Multilayer films and articles containing them

Abstract

The present invention relates to a multilayer film. In one embodiment, the multilayer film has a modulus of at least 0.965 g / cm 3 a first polyethylene composition as further described herein having a density of 0.924 g / cm 3 ~0.936g / cm 3 and a second polyethylene composition, as further described herein, wherein the multilayer film comprises 40 weight percent or less of the first polyethylene composition, based on the total weight of the multilayer film.

Description

[Technical Field]

[0001] The present invention relates to multilayer films and articles containing such films.

[0002] Introduction Flexible packaging film structures are often formed from multiple types of polymer materials, such as polyethylene, polypropylene, ethylene vinyl alcohol, polyethylene terephthalate, and polyamide. These materials are typically combined to achieve a balance of properties unattainable with a single type of material. However, due to the differences between these materials, the final packaging is typically not easy to recycle. Therefore, there is a movement towards single-component structures (e.g., structures made entirely of polyethylene) to improve the recyclability profile. For example, in the case of all-polyethylene structures, it becomes necessary to enhance certain performance metrics (e.g., mechanical properties) to maintain the performance levels expected of these structures when formed from different polymer materials, while improving recyclability.

[0003] In the design of films for packaging and other applications, improving one property of the film often comes at the expense of another. For example, using polyethylene with a lower density may improve some mechanical properties (e.g., dirt resistance), but may degrade other properties such as secant coefficient and / or barrier properties.

[0004] It is desirable to have a novel multilayer film containing different polyethylenes that provides an improved balance of properties. [Overview of the Initiative]

[0005] The present invention provides multilayer films comprising combinations of polyethylene compositions having desirable and / or improved properties. In some embodiments, the multilayer films of the present invention also provide a higher modulus of elasticity and / or higher gas barrier properties, while simultaneously providing improved dirt resistance. In some embodiments, for example, a higher density polyethylene can be incorporated into the multilayer film to provide a higher overall film density, while also surprisingly improving dirt resistance.

[0006] In one embodiment, the multilayer film is (a) A first polyethylene composition, (1) 25-37 weight percent, 0.935-0.947 g / cm³ 3 A first polyethylene fraction having a density in the range of and a melt index (I2) of less than 0.1 g / 10 min, and (2) A second polyethylene fraction of 63-75 weight percent, Includes, 13 When measured using 13C NMR, it has less than 0.10 branching per 1,000 carbon atoms and a density of at least 0.965 g / cm³. 3 A first polyethylene composition having a melt index (I2) of 0.5 to 10 g / 10 min, (b) A second polyethylene composition, (1) A first polyethylene fraction having a single peak in the temperature range of 45°C to 87°C in the elution profile via improved comonomer composition distribution (iCCD) analysis, wherein the first polyethylene area fraction is the area in the elution profile directly below the single peak of the first polyethylene fraction in the temperature range of 45°C to 87°C, and (2) A second polyethylene fraction having a single peak in the temperature range of 95°C to 120°C in the elution profile obtained by iCCD analysis, wherein the second polyethylene area fraction is the area in the elution profile directly below the single peak of the second polyethylene fraction at 95°C to 120°C, Includes, The second polyethylene composition is 0.924 g / cm³ 3 ~0.936 g / cm³ 3 A second polyethylene composition comprising: having a density and a melt index (I2) of 0.25 g / 10 min to 2.0 g / 10 min, wherein the area of ​​the second polyethylene fraction constitutes at least 40% of the total area of ​​the elution profile, the ratio of the area of ​​the first polyethylene fraction to the area of ​​the second polyethylene fraction is 0.75 to 2.5, and the width of the single peak of the second polyethylene fraction at the 50 percent peak height is less than 5.0°C; The multilayer film contains 40 weight percent or less of the first polyethylene composition based on the total weight of the multilayer film. In some embodiments, the first polyethylene composition and the second polyethylene composition are present in different layers of the multilayer film. In some embodiments, at least one layer of the multilayer film contains the first polyethylene composition and the second polyethylene composition.

[0007] In some embodiments, the outer layer of the multilayer film comprises a third polyethylene composition, the third polyethylene composition is (a) A first polyethylene fraction having at least one peak in the temperature range of 35°C to 70°C in the elution profile obtained via an improved comonomer composition distribution (iCCD) analysis method, wherein the first polyethylene area fraction is the area in the elution profile at 35°C to 70°C, and the area of ​​the first polyethylene fraction constitutes 25% to 65% of the total area of ​​the elution profile, (b) A second polyethylene fraction in the elution profile obtained via iCCD analysis, which includes at least one peak in the temperature range of 85°C to 120°C, wherein the second polyethylene area fraction is the area in the elution profile at 85°C to 120°C, and the area of ​​the second polyethylene fraction constitutes at least 20% of the total area of ​​the elution profile, (c) A third polyethylene fraction in the elution profile obtained via iCCD analysis, in the temperature range of 70°C to 85°C, wherein the third polyethylene area fraction is the area in the elution profile at 70°C to 85°C, and the area of ​​the third polyethylene fraction constitutes less than 10% of the total area of ​​the elution profile, including the third polyethylene fraction, The third polyethylene composition is 0.880 g / cm³ 3 ~0.910 g / cm³ 3 It has a density of 0.50 g / 10 min to 6.0 g / 10 min (I2), and a zero shear viscosity ratio of less than 2.0.

[0008] The present invention also relates to articles. In one embodiment, the article comprises any of the multilayer films of the present invention disclosed herein.

[0009] These and other embodiments are described in more detail in “Modes for Carrying Out the Invention.” [Brief explanation of the drawing]

[0010] For the purpose of illustrating the embodiments disclosed herein, exemplary forms are shown in the drawings, but it should be understood that these embodiments are not limited to the exact arrangements and means shown. [Figure 1] This figure schematically shows the iCCD elution profile according to one or more embodiments described herein. [Figure 2] This figure schematically shows the iCCD elution profile of a second polyethylene composition according to one or more embodiments described herein. [Modes for carrying out the invention]

[0011] Unless otherwise stated, implicitly indicated by the context, and customary in the art, all parts and percentages are based on weight, all temperatures are in °C, and all test methods are current as of the filing date of this disclosure.

[0012] As used herein, the term “composition” refers to the materials comprising the composition, as well as the mixture of reaction products and decomposition products formed from the materials of the composition.

[0013] The term "polymer" refers to a polymer compound prepared by polymerizing monomers, whether of the same or different types. Therefore, the generic term polymer encompasses the terms homopolymer and interpolymer, as defined below. Trace amounts of impurities (e.g., catalyst residues) may be introduced into and / or within the polymer. A polymer can be a single polymer, a polymer blend, or a polymer mixture containing a mixture of polymers formed in situ during polymerization.

[0014] As used herein, the term “homopolymer” refers to a polymer prepared from only one monomer, with the understanding that trace amounts of impurities may be incorporated into the polymer structure.

[0015] As used herein, the term “interpolymer” refers to a polymer prepared by the polymerization of at least two different monomers. Thus, the collective term “interpolymer” includes copolymers (used to refer to polymers prepared from two different monomers) and polymers prepared from more than two different types of monomers.

[0016] As used herein, the terms “olefinic polymer” or “polyolefin” refer to a polymer comprising, on a basis of weight of the polymer, a majority of an olefin monomer, such as ethylene or propylene, in a polymeric form, and optionally comprising one or more comonomers.

[0017] As used herein, the term "ethylene / α-olefin interpolymer" refers to an interpolymer in which, in its polymerized form, the majority (more than 50 mol%) of units are derived from ethylene monomers and the remaining amount is derived from one or more α-olefins. Typical α-olefins used in the formation of ethylene / α-olefin interpolymers are C3-C3. 10 It is an alkene.

[0018] As used herein, the term "ethylene / α-olefin copolymer" refers to a copolymer in which, in its polymerized form, comprises only two monomers: a majority (more than 50 mol%) of ethylene monomer and an α-olefin.

[0019] As used herein, the term "α-olefin" refers to an alkene having a double bond at the primary or alpha (α) position.

[0020] "Polyethylene" or "ethylene polymer" shall mean a polymer containing a majority (more than 50 mol%) of units derived from ethylene monomers. This includes polyethylene homopolymers or copolymers (meaning units derived from two or more comonomers). Common forms of polyethylene known in the art include Low Density Polyethylene (LDPE), Linear Low Density Polyethylene (LLDPE), Ultra Low Density Polyethylene (ULDPE), Very Low Density Polyethylene (VLDPE), single-site catalyst linear low density polyethylene (m-LLDPE) including both linear low density resin and substantially linear low density resin, ethylene-based plastomer (POP) and ethylene-based elastomer (POE), Medium Density Polyethylene (MDPE), and High Density Polyethylene (HDPE). These polyethylene materials are generally known in the art. However, the following description may be useful in understanding the differences among some of these different polyethylene resins.

[0021] The term "LDPE" may also be referred to as "high pressure ethylene polymer" or "highly branched polyethylene", and is defined to mean that the polymer is partially or completely homopolymerized or copolymerized in an autoclave or tubular reactor at a pressure above 14,500 psi (100 MPa) using a free radical initiator such as peroxide (see, for example, U.S. Patent No. 4,599,392, which is incorporated by reference). LDPE resins typically have a density within the range of 0.916 - 3 3 0.935 g / cm.

[0022] The term "LLDPE" includes both resins produced using single-site catalysts, including but not limited to traditional Ziegler-Natta catalyst systems and chromium-based catalysts, as well as mono- or bis-cyclopentadienyl catalysts (typically referred to as metallocenes), geometrically constrained catalysts, phosphineimine catalysts, and polyvalent aryloxyether catalysts (typically referred to as bisphenylphenoxy), and includes linear, substantially linear, or heterogeneous polyethylene copolymers or homopolymers. LLDPEs contain fewer long-chain branches than LDPEs and include substantially linear ethylene polymers as further defined in U.S. Patents 5,272,236, 5,278,272, 5,582,923, and 5,733,155; homogeneously branched linear ethylene polymer compositions such as those in U.S. Patent 3,645,992; heterogeneously branched ethylene polymers such as those prepared according to the process disclosed in U.S. Patent 4,076,698; and / or blends thereof (such as those disclosed in U.S. Patents 3,914,342 or 5,854,045). LLDPEs can be produced via gas-phase, solution-phase, or slurry polymerization, or any combination thereof, using any type of reactor or reactor configuration known in the art.

[0023] The term "MDPE" refers to 0.926-0.935 g / cm³ 3 "MDPE" refers to polyethylene having a density of 2.5. "MDPE" is typically produced using chromium or Ziegler-Natta catalysts, or single-site catalysts including, but not limited to, substituted mono- or bis-cyclopentadienyl catalysts (typically referred to as metallocenes), bound structure catalysts, phosphineimine catalysts, and polyvalent aryloxyether catalysts (typically referred to as bisphenylphenoxy), and typically has a molecular weight distribution ("molecular weight distribution, MWD") greater than 2.5.

[0024] The term "HDPE" generally refers to single-site catalysts, including but not limited to Ziegler-Natta catalysts, chromium catalysts, or substituted mono- or bis-cyclopentadienyl catalysts (typically referred to as metallocenes), geometrically constrained catalysts, phosphineimine catalysts, and polyvalent aryloxyether catalysts (typically referred to as bisphenylphenoxy), prepared at a concentration of approximately 0.935 g / cm³. 3 Super ~ maximum approx. 0.980g / cm 3 This refers to polyethylene having a certain density.

[0025] The term "ULDPE" generally refers to single-site catalysts, including but not limited to Ziegler-Natta catalysts, chromium catalysts, or substituted mono- or bis-cyclopentadienyl catalysts (typically referred to as metallocenes), geometrically constrained catalysts, phosphineimine catalysts, and polyvalent aryloxyether catalysts (typically referred to as bisphenylphenoxy), prepared using these catalysts at concentrations of 0.855–0.912 g / cm³. 3 This refers to polyethylene having a density of 0.855 to 0.912 g / cm³. Examples of ULDPE include, but are not limited to, polyethylene (ethylene-based) plastomers and polyethylene (ethylene-based) elastomers. Polyethylene (ethylene-based) elastomer plastomers generally have a density of 0.855 to 0.912 g / cm³. 3 It has a density of .

[0026] The terms “blend,” “polymer blend,” and similar terms mean a composition of two or more polymers. Such a blend may or may not be miscible. Such a blend may or may not be phase-separated. Such a blend may or may not contain one or more domain configurations, as determined by transmission electron spectroscopy, light scattering, X-ray scattering, and any other method known in the art. A blend is not a laminate, but one or more layers of a laminate may contain a blend. Such a blend may be prepared as a dry blend, or formed in situ (e.g., in a reactor), as a molten blend, or by other techniques known to those skilled in the art.

[0027] As described herein, the polyethylene “fraction” refers to a portion of the entire composition of a polyethylene composition as described herein. Certain polyethylene compositions described herein include at least a “first polyethylene fraction” and a “second polyethylene fraction.” Some polyethylene compositions may also include a “third polyethylene fraction” and a “fourth polyethylene fraction.” The various fractions contained in such polyethylene compositions can be quantified by their temperature range in the elution profile via an improved comonomer composition distribution (iCCD) analysis method. Unless otherwise specified, any elution profile referred to herein is an elution profile observed via iCCD. Examples of such fractions will be better understood by considering the examples provided herein. Certain polyethylene compositions described herein may be described as “multimodal,” meaning that their elution profile contains at least two peaks. Certain polyethylene compositions described herein may be described as “bimodal,” meaning that there are two main peaks. Others may be described as “trimodal,” meaning that there are three peaks. As used herein, “single peak” refers to an iCCD in which a particular fraction contains only a single peak. In other words, in some embodiments, the iCCD in a particular fraction may have only an upward-sloping region followed by a downward-sloping region, forming a single peak.

[0028] The terms “comprising,” “including,” and “having,” and their derivatives, are not intended to exclude the presence of any additional components, processes, or procedures, whether or not they are specifically disclosed. To avoid any doubt, all compositions claimed through the use of the term “comprising” may include any additional additives, adjuvants, or compounds, whether polymeric or otherwise, unless otherwise stated. In contrast, the term “consisting essentially of” excludes any other components, processes, or procedures from the scope of any subsequent description, except those not essential to operability. The term “consisting of” excludes any components, processes, or procedures not specifically described or listed.

[0029] The present invention provides a multilayer film comprising a combination of polyethylene compositions and having desirable and / or improved properties. In some embodiments, the multilayer film of the present invention also provides a higher modulus of elasticity and / or higher gas barrier properties, while simultaneously providing improved dirt. In some embodiments, for example, a higher density polyethylene can be incorporated into the multilayer film to provide a higher overall film density, while also surprisingly improving dirt performance.

[0030] In one embodiment, the multilayer film is (a) A first polyethylene composition, (1) 25-37 weight percent, 0.935-0.947 g / cm³ 3 A first polyethylene fraction having a density in the range of and a melt index (I2) of less than 0.1 g / 10 min, and (2) A second polyethylene fraction of 63-75 weight percent, Includes, 13When measured using 13C NMR, it has less than 0.10 branching per 1,000 carbon atoms and a density of at least 0.965 g / cm³. 3 A first polyethylene composition having a melt index (I2) of 0.5 to 10 g / 10 min, (b) A second polyethylene composition, (1) A first polyethylene fraction having a single peak in the temperature range of 45°C to 87°C in the elution profile via an improved comonomer composition distribution (iCCD) analysis method, wherein the first polyethylene area fraction is the area in the elution profile directly below the single peak of the first polyethylene fraction in the 45°C to 87°C range, and (2) A second polyethylene fraction having a single peak in the temperature range of 95°C to 120°C in the elution profile obtained by iCCD analysis, wherein the second polyethylene area fraction is the area in the elution profile directly below the single peak of the second polyethylene fraction at 95°C to 120°C, Includes, The second polyethylene composition is 0.924 g / cm³ 3 ~0.936 g / cm³ 3 A second polyethylene composition comprising: having a density and a melt index (I2) of 0.25 g / 10 min to 2.0 g / 10 min, wherein the area of ​​the second polyethylene fraction constitutes at least 40% of the total area of ​​the elution profile, the ratio of the area of ​​the first polyethylene fraction to the area of ​​the second polyethylene fraction is 0.75 to 2.5, and the width of the single peak of the second polyethylene fraction at the 50 percent peak height is less than 5.0°C; The multilayer film contains 40 weight percent or less of the first polyethylene composition, based on the total weight of the multilayer film. In some embodiments, the first polyethylene composition and the second polyethylene composition are present in different layers of the multilayer film. In some embodiments, at least one layer of the multilayer film contains the first polyethylene composition and the second polyethylene composition. Additional details regarding various embodiments of the first polyethylene composition are provided in the following chapter on the first polyethylene composition. Additional details regarding various embodiments of the second polyethylene composition are provided in the following chapter on the second polyethylene composition.

[0031] In some embodiments, the layer comprising the first polyethylene composition further comprises 20 to 5000 ppm of a nucleating agent based on the total weight of the layer, wherein the nucleating agent comprises a calcium salt of 1,2-cyclohexanedicarboxylic acid or sodium 4-[(4-chlorobenzoyl)amino]benzoate.

[0032] In some embodiments, the outer layer of the multilayer film comprises a third polyethylene composition, the third polyethylene composition is (a) A first polyethylene fraction having at least one peak in the temperature range of 35°C to 70°C in the elution profile obtained via an improved comonomer composition distribution (iCCD) analysis method, wherein the first polyethylene area fraction is the area in the elution profile at 35°C to 70°C, and the area of ​​the first polyethylene fraction constitutes 25% to 65% of the total area of ​​the elution profile, (b) A second polyethylene fraction in the elution profile obtained via iCCD analysis, which includes at least one peak in the temperature range of 85°C to 120°C, wherein the second polyethylene area fraction is the area in the elution profile at 85°C to 120°C, and the area of ​​the second polyethylene fraction constitutes at least 20% of the total area of ​​the elution profile, (c) A third polyethylene fraction in the elution profile obtained via iCCD analysis, in the temperature range of 70°C to 85°C, wherein the third polyethylene area fraction is the area in the elution profile at 70°C to 85°C, and the area of ​​the third polyethylene fraction constitutes less than 10% of the total area of ​​the elution profile, including the third polyethylene fraction, The third polyethylene composition is 0.880 g / cm³ 3 ~0.910 g / cm³ 3 The polyethylene composition has a density of 0.50 g / 10 min to 6.0 g / 10 min (I2), and a zero shear viscosity ratio of less than 2.0. Additional details regarding various embodiments of the third polyethylene composition are provided in the following chapter on the third polyethylene composition.

[0033] In some further embodiments, the first polyethylene composition and the second polyethylene composition are present in different layers of the film, with the layer containing the second polyethylene composition being located between the outer layer containing the third polyethylene composition and the layer containing the first polyethylene composition.

[0034] In some embodiments, at least one layer further comprises linear low-density polyethylene, low-density polyethylene, or a combination thereof.

[0035] In another embodiment, the present invention relates to articles such as packaging. In one embodiment, the article comprises any of the multilayer films of the present invention disclosed herein.

[0036] First polyethylene composition As discussed above, the multilayer film of the present invention comprises at least one layer containing a first polyethylene composition having specific properties. The first polyethylene composition used in embodiments of the present invention is (i) 25 to 37 weight percent, 0.935 to 0.947 g / cm³ 3(ii) a first polyethylene fraction having a density in the range and a melt index (I2) of less than 0.1 g / 10 min, and (ii) a second polyethylene fraction of 63 to 75 weight percent, wherein the first polyethylene composition is 13 When measured using 13C NMR, the first polyethylene composition has fewer than 0.10 branchings per 1,000 carbon atoms, and its density is at least 0.965 g / cm³. 3 The melt index (I2) of the first polyethylene composition is 0.5 to 10 g / 10 min.

[0037] In some embodiments, the first polyethylene composition has a melt index (I2) of 2.5 g / 10 min or less.

