Polyethylene composition and film comprising the same

Abstract

The present invention relates to polyethylene compositions. In one aspect, the polyethylene composition comprises (1) a first polyethylene fraction having a single peak in a temperature range from 50°C to 85°C in an elution profile obtained by an iCCD analysis method, (2) a second polyethylene fraction having a single peak in a temperature range from 85°C to 100°C in the elution profile obtained by the iCCD analysis method, and (3) a third polyethylene fraction having a single peak in a temperature range from 100°C to 120°C in the elution profile obtained by the iCCD analysis method, wherein the first polyethylene area fraction comprises from 25% to 50% of the total area of the elution profile, wherein the second polyethylene area fraction comprises from 30% to 50% of the total area of the elution profile, and wherein the third polyethylene area fraction comprises from 15% to 35% of the total area of the elution profile.

Description

Technical Field

[0001] This invention relates to polyethylene compositions and films comprising such compositions. Background Technology

[0002] Flexible packaging film structures are typically formed from multiple types of polymer materials, including, for example, polyethylene, polypropylene, ethylene vinyl alcohol, polyethylene terephthalate, polyamide, etc. These materials are often combined to achieve a balance of properties beyond what can be achieved with a single material type. However, due to the differences between these materials, the final packaging is often not easily recyclable. Therefore, there is also a movement towards single-component structures (e.g., all-polyethylene structures) to improve the recyclability profile. For example, in the case of an all-polyethylene structure, it will be necessary to enhance certain performance indicators (e.g., mechanical properties) to maintain the expected performance levels of these structures when formed from different polymer materials, while simultaneously improving recyclability.

[0003] Typically, when designing films for packaging and other applications, an improvement in one property of the film may lead to a decrease in another. For example, using polyethylene with a lower density may improve some mechanical properties (e.g., dart impact), but reduce other properties, such as secant modulus and / or barrier properties. For some packaging applications, such as heavy-duty shipping bags, stand-up pouches, and pet food packaging, a good balance of stiffness and toughness may be the desired combination of properties.

[0004] Novel polyethylene compositions are desired that can be used in membranes to provide improved properties. Summary of the Invention

[0005] This invention provides polyethylene compositions that can be used in films to provide desired and / or improved properties. In some embodiments, films formed from the polyethylene compositions of this invention provide improved dart impact resistance.

[0006] In one aspect, the polyethylene composition comprises:

[0007] (1) A first polyethylene fraction, wherein the first polyethylene fraction has a single peak in the elution curve obtained by an improved comonomer composition distribution (iCCD) analysis method in the temperature range of 50°C to 85°C, wherein the first polyethylene area fraction is the area below the single peak of the first polyethylene fraction in the elution curve between 50°C and 85°C, and wherein, when measured using the iCCD analysis method, the average M in the first polyethylene fraction is... w The range is from 100,000 g / mol to 225,000 g / mol;

[0008] (2) A second polyethylene fraction, wherein the second polyethylene fraction has a single peak in the elution curve obtained by the iCCD analysis method in the temperature range of 85°C to 100°C, wherein the second polyethylene area fraction is the area below the single peak of the second polyethylene fraction in the elution curve between 85°C and 100°C, and wherein, when measured using the iCCD analysis method, the average M in the second polyethylene fraction is... w From 30,000 g / mol to 60,000 g / mol; and

[0009] (3) A third polyethylene fraction, wherein the third polyethylene fraction has a single peak in the elution curve obtained by iCCD analysis in the temperature range of 100°C to 120°C, wherein the third polyethylene area fraction is the area below the single peak of the third polyethylene fraction in the elution curve between 100°C and 120°C, and wherein the average M in the third polyethylene fraction is measured using the iCCD analysis method. w The range is from 100,000 g / mol to 225,000 g / mol;

[0010] The first polyethylene area fraction accounts for 25% to 50% of the total area of ​​the elution curve, the second polyethylene area fraction accounts for 30% to 50% of the total area of ​​the elution curve, and the third polyethylene area fraction accounts for 15% to 35% of the total area of ​​the elution curve.

[0011] These and other implementation schemes are described in more detail in the specific embodiments. Attached Figure Description

[0012] For the purpose of illustrating embodiments of the invention disclosed herein, exemplary forms are shown in the accompanying drawings; however, it should be understood that these embodiments are not limited to the precise arrangement and tools shown.

[0013] Figure 1 iCCD elution curves of polyethylene compositions according to one or more embodiments described in this invention are schematically depicted.

[0014] Figure 2 The iCCD elution curves of the second polyethylene component according to one or more embodiments described in this invention are schematically depicted.

[0015] Figure 3 The iCCD elution curves of the second polyethylene component according to one or more embodiments described in this invention are illustrated graphically. Detailed Implementation

[0016] Unless stated to the contrary, implied by the context or customary in the art, all parts and percentages are by weight, all temperatures are in °C, and all test methods are current methods as of the date of this disclosure.

[0017] As used herein, the term "composition" refers to a mixture of materials comprising the composition, as well as reaction products and decomposition products formed from the materials of the composition.

[0018] "Polymer" means a polymeric compound prepared by polymerizing monomers (whether of the same or different types). Therefore, the general term polymer includes the terms homopolymer and interpolymer as defined below. Trace impurities (e.g., catalyst residues) may be incorporated into and / or within a polymer. A polymer can be a single polymer, a polymer blend, or a mixture of polymers comprising a mixture of polymers formed in situ during polymerization.

[0019] As used in this article, the term "homogeneous polymer" refers to a polymer prepared from only one type of monomer. It should be understood that trace impurities can also be incorporated into the polymer structure.

[0020] As used herein, the term "interpolymer" refers to a polymer prepared by polymerizing at least two different types of monomers. Therefore, the general term interpolymer includes copolymers (used to refer to polymers prepared from two different types of monomers) and polymers prepared from more than two different types of monomers.

[0021] As used herein, the term "olefin polymer" or "polyolefin" refers to a polymer that comprises a majority amount of olefin monomers, such as ethylene or propylene (by weight of the polymer), in polymeric form, and optionally may include one or more comonomers.

[0022] As used herein, the term "ethylene / α-olefin interpolymer" refers to an interpolymer comprising, in polymeric form, a majority (>50 mol%) unit derived from ethylene monomers and the remaining units derived from one or more α-olefins. Typical α-olefins used to form ethylene / α-olefin interpolymers are C3-C64 ... 10 Olefins.

[0023] As used herein, the term "ethylene / α-olefin copolymer" refers to a copolymer comprising a majority amount (>50 mol%) of ethylene monomer and α-olefin as the only two monomer types.

[0024] As used herein, the term "α-olefin" refers to an olefin having a double bond at the primary or α (alpha) position.

[0025] "Polyethylene" or "ethylene-based polymer" should mean a polymer comprising units derived from ethylene monomers in a majority amount (>50 mol%). 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); single-point catalytic linear low-density polyethylene, including linear and substantially linear low-density resins (m-LLDPE); ethylene-based plastomers (POP) and ethylene-based elastomers (POE); medium-density polyethylene (MDPE); and high-density polyethylene (HDPE). These polyethylene materials are generally known in the art; however, the following description may help to understand the differences between some of these different polyethylene resins.

[0026] The term "LDPE" can also be referred to as "high-pressure ethylene polymer" or "highly branched polyethylene," and it is defined as meaning that the polymer is partially or wholly homopolymerized or copolymerized in an autoclave or tubular reactor at pressures above 14,500 psi (100 MPa) using a free radical initiator (such as peroxide) (see, for example, US 4,599,392, which is hereby incorporated herein by reference). The density of LDPE resin is typically around 0.916 g / cm³. 3 Up to 0.935 g / cm 3 Within the range.

[0027] The term "LLDPE" encompasses two resins prepared using conventional Ziegler-Natta catalyst systems and chromium-based catalyst systems, as well as single-site catalysts (including, but not limited to, substituted mono- or dicyclopentadienyl catalysts (commonly referred to as metallocenes), confined geometry catalysts, phosphine imine catalysts, and polyvalent aryloxy ether catalysts (commonly referred to as diphenylphenoxys), and comprising linear, substantially linear, or heterogeneous polyethylene copolymers or homopolymers. Compared to LDPE, LLDPE comprises less long-chain branching and comprises substantially linear ethylene polymers, as further defined in U.S. Patents 5,272,236, 5,278,272, 5,582,923, and 5,733,155; homogeneous branched linear ethylene polymer compositions, such as those in U.S. Patent No. 3,645,992; multiphase branched ethylene polymers, such as those prepared according to the process disclosed in U.S. Patent No. 4,076,698; and / or blends thereof (such as those in U.S. Patent No. 4,076,698). (Those disclosed in US 3,914,342 or US 5,854,045). LLDPE can be prepared by gas-phase, solution-phase, or slurry polymerization or any combination thereof, using any type of reactor or reactor configuration known in the art.

[0028] The term "MDPE" refers to a material with a density of 0.926 g / cm³. 3 Up to 0.935 g / cm 3 Polyethylene. “MDPE” is typically prepared using chromium or Ziegler-Natta catalysts or using single-point catalysts, including but not limited to substituted mono- or di-cyclopentadienyl catalysts (commonly known as metallocenes), confined geometry catalysts, phosphine imine catalysts, and polyvalent aryloxy ether catalysts (commonly known as bisphenylphenoxy), and typically has a molecular weight distribution (“MWD”) greater than 2.5.

[0029] The term "HDPE" refers to a material with a density greater than approximately 0.935 g / cm³. 3 And at most about 0.980 g / cm 3 Polyethylene is generally prepared using Ziegler-Natta catalysts, chromium catalysts, or single-point catalysts (including but not limited to substituted mono- or di-cyclopentadienyl catalysts (commonly known as metallocenes), confined geometry catalysts, phosphine imine catalysts, and polyvalent aryloxy ether catalysts (commonly known as bisphenylphenoxy).

[0030] The term "ULDPE" refers to a material with a density of 0.855 g / cm³. 3 Up to 0.912 g / cm 3Polyethylene, typically prepared using Ziegler-Natta catalysts, chromium catalysts, or single-point catalysts (including but not limited to substituted mono- or di-cyclopentadienyl catalysts (commonly known as metallocenes), confined geometry catalysts, phosphine imine catalysts, and polyvalent catalysts (commonly known as bisphenylphenoxys)). ULDPE includes, but is not limited to, polyethylene (ethylene-based) plastomers and polyethylene (ethylene-based) elastomers. Polyethylene (ethylene-based) elastomers and plastomers typically have a content of 0.855 to 100 g / cm³. 3 0.912g / cm 3 The density.

[0031] The terms “blend” and “polymer blend” mean a composition of two or more polymers. Such blends may or may not be miscible. Such blends may or may not be phase-separated. As determined by transmission electron spectroscopy, light scattering, X-ray scattering, and any other method known in the art, such blends may or may not contain one or more domain configurations. Blends are not laminates, but one or more layers of a laminate may contain blends. Such blends can be prepared as dry blends, in-situ formed (e.g., in a reactor), melt blends, or using other techniques known to those skilled in the art.

[0032] As described herein, a polyethylene “fraction” refers to a portion of the overall composition of the polyethylene composition. Some polyethylene compositions described herein include at least a “first polyethylene fraction” and a “second polyethylene fraction.” Some polyethylene compositions may include a “third polyethylene fraction” and a “fourth polyethylene fraction.” The various fractions contained in such polyethylene compositions can be quantified by the temperature range of their elution profiles obtained by an improved comonomer composition distribution (iCCD) analytical method. Unless otherwise stated, any elution profiles mentioned herein are elution profiles observed by iCCD. Examples of such fractions will be better understood given the examples provided herein. Some polyethylene compositions described herein may be referred to as “multimodal,” meaning they include at least two peaks in their elution profiles. Some polyethylene compositions described herein may be “bimodal,” meaning there are two main peaks. Others may be described as “trimodal,” meaning there are three peaks. As used herein, “single-peak” refers to an ICCD in which a particular fraction includes only a single peak. That is, in some embodiments, the iCCD of a particular fraction may have only one upward-sloping region followed by a downward-sloping region to form a single peak.

[0033] The terms “comprising,” “including,” “having,” and their derivatives are not intended to exclude the presence of any additional components, steps, or procedures, whether or not such components, steps, or procedures are specifically disclosed. For the avoidance of any doubt, unless stated otherwise, all compositions claimed using the term “comprising” may include any additional additives, adjuvants, or compounds, whether polymerized or otherwise. In contrast, the term “substantially constitutes…” excludes any other components, steps, or procedures from any subsequently listed scope, except those that are not essential for operability. The term “consisting of…” excludes any ingredients, steps, or procedures not specifically described or listed.

[0034] This invention provides polyethylene compositions that can be used in films to provide desired and / or improved properties. In some embodiments, films formed from the polyethylene compositions of this invention provide improved dart impact resistance.

[0035] In one aspect, the polyethylene composition comprises:

[0036] (1) A first polyethylene fraction, wherein the first polyethylene fraction has a single peak in the elution curve obtained by an improved comonomer composition distribution (iCCD) analysis method in the temperature range of 50°C to 85°C, wherein the first polyethylene area fraction is the area below the single peak of the first polyethylene fraction in the elution curve between 50°C and 85°C, and wherein, when measured using the iCCD analysis method, the average M in the first polyethylene fraction is... w The range is from 100,000 g / mol to 225,000 g / mol;

[0037] (2) A second polyethylene fraction, wherein the second polyethylene fraction has a single peak in the elution curve obtained by the iCCD analysis method in the temperature range of 85°C to 100°C, wherein the second polyethylene area fraction is the area below the single peak of the second polyethylene fraction in the elution curve between 85°C and 100°C, and wherein, when measured using the iCCD analysis method, the average M in the second polyethylene fraction is... w From 30,000 g / mol to 60,000 g / mol; and

[0038] (3) A third polyethylene fraction, wherein the third polyethylene fraction has a single peak in the elution curve obtained by iCCD analysis in the temperature range of 100°C to 120°C, wherein the third polyethylene area fraction is the area below the single peak of the third polyethylene fraction in the elution curve between 100°C and 120°C, and wherein the average M in the third polyethylene fraction is measured using the iCCD analysis method. w The range is from 100,000 g / mol to 225,000 g / mol;

[0039] The first polyethylene area fraction accounts for 25% to 50% of the total area of ​​the elution curve, the second polyethylene area fraction accounts for 30% to 50% of the total area of ​​the elution curve, and the third polyethylene area fraction accounts for 15% to 35% of the total area of ​​the elution curve.

[0040] In some embodiments, the first polyethylene area fraction accounts for 30% to 45% of the total area of ​​the elution curve, the second polyethylene area fraction accounts for 35% to 45% of the total area of ​​the elution curve, and the third polyethylene area fraction accounts for 15% to 30% of the total area of ​​the elution curve. In some embodiments, the polyethylene composition has a concentration of 0.940 g / cm³. 3 Up to 0.949 g / cm 3 The overall density. In some embodiments, the polyethylene composition has a density of 0.941 g / cm³. 3 Up to 0.947 g / cm 3 The overall density. In some embodiments, the polyethylene composition has a melt index (I2) of 0.5 g / 10 min to 2 g / 10 min. In some embodiments, the polyethylene composition has a melt index (I2) of 0.8 g / 10 min to 1.1 g / 10 min.

[0041] In some embodiments, the polyethylene composition further comprises 20 ppm to 5000 ppm of a nucleating agent based on the total weight of the composition, wherein the nucleating agent comprises calcium 1,2-cyclohexanedicarboxylate or sodium 4-[(4-chlorobenzoyl)amino]benzoate.

[0042] In some embodiments, the polyethylene composition is a blend of the following substances:

[0043] (a) A first polyethylene component, the first polyethylene component comprising:

[0044] (1) 25% to 37% by weight of a first polyethylene fraction, the first polyethylene fraction having a content of 0.935 g / cm³. 3 Up to 0.947 g / cm 3Density within the range and melt index (I2) less than 0.1 g / 10 min; and

[0045] (2) 63% to 75% by weight of the second polyethylene fraction; and

[0046] When using 13 During C NMR measurement, the first polyethylene component has less than 0.10 branches per 1,000 carbon atoms, and the density of the first polyethylene component is at least 0.965 g / cm³. 3 And wherein the melt index (I2) of the first polyethylene component is 0.5 g / 10 min to 10 g / 10 min; and

[0047] (b) a second polyethylene component, the second polyethylene component comprising:

[0048] (1) A first polyethylene fraction, wherein the first polyethylene fraction has a single peak in the elution curve obtained by an improved comonomer composition distribution (iCCD) analysis method in the temperature range of 45°C to 87°C, wherein the first polyethylene area fraction is the area below the single peak of the first polyethylene fraction in the elution curve between 45°C and 87°C; and

[0049] (2) A second polyethylene fraction, wherein the second polyethylene fraction has a single peak in the elution curve obtained by iCCD analysis in the temperature range of 95°C to 120°C, and wherein the second polyethylene area fraction is the area below the single peak of the second polyethylene fraction in the elution curve between 95°C and 120°C.

[0050] The second polyethylene component has a content of 0.924 g / cm³. 3 Up to 0.936 g / cm 3 The density and melt index (I2) of the second polyethylene fraction are 0.25 g / 10 min to 2.0 g / 10 min, wherein the area of ​​the second polyethylene fraction of the second component accounts for at least 40% of the total area of ​​the elution curve, wherein the ratio of the area of ​​the first polyethylene fraction of the second component to the area of ​​the second polyethylene fraction of the second component is 0.75 to 2.5, and wherein the width of the single peak of the second polyethylene fraction of the second component at 50% peak height is less than 5.0 °C.

[0051] Based on the total weight of the polyethylene composition, the polyethylene composition comprises 30% to 60% by weight of the first polyethylene component and 40% to 70% by weight of the second polyethylene component. Additional details regarding various embodiments of the first polyethylene component are provided in the following first polyethylene component section. Additional details regarding various embodiments of the second polyethylene component are provided in the following second polyethylene component section.

