Polyolefin composition

Abstract

Embodiments relate to polyolefin compositions comprising a high molecular weight polyolefin and a low molecular weight polyolefin.

Description

[0001] open field

[0002] Embodiments of this disclosure relate to polyolefin compositions, and more specifically, to polyolefin compositions comprising high molecular weight polyolefins and low molecular weight polyolefins. Background Technology

[0003] Different polymers are prepared using various polymerization methods and / or different reactant compositions. For example, different polymers can be prepared using solution, slurry, or gas-phase polymerization methods. Various polymerization methods can utilize different catalysts, such as Ziegler-Natta catalysts, chromium-based catalysts, metallocene catalysts, or combinations thereof. Different polymerization methods and different reactant compositions are used to prepare polymers with different properties. There is a constant need for new polyolefin compositions. Summary of the Invention

[0004] This disclosure provides polyolefin compositions comprising...

[0005] High molecular weight polyolefin, which has a molecular weight of 0.9200 g / cm³ 3 Up to 0.9450 g / cm 3 The density; and low molecular weight polyolefins having an I2 content of 5 g / 10 min to 200 g / 10 min.

[0006] The polyolefin composition provides a cumulative detector fraction (CDF) at molecular weights ≥10,000,000 g / mol. LS () greater than 0.085.

[0007] This disclosure provides polyolefin compositions comprising high molecular weight polyolefins and low molecular weight polyolefins, wherein the polyolefin composition has a molecular weight of 0.930 g / cm³. 3 Up to 0.970 g / cm 3 The density of M is greater than 17. w / M n Melt index (I) of 15 g / 10 min to 40 g / 10 min 21 And provides a time greater than 0.3087 + 0.00404 * (0.02 seconds). -1 (Eta) / (200 seconds) -1 The value of G′ / G″ (0.02 seconds) is calculated as follows: (Eta) - 0.224 * HMW share. -1 The values ​​of G′ (G″ = 3000 Pa) range from 1650 Pa to 1870 Pa.

[0008] The foregoing description of this invention is not intended to describe every disclosed embodiment or every implementation of this disclosure. The following description illustrates exemplary embodiments in more detail. Throughout this application, guidance is provided by a list of examples, which may be used in various combinations. In each case, the enumerated list serves only as a representative group and should not be construed as an exclusive list. Detailed Implementation

[0009] This document discloses polyolefin compositions. Polyolefin compositions can provide a combination of properties desired for many applications, such as blow molding. Previous polymer compositions having a combination of properties desired for blow molding have processability issues (such as low expansion), poor ESCR (Environmental Stress Cracking) performance, or manufacturability issues. Therefore, the polyolefin compositions disclosed herein are needed.

[0010] Advantageously, the polyolefin compositions disclosed herein offer a combination of properties desired for a wide range of applications. The polyolefin compositions provide desired extrusion swell (which may simply be referred to as swell) and desired environmental stress cracking resistance (ESCR). Additionally, the polyolefin compositions disclosed herein provide desired melt flow index.

[0011] The polyolefin compositions disclosed herein are prepared using multiple gas-phase reactors (i.e., polymerization reactors) arranged in series. For example, the polyolefin compositions can be prepared using a first fluidized bed reactor and a second fluidized bed reactor, wherein the first and second fluidized bed reactors are connected in series. The polyolefin compositions are prepared from high molecular weight polyolefins (which may also be referred to as high molecular weight polyolefin polymers) and low molecular weight polyolefins (which may also be referred to as low molecular weight polyolefin polymers). As mentioned, the first fluidized bed reactor is arranged in series, i.e., a gas-phase reactor located before the second fluidized bed reactor. Gas-phase reactors are known, and known components can be used in the first and second fluidized bed reactors. Embodiments of this disclosure provide that, compared to a second fluidized bed reactor arranged in series, the first fluidized bed reactor is used to prepare high molecular weight polyolefins. The second fluidized bed reactor arranged in series is used to prepare low molecular weight polyolefins.

[0012] As used herein, an "olefin" that may be referred to as an "alkene" is a straight-chain, branched, or cyclic compound comprising carbon and hydrogen and having at least one double bond. As used herein, when a polyolefin, polymer, and / or copolymer is referred to as containing an olefin (e.g., prepared from an olefin), the olefin present in such polymer or copolymer is an olefin in its polymerized form. For example, when a copolymer is claimed to contain 75 wt% to 85 wt% ethylene, it should be understood that the polymer units in the copolymer are derived from ethylene in the polymerization reaction, and that the derived units are present at 75 wt% to 85 wt% based on the total weight of the polymer. Higher α-olefins refer to α-olefins having three or more carbon atoms.

[0013] Polyolefins include polymers prepared from olefin monomers such as ethylene, i.e., polyethylene, and straight-chain or branched high-carbon α-olefin monomers containing 3 to 20 carbon atoms. Examples of higher α-olefin monomers include, but are not limited to, propylene, butene, pentene, hexene, and 1-octene. Examples of polyolefins include ethylene-based polymers having at least 50 wt% ethylene, including copolymers of ethylene-1-butene, ethylene-1-hexene, and ethylene-1-octene. One or more embodiments provide a polymer based on its total weight, wherein the polymer may contain 50 wt% to 99.9 wt% of ethylene-derived units. This includes all individual values ​​and sub-ranges from 50 wt% to 99.9 wt%; for example, based on the total weight of the polymer, the polymer may contain ethylene-derived units ranging from a lower limit of 50 wt%, 60 wt%, 70 wt%, 80 wt%, or 90 wt% to an upper limit of 99.9 wt%, 99.7 wt%, 99.4 wt%, 99 wt%, 96 wt%, 93 wt%, 90 wt%, or 85 wt% based on the total weight of the polymer. Based on the total weight of the polymer, the polymer may contain 0.1 wt% to 50 wt% units derived from the comonomer. One or more embodiments provide ethylene as the monomer and hexene as the comonomer.

[0014] As mentioned, embodiments of this disclosure provide a first fluidized bed reactor in series for preparing high molecular weight polyolefins, compared to polyolefins prepared in a second fluidized bed reactor in series.

[0015] The first fluidized bed reactor can have a reaction temperature of 70°C to 95°C. This includes all individual values ​​and sub-ranges of 70°C to 95°C; for example, the first fluidized bed reactor can have a reaction temperature from a lower limit of 70°C, 75°C, or 78°C to an upper limit of 95°C, 90°C, or 88°C.

[0016] The first fluidized bed reactor can have an ethylene partial pressure ranging from 20.0 psi to 55.0 psi. This includes all individual values ​​and sub-ranges from 20.0 to 55.0; for example, the first fluidized bed reactor can have an ethylene partial pressure ranging from a lower limit of 20.0 psi, 23.0 psi, or 27.0 psi to an upper limit of 55.0 psi, 50.0 psi, or 45.0 psi.

[0017] One or more embodiments provide that ethylene is used as a monomer and hexene is used as a comonomer in a first fluidized bed reactor, i.e., the high molecular weight polyolefin is an ethylene-hexene copolymer. One or more embodiments provide that the comonomer is hexene. The first fluidized bed reactor may have a comonomer to ethylene molar ratio of 0.002 to 0.100, for example, C6 / C2. This includes all individual values ​​and sub-ranges from 0.002 to 0.100; for example, the first fluidized bed reactor may have a comonomer to ethylene molar ratio from a lower limit of 0.002, 0.003, or 0.004 to an upper limit of 0.100, 0.050, or 0.030.

[0018] The first fluidized bed reactor can have a hydrogen to ethylene molar ratio (H2 / C2) of 0.01 to 1.00. This includes all individual values ​​and sub-ranges from 0.01 to 1.00; for example, the first fluidized bed reactor can have an H2 / C2 ratio with a lower limit of 0.01, 0.08, or 0.10 to an upper limit of 1.00, 0.50, or 0.20.

[0019] The first fluidized bed reactor can have an isopentane mol% concentration from 5.0% to 20.0%. This includes all individual values ​​and sub-ranges from 5.0% to 20.0%; for example, the first fluidized bed reactor can have an isopentane mol% concentration from a lower limit of 5.0%, 6.0%, 7.0%, 8.0%, or 9.0% to an upper limit of 20.0%, 18.0%, 15.0%, 13.0%, or 11.0%.

