Patent MX-2009013622-A (MX)
Title: Polyethylene compositions, method of producing the same, articles made therefrom, and method making the same.
Inventor: MICHIE WILLIAM
IPC: B29C45/00
Filed: 2009-01-23
Abstract: The instant invention is a polyethylene composition, method of producing the same, articles made therefrom, and method of making the same. The polyethylene composition according to the instant invention comprises (1) less than or equal to 100 percent by weight of the units derived from ethylene; and (2) less than 15 percent by weight of units derived from one or more a-olefin comonomers. The polyethylene composition according the instant invention has a density in the range of 0.907 to 0.975 g/cm3, a molecular weight distribution (Mw/Mn) in the range of 1.70 to 3.62, a melt index (I2) in the range of 2 to 1000 g/10 minutes, a molecular weight distribution (Mz/Mw) in the range of less than 2.5, and a vinyl unsaturation of less than 0.06 vinyls per one thousand carbon atoms present in the backbone of the composition. The process for producing a polyethylene composition according to the instant invention comprises the steps of: (1) (co)polymerizing ethylene and at least one or more a-olefin comonomers in the presence of a hafnium based metallocene catalyst via a gas phase (co)polymerization process in a single stage reactor; and (2) thereby producing the inventive polyethylene composition, wherein the polyethylene composition has a density in the range of 0.907 to 0.975 g/cm3, a molecular weight distribution (Mw/Mn) in the range of 1.70 to 3.62, a melt index (I2) in the range of 2 to 1000 g/10 minutes, a molecular weight distribution (Mz/Mw) in the range of less than 2.5, and a vinyl unsaturation of less than 0.06 vinyls per one thousand carbon atoms present in the backbone of said composition. The injection molded articles according to the instant invention comprise a polyethylene composition comprising (1) less than or equal to 100 percent by weight of the units derived from ethylene; and (2) less than 15 percent by weight of units derived from one or more a-olefin comonomers; wherein the polyethylene composition has a density in the range of 0.907 to 0.975 g/cm3, a molecular weight distribution (Mw/Mn) in the range of 1.70 to 3.62, a melt index (I2) in the range of 2 to 1000 g/10 minutes, a molecular weight distribution (Mz/Mw) in the range of less than 2.5, vinyl unsaturation of less than 0.06 vinyls per one thousand carbon atoms present in the backbone of said composition. The process for making an injection molded article according to the instant invention comprises the steps of: (a) selecting a polyethylene composition comprising (1) less than or equal to 100 percent by weight of the units derived from ethylene; and (2) less than 15 percent by weight of units derived from one or more a-olefin comonomers; wherein the polyethylene composition has a density in the range of 0.907 to 0.975 g/cm3, a molecular weight distribution (Mw/Mn) in the range of 1.70 to 3.62, a melt index (I2) in the range of 2 to 1000 g/10 minutes, a molecular weight distribution (Mz/Mw) in the range of less than 2.5, vinyl unsaturation of less than 0.06 vinyls per one thousand carbon atoms present in the backbone of said composition; (b) injection molding said polyethylene composition; and (c) thereby forming the injection molded article.