[0052] In some embodiments, a monolayer film formed of a polyethylene composition and having a thickness of 3 to 4 mil exhibits a normalized dart impact of at least 110 g / mil. In some embodiments, a monolayer film formed of a polyethylene composition and having a thickness of 3 to 4 mil exhibits a normalized dart impact of up to 200 g / mil.

[0053] The present invention also relates to membranes. In one aspect, the membrane comprises any of the polyethylene compositions of the present invention disclosed herein. In another aspect, the present invention also relates to articles, such as packaging. In one aspect, the article comprises any of the polyethylene compositions of the present invention disclosed herein. In another aspect, the article comprises any of the films of the present invention disclosed herein.

[0054] In another respect, the present invention relates to articles, such as packaging. In one aspect, the articles comprise any of the multilayer films of the present invention disclosed herein.

[0055] iCCD elution curves of polyethylene compositions

[0056] In some embodiments, the polyethylene compositions of the present invention are characterized by their elution profiles obtained by an improved comonomer composition distribution (iCCD) analytical method. In one embodiment, the polyethylene composition comprises:

[0057] (1) A first polyethylene fraction, wherein the first polyethylene fraction has a single peak in the elution curve obtained by an improved comonomer composition distribution (iCCD) analysis method in the temperature range of 50°C to 85°C, wherein the first polyethylene area fraction is the area below the single peak of the first polyethylene fraction in the elution curve between 50°C and 85°C, and wherein, when measured using the iCCD analysis method, the average M in the first polyethylene fraction is... w The range is from 100,000 g / mol to 225,000 g / mol;

[0058] (2) A second polyethylene fraction, wherein the second polyethylene fraction has a single peak in the elution curve obtained by the iCCD analysis method in the temperature range of 85°C to 100°C, wherein the second polyethylene area fraction is the area below the single peak of the second polyethylene fraction in the elution curve between 85°C and 100°C, and wherein, when measured using the iCCD analysis method, the average M in the second polyethylene fraction is... w From 30,000 g / mol to 60,000 g / mol; and

[0059] (3) A third polyethylene fraction, wherein the third polyethylene fraction has a single peak in the elution curve obtained by iCCD analysis in the temperature range of 100°C to 120°C, wherein the third polyethylene area fraction is the area below the single peak of the third polyethylene fraction in the elution curve between 100°C and 120°C, and wherein the average M in the third polyethylene fraction is measured using the iCCD analysis method. w The range is from 100,000 g / mol to 225,000 g / mol;

[0060] The first polyethylene area fraction accounts for 25% to 50% of the total area of ​​the elution curve, the second polyethylene area fraction accounts for 30% to 50% of the total area of ​​the elution curve, and the third polyethylene area fraction accounts for 15% to 35% of the total area of ​​the elution curve.

[0061] Referring to the described iCCD distribution, Figure 1 The sample iCCD distribution 5 and the cumulative weight fraction curve 10 are schematically depicted. Figure 1 This roughly depicts several characteristics of the iCCD curves of the polyethylene compositions discussed in detail in this paper, such as the first fraction, second fraction, and third peak fraction. Therefore, Figure 1 This can be used as a reference regarding publicly available information related to the iCCD curves provided herein. Specifically, the first fraction 12, the second fraction 16, and the third fraction 20 are depicted. The first fraction 12 has peak 14, the second fraction 106 has peak 18, and the third fraction has peak 22. It should be understood that... Figure 1 The curves are not derived from experiments or observations, but rather provide information for the purpose of describing specific characteristics of iCCD elution curves.

[0062] In one or more embodiments, the first polyethylene fraction of the polyethylene composition may have a single peak in the elution profile obtained by iCCD within a temperature range of 50°C to 85°C. In one or more embodiments, the single peak of the first polyethylene fraction may be within a temperature range of 60°C to 85°C, such as 70°C to 85°C. When measured using iCCD analytical methods, the weight-average molecular weight (M) of the first polyethylene fraction is... w The concentration of polyethylene (PE) is from 100,000 g / mol to 225,000 g / mol. In some embodiments, the first polyethylene area fraction accounts for 25% to 50% of the total area of ​​the elution curve. In some embodiments, the first polyethylene area fraction accounts for 30% to 45% of the total area of ​​the elution curve.

[0063] It should be understood that peaks in the first, second, or third polyethylene fraction may not be formed by local minima in the corresponding polyethylene fraction at defined temperature boundaries. That is, the peaks must be peaks across the entire spectral range, not peaks formed by the threshold temperature of the polyethylene fraction. For example, if a polyethylene fraction contains a single peak followed by a single valley (sloping upwards, then downwards, then upwards again), then only a single peak will exist in such a polyethylene fraction.

[0064] In one or more embodiments, the second polyethylene fraction of the polyethylene composition may have a single peak in the elution profile obtained by iCCD within a temperature range of 85°C to 100°C. In one or more embodiments, the single peak of the first polyethylene fraction may be within a temperature range of 90°C to 100°C. When measured using iCCD analytical methods, the weight-average molecular weight (M) of the second polyethylene fraction... w The concentration of polyethylene (PE) is 30,000 g / mol to 60,000 g / mol. In some embodiments, the area fraction of the second polyethylene accounts for 30% to 50% of the total area of ​​the elution curve. In some embodiments, the area fraction of the second polyethylene accounts for 35% to 45% of the total area of ​​the elution curve.

[0065] In one or more embodiments, the third polyethylene fraction of the polyethylene composition may have a single peak in the elution profile obtained by iCCD within a temperature range of 100°C and 120°C. In one or more embodiments, the single peak of the first polyethylene fraction may be in the temperature range of 100°C to 110°C. When measured using iCCD analytical methods, the weight-average molecular weight (M) of the third polyethylene fraction... w The concentration of polyethylene (PE) is 100,000 g / mol to 225,000 g / mol. In some embodiments, the area fraction of PE accounts for 15% to 35% of the total area of ​​the elution curve.

[0066] In the embodiments described herein, the area of ​​the first polyethylene fraction is the area below the single peak of the first polyethylene fraction in the elution curve between 50°C and 85°C. Similarly, the area of ​​the second polyethylene fraction is the area below the single peak of the second polyethylene fraction in the elution curve between 85°C and 100°C. The area of ​​the third polyethylene fraction is the area below the single peak of the third polyethylene fraction in the elution curve between 100°C and 120°C. The areas of the first, second, and third polyethylene fractions typically correspond to the total relative mass of each polymer fraction in the polyethylene composition. Generally, the area of ​​the polyethylene fraction in the iCCD curve can be determined by integrating the iCCD curve between specified start and end temperatures. In some embodiments, the first polyethylene area fraction accounts for 25% to 50% of the total area of ​​the elution curve, the second polyethylene area fraction accounts for 30% to 50% of the total area of ​​the elution curve, and the third polyethylene area fraction accounts for 15% to 35% of the total area of ​​the elution curve. In some embodiments, the first polyethylene area fraction accounts for 30% to 45% of the total area of ​​the elution curve, the second polyethylene area fraction accounts for 35% to 45% of the total area of ​​the elution curve, and the third polyethylene area fraction accounts for 15% to 30% of the total area of ​​the elution curve.

[0067] In some embodiments of the present invention, a polyethylene composition having the elution curves (a first polyethylene area fraction between 50°C and 85°C, a second polyethylene fraction area between 85°C and 100°C, and a third polyethylene fraction area between 100°C and 120°C, as described above) obtained by an improved comonomer composition distribution (iCCD) analysis method may be formed from a blend of a first polyethylene component (described below) and a second polyethylene component (described below).

[0068] First polyethylene component

[0069] As described above, the polyethylene composition of the present invention comprises a first polyethylene component having certain properties. The first polyethylene component used in embodiments of the present invention comprises (i) 25% to 37% by weight of a first polyethylene fraction having a first polyethylene fraction having a density of 0.935 g / cm³. 3 Up to 0.947 g / cm 3 (ii) a density within the range and a melt index (I2) of less than 0.1 g / 10 min; and (ii) a second polyethylene fraction of 63 wt% to 75 wt%, wherein when using 13 During C NMR measurement, the first polyethylene component has less than 0.10 branches per 1,000 carbon atoms, and the density of the first polyethylene component is at least 0.965 g / cm³. 3 And the melt index (I2) of the first polyethylene component is 0.5 g / 10 min to 10 g / 10 min.

[0070] In some implementations, the first polyethylene component has a melt index (I2) of 2.5 g / 10 min or less.

[0071] In some embodiments, the first polyethylene component comprises 25% to 37% by weight of a material with a density of 0.940 g / cm³. 3 Up to 0.947 g / cm 3 The first polyethylene fraction within the range and 63% to 75% by weight have a density of 0.970 g / cm³. 3 Or a larger second polyethylene fraction.

[0072] The first polyethylene component may comprise a combination of two or more embodiments as described herein.

[0073] In one embodiment, the first polyethylene component has a content of at least 0.965 g / cm³. 3 The density. In some embodiments, the first polyethylene component has a density of at least 0.968 g / cm³. 3 The density. In some embodiments, the first polyethylene component has a density of up to 0.976 g / cm³. 3 The density. In some embodiments, the first polyethylene component has a density of 0.965 g / cm³. 3 Up to 0.976 g / cm 3 For example, 0.965 g / cm³ 3 Up to 0.970 g / cm 3 , or 0.967 g / cm 3 Up to 0.969 g / cm 3 , or 0.965g / cm 3 Up to 0.970 g / cm 3 Density within a certain range. For example, the density could be 0.965 g / cm³. 3 Or 0.967 g / cm 3 The lower limit is 0.970 g / cm³. 3 0.972 g / cm 3 0.975g / cm 3 Or 0.976 g / cm 3 The upper limit.

[0074] The first polyethylene component has a melt index (I2 or I2; at 190°C / 2.16 kg) of 0.5 g / 10 min to 10 g / 10 min. For example, the melt index (I2 or I2; at 190°C / 2.16 kg) can be from a lower limit of 0.5 g / 10 min, 0.7 g / 10 min, 0.9 g / 10 min, 1.0 g / 10 min, 1.1 g / 10 min, 1.2 g / 10 min, 1.5 g / 10 min, 2 g / 10 min, 3 g / 10 min, 4 g / 10 min or 5 g / 10 min to an upper limit of 1.5 g / 10 min, 2 g / 10 min, 2.5 g / 10 min, 3 g / 10 min, 4 g / 10 min, 5 g / 10 min, 6 g / 10 min, 7 g / 10 min, 8 g / 10 min, 9 g / 10 min or 10 g / 10 min. In some embodiments, the first polyethylene component has a melt index (I2) of 0.5 g / 10 min to 5 g / 10 min, or 0.5 g / 10 min to 2.5 g / 10 min, or 0.7 g / 10 min to 3 g / 10 min, or 1.0 g / 10 min to 2.0 g / 10 min, or 1.0 g / 10 min to 1.5 g / 10 min.

[0075] In some implementations, the melt index ratio of the first polyethylene component is (I 10 / I2) is 10 or greater. In some embodiments, the melt index ratio (I / I2) of the first polyethylene component is 10 or greater. 10 / I2) is at most 17. In some embodiments, the melt index ratio (I) of the first polyethylene component is... 10 The melt index ratio (I2) is 10 to 17. In some embodiments, the melt index ratio (I2) of the first polyethylene component is... 10 / I2) is 12 to 17.

[0076] The first polyethylene component has a low level of branching. In some embodiments, when using 13 During CNMR measurements, the first polyethylene component has fewer than 0.10 branches per 1,000 carbon atoms. In some embodiments, when using 13 During C NMR measurements, the first polyethylene component has fewer than 0.07 branches per 1,000 carbon atoms. In some embodiments, when using 13 During C NMR measurements, the first polyethylene component has fewer than 0.05 branches per 1,000 carbon atoms. In some embodiments, when using 13 During C NMR measurements, the first polyethylene component had fewer than 0.03 branches per 1,000 carbon atoms.

[0077] In some embodiments, the first polyethylene component has a low level of non-vinyl unsaturation. In some embodiments, when using1 When measured by 1H NMR, the first polyethylene component has less than 25 non-vinyl unsaturations per million carbon atoms. In some embodiments, when using 1 When measured by HNMR, the first polyethylene component has less than 20 non-vinyl unsaturations per million carbon atoms.

[0078] In one embodiment, the first polyethylene component has a zero shear viscosity ratio (ZSVR) value of less than 2.0, or 1.0 to 2.0, or 1.2 to 1.8, or 1.3 to 1.7.

[0079] In one embodiment, the first polyethylene component has a molecular weight distribution in the range of 8.0 to 14.0, expressed as the ratio of weight-average molecular weight to number-average molecular weight (M). w / M n (Measured by conventional GPC). For example, this molecular weight distribution (M... w / M n The value can be a lower limit of 8.0, 8.5, 9.0, or 9.5 to an upper limit of 10.0, 11.0, 11.5, 12.0, 12.5, 13.0, 13.5, or 14.0. In some implementations, M... w / M n The range is from 10.0 to 12.0.

[0080] In one embodiment, the number-average molecular weight (M) of the first polyethylene component n (As determined by conventional GPC) in the range of 8,000 g / mol to 20,000 g / mol. For example, the number-average molecular weight can be from the lower limit of 8,000 g / mol, 9,000 g / mol, 10,000 g / mol or 11,000 g / mol to the upper limit of 12,000 g / mol, 13,000 g / mol, 15,000 g / mol or 20,000 g / mol.

[0081] In one embodiment, the weight-average molecular weight (M) of the first polyethylene component w (As determined by conventional GPC) in the range of 100,000 g / mol to 125,000 g / mol. For example, the weight-average molecular weight can be from a lower limit of 100,000 g / mol, 105,000 g / mol or 110,000 g / mol to an upper limit of 115,000 g / mol, 120,000 g / mol or 124,000 g / mol.

[0082] In one embodiment, the z-average molecular weight (M) of the first polyethylene component Z(As determined by conventional GPC) is at least 350,000 g / mol, such as in the range of 350,000 g / mol to 600,000 g / mol. For example, the z-average molecular weight can be from a lower limit of 350,000 g / mol, 375,000 g / mol, 400,000 g / mol, 405,000 g / mol or 410,000 g / mol to an upper limit of 420,000 g / mol, 425,000 g / mol, 450,000 g / mol, 475,000 g / mol, 500,000 g / mol, 550,000 g / mol or 600,000 g / mol.

[0083] In one embodiment, M of the first polyethylene component z / M w The ratio (each as determined by conventional GPC) is greater than 3.0. In some embodiments, the M of the first polyethylene component... z / M w The ratio (each as determined by conventional GPC) is greater than 3.5. In some embodiments, M z / M w It can be 3.0 to 4.0, or in some implementations it is 3.5 to 4.5, or in some implementations it is 3.5 to 4.0.

[0084] In one embodiment, the ZSVR of the first polyethylene component is less than 2.0 and M z / M w The ratio (each as determined by conventional GPC) is greater than 3.0. In another embodiment, the ZSVR of the first polyethylene component is less than 2.0 and M z / M w The ratio (each as determined by conventional GPC) is greater than 3.5.

[0085] The first polyethylene component preferably comprises an ethylene-based polymer formed in the absence of a comonomer. In some embodiments, the first polyethylene component comprises at least 99% by weight of an ethylene-based polymer formed in the absence of a comonomer. In some embodiments, the first polyethylene component comprises at least 99% by weight of a polymer comprising a majority amount (>99 mol%) of units derived from ethylene monomers.

[0086] The first polyethylene component contains two polyethylene grades.

[0087] The first polyethylene grade has a content of 0.935 g / cm³. 3 Up to 0.947 g / cm 3 The density. In some embodiments, the first polyethylene fraction has a density of 0.940 g / cm³. 3 Up to 0.947 g / cm3 The density. The melt index (I2) of the first polyethylene fraction is less than 0.1 g / 10 min. In some embodiments, the melt index (I2) of the first polyethylene fraction is 0.01 g / 10 min or greater. In some embodiments, the first polyethylene fraction has a melt index of 0.05 g / 10 min to 0.1 g / 10 min. In some embodiments, when using 13 During C NMR measurements, the first polyethylene fraction had fewer than 0.10 branches per 1,000 carbon atoms.

[0088] In some embodiments, the ethylene-based polymer has a concentration of 0.970 g / cm³. 3 Or higher density. In some embodiments, the first polyethylene fraction has a density of 0.940 g / cm³. 3 Up to 0.947 g / cm 3 The density of the second polyethylene fraction is 0.970 g / cm³. 3 Or a higher density. In some embodiments, the melt index (I2) of the second polyethylene fraction is at least 100 g / 10 min. In some embodiments, the melt index (I2) of the second polyethylene fraction is at least 100 g / 10 min and at most 10,000 g / 10 min or higher. In some embodiments, the second polyethylene fraction has a melt index (I2) of at least 100 g / 10 min and at most 10,000 g / 10 min. In some embodiments, the second polyethylene fraction has a melt index (I2) of at least 100 g / 10 min and at most 1,000 g / 10 min.

[0089] In some embodiments, the ratio of the melt index (I2) of the second polyethylene fraction to the melt index (I2) of the first polyethylene fraction is at least 1,000.

[0090] Based on the total weight of the first polyethylene component, the first polyethylene component comprises 25% to 37% by weight of a first polyethylene fraction and 63% to 75% by weight of a second polyethylene fraction. In some embodiments, based on the total weight of the first polyethylene component, the first polyethylene component comprises 30% to 37% by weight of a first polyethylene fraction and 63% to 70% by weight of a second polyethylene fraction.

[0091] The following discussion focuses on the preparation of the first polyethylene component used in embodiments of the present invention.

