Polyethylene composition and film containing the polyethylene composition

Abstract

0.910g / cm 3 ~0.924g / cm 3 and a melt index (I2) of 0.1 g / 10 min to 0.5 g / 10 min, and the polyethylene composition comprises, by improved comonomer composition distribution (iCCD) analysis, a first polyethylene fraction region in the temperature range of 45°C to 80°C of the elution profile, a second polyethylene fraction region in the temperature range of 80°C to 95°C of the elution profile, and a third polyethylene fraction region in the temperature range of 95°C to 110°C of the elution profile. The second polyethylene fraction region may comprise at least 5% of the total area of ​​the elution profile. The third polyethylene fraction region may comprise at least 25% of the total area of ​​the elution profile. The ratio of the first polyethylene fraction region to the second polyethylene fraction region may be 6 to 15.

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 046,386, filed Jun. 30, 2020, the entire contents of which are incorporated herein by reference.

[0002] (Field of the Invention) Embodiments described herein generally relate to polyethylene compositions, and more particularly to multilayer films comprising such polyethylene compositions.

Background Art

[0003] Multilayer films are used in packaging applications, including flexible packaging applications. Single - layer and multilayer polymer films, which may include inflation films or cast films, are beneficial in that they allow for material cost reduction, for example, by down - gauging (i.e., using a thinner film thickness) or reducing or eliminating relatively expensive materials such as polyamides, while exhibiting sufficient toughness and puncture properties.

Summary of the Invention

[0004] Various polymerization techniques using different catalyst systems are used to produce such polyolefin compositions suitable for packaging applications. However, despite research efforts in developing compositions suitable for packaging applications, there is still a need for compositions suitable for packaging applications that have a good balance of physical properties at a desirable polymer composition density. Also, to achieve this balance, conventional methods may incorporate polar materials such as polyamides, which can increase the complexity of the process, increase the complexity of the film structure, result in the production of non - recyclable multilayer films, and increase material costs compared to using other polyolefins.

[0005] Accordingly, it is beneficial for single-layer and multilayer polymer films, which may include inflation films or cast films, to exhibit toughness while enabling reduction of material costs and / or improvement of recyclability. There is a need for multilayer films that exhibit stiffness and physical properties (e.g., puncture properties) that meet customer and industrial requirements.

[0006] Embodiments of the present disclosure meet these needs by providing a polyethylene composition that can provide an improved balance of stiffness and resistance to abusive conditions (e.g., dirt, puncture energy, tear) when utilized in single-layer or multilayer films. In one or more embodiments, the polyethylene composition may include a first polyethylene fraction region, a second polyethylene fraction region, and a third polyethylene fraction region, each fraction having a region within the elution profile described herein. Use of such a polyethylene composition may enable a favorable ratio of puncture properties to modulus of elasticity.

[0007] According to one or more embodiments, a polyethylene composition is provided. The polyethylene composition may include a first polyethylene fraction region within a temperature range of 45°C to 80°C of the elution profile, a second polyethylene fraction region within a temperature range of 80°C to 95°C of the elution profile, and a third polyethylene fraction region within a temperature range of 95°C to 120°C of the elution profile, by improved comonomer composition distribution (iCCD) analysis. The second polyethylene fraction region may include at least 5% of the total area of the elution profile. The third polyethylene fraction region may include at least 25% of the total area of the elution profile. The ratio of the first polyethylene fraction region to the second polyethylene fraction region may be from 6 to 15. The polyethylene composition may have a density of 0.910 g / cm 3 ~0.924 g / cm 3 and a melt index (I2) of 0.1 g / 10 min to 0.5 g / 10 min.

[0008] According to one or more embodiments, a polyethylene composition is provided. The polyethylene composition has, by an improved comonomer composition distribution (iCCD) analysis method, a first polyethylene fraction region within a temperature range of 45°C to 80°C of an elution profile, and a second polyethylene fraction region within a temperature range of 80°C to 95°C of the elution profile by the ICCD analysis method, the second polyethylene fraction region constituting at least 5% of the total area of the elution profile, and a third polyethylene fraction region within a temperature range of 95°C to 120°C of the elution profile by the ICCD analysis method, the third polyethylene fraction region constituting at least 25% of the total area of the elution profile, and may include. The polyethylene composition has a density of 0.910 g / cm 3 ~0.924 g / cm 3 and a melt index (I2) of 0.1 g / 10 min to 0.5 g / 10 min, and a molecular weight distribution represented as a ratio (Mw / Mn) of the weight average molecular weight to the number average molecular weight within a range of 2.0 to 5.0.

[0009] According to one or more additional embodiments, a film is provided. The film may be a single-layer film or a multilayer film including the polyethylene composition in at least one layer of the film. The polyethylene composition has, by an improved comonomer composition distribution (iCCD) analysis method, a first polyethylene fraction region within a temperature range of 45°C to 80°C of an elution profile, a second polyethylene fraction region within a temperature range of 80°C to 95°C of the elution profile by the ICCD analysis method, and a third polyethylene fraction region within a temperature range of 95°C to 120°C of the elution profile by the ICCD analysis method, and may include. The second polyethylene fraction region may include at least 5% of the total area of the elution profile. The third polyethylene fraction region may include at least 25% of the total area of the elution profile. The ratio of the first polyethylene fraction region to the second polyethylene fraction region may be 6 to 15. The polyethylene composition has a density of 0.910 g / cm 3 ~0.924 g / cm 3It may have a density of and a melt index (I2) of 0.1 g / 10 min to 0.5 g / 10 min.

[0010] These and the embodiments will be described in more detail in the following mode for carrying out the invention in conjunction with the accompanying drawings.

Brief Description of the Drawings

[0011] The following mode for carrying out the invention of the specific embodiments of the present disclosure can be best understood when read in conjunction with the following drawings, in which like structures are denoted by like reference numerals.

Figure 1

Figure 2

Mode for Carrying Out the Invention

[0012] Here, specific embodiments of the present application will be described. These embodiments are provided so that the present disclosure is detailed and complete and fully conveys the scope of the claimed subject matter to those skilled in the art.

[0013] The term "polymer" refers to a polymer compound prepared by polymerizing monomers, whether of the same type or different types. Thus, the general term "polymer" usually includes the term "homopolymer" which refers to a polymer prepared from only one type of monomer, and the term "copolymer" which refers to a polymer prepared from two or more different monomers. As used herein, the term "interpolymer" refers to a polymer prepared by the polymerization of at least two different types of monomers. Thus, the general term "interpolymer" includes copolymers or polymers prepared from two or more different monomers, such as terpolymers.

[0014] "Polyethylene" or "ethylene polymer" shall mean a polymer containing units derived from more than 50 mol% of ethylene monomers. This includes ethylene homopolymers or copolymers (meaning units are derived from two or more comonomers). General forms of ethylene polymers known in the art include, but are not limited to, 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, Medium Density Polyethylene (MDPE), and High Density Polyethylene (HDPE).

[0015] As used herein, the term "composition" refers to a mixture of materials including the composition, as well as reaction products and decomposition products formed from the materials of the composition.

[0016] As used herein, the term "polypropylene" or "propylene polymer" refers to a polymer comprising units derived from more than 50 mol% of propylene monomers in a polymerized form. This includes propylene homopolymers, random copolymer polypropylene, impact copolymer polypropylene, propylene / α-olefin copolymers, and propylene / α-olefin copolymers.

[0017] The term "LDPE" is sometimes also 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 exceeding 14,500 psi (100 MPa) by using a free radical initiator such as a peroxide (see, for example, U.S. Patent No. 4,599,392, which is incorporated herein by reference in its entirety). LDPE resins typically have a density in the range of 3 ~0.916 g / cm 3 to 0.940 g / cm.

[0018] The term "LLDPE" includes resins made using Ziegler-Natta catalyst systems, as well as resins made using single-site catalysts including, but not limited to, bis-metallocene catalysts (sometimes referred to as "m-LLDPE"), phosphine imines, and constrained geometry catalysts, and resins made using post-metallocene molecular catalysts including, but not limited to, bis(biphenylphenoxy) catalysts (also referred to as polyaryl ether catalysts). LLDPE includes linear, substantially linear, or non-uniform ethylene copolymers or homopolymers. LLDPE contains fewer long-chain branches than LDPE and includes substantially linear ethylene polymers, which are further defined in U.S. Patent Nos. 5,272,236, 5,278,272, 5,582,923, and 5,733,155 (each of these patent documents is hereby incorporated by reference in its entirety), and LLDPE also includes uniformly branched linear ethylene polymer compositions such as those in U.S. Patent No. 3,645,992, which is hereby incorporated by reference in its entirety, non-uniformly branched ethylene polymers prepared according to the processes disclosed in U.S. Patent No. 4,076,698, which is hereby incorporated by reference in its entirety, and blends thereof (such as those disclosed in U.S. Patent Nos. 3,914,342 and 5,854,045, which are hereby incorporated by reference in their entirety). LLDPE resins can be made by gas-phase polymerization, solution-phase polymerization, or slurry polymerization, or any combination thereof, using any type of reactor or reactor configuration known in the art.

[0019] The term "HDPE" generally refers to resins prepared using 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), constrained geometry catalysts, phosphine imine catalysts, and polyaryl ether catalysts (typically referred to as bisphenylphenoxy), having a density of 0.935 g / cm 3 Ultra - up to about 0.980 g / cm3 refers to polyethylene having a density of...

[0020] The term "ULDPE" generally refers to polyethylene having a density of 0.855 g / cm³ to 0.912 g / cm³, which is prepared using 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), constrained geometry catalysts, phosphine imine catalysts, and polyvalent aryloxy ether catalysts (typically referred to as bisphenol phenoxy). 3 ~0.912 g / cm³ 3 ULDPE includes, but is not limited to, polyethylene (ethylene-based) plastomers and polyethylene (ethylene-based) elastomers. Polyethylene (ethylene-based) elastomer plastomers generally have a density of 0.855 g / cm³ to 0.912 g / cm³. 3 ~0.912 g / cm³ 3 and have such a density.

[0021] The terms "blend", "polymer blend", etc. mean a composition of two or more polymers. Such blends may or may not be miscible. Such blends may or may not be phase-separated. Such blends may or may not contain one or more domain structures 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 blends can be prepared as dry blends or formed in situ (e.g., in a reactor) as melt blends or formed using other techniques known to those skilled in the art.

[0022] The term "multilayer structure" or "multilayer film" means any structure having two or more layers. For example, a multilayer structure (e.g., a film) can have two, three, four, five, six, seven, or more layers. A multilayer structure can be described as having layers designated by letters. For example, a three-layer structure designated as A / B / C can have a core layer (B), as well as two outer layers (A) and (C).

[0023] The terms "comprising", "including", "having" and their derivatives are not intended to exclude the presence of any additional components, steps, or procedures, whether or not they are specifically disclosed. To avoid any doubt, all compositions claimed through the use of the term "comprising" can include any additional additives, adjuvants, or compounds, whether polymeric or otherwise, unless there is a contradictory description. In contrast, the term "consisting essentially of" excludes any other components, steps, or procedures from the scope of any subsequent description, except for those that are not essential for operation. The term "consisting of" excludes any component, step, or procedure that is not specifically depicted or listed.

[0024] Multimodal polyethylene composition and property evaluation As used herein, the polyethylene compositions of the present disclosure may be referred to as "multimodal polyethylene compositions". In one or more embodiments, the multimodal polyethylene composition is formed from the polymerization of ethylene and a comonomer such as a C3-C 12 alkene. Exemplary comonomers include C6-C9 alkenes such as 1-octene and 1-hexene. In one or more embodiments, the comonomer is 1-octene.

[0025] In one or more embodiments, the multimodal polyethylene composition has a density of 0.910 g / cm 3 ~0.924 g / cm 3may have a density. In an embodiment, the multimodal polyethylene composition of the present disclosure has a density of 0.910 g / cm 3 to 0.922 g / cm 3 ; 0.910 g / cm 3 to 0.920 g / cm 3 ; 0.910 g / cm 3 to 0.918 g / cm 3 ; 0.910 g / cm 3 to 0.916 g / cm 3 ; 0.910 g / cm 3 to 0.914 g / cm 3 ; 0.910 g / cm 3 to 0.912 g / cm 3 ; 0.912 g / cm 3 to 0.924 g / cm 3 ; 0.912 g / cm 3 to 0.922 g / cm 3 ; 0.912 g / cm 3 to 0.920 g / cm 3 ; 0.912 g / cm 3 to 0.918 g / cm 3 ; 0.912 g / cm 3 to 0.916 g / cm 3 ; 0.912 g / cm 3 to 0.914 g / cm 3 ; 0.914 g / cm 3 to 0.924 g / cm 3 ; 0.914 g / cm 3 to 0.922 g / cm 3 ; 0.914 g / cm 3 to 0.920 g / cm 3 ; 0.914 g / cm 3 to 0.918 g / cm 3 ; 0.914 g / cm 3 to 0.916 g / cm 3 ; 0.916 g / cm 3 to 0.924 g / cm 3 ; 0.916 g / cm 3 to 0.922 g / cm 3 ; 0.916 g / cm 3 to 0.920 g / cm 3 ; 0.916 g / cm 3~0.918 g / cm 3 、0.918 g / cm 3 ~0.924 g / cm 3 、0.918 g / cm 3 ~0.922 g / cm 3 、0.918 g / cm 3 ~0.920 g / cm 3 、0.920 g / cm 3 ~0.924 g / cm 3 、0.920 g / cm 3 ~0.922 g / cm 3 、0.922 g / cm 3 ~0.924 g / cm 3 、 or may have a density that is any combination of these ranges.

[0026] In one or more embodiments, the multimodal polyethylene composition may have a melt index (I2) of 0.1 g / 10 min to 0.5 g / 10 min when measured at 190 °C and 2.16 kg according to ASTM D-1238. In embodiments, the multimodal polyethylene composition may have a melt index (I2) of 0.1 g / 10 min to 0.4 g / 10 min, 0.1 g / 10 min to 0.3 g / 10 min, 0.1 g / 10 min to 0.2 g / 10 min, 0.2 g / 10 min to 0.5 g / 10 min, 0.2 g / 10 min to 0.4 g / 10 min, 0.2 g / 10 min to 0.3 g / 10 min, 0.3 g / 10 min to 0.5 g / 10 min, 0.3 g / 10 min to 0.4 g / 10 min, 0.4 g / 10 min to 0.5 g / 10 min, or any combination of these ranges when measured at 190 °C and 2.16 kg according to ASTM D-1238.

