Single reactor bimodal polyethylene with improved modulus for extrusion blow molding drum applications

Abstract

In various embodiments, the bimodal polyethylene composition may have a 3 Up to 0.957g / cm 3 Density (ρ), high load melt index (I 21 ) and a z-average molecular weight (M) of 3,200,000 g / mol to 5,000,000 g / mol z(GPC) The bimodal polyethylene composition may also have a peak molecular weight (M) defined by the formula p(GPC) ): M p(GPC) <‑2,805.3MWD+102,688, where MWD is the molecular weight distribution defined by the formula: MWD=M w(GPC) / M n(GPC) , M w(GPC) is the weight average molecular weight of the bimodal polyethylene composition, M n(GPC) is the number average molecular weight of the bimodal polyethylene composition. Additionally, the ratio of (Mz(GPC)) to Mw(GPC) of the bimodal polyethylene composition is from 8.5 to 10.5. Also provided are articles made from the bimodal polyethylene composition, such as articles made by blow molding.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application Serial No. 63 / 031,712 filed on May 29, 2020, which is incorporated by reference in its entirety. Technical Field

[0003] Embodiments of the present disclosure relate generally to polymer compositions, particularly bimodal polyethylene compositions and articles comprising the bimodal polyethylene compositions, having improved properties and processability. Background Art

[0004] When manufacturing molded articles such as plastic closures and plastic containers, the performance and processability of the polymer used to manufacture the molded articles are critical to ensure that the manufacture and use of the molded articles are successful. For example, the environmental stress crack resistance (ESCR) of the molded article is critical to prevent the uncontrolled release of the container material, but the molded article should also have sufficient rigidity exhibited by the modulus to prevent deformation when stacked during transportation and storage. Typically, polymers with relatively high density such as high-density polyethylene (HDPE) are used to manufacture molded articles to achieve sufficient rigidity. Although rigidity can increase with the increase of polymer density, the processability of the polymer and the ESCR of the resulting molded article will decrease. Therefore, there has always been a need to balance performance and processability of polymer compositions by achieving sufficient rigidity while also maintaining sufficient ESCR and processability. Summary of the invention

[0005] Embodiments of the present disclosure address these needs by providing bimodal polyethylene compositions that can have a molecular weight of 0.952 g / cm3 when measured according to ASTM D792-08 Method B. 3 ) to 0.957 g / cm 3 Density (ρ), high load melt index (I) from 1.0 decigram / minute (dg / min) to 10 dg / min when measured at 190 degrees Celsius (°C) and 21.6 kilograms (kg) load according to ASTM D1238 21 ), and a z-average molecular weight (M) of 3,200,000 to 5,000,000 g / mol as measured using gel permeation chromatography (GPC). z(GPC) The bimodal polyethylene composition may also have a peak molecular weight (M) defined by the formula p(GPC) ): M p(GPC) <-2,805.3×MWD+102,688, where MWD is the molecular weight distribution defined by the formula: MWD=M w(GPC) / M n(GPC) , Mw(GPC) is the weight average molecular weight of the bimodal polyethylene composition, M n(GPC) is the number average molecular weight of the bimodal polyethylene composition, and M p(GPC) 、M w(GPC) and M n(GPC) Measured using GPC. Additionally, the bimodal polyethylene composition has a ratio of (Mz(GPC)) to Mw(GPC) of 8.5 to 10.5.

[0006] These and additional features provided by embodiments of the present disclosure will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings. DETAILED DESCRIPTION

[0007] Embodiments of the present disclosure are directed to bimodal polyethylene compositions and articles comprising the bimodal polyethylene compositions having improved properties and processability. Embodiments of the present disclosure are directed to bimodal polyethylene compositions having a molecular weight of 0.952 g / cm2 as measured according to ASTM D792-08 Method B. 3 Up to 0.957g / cm 3 Density (ρ), high load melt index (I) of 1.0 dg / min to 10 dg / min when measured at 190°C and 21.6 kg load according to ASTM D1238 21 ), and a z-average molecular weight (M) greater than 3,200,000 g / mol as measured using gel permeation chromatography (GPC). z(GPC) The bimodal polyethylene composition may also have a peak molecular weight (M) defined by the formula p(GPC) ): M p(GPC) <-2,805.3×MWD+102,688, where MWD is the molecular weight distribution defined by the formula: MWD=M w(GPC) / M n(GPC) , M w(GPC) is the weight average molecular weight of the bimodal polyethylene composition, M n(GPC) is the number average molecular weight of the bimodal polyethylene composition, and M p(GPC) 、M w(GPC) and M n(GPC) Measured using GPC.

[0008] The term "polymer" refers to a polymeric compound prepared by polymerizing monomers of the same or different types. Thus, the general term polymer encompasses the term "homopolymer," which is usually employed to refer to polymers prepared from only one type of monomer, and the term "copolymer," which is usually employed to refer to polymers prepared from two or more different monomers.

[0009] "Interpolymer" refers to a polymer prepared by polymerizing at least two different types of monomers. Thus, the generic term interpolymer includes copolymers and other polymers, such as terpolymers, prepared by polymerizing two or more different types of monomers.

[0010] The terms "polyethylene" and "ethylene-based polymer" refer to polymers comprising greater than 50 mole percent (%) of units derived from ethylene monomers. This includes polyethylene homopolymers or copolymers (meaning units derived from two or more comonomers). Common forms of polyethylene known in the art include low density polyethylene (LDPE); linear low density polyethylene (LLDPE); ultra low density polyethylene (ULDPE); very low density polyethylene (VLDPE); medium density polyethylene (MDPE); and high density polyethylene (HDPE).

[0011] The term "multimodal" refers to a composition that can be characterized by having at least two polymer fractions having different density, weight average molecular weight, and optionally melt index values. A multimodal composition can also be characterized by having at least two distinct peaks in a gel permeation chromatography (GPC) chromatogram depicting the molecular weight distribution of the composition. Thus, the generic term multimodal encompasses the term "bimodal", which refers to a composition having two main fractions: a first ethylene-based polymer fraction, which may be a low molecular weight fraction, and a second ethylene-based polymer fraction, which may be a high molecular weight fraction; and the term "trimodal", which refers to a composition having three main fractions: a first ethylene-based polymer fraction, a second ethylene-based polymer fraction, and a third ethylene-based polymer fraction.

[0012] The terms "polyolefin", "polyolefin polymer" and "polyolefin resin" refer to a polyolefin composed as monomers of simple olefins (also known as polyolefins having the general formula C n H 2n Polyolefins are polymers produced by polymerizing ethylene with or without one or more comonomers, polypropylene is produced by polymerizing propylene with or without one or more comonomers, etc. Thus, polyolefins include interpolymers, such as ethylene-α-olefin copolymers, propylene-α-olefin copolymers, and the like.

[0013] As used herein, the term "composition" refers to a mixture that includes the materials of the composition, as well as reaction products and decomposition products formed from the materials of the composition.

[0014] The terms "comprising," "including," "having," and derivatives thereof are not intended to exclude the presence of any additional components, steps, or procedures, whether or not specifically disclosed. For the avoidance of any doubt, all compositions claimed through use of the term "comprising" may include any additional additives, adjuvants, or compounds, whether polymeric or otherwise, unless stated to the contrary. In contrast, the term "consisting essentially of excludes from the scope of any subsequently recited component, step, or procedure, except those that are not essential to operability. The term "consisting of excludes any ingredient, step, or procedure not specifically recited or listed.

[0015] Symbols used in the formulas included herein refer to their standard meanings understood in the mathematical arts. For example, "=" means equal to, "×" means multiplication, "+" means addition, "-" means subtraction, ">" is a "greater than" symbol, "<" is a "less than" symbol, and " / " means division.

[0016] Embodiments of bimodal polyethylene compositions may be ethylene monomer and at least one C 3 -C 12 The polymerization reaction product of α-olefin comonomers. For example, an embodiment of a bimodal polyethylene composition can be a polymerization reaction product of ethylene monomer and 1-butene, 1-hexene, or both. Alternatively, an embodiment of a bimodal polyethylene composition can be a polymerization reaction product of ethylene monomer and 1-butene, 1-octene, or both. An embodiment of a bimodal polyethylene can also be a polymerization reaction product of ethylene monomer and 1-hexene, 1-octene, or both. In some embodiments, C 3 -C 12 The α-olefin comonomer may not be propylene. That is, at least one C 3 -C 12 The α-olefin comonomer may be substantially free of propylene. The term "substantially free" of a compound means that the material or mixture contains less than 1.0 wt. % of the compound. For example, at least one C 3 -C 12 The α-olefin comonomer may comprise less than 1.0 wt% propylene, such as less than 0.8 wt% propylene, less than 0.6 wt% propylene, less than 0.4 wt% propylene, or less than 0.2 wt% propylene.

[0017] Embodiments of the bimodal polyethylene compositions may have a molecular weight greater than or equal to 0.952 g / cm2 when measured according to ASTM D792-08, Method B. 3For example, embodiments of the bimodal polyethylene composition may have a density greater than or equal to 0.953 g / cm 3 , greater than or equal to 0.954g / cm 3 , greater than or equal to 0.955g / cm 3 or greater than or equal to 0.956 g / cm 3 Embodiments of the bimodal polyethylene composition may also have a density of less than or equal to 0.957 g / cm when measured according to ASTM D792-08 Method B. 3 For example, embodiments of the bimodal polyethylene composition may also have a density of less than or equal to 0.956 g / cm when measured according to ASTM D792-08 Method B. 3 , less than or equal to 0.955g / cm 3 , less than or equal to 0.954g / cm 3 or less than or equal to 0.953 g / cm 3 In an embodiment, the bimodal polyethylene composition may have a density of 0.952 g / cm 3 Up to 0.957g / cm 3 For example, an embodiment of a bimodal polyethylene composition may have a density of 0.952 g / cm 3 Up to 0.956g / m 3 , 0.952g / cm 3 Up to 0.955g / cm 3 , 0.952g / cm 3 Up to 0.954g / m 3 , 0.952g / cm 3 Up to 0.953g / cm 3 , 0.953g / cm 3 Up to 0.957g / cm 3 , 0.953g / cm 3 Up to 0.956g / cm 3 , 0.953g / cm 3 Up to 0.955g / cm 3 , 0.953g / cm 3 Up to 0.954g / cm 3 , 0.954g / cm 3 Up to 0.957g / cm 3 , 0.954g / cm 3 Up to 0.956g / cm 3 , 0.954g / cm 3Up to 0.955g / cm 3 、0.955g / cm 3 Up to 0.957g / cm 3 、0.955g / cm 3 Up to 0.956g / cm 3 or 0.956 g / cm 3 Up to 0.957g / cm 3 density.