[0092] polymerization

[0093] The first polyethylene component can be produced using any conventional polymerization method. Such conventional polymerization methods include, but are not limited to, slurry polymerization methods and solution polymerization methods using one or more conventional reactors, such as loop reactors in parallel or in series, isothermal reactors, stirred tank reactors, batch reactors, and / or any combination thereof. The first polyethylene component can be produced, for example, by solution-phase polymerization methods using one or more loop reactors, isothermal reactors, and combinations thereof.

[0094] Typically, solution-phase polymerization occurs in one or more well-mixed reactors, such as one or more isothermal loop reactors and / or one or more adiabatic reactors, at temperatures ranging from 115°C to 250°C; for example, from 115°C to 200°C, and at pressures ranging from 300 psi to 1,000 psi; for example, from 400 psi to 750 psi, in one or more well-stirred reactors (such as one or more loop reactors). In one embodiment, in a dual-reactor configuration, the temperature in the first reactor is in the range of 115°C to 190°C (e.g., 115°C to 175°C), while the temperature in the second reactor is in the range of 150°C to 250°C (e.g., 130°C to 165°C). In another embodiment, in a single reactor, the temperature in the reactor is in the range of 115°C to 250°C (e.g., 115°C to 225°C).

[0095] Residence times in solution-phase polymerization are typically between 2 and 30 minutes; for example, between 10 and 20 minutes. Ethylene, solvent, hydrogen, one or more catalyst systems, optionally one or more cocatalysts, and optionally one or more comonomers are continuously fed into one or more reactors. Exemplary solvents include, but are not limited to, isoparaffins. For example, such solvents may be available under the name ISOPAR E from ExxonMobil Chemical Co., Houston, Texas. The resulting mixture of the first polyethylene component and solvent is then removed from the reactor, and the first polyethylene component is separated. The solvent is typically recovered via a solvent recovery unit (i.e., a heat exchanger and a vapor-liquid separator drum) and subsequently recycled back into the polymerization system.

[0096] In one embodiment, the first polyethylene component can be produced by solution polymerization in a dual-reactor system, such as a dual-loop reactor system, wherein ethylene is polymerized in the presence of one or more catalyst systems. In some embodiments, only ethylene is polymerized. Additionally, one or more co-catalysts may be present. In another embodiment, the first polyethylene component can be produced by solution polymerization in a single-reactor system, such as a single-loop reactor system, wherein ethylene is polymerized in the presence of two catalyst systems. In some embodiments, only ethylene is polymerized.

[0097] catalyst system

[0098] Specific embodiments of the catalyst system that can be used to produce the first polyethylene component described herein will now be described. It should be understood that the catalyst system of this disclosure may be embodied in different forms and should not be construed as limited to the specific embodiments set forth in this disclosure. Rather, the provision of embodiments makes this disclosure thorough and complete, and the embodiments will fully convey the scope of the subject matter to those skilled in the art.

[0099] The term "independently chosen" is used in this document to indicate R groups (such as R...). 1 R 2 R 3 R 4 and R 5 ) can be the same or different (e.g., R) 1 R 2 R 3 R 4 and R 5 Both can be substituted alkyl groups, or R 1 and R 2 It can be a substituted alkyl group and R 3 (This can be aryl, etc.). The use of the singular form includes the use of the plural form, and vice versa (e.g., hexane solvent includes various hexanes). The named R group will generally have a structure recognized in the art as corresponding to the R group having that name. These definitions are intended to supplement and illustrate, rather than exclude, definitions known to those skilled in the art.

[0100] The term "procatalyst" refers to a compound that exhibits catalytic activity when combined with an activator. The term "activator" refers to a compound that chemically reacts with the procatalyst in a manner that converts the procatalyst into a catalytically active catalyst. As used herein, the terms "co-catalyst" and "activator" are interchangeable.

[0101] When used to describe certain carbon-containing chemical groups, it has the form "(C x -C y The insertion of ")" indicates that the unsubstituted form of the chemical group has x to y carbon atoms, including both x and y. For example, (C1-C 40 Alkyl groups are alkyl groups having 1 to 40 carbon atoms in their unsubstituted form. In some embodiments and general structures, certain chemical groups may be substituted by one or more substituents such as RS. The parenthetical phrase "(C x -C y The chemical group defined by )” is R S The substituted version can contain more than y carbon atoms, depending on any group R.S The identity. For example, "using exactly one group R..." S Replacement (C1-C) 40 ) alkyl, wherein R S "Phenyl (-C6H5)" can contain 7 to 46 carbon atoms. Therefore, it is common practice to use "(C6H5)" when referring to phenyl groups. x -C y The inserted chemical group is replaced by one or more carbon-containing substituents R. S During substitution, both x and y are added with substituents R from all carbon atoms. S The minimum and maximum total number of carbon atoms in a chemical group are determined by the sum of the combinations of carbon atoms.

[0102] The term "substitution" means that at least one hydrogen atom (-H) bonded to a carbon atom or heteroatom in the corresponding unsubstituted compound or functional group is substituted by a substituent (e.g., R). S Substitution. The term "total substitution" means that each hydrogen atom (H) bonded to the carbon atom or heteroatom of the corresponding unsubstituted compound or functional group is replaced by a substituent (e.g., R). S Substitution. The term "multi-substitution" means that at least two, but fewer than all, hydrogen atoms bonded to the corresponding unsubstituted carbon or heteroatom of a compound or functional group are replaced by substituents.

[0103] The term "-H" refers to a hydrogen atom or a hydrogen group covalently bonded to another atom. "Hydrogen" and "-H" are interchangeable and have the same meaning unless explicitly stated otherwise.

[0104] The term "(C1-C)" 40 "(C1-C) hydrocarbon group" refers to a hydrocarbon group having 1 to 40 carbon atoms, and the term "(C1-C) hydrocarbon group" is used in conjunction with other hydrocarbon groups. 40 "Hydroalkylene" refers to a hydrocarbon diester having 1 to 40 carbon atoms, wherein each hydrocarbon group and each hydrocarbon diester is aromatic or non-aromatic, saturated or unsaturated, straight or branched, cyclic (including monocyclic and polycyclic, fused and non-fused polycyclic, including bicyclic; 3 or more carbon atoms) or acyclic, and is not substituted or surrounded by one or more R groups. S replace.

[0105] In this disclosure, (C1-C 40 The hydrocarbon group can be unsubstituted or substituted (C1-C2). 40 )alkyl, (C3-C 40 )cycloalkyl, (C3–C 20 )cycloalkyl-(C1-C 20 )alkylene, (C6-C 40 ) aryl or (C6-C 20 )aryl-(C1-C 20) alkylene. In some embodiments, the aforementioned (C1-C 40 Each of the hydrocarbon groups has a maximum of 20 carbon atoms (i.e., (C1-C2)). 20 (hydrocarbon group), and in each embodiment, has a maximum of 12 carbon atoms.

[0106] The term "(C1-C)" 40 alkyl and (C1-C) 18 "alkyl" refers to a saturated straight-chain or branched hydrocarbon group having 1 to 40 carbon atoms or 1 to 18 carbon atoms, which is either unsubstituted or substituted by one or more RS groups. Unsubstituted (C1-C2) 40 Examples of alkyl groups are unsubstituted (C1-C1) alkyl groups. 20 )alkyl; unsubstituted (C1-C 10 Alkyl; unsubstituted (C1-C5)alkyl; methyl; ethyl; 1-propyl; 2-propyl; 1-butyl; 2-butyl; 2-methylpropyl; 1,1-dimethylethyl; 1-pentyl; 1-hexyl; 1-heptyl; 1-nonyl; and 1-decyl. Substituted (C1-C5)alkyl 40 Examples of alkyl groups are substituted (C1-C2) 20 )alkyl, substituted (C1-C 10 )alkyl, trifluoromethyl and [C 45 Alkyl group. The term "[C]" 45 Alkyl (in square brackets) means that the group (including substituents) contains a maximum of 45 carbon atoms, and is, for example, divided by an R S Replacement (C) 27 -C 40 )alkyl, the R S It is a (C1-C5) alkyl group. Each (C1-C5) alkyl group can be methyl, trifluoromethyl, ethyl, 1-propyl, 1-methylethyl or 1,1-dimethylethyl.

[0107] The term "(C6-C)" 40 "Aryl" refers to an unsubstituted or substituted compound with 6 to 40 carbon atoms (one or more R groups). S A substituted monocyclic, bicyclic, or tricyclic aromatic hydrocarbon group, wherein at least 6 to 14 carbon atoms of the aromatic hydrocarbon group are aromatic ring carbon atoms, and the monocyclic, bicyclic, or tricyclic group comprises 1, 2, or 3 rings, respectively; wherein one ring is an aromatic ring, and the 2 or 3 rings are independently fused or non-fused rings, and at least one of the 2 or 3 rings is an aromatic ring. Unsubstituted (C6-C) 40 An example of an aryl group is the unsubstituted (C6-C) 20 ) aryl; unsubstituted (C6-C 18) aryl; 2-(C1-C5)alkyl-phenyl; 2,4-bis(C1-C5)alkyl-phenyl; phenyl; fluorenyl; tetrahydrofluorenyl; dicyclopentadienylphenyl; hexahydrodicyclopentadienylphenyl; indene; dihydroindene; naphthyl; tetrahydronaphthyl; and phenanthrene. Substituted (C6-C 40 Examples of aryl groups are substituted (C1-C) 20 ) aryl; substituted (C6-C 18 )aryl; 2,4-bis[(C 20 [alkyl]-phenyl; polyfluorophenyl; pentafluorophenyl; and fluorene-9-one-1-yl.

[0108] The term "(C3-C)" 40 "Cycloalkyl" refers to a saturated cyclic hydrocarbon group with 3 to 40 carbon atoms that is not substituted or is surrounded by one or more R groups. S Substitution. Other cycloalkyl groups (e.g., (C x -C y Cycloalkyl groups are defined in a similar manner as having x to y carbon atoms and being unsubstituted or derived from one or more R groups. S Replaced. Unreplaced (C3-C) 40 Examples of cycloalkyl groups are unsubstituted (C3–C4) cycloalkyl groups. 20 )cycloalkyl, unsubstituted (C3–C 10 Cycloalkyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, and cyclodecyl. Substituted (C3-C) 40 Examples of cycloalkyl groups are substituted (C3-C4) 20 )cycloalkyl, substituted (C3-C 10 )cycloalkyl, cyclopentanone-2-yl and 1-fluorocyclohexyl.

[0109] (C1-C 40 Examples of alkylene groups include unsubstituted or substituted (C6-C) groups. 40 ()Asyl, (C3-C 40 )cycloalkylene and (C1-C 40 )alkylene (e.g., (C1-C 20 (alkylene). In some embodiments, the bimolecular group is located on the same carbon atom (e.g., -CH2-) or on adjacent carbon atoms (i.e., 1,2-bimolecular group), or separated by one, two, or more than two intercalary carbon atoms (e.g., the corresponding 1,3-bimolecular, 1,4-bimolecular, etc.). Some bimolecular groups include α,ω-bimolecular groups. α,ω-bimolecular groups are bimolecular groups with the largest intercarbon backbone spacing between the group carbons. (C2-C) 20Some examples of alkylene α,ω-bisyl groups include ethyl-1,2-diyl (i.e., -CH2CH2-), propan-1,3-diyl (i.e., -CH2CH2CH2-), and 2-methylpropan-1,3-diyl (i.e., -CH2CH(CH3)CH2-). (C6-C) 50 Some examples of arylene α,ω-dimethyl groups include phenyl-1,4-dimethyl, naphth-2,6-dimethyl, or naphth-3,7-dimethyl.

[0110] The term "(C1-C)" 40 "Alkylene" means an unsubstituted or compounded alkylene with 1 to 40 carbon atoms. S Substituted saturated straight-chain or branched divalent groups (i.e., the divalent group is not on a ring atom). Unsubstituted (C1-C) 50 Examples of alkylene groups are unsubstituted (C1-C1) 20 Alkylenes, including unsubstituted -CH2CH2-, -(CH2)3-, -(CH2)4-, -(CH2)5-, -(CH2)6-, -(CH2)7-, -(CH2)8-, -CH2C*HCH3 and -(CH2)4C*(H)(CH3), where "C*" indicates the carbon atom from which a hydrogen atom is removed to form a secondary or tertiary alkyl group. Substituted (C1-C 50 Examples of alkylene groups are substituted (C1-C2) 20 Alkylene, -CF2-, -C(O)-, and -(CH2) 14 C(CH3)2(CH2)5- (i.e., 6,6-dimethyl-substituted n-1,20-eicosene). As previously mentioned, the two R... S They can combine to form (C1-C) 18 )alkylene, substituted (C1-C 50 Examples of alkylene groups also include 1,2-bis(methylene)cyclopentane, 1,2-bis(methylene)cyclohexane, 2,3-bis(methylene)-7,7-dimethyl-bicyclo[2.2.1]heptane and 2,3-bis(methylene)bicyclo[2.2.2]octane.

[0111] The term "(C3-C)" 40 "Cycloalkylene" means an unsubstituted or compounded alkylene oxide having 3 to 40 carbon atoms. S Substituted cyclic bimolecular groups (i.e., groups on ring atoms).

[0112] The term "heteroatom" refers to an atom other than hydrogen or carbon. Examples of heteroatoms include O, S, S(O), S(O)₂, and Si(R). C 2. P(R) P ), N(R N–N=C(R) C )2、–Ge(R C )2– or –Si(R C )–, where each R C Each R N and each R P It is unreplaced (C1-C) 18 The term "heterohydrocarbon" refers to a molecule or molecular framework in which one or more carbon atoms are replaced by heteroatoms. The term "(C1-C)" is used in conjunction with the hydrocarbon group or -H. 40 "(C1-C4)" refers to a heterohydrocarbon group having 1 to 40 carbon atoms, and the term "(C1-C4)" is used in conjunction with the meaning of "(C1-C4)" in this context. 40 "Hydroalkyl group" refers to a heteroalkyl bibase having 1 to 40 carbon atoms, and each heteroalkyl group has one or more heteroatoms. The bibase of the heteroalkyl group is located on a carbon atom or a heteroatom, and the bibase of the heteroalkyl group can be located on: (1) one or two carbon atoms, (2) one or two heteroatoms, or (3) a carbon atom and a heteroatom. Each (C1-C 50 ) heterohydrocarbon groups and (C1-C 50 The heteroalkyl group can be unsubstituted or (substituted by one or more R groups). S Substituted, aromatic or non-aromatic, saturated or unsaturated, straight or branched, cyclic (including monocyclic and polycyclic, fused and non-fused polycyclic) or acyclic.

[0113] (C1-C 40 Heteroalkyl groups can be unsubstituted or substituted (C1-C2). 40 (heteroalkyl, (C1-C) 40 )hydrocarbon group -O-, (C1-C 40 )hydrocarbon group -S-, (C1-C 40 )hydrocarbon group -S(O)-, (C1-C 40 )hydrocarbon group -S(O)2-, (C1-C 40 )hydrocarbon-Si(R C )2-、(C1-C 40 )hydrocarbon-N(R N )-、(C1-C 40 )hydrocarbon-P(R P )-、(C2-C 40 Heterocyclic alkyl groups, (C2-C 19 Heterocyclic alkyl-(C1-C) 20 )alkylene, (C3-C 20 )cycloalkyl-(C1-C 19 )heteroalkylene, (C2-C 19 Heterocyclic alkyl-(C1-C) 20 )heteroalkylene, (C1-C 40() heteroaryl, (C1-C 19 ) heteroaryl-(C1-C 20 )alkylene, (C6-C 20 )aryl-(C1-C 19 )heteroalkylene or (C1-C 19 ) heteroaryl-(C1-C 20 ) Heteroalkylene.

[0114] The term "(C4-C)" 40 "Heteroaryl" refers to an unsubstituted or modified (one or more R) aryl group having a total carbon number of 4 to 40 and a total heteroatom number of 1 to 10. S The substituted monocyclic, bicyclic, or tricyclic heteroaromatic hydrocarbon group comprises one, two, or three rings, respectively; wherein two or three rings are independently fused or unfused, and at least one of the two or three rings is heteroaromatic. Other heteroaryl groups (e.g., typically (C...) x -C y ) heteroaryl, such as (C4-C 12 (Heteroaryl) is defined in a similar manner as having x to y carbon atoms (e.g., 4 to 12 carbon atoms) and being unsubstituted or converted by one or more R atoms. SSubstituted. Monocyclic heteroaromatic hydrocarbon groups are 5- or 6-membered rings. A 5-membered ring has 5 minus h carbon atoms, where h is the number of heteroatoms and can be 1, 2, or 3; and each heteroatom can be O, S, N, or P. Examples of 5-membered heteroaromatic hydrocarbon groups are pyrrolo-1-yl; piperidin-2-yl; furan-3-yl; thiophene-2-yl; pyrazol-1-yl; isoxazol-2-yl; isothiazol-5-yl; imidazole-2-yl; oxazol-4-yl; thiazol-2-yl; 1,2,4-triazol-1-yl; 1,3,4-oxadiazol-2-yl; 1,3,4-thiadiazol-2-yl; tetrazol-1-yl; tetrazol-2-yl; and tetrazol-5-yl. A 6-membered ring has 6 minus h carbon atoms, where h is the number of heteroatoms and can be 1 or 2, and the heteroatom can be N or P. Examples of 6-membered ring heteroaromatic hydrocarbon groups are pyridin-2-yl; pyrimidin-2-yl; and pyrazin-2-yl. Bicyclic heteroaromatic hydrocarbon groups can be fused 5,6- or 6,6-cyclic systems. Examples of fused 5,6-cyclic bicyclic heteroaromatic hydrocarbon groups are indol-1-yl; and benzimidazol-1-yl. Examples of fused 6,6-cyclic bicyclic heteroaromatic hydrocarbon groups are quinoline-2-yl; and isoquinoline-1-yl. Bicyclic heteroaromatic hydrocarbon groups can be fused 5,6,5-cyclic systems; 5,6,6-cyclic systems; 6,5,6-cyclic systems; or 6,6,6-cyclic systems. An example of a fused 5,6,5-cyclic system is 1,7-dihydropyrrolo[3,2-f]indol-1-yl. An example of a fused 5,6,6-cyclic system is 1H-benzo[f]indol-1-yl. An example of a fused 6,5,6-cyclic system is 9H-carbazole-9-yl. An example of a fused 6,5,6-cyclic system is 9H-carbazole-9-yl. An example of a fused 6,6,6-cyclic system is acridine-9-yl.

