Abstract: Multimodal polyethylenes possessing a density from 0.940 to 0.965 g/cm3, and an I21 from 4 to 20 dg/min, and comprising a low molecular weight ethylene copolymer having a weight average molecular weight from 5,000 amu to 50,000 amu; and a high molecular weight ethylene copolymer having a weight average molecular weight from 60,000 amu to 800,000 amu, both components having a desirable balance of short chain branching making the multimodal polyethylene suitable for films, pipes, rotomolding applications and blow molding applications.

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: Embodiments of our invention relate generally to methods of monitoring and controlling polymerization reactions including reactions producing multimodal polymer products using multiple catalysts in a single reactor. Embodiments of the invention provide methods of rapidly monitoring and controlling polymerization reactions without the need to sample and test the polymer properties. The method uses reactor control data and material inventory data in a mathematical leading indicator function to control the reactor conditions, and thereby the products produced under those conditions.

Abstract: The present invention relates to catalyst systems for polyolefin production, and more particularly, to catalyst systems for polyolefins used in producing films.

Abstract: Disclosed herein are various processes, including continuous fluidized-bed gas-phase polymerization processes for making a high strength, high density polyethylene copolymer, comprising (including): contacting monomers that include ethylene and optionally at least one non-ethylene monomer with fluidized catalyst particles in a gas phase in the presence of hydrogen gas at an ethylene partial pressure of 100 psi or more and a polymerization temperature of 120° C. or less to produce a polyethylene copolymer having a density of 0.945 g/cc or more and an ESCR Index of 1.0 or more wherein the catalyst particles are prepared at an activation temperature of 700° C. or less, and include silica, chromium, and titanium.

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: 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: The present invention is directed to the use of aluminum alkyl activators and co-catalysts to improve the performance of chromium-based catalysts. The aluminum alkyls allow for the variable control of polymer molecular weight, control of side branching while possessing desirable productivities, and may be applied to the catalyst directly or separately to the reactor. Adding the alkyl aluminum compound directly to the reactor (in-situ) eliminates induction times.

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 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 15 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: 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 a Ziegler-Natta-type catalyst system 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: A gas phase polymerization process comprising: (1) preparing a solution of a catalyst precursor comprising a mixture of magnesium and titanium compounds, an electron donor and a solvent; (2) adding a filler to the solution from step (1) to form a slurry; (3) spray drying the slurry from step (2) at a temperature of 100 to 140° C. to form a spray dried precursor, (4) slurring the spray dried precursor from step (3) in mineral oil, (5) partially or fully pre-activating the catalyst precursor by contacting the slurry of (4) with one or more Lewis Acids, and (6) transferring the partially or fully activated precursor from step (5) into a gas phase reactor in which an olefin polymerization reaction is in progress.

Abstract: The present invention is directed to the use of aluminum alkyl activators and co-catalysts to improve the performance of chromium-based catalysts. The aluminum alkyls allow for the variable control of polymer molecular weight, control of side branching while possessing desirable productivities, and may be applied to the catalyst directly or separately to the reactor. Adding the alkyl aluminum compound directly to the reactor (in-situ) eliminates induction times.

Abstract: Disclosed herein are various processes, including a process for producing a film, comprising (including) forming a film from a blended polyolefin composition at a line speed of at least 170 feet per minute, wherein the blended polyolefin composition comprises: (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 wherein the high and low molecular weight polyethylene components of the bimodal polyethylene component are formed in a single reactor; and (b) a unimodal polyethylene component that occupies more than 15 wt % of the composition.

Abstract: Bimodal polyethylene compositions and blow molded bottles made therefrom are provided. In at least one specific embodiment, the composition includes at least one high molecular weight polyethylene component having a molecular weight distribution (MWD) of about 6 to about 9, a short chain branch content of less than about 2 branches per 1,000 main chain carbons, and a Mz of about 1,100,000 or more. The composition also includes at least one low molecular weight polyethylene component where a ratio of weight average molecular weight of the high molecular weight polyethylene component to weight average molecular weight of the low molecular weight polyethylene component is about 20 or less. The polyethylene composition has a density of about 0.94 g/cc or more, an ESCR of about 600 hours or more, a percent die swell of about 70% or more, and may comprise at least 70% ethylene-derived units.

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: Generally, a method of monitoring a polymerization reaction in a fluid bed reactor to generate, in on-line fashion, data indicative of the imminent occurrence of a discontinuity event (for example, sheeting) and optionally also control the reaction to prevent the occurrence of the discontinuity event is provided. Typical embodiments include the steps of generating in on-line fashion at least one of bed static data indicative of static charge in the fluidized bed and carryover static data indicative of carryover static; and generating at least one of temperature data (in on-line fashion using at least one monitored reaction parameter) indicative of a first temperature and acoustic emission data indicative of resin stickiness in the reactor, where the first temperature is indicative of at least one of degree of resin stickiness in the reactor and a characteristic of melting behavior of polymer resin in the reactor in the presence of at least one diluent.

Abstract: A bimodal polyethylene composition that includes ethylene-derived units, and, optionally, one or more other olefin-derived units, wherein the bimodal polyethylene composition possesses a density of at least 0.940 g/cc, an average molecular weight (Mw) of from 200,000 to 370,000, a z-average molecular weight (Mz) of from 1,500,000 to 3,400,000 Daltons, and a z+1 average molecular weight (Mz+1) of from 2,500,000 to 6,800,000 Daltons, is provided in various embodiments. Articles made therefrom and methods of making the same are also provided.

Abstract: The present invention relates to a supported, treated catalyst system and its use in a process for polymerizing olefin(s). More particularly, it provides a supported, treated catalyst system produced by a process comprising the steps of: (a) forming a supported bimetallic catalyst system comprising a first catalyst component and a metallocene catalyst compound; and (b) contacting the supported bimetallic catalyst system of (a) with at least one methylalumoxane-activatable compound.

Abstract: The present invention relates to a process for the polymerization of monomers utilizing a bulky ligand hafnium transition metal metallocene-type catalyst compound, to the catalyst compound itself and to the catalyst compound in combination with an activator. The hafnocene comprises at least one cyclopentadienyl ligand including at least one linear or isoalkyl substituent of at least 3 carbon atoms.