[0018] Embodiments of the bimodal polyethylene composition may have a high load melt index (I MFI) greater than or equal to 1.0 dg / min when measured according to ASTM D1238 at 190°C and 21.6 kg load. 21 For example, embodiments of the bimodal polyethylene composition can have a high load melt index (I MRI) greater than, or equal to, 1.0 dg / min, greater than, or equal to, 4.0 dg / min, or greater than, or equal to, 7.0 dg / min, when measured according to ASTM D1238 at 190°C and 21.6 kg load. 21 Embodiments of the bimodal polyethylene composition may also have a high load melt index (I MRI) less than or equal to 10 dg / min when measured according to ASTM D1238 at 190°C and 21.6 kg load. 21 For example, embodiments of the bimodal polyethylene composition can have a high load melt index (IMI) less than or equal to 10 dg / min, less than or equal to 7.0 dg / min, or less than or equal to 4.0 dg / min, when measured according to ASTM D1238 at 190°C and 21.6 kg load. 21 In an embodiment, the bimodal polyethylene composition may have a high load melt index (I ) of 1.0 dg / min to 10 dg / min when measured according to ASTM D1238 at 190°C and 21.6 kg load. 21 dg / min, 4.0 dg / min to 7.0 dg / min, or 7.0 dg / min to 10 dg / min, when measured according to ASTM D1238 at 190°C and 21.6 kg load. 21 ).

[0019] Embodiments of the bimodal polyethylene composition may have a melt flow ratio (MFR) greater than 20. 5 ). The term “MFR 5” refers to the ratio of melt indices, specifically the high load melt index (I ) of bimodal polyethylene measured at 190°C and 5.0 kg load according to ASTM D1238. 21 ) and melt index (I 5 ). For example, embodiments of the bimodal polyethylene composition may have an MFR greater than 22, greater than 24, greater than 26, greater than 28, or greater than 30. 5 Embodiments of bimodal polyethylene may also have an MFR of less than 32 5 For example, embodiments of the bimodal polyethylene composition may have an MFR of less than 30, less than 28, less than 26, less than 24, or less than 22. 5 In some embodiments, the bimodal polyethylene composition may have an MFR of 20 to 32. 5 For example, embodiments of the bimodal polyethylene compositions may have an MFR of 20 to 30, 20 to 28, 20 to 26, 20 to 24, 20 to 22, 22 to 32, 22 to 30, 22 to 28, 22 to 26, 22 to 24, 24 to 32, 24 to 30, 24 to 28, 24 to 26, 26 to 32, 26 to 30, 26 to 28, 28 to 32, 28 to 30, or 30 to 32. 5 .

[0020] Embodiments of the bimodal polyethylene composition may have a z-average molecular weight (M) greater than 3,200,000 g / mol as measured using gel permeation chromatography (GPC). z(GPC) For example, embodiments of the bimodal polyethylene compositions can have a z-average molecular weight (M) greater than 3,400,000 g / mol, greater than 3,600,000 g / mol, greater than 3,800,000 g / mol, greater than 4,000,000 g / mol, greater than 4,200,000 g / mol, greater than 4,400,000 g / mol, greater than 4,600,000 g / mol, or greater than 4,800,000 g / mol as measured using gel permeation chromatography (GPC). z(GPC) Embodiments of the bimodal polyethylene composition may also have a z-average molecular weight (M) of less than 5,000,000 g / mol as measured using gel permeation chromatography (GPC). z(GPC)For example, embodiments of the bimodal polyethylene compositions can have a z-average molecular weight (M) of less than 4,800,000 g / mol, less than 4,600,000 g / mol, less than 4,400,000 g / mol, less than 4,200,000 g / mol, less than 4,000,000 g / mol, less than 3,800,000 g / mol, less than 3,600,000 g / mol, or less than 3,400,000 g / mol as measured using gel permeation chromatography (GPC). z(GPC) In an embodiment, the bimodal polyethylene composition may have a z-average molecular weight (M) of 3,200,000 g / mol to 5,000,000 g / mol as measured using gel permeation chromatography (GPC). z(GPC)). For example, embodiments of the bimodal polyethylene composition can have a molecular weight as measured using gel permeation chromatography (GPC) of 3,200,000 g / mol to 4,800,000 g / mol, 3,200,000 g / mol to 4,600,000 g / mol, 3,200,000 g / mol to 4,400,000 g / mol, 3,200,000 g / mol to 4,200,000 g / mol, 3,200,000 g / mol to 4,000,000 g / mol, 3,200,000 g / mol to 3,800,000 g / mol, 3,200,000 g / mol to 3,600,000 g / mol, 3,200,000 g / mol to 4,400,000 g / mol. 200,000 g / mol to 3,400,000 g / mol, 3,400,000 g / mol to 5,000,000 g / mol, 3,400,000 g / mol to 4,800,000 g / mol, 3,400,000 g / mol to 4,600,000 g / mol, 3,400,000 g / mol to 4,400,000 g / mol, 3,400,000 g / mol to 4,200,000 g / mol, 3,400,000 g / mol to 4,000,000 g / mol, 3,400,000 g / mol to 3,800,000 g / mol, 3,400,000 g / mol to 3,400,000 g / mol 3,600,000 g / mol to 3,600,000 g / mol, 3,600,000 g / mol to 5,000,000 g / mol, 3,600,000 g / mol to 4,800,000 g / mol, 3,600,000 g / mol to 4,600,000 g / mol, 3,600,000 g / mol to 4,400,000 g / mol, 3,600,000 g / mol to 4,200,000 g / mol, 3,600,000 g / mol to 4,000,000 g / mol, 3,600,000 g / mol to 3,800,000 g / mol, 3,800,000 g / mol to 5,000,000 g / mol 00 g / mol, 3,800,000 g / mol to 4,800,000 g / mol, 3,800,000 g / mol to 4,600,000 g / mol, 3,800,000 g / mol to 4,400,000 g / mol, 3,800,000 g / mol to 4,200,000 g / mol, 3,800,000 g / mol to 4,000,000 g / mol, 4,000,000 g / mol to 5,000,000 g / mol, 4,000,000 g / mol to 4,800,000 g / mol, 4,000,000 g / mol to 4,600,000 g / mol, 4,000,000 g / mol to 4,400,000 g / mol, 4,000,000 g / mol to 4,200,000 g / mol, 4,200,000 g / mol to 5,000,000 g / mol, 4,200,000 g / mol to 4,800,000 g / mol, 4,200,000 g / mol to 4,600,000 g / mol, 4,200,000 g / mol to 4,400,000 g / mol, 4,400 The z-average molecular weight (M, ) is from 4,000 g / mol to 5,000,000 g / mol, 4,400,000 g / mol to 4,800,000 g / mol, 4,400,000 g / mol to 4,600,000 g / mol, 4,600,000 g / mol to 5,000,000 g / mol, 4,600,000 g / mol to 4,800,000 g / mol, or 4,800,000 g / mol to 5,000,000 g / mol. z(GPC) ).

[0021] Embodiments of the bimodal polyethylene composition may have a number average molecular weight (M) greater than 28,000 g / mol as measured using gel permeation chromatography (GPC). n(GPC) For example, embodiments of the bimodal polyethylene composition can have a number average molecular weight (M) greater than 30,000 g / mol, greater than 32,000 g / mol, greater than 34,000 g / mol, greater than 36,000 g / mol, or greater than 38,000 g / mol as measured using gel permeation chromatography (GPC). n(GPC) Embodiments of the bimodal polyethylene composition may also have a number average molecular weight (M) of less than 40,000 g / mol as measured using gel permeation chromatography (GPC). n(GPC) For example, embodiments of the bimodal polyethylene composition can have a number average molecular weight (M) of less than 38,000 g / mol, less than 36,000 g / mol, less than 34,000 g / mol, less than 32,000 g / mol, or less than 30,000 g / mol as measured using gel permeation chromatography (GPC). n(GPC) In an embodiment, the bimodal polyethylene composition may have a number average molecular weight (M) of 28,000 to 40,000 g / mol as measured using gel permeation chromatography (GPC). n(GPC)). For example, embodiments of the bimodal polyethylene composition can have a molecular weight as measured using gel permeation chromatography (GPC) of 28,000 g / mol to 38,000 g / mol, 28,000 g / mol to 36,000 g / mol, 28,000 g / mol to 34,000 g / mol, 28,000 g / mol to 32,000 g / mol, 28,000 g / mol to 30,000 g / mol, 30,000 g / mol to 40,000 g / mol, 30,000 g / mol to 38,000 g / mol, 30,000 g / mol to 36,000 g / mol, 30,000 g / mol to 34,000 g / mol, 30,000 g / mol to 32,000 g / mol, The number average molecular weight (M) of the present invention is 2,400 g / mol to 3,500 g / mol, 2,400 g / mol to 3,500 g / mol, 2,500 g / mol to 3,500 g / mol, 2,500 g / mol to 3,500 g / mol, 2,500 g / mol to 3,500 g / mol, 2,500 g / mol to 3,500 g / mol, 2,500 g / mol to 3,500 g / mol, 2,500 g / mol to 3,500 g / mol, 2,500 g / mol to 3,500 g / mol, 2,500 g / mol to 3,500 g / mol, 2,500 g / mol to 3,500 g / mol, n(GPC) ).

[0022] Embodiments of the bimodal polyethylene composition may have a weight average molecular weight (M) greater than 380,000 g / mol as measured using gel permeation chromatography (GPC). w(GPC) For example, embodiments of the bimodal polyethylene composition can have a weight average molecular weight (M) greater than 400,000 g / mol, greater than 420,000 g / mol, greater than 440,000 g / mol, greater than 460,000 g / mol, or greater than 480,000 g / mol as measured using gel permeation chromatography (GPC). w(GPC) Embodiments of the bimodal polyethylene composition may also have a weight average molecular weight (M) of less than 500,000 g / mol as measured using gel permeation chromatography (GPC). w(GPC) For example, embodiments of the bimodal polyethylene composition can have a weight average molecular weight (M) of less than 480,000 g / mol, less than 460,000 g / mol, less than 440,000 g / mol, less than 420,000 g / mol, or less than 400,000 g / mol as measured using gel permeation chromatography (GPC). w(GPC)In an embodiment, the bimodal polyethylene composition may have a weight average molecular weight (M) of 380,000 g / mol to 500,000 g / mol as measured using gel permeation chromatography (GPC). w(GPC) ). For example, embodiments of the bimodal polyethylene composition can have a molecular weight as measured using gel permeation chromatography (GPC) of 380,000 g / mol to 480,000 g / mol, 380,000 g / mol to 460,000 g / mol, 380,000 g / mol to 440,000 g / mol, 380,000 g / mol to 420,000 g / mol, 380,000 g / mol to 400,000 g / mol, 400,000 g / mol to 500,000 g / mol, 400,000 g / mol to 480,000 g / mol, 400,000 g / mol to 460,000 g / mol, 400,000 g / mol to 440,000 g / mol, 400,000 g / mol to 420,000 g / mol, The weight average molecular weight (M) of the present invention may be from 1 to 420,000 g / mol, 1 to 500,000 g / mol, 1 to 480,000 g / mol, 1 to 460,000 g / mol, 1 to 420,000 g / mol, 1 to 440,000 g / mol, 1 to 500,000 g / mol, 1 to 480,000 g / mol, 1 to 440,000 g / mol, 1 to 460,000 g / mol, 1 to 500,000 g / mol, 1 to 480,000 g / mol, 1 to 460,000 g / mol, 1 to 500,000 g / mol, 1 to 480,000 g / mol, or 1 to 500,000 g / mol. w(GPC) ).