[0027] According to an embodiment, the multimodal polyethylene composition may have a molecular weight distribution (expressed as the ratio of the weight average molecular weight to the number average molecular weight (Mw / Mn)) within the range of 2.0 to 5.0. In an embodiment, the multimodal polyethylene composition may have a molecular weight distribution of 2.0 to 4.5, 2.0 to 4.0, 2.0 to 3.5, 2.0 to 3.0, 2.0 to 2.5, 2.5 to 5.0, 2.5 to 4.5, 2.5 to 4.0, 2.5 to 3.5, 2.5 to 3.0, 3.0 to 5.0, 3.0 to 4.5, 3.0 to 4.0, 3.0 to 3.5, 3.5 to 5.0, 3.5 to 4.5, 3.5 to 4.0, 4.0 to 5.0, 4.0 to 4.5, 4.5 to 5.0, or any combination of these ranges. As described herein, the molecular weight distribution can be calculated according to gel permeation chromatography (GPC) techniques as described herein.

[0028] According to one or more embodiments, the multimodal polyethylene composition may have a zero shear viscosity ratio of 3.0 to 6.0. In an embodiment, the multimodal polyethylene composition may have a zero shear viscosity ratio of 3.0 to 5.5, 3.0 to 5.0, 3.0 to 4.5, 3.0 to 4.0, 3.0 to 3.5, 3.5 to 6.0, 3.5 to 5.5, 3.5 to 5.0, 3.5 to 4.5, 3.5 to 4.0, 4.0 to 6.0, 4.0 to 5.5, 4.0 to 5.0, 4.0 to 4.5, 4.5 to 6.0, 4.5 to 5.5, 4.5 to 5.0, 5.0 to 6.0, 5.0 to 5.5, 5.5 to 6.0, or any combination of these ranges.

[0029] According to additional embodiments, the multimodal polyethylene composition may have a Dow Rheology Index of 5 or less, such as 4 or less, 3 or less, 2 or less, or even 1 or less.

[0030] In one or more embodiments, the multimodal polyethylene composition of the present disclosure may further include additional components such as one or more 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, antibacterial agents, odor reducing agents, antifungal agents, and combinations thereof. The multimodal polyethylene composition may contain such additives in a combined amount of 0.1 to 10 weight percent, based on the weight of the multimodal polyethylene composition containing such additives.

[0031] As described herein, a polyethylene “fraction” refers to a portion of the overall composition of a multimodal polyethylene composition. Embodiments of the present disclosure include at least a “first polyethylene fraction,” a “second polyethylene fraction,” and a “third polyethylene fraction.” The various fractions contained within a multimodal polyethylene composition can be quantified for their respective temperature ranges in an elution profile by an improved comonomer composition distribution (iCCD) analysis method. Unless otherwise specified, any elution profile referred to herein is the elution profile observed by iCCD. Examples of such fractions will be better understood in view of the examples provided herein. Generally, the first fraction can include a peak within the temperature range of the first fraction, the second fraction can include a peak within the temperature range of the second fraction, and the third fraction can include a peak within the temperature range of the third fraction. The multimodal polyethylene compositions described herein can be referred to as “multimodal,” which means that the multimodal polyethylene composition includes at least two peaks in their elution profiles. Some embodiments can be “trimodal,” which means that three major peaks are present.

[0032] Referring to the iCCD distribution described, FIG. 1 schematically shows the iCCD distribution 100 of the sample, along with the cumulative weight fraction curve 200. FIG. 1 schematically shows some features of the iCCD profile, including fraction 102 and fraction 106. Fraction 102 has a peak 104, and fraction 106 has a peak 108. Each fraction has a half-peak width 110 and 112. The profile of FIG. 1 is not derived from an experiment or observation, but rather is provided for the purpose of providing information describing certain features of the iCCD elution profile.

[0033] In one or more embodiments, the multimodal polyethylene composition described herein may have a first polyethylene fraction defined by the area in the temperature range of 45°C to 80°C of the elution profile by an improved comonomer composition distribution (iCCD) analysis method. As used herein, in some embodiments, the first polyethylene fraction region may be defined as the region under the single peak of the first polyethylene fraction at 45°C to 80°C in the elution profile. The first polyethylene region fraction may correspond to the total relative mass of the polymer fraction in the multimodal polyethylene composition.

[0034] In an embodiment, the first polyethylene fraction may have a single peak within a temperature range of 45°C to 80°C in the elution profile by iCCD. As used herein, "single peak" refers to an iCCD in which a particular fraction contains only a single peak. That is, in some embodiments, the iCCD of the first polyethylene fraction includes only an upward slope and a downward slope region following that region to form a single peak. In one or more embodiments, the single peak of the first polyethylene fraction may be within a temperature range of 45°C to 80°C, such as 40°C to 75°C. Without being bound by theory, in at least some embodiments of the polyethylene compositions of the present disclosure where a double reactor design is used for polymerization, a combination of a higher density crystalline domain and a lower density amorphous domain may be present. The impact strength is mainly controlled by the amorphous region or the bond concentration connecting adjacent lamellae. When the density is less than 0.910 g / cm 3 the relative bond chain concentration is presumed to be relatively large. The peak of the first polymer fraction in the composition of the present disclosure may be within a temperature range of 45°C to 80°C, which can provide a higher bond chain concentration for functional benefits such as improved toughness.

[0035] It should be understood that the peak in the first polyethylene fraction may not be formed by the minimum value in each polyethylene fraction at a defined temperature boundary. That is, the peak must be a peak from the perspective of the entire range, not a peak formed by the threshold temperature of the polyethylene fraction. For example, if a single peak following a single valley is present in the polyethylene fraction (an upward slope followed by a downward slope followed by an upward slope), such a polyethylene fraction will have only a single peak.

[0036] In one or more embodiments, the first polyethylene fraction region may comprise 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 first polyethylene fraction region may comprise from 40% to 65% of the total area of the elution profile, such as from 40% to 60%, 40% to 55%, 40% to 50%, 40% to 45%, 45% to 65%, 45% to 60%, 45% to 55%, 45% to 50%, 50% to 65%, 50% to 60%, 50% to 55%, 55% to 65%, 55% to 60%, or 60% to 65% of the total area of the elution profile.

[0037] In one or more embodiments, the weight average molecular weight of the first polyethylene fraction can be 20,000 g / mol to 250,000 g / mol, or 20,000 g / mol to 200,000 g / mol, etc., and can be 250,000 g / mol or less. In an embodiment, the weight average molecular weight of the first polyethylene fraction is 20,000 g / mol to 250,000 g / mol, 20,000 g / mol to 200,000 g / mol, 20,000 g / mol to 150,000 g / mol, 20,000 g / mol to 100,000 g / mol, 20,000 g / mol to 50,000 g / mol, 50,000 g / mol to 250,000 g / mol, 50,000 g / mol to 200,000 g / mol, 50,000 g / mol to 150,000 g / mol, 50,000 g / mol to 100,000 g / mol, 100,000 g / mol to 250,000 g / mol, 100,000 g / mol to 200,000 g / mol, 100,000 g / mol to 150,000 g / mol, 150,000 g / mol to 250,000 g / mol, 150,000 g / mol to 200,000 g / mol, 200,000 g / mol to 250,000 g / mol, or any combination of these ranges. The molecular weight of the polyethylene fraction can be calculated based on the GPC results, as described later in this specification.

[0038] In one or more embodiments, the multimodal polyethylene composition may have a second polyethylene fraction defined by the area in the temperature range of 80 °C to 95 °C of the elution profile by an improved compositional comonomer distribution (iCCD) analysis method. As used herein, in some embodiments, the second polyethylene fraction region may be defined as the region under the single peak of the second polyethylene fraction at 80 °C to 95 °C in the elution profile. Without being bound by theory, it is believed that the comonomer distribution in the second polyethylene fraction may contribute to the improvement of the properties when the multimodal polyethylene composition is extrusion molded into a film. For example, such improved properties may include improved puncture properties.

[0039] The second polyethylene region fraction may correspond to the total relative mass of the polymer fraction in the multimodal polyethylene composition. In one or more embodiments, the second polyethylene fraction may include a minimum value in the elution profile. This minimum value may exist between the peak of the first polyethylene fraction and the peak of the third polyethylene fraction.

[0040] According to one or more embodiments, the second polyethylene fraction region may include at least 5% (e.g., at least 6%, at least 8%, or even at least 10%) of the total area of the elution profile. For example, the first polyethylene fraction region may include 5% to 15%, 5% to 10%, or 10% to 15% of the total area of the elution profile.

[0041] According to some embodiments, the ratio of the first polyethylene fraction region to the second polyethylene fraction region may be 6 to 15, 6 to 10, 10 to 15, or any combination of these ranges.

[0042] According to some embodiments, the ratio of the weight average molecular weight of the first polyethylene fraction region to the weight average molecular weight of the second polyethylene fraction region may be 0.75 to 1.50, 0.75 to 1.25, 0.75 to 1.00, 1.00 to 1.50, 1.00 to 1.25, 1.25 to 1.50, or any combination of these ranges.

[0043] In one or more embodiments, the weight average molecular weight of the second polyethylene fraction may be from 80,000 g / mol to 200,000 g / mol, or from 80,000 g / mol to 150,000 g / mol. In additional embodiments, the weight average molecular weight of the second polyethylene fraction may be from 80,000 g / mol to 200,000 g / mol, from 80,000 g / mol to 150,000 g / mol, from 80,000 g / mol to 100,000 g / mol, from 100,000 g / mol to 200,000 g / mol, from 100,000 g / mol to 150,000 g / mol, from 150,000 g / mol to 200,000 g / mol, or any combination of these ranges. The molecular weight of the polyethylene fraction can be calculated based on the GPC results, as described later in this specification.

[0044] In one or more embodiments, the multimodal polyethylene composition may have a third polyethylene fraction defined by the area in the temperature range of 95°C to 120°C of the elution profile by improved comonomer composition distribution (iCCD) analysis. As used herein, in some embodiments, the third polyethylene fraction region may be defined as the region under the single peak of the third polyethylene fraction at 95°C to 120°C in the elution profile. The first polyethylene region fraction may correspond to the total relative mass of the polymer fraction in the multimodal polyethylene composition.

[0045] In one or more embodiments, the third polyethylene fraction may have a single peak within a temperature range of 95°C to 120°C in the elution profile by iCCD. It should be understood that the peak in the third polyethylene fraction may not be formed by the minima in each polyethylene fraction at 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 following a single valley is present in the polyethylene fraction (an upward slope followed by a downward slope followed by an upward slope), such a polyethylene fraction will have only a single peak. The temperature range of the third polyethylene fraction may desirably be in the range of 95°C to 120°C, because at 95°C to 120°C, due to the low molecular weight high density component, polyethylene can achieve a higher overall density while maintaining a lower density fraction.

[0046] In one or more embodiments, the width at 50 percent peak height of the single peak of the third polyethylene fraction can be 2°C to 10°C, 2°C to 8°C, 2°C to 6°C, 2°C to 4°C, 4°C to 10°C, 4°C to 8°C, 4°C to 6°C, 6°C to 10°C, 6°C to 8°C, or 8°C to 10°C. Generally, a smaller temperature range at 50 percent peak height corresponds to a "sharper" peak. Without being 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 comonomer incorporation into a higher density fraction, enabling a higher density partitioning between the first polyethylene fraction and the third polyethylene fraction.

[0047] According to one or more embodiments, the third polyethylene fraction region may include at least 25% (e.g., at least 30%, at least 35%, or even at least 40%) of the total area of the elution profile. For example, the first polyethylene fraction region may include from 25% to 50%, from 25% to 45%, from 25% to 40%, from 25% to 35%, from 25% to 30%, from 30% to 50%, from 30% to 45%, from 30% to 40%, from 30% to 35%, from 35% to 50%, from 35% to 45%, from 35% to 40%, from 40% to 50%, from 40% to 45%, or from 45% to 50% of the total area of the elution profile.

[0048] In one or more embodiments, the weight average molecular weight of the third polyethylene fraction can be 120,000 g / mol or less, such as, for example, from 20,000 g / mol to 120,000 g / mol, or from 40,000 g / mol to 65,000 g / mol. In additional embodiments, the weight average molecular weight of the third polyethylene fraction can be from 20,000 g / mol to 40,000 g / mol, from 40,000 g / mol to 60,000 g / mol, from 60,000 g / mol to 80,000 g / mol, from 80,000 g / mol to 100,000 g / mol, from 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 the results of GPC as described below.

[0049] 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 5°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 6°C, 7°C, 8°C, 9°C, 10°C, 11°C, 12°C, 14°C, 16°C, 18°C, or even at least 20°C.

[0050] Polymerization To produce the multimodal polyethylene composition described herein, any conventional polymerization process may be used. Such conventional polymerization processes include, but are not limited to, slurry polymerization processes and solution polymerization processes that use one or more conventional reactors, such as loop reactors, isothermal reactors, stirred tank reactors, parallel, continuous batch reactors, and / or any combination thereof. The multimodal polyethylene composition can be produced, for example, via a solution phase polymerization process that uses one or more loop reactors, isothermal reactors, and combinations thereof.

[0051] Generally, the solution phase polymerization process can be carried out in one or more well-stirred 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 210 °C) and a pressure in the range of 300 to 1,000 psi (for example, 400 to 800 psi). In some embodiments, in a dual reactor, the temperature in the first reactor is in the range of 115 to 190 °C (for example, 160 to 180 °C), and the temperature in the second reactor is in the range of 150 to 250 °C (for example, 180 to 220 °C). In embodiments, in a single reactor, the temperature of the reactor is in the range of 115 to 250 °C (for example, 115 to 225 °C).

[0052] The residence time in the solution phase polymerization process can be in the range of 2 to 30 minutes (for example, 5 to 25 minutes). Ethylene, solvent, hydrogen, one or more catalyst systems, optionally one or more cocatalysts, and optionally one or more comonomers are continuously fed into one or more reactors. Exemplary solvents include, but are not limited to, isoparaffin. For example, such a solvent is commercially available from ExxonMobil Chemical Co. (Houston, Texas) under the name ISOPAR E. The resulting mixture of the multimodal polyethylene composition and the solvent is then removed from the reactor, and the multimodal polyethylene composition is isolated. The solvent is typically recovered via a solvent recovery unit, such as a heat exchanger and a gas-liquid separation drum, and then recycled to the polymerization system.