[0115] The aforementioned heteroalkyl group may contain (C1–C1) 50 A saturated straight-chain or branched group containing one or fewer carbon atoms and one or more heteroatoms. Similarly, a heteroalkylene group can be a saturated straight-chain or branched bimolecular group containing 1 to 50 carbon atoms and one or more heteroatoms. Heteratoms as defined above can include Si(R) C 3. Ge(R) C 3. Si(R) C )2、Ge(R C 2. P(R) P 2. P(R) P ), N(R N )2、N(R N ), N, O, OR C , S, SR C S(O) and S(O)2, wherein each of the heteroalkyl and heteroalkylene groups is unsubstituted or is formed by one or more R groups. S replace.

[0116] Unreplaced (C2-C) 40 Examples of heterocyclic alkyl groups are unsubstituted (C2-C) 20 Heterocyclic alkyl groups, unsubstituted (C2-C) 10 Heterocyclic alkyl groups, aziridin-1-yl, oxetane-2-yl, tetrahydrofuran-3-yl, pyrrolidine-1-yl, tetrahydrothiophene-S,S-dioxo-2-yl, morpholin-4-yl, 1,4-dioxane-2-yl, hexahydroacetane-4-yl, 3-oxacyclooctyl, 5-thiocyclononyl, and 2-azacyclodecyl.

[0117] The term "halogen atom" or "halogen" refers to a free radical of a fluorine atom (F), chlorine atom (Cl), bromine atom (Br), or iodine atom (I). The term "halide" refers to the anionic form of a halogen atom: fluoride ion (F-), chloride ion (Cl-), bromide ion (Br-), or iodide ion (I-).

[0118] The term "saturated" refers to the absence of carbon-carbon double bonds, carbon-carbon triple bonds, and (in heteroatom-containing groups) carbon-nitrogen, carbon-phosphorus, and carbon-silicon double bonds. In saturated chemical groups, the presence of one or more substituents R... S In the case of substitution, one or more double and / or triple bonds may or may not be present in the substituent R. S In Chinese, the term "unsaturated" means containing one or more carbon-carbon double bonds, carbon-carbon triple bonds, and (in heteroatom-containing groups) carbon-nitrogen, carbon-phosphorus, and carbon-silicon double bonds, excluding those that may exist in substituents R. S (If present) any such double bond in or that may exist in (hetero)aromatic rings (if present).

[0119] According to some embodiments, the catalyst system for generating the first polyethylene component comprises a metal-ligand complex according to formula (I):

[0120]

[0121] In formula (I), M is a metal selected from titanium, zirconium, or hafnium, in the form of an oxidation state of +2, +3, or +4; n is 0, 1, or 2; when n is 1, X is a monodentate or bidentate ligand; when n is 2, each X is a monodentate ligand and may be the same or different; the metal-ligand complex is electrically neutral overall; each Z is independently selected from -O-, -S-, -N(R-) N - or - P(R) P )-; L is (C1-C 40 ) hydrocarbon group or (C1-C 40 ) heterohydrocarbon group, of which (C1-C 40The alkylene group has a portion of the main chain consisting of two Z groups in formula (I) with 1-carbon to 10-carbon atoms connected (L bonded to it), or (C1-C 40 The heteroalkyl group has a portion of the main chain consisting of 1- to 10-atoms of two Z groups in formula (I), wherein (C1-C 40 The 1- to 10-atom connections of the heteroalkyl group to the 1- to 10 atoms of the main chain are each independently a carbon atom or a heteroatom, wherein each heteroatom is independently O, S, S(O), S(O)2, Si(R)2, or S(O)2. C )2、Ge(R C 2. P(R) C ) or N(R C ), where each R C Independently is (C1-C 30 ) hydrocarbon group or (C1-C 30 ) heterohydrocarbon group; R 1 and R 8 Independently select from the following groups: -H, (C1-C 40 ) hydrocarbon group, (C1-C 40 heterohydrocarbon group, -Si(R) C )3、-Ge(R C 3. -P(R) P )2、-N(R N )2、-OR C -SR C -NO2, -CN, -CF3, R C S(O)-、R C S(O)2-、(R C )2C=N-、R C C(O)O-、R C OC(O)-, R C C(O)N(R N )-、(R N )2NC(O)-, halogens and groups having formula (II), (III) or (IV):

[0122]

[0123] In equations (II), (III), and (IV), R 31-35 R 41-48 Or R 51-59 Each of them is independently selected from (C1-C) 40 ) hydrocarbon group, (C1-C 40 heterohydrocarbon group, -Si(R) C )3、-Ge(R C 3. -P(R) P)2、-N(R N 2. -N=CHR C -OR C -SR C -NO2, -CN, -CF3, R C S(O)-、R C S(O)2-、(R C )2C=N-、R C C(O)O-、R C OC(O)-, R C C(O)N(R N )-、(R N )2NC(O)-, halogen or -H, condition R 1 Or R 8 At least one of them is a group having formula (II), formula (III) or formula (IV).

[0124] In equation (I), R 2-4 R 5-7 and R 9-16 Each of them is independently selected from (C1-C) 40 ) hydrocarbon group, (C1-C 40 heterohydrocarbon group, -Si(R) C )3、-Ge(R C 3. -P(R) P )2、-N(R N 2. -N=CHR C -OR C -SR C -NO2, -CN, -CF3, R C S(O)-、R C S(O)2-、(R C )2C=N-、R C C(O)O-、R C OC(O)-, R C C(O)N(R N )-、(R C )2NC(O)-, halogens and -H.

[0125] In some embodiments, the first polyethylene component is formed using a first catalyst according to formula (I) in a first reactor and a different catalyst according to formula (I) in a second reactor.

[0126] In one exemplary embodiment using a dual-loop reactor, the precatalyst used in the first loop is [[2,2”'-[[bis[1-methylethyl)germanene]bis(methyleneoxy-κO)]bis[3”,5,5”-tris(1,1-dimethylethyl)-5'-octyl[1,1':3',1”-terphenyl]-2'-root-κO]](2-)]dimethylzirconium, having the chemical formula C 86 H 128 F2GeO4Zr and the following structures:

[0127]

[0128] In such embodiments, the precatalyst used in the second ring is [[2,2”'-[1,3-propanediylbis(oxy-κO)]bis[3-[2,7-bis(1,1-dimethylethyl)-9H-carbazole-9-yl]]-5'-(dimethyloctylsilyl)-3'-methyl-5-(1,1,3,3-tetramethylbutyl)[1,1]-biphenyl]-2-root-κO]](2-)]dimethylzirconium, having the chemical formula C 107 H 154 N2O4Si2Zr and the following structures:

[0129]

[0130] In other embodiments, the precatalyst used in the second ring tube is [[2,2”'-[1,3-propanediylbis(oxy-κO)]bis[3-[2,7-bis(1,1-dimethylethyl)-9H-carbazole-9-yl]]-5'-(dimethyloctylsilyl)-3'-methyl-5-(1,1,3,3-tetramethylbutyl)[1,1]-biphenyl]-2-root-κO]](2-)]dimethylhafnium, having the chemical formula C 107 H 154 N2O4Si2Hf and the following structures:

[0131]

[0132] co-catalyst components

[0133] Catalytic activity can be achieved by any technique known in the art for activating metal-based catalysts for olefin polymerization reactions, including metal-ligand complexes of formula (I). For example, a system comprising a metal-ligand complex of formula (I) can be made catalytically active by contacting the complex with an activating cocatalyst or by combining the complex with an activating cocatalyst. Activating cocatalysts suitable for this document include alkylaluminum; polymeric or oligomeric aluminum oxanes (also known as aluminum oxanes); neutral Lewis acids; and non-polymeric, non-coordinated, ion-forming compounds (including those used under oxidizing conditions). A suitable activation technique is bulk electrolysis. Combinations of one or more of the aforementioned activating cocatalysts and techniques are also contemplated. The term "alkylaluminum" means dihydrogenated monoalkylaluminum or dihalogenated monoalkylaluminum, hydrogenated dialkylaluminum or halodialkylaluminum, or trialkylaluminum. Examples of polymeric or oligomeric aluminum oxanes include methylaluminoxane, methylaluminoxane modified with triisobutylaluminum, and isobutylaluminoxane.

[0134] Lewis acid activators (co-catalysts) include those containing one to three (C1-C1) atoms as described herein. 20 A Group 13 metal compound with a hydrocarbon substituent. In one embodiment, the Group 13 metal compound is a tri((C1-C) group 13 metal compound. 20 ()hydrocarbon-substituted aluminum or tri((C1-C) 20 (Hydrocarbon)-boron compounds. In other embodiments, the Group 13 metal compound is a tri(hydrocarbon)-substituted aluminum, tri((C1-C)-boron compound. 20 )hydro-boron compounds, tri((C1-C 10 Alkyl aluminum, tri((C6-C) 18 (Aryl)boron compounds and their halogenated (including perhalogenated) derivatives. In other embodiments, the Group 13 metal compound is tri(fluorosubstituted phenyl)borane or tri(pentafluorophenyl)borane. In some embodiments, the activating cocatalyst is tri((C1-C)borane. 20 )hydrocarbonyl)borates (e.g., triphenylmethyltetrafluoroborate) or tri((C1-C 20 )hydro-based)ammonium tetra((C1-C 20 (e.g., bis(octadecyl)methylammonium tetra(pentafluorophenyl)borane). As used herein, the term "ammonium" refers to a nitrogen cation that is ((C1-C2) 20 )hydrocarbon group)4N + 、((C1-C 20 )hydrocarbon group)3N(H) + 、((C1-C 20 )hydrocarbon group)2N(H)2 + (C1-C) 20 )hydrocarbon N(H)3 + or N(H)4 +, where each (C1-C 20 The hydrocarbon groups can be the same or different (when there are two or more).

[0135] Combinations of neutral Lewis acid activators (co-catalysts) include tris((C1-C4)alkyl)aluminum and tri((C6-C4)halogenated tris((C6-C4)alkyl)aluminum. 18 Mixtures of aryl(boron) compounds, particularly tris(pentafluorophenyl)borane. Other embodiments are combinations of such neutral Lewis acid mixtures with polymeric or oligomeric aluminum oxanes, and combinations of single neutral Lewis acids (especially tris(pentafluorophenyl)borane) with polymeric or oligomeric aluminum oxanes. The molar ratio of (metal-ligand complex):(tris(pentafluorophenylborane):(aluminoxane) [e.g., (Group 4 metal-ligand complex):(tris(pentafluorophenylborane):(aluminoxane)] is from 1:1:1 to 1:10:30, and in other embodiments from 1:1:1.5 to 1:5:10.

[0136] Catalytic systems comprising metal-ligand complexes of formula (I) can be activated to form active catalyst compositions by combination with one or more cocatalysts (e.g., cation-forming cocatalysts, strong Lewis acids, or combinations thereof). Suitable activation cocatalysts comprise polymeric or oligomeric aluminum oxanes (especially methylaluminoxanes) and inert, compatible, noncoordinate, ion-forming compounds. Exemplary suitable cocatalysts include, but are not limited to: modified methylaluminoxane (MMAO), bis(hydrogenated tallow alkyl)methyltetra(pentafluorophenyl)boronic acid (1... - )amines, and combinations thereof.

[0137] In some embodiments, one or more of the aforementioned activation cocatalysts are used in combination with each other. A particularly preferred combination is a mixture of tris((C1-C4)alkyl)aluminum, tris((C1-C4)alkyl)borane, or ammonium borate with oligomeric or polymeric aluminum oxane compounds. The ratio of the total molar number of one or more metal-ligand complexes of formula (I) to the total molar number of one or more activation cocatalysts in the activation cocatalyst is from 1:10,000 to 100:1. In some embodiments, the ratio is at least 1:5000, in some other embodiments at least 1:1000; and 10:1 or less, and in some other embodiments 1:1 or less. When an aluminum oxane is used alone as an activation cocatalyst, preferably, the molar number of the aluminum oxane used is at least 100 times the molar number of the metal-ligand complex of formula (I). In some other embodiments, when tris(pentafluorophenyl)borane is used alone as an activation cocatalyst, the molar ratio of tris(pentafluorophenyl)borane to the total molar ratio of one or more metal-ligand complexes of formula (I) is from 0.5:1 to 10:1, 1:1 to 6:1, or 1:1 to 5:1. The remaining activation cocatalyst is typically used in a molar amount approximately equal to the total molar amount of one or more metal-ligand complexes of formula (I).

[0138] nucleating agent

[0139] In some embodiments, the polyethylene composition may also contain a nucleating agent, which is calcium 1,2-cyclohexanedicarboxylate or sodium 4-[(4-chlorobenzoyl)amino]benzoate. For example, the first polyethylene component and the nucleating agent may be blended together before being blended with the second polyethylene component to form the polyethylene composition. When used in appropriate amounts and in combination with the first polyethylene component described herein, such nucleating agents are believed to provide a more uniform crystal distribution and crystal size, more uniform melt behavior, and one or more other improvements to the resulting film (e.g., stiffness, barrier properties, and / or optical properties) when used in polyethylene films.

[0140] In some embodiments, the nucleating agent is calcium 1,2-cyclohexanedicarboxylate. In some embodiments, the nucleating agent is sodium 4-[(4-chlorobenzoyl)amino]benzoate. In some embodiments, such polyethylene-based compositions comprise both calcium 1,2-cyclohexanedicarboxylate and sodium 4-[(4-chlorobenzoyl)amino]benzoate.

[0141] Nucleating agents such as calcium 1,2-cyclohexanedicarboxylate or sodium 4-[(4-chlorobenzoyl)amino]benzoate are heterogeneous nucleating agents. The amount and type of heterogeneous nucleating agent are important in providing the desired performance. In some embodiments, based on the total weight of the polyethylene composition, the polyethylene composition contains 20 ppm to 5000 ppm of a heterogeneous nucleating agent in the form of calcium 1,2-cyclohexanedicarboxylate or sodium 4-[(4-chlorobenzoyl)amino]benzoate, with the balance being the first and second polyethylene components described herein. In some embodiments, based on the total weight of the polyethylene composition, the polyethylene composition contains 20 ppm to 2000 ppm of calcium 1,2-cyclohexanedicarboxylate or sodium 4-[(4-chlorobenzoyl)amino]benzoate, with the balance being the first and second polyethylene components described herein. In some embodiments, based on the total weight of the polyethylene composition, the polyethylene composition contains 500 ppm to 2000 ppm of calcium 1,2-cyclohexanedicarboxylate or sodium 4-[(4-chlorobenzoyl)amino]benzoate, with the balance being the first and second polyethylene components described herein.

[0142] In some embodiments, the heterogeneous nucleating agent may be provided together with a fatty acid metal salt such as zinc stearate, zinc palmitate, and mixtures thereof. Depending on the commercial preparation method of zinc stearate, some zinc palmitate may also be present, as commercial stearic acid typically contains a large amount of palmitic acid. In some such embodiments, the polyethylene composition contains 45 ppm to 1000 ppm of at least one of zinc stearate and zinc palmitate, based on the total weight of the polyethylene composition. In some embodiments, the polyethylene composition contains 50 ppm to 700 ppm of zinc stearate and / or zinc palmitate, based on the total weight of the polyethylene composition. In some embodiments, the polyethylene composition contains 85 ppm to 600 ppm of zinc stearate and / or zinc palmitate, based on the total weight of the polyethylene composition.

[0143] A non-limiting example of a calcium 1,2-cyclohexanedicarboxylate salt that can be used in embodiments of the present invention is Hyperform HPN-20E from Millicken Chemical, Spartanburg, South Carolina. Hyperform HPN-20E comprises 60% to 70% by weight of calcium 1,2-cyclohexanedicarboxylate and 30% to 40% by weight of zinc stearate / zinc palmitate. In some embodiments, the polyethylene composition comprises 20 ppm to 5000 ppm of Hyperform HPN-20E based on the total weight of the polyethylene composition. In some embodiments, the polyethylene composition comprises 20 ppm to 2000 ppm of Hyperform HPN-20E based on the total weight of the polyethylene composition.

[0144] A non-limiting example of sodium 4-[(4-chlorobenzoyl)amino]benzoate that can be used in embodiments of the present invention is Hyperform HPN 210M from Millicken Chemical, Spartanburg, South Carolina.

[0145] In some embodiments, calcium 1,2-cyclohexanedicarboxylate or sodium 4-[(4-chlorobenzoyl)amino]benzoate (and fatty acid metal salts (e.g., zinc stearate and / or zinc palmitate, when also included) may be provided as a masterbatch by blending it with a carrier resin prior to combination with the first polyethylene component described herein. In some such embodiments, the carrier resin is polyethylene with a melt index (I2) of 1 g / 10 min to 12 g / 10 min. In some embodiments where calcium 1,2-cyclohexanedicarboxylate and zinc stearate / zinc palmitate are provided as masterbatches, the masterbatch comprises 2 wt% to 4 wt% of calcium 1,2-cyclohexanedicarboxylate and zinc stearate / zinc palmitate based on the total weight of the masterbatch. In one embodiment, the carrier resin is a high-density polyethylene homopolymer having a density of 0.965 and a melt index (I2) of 8 g / 10 min to 9 g / 10 min with a narrow molecular weight distribution. In some embodiments, the masterbatch may also contain other additives. Depending on the total amount of additives contained, the masterbatch may contain 85% to 98% by weight of carrier resin based on the total weight of the masterbatch.

