Patent application number | Description | Published |
20090131616 | Methods for Improving Heat Transfer in Polymerization Processes - Methods for improving heat transfer in polymerization processes are described herein. The methods generally include contacting olefin monomer with a catalyst system within a reaction zone to form particles having a first average particle size and altering the reaction zone to improve heat transfer and form polymer particles having a second average particle size. For example, the second average particle size may be larger than the first average particle size and the second particle size results in improved heat transfer over the first particle size. | 05-21-2009 |
20090198026 | Preparation of supported chromium catalyst and polymerization process - A process for the preparation of a chromium-type supported olefin polymerization catalyst. A fluidized bed of support particles in an inert carrier gas is established. A chromium (III) compound is added to the fluidized support particles to provide a supported catalyst component. The supported catalyst component is activated to convert at least a portion of the chromium (III) to Chromium (VI). The chromium (III) containing particles may be recovered from the fluidized bed and then activated or they may be activated in the fluidized bed. Also the support particles can be treated in the fluidized bed with other treatment agents. The support particles may be pretreated with a solution of a boron treating agent prior to incorporation of the support in the fluidized bed. | 08-06-2009 |
20090203856 | Ziegler-Natta catalyst - The present invention relates generally to catalysts, to methods of making catalysts, to methods of using catalysts, to methods of polymerizing, and to polymers made with such catalysts. More particularly, the present invention relates to polyolefin catalysts and to Ziegler-Natta catalysts, to methods of making such catalysts, to methods of using such catalysts, to polyolefin polymerization, and to polyolefins. | 08-13-2009 |
20100184920 | Methods of making styrenic polymeric compositions and methods of using same - A method comprising preparing a reaction mixture comprising a styrene monomer, an antioxidant, and a reaction rate improving additive, contacting the reaction mixture with an antioxidant reactive compound, and placing the reaction mixture under conditions suitable for polymerization of the styrene monomer to a styrenic polymer wherein the polymerization occurs at an overall reaction rate that is increased by equal to or less than 20% when compared to an otherwise similar polymerization process carried out in the absence of the reaction rate improving additive A method comprising preparing a reaction mixture comprising a styrene monomer, an elastomer, an antioxidant, a sodium or calcium salt of an organic acid, and an initiator; and placing the reaction mixture under conditions suitable for polymerization of the styrene monomer to a styrenic polymer, wherein the sodium or calcium salt of an organic acid protects the initiator such that the polymerization is carried out at a reaction rate greater than would otherwise be the rate in the absence of the sodium or calcium salt of an organic acid. | 07-22-2010 |
20100210797 | Polyethylene Films having Improved Barrier Properties - Blown films and processes of forming the same are described herein. The blown films generally include high density polyethylene exhibiting a molecular weight distribution of from about 1.5 to about 8.0 and a density of from 0.94 g/cc to less than 0.96 g/cc. | 08-19-2010 |
20100267909 | Bimodal Pipe Resin and Products Made Therefrom - Disclosed is a bimodal Ziegler-Natta catalyzed polyethylene, having a density of from 0.930 g/cc to 0.960 g/cc, and a molecular weight distribution of from 10 to 25, wherein an article formed therefrom has a PENT of at least 1500. Also disclosed is a method of preparing a tubular article including obtaining a bimodal polyethylene having a density of from 0.930 g/cc to 0.960 g/cc and a molecular weight distribution of from 10 to 25, and processing the polyethylene under conditions where a specific energy input (SEI) is less than 300 kW·h/ton, and wherein the article has a PENT of at least 1500. Further disclosed is a method for controlling the degradation of polyethylene including polymerizing ethylene monomer, recovering polyethylene, extruding the polyethylene, and controlling the degradation of polyethylene by measuring the SEI to the extruder and adjusting throughput and/or gear suction pressure keep SEI less than 300 kW·h/ton, and forming an article. | 10-21-2010 |
20110172379 | Ziegler-Natta Catalyst Systems and Polymers Formed Therefrom - Processes of forming catalyst systems, catalyst systems and polymers formed therefrom are described herein. The processes generally include providing a first compound including a magnesium dialkoxide, contacting the first compound with a second compound to form a solution of reaction product “A”, wherein the second compound is generally represented by the formula: | 07-14-2011 |
20110275509 | ZIEGLER-NATTA CATALYST - The present invention relates generally to catalysts, to methods of making catalysts, to methods of using catalysts, to methods of polymerizing, and to polymers made with such catalysts. More particularly, the present invention relates to polyolefin catalysts and to Ziegler-Natta catalysts, to methods of making such catalysts, to methods of using such catalysts, to polyolefin polymerization, and to polyolefins. | 11-10-2011 |
20110313116 | Polymerization Process Utilizing Hydrogen - Ethylene polymerization processes and polymers formed from the same are discussed herein. The ethylene polymerization processes generally include introducing ethylene monomer into a polymerization reaction zone; introducing a chromium oxide based catalyst into the polymerization reaction zone; introducing a quantity of hydrogen into the polymerization reaction zone; and contacting the ethylene monomer with the chromium oxide based catalyst in the polymerization reaction zone in the presence of hydrogen to form polyethylene, wherein the polyethylene formed in the presence of hydrogen exhibits an MI | 12-22-2011 |
20120083405 | Ziegler-Natta Catalyst Systems and Polymers Formed Therefrom - Processes of forming catalyst systems, catalyst systems and polymers formed therefrom are described herein. The processes generally include providing a first compound including a magnesium dialkoxide, contacting the first compound with a second compound to form a solution of reaction product “A”, wherein the second compound is generally represented by the formula: | 04-05-2012 |
