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| 20080242821 | Hindered polyalicyclic alkyl catalysts and their use in a gas-phase polymerization reactor - Embodiments of the present invention include a method of polymerizing olefins comprising contacting olefins with a catalyst composition made by the process of combining a hindered polyalicyclic alkyl catalyst precursor with a particulate inorganic oxide for a deposition time greater than 2 hours to form a catalyst composition. Embodiments of the present invention also include catalyst compositions comprising a hindered polyalicyclic alkyl catalyst precursor made by the process of combining the hindered polyalicyclic alkyl catalyst precursor with a particulate inorganic oxide for a deposition time greater than 2 hours to form the catalyst composition. In one embodiment, the hindered polyalicyclic alkyl catalyst precursor is formed by first combining an acid, a compound having the formula RX, and a metal oxide selected from the group consisting of Group 3 to Group 10 oxide compounds to produce a catalyst precursor; characterized in that R is selected from the group consisting of hindered polyalicyclic alkyls, and substituted derivatives thereof, and X is selected from the group consisting of any suitable leaving group. | 10-02-2008 |
| 20100137533 | HINDERED POLYALICYCLIC ALKYL CATALYSTS AND THEIR USE IN A GAS-PHASE POLYMERIZATION REACTOR - Embodiments of the present invention include a method of polymerizing olefins comprising contacting olefins with a catalyst composition made by the process of combining a hindered polyalicyclic alkyl catalyst precursor with a particulate inorganic oxide for a deposition time greater than 2 hours to form a catalyst composition. Embodiments of the present invention also include catalyst compositions comprising a hindered polyalicyclic alkyl catalyst precursor made by the process of combining the hindered polyalicyclic alkyl catalyst precursor with a particulate inorganic oxide for a deposition time greater than 2 hours to form the catalyst composition. In one embodiment, the hindered polyalicyclic alkyl catalyst precursor is formed by first combining an acid, a compound having the formula RX, and a metal oxide selected from the group consisting of Group 3 to Group 10 oxide compounds to produce a catalyst precursor; characterized in that R is selected from the group consisting of hindered polyalicyclic alkyls, and substituted derivatives thereof, and X is selected from the group consisting of any suitable leaving group. | 06-03-2010 |
| 20110060111 | Production of Polyethylene - 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. | 03-10-2011 |
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| 20090215970 | Blow Molding Polyethylene Resins - 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. | 08-27-2009 |
| 20090312506 | PRODUCTION OF POLYETHYLENE - 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. | 12-17-2009 |
| 20100160580 | Blow molding Polyethylene Resins - 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 105° 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. | 06-24-2010 |
| 20100291334 | Broad Molecular Weight Polyethylene Having Improved Properties - Disclosed herein is a polyolefin polymer having improved properties wherein the polymer is produced using a chromium based catalyst in combination with aluminum alkyl activators and co-catalysts. Also disclosed is a pipe comprising the inventive polymer and a film comprising the inventive polymer, each having improved properties over those known in the art. | 11-18-2010 |
| 20110010938 | Modified Chromium-Based Catalysts and Polymerization Processes for Using the Same - Embodiments disclosed herein generally relate to olefin polymerization catalysts, and more specifically to chromium-based catalysts and methods of use of chromium-based catalysts for the production of polyolefins, and even more specifically to methods for controlling or tailoring the flow index response of chromium-based catalysts through the controlled addition of a reducing agent to the catalysts under controlled mixing conditions. | 01-20-2011 |
