High-density polyethylene compositions, method of making the same, injection molded articles made therefrom, and method of making such articles

Abstract

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/cm 3 , 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/cm 3 , and a melt index (I 2 ) in the range of 30 to 1500 g/10 minutes. The high-density polyethylene composition has a melt index (I 2 ) of at least 1, a density in the range of 0.950 to 0.960 g/cm 3 . 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/cm 3 , 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/cm 3 , and a melt index (I 2 ) 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 (I 2 ) of at least 1, a density in the range of 0.950 to 0.960 g/cm 3 . 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.

1 . A high-density polyethylene composition comprising:
 a first component, said first component being a high molecular weight ethylene alpha-olefin copolymer having a density in the range of 0.920 to 0.946 g/cm 3 , and a melt index (I 21.6 ) in the range of 1 to 15 g/10 minutes; and   a second component, said second component being a low molecular weight ethylene polymer having a density in the range of 0.965 to 0.980 g/cm 3 , and a melt index (I 2 ) in the range of 30 to 1500 g/10 minutes;   wherein said high-density polyethylene composition having a melt index (I 2 ) of at least 1 g/10 minutes, a density in the range of 0.950 to 0.960 g/cm 3 ; wherein said high-density polyethylene composition further comprising 100 to 10,000 ppm by weight of a nucleator.   
     
     
         2 - 36  (canceled) 
     
     
         37 . An article comprising the high-density polyethylene composition of  claim 1 . 
     
     
         38 . (canceled) 
     
     
         39 . The article according to  claim 37 , wherein said article being a wire cable jacketing, a conduit pipe, or an injection blow molded bottle. 
     
     
         40 . A bottle cap closure comprising the high-density polyethylene composition of  claim 1 . 
     
     
         41 - 47 . (canceled) 
     
     
         48 . The high-density polyethylene composition according to  claim 1 , wherein nucleator is potassium stearate or HPN-20E, wherein the inventive high-density polyethylene composition having a standard deviation of flow direction shrinkage of less than 4 percent across different colors. 
     
     
         49 . The high-density polyethylene composition according to  claim 1 , wherein said nucleator is potassium stearate or HPN-20E, wherein the high-density polyethylene composition having a standard deviation of flow direction shrinkage of less than 3 percent across different colors. 
     
     
         50 . (canceled) 
     
     
         51 . The high-density polyethylene composition according to  claim 1 , wherein said high-density polyethylene composition having a 1% secant modulus in psi of equal or greater to the following relationship [(7,492,165*density (g/cm 3 ))−6,975,000] psi/(g/cm3)).