[0020] As mentioned, embodiments of this disclosure provide a second fluidized bed reactor in series for the preparation of low molecular weight polyolefins. The second fluidized bed reactor can have a reaction temperature from 85°C to 120°C. This includes all individual values ​​and sub-ranges of 85°C to 120°C; for example, the second fluidized bed reactor can have a reaction temperature from a lower limit of 85°C, 90°C, or 95°C to an upper limit of 120°C, 117°C, or 115°C.

[0021] The second fluidized bed reactor can have an ethylene partial pressure of 65.0 psi to 125.0 psi. This includes all individual values ​​and sub-ranges from 65.0 to 125.0; for example, the second fluidized bed reactor can have an ethylene partial pressure ranging from a lower limit of 65.0 psi, 68.0 psi, or 70.0 psi to an upper limit of 125.0 psi, 120.0 psi, or 118.0 psi.

[0022] The second fluidized bed reactor can have a hydrogen to ethylene molar ratio (H2 / C2) of 0.05 to 2.50. This includes all individual values ​​and sub-ranges from 0.05 to 2.50; for example, the second fluidized bed reactor can have an H2 / C2 ratio from a lower limit of 0.05, 0.06, or 0.08 to an upper limit of 2.50, 2.30, or 2.00.

[0023] The second fluidized bed reactor can have a comonomer to ethylene molar ratio of 0.000 to 0.100, for example, C6 / C2. This includes all individual values ​​and sub-ranges from 0.000 to 0.100; for example, the second fluidized bed reactor can have an H2 / C2 ratio with a lower limit of 0.000, 0.002, or 0.004 to an upper limit of 0.100, 0.050, or 0.030. Comonomers can be fed into, for example, directly added to, the second fluidized bed reactor, and / or transferred from the first fluidized bed reactor to the second fluidized bed reactor, for example, as residual comonomers. Comonomers directly added to the second fluidized bed reactor (referred to as direct-feed comonomers) are not considered residual comonomers compared to comonomers transferred from the first fluidized bed reactor to the second fluidized bed reactor.

[0024] As mentioned, the polyolefin composition is prepared from high molecular weight polyolefins and low molecular weight polyolefins.

[0025] The second fluidized bed reactor can have isopentane mol% from 1.0% to 20.0%. This includes all individual values ​​and sub-ranges from 1.0% to 20.0%; for example, the second fluidized bed reactor can have isopentane mol% from a lower limit of 1.0%, 2.0%, 3.0%, 4.0%, 4.5%, or 5.0% to an upper limit of 20.0%, 18.0%, 16.0%, 15.0%, 13.0%, or 11.0%.

[0026] High molecular weight polyolefins prepared in a first fluidized bed reactor connected in series with a second fluidized bed reactor can have a molecular weight of 0.920 g / cm³. 3 Up to 0.945 g / cm 3 The density. Density can be determined according to ASTM D792. This includes 0.920 g / cm³. 3 Up to 0.945 g / cm 3All individual values ​​and sub-ranges; for example, high molecular weight polyolefins can have a lower limit of 0.920 g / cm³. 3 0.925g / cm 3 0.930g / cm 3 0.936 g / cm 3 Or 0.937g / cm 3 The upper limit is 0.945 g / cm³. 3 0.943 g / cm 3 Or 0.941 g / cm 3 The density.

[0027] High molecular weight polyolefins can have melt index (I) ranging from 0.45 g / 10 min to 1.50 g / 10 min. 21 ). I 21 It can be determined according to ASTM D1238 (190°C, 21.6 kg). This includes all individual values ​​and sub-ranges from 0.45 g / 10 min to 1.50 g / 10 min; for example, high molecular weight polyolefins can have a lower limit of 0.45 g / 10 min, 0.50 g / 10 min, or 0.55 g / 10 min to an upper limit of 1.50 g / 10 min, 1.30 g / 10 min, or 1.15 g / 10 min. 21 .

[0028] As mentioned, low molecular weight polyolefins are prepared in a second fluidized bed reactor connected in series with a first fluidized bed reactor. Embodiments of this disclosure provide the transfer of high molecular weight polyolefins prepared in the first fluidized bed reactor connected in series to the second fluidized bed reactor connected in series, and the preparation of low molecular weight polyolefins in the second fluidized bed reactor connected in series in the presence of the transferred high molecular weight polyolefins. Embodiments of this disclosure provide a method for preparing a polyolefin composition, the method comprising: polymerizing ethylene and an α-olefin comonomer (e.g., 1-hexene) in the first fluidized bed reactor under first process conditions using an olefin polymerization catalyst to prepare a high molecular weight polyolefin containing the olefin polymerization catalyst; transferring the high molecular weight polyolefin containing the olefin polymerization catalyst to the second fluidized bed reactor connected in series with the first fluidized bed reactor; and polymerizing ethylene in the second fluidized bed reactor under second process conditions to prepare a low molecular weight polyolefin, wherein the first process conditions in the first fluidized bed reactor are configured for preparing a high molecular weight polyolefin, and the second process conditions in the second fluidized bed reactor are configured for preparing a low molecular weight polyolefin, thereby preparing a polyolefin composition. The density and I2 value of low molecular weight polyolefins can be obtained individually in a single-reactor process under the same process conditions as those used in a second fluidized bed reactor in series, i.e., in the absence of high molecular weight polyolefins. These identical process conditions include reactor temperature, the molar ratio of hydrogen to ethylene (H2 / C2 molar ratio), and the molar ratio of comonomer to ethylene (C2 / C2 molar ratio). x The molar ratio of 1-hexene to ethylene (C6 / C2 molar ratio) is used to characterize low molecular weight polyolefins (LMWPEs) by preparing polyolefins separate from high molecular weight polyolefins. For example, to determine density and I2 value, a polyolefin can be prepared in a single reactor under appropriate reactor conditions, which is then used to prepare LMWPEs while operating a second fluidized bed reactor in series with a first fluidized bed reactor. Unbound by theory, it is believed that LMWPEs prepared under process conditions in a single reactor in the absence of high molecular weight polyolefins (the same as those used to prepare LMWPEs in the presence of high molecular weight polyolefins in a second fluidized bed reactor in series) will have the same properties (such as density and I2 value) as those prepared in the second fluidized bed reactor in series.

[0029] Low molecular weight polyolefins prepared in a second fluidized bed reactor connected in series with the first fluidized bed reactor can have a molecular weight of 0.966 g / cm³. 3 Up to 0.980 g / cm 3 The density. Density can be determined according to ASTM D792. This includes 0.950 g / cm³. 3 Up to 0.980 g / cm3 All individual values ​​and sub-ranges; for example, low molecular weight polyolefins can have a lower limit of 0.950 g / cm³. 3 0.955g / cm 3 0.960 g / cm 3 0.965g / cm 3 0.966 g / cm 3 Or 0.967 g / cm 3 The upper limit is 0.980 g / cm³. 3 0.977g / cm 3 Or 0.975g / cm 3 The density.

[0030] Low molecular weight polyolefins can have melt flow index (I2) ranging from 15 g / 10 min to 200 g / 10 min. I2 can be determined according to ASTM D1238 (190 °C, 2.16 kg). This includes all individual values ​​and sub-ranges from 15 g / 10 min to 200 g / 10 min; for example, low molecular weight polyolefins can have I2 values ​​ranging from a lower limit of 15 g / 10 min, 17 g / 10 min, or 19 g / 10 min to an upper limit of 200 g / 10 min, 150 g / 10 min, or 100 g / 10 min.

[0031] With I ranging from 0.45 g / 10 minutes to 1.50 g / 10 minutes 21 The high molecular weight polyolefins and the low molecular weight polyolefins with I2 of 15 g / 10 min to 200 g / 10 min indicate that the polyolefin compositions disclosed herein are bimodal.