[0038] In some embodiments, the first polyethylene composition is 25-37 weight percent, or 0.940-0.947 g / cm³. 3 A first polyethylene fraction having a density in the range of 0.970 g / cm³, and 63-75 weight percent of 0.970 g / cm³. 3 It comprises a second polyethylene fraction having the above density.

[0039] The first polyethylene composition may include a combination of two or more embodiments described herein.

[0040] In one embodiment, the first polyethylene composition is at least 0.965 g / cm³ 3 It has a density of . In some embodiments, the first polyethylene composition has a density of at least 0.968 g / cm³. 3 It has a density of . In some embodiments, the first polyethylene composition has a density of up to 0.976 g / cm³. 3 It has a density of 0.965 to 0.976 g / cm³. In some embodiments, the first polyethylene composition has a density of 0.965 to 0.976 g / cm³. 3 For example, 0.965-0.970, or 0.967-0.969, or 0.965-0.970 g / cm³ 3 It has a density in the range of 0.965 or 0.967 g / cm³. For example, the density has a lower limit of 0.965 or 0.967 g / cm³. 3, and its upper limits are 0.970, 0.972, 0.975, or 0.976 g / cm³. 3 It is possible.

[0041] The first polyethylene composition has a melt index (I2 or I2; 190°C / 2.16kg) of 0.5 to 10 g / 10 min. For example, the melt index (I2 or I2; 190°C / 2.16kg) may have a lower limit of 0.5, 0.7, 0.9, 1.0, 1.1, 1.2, 1.5, 2, 3, 4, or 5 g / 10 min and an upper limit of 1.5, 2, 2.5, 3, 4, 5, 6, 7, 8, 9, or 10 g / 10 min. In some embodiments, the first polyethylene composition has a melt index (I2) of 0.5 to 5 g / 10 min, or 0.5 to 2.5 g / 10 min, or 0.7 to 3 g / 10 min, or 1.0 to 2.0 g / 10 min, or 1.0 to 1.5 g / 10 min.

[0042] In some embodiments, the first polyethylene composition has a melt index ratio of 10 or more (I 10 The first polyethylene composition has a melt index ratio (I2) up to 17 in some embodiments. 10 In some embodiments, the first polyethylene composition has a melt index ratio (I2) of 10 to 17. 10 The first polyethylene composition has a melt index ratio (I2) of 12 to 17 in some embodiments. 10 It has / I2).

[0043] The first polyethylene composition has a low level of branching. In some embodiments, the first polyethylene composition has a low level of branching. 13 When measured using 13C NMR, it has less than 0.10 branching per 1,000 carbon atoms. The first polyethylene composition, in some embodiments, 13 When measured using 13C NMR, it has less than 0.07 branching per 1,000 carbon atoms. The first polyethylene composition, in some embodiments, 13When measured using 13C NMR, it has less than 0.05 branching per 1,000 carbon atoms. In some embodiments, the first polyethylene composition is 13 When measured using 13C NMR, it has less than 0.03 branching per 1,000 carbon atoms.

[0044] In some embodiments, the first polyethylene composition has a low level of non-vinyl unsaturation. In some embodiments, the first polyethylene composition is 1 When measured using 1H NMR, it has less than 25 non-vinyl unsaturated carbon atoms per million carbon atoms. The first polyethylene composition, in some embodiments, 1 When measured using 1H NMR, it exhibits less than 20 non-vinyl unsaturation levels per million carbon atoms.

[0045] While we do not wish to be bound by theory, the combination of low branching and low levels of unvinyl unsaturation in the first polyethylene composition is thought to provide a greater degree of crystallinity in the first polyethylene composition, thereby improving its barrier properties when formed into a film.

[0046] In one embodiment, the first polyethylene composition has a 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.

[0047] In one embodiment, the first polyethylene composition has a ratio (M) of weight-average molecular weight to number-average molecular weight. w / M n It has a molecular weight distribution in the range of 8.0 to 14.0, expressed as (measured by conventional GPC). For example, molecular weight distribution (M w / M n ) may have a lower limit of 8.0, 8.5, 9.0, or 9.5, and an upper limit of 10.0, 11.0, 11.5, 12.0, 12.5, 13.0, 13.5, or 14.0. In some embodiments, M w / M n The range is 10.0 to 12.0.

[0048] In one embodiment, the number average molecular weight (M) of the first polyethylene composition n The number-average molecular weight (determined by conventional GPC) is in the range of 8,000 to 20,000 g / mol. For example, the lower limit of the number-average molecular weight may be 8,000, 9,000, 10,000, or 11,000 g / mol, and the upper limit may be 12,000, 13,000, 15,000, or 20,000 g / mol.

[0049] In one embodiment, the weight-average molecular weight (M) of the first polyethylene composition is w The weight-average molecular weight (determined by conventional GPC) is in the range of 100,000 to 125,000 g / mol. For example, the weight-average molecular weight may have a lower limit of 100,000, 105,000, or 110,000 g / mol and an upper limit of 115,000, 120,000, or 124,000 g / mol.

[0050] In one embodiment, the z-average molecular weight (M) of the first polyethylene composition is Z The molecular weight (determined by conventional GPC) is at least 350,000 g / mol, within the range of, for example, 350,000 to 600,000 g / mol. For example, the z-average molecular weight may have a lower limit of 350,000, 375,000, 400,000, 405,000, or 410,000 g / mol, and an upper limit of 420,000, 425,000, 450,000, 475,000, 500,000, 550,000, or 600,000 g / mol.

[0051] In one embodiment, the M of the first polyethylene composition z / M w The ratio (each determined by conventional GPC) is greater than 3.0. M of the first polyethylene composition z / M w The ratio (each determined by conventional GPC) is greater than 3.5 in some embodiments. z / M w In some embodiments, this may be 3.0 to 4.0, or in some embodiments, 3.5 to 4.5, or in some embodiments, 3.5 to 4.0.

[0052] In one embodiment, the first polyethylene composition has a ZSVR of less than 2.0 and an M of greater than 3.0 z / M w The ratios (each determined by conventional GPC) are as follows: In another embodiment, the first polyethylene composition has a ZSVR of less than 2.0 and a M ratio of more than 3.5 z / M w It has a ratio (each determined by conventional GPC).

[0053] The first polyethylene composition preferably comprises an ethylene-based polymer formed in the absence of a comonomer. In some embodiments, the first polyethylene composition comprises at least 99% by weight of an ethylene-based polymer formed in the absence of a comonomer. In some embodiments, the first polyethylene composition comprises a polymer comprising at least 99% by weight of a polymer containing the majority (more than 99 mol%) of units derived from ethylene monomers.

[0054] The first polyethylene composition contains two fractions of polyethylene.

[0055] The first polyethylene fraction is 0.935-0.947 g / cm³. 3 It has a density of 0.940 to 0.947 g / cm³. In some embodiments, the first polyethylene fraction has a density of 0.940 to 0.947 g / cm³. 3 It has a density of . The first polyethylene fraction has a melt index (I2) of less than 0.1 g / 10 min. In some embodiments, the first polyethylene fraction has a melt index (I2) of 0.01 g / 10 min or more. In some embodiments, the first polyethylene fraction has a melt index of 0.05 to 0.1 g / 10 min. In some embodiments, the first polyethylene fraction has, 13 When measured using 13C NMR, it has less than 0.10 branching per 1,000 carbon atoms.

[0056] In some embodiments, the second polyethylene fraction is 0.970 g / cm³. 3It has a density of 0.940 to 0.947 g / cm³. In some embodiments, the first polyethylene fraction has a density of 0.940 to 0.947 g / cm³. 3 The second polyethylene fraction has a density of 0.970 g / cm³. 3 It has the above density. In some embodiments, the second polyethylene fraction has a melt index (I2) of at least 100 g / 10 min. In some embodiments, the second polyethylene fraction has a melt index (I2) of at least 100 g / 10 min and up to 10,000 g / 10 min or more. In some embodiments, the second polyethylene fraction has a melt index (I2) of at least 100 g / 10 min and up to 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 up to 1,000 g / 10 min.

[0057] 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.

[0058] The first polyethylene composition comprises, based on the total weight of the first polyethylene composition, a first polyethylene fraction of 25 to 37 weight percent and a second polyethylene fraction of 63 to 75 weight percent. In some embodiments, the first polyethylene composition comprises, based on the total weight of the first polyethylene composition, a first polyethylene fraction of 30 to 37 weight percent and a second polyethylene fraction of 63 to 70 weight percent.

[0059] The following discussion will focus on the preparation of a first polyethylene composition for use in embodiments of the present invention.

[0060] polymerization The first polyethylene composition can be produced using any conventional polymerization process. Such conventional polymerization processes include, but are not limited to, slurry polymerization processes and solution polymerization processes using one or more conventional reactors, such as loop reactors, isothermal reactors, stirred-tank reactors, parallel or series batch reactors, and / or any combination thereof. The first polyethylene composition may be produced, for example, via a solution-phase polymerization process using one or more loop reactors, isothermal reactors, and combinations thereof.

[0061] Generally, solution-phase polymerization processes can occur in one or more well-agitated reactors, such as one or more isothermal loop reactors or one or more adiabatic reactors, at a temperature in the range of 115 to 250°C, for example, 115 to 200°C, and a pressure in the range of 300 to 1,000 psi, for example, 400 to 750 psi. In some embodiments, in a double reactor, the temperature of the first reactor is in the range of 115 to 190°C, for example, 115 to 175°C, and the temperature of the second reactor is in the range of 150 to 250°C, for example, 130 to 165°C. In other embodiments, in a single reactor, the reactor temperature is in the range of 115 to 250°C, for example, 115 to 225°C.

[0062] The residence time in the solution-phase polymerization process can be in the range of 2 to 30 minutes, for example, 10 to 20 minutes. Ethylene, solvent, hydrogen, one or more catalyst systems, optionally one or more co-catalysts, and optionally one or more comonomers are continuously supplied to one or more reactors. Exemplary solvents include, but are not limited to, isoparaffins. For example, such solvents are commercially available from ExxonMobil Chemical Co. (Houston, Texas) under the name ISOPAR E. The resulting mixture of the first polyethylene composition and solvent is then removed from the reactor to isolate the first polyethylene composition. The solvent is typically recovered via a solvent recovery unit, i.e., a heat exchanger and a gas-liquid separator drum, and then recycled back into the polymerization system.

[0063] In one embodiment, the first polyethylene composition may be produced by solution polymerization in a double reactor system, for example, a double-loop reactor system, where ethylene is polymerized in the presence of one or more catalyst systems. In some embodiments, only ethylene is polymerized. In addition, one or more co-catalysts may be present. In another embodiment, the first polyethylene composition may be produced by solution polymerization in a single reactor system, for example, a single-loop reactor system, where ethylene is polymerized in the presence of two catalyst systems. In some embodiments, only ethylene is polymerized.

[0064] Catalyst system Specific embodiments of the catalyst systems that can be used to produce the first polyethylene composition described herein are described below. It should be understood that the catalyst systems of this disclosure may be embodied in different forms and should not be construed as being limited to the specific embodiments described herein. Rather, the embodiments are provided so that this disclosure is thorough and complete and fully conveys the scope of the subject matter to those skilled in the art.

[0065] The term "independently selected" is used in R 1 , R 2 , R 3 , R 4 , and R 5 The R groups, such as R, may be the same or different (for example, R 1 , R 2 , R 3 , R 4 , and R 5 However, all are substituted alkyls, or R 1 and R 2 However, it is a substituted alkyl, R 3 The term R is used herein to indicate that, for example, it may be an aryl group. The use of the singular form includes the use of the plural form, and vice versa (for example, hexane solvent contains multiple hexanes). A named R group is generally considered to have a structure that is recognized in the art as corresponding to the R group bearing that name. These definitions are intended to supplement and illustrate, and not to exclude, definitions known to those skilled in the art.

[0066] The term "precursor catalyst" refers to a compound that has catalytic activity when combined with an activator. The term "activator" refers to a compound that chemically reacts with the precursor catalyst to convert it into a catalytically active catalyst. As used herein, the terms "promoter" and "activator" are interchangeable terms.

[0067] When used to describe a chemical group containing a specific carbon atom, the bracketed expression in the form of "(C x ~C y )" means that the unsubstituted form of the chemical group has from x to y carbon atoms including x and y. For example, (C1~C 40 ) alkyl is an alkyl group having from 1 to 40 carbon atoms in its unsubstituted form. In some embodiments and general structures, a particular chemical group may be substituted by one or more substituents such as R S . The R x -substituted version of the chemical group defined using the bracketed "(C y )" may contain more than y carbon atoms depending on the identity of any group R S . For example, "(C1~C S ) alkyl substituted by exactly one group R S where R S is phenyl (-C6H5)" may contain from 7 to 46 carbon atoms. Thus, generally, when a chemical group defined using the bracketed "(C 40 )" is substituted by a substituent R x ~C y containing one or more carbon atoms, the minimum and maximum total number of carbon atoms of the chemical group is determined by adding to both x and y the total number of carbon atoms from all substituents R S containing carbon atoms. S

[0068] The term "substituted" means that at least one hydrogen atom (-H) bonded to a carbon atom or heteroatom of the corresponding unsubstituted compound or functional group is replaced by a substituent (e.g., R SThis means that all hydrogen atoms (H) bonded to the carbon or heteroatom of the corresponding unsubstituted compound or functional group are replaced by substituents (e.g., R S This means that the atoms are replaced by the substituents. The term "polysubstituted" means that at least two, but fewer than all, hydrogen atoms bonded to the carbon or heteroatom of the corresponding unsubstituted compound or functional group are replaced by the substituents.

[0069] The term "-H" refers to hydrogen or a hydrogen radical covalently bonded to another atom. "Hydrogen" and "-H" are interchangeable and mean the same thing unless otherwise specified.

[0070] (C1~C 40 The term "hydrocarbyl" refers to a hydrocarbon radical consisting of 1 to 40 carbon atoms. 40 The term "hydrocarbylene" means a hydrocarbon diradical having 1 to 40 carbon atoms, and each hydrocarbon radical and each hydrocarbon diradical is aromatic or non-aromatic, saturated or unsaturated, linear or branched, cyclic (including monocyclic and polycyclic, condensed and non-condensed polycyclic, including bicyclic, with 3 or more carbon atoms) or acyclic, unsubstituted or with one or more R S It has been replaced by.

[0071] In this disclosure, (C1~C 40 ) Hydrocarbyl is either unsubstituted or substituted (C1~C 40 ) alkyl, (C3~C 40 )Cycloalkyl, (C3~C 20 )Cycloalkyl-(C1~C 20 ) Alkilen, (C6~C 40 )aryl, or (C6~C 20 )aryl-(C1~C 20 ) may be alkylene. In some embodiments, the above (C1~C 40 Each of the hydrocarbyl groups has up to 20 carbon atoms (i.e., (C1~C 20(Hydrocarbyl), in other embodiments, having up to 12 carbon atoms.

[0072] (C1~C 40 )alkyl" and "(C1~C 18 The term "alkyl" refers to a saturated linear or branched hydrocarbon radical consisting of 1 to 40 carbon atoms or 1 to 18 carbon atoms, which is either unsubstituted or substituted by one or more RS groups. 40 Examples of alkyl groups include unsubstituted (C1~C 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~C 40 Examples of alkyl groups include substitutions (C1~C 20 ) alkyl, substituted (C1~C 10 ) alkyl, trifluoromethyl, and [C 45 It is alkyl. [C 45 The term ]alkyl (in square brackets) means that there are up to 45 carbon atoms in the radical, including substituents, for example, one R is (C1-C5)alkyl. S Replaced by (C 27 ~C 40 Each (C1-C5) alkyl group may be methyl, trifluoromethyl, ethyl, 1-propyl, 1-methylethyl, or 1,1-dimethylethyl.

[0073] (C6~C 40 The term "aryl" refers to an unsubstituted or (one or more R) molecule having 6 to 40 carbon atoms, of which at least 6 to 14 are aromatic ring carbon atoms. SThis refers to monocyclic, bicyclic, or tricyclic aromatic hydrocarbon radicals substituted by (C6~C6). These monocyclic, bicyclic, or tricyclic radicals each contain one, two, or three rings, the monocyclic ring is aromatic, and the two or three rings are independently condensed or uncondensed, with at least one of the two or three rings being aromatic. Unsubstituted (C6~C6) 40 Examples of aryls include unsubstituted (C6~C 20 ) Aryl non-substituted (C6~C 18 These are aryl, 2-(C1~C5)alkylphenyl, 2,4-bis(C1~C5)alkylphenyl, phenyl, fluorenyl, tetrahydrofluorenyl, indacenyl, hexahydroindacenyl, indenyl, dihydroindenyl, naphthyl, tetrahydronaphthyl, and phenanthrene. Substitutions (C6~C 40 )Examples of aryl substitutions (C1~C 20 ) Aryl, substitution (C6-C 18 )aryl, 2,4-bis[(C 20 These are alkyl-phenyl, polyfluorophenyl, pentafluorophenyl, and fluoren-9-on-1-yl.

[0074] (C3~C 40 The term "cycloalkyl" refers to unsubstituted or one or more R S This refers to saturated cyclic hydrocarbon radicals of 3 to 40 carbon atoms that are substituted with other cycloalkyl groups (e.g., (C) x ~C y A cycloalkyl group has x to y carbon atoms and is either unsubstituted or has one or more R atoms. S It is defined in a similar format as either being replaced by (C3~C). 40 Examples of cycloalkyl groups include unsubstituted (C3~C) 20 ) Cycloalkyl, unsubstituted (C3~C 10 These are cycloalkyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, and cyclodecyl. Substitutions (C3~C 40 Examples of cycloalkyl groups include substitutions (C3~C 20)Cycloalkyl, substituted (C3~C 10 These are cycloalkyl, cyclopentanon-2-yl, and 1-fluorocyclohexyl.

[0075] (C1~C 40 Examples of hydrocarbylenes include unsubstituted or substituted (C6~C 40 ) Alliren, (C3~C 40 )Cycloalkylene, and (C1~C 40 ) Alkylene (for example (C1~C 20 Examples include alkylenes. In some embodiments, diradicals are located on the same carbon atom (e.g., -CH2-), on adjacent carbon atoms (i.e., 1,2-diradicals), or separated by one, two, or more intervening carbon atoms (e.g., 1,3-diradicals, 1,4-diradicals, etc.). Some diradicals include α,ω-diradicals. α,ω-diradicals are diradicals that have the largest possible carbon skeleton spacing between radical carbons. (C2~C 20 Some examples of alkylene α,ω-diradicals include ethane-1,2-diyl (i.e., -CH2CH2-), propane-1,3-diyl (i.e., -CH2CH2CH2-), and 2-methylpropane-1,3-diyl (i.e., -CH2CH(CH3)CH2-). (C6~C 50 Some examples of arylene α,ω-diradicals include phenyl-1,4-diyl, naphthalene-2,6-diyl, or naphthalene-3,7-diyl.

[0076] (C1~C 40 The term "alkylene" refers to an unsubstituted or one or more R S This refers to a saturated linear or branched diradical of 1 to 40 carbon atoms that is substituted by (i.e., the radical is not present on the ring atom). Unsubstituted (C1~C 50 Examples of alkylenes include unsubstituted -CH2CH2-, -(CH2)3-, -(CH2)4-, -(CH2)5-, -(CH2)6-, -(CH2)7-, -(CH2)8-, and -CH2C. *HCH3 and -(CH2)4C * (H)CH3 unsubstituted (C1~C 20 ) is an alkylene, and in the formula, "C * " represents a carbon atom from which a hydrogen atom is removed in order to form a secondary or tertiary alkyl radical. Substitution (C1~C 50 ) An example of alkylene is substitution (C1~C 20 ) Alkylene, -CF2-, -C(O)-, and -(CH2) 14 It is C(CH3)2(CH2)5- (i.e., 6,6-dimethyl-substituted n-1,20-eicosylene). As mentioned above, there are two R S They come together (C1~C 18 )Alkylenes can be formed, so substitution (C1~C 50 Examples of alkylenes 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.

