cyclic organosilicon compounds as an electron donor, methods of making the polymerization catalyst systems, and polymerization processes to produce polyolefin are disclosed. The organosilicon compounds, which are useful as electron donors in polymerization catalyst systems for the production of polyolefins, are represented by the formula: where Q1, Q2, Q3, and Q4 may be identical or different and are each hetero-atoms selected from the group consisting of N, O, S, Si, B, and P. R1, R2, R3, and R4 may be identical or different and are each hydrocarbon-based substituents to Q1, Q2, Q3, and Q4, respectively. The subscripts i, j, m, and n are independently 0 to 3 R5 and R6 may be identical or different and are each a bridging group with a backbone chain length between the two hetero-atoms Q1 and Q3, and Q2 and Q4, respectively, 1-8 atoms.

Abstract: A magnesium compound obtainable by reacting metal magnesium, ethanol, an alcohol having from 3 to 10 carbon atoms and a halogen and/or a halogen-containing compound containing at least 0.0001 gram atom of a halogen atom relative to one gram atom of the metal magnesium at 0 to 70° C., which comprises composition represented by the formula (I), and which has a particle diameter D50 corresponding to 50% of cumulative weight fraction of from 4 to 20 ?m and a particle size distribution index (P) of P<4.0: Mg(OC2H5)2?n(OR1)n??(I) where n is a numerical value satisfying 0<n<0.35, R1 is CmH2m+1, and m is an integer of from 3 to 10.

Abstract: A method for monitoring a polymer resin-producing polymerization reaction in a fluid bed reactor, including by determining in on-line fashion a maximum diluent (e.g., ICA) concentration and an optimal diluent (e.g., ICA) concentration in the reactor, whereby performing the reaction with diluent (e.g., ICA) concentration less than the maximum diluent concentration ensures an acceptably low risk that the resin in the reactor in the presence of condensable diluent gas will reach a condition of limiting stickiness. Preferably, the optimal diluent concentration maximizes production rate subject to relevant constraints. The method can also include at least one of the steps of controlling the reaction to achieve a desired production rate by controlling diluent (e.g.

Abstract: A process for transitioning between Ziegler Natta (Z/N) polymerization catalysts and Second Polymerization catalysts in a polymerization system which includes at least two polymerization reactors. During the transition, the Z/N catalyst is used in the “downstream” reactor, thereby providing a flow of polymer to finishing operations. This eliminates the need for lengthy shutdowns of finishing equipment and thereby improves the efficiency of the plant operations.