[0023] In an embodiment, the z-average molecular weight (M) of the bimodal polyethylene composition is z(GPC) ) and the weight average molecular weight (M w(GPC) ) ratio may be greater than 8.5. For example, the z-average molecular weight (M) of the bimodal polyethylene composition z(GPC) ) and the weight average molecular weight (M w(GPC) ) ratio may be greater than 9.0, greater than 9.5, or greater than 10.0. In an embodiment, the z-average molecular weight (M) of the bimodal polyethylene composition is z(GPC) ) and the weight average molecular weight (M w(GPC) ) ratio may be less than 10.5. For example, the z-average molecular weight (M) of the bimodal polyethylene composition z(GPC) ) and the weight average molecular weight (M w(GPC)) ratio may be less than 10.0, less than 9.5, or less than 9.0. In an embodiment, the z-average molecular weight (M) of the bimodal polyethylene composition is z(GPC) ) and the weight average molecular weight (M w(GPC) ) may be in the range of 8.5 to 10.5. For example, the z-average molecular weight (M) of the bimodal polyethylene composition is z(GPC) ) and the weight average molecular weight (M w(GPC) ) may be in the range of 8.5 to 10.0, 8.5 to 9.5, 8.5 to 9.0, 9.0 to 10.5, 9.0 to 10.0, 9.0 to 9.5, 9.5 to 10.5, 9.5 to 10.0, or 10.0 to 10.5.

[0024] Embodiments of the bimodal polyethylene composition may have a peak molecular weight (M) greater than 55,000 g / mol as measured using gel permeation chromatography (GPC). p(GPC) For example, embodiments of the bimodal polyethylene composition can have a peak molecular weight (M) greater than 57,000 g / mol, greater than 59,000 g / mol, greater than 61,000 g / mol, or greater than 63,000 g / mol as measured using gel permeation chromatography (GPC). p(GPC) Embodiments of the bimodal polyethylene composition may also have a peak molecular weight (M) of less than 65,000 g / mol as measured using gel permeation chromatography (GPC). p(GPC) For example, embodiments of the bimodal polyethylene composition can have a peak molecular weight (M) of less than 63,000 g / mol, less than 61,000 g / mol, less than 59,000 g / mol, or less than 57,000 g / mol as measured using gel permeation chromatography (GPC). p(GPC) In an embodiment, the bimodal polyethylene composition may have a peak molecular weight (M) of 55,000 g / mol to 65,000 g / mol as measured using gel permeation chromatography (GPC). p(GPC)). For example, embodiments of the bimodal polyethylene composition can have a molecular weight as measured using gel permeation chromatography (GPC) of 55,000 g / mol to 63,000 g / mol, 55,000 g / mol to 61,000 g / mol, 55,000 g / mol to 59,000 g / mol, 55,000 g / mol to 57,000 g / mol, 57,000 g / mol to 65,000 g / mol, 57,000 g / mol to 63,000 g / mol, 57,000 g / mol to 63,000 g / mol, 57,000 g / mol to 64,000 g / mol, 57,000 g / mol to 65,000 g / mol, 57,000 g / mol to 66,000 g / mol, 57,000 g / mol to 68,000 g / mol, 57,000 g / mol to 69,000 g / mol, 58 ... The peak molecular weight (M) of the present invention is 50,000 g / mol to 61,000 g / mol, 57,000 g / mol to 59,000 g / mol, 59,000 g / mol to 65,000 g / mol, 59,000 g / mol to 63,000 g / mol, 59,000 g / mol to 61,000 g / mol, 61,000 g / mol to 65,000 g / mol, 61,000 g / mol to 63,000 g / mol, or 63,000 g / mol to 65,000 g / mol. p(GPC) ).

[0025] Embodiments of the bimodal polyethylene composition may have a molecular weight distribution (MWD) greater than 12.5. The term "MWD" refers to the weight average molecular weight (MWD) of the bimodal polyethylene composition. w(GPC) ) and the number average molecular weight (M n(GPC) ). For example, embodiments of the bimodal polyethylene composition may have a MWD greater than 13.5, greater than 14.5, or greater than 15.5. Embodiments of the bimodal polyethylene composition may also have a MWD less than 16.5. For example, embodiments of the bimodal polyethylene composition may also have a MWD less than 15.5, less than 14.5, or less than 13.5. In some embodiments, the bimodal polyethylene composition may have a MWD of 12.5 to 16.5. For example, embodiments of the bimodal polyethylene composition may have a MWD of 12.5 to 15.5, 12.5 to 14.5, 12.5 to 13.5, 13.5 to 16.5, 13.5 to 15.5, 13.5 to 14.5, 14.5 to 16.5, 14.5 to 15.5, or 15.5 to 16.5.

[0026] Embodiments of the bimodal polyethylene composition may have a secant modulus (E s For example, embodiments of the bimodal polyethylene composition may have an E greater than 995 MPa, greater than 1,025 MPa, or greater than 1,055 MPa. s Embodiments of the bimodal polyethylene composition may also have an E less than 1,085 MPa. sFor example, embodiments of the bimodal polyethylene composition may have an E less than 1,055 MPa, less than 1,025 MPa, or less than 995 MPa. s In some embodiments, the bimodal polyethylene composition may have an E of 965 MPa to 1,085 MPa. s For example, embodiments of the bimodal polyethylene composition may have an E of 965 MPa to 1,055 MPa, 965 MPa to 1,025 MPa, 965 MPa to 995 MPa, 995 MPa to 1,085 MPa, 995 MPa to 1,055 MPa, 995 MPa to 1,025 MPa, 1,025 MPa to 1,085 MPa, 1,025 MPa to 1,055 MPa, or 1,055 MPa to 1,085 MPa. s .

[0027] In an embodiment, a bimodal polyethylene composition can be prepared in a single reactor with a catalyst system. As used herein, a "catalyst system" may include a main catalyst, a trim catalyst, and optionally at least one activator. The catalyst system may also include other components, such as a carrier, and is not limited to a main catalyst, a trim catalyst, and optionally at least one activator. An embodiment of the catalyst system may include a main catalyst and a metallocene trim catalyst. An embodiment of the catalyst system may also include one or more additives commonly used in the field of olefin polymerization. For example, an embodiment of the catalyst system may include one or more continuity additives, a flow aid, and an antistatic aid. In some embodiments, the reactor may be a gas phase reactor, but a slurry phase reactor may also be used.

[0028] Embodiments of the catalyst system may comprise at least one catalyst for producing a high molecular weight fraction of a bimodal polyethylene composition by polymerization (sometimes referred to herein as a "HMW catalyst"), and at least one catalyst compound for producing a low molecular weight fraction of a bimodal polyethylene composition by polymerization (sometimes referred to herein as a "LMW catalyst").

[0029] HMW catalysts and LMW catalysts can have different hydrogen responses. That is, when the molar ratio of hydrogen to ethylene (H 2 / C 2 The term "high hydrogen response" means that when H 2 / C 2 The term "low hydrogen response" refers to a catalyst that shows a relatively large change in the average molecular weight of polyethylene when the molar ratio is changed by a set amount. 2 / C 2The average molecular weight of polyethylene shows relatively low changes when the molar ratio is changed by the same set amount of catalyst.

[0030] HMW catalysts and LMW catalysts may have different comonomer responses. That is, the comonomer content of the polyethylene prepared by each of the catalyst compounds, such as weight percentage, may be different. The term "good binder" refers to a catalyst that shows a relatively high degree of comonomer binding, while a "poor binder" binds relatively less comonomer. For a catalyst system using a relatively good binder HMW catalyst and a relatively poor binder LMW catalyst, a "reverse comonomer distribution" with a higher comonomer content is produced in the HMW component. In contrast, a good binder LMW catalyst used together with a poor binder HMW catalyst produces a "normal comonomer distribution".

[0031] Embodiments of the catalyst system may be referred to as "bimodal catalyst systems". Such catalyst systems produce bimodal polyethylene compositions having separate, identifiable high molecular weight and low molecular weight distributions. The term "bimodal catalyst system" may include any formulation, mixture or system comprising at least two different catalyst compounds, each having the same or different metal groups, but typically having different ligands or catalyst structures, including "bicatalysts". Alternatively, each different catalyst compound of the bimodal catalyst system is present on a single carrier particle, in which case the bicatalyst is considered to be a supported catalyst. However, the term "bimodal catalyst system" also broadly includes systems or mixtures in which one catalyst is present on one carrier particle set and another catalyst is present on another carrier particle set. In such embodiments, two supported catalysts are introduced simultaneously or sequentially into a single reactor, and polymerization is carried out in the presence of two supported catalyst sets. Alternatively, the bimodal catalyst system may include a mixture of non-supported catalysts in the form of a slurry.

[0032] Embodiments of the catalyst system may include a main catalyst and a trim catalyst. In such embodiments, the main catalyst includes at least one catalyst compound ("main catalyst compound") and a carrier, and may also include an activator and / or any other additives such as those described above. The main catalyst may be transported as a slurry in a hydrocarbon diluent such as mineral oil. The trim catalyst includes a trim catalyst compound. The trim catalyst compound may also be present in the main catalyst system. The trim catalyst may also include a solvent such as a hydrocarbon, and other additives.

[0033] Embodiments of fine-tuning catalyst compounds may include molecular catalyst compounds, such as, for example, metallocene catalyst compounds. In some embodiments, the fine-tuning catalyst can be used to produce a low molecular weight polymer fraction. In such embodiments, the main catalyst can be used to produce a high molecular weight polymer fraction.

[0034] Embodiments of the procatalyst compound may include one or more catalyst compounds containing a Group 15 metal. The Group 15 metal-containing compound may generally include a Group 3 to Group 14 metal atom, or a Group 3 to Group 7, or a Group 4 to Group 6, or a Group 4 metal atom bonded to at least one leaving group and at least two Group 15 atoms, at least one of which is also bonded to a Group 15 or Group 16 atom through another group. At least one of the Group 15 atoms may be bonded to a Group 15 or Group 16 atom through another group, which may be a C 1 To C 20 A hydrocarbon group, a heteroatom-containing group, silicon, germanium, tin, lead or phosphorus, wherein the Group 15 or Group 16 atom may be unbonded or bonded to hydrogen, a Group 14 atom-containing group, a halogen or a heteroatom-containing group, and wherein each of the two Group 15 atoms is also bonded to a cyclic group and may optionally be bonded to hydrogen, a halogen, a heteroatom or a hydrocarbon group or a heteroatom-containing group.

