HIGH-DENSITY POLYETHYLENE COMPOSITIONS, METHOD OF MAKING THE SAME, INJECTION MOLDED ARTICLES MADE THEREFROM, AND METHOD OF MAKING SUCH ARTICLES

摘要

The instant invention is a high-density polyethylene composition, method of producing the same, injection molded articles made therefrom, and method of making such articles. The high-density polyethylene composition of the instant invention includes a first component, and a second component. The first component is a high molecular weight ethylene alpha-olefin copolymer having a density in the range of 0.920 to 0.946 g/cm³, and a melt index (I_21.6) in the range of 1 to 15 g/10 minutes. The second component is a low molecular weight ethylene polymer having a density in the range of 0.965 to 0.980 g/cm³, and a melt index (I₂) in the range of 30 to 1500 g/10 minutes. The high-density polyethylene composition has a melt index (I₂) of at least 1, a density in the range of 0.950 to 0.960 g/cm³. The method of producing a high-density polyethylene composition includes the following steps: (1) introducing ethylene, and one or more alpha-olefin comonomers into a first reactor; (2) (co)polymerizing the ethylene in the presence of one or more alpha-olefin comonomers in the first reactor thereby producing a first component, wherein the first component being a high molecular weight ethylene alpha-olefin copolymer having a density in the range of 0.920 to 0.946 g/cm³, and a melt index (I_21.6) in the range of 1 to 15 g/10 minutes; (3) introducing the first component and additional ethylene into a second reactor; (4) polymerizing the additional ethylene in the second reactor thereby producing a second component, wherein the second component being a low molecular weight ethylene polymer having a density in the range of 0.965 to 0.980 g/cm³, and a melt index (I₂) in the range of 30 to 1500 g/10 minutes; and (5) thereby producing the high-density polyethylene composition, wherein the high-density polyethylene composition having a melt index (I₂) of at least 1, a density in the range of 0.950 to 0.960 g/cm³. The injection molded articles according to instant invention comprise the above-described inventive high-density polyethylene composition, and such articles are made via injection molding.