[0077] (C3~C 40 The term "cycloalkylene" refers to an unsubstituted or one or more R S This refers to a cyclic diradical of 3 to 40 carbon atoms that is substituted by (i.e., the radical resides on the ring atoms).

[0078] 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 )- are listed, and in the formula, each R C , each R N , and each R P is non-substitutable (C1~C 18) Hydrocarbyl or -H. The term "heterohydrocarbon" refers to a molecule or molecular skeleton in which one or more carbon atoms are replaced by heteroatoms. (C1~C 40 The term "heterohydrocarbyl" means a heterohydrocarbon radical with 1 to 40 carbon atoms. 40 The term "heterohydrocarbile" refers to a heterohydrocarbon diradical having 1 to 40 carbon atoms, where each heterohydrocarbon has one or more heteroatoms. Heterohydrocarbile radicals reside on carbon atoms or heteroatoms, and heterohydrocarbile diradicals may reside on (1) one or two carbon atoms, (2) one or two heteroatoms, or (3) one carbon atom and one heteroatom. Each (C1~C 50 )heterohydrocarbyl and (C1~C 50 ) Heterohydrocarbylene may be unsubstituted, (one or more R S They may be substituted by, and may be aromatic or non-aromatic, saturated or unsaturated, linear or branched, cyclic (including monocyclic and polycyclic, condensed and non-condensed polycyclic) or acyclic.

[0079] (C1~C 40 ) Heterohydrocarbyls are either unsubstituted or substituted (C1~C 40 ) Heteroalkyl, (C1~C 40 ) Hydrocarbyl-O-, (C1~C 40 ) Hydrocarbyl-S-, (C1~C 40 ) Hydrocarbyl-S(O)-, (C1~C 40 )hydrocarbyl-S(O)2-, (C1~C 40 ) Hydrocarbyl-Si(R C )2-, (C1~C 40 ) Hydrocarbyl-N(R N )-, (C1~C 40 ) Hydrocarbyl-P(R P )-, (C2~C 40 ) Heterocycloalkyl, (C2~C 19 ) Heterocycloalkyl-(C1~C 20 ) Alkilen, (C3~C 20 )Cycloalkyl-(C1~C19 ) Heteroalkylene, (C2~C 19 ) Heterocycloalkyl-(C1~C 20 ) Heteroalkylene, (C1~C 40 ) Heteroaryl, (C1~C 19 ) Heteroaryl-(C1~C 20 ) Alkilen, (C6~C 20 )aryl-(C1~C 19 ) Heteroalkylene, or (C1~C 19 ) Heteroaryl-(C1~C 20 ) It may be a heteroalkylene.

[0080] (C4~C 40 The term "heteroaryl" refers to a total of 4 to 40 carbon atoms and 1 to 10 heteroatoms, either unsubstituted or substituted (one or more R) atoms. S (by) means a monocyclic, bicyclic, or tricyclic heteroaromatic hydrocarbon radical, which each contains one, two, or three rings, the two or three rings being independently condensed or uncondensed, and at least one of the two or three rings being heteroaromatic. Other heteroaryl groups (e.g., generally (C) x -C y ) Heteroaryls, for example (C4-C 12 Similarly, heteroaryl compounds have x to y carbon atoms (for example, 4 to 12 carbon atoms) and are either unsubstituted or have one or more than one R SIt is defined as being substituted by a monocyclic heteroaromatic hydrocarbon radical. A monocyclic heteroaromatic hydrocarbon radical is a five-membered or six-membered ring. A five-membered ring has 5 minus h carbon atoms, where h is the number of heteroatoms, which may be 1, 2, or 3, and each heteroatom may be O, S, N, or P. Examples of five-membered heteroaromatic hydrocarbon radicals are pyrrole-1-yl, pyrrole-2-yl, furan-3-yl, thiophen-2-yl, pyrazole-1-yl, isoxazole-2-yl, isothiazol-5-yl, imidazole-2-yl, oxazole-4-yl, thiazol-2-yl, 1,2,4-triazole-1-yl, 1,3,4-oxadiazole-2-yl, 1,3,4-thiadiazole-2-yl, tetrazole-1-yl, tetrazole-2-yl, and tetrazole-5-yl. A six-membered ring has 6 minus h carbon atoms, where h is the number of heteroatoms, which may be 1 or 2, and the heteroatoms may be N or P. Examples of six-membered ring heteroaromatic hydrocarbon radicals are pyridine-2-yl, pyrimidine-2-yl, and pyrazine-2-yl. Bicyclic heteroaromatic hydrocarbon radicals may be condensed 5,6- or 6,6-ring systems. Examples of condensed 5,6-ring bicyclic heteroaromatic hydrocarbon radicals are indole-1-yl and benzimidazole-1-yl. Examples of condensed 6,6-ring bicyclic heteroaromatic hydrocarbon radicals are quinoline-2-yl and isoquinoline-1-yl. Tricyclic heteroaromatic hydrocarbon radicals may be condensed 5,6,5-, 5,6,6-, 6,5,6-, or 6,6,6-ring systems. An example of a condensed 5,6,5-ring system is 1,7-dihydropyrrolo[3,2-f]indole-1-yl. An example of a condensed 5,6,6-ring system is 1H-benzo[f]indole-1-yl. An example of a condensed 6,5,6-ring system is 9H-carbazole-9-yl. An example of a condensed 6,5,6-ring system is 9H-carbazole-9-yl. An example of a condensed 6,6,6-ring system is acridine-9-yl.

[0081] The aforementioned heteroalkyls are (C1~C 50) may be a saturated linear or branched radical containing carbon atoms or fewer carbon atoms and one or more heteroatoms. Similarly, heteroalkylenes may be saturated linear or branched diradicals containing 1 to 50 carbon atoms and one or more heteroatoms. Heteroatoms as defined above 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 It may also contain S(O) and S(O)2, and each of the heteroalkyl group and heteroalkylene group is unsubstituted or has one or more R S It is replaced by.

[0082] Unsubstituted (C2~C 40 Examples of heterocycloalkyls include unsubstituted (C2~C 20 ) Heterocycloalkyl, unsubstituted (C2~C 10 These include heterocycloalkyl compounds, aziridine-l-yl, oxetan-2-yl, tetrahydrofuran-3-yl, pyrrolidine-l-yl, tetrahydrothiophen-S,S-dioxide-2-yl, morpholine-4-yl, 1,4-dioxan-2-yl, hexahydroazepine-4-yl, 3-oxacyclooctyl, 5-thiocyclononyl, and 2-azacyclodecyl.

[0083] The terms "halogen atom" or "halogen" refer to the radicals of fluorine (F), chlorine (Cl), bromine (Br), or iodine (I). The term "halide" refers to the anionic forms of halogen atoms, such as fluoride (F-), chloride (Cl-), bromide (Br-), or iodide (I-).

[0084] The term "saturated" means lacking carbon-carbon double bonds, carbon-carbon triple bonds, and (in heteroatom-containing groups) carbon-nitrogen, carbon-phosphorus, and carbon-silicon double bonds. A saturated chemical group has one or more substituents R S If substituted by, one or more double and / or triple bonds may optionally be substituted by substituent R S It may or may not be present. The term "unsaturated" means containing one or more carbon-carbon double bonds, carbon-carbon triple bonds, and carbon-nitrogen, carbon-phosphorus, and carbon-silicon double bonds (in heteroatom-containing groups), provided that substituent R is present if present. S This means that it does not include any double bonds that may or may be present in a (hetero)aromatic ring.

[0085] According to some embodiments, the catalyst system for producing the first polyethylene composition comprises a metal-ligand complex according to formula (I).

[0086] [ka]

[0087] In formula (I), M is a metal selected from titanium, zirconium, or hafnium, the metal is in a formal oxidation state of +2, +3, or +4, n is 0, 1, or 2, if n is 1, X is a monodentate or bidentate ligand, if n is 2, each X is a monodentate ligand, the same or different, the metal-ligand complex is charge-neutral overall, and each Z is independently -O-, -S-, or -N(R) N )-, or -P(R P )- is selected from, and L is (C1~C 40 ) Hydrocarbylene or (C1~C 40 ) is a heterohydrocarbylene, (C1~C 40 Hydrocarbylene has a portion containing a linker skeleton of 1 to 10 carbon atoms that connects the two Z groups in formula (I) (to which L is bonded), or (C1 to C 40) Heterohydrocarbylene has a portion containing a linker skeleton of 1 to 10 atoms that connects the two Z groups in formula (I), (C1 to C 40 Each of the 1 to 10 atoms in the linker skeleton of heterohydrocarbylene is independently a carbon atom or a heteroatom, and each heteroatom is independently O, S, S(O), S(O)2, Si(R) C )2, Ge(R C )2, P(R C ), or N(R C ) and independently, each R C (C1~C 30 ) Hydrocarbyl or (C1~C 30 ) is a heterohydrocarbyl, R 1 and R 8 These are independently -H, (C1~C 40 ) Hydrocarbyl, (C1~C 40 ) Heterohydrocarbyl, -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 ) Selected from the group consisting of 2NC(O)-, halogens, and radicals having formula (II), formula (III), or formula (IV).

[0088] [ka] In equations (II), (III), and (IV), R 31~35 , R 41~48 , or R 51~59 Each of these is independent of (C1~C 40 ) Hydrocarbyl, (C1~C 40) Heterohydrocarbyl, -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 ) Selected from 2NC(O)-, halogen, or -H, however, R 1 or R 8 The condition is that at least one of them is a radical having formula (II), formula (III), or formula (IV).

[0089] In formula (I), R 2~4 , R 5~7 , and R 9~16 Each of these is independent of (C1~C 40 ) Hydrocarbyl, (C1~C 40 ) Heterohydrocarbyl, -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 ) Selected from 2NC(O)-, halogen, and -H.

[0090] In some embodiments, the first polyethylene composition 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.

[0091] In one exemplary embodiment in which a double-loop reactor is used, the pro-catalyst used in the first loop is zirconium,[[2,2'''-[[bis[1-methylethyl]germylene]bis(methyleneoxy-κO)]bis[3'',5,5''-tris(1,1-dimethylethyl)-5'-octyl[1,1':3',1''-terphenyl]-2'-orato-κO]](2-)]dimethyl-, which has the chemical formula C 86 H 128 It has F2GeO4Zr and the following structure.

[0092] [ka] In such embodiments, the procatalyst used in the second loop is zirconium, [[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-orato-κO]](2-)]dimethyl, with chemical formula C 107 H 154 It has N2O4Si2Zr and the following structure.

[0093] [ka]

[0094] In other embodiments, the procatalyst used in the second loop is hafnium,[[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-orato-κO]](2-)]dimethyl, with chemical formula C 107 H 154 It has N2O4Si2Hf and the following structure.

[0095] [ka]

[0096] Co-catalyst components A catalyst system comprising the metal-ligand complex of formula (I) can be catalytically activated by any technique known in the art for activating metal catalysts in olefin polymerization reactions. For example, a system comprising the metal-ligand complex of formula (I) can be catalytically activated by contacting the complex with an activating co-catalyst or by combining the complex with an activating co-catalyst. Suitable activating co-catalysts for use herein include alkylaluminum, polymers or oligomeric aluminoxanes (also known as aluminoxanes), neutral Lewis acids, and nonpolymers, non-coordinating, ion-forming compounds (including the use of such compounds under oxidizing conditions). A preferred activation technique is bulk electrolysis. Combinations of one or more of the aforementioned activating co-catalysts and techniques are also contemplated. The term "alkylaluminum" means monoalkylaluminum dihydride or monoalkylaluminum dihalide, dialkylaluminum hydride or dialkylaluminum halide, or trialkylaluminum. Examples of polymeric or oligomeric almoxanes include methyl almoxane, triisobutylaluminum-modified methyl almoxane, and isobutyl almoxane.

[0097] Lewis acid activators (co-catalysts) are provided in the form of 1 to 3 (C1-C) as described herein. 20 )Includes a group 13 metal compound containing a hydrocarbyl substituent.In one embodiment, the group 13 metal compound is tri((C1~C 20 )hydrocarbyl) substituted aluminum or tri((C1~C 20 In other embodiments, the group 13 metal compound is tri(hydrocarbyl)-substituted aluminum, tri((C1-C 20 (Hydrocarbyl)-boron compounds, tri((C1-C 10 )Alkyl)Aluminum, Tri((C6-C 18 The aryl)boron compounds and their halogenated (including perhalated) derivatives. In further embodiments, the Group 13 metal compounds are tris(fluorosubstituted phenyl)borane and tris(pentafluorophenyl)borane. In some embodiments, the activation co-catalyst is tris((C1~C 20 ) Hydrocarbyl borate (e.g., trityltetrafluoroborate) or tri((C1~C 20 ) Hydrocarbyl ammonium tetra((C1~C 20 (Hydrocarbyl)borane (e.g., bis(octadecyl)methylammoniumtetrakis(pentafluorophenyl)borane). As used herein, the term "ammonium" means ((C1-C 20 ) Hydrocarbyl 4N + , ((C1-C 20 ) Hydrocarbyl 3N(H) + , ((C1-C 20 )hydrocarbyl)2N(H)2 + , (C1-C 20 ) Hydrocarbyl N(H)3 + , or N(H)4 + This refers to nitrogen cations, and each (C1-C 20 ) If two or more hydrocarbyl molecules are present, they may be the same or different.

[0098] A combination of neutral Lewis acid activators (co-catalysts) is tri((C1~C4)alkyl)aluminum and halogenated tri((C6~C 18 Examples include mixtures containing aryl)boron compounds, particularly combinations with tris(pentafluorophenyl)borane. Other embodiments include combinations of such neutral Lewis acid mixtures with polymers or oligomers of almoxane, and combinations of a single neutral Lewis acid, particularly tris(pentafluorophenyl)borane, with polymers or oligomers of almoxane. The molar ratio of (metal-ligand complex):(tris(pentafluorophenylborane):(almoxane) [e.g., Group 4 metal-ligand complex):(tris(pentafluorophenylborane):(almoxane)] is 1:1:1 to 1:10:30, and in other embodiments, 1:1:1.5 to 1:5:10.

[0099] A catalyst system containing a metal-ligand complex of formula (I) can be activated to form an activated catalyst composition in combination with one or more co-catalysts, such as a cation-forming co-catalyst, a strong Lewis acid, or a combination thereof. Suitable activation co-catalysts include polymers or oligomers of aluminoxanes, particularly methylaluminoxanes, and inert, miscible, non-coordinating, and ion-forming compounds. Examples of suitable co-catalysts include modified methyl aluminoxane (MMAO), bis(hydrolyzyl hydride), and tetrakis(pentafluorophenyl)borate (1 - Examples include, but are not limited to, amines and combinations thereof.

[0100] In some embodiments, one or more of the aforementioned activated cocatalysts are used in combination with each other. Particularly preferred combinations are mixtures of tri((C1-C4)hydrocarbyl)aluminum, tri((C1-C4)hydrocarbyl)borane, or ammonium borate with an oligomer or polymer-almoxane compound. The ratio of the total number of moles of one or more metal-ligand complexes of formula (I) to the total number of moles of one or more activated cocatalysts is 1:10,000 to 100:1. In some embodiments, this ratio is at least 1:5000, in some other embodiments it is at least 1:1000 and 10:1 or less, and in some other embodiments it is 1:1 or less. When an almoxane is used alone as an activated cocatalyst, the number of moles of the almoxane used is preferably at least 100 times the number of moles of the metal-ligand complex of formula (I). When tris(pentafluorophenyl)borane is used alone as an activation co-catalyst, in some other embodiments, the number of moles of tris(pentafluorophenyl)borane used relative to the total number of moles of one or more metal-ligand complexes of formula (I) is 0.5:1 to 10:1, 1:1 to 6:1, or 1:1 to 5:1. The remaining activation co-catalyst is generally used in a molar amount approximately equal to the total number of moles of one or more metal-ligand complexes of formula (I).

[0101] Nucleating agent According to some embodiments, the layer into which the first polyethylene composition is incorporated in the multilayer film of the present invention may further contain a nucleating agent, which is a calcium salt of 1,2-cyclohexanedicarboxylic acid or sodium 4-[(4-chlorobenzoyl)amino]benzoate. In some embodiments, the first polyethylene composition and the nucleating agent can be blended to provide a polyethylene-based composition. In some embodiments, such a polyethylene-based composition may be co-extruded with other layers to form a multilayer film. When used in appropriate amounts and in combination with the polyethylene compositions described herein, such a nucleating agent is thought to provide a more homogeneous crystal distribution and crystal size in the polyethylene film, a more uniform melting behavior of the resulting polyethylene-based composition and the film formed from the polyethylene-based composition, and one or more other improvements in the resulting film (e.g., rigidity, barrier, and / or optical system).

[0102] In some embodiments, the nucleating agent is the calcium salt of 1,2-cyclohexanedicarboxylic acid. In some embodiments, the nucleating agent is sodium 4-[(4-chlorobenzoyl)amino]benzoate. In some embodiments, such polyethylene-based compositions include both the calcium salt of 1,2-cyclohexanedicarboxylic acid and sodium 4-[(4-chlorobenzoyl)amino]benzoate.

[0103] Nucleating agents such as calcium salt of 1,2-cyclohexanedicarboxylic acid or sodium 4-[(4-chlorobenzoyl)amino]benzoate are heterogeneous nucleating agents. The amount and type of heterogeneous nucleating agent are important for providing the desired performance. In some embodiments, the polyethylene composition contains 20 to 5000 ppm of heterogeneous nucleating agent, based on the total weight of the polyethylene composition, in the form of calcium salt of 1,2-cyclohexanedicarboxylic acid or sodium 4-[(4-chlorobenzoyl)amino]benzoate, with the remainder being the first polyethylene composition described herein. In some embodiments, the polyethylene composition contains 20 to 2000 ppm of calcium salt of 1,2-cyclohexanedicarboxylic acid or sodium 4-[(4-chlorobenzoyl)amino]benzoate, based on the total weight of the polyethylene composition, with the remainder being the first polyethylene composition described herein. In some embodiments, the polyethylene composition comprises 500 to 2000 ppm of a calcium salt of 1,2-cyclohexanedicarboxylic acid or sodium 4-[(4-chlorobenzoyl)amino]benzoate based on the total weight of the polyethylene composition, the remainder being the first polyethylene composition described herein.

[0104] In some embodiments, heterogeneous nucleating agents may be provided with fatty acid metal salts such as zinc stearate, zinc palmitate, and mixtures thereof. Based on how zinc stearate is commercially prepared, commercially available stearic acid often contains a considerable amount of palmitic acid, so some zinc palmitate may also be present. In some such embodiments, the polyethylene composition contains at least one of zinc stearate and zinc palmitate in amounts of 45 to 1000 ppm, based on the total weight of the polyethylene composition. In some embodiments, the polyethylene composition contains 50 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 to 600 ppm of zinc stearate and / or zinc palmitate, based on the total weight of the polyethylene composition.

[0105] A non-limiting example of a calcium salt of 1,2-cyclohexanedicarboxylic acid that can be used in embodiments of the present invention is Hyperform HPN-20E manufactured by Milliken Chemical (Spartanburg, South Carolina). Hyperform HPN-20E contains 60–70 weight percent of a calcium salt of 1,2-cyclohexanedicarboxylic acid and 30–40 weight percent of zinc stearate / zinc palmitate. In some embodiments, the polyethylene composition contains 20–5000 ppm of Hyperform HPN-20E based on the total weight of the polyethylene composition. In some embodiments, the polyethylene composition contains 20–2000 ppm of Hyperform HPN-20E based on the total weight of the polyethylene composition.

[0106] 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 manufactured by Milliken Chemical (Spartanburg, South Carolina).