[0053] In some embodiments, the multimodal polyethylene composition can be produced via solution polymerization in a dual reactor system, e.g., a dual loop reactor system, where ethylene is polymerized in the presence of one or more catalyst systems. In some embodiments, only ethylene is polymerized. Additionally, one or more cocatalysts may be present. In another embodiment, the multimodal polyethylene composition can be produced by solution polymerization in a single reactor system, e.g., a single loop reactor system, where ethylene is polymerized in the presence of two catalyst systems. In some embodiments, only ethylene is polymerized.

[0054] Catalyst system Specific embodiments of catalyst systems that can be used in one or more embodiments to produce the multimodal polyethylene compositions described herein are described herein. It is to be understood that the catalyst systems of the present disclosure can be embodied in different forms and should not be construed as limited to the specific embodiments described in the present disclosure. Rather, the embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the subject matter to those skilled in the art.

[0055] The term "independently selected" means that R 1 , R 2 , R 3 , R 4 , and R 5 such R groups may be the same or different (e.g., R 1 , R 2 , R 3 , R 4 , and R 5 are all substituted alkyl, or R 1 and R 2 are substituted alkyl and R 3which may be aryl, etc.) are used herein to indicate. The use of the singular includes the use of the plural and vice versa (e.g., a hexane solvent includes a plurality of hexanes). The named R groups will generally have structures that are recognized to correspond to the R groups having that name in the art. These definitions are intended to supplement and exemplify, not exclude, definitions known to those skilled in the art.

[0056] 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 a precursor catalyst to convert it into a catalytically active catalyst. As used herein, the terms "promoter" and "activator" are interchangeable terms.

[0057] When used to describe a particular carbon atom-containing chemical group, the parenthetical expression in the form of "(C x ~C y )" means that the unsubstituted form of the chemical group has x carbon atoms to y carbon atoms, including x and y. For example, (C1~C 40 ) alkyl is an alkyl group having 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 etc. The R x ~C y )" defined using the parenthetical "(C S substituted version of the defined chemical group may contain more than y carbon atoms depending on what any group R S is. For example, "R S is phenyl (-C6H5), exactly one group R S substituted (C1~C 40 ) alkyl" may contain 7 to 46 carbon atoms. Thus, generally, a chemical group defined using the parenthetical "(C x ~C y )" is a carbon atom-containing substituent R SWhen replaced by, 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 carbon atom-containing substituents R S derived therefrom.

[0058] 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 S ). The term "over-substituted" means that all hydrogen atoms (H) bonded to a carbon atom or heteroatom of the corresponding unsubstituted compound or functional group are replaced by a substituent (e.g., R S ). The term "multi-substituted" means that at least two, but less than all, hydrogen atoms bonded to a carbon atom or heteroatom of the corresponding unsubstituted compound or functional group are replaced by a substituent.

[0059] The term "-H" means hydrogen or a hydrogen radical covalently bonded to another atom. "Hydrogen" and "-H" are interchangeable and mean the same thing unless otherwise specified.

[0060] The term "(C1-C 40 ) hydrocarbyl" means a hydrocarbon radical having 1 to 40 carbon atoms, and the term "(C1-C 40 ) hydrocarbylene" means a hydrocarbon diradical having 1 to 40 carbon atoms. Each hydrocarbon radical and each hydrocarbon diradical is aromatic or non-aromatic, saturated or unsaturated, straight-chain or branched-chain, cyclic (including monocyclic and polycyclic, fused and non-fused polycyclic containing bicyclic and having 3 or more carbon atoms) or acyclic, and is unsubstituted or substituted by one or more R S .

[0061] In the present disclosure, (C1-C 40 ) hydrocarbyl is unsubstituted or substituted (C1-C 40 ) alkyl, (C3-C 40 ) cycloalkyl, (C3-C 20)Cycloalkyl-(C1-C 20 )alkylene, (C6-C 40 )aryl, or (C6-C 20 )aryl-(C1-C 20 )alkylene. In some embodiments, each of the aforementioned (C1-C 40 )hydrocarbyl groups has a maximum of 20 carbon atoms (i.e., (C1-C 20 )hydrocarbyl), and in embodiments, has a maximum of 12 carbon atoms.

[0062] The terms “(C1-C 40 )alkyl” and “(C1-C 18 )alkyl” each mean a saturated straight-chain or branched-chain hydrocarbon radical of 1 to 40 carbon atoms or 1 to 18 carbon atoms that is unsubstituted or substituted by one or more R S . Examples of unsubstituted (C1-C 40 )alkyl are 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. Examples of substituted (C1-C 40 )alkyl are substituted (C1-C 20 )alkyl, substituted (C1-C 10 )alkyl, trifluoromethyl, and [C 45 alkyl. The term “[C 45 alkyl” (in brackets) means that there are a maximum of 45 carbon atoms in the radical including substituents, for example, (C 27 ~C 40 )alkyl substituted by one R S which is each (C1-C5)alkyl. Each (C1-C5)alkyl can be methyl, trifluoromethyl, ethyl, 1-propyl, 1-methylethyl, or 1,1-dimethylethyl.

[0063] “(C6-C40 ) The term "aryl" means an unsubstituted or substituted (by one or more R S ) monocyclic, bicyclic, or tricyclic aromatic hydrocarbon radical having 6 to 40 carbon atoms, at least 6 to 14 of which are aromatic ring carbon atoms, and the monocyclic, bicyclic, or tricyclic radical contains 1, 2, or 3 rings respectively, wherein the monocyclic ring is aromatic, and the 2 or 3 rings are independently fused or unfused, and at least 1 of the 2 or 3 rings is aromatic. Examples of unsubstituted (C6-C 40 ) aryl include unsubstituted (C6-C 20 ) aryl, unsubstituted (C6-C 18 ) aryl, 2-(C1-C5)alkyl-phenyl, 2,4-bis(C1-C5)alkyl-phenyl, phenyl, fluorenyl, tetrahydrofluorenyl, indacenyl, hexahydroindacenyl, indenyl, dihydroindenyl, naphthyl, tetrahydronaphthyl, and phenanthrene. Examples of substituted (C6-C 40 ) aryl include substituted (C1-C 20 ) aryl, substituted (C6-C 18 ) aryl, 2,4-bis[(C 20 )alkyl]-phenyl, polyfluorophenyl, pentafluorophenyl, and fluoren-9-one-1-yl.

[0064] The term "(C3-C 40 ) cycloalkyl" means an unsubstituted or substituted (by one or more R S ) saturated cyclic hydrocarbon radical having 3 to 40 carbon atoms. Other cycloalkyl groups (e.g., (C x -C y ) cycloalkyl) are defined in a similar manner as having x to y carbon atoms and being either unsubstituted or substituted by one or more R S . Examples of unsubstituted (C3-C 40 ) cycloalkyl include unsubstituted (C3-C 20 ) cycloalkyl, unsubstituted (C3-C 10)It is cycloalkyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, and cyclodecyl. Substituted (C3-C 40 )Examples of cycloalkyl are substituted (C3-C 20 )cycloalkyl, substituted (C3-C 10 )cycloalkyl, cyclopentanone-2-yl, and 1-fluorocyclohexyl.

[0065] (C1-C 40 )Examples of (C1-C 40 )hydrocarbylene include unsubstituted or substituted (C6-C 40 )arylene, (C3-C 40 )cycloalkylene, and (C1-C 20 )alkylene (e.g., (C1-C 20 )alkylene). In some embodiments, the diradical is on the same carbon atom (e.g., -CH2-), or on adjacent carbon atoms (i.e., 1,2-diradical), or is separated by one, two, or more intervening carbon atoms (e.g., each 1,3-diradical, 1,4-diradical, etc.). Some diradicals include α,ω-diradicals. An α,ω-diradical is a diradical having the maximum carbon skeleton spacing between the radical carbons. Some examples of (C2-C 50 )alkylene α,ω-diradicals include ethane-1,2-diyl (i.e., -CH2CH2-), propane-1,3-diyl (i.e., -CH2CH2CH2-), 2-methylpropane-1,3-diyl (i.e., -CH2CH(CH3)CH2-). Some examples of (C6-C

[0066] The term “(C1-C 40 )alkylene” means unsubstituted or one or more R Smeans a saturated straight-chain or branched-chain diradical having 1 to 40 carbon atoms (i.e., the radicals are not on ring atoms) replaced by. Unsubstituted (C1-C 50 ) alkylene examples are unsubstituted -CH2CH2-, -(CH2)3-, -(CH2)4-, -(CH2)5-, -(CH2)6-, -(CH2)7-, -(CH2)8-, -CH2C * HCH3, and -(CH2)4C * (H)(CH3), which are unsubstituted (C1-C 20 ) alkylene. In the formula, "C * " indicates a carbon atom from which a hydrogen atom has been removed to form a secondary or tertiary alkyl radical. Examples of substituted (C1-C 50 ) alkylene are substituted (C1-C 20 ) alkylene, -CF2-, -C(O)-, and -(CH2) 14 C(CH3)2(CH2)5- (i.e., 6,6-dimethyl-substituted normal-1,20-eicosylene). As described above, since the two R S s can together form (C1-C 18 ) alkylene, examples of substituted (C1-C 50 ) alkylene also include 1,2-bis(methylene)cyclopentane, 1,2-bis(methylene)cyclohexane, 2,3-bis(methylene)-7,7-dimethyl-bicyclo[2.2.1]heptane, and 2,3-bis(methylene)bicyclo[2.2.2]octane.

[0067] The term "(C3-C 40 ) cycloalkylene" means an unsubstituted or cyclic diradical having 3 to 40 carbon atoms substituted by one or more R S (i.e., the radicals are on ring atoms).

[0068] The term "heteroatom" refers to an atom other than hydrogen or carbon. Examples of heteroatoms include O, S, S(O), S(O)2, Si(R C )2, P(R P ), N(R N ), -N=C(R C )2, -Ge(RC ) 2-, or -Si(R C )-, and each R C , each R N , and each R P is unsubstituted (C1-C 18 ) hydrocarbyl or -H. The term "heterohydrocarbon" refers to a molecule or molecular backbone in which one or more carbon atoms are substituted with heteroatoms. The term "(C1-C 40 ) heterohydrocarbyl" means a heterohydrocarbon radical having 1 to 40 carbon atoms, and the term "(C1-C 40 ) heterohydrocarbylene" means a heterohydrocarbon diradical having 1 to 40 carbon atoms, and each heterohydrocarbon has one or more heteroatoms. The radical of heterohydrocarbyl is present on a carbon atom or a heteroatom, and the diradical of heterohydrocarbyl can be present 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 can be unsubstituted or substituted (by one or more R S ), and can be aromatic or non-aromatic, saturated or unsaturated, straight-chain or branched-chain, cyclic (including monocyclic and polycyclic, fused and non-fused polycyclic) or acyclic.

[0069] (C1-C 40 ) heterohydrocarbyl is 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-C40 heterocycloalkyl, (C2-C 19 )heterocycloalkyl-(C1-C 20 )alkylene, (C3-C 20 )cycloalkyl-(C1-C 19 )heteroalkylene, (C2-C 19 )heterocycloalkyl-(C1-C 20 )heteroalkylene, (C1-C 40 )heteroaryl, (C1-C 19 )heteroaryl-(C1-C 20 )alkylene, (C6-C 20 )aryl-(C1-C 19 )heteroalkylene, or (C1-C 19 )heteroaryl-(C1-C 20 )heteroalkylene.

[0070] The term “(C4-C 40 )heteroaryl” means an unsubstituted or substituted (by one or more R S ) monocyclic, bicyclic, or tricyclic heteroaromatic hydrocarbon radical having from 4 to 40 total carbon atoms and from 1 to 10 heteroatoms, wherein the monocyclic, bicyclic, or tricyclic radical contains 1, 2, or 3 rings, respectively, and the 2 or 3 rings are independently fused or unfused, and at least one of the 2 or 3 rings is heteroaromatic. Other heteroaryl groups (e.g., (C4-C 12 )heteroaryl and the like, (C x -C y )heteroaryl in general) have from x to y carbon atoms (such as from 4 to 12 carbon atoms) and are unsubstituted or substituted by one or more R SIt is defined in a similar manner as being replaced by. The monocyclic heteroaromatic hydrocarbon radical is a 5-membered or 6-membered ring. The 5-membered ring has 5 minus h carbon atoms, where h is the number of heteroatoms and can be 1, 2, or 3, and each heteroatom can be O, S, N, or P. Examples of 5-membered ring heteroaromatic hydrocarbon radicals include pyrrol-1-yl, pyrrol-2-yl, furan-3-yl, thiophen-2-yl, pyrazol-1-yl, isoxazol-2-yl, isothiazol-5-yl, imidazol-2-yl, oxazol-4-yl, thiazol-2-yl, 1,2,4-triazol-1-yl, 1,3,4-oxadiazol-2-yl, 1,3,4-thiadiazol-2-yl, tetrazol-1-yl, tetrazol-2-yl, and tetrazol-5-yl. The 6-membered ring has 6 minus h carbon atoms, where h is the number of heteroatoms and can be 1 or 2, and the heteroatom can be N or P. Examples of 6-membered ring heteroaromatic hydrocarbon radicals include pyridin-2-yl, pyrimidin-2-yl, and pyrazin-2-yl. The bicyclic heteroaromatic hydrocarbon radical can be a fused 5,6- or 6,6-ring system. Examples of fused 5,6-ring system bicyclic heteroaromatic hydrocarbon radicals include indol-1-yl and benzimidazol-1-yl. Examples of fused 6,6-ring system bicyclic heteroaromatic hydrocarbon radicals include quinolin-2-yl and isoquinolin-1-yl. The tricyclic heteroaromatic hydrocarbon radical can be a fused 5,6,5-, 5,6,6-, 6,5,6-, or 6,6,6-ring system. An example of a fused 5,6,5-ring system is 1,7-dihydropyrrolo[3,2-f]indol-1-yl. An example of a fused 5,6,6-ring system is 1H-benzo[f]indol-1-yl. An example of a fused 6,5,6-ring system is 9H-carbazol-9-yl. An example of a fused 6,5,6-ring system is 9H-carbazol-9-yl. An example of a fused 6,6,6-ring system is acridin-9-yl.

[0071] The aforementioned heteroalkyl is (C1 to C 50can be a saturated straight-chain or branched radical containing the carbon atoms of (), or fewer carbon atoms and one or more heteroatoms. Similarly, heteroalkylene may be a saturated straight-chain or branched diradical containing 1 to 50 carbon atoms and one or two 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 , S(O), and S(O)2, and each of the heteroalkyl group and the heteroalkylene group may be unsubstituted or substituted by one or more R S .