[0035] The compound containing the Group 15 metal can be represented by the following formula:

[0036]

[0037] or

[0038]

[0039] Wherein M is a transition metal from Group 3 to Group 12 or a main group metal from Group 13 or Group 14, or a metal from Group 4, Group 5 or Group 6, or a metal from Group 4, or zirconium, titanium or hafnium, and each X is independently a leaving group. X can be an anionic leaving group. X can be hydrogen, a hydrocarbon group, a heteroatom or a halogen. X can be an alkyl group, y can be 0 or 1 (when y is 0, the group L' is absent), n is the oxidation state of M, which can be +3, +4 or +5, or can be +4, m is the formal charge of the YZL or YZL' ligand, which can be 0, -1, -2 or -3, or can be -2, L is a Group 15 or Group 16 element, preferably nitrogen, L' is a Group 15 or Group 16 element or a group containing Group 14, preferably carbon, silicon or germanium, Y is a Group 15 element, preferably nitrogen or phosphorus, more preferably nitrogen, Z is a Group 15 element, preferably nitrogen or phosphorus, more preferably nitrogen, R 1 and R 2 Independently C 1 To C 20 hydrocarbon radical, a heteroatom-containing radical having up to 20 carbon atoms, silicon, germanium, tin, lead, halogen or phosphorus, preferably C 2 To C 20 An alkyl group, an aryl group or an aralkyl group, more preferably a linear, branched or cyclic C 2To C 20 Alkyl groups, most preferably C 2 To C 6 Hydrocarbon group. 1 and R 2 They can also be interconnected, R 3 is absent or is a hydrocarbon group, hydrogen, halogen, a group containing a heteroatom, preferably a linear, cyclic or branched alkyl group having 1 to 20 carbon atoms, more preferably R 3 is absent, is hydrogen or an alkyl group, most preferably hydrogen, R 4 and R 5 is independently an alkyl group, an aryl group, a substituted aryl group, a cyclic alkyl group, a substituted cyclic alkyl group, a cyclic aralkyl group, a substituted cyclic aralkyl group or a polycyclic ring system, preferably having up to 20 carbon atoms, more preferably 3 to 10 carbon atoms, even more preferably C 1 To C 20 Hydrocarbon group, C 1 To C 20 Aryl group or C 1 To C 20 Aralkyl groups, or groups containing heteroatoms, such as PR 3 , where R is an alkyl group, R 1 and R 2 can be interconnected with each other, and / or R 4 and R 5 Can be interconnected with each other, R 6 and R 7 R is independently absent or is hydrogen, an alkyl group, a halogen, a heteroatom or a hydrocarbon group, preferably a straight chain, cyclic or branched alkyl group having 1 to 20 carbon atoms, more preferably absent, and *R is absent or is hydrogen, a group containing a Group 14 atom, a halogen or a heteroatom-containing group.

[0040] The "formal charge of the YZL or YZL' ligand" refers to the charge of the entire ligand without the metal and leaving group X present.

[0041] “R 1 and R 2 can also be interconnected" refers to R 1 and R 2 They may be directly bonded to each other or may be bonded to each other through other groups. 4 and R 5 can also be interconnected" refers to R 4 and R 5 They may be directly bonded to each other or may be bonded to each other through other groups.

[0042] The alkyl group can be a straight or branched chain alkyl, or an alkenyl, alkynyl, cycloalkyl or aryl, acyl, aroyl, alkoxy, aryloxy, alkylthio, dialkylamino, alkoxycarbonyl, aryloxycarbonyl, carbamoyl, alkyl- or dialkyl-carbamoyl, acyloxy, acylamino, aroylamino, straight chain, branched or cyclic alkylene or a combination thereof. Aralkyl groups are defined as substituted aryl groups.

[0043] R 4 and R 5 may be independently a group represented by the following formula III:

[0044]

[0045] Where R 8 To R 12 are independently hydrogen, C 1 To C 40 Alkyl groups, halogens, heteroatoms, heteroatom-containing groups containing up to 40 carbon atoms, preferably C 1 To C 20 Straight or branched alkyl groups, preferably methyl, ethyl, propyl or butyl, any two R groups may form a cyclic group and / or a heterocyclic group. The cyclic group may be aromatic. 9 , R 10 and R 12 In a preferred embodiment, any three of the R groups of formula III may be methyl, and any two of the other R groups of formula III may be hydrogen. In a preferred embodiment of the present invention, R 9 , R 10 and R 12 is methyl, and R 8 and R 11 For hydrogen.

[0046] R 4 and R 5 They may all be groups represented by the following formula IV:

[0047]

[0048] wherein M is a Group 4 metal, preferably zirconium, titanium or hafnium, and even more preferably zirconium; each of L, Y and Z is nitrogen; R 1 and R 2 Each of -CH 2 -CH 2 -; R 3 is hydrogen; and R 6 and R 7 Does not exist.

[0049] The Group 15 metal-containing compound may be Compound I (also known as "bis(arylamido)dibenzylzirconium"), as shown below:

[0050]

[0051] In the representation of Compound 1, "Bn" represents a benzyl group.

[0052] The Group 15 metal-containing catalyst compound may be prepared by methods known in the art. In some cases, the methods disclosed in European Patent Application Publication No. EP 0 893 454 A1, US Pat. No. 5,889,128, and references cited in US Pat. No. 5,889,128 are suitable.

[0053] In some embodiments, the direct synthesis of these compounds comprises reacting a neutral ligand (eg, YZL or YZL' of Formula I or Formula II) with M n X n (M is a metal of Group 3 to Group 14, n is the oxidation state of M, and each X is an anionic group such as a halide) in a non-coordinating or weakly coordinating solvent such as ether, toluene, xylene, benzene, dichloromethane and / or hexane or other solvents with a boiling point above 60°C at 20°C to 150°C (such as 20°C to 100°C) for 24 hours or more, and then the mixture is treated with an excess (such as 4 equivalents or more) of an alkylating agent such as methylmagnesium bromide in ether. The magnesium salt is removed by filtration and the metal complex is isolated by standard techniques.

[0054] The Group 15 metal-containing compound can be prepared by a process comprising the steps of: reacting a neutral ligand (eg, YZL or YZL' of Formula I or Formula II) with a ligand of Formula M n X n A compound represented by (wherein M is a metal of Group 3 to Group 14, n is the oxidation state of M, and each X is an anionic leaving group) is reacted in a non-coordinating or weakly coordinating solvent at 20° C. or higher (preferably 20 to 100° C.), and then the mixture is treated with an excess of an alkylating agent, and then the metal complex is recovered. The solvent may have a boiling point higher than 60° C., such as toluene, xylene, benzene and / or hexane. The solvent may include ether and / or dichloromethane.

[0055] Generally, metallocene compounds can include half-sandwich and full-sandwich compounds having one or more ligands bonded to at least one metal atom. Typical metallocene compounds are generally described as comprising one or more ligands and one or more leaving groups bonded to at least one metal atom.

[0056] Ligand is usually represented by one or more open rings, acyclic or condensed rings or ring systems or their combinations. These ligands, preferably rings or ring systems can be composed of atoms selected from the 13th to 16th group of atoms of the periodic table of elements. Atoms can be selected from carbon, nitrogen, oxygen, silicon, sulfur, phosphorus, germanium, boron and aluminum or their combinations. Rings or ring systems can be composed of carbon atoms, such as but not limited to those cyclopentadienyl ligands or cyclopentadienyl type ligand structures or other similar functional ligand structures such as pentadiene, cyclooctatetraene diyl or imide ligands. Metal atoms can be selected from the 3rd to 15th groups of the periodic table of elements and lanthanides or actinides. Metal can be a transition metal from the 4th to the 12th group, or the 4th, 5th and 6th groups, or the transition metal is from the 4th group.

[0057] The catalyst composition may include one or more metallocene catalyst compounds represented by Formula V:

[0058] L A L B MQ n Formula V

[0059] Wherein M is a metal atom of the periodic table, and may be a metal of Group 3 to Group 12 of the periodic table, or a lanthanide or actinide. M may be a transition metal of Group 4, Group 5 or Group 6, or M is a transition metal of Group 4, or M is zirconium, hafnium or titanium. Ligand L A and L B It can be an open ring, acyclic or condensed ring or ring system, and can be any auxiliary ligand system, including unsubstituted or substituted cyclopentadienyl ligands or cyclopentadienyl type ligands, heteroatom substituted and / or heteroatom-containing cyclopentadienyl type ligands. Non-limiting examples of ligands include cyclopentadienyl ligands, cyclopentaphenanthryl ligands, indenyl ligands, benzindenyl ligands, fluorenyl ligands, octahydrofluorenyl ligands, cyclooctatetraene diyl ligands, cyclopentacyclododecene ligands, nitrenyl ligands, azulene ligands, pentalylene ligands, phosphoryl ligands, phosphinimines (WO 99 / 40125), pyrrole ligands, pyrazolyl ligands, carbazolyl ligands, borabenzene ligands, etc., including hydrogenated forms thereof, such as tetrahydroindenyl ligands. L A and L B It can be any other ligand structure that can π-bond to M. A and L B The atomic molecular weight of L may exceed 60a.mu, or may exceed 65a.mu. A and L B One or more heteroatoms may be included, such as nitrogen, silicon, boron, germanium, sulfur and phosphorus, in combination with carbon atoms to form an open, acyclic or preferably fused ring or ring system, such as a heterocyclopentadienyl ancillary ligand. A and L BLigands include, but are not limited to, amides, phosphides, alkoxides, aryloxides, imides, carbides, borides, porphyrins, phthalocyanines, corrins, and other polyazo macrocycles. A and L B It may be the same or different type of ligand bonded to M. In one alternative of Formula V, only L may be present. A and L B one of them.