20120091621 | BIMODAL PIPE RESIN AND PRODUCTS MADE THEREFROM - Disclosed is a bimodal Ziegler-Natta catalyzed polyethylene, having a density of from 0.930 glee to 0.960 glee, and a molecular weight distribution of from 10 to 25, wherein an article formed therefrom has a PENT of at least 1500. Also disclosed is a method of preparing a tubular article including obtaining a bimodal polyethylene having a density of from 0.930 glee to 0.960 Wee and a molecular weight distribution of from 10 to 25, and processing the polyethylene under conditions where a specific energy input (SET) is less than 300 kW.h/ton, and wherein the article has a PENT of at least 1500. Further disclosed is a method for controlling the degradation of polyethylene including polymerizing ethylene monomer, recovering polyethylene, extruding the polyethylene, and controlling the degradation of polyethylene by measuring the SEI to the extruder and adjusting throughput and/or gear suction pressure keep SEI less than 300 kW.h/ton, and forming an article. | 04-19-2012 |
20120108769 | MULTI-COMPONENT CATALYST SYSTEMS INCLUDING CHROMIUM BASED CATALYSTS AND POLYMERIZATION PROCESSES FOR FORMING POLYOLEFINS - Polymerization processes and polymers formed therefrom are described herein. The polymerization processes generally include contacting ethylene and propylene with a multi-component catalyst composition including a first catalyst component including a chromium oxide based catalyst and a second catalyst component selected from metallocene and Ziegler-Natta catalysts within a polymerization reaction vessel to form a random copolymer, wherein the second catalyst component exhibits a higher comonomer response than the first catalyst component. | 05-03-2012 |
20120208694 | PREPARATION OF SUPPORTED CHROMIUM CATALYST AND POLYMERIZATION PROCESS - A process for the preparation of a chromium-type supported olefin polymerization catalyst. A fluidized bed of support particles in an inert carrier gas is established. A chromium (III) compound is added to the fluidized support particles to provide a supported catalyst component. The supported catalyst component is activated to convert at least a portion of the chromium (III) to Chromium (VI). The chromium (III) containing particles may be recovered from the fluidized bed and then activated or they may be activated in the fluidized bed. Also the support particles can be treated in the fluidized bed with other treatment agents. The support particles may be pretreated with a solution of a boron treating agent prior to incorporation of the support in the fluidized bed. | 08-16-2012 |
20120208969 | ZIEGLER-NATTA CATALYSTS DOPED WITH NON-GROUP IV METAL CHLORIDES - Ziegler-Natta catalysts, processes of forming the same and using the same are described herein. The process generally includes contacting a metal component with a magnesium dihalide support material to form a Ziegler-Natta catalyst precursor; contacting the support material with a dopant including a non-Group IV metal halide to form a doped catalyst precursor; and activating the doped catalyst precursor by contact with an organoaluminum compound to form a Ziegler-Natta catalyst. | 08-16-2012 |
20120208970 | HEAT-TREATED ZIEGLER-NATTA CATALYSTS FOR ETHYLENE POLYMERIZATION - Catalyst systems, processes of forming the same and polymers formed therefrom are described herein. The processes of forming the catalyst systems generally include contacting a blend of an alkyl magnesium compound and an organoaluminum compound with an alcohol to form a magnesium dialkoxide compound; contacting the magnesium dialkoxide compound with a first agent to form a solution of reaction product “A”, the first agent including a halogenating/titanating agent; contacting the solution of reaction product “A” with a second agent to form a solid reaction product “B”, the second agent including a blend of a first metal halide and a metal alkoxide; contacting the solid reaction product “B” with a third agent to form a solid reaction product “C”, the third agent including a second metal halide; contacting the solid reaction product “C” with a fourth agent to form a solid reaction product “D”, the fourth agent including a third metal halide; contacting the solid reaction product “D” with a fifth agent to form a catalyst component, the fifth agent including a reducing agent; and heating an intermediate selected from reaction product “A”, reaction product “B”, reaction product “C”, reaction product “D” and combinations thereof to form a heat-treated catalyst that results in a shear response and a molecular weight distribution for a polymer produced by the heat-treated catalyst that are greater than a shear response and a molecular weight distribution for a polymer produced by an identical non-heat-treated catalyst. | 08-16-2012 |
20120245285 | METHODS OF MAKING STYRENIC POLYMERIC COMPOSITIONS AND METHODS OF USING SAME - A method of preparing a reaction mixture comprising a styrene monomer, an antioxidant, and a reaction rate improving additive, contacting the reaction mixture with an antioxidant reactive compound, and placing the reaction mixture under conditions suitable for polymerization of the styrene monomer to a styrenic polymer wherein the polymerization occurs at an overall reaction rate that is increased by equal to or less than 20% when compared to an otherwise similar polymerization process carried out in the absence of the reaction rate improving additive. The reaction rate improving additive can be a sodium or calcium salt of an organic acid. | 09-27-2012 |
20120277375 | Increasing Rubber Phase Volume in Rubber-Modified Polystyrene - A process for producing rubber modified polymers having an increased rubber phase volume, including feeding a vinyl aromatic monomer and an elastomer to a polymerization reactor to form a reaction mixture, polymerizing the reaction mixture, combining a copolymer to the polymerized reaction mixture to form a combined mixture, subjecting the combined mixture to further polymerization, and obtaining a rubber modified polymer product from the further polymerization. | 11-01-2012 |
20140323654 | Increasing Rubber Phase Volume in Rubber-Modified Polystyrene - A process for producing rubber modified polymers having an increased rubber phase volume, including feeding a vinyl aromatic monomer and an elastomer to a polymerization reactor to form a reaction mixture, polymerizing the reaction mixture, combining a copolymer to the polymerized reaction mixture to form a combined mixture, subjecting the combined mixture to further polymerization, and obtaining a rubber modified polymer product from the further polymerization. | 10-30-2014 |