Hdpe resins for use in pressure pipe and related applications

{
  "publication_number": "US2010190926A1",
  "country": "US",
  "kind": "A1",
  "title": "Hdpe resins for use in pressure pipe and related applications",
  "abstract": "The present invention provides bimodal polyethylene resins in which the high molecular weight ethylene copolymer component typically has a relatively narrow molecular weight distribution, with short chain branching content being substantially constant across its molecular weight distribution. The resins of this invention are typically characterized by improved toughness and resistance to slow crack propagation properties making them useful for pressure pipe applications.",
  "claims": [
    "33. A method of making a composition comprising a high molecular weight component and a low molecular weight component, the method comprising: (i) blending the high molecular weight component and the low molecular weight component to form the composition; or (ii) producing the high molecular weight component and the low molecular weight component in a multiple polymerization reactor system comprising at least two polymerization reactors configured in series or in parallel, and combining the high molecular weight component and the low molecular weight component in the reactor system to form the composition; or (iii) both (i) and (ii); wherein: a) the high molecular weight component comprises an ethylene copolymer characterized by a M w /M n less than or equal to about 3.5, a substantially constant short-chain branching (SCB) profile across the molecular weight distribution, and a number of short-chain branches (SCB) per 1000 backbone carbon atoms from about 4 to about 8; and b) the low molecular weight component comprises an ethylene homopolymer characterized by a M w from 25 to 60 kg/mol.",
    "34. The method of claim 33, wherein the polymerization reactor system comprises slurry polymerization reactors, loop slurry polymerization reactors, gas phase polymerization reactors, fluidized bed gas phase reactors, solution polymerization reactors, stirred tank reactors, or any combination thereof.",
    "35. The method of claim 33, wherein the high molecular weight component is produced in one or more polymerization reactors and the low molecular weight component is produced in one or more polymerization reactors, wherein the high molecular weight component and the low molecular weight component are produced in separate polymerization reactors.",
    "36. The method of claim 33, wherein the composition comprises from about 45 to about 75 parts by weight high molecular weight component and from about 55 to about 25 parts by weight low molecular weight component.",
    "37. The method of claim 33, wherein the composition is characterized by a M w /M n less than or equal to about 30, and a M z /M w less than or equal to about 10.",
    "38. The method of claim 33, wherein: the ethylene copolymer of the high molecular weight component is produced using a Ziegler-Natta catalyst system or a metallocene catalyst system; or the ethylene homopolymer of the low molecular weight component is produced using a Ziegler-Natta catalyst system or a metallocene catalyst system; or both the ethylene copolymer of the high molecular weight component and the ethylene homopolymer of the low molecular weight component are produced using a Ziegler-Natta catalyst system or a metallocene catalyst system.",
    "39. The method of claim 33, wherein the high molecular weight component comprises a copolymer of ethylene and a mono-1-olefin co-monomer having from 3 to about 12 carbon atoms.",
    "40. The method of claim 33, wherein the ethylene copolymer of the high molecular weight component is further characterized by a M w in a range from about 250 to about 1,000 kg/mol, and a M z /M w less than or equal to about 2.5.",
    "41. The method of claim 33, wherein the ethylene homopolymer of the low molecular weight component is characterized by a M w from about 30 to about 50 kg/mol.",
    "42. A method of making a composition comprising a high molecular weight component and a low molecular weight component, the method comprising: (i) blending the high molecular weight component and the low molecular weight component to form the composition; or (ii) producing the high molecular weight component and the low molecular weight component in a multiple polymerization reactor system comprising at least two polymerization reactors configured in series or in parallel, and combining the high molecular weight component and the low molecular weight component in the reactor system to form the composition; or (iii) both (i) and (ii); wherein: a) the high molecular weight component comprises an ethylene copolymer characterized by a M w /M n less than or equal to about 3.5, a substantially constant short-chain branching (SCB) profile across the molecular weight distribution, and a number of short-chain branches (SCB) per 1000 backbone carbon atoms from 5 to about 8; and b) the low molecular weight component comprises an ethylene homopolymer or copolymer characterized by a M w from 25 to 60 kg/mol.",
    "43. The method of claim 42, wherein the polymerization reactor system comprises slurry polymerization reactors, loop slurry polymerization reactors, gas phase polymerization reactors, fluidized bed gas phase reactors, solution polymerization reactors, stirred tank reactors, or any combination thereof.",
    "44. The method of claim 42, wherein the high molecular weight component is produced in one or more polymerization reactors and the low molecular weight component is produced in one or more polymerization reactors, wherein the high molecular weight component and the low molecular weight component are produced in separate polymerization reactors.",
    "45. The method of claim 42, wherein the composition comprises from about 45 to about 75 parts by weight high molecular weight component and from about 55 to about 25 parts by weight low molecular weight component.",