[0107] In some embodiments, the calcium salt of 1,2-cyclohexanedicarboxylic acid or sodium 4-[(4-chlorobenzoyl)amino]benzoate (and, if included, fatty acid metal salts (e.g., zinc stearate and / or zinc palmitate)) may be provided as a masterbatch by blending with a carrier resin before combining with the first polyethylene composition described herein. In some such embodiments, the carrier resin is polyethylene having a melt index (I2) of 1 to 12 g / 10 min. In some embodiments where the calcium salt of 1,2-cyclohexanedicarboxylic acid and zinc stearate / zinc palmitate are provided as masterbatches, the masterbatch comprises 2 to 4 weight percent of the calcium salt of 1,2-cyclohexanedicarboxylic acid 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 with a narrow molecular weight distribution, having a density of 0.965 and a melt index (I2) of 8 to 9 g / 10 min. In some embodiments, the masterbatch may also contain other additives. Depending on the total amount of additives included, the masterbatch may contain 85 to 98 weight percent of the carrier resin, based on the total weight of the masterbatch.

[0108] Other nucleating agents that can be used in some embodiments of the present invention include those disclosed in U.S. Patent Applications Publications 2015 / 0087758, 2015 / 0087759, and 2015 / 0086736, which are incorporated herein by reference. In some embodiments, the polyethylene composition contains 20 to 5000 ppm of such nucleating agents based on the total weight of the polyethylene composition. In some embodiments, the polyethylene composition contains 20 to 2000 ppm of such nucleating agents based on the total weight of the polyethylene composition.

[0109] Second polyethylene composition As discussed above, the multilayer film of the present invention comprises at least one layer containing a second polyethylene composition having specific properties. In some embodiments, the layers in the multilayer film of the present invention contain both the first polyethylene composition and the second polyethylene composition. In other embodiments, the first polyethylene composition and the second polyethylene composition are present in different layers.

[0110] A second polyethylene composition used in embodiments of the present invention comprises: (1) a first polyethylene fraction having a single peak in the temperature range of 45°C to 87°C in an elution profile via an improved comonomer composition distribution (iCCD) analysis method, wherein the first polyethylene area fraction is the area in the elution profile directly below the single peak of the first polyethylene fraction at 45°C to 87°C; and (2) a second polyethylene fraction having a single peak in the temperature range of 95°C to 120°C in an elution profile via an iCCD analysis method, wherein the second polyethylene area fraction is the area in the elution profile directly below the single peak of the second polyethylene fraction at 95°C to 120°C. The second polyethylene composition is 0.924 g / cm³ 3 ~0.936 g / cm³ 3 It has a density and a melt index (I2) of 0.25 g / 10 min to 2.0 g / 10 min, the area of ​​the second polyethylene fraction constitutes at least 40% of the total area of ​​the elution profile, the ratio of the area of ​​the first polyethylene fraction to the area of ​​the second polyethylene fraction is 0.75 to 2.5, and the width of the single peak of the second polyethylene fraction at the 50 percent peak height is less than 5.0°C.

[0111] In one or more embodiments, the second polyethylene composition is 0.924 g / cm³ 3 ~0.936 g / cm³ 3 It may have a density of 0.924 g / cm³. For example, an embodiment of the second polyethylene composition disclosed herein has a density of 0.924 g / cm³. 3 ~0.931 g / cm³ 3 , 0.924 g / cm³ 3 ~0.928 g / cm³3 , 0.927 g / cm³ 3 ~0.931 g / cm³ 3 , or 0.929 g / cm³ 3 ~0.933g / cm 3 It may have a density of 0.924 to 0.928 g / cm³. According to an additional embodiment, the second polyethylene composition has a density of 0.924 to 0.928 g / cm³. 3 ~0.932 g / cm³ 3 , 0.932 g / cm³ 3 ~0.936 g / cm³ 3 , or the density may be any combination of these ranges.

[0112] In one or more embodiments, the second polyethylene composition may have a melt index (I2) of 0.25 g / 10 min to 2.0 g / 10 min, for example, 0.5 g / 10 min to 1.2 g / 10 min. For example, in one or more embodiments, the second polyethylene composition 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 an additional embodiment, the second polyethylene composition may have a melt index (I2) of 0.65 to 1.05.

[0113] According to the embodiment, the second polyethylene composition 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 composition 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 an additional embodiment, the second polyethylene composition may have a molecular weight distribution of 3.0 to 5.0. As described herein, the molecular weight distribution may be calculated according to gel permeation chromatography (GPC) techniques as described herein.

[0114] According to one or more additional embodiments, the second polyethylene composition may have a zero shear viscosity ratio of less than 3.0. For example, the second polyethylene composition 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 composition may have a zero shear viscosity ratio of at least 1.0.

[0115] Referring to the iCCD distribution described herein, Figure 1 schematically shows the iCCD distribution 100 of the sample, along with the cumulative weight fraction curve 200. Figure 1 generally shows some features of the iCCD profile of the second polyethylene composition, such as the first fraction, the second fraction, and half-peak widths, which are discussed in detail herein. Therefore, Figure 1 can be used as a reference with respect to disclosures relating to the iCCD profile provided herein. Specifically, the first fraction 102 and the second fraction 106 are illustrated. The first fraction 102 has a peak 104, and the second fraction 106 has a peak 108. Each fraction has half-peak widths 110 and 112. It should be understood that the profiles in Figure 1 are not derived from experiments or observations, but are instead provided for informational purposes to describe certain features of the iCCD elution profile.

[0116] In one or more embodiments, the first polyethylene fraction of the second polyethylene composition may have a single peak in the elution profile via iCCD within the temperature range of 45°C to 87°C. In one or more embodiments, the single peak of the first polyethylene fraction may be located within the temperature range of 60°C to 85°C, such as 70°C to 85°C. While we do not wish to be bound by theory, it is conceivable that in at least some embodiments of the second polyethylene composition in which a double reactor design is used for polymerization, a combination of higher density crystalline domains and lower density amorphous domains may exist. Impact strength is primarily controlled by amorphous regions or binding concentrations connecting adjacent lamellae. When the density is less than 0.910 g / cc, the relative binding chain concentration is estimated to be relatively large. The peak of the first polymer fraction in the compositions disclosed herein may be located within the temperature range of 60°C to 85°C, which can provide a higher binding chain concentration for functional benefits such as improved toughness.

[0117] It should be understood that the peaks in the first or second polyethylene fraction may not be formed by the minima in each polyethylene fraction at the defined temperature boundaries. That is, the peak must be a peak from the perspective of the entire range, rather than a peak formed by the threshold temperature of the polyethylene fraction. For example, if a single peak followed by a single valley exists in the polyethylene fraction (an upward slope followed by a downward slope followed by an upward slope), there will be only a single peak in such a polyethylene fraction.

[0118] In one or more embodiments, the second polyethylene fraction may have a single peak within a temperature range of 95°C to 120°C in the elution profile via iCCD. Due to the low molecular weight, high density components at 95°C to 120°C, polyethylene can achieve a higher overall density while maintaining a lower density fraction as described by the ratio of these two fractions, so the temperature range of the second polyethylene fraction from 95°C to 120°C may be desirable.

[0119] In one or more embodiments, the width of the single peak of the second polyethylene fraction at 50 percent peak height may be less than 5.0°C, less than 4°C, or even less than 3°C. Generally, a smaller temperature range at 50 percent peak height corresponds to a "sharper" peak. While not wishing to be bound by any particular theory, a "sharper" or "narrower" peak is a characteristic caused by a molecular catalyst and is thought to indicate a minimum incorporation of comonomer into the higher density fraction, enabling a higher density separation between the two fractions.

[0120] In one or more embodiments, the second polyethylene composition may have a minimum within a temperature range of 80°C to 90°C in the elution profile via iCCD. This minimum may fall between the peak of the first polyethylene fraction and the peak of the second polyethylene fraction.

[0121] In the embodiments described herein, the area of the first polyethylene fraction is the area in the elution profile from 45°C to 87°C directly below the single peak of the first polyethylene fraction °C. Similarly, the area of the second polyethylene fraction is the area in the elution profile from 95°C to 120°C directly below the single peak of the second polyethylene fraction. The area of the first polyethylene fraction and the area of the second polyethylene fraction may each generally correspond to the total relative mass of each polymer fraction in the polyethylene composition. Generally, the area of the polyethylene fraction in the iCCD profile can be determined by integrating the iCCD profile between the specified start temperature and end temperature.

[0122] 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.

[0123] In one or more embodiments, the first polyethylene fraction region can include at least 40% of the total area of the elution profile (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 profile). For example, the area of the first polyethylene fraction can constitute 40% - 65% of the total area of the elution profile, such as 42% - 58%, 43% - 45%, 45% - 47%, 53% - 55%, or 55% - 57%.

[0124] According to one or more embodiments, the area of the second polyethylene fraction can constitute at least 25% of the total area of the elution profile (e.g., at least 30%, at least 35%, or even at least 40% of the total area of the elution profile). For example, the area of the first polyethylene fraction can constitute 20% - 50%, 27% - 31%, or 41% - 48% of the total area of the elution profile.

[0125] According to some embodiments, 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 (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).

[0126] In one or more embodiments, the second polyethylene composition is formed by polymerization of ethylene with a comonomer such as a C3-C12 alkene. Examples of intended comonomers include C6-C9 alkenes such as 1-octene and 1-hexene. In one or more embodiments, the comonomer is 1-octene.

[0127] In one or more embodiments, the difference between a single peak in the second polyethylene fraction and a single peak in the first polyethylene fraction is at least 10°C, at least 12.5°C, at least 15°C, at least 17.5°C, or even more than 20°C.

[0128] In one or more embodiments, the first polyethylene fraction may have a melt index (I2) of 0.01 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.

[0129] In one or more embodiments, the second polyethylene fraction may have a melt index (I2) of 1 to 10,000 g / 10 min. For example, in 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.

[0130] In one or more embodiments, the weight-average molecular weight of the second polyethylene fraction may be 120,000 g / mol or less, for example, 20,000 g / mol to 120,000 g / mol, or 40,000 g / mol to 65,000 g / mol. In additional embodiments, 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 can be calculated based on GPC results, as described later in this specification.

[0131] According to an additional embodiment, the second polyethylene composition may have a Dow Rheology Index of 5 or less, for example, 4 or less, 3 or less, 2 or less, or even 1 or less.

[0132] In one or more embodiments, the second polyethylene composition may further contain one or more additional components, such as additives. Such additives include, but are not limited to, antistatic agents, color enhancers, dyes, lubricants, fillers such as TiO2 or CaCO3, opacifiers, nucleating agents, processing aids, pigments, primary antioxidants, secondary antioxidants, UV stabilizers, antiblocking agents, slip agents, tackifiers, flame retardants, antimicrobial agents, odor reducers, antifungal agents, and combinations thereof. The second polyethylene composition may contain such additives in a total weight of about 0.1 to about 10 weight percent, based on the weight of the second polyethylene composition containing such additives.

[0133] polymerization Any conventional polymerization process may be used to produce the second polyethylene composition described herein. Such conventional polymerization processes include, but are not limited to, slurry polymerization processes and solution polymerization processes using one or more conventional reactors, such as loop reactors, isothermal reactors, stirred-tank reactors, parallel and series batch reactors, and / or any combination thereof. The polyethylene composition may be produced, for example, via a solution-phase polymerization process using one or more loop reactors, isothermal reactors, and combinations thereof.

[0134] Generally, solution-phase polymerization processes can be carried out in one or more well-agitated reactors, such as one or more isothermal loop reactors or one or more adiabatic reactors, at temperatures in the range of 115 to 250°C (e.g., 115 to 210°C) and pressures in the range of 300 to 1,000 psi (e.g., 400 to 800 psi). In some embodiments, in a double reactor, the temperature in the first reactor is in the range of 115 to 190°C (e.g., 160 to 180°C), and the temperature in the second reactor is in the range of 150 to 250°C (e.g., 180 to 220°C). In other embodiments, in a single reactor, the reactor temperature is in the range of 115 to 250°C (e.g., 115 to 225°C).

[0135] The residence time in the solution-phase polymerization process can be in the range of 2 to 30 minutes (e.g., 5 to 25 minutes). Ethylene, solvent, hydrogen, one or more catalyst systems, optionally one or more co-catalysts, and optionally one or more comonomers are continuously supplied to one or more reactors. Examples of solvents include, but are not limited to, isoparaffins. For example, such solvents are commercially available from ExxonMobil Chemical Co. (Houston, Texas) under the name ISOPAR E. The resulting mixture of the polyethylene composition and solvent is then removed from the reactor, and the polyethylene composition is isolated. The solvent is typically recovered via a solvent recovery unit, e.g., a heat exchanger and a gas-liquid separator drum, and then returned to the polymerization system for reuse.

[0136] In some embodiments, the second polyethylene composition can be produced by solution polymerization in a double reactor system, for example, a double-loop reactor system, where ethylene is polymerized in the presence of one or more catalyst systems. In some embodiments, only ethylene is polymerized. In addition, one or more co-catalysts may be present. In another embodiment, the second polyethylene composition can be produced by solution polymerization in a single reactor system, for example, a single-loop reactor system, where ethylene is polymerized in the presence of two catalyst systems. In some embodiments, only ethylene is polymerized.

[0137] Catalyst system The polyethylene composition of the second composition can be produced using the same catalyst system described in relation to the production of the first polyethylene composition. As described in the Examples chapter, the production processes for the first and second polyethylene compositions differ such that the resulting polyethylene compositions have different properties as described herein.

[0138] Multilayer film The multilayer film of the present invention comprises both a first polyethylene composition and a second polyethylene composition. In some embodiments, the layers in the multilayer of the present invention comprise both the first polyethylene composition and the second polyethylene composition. In other embodiments, the first polyethylene composition and the second polyethylene composition are present in different layers.

[0139] In some embodiments of the multilayer film of the present invention, the multilayer film may contain the described first polyethylene composition in one or more layers, while in other embodiments, the first polyethylene composition is provided in a single layer. The multilayer film contains 40 weight percent or less of the first polyethylene composition based on the total weight of the multilayer film. In some embodiments, the multilayer film contains at least 20 weight percent of the first polyethylene composition based on the total weight of the multilayer film. In some embodiments, the multilayer film contains 20 weight percent to 40 weight percent of the first polyethylene composition based on the total weight of the multilayer film. For example, the multilayer film may contain 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 weight percent to 31, 32, 33, 34, 35, 36, 37, 38, 39, or 40 weight percent of the first polyethylene composition based on the total weight of the multilayer film. In some embodiments, the multilayer film contains 30 weight percent to 40 weight percent of the first polyethylene composition based on the total weight of the multilayer film.

[0140] The amount of the second polyethylene composition used in the film of the present invention may depend on a number of factors, including, for example, other layers in the film, desired properties of the film, and the end use of the film. In some embodiments, the multilayer film contains 20% to 80% by weight of the second polyethylene composition, based on the total weight of the multilayer film. For example, the multilayer film may contain 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30% by weight to 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, or 80% by weight of the second polyethylene composition, based on the total weight of the multilayer film. In some embodiments, the multilayer film contains 20% to 70% by weight of the second polyethylene composition, based on the total weight of the multilayer film.

[0141] The number of layers in a film can vary depending on a number of factors, including, for example, the desired properties of the film, the desired thickness of the film, the content of other layers in the film, the end use of the film, and the equipment available for manufacturing the film. In various embodiments, the multilayer film of the present invention may contain up to 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11 layers. In some embodiments, the multilayer film is a 5-layer film. In some embodiments, the multilayer film is a 3-layer film.

[0142] One or more layers in the multilayer film may further contain other polymers in addition to the first and second polyethylene compositions. For example, in some embodiments, one or more layers of the multilayer film may further contain low-density polyethylene (LDPE) or linear low-density polyethylene (LLDPE) in addition to the first and second polyethylene compositions described above. For example, LDPE may be included in some layers to facilitate processing. In some embodiments in which LDPE is used in the film, the LDPE may amount to less than 1 to 50 weight percent based on the total weight of the multilayer film. In some embodiments, the multilayer film may contain 1 to 30 weight percent of LDPE based on the total weight of the film. In some embodiments, the multilayer film may contain 20 to 30 weight percent of LDPE based on the total weight of the film. Examples of commercially available LDPEs that can be used in some embodiments of the present invention include LDPEs available from The Dow Chemical Company, such as DOW® LDPE 132I, DOW® LDPE 203M, DOW® 586A, DOW® LDPE 230N, and AGILITY® 1021. In some embodiments in which LLDPE is used in a film, the LLDPE may contain 1 to less than 50 weight percent of LDPE based on the total weight of the multilayer film. In some embodiments, the multilayer film may contain 20 to 50 weight percent of LLDPE based on the total weight of the film. Examples of commercially available LLDPEs that can be used in some embodiments of the present invention include LLDPEs available from The Dow Chemical Company, such as DOWLEX® GM 8051F, DOWLEX® GM 8051G, DOWLEX® GM 8051, DOWLEX® GM 8070, DOWLEX® TG 2085B, INNATE® ST50, ELITE® NG5400B, ELITE® NG5401B, ELITE® 5400G, and ELITE® 5401G.

[0143] In some embodiments, one outer layer of the multilayer film is a sealant layer. The sealant layer can be used to form an article or package by adhering the film to another film, laminate, or itself using the sealant layer. Thus, the sealant layer is the outermost layer of the multilayer film.

[0144] In some embodiments, the sealant layer can include any resin known to those skilled in the art to be useful as a sealant layer.

[0145] In some embodiments, the sealant layer can include one or more ethylene-based polymers having a density of 0.890 to 0.925 g / cm 3 and a melt index (I2) of 0.1 to 2.0 g / 10 minutes. In further embodiments, the ethylene-based polymer of the sealant film (or sealant layer) can have a density of 0.900 to 0.925 g / cm 3 or 0.910 to 0.925 g / cm 3 . Additionally, the ethylene-based polymer of the sealant film (or sealant layer) can have a melt index (I2) of 0.1 to 2.0 g / 10 minutes or 0.1 to 1.5 g / 10 minutes. Various commercially available polyethylenes are considered suitable for the sealant film. Suitable commercial examples include ELITE™ 5400G, ELITE™ 5401B, and various AFFINITY™ polyolefin plastomers (e.g., AFFINITY™ 1888, AFFINITY™ 1140, and AFFINITY™ 1146), which are each available from The Dow Chemical Company (Midland, MI).

[0146] In further embodiments, the sealant layer of the multilayer film may include additional ethylene-based polymers, such as polyolefin plastomers, LDPEs, LLDPEs, or others. Generally, the LDPE in the sealant film or sealant layer may include any LDPE known to those skilled in the art, such as DOW® LDPE 132I and DOW® LDPE 586A. In embodiments using polyolefin plastomers, the polyolefin plastomer may have a melt index (I2) of 0.2 to 5 g / 10 min or 0.5 to 2.0 g / 10 min. Furthermore, the polyolefin plastomer may have a melt index (I2) of 0.890 g / cc to 0.920 g / cc or 0.900 to 0.910 g / cm³. 3 It may have a density of . Various commercially available polyolefin plastomers are considered suitable for sealant films. Preferred examples include AFFINITY® PL 1881G, AFFINITY® PL 1888G, AFFINITY® PF 1140G, and AFFINITY® PF 1146G from The Dow Chemical Company (Midland, MI). In embodiments in which the sealant layer contains LLDPE, the LLDPE may generally include any LLDPE known to those skilled in the art, including commercially available products from The Dow Chemical Company such as DOWLEX® NG2045B, DOWLEX® TG2085B, DOWLEX® GM8051, DOWLEX® GM8070, DOWLEX® GM8085, and DOWLEX® 5056G. Another example of an ethylene-based polymer that can be included is 0.918 g / cm³ 3 The following are INNATE® polyethylene resins with the following densities, which are commercially available from The Dow Chemical Company as INNATE® ST50 and INNATE® TH60.