[0032] The polyolefin compositions disclosed herein may be referred to as blends, i.e., blends of high molecular weight polyolefins and low molecular weight polyolefins. These blends are prepared in situ; in other words, these blends are prepared using a first fluidized bed reactor and a second fluidized bed reactor, wherein the first and second fluidized bed reactors are connected in series. The polyolefin compositions disclosed herein may have a high molecular weight share of less than 50%. As used herein, share refers to the high molecular weight component, i.e., the weight percentage of the high molecular weight polyolefin. For example, the polyolefin compositions disclosed herein may have a high molecular weight share from 30% to 49.5%. This includes all individual values ​​and sub-ranges from 30% to 49.5%; for example, the polyolefin compositions disclosed herein may have a high molecular weight share from a lower limit of 30%, 35%, or 38% to an upper limit of 49.5%, 49.0%, or 48.5%. As an example, if the polyolefin composition has a high molecular weight share of 35%, then the polyolefin composition comprises 35% high molecular weight polyolefin and 65% low molecular weight polyolefin.

[0033] Embodiments of the polyolefin composition may have any of the limitations (i) to (vii): (i) wherein the polyolefin composition has a high molecular weight share of 39% to 49%; (ii) wherein the high molecular weight polyolefin has a molecular weight of 0.937 g / cm³. 3 Up to 0.941 g / cm 3 (iii) wherein the low molecular weight polyolefin has a melt index (I2) of 16.5 g / 10 min to 129 g / 10 min; (iv) limiting both (i) and (ii); (v) limiting both (i) and (iii); (vi) limiting both (ii) and (iii); and (vii) limiting each of the limitations in (i), (ii) and (iii).

[0034] The polyolefin compositions (i.e., high molecular weight polyolefins and low molecular weight polyolefins) disclosed herein are prepared using Ziegler-Natta catalysts. Ziegler-Natta catalysts are known in the art and can refer to catalyst systems comprising: a solid catalyst compound containing a transition metal, which may be referred to as a master catalyst; an organometallic compound, which may be referred to as a co-catalyst; and optionally one or more electron donor compounds, such as external electron donors. One or more embodiments provide a Ziegler-Natta catalyst prepared according to U.S. Patent 4,544,647.

[0035] High molecular weight polyolefins can be prepared using Ziegler-Natta catalysts with an aluminum to titanium molar ratio of 5:1 to 15:1. This includes all individual values ​​and sub-ranges from 5:1 to 15:1; for example, high molecular weight polyolefins can be prepared using Ziegler-Natta catalysts with an aluminum to titanium molar ratio ranging from a lower limit of 5:1, 6:1, or 7:1 to an upper limit of 15:1, 13:1, or 10:1.

[0036] Low molecular weight polyolefins can be prepared using Ziegler-Natta catalysts with an aluminum to titanium molar ratio of 10:1 to 25:1. This includes all individual values ​​and sub-ranges from 10:1 to 25:1; for example, low molecular weight polyolefins can be prepared using Ziegler-Natta catalysts with an aluminum to titanium molar ratio ranging from a lower limit of 10:1, 11:1, or 12:1 to an upper limit of 25:1, 20:1, or 18:1.

[0037] The polyolefin compositions disclosed herein (i.e., blends of high molecular weight polyolefins and low molecular weight polyolefins) have a cumulative detector fraction (CDF) at a molecular weight (MW) of ≥10,000,000 g / mol. LS (greater than 0.085). One or more implementations provide CDF. LS Greater than 0.089 or greater than 0.10. CDF LSA value greater than 0.085 indicates a particularly high molecular weight fraction, i.e., a significantly high molecular weight fraction or tail (HMW fraction or HMW tail). When one does not wish to be bound by theory, this high molecular weight tail is believed to contribute to improved swelling compared to other resins (e.g., bimodal resins). CDF LS CDF can be determined using small-angle laser light scattering (LALLS). LS The following measurements can be taken.

[0038] A chromatographic system can be used. This system can include a PolymerChar GPC-IR (Valencia, Spain) high-temperature GPC chromatograph equipped with an internal IR5 infrared detector (IR5) connected to an Agilent Technologies 2-angle laser light scattering (LS) detector model 2040 and a 4-capillary viscometer (DV). A 15-degree angle can be used for all light scattering measurements. The autosampler chamber can be set to 165°C, and the column chamber can be set to 155°C. The column can be a 4TSKgel GMHH. HR -H(30)HT2 (TOSOH 7.8mm×30cm, 30um particle size). The chromatographic solvent can be 1,2,4-trichlorobenzene and can contain 200ppm of butylated hydroxytoluene (BHT). The solvent source can be bubbled with nitrogen. The injection volume can be 200 μL and the flow rate can be 1.0 mL / min. The determination of multi-detector bias can be consistent with the publications of Balke, Mourey et al. (Mourey and Balke, Chromatography Polym., Chapter 12, (1992)) (Balke, Thitiratsakul, Lew, Cheung, Mourey, Chromatography Polym., Chapter 13 (1992)), thereby optimizing the standard from the broad homopolymer polyethylene (M) using PolymerChar GPCOne software. w / M n>2.7) triple detector logarithmic (MW and IV) results are compared with narrow standard column calibration results from narrow standard calibration curves. As used herein, “MW” refers to molecular weight. Absolute molecular weight data can be obtained using PolymerCharGPCOne software in a manner consistent with the following publications: Zimm (Zimm, BH, *Journal of Physical Chemistry*, 16, 1099 (1948)) and Kratochvil (Kratochvil, P., *Classical Light Scattering from Polymer Solutions*, Elsevier, Oxford, NY (1987)). The concentration at each elution volume can be assumed to be infinitely diluted, and therefore no second-dimensional correction is used. Only 15 degrees are used without any correction from the shape factor. The total injection concentration used to determine the molecular weight can be obtained from the mass detector area and the mass detector constant, derived from one of the suitable linear polyethylene homopolymers or polyethylene standards with a known weight-average molecular weight, such as homopolymer polyethylene. The calculated molecular weight (using GPCOne) can be obtained using the light scattering constant and a refractive index concentration coefficient dn / dc of 0.104 from one or more polyethylene standards mentioned below. The mass detector response (IR5) and light scattering constant (determined using GPCOne) can be determined using a homopolymer polyethylene standard with a molecular weight of 120,000 g / mol. Viscometer calibration (using GPCOne) can be performed using the method described by the manufacturer, or alternatively, using published values ​​from a suitable linear standard, such as Standard Reference Material (SRM) 1475a (purchased from the National Institute of Standards and Technology, NIST). The viscometer constant (obtained using GPCOne) is calculated, which correlates the specific viscosity area (DV) and injection mass of the calibration standard with the intrinsic viscosity (IV) of that calibration standard. It can be assumed that the chromatographic concentration is low enough to eliminate the effect of the second virial coefficient (the effect of concentration on molecular weight). Absolute weight-average molecular weight (M w (Abs) can be obtained (using GPCOne) by dividing the area (calculated from the light scattering constant) of the light scattering (LS) integral chromatography by the mass recovered from the mass constant and the area of ​​the mass detector (IR5) per elution volume. The molecular weight and intrinsic viscosity responses can be extrapolated at the chromatographic end where the signal-to-noise ratio decreases (using GPCOne). Other corresponding moments M can be calculated according to the following equation. n(Abs) and M z (Abs):

[0039]

[0040]

[0041] The equivalent molecular weight distribution of polyethylene, which can be referred to as conventional GPC, can be measured under the same experimental conditions using exactly the same instruments and columns. GPC column calibration can be performed using 21 narrow molecular weight distribution polystyrene standards (available from Agilent Technologies) with molecular weights ranging from 580 g / mol to 8,400,000 g / mol, arranged in a six-cocktail mixture, with individual molecular weights spaced at least ten times apart. For molecular weights equal to or greater than 1,000,000 g / mol, polystyrene standards can be prepared at 0.025 g per 50 mL of solvent, while for molecular weights less than 1,000,000 g / mol, 0.05 g per 50 mL of solvent is used. Polystyrene standards can be dissolved at 80°C by gentle stirring for 30 minutes. The peak molecular weight of polystyrene standards can be converted to the molecular weight of polyethylene using the following equation (as described by Williams and Ward, *Journal of Polymer Science: Polymer Letters*, 6, 621 (1968)):

[0042] MW 聚乙烯 =A×(Mw 聚苯乙烯 ) B Equation 3

[0043] Where MW is the molecular weight, A is 0.4315 and B is 1.0.