    "46. The method of claim 42, wherein the composition is characterized by a M w /M n less than or equal to about 30, and a M z /M w less than or equal to about 10.",
    "47. The method of claim 42, wherein: the ethylene copolymer of the high molecular weight component is produced using a Ziegler-Natta catalyst system or a metallocene catalyst system; or the ethylene homopolymer or copolymer of the low molecular weight component is produced using a Ziegler-Natta catalyst system or a metallocene catalyst system; or both the ethylene copolymer of the high molecular weight component and the ethylene homopolymer or copolymer of the low molecular weight component are produced using a Ziegler-Natta catalyst system or a metallocene catalyst system.",
    "48. The method of claim 42, wherein: the high molecular weight component comprises a copolymer of ethylene and a mono-1-olefin co-monomer having from 3 to about 12 carbon atoms; or the low molecular weight component comprises a copolymer of ethylene and a mono-1-olefin co-monomer having from 3 to about 12 carbon atoms; or both the high molecular weight component and the low molecular weight component comprise a copolymer of ethylene and a mono-1-olefin co-monomer having from 3 to about 12 carbon atoms.",
    "49. The method of claim 42, wherein the ethylene copolymer of the high molecular weight component is further characterized by a M w in a range from about 250 to about 1,000 kg/mol, and a M z /M w less than or equal to about 2.5.",
    "50. The method of claim 42, wherein the ethylene homopolymer or copolymer of the low molecular weight component is characterized by a M w from about 30 to about 50 kg/mol.",
    "51. A method of making a composition comprising a high molecular weight component and a low molecular weight component, the method comprising: (i) blending the high molecular weight component and the low molecular weight component to form the composition; or (ii) producing the high molecular weight component and the low molecular weight component in a multiple polymerization reactor system comprising at least two polymerization reactors configured in series or in parallel, and combining the high molecular weight component and the low molecular weight component in the reactor system to form the composition; or (iii) both (i) and (ii); wherein: a) the high molecular weight component comprises an ethylene copolymer characterized by a M w /M n less than or equal to about 3.5, a substantially constant short-chain branching (SCB) profile across the molecular weight distribution, and a number of short-chain branches (SCB) per 1000 backbone carbon atoms from about 4 to about 8; and b) the low molecular weight component comprises an ethylene homopolymer or copolymer characterized by a M w from 25 to 60 kg/mol and a M w /M n greater than or equal to 5.",
    "52. The method of claim 51, wherein the polymerization reactor system comprises slurry polymerization reactors, loop slurry polymerization reactors, gas phase polymerization reactors, fluidized bed gas phase reactors, solution polymerization reactors, stirred tank reactors, or any combination thereof.",
    "53. The method of claim 51, wherein the high molecular weight component is produced in one or more polymerization reactors and the low molecular weight component is produced in one or more polymerization reactors, wherein the high molecular weight component and the low molecular weight component are produced in separate polymerization reactors.",
    "54. The method of claim 51, wherein the composition comprises from about 45 to about 75 parts by weight high molecular weight component and from about 55 to about 25 parts by weight low molecular weight component.",
    "55. The method of claim 51, wherein the composition is characterized by a M w /M z less than or equal to about 30, and a M z /M w less than or equal to about 10.",
    "56. The method of claim 51, wherein: the ethylene copolymer of the high molecular weight component is produced using a Ziegler-Natta catalyst system or a metallocene catalyst system; or the ethylene homopolymer or copolymer of the low molecular weight component is produced using a Ziegler-Natta catalyst system or a metallocene catalyst system; or both the ethylene copolymer of the high molecular weight component and the ethylene homopolymer or copolymer of the low molecular weight component are produced using a Ziegler-Natta catalyst system or a metallocene catalyst system.",
    "57. The method of claim 51, wherein: the high molecular weight component comprises a copolymer of ethylene and a mono-1-olefin co-monomer having from 3 to about 12 carbon atoms; or the low molecular weight component comprises a copolymer of ethylene and a mono-1-olefin co-monomer having from 3 to about 12 carbon atoms; or both the high molecular weight component and the low molecular weight component comprise a copolymer of ethylene and a mono-1-olefin co-monomer having from 3 to about 12 carbon atoms.",
    "58. The method of claim 51, wherein the ethylene copolymer of the high molecular weight component is further characterized by a M w in a range from about 250 to about 1,000 kg/mol, and a M z /M w less than or equal to about 2.5.",
    "59. The method of claim 51, wherein the ethylene homopolymer or copolymer of the low molecular weight component is characterized by a M w from about 30 to about 50 kg/mol.",