[0147] In some embodiments, the sealant layer is 0.900 to 0.925 g / cm³. 3The present invention comprises a blend of an ethylene-based polymer having a density and a melt index (I2) of 0.1 to 2.0 g / 10 min with a polyolefin plastomer. For example, in some embodiments, such a blend may include ELITE® 5400G or ELITE® 5401B and AFFINITY® PL1881G. As another example, in some embodiments, such a blend may include INNATE® ST50 and AFFINITY® PL 1881G.

[0148] In some embodiments, the sealant layer comprises a blend of LLDPE and polyolefin plastomer. For example, in some embodiments, such a blend may include DOWLEX® NG2045B or DOWLEX® GM8051 and AFFINITY® PL1881G.

[0149] In some embodiments, the sealant layer comprises a blend of LLDPE and LDPE. For example, in some embodiments, such a blend may include DOWLEX® NG 2045B or DOWLEX® GM 8051 as the LLDPE and DOW® LDPE 132I or DOW® LDPE 586A as the LDPE. In some such embodiments, the amount of LDPE is 30 weight percent or less based on the weight of the sealant layer.

[0150] In some embodiments, the sealant layer comprises a blend of polyolefin plastomer and LDPE. For example, in some embodiments, such a blend may include AFFINITY® PL 1881G, AFFINITY® PL 1888G, AFFINITY® PF 1140G, and AFFINITY® PF 1146G as polyolefin plastomer components, and DOW® LDPE 132I or DOW® LDPE 586A as LDPE. In some such embodiments, the amount of LDPE is 30 weight percent or less based on the weight of the sealant layer.

[0151] In some embodiments, it may be particularly advantageous to use a third polyethylene composition (or sealant resin) for the sealant layer. For example, in some embodiments, the third polyethylene composition (or sealant resin) can provide a lower heat seal initiation temperature (similar to polyolefin plastomers) but exhibit less bubble blocking compared to polyolefin plastomers having equivalent heat seal initiation temperatures. The third polyethylene composition (sealant resin) will be described further below.

[0152] It should be understood that in some embodiments, any of the layers within the film may further contain one or more additives known to those skilled in the art (in addition to those described above for polyethylene compositions), such as antioxidants, ultraviolet stabilizers, heat stabilizers, slip agents, anti-tack agents, pigments or colorants, processing aids, crosslinking catalysts, flame retardants, fillers, and foaming agents.

[0153] In some embodiments, the multilayer film is formed primarily from polyethylene. Being polyethylene-based, according to some embodiments of the present invention, the multilayer film can be incorporated into articles composed primarily of polyethylene, if not substantially or entirely, to provide articles that are more easily recyclable. For example, a multilayer film primarily containing polyethylene has an improved recyclability profile, in addition to other advantages that may be provided by using such polymers. For example, in some embodiments, the multilayer film is composed entirely of ethylene-based polymers, apart from additives. In some embodiments, the multilayer film may contain, based on the total weight of the multilayer film, 90% by weight of ethylene-based polymer, 95% by weight of ethylene-based polymer in some embodiments, 99% by weight of ethylene-based polymer in some embodiments, 99.9% by weight of ethylene-based polymer in some embodiments, or 100% by weight of ethylene-based polymer in some embodiments.

[0154] Multilayer films can have varying thicknesses, depending, for example, the number of layers, the intended use of the film, and other factors. Such multilayer films may have a total thickness of less than 200 micrometers in some embodiments, or less than 150 micrometers in some embodiments, or less than 120 micrometers in some embodiments. In some embodiments, the multilayer film of the present invention may have a total thickness of 30 to 200 micrometers, or 30 to 150 micrometers, or 30 to 120 micrometers.

[0155] Multilayer films can be formed using techniques known to those skilled in the art, based on the teachings herein. For example, films can be prepared as inflation films (e.g., water-quenched inflation films) or cast films. For example, in the case of multilayer films, with respect to layers that can be co-extruded, such layers can be co-extruded as inflation films or cast films using techniques known to those skilled in the art, based on the teachings herein.

[0156] The multilayer film of the present invention may exhibit one or more desirable properties. For example, in some embodiments, the multilayer film may exhibit a desirable dirt impact value, secant coefficient, barrier properties, and / or others. In particular, in some embodiments, the multilayer film of the present invention can remarkably exhibit a good balance between dirt impact (toughness) and secant coefficient when compared to a multilayer film having the same overall density. Furthermore, in some embodiments, the barrier properties of the multilayer film can also be increased by increasing the density of the multilayer film of the present invention.

[0157] In one exemplary embodiment, the multilayer film of the present invention is a three-layer film in which a first polyethylene composition is present in the core layer described herein, and two outer layers comprise the second polyethylene composition described herein.

[0158] In another exemplary embodiment, the multilayer film of the present invention is a three-layer film having an A / B / C layer arrangement, where layer A is the sealant layer (as described above), layer B comprises the first polyethylene composition described herein, and layer C comprises the second polyethylene composition described herein. In a further embodiment, layer A comprises the third polyethylene composition described herein.

[0159] In another exemplary embodiment, the multilayer film of the present invention is a five-layer film having a layer arrangement of A / B / C / B / D, where layer A is the sealant layer (as described above), layer B comprises the second polyethylene composition described herein, layer C comprises the first polyethylene composition described herein, and layer D comprises linear low-density polyethylene. In a further embodiment, layer A comprises the third polyethylene composition described herein.

[0160] In another exemplary embodiment, the multilayer film of the present invention is a five-layer film having an A / B / C / C / B layer arrangement, where layer A is the sealant layer (as described above), layer B comprises the second polyethylene composition described herein, and layer C comprises the first polyethylene composition described herein. In a further embodiment, layer A comprises the third polyethylene composition described herein.

[0161] In another exemplary embodiment, the multilayer film of the present invention is a five-layer film having a layer arrangement of A / B / C / B / D, where layer A is a sealant layer (as described above), layer B comprises the first polyethylene composition described herein, layer C comprises the second polyethylene composition described herein, and layer D comprises linear low-density polyethylene. In a further embodiment, layer A comprises the third polyethylene composition described herein.

[0162] In another exemplary embodiment, the multilayer film of the present invention is a five-layer film having an A / B / C / B / C layer arrangement, where layer A is the sealant layer (as described above), layer B comprises the second polyethylene composition described herein, and layer C comprises the first polyethylene composition described herein. In a further embodiment, layer A comprises the third polyethylene composition described herein.

[0163] In another exemplary embodiment, the multilayer film of the present invention is a five-layer film having an A / B / A / B / A layer arrangement, wherein layer A comprises the second polyethylene composition described herein, and layer B comprises the first polyethylene composition described herein.

[0164] Third polyethylene composition (sealant resin) As described above, in some embodiments, the multilayer film of the present invention includes an outer layer which is a sealant layer comprising a third polyethylene composition. In some embodiments, the third polyethylene composition comprises (a) a first polyethylene fraction having at least one peak in the temperature range of 35°C to 70°C in the elution profile via an improved comonomer composition distribution (iCCD) analysis method, wherein the first polyethylene area fraction is the area in the elution profile at 35°C to 70°C, and the area of ​​the first polyethylene fraction constitutes 25% to 65% of the total area of ​​the elution profile; and (b) a second polyethylene fraction having at least one peak in the temperature range of 85°C to 120°C in the elution profile via an iCCD analysis method. (c) A polyethylene fraction comprising a second polyethylene area fraction, wherein the second polyethylene area fraction is the area in the elution profile at 85°C to 120°C, and the area of ​​the second polyethylene fraction constitutes at least 20% of the total area of ​​the elution profile; and a third polyethylene fraction in the elution profile obtained via iCCD analysis, within the temperature range of 70°C to 85°C, wherein the third polyethylene area fraction is the area in the elution profile at 70°C to 85°C, and the area of ​​the third polyethylene fraction constitutes less than 10% of the total area of ​​the elution profile. The third polyethylene composition is 0.880 g / cm³ 3 ~0.910 g / cm³ 3 The third polyethylene composition may have a density of 0.50 g / 10 min to 6.0 g / 10 min (I2), and a zero shear viscosity ratio of less than 2.0.

[0165] In one or more embodiments, the third polyethylene composition is 0.880 g / cm³ 3 ~0.910 g / cm³ 3 It may have a density of 0.880 g / cm³. For example, an embodiment of the third polyethylene composition has a density of 0.880 g / cm³. 3 ~0.908 g / cm³ 3 , 0.880 g / cm³ 3 ~0.906 g / cm³ 3 , 0.880 g / cm³ 3 ~0.904 g / cm³ 3, 0.880 g / cm³ 3 ~0.902 g / cm³ 3 , 0.880 g / cm³ 3 ~0.900g / cm 3 , 0.900 g / cm³ 3 ~0.908 g / cm³ 3 , 0.900 g / cm³ 3 ~0.906 g / cm³ 3 , 0.900 g / cm³ 3 ~0.904 g / cm³ 3 , 0.900 g / cm³ 3 ~0.902 g / cm³ 3 , 0.902 g / cm³ 3 ~0.910 g / cm³ 3 , 0.902 g / cm³ 3 ~0.908 g / cm³ 3 , 0.902 g / cm³ 3 ~0.906 g / cm³ 3 , 0.902 g / cm³ 3 ~0.904 g / cm³ 3 , 0.904 g / cm³ 3 ~0.910 g / cm³ 3 , 0.904 g / cm³ 3 ~0.908 g / cm³ 3 , 0.904 g / cm³ 3 ~0.906 g / cm³ 3 , 0.906 g / cm³ 3 ~0.910 g / cm³ 3 , 0.906 g / cm³ 3 ~0.908 g / cm³ 3 , 0.908 g / cm³ 3 ~0.910 g / cm³ 3 , or the density may be any combination of these ranges.

[0166] In one or more embodiments, the third polyethylene composition may have a melt index (I2) of 0.50 g / 10 min to 6.0 g / 10 min. For example, in one or more embodiments, the third polyethylene composition may have a melt index (I2) of 0.5 g / 10 min to 5.0 g / 10 min, 0.5 g / 10 min to 4.0 g / 10 min, 0.5 g / 10 min to 3.0 g / 10 min, 0.5 g / 10 min to 2.0 g / 10 min, 0.5 g / 10 min to 1.0 g / 10 min, 1.0 g / 10 min to 6.0 g / 10 min, 1.0 g / 10 min to 5.0 g / 10 min, 1.0 g / 10 min to 4.0 g / 10 min, 1.0 g / 10 min to 3.0 g / 10 min, 1.0 g / 10 min to 2.0 g / 10 min, 2.0 The melt index (I2) may be in the following ranges: g / 10 min to 6.0 g / 10 min, 2.0 g / 10 min to 5.0 g / 10 min, 2.0 g / 10 min to 4.0 g / 10 min, 2.0 g / 10 min to 3.0 g / 10 min, 3.0 g / 10 min to 6.0 g / 10 min, 3.0 g / 10 min to 5.0 g / 10 min, 3.0 g / 10 min to 4.0 g / 10 min, 4.0 g / 10 min to 6.0 g / 10 min, 4.0 g / 10 min to 5.0 g / 10 min, 5.0 g / 10 min to 6.0 g / 10 min, or any combination of these ranges.

[0167] According to the embodiment, the third polyethylene composition may have a molecular weight distribution in the range of 2.0 to 6.0, expressed as the ratio of weight-average molecular weight to number-average molecular weight (Mw / Mn). For example, the third polyethylene composition may have a molecular weight distribution of 2.0-5.5, 2.0-5.0, 2.0-4.5, 2.0-4.0, 2.0-3.5, 2.0-3.0, 2.0-2.5, 2.5-6.0, 3.0-5.5, 3.0-5.0, 3.0-4.5, 3.0-4.0, 3.0-3.5, 3.5-6.0, 3.5-5.5, 3.5-5.0, 3.5-4.5, 3.5-4.0, 4.0-6.0, 4.0-5.5, 4.0-4.5, 4.0-4.5, 4.5-6.0, 4.5-5.5, 4.5-5.0, 5.0-6.0, 5.0-5.5, or 5.5-6.0, or any combination of these ranges. As described herein, the molecular weight distribution may be calculated according to gel permeation chromatography (GPC) techniques as described herein.

[0168] According to one or more additional embodiments, the third polyethylene composition may have a zero shear viscosity ratio of less than 2.0. For example, the third polyethylene composition may have a zero shear viscosity ratio of 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 third polyethylene composition may have a zero shear viscosity ratio of at least 1.0. In the embodiment, the third polyethylene composition may have a zero shear viscosity ratio of 1.0-2.0, 1.0-1.8, 1.0-1.6, 1.0-1.4, 1.0-1.2, 1.2-2.0, 1.2-1.8, 1.2-1.6, 1.2-1.4, 1.4-2.0, 1.4-1.8, 1.4-1.6, 1.6-2.0, 1.6-1.8, or 1.8-2.0.

[0169] Tan delta (tan δ) is a measure of how close a material is to a perfectly elastic solid (d=0°, tan delta=0) or a perfectly Newtonian liquid (d=90°, tan delta ≈ infinity). Therefore, a lower value of tan d reflects higher elasticity. Tan delta is a function of long chain branching (LCB) and molecular weight distribution (MWD) at the same overall molecular weight. A higher tan delta value indicates a lower LCB. In this embodiment, the third polyethylene composition is 10-100, 10-90, 10-80, 10-70, 10-60, 10-50, 10-40, 10-30, 10-20, 20-100, 20-90, 20-80, 20-70, 20-60, 20-50, 20-40, 20-30, 30-100, 30-90, 30-80, 30-70, 30-60, 30-50, 30- It may have a tandelta of 0.1 radians / second and 190°C in the following ranges: 40, 40-100, 40-90, 40-80, 40-70, 40-60, 40-50, 50-100, 50-90, 50-80, 50-70, 50-60, 60-100, 60-90, 60-80, 60-70, 70-100, 70-90, 70-80, 80-100, 80-90, or 90-100.

[0170] The third polyethylene composition may comprise at least a first polyethylene fraction and a second polyethylene fraction. Embodiments may comprise a third polyethylene fraction and a fourth polyethylene fraction. The various fractions contained in the third polyethylene composition may be defined by their temperature ranges in the elution profiles via improved comonomer composition distribution (iCCD) analysis. Examples of such fractions will be better understood by considering the examples provided herein. Generally, the first fraction may contain at least one peak within its temperature range. The second fraction may contain at least one peak within its temperature range. The fourth fraction may contain at least one peak within its temperature range. The first polyethylene area fraction, the second polyethylene fraction, the third polyethylene fraction, and the fourth polyethylene fraction may each contain a portion of the total mass of the third polyethylene composition.

[0171] In one or more embodiments, one or more of the first polyethylene fraction, the second polyethylene fraction, and the fourth polyethylene fraction may have a single peak.

[0172] It should be understood that the peaks in one or more of the first, second, and fourth polyethylene fractions cannot be formed by local minima in each polyethylene fraction at the defined temperature boundary. In other words, the peaks must be peaks in terms of the entire range, not peaks formed by the threshold temperature of the polyethylene fraction. For example, if a polyethylene fraction has a single peak followed by a single trough (an upward slope followed by a downward slope followed by an upward slope), then such a polyethylene fraction will have only a single peak.

[0173] In one or more embodiments, the first polyethylene fraction may be the area in the elution profile at 35°C to 70°C. In additional embodiments, the first polyethylene fraction may be the area in the elution profile via iCCD within the temperature ranges of 35°C to 60°C, 35°C to 50°C, 40°C to 70°C, 40°C to 60°C, 40°C to 50°C, 50°C to 70°C, 50°C to 60°C, 60°C to 70°C, or any combination thereof.

[0174] According to one or more embodiments, the first polyethylene fraction area may constitute at least 25% of the total area of ​​the elution profile (e.g., at least 30%, at least 40%, at least 50%, or even more than 60% of the total area of ​​the elution profile). For example, the first polyethylene fraction area may constitute 25% to 65%, 25% to 55%, 25% to 45%, 25% to 35%, 35% to 65%, 35% to 55%, 35% to 45%, 45% to 65%, 45% to 55%, 55% to 65%, or any combination of these amounts.

[0175] In one or more embodiments, the first polyethylene fraction may have at least one peak in the elution profile via iCCD within the temperature range of 35°C to 70°C. In one or more embodiments, the first polyethylene fraction may have at least one peak in the elution profile via iCCD within the temperature ranges of 35°C to 60°C, 35°C to 50°C, 40°C to 70°C, 40°C to 60°C, 40°C to 50°C, 50°C to 70°C, 50°C to 60°C, 60°C to 70°C, or any combination thereof.

[0176] A temperature range of 35°C to 70°C for the first polyethylene fraction may be desirable, as it can accommodate the low-density component of the third polyethylene composition. In embodiments, the low-density component can provide a lower hot tack initiation temperature, a lower heat seal initiation temperature, or both. Therefore, by increasing the amount of the first polyethylene fraction that may contain the low-density component, the hot tack initiation temperature, the heat seal initiation temperature, or both of the third polyethylene composition can be reduced, improving the hot tack strength and hot tack window.

[0177] In one or more embodiments, the second polyethylene fraction may be the area in the elution profile at 85°C to 120°C. In additional embodiments, the second polyethylene fraction may be the area in the elution profile via iCCD within the temperature ranges of 85°C to 110°C, 85°C to 100°C, 85°C to 90°C, 90°C to 120°C, 90°C to 110°C, 90°C to 100°C, 100°C to 120°C, 100°C to 110°C, 110°C to 120°C, or any combination thereof.

[0178] According to one or more embodiments, the second polyethylene fraction area may constitute at least 20% of the total area of ​​the elution profile (e.g., at least 30%, at least 35%, at least 40%, or at least 45% of the total area of ​​the elution profile). For example, the second polyethylene fraction area may constitute 20% to 60%, 20% to 50%, 20% to 40%, 20% to 30%, 30% to 60%, 30% to 50%, 30% to 40%, 40% to 60%, 40% to 50%, 50% to 60%, or any combination of these amounts.

[0179] In one or more embodiments, the second polyethylene fraction may have at least one peak in the elution profile via iCCD within the temperature range of 85°C to 120°C. In one or more embodiments, the second polyethylene fraction may have at least one peak in the elution profile via iCCD within the temperature ranges of 85°C to 110°C, 85°C to 100°C, 85°C to 90°C, 90°C to 120°C, 90°C to 110°C, 90°C to 100°C, 100°C to 120°C, 100°C to 110°C, 110°C to 120°C, or any combination thereof.

[0180] A temperature range of 85°C to 120°C for the second polyethylene fraction may be desirable to accommodate high-density components. In the embodiment, increasing the high-density component can increase the overall density of the third polyethylene composition. Therefore, by increasing the second polyethylene fraction, it is possible to increase the high-density component and provide a polyethylene composition with a higher overall density. In addition, increasing the second polyethylene fraction can improve the blocking properties of the third polyethylene composition. Although not bound by theory, it is thought that larger crystals are formed in the high-density fraction, providing a rougher surface. Since a rougher surface reduces the contact area, the blocking properties of the third polyethylene composition can be improved.

[0181] In one or more embodiments, the third polyethylene composition may have a minimum value in the iCCD elution profile within the temperature range of 65°C to 85°C. This minimum value may fall between the peak of the first polyethylene fraction and the peak of the second polyethylene fraction.

[0182] In one or more embodiments, the third polyethylene area fraction may be the area in the elution profile at 70°C to 85°C. In additional embodiments, the third polyethylene fraction may be the area in the elution profile via iCCD within the temperature ranges of 70°C to 80°C, 70°C to 75°C, 75°C to 85°C, 75°C to 80°C, 80°C to 85°C, or any combination thereof.

[0183] According to one or more embodiments, the third polyethylene fraction area may constitute less than 10% of the total area of ​​the elution profile (e.g., less than 8%, less than 6%, or less than 4% of the total area of ​​the elution profile). For example, the third polyethylene fraction area may constitute 4% to 10%, 4% to 8%, 4% to 6%, 6% to 10%, 6% to 8%, 8% to 10%, or any combination of these amounts.