[0044] A fifth-order polynomial can be used to fit the calibration point for the corresponding polyethylene equivalent. Small adjustments to A (approximately 0.3950 to 0.440) can be made to correct for changes in column resolution during column use, resulting in linear homopolymer polyethylene standards at 120,000 MW. Total plate counts for GPC column groups can be performed using decane (prepared as 0.04 g in 50 mL TCB). Plate counts can be measured with a 200 μL injection (Equation 4) and symmetry (Equation 5) according to the following equations:

[0045]

[0046] Where RV is the retention volume in milliliters, peak width is in milliliters, peak maximum is the maximum height of the peak, and 1 / 2 height is 1 / 2 the height of the peak maximum.

[0047]

[0048] Where RV is the retention volume in milliliters, and peak width is in milliliters, peak maximum is the position of the peak, one-tenth height is 1 / 10 of the height of the peak maximum, and a trailing peak refers to the peak tail whose retention volume is later than the peak maximum, while a preceding peak refers to the peak front whose retention volume is earlier than the peak maximum. The plate count of the chromatographic system should be greater than 15,000, and the symmetry should be between 0.98 and 1.22. Samples can be prepared semi-automatically using PolymerChar "Instrument Control" software, where the target weight of these samples is set to 1 mg / ml, and the solvent (containing 200 ppm BHT) is added to a pre-bubbled, septum-capped vial using a PolymerChar high-temperature autosampler. The sample can be dissolved at 165°C for 3 hours with "low speed" shaking.

[0049] Mn(Conv), Mw(Conv), and Mz(Conv) can be calculated using PolymerChar GPCOne software based on the GPC results obtained from the internal IR5 detector (measurement channel) of the PolymerChar GPC-IR chromatograph according to Equations 6 to 8, the baseline-subtracted IR chromatograms at each equally spaced data collection point (i), and the polyethylene equivalent molecular weight obtained from the narrow standard calibration curve at point (i) according to Equation 1.

[0050]

[0051]

[0052]

[0053] In the low molecular weight region of a GPC elution profile, the presence of a significant peak known to be caused by the presence of antioxidants or other additives can lead to an underestimation of the number-average molecular weight (Mn) of the polymer sample, resulting in an overestimation of the sample polydispersity, defined as Mw / Mn, where Mw is the weight-average molecular weight. Therefore, by eliminating this additional peak (if present), the true molecular weight distribution of the polymer sample can be calculated from the GPC elution. This process can be described as peak skimming in a data processing procedure for liquid chromatography analysis. In this method, this additional peak is skimmed from the GPC elution profile before performing the sample molecular weight calculation from the GPC elution profile. To monitor pump performance over time, a flow rate marker (decane) can be introduced into each sample using a micropump controlled by a PolymerChar GPC-IR system. This flow rate marker (FM) can be used to linearly correct the pump flow rate (nominal flow rate) of each sample by comparing the RV (RV(FM sample)) of the corresponding decane peak within the sample with the RV (RV(FM calibrated)) of the decane peak within the narrow standard calibration. The first derivative of the quadratic equation can then be used to solve for the true peak position. After the flow marker-based peak calibration system, the effective flow rate (relative to the narrow standard calibration) can be calculated according to Equation 9. Flow marker peak processing can be performed using PolymerChar GPCOne software. An acceptable flow rate correction is one where the effective flow rate should be within + / - 0.5% of the nominal flow rate.

[0054] Flow rate (effective) = Flow rate (nominal) * (RV (FM calibrated) / RV (FM sample)) (Equation 9)

[0055] Calculation of Cumulative Detector Fraction (CDF) for Small-Angle Laser Light Scattering Detectors ("CDF") LsThe following can be achieved: 1) The chromatogram is corrected based on the relative retention volume ratio between the sample and the air peak of a consistent narrow standard cocktail mixture. 2) The light scattering detector bias (effective bias) is corrected relative to IR5, as previously stated. 3) The molecular weight at each retention volume (RV) data slice is calculated based on the polystyrene calibration curve, modified by a polystyrene-polyethylene conversion factor of approximately (0.395 to 0.440). 4) The baseline is subtracted from the light scattering chromatogram and the IR5 chromatogram, and the integration window is set using standard GPC practice to ensure that all low molecular weight retention volume ranges observed from the IR5 chromatogram are integrated in the light scattering chromatogram (thus setting the highest RV limit in each chromatogram to the same exponent). No material corresponding to less than 150 Daltons in either chromatogram is included in the integration. 5) The small-angle laser light scattering (LALLS) chromatogram (CDF) is calculated based on the peak height (H) of the high to low molecular weight (low to high retention volume) minus the baseline at each data slice (j) according to the following equation. LS Cumulative detector score (CDF) LS ):

[0056]

[0057] The polyolefin composition disclosed herein has a content of 0.930 g / cm³. 3 Up to 0.970 g / cm 3 The density, including 0.930 g / cm³. 3 Up to 0.980 g / cm 3 All individual values ​​and sub-ranges; for example, a polyolefin composition may have a lower limit of 0.930 g / cm³. 3 0.935g / cm 3 or 0.940 g / cm 3 The upper limit is 0.970 g / cm³. 3 0.968g / cm 3 Or 0.965g / cm 3 The density.

[0058] The polyolefin compositions disclosed herein have a melt index (I2) of 0.03 g / 10 min to 0.50 g / 10 min. This includes all individual values ​​and sub-ranges from 0.03 g / 10 min to 0.50 g / 10 min; for example, the polyolefin composition may have an I2 of a lower limit of 0.03 g / 10 min, 0.05 g / 10 min, or 0.10 g / 10 min to an upper limit of 0.50 g / 10 min, 0.40 g / 10 min, or 0.30 g / 10 min.

[0059] The polyolefin compositions disclosed herein have a melt index (I5) of 0.3 g / 10 min to 2.0 g / 10 min. This includes all individual values ​​and sub-ranges from 0.3 g / 10 min to 2.0 g / 10 min; for example, the polyolefin composition may have an I5 from a lower limit of 0.3 g / 10 min, 0.5 g / 10 min, or 0.7 g / 10 min to an upper limit of 2.0 g / 10 min, 1.7 g / 10 min, or 1.5 g / 10 min.

[0060] The polyolefin compositions disclosed herein have a melt index (I) of 15 g / 10 min to 40 g / 10 min. 21 This includes all individual values ​​and sub-ranges from 15 g / 10 min to 40 g / 10 min; for example, polyolefin compositions can have a lower limit of 15 g / 10 min, 16 g / 10 min, 17 g / 10 min or 18 g / 10 min to an upper limit of 40 g / 10 min, 35 g / 10 min or 30 g / 10 min. 21 .

[0061] The polyolefin compositions disclosed herein may have an I content greater than 22. 21 The ratio of I5 (I) 21 / I5). For example, the polyolefin compositions described herein may have an I of 22 to 35. 21 / I5. This includes all individual values ​​and sub-ranges from 22 to 35; for example, a polyolefin composition may have I values ​​ranging from a lower limit of 22.1, 22.3, or 22.5 to an upper limit of 35, 33, or 30. 21 / I5.

[0062] The polyolefin compositions disclosed herein can have a weight-average molecular weight (M0.05) from 175,000 g / mol to 350,000 g / mol. w (Conv)). As used in this article, M w (Conv) can be more simply called M w This includes all individual values ​​and sub-ranges from 175,000 g / mol to 350,000 g / mol; for example, polyolefin compositions can have Mw with lower limits of 175,000 g / mol, 200,000 g / mol, or 225,000 g / mol to upper limits of 350,000 g / mol, 325,000 g / mol, or 300,000 g / mol. Mw can be determined by conventional gel permeation chromatography (GPC) as is known in the art. w This article discusses conventional GPC.

[0063] The polyolefin compositions disclosed herein can have an absolute weight-average molecular weight (M0.05) of 350,000 g / mol to 800,000 g / mol. w(Abs)). This includes all individual values ​​and sub-ranges from 350,000 g / mol to 800,000 g / mol; for example, polyolefin compositions can have M values ​​from a lower limit of 350,000 g / mol, 450,000 g / mol, or 500,000 g / mol to an upper limit of 800,000 g / mol, 750,000 g / mol, or 700,000 g / mol. w (Abs). As is known in the art, M can be determined by absolute gel permeation chromatography (GPC). w (Abs). This paper discusses absolute GPC.