[0060] Independently, each L A and L B It can be unsubstituted or substituted by a combination of substituents R. Non-limiting examples of substituents R include one or more selected from the group consisting of: hydrogen, or straight chain, branched alkyl, or alkenyl, alkynyl, cycloalkyl or aryl, acyl, aroyl, alkoxy, aryloxy, alkylthio, dialkylamino, alkoxycarbonyl, aryloxycarbonyl, carbamoyl, alkyl- or dialkyl-carbamoyl, acyloxy, acylamino, aroylamino, straight chain, branched or cyclic alkylene or a combination thereof. In a preferred embodiment, substituent R has up to 50 non-hydrogen atoms, preferably 1 to 30 carbons, which can also be substituted by halogen or heteroatoms, etc. Non-limiting examples of alkyl substituents R include methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclopentyl, cyclohexyl, benzyl or phenyl, etc., including all their isomers, such as tert-butyl, isopropyl, etc. Other hydrocarbon groups include fluoromethyl, fluoroethyl, difluoroethyl, iodopropyl, bromohexyl, chlorobenzyl and hydrocarbon-substituted organometallic groups including trimethylsilyl, trimethylgermyl, methyldiethylsilyl, etc.; and halocarbyl-substituted organometallic groups including tris(trifluoromethyl)-silyl, methyl-bis(difluoromethyl)silyl, bromomethyldimethylgermyl, etc.; and disubstituted boron groups including, for example, dimethylboron; and disubstituted phosphorus groups including dimethylamine, dimethylphosphine, diphenylamine, methylphenylphosphine; and chalcogen groups including methoxy, ethoxy, propoxy, phenoxy, methyl sulfide and ethyl sulfide. Non-hydrogen substituents R include carbon atoms, silicon, boron, aluminum, nitrogen, phosphorus, oxygen, tin, sulfur, germanium, etc., including olefins such as, but not limited to, olefinically unsaturated substituents including vinyl-terminated ligands such as but-3-enyl, prop-2-enyl, hex-5-enyl, etc. In addition, at least two R groups, preferably two adjacent R groups, are linked to form a ring structure having 3 to 30 atoms selected from carbon, nitrogen, oxygen, phosphorus, silicon, germanium, aluminum, boron or a combination thereof. In addition, the substituent R can form a carbon sigma bond with the metal M.

[0061] Other ligands may be bonded to the metal M, such as at least one leaving group Q. Q may be a monoanionic labile ligand having a sigma bond with M. Depending on the oxidation state of the metal, the value of n may be 0, 1 or 2, such that the above formula V represents a neutral metallocene catalyst compound.

[0062] The non-limiting examples of Q ligands may include weak bases such as amines, phosphines, ethers, carboxylates, dienes, hydrocarbon groups with 1 to 20 carbon atoms, hydrides or halogens, etc. or combinations thereof. Two or more Qs may form a part of a condensed ring or ring system. Other examples of Q ligands include those substituents of R as described above, including cyclobutyl, cyclohexyl, heptyl, tolyl, trifluoromethyl, tetramethylene, pentamethylene, methylene, methoxy, ethoxy, propoxy, phenoxy, bis(N-methylaniline), dimethylamide, dimethylphosphide groups, etc.

[0063] The catalyst composition may include one or more metallocene catalyst compounds, wherein L of Formula V A and L B The two groups are bridged to each other through at least one bridging group A, as shown in Formula VI:

[0064] L A AL B MQ n Formula VI

[0065] The compound of formula VI is referred to as a bridged metallocene catalyst compound. A , L B , M, Q and n are as defined above. Non-limiting examples of bridging group A include bridging groups containing at least one 13th to 16th family atom, commonly referred to as divalent moieties, such as but not limited to at least one of carbon, oxygen, nitrogen, silicon, aluminum, boron, germanium and tin atoms or combinations thereof. Bridging group A may include carbon, silicon or germanium atoms, preferably A includes at least one silicon atom or at least one carbon atom. Bridging group A may also include substituents R as defined above, including halogens and iron. Non-limiting examples of bridging group A may be R' 2 C. R' 2 Si, R' 2 Si R' 2 Si, R' 2 Ge, R'P represents, wherein R' is independently a group, the group is a hydride, a hydrocarbon group, a substituted hydrocarbon group, a halogenated carbon group, a substituted halogenated carbon group, a hydrocarbon group substituted organic metal, a halogenated carbon group substituted organic metal, a disubstituted boron, a disubstituted pnictium element, a substituted chalcogen or a halogen, or two or more R' can be connected to form a ring or ring system. The bridged metallocene catalyst compound of formula IV can have two or more bridging groups A (EP 0664 301 B1).

[0066] The metallocene catalyst compound may be a ligand L of formula V and VI A and L B The R substituents on the ligands are substituted with the same or different numbers of substituents on each ligand. A and L B Can be different from each other.

[0067] The procatalyst system includes a procatalyst compound represented by Formula II above, such as a procatalyst having the formula [(2,3,4,5,6-Me 5 C 6 )NCH 2 CH 2 ] 2 BYZGR 2 Compounds of which 2,3,4,5,6-Me 5 C 6 represents pentamethylphenyl, and Bn is benzyl. Optionally, the procatalyst system may include a second procatalyst compound represented by Formula V above, such as a zirconocene compound, such as (n-butylcyclopentadienyl) 2 Zirconium (IV) dichloride or (propylcyclopentadienyl)(1,3-dimethyl-4,5,6,7-tetrahydroindenyl)zirconium (IV) dimethyl.

[0068] The molar ratio of the HMW catalyst compound to the LMW catalyst compound in the catalyst formulation may range from 1:20 to 20:1, or 1:10 to 10:1, or 1:5 to 5:1, or 1:1 to 5:1, or 1:1 to 3:1.

[0069] The trim catalyst may include a catalyst compound that may be represented by Formula VII below; specifically, Formula VII shows (cyclopentadienyl)(1,3-dimethyl-4,5,6,7-tetrahydroindenyl)zirconium dimethyl:

[0070]

[0071] As used herein, the term "activator" may include any combination of agents that increase the rate at which a transition metal compound oligomerizes or polymerizes unsaturated monomers such as olefins. The activator may also affect the molecular weight, degree of branching, comonomer content, or other properties of the oligomer or polymer. The transition metal compound may be activated for oligomerization and / or polymerization catalysis in any manner sufficient to allow coordinated or cationic oligomerization and / or polymerization.

[0072] Aluminoxane activators can be used as activators for one or more of the catalyst compositions. Aluminoxanes are typically oligomeric compounds comprising --Al(R)--O--subunits, wherein R is an alkyl group. Examples of aluminoxanes include methylaluminoxane (MAO), modified methylaluminoxane (MMAO), ethylaluminoxane, and isobutylaluminoxane. Alkylaluminoxanes and modified alkylaluminoxanes are suitable as catalyst activators, particularly when the extractable ligand is a halide. Mixtures of different aluminoxanes and modified aluminoxanes can also be used. For further description, see U.S. Patent Nos. 4,665,208, 4,952,540, 5,041,584, 5,091,352, 5,206,199, 5,204,419, 4,874,734, 4,924,018, 4,908,463, 4,968,827, 5,329,032, 5,248,801, 5,235,081, 5,157,137, 5,103,031 and EP 0 561 476, EP 0 279 586, EP 0 516 476, EP 0 594 218 and WO 94 / 10180.

[0073] When the activator is an alumoxane (modified or unmodified), the maximum amount of activator can be selected to be a 5000-fold molar excess of Al / M relative to the catalyst precursor (per metal catalytic site). Alternatively or in addition, the minimum amount of activator to catalyst precursor can be set to a 1:1 molar ratio.

[0074] Alkyl aluminum or organoaluminum compounds that can be used as activators (or scavengers) include trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, tri-n-hexylaluminum, tri-n-octylaluminum, and the like.

[0075] The catalyst system may include a carrier material or a support. For example, at least one or more catalyst compounds and / or one or more activators may be deposited on, contacted with, vaporized with, combined with, incorporated into, adsorbed or absorbed therein or thereon, one or more carriers or supports. Therefore, the above-mentioned catalyst compounds and other transition metal catalyst compounds and / or catalyst systems may be combined with one or more carrier materials or supports using one of the carrier methods known in the art or as described below. For example, a metallocene catalyst compound or catalyst system is in a supported form, such as when deposited on, contacted with, incorporated into, adsorbed or absorbed therein or thereon, one or more carriers or supports.

[0076] As used herein, the terms "support" and "carrier" are used interchangeably and are any carrier material, including porous carrier materials such as talc, inorganic oxides and inorganic chlorides. Other carriers include resin carrier materials such as polystyrene, functionalized or cross-linked organic carriers such as polystyrene divinyl benzene polyolefins or other polymers, zeolites, clays or any other organic or inorganic carrier materials, etc., or mixtures thereof.

[0077] Exemplary support materials such as inorganic oxides include Group 2, 3, 4, 5, 13 or 14 metal oxides. Preferred supports include dehydrated or non-dehydrated silica, fumed silica, alumina (see, e.g., WO 99 / 60033), silica-alumina and mixtures thereof. Other useful supports include magnesium oxide, titanium dioxide, zirconium oxide, magnesium chloride (U.S. Pat. No. 5,965,477), montmorillonite (EP 0 511 665), phyllosilicates, zeolites, talc, clay (U.S. Pat. No. 6,034,187), etc. In addition, combinations of these support materials may be used, such as silica-chromium, silica-alumina, silica-titania, etc. Additional support materials may include those porous acrylic polymers described in EP 0767 184, which is incorporated herein by reference. Other support materials include nanocomposites as disclosed in WO 99 / 47598, aerogels as disclosed in WO 99 / 48605, spheroids as disclosed in US Pat. No. 5,972,510, and polymer beads as disclosed in WO 99 / 50311.

[0078] In some embodiments, all catalyst compounds of the catalyst system may be unloaded independently, or loaded on a support material, in the latter case, the catalyst system is a supported catalyst system. When each catalyst compound is loaded, the catalyst compound may be present on the same support material (e.g., the same particles), or on different support materials (e.g., different particles). The bimodal catalyst system includes a mixture of unloaded catalyst compounds in the form of slurry and / or solution. The support material may be silica (e.g., fumed silica), alumina, clay, or talcum. The fumed silica may be hydrophilic (untreated), alternatively hydrophobic (treated). In some aspects, the carrier is hydrophobic smoky silica, which may be prepared by treating untreated smoky silica with a treating agent such as dimethyldichlorosilane, polydimethylsiloxane fluid, or hexamethyldisilazane. In some aspects, the treating agent is dimethyldichlorosilane.

[0079] In some embodiments, support materials such as inorganic oxides may have a 10 m 2 / g to 700m 2 Surface area in the range of 0.1 cm / g3 / g to 4.0cm 3 / g range and an average particle size in the range of 5 microns to 500 microns. More preferably, the surface area of ​​the support material may be in the range of 50 m 2 / g to 500m 2 / g range, pore volume is 0.5cm 3 / g to 3.5cm 3 / g range, and the average particle size is in the range of 10 microns to 200 microns. Most preferably, the surface area of ​​the support material can be 100m 2 / g to 400m 2 / g range, pore volume is 0.8cm 3 / g to 3.0cm 3 / g range, and the average particle size is in the range of 5 microns to 100 microns. The average pore size of the carrier is generally in the range of 10 angstroms to 1,000 angstroms, or 50 angstroms to 500 angstroms, and in some embodiments 75 angstroms to 350 angstroms. Various other methods for supporting polymerization catalyst compounds or catalyst systems exist in the art. For example, the metallocene catalyst compound may include a polymer-bound ligand, as described in U.S. Patents 5,473,202 and 5,770,755. The metallocene catalyst compound can be spray-dried as described in, for example, U.S. Patent 5,648,310. The carrier used with the metallocene catalyst compound can be functionalized, as described in EP 0 802 203, or at least one substituent or leaving group is selected as described in U.S. Patent 5,688,880.

