| 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 |