[0072] Examples of unsubstituted (C2-C 40 ) heterocycloalkyl include unsubstituted (C2-C 20 ) heterocycloalkyl, unsubstituted (C2-C 10 ) heterocycloalkyl, aziridin-1-yl, oxetan-2-yl, tetrahydrofuran-3-yl, pyrrolidin-1-yl, tetrahydrothiophene-S,S-dioxide-2-yl, morpholin-4-yl, 1,4-dioxan-2-yl, hexahydroazepin-4-yl, 3-oxa-cyclooctyl, 5-thia-cyclononyl, and 2-aza-cyclodecyl.

[0073] The term "halogen atom" or "halogen" means a radical of a fluorine atom (F), a chlorine atom (Cl), a bromine atom (Br), or an iodine atom (I). The term "halide" means an anionic form of a halogen atom such as fluoride (F - ), chloride (Cl - ), bromide (Br - ), or iodide (I - ).

[0074] The term "saturated" means lacking carbon-carbon double bonds, carbon-carbon triple bonds, and carbon-nitrogen, carbon-phosphorus, and carbon-silicon double bonds (in heteroatom-containing groups). When a saturated chemical group is substituted by one or more substituents R S one or more double and / or triple bonds may or may not optionally be present in the substituent R S . 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 any double bonds that may be present in the substituent R S or, if present, in a (hetero)aromatic ring are not included.

[0075] According to some embodiments, a catalyst system for producing a polyethylene composition comprises a metal-ligand complex according to formula (I).

[0076] [Chemical formula]

[0077] 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, 2, or 3. When n is 0 and X is absent, or for each non-zero n, each X is independently a monodentate ligand that is neutral, monoanionic, or dianionic; or two Xs together form a bidentate ligand that is neutral, monoanionic, or dianionic. When n is 1, X is a monodentate or bidentate ligand, when n is 2, each X is a monodentate ligand, which may be the same or different, the metal-ligand complex is overall charge-neutral, each Z is independently selected from -O-, -S-, -N(R N ), or -P(R P ), L is a (C1-C 40 ) hydrocarbylene or (C1-C 40) It is a hetero hydrocarbylene, (C1 - C 40 ) The hydrocarbylene has a portion (to which L is attached) containing a linker skeleton of 1 to 10 carbon atoms connecting two Z groups in formula (I), or (C1 - C 40 ) The hetero hydrocarbylene has a portion containing a linker skeleton of 1 to 10 atoms connecting two Z groups in formula (I), (C1 - C 40 ) Each of the 1 to 10 atoms of the 1 - to 10 - atom linker skeleton of the hetero hydrocarbylene is independently a carbon atom or a hetero atom, and each hetero atom 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 each R C is independently (C1 - C 30 ) hydrocarbyl or (C1 - C 30 ) hetero hydrocarbyl, and R 1 and R 8 are independently -H, (C1 - C 40 ) hydrocarbyl, (C1 - C 40 ) hetero hydrocarbyl, -Si(R C )3, -Ge(R C )3, -P(R P )2, -N(R N )2, -OR C , -SR C , -NO2, -CN, -CF3, R C S(O)-, R C S(O)2-, (R C )2C=N-, R C C(O)O-, R C OC(O)-, R C C(O)N(R N ), (R N )2NC(O)-, halogen, and a radical having formula (II), formula (III), or formula (IV), and is selected from the group consisting of.

[0078] [Chemical formula]

[0079] In formulas (II), (III), and (IV), R 31~35 , R 41~48 , or R 51~59 each independently is (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 )2NC(O)-, halogen, or -H, provided that at least one of R 1 or R 8 is a radical having formula (II), formula (III), or formula (IV).

[0080] In formula (I), each of R 2~4 , R 5~7 , and R 9~16 independently is (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 COC(O)-, R C C(O)N(R N )-, (R C )2NC(O)-, halogen, and -H.

[0081] In some embodiments, the multimodal 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.

[0082] In one exemplary embodiment where a series double reactor configuration is used, the procatalyst used in the first reactor, such as a continuously stirred tank reactor (CSTR), can contain a hafnium metal center (M), and the structure is shown in the following structure (V).

[0083]

Chemical formula

[0084] In such an embodiment, the procatalyst used in the second reactor, such as a loop reactor, can contain a hafnium metal center (M), and its structure is shown in the following structure (VI).

[0085]

Chemical formula

[0086] Cocatalyst component The catalyst system comprising the metal-ligand complex of formula (I) can be catalytically activated by any technique known in the art for activating metal-based catalysts for 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 cocatalyst or by combining the complex with an activating cocatalyst. Suitable activating cocatalysts for use herein include alkylaluminum, polymeric or oligomeric aluminoxane (also known as aluminoxane); neutral Lewis acids, and non-polymeric, non-coordinating, ion-forming compounds (including the use of such compounds under oxidizing conditions). A preferred activating technique is bulk electrolysis. Combinations of one or more of the foregoing activating cocatalysts 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 aluminoxanes include methylaluminoxane, triisobutylaluminum-modified methylaluminoxane, and isobutylaluminoxane.

[0087] Examples of Lewis acid activators (cocatalysts) include Group 13 metal compounds containing 1 to 3 (C1-C 20 ) hydrocarbyl substituents as described herein. In one embodiment, the Group 13 metal compound is a tri((C1-C 20 ) hydrocarbyl)-substituted-aluminum or a tri((C1-C 20 ) hydrocarbyl)-boron compound. In embodiments, the Group 13 metal compound is a tri(hydrocarbyl)-substituted aluminum, a tri((C1-C 20 ) hydrocarbyl)-boron compound, a tri((C1-C 10 ) alkyl)aluminum, a tri((C6-C 18)They are aryl boron compounds and their halogenated (including perhalogenated) derivatives. In a further embodiment, the Group 13 metal compound is tris(fluorosubstituted phenyl)borane, tris(pentafluorophenyl)borane. In some embodiments, the activating cocatalyst is tris((C1-C 20 )hydrocarbylborate (e.g., trityltetrafluoroborate) or tri((C1-C 20 )hydrocarbyl)ammonium tetra((C1-C 20 )hydrocarbyl)borane (e.g., bis(octadecyl)methylammonium tetrakis(pentafluorophenyl)borane). As used herein, the term "ammonium" means a nitrogen cation that is ((C1-C 20 )hydrocarbyl)4N + , ((C1-C 20 )hydrocarbyl)3N(H) + , ((C1-C 20 )hydrocarbyl)2N(H)2 + , (C1-C 20 )hydrocarbylN(H)3 + , or N(H)4 + , and each (C1-C 20 )hydrocarbyl may be the same or different if more than two are present.

[0088] Examples of the combination of neutral Lewis acid activating agents (cocatalysts) include tri((C1-C4)alkyl)aluminum and tri((C6-C 18)Mixtures comprising an (aryl)boron compound, especially in combination with tris(pentafluorophenyl)borane, are included. Embodiments are combinations of such neutral Lewis acid mixtures with a polymer or oligomeric alumoxane, and combinations of a single neutral Lewis acid, especially tris(pentafluorophenyl)borane, with a polymer or oligomeric alumoxane. The molar ratio of (metal-ligand complex):(tris(pentafluoro-phenyl)borane):(alumoxane) [e.g., (Group 4 metal-ligand complex):(tris(pentafluoro-phenyl)borane):(alumoxane)] is from 1:1:1 to 1:10:30, or in an embodiment, from 1:1:1.5 to 1:5:10.

[0089] An active catalyst composition can be formed by activating a catalyst system comprising a metal-ligand complex of formula (I) and combining it with one or more cocatalysts, such as a cation-forming cocatalyst, a strong Lewis acid, or a combination thereof. Suitable activating cocatalysts include polymeric or oligomeric aluminoxanes, especially methylaluminoxane, and inert, compatible, noncoordinating, ion-forming compounds. Examples of suitable cocatalysts include modified methyl aluminoxane (MMAO), bis(hydrogenated tallow alkyl)methyl, tetrakis(pentafluorophenyl)borate(1 - )amine, and combinations thereof, but are not limited thereto.

[0090] In some embodiments, one or more of the aforementioned activating cocatalysts are used in combination with each other. Particularly preferred combinations are tri((C1-C4)hydrocarbyl)aluminum, tri((C1-C4)hydrocarbyl)borane, or a mixture of ammonium borate and an oligomeric or polymeric alumoxane compound. The ratio of the total molar number of one or more activating cocatalysts to the total molar number of one or more metal-ligand complexes of formula (I) is from 1:10,000 to 100:1. In some embodiments, this ratio is at least 1:5000, in some embodiments at least 1:1000, and 10:1 or less, and in still some embodiments, 1:1 or less. When using an alumoxane alone as the activating cocatalyst, the molar number of the alumoxane used is preferably at least 100 times the molar number of the metal-ligand complex of formula (I). When using tris(pentafluorophenyl)borane alone as the activating cocatalyst, in some embodiments, the molar number of tris(pentafluorophenyl)borane used relative to the total molar number 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 activating cocatalysts are generally used in a molar amount approximately equal to the total molar amount of one or more metal-ligand complexes of formula (I).

[0091] Multilayer film Reference is now made to embodiments of the multilayer films described herein.

[0092] The multilayer films of the present disclosure may include at least two layers, and further may include 3, 4, 5, 6, 7, 9, 11, 13 or more layers. The number of layers of the multilayer film may depend on a number of factors including, for example, the composition of each layer of the multilayer film, the desired properties of the multilayer film, the desired end use of the multilayer film, the manufacturing process of the multilayer film, and the like. As described in more detail herein, embodiments of the multilayer film may include a first layer described later in the present disclosure, a second layer described later in the present disclosure, and one or more subskin layers described later in the present disclosure. The first layer, the second layer, or both may include the multimodal polyethylene composition described herein.

[0093] The multilayer film may be a two-layer film referred to as A / B, the first layer may be referred to as (A), and the second layer may be referred to as (B). As used herein, "direct contact" means that there may be no other layer disposed between two layers in direct contact with each other. In an embodiment, the first layer (A) may be in direct contact with the second layer (B).

[0094] In an embodiment, the multilayer film may be a three-layer film referred to as A / B / C, the first layer may be referred to as (A), the second layer may be referred to as (B), and the third layer may be referred to as (C). In an embodiment, the second layer (B) may be positioned between the first layer (A) and the third layer (C), and the second layer (B) may be referred to as an "intermediate layer" or a "core layer". In an embodiment, one or both of the first layer (A) and the third layer (C) may be the outermost layer of the multilayer film, and they may be referred to as "outer layers". As used herein, the outermost layer of the multilayer film can be understood to mean that there may be no other layer deposited on the outermost layer such that the outermost layer is in direct contact with the surrounding air. In an embodiment, the first layer (A) may be in direct contact with the second layer (B). In an embodiment, the second layer (B) may be in direct contact with the third layer (C).

[0095] In an embodiment, the multilayer film may include one or more layers in addition to the outer layer and the core layer. Such additional layers may include additional layers containing polyethylene, and such additional layers containing polyethylene may or may not include the multimodal polyethylene composition described herein. In one or more embodiments, the additional polyethylene layer may include a blend of LLDPE, LDPE, MDPE, HDPE, the multimodal polyethylene composition described herein, and combinations thereof. Various polyethylene components (e.g., LLDPE, LDPE, HDPE, and the multimodal polyethylene composition described herein) may be included in the additional polyethylene layer in any desired amounts according to the properties of the multilayer film to be achieved. Such additional layers may alternatively or additionally include one or more additional tie layers.

[0096] Any of the foregoing layers may further include one or more additives known to those skilled in the art, such as plasticizers, stabilizers including viscosity stabilizers, hydrolysis stabilizers, primary and secondary antioxidants, ultraviolet absorbers, antistatic agents, dyes, pigments, or other colorants, inorganic fillers, flame retardants, lubricants, reinforcing agents such as glass fibers and flakes, synthetic (e.g., aramid) fibers or pulp, forming agents or foaming agents, processing aids, slip additives, anti-blocking agents such as silica or talc, release agents, tackifying resins, or combinations of two or more thereof. Inorganic fillers such as calcium carbonate and the like can also be incorporated into one or more of the first layer, the second layer, the third layer, and combinations thereof. In some embodiments, the skin layer, the sub-skin layer, the bonding layer, the barrier layer, and combinations may each contain up to 5 weight percent of such additional additives based on the total weight of each layer. All individual values and sub-ranges from 0 weight percent to 5 weight percent are included and disclosed herein. For example, the total amount of additives in the first layer, the second layer, or the third layer can be 0.5 weight percent to 5 weight percent, 0.5 weight percent to 4 weight percent, 0.5 weight percent to 3 weight percent, 0.5 weight percent to 2 weight percent, 0.5 weight percent to 1 weight percent, 1 weight percent to 5 weight percent, 1 weight percent to 4 weight percent, 1 weight percent to 3 weight percent, 1 weight percent to 2 weight percent, 2 weight percent to 5 weight percent, 2 weight percent to 4 weight percent, 2 weight percent to 3 weight percent, 3 weight percent to 5 weight percent, 3 weight percent to 4 weight percent, or 4 weight percent to 5 weight percent, based on the total weight of each respective layer. Incorporation of the additives can be carried out by any known process, such as dry blending, extrusion of mixtures of various components, conventional masterbatch techniques, and the like.

[0097] The multilayer films of the present disclosure can have various thicknesses. The thickness of the multilayer film can depend on a number of factors including, for example, the number of layers of the multilayer film, the composition of the layers of the multilayer film, the desired properties of the multilayer film, the desired end use of the film, the manufacturing process of the multilayer film, and the like. In embodiments, the multilayer film can have a thickness of less than 205 micrometers (μm or microns). In embodiments, the multilayer film can have a thickness of 15 μm to 205 μm, 20 μm to 180 μm, 15 μm to 180 μm, 15 μm to 160 μm, 15 μm to 140 μm, 15 μm to 120 μm, 15 μm to 100 μm, 15 μm to 80 μm, 15 μm to 60 μm, 15 μm to 40 μm, 20 μm to 160 μm, 20 μm to 140 μm, 20 μm to 120 μm, 20 μm to 100 μm, 20 μm to 80 μm, 20 μm to 60 μm, or 20 μm to 40 μm.