[0080] The polyethylene formulation disclosed herein can be prepared by a gas phase process. The formulation can be prepared in a single reactor. The polyethylene formulation disclosed herein can also be prepared in a single gas phase reactor. In one embodiment of the present invention, the reactor is a gas phase fluidized bed polymerization reactor.

[0081] Polyethylene can be produced using staged gas phase reactors. Commercial polymerization systems are described, for example, in "Volume 2, Metallocene-Based Polyolefins", pages 366 to 378 (John Scheirs & W. Kaminsky, eds., John Wiley & Sons, Ltd. 2000); U.S. Patents 5,665,818, 5,677,375 and 6,472,484; and EP 0 517 868 and EP 0 794 200.

[0082] Gas phase processes can utilize fluidized bed reactors. Fluidized bed reactors can include a reaction zone and a so-called deceleration zone. The reaction zone can include a bed of growing polymer particles, formed polymer particles, and a small amount of catalyst particles, which is fluidized by a continuous flow of gaseous monomers and diluents to remove the heat of polymerization through the reaction zone. Optionally, some of the recycle gas can be cooled and compressed to form a liquid that increases the heat removal capacity of the circulating gas stream when it reenters the reaction zone. Suitable gas flow rates can be easily determined by simple experiments. The rate at which gaseous monomers are supplemented to the circulating gas stream can be equal to the rate at which the particulate polymer product and the monomers associated therewith can be discharged from the reactor, and the composition of the gas passing through the reactor can be adjusted to maintain a substantially steady-state gaseous composition in the reaction zone. The gas leaving the reaction zone can pass through the deceleration zone, where entrained particles are removed. Finer entrained particles and dust can be removed in a cyclone dust collector and / or a fine filter. The gas can pass through a heat exchanger, where the heat of polymerization can be removed, compressed in a compressor, and then returned to the reaction zone. Additional reactor details and means for operating the reactors are described in, for example, U.S. Patent Nos. 3,709,853, 4,003,712, 4,011,382, 4,302,566, 4,543,399, 4,882,400, 5,352,749, and 5,541,270; EP 0802202; and Belgian Patent 839,380.

[0083] The reactor temperature of the fluidized bed process may be in the range of 30°C or 40°C or 50°C to 90°C or 100°C or 110°C or 120°C or 150°C. Typically, the reactor temperature may be operated at the highest temperature feasible, taking into account the sintering temperature of the ethylene-based polymer product within the reactor. Regardless of the process used to prepare the polyolefin, such as bimodal polyethylene, the polymerization temperature or reaction temperature should be below the melting or "sintering" temperature of the ethylene-based polymer to be formed. Therefore, the upper temperature limit may be the melting temperature of the polyolefin produced in the reactor.

[0084] Hydrogen can be used in olefin polymerization to control the final properties of the polyolefin, such as described in "Polypropylene Handbook" pp. 76 to 78 (Hanser Publishers, 1996). The amount of hydrogen in the polymerization can be expressed as a molar ratio relative to the total polymerizable monomers, such as ethylene or a blend of ethylene and 1-hexene or propylene. The amount of hydrogen used in the polymerization process can be the amount necessary to obtain the desired MFR or FI of the final polyolefin resin. The amount of hydrogen used in the polymerization process can also be the amount necessary to obtain the desired bimodal molecular weight distribution between the high molecular weight component and the low molecular weight component of the bimodal polyolefin.

[0085] The catalyst system can also be used to further control the characteristics of the polyethylene formulation. For example, the amount of the fine-tuning catalyst can be adjusted to change the ratio of the catalyst compound of the catalyst system in the reactor, so as to achieve the desired flow index or flow index splitting. The fine-tuning catalyst can be fed directly to the reactor independently of the main catalyst compound of the catalyst system. The fine-tuning catalyst can also be mixed with the main catalyst compound of the catalyst system before feeding to the reactor. The fine-tuning catalyst can also be continuously mixed with other compounds of the catalyst system, and the resulting mixture is continuously fed to the reactor. The fine-tuning catalyst can be continuously mixed with a supported catalyst, and the resulting mixture is continuously fed to the reactor. The fine-tuning catalyst can be a supported catalyst or a non-supported catalyst. When the fine-tuning catalyst is a non-supported catalyst, it can be "online" loaded, for example, by contacting with a supported catalyst before feeding to the reactor. The supported fine-tuning catalyst may include an activator, which can "online" activate the fine-tuning catalyst before feeding to the reactor.

[0086] The fine-tuning catalyst may be provided in a form that is the same as or different from the form of the main catalyst compound (or one of the main catalyst compounds) of the catalyst system. However, upon activation with a suitable activator, the active catalyst species produced by the fine-tuning catalyst may be the same as the active catalyst species produced by one of the at least two different catalyst compounds of the catalyst. One skilled in the art will appreciate that, for example, a metallocene dihalide and a metallocene dialkyl may produce the same active catalyst species when treated with a suitable activator. For example, a metallocene such as (cyclopentadienyl)(1,3-dimethyl-4,5,6,7-tetrahydroindenyl)zirconium(X) 2 (wherein X may be a halide, an alkyl group or any other leaving group as described above) may be used in the dichloride form to prepare a supported catalyst. When used as a fine-tuning catalyst, it may be provided in a dialkyl form such as a dimethyl form. This may be advantageous in terms of solubility, where the dialkyl form may have enhanced solubility in, for example, aliphatic hydrocarbons.

[0087] The catalyst system may comprise at least one or two or more catalyst compounds comprising titanium, zirconium or hafnium atoms. The catalyst system may comprise at least one or two or more of the following:

[0088] (Pentamethylcyclopentadienyl)(n-propylcyclopentadienyl)MX 2 ;

[0089] (Tetramethylcyclopentadienyl)(n-propylcyclopentadienyl)MX 2 ;

[0090] (Tetramethylcyclopentadienyl)(n-butylcyclopentadienyl)MX 2 ;

[0091] (n-propylcyclopentadienyl)(1,3-dimethyl-4,5,6,7-tetrahydroindenyl)MX 2 ;

[0092] (Methylcyclopentadienyl)(1,3-dimethyl-4,5,6,7-tetrahydroindenyl)MX 2 ;

[0093] (Cyclopentadienyl)(1,3-dimethyl-4,5,6,7-tetrahydroindenyl)MX 2 ;

[0094] (Methylcyclopentadienyl)(1-methyl-4,5,6,7-tetrahydroindenyl)MX 2 ;

[0095] Me 2 Si(Indenyl) 2 MX 2 ;

[0096] Me 2 Si(4,5,6,7-tetrahydroindenyl) 2 MX 2 ;

[0097] (n-propylcyclopentadienyl) 2 MX 2 ;

[0098] (n-Butylcyclopentadienyl) 2 MX 2 ;

[0099] (1-Methyl, 3-butylcyclopentadienyl) 2 MX 2 ;

[0100] [HN(CH 2 CH 2 N(2,4,6-Me 3 C 6 H 2 )) 2 ]MX 2 ;

[0101] [HN(CH 2 CH 2 N(2,3,4,5,6-Me 5 C 6 )) 2 ]MX 2 ;

[0102] and mixtures thereof, wherein M is Zr or Hf, and X is selected from F, Cl, Br, I, Me, benzyl, CH 2 SiMe 3 and C1 To C 5 Alkyl or alkenyl.

[0103] The molar ratio of hydrogen to total monomers (H 2 :monomer) can be in the range of greater than 0.0001, greater than 0.0005, or greater than 0.001, and less than 10, less than 5, less than 3, or less than 0.10, wherein the desired range may include any combination of any upper molar ratio limit with any lower molar ratio limit described herein. Expressed in another way, the amount of hydrogen in the reactor at any time can be up to 5,000 ppm, up to 4,000 ppm, or up to 3,000 ppm, or between 50 ppm and 5,000 ppm, or between 500 ppm and 2,000 ppm.

[0104] The pressure of one or more reactors in a gas phase process (single stage or two or more stages) may vary between 690 kPa (100 psig) and 3,448 kPa (500 psig). For example, they may range from 1,379 kPa (200 psig) to 2,759 kPa (400 psig) or from 1,724 kPa (250 psig) to 2,414 kPa (350 psig).

[0105] Bimodal polyethylene compositions can be used for a variety of products and end-use applications. Bimodal polyethylene compositions can also be blended and / or coextruded with any other polymer. Non-limiting examples of other polymers include linear low density polyethylene, elastomers, plastomers, high pressure low density polyethylene, high density polyethylene, polypropylene, etc. Bimodal polyethylene compositions and blends thereof can be used to produce blow molded parts or products, as well as various other end uses. Bimodal polyethylene compositions and blends thereof can be used for forming operations such as film, sheet and fiber extrusion and coextrusion as well as blow molding, injection molding and rotational molding. Films can include blown or cast films formed by coextrusion or lamination, which can be used as shrink films, cling films, stretch films, sealing films, oriented films, snack packaging, heavy duty bags, grocery store sacks, baked and frozen food packaging, medical packaging, industrial pads and films in food contact and non-food contact applications. Fibers can include melt spinning, solution spinning and melt-blown fiber operations, used to make filter paper, diaper fabrics, medical garments and geotextiles in woven or nonwoven forms. Extruded articles may include medical catheters, wire and cable coatings, pipes, geomembranes, and pond liners. Molded articles may include single and multilayer constructions in the form of bottles, cans, large hollow articles, rigid food containers, and toys.

[0106] Embodiments of articles made from the bimodal polyethylene composition may have an environmental stress crack resistance (ESCR) of greater than 150 hours. ESCR is a measure of the strength of an article in terms of its ability to resist failure caused by stress crack growth. High ESCR values ​​are important because the article should last for the designed application life. ESCR testing is performed according to ASTM D1693 Procedure B. This is an accelerated test that uses a 10% Igepal CO-630 nonionic surfactant solution at 50°C to determine the time to failure. The time to failure (F) of 50% of the tested samples is estimated from the measured values. 50 Hours). For example, embodiments of articles made from the bimodal polyethylene composition may have an ESCR of greater than 160 hours, greater than 170 hours, greater than 180 hours, or greater than 190 hours. Embodiments of articles made from the bimodal polyethylene composition may have an ESCR of less than 200 hours. For example, embodiments of articles made from the bimodal polyethylene composition may also have an ESCR of less than 190 hours, less than 180 hours, less than 170 hours, or less than 150 hours. In some embodiments, articles made from the bimodal polyethylene composition may also have an ESCR of 150 hours to 200 hours. For example, embodiments of articles made from the bimodal polyethylene composition may also have an ESCR of 150 hrs to 190 hrs, 150 hrs to 180 hrs, 150 hrs to 170 hrs, 150 hrs to 160 hrs, 160 hrs to 200 hrs, 160 hrs to 190 hrs, 160 hrs to 180 hrs, 160 hrs to 170 hrs, 170 hrs to 200 hrs, 170 hrs to 190 hrs, 170 hrs to 180 hrs, 180 hrs to 200 hrs, 180 hrs to 190 hrs, or 190 hrs to 200 hrs.