[0146] Other nucleating agents that may be used in some embodiments of the invention include those disclosed in U.S. Patent Publications 2015 / 0087758, 2015 / 0087759, and 2015 / 0086736, which are hereby incorporated herein by reference. In some embodiments, the polyethylene composition contains 20 ppm to 5000 ppm of such nucleating agents based on the total weight of the polyethylene composition. In some embodiments, the polyethylene composition contains 20 ppm to 2000 ppm of such nucleating agents based on the total weight of the polyethylene composition.

[0147] Second polyethylene component

[0148] As described above, the polyethylene composition of the present invention further comprises a second polyethylene component having certain properties. The second polyethylene component used in embodiments of the present invention comprises (1) a first polyethylene fraction having a single peak in an elution curve obtained by an improved comonomer composition distribution (iCCD) analysis method in a temperature range of 45°C to 87°C, wherein the first polyethylene area fraction is the area below the single peak of the first polyethylene fraction in the elution curve between 45°C and 87°C, and (2) a second polyethylene fraction having a single peak in an elution curve obtained by an iCCD analysis method in a temperature range of 95°C to 120°C, wherein the second polyethylene area fraction is the area below the single peak of the second polyethylene fraction in the elution curve between 95°C and 120°C. The second polyethylene component has a content of 0.924 g / cm³. 3 Up to 0.936 g / cm 3 The density and melt index (I2) of the second polyethylene fraction are from 0.25 g / 10 min to 2.0 g / 10 min, wherein the area of ​​the second polyethylene fraction accounts for at least 40% of the total area of ​​the elution curve, wherein the ratio of the area of ​​the first polyethylene fraction to the area of ​​the second polyethylene fraction is from 0.75 to 2.5, and wherein the width of the single peak of the second polyethylene fraction at 50% peak height is less than 5.0 °C.

[0149] In one or more embodiments, the second polyethylene component may have a content of 0.924 g / cm³. 3 Up to 0.936 g / cm 3 The density. For example, embodiments of the second polyethylene component of this disclosure may have a density of 0.924 g / cm³. 3 Up to 0.931 g / cm 3 0.924 g / cm 3 Up to 0.928 g / cm 3 0.927g / cm 3 Up to 0.931 g / cm 3 Or 0.929 g / cm 3 Up to 0.933 g / cm 3 The density. According to another embodiment, the second polyethylene component may have a density of 0.924 g / cm³. 3 Up to 0.928 g / cm 3 0.928g / cm 3 Up to 0.932 g / cm 3 0.932g / cm 3 Up to 0.936 g / cm 3 Or the density of any combination of these ranges.

[0150] In one or more embodiments, the second polyethylene component may have a melt index (I2) of 0.25 g / 10 min to 2.0 g / 10 min, such as 0.5 g / 10 min to 1.2 g / 10 min. For example, in one or more embodiments, the second polyethylene component may have a melt index (I2) of 0.25 g / 10 min to 0.5 g / 10 min, 0.5 g / 10 min to 0.7 g / 10 min, 0.7 g / 10 min to 0.9 g / 10 min, 0.59 g / 10 min to 1.1 g / 10 min, 1.1 g / 10 min to 1.3 g / 10 min, 1.3 g / 10 min to 1.5 g / 10 min, 1.5 g / 10 min to 1.7 g / 10 min, 1.7 g / 10 min to 2.0 g / 10 min, or any combination of these ranges. According to another embodiment, the second polyethylene component may have a melt index (I2) of 0.65 to 1.05.

[0151] According to the embodiments, the second polyethylene component may have a molecular weight distribution in the range of 2.5 to 8.0, expressed as the ratio of weight-average molecular weight to number-average molecular weight (Mw / Mn). For example, the second polyethylene component may have a molecular weight distribution of 2.5 to 3.0, 3.0 to 3.5, 3.5 to 4.0, 4.0 to 4.5, 4.5 to 5.0, 5.0 to 5.5, 5.5 to 6.0, 6.0 to 6.5, 6.5 to 7.0, 7.0 to 7.5, 7.5 to 8.0, or any combination of these ranges. In another embodiment, the second polyethylene component may have a molecular weight distribution of 3.0 to 5.0. As described herein, the molecular weight distribution can be calculated using gel permeation chromatography (GPC) techniques as described herein.

[0152] According to one or more other embodiments, the second polyethylene component may have a zero-shear viscosity ratio of less than 3.0. For example, the second polyethylene component may have a zero-shear viscosity ratio of less than 2.9, less than 2.8, less than 2.7, less than 2.6, less than 2.5, less than 2.4, less than 2.3, less than 2.2, less than 2.1, less than 2.0, less than 1.9, less than 1.8, less than 1.7, less than 1.6, less than 1.5, less than 1.4, less than 1.3, less than 1.2, or even less than 1.1. In one or more embodiments, the second polyethylene component may have a zero-shear viscosity ratio of at least 1.0.

[0153] Referring to the described iCCD distribution, Figure 2 The sample iCCD distribution 100 and the cumulative weight fraction curve 200 are schematically depicted. Figure 2 This roughly outlines several characteristics of the iCCD curves of the second polyethylene component discussed in detail in this paper, such as the first fraction, the second fraction, and the full width at half maximum (FWHM). Therefore, Figure 2This can be used as a reference regarding public information related to the iCCD curves provided herein. Specifically, the first segment 102 and the second segment 106 are depicted. The first segment 102 has a peak 104 and the second segment 106 has a peak 108. Each segment has a half-width at half-maximum (HWHM) of 110 and a half-width at half-maximum (HWHM) of 112. It should be understood that... Figure 2 The curves are not derived from experiments or observations, but rather provide information for the purpose of describing specific characteristics of iCCD elution curves.

[0154] In one or more embodiments, the first polyethylene fraction of the second polyethylene component may have a single peak in the elution profile obtained by iCCD within a temperature range of 45°C to 87°C. In one or more embodiments, the single peak of the first polyethylene fraction may be in the temperature range of 60°C to 85°C, such as 70°C to 85°C. Without being bound by theory, it is believed that in at least some embodiments of the second polyethylene component, where a dual-reactor design is used for polymerization, a combination of high-density crystalline domains and low-density amorphous domains may exist. Impact strength is primarily controlled by the concentration of amorphous regions or the linkages connecting adjacent lamellar crystals. When the density is less than 0.910 g / cc, the relative linkage concentration is estimated to be relatively high. The peak of the first polymer fraction in the compositions disclosed in this invention may be located in the temperature range of 60°C to 85°C, which can provide a greater linkage concentration to obtain functional benefits, such as improved toughness.

[0155] It should be understood that the peaks in the first or second polyethylene fraction may not be formed by local minima in the corresponding polyethylene fraction under defined temperature boundaries. That is, the peaks must be peaks across the entire spectral range, not peaks formed by the threshold temperature of the polyethylene fraction. For example, if there is a single peak followed by a single valley (sloping upwards, then downwards, then upwards) in a polyethylene fraction, then only a single peak will exist in such a polyethylene fraction.

[0156] In one or more embodiments, the second polyethylene fraction may have a single peak in the elution profile obtained by iCCD within a temperature range of 95°C to 120°C. This 95°C to 120°C temperature range for the second polyethylene fraction may be desirable because the low molecular weight, high-density component at 95°C to 120°C allows for higher total polyethylene density while maintaining a lower density fraction, as described by the ratio of the two fractions.

[0157] In one or more embodiments, the width of the single peak of the second polyethylene fraction at 50% peak height may be less than 5.0°C, less than 4°C, or even less than 3°C. Typically, a smaller temperature range at 50% peak height corresponds to a “sharper” peak. Without being bound by any particular theory, it is believed that “sharper” or “narrower” peaks are characteristic of molecular catalysts and indicate minimal comonomer incorporation in the higher density fraction, thereby enabling higher density separation between the two fractions.

[0158] In one or more embodiments, the second polyethylene component may have a local minimum in the elution profile obtained by iCCD within a temperature range of 80°C to 90°C. This local minimum may fall between the peaks of the first polyethylene fraction and the peaks of the second polyethylene fraction.

[0159] In the embodiments described herein, the area of ​​the first polyethylene fraction is the area below the single peak of the first polyethylene fraction in the elution curve between 45°C and 87°C. Similarly, the area of ​​the second polyethylene fraction is the area below the single peak of the second polyethylene fraction in the elution curve between 95°C and 120°C. The areas of the first and second polyethylene fractions typically correspond to the total relative masses of the polymer fractions in the polyethylene composition, respectively. Generally, the area of ​​the polyethylene fraction in the iCCD curve can be determined by integrating the iCCD curve between specified start and end temperatures.

[0160] According to one or more embodiments, the difference between the single peak of the second polyethylene fraction and the single peak of the first polyethylene fraction can be at least 10°C. For example, the difference between the single peak of the second polyethylene fraction and the single peak of the first polyethylene fraction can be at least 12°C, 14°C, 16°C, 18°C, or even at least 20°C.

[0161] In one or more embodiments, the area of ​​the first polyethylene fraction may account for at least 40% of the total area of ​​the elution curve (e.g., at least 42%, at least 44%, at least 46%, at least 48%, at least 50%, at least 52%, or even at least 54% of the total area of ​​the elution curve). For example, the area of ​​the first polyethylene fraction may account for 40% to 65% of the total area of ​​the elution curve, such as 42% to 58%, 43% to 45%, 45% to 47%, 53% to 55%, or 55% to 57%.

[0162] According to one or more embodiments, the area of ​​the second polyethylene fraction may account for at least 25% of the total area of ​​the elution curve (e.g., at least 30%, at least 35%, or even at least 40% of the total area of ​​the elution curve). For example, the area of ​​the first polyethylene fraction may account for 20% to 50%, 27% to 31%, or 41% to 48% of the total area of ​​the elution curve.

[0163] According to some implementation schemes, the ratio of the area of ​​the first polyethylene fraction to the area of ​​the second polyethylene fraction may be 0.75 to 2.5 (such as 0.75 to 1.0, 1.0 to 1.25, 1.25 to 1.5, 1.5 to 1.75, 1.75 to 2.0, 2.0 to 2.25, 2.25 to 2.5 or any combination of these ranges).

[0164] In one or more embodiments, the second polyethylene component is formed by the polymerization of ethylene and comonomers such as C3-C12 olefins. Considered comonomers include C6-C9 olefins, such as 1-octene and 1-hexene. In one or more embodiments, the comonomer is 1-octene.

[0165] In one or more embodiments, the difference between the single peak of the second polyethylene fraction and the single peak of the first polyethylene fraction may be at least 10°C, at least 12.5°C, at least 15°C, at least 17.5°C, or even at least 20°C.

[0166] In one or more embodiments, the first polyethylene fraction may have a melt index (I2) of 0.01 g / 10 min to 0.18 g / 10 min. For example, according to one or more embodiments, the first polyethylene fraction may have a melt index (I2) of 0.01 g / 10 min to 0.03 g / 10 min, 0.03 g / 10 min to 0.05 g / 10 min, 0.05 g / 10 min to 0.07 g / 10 min, 0.07 g / 10 min to 0.09 g / 10 min, 0.09 g / 10 min to 0.11 g / 10 min, 0.11 g / 10 min to 0.13 g / 10 min, 0.13 g / 10 min to 0.15 g / 10 min, 0.15 g / 10 min to 0.18 g / 10 min, or any combination of these ranges.

[0167] In one or more embodiments, the second polyethylene fraction may have a melt index (I2) of 1 g / 10 min to 10,000 g / 10 min. For example, according to one or more embodiments, the second polyethylene fraction may have a melt index (I2) of 10 g / 10 min to 1,000 g / 10 min, 20 g / 10 min to 800 g / 10 min, 1 g / 10 min to 100 g / 10 min, 100 g / 10 min to 1,000 g / 10 min, 1,000 g / 10 min to 10,000 g / 10 min, or any combination of these ranges.

[0168] In one or more embodiments, the weight-average molecular weight of the second polyethylene fraction may be less than or equal to 120,000 g / mol, such as 20,000 g / mol to 120,000 g / mol or 40,000 g / mol to 65,000 g / mol. In another embodiment, the weight-average molecular weight of the second polyethylene fraction may be 20,000 g / mol to 40,000 g / mol, 40,000 g / mol to 60,000 g / mol, 60,000 g / mol to 80,000 g / mol, 80,000 g / mol to 100,000 g / mol, 100,000 g / mol to 120,000 g / mol, or any combination of these ranges. The molecular weight of the polyethylene fraction may be calculated based on GPC results, as described below.

[0169] According to another embodiment, the second polyethylene component may have a Dow Rheology Index of less than or equal to 5, such as less than or equal to 4, less than or equal to 3, less than or equal to 2, or even less than or equal to 1.

[0170] In one or more embodiments, the second polyethylene component may also comprise additional components, such as one or more additives. Such additives include, but are not limited to, antistatic agents, colorants, dyes, lubricants, fillers (such as TiO2 or CaCO3), opacifiers, nucleating agents, processing aids, pigments, primary antioxidants, secondary antioxidants, UV stabilizers, anti-caking agents, slip agents, lubricants, flame retardants, antimicrobial agents, deodorizers, antifungal agents, and combinations thereof. Based on the weight of the second polyethylene component containing such additives, the total weight of such additives contained in the second polyethylene component is from about 0.1% to about 10%.

[0171] polymerization

[0172] The second polyethylene component described herein can be produced using any conventional polymerization method. Such conventional polymerization methods include, but are not limited to, slurry polymerization methods and solution polymerization methods using one or more conventional reactors, such as loop reactors in parallel or in series, isothermal reactors, stirred tank reactors, batch reactors, and / or any combination thereof. The polyethylene component can be produced, for example, via solution-phase polymerization methods using one or more loop reactors, isothermal reactors, and combinations thereof.

[0173] Typically, solution-phase polymerization can be carried out at temperatures ranging from 115°C to 250°C (e.g., 115°C to 210°C) and pressures ranging from 300 psi to 1,000 psi (e.g., 400 psi to 800 psi) in one or more well-mixed reactors, such as one or more isothermal loop reactors or one or more adiabatic reactors. In one embodiment, in a dual-reactor configuration, the temperature in the first reactor is in the range of 115°C to 190°C (e.g., 160°C to 180°C), while the temperature in the second reactor is in the range of 150°C to 250°C (e.g., 180°C to 220°C). In other embodiments, in a single reactor, the temperature in the reactor is in the range of 115°C to 250°C (e.g., 115°C to 225°C).

[0174] Residence time in solution-phase polymerization can range from 2 to 30 minutes (e.g., 5 to 25 minutes). Ethylene, solvent, hydrogen, one or more catalyst systems, optionally one or more cocatalysts, and optionally one or more comonomers are continuously fed into one or more reactors. Exemplary solvents include, but are not limited to, isoparaffins. For example, such solvents may be available under the name ISOPAR E from ExxonMobil Chemical Co., Houston, Texas. The resulting mixture of polyethylene component and solvent is then removed from the reactor, and the polyethylene component is separated. The solvent is typically recovered via a solvent recovery unit (i.e., a heat exchanger and a vapor-liquid separator drum) and subsequently recycled back into the polymerization system.

[0175] In some embodiments, the second polyethylene component can be produced by solution polymerization in a dual-reactor system, such as a dual-loop reactor system, wherein ethylene is polymerized in the presence of one or more catalyst systems. In some embodiments, only ethylene is polymerized. Additionally, one or more co-catalysts may be present. In another embodiment, the second polyethylene component can be produced by solution polymerization in a single-reactor system, such as a single-loop reactor system, wherein ethylene is polymerized in the presence of two catalyst systems. In some embodiments, only ethylene is polymerized.

[0176] catalyst system

[0177] The same catalyst system described in connection with the generation of the first polyethylene component can be used to generate a polyethylene composition of the second composition. As described in the Examples section, the preparation methods of the first and second polyethylene components are different, resulting in polyethylene compositions with different properties as described herein.

[0178] As described above, some embodiments of the polyethylene composition of the present invention having the elution profiles (first polyethylene area fraction between 50°C and 85°C, second polyethylene fraction area between 85°C and 100°C, and third polyethylene fraction area between 100°C and 120°C, as described above) obtained by an improved comonomer composition distribution (iCCD) analysis method can be formed from a blend of a first polyethylene component (as described above) and a second polyethylene component (as described above). In some such embodiments, the polyethylene composition comprises 30% to 60% by weight of the first polyethylene component according to any one of the embodiments described herein and 40% to 70% by weight of the second polyethylene component according to any one of the embodiments described herein, each based on the total weight of the polyethylene composition. In some such embodiments, the polyethylene composition comprises 32% to 56% by weight of the first polyethylene component according to any one of the embodiments described herein and 44% to 68% by weight of the second polyethylene component according to any one of the embodiments described herein, each based on the total weight of the polyethylene composition. In some embodiments, such polyethylene compositions further contain 20 ppm to 5000 ppm of a nucleating agent based on the total weight of the polyethylene composition, wherein the nucleating agent comprises calcium 1,2-cyclohexanedicarboxylate or sodium 4-[(4-chlorobenzoyl)amino]benzoate.

[0179] membrane

[0180] Some embodiments of the present invention relate to films formed from any of the polyethylene compositions of the present invention described herein. In some embodiments, the film of the present invention is a single-layer film comprising any of the polyethylene compositions of the present invention described herein. In some embodiments, the film of the present invention is a multilayer film, wherein at least one layer comprises any of the polyethylene compositions described herein.

[0181] For multilayer membranes, the number of layers can depend on many factors, including, for example, the desired properties of the membrane, the desired thickness of the membrane, the contents of the other layers, the end-use application of the membrane, and the equipment that can be used to manufacture the membrane. In various embodiments, the multilayer membrane of the present invention may comprise up to 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11 layers. In some embodiments, the multilayer membrane is a five-layer membrane. In some embodiments, the multilayer membrane is a three-layer membrane.