[0064] The polyolefin compositions disclosed herein can have a number average molecular weight (M0.05) from 8,000 g / mol to 25,000 g / mol. n (Conv)). As used in this article, M n (Conv) can be more simply called M n This includes all individual values ​​and sub-ranges from 8,000 g / mol to 25,000 g / mol; for example, polyolefin compositions can have M values ​​from a lower limit of 8,000 g / mol, 9,000 g / mol, or 10,000 g / mol to an upper limit of 25,000 g / mol, 20,000 g / mol, or 16,000 g / mol. n As is known in the art, M can be determined by conventional gel permeation chromatography (GPC). n This article discusses conventional GPC.

[0065] The polyolefin compositions disclosed herein can have an absolute number-average molecular weight (M0.05) from 8,000 g / mol to 25,000 g / mol. n (Abs)). This includes all individual values ​​and sub-ranges from 8,000 g / mol to 25,000 g / mol; for example, polyolefin compositions can have M values ​​from a lower limit of 8,000 g / mol, 9,000 g / mol, or 10,000 g / mol to an upper limit of 25,000 g / mol, 20,000 g / mol, or 16,000 g / mol. n (Abs). As is known in the art, Mn(Abs) can be determined by absolute gel permeation chromatography (GPC). Absolute GPC is discussed in this paper.

[0066] The polyolefin compositions disclosed herein can have a Z-average molecular weight (M0.05) from 1,500,000 g / mol to 5,500,000 g / mol. z (Conv)). As used in this article, M z (Conv) can be more simply called M zThis includes all individual values ​​and sub-ranges from 1,500,000 g / mol to 5,500,000 g / mol; for example, polyolefin compositions can have M values ​​from a lower limit of 1,500,000 g / mol, 1,750,000 g / mol, or 2,250,000 g / mol to an upper limit of 5,500,000 g / mol, 5,000,000 g / mol, or 4,250,000 g / mol. z As is known in the art, M can be determined by conventional gel permeation chromatography (GPC). z This article discusses conventional GPC.

[0067] The polyolefin compositions disclosed herein can have an absolute Z-average molecular weight (M0.05) from 3,500,000 g / mol to 12,000,000 g / mol. z (Abs)). This includes all individual values ​​and sub-ranges from 3,500,000 g / mol to 12,000,000 g / mol; for example, polyolefin compositions can have M values ​​from lower limits of 3,500,000 g / mol, 4,500,000 g / mol, or 5,000,000 g / mol to upper limits of 12,000,000 g / mol, 11,000,000 g / mol, 10,000,000 g / mol, 8,000,000 g / mol, or 6,000,000 g / mol. z (Abs). As is known in the art, M can be determined by absolute gel permeation chromatography (GPC). z (Abs). This paper discusses absolute GPC.

[0068] The polyolefin compositions disclosed herein can have a weight-average molecular weight to number-average molecular weight ratio (M0.05) greater than 17. w / M n For example, the polyolefin compositions described herein may have an M of 17 to 30. w / M n This includes all individual values ​​and sub-ranges from 17 to 30; for example, a polyolefin composition may have an M value ranging from a lower limit of 17, 17.5, or 17.9 to an upper limit of 30, 28, 26, 24, 22, or 20. w / M n .

[0069] For the polyolefin compositions disclosed herein, the storage modulus (G′), loss modulus (G″), and complex viscosity (eta or η) can be determined as follows. For preparation, the test sample can be placed in a 1.5-inch diameter mold with a thickness of 3.10 mm and compressed at 2500 lb for 6.5 minutes at 190 °C. After cooling to room temperature, the sample can be removed for rheological testing. DMS (Dynamic Mechanical Spectroscopy) frequency scanning can be performed using 25 mm parallel plates at frequencies ranging from 0.02 radians / second to 200 radians / second. The test gap separating the plates can be 2 mm, and linear viscoelastic strips can be used. The sample is subjected to 10% strain; each test can be performed isothermally at 190°C. Before starting the DMS test, the rheometer oven can be equilibrated at the test temperature for at least 30 minutes. After equilibration at the test temperature, the sample can be loaded into the rheometer, and the plates can be gradually reduced to a gap of 2.8 mm and trimmed. The sample can then be equilibrated for 2.5 minutes before reducing the parallel plates to the final test gap of 2 mm. Finally, the sample can be trimmed again to ensure there are no protrusions, and the test can begin under nitrogen sealing to help ensure thermal stability. During the test, the shear modulus (G′), viscous modulus (G″), and complex viscosity can be measured. All DMS frequency tests can be performed on the ARES-G2 rheometer (manufactured by TA Instruments). Data analysis can be performed using TA Instruments TRIO S software.

[0070] The polyolefin compositions disclosed herein can provide G′ (G″ = 3000 Pa) values ​​from 1650 Pa to 1870 Pa. This includes all individual values ​​and sub-ranges from 1650 Pa to 1870 Pa; for example, the polyolefin compositions can provide G′ (G″ = 3000 Pa) values ​​from a lower limit of 1650 Pa, 1660 Pa, or 1670 Pa to an upper limit of 1870 Pa, 1860 Pa, or 1850 Pa.

[0071] The polyolefin compositions disclosed herein can be expected to provide G′ / G″ (0.02 seconds) greater than Equation 1 below. -1 )value:

[0072] 0.3087 + 0.00404 * (0.02 seconds) -1 (Eta) / (200 seconds) -1 The share of Eta)-0.224*HMW.

[0073] The polyolefin compositions disclosed herein can be expected to provide G′ (G′ = 3000 Pa) values ​​greater than those in Equation 2 below:

[0074] 1242.6+17.5*(I 21 / I5)-5.6*I 21 .

[0075] Unexpectedly high G′ / G″ (0.02 sec) values ​​were observed in the polyolefin compositions disclosed herein. -1 (e.g., by using 0.02 seconds as a relevant metric for MWD) -1 (Eta) / (200 seconds) -1 The higher G′ / G″ ratio is associated with greater elasticity and can lead to higher expansion and higher melt strength. (Eta) and HMS share, which is characterized as another MWD-related metric.

[0076] The polyolefin compositions disclosed herein can desiccably provide melt strengths from 6.5 cN to 12.0 cN. This includes all individual values ​​and sub-ranges from 16.5 cN to 12.0 cN; for example, the polyolefin compositions can provide melt strengths from a lower limit of 6.5 cN, 7.0 cN, or 7.5 cN to an upper limit of 12.0 cN, 11.0 cN, or 10.0 cN. Melt strength can be determined as follows. Melt strength (MS) measurements can be performed using a Gottfert Rheotens 71.97 (Gottfert Inc.; RockHill, SC) attached to a Gottfert Rheotester 2000 capillary rheometer. The polymer melt (approximately 20 to 30 grams, granules) is extruded through a capillary die having a flat inlet angle (180 degrees), wherein the capillary diameter is 2.0 mm and the aspect ratio (capillary length / capillary diameter) is 15. After equilibrating the sample at 190°C for 10 minutes, the piston can be driven at a constant piston speed of 0.265 mm / s. The standard test temperature is 190°C. The sample is uniaxially stretched to a set of accelerating slits located 100 mm below the die, with an acceleration of 2.4 mm / s. 2 Tension can be recorded as a function of the roll winding speed. Melt strength is reported as the force (cN) in the flat zone before chain breakage. The following conditions can be used in melt strength measurement: plunger speed 0.265 mm / s; wheel acceleration 2.4 mm / s. 2 The capillary diameter is 2.0 mm; the capillary length is 30 mm; and the tube diameter is 12 mm.

[0077] The polyolefin compositions disclosed herein can desirously provide a maximum load greater than 200 g. For example, the polyolefin compositions disclosed herein can provide a maximum load from 201 g to 375 g. This includes all individual values ​​and sub-ranges from 201 g to 375 g; for example, the polyolefin compositions disclosed herein can provide a maximum load from a lower limit of 201 g, 210 g, or 220 g to an upper limit of 375 g, 350 g, or 325 g. The maximum load can be determined as is known to those skilled in the art.

[0078] The polyolefin compositions disclosed herein can be expected to provide [performance] in 1000 seconds. -1 The expansion at a shear rate (t1000) is greater than 6.5 seconds. For example, the polyolefin compositions described herein can provide expansion (t1000) greater than 6.5 seconds (e.g., 6.51 seconds) to 10.0 seconds. This includes all individual values ​​and sub-ranges from 6.51 seconds to 10.00 seconds; for example, the polyolefin compositions can provide expansion (t1000) from a lower limit of 6.51 seconds, 6.53 seconds, or 6.55 seconds to an upper limit of 10.0 seconds, 9.0 seconds, or 8.0 seconds.