[0098] The multilayer films of the present disclosure can have an overall density that depends on a number of factors including, for example, the number of layers of the multilayer film, the composition of the layers of the multilayer film, the desired properties of the multilayer film, the desired end use of the film, the manufacturing process of the multilayer film, and the like. In embodiments, the multilayer film can have an overall density of at least 0.925 grams per cubic centimeter (g / cm 3 ). In embodiments, the overall density of the multilayer film is 0.925 g / cm 3 to 0.970 g / cm 3 , 0.925 g / cm 3 to 0.940 g / cm 3 , 0.925 g / cm 3 to 0.935 g / cm 3 , 0.925 g / cm 3 to 0.930 g / cm 3 , 0.930 g / cm 3 to 0.940 g / cm 3 , 0.930 g / cm 3 to 0.935 g / cm 3 , 0.935 g / cm 3 to 0.940 g / cm 3 , or 0.935 g / cm 3 to 0.950 g / cm 3 and can be.

[0099] In one or more embodiments, the multilayer film of the present disclosure can have a puncture force of at least 1 newton per micrometer (N / μm) of film when measured according to ASTM D 5748-95. In embodiments, the multilayer film of the present disclosure can have a puncture force of 1 N / μm to 1.5 N / μm, 1 N to 1.25 N / μm, or 1.25 N / μm to 1.5 N / μm when measured according to ASTM D 5748-95.

[0100] In one or more embodiments, the multilayer film of the present disclosure has a puncture resistance of more than 10 joules per cubic centimeter (J / cm 3 ) when measured according to ASTM D 5748-95. In embodiments, the multilayer film of the present disclosure has a puncture resistance of more than 8 J / cm 3 or more than 10 J / cm 3 when measured according to ASTM D 5748-95.

[0101] The multilayer film of the present disclosure can have a puncture elongation of at least 55 millimeters (mm) when measured according to ASTM D 5748-95. In embodiments, the multilayer film of the present disclosure has a puncture elongation of 55 mm to 150 mm, 55 mm to 100 mm, 55 mm to 80 mm, 55 mm to 60 mm, 60 mm to 150 mm, 60 mm to 100 mm, 60 mm to 80 mm, or 80 mm to 100 mm when measured according to ASTM D 5748-95.

[0102] Outer layer As described above, the multilayer film of the present disclosure can include one or more outer layers. The outermost layer of the multilayer film (which may also be referred to as the "outer layer") can be understood to mean that there may be no other layer deposited on the outermost layer such that the outermost layer is in direct contact with the surrounding air. The outer layer can impart properties to the multilayer film that assist with elongation, processability, etc. The outer layer may also be referred to as a skin layer. In embodiments, one or both of the first layer (A) and the third layer (C) can be the outermost layer of the multilayer film, and they can be referred to as the "outer layer".

[0103] The outer layer may include a sealant layer. The sealant layer is generally the outer layer of the film that can be used to adhere the film to another film, a rigid material (e.g., a tray), or itself. Those skilled in the art will recognize, based on the teachings herein, that in various embodiments, various olefinic polymers can be used as the sealant layer. In some embodiments, polyethylene may be the main component of each sealant layer to promote reusability. One non-limiting example of a resin that can be used as the sealant layer is, according to some embodiments, SEALUTION™ 220. Other resins that can be used to form the sealant layer include, but are not limited to, AFFINITY™ resin, ELITE AT™ resin, and ELITE™ resin commercially available from The Dow Chemical Company.

[0104] In embodiments, at least one outer layer may include the multimodal polyethylene composition described herein. In embodiments, the outer layer containing the multimodal polyethylene composition described herein may be blended with polyethylene having a density of 0.870 g / cm 3 to 0.970 g / cm 3 . In embodiments, at least one outer layer may contain more than 20% by weight of the multimodal polyethylene composition described herein below, based on the total weight of each layer. In one or more embodiments, each outer layer may contain more than 20% by weight of the multimodal polyethylene composition described herein, based on the total weight of each layer. In some embodiments, each outer layer may contain from 0% to 100%, 30% to 100%, 50% to 80%, 50% to 60%, 60% to 100%, 60% to 80%, or 80% to 100% by weight, based on the total weight of each layer, of the multimodal polyethylene composition described herein. In some embodiments, the outer layer that does not contain the multimodal polyethylene composition described herein has a density of 0.870 g / cm 3 to 0.970 g / cm 3It may contain polyethylene having a density of. In embodiments, each outer layer may contain LLDPE, HDPE, the multimodal polyethylene compositions described herein, MDPE, LDPE, and combinations thereof.

[0105] In one or more embodiments, each outer layer has a density of 0.905 g / cm 3 ~0.930 g / cm 3 when measured in accordance with ASTM D792 and may contain linear low density polyethylene (LLDPE). In another embodiment, the density of the linear low density polyethylene is 0.905 g / cm 3 ~0.925 g / cm 3 、0.905 g / cm 3 ~0.920 g / cm 3 、0.905 g / cm 3 ~0.915 g / cm 3 、0.905 g / cm 3 ~0.910 g / cm 3 、0.910 g / cm 3 ~0.930 g / cm 3 、0.910 g / cm 3 ~0.925 g / cm 3 、0.910 g / cm 3 ~0.920 g / cm 3 、0.910 g / cm 3 ~0.915 g / cm 3 、0.915 g / cm 3 ~0.930 g / cm 3 、0.915 g / cm 3 ~0.925 g / cm 3 、0.915 g / cm 3 ~0.920 g / cm 3 、0.920 g / cm 3 ~0.930 g / cm 3 、0.920 g / cm 3 ~0.925 g / cm 3 、0.925 g / cm 3 ~0.930 g / cm 3 and may be.

[0106] In one or more embodiments, each outer layer may include linear low-density polyethylene (LLDPE) having a melt index (I2) of from 0.2 grams per 10 minutes (g / 10 min) to 6.0 g / 10 min as measured according to ASTM D1238. It is also contemplated that the melt index (I2) of the linear low-density polyethylene may be from 0.2 g / 10 min to 5.5 g / 10 min, from 0.2 g / 10 min to 5.0 g / 10 min, from 0.2 g / 10 min to 4.5 g / 10 min, from 0.5 g / 10 min to 4.0 g / 10 min, from 0.5 g / 10 min to 3.5 g / 10 min, from 0.5 g / 10 min to 3.0 g / 10 min, from 1.0 g / 10 min to 2.0 g / 10 min, from 1.0 g / 10 min to 1.5 g / 10 min, or from 1.5 g / 10 min to 2.0 g / 10 min.

[0107] According to an embodiment, the linear low-density polyethylene may have a molecular weight distribution in the range of 3.5 to 5.5, expressed as the ratio of weight-average molecular weight to number-average molecular weight (Mw / Mn). In additional embodiments, the linear low-density polyethylene may have a molecular weight distribution in the range of 3.5 to 4.5 or 4.5 to 5.5.

[0108] According to one or more additional embodiments, the linear low-density polyethylene may have a zero-shear viscosity ratio of from 1.2 to 3.0 as measured according to the test methods described herein. In an embodiment, the linear low-density polyethylene may have a zero-shear viscosity ratio of from 1.2 to 2.5, from 1.2 to 2.0, from 2.0 to 3.0, from 2.0 to 2.5, or from 2.5 to 3.0.

[0109] Regarding the production of linear low density polyethylene, various methodologies are contemplated. For example, linear low density polyethylene resins can be made using resins made with single site catalysts including, but not limited to, Ziegler-Natta catalyst systems, bis-metallocene catalysts and constrained geometry catalysts, resins made using post-metallocene molecular catalysts. Linear low density polyethylene resins can include linear, substantially linear, or non-uniform, polyethylene copolymers or homopolymers. Linear low density polyethylene resins may contain fewer long chain branches than LDPE, substantially linear polyethylene as further defined in U.S. Patent No. 5,272,236, U.S. Patent No. 5,278,272, U.S. Patent No. 5,582,923, and U.S. Patent No. 5,733,155, homogeneous branched linear ethylene polymer compositions such as those of U.S. Patent No. 3,645,992, non-uniformly branched ethylene polymers prepared according to the process disclosed in U.S. Patent No. 4,076,698, and blends thereof (such as those disclosed in U.S. Patent No. 3,914,342 or U.S. Patent No. 5,854,045). Linear low density polyethylene resins can be made by gas phase, solution phase, or slurry polymerization, or any combination thereof, using any type of reactor or reactor configuration known in the art.

[0110] In one or more embodiments, each outer layer can contain more than 50 wt% linear low density polyethylene, based on the total weight of each layer. In some embodiments, the second layer, the third layer, or both can contain 50 wt% - 100 wt%, 50 wt% - 80 wt%, 50 wt% - 60 wt%, 60 wt% - 100 wt%, 60 wt% - 80 wt%, or 80 wt% - 100 wt% LLDPE, based on the total weight of each layer.

[0111] In an embodiment, each outer layer has a density of 0.935 g / cm 3 ~ up to 0.980 g / cm 3It may include high-density polyethylene (HDPE) having a density of. In another embodiment, the density of the high-density polyethylene is 0.935 g / cm 3 ~0.970 g / cm 3 、0.935 g / cm 3 ~0.960 g / cm 3 、0.935 g / cm 3 ~0.950 g / cm 3 、0.935 g / cm 3 ~0.940 g / cm 3 、0.940 g / cm 3 ~0.980 g / cm 3 、0.940 g / cm 3 ~0.970 g / cm 3 、0.940 g / cm 3 ~0.960 g / cm 3 、0.940 g / cm 3 ~0.950 g / cm 3 、0.950 g / cm 3 ~0.980 g / cm 3 、0.950 g / cm 3 ~0.970 g / cm 3 、0.950 g / cm 3 ~0.960 g / cm 3 、0.960 g / cm 3 ~0.980 g / cm 3 、0.960 g / cm 3 ~0.970 g / cm 3 、0.970 g / cm 3 ~0.980 g / cm 3 may be.

[0112] In one or more embodiments, each outer layer may include high-density polyethylene having a melt index (I2) of 0.1 gram per 10 minutes (g / 10 min) to 10.0 g / 10 min as measured according to ASTM D1238 at a load of 2.16 kg and a temperature of 190 °C. It is also contemplated that the melt index (I2) of the high-density polyethylene may be 0.1 g / 10 min to 5.0 g / 10 min, 0.1 g / 10 min to 1.0 g / 10 min, 1.0 g / 10 min to 10.0 g / 10 min, 1.0 g / 10 min to 5.0 g / 10 min, or 5.0 g / 10 min to 10.0 g / 10 min.

[0113] For the production of high-density polyethylene, various methodologies are contemplated. For example, high-density polyethylene resins can be made using a Ziegler-Natta catalyst system, a chromium catalyst, or a single-site catalyst including but not limited to bis-metallocene catalysts and constrained geometry catalysts.

[0114] In one or more embodiments, each outer layer can contain up to 50 wt% high-density polyethylene, based on the total weight of each layer. In some embodiments, each outer layer can contain from 0 wt% to 90 wt%, 15 wt% to 80 wt%, 15 wt% to 50 wt%, 20 wt% to 50 wt%, 30 wt% to 40 wt%, or 35 wt% to 50 wt% high-density polyethylene, based on the total weight of each layer.

[0115] In one or more embodiments, each outer layer may contain MDPE. The term "MDPE", when used alone, refers to polyethylene having a density of 0.917 to 0.936 g / cm 3 . MDPE is typically made using a chromium or Ziegler-Natta catalyst, or a single-site catalyst including but not limited to substituted mono- or bis-cyclopentadienyl catalysts (typically referred to as metallocenes), geometrically constrained catalysts, phosphine imine catalysts, and polyvalent aryloxy ether catalysts (typically referred to as bisphenol phenoxy). Note that MDPE can be used in one or more outer layers.

[0116] In one or more embodiments, each outer layer can contain up to 50 wt% MDPE, based on the total weight of each layer. In some embodiments, each outer layer can contain from 0 wt% to 90 wt%, 15 wt% to 80 wt%, 15 wt% to 50 wt%, 20 wt% to 50 wt%, 30 wt% to 40 wt%, or 35 wt% to 50 wt% MDPE, based on the total weight of each layer.

[0117] In an embodiment, each outer layer may include low-density polyethylene (LDPE). In one or more embodiments, the low-density polyethylene may have a melt index of 0.1 g / 10 min to 10.0 g / 10 min when measured according to ASTM D1238 at a load of 2.16 kg and a temperature of 190 °C. In an embodiment, the low-density polyethylene may have a melt index of 0.1 g / 10 min to 5.0 g / 10 min, or 0.5 g / 10 min to 5.0 g / 10 min, or 0.5 g / 10 min to 2.0 g / 10 min. In an embodiment, the low-density polyethylene may have a density of 0.916 g / cm 3 ~ 0.935 g / cm 3 when measured according to ASTM D792. In another embodiment, the low-density polyethylene may have a density of 0.916 g / cm 3 ~ 0.925 g / cm 3 when measured according to ASTM D792.

[0118] In one or more embodiments, each outer layer may include less than 50 wt% low-density polyethylene based on the total weight of each layer. In some embodiments, each outer layer may include 0 wt% to 50 wt%, 0 wt% to 40 wt%, 0 wt% to 35 wt%, 5 wt% to 35 wt%, 10 wt% to 35 wt%, or 15 wt% to 35 wt% low-density polyethylene based on the total weight of each layer.

[0119] In an embodiment, the outer layer of the multilayer film of the present disclosure may have various thicknesses. The thickness of each outer layer may depend on many factors including, for example, the composition of each outer layer, the desired processability characteristics of the multilayer film, etc. In an embodiment, each outer layer may have a thickness of 1 micrometer (μm or micron) to 40 μm. In an embodiment, each outer layer may have a thickness of 1 μm to 40 μm, 1 μm to 30 μm, 1 μm to 20 μm, 1 μm to 10 μm, 10 μm to 40 μm, 10 μm to 30 μm, 10 μm to 20 μm, 20 μm to 40 μm, 20 μm to 30 μm, or 30 μm to 40 μm.

[0120] The thickness of each outer layer of the multilayer film disclosed in this specification may constitute 5% to 20% of the total thickness of the multilayer film. In some embodiments, the thickness of each outer layer may constitute 5% to 15%, 5% to 10%, 10% to 20%, 10% to 15%, or 15% to 20% of the total thickness of the multilayer film.

[0121] Sub-skin layer As described above, the multilayer film of the present disclosure may include one or more sub-skin layers. As used herein, a sub-skin layer may refer to a layer positioned between outer layers of a multilayer film. As used herein, the central sub-skin layer of a multilayer film may be referred to as an "intermediate layer" or a "core layer". In various embodiments, each sub-skin layer may include one or more materials that impart improved dirt and puncture properties to the multilayer film as compared to conventional multilayer films.