[0184] In the embodiments described herein, the third polyethylene area fraction may be the area in the elution profile at 70°C to 85°C. In one or more embodiments, the third polyethylene area fraction may be the area in the elution profile via iCCD at 70°C to 85°C, 70°C to 80°C, 70°C to 75°C, 75°C to 85°C, 75°C to 80°C, 80°C to 85°C, or any combination thereof.

[0185] It may be desirable to minimize the third polyethylene fraction within the temperature range of 70°C to 85°C; otherwise, higher-density components will shift from the second polyethylene fraction towards lower temperature ranges in the elution profile. While we do not wish to be bound by theory, it is conceivable that a shift of high-density components towards lower temperature ranges in the elution profile may prevent the third polyethylene composition from achieving the desired blocking properties.

[0186] In one or more embodiments, the fourth polyethylene area fraction may be the area in the elution profile at 20°C to 35°C. In additional embodiments, the fourth polyethylene fraction may be the area in the elution profile via iCCD within the temperature ranges of 20°C to 30°C, 20°C to 25°C, 25°C to 35°C, 25°C to 30°C, 30°C to 35°C, or any combination thereof.

[0187] According to one or more embodiments, the fourth polyethylene fraction area may constitute less than 35% of the total area of ​​the elution profile (e.g., less than 30%, less than 20%, less than 10%, less than 5%, or even less than 2% of the total area of ​​the elution profile). For example, the fourth polyethylene fraction area may constitute 0% to 35%, 0% to 20%, 0% to 10%, 0% to 5%, 5% to 35%, 5% to 20%, 5% to 10%, 10% to 35%, 10% to 20%, 20% to 35%, or any combination of these.

[0188] In the embodiments described herein, the fourth polyethylene area fraction is the area in the elution profile directly below at least one peak of the fourth polyethylene fraction between 20°C and 35°C. In one or more embodiments, the fourth polyethylene fraction may have at least one peak in the elution profile via iCCD within the temperature ranges of 20°C to 30°C, 20°C to 25°C, 25°C to 35°C, 25°C to 30°C, 30°C to 35°C, or any combination thereof. In some cases, it is desirable to minimize the fourth polyethylene fraction within the temperature range of 20°C to 35°C. While we do not wish to be bound by theory, it is thought that the presence of a large amount of the fourth polyethylene fraction may prevent the third polyethylene composition from achieving the desired blocking properties.

[0189] In one or more embodiments, the third polyethylene composition may have a minimum value in the elution profile via iCCD within the temperature range of 30°C to 40°C. This minimum value may fall between the peak of the fourth polyethylene fraction and the peak of the first polyethylene fraction.

[0190] It should be understood that two or more polyethylene fractions may overlap. In one or more embodiments, the first polyethylene area fraction and the fourth polyethylene area fraction may overlap.

[0191] In one or more embodiments, the third polyethylene composition is formed by polymerization of ethylene with a comonomer such as a C3-C12 alkene. Examples of intended comonomers include C6-C9 alkenes such as 1-octene and 1-hexene. In one or more embodiments, the comonomer is 1-octene.

[0192] In one or more embodiments, the weight-average molecular weight of the first polyethylene fraction may be 225,000 g / mol or less, or any combination of these ranges, such as 30,000 g / mol to 225,000 g / mol, 60,000 g / mol to 150,000 g / mol, or 90,000 g / mol to 120,000 g / mol. The molecular weight of the polyethylene fraction may be calculated based on the iCCD results as described below.

[0193] In one or more embodiments, the weight-average molecular weight of the second polyethylene fraction may be 225,000 g / mol or less, or any combination of these ranges, such as 25,000 g / mol to 225,000 g / mol, 50,000 g / mol to 150,000 g / mol, or 75,000 g / mol to 125,000 g / mol. The molecular weight of the polyethylene fraction may be calculated based on the iCCD results as described below.

[0194] In the embodiment, the ratio of the molecular weight elution profile of the first polyethylene area fraction to the molecular weight of the total area is 0.5 to 1.5. In the embodiment, the ratio may be 0.5 to 1.5, 0.5 to 1.0, or 1.0 to 1.5.

[0195] polymerization A third polyethylene composition can be produced using any conventional polymerization process. Such conventional polymerization processes include, but are not limited to, gas-phase polymerization processes, slurry polymerization processes, and solution polymerization processes using one or more conventional reactors, such as loop reactors, isothermal reactors, stirred-tank reactors, pipe-flow reactors, plug-flow reactors, parallel and series batch reactors, and / or any combination thereof. The third polyethylene composition may be produced, for example, via a solution-phase polymerization process using one or more loop reactors, isothermal reactors, and combinations thereof. Generally, solution-phase polymerization processes can be carried out in one or more well-mixed reactors, such as one or more isothermal loop reactors or one or more adiabatic reactors, at temperatures in the range of 115°C to 250°C (e.g., 115°C to 210°C) and pressures in the range of 300 psi to 3,000 psi (e.g., 400 psi to 800 psi). In some embodiments, in a double reactor, the temperature in the first reactor is in the range of 115°C to 190°C (e.g., 150°C to 180°C), and 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).

[0196] The residence time in the solution-phase polymerization process can be in the range of 2 to 30 minutes (e.g., 5 to 25 minutes). Ethylene, solvent, hydrogen, one or more catalyst systems, optionally one or more co-catalysts, and optionally one or more comonomers are continuously supplied to one or more reactors. Examples of solvents include, but are not limited to, isoparaffins. For example, such solvents are commercially available from ExxonMobil Chemical Co. (Houston, Texas) under the name ISOPAR E. The resulting mixture of the third polyethylene composition and solvent is then removed from the reactor to isolate the polyethylene composition. The solvent is typically recovered via a solvent recovery unit, e.g., a heat exchanger and a gas-liquid separator drum, and then returned to the polymerization system for reuse.

[0197] In some embodiments, the third polyethylene composition may be produced by solution polymerization in a double reactor system, for example, a double-loop reactor system, in the presence of one or more catalyst systems and one or more comonomers. In some embodiments, only ethylene is polymerized. In addition, one or more co-catalysts may be present. In another embodiment, the third polyethylene composition may be produced by solution polymerization in a single reactor system, for example, a single-loop reactor system, in the presence of two catalyst systems and one or more monomers.

[0198] Catalyst system The polyethylene composition of the second composition can be produced using the same catalyst system described in relation to the production of the first polyethylene composition. As described in the Examples chapter, the production processes for the first and second polyethylene compositions differ such that the resulting polyethylene compositions have different properties as described herein.

[0199] Goods Embodiments of the present invention also relate to articles such as packaging and laminates formed from (or from laminates incorporating such films) the stretched multilayer polyethylene film of the present invention. Such packaging may be formed from any of the films or laminates described herein.

[0200] Examples of such articles include flexible packaging, pouches, self-standing pouches, and ready-made packaging or ready-made pouches. In some embodiments, the stretched multilayer polyethylene film or laminate of the present invention may be used for food packaging. Examples of foods that may be contained in such packaging include meat, cheese, cereals, nuts, juices, sauces, pet food, etc. Such packaging may be formed using techniques known to those skilled in the art, based on the teachings herein and on the specific use of the packaging (e.g., type of food, quantity of food, etc.).

[0201] Embodiments of the articles of the present invention may be laminates incorporating the multilayer films of the present invention. In some embodiments, the multilayer films according to embodiments of the present invention may be laminated onto another film. The other film in such embodiments may be a polyethylene sealant film, polyethylene terephthalate, polypropylene, or polyamide. The polyethylene sealant film may be a single-layer or multilayer film substantially formed from polyethylene (e.g., containing more than 90% by weight of an ethylene-based polymer, or more than 95% by weight of an ethylene-based polymer, or more than 99% by weight of an ethylene-based property), which, when heated as part of a laminate structure, can seal the laminate to another film, to another laminate, or to itself. Any polyethylene sealant film known to those skilled in the art based on the teachings herein may be used. If the other film contains polyethylene terephthalate, polypropylene, or polyamide, the entire film may be formed from polyethylene terephthalate, polypropylene, or polyamide, or the film may contain at least one layer containing polyethylene terephthalate, polypropylene, or polyamide. Those skilled in the art can, based on the teachings herein, select films containing polyethylene terephthalate, polypropylene, or polyamide for use in such embodiments.

[0202] 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, a multilayer film can be laminated onto another film using an adhesive. Various adhesive compositions are considered suitable for use in the preparation of the laminate. These may include polyurethane, epoxy, acrylic, and the like. In one embodiment, the laminate may include an adhesive layer containing a polyurethane adhesive. The polyurethane adhesive may be solvent-free, aqueous, or solvent-based. Furthermore, the polyurethane adhesive may be a two-component formulation. The weight or thickness of the adhesive layer may depend on a number of factors, including, for example, the desired thickness of the laminate, the type of adhesive used, and other factors. In some embodiments, the adhesive layer may be up to 5.0 grams / m² 2 , or 1.0~4.0g / m 2 , or 2.0~3.0g / m 2 It is applied.

[0203] Laminates according to some embodiments of the present invention can also be formed by extrusion lamination.

[0204] Test method Unless otherwise specified herein, the following analytical methods are used in describing aspects of the present invention.

[0205] Melt Index Melt index I2 (or I2) and I 10 (or I10) were measured at 190°C with loads of 2.16 kg and 10 kg, respectively, according to ASTM D-1238 (Method B). These values ​​should be reported in g / 10 min.

[0206] density Samples for density measurement were prepared according to ASTM D4703. Measurements were performed within one hour of sample pressurization, according to ASTM D792, Method B.

[0207] Conventional gel permeation chromatography (conventional GPC) The GPC-IR high-temperature chromatography system at PolymerChar (Valencia, Spain) is equipped with a Precision Detectors (Amherst, MA) Model 2040 dual-angle laser light scattering detector, an IR5 infrared detector, and a 4-capillary viscometer, both manufactured by PolymerChar. Data acquisition is performed using PolymerChar's Instrument Control software and data acquisition interface. The system also includes an online solvent degassing device and pump system from Agilent Technologies (Santa Clara, CA).

[0208] The injection temperature is controlled to 150°C. The columns used are three 10 μm "Mixed-B" columns manufactured by Polymer Laboratories (Shropshire, UK). The solvent used is 1,2,4-trichlorobenzene. The sample is prepared at a concentration of "0.1 grams of polymer in 50 milliliters of solvent". The chromatography solvent and the sample preparation solvent each contained "200 ppm butylated hydroxytoluene (BHT)". Both solvent sources are sparged with nitrogen. The ethylene polymer sample is gently stirred at 160°C for 3 hours. The injection volume is "200 microliters" and the flow rate is "1 milliliter / min". The GPC column set is calibrated using 21 polystyrene standards with a "narrow molecular weight distribution". The molecular weight ("MW") of the standard substances ranges from 580 to 8,400,000 g / mol, and the standard substances are contained in six "cocktail" mixtures. Each standard substance mixture has at least a 10-fold gap between the individual molecular weights. The standard substance mixtures are purchased from Polymer Laboratories. Polystyrene standards are prepared at a dose of "0.025 g in 50 mL of solvent" for molecular weights of 1,000,000 g / mol or more, and at a dose of "0.050 g in 50 mL of solvent" for molecular weights less than 1,000,000 g / mol.

[0209] Dissolve the polystyrene standard material at 80°C with gentle stirring for 30 minutes. Perform the narrow standard material mixture first, in an order where the "highest molecular weight component" gradually decreases, to minimize decomposition. Convert the peak molecular weight of the polystyrene standard material to the polyethylene molecular weight using Equation 1 (as described in Williams and Ward, J. Polym. Sci., Polym. Letters, 6, 621 (1968)). M polyethylene = A × (M polystyrene) B (Formula 1), (In the formula, M is the molecular weight, A is equal to 0.4316, and B is equal to 1.0).

[0210] The number-average molecular weight (Mn (conventional gpc)), weight-average molecular weight (Mw (conventional gpc)), and z-average molecular weight (Mz (conventional gpc)) are calculated according to equations 2 to 4 below.

[0211]

number

[0212] In equations 2-4, RV is the column retention volume (linearly spaced) collected at "one point per second", IR is the baseline subtracted IR detector signal in volts from the IR5 measurement channel of the GPC instrument, and M PE This is the polyethylene equivalent in MW determined from Equation 1. Data calculations are performed using PolymerChar's "GPC One software (version 2.013H)".

[0213] Creep-zero shear viscosity measurement method Zero shear viscosity is obtained via a creep test performed on an AR G2 stress-controlled rheometer (TA Instruments; New Castle, Del) at 190°C using parallel plates with a diameter of 25 mm. Before zeroing the mounting fixture, the rheometer oven is set to the test temperature for at least 30 minutes. At that test temperature, the compression-molded sample disc is inserted between the plates and allowed to equilibrate for 5 minutes. The upper plate is then lowered to 50 μm (instrument setting) above the desired test gap (1.5 mm). Excess material is trimmed and removed, and the upper plate is lowered to the desired gap. The measurement is performed under a nitrogen purge at a flow rate of 5 L / min. The default creep time is set to 2 hours. Each sample is compression-molded into a circular plaque of 2 mm thickness × 25 mm diameter in air at 177°C for 5 minutes under a pressure of 10 MPa. The sample is then removed from the compressor and placed on a counter to cool.

[0214] To ensure that the steady-state shear rate is low enough to fall within the Newtonian domain, a constant low shear stress of 20 Pa is applied to all samples. The resulting steady-state shear rate for the samples in this test is 10 -3 ~10 -4 s -1 The range is as follows. The steady state is determined by taking a linear regression for all data within the last 10% time window of the “log(J(t)) vs log(t)” plot, where J(t) is the creep compliance and t is the creep time. If the slope of the linear regression is greater than 0.97, the steady state is considered to have been reached, and the creep test is then stopped. In all cases in this test, the slope meets the criterion within 1 hour. The steady-state shear rate is determined from the slope of all linear regressions for all data points within the last 10% time window of the “ε vs t” plot (where ε is strain). The creep-zero shear viscosity is determined from the ratio of the applied stress to the steady-state shear rate.

[0215] To determine whether the sample deteriorated during the creep test, small-amplitude vibration shear tests were performed on the same sample before and after the creep test at 0.1–100 radians / second. The complex viscosity values ​​of the two tests were compared. If the difference in viscosity values ​​at 0.1 radians / second was greater than 5%, the sample was considered to have deteriorated during the creep test, and the results were discarded.

[0216] Zero-shear viscosity ratio (ZSVR) The zero shear viscosity ratio (ZSVR) is defined as the ratio of the zero shear viscosity (ZSV) of a branched polyethylene material at the equivalent average molecular weight to the ZSV of a linear polyethylene material, according to the following equation. ZSVR=η 0B / η 0L =η 0B / (2.29 -15 × Mwt 3.65 ) ZSV values ​​are obtained from creep tests at 190°C via the method described above. Mwt is determined using conventional gel permeation chromatography, as described above. The correlation between the ZSV of linear polyethylene and its molecular weight was established based on a series of linear polyethylene reference samples. Lower ZSV values ​​indicate lower levels of long-chain branching.

[0217] 13 Branching measurement using 13C NMR Sample preparation The sample is prepared by adding approximately 2.7 g of a 50 / 50 mixture of tetrachloroethane-d2 / orthodichlorobenzene containing 0.025 M Cr(AcAc)3 as a mitigating agent to 0.20-0.30 g of the sample in a 10 mm Norell NMR tube (product no. 1001-7). Oxygen is removed by purging the tube with N2 for 1 minute. The sample is dissolved and homogenized by heating the tube and its contents to 120-140°C using a heating block and vortex mixer. Homogeneity is confirmed by visual inspection of each sample. The completely mixed sample cannot be cooled before insertion into a heated NMR sample changer and / or NMR probe.

[0218] Data acquisition parameters Data are acquired using a Bruker 600 MHz spectrometer equipped with a Bruker 10 mm multinuclear high-temperature cryoprobe. Data are acquired at a sample temperature of 120°C using 1280 transient voltages per data file, a 7.8-second pulse repetition delay, a 90-degree flip angle, and reverse-gated decoupling. All measurements are performed on non-rotating samples in locked mode. Samples are thermally equilibrated before data acquisition. 13 The 3C NMR chemical shift uses the EEE triad at 30.0 ppm as an internal reference. The data is processed into spectra, appropriate peaks are merged (to quantify branches), and then one or more peak integral values ​​are used, or averaged against total branches / 1000C. If no branches are detected, the detection limit of the spectrum is calculated using the integral values ​​of peaks, such as those at the chain ends, and the signal-to-noise ratio.

[0219] 1 Degree of unsaturation measurement using 1H NMR Add the stock solution (3.26 g) to 0.10-0.13 g of polymer sample in a 10 mm NMR tube. The stock solution is a mixture of tetrachloroethane-d2 (TCE) and perchloroethylene (50:50, w:w), and contains 0.001 M Cr 3+ A mixture containing, or 0.001M Cr 3+ It is either 100% TCE having [specific properties]. Purge the solution in the tube with N2 for 5 minutes to reduce the amount of oxygen. Dissolve the sample at 120-140°C while periodically vortex mixing. Each 1 ¹H NMR analysis is performed using a Bruker AVANCE 600MHz spectrometer at 120°C with a 10mm frozen probe.

[0220] Two experiments were performed to measure the degree of unsaturation: one as a control experiment and the other as a double pre-saturation experiment. In the control experiment, the data were processed with an exponential window function with a linewidth expansion of 0.7 Hz. Residual TCE 1Set the signal from H to 100, and the integral value is approximately -0.5 to 3 ppm (I 合計 ) is used as the signal from all polymers in the control experiment. The total number of carbon atoms NC in the polymer is calculated using equation 1A as follows: NC=I 合計 / 2 (Equation 1A).

[0221] In the double pre-saturation experiment, the data was processed with an exponential window function having a linear expansion of 0.7 Hz, correcting the baseline to approximately 7–4 ppm. TCE residue 1 Set the signal from H to 100, and the corresponding integral value for unsaturation (I ビニレン , I 三置換 , I ビニル , and I ビニリデン Integrate ). It is well known that NMR spectroscopy is used to determine polyethylene unsaturation; see, for example, Busico, V., et al., Macromolecules, 2005, 38, 6988. The number of unsaturated units of vinylene, trisubstituted, vinyl, and vinylidene is calculated as follows: N ビニレン =I ビニレン / 2 (formula 2A), N 三置換 =I 三置換 (Formula 3A), N ビニル =I ビニル / 2 (formula 4A), N ビニリデン =I ビニリデン / 2 (Formula 5A).

[0222] The unsaturated units per 1,000 total carbon atoms, i.e., all polymer carbons including the main chain and branched chains, are calculated as follows: N ビニレン / 1,000C=(N ビニレン / NC) * 1,000 (Formula 6A), N 三置換 / 1,000C=(N 三置換 / NC) * 1,000 (Formula 7A), N ビニル / 1,000C=(N ビニル / NCH2)* 1,000 (Formula 8A), N ビニリデン / 1,000C=(N ビニリデン / NC) * 1,000 (Formula 9A).

[0223] From residual protons from TCE-d2 1 For the H signal, the chemical shift standard is set to 6.0 ppm. Control is performed with a ZG pulse, NS=16, DS=2, AQ=1.82s, D1=14s (D1 is relaxation delay). The double pre-saturation experiment is performed with a modified pulse train with O1P=1.354 ppm, O2P=0.960 ppm, NS=50, AQ=1.82s, D1=1s (D1 is pre-saturation time), D13=13s (D13 is relaxation delay).