[0079] The polyolefin compositions disclosed herein can be expected to provide [results] in 300 seconds. -1 The expansion at a shear rate (t300) is greater than 17.0 seconds. For example, the polyolefin compositions described herein can provide an expansion (t300) of 17.0 seconds to 25.0 seconds. This includes all individual values ​​and sub-ranges from 17.0 seconds to 25.0 seconds; for example, the polyolefin compositions can provide an expansion (t300) from a lower limit of 17.0 seconds, 17.5 seconds, or 18.0 seconds to an upper limit of 25.0 seconds, 22.0 seconds, or 21.0 seconds.

[0080] Expansion can be measured as follows. The polymer chain can be measured using a piston-driven capillary rheometer (equipped with a 12mm diameter cylinder and a 10mm long, 1mm diameter circular mold). Rheograph 2003, the circular mold (with a 90° entrance angle) in 300 seconds -1 Or 1000 seconds -1 The shear rate is determined at 190°C. The volumetric flow rate remains constant. The chain can be cut at a distance of 4 cm from the die exit, and a timer is started. The timer is stopped when the chain reaches a total length of 27 cm (i.e., an increment of 23 cm after the timer starts). High-expansion materials produce thicker extrudates, and their length increases more slowly than that of low-expansion materials. The recording time for the chain to reach the 23 cm increment is related to extrudate expansion. The measurement is repeated five times to account for measurement variations, and the average result is reported. Extrudate expansion is reported in this paper as the extrudate expanding in 1000 seconds. -1 (t1000) shear rate and at 300 seconds-1 The time required to cover a 23cm distance when extruding at the shear rate of (t300).

[0081] The polyolefin compositions disclosed herein are expected to provide an ESCR F of more than 140 hours. 50 For example, the polyolefin compositions described herein can provide ESCR F of 140.5 hours to 550 hours. 50 This includes all individual values ​​and sub-ranges from 140 hours to 550 hours; for example, polyolefin compositions can be provided with an ESCR F value ranging from a lower limit of 140.5 hours or 141 hours to an upper limit of 550 hours, 500 hours, or 450 hours. 50 ESCR F can be determined in a 10% (v / v) aqueous Igepal CO-630 solution according to ASTM D-1693, Method B. 50 .

[0082] The polyolefin compositions disclosed herein can be used in a wide range of applications, including but not limited to molded articles, extruded articles, films, fibers, nonwoven fabrics, and / or woven fabrics. The polyolefin compositions disclosed herein may be particularly advantageous for blow molding applications, such as in the manufacture of bottles, cans, hollow articles, rigid food containers, toys, and other molded articles.

[0083] Several aspects of this disclosure are provided below.

[0084] Aspect 1 provides a polyolefin composition comprising: a high molecular weight polyolefin having a molecular weight of 0.920 g / cm³. 3 Up to 0.945 g / cm 3 The density; and a low molecular weight polyolefin having an I2 content of 5 g / min to 200 g / 10 min, wherein the polyolefin composition provides a cumulative detector fraction (CDF) at a molecular weight of ≥10,000,000 g / mol. Ls () greater than 0.085.

[0085] Aspect 2 provides the polyolefin composition of Aspect 1, wherein the high molecular weight polyolefin has a high load melt index (I0) of 0.45 g / 10 min to 1.50 g / 10 min. 21 ) an ethylene / 1-hexene copolymer, wherein the low molecular weight polyolefin is a polyethylene homopolymer.

[0086] Aspect 3 provides a polyolefin composition of Aspect 1 and / or Aspect 2, wherein the polyolefin composition provides an environmental stress cracking resistance of greater than 140 hours. 50 Condition B (10% IGEPAL).

[0087] Aspect 4 provides a polyolefin composition of Aspect 1, Aspect 2 and / or Aspect 3, wherein the polyolefin composition provides an expansion of more than 6.5 seconds (t1000).

[0088] Aspect 5 provides polyolefin compositions of Aspects 1, 2, 3 and / or 4, wherein the polyolefin composition has a content of 0.930 g / cm³. 3 Up to 0.970 g / cm 3 The density of M is greater than 17. w / M n Melt index (I) of 15 g / 10 min to 40 g / 10 min 21 And provides a time greater than 0.3087 + 0.00404 * (0.02 seconds). -1 (Eta) / (200 seconds) -1 The value of G′ / G″ (0.02 seconds) is calculated as follows: (Eta) - 0.224 * HMW share. -1) The values ​​and G′ (G″ = 3000 Pa) values ​​from 1650 Pa to 1870 Pa.

[0089] Aspect 6 provides a polyolefin composition comprising: a high molecular weight polyolefin; and a low molecular weight polyolefin, wherein the polyolefin composition has a molecular weight of 0.930 g / cm³. 3 Up to 0.970 g / cm 3 The density of M is greater than 17. w / M n Melt index (I) of 15 g / 10 min to 40 g / 10 min 21 And provides a time greater than 0.3087 + 0.00404 * (0.02 seconds). -1 (Eta) / (200 seconds) -1 The value of G′ / G″ (0.02 seconds) is calculated as follows: (Eta) - 0.224 * HMW share. -1 The values ​​of G′ (G″ = 3000 Pa) range from 1650 Pa to 1870 Pa.

[0090] Aspect 7 provides the polyolefin composition of aspect 6, wherein the polyolefin composition provides a content greater than 1242.6 + 17.5*(I 21 / I5)-5.6*I 21 The value of G′ (G″ = 3000 Pa).

[0091] Aspect 8 provides polyolefin compositions of Aspects 1, 2, 3, 4, 5, 6 and / or 7, wherein the polyolefin composition has a high molecular weight share of less than 50%.

[0092] Aspect 9 provides polyolefin compositions of Aspects 1, 2, 3, 4, 5, 6, 7 and / or 8, wherein the polyolefin composition provides a melt strength of 6.5 cN to 12.0 cN.

[0093] Aspect 10 provides polyolefin compositions of aspects 1, 2, 3, 4, 5, 6, 7, 8 and / or 9, wherein the polyolefin composition provides a maximum load of greater than 200 grams; or wherein the polyolefin composition provides a maximum load of less than 279 grams; or both.

[0094] Aspect 11 provides polyolefin compositions of Aspects 1, 2, 3, 4, 5, 6, 7, 8, 9 and / or 10, wherein the polyolefin composition has an absolute Z-average molecular weight (M0) of 3,500,000 g / mol to 12,000,000 g / mol. z (Abs)), or wherein the polyolefin composition has an absolute weight-average molecular weight (M) of 350,000 g / mol to 800,000 g / mol. w (Abs)); or both.

[0095] Aspect 12 provides polyolefin compositions of Aspects 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and / or 11, wherein the polyolefin composition has a weight-average molecular weight (M2) of 1,500,000 g / mol to 5,500,000 g / mol. z ).

[0096] Aspect 13 provides polyolefin compositions of Aspects 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 and / or 12, wherein the polyolefin composition provides a cumulative detector fraction (CDF) at a molecular weight of ≥10,000,000 g / mol. LS The cumulative detector fraction (CDF) is greater than 0.10; or the polyolefin composition provides a cumulative detector fraction (CDF) at a molecular weight of ≥10,000,000 g / mol. Ls Less than 0.140; or both.

[0097] Aspect 14 provides polyolefin compositions of Aspects 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 and / or 13, wherein the polyolefin composition has any one of the limitations (i) to (vii): (i) wherein the polyolefin composition has a high molecular weight share of 39% to 49%; (ii) wherein the high molecular weight polyolefin has a molecular weight of 0.937 g / cm³.3 Up to 0.941 g / cm 3 (iii) wherein the low molecular weight polyolefin has a melt index (I2) of 16.5 g / 10 min to 129 g / 10 min; (iv) limiting both (i) and (ii); (v) limiting both (i) and (iii); (vi) limiting both (ii) and (iii); and (vii) limiting each of the limitations in (i), (ii) and (iii).