[0182] In addition to the polyethylene compositions of the present invention, one or more layers of such multilayer films may also comprise other polymers. For example, in some embodiments, in addition to the polyethylene compositions of the present invention, one or more layers of the multilayer film may also comprise low-density polyethylene (LDPE) or linear low-density polyethylene (LLDPE). For example, LDPE may be included in some layers for ease of processing. In some embodiments using LDPE in the film, the LDPE may comprise from 1 wt% to less than 50 wt% of the total weight of the multilayer film. In some embodiments, the multilayer film may comprise from 1 wt% to 30 wt% of the total weight of the film. In some embodiments, the multilayer film may comprise from 20 wt% to 30 wt% of the total weight of the film. Examples of commercially available LDPEs that may be used in some embodiments of the present invention include LDPEs available from The Dow Chemical Company, such as DOW... TM LDPE 132I, DOW TM LDPE 203M, DOW TM 586A, DOW TM LDPE 230N and AGILITY TM 1021. In some embodiments of the use of LLDPE in membranes, the LLDPE may comprise from 1% to less than 50% by weight of LDPE based on the total weight of the multilayer membrane. In some embodiments, the multilayer membrane may comprise from 20% to 50% by weight of LLDPE based on the total weight of the membrane. Examples of commercially available LLDPEs that may be used in some embodiments of the invention include LLDPEs available from Dow Chemical Company, such as DOWLEX. TM GM 8051F, DOWLEX TM GM 8051G, DOWLEX TM GM 8051, DOWLEX TM GM 8070, DOWLEX TM TG 2085B, INNATE TM ST50, ELITE TM NG5400B, ELITE TM NG5401B, ELITE TM 5400G and ELITE TM 5401G.

[0183] In some embodiments, one outer layer of the multilayer film is a sealant layer. The sealant layer can be used to form articles or packaging by adhering the film to another film, laminate, or itself using the sealant layer. Therefore, the sealant layer is the outermost layer of the multilayer film.

[0184] In some embodiments, the sealant layer may comprise any resin known to those skilled in the art as a sealant layer.

[0185] In some embodiments, the sealant layer may contain one or more components with a density of 0.870 g / cm³. 3 Up to 0.925 g / cm 3 The ethylene-based polymer has a melt index (I2) of 0.1 g / 10 min to 2.0 g / 10 min. In other embodiments, the ethylene-based polymer of the sealant film (or sealant layer) may have an I2 of 870 g / cm³. 3 Up to 0.925 g / cm 3 or 0.900g / cm 3 Up to 0.925 g / cm 3 or 0.910 g / cm 3 Up to 0.925 g / cm 3 The density. Additionally, the ethylene-based polymer of the sealant film (or sealant layer) may have a melt index (I2) of 0.1 g / 10 min to 2.0 g / 10 min or 0.1 g / 10 min to 1.5 g / 10 min. Various commercially available polyethylenes are considered suitable for sealant films. Suitable commercial examples may include ELITE. TM 5400G, ELITE TM 5401B and various AFFINITY TM Polyolefin plasmons (e.g., AFFINITY) TM PL 1888, AFFINITY TM PF 1140 and AFFINITY TM PF 1146, AFFINITY TM VP 8770G1), each of which is available from Dow Chemical Company (Midland, MI).

[0186] In other embodiments, the sealant layer of the multilayer film may comprise an additional ethylene-based polymer, such as a polyolefin plasmid, LDPE, LLDPE, etc. The LDPE in the sealant film or sealant layer can typically include any LDPE known to those skilled in the art, including, for example, DOWN. TM LDPE 132I and DOW TMLDPE 586A. In embodiments using polyolefin plastomers, the polyolefin plastomers may have a melt index (I2) of 0.2 g / 10 min to 5 g / 10 min or 0.5 g / 10 min to 2.0 g / 10 min. Furthermore, the polyolefin plastomers may have a melt index (I2) of 0.870 g / cc to 0.920 g / cc, or 0.870 g / cc to 0.910 g / cc, or 0.900 g / cm³. 3 Up to 0.910 g / cm 3 The density. Various commercially available polyolefin plastomers are considered suitable for sealant films. Suitable examples include AFFINITY from Dow Chemical Company (Midland, Michigan). TM PL 1881G, AFFINITY TM PL 1888G, AFFINITY TM PF 1140G, AFFINITY TM PF 1146G and AFFINITY TM VP 8770G1. In embodiments where the sealant layer includes LLDPE, the LLDPE may typically include any LLDPE known to those skilled in the art, including, for example, those commercially available from Dow Chemical Company, such as DOWLEX. TM NG2045B, DOWLEX TM TG2085B, DOWLEX TM GM 8051, DOWLEX TM GM 8070, DOWLEX TM GM 8085 and DOWLEX TM 5056G. Another example of an ethylene-based polymer that can be included is one with 0.918 g / cm³. 3 Or even lower density INNATE TM Polyethylene resin can be infused. TM ST50 and INNATE TM TH60 was purchased commercially from Dow Chemical Company.

[0187] In some embodiments, the sealant layer contains a density of 0.870 g / cm³. 3 Up to 0.925 g / cm 3 Blends of ethylene-based polymers with polyolefin plastomers having a melt index (I2) of 0.1 g / 10 min to 2.0 g / 10 min. For example, in some embodiments, such blends may contain ELITE. TM 5400G or ELITE TM 5401B and AFFINITY TMPL 1881G. For example, in some embodiments, such blends may contain INNATE. TM ST50 and AFFINITY TM PL 1881G.

[0188] In some embodiments, the sealant layer comprises a blend of LLDPE and a polyolefin plastide. For example, in some embodiments, such a blend may contain DOWLEX. TM NG 2045B or DOWLEX TM GM 8051, AFFINITY TM PL1881G, AFFINITY TM PF 1140G, AFFINITY TM PF 1146G and AFFINITY TM VP 8770G1.

[0189] In some embodiments, the sealant layer comprises a blend of LLDPE and LDPE. For example, in some embodiments, such a blend may contain DOWLEX as LLDPE. TM NG 2045B or DOWLEX TM GM 8051 and DOW as LDPE TM LDPE 132I or DOW TM LDPE 586A. In some such embodiments, the amount of LDPE is 30% by weight or less, based on the weight of the sealant layer.

[0190] In some embodiments, the sealant layer comprises a blend of a polyolefin plastomer and LDPE. For example, in some embodiments, such a blend may contain AFFINITY as a polyolefin plastomer component. TM PL 1881G, AFFINITY TM PL1888G, AFFINITY TM PF 1140G and AFFINITY TM PF 1146G and AFFINITY TM VP 8770G1 and DOW as LDPE TM LDPE 132I or DOW TM LDPE 586A. In some such embodiments, the amount of LDPE is 30% by weight or less, based on the weight of the sealant layer.

[0191] It should be understood that, in some embodiments, any layer within the membrane may further include one or more additives known to those skilled in the art (in addition to the additives described above for polyethylene-based compositions), such as antioxidants, UV stabilizers, heat stabilizers, slip agents, anti-caking agents, pigments or colorants, processing aids, crosslinking catalysts, flame retardants, fillers, and foaming agents.

[0192] In some embodiments, the membrane of the present invention is primarily formed of polyethylene. According to some embodiments of the invention, because it is polyethylene-based, the membrane of the present invention can be incorporated into articles primarily (if not substantially or entirely) composed of polyethylene to provide articles that are easier to recycle. For example, in addition to other advantages that can be provided by using such polymers, multilayer membranes primarily comprising polyethylene also have improved recyclability. For example, in some embodiments, the multilayer membrane is entirely composed of ethylene-based polymers, except for additives. Based on the total weight of the multilayer membrane, in some embodiments, the multilayer membrane may comprise 90% by weight of ethylene-based polymers, or in some embodiments, 95% by weight of ethylene-based polymers, or in some embodiments, 99% by weight of ethylene-based polymers, or in some embodiments, 99.9% by weight of ethylene-based polymers, or in some embodiments, 100% by weight of ethylene-based polymers.

[0193] The membranes of the present invention can have various thicknesses, depending on factors such as the number of layers, the intended use of the membrane, and other factors. In some embodiments, the total thickness of such membranes is less than 200 micrometers, or less than 150 micrometers, or less than 120 micrometers. In some embodiments, the membranes of the present invention have a total thickness of 30 to 200 micrometers, or 30 to 150 micrometers, or 30 to 120 micrometers.

[0194] Based on the teachings herein, techniques known to those skilled in the art can be used to form the film. For example, the film can be prepared as a blown film (e.g., a water-quenched blown film) or a cast film. For example, in the case of a multilayer film, for those layers that can be co-extruded, based on the teachings herein, these layers can be co-extruded into a blown film or a cast film using techniques known to those skilled in the art.

[0195] The membranes of the present invention can exhibit one or more desired properties. For example, in some embodiments, the multilayer membranes can exhibit desired dart impact values, secant modulus, barrier properties, and / or other properties. Specifically, in some embodiments, the multilayer membranes of the present invention can surprisingly exhibit a good balance between dart impact (toughness) and secant modulus when compared to multilayer membranes with the same overall density. Furthermore, in some embodiments, the increased density of the multilayer membranes of the present invention can also improve the barrier properties of the multilayer membranes.

[0196] In some embodiments, a monolayer film formed from the polyethylene composition of the present invention and having a thickness of 3 to 4 mil exhibits a normalized dart impact of at least 110 g / mil. In some embodiments, a monolayer film formed from the polyethylene composition of the present invention and having a thickness of 3 to 4 mil exhibits a normalized dart impact of up to 200 g / mil. In some embodiments, a monolayer film formed from the polyethylene composition of the present invention and having a thickness of 3 to 4 mil exhibits a normalized dart impact of up to 160 g / mil. In some embodiments, a monolayer film formed from the polyethylene composition of the present invention and having a thickness of 3 to 4 mil exhibits a normalized dart impact of 110 g / mil to 200 g / mil. In some embodiments, a monolayer film formed from the polyethylene composition of the present invention and having a thickness of 3 to 4 mil exhibits a normalized dart impact of 110 g / mil to 160 g / mil.

[0197] Products

[0198] Embodiments of the invention also relate to articles, such as laminates and packaging, formed from or incorporating the oriented multilayer polyethylene film of the invention (or from a laminate incorporating such a film). Such packaging can be formed from any of the films or laminates described herein.

[0199] Examples of such articles may include flexible packaging, bags, stand-up pouches, and prefabricated packaging or bags. In some embodiments, the oriented multilayer polyethylene film or laminate of the present invention can be used for food packaging. Examples of foods that may be included in such packaging include meat, cheese, grains, nuts, juices, sauces, pet food, etc. Based on the teachings herein and the specific purpose of the packaging (e.g., the type of food, the quantity of food, etc.), such packaging can be formed using techniques known to those skilled in the art.

[0200] Embodiments of the article of the present invention may also be laminates incorporating a membrane comprising any of the polyethylene compositions of the present invention described herein. In some embodiments, a membrane incorporating the polyethylene composition of the present invention may be laminated onto another membrane. Other membranes in such embodiments may be polyethylene sealant films, polyethylene terephthalate, polypropylene, or polyamide. A polyethylene sealant film may be a single-layer or multi-layer film formed substantially of polyethylene (e.g., comprising greater than 90% by weight of an ethylene-based polymer, or greater than 95% by weight of an ethylene-based polymer, or greater than 99% by weight of an ethylene-based polymer), which, when heated as part of a laminate structure, can seal the laminate onto another membrane, another laminate, or itself. Any polyethylene sealant film known to those skilled in the art based on the teachings herein may be used. When the other membrane comprises polyethylene terephthalate, polypropylene, or polyamide, the entire membrane may be formed of polyethylene terephthalate, polypropylene, or polyamide, or the membrane may comprise at least one layer comprising polyethylene terephthalate, polypropylene, or polyamide. Those skilled in the art may choose membranes, including polyethylene terephthalate, polypropylene, or polyamide, for such embodiments based on the teachings herein.

[0201] Laminates according to embodiments of the present invention can be formed using techniques known to those skilled in the art based on the teachings herein. For example, an adhesive can be used to laminate a film comprising the polyethylene composition of the present invention onto another film. A variety of adhesive compositions are considered suitable for use in preparing the laminate. These adhesives may include polyurethane, epoxy, acrylic, etc. In one embodiment, the laminate may include an adhesive layer comprising a polyurethane adhesive. The polyurethane adhesive may be solvent-free, aqueous, or solvent-based. Furthermore, the polyurethane adhesive may be a two-part formulation. The weight or thickness of the adhesive layer may depend on various factors, including, for example, the desired thickness of the laminate, the type of adhesive used, and other factors. In some embodiments, the adhesive layer is applied up to 5.0 g / m³. 2 or 1.0g / m 2 Up to 4.0g / m 2 or 2.0g / m 2 Up to 3.0g / m 2 .

[0202] Laminates according to some embodiments of the present invention can also be formed by extrusion lamination.

[0203] Test methods

[0204] Unless otherwise indicated herein, the following analytical methods are used to describe various aspects of the invention:

[0205] Melt Flow Index

[0206] Melt index I2 (or I2) and I 10 (Or I10) Measured according to ASTM D-1238 (Method B) at 190°C and under loads of 2.16 kg and 10 kg respectively. The values ​​are reported in g / 10 min.

[0207] density

[0208] Samples for density measurement are prepared according to ASTM D4703. According to ASTM D792, Method B involves measuring the sample within one hour of pressing it.

[0209] Conventional gel permeation chromatography (conventional GPC)

[0210] The GPC-IR high-temperature chromatography system from PolymerChar (Valencia, Spain) is equipped with a precision detector (Amherst, MA), a 2-angle laser scattering detector (Model 2040), an IR5 infrared detector, and a 4-capillary viscometer (both from PolymerChar). Data collection is performed using PolymerChar Instrument Control software and a data acquisition interface. The system is also equipped with an online solvent degassing unit and pumping system from Agilent Technologies (Santa Clara, CA).

[0211] The injection temperature was controlled at 150°C. Three 10-micron "Hybrid B" columns from Polymer Laboratories (Shropshire, UK) were used. 1,2,4-Trichlorobenzene was used as the solvent. Samples were prepared at a concentration of 0.1 g of polymer in 50 mL of solvent. Both the chromatographic solvent and the sample preparation solvent contained 200 ppm butylated hydroxytoluene (BHT). Both solvent sources were bubbled with nitrogen. The ethylene-based polymer sample was gently stirred at 160°C for three hours. The injection volume was 200 μL, and the flow rate was 1 mL / min. The GPC column assembly was calibrated by running 21 polystyrene standards with narrow molecular weight distributions. The standards ranged in molecular weight (MW) from 580 g / mol to 8,400,000 g / mol and were contained in six "cocktail" mixtures. Each standard mixture had at least a tenfold interval between individual molecular weights. The standard mixture was purchased from Polymer Laboratories. Polystyrene standards were prepared as follows: for molecular weights equal to or greater than 1,000,000 g / mol, 0.025 g in 50 mL solvent was used, and for molecular weights less than 1,000,000 g / mol, 0.050 g in 50 mL solvent was used.

[0212] Dissolve the polystyrene standard at 80°C for 30 minutes with gentle stirring. First, operate the narrow standard mixture, following the order of highest molecular weight components in descending order to minimize degradation. Use Equation 1 to convert the peak molecular weight of the polystyrene standard to the molecular weight of polyethylene (as described by Williams and Ward, J. Polym. Sci. Polym. Letters, 6, 621 (1968)):

[0213] Mpolyethylene = A × (Mpolystyrene) B (Equation 1)

[0214] Where M is the molecular weight, A equals 0.4316 and B equals 1.0.

[0215] Calculate the number-average molecular weight (Mn(conv gpc)), weight-average molecular weight (Mw-conv gpc), and z-average molecular weight (Mz(conv gpc)) using the following equations 2-4.

[0216]

[0217]

[0218]

[0219] In equations 2 through 4, RV is the column retention volume (linear interval), collected at “1 point per second”, IR is the IR detector signal from the IR5 measurement channel of the GPC instrument minus the baseline, in volts, and M PE Let MW be the equivalent polyethylene value determined by Equation 1. The data was calculated using GPC One software (version 2.013H) from PolymerChar.

[0220] Creep zero-shear viscosity measurement method

[0221] Zero shear viscosity was obtained through creep testing performed on an AR G2 stress-controlled rheometer (TA Instruments; New Castle, Del) using parallel plates with a diameter of 25 mm at 190 °C. The rheometer oven was set to the test temperature for at least 30 minutes before zeroing the fixture. At the test temperature, the compressed sample disc was inserted between the plates and allowed to equilibrate for five minutes. The upper plate was then lowered to 50 μm above the desired test gap (1.5 mm) (instrument setting). Any excess material was trimmed off, and the upper plate was lowered to the desired gap. Measurements were performed under nitrogen purging at a flow rate of 5 L / min. The default creep time was set to two hours. Each sample was compressed into a circular plate of “2 mm thickness × 25 mm diameter” at 10 MPa pressure in air for five minutes at 177 °C. The samples were then removed from the press and placed on a counter to cool.

[0222] A constant low shear stress of 20 Pa was applied to all samples to ensure that the steady-state shear rate was low enough to fall within the Newtonian region. For the samples in this study, the obtained steady-state shear rates were within 10 Pa. -3 s -1 Up to 10 -4 s -1 Within the range of [values ​​to be filled in], steady state was determined by linear regression of all data points in the last 10% time window of the "log(J(t)) vs. log(t)" graph, where J(t) is the creep compliance and t is the creep time. If the slope of the linear regression was greater than 0.97, steady state was considered reached, and the creep test was stopped. In all cases of this study, the slope met the stated criterion within one hour. The steady-state shear rate was determined by the slope of the linear regression of all data points in the last 10% time window of the "ε vs. t" graph, where ε is the strain. Zero-shear viscosity was determined by the ratio of applied stress to the steady-state shear rate.