[0107] Test Method

[0108] density

[0109] After conditioning at 23±2°C and 50±10% relative humidity for not less than 40 hours, the density of the samples was measured according to ASTM D792-13 Method B and is expressed in grams per cubic centimeter (g / cm 3 )Report.

[0110] High load melt index

[0111] High load melt index (I 21 ) is measured according to ASTM D1238 at 190°C and 21.6 kg load and is reported in decigrams per minute (dg / min).

[0112] Melt index (I 5 )

[0113] Melt index (I 5 ) is measured according to ASTM D1238 at 190°C and 5.0 kg load and is reported in decigrams per minute (dg / min).

[0114] Molecular weight

[0115] Molecular weights were measured using conventional gel permeation chromatography (GPC), including peak molecular weight (M p(GPC) ), weight average molecular weight (M w(GPC) ), number average molecular weight (M n(GPC) ) and z-average molecular weight (M z(GPC) ) and are reported in grams per mole (g / mol).

[0116] The chromatographic system consists of a PolymerChar GPC-IR (Valencia, Spain) high temperature GPC chromatograph equipped with an internal IR5 infrared detector (IR5). The autosampler oven chamber is set to 160°C and the column chamber is set to 150°C. The columns used are four Agilent "Mixed A" 30 cm 20 micron linear mixed bed columns. The chromatographic solvent used is 1,2,4-trichlorobenzene and contains 200 parts per million (ppm) of butylated hydroxytoluene (BHT). The solvent source is nitrogen sparged. The injection volume used is 200 microliters (μl) and the flow rate is 1.0 milliliters per minute (ml / min).

[0117] The column was calibrated with at least 20 narrow molecular weight distribution polystyrene standards ranging from 580 g / mol to 8,400,000 g / mol and arranged in 6 "cocktail" mixtures with at least ten times of separation between molecular weights. Standards were purchased from Agilent Technologies. For molecular weights equal to or greater than 1,000,000 g / mol, standards were prepared at 0.025 g in 50 ml of solvent, and for molecular weights less than 1,000,000 g / mol, standards were prepared at 0.05 g in 50 ml of solvent. The standards were dissolved by gentle stirring at 80°C for 30 minutes. The standard peak molecular weight was converted to the molecular weight of an ethylene-based polymer using equation 1 (as described in Williams and Ward, J. Polym. Sci., Polym. Let., 6, 621 (1968)):

[0118] M 聚乙烯 =A×(M 聚苯乙烯 ) B Equation 1

[0119] Where M is the molecular weight, A has a value of 0.4315, and B equals 1.0.

[0120] A fifth order polynomial was used to fit the corresponding ethylene-based polymer-equivalent calibration points. A minor adjustment was made to A (from approximately 0.39 to 0.44) to correct for column resolution and band broadening effects, resulting in a NIST standard NBS 1475 with a molecular weight of 52,000 g / mol.

[0121] Total plate counts of the column were performed with eicosane (prepared at 0.04 g in 50 ml TCB and dissolved for 20 min under gentle stirring). Plate counts (Equation 2) and symmetry (Equation 3) were measured at 200 μl injections according to the following equations:

[0122]

[0123] where RV is the retention volume in milliliters, peak width is in milliliters, peak maximum is the maximum height of the peak, and half height is one-half the height of the peak maximum, and

[0124]

[0125] Where RV is the retention volume in milliliters, peak width is in milliliters, peak maximum is the maximum height of the peak, tenth height is one tenth the height of the peak maximum, post peak is the tail of the peak at a retention volume later than the peak maximum, and front peak is the front of the peak at a retention volume earlier than the peak maximum. The plate count of the chromatographic system should be greater than 22,000, and the symmetry should be between 0.98 and 1.22.

[0126] The samples were prepared semi-automatically using the PolymerChar "Instrument Control" software, where the sample weight was targeted at 2 mg / ml and the solvent containing 200 ppm BHT was added to a septum-capped vial previously sparged with nitrogen via the PolymerChar high temperature autosampler. The samples were dissolved by shaking at "low speed" for 3 hours at 160°C.

[0127] Based on the GPC results using the internal IR5 detector (measurement channel) of the PolymerChar GPC-IR spectrometer according to Equations 4 to 7, the TM Software, at each equally spaced data collection point i(IR i ) and the baseline-subtracted IR chromatogram at point i (M 聚乙烯,i M was determined based on the ethylene-equivalent molecular weight of the polymer obtained using a narrow standard calibration curve (in g / mol) n(GPC) 、Mw(GPC) and M z(GPC) Subsequently, a GPC molecular weight distribution (GPC-MWD) plot (wt GPC (1 g MW)) versus 1 g MW, where wt GPC (1 g MW) is the weight fraction of ethylene-based polymer molecules with a molecular weight of 1 g MW. Molecular weight (MW) is in g / mol, wt GPC (lgMW) follows Eq. 4.

[0128] ∫wt GPC (Ig MW)dlg MW=1.00 Equation 4

[0129] M n(GPC) 、M w(GPC) and M z(GPC) Calculated by the following equation:

[0130]

[0131]

[0132]

[0133] M p(GPC) On the GPC-MWD plot, wt GPC (lgMW) has the highest molecular weight.

[0134] To monitor deviations over time, a flow rate marker (decane) was introduced into each sample via a micropump controlled by the PolymerChar GPC-IR system. This flow rate marker (FM) was used to linearly correct the pump flow rate for each sample (Flow Rate (Nominal)) by comparing the RV of the corresponding decane peak in the sample (RV (FM Sample)) with the RV of the decane peak in the narrow standard calibration (RV (FM Calibrated)). It was then assumed that any changes in the decane marker peak time were related to linear changes in the flow rate (Flow Rate (Effective)) throughout the run. To facilitate the highest accuracy in measuring the RV of the flow marker peak, a least squares fitting procedure was used to fit the peak of the flow marker concentration chromatogram to a quadratic equation. The first derivative of the quadratic equation was then used to solve for the true peak position. After the system was calibrated based on the flow marker peak, the effective flow rate (relative to the narrow standard calibration) was calculated according to Equation 11. By PolymerChar GPCOne TM The software completes the processing of the flow marker peak. An acceptable flow rate correction is such that the effective flow rate should be within 0.5% of the nominal flow rate.

[0135] Flow rate有效 = Flow rate 标称 ×(RV(FM 校准 ) / RV(FM 样品 )) Equation 11

[0136] Environmental Stress Crack Resistance (ESCR)

[0137] Samples for ESCR measurement were prepared according to ASTM D4703 Appendix A.1 Procedure C. The samples were compression molded into 0.075 inch sheets at 190°C, conditioned at 23±2°C and 50±5% relative humidity for at least 24 hours, and then individual specimens were punched out using a suitable die. The specimen dimensions were 38 millimeters (mm) × 13 mm and 1.90 mm thick. The specimens were further conditioned at 23±2°C and 50±5% relative humidity and tested at least 40 hours after compression molding but within 96 hours after compression molding. ESCR was measured according to ASTM-D 1693-01 Condition B. The sample thicknesses were measured to ensure that they were within the ASTM 1693-01 specification. Immediately prior to testing, the samples were grooved to the desired depth, then bent and loaded into a sample holder. The holder was then placed in a test tube filled with a 10 volume % aqueous solution of Igepal CO-630 (supplier Rhone-Poulec, NJ) and maintained at 50°C. Report F 50 Expiration time.

[0138] Modulus

[0139] 2% Secant Flexural Modulus is measured according to ASTM D790. Specimens are prepared by compression molding according to ASTM D4703 and tested by 3-point flexure with a standard span of 2 inches and a specimen thickness of 0.12 inches to 0.13 inches. The test speed is 0.5 inches per minute. The standard specimen is 1 / 2 inch wide by 5 inches long. The modulus is measured when the specimen reaches 5% strain. 2% Secant Modulus is reported in megapascals (MPa) and / or kilopascals per square inch (ksi).

[0140] Example

[0141] Example 1

[0142] To prepare Example 1, bimodal polyethylene was prepared by gas phase polymerization in a single reactor. TM The procatalyst, BMC-300, commercially available from Univation Technologies, was fed via a 0.25 inch (") injection tube into a Univation catalyst. TMA polyethylene reactor commercially available from Univation Technologies was also fed to the polyethylene reactor via the same 0.25" injection tube at a rate sufficient to provide the desired resin flow index. The trim catalyst was a mixture of 0.04 weight percent (wt.%) bis(n-butylcyclopentadienyl)dimethylzirconium in isopentane. The reactor was heated to 100 rpm by a flow rate sufficient to maintain an ethylene partial pressure of 220 pounds per square inch (psi), n-hexene (C 6 ) and ethylene (C 2 ) has a molar ratio of 0.0004, hydrogen (H 2 ) and ethylene (C 2 The reactor gas composition was controlled by metering feed into the polyethylene reactor at a rate of 0.0007 molar ratio of ethylene to isopentane and 13.9 mole percent (mol.%). An additive commercially available as CA-300 from Univation Technologies was fed separately to the polyethylene reactor at a rate sufficient to maintain an additive concentration of about 45 parts by weight per million parts by weight (ppmw) based on the rate of ethylene feed to the reactor. The polyethylene reactor temperature was maintained at 105 degrees Celsius (°C) and the reactor residence time was about 2.8 hours. The reactor bed weight was maintained by discharging the granular resin into a discharge tank, which was purged with nitrogen and again with a mixture of nitrogen and steam before dumping the discharge tank into the fiber bag.

[0143] Example 2

[0144] To prepare Example 2, bimodal polyethylene was prepared by gas phase polymerization in a single reactor. TM The primary catalyst, BMC-300, commercially available from Univation Technologies, was fed via a 0.25" injection tube into a container that can be used as a UNIPOL TM A polyethylene reactor commercially available from Univation Technologies was also fed to the polyethylene reactor via the same 0.25" injection tube at a rate sufficient to provide the desired resin flow index. The trim catalyst was a mixture of 0.04 wt.% bis(n-butylcyclopentadienyl)dimethylzirconium in isopentane. The reactor was heated to 100 rpm with a flow rate sufficient to maintain an ethylene partial pressure of 220 psi, n-hexene (C 6 ) and ethylene (C 2 ) has a molar ratio of 0.0002, hydrogen (H 2 ) and ethylene (C 2The reactor gas composition was controlled by metering feed into the polyethylene reactor at a rate of 0.0004 molar ratio of ethylene to isopentane and 7 mol.%. An additive commercially available as CA-300 from Univation Technologies was fed separately to the polyethylene reactor at a rate sufficient to maintain an additive concentration of about 45 ppmw based on the rate of ethylene feed to the reactor. The polyethylene reactor temperature was maintained at 105°C and the reactor residence time was about 2.8 hours. The reactor bed weight was maintained by discharging the granular resin into a discharge tank, which was purged with nitrogen and again with a mixture of nitrogen and steam before dumping the discharge tank into the fiber bag.

