Abstract: In some embodiments, a method for determining initial conditions for a transition from an initial reaction to a target reaction to minimize (or substantially minimize) the amount of off-grade material produced during the transition, and optionally also process control variables for implementing the transition. Some embodiments also include the steps of setting the reaction conditions to determined initial conditions and then implementing the transition.

Abstract: Broad molecular weight polyethylene and polyethylene having a bimodal molecular weight profile can be produced with chromium oxide based catalyst systems employing alkyl silanols. The systems may also contain various organoaluminum compounds. Catalyst activity and molecular weight of the resulting polyethylene may also be tuned using the present invention.

Abstract: A supported catalyst composition having improved flow properties is disclosed comprising an alkylalumoxane, a metallocene-alkyl an inorganic oxide support having an average particle size of from 0.1 to 50 ?m and calcined at a temperature greater than 600° C., and optionally an antifoulant agent and. In one embodiment, the metallocene-alkyl is a Group 4, 5 or 6 metallocene-alkyl, and in another embodiment is a hafnocene-alkyl. Also disclosed is a method of polymerization using such a supported catalyst composition.

Abstract: Disclosed herein are various compositions, including a high density polyethylene composition, comprising: (a) a bimodal polyethylene component that includes a high molecular weight polyethylene component having a high average molecular weight (MWHMW) and a low molecular weight polyethylene component having a low average molecular weight (MWLMW), wherein the ratio of the high average molecular weight to the low average molecular weight (MWHMW:MWLMW) is 20 or more; and (b) a unimodal polyethylene component that occupies more than 15 wt % of the composition; wherein: (c) the composition has a density of 0.935 g/cc or more, and a Maximum Line Speed of 170 feet per minute or more.

Abstract: The present invention relates to a catalyst composition and a method for making the catalyst composition of a polymerization catalyst and a static charge modifier. The invention is also directed to the use of the catalyst composition in the polymerization of olefin(s). In particular, the polymerization catalyst system is supported on a carrier. More particularly, the polymerization catalyst comprises a bulky ligand metallocene-type catalyst system.

Abstract: A method of polymerizing olefins comprising combining in one embodiment ethylene and optionally one or more ?-olefins with a catalyst composition in a continuous polymerization reactor at a pressure of less than 10,000 kPa; wherein the catalyst composition comprises a hafnocene; and isolating a polyethylene having a density in the range of from 0.930 to 0.975 g/cm3. Also provided is a method of transitioning a continuous polymerization reactor from production of a low density polyethylene to a medium or high density polyethylene. Also provided is a medium to high density polyethylene suitable for injection or rotomolding applications. Also provided is a single catalyst composition suitable for such needs.

Abstract: The present invention relates to a continuous gas phase process comprising polymerizing one or more hydrocarbon monomer(s) in a fluidized bed reactor in the presence of catalyst system or polymerization catalyst and a condensable fluid for a period of at least 12 hours where the bed temperature is less than the Critical Temperature and the dew point temperature of the gas composition in the reactor is within 25° C. of the bed temperature.

Abstract: This invention relates to a method to support one or more catalyst compounds comprising contacting the catalyst compounds with a pretreatment agent comprising an aluminum alkyl and or an alumoxane in solution and thereafter contacting the combination with a supported activator.

Abstract: Disclosed are various compositions, including but not limited to a high density multimodal polyethylene composition, that has a density of 0.935 g/cc or more, and that includes a blend of a first polyethylene component and a second polyethylene component, in which: the first polyethylene component includes a bimodal polyethylene; and the second polyethylene component includes a unimodal polyethylene that is made from a polymerization conducted in the presence of a metallocene having two cyclopentadienyl rings.

Abstract: A method for preparing a spray dried catalyst and a low viscosity, low foam spray dried catalyst system for olefin polymerization are provided. In one aspect, the method includes preparing a catalyst system including one or more components selected from metallocenes, non-metallocenes, and activators, adding mineral oil to the catalyst system to form a slurry, and adding one or more liquid alkanes having three or more carbon atoms to the slurry in an amount sufficient to reduce foaming and viscosity of the slurry. In one aspect, the catalyst system includes one or more catalysts selected from metallocenes, non-metallocenes, and a combination thereof, wherein the catalyst system is spray dried. The system further includes mineral oil to form a slurry including a catalyst system, and one or more liquid alkanes having three or more carbon atoms in an amount sufficient to reduce foaming and viscosity of the slurry.

Abstract: An improved angled annular deflector for a gas-phase polymerization reactor and improved method for delivery of a stream of polymerizable fluid to a gas-phase polymerization reator. The angled annular deflector has an outer surface with a conical shape, an inner surface, and an inner cavity along a central axis, said cavity open at both ends, the inner surface having a first end and a second end, and the first end of the inner surface mated to the apex end of the outer surface: and an upper surface mated to the base end of the outer surface and to the second end of the inner surface; wherein the outer surface, the inner surface, and the upper surface form a substantially closed chamber. The angled annular deflector being adapted to associate with a cone-shaped bottom portion of a fluidized bed polymerization reactor vessel.