[0098] Aspect 15 provides a method for preparing a polyolefin composition according to any of the preceding aspects, the method comprising: polymerizing ethylene and 1-hexene in a first fluidized bed reactor under first process conditions using a Ziegler-Natta catalyst to prepare a high molecular weight polyolefin containing an olefin polymerization catalyst; transferring the high molecular weight polyolefin containing the olefin polymerization catalyst to a second fluidized bed reactor connected in series with the first fluidized bed reactor; and polymerizing ethylene in the second fluidized bed reactor under second process conditions to prepare a low molecular weight polyolefin, wherein the first process conditions in the first fluidized bed reactor are configured for preparing the high molecular weight polyolefin, and the second process conditions in the second fluidized bed reactor are configured for preparing the low molecular weight polyolefin, thereby preparing the polyolefin composition.

[0099] Example

[0100] Polymerization catalyst-1, namely the Ziegler-Natta catalyst, was prepared as described below according to U.S. Patent No. 4,526,942. Dibutylmagnesium (in solution in heptane or hexane; obtained from Lithium Corporation of America); dihexylmagnesium (in solution in hexane; obtained from Ethyl Corporation or Texas Alkyls, Inc.); and butylethylmagnesium (in solution in hexane; obtained from Texas Alkyls, Inc.); triisobutylaluminum (in solution in hexane; 0.616 mol; obtained from Ethyl Corporation or Texas Alkyls, Inc.); and ethylaluminum dichloride (in solution in hexane; 1.53 mol; obtained from Ethyl Corporation or Texas Alkyls, Inc.).

[0101] A masterbatch solution was prepared by mixing butylethyl magnesium (391.5 ml, 0.637 M; 250 mmol) and triisobutylaluminum (202.9 ml, 0.616 M; 125 mmol). Pure propanol (65.4 ml; 875 mmol) was then added dropwise to maintain the temperature at approximately 40 °C. The solution was then diluted to 750 ml with hexane. The magnesium concentration in this masterbatch solution was 0.3333 M. The ROH:R group ratio (i.e., the added ROH to the R groups attached to magnesium and aluminum in component A) was 1:1. Tetraisopropoxytitanium (1.5 ml, 5.04 mmol) was then added dropwise to the masterbatch solution (75 ml aliquot; containing 25 mmol magnesium). Ethylaluminum dichloride (65.5 ml; 100.22 mmol) was then added dropwise at approximately 22 °C. After complete addition of ethylaluminum dichloride, a brown slurry was produced to provide polymerization catalyst-1; the catalyst volume was adjusted to 200 ml, and fresh hexane and 50 ml of aliquots were set aside for polymerization. The Mg:Ti and Cl:Mg atomic ratios of polymerization catalyst-1 were 4.96:1 and 8.02:1, respectively.

[0102] Example 1, i.e., bimodal polyethylene, was prepared using polymerization catalyst-1 as follows. Ethylene was copolymerized with 1-hexene in the first of two tandem fluidized bed reactors; no comonomer was used in the second tandem fluidized bed reactor. For Example 1, a high molecular weight polymer was prepared in the first tandem fluidized bed reactor (compared to the second tandem fluidized bed reactor), and a low molecular weight polymer was prepared in the second tandem fluidized bed reactor. Each polymerization was carried out continuously under the conditions described in Table I after reaching equilibrium. Polymerization was initiated in the first reactor by continuously feeding the above-described catalyst precursor and co-catalyst TEA (trimethylaluminum) with ethylene, 1-hexene, and hydrogen into a fluidized bed of polyethylene particles. The co-catalyst was first dissolved in isopentane. The resulting copolymer, mixed with the active catalyst, was extracted from the first reactor and transferred to the second reactor using the gas from the second reactor as a transfer medium. The second reactor also contained a fluidized bed of polyethylene particles. Ethylene and hydrogen are introduced into a second reactor, where they contact the polymer and catalyst from the first reactor. In the second reactor, the co-catalyst TEA is introduced again. Example 1 is continuously withdrawn from the second reactor.

[0103] Examples 2, 3, 4, 5, and 6 were prepared as in Example 1, with any variations shown in Table 1. The polyolefin compositions of Examples 1 to 6 of the present invention are bimodal polyethylene resins comprising a high molecular weight polyolefin component (prepared in a first polymerization reactor in series) (the high molecular weight polyolefin component is an ethylene / 1-hexene copolymer) and a low molecular weight polyolefin component (prepared in a second polymerization reactor in series), wherein no direct-feed comonomers are used.

[0104] Table 1

[0105]

[0106]

[0107] Comparative Example A and Comparative Example B were prepared as in Example 1, with any variations shown in Table 2.

[0108] Table 2

[0109]

[0110] Various properties were measured for Examples 1 to 6 and Comparative Examples A to B. Furthermore, comparative examples C (MARLEX HHM 5202BN; ethylene copolymer; obtained from Chevron Phillips) and D (UNIVAL) were also measured. TM DMDA-6200 (HDPE; obtained from The Dow Chemical Company); Comparative Example E (DOW 35060L; HDPE; obtained from Dow Chemical Company); and Comparative Example F (CONTINUUM TM DMDD-6620 (bimodal polyethylene; obtained from Dow Chemical Company) was used to determine various properties. The results are reported in Tables 5, 6, 7, 8, and 9.

[0111] Density was determined according to ASTM D792.

[0112] Melt flow index (I2, I5, and I6) was determined according to ASTM 1238. 21 ).

[0113] The I2 of low molecular weight polyolefins was determined as follows. Ethylene was copolymerized with 1-hexene in a fluidized bed reactor. Multiple polymerizations were carried out using different process conditions (Run 1 to Run 4). After reaching equilibrium, each polymerization was carried out continuously under the corresponding process conditions described in the table below (see Table 3). Polymerization was initiated by continuously feeding polymerization catalyst-1 as described herein and a co-catalyst dissolved in isopentane into a fluidized bed of polyethylene particles along with ethylene, 1-hexene (when used), and hydrogen. Inert gases, nitrogen, and isopentane constituted the residual pressure in the reactor. The properties of the polyolefin samples prepared by these polymerizations were characterized as follows (see Table 4). This data was modeled to control a second tandem reactor, thereby providing the determined I2.

[0114] Table 3

[0115]

[0116]

[0117] Table 4

[0118]

[0119] Interpolate 200 g / 10 min I2 from runs 1 to 4. Obtain 5 g / 10 min I2 by small extrapolation from runs 1 to 4.

[0120] The cumulative detector fraction (CDF) is determined as discussed in this paper.

[0121] The high molecular weight fraction was determined as follows. The molecular weight distribution of the resin was measured by conventional gel permeation chromatography (GPC). The molecular weight distributions of the separated HMW and LMW resins were overlaid on the resin prepared using a tandem reactor system. The ratio of HMW to LMW was adjusted so that the sum of the two distributions matched the distribution of the resin produced in the tandem reactor. For Examples 2 and 3 (in Table 5) (where no separated LMW resin was produced in a single reactor operation, directly equivalent to the conditions used in those examples), the fraction was determined using density and I² models developed for LMW reactors and a resin property mixing model developed to predict the final bimodal polymer properties.

[0122] As discussed in this article, extrusion swell is measured.

[0123] ESCR F was determined in a 10% (v / v) aqueous Igepal CO-630 solution according to ASTM D-1693, Method B. 50 .

[0124] The weight-average molecular weight (M) was determined by conventional gel permeation chromatography (GPC). w (Conv)), number-average molecular weight (M) n (Conv)) and Z-average molecular weight (M z (Conv)); The results are reported in Table 4.

[0125] The absolute weight-average molecular weight (M) was determined by absolute gel permeation chromatography (GPC). w (Abs)), absolute number average molecular weight (M n (Abs) and absolute Z-mean molecular weight (M z (Abs); the results are reported in Table 7.

[0126] G′ (where G″ = 3000 Pa) and Eta (at 0.02 seconds) were measured using an ARES-G2 rheometer (manufactured by TA Instruments). -1 (below) and Eta (in 200 seconds) -1 (Below), and the data is implemented using the TA instrument TRIOS software, as discussed in this article.

[0127] Determine melt strength as discussed in this article.

[0128] The maximum load is determined as discussed in this article.