[0122] In embodiments including a plurality of sub-skin layers, each sub-skin layer may include the same material or each sub-skin layer may include different materials. For example, in a five-layer film designated as A / B / C / D / E, layers (B) and (D) may include the same material or different materials. In a seven-layer film designated as A / B / C / D / E / F / G, one or more of layers (B), (C), (E), and (F) may include the same material or different materials. In a nine-layer film designated as A / B / C / D / E / F / G / H / I, one or more of layers (B), (C), (G), and (H) may include the same material or different materials.

[0123] In embodiments, at least one sub-skin layer may include the multimodal polyethylene composition described herein. In embodiments, the sub-skin layer including the multimodal polyethylene composition described herein has a density of 0.870 g / cm 3 ~0.970 g / cm 3It can be blended with polyethylene having a density of. In embodiments, at least one sub-skin layer may comprise a multimodal polyethylene composition as described herein that exceeds 20% by weight based on the total weight of each layer. In one or more embodiments, each sub-skin layer may comprise a multimodal polyethylene composition as described herein that exceeds 20% by weight based on the total weight of each layer. In some embodiments, each sub-skin layer may comprise from 30% to 100%, from 50% to 80%, from 50% to 60%, from 60% to 100%, from 60% to 80%, or from 80% to 100% of the multimodal polyethylene composition as described herein, based on the total weight of each layer.

[0124] In embodiments, each sub-skin layer may comprise LLDPE, HDPE, the multimodal polyethylene composition as described herein, MDPE, LDPE, and combinations thereof. In some embodiments, a sub-skin layer that does not comprise the multimodal polyethylene composition as described herein may comprise a polyethylene composition having a density of 3 ~0.970 g / cm 3

[0125] In one or more embodiments, each sub-skin layer may comprise linear low density polyethylene (LLDPE) having a density of 0.905 g / cm 3 ~0.930 g / cm 3 when measured according to ASTM D792. In another embodiment, the density of the linear low density polyethylene is 0.905 g / cm 3 ~0.925 g / cm 3 、0.905 g / cm 3 ~0.920 g / cm 3 、0.905 g / cm 3 ~0.915 g / cm 3 、0.905 g / cm 3 ~0.910 g / cm 3 、0.910 g / cm 3 ~0.930 g / cm 3 、0.910 g / cm 3 ~0.925 g / cm 3 ​, 0.910 g / cm 3 ~0.920 g / cm 3 , 0.910 g / cm 3 ~0.915 g / cm 3 , 0.915 g / cm 3 ~0.930 g / cm 3 , 0.915 g / cm 3 ~0.925 g / cm 3 , 0.915 g / cm 3 ~0.920 g / cm 3 , 0.920 g / cm 3 ~0.930 g / cm 3 , 0.920 g / cm 3 ~0.925 g / cm 3 , 0.925 g / cm 3 ~0.930 g / cm 3 can be.

[0126] In one or more embodiments, each subskin layer may include linear low density polyethylene (LLDPE) having a melt index (I2) of 0.2 grams per 10 minutes (g / 10 min) to 6.0 g / 10 min as measured according to ASTM D1238. It is also contemplated that the melt index (I2) of the linear low density polyethylene can be 0.2 g / 10 min to 5.5 g / 10 min, 0.2 g / 10 min to 5.0 g / 10 min, 0.2 g / 10 min to 4.5 g / 10 min, 0.5 g / 10 min to 4.0 g / 10 min, 0.5 g / 10 min to 3.5 g / 10 min, 0.5 g / 10 min to 3.0 g / 10 min, 1.0 g / 10 min to 2.0 g / 10 min, 1.0 g / 10 min to 1.5 g / 10 min, or 1.5 g / 10 min to 2.0 g / 10 min.

[0127] According to an embodiment, the linear low density polyethylene may have a molecular weight distribution in the range of 3.5 to 5.5, expressed as the ratio of weight average molecular weight to number average molecular weight (Mw / Mn). In additional embodiments, the linear low density polyethylene may have a molecular weight distribution in the range of 3.5 to 4.5 or 4.5 to 5.5.

[0128] According to one or more additional embodiments, the linear low density polyethylene may have a zero shear viscosity ratio of 1.2 to 3.0 when measured according to the test methods described herein. In embodiments, the linear low density polyethylene may have a zero shear viscosity ratio of 1.2 to 2.5, 1.2 to 2.0, 2.0 to 3.0, 2.0 to 2.5, or 2.5 to 3.0.

[0129] Regarding the production of linear low density polyethylene, various methodologies are contemplated. For example, the linear low density polyethylene resin can be made using resins made using single site catalysts including, but not limited to, Ziegler-Natta catalyst systems, bis-metallocene catalysts and constrained geometry catalysts, resins made using post-metallocene molecular catalysts. The linear low density polyethylene resin can include linear, substantially linear, or non-uniform, polyethylene copolymers or homopolymers. The linear low density polyethylene resin may contain fewer long chain branches than LDPE, substantially linear polyethylene as further defined in U.S. Patent No. 5,272,236, U.S. Patent No. 5,278,272, U.S. Patent No. 5,582,923, and U.S. Patent No. 5,733,155, homogeneous branched linear ethylene polymer compositions such as those of U.S. Patent No. 3,645,992, non-uniformly branched ethylene polymers prepared according to the process disclosed in U.S. Patent No. 4,076,698, and blends thereof (such as those disclosed in U.S. Patent No. 3,914,342 or U.S. Patent No. 5,854,045). The linear low density polyethylene resin can be made by gas phase, solution phase, or slurry polymerization, or any combination thereof, using any type of reactor or reactor configuration known in the art.

[0130] In one or more embodiments, each sub-skin layer may contain 0 wt% to 80 wt%, 0 wt% to 60 wt%, 0 wt% to 40 wt%, 0 wt% to 20 wt%, 20 wt% to 80 wt%, 20 wt% to 60 wt%, 20 wt% to 40 wt%, 40 wt% to 80 wt%, 40 wt% to 60 wt%, or 60 wt% to 80 wt% of LLDPE, based on the total weight of each layer.

[0131] In an embodiment, each sub-skin layer may comprise low density polyethylene (LDPE). In one or more embodiments, the low density polyethylene may have a melt index of 0.1 g / 10 min to 10.0 g / 10 min when measured according to ASTM D1238 at a load of 2.16 kg and a temperature of 190 °C. In an embodiment, the low density polyethylene may have a melt index of 0.1 g / 10 min to 5.0 g / 10 min, or 0.5 g / 10 min to 5.0 g / 10 min, or 0.5 g / 10 min to 2.0 g / 10 min. In an embodiment, the low density polyethylene has a density of 0.916 g / cm 3 ~0.935 g / cm 3 when measured according to ASTM D792. In another embodiment, the low density polyethylene may have a density of 0.916 g / cm 3 ~0.925 g / cm 3 when measured according to ASTM D792.

[0132] In one or more embodiments, each sub-skin layer may comprise less than 50 wt% LDPE based on the total weight of each layer. In some embodiments, each sub-skin layer may comprise 0 wt% to 50 wt%, 0 wt% to 40 wt%, 0 wt% to 35 wt%, 5 wt% to 35 wt%, 10 wt% to 35 wt%, or 15 wt% to 35 wt% LDPE based on the total weight of each layer.

[0133] In one or more embodiments, each sub-skin layer may include medium density polyethylene (MDPE). "MDPE" is typically made using a chromium or Ziegler-Natta catalyst, or a single-site catalyst including, but not limited to, a substituted mono- or bis-cyclopentadienyl catalyst (typically referred to as a metallocene), a geometrically constrained catalyst, a phosphine imine catalyst, and a polyvalent aryloxy ether catalyst (typically referred to as bisphenol phenoxy). Note that MDPE can be used in one or more sub-skin layers.

[0134] In one or more embodiments, each sub-skin layer may comprise more than 20% by weight of MDPE, based on the total weight of each layer. In some embodiments, each sub-skin layer may comprise from 30% to 100%, 50% to 80%, 50% to 60%, 60% to 100%, 60% to 80%, or 80% to 100% by weight of MDPE, based on the total weight of each layer.

[0135] In embodiments, each sub-skin layer may comprise high density polyethylene (HDPE) having a density of from 0.935 g / cm 3 to a maximum of 0.980 g / cm 3 as measured according to ASTM D792. In another embodiment, the density of the HDPE may be from 0.935 g / cm 3 to 0.970 g / cm 3 , from 0.935 g / cm 3 to 0.960 g / cm 3 , from 0.935 g / cm 3 to 0.950 g / cm 3 , from 0.935 g / cm 3 to 0.940 g / cm 3 , from 0.940 g / cm 3 to 0.980 g / cm 3 , from 0.940 g / cm 3 to 0.970 g / cm 3 , from 0.940 g / cm 3 to 0.960 g / cm 3 , from 0.940 g / cm 3 to 0.950 g / cm 3 , from 0.950 g / cm 3 to 0.980 g / cm 3 , from 0.950 g / cm 3 to 0.970 g / cm 3 , from 0.950 g / cm 3 to 0.960 g / cm 3 , from 0.960 g / cm 3 to 0.980 g / cm 3 , from 0.960 g / cm 3 to 0.970 g / cm 3 , or from 0.970 g / cm 3 to 0.980 g / cm 3 and may be.

[0136] In one or more embodiments, each sub-skin layer may comprise HDPE having a melt index (I2) of from 0.1 gram per 10 minutes (g / 10 min) to 10.0 g / 10 min as measured according to ASTM D1238 at a load of 2.16 kg and a temperature of 190°C. It is also contemplated that the melt index (I2) of the high-density polyethylene may be from 0.1 g / 10 min to 5.0 g / 10 min, from 0.1 g / 10 min to 1.0 g / 10 min, from 1.0 g / 10 min to 10.0 g / 10 min, from 1.0 g / 10 min to 5.0 g / 10 min, or from 5.0 g / 10 min to 10.0 g / 10 min.

[0137] For the production of high-density polyethylene, various methodologies are contemplated. For example, the HDPE resin can be made using a Ziegler-Natta catalyst system, a chromium catalyst, or a single-site catalyst including but not limited to bis-metallocene catalysts and constrained geometry catalysts.

[0138] In one or more embodiments, each sub-skin layer may comprise up to 50 wt% HDPE, based on the total weight of each layer. In some embodiments, each sub-skin layer may comprise from 0 wt% to 90 wt%, from 15 wt% to 80 wt%, from 15 wt% to 50 wt%, from 20 wt% to 50 wt%, from 30 wt% to 40 wt%, or from 35 wt% to 50 wt% HDPE, based on the total weight of each layer.

[0139] In embodiments, each sub-skin layer of the multi-layer film of the present disclosure may have various thicknesses. The thickness of each sub-skin layer may depend on many factors including, for example, the composition of the sub-skin layer, the desired overall dirt and puncture characteristics of the multi-layer film, etc. In embodiments, each sub-skin layer may have a thickness of from 1 micrometer (μm) to 85 μm. In embodiments, each outer layer may have a thickness of from 1 μm to 80 μm, from 1 μm to 60 μm, from 1 μm to 40 μm, from 1 μm to 20 μm, from 20 μm to 80 μm, from 20 μm to 60 μm, from 20 μm to 40 μm, from 40 μm to 80 μm, from 40 μm to 60 μm, or from 60 μm to 80 μm.

[0140] In an embodiment of the multilayer film where a subskin layer is present, the thickness of each subskin layer of the multilayer film can constitute 5% to 40% of the total thickness of the multilayer film. In some embodiments, each subskin layer can constitute 5% to 20 wt%, 5% to 15%, 5% to 10%, 10% to 40%, 10% to 20%, 10% to 15%, 15% to 40%, 15% to 20%, or 20% to 40% of the total thickness of the multilayer film.

[0141] Barrier layer In an embodiment, the multilayer film can include a barrier layer. As used herein, the term "barrier layer" refers to a layer that reduces the diffusion of vapor or gas into and out of the multilayer film. For example, the barrier layer can reduce the diffusion of fragrance, water, or oxygen into and out of the multilayer film.

[0142] In an embodiment, the barrier layer may comprise a polar material. As used herein, the term "polar material" refers to a polymer formed from at least one monomer containing at least one heteroatom. Some examples of heteroatoms include O, N, P, and S. In various embodiments, the polar material may be selected from an ethylene vinyl alcohol polymer (EVOH) (such as Eval H171B sold by Kuraray) or a combination of EVOH and polyamide (PA) (such as Nylon6, Nylon66, and Nylon6 / 66 sold by DuPont). In various embodiments, the barrier layer consists of ethylene vinyl alcohol (EVOH). In some embodiments, the barrier layer does not contain or substantially does not contain polyamide. As used herein, "substantially does not contain" may mean that the barrier layer contains less than 1% by weight of polyamide based on the total weight of the barrier layer. In an embodiment, the barrier layer may contain less than 0.5% by weight or less than 0.1% by weight of polyamide. It should be understood that in an embodiment, the barrier layer containing a polar material may contain or consist of a polar material. In an embodiment where the layer containing a polar material contains a polar material, the polar material may be blended with any polymer including polyethylene such as LLDPE, LDPE, ULDPE, MDPE, HDPE, and the multimodal polyethylene compositions described herein. In various embodiments, the polar material has a melt index (I2) (2.16 kg, 190 °C) of 0.1 g / 10 min to 40 g / 10 min, 0.2 g / 10 min to 20 g / 10 min, or 0.5 g / 10 min to 10 g / 10 min. In various embodiments, the polar material has a density of 1.00 g / cm 3 ~1.30 g / cm 3 or 1.10 g / cm 3 ~1.20 g / cm 3 (1 cm 3 = 1 cc).

[0143] In embodiments, the barrier layer of the multilayer film of the present disclosure can have various thicknesses. The thickness of the barrier layer can depend on many factors including, for example, the composition of the barrier layer, the desired overall recyclability of the multilayer film, and the barrier properties. In embodiments, the barrier layer can have a thickness of 0.1 μm to 20 μm, 0.1 μm to 15 μm, 0.1 μm to 10 μm, 0.1 μm to 5 μm, 0.1 μm to 1 μm, 0.1 μm to 0.5 μm, 0.5 μm to 20 μm, 0.5 μm to 15 μm, 0.5 μm to 10 μm, 0.5 μm to 5 μm, 0.5 μm to 1 μm, 1 μm to 20 μm, 1 μm to 15 μm, 1 μm to 10 μm, 1 μm to 5 μm, 5 μm to 20 μm, 5 μm to 15 μm, 5 μm to 10 μm, 10 μm to 20 μm, 10 μm to 15 μm, or 15 μm to 20 μm.