    "60. A method of making a composition comprising a high molecular weight component and a low molecular weight component, the method comprising: (i) blending the high molecular weight component and the low molecular weight component to form the composition; or (ii) producing the high molecular weight component and the low molecular weight component in a multiple polymerization reactor system comprising at least two polymerization reactors configured in series or in parallel, and combining the high molecular weight component and the low molecular weight component in the reactor system to form the composition; or (iii) both (i) and (ii); wherein: a) the high molecular weight component comprises an ethylene copolymer characterized by a M w /M n less than or equal to about 3.5, a substantially constant short-chain branching (SCB) profile across the molecular weight distribution, and a number of short-chain branches (SCB) per 1000 backbone carbon atoms from about 4 to about 8; and b) the low molecular weight component comprises an ethylene homopolymer or copolymer characterized by a M w from 25 to 60 kg/mol, and substantially zero short-chain branches (SCB) per 1000 backbone carbon atoms.",
    "61. The method of claim 60, wherein the polymerization reactor system comprises slurry polymerization reactors, loop slurry polymerization reactors, gas phase polymerization reactors, fluidized bed gas phase reactors, solution polymerization reactors, stirred tank reactors, or any combination thereof.",
    "62. The method of claim 60, wherein the high molecular weight component is produced in one or more polymerization reactors and the low molecular weight component is produced in one or more polymerization reactors, wherein the high molecular weight component and the low molecular weight component are produced in separate polymerization reactors.",
    "63. The method of claim 60, wherein the composition comprises from about 45 to about 75 parts by weight high molecular weight component and from about 55 to about 25 parts by weight low molecular weight component.",
    "64. The method of claim 60, wherein the composition is characterized by a M w /M n less than or equal to about 30, and a M z /M n less than or equal to about 10.",
    "65. The method of claim 60, wherein: the ethylene copolymer of the high molecular weight component is produced using a Ziegler-Natta catalyst system or a metallocene catalyst system; or the ethylene homopolymer or copolymer of the low molecular weight component is produced using a Ziegler-Natta catalyst system or a metallocene catalyst system; or both the ethylene copolymer of the high molecular weight component and the ethylene homopolymer or copolymer of the low molecular weight component are produced using a Ziegler-Natta catalyst system or a metallocene catalyst system.",
    "66. The method of claim 60, wherein: the high molecular weight component comprises a copolymer of ethylene and a mono-1-olefin co-monomer having from 3 to about 12 carbon atoms; or the low molecular weight component comprises a copolymer of ethylene and a mono-1-olefin co-monomer having from 3 to about 12 carbon atoms; or both the high molecular weight component and the low molecular weight component comprise a copolymer of ethylene and a mono-1-olefin co-monomer having from 3 to about 12 carbon atoms.",
    "67. The method of claim 60, wherein the ethylene copolymer of the high molecular weight component is further characterized by a M w in a range from about 250 to about 1,000 kg/mol, and a M z /M w less than or equal to about 2.5.",
    "68. The method of claim 60, wherein the ethylene homopolymer or copolymer of the low molecular weight component is characterized by a M w from about 30 to about 50 kg/mol."
  ],
  "description_excerpt": "This invention relates to the field of polyolefin compositions, methods for producing polyolefin compositions, articles of manufacture using polyolefin compositions, and processes for producing articles of manufacture using polyolefin compositions.\n\nPolyethylene (PE) is consumed in the USA at the rate of over ten million metric tons every year. The semi-crystalline nature of polyethylene makes it a material of choice for many commodity and specialty applications. Crystallinity offers many desirable features to PE such as stiffness, strength, barrier to gas transport, chemical resistance, and dimensional stability. The non-crystalline phase can impart such attributes as toughness and resistance to slow crack growth.\n\nPresently, a variety of PE resins can be used to produce high stiffness pipe used in water, gas, and other fluid transport applications. Polyethylene pipe classified as PE-100, MRS 10, or ASTM D3350 typical cell classification 345566C is especially desirable for use under conditions requiring higher pressure ratings. To obtain a PE-100 classification, PE-100 pipe is required to meet certain standards specifying stiffness, resistance to slow crack growth, resistance to chemical attack, and low-temperature toughness (expressed as rapid crack propagation). Further, such pipe must meet a deformation standard which is determined under pressure at elevated temperatures. Resin which can be employed to produce both small diameter (1 inch to 12 inches in diameter) and large diameter (greater than 12 inches in diameter) PE-100 pipe is described in U.S. Patent Application Pub. No. 2003/0199648 A1 (U.S.",
  "cpc": [
    "C08L 23/04",
    "C08L 2205/02",
    "C08L 2205/025",
    "C08L 23/06",
    "C08L 23/0815",
    "F16L 9/127"
  ],
  "ipc": [
    "C08F 2/01",
    "B29C 48/32",
    "C08L 23/04",
    "C08L 23/08",
    "C08L 23/00"
  ],
  "assignees": [
    "Chevron Phillips Chemical Co LP"
  ],
  "inventors": [
    "Rajendra K. Krishnaswamy",
    "Qing Yang"
  ],
  "filing_date": "2010-03-17",
  "publication_date": "2010-07-29",
  "priority_date": "2004-04-30",
  "application_number": "US-72549310-A",
  "family_id": "34967706",
  "cited_by_count": 23,
  "citations": [
    "US4438238A",
    "US4461873A",
    "US4547551A",
    "US6120887A",
    "US5744666A",
    "US6114477A",
    "US6878784B1",
    "US6025512A",
    "US6187880B1",
    "US6291382B1",
    "US6175027B1",
    "US20040054088A1",
    "US6534665B1",
    "US20030199648A1",
    "US6632680B1",
    "US6649698B1",
    "US20050245689A1"
  ]
}