Abstract: Improved catalyst compositions, and polymerization processes using such improved catalyst compositions, are provided. An example of an improved catalyst composition is a supported catalyst system that includes at least one titanium compound, at least one magnesium compound, at least one electron donor compound, at least one activator compound, and at least one silica support material, the at least one silica support material having a median particle size in the range of from 20 to 50 microns with no more than 10% of the particles having a size less than 10 microns and no more than 10% of the particles having a size greater than 50 microns and average pore diameter of at least <220 angstroms.

Abstract: The present invention relates to a polymerization process using improved metallocene catalyst systems. Specifically, the catalyst systems of the present invention relate to a metallocene compound having optimized metals loading and activator concentration, and demonstrate improved operability and productivity. In an exemplary embodiment, the improved metallocene catalyst system of the present invention comprises a metallocene catalyst compound activated by methylaluminoxane, and a support material, the methylaluminoxane being present in the range of from 3 to 9 mmole methylaluminoxane per gram of support material, and the metallocene being present in the range of from 0.01 to 1.0 mmole metallocene per gram of support material.

Abstract: Methods of controlling the flow index and/or molecular weight split of a polymer composition are disclosed. The method of producing a polymer composition in one embodiment comprises incorporating a high molecular weight polymer into a low molecular weight polymer to form the polymer composition in a single polymerization reactor in the presence of polymerizable monomers, a bimetallic catalyst composition and at least one control agent; wherein the control agent is added in an amount sufficient to control the level of incorporation of the high molecular weight polymer, the level of low molecular weight polymer, or both. Examples of control agents include alcohols, ethers, amines and oxygen.

Abstract: A method of polymerizing olefins comprising combining in one embodiment ethylene and optionally one or more ?-olefins with a catalyst composition in a continuous polymerization reactor at a pressure of less than 10,000 kPa; wherein the catalyst composition comprises a hafnocene; and isolating a polyethylene having a density in the range of from 0.930 to 0.975 g/cm3. Also provided is a method of transitioning a continuous polymerization reactor from production of a low density polyethylene to a medium or high density polyethylene. Also provided is a medium to high density polyethylene suitable for injection or rotomolding applications. Also provided is a single catalyst composition suitable for such needs.

Abstract: The present invention relates to a supported catalyst composition and a method for making the supported catalyst composition and its use in a process for polymerizing olefin(s). In particular, the invention is directed to a method for making a supported catalyst composition by contacting a supported activator with a bulky ligand and a metal compound.

Abstract: The present invention provides a catalyst precursor, a catalyst system comprising the precursor, and a polymerization method using the catalyst system, an embodiment of the precursor is selected from the following structures: wherein T is a bridging group; M is selected from Groups 3 to 13 atoms, and the Lanthanide series of atoms the Periodic Table of the Elements; Z is a coordination ligand; each L is a monovalent, bivalent, or trivalent anionic ligand; X and Y are each independently selected from nitrogen, oxygen, sulfur, and phosphorus; each R can be the same or different and is a bulky substituent that is sterically hindering with respect to X and Y.

Abstract: A process for preparing a mixed catalyst compound used in the polymerization of polyolefins to produce bimodal polyethylenes is disclosed. In an embodiment, a process of preparing the mixed catalyst system includes: mixing a first catalyst and an activator in a first liquid medium to form a first mixture, combining a support with the first mixture to form a first support slurry, drying the first support slurry in an extent sufficient to provide a dried supported first catalyst, mixing the dried supported first catalyst in a second liquid medium to form a second support slurry, and combining one or more additional catalysts with the second support slurry to provide the mixed catalyst compound.

Abstract: A catalyst composition and method for olefin polymerization are provided. In one aspect, the catalyst composition is represented by the formula ?a?b?gMXn wherein M is a metal; X is a halogenated aryloxy group; ? and ? are groups that each comprise at least one Group 14 to Group 16 atom; ? is a linking moiety that forms a chemical bond to each of ? and ?; and a, b, g, and n are each integers from 1 to 4.

Abstract: Disclosed are various compositions, including but not limited to a high strength bimodal polyethylene composition having a density of 0.940 g/cc or more, the composition comprising a high molecular weight polyethylene component having a higher weight average molecular weight (MwHMW) and a low molecular weight polyethylene component having a lower weight average molecular weight (MwLMW), wherein: the ratio of the higher weight average molecular weight to the lower weight average molecular weight (MwHMW:MwLMW) is 30 or more; and the composition qualifies as a PE 100 material such that in accordance with ISO 1167 a pipe formed from the composition that is subjected to internal pipe resistance has an extrapolated stress of 10 MPa or more when the internal pipe resistance curve is extrapolated to 50 or 100 years in accordance with ISO 9080:2003(E).