[0224] Improved method for comonomer content distribution (iCCD) analysis The improved comonomer content analysis method (iCCD) was developed in 2015 (Cong and Parrott et al., International Publication No. 2017040127(A1)). The iCCD test was performed using a Crystallization Elution Fractionation (CEF) instrument (PolymerChar, Spain) equipped with an IR-5 detector (PolymerChar, Spain) and a two-angle light scattering detector Model 2040 (Precision Detectors, now Agilent Technologies). A guard column made of stainless steel packed with 20-27 micron glass (MoSCi Corporation, USA), measuring 5 cm or 10 cm (length) × 1 / 4 inch (ID), was placed directly in front of the IR-5 detector in the detector oven. Ortho-dichlorobenzene (ODCB, 99% anhydrous or technical grade) was used. Silica gel 40 (particle size 0.2-0.5 mm, catalog number 10181-3) was obtained from EMD Chemicals (it can be used to dry the ODCB solvent beforehand). The CEF instrument is equipped with an autosampler with N2 purging capability. Before use, the ODCB was spurged with dry nitrogen (N2) for 1 hour. Samples were prepared using the autosampler at 4 mg / mL (unless otherwise specified) under shaking at 160°C for 1 hour. The injection volume was 300 μL. The iCCD temperature profile was crystallization from 105°C to 30°C at 3°C / min, thermal equilibrium at 30°C for 2 minutes (including setting the soluble fraction elution time to 2 minutes), 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 1 data point / second.

[0225] The iCCD column was packed with gold-coated nickel particles (Bright 7GNM8-NiS, Nippon Chemical Industrial Co.) in a 15 cm (length) x 1 / 4 inch (ID) stainless steel tube. Column packing and preparation were performed using the slurry method described in the reference (Cong, R.; Parrott, A.; Hollis, C.; Cheatham, M. International Publication No. 2017040127(A1)). The final pressure using TCB slurry packing was 150 bar.

[0226] Column temperature calibration is performed using linear homopolymer polyethylene (CO2) as the reference material in the ODCB (comonomer content zero, melt index (I2) 1.0, polydispersity M). w / M n This was performed using conventional gel permeation chromatography with a mixture of approximately 2.6 mg / mL (1.0 mg / mL) and eicosan (2 mg / mL). iCCD temperature calibration consisted of the following four steps: (1) calculating the delay volume, defined as the temperature offset between the measured peak elution temperatures of eicosane minus 30.00°C; (2) subtracting the temperature offset of the elution temperature from the iCCD raw temperature data (note that this temperature offset is a function of experimental conditions such as elution temperature and elution flow rate); (3) creating a linear calibration curve that converts the elution temperature over the range of 30.00°C to 140.00°C such that the linear homopolymer polyethylene reference material has a peak temperature of 101.0°C and eicosane has a peak temperature of 30.0°C; (4) linearly extrapolating elution temperatures below 30.0°C for the soluble fraction measured isothermally at 30°C by using an elution heating rate of 3°C / min according to the reference (Cerk and Cong et al., U.S. Patent No. 9,688,795).

[0227] The comonomer content versus iCCD elution temperature was constructed using 12 reference materials (ethylene homopolymers and ethylene-octene random copolymers prepared with single-site metallocene catalysts, with ethylene equivalent weight-average molecular weights ranging from 35,000 to 128,000). All of these reference materials were analyzed at 4 mg / mL using the same method as previously specified. The reported elution peak temperatures linearly fit to the linear equation y = -6.3515x + 101.00, where y represents the elution temperature of iCCD, x represents the octene mole%, and R 2 The value was 0.978.

[0228] The molecular weights of the polymer and polymer fractions were determined directly from an LS detector (90-degree angle) and a concentration detector (IR-5) according to the Rayleigh-Gans-Debys approximation (Striegel and Yau, Modern Size Exclusion Liquid Chromatogram, Pages 242 and 263), by assuming a form factor of 1 and zero virial coefficients. An integration window was set to integrate all chromatograms at elution temperatures in the range of 23.0–120°C (temperature calibration as specified above).

[0229] Calculating the molecular weight (Mw) from an iCCD involves the following four steps: (1) Step of measuring the inter-detector offset. The offset is defined as the geometric volume offset between the LS detectors relative to the concentration detector. This is calculated as the difference in the amount of polymer peak eluted (mL) between the concentration detector and the LS chromatogram. This is converted to a temperature offset by using the elution thermal rate and elution flow rate. Linear high-density polyethylene (comonomer content zero, melt index (I2) 1.0, polydispersity M w / M nThis method uses conventional gel permeation chromatography (approximately 2.6%). The same experimental conditions as the standard iCCD method described above are used, except for the following parameters: crystallization from 140°C to 137°C at 10°C / min, thermal equilibrium at 137°C for 1 minute as the soluble fraction elution time, soluble fraction (SF) time of 7 minutes, and elution from 137°C to 142°C at 3°C / min. The flow rate during crystallization is 0.0 mL / min. The flow rate during elution is 0.80 mL / min. The sample concentration is 1.0 mg / mL. (2) Shift each LS data point in the LS chromatogram to correct the inter-detector offset before integration. (3) The baseline-subtracted LS and concentration chromatogram are integrated over the entire elution temperature range of step (1). The MW detector constant is calculated using HDPE samples with known MW values ​​in the range of 100,000 to 140,000 Mw, and the area ratio of the LS to the concentration integrated signal. (4) The Mw of the polymer was calculated using the ratio of the integrated light scattering detector (90-degree angle) and the concentration detector, and the MW detector constant.

[0230] The calculation of the full width at half maximum is defined as the temperature difference between the forward and backward temperatures at half the maximum peak height. The forward temperature at half the maximum peak is explored starting from 35.0°C and backward from 119.0°C.

[0231] Dynamic shear rheology The sample was compressed in air at 190°C and a pressure of 25,000 pounds for 6.5 minutes, and then the plaque was cooled on a workbench. The plaque thickness was approximately 3 mm. Constant temperature-frequency sweep measurements were performed using an ARES strain-controlled parallel plate rheometer (TA Instruments) equipped with 25 mm parallel plates under nitrogen purging. For each measurement, the rheometer was thermally equilibrated for at least 30 minutes before the gap was reduced to zero. The sample was placed on the plate and melted at 190°C for 5 minutes. The plate was then closed to 2 mm, the sample was trimmed, and then the test was started. This method incorporated an additional 5-minute delay to allow for thermal equilibrium. This experiment was performed at 190°C, at 5 points per 10x interval, over a frequency range of 0.1 to 100 radians / second. The strain amplitude was constant at 10%. The stress response is analyzed with respect to amplitude and phase, and from there the storage modulus (G'), loss modulus (G''), and complex modulus (G * ), dynamic complex viscosity (η * ), and tan(δ) or tan-delta were calculated.

[0232] Water vapor permeability Water vapor transmission rate (WVTR) is measured at 37°C and 90% relative humidity according to ASTM E-398.

[0233] Oxygen permeability Oxygen permeability, or "OTR," is determined according to ASTM D3985 using the Mocon Oxtran OTR test system at 100% oxygen content, 85% relative humidity, and a temperature of 23°C.

[0234] Dirt Impact After the film was produced, it was acclimatized to 23°C (+ / -2°C) and 50%RH (+ / -5) for at least 40 hours according to ASTM standards. The standard test conditions are 23°C (±2°C) and 50%RH (±5) according to ASTM standards.

[0235] The thickness of the specimen was measured at its center, and the specimen was then secured in an annular specimen holder with an inner diameter of 5 inches. The dart was loaded above the center of the specimen and released by either pneumatic or electromagnetic mechanism.

[0236] The tests were conducted according to the "step" method. If a sample broke, a new sample was tested with the dart weight reduced by a known fixed amount. If a sample did not break, a new sample was tested with the dart weight increased by a known amount. After testing 20 test pieces, the number of breaks was determined. If this number was 10, the test was completed. If this number was less than 10, the test was continued until 10 breaks were recorded. If this number was greater than 10, the test was continued until the total number of non-breaks was 10. The dart impact value was determined from these data and expressed in grams according to ASTM D1709. The test results in this example are reported according to Method A (Type A dart drop impact).

[0237] The terms “dirt drop impact” and “dirt impact” are used synonymously herein to refer to this test method.

[0238] Secant coefficient (2%) In accordance with ASTM D882-12, the secant coefficients at 2% strain are measured in the longitudinal (MD) and transverse (CD) directions using an Instron Universal testing machine.

[0239] Herein, several embodiments of the present invention will be described in detail in the following examples. [Examples]

[0240] First polyethylene composition The following are examples of first polyethylene compositions that can be used in embodiments of the multilayer film of the present invention. The first polyethylene composition 1 is prepared according to the following process and based on the reaction conditions reported in Table 1.

[0241] Before introducing them into the reaction environment, all raw materials (ethylene monomers) and process solvents (high-purity isoparaffin solvent with a narrow boiling point range, Isopar-E) are purified using molecular sieves. Hydrogen is supplied under pressure as a high-purity grade and is not purified further. The monomer feed stream to the reactor is pressurized to a pressure higher than the reaction pressure by a mechanical compressor. The solvent feed is pressurized to a pressure higher than the reaction pressure by a pump. Individual catalyst components are manually batch-diluted to the specified component concentrations using the purified solvent and pressurized to a pressure higher than the reaction pressure. All reaction feed streams are measured using mass flow meters and independently controlled by a computer-automated valve control system.

[0242] A continuous solution polymerization reactor consists of two liquid-filled, non-adiabatic, isothermal circulating loop reactors, similar to a continuously stirred tank reactor (CSTR) with heat removal. Independent control of all fresh solvent, monomer, hydrogen, and catalyst component feeds to each reactor is possible. The entire fresh feed stream (solvent, monomer, and hydrogen) to each reactor is temperature-controlled by passing the feed stream through a heat exchanger. The entire fresh feed to each polymerization reactor is injected into the reactor at two locations per reactor, with approximately equal reactor volumes between each injection position. The unused feed to the first reactor is typically controlled so that each injector receives half of the total mass flow rate of the fresh feed. The fresh feed to the second reactor, in series, is typically controlled to maintain half of the total ethylene mass flow rate near each injector, and since unreacted ethylene from the first reactor enters the second reactor adjacent to the low-pressure fresh feed, this injector usually receives less than half of the total mass flow rate of the fresh feed to the second reactor.

[0243] The catalyst / co-catalyst components for each reactor are injected into the polymerization reactor through specially designed injection stingers. Each catalyst / co-catalyst component is injected separately into the same relative position within the reactor without any prior contact time. The main catalyst component is computer-controlled to maintain monomer conversion in each reactor at a specific target value. The co-catalyst components are supplied relative to the main catalyst component based on a calculated specific molar ratio.

[0244] The catalyst used in the first reactor is zirconium,[[2,2'''-[[bis[1-methylethyl]germylene]bis(methyleneoxy-κO)]bis[3'',5,5''-tris(1,1-dimethylethyl)-5'-octyl[1,1':3',1''-terphenyl]-2'-orato-κO]](2-)]dimethyl-, which has the chemical formula C 86 H 128 It has F2GeO4Zr and the following structure ("Catalyst 1").

[0245] [ka] The catalyst used in the second reactor is zirconium,[[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-orato-κO]](2-)]dimethyl, with chemical formula C 107 H 154 It has N2O4Si2Zr and the following structure ("Catalyst 2").

[0246] [ka]

[0247] Immediately after the injection point of each reactor feed, the feed stream is mixed with the contents of a circulating polymerization reactor having a static mixing element. The contents of each reactor are continuously circulated to a heat exchanger, which plays a role in removing most of the reaction heat, at the temperature of the coolant side, which plays a role in maintaining an isothermal reaction environment at a specific reaction temperature. Circulation around each reactor loop is provided by a pump.

[0248] The effluent from the first polymerization reactor (containing solvent, monomer, hydrogen, catalyst components, and molten polymer) exits the first reactor loop, passes through a control valve (which maintains the pressure in the first reactor at a specific target value), and is injected into a second polymerization reactor of a similar design. The final effluent from the second polymerization reactor enters a zone where the effluent is deactivated by the addition and reaction of a suitable reagent (water). At this same reactor outlet location, other additives are added to stabilize the polymer. This final effluent flow passes through another set of static mixing elements to facilitate catalyst deactivation and additive dispersion.

[0249] Following catalyst deactivation and additive addition, the reactor effluent enters a devolving system where the polymer is removed from the non-polymer stream. The isolated polymer molten material is pelletized and recovered. The non-polymer stream passes through various devices that separate most of the ethylene removed from the system. Most of the solvent passes through a purification system and is then recycled back into the reactor. A small amount of solvent is purged from the process. Polyethylene composition 1 was stabilized with a small amount (ppm level) of stabilizer.

[0250] The polymerization conditions for the first polyethylene composition 1 are reported in Table 1. As shown in Table 1, co-catalyst 1 (bis(hydrohydrate tulloalkyl)methyl, tetrakis(pentafluorophenyl)borate(1-)amine) and co-catalyst 2 (modified methylaluminoxane (MMAO)) are used as co-catalysts for catalyst 1 and catalyst 2, respectively.

[0251] The first polyethylene composition 2 is prepared using the same catalyst system as polyethylene composition 1, under equivalent reaction conditions, and using the same process.

[0252] Additional properties of the first polyethylene composition 1 and the first polyethylene composition 2 are measured using the test method described above and 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.

[0253] [Table 1]

[0254] [Table 2] * The detection limit for this measurement was less than 3. ** the goal The densities of the first polyethylene fraction of the first polyethylene composition 1, the entire first polyethylene composition 1, and the entire first polyethylene composition 2 are measured as described in the Test Methods section. The density of the first polyethylene fraction of the first polyethylene composition 2 is the target value. The density of the second polyethylene fraction is calculated using the following blending rules.

[0255]

number

[0256] Additional properties of the first polyethylene composition 1 and the first polyethylene composition 2 are evaluated and reported in Table 3.

[0257] [Table 3]

[0258] The first polyethylene composition 1 may be dry-blended with Hyperform HPN-20E nucleating agent (Milliken Chemical) provided in a masterbatch to target different final loadings of HPN-20E nucleating agent ("HPN-20E"). An example of a masterbatch containing HPN-20E includes 3 wt percent HPN-20E, 1.5 wt percent silica, 0.5 wt percent hydrotalcite, 5 wt percent antioxidant, and 90 wt percent carrier resin. The carrier resin is 0.965 g / cm³ 3 It may be a high-density polyethylene homopolymer with a narrow molecular weight distribution having a density and a melt index (I2) of 8.0 g / 10 min. Hyperform HPN-20E contains about 66 wt percent of the calcium salt of 1,2-cyclohexanedicarboxylic acid and about 34 wt percent of zinc stearate / zinc palmitate. This masterbatch formed with the Hyperform HPN-20E nucleating agent is called the "nucleating agent masterbatch".

[0259] In the preparation of the multilayer films in the following examples, the first polyethylene composition is prepared using the same catalyst system as polyethylene composition 1 and polyethylene composition 2, and using the same process under equivalent reaction conditions so that the first polyethylene composition has properties consistent with polyethylene composition 2. This first polyethylene composition is melt-blended with a nucleating masterbatch to provide a target loading of 750 ppm of Hyperform HPN-20E nucleating agent. References to the first polyethylene composition 3 in the formation of the films and comparative films of the present invention below should be understood as this first polyethylene composition incorporating a nucleating masterbatch having a target loading of 750 ppm of Hyperform HPN-20E.

[0260] Second polyethylene composition The following are examples of second polyethylene compositions that can be used in embodiments of the multilayer film of the present invention.

[0261] Second polyethylene compositions 1 to 5, as described in accordance with one or more embodiments of "Modes for Carrying Out the Invention," are prepared by the following method and using the following catalyst and reactor.

[0262] Before introducing them into the reaction environment, all raw materials (monomers and comonomers) and process solvent (high-purity isoparaffin solvent with a narrow boiling point range, Isopar-E) are purified using molecular sieves. Hydrogen is supplied under pressure as a high-purity grade and is not purified further. The monomer feed stream to the reactor is pressurized to a pressure higher than the reaction pressure by a mechanical compressor. The solvent and comonomer feed streams are also pressurized to a pressure higher than the reaction pressure by pumps. Individual catalyst components are manually batch diluted using the purified solvent and pressurized to a pressure higher than the reaction pressure. All reaction feed streams are measured using mass flow meters and independently controlled by a computer-automated valve control system.

[0263] Two reactor systems are used in a series configuration. Each continuous solution polymerization reactor consists of a liquid-filled, non-adiabatic isothermal circulating loop reactor, mimicking a continuous stirred-tank reactor (CSTR) that removes heat. All fresh solvent, monomer, comonomer, hydrogen, and catalyst component feeds are independently controlled. The total fresh feed streams to each reactor (solvent, monomer, comonomer, and hydrogen) are temperature-controlled to maintain a single solution phase by passing the feed streams 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 the injection points. The fresh feed is controlled so that each injector accepts half of the total fresh feed flow rate. Catalyst components are injected into the polymerization reactor through injection stingers. The main catalyst component feed is computer-controlled to maintain monomer conversion in each reactor at a specific target value. Co-catalyst components are supplied based on a specific molar ratio calculated relative to the main catalyst component. Immediately after the injection point of each reactor feed, the feed stream is mixed with the contents of a circulating polymerization reactor having a static mixing element. The contents of each reactor are continuously circulated to a heat exchanger, which plays a role in removing most of the reaction heat, at the temperature of the coolant side, which plays a role in maintaining an isothermal reaction environment at a specific temperature. Circulation around each reactor loop is provided by pumps.

[0264] In a double series reactor configuration, the effluent from the first polymerization reactor (containing solvent, monomer, comonomer, hydrogen, catalyst components, and polymer) exits the first reactor loop and is added to the second reactor loop.

[0265] The second reactor effluent enters a zone where a suitable reagent (water) is added and reacts with it to deactivate the effluent. At this same reactor outlet location, other additives are added for polymer stabilization (typical antioxidants suitable for stabilization during extrusion and film production, such as octadecyl 3,5-di-Tert-butyl-4-hydroxyhydrocinnamate, tetrakis(methylene(3,5-di-Tert-butyl-4-hydroxyhydrocinnamate))methane, and tris(2,4-di-Tert-butyl-phenyl)phosphite).

[0266] Following catalyst deactivation and additive addition, the reactor effluent enters a devolving system where the polymer is removed from the non-polymer stream. The isolated polymer molten material is pelletized and recovered. The non-polymer stream passes through various devices that separate most of the ethylene removed from the system. Most of the solvent and unreacted comonomers are recycled back into the reactor after passing through a purification system. Small amounts of solvent and comonomers are purged from the process.

[0267] The polymerization conditions for the second polyethylene compositions 1 to 5 are reported in Table 4. Table 5 shows the catalysts referenced in Table 4.

[0268] [Table 4]

[0269] [Table 5]

[0270] A second polyethylene composition 6, as described in accordance with one or more of the "Modes for Carrying Out the Invention," is prepared by the following method and using the following catalyst and reactor.

[0271] Before introducing them into the reaction environment, all raw materials (monomers and comonomers) and process solvent (high-purity isoparaffin solvent with a narrow boiling point range, Isopar-E) are purified using molecular sieves. Hydrogen is supplied under pressure as a high-purity grade and is not purified further. The monomer feed stream to the reactor is pressurized to a pressure higher than the reaction pressure by a mechanical compressor. The supply of solvent and comonomers is also pressurized to a pressure higher than the reaction pressure via pumps. Individual catalyst components are manually batch diluted using the purified solvent and pressurized to a pressure higher than the reaction pressure. All reaction feed streams are measured using mass flow meters and independently controlled by a computer-automated valve control system.

[0272] Two reactor systems are used in a parallel configuration. Each continuous solution polymerization reactor consists of a liquid-filled, non-adiabatic isothermal circulating loop reactor, mimicking a continuous stirred-tank reactor (CSTR) that removes heat. All fresh solvent, monomer, comonomer, hydrogen, and catalyst component feeds are independently controlled. The total fresh feed streams to each reactor (solvent, monomer, comonomer, and hydrogen) are temperature-controlled to maintain a single solution phase by passing the feed streams 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 so that each injector receives half of the total fresh feed flow rate. Catalyst components are injected into the polymerization reactor through specially designed injection stingers. The main catalyst component feed is computer-controlled to maintain monomer conversion in each reactor at a specific target value. Co-catalyst components are supplied based on a calculated specific molar ratio to the main catalyst component. Immediately after the injection point of each reactor feed, the feed stream is mixed with the contents of a circulating polymerization reactor having a static mixing element. The contents of each reactor are continuously circulated to a heat exchanger, which plays a role in removing most of the reaction heat, at the temperature of the coolant side, which plays a role in maintaining an isothermal reaction environment at a specific temperature. Circulation around each reactor loop is provided by a pump.

