Patent application number | Description | Published |
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 |
20110245428 | Polystyrene Blends - A method of preparing a polystyrene blend that includes combining a first polystyrene composition having a first melt flow index with a second polystyrene composition having a second melt flow index and forming a polystyrene blend, the second melt flow index being at least 2 dg/min higher that the first melt flow index. The polystyrene blend has an observed tensile strength value greater than 3% above the expected tensile strength value. The second polystyrene composition can include a recycled polystyrene material, which can include expanded polystyrene. An alternate method of preparing the polystyrene blend includes combining a polystyrene composition with a styrene monomer to form a reaction mixture, polymerizing the reaction mixture and obtaining a polystyrene blend, where the polystyrene containing composition has a melt flow index at least 2 dg/min higher than the melt flow index of the styrene monomer after it has been polymerized. | 10-06-2011 |
20110267920 | Method and Apparatus for Controlling Residence Time Distribution in Continuous Stirred-Tank Reactors - The present invention includes an apparatus and method for narrowing the residence time distribution of a continuous stirred-tank reactor, or CSTR, which includes the optional procedures of: decreasing the vertical cross-sectional area of the reactor's agitator blades; decreasing the RPM of the agitator blades; and increasing the reactor's L/D ratio. The CSTR can be used in the production of monovinylidene aromatic polymers, such as high impact polystyrene. | 11-03-2011 |
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 |
20120108747 | Methods of Making High Impact Polystyrene - A process for producing high impact polystyrene including feeding at least one vinyl aromatic monomer, an elastomer, and a free radical initiator to a first linear flow reactor to form a reaction mixture. Polymerizing the reaction mixture in the first linear flow reactor to a point below the point at which phase inversion occurs to produce a first polymerization mixture and feeding the first polymerization mixture from the first linear flow reactor to a second linear flow reactor. Polymerizing the reaction mixture in the second linear flow reactor to at least a phase inversion point of the mixture to produce a second polymerization mixture and feeding the second polymerization mixture from the second linear flow reactor to at least a third linear flow reactor for post-inversion polymerization of the second polymerization mixture. The product stream can have an ESCR value of at least 10% toughness retained with less than 10 wt % rubber content. | 05-03-2012 |
20120259071 | Polystyrene Blends - A method of preparing a polystyrene blend that includes combining a first polystyrene composition having a first melt flow index with a second polystyrene composition having a second melt flow index and forming a polystyrene blend, the second melt flow index being at least 2 dg/min higher that the first melt flow index. The polystyrene blend has an observed tensile strength value greater than 3% above the expected tensile strength value. The second polystyrene composition can include a recycled polystyrene material, which can include expanded polystyrene. An alternate method of preparing the polystyrene blend includes combining a polystyrene composition with a styrene monomer to form a reaction mixture, polymerizing the reaction mixture and obtaining a polystyrene blend, where the polystyrene containing composition has a melt flow index at least 2 dg/min higher than the melt flow index of the styrene monomer after it has been polymerized. | 10-11-2012 |