[0145] Comparative Example 1

[0146] To prepare Comparative Example 1, bimodal polyethylene was prepared by gas phase polymerization in a single reactor. TM The primary catalyst, BMC-300, commercially available from Univation Technologies, was fed via a 0.25" injection tube into a container that can be used as a UNIPOL TM A polyethylene reactor commercially available from Univation Technologies was also fed to the polyethylene reactor via the same 0.25" injection tube at a rate sufficient to provide the desired resin flow index. The trim catalyst was a mixture of 0.04 wt.% bis(n-butylcyclopentadienyl)dimethylzirconium in isopentane. The reactor was heated to 100 rpm with a flow rate sufficient to maintain an ethylene partial pressure of 220 psi, n-hexene (C 6 ) and ethylene (C 2 ) has a molar ratio of 0.0009, hydrogen (H 2 ) and ethylene (C 2 The reactor gas composition was controlled by metering feed into the polyethylene reactor at a rate of 0.0007 molar ratio of ethylene to isopentane and 15.2 mol.%. An additive commercially available as CA-300 from Univation Technologies was fed separately to the polyethylene reactor at a rate sufficient to maintain an additive concentration of about 45 ppmw based on the rate of ethylene feed to the reactor. The polyethylene reactor temperature was maintained at 105°C and the reactor residence time was about 2.8 hours. The reactor bed weight was maintained by discharging the granular resin into a discharge tank, which was purged with nitrogen and again with a mixture of nitrogen and steam before dumping the discharge tank into the fiber bag.

[0147] Comparative Example 2

[0148] To prepare Comparative Example 6, bimodal polyethylene was prepared by gas phase polymerization in a single reactor.TM The primary catalyst, BMC-300, commercially available from Univation Technologies, was fed via a 0.25" injection tube into a container that can be used as a UNIPOL TM A polyethylene reactor commercially available from Univation Technologies was also fed to the polyethylene reactor via the same 0.25" injection tube at a rate sufficient to provide the desired resin flow index. The trim catalyst was a mixture of 0.04 wt.% bis(n-butylcyclopentadienyl)dimethylzirconium in isopentane. The reactor was heated to 100 rpm with a flow rate sufficient to maintain an ethylene partial pressure of 220 psi, n-hexene (C 6 ) and ethylene (C 2 ) has a molar ratio of 0.0005, hydrogen (H 2 ) and ethylene (C 2 The reactor gas composition was controlled by metering feed into the polyethylene reactor at a rate of 0.0004 molar ratio of ethylene to isopentane and 6 mol.%. An additive commercially available as CA-300 from Univation Technologies was fed separately to the polyethylene reactor at a rate sufficient to maintain an additive concentration of about 45 ppmw based on the rate of ethylene feed to the reactor. The polyethylene reactor temperature was maintained at 105°C and the reactor residence time was about 2.8 hours. The reactor bed weight was maintained by discharging the granular resin into a discharge tank, which was purged with nitrogen and again with a mixture of nitrogen and steam before dumping the discharge tank into the fiber bag.

[0149] Reactor Conditions of Examples 1 & 2 and Comparative Examples 1 & 2

[0150] The reactor conditions for Examples 1 and 2 and Comparative Examples 1 and 2 are summarized and reported in Table 1. Examples 1 and 2 include lower C 6 / C 2 Molar ratio.

[0151] Table 1

[0152] Example# Example 1 Example 2 Comparative Example 1 Comparative Example 2 Reactor bed temperature (℃) 105 86 105 86 Reactor total pressure (psig) 348 351 350 300 Bed weight (lbs) 99 112 104 473 Bed height (ft) 6.2 7.0 6.2 22.2 Reactor gas velocity (ft / s) 2.06 2.05 1.76 1.94 Ethylene partial pressure (psi) 220 220 220 220 <![CDATA[C 6 / C- 2 Molar Ratio]]> 0.0004 0.0002 0.0009 0.0005 <![CDATA[H 2 / C 2 Molar Ratio]]> 0.0007 0.0004 0.0007 0.0004 Isopentane (mol.%) 13.9 7 15.2 6

[0153] Molecular weight values ​​of Examples 1 & 2 and Comparative Examples 1 & 2

[0154] The molecular weight values ​​of Examples 1 and 2 and Comparative Examples 1 and 2, such as M n(GPC) 、M w(GPC) 、M z(GPC) and M p(GPC) They are summarized and reported in Table 2.

[0155] Table 2

[0156]

[0157]

[0158] Characteristics of Examples 1 & 2 and Comparative Examples 1 & 2

[0159] Various properties such as density, high load melt index, secant modulus, and ESCR of Examples 1 and 2 and Comparative Examples 1 and 2 are summarized and reported in Table 3.

[0160] Table 3

[0161] Example# Example 1 Example 2 Comparative Example 1 Comparative Example 2 <![CDATA[Density (g / cm 3 )]]> 0.955 0.954 0.952 0.955 <![CDATA[I 21 (day / min)]]> 6.0 5.3 5.3 6.7 <![CDATA[MFR5(I 21 / I 5 )]]> 29 23 30 23 <![CDATA[Secant modulus (E s )(ksi)]]> 152 143 140 131 -2,622+2,822×density+2.5×MFR5 146 128 140 131 MWD 16.2 12.9 19.9 12.3 -4,570.6+4,883×density+3.1×MWD 143 128 140 131 ESCR (10%, F50) (Hr) 180 164 557 102

[0162] As shown in Table 2 and Table 3, Example 1 and Example 2 have a value of 0.952 g / cm 3 Up to 0.957g / cm 3 density, high load melt index (I 21 ), M greater than 3,200,000 g / mol z(GPC) and M is less than 2,805.3 times MWD plus 102,688 p(GPC) Examples 1 and 2 also have an E greater than 965 MPa (about 140 ksi). s and ESCR greater than 150 hours. In contrast, neither Comparative Example 1 nor Comparative Example 2 has an M greater than 3,200,000 g / mol. z(GPC) or less than MWD plus 2805.3 times 102,688 p(GPC) .

[0163] In addition, Example 2 and Comparative Example 2 have similar MFR5 values, which are related to the processability of the sample; however, Example 2 has a higher secant modulus and ESCR than Comparative Example 2. That is, Comparative Example 2 may have similar processability to Example 2, but at the expense of secant modulus and ESCR. Similarly, Example 1 exhibits an EFR5 greater than Comparative Example 1. s , which is related to the stiffness of the sample while maintaining similar MFR5 values ​​and suitable ESCR. That is, compared with Comparative Examples 1 and 2, Examples 1 and 2 are improved in the balance of stiffness, ESCR and processability.

[0164] The dimensions and values ​​disclosed herein should not be understood as being strictly limited to the exact numerical values ​​recited. Indeed, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a value disclosed as "40 g / cm 3 " is intended to mean "approximately 40g / cm 3”.

[0165] Unless expressly excluded or otherwise limited, each document cited herein, if any, including any cross-referenced or related patent or patent application to which this application claims priority or rights, and any patent or patent application are hereby incorporated by reference in their entirety. The citation of any document does not admit that it is prior art with respect to any embodiment disclosed or claimed herein, or that it alone or in combination with any other reference document or multiple reference documents teaches, indicates or discloses any such embodiment. In addition, in the event that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to the term in this document shall prevail.

Claims

1. A bimodal polyethylene composition, the bimodal polyethylene composition having: 0.952 g / cm2 when measured according to ASTM D792-08 Method B 3 Up to 0.957g / cm 3 The density ρ; High load melt index I of 1.0 dg / min to 10 dg / min when measured at 190°C and 21.6 kg load according to ASTM D1238 21 ; The peak molecular weight M is defined by the following formula p(GPC) :M p(GPC) <-2,805.3×MWD+102,688, where MWD is the molecular weight distribution defined by the formula: MWD=M w(GPC) / M n(GPC) , M w(GPC) is the weight average molecular weight of the bimodal polyethylene composition, and M n(GPC) is the number average molecular weight of the bimodal polyethylene composition, and wherein M p(GPC) 、M w(GPC) and M n(GPC) Gel permeation chromatography (GPC) was used to measure the M n(GPC) Greater than 28,000 g / mol; A z-average molecular weight M of greater than 3,200,000 g / mol to 5,000,000 g / mol as measured using GPC z(GPC) ;as well as 8.5 to 10.5 M z(GPC) With M w(GPC) ratio; The M p(GPC) 55,000 g / mol to 65,000 g / mol; and wherein the bimodal polyethylene composition is ethylene monomer and at least one C 3 -C 12 The polymerization product of α-olefin comonomers.

2. The bimodal polyethylene composition according to claim 1, wherein the M w(GPC) Greater than 380,000 g / mol.

3. The bimodal polyethylene composition according to claim 1 or 2, wherein the bimodal polyethylene composition has: The secant modulus E is defined by s :E s >-2,622+2,822×ρ+2.5×MFR 5 , Where MFR 5 is the high load melt index I of the bimodal polyethylene composition 21 Melt index I measured at 190°C and 5.0 kg load according to ASTM D1238 5 ratio.

4. The bimodal polyethylene composition according to claim 1 or 2, having a secant modulus E defined by the formula: s :E s >-4,570.6+4,883×ρ+3.1×MWD.

5. The bimodal polyethylene composition according to claim 1 or 2, wherein the M w(GPC) 380,000 g / mol to 500,000 g / mol.

6. The bimodal polyethylene composition according to claim 1 or 2, wherein MFR 5 is 20 to 32, wherein the MFR 5 is the high load melt index I of the bimodal polyethylene composition 21 Melt index I measured at 190°C and 5.0 kg load according to ASTM D1238 5 ratio.

7. The bimodal polyethylene composition according to claim 1 or 2, wherein the M n(GPC) 28,000 g / mol to 40,000 g / mol.

8. The bimodal polyethylene composition according to claim 1 or 2, wherein the secant modulus E of the bimodal polyethylene composition is s Greater than 965MPa.

9. The bimodal polyethylene composition of claim 1 or 2, having an environmental stress cracking resistance F of greater than 150 hours when measured according to ASTM D1693, procedure B using 10% Igepal. 50 .

10. An article produced using the bimodal polyethylene composition according to any one of claims 1 to 9.

11. The article of claim 10, wherein the article is a blow molded article.

12. A process for preparing a bimodal polyethylene composition according to any one of claims 1 to 9, said process comprising reacting ethylene and at least one C 3 -C 12 An alpha-olefin comonomer is polymerized to produce the bimodal polyethylene composition.

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