[0273] The effluent flows from the first and second polymerization reactors are combined before any additional processing. This combined final reactor effluent enters a zone to which a suitable reagent (water) is added and reacts with it to deactivate the effluent. At this same reactor outlet location, other additives are added for polymer stabilization (typical antioxidants suitable for stabilization during extrusion and inflation film production, such as octadecyl 3,5-di-Tert-butyl-4-hydroxyhydrocinnamate, tetrakis(methylene(3,5-di-Tert-butyl-4-hydroxyhydrocinnamate))methane, and tris(2,4-di-Tert-butyl-phenyl)phosphite).

[0274] Following catalyst deactivation and additive addition, the reactor effluent enters a devolving system where the polymer is removed from the non-polymer stream. The isolated polymer molten material is pelletized and recovered. The non-polymer stream passes through various devices that separate most of the ethylene removed from the system. Most of the solvent and unreacted comonomers are recycled back into the reactor after passing through a purification system. Small amounts of solvent and comonomers are purged from the process.

[0275] The polymerization conditions for the second polyethylene composition 6 are reported in Table 6. Table 5 shows the catalysts referenced in Table 6.

[0276] [Table 6]

[0277] The second polyethylene compositions 1, 3, 5, and 6 are analyzed by iCCD. The iCCD data for the second polyethylene composition 5 is provided in Figure 2. Additional data derived from the iCCD tests of these samples are provided in Tables 7A and 7B. Specifically, Tables 7A and 7B include the analysis of iCCD data, including the area of ​​the first and second polyethylene fractions (45-87°C and 95-120°C), respectively. Additional data for these samples, including overall density, melt index, and weight-average molecular weight in the second PE fraction, are also provided. These properties are entirely based on single-layer inflation films made from each polyethylene sample.

[0278] [Table 7]

[0279] [Table 8]

[0280] Films 1-3 and comparative films A-E of the present invention The first polyethylene composition 3 and the second polyethylene composition 5 described above are used to prepare the film of the present invention and a comparative film. Furthermore, the polyethylene resins shown in Table 8 are used to prepare the film of the present invention and a comparative film discussed below. Each resin is commercially available from The Dow Chemical Company.

[0281] [Table 9]

[0282] Film 1 and comparative films A-C of the present invention Film 1 and comparative films A-C of the present invention are three-layer (A / B / A) co-extruded films prepared as follows. Film 1 and comparative films A-C of the present invention have the following structures.

[0283] [Table 10] The film is produced using a Dr.Collin 3-layer co-extrusion inflation film line. This line included three 25:1 L / D single-screw extruders with grooved feed zones. The screw diameters were 25 mm for the two outer layer (layer A) extruders and 30 mm for the inner layer extruder (formed from layer B). The melting temperature was 190°C to 210°C. The die diameter was 80 mm and the die gap was 1.8 mm. The blow-up ratio was 2.5:1. The output speed was 22.42 kg / hour. The temperature profiles were 190 / 210 / 220 / 235 / 235 / 235 / 235°C. The nominal thickness of each film was 90 micrometers, and the layer distribution was A(33%) / B(34%) / A(33%).

[0284] Using the method described above, the impact of the dirt drop, the 2% secant coefficient in the machine direction, the water vapor permeability, and the oxygen permeability were measured. The results are shown in Table 10.

[0285] [Table 11] As shown in Table 10, the combination of the first polyethylene composition and the second polyethylene composition provided a unique combination of stiffness (secant coefficient) and toughness (dirt impact). In addition, the inclusion of a high-density first polyethylene composition significantly improved water vapor permeability and oxygen permeability.

[0286] Films 2-3 and comparative films D-E of the present invention The films 2-3 and comparative films D-E of the present invention are five-layer (A / B / C / D / E) co-extruded films prepared as follows. Film 2 and comparative films D-F of the present invention have the following structures:

[0287] [Table 12] The film is produced using a Dr.Collin 5-layer co-extrusion inflation film line. This line consists of five 25:1 L / D single-screw extruders with grooved feed zones. The screw diameter is 30 mm for the two outer layer (layers A and E) extruders and 25 mm for the inner layer extruders (layers B to D). The melting temperature is 190°C to 210°C. The die diameter is 80 mm and the die gap is 1.8 mm. The blow-up ratio is 2.5:1. The output speed is 22.42 kg / hour. The temperature profiles are 190 / 210 / 220 / 235 / 235 / 235 / 235°C. The nominal thickness of each film is 90 micrometers, and the layer distribution is as specified in Table 11.

[0288] Using the method described above, the impact of the dirt drop, the 2% secant coefficient in the machine direction, the water vapor permeability, and the oxygen permeability were measured. The results are shown in Table 12.

[0289] [Table 13] As shown in Table 12, the combination of the first polyethylene composition and the second polyethylene composition provided a unique combination of stiffness (secant coefficient) and toughness (dirt drop impact), especially when the second polyethylene composition was present in an amount of 20% by weight or more. Furthermore, when the amount of the first polyethylene composition was less than 40% by weight, a good balance between stiffness (secant coefficient) and toughness (dirt drop impact) was achieved. For example, in comparative film E, the first polyethylene composition was present in an amount of 50% by weight, and the dirt drop impact value was significantly reduced.

[0290] Other embodiments of the present invention As described above, in some embodiments, the multilayer film of the present invention includes an outer layer which is a sealant layer containing a third polyethylene composition. For example, in the film of the present invention described above, one of the outer layers (e.g., layer A) may be a sealant layer containing a third polyethylene composition. Embodiments of the third polyethylene composition can be prepared as follows.

[0291] Third polyethylene compositions 1 to 3, as described in accordance with one or more embodiments of the "Modes for Carrying Out the Invention," can be prepared by the following method and using the following catalyst and reactor.

[0292] Before introducing them into the reaction environment, all raw materials (monomers and comonomers) and process solvent (high-purity isoparaffin solvent with a narrow boiling point range, Isopar-E) were purified using molecular sieves. Hydrogen was supplied under pressure as a high-purity grade and no further purification was performed. The reactor monomer feed stream was pressurized to a pressure exceeding the reaction pressure via a mechanical compressor. The solvent and comonomer feed streams were pumped to a pressure higher than the reaction pressure. Individual catalyst components were manually batch diluted with purified solvent and pressurized to the above reaction pressure. All reaction feed streams were measured with mass flow meters and independently controlled by a computer-controlled automatic valve control system.

[0293] Two reactor systems were used. Each continuous solution polymerization reactor utilized a liquid-filled, non-adiabatic, isothermal, circulating, loop reactor that mimicked a continuously stirred tank reactor (CSTR) for heat removal. Independent control of all fresh solvent, monomer, comonomer, hydrogen, and catalyst component feeds was possible. All fresh feed flows to each reactor (solvent, monomer, comonomer, and hydrogen) were temperature-controlled to maintain a single solution phase by passing the feed flow through a heat exchanger. The total fresh feed to each polymerization reactor was injected into the reactor at two locations, with approximately equal reactor volumes between the injection points. The fresh feed was controlled so that each injector received half of the total unused feed flow rate. Catalyst components were injected into the polymerization reactor by injection stingers. The catalyst feed was computer-controlled to maintain monomer conversion in each reactor at specific target values. Co-catalyst components were supplied to the primary catalyst components based on a calculated specific molar ratio. Immediately after the injection point of the reactor feed, the feed was mixed with the contents of the circulating polymerization reactor using a static mixing element. The contents of each reactor were continuously circulated through a heat exchanger, which played a role in removing most of the reaction heat, at the temperature of the coolant side, which played a role in maintaining an isothermal reaction environment at a specific temperature. Circulation around each reactor loop was provided by pumps.

[0294] The effluent (containing solvent, monomer, comonomer, hydrogen, catalyst components, and polymer) from the first polymerization reactor exited the first reactor loop and was added to the second reactor loop.

[0295] The second reactor effluent entered a zone where the effluent was deactivated by the addition and reaction with a suitable reagent (water). At this same reactor outlet location, other additives were added for polymer stabilization (typical antioxidants suitable for stabilization during extrusion and film production, such as octadecyl 3,5-di-Tert-butyl-4-hydroxyhydrocinnamate, tetrakis(methylene(3,5-di-Tert-butyl-4-hydroxyhydrocinnamate))methane, and tris(2,4-di-Tert-butyl-phenyl)phosphite).

[0296] Following catalyst inactivation and additive addition, the reactor effluent entered a devolving system where the polymer was removed from the non-polymer stream. The isolated polymer molten material was pelletized and collected. The non-polymer stream passed through various instruments that separated most of the ethylene removed from the system. Most of the solvent and unreacted comonomers were passed through a purification system and then recycled back into the reactor. Small amounts of solvent and comonomers were purged from the process.

[0297] Reactor flow feed data flow corresponding to the values ​​in Table 13. The data is presented to account for the complexity of the solvent recirculation system and to allow for easier processing of the reaction system as a through-flow diagram. Table 14 shows the catalysts referenced in Table 13.

[0298] [Table 14]

[0299] [Table 15]

[0300] Third polyethylene compositions 1-3 are analyzed by iCCD. Data obtained from iCCD tests of all samples (third polyethylene compositions 1-3) are provided in Tables 15A and 15B. Specifically, Table 15A includes the analysis of iCCD data at a temperature increment of 5°C.

[0301] [Table 16]

[0302] Table 15B shows the iCCD data further delineated to include the area of ​​each polyethylene fraction (25°C to 35°C, 35°C to 70°C, 70°C to 85°C, and 85°C to 120°C).

[0303] [Table 17]

[0304] Table 16 provides additional data for the third polyethylene compositions 1-3, including overall density, melt index, ZSVR, and the ratio of the molecular weight of the first fraction to the total molecular weight. These properties were measured based on the test methods described herein.

[0305] [Table 18] As previously stated in this disclosure, tan delta (tan δ) is a measure of how close a material is to a perfectly elastic solid (d=0°, tan delta=0) or a perfectly Newtonian liquid (d=90°, tan delta ≈ infinity). Therefore, a lower value of tan d reflects higher elasticity. Tan d is a function of LCB and MWD at the same overall molecular weight. A higher tan d value indicates a lower LCB.

[0306] [Table 19] This application provides, for example, the following inventions: [1] A multilayer film, (a) A first polyethylene composition, (1) 25-37 weight percent, 0.935-0.947 g / cm³ 3 Density in the range and melt index (I) of less than 0.1 g / 10 min 2 A first polyethylene fraction having ) and (2) A second polyethylene fraction of 63-75 weight percent, Includes, 13 When measured using 13C NMR, it has less than 0.10 branching per 1,000 carbon atoms and a density of at least 0.965 g / cm³. 3 And the melt index (I 2 A first polyethylene composition having a concentration of 0.5 to 10 g / 10 min, (b) A second polyethylene composition, (1) A first polyethylene fraction having a single peak in the temperature range of 45°C to 87°C in the elution profile via an improved comonomer composition distribution (iCCD) analysis method, wherein the first polyethylene area fraction is the area in the elution profile directly below the single peak of the first polyethylene fraction in the 45°C to 87°C range, and (2) A second polyethylene fraction having a single peak in the temperature range of 95°C to 120°C in the elution profile obtained by iCCD analysis, wherein the second polyethylene area fraction is the area in the elution profile directly below the single peak of the second polyethylene fraction at 95°C to 120°C, Includes, The second polyethylene composition is 0.924 g / cm³ 3 ~0.936 g / cm³ 3 Density and melt index (I) of 0.25g / 10min to 2.0g / 10min 2 A second polyethylene composition comprising: ) wherein the second polyethylene fraction area constitutes at least 40% of the total area of ​​the elution profile, the ratio of the first polyethylene fraction area to the second polyethylene fraction area is 0.75 to 2.5, and the width of the single peak of the second polyethylene fraction at the 50 percent peak height is less than 5.0°C; A multilayer film comprising the first polyethylene composition in an amount of 40 weight percent or less based on the total weight of the multilayer film. [2] The multilayer film according to [1], wherein at least one layer of the multilayer film comprises the first polyethylene composition and the second polyethylene composition. [3] The multilayer film according to [1] or [2] above, wherein the layer comprising the first polyethylene composition further comprises 20 to 5000 ppm of a nucleating agent based on the total weight of the layer, the nucleating agent comprising a calcium salt of 1,2-cyclohexanedicarboxylic acid or sodium 4-[(4-chlorobenzoyl)amino]benzoate. [4] A multilayer film according to any of [1] to [3] above, wherein the outer layer of the film comprises a third polyethylene composition, and the third polyethylene composition comprises (a) A first polyethylene fraction having at least one peak in the temperature range of 35°C to 70°C in the elution profile obtained via an improved comonomer composition distribution (iCCD) analysis method, wherein the first polyethylene area fraction is the area in the elution profile at 35°C to 70°C, and the area of ​​the first polyethylene fraction constitutes 25% to 65% of the total area of ​​the elution profile, (b) A second polyethylene fraction in the elution profile obtained via iCCD analysis, which includes at least one peak in the temperature range of 85°C to 120°C, wherein the second polyethylene area fraction is the area in the elution profile at 85°C to 120°C, and the area of ​​the second polyethylene fraction constitutes at least 20% of the total area of ​​the elution profile, (c) A third polyethylene fraction in the elution profile obtained via iCCD analysis, in the temperature range of 70°C to 85°C, wherein the third polyethylene area fraction is the area in the elution profile at 70°C to 85°C, and the area of ​​the third polyethylene fraction constitutes less than 10% of the total area of ​​the elution profile, The third polyethylene composition is 0.880 g / cm³ 3 ~0.910 g / cm³ 3 Density, melt index (I) of 0.50g / 10min to 6.0g / 10min 2 A multilayer film having a zero shear viscosity ratio of less than 2.0. [5] The multilayer film according to any one of [1] to [4] above, wherein the first polyethylene composition and the second polyethylene composition are present in different layers of the film, and the layer containing the second polyethylene composition is located between the outer layer containing the third polyethylene composition and the layer containing the first polyethylene composition. [6] The multilayer film according to any one of [1] to [5] above, wherein at least one layer further comprises linear low-density polyethylene, low-density polyethylene, or a combination thereof. [7] An article comprising any of the multilayer films described in [1] to [6] above.

Claims

1. It is a multilayer film, (a) A first polyethylene composition, (1) 25–37 weight percent, 0.935–0.947 g / cm³ ３ Density in the range of 0.1 g / 10 min and melt index (I ２ A first polyethylene fraction having ) and (2) A second polyethylene fraction of 63-75% by weight, Includes, １３ When measured using 13C NMR, it has less than 0.10 branching per 1,000 carbon atoms and a density of at least 0.965 g / cm³. ３ And the melt index (I ２ A first polyethylene composition having a concentration of 0.5 to 10 g / 10 min, (b) A second polyethylene composition, (1) A first polyethylene fraction having a single peak in the temperature range of 45°C to 87°C in the elution profile obtained by an improved comonomer composition distribution (iCCD) analysis method, wherein the first polyethylene area fraction is the area in the elution profile directly below the single peak of the first polyethylene fraction in the temperature range of 45°C to 87°C, and (2) A second polyethylene fraction having a single peak in the temperature range of 95°C to 120°C in the elution profile obtained by iCCD analysis, wherein the second polyethylene area fraction is the area in the elution profile directly below the single peak of the second polyethylene fraction in the temperature range of 95°C to 120°C, Includes, The second polyethylene composition is 0.924 g / cm³ ３ ~0.936g / cm ３ Density and melt index (I) of 0.25 g / 10 min to 2.0 g / 10 min ２ A second polyethylene composition comprising: ) wherein the second polyethylene fraction area constitutes at least 40% of the total area of ​​the elution profile, the ratio of the first polyethylene fraction area to the second polyethylene fraction area is 0.75 to 2.5, and the width of the single peak of the second polyethylene fraction at the 50 percent peak height is less than 5.0°C; A multilayer film comprising the first polyethylene composition in a weight of 40 percent or less based on the total weight of the multilayer film.

2. The multilayer film according to claim 1, wherein at least one layer of the multilayer film comprises the first polyethylene composition and the second polyethylene composition.

3. The multilayer film according to claim 1 or claim 2, wherein the layer comprising the first polyethylene composition further comprises 20 to 5000 ppm of a nucleating agent based on the total weight of the layer, the nucleating agent comprising a calcium salt of 1,2-cyclohexanedicarboxylic acid or sodium 4-[(4-chlorobenzoyl)amino]benzoate.

4. A multilayer film according to any one of claims 1 to 3, wherein the outer layer of the film comprises a third polyethylene composition, and the third polyethylene composition comprises (a) A first polyethylene fraction having at least one peak in the temperature range of 35°C to 70°C in the elution profile obtained via an improved comonomer composition distribution (iCCD) analysis method, wherein the first polyethylene area fraction is the area in the elution profile at 35°C to 70°C, and the area of ​​the first polyethylene fraction constitutes 25% to 65% of the total area of ​​the elution profile, (b) A second polyethylene fraction in the elution profile obtained by iCCD analysis, which includes at least one peak in the temperature range of 85°C to 120°C, wherein the second polyethylene area fraction is the area in the elution profile at 85°C to 120°C, and the area of ​​the second polyethylene fraction constitutes at least 20% of the total area of ​​the elution profile, (c) A third polyethylene fraction in the elution profile obtained by iCCD analysis, in the temperature range of 70°C to 85°C, wherein the third polyethylene area fraction is the area in the elution profile at 70°C to 85°C, and the area of ​​the third polyethylene fraction constitutes less than 10% of the total area of ​​the elution profile, The third polyethylene composition has a density of 0.880 g / cm ３ to 0.910 g / cm ３ , a melt index (I ２ ) of 0.50 g / 10 min to 6.0 g / 10 min, and a zero shear viscosity ratio of less than 2.0, a multilayer film.

5. The multilayer film according to claim 1, wherein the first polyethylene composition and the second polyethylene composition are present in different layers of the film, and the layer containing the second polyethylene composition is located between the outer layer containing the third polyethylene composition and the layer containing the first polyethylene composition, The polyethylene composition described in the third above is (a) A first polyethylene fraction having at least one peak in the temperature range of 35°C to 70°C in the elution profile obtained via an improved comonomer composition distribution (iCCD) analysis method, wherein the first polyethylene area fraction is the area in the elution profile at 35°C to 70°C, and the area of ​​the first polyethylene fraction constitutes 25% to 65% of the total area of ​​the elution profile, (b) A second polyethylene fraction in the elution profile obtained by iCCD analysis, which includes at least one peak in the temperature range of 85°C to 120°C, wherein the second polyethylene area fraction is the area in the elution profile at 85°C to 120°C, and the area of ​​the second polyethylene fraction constitutes at least 20% of the total area of ​​the elution profile, (c) A third polyethylene fraction in the elution profile obtained by iCCD analysis, in the temperature range of 70°C to 85°C, wherein the third polyethylene area fraction is the area in the elution profile at 70°C to 85°C, and the area of ​​the third polyethylene fraction constitutes less than 10% of the total area of ​​the elution profile, The third polyethylene composition is a multilayer film having a density of 0.880 g / cm³ to 0.910 g / cm³, a melt index (I²) of 0.50 g / 10 min to 6.0 g / 10 min, and a zero shear viscosity ratio of less than 2.

0.

6. The multilayer film according to claim 2, wherein at least one layer of the multilayer film further comprises linear low-density polyethylene, low-density polyethylene, or a combination thereof.

7. An article comprising a multilayer film according to any one of claims 1 to 6.

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