Patent application number | Description | Published |
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 |
20090018279 | Method for controlling sheeting in gas phase reactors - Embodiments of the present invention relate to measuring and controlling static in a gas phase reactor polymerization. In particular, embodiments relate to monitoring carryover static in an entrainment zone during gas phase polymerization to determine the onset of reactor discontinuity events such as chunking and sheeting. Embodiments also relate to monitoring carryover static to determine the need for effective additions of continuity additives that minimize reactor static activity and thereby preventing discontinuity events. | 01-15-2009 |
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 |
20100105849 | SYSTEMS AND METHODS FOR FABRICATING POLYOLEFINS - Various methods and systems for using oxygen in a polyolefin polymerization reactor system are provided. In certain embodiments, the methods are performed in conjunction with a polymerization reactor system such as a gas-phase reactor system. | 04-29-2010 |
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 |
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 |
20100298511 | METALLOCENE CATALYSTS AND THEIR USE IN POLYMERIZATION PROCESSES - A process for polymerizing olefin(s) utilizing a cyclic bridged metallocene catalyst system to produce polymers with improved properties is provided. The catalyst system may include a cyclic bridged metallocene, L | 11-25-2010 |
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 |
20110098422 | POLYETHYLENE COMPOSITIONS HAVING IMPROVED PROPERTIES - Polyethylene compositions having improved properties are provided. In one aspect, a polyethylene composition having a long chain branching index (g′ | 04-28-2011 |
20110218307 | Systems and Methods for Fabricating Polymers - The present invention is broadly directed to various methods and systems for gas and liquid phase polymer production. In certain embodiments, the methods are performed in conjunction with a polymerization reactor system such as gas phase reactor system or liquid phase reactor system. The invention is also broadly directed to various systems in which polymer properties are manipulated by addition of DEALE directly to a polymerization reactor system. | 09-08-2011 |
20110237763 | Systems and Methods for Fabricating Polymers - Disclosed herein are various methods and systems for gas and liquid phase polymer production. In certain embodiments, the methods comprise manipulating properties of polymers produced by adjusting the hydrogen feed rate. | 09-29-2011 |
20110294973 | Method for Seed Bed Treatment for a Polymerization Reaction - A method for preparing a reactor for performance of a polymerization reaction, the method including providing at least one seed bed into the reactor; wherein the at least one seed bed includes at least one organometallic compound and polymer particles. | 12-01-2011 |
20120252994 | Methods for Making Polyolefin Products Having Different Shear Thinning Properties and Haze - Provided is a method for making a polyolefin comprising contacting one or more olefins in a reactor containing a catalyst; polymerizing the one or more olefins to produce an olefin polymer characterized by a first melt flow ratio (MFR) and a first haze; and altering the reaction temperature in the reactor to shift the first MFR to a MFR that is different than the first MFR and to shift the first haze to a haze that is different than the first haze. | 10-04-2012 |
20130035463 | Catalyst Systems And Methods For Using Same To Produce Polyolefin Products - Catalyst systems and methods for making and using the same. The catalyst system can include a single site catalyst compound, a support comprising fluorinated alumina, and an aluminoxane. The aluminoxane can be present in an amount of about 10 mmol or less per gram of the support. | 02-07-2013 |
20140179882 | Systems and Methods for Fabricating Polymers - The present invention is broadly directed to various methods and systems for gas and liquid phase polymer production. In certain embodiments, the methods are performed in conjunction with a polymerization reactor system such as gas phase reactor system or liquid phase reactor system. The invention is also broadly directed to various systems in which polymer properties are manipulated by addition of DEALE directly to a polymerization reactor system. | 06-26-2014 |
20140378640 | Methods and Systems for Catalyst Delivery - A method for the delivery of a catalyst to a polymerization reactor is disclosed, comprising: contacting a catalyst with a carrier fluid comprising an inert hydrocarbon in gaseous form, the inert hydrocarbon having a normal boiling point of about −1° C. to about 81° C.; and flowing the carrier fluid to the polymerization reactor such that the carrier fluid transports the catalyst to the polymerization reactor. A catalyst delivery system is disclosed, comprising: a catalyst vessel for containing a catalyst; a catalyst injection line for delivering the catalyst to a polymerization reactor, the catalyst injection line being in fluid communication with the catalyst vessel and the polymerization reactor; and a carrier fluid line in fluid communication with the catalyst injection line for delivering a carrier fluid comprising an inert hydrocarbon to the catalyst injection line, the inert hydrocarbon having a normal boiling point of about −1° C. to about 81° C. | 12-25-2014 |