[0144] The thickness of the barrier layer of the multilayer film disclosed herein can constitute 1% to 10%, 1% to 8%, 1% to 6%, 1% to 4%, 1% to 2%, 2% to 10%, 2% to 8%, 2% to 6%, 2% to 4%, 4% to 10%, 4% to 8%, 4% to 6%, 6% to 10%, 6% to 8%, or 8% to 10% of the total thickness of the multilayer film.

[0145] Adhesive layer In embodiments, the multilayer film can include one or more adhesive layers. As used herein, the term "adhesive layer" refers to a layer that adheres two layers to each other. For example, the adhesive layer can bond a polar material to one or more layers that do not contain a polar material. For example, the adhesive layer can be disposed adjacent to a layer containing a polar material to bond the layer containing the polar material to a layer containing polyethylene. In embodiments, the adhesive layer can be disposed adjacent to the barrier layer to bond the barrier layer containing a polar material to one or more layers containing polyethylene, such as one or more subskin layers or outer layers.

[0146] In embodiments, based on the teachings herein, a variety of polymers known to those skilled in the art as useful for bonding a layer containing a polar material (such as EVOH or polyamide, etc.) to a layer containing polyethylene can be used for the adhesive layer.

[0147] In an embodiment, the tie layer may include an ethylene and acid copolymer. In one or more embodiments, the tie layer may include an anhydride grafted ethylene / alpha-olefin interpolymer. As used herein, the term "anhydride grafted ethylene / alpha-olefin interpolymer" refers to an ethylene / alpha-olefin interpolymer that includes at least one anhydride group linked by a covalent bond. The anhydride grafted ethylene / alpha-olefin interpolymer may be an ethylene-based polymer onto which an anhydride grafting monomer is grafted. Suitable ethylene-based polymers for low melt viscosity maleic anhydride grafted polyolefins include, but are not limited to, polyethylene homopolymers and copolymers with alpha-olefins, copolymers of ethylene and vinyl acetate, and copolymers of ethylene and one or more alkyl (meth)acrylates. In certain embodiments, the anhydride grafted ethylene / alpha-olefin interpolymer may include maleic anhydride grafted linear low density polyethylene (LLDPE).

[0148] In one or more embodiments, the anhydride grafted ethylene / alpha-olefin interpolymer includes up to 10 wt%, up to 5 wt%, or 1 - 4 wt% maleic anhydride grafting monomer, based on the total weight of the anhydride grafted ethylene / alpha-olefin interpolymer. The weight percent of the ethylene-based polymer is complementary to the amount of maleic anhydride grafting monomer such that the sum of the weight percents of the ethylene-based polymer and maleic anhydride grafting monomer is 100 wt%. Thus, the anhydride grafted ethylene / alpha-olefin interpolymer includes up to 90 wt%, up to 95 wt%, or 96 - 99 wt% ethylene-based polymer, based on the total weight of the maleic anhydride grafted polyolefin.

[0149] Examples of the anhydride grafting moiety include, but are not limited to, maleic anhydride, citraconic anhydride, 2-methylmaleic anhydride, 2-chloromaleic anhydride, 2,3-dimethylmaleic anhydride, bicyclo[2,2,1]-5-heptane-2,3-dicarboxylic anhydride, and 4-methyl-4-cyclohexene-1,2-dicarboxylic anhydride, bicyclo(2.2.2)oct-5-ene-2,3-dicarboxylic anhydride, lo-octahydronaphthalene-2,3-dicarboxylic anhydride, 2-oxa-1,3-diketospiro(4.4)nona-7-ene, bicyclo(2.2.1)hepta-5-ene-2,3-dicarboxylic anhydride, tetrahydrophthalic anhydride, norbor-5-ene-2,3-dicarboxylic anhydride, nadic anhydride, methyl nadic anhydride, himic anhydride, methyl himic anhydride, and x-methyl-bicyclo(2.2.1)hepta-5-ene-2,3-dicarboxylic anhydride. In one embodiment, the anhydride grafting moiety comprises maleic anhydride.

[0150] In a further embodiment, the maleic anhydride grafted ethylene / alpha-olefin interpolymer has a density of less than 0.940 grams per cubic centimeter (g / cm 3 ) as measured according to ASTM method D792-91, or from 0.855 g / cm 3 to 0.940 g / cm 3 . Another density range is from 0.855 g / cm 3 to 0.900 g / cm 3 , from 0.855 g / cm 3 to 0.880 g / cm 3 , from 0.855 g / cm 3 to 0.860 g / cm 3 , from 0.860 g / cm 3 to 0.940 g / cm 3 , from 0.860 g / cm 3 to 0.910 g / cm 3 , from 0.860 g / cm 3 to 0.880 g / cm 3 , from 0.880 g / cm 3 to 0.910 g / cm 3, or 0.880 g / cm 3 ~0.900 g / cm 3 may be present.

[0151] In one or more embodiments, the anhydride-grafted ethylene / alpha-olefin interpolymer may have a melt index (I2) of 300 grams per 10 minutes (g / 10 min) to 1500 g / 10 min, or 300 g / 10 min to 1000 g / 10 min, 500 g / 10 min to 800 g / 10 min, 500 g / 10 min to 600 g / 10 min, 600 g / 10 min to 1000 g / 10 min, 600 g / 10 min to 800 g / 10 min, or 800 g / 10 min to 1000 g / 10 min as determined according to ASTM method D1238 at 190° C. and 2.16 kg.

[0152] In one or more embodiments, the anhydride-grafted ethylene / alpha-olefin interpolymer may have a melt viscosity of less than 200,000 cP when measured at 177° C. according to the test methods described hereinafter in the present disclosure. In embodiments, the anhydride-grafted ethylene / alpha-olefin interpolymer may have a melt viscosity of 2,000 cP to 200,000 cP, 2,000 cP to 100,000 cP, 2,000 cP to 50,000 cP, 2,000 cP to 10,000 cP, 10,000 cP to 200,000 cP, 10,000 cP to 100,000 cP, 10,000 cP to 50,000 cP, 50,000 cP to 200,000 cP, 50,000 cP to 100,000 cP, or 100,000 cP to 200,000 cP when measured at 177° C. according to the test methods described hereinafter in the present disclosure.

[0153] Various commercial embodiments are considered to be suitable. For example, a suitable anhydride-grafted ethylene / alpha-olefin interpolymer may be commercially available from The Dow Chemical Company under the trademark BYNEL® 41E710.

[0154] Varying amounts of ethylene and acid copolymers or anhydride grafted ethylene / alpha-olefin interpolymers are considered suitable within the tie layers of the multilayer films described herein. In some embodiments, the tie layer may comprise 20 wt% or less of ethylene and acid copolymer or anhydride grafted ethylene / alpha-olefin interpolymer, based on the total weight of the tie layer. In embodiments, the tie layer may comprise 5 wt% to 15 wt%, or 10 wt% to 15 wt% of ethylene and acid copolymer or anhydride grafted ethylene / alpha-olefin interpolymer, based on the total weight of the tie layer. The remaining portion of the tie layer may be polyethylene such as LDPE, HDPE, MDPE, or the multimodal polyethylene compositions described herein.

[0155] Without being bound by theory, it is believed that an anhydride grafted ethylene / alpha-olefin interpolymer can be disposed adjacent to a layer containing a polar material to bond the layer containing the polar material to a nonpolar layer. In embodiments, the tie layer may be disposed in direct contact with the layer containing the polar material. In embodiments, the tie layer may be disposed between and in direct contact with the layer containing the polar material and the layer containing the multimodal polyethylene composition described herein.

[0156] In embodiments, each tie layer of the multilayer films of the present disclosure may have varying thicknesses. The thickness of each tie layer may depend on many factors including, for example, the adhesion properties of the tie layer. In embodiments, each tie layer may have a thickness of 0.1 μm to 20 μm. In embodiments, each tie layer may have a thickness of 0.1 μm to 15 μm, 0.1 μm to 10 μm, 0.1 μm to 5 μm, 0.1 μm to 1 μm, 0.1 μm to 0.5 μm, 0.5 μm to 20 μm, 0.5 μm to 15 μm, 0.5 μm to 10 μm, 0.5 μm to 5 μm, 0.5 μm to 1 μm, 1 μm to 20 μm, 1 μm to 15 μm, 1 μm to 10 μm, 1 μm to 5 μm, 5 μm to 20 μm, 5 μm to 15 μm, 5 μm to 10 μm, 10 μm to 20 μm, 10 μm to 15 μm, or 15 μm to 20 μm.

[0157] The thickness of each bonding layer of the multilayer film disclosed in this specification may constitute 1% - 10%, 1% - 8%, 1% - 6%, 1% - 4%, 1% - 2%, 2% - 10%, 2% - 8%, 2% - 6%, 2% - 4%, 4% - 10%, 4% - 8%, 4% - 6%, 6% - 10%, 6% - 8%, or 8% - 10% of the total thickness of the multilayer film.

[0158] The method for producing the film described in this specification Regarding the production of the multilayer film, various methodologies are contemplated. In one or more embodiments, the process for producing the multilayer film may include the extrusion of a cast film or the extrusion of an inflation film.

[0159] In some embodiments, the process for producing the multilayer film may include forming an inflation film bubble. In some embodiments, the inflation film bubble may be a multilayer inflation film bubble. According to this embodiment, further, the multilayer inflation film bubble may include at least two, three, five, seven, nine, or more layers. Also, these layers may be adhered to each other.

[0160] In an embodiment of the inflation film process, an extruded film from an extrusion die can be formed (inflated) and pulled upward to a nip over a tower. Next, the film can be wound around a core. Before winding the film around the core, a folding device can be used to cut and fold the end of the film. Thereby, it becomes difficult to separate the layers of the film, which may be important for general transportation applications or for use in durable transport sacks.

[0161] In a further embodiment, the inflation film bubble can be formed via an inflation film extrusion line having a length-to-diameter (“L / D”) ratio of 30:1 or greater. In some embodiments, the extrusion line can have a blow-up ratio of 1-5, 1-3, 2-5, or 2-3. In some embodiments, the extrusion line can utilize a die having internal bubble cooling. In some embodiments, the die gap can be 1 millimeter (mm) to 5 mm, 1 mm to 3 mm, 2 mm to 5 mm, or 2 mm to 3 mm.

[0162] In some embodiments, the extrusion line can utilize a film thickness gauge scanner. In some embodiments, during the extrusion process, the multilayer film thickness can be maintained at 15 μm to 115 μm. In embodiments, the multilayer film thickness can be maintained at 15 μm to 100 μm, 15 μm to 75 μm, 15 μm to 50 μm, 15 μm to 25 μm, 25 μm to 115 μm, 25 μm to 100 μm, 25 μm to 75 μm, 25 μm to 50 μm, 50 μm to 115 μm, 50 μm to 100 μm, 50 μm to 75 μm, 75 μm to 115 μm, 75 μm to 100 μm, or 100 μm to 115 μm.

[0163] In some embodiments, the multilayer inflation film bubble forming step can be performed at a temperature of 350 - 500°F, or 375 - 475°F. The output rate can be 5 lb / hr / in to 25 lb / hr / in, 5 lb / hr / in to 20 lb / hr / in, 5 lb / hr / in to 15 lb / hr / in, 5 lb / hr / in to 10 lb / hr / in, 10 lb / hr / in to 25 lb / hr / in, 10 lb / hr / in to 20 lb / hr / in, 10 lb / hr / in to 15 lb / hr / in, 15 lb / hr / in to 25 lb / hr / in, 15 lb / hr / in to 20 lb / hr / in, or 20 lb / hr / in to 25 lb / hr / in.

[0164] Article Embodiments of the present disclosure also relate to articles such as packages formed from the multilayer films of the present disclosure. Such packages can be formed from any of the multilayer films of the present disclosure described herein. The multilayer films of the present disclosure are particularly useful in articles where good puncture properties are desired.

[0165] Examples of such articles can include flexible packaging materials, pouches, stand-up pouches, and pre-made packaging materials or pre-made pouches.

[0166] Various methods for manufacturing article embodiments from the multilayer films disclosed herein will be well known to those skilled in the art.

[0167] Test Methods The test methods include the following.

[0168] Melt Index The melt indices I2 (or I2) and I 10 (or I10) of the polymer sample were measured according to ASTM D-1238 (Method B) at 190 °C and loads of 2.16 kg and 10 kg, respectively. Those values are reported with the unit of g / 10 min. The fraction of the polymer sample was measured by collecting the product polymer from the reactor that produces that particular fraction or portion of the polymer composition. For example, the first polyethylene fraction can be collected from the reactor that produces the lower density and higher molecular weight components of the polymer composition. Before the melt index measurement, the polymer solution is dried under vacuum.

[0169] Density Samples for density measurement were prepared according to ASTM D4703. The measurement was carried out according to ASTM D792, Method B within 1 hour of sample pressurization.

[0170] Dart Drop of ASTM D1709 The film dirt drop test determines the energy required to break a plastic film under specified conditions of impact by free-falling dirt. The test results are expressed as the energy in terms of the weight of the striking body falling from a specified height that will cause 50% breakage of the test specimens being tested.

[0171] After the film is produced, it is conditioned for at least 40 hours at 23°C (±2°C) and 50% (±5) relative humidity in accordance with ASTM standards. The standard test conditions are 23°C (±2°C) and 50% relative humidity (±5) in accordance with ASTM standards.

[0172] The test results are reported by Method B using a 2-inch diameter dirt head and a 60-inch drop height. The thickness of the sample is measured at the center of the sample, and then the sample is secured in an annular specimen holder with a 5-inch inner diameter. The dirt is loaded above the center of the sample and released by either a pneumatic or electromagnetic mechanism.

[0173] The test is conducted according to the "staircase" method. If the sample breaks, a new sample is tested with the weight of the dirt reduced by a known fixed amount. If the sample does not break, a new sample is tested with the weight of the dirt increased by a known amount. After 20 specimens have been tested, the number of broken specimens is determined. If this number is 10, the test is completed. If this number is less than 10, the test is continued until 10 breaks are recorded. If the number is greater than 10, the test is continued until the total number of specimens that did not break is 10. The dirt drop strength is determined from these data in accordance with ASTM D1709 and expressed in grams as Type B dirt drop impact resistance.

[0174] Instrumented Dirt Impact The Instrumented Dart Impact Method is measured on plastic film specimens in accordance with ASTM D7192 using a CEAST 9350 impact tester manufactured by Instron. The test is performed using a 12.7 mm diameter tap with a hemispherical head and a 75 mm diameter clamp assembly with a rubber-faced grip. The instrument is equipped with an environmental chamber for testing at low or high temperatures. The typical specimen size is 125 mm × 125 mm. The standard test speed is 200 m / min. The film thickness is 2 mils.