[0223] To determine whether a sample degraded during the creep test, the same sample was subjected to small-amplitude oscillatory shear tests ranging from 0.1 rad / s to 100 rad / s before and after the creep test. The complex viscosity values ​​of the two tests were compared. If the difference in viscosity values ​​was greater than 5% at 0.1 rad / s, the sample was considered to have degraded during the creep test, and the results were discarded.

[0224] Zero shear viscosity ratio (ZSVR)

[0225] Zero-shear viscosity ratio (ZSVR) is defined as the ratio of the zero-shear viscosity (ZSV) of branched polyethylene to that of linear polyethylene at equivalent average molecular weight. According to the equation:

[0226] ZSVR=η 0B / η 0L =η 0B / (2.29 -15 X Mwt 3.65 )

[0227] ZSV values ​​were obtained from creep tests at 190°C using the method described above. Mwt was determined using conventional gel permeation chromatography, as mentioned above. A correlation between the ZSV and molecular weight of linear polyethylene was established based on a series of linear polyethylene reference materials. Lower ZSVR indicates a lower level of long-chain branching.

[0228] use 13 C NMR branching measurement

[0229] Sample preparation

[0230] Samples were prepared by adding approximately 2.7 g of a 50 / 50 mixture of tetrachloroethane-d2 / o-dichlorobenzene containing 0.025 M Cr(AcAc)3 to 0.20 g to 0.30 g of sample in a Norell 1001-7 10 mm NMR tube. Oxygen was removed by purging the tube with N2 for 1 minute. The sample was dissolved and homogenized by heating the tube and its contents to 120 °C to 140 °C using a heating block and vortex mixer. Each sample was visually inspected to ensure homogeneity. Thoroughly mixed samples were not allowed to cool before insertion of the heated NMR sample converter and / or NMR probe.

[0231] Data acquisition parameters

[0232] Data were collected using a Bruker 600MHz spectrometer equipped with a Bruker 10mm multi-core high-temperature CryoProbe. Data were acquired at a sample temperature of 120°C using 1280 transients per data file, a 7.8-second pulse repetition delay, a 90-degree flip angle, and reverse-gated decoupling. All measurements were performed on non-spin samples in locked mode. The samples were allowed to thermally equilibrate before data acquisition. 13 The internal reference chemical shift for C NMR is the EEE triunit group at 30.0 ppm. Data are processed into spectra, and appropriate peaks are integrated (to quantify branching). The integrated values ​​of one or more peaks are then used, or the total branching / 1000C is averaged. If branching is not detected, the detection limit of the spectrum is calculated using the integral of peaks such as those caused by chain ends and the signal-to-noise ratio.

[0233] use 1 H NMR measurement of unsaturation

[0234] In a 10 mm NMR tube, a stock solution (3.26 g) was added to a polymer sample ranging from 0.10 g to 0.13 g. The stock solution was tetrachloroethane-d2 (TCE) and perchloroethylene (50:50, w:w) with 0.001 M Cr. 3+ Or 100% TCE with 0.001M Cr 3+ The mixture. Purge the solution in the tube with N2 for 5 minutes to reduce oxygen levels. Dissolve the sample at 120°C to 140°C by periodic vortex mixing. Each time... 1 1H NMR analysis was performed on a Bruker AVANCE 600MHz spectrometer at 120°C using a 10mm cryoprobe.

[0235] Two experiments were conducted to measure unsaturation: a control experiment and a double presaturation experiment. For the control experiment, data were processed using an exponential window function with a 0.7 Hz line widening. Residual data from the TCE were then processed. 1 The H signal is set to 100, and the integration (I) will be approximately -0.5ppm to 3ppm. 总 This signal is used as the whole polymer in the control experiment. The total number of carbons NC in the polymer is calculated using the following equation 1A:

[0236] NC = I 总计 / 2(Equation 1A).

[0237] For the double presaturation experiment, the data were processed using an exponential window function, which broadened the spectral line at 0.7 Hz and corrected the baseline from approximately 7 ppm to 4 ppm. Residual data from TCE were then processed. 1 The signal H is set to 100, and the integral is applied to the corresponding unsaturation (I). 亚乙烯基 I 三取代 I乙烯基 and I 乙烯叉 Integrate the results. It is well known that NMR spectroscopy can be used to determine the degree of unsaturation of polyethylene; see, for example, Busico, V. et al., Macromolecules, 2005, 38, 6988. The number of unsaturated units for vinylene, trisubstituted, vinyl, and ethyleneide is calculated as follows:

[0238] N 亚乙烯基 =I 亚乙烯基 / 2 (Equation 2A),

[0239] N 三取代 =I 三取代 (Equation 3A)

[0240] N 乙烯基 =I 乙烯基 / 2 (Equation 4A),

[0241] N 乙烯叉 =I 乙烯叉 / 2 (Equation 5A).

[0242] The number of unsaturated units per 1,000 total carbon atoms (i.e., all polymer carbon atoms including the main chain and branches) is calculated as follows:

[0243] N 亚乙烯基 / 1,000C=(N 亚乙烯基 / NC)*1,000 (Equation 6A),

[0244] N 三取代 / 1,000C=(N 三取代 / NC)*1,000 (Equation 7A),

[0245] N 乙烯基 / 1,000C=(N 乙烯基 / NCH2)*1,000 (Equation 8A),

[0246] N 乙烯叉 / 1,000C=(N 乙烯叉 / NC)*1,000 (Equation 9A).

[0247] For the residual protons from TCE-d2 1 The H signal was used, with the chemical shift reference value set at 6.0 ppm. Control was performed using ZG pulses: NS = 16, DS = 2, AQ = 1.82 s, D1 = 14 s (where D1 is the relaxation delay). The double presaturation experiment was performed using a modified pulse sequence: O1P = 1.354 ppm, O2P = 0.960 ppm, NS = 50, AQ = 1.82 s, D1 = 1 s (where D1 is the presaturation time), D13 = 13 s (where D13 is the relaxation delay).

[0248] Methods for improving comonomer content distribution analysis (iCCD)

[0249] An improved method for comonomer content analysis (iCCD) was developed in 2015 (Cong and Parrott et al., WO2017040127A1). iCCD tests were performed using a Crystallization Elution Fractionation (CEF) instrument (Perimocha, Spain) equipped with an IR-5 detector (PolymerChar, Spain) and a two-corner light scattering detector model 2040 (Precision Detectors, now Agilent Technologies). A guard column filled with 20-27 micron glass (MoSCi Corporation, USA) was installed just before the IR-5 detector in the detector oven. o-Dichlorobenzene (ODCB, 99% anhydrous or industrial grade) was used. The results were obtained from EMD. Chemicals obtained silica gel 40 (particle size 0.2–0.5 mm, catalog number 10181-3) (previously used as a solvent for drying ODCB). The CEF instrument was equipped with an autosampler with N2 sweep capability. ODCB was bubbled with dry nitrogen (N2) for one hour before use. Sample preparation was performed at 160°C with shaking at a concentration of 4 mg / mL (unless otherwise specified) using the autosampler for 1 hour. The injection volume was 300 μL. The iCCD temperature profile was as follows: crystallization from 105°C to 30°C at 3°C / min, thermal equilibration at 30°C for 2 minutes (including a 2-minute elution time for the soluble fraction), and elution from 30°C to 140°C at 3°C / min. The flow rate during crystallization was 0.0 mL / min. The flow rate during elution was 0.50 mL / min. Data was collected at a rate of one data point per second.

[0250] An iCCD column was filled with gold-plated nickel particles (Bright7GNM8-NiS, Nippon Chemical Industrial Co.) in a 15cm (length) x 1 / 4” (ID) stainless steel tube. The column was filled and conditioned using a slurry method, following references (Cong, R.; Parrott, A.; Hollis, C.; Cheatham, M. WO2017040127A1). The final pressure for TCB slurry filling was 150 bar.

[0251] Column temperature calibration was performed using a mixture of a reference material, linear homopolymer polyethylene (with zero comonomer content, melt index (I2) of 1.0, polydispersity Mw / Mn of approximately 2.6 by conventional gel permeation chromatography, 1.0 mg / ml) and ODCB containing eicosane (2 mg / ml). The iCCD temperature calibration consisted of four steps: (1) calculating the delay volume, which was defined as the measured peak elution temperature of eicosane minus the temperature bias between 30.00 °C and the measured peak elution temperature; and (2) subtracting the temperature bias of the elution temperature from the raw iCCD temperature data. It should be noted that the temperature bias is a function of experimental conditions, such as elution temperature, elution flow rate, etc.; (3) Create a linear calibration line by switching the elution temperature in the range of 30.00℃ to 140.00℃, so that the linear homopolymer polyethylene reference has a peak temperature of 101.0℃ and the eicosane has a peak temperature of 30.0℃; (4) For the soluble fraction measured isothermally at 30℃, the elution temperature below 30.0℃ is linearly extrapolated by using an elution heating rate of 3℃ / min, according to the reference (Cerk and Cong et al., US9,688,795).

[0252] A relationship between comonomer content and iCCD elution temperature was constructed using 12 reference materials (ethylene homopolymers and ethylene-octene random copolymers prepared with unit-point metallocene catalysts, with ethylene equivalent weight-average molecular weights ranging from 35,000 to 128,000). All these reference materials were analyzed in the same manner as previously specified at 4 mg / mL. The reported elution peak temperatures were linearly fitted to the linear equation y = -6.3515x + 101.00, where y represents the iCCD elution temperature, x represents octene mol%, and R0... 2 It is 0.978.

[0253] By assuming a shape factor of 1 and all virial coefficients equal to zero, the molecular weight of the polymer and polymer fractions were determined directly from the LS detector (90-degree angle) and the concentration detector (IR-5) according to the Rayleigh-Gans-Debys approximation (Striegel and Yau, Modern Size Exclusion Liquid Chromatogram, pp. 242 and 263). An integration window was set to integrate all chromatograms over an elution temperature range of 23.0 °C to 120 °C (temperature calibration specified above).

[0254] Calculating molecular weight (Mw) from an iCCD involves the following four steps:

[0255] (1) Measurement of the bias between detectors. The bias is defined as the geometric volume bias between the LS detector and the concentration detector. It is calculated as the difference in elution volume (mL) of the polymer peak between the concentration detector and the LS chromatogram. This is converted to temperature bias using elution heat rate and elution flow rate. Linear high-density polyethylene (comonomer content of zero, melt index (I2) of 1.0) was used, and polydispersity M2 was obtained by conventional gel permeation chromatography. w / M n (Approximately 2.6). The same experimental conditions as the standard iCCD method described above were used, except for the following parameters: crystallization from 140°C to 137°C at 10°C / min, followed by 1 minute of thermal equilibration at 137°C as the elution time for the soluble fraction, and elution of the soluble fraction (SF) from 137°C to 142°C at 3°C / min. The flow rate during crystallization was 0.0 mL / min. The flow rate during elution was 0.80 mL / min. The sample concentration was 1.0 mg / mL.

[0256] (2) Before integration, each LS data point in the LS chromatogram is shifted to correct for detector bias.

[0257] (3) The baseline minus the LS and concentration chromatograms over the entire elution temperature range of step (1) is integrated. The MW detector constant is calculated using known MW HDPE samples in the range of 100,000 to 140,000 Mw and the area ratio of the integrated LS and concentration signals.

[0258] (4) The Mw of the polymer was calculated by using the ratio of the integrated light scattering detector (90-degree angle) to the concentration detector and the MW detector constant.

[0259] The half-peak width is calculated as the temperature difference between the front and back of the maximum peak height at half the peak height. The front temperature at half the maximum peak height is searched forward from 35.0℃, while the back temperature at half the maximum peak height is searched backward from 119.0℃.

[0260] Dynamic shear rheology

[0261] The sample was compressed and molded in air for 6.5 minutes at 190°C and 25,000 psi, and then the plate was cooled on a laboratory workbench. The plate thickness was approximately 3 mm. Isothermal frequency scanning measurements were performed under nitrogen purging on an ARES strain-controlled parallel plate rheometer (TA Instruments) equipped with a 25 mm parallel plate. For each measurement, the rheometer was thermally equilibrated for at least 30 minutes before the gap was zeroed. The sample was placed on the plate and allowed to melt at 190°C for five minutes. The plate was then brought closer together to 2 mm to trim the sample, and the test was then started. The method included an additional five-minute delay to allow for temperature equilibration. Experiments were conducted at 190°C at five points every tenfold intervals in the frequency range of 0.1 rad / s–100 rad / s. The strain amplitude was kept constant at 10%. The stress response was analyzed based on amplitude and phase, from which the storage modulus (G'), loss modulus (G”), complex modulus (G*), dynamic complex viscosity (η*), and tanδ (or tanδ) were calculated.

[0262] Dart Impact

[0263] After membrane preparation, the membrane was conditioned for at least 40 hours at 23°C (+ / -2°C) and 50% RH (+ / -5) according to ASTM standards. The standard test conditions according to ASTM standards are 23°C (+ / -2°C) and 50% RH (+ / -5).

[0264] The sample thickness at the center is measured, and then the sample is clamped using a ring-shaped sample holder with an internal diameter of 5 inches. A dart is loaded above the sample center and released via a pneumatic or electromagnetic mechanism.

[0265] The test is performed using a 'ladder' method. If a sample fails, a new sample is tested with the dart weight reduced by a known and fixed amount. If a sample does not fail, a new sample is tested with the dart weight increased by a known amount. After testing 20 samples, the number of failures is determined. If this number is 10, the test is complete. If the number is less than 10, the test continues until 10 failures are recorded. If the number is greater than 10, the test continues until the total number of unfailed failures is 10. The dart impact value is determined from these data according to ASTM D1709 and expressed in grams. The test results in the examples are reported using Method A (Type A dart impact).

[0266] The terms “dart drop impact” and “dart impact” are used synonymously in this document to refer to this test method. The term “normalized dart drop impact” refers to the measured dart drop impact divided by the film thickness.

[0267] Some embodiments of the present invention will now be described in detail in the following examples.

[0268] Example

[0269] First polyethylene component

[0270] The following are examples of the first polyethylene component used in embodiments of the polyethylene compositions of the present invention. The first polyethylene component 1 was prepared according to the following process and based on the reaction conditions reported in Table 1.

[0271] All feedstocks (ethylene monomer) and process solvents (narrow-boiling-range, high-purity isoparaffin solvent, Isopar-E) were purified using molecular sieves before being introduced into the reaction environment. Hydrogen was supplied pressurized at a high purity level without further purification. The monomer feed stream to the reactor was pressurized to above the reaction pressure via a mechanical compressor. The solvent feed stream was pressurized to above the reaction pressure via a pump. Each catalyst component was manually diluted in batches to the specified concentration using purified solvent and then pressurized to above the reaction pressure. All reaction feed streams were measured using mass flow meters and independently controlled by a computer-automated valve control system.

[0272] The continuous solution polymerization reactor consists of two liquid-filled, non-adiabatic isothermal loop reactors mimicking a continuous stirred tank reactor (CSTR) with heat removal. The feed of all fresh solvent, monomer, hydrogen, and catalyst components to each reactor can be controlled independently. The temperature of the entire fresh feed stream (solvent, monomer, and hydrogen) entering each reactor is controlled by passing the feed stream through a heat exchanger. The total fresh feed to each polymerization reactor is injected into the reactor at two locations, with approximately equal reactor volumes between each injection location. The fresh feed entering the first reactor is typically controlled to receive half the total fresh feed mass flow rate at each injector. The fresh feed to the second reactor in series is typically controlled to maintain half the total ethylene mass flow rate near each injector, and because unreacted ethylene from the first reactor enters the second reactor adjacent to the low-pressure fresh feed, this injector typically receives less than half the total fresh feed mass flow rate entering the second reactor.

[0273] The catalyst / co-catalyst components for each reactor are injected into the polymerization reactor through specially designed injection plugs. Each catalyst / co-catalyst component is injected into the same relative position within the reactor, with no contact time prior to injection. The main catalyst component is computer-controlled to maintain the monomer conversion of each individual reactor at a specified target. The co-catalyst component is fed based on a calculated specified molar ratio to the main catalyst component.

[0274] The catalyst used in the first reactor is [[2,2”'-[[bis[1-methylethyl)germanene]bis(methyleneoxy-κO)]bis[3”,5,5”-tris(1,1-dimethylethyl)-5'-octyl[1,1':3',1”-terphenyl]-2'-root-κO]](2-)]dimethylzirconium, with the chemical formula C 86 H 128 F2GeO4Zr and the following structure (“Catalyst 1”):

[0275]

[0276] The catalyst used in the second reactor is [[2,2”'-[1,3-propanediylbis(oxy-κO)]bis[3-[2,7-bis(1,1-dimethylethyl)-9H-carbazole-9-yl]]-5'-(dimethyloctylsilyl)-3'-methyl-5-(1,1,3,3-tetramethylbutyl)[1,1]-biphenyl]-2-root-κO]](2-)]dimethylzirconium, with the chemical formula C 107 H 154 N2O4Si2Zr and the following structure (“Catalyst 2”):

[0277]

[0278] Following the feed injection point at each reactor, a static mixing element mixes the feed stream with the contents of the circulating polymerization reactor. The contents of each reactor are continuously circulated through a heat exchanger, which removes most of the heat of reaction, and the coolant side temperature is responsible for maintaining the isothermal reaction environment at the designated reactor temperature. Circulation around each reactor loop is provided by a pump.

[0279] The effluent from the first polymerization reactor (containing solvent, monomer, hydrogen, catalyst components, and molten polymer) exits the first reactor loop and passes through a control valve (responsible for controlling the pressure of the first reactor at a specified target) and is injected into a similarly designed second polymerization reactor. The final effluent from the second polymerization reactor enters a region where it is deactivated by adding and reacting with a suitable reagent (water). At the same reactor outlet location, additional additives are added for polymer stabilization. This final effluent stream passes through another set of static mixing elements to promote catalyst deactivation and additive dispersion.