[0129] Table 5

[0130]

[0131]

[0132]

[0133] The data in Table 5 show that each of Embodiments 1 to 6 of the present invention advantageously has an expansion time (t1000) greater than 6.5 seconds and an ESCR F greater than 140 hours. 50 The data in Table 5 show that none of Comparative Examples A to F achieved a combination of expansion (t1000) greater than 6.5 seconds and ESCR greater than 140 hours. The data in Table 5 also show that each of Examples 1 to 6 of the present invention ideally has a density of 0.9200 g / cm³ for the HMW polyolefin prepared in the first tandem reactor. 3 Up to 0.9450 g / cm 3 The data in Table 5 show that each of the embodiments of the present invention, from Embodiment 1 to Embodiment 6, is expected to have 12 LMW polyolefins ranging from 5 g / 10 min to 200 g / 10 min.

[0134] Table 6

[0135]

[0136]

[0137]

[0138] The data in Table 6 show that each of the embodiments of the present invention, from Embodiment 1 to Embodiment 6, advantageously has an M greater than 17. w / M n The data in Table 6 show that each of the embodiments of the present invention, from Embodiment 1 to Embodiment 6, advantageously has an I content of 15 g / 10 min to 40 g / 10 min. 21 The data in Table 6 show that each of the embodiments of the present invention, from Embodiment 1 to Embodiment 6, advantageously has an I greater than 22. 21 / I5.

[0139] Table 7

[0140]

[0141]

[0142] Table 8

[0143]

[0144] The data in Table 8 shows that each of the embodiments of the present invention, from Embodiment 1 to Embodiment 6, is expected to have a G′ / G″ greater than the corresponding Equation 1.

[0145] (0.02 seconds) -1 The values ​​are as discussed previously herein. The data in Table 8 show that each of the embodiments of the present invention, from Embodiment 1 to Embodiment 6, is expected to have a G′ (G″ = 3000 Pa) value greater than that in the corresponding Equation 2, as discussed previously herein.

[0146] Table 9

[0147]

[0148] The data in Table 9 indicate that each of Embodiments 1 to 6 of the present invention is expected to have a melt strength of 6.5 cN to 12.0 cN. The data in Table 9 also indicate that each of Embodiments 1, 2, and 3 is expected to have a maximum load greater than 200 grams.

Claims

1. A polyethylene composition comprising: High molecular weight polyethylene, wherein the high molecular weight polyethylene has a molecular weight of 0.920 g / cm³. 3 Up to 0.945 g / cm 3 The density; and Low molecular weight polyethylene, wherein the low molecular weight polyethylene has an I2 content of 5 g / 10 min to 200 g / 10 min, The polyethylene composition described herein has a high molecular weight share of 39% to 49% and an absolute Z-average molecular weight M of 3,500,000 g / mol to 12,000,000 g / mol. z (Abs); or the polyethylene composition wherein the absolute weight-average molecular weight M is from 350,000 g / mol to 800,000 g / mol. w (Abs), and the polyethylene composition provides a cumulative detector fraction (CDF) greater than 0.085 at molecular weights >10,000,000 g / mol. LS , The polyethylene composition is prepared using a first fluidized bed reactor and a second fluidized bed reactor arranged in series, wherein the high molecular weight polyethylene is obtained by reacting ethylene and α-olefin in the first fluidized bed reactor with a Ziegler-Natta catalyst; and the low molecular weight polyethylene is obtained by polymerizing ethylene in the second fluidized bed reactor.

2. The polyethylene composition according to claim 1, wherein the high molecular weight polyethylene has a high load melt index of 1, ranging from 0.45 g / 10 min to 1.50 g / 10 min. 21 The ethylene / 1-hexene copolymer, wherein the low molecular weight polyethylene is a polyethylene homopolymer.

3. The polyethylene composition of claim 1, wherein the polyethylene composition provides greater than 140 hours of environmental stress cracking resistance in 10% IGEPEAL. 50 Condition B.

4. The polyethylene composition of claim 1, wherein the polyethylene composition provides an expansion t1000 of greater than 6.5 seconds.

5. The polyethylene composition according to claim 1, wherein the polyethylene composition has a content of 0.930 g / cm³. 3 Up to 0.970 g / cm 3 The density of M is greater than 17. w / M n Melt index I: 15 g / 10 min to 40 g / 10 min 21 ,and Provides a time greater than 0.3087 + 0.00404 * (0.02 seconds) -1 (Eta) / (200 seconds) -1 The second of Eta) - 0.224 * HMW share is 0.02 seconds. -1 The G' / G" value below, and The value of G' when G” = 3000Pa, ranging from 1650Pa to 1870Pa.

6. A polyethylene composition comprising: High molecular weight polyethylene has a density of 0.920 to 0.945 g / cm³. 3 ;as well as Low molecular weight polyethylene, with an I2 content of 5 to 200 g / 10 min. The polyethylene composition wherein the polyethylene composition has a high molecular weight content of 39% to 49% and a molecular weight of 0.930 g / cm³. 3 Up to 0.970 g / cm 3 The density of M is greater than 17. w / M n Melt index I: 15 g / 10 min to 40 g / 10 min 21 ,and Provides a time greater than 0.3087 + 0.00404 * (0.02 seconds) -1 (Eta) / (200 seconds) -1 The second of Eta) - 0.224 * HMW share is 0.02 seconds. -1 The G' / G" value below, and The value of G' when G” = 3000Pa, ranging from 1650Pa to 1870Pa. The polyethylene composition provides a cumulative detector fraction (CDF) greater than 0.085 at molecular weights >10,000,000 g / mol. LS , The polyethylene composition is prepared using a first fluidized bed reactor and a second fluidized bed reactor arranged in series. The high molecular weight polyethylene is obtained by polymerizing ethylene and α-olefin in the first fluidized bed reactor using a Ziegler-Natta catalyst. The low molecular weight polyethylene is obtained by polymerizing ethylene in the second fluidized bed reactor.

7. The polyethylene composition of claim 6, wherein the polyethylene composition provides a value greater than 1242.6 + 17.5 * (I 21 / I5)-5.6*I 21 The value of G' when G” = 3000Pa.

8. The polyethylene composition of claim 1, wherein the polyethylene composition provides a melt strength of 6.5 cN to 12.0 cN.

9. The polyethylene composition of claim 1, wherein the polyethylene composition provides a maximum load of more than 200 grams; or wherein the polyethylene composition provides a maximum load of less than 279 grams; or both.

10. The polyethylene composition according to claim 1, wherein the polyethylene composition has a weight-average molecular weight M of 1,500,000 g / mol to 5,500,000 g / mol. z .

11. The polyethylene composition of claim 1, wherein the polyethylene composition provides a cumulative detector fraction (CDF) greater than 0.10 at a molecular weight of >10,000,000 g / mol. LS ; or the polyethylene composition thereof provides a cumulative detector fraction (CDF) of less than 0.140 at a molecular weight of >10,000,000 g / mol. LS ; or both.

12. The polyethylene composition according to claim 1, wherein the polyethylene composition has any one of the limitations (i) to (vii): (i) wherein the polyethylene composition has a high molecular weight content of 39% to 49%; (ii) wherein the high molecular weight polyethylene has a molecular weight of 0.937 g / cm³. 3 Up to 0.941 g / cm 3 The density; (iii) wherein the low molecular weight polyethylene has a melt index I2 of 16.5 g / 10 min to 129 g / 10 min; (iv) Restrict both (i) and (ii); (v) Restrict both (i) and (iii); (vi) restricts both (ii) and (iii); and (vii) Restrict each of the restrictions in (i), (ii) and (iii).

13. A method for preparing the polyethylene composition according to claim 1, the method comprising: In a first process condition, ethylene and 1-hexene are polymerized in a first fluidized bed reactor using a Ziegler-Natta catalyst to prepare high molecular weight polyethylene containing the Ziegler-Natta catalyst; the high molecular weight polyethylene containing the Ziegler-Natta catalyst is transferred to a second fluidized bed reactor connected in series with the first fluidized bed reactor; and in a second process condition, ethylene is polymerized in the second fluidized bed reactor to prepare low molecular weight polyethylene, wherein the first process condition in the first fluidized bed reactor is configured to prepare the high molecular weight polyethylene, and the second process condition in the second fluidized bed reactor is configured to prepare the low molecular weight polyethylene, thereby preparing the polyethylene composition.

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