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 .   
   
   
       2 . The high-density polyethylene composition according to  claim 1 , wherein said first component having a density in the range of 0.925 to 0.945 g/cm 3 . 
   
   
       3 . The high-density polyethylene composition according to  claim 1 , wherein said first component having a density in the range of 0.928 to 0.944 g/cm 3 . 
   
   
       4 . The high-density polyethylene composition according to  claim 1 , wherein said first component having a melt index (I 21.6 ) in the range of 2 to 12 g/10 minutes. 
   
   
       5 . The high-density polyethylene composition according to  claim 1 , wherein said first component having a melt index (I 21.6 ) in the range of 2.5 to 11 g/10 minutes. 
   
   
       6 . The high-density polyethylene composition according to  claim 1 , wherein said second component having a density in the range of 0.965 to 0.975 g/cm 3 . 
   
   
       7 . The high-density polyethylene composition according to  claim 1 , wherein said second component having a melt index (I 2 ) in the range of 40 to 1300 g/10 minutes. 
   
   
       8 . The high-density polyethylene composition according to  claim 1 , wherein said second component having a melt index (I 2 ) in the range of 50 to 1000 g/10 minutes. 
   
   
       9 . The high-density polyethylene composition according to  claim 1 , wherein said high-density polyethylene composition having a melt index (I 2 ) in the range of 1 to 2 g/10 minutes. 
   
   
       10 . The high-density polyethylene composition according to  claim 1 , wherein said high-density polyethylene composition having a melt index (I 2 ) of at least 2 g/10 minutes. 
   
   
       11 . The high-density polyethylene composition according to  claim 1 , wherein said first component having a molecular weight in the range of 150,000 to 300,000. 
   
   
       12 . The high-density polyethylene composition according to  claim 1 , wherein said second component having a molecular weight in the range of 12,000 to 45,000. 
   
   
       13 . The high-density polyethylene composition according to  claim 1 , wherein said first component having a density in the range of 0.928 to 0.944 g/cm 3 , and a melt index (I 21.6 ) in the range of 2.5 to 11 g/10 minutes; wherein said second component having a density in the range of 0.965 to 0.975 g/cm 3 , and a melt index (I 2 ) in the range of 50 to 1000 g/10 minutes. 
   
   
       14 . The high-density polyethylene composition according to  claim 1 , wherein said first component being substantially free of any long chain branching, and said second component being substantially free of any long chain branching. 
   
   
       15 . The high-density polyethylene composition according to  claim 14 , wherein said high-density polyethylene composition being substantially free of any long chain branching. 
   
   
       16 . The high-density polyethylene composition according to  claim 1 , wherein said high-density polyethylene composition having a single ATREF temperature peak, wherein said ATREF temperature peak having a temperature peak maximum between about 90° C. to about 105° C.;
 wherein said high-density polyethylene composition having a calculated purge fraction of less than 15.5 percent.   
   
   
       19 . A method of producing a high-density polyethylene composition comprising the steps of:
 introducing ethylene, and an alpha-olefin comonomer into a first reactor;   polymerizing said ethylene in the presence of said alpha-olefin comonomer in said first reactor thereby producing a first component, wherein 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 ) in the range of 1 to 15 g/10 minutes;   introducing said first component and additional ethylene into a second reactor;   polymerizing said additional ethylene in said second reactor thereby producing a second component, wherein 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; and   thereby producing said high-density polyethylene composition, wherein 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 .   
   
   
       20 . The method of producing a high-density polyethylene composition according to  claim 19 , wherein said first component having a density in the range of 0.925 to 0.945 g/cm 3 . 
   
   
       21 . The method of producing a high-density polyethylene composition according to  claim 19 , wherein said first component having a density in the range of 0.928 to 0.944 g/cm 3 . 
   
   
       22 . The method of producing a high-density polyethylene composition according to  claim 19 , wherein said first component having a melt index (I 21.6 ) in the range of 2 to 12 g/10 minutes. 
   
   
       23 . The method of producing a high-density polyethylene composition according to  claim 19 , wherein said first component having a melt index (I 21.6 ) in the range of 2.5 to 11 g/10 minutes. 
   
   
       24 . The method of producing a high-density polyethylene composition according to  claim 19 , wherein said second component having a density in the range of 0.965 to 0.975 g/cm 3 . 
   
   
       25 . The method of producing a high-density polyethylene composition according to claim  17 , wherein said second component having a melt index (I 2 ) in the range of 40 to 1300 g/10 minutes. 
   