[0280] After catalyst deactivation and the addition of additives, the reactor effluent enters the volatilization system, where polymers are removed from the non-polymer stream. The separated polymer melt is granulated and collected. The non-polymer stream is separated by various devices that handle most of the ethylene removed from the system. Most of the solvent is recycled back to the reactor after passing through a purification system. Small amounts of solvent are removed from the process. Polyethylene composition 1 is stabilized with a small amount (ppm) of stabilizer.

[0281] The polymerization conditions of the first polyethylene component 1 are shown in Table 1. As shown in Table 1, co-catalyst 1 (bis(hydrogenated tallow alkyl)methyltetra(pentafluorophenyl)boronic acid (1-)amine) and co-catalyst 2 (modified methylaluminoxane (MMAO)) are used as co-catalysts for catalyst 1 and catalyst 2, respectively.

[0282] The first polyethylene component 2 was prepared using the same catalyst system as polyethylene component 1 and the same method with comparable reaction conditions.

[0283] Other properties of the first polyethylene component 1 and the first polyethylene component 2 were measured using the test methods described above and are reported in Table 2. The first polyethylene fraction refers to the polyethylene component from the first reactor, and the second polyethylene fraction refers to the polyethylene fraction from the second reactor.

[0284] Table 1

[0285]

[0286]

[0287] Table 2

[0288]

[0289]

[0290] *The detection limit for this measurement is <3.

[0291] **Target

[0292] As described in the Test Methods section above, the densities of the first polyethylene fractions of first polyethylene component 1, total first polyethylene component 1, and total first polyethylene component 2 were measured. The density of the first polyethylene fraction of first polyethylene component 2 is the target value. The density of the second polyethylene fraction was calculated using the following blending rules:

[0293]

[0294] The first polyethylene component 1 can be dry-blended with the Hyperform HPN-20E nucleating agent (Milliken Chemical) provided in the masterbatch to obtain different final loadings of HPN-20E nucleating agent (“HPN-20E”). An example of a masterbatch containing HPN-20E comprises 3 wt% HPN-20E, 1.5 wt% silica, 0.5 wt% hydrotalcite, 5 wt% antioxidant, and 90 wt% carrier resin. The carrier resin may have a density of 0.965 g / cm³. 3 It is a high-density polyethylene homopolymer with a narrow molecular weight distribution and a melt index (I2) of 8.0 g / 10 min. Hyperform HPN-20E contains approximately 66 wt% calcium 1,2-cyclohexanedicarboxylate and approximately 34 wt% zinc stearate / zinc palmitate. This masterbatch formed using Hyperform HPN-20E as a nucleating agent will be referred to as "nucleating agent masterbatch".

[0295] In preparing the membranes in the following embodiments, the same catalyst system as polyethylene component 1 and polyethylene component 2 was used, and the same process and comparable reaction conditions were used to prepare the first polyethylene component, such that the first polyethylene component has properties consistent with polyethylene component 2. This first polyethylene component was melt-blended with a nucleating masterbatch to provide a target loading of 750 ppm of Hyperform HPN-20E nucleating agent. The first polyethylene component 3 mentioned below in the formation of the membranes of the present invention and comparative membranes should be understood as the first polyethylene component incorporating a nucleating masterbatch with a target loading of 750 ppm Hyperform HPN-20E.

[0296] Second polyethylene component

[0297] The following are examples of the second polyethylene component that can be used in embodiments of the multilayer film of the present invention.

[0298] The second polyethylene components 1 to 5, as described in one or more embodiments in the detailed description, are prepared by the following method and using the following catalyst and reactor.

[0299] All feedstocks (monomers and comonomers) and process solvents (narrow-boiling-range, high-purity isoparaffin solvent, Isopar-E) were purified using molecular sieves before being introduced into the reaction environment. Hydrogen was supplied pressurized at a high purity level without further purification. The monomer feed stream to the reactor was pressurized to above the reaction pressure via a mechanical compressor. The solvent and comonomer feed streams were pressurized to above the reaction pressure via pumps. Individual catalyst components were manually diluted in batches with purified solvent and pressurized to above the reaction pressure. All reaction feed streams were measured by mass flow meters and independently controlled by a computer-automated valve control system.

[0300] Two reactor systems are used in series. Each continuous solution polymerization reactor consists of a liquid-filled, non-adiabatic isothermal circulating loop reactor simulating a continuous stirred tank reactor (CSTR) with deheating. All fresh solvent, monomer, comonomer, hydrogen, and catalyst components can be independently controlled. The total fresh feed stream (solvent, monomer, comonomer, and hydrogen) to each reactor is temperature-controlled to maintain a single solution phase by passing the feed stream through a heat exchanger. The total fresh feed to each polymerization reactor is injected into the reactor at two locations, with approximately equal reactor volumes between each injection point. The fresh feed is controlled by receiving half the total fresh feed mass flow rate at each injector. The catalyst component is injected into the polymerization reactor through an injection insert. The main catalyst component feed is computer-controlled to maintain the monomer conversion of each reactor at a specified target. The cocatalyst component is fed based on a calculated specified molar ratio to the main catalyst component. Immediately following each reactor feed injection point, the feed stream is mixed with the contents of the circulating polymerization reactor using static mixing elements. The contents of each reactor are continuously circulated through a heat exchanger, which removes most of the heat of reaction, and the temperature on the coolant side is responsible for maintaining the isothermal reaction environment at the specified temperature. Circulation around each reactor loop is provided by a pump.

[0301] In a dual-series reactor configuration, the effluent from the first polymerization reactor (containing solvent, monomer, comonomer, hydrogen, catalyst components, and polymer) leaves the first reactor loop and is added to the second reactor loop.

[0302] The effluent from the second reactor enters a region where the polymer is deactivated by adding a suitable reagent (water) and reacting with it. At the same reactor outlet location, additional additives are added to stabilize the polymer (typical antioxidants suitable for stability during extrusion and film manufacturing processes, such as octadecyl 3,5-di-tert-butyl-4-hydroxyhydrocinnamate, tetra(methylene(3,5-di-tert-butyl-4-hydroxyhydrocinnamate))methane, and tris(2,4-di-tert-butyl-phenyl)phosphite).

[0303] After catalyst deactivation and the addition of additives, the reactor effluent enters the volatilization system, where polymers are removed from the non-polymer stream. The separated polymer melt is granulated and collected. The non-polymer stream is separated by various devices that handle most of the ethylene removed from the system. Most of the solvent and unreacted comonomers are recycled back to the reactor after passing through a purification system. Small amounts of solvent and comonomers are removed from the process.

[0304] The polymerization conditions for the second polyethylene components 1 to 5 are shown in Table 3. Table 4 shows the catalysts mentioned in Table 3.

[0305] Table 3

[0306]

[0307]

[0308]

[0309] Table 4

[0310]

[0311] The second polyethylene component 6, as described in one or more embodiments in the detailed description, is prepared by the following method and using the following catalyst and reactor.

[0312] All feedstocks (monomers and comonomers) and process solvents (narrow-boiling-range, high-purity isoparaffin solvent, Isopar-E) were purified using molecular sieves before being introduced into the reaction environment. Hydrogen was supplied pressurized at a high purity level without further purification. The monomer feed stream to the reactor was pressurized to above the reaction pressure via a mechanical compressor. The solvent and comonomer feed streams were pressurized to above the reaction pressure via pumps. Individual catalyst components were manually diluted in batches with purified solvent and pressurized to above the reaction pressure. All reaction feed streams were measured by mass flow meters and independently controlled by a computer-automated valve control system.

[0313] The two reactor systems are used in parallel configuration. Each continuous solution polymerization reactor consists of a liquid-filled, non-adiabatic isothermal circulating loop reactor simulating a continuous stirred tank reactor (CSTR) with deheating. All fresh solvent, monomer, comonomer, hydrogen, and catalyst components can be independently controlled. The total fresh feed stream (solvent, monomer, comonomer, and hydrogen) to each reactor is temperature-controlled to maintain a single solution phase by passing the feed stream through a heat exchanger. The total fresh feed to each polymerization reactor is injected into the reactor at two locations, with approximately equal reactor volumes between each injection point. The fresh feed is controlled by receiving half the total fresh feed mass flow rate at each injector. The catalyst component is injected into the polymerization reactor through a specially designed injection plug. The main catalyst component feed is computer-controlled to maintain the monomer conversion of each reactor at a specified target. The cocatalyst component is fed based on a calculated specified molar ratio to the main catalyst component. Immediately following each reactor feed injection point, the feed stream is mixed with the contents of the circulating polymerization reactor using static mixing elements. The contents of each reactor are continuously circulated through a heat exchanger, which removes most of the heat of reaction, and the temperature on the coolant side is responsible for maintaining the isothermal reaction environment at the specified temperature. Circulation around each reactor loop is provided by a pump.

[0314] The effluent streams from the first and second polymerization reactors are combined before any further processing. This final combined reactor effluent enters a region where the polymer is deactivated by adding and reacting with a suitable reagent (water). At the same reactor outlet location, additional additives are added to stabilize the polymer (typical antioxidants suitable for stability during extrusion and blown film manufacturing, such as octadecyl 3,5-di-tert-butyl-4-hydroxycinnamate, tetra(methylene(3,5-di-tert-butyl-4-hydroxycinnamate))methane, and tris(2,4-di-tert-butyl-phenyl)phosphite).

[0315] After catalyst deactivation and the addition of additives, the reactor effluent enters the volatilization system, where polymers are removed from the non-polymer stream. The separated polymer melt is granulated and collected. The non-polymer stream is separated by various devices that handle most of the ethylene removed from the system. Most of the solvent and unreacted comonomers are recycled back to the reactor after passing through a purification system. Small amounts of solvent and comonomers are removed from the process.

[0316] The polymerization conditions for the second polyethylene component 6 are shown in Table 5. Table 4 shows the catalysts mentioned in Table 5.

[0317] Table 5

[0318]

[0319] The second polyethylene components 1, 3, 5, and 6 were analyzed using iCCD. iCCD data for the second polyethylene component 5 are provided in... Figure 3 Additional data generated from iCCD testing of these samples are provided in Tables 6A and 6B. Specifically, Tables 6A and 6B include analysis of the iCCD data, including the area of ​​the first and second polyethylene fractions (45°C to 87°C and 95°C to 120°C), respectively. Additional data for these samples are also provided, including the overall density, melt index, and weight-average molecular weight in the second PE fraction. These properties are based on a single-layer blown film composed entirely of each polyethylene sample.

[0320] Table 6A

[0321]

[0322] Table 6B

[0323]

[0324] Polyethylene compositions 1 to 7 of the present invention and comparative polyethylene compositions A to C

[0325] First component 3 (“first PE component”) and second polyethylene component 5 (“second PE component”) were dry-blended in various amounts to provide the polyethylene compositions 1 to 7 of the present invention and comparative polyethylene compositions A to B as shown in Table 7. Blending was carried out in a single-screw extruder at 220°C. Comparative polyethylene composition C is ELITE, commercially available from Dow Chemical Company. TM 5940. Analysis of the polyethylene compositions of the present invention and comparative polyethylene compositions by iCCD. Table 7 includes the analysis of iCCD data, including the area (50°C to 85°C, 85°C to 100°C, and 100°C to 120°C) and molecular weight (M) of the first, second, and third polyethylene fractions. w Table 7 also provides the overall densities of the polyethylene compositions of the present invention and comparative polyethylene compositions. These densities were calculated using the blending rules provided in the description of the first polyethylene component above. These properties are based on a single-layer blown film composed entirely of each polyethylene sample.

[0326] Table 7

[0327]

[0328] Membranes 1 to 7 of the present invention and comparative membranes A to C

[0329] Films 1 to 7 of the present invention and comparative films A to C are respectively formed from polyethylene compositions 1 to 7 of the present invention and comparative polyethylene compositions. The films are single-layer films manufactured using a Dr. Collin 7-layer blown film production line and the following manufacturing conditions:

[0330] ● Mold clearance: 1.8mm

[0331] ●BUR: 2.5

[0332] ●Air temperature: 18℃

[0333] ● Mold temperature: 210℃

[0334] ●Extrusion temperature: 190℃ to 220℃

[0335] ●Retrieval speed: 3.5m / min

[0336] ● Output rate: 5.92 kg / h

[0337] ●Thickness: ~3.54mil

[0338] Normalized dart impact strength of the membranes was measured using the methods described in the Test Methods section above. Table 8 includes the thickness and normalized dart impact strength of each membrane. The secant modulus in the longitudinal direction of the membranes of the present invention was measured at 2% strain, and each of the membranes of the present invention exhibits a 2% secant modulus greater than 500 MPa.

[0339] Table 8

[0340]

[0341] As shown in Table 8, each of the films of the present invention exhibits a normalized dart impact of 116 g / mil or higher. Simultaneously, the films of the present invention maintain a 2% secant modulus greater than 500 MPa in the longitudinal direction. This indicates that the polyethylene compositions of the present invention provide an excellent balance between stiffness (characterized by secant modulus) and toughness (characterized by dart impact).

Claims

1. A polyethylene composition comprising: (1) A first polyethylene fraction, wherein the first polyethylene fraction has a single peak in the elution curve obtained by an improved comonomer composition distribution iCCD analysis method in the temperature range of 50°C to 85°C, wherein the first polyethylene area fraction is the area below the single peak of the first polyethylene fraction in the elution curve between 50°C and 85°C, and wherein, when measured using the iCCD analysis method, the average M in the first polyethylene fraction is... w The range is from 100,000 g / mol to 225,000 g / mol; (2) A second polyethylene fraction, wherein the second polyethylene fraction has a single peak in the elution curve obtained by the iCCD analysis method in the temperature range of 85°C to 100°C, wherein the second polyethylene area fraction is the area below the single peak of the second polyethylene fraction in the elution curve between 85°C and 100°C, and wherein, when measured using the iCCD analysis method, the average M in the second polyethylene fraction is... w From 30,000 g / mol to 60,000 g / mol; and (3) A third polyethylene fraction, wherein the third polyethylene fraction has a single peak in the elution curve obtained by iCCD analysis in the temperature range of 100°C to 120°C, wherein the third polyethylene area fraction is the area below the single peak of the third polyethylene fraction in the elution curve between 100°C and 120°C, and wherein the average M in the third polyethylene fraction is measured using the iCCD analysis method. w The range is from 100,000 g / mol to 225,000 g / mol; The first polyethylene area fraction accounts for 25% to 50% of the total area of ​​the elution curve, the second polyethylene area fraction accounts for 30% to 50% of the total area of ​​the elution curve, and the third polyethylene area fraction accounts for 15% to 35% of the total area of ​​the elution curve.

2. The polyethylene composition according to claim 1, wherein the first polyethylene area fraction accounts for 30% to 45% of the total area of ​​the elution curve, wherein the second polyethylene area fraction accounts for 35% to 45% of the total area of ​​the elution curve, and wherein the third polyethylene area fraction accounts for 15% to 30% of the total area of ​​the elution curve.

3. The polyethylene composition according to claim 1 or claim 2, wherein the polyethylene composition has a content of 0.940 g / cm³. 3 Up to 0.949 g / cm 3 The overall density.

4. The polyethylene composition according to claim 1 or 2, wherein the polyethylene composition has a melt index I2 of 0.5 g / 10 min to 2 g / 10 min.

5. The polyethylene composition according to claim 1 or 2, further comprising 20 ppm to 5000 ppm of a nucleating agent based on the total weight of the composition, wherein the nucleating agent comprises calcium 1,2-cyclohexanedicarboxylate or sodium 4-[(4-chlorobenzoyl)amino]benzoate.

6. The polyethylene composition according to claim 1 or 2, wherein the composition is a blend of the following substances: (a) A first polyethylene component, the first polyethylene component comprising: (1) 25% to 37% by weight of a first polyethylene fraction, the first polyethylene fraction having a content of 0.935 g / cm³. 3 Up to 0.947 g / cm 3 Density within the range and melt index I2 less than 0.1 g / 10 min; and (2) 63% to 75% by weight of the second polyethylene fraction; and When using 13 During C NMR measurement, the first polyethylene component has less than 0.10 branches per 1,000 carbon atoms, and the density of the first polyethylene component is at least 0.965 g / cm³. 3 And wherein the melt index I2 of the first polyethylene component is 0.5 g / 10 min to 10 g / 10 min; and (b) a second polyethylene component, the second polyethylene component comprising: (1) A first polyethylene fraction, wherein the first polyethylene fraction has a single peak in the elution curve obtained by an improved comonomer composition distribution iCCD analysis method in the temperature range of 45°C to 87°C, wherein the first polyethylene area fraction is the area below the single peak of the first polyethylene fraction in the elution curve between 45°C and 87°C; and (2) A second polyethylene fraction, wherein the second polyethylene fraction has a single peak in the elution curve obtained by iCCD analysis in the temperature range of 95°C to 120°C, and wherein the second polyethylene area fraction is the area below the single peak of the second polyethylene fraction in the elution curve between 95°C and 120°C. The second polyethylene component has a content of 0.924 g / cm³. 3 Up to 0.936 g / cm 3 The density and melt index I2 of the second polyethylene fraction are 0.25 g / 10 min to 2.0 g / 10 min, wherein the area of ​​the second polyethylene fraction of the second component accounts for at least 40% of the total area of ​​the elution curve, wherein the ratio of the area of ​​the first polyethylene fraction of the second component to the area of ​​the second polyethylene fraction of the second component is 0.75 to 2.5, and wherein the width of the single peak of the second polyethylene fraction of the second component at 50% peak height is less than 5.0 °C. The polyethylene composition comprises, based on the total weight of the polyethylene composition, 30% to 60% by weight of the first polyethylene component and 40% to 70% by weight of the second polyethylene component.

7. The polyethylene composition according to claim 1 or 2, wherein a monolayer film formed from said polyethylene composition and having a thickness of 3 to 4 mil exhibits a normalized dart impact of at least 110 g / mil.

8. A membrane comprising a polyethylene composition according to any one of claims 1 to 7.

9. An article comprising the polyethylene composition according to any one of claims 1 to 7.

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