   
       26 . The method of producing a high-density polyethylene composition according to  claim 19 , wherein said second component having a melt index (I 2 ) in the range of 50 to 1000 g/10 minutes. 
   
   
       27 . The method of producing a high-density polyethylene composition according to  claim 19 , wherein said high-density polyethylene composition having a melt index (I 2 ) in the range of 1 to 2 g/10 minutes. 
   
   
       28 . The method of producing a high-density polyethylene composition according to  claim 19 , wherein said high-density polyethylene composition having a melt index (I 2 ) of at least 2 g/10 minutes. 
   
   
       29 . The method of producing a high-density polyethylene composition according to  claim 19 , wherein said first component having a molecular weight in the range of 150,000 to 300,000. 
   
   
       30 . The method of producing a high-density polyethylene composition according to  claim 19 , wherein said second component having a molecular weight in the range of 12,000 to 45,000. 
   
   
       31 . The method of producing a high-density polyethylene composition according to  claim 19 , wherein said first component having a density in the range of 0.928 to 0.944 g/cm 3 , and a melt index (I 21.6 ) in the range of 2.5 to 11 g/10 minutes; wherein said second component having a density in the range of 0.965 to 0.975 g/cm 3 , and a melt index (I 2 ) in the range of 50 to 1000 g/10 minutes. 
   
   
       32 . The method of producing a high-density polyethylene composition according to  claim 19 , wherein said first component being substantially free of any long chain branching, and said second component being substantially free of any long chain branching. 
   
   
       33 . The method of producing a high-density polyethylene composition according to  claim 32 , wherein said high-density polyethylene composition being substantially free of any long chain branching. 
   
   
       34 . The method of producing a high-density polyethylene composition according to  claim 19 , wherein said high-density polyethylene composition having a single ATREF temperature peak, wherein said ATREF temperature peak having a temperature peak maximum between about 90° C. to about 105° C.;
 wherein said high-density polyethylene composition having a calculated purge fraction of less than 15.5 percent.   
   
   
       37 . An article comprising:
 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 . 
   
   
   
       38 . The article according to  claim 37 , wherein said high-density composition having an environmental stress crack resistance of at least 10 hours measured via ASTM D-1693 condition B, 10% Igepal, or at least 100 hours measured via ASTM D-1693 condition B, 100% Igepal. 
   
   
       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:
 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 . 
   
   
   
       41 . The bottle cap closure of according to  claim 40 , wherein said high-density polyethylene composition having an environmental stress crack resistance of at least 10 hours measured via ASTM D-1693 condition B, 10% Igepal, or at least 100 hours measured via ASTM D-1693 condition B, 100% Igepal. 
   
   
       42 . A method of improving bottle cap closures comprising the steps of:
 providing 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 ; 
   compression molding, blow molding, or injection molding said high-density polyethylene composition thereby forming said improved bottle cap closures.   
   
   
       43 . A method of producing an article comprising the steps of:
 providing 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 ; 
   compression molding, blow molding, or injection molding said high-density polyethylene composition thereby forming said article.   
   
   
       44 . The high-density polyethylene composition according to  claim 1 , wherein said high-density polyethylene composition having a standard deviation of flow direction shrinkage of less than 7 percent across different colors. 
   
   
       45 . The high-density polyethylene composition according to  claim 1 , wherein said high-density polyethylene composition having a standard deviation of flow direction shrinkage of less than 6 percent across different colors. 
   
   
       46 . The high-density polyethylene composition according to  claim 1 , wherein said high-density polyethylene composition having a standard deviation of flow direction shrinkage of less than 4.5 percent across different colors. 
   
   
       47 . The high-density polyethylene composition according to  claim 1 , wherein said high-density polyethylene composition further comprising 100 to 10,000 ppm by weight of a nucleator. 
   
   
       48 . The high-density polyethylene composition according to  claim 1 , wherein said high-density polyethylene composition further comprising 100 to 10,000 ppm by weight of potassium stearate or HPN-20E as a nucleator, 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 high-density polyethylene composition further comprising 100 to 10,000 ppm by weight of potassium stearate or HPN-20E as a nucleator, wherein the inventive high-density polyethylene composition having a standard deviation of flow direction shrinkage of less than 3 percent across different colors. 
   
   
       50 . The high-density polyethylene composition according to  claim 1 , wherein said high-density polyethylene composition further comprising 100 to 10,000 ppm by weight of potassium stearate or HPN-20E as a nucleator, wherein the inventive high-density polyethylene composition having a standard deviation of flow direction shrinkage of less than 2 percent across different colors. 
   
   
       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/cm 3 )).