[0175] Creep Zero Shear Viscosity Measurement Method The zero shear viscosity is obtained via a creep test performed on an AR-G2 stress-controlled rheometer (TA Instruments, New Castle, Delaware) using a 25 mm diameter parallel plate at 190 °C. Before zeroing the mounting fixture, the rheometer oven is set to the test temperature for at least 30 minutes. At that test temperature, a compression-molded sample disk is inserted between the plates and allowed to equilibrate for 5 minutes. The upper plate is then lowered 50 μm above the desired test gap (1.5 mm). Any excess material is trimmed away 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 initial creep time is set to 2 hours.

[0176] To ensure that the steady-state shear rate is low enough in the Newtonian region, a constant low shear stress of 20 Pa is applied to all of the samples. The resulting steady-state shear rate is, for the samples in this investigation, 10 -3 ~10 -4within the range of / second. The steady state is determined by taking a linear regression for all the 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, it is considered that the steady state has been reached, and then the creep test is stopped. In this investigation, in all cases, the slope meets the criterion within 2 hours. The steady state shear rate is determined from the slope of the linear regression of all the data points within the last 10% time window of the ε vs. t (where ε is the strain) plot. The zero shear viscosity is determined from the ratio of the steady state shear rate of the applied stress.

[0177] To determine whether the sample has deteriorated during the creep test, a small amplitude oscillatory shear test is performed on the same specimen before and after the creep test at 0.1 - 100 rad / second. The complex viscosity values of the two tests are compared. If the difference in the viscosity values at 0.1 rad / second is greater than 5%, it is considered that the sample has deteriorated during the creep test, and the results are discarded.

[0178] Gel Permeation Chromatography (GPC) The chromatography system consists of a PolymerChar (Valencia, Spain) GPC-IR high temperature GPC chromatograph equipped with an internal IR5 infrared detector (IR5). The autosampler oven compartment was set to 160 °C and the column compartment was set to 150 °C. Four Agilent "Mixed A" 30 cm 20 micron linear mixed bed columns and a 20 μm pre-column were used for the columns. The chromatography solvent used was 1,2,4-trichlorobenzene, which contained 200 ppm of butylated hydroxytoluene (BHT). The solvent source was nitrogen sparged. The injection volume used was 200 μL and the flow rate was 1.0 mL / min.

[0179] The calibration of the GPC column set was performed using 21 narrow molecular weight distribution polystyrene standards having molecular weights in the range of 580 to 8,400,000 and placed in six “cocktail” mixtures having at least a 10-fold interval between individual molecular weights. The standards were purchased from Agilent Technologies. For molecular weights above 1,000,000, the polystyrene standards were prepared at 0.025 g in 50 mL of solvent, and for molecular weights below 1,000,000, at 0.05 g in 50 mL of solvent. The polystyrene standards were dissolved at 80 degrees Celsius for 30 minutes with gentle stirring. The peak molecular weight of the polystyrene standards was converted to polyethylene molecular weight using Equation 1 (as described in Williams and Ward, J. Polym. Sci., Polym. Let., 6, 621 (1968)).

[0180]

Number

[0181] A fifth-degree polynomial was used and applied to each polyethylene equivalent calibration point. A slight adjustment (about 0.375 - 0.445) was made to A to correct for column resolution and band broadening effects such that a linear homopolymer polyethylene standard gave 120,000 Mw.

[0182] The total plate count of the GPC column set was performed using decane (prepared at 0.04 g in 50 mL of TCB and dissolved for 20 minutes with gentle stirring). The plate count (Equation 2) and symmetry (Equation 3) were measured for a 200 μL injection according to the following equations.

[0183]

Number

[0184]

Number

[0185] The sample was prepared in a semi-automatic mode using the "Instrument Control" software manufactured by PolymerChar, with 2 mg / mL as the target weight of the sample. Through a high-temperature autosampler manufactured by PolymerChar, a solvent (containing 200 ppm of BHT) was added to a vial with a septum cap that had been previously nitrogen-sparged. The sample was dissolved at 160 degrees Celsius for 2 hours under "low-speed" shaking.

[0186] Mn (GPC) 、Mw (GPC) 、and Mz (GPC) The calculations of, were based on the GPC results using the GPCOne (trademark) software manufactured by PolymerChar, the IR chromatogram with the baseline subtracted at each equally spaced data collection point (i), and the polyethylene equivalent molecular weight obtained from the narrow standard calibration curve at point (i) of Equation 1, and using the internal IR5 detector (measurement channel) of the GPC-IR chromatograph manufactured by PolymerChar in accordance with Equations 4 to 6.

[0187]

Number

[0188] To monitor the deviation over time, a flow rate marker (decane) was introduced into each sample via a micropump controlled by a PolymerChar GPC-IR system. Using this flow rate marker (FM), the pump flow rate (apparent flow rate) of each sample was linearly corrected by RV-aligning each decane peak in the sample (RV(FM sample)) with that of the decane peak within the narrow standard calibration (RV(FM calibrated)). Then, any change in the time of the decane marker peak is presumed to be related to a linear shift in the flow rate (effective flow rate) over the course of the run. To facilitate the highest accuracy in RV measurement of the flow rate marker peak, a least-squares fitting routine that fits the peak of the flow rate marker concentration chromatogram to a quadratic equation is used. The first derivative of the quadratic equation is then used to solve for the true peak position. After calibrating the system based on the flow rate marker peak, the effective flow rate (relative to the narrow standard calibration) is calculated as Equation 7. The processing of the flow rate marker peak was performed via PolymerChar GPCOne (trademark) software. The acceptable flow rate correction is such that the effective flow rate must be within ±0.5% of the nominal flow rate.

[0189]

Number

[0190] Improved method (iCCD) for comonomer content 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 carried out using a crystallization elution fractionation (CEF) instrument (manufactured by PolymerChar, Spain) equipped with an IR-5 detector (PolymerChar, Spain) and a dual-angle light scattering detector model 2040 (manufactured by Precision Detectors, now Agilent Technologies). Immediately before the IR-5 detector in the detector oven, a guard column filled with 20 - 27 micron glass (MoSCi Corporation, USA) in 5 cm or 10 cm (length) × 1 / 4 inch (ID) stainless steel was installed. Ortho-dichlorobenzene (ODCB, 99% anhydrous grade or technical grade) was used. Silica gel 40 (particle size 0.2 - 0.5 mm, catalog number 10181-3) was obtained from EMD Chemicals (which can be used to dry the ODCB solvent first). The CEF instrument was equipped with an autosampler with N2 purge capability. Before use, ODCB was sparged with dry nitrogen (N2) for 1 hour. Sample preparation was carried out using the autosampler at 4 mg / mL while shaking at 160 °C for 1 hour (unless otherwise specified). The injection volume was 300 μL. The temperature profile of iCCD 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.

[0191] The iCCD column was filled with nickel particles (Bright 7GNM8-NiS (manufactured by Nippon Chemical Industrial Co.)) coated with gold in a 15 cm (length) × 1 / 4 inch (ID) stainless steel tube. Column filling and conditioning were performed by the slurry method according to the reference (Cong, R.; Parrott, A.; Hollis, C.; Cheatham, M. International Publication No. 2017040127 (A1)). The final pressure using TCB slurry filling was 150 bar.

[0192] Column temperature calibration was performed using a mixture of a linear homopolymer polyethylene (comonomer content zero, melt index (I2) 1.0, polydispersity M w / M n of about 2.6, 1.0 mg / mL) of a reference substance in ODCB and eicosane (2 mg / mL). The iCCD temperature calibration consisted of the following four steps: (1) calculating the delay volume defined as 30.00 °C subtracted from the temperature offset between the measured peak elution temperatures of eicosane; (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, elution flow rate, etc.); (3) creating a linear calibration line that converts the elution temperature over the range of 30.00 °C to 140.00 °C such that the linear homopolymer polyethylene reference substance 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 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).

[0193] The elution temperature of iCCD versus comonomer content was constructed by using 12 reference materials (ethylene homopolymers and ethylene-octene random copolymers made with single-site metallocene catalysts, having ethylene equivalent weight average molecular weights in the range of 35,000 to 128,000). All of these reference materials were analyzed in the same manner as previously specified at 4 mg / mL. The reported elution peak temperatures were fitted to the linear equation y = -6.3515x + 101.00, where y represents the elution temperature of iCCD, x represents the mole % of octene, and R 2 was 0.978.

[0194] The molecular weight of the polymer and the molecular weights of the polymer fractions were determined directly from the LS detector (at 90 degrees angle) and the concentration detector (IR-5) according to the Rayleigh-Gans-Debye approximation (Striegel and Yau, "Modern Size Exclusion Liquid Chromatogram", pages 242 and 263), assuming a form factor of 1 and all virial coefficients to be zero. An integration window was set to integrate all chromatograms at elution temperatures in the range of 23.0 to 120 °C (temperature calibration as specified above).

[0195] The calculation of the molecular weight (Mw) from iCCD involves the following four steps. (1) Steps to measure the detector offset. The offset is defined as the geometric volume offset between the LS detectors with respect to the concentration detector. This is calculated as the difference in the elution volume (mL) of the polymer peak between the concentration detector and the LS chromatogram. This is converted to a temperature offset by using the heat elution rate and the elution flow rate. Linear high-density polyethylene (comonomer content is zero, melt index (I2) is 1.0, polydispersity Mw / Mn is approximately 2.6 in conventional gel permeation chromatography) is used. The same experimental conditions as the above normal iCCD method are used, except for the following parameters: crystallization from 140 °C to 137 °C at 10 °C / min, 1 minute of thermal equilibrium as the soluble fraction elution time at 137 °C, 7 minutes of soluble fraction (SF) time, 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) Steps to shift each LS data point of the LS chromatogram to correct the detector offset before integration. (3) Steps where the LS and concentration chromatograms with the baseline subtracted are integrated over the entire elution temperature range of step (1). The MW detector constant is calculated using known MW HDPE samples in the range of 100,000 - 140,000 Mw and the area ratio of the LS and concentration integration signals. (4) Steps to calculate the Mw of the polymer using the ratio of the integrated light scattering detector (at a 90-degree angle) to the concentration detector and using the MW detector constant.

[0196] The calculation of the half-width is defined as the temperature difference between the forward temperature and the backward temperature at half of the maximum peak height. The forward temperature at half of the maximum peak is searched forward from 35.0 °C, and the backward temperature at half of the maximum peak is searched backward from 119.0 °C.

[0197] Zero-Shear Viscosity Ratio (ZSVR) ZSVR is defined as the ratio of the zero shear viscosity (ZSV) of a branched polyethylene material to the ZSV of a linear polyethylene material in terms of the equivalent weight average molecular weight (Mw-gpc) according to the following equations (EQ) 8 and 9.

[0198] [Number]

[0199] The ZSV values were obtained from a creep test at 190 °C by the method described above. The Mw-gpc values were determined by the conventional GPC method (Equation 5 in the description of the conventional GPC method). The correlation between the ZSV and its Mw-gpc of linear polyethylene was established based on a series of linear polyethylene reference materials. An explanation of the ZSV-Mw relationship can be found in ANTEC Abstract: Karjala, Teresa P., Sammler, Robert L., Mangnus, Marc A., Hazlitt, Lonnie G., Johnson, Mark S., Hagen, Charles M. Jr., Huang, Joe W.L., Reichek, Kenneth N., "Detection of low levels of long-chain branching in polyolefins", Annual Technical Conference - Society of Plastics Engineers (2008), 66th 887 - 891.

[0200] MD Tear MD Tear was measured according to ASTM D - 1922. The force (grams) required to propagate a tear across a film specimen is measured using an Elmendorf Tear tester. Actuated by gravity, the pendulum swings in an arc and tears the specimen from a pre-cut slit. The tear propagates in the transverse direction. The sample is conditioned at the pre-test temperature for a minimum of 40 hours.

[0201] Dynamic Rheological Analysis To characterize the rheological behavior of substantially linear ethylene polymers, S Lai and G.W. Knight introduced the Dow Rheology Index (DRI), a new rheological measurement that represents the "normalized relaxation time as a result of long chain branching" of the polymer (ANTEC’93 Proceedings, Insite(TM) Technology Polyolefins(ITP)-New Rules in the Structure / Rheology Relationship of Ethylene &-01efin Copolymers, New Orleans, La., May 1993). S. Lai et al; (ANTEC’94, Dow Rheology Index (DRI) for Insite(TM) Technology Polyolefins(ITP): Unique structure-Processing Relationships, pp.1814-1815) defined the DRI as the extent to which the rheology of ethylene-octene copolymers known as ITP (Dow’s Insite Technology Polyolefins) that incorporate long chain branches into the polymer backbone deviates from the rheology of conventional linear homogeneous polyolefins that are reported to have no long chain branches (LCB) by the following normalized equation:

[0202] [Number] where τ0 is the characteristic relaxation time of the material and is the zero shear rate complex viscosity of the material. The DRI was calculated by the least squares fitting of the rheological curve (dynamic complex viscosity η * (ω) versus the applied frequency (ω), e.g., 0.01 - 100 rad / sec) using the following generalized Cross equation as described in U.S. Patent No. 6,114,486, i.e.,

[0203] [Number] where n is the power law index of the material, η *(ω) and ω are the measured complex viscosity and applied frequency data, respectively.

[0204] Dynamic rheological measurements are performed in an inert atmosphere using a dynamic rheometer equipped with 25 mm diameter parallel plates in dynamic mode (e.g., ARES rheometer from TA Instruments) according to ASTM D4440. For all experiments, the rheometer is thermally stabilized at 190 °C for at least 30 minutes before inserting the compression molded sample (using antioxidant additives) onto the parallel plates. The plates are then closed with a positive normal force registered by the meter to ensure good contact. After about 5 minutes at 190 °C, the plates are lightly compressed to trim excess polymer around the plates. It takes an additional 10 minutes until the thermal stability and normal force return to zero. That is, all measurements are performed after the sample has been equilibrated at 190 °C for about 15 minutes and are performed under a complete nitrogen blanket.

[0205] Two strain sweep (SS) experiments are first performed at 190 °C to determine the linear viscoelastic strain that produces a torque signal greater than 10% of the lower scale of the transducer over the entire frequency range (e.g., 0.01 - 100 rad / s). The first SS experiment is performed at a low applied frequency of 0.1 rad / s. This test is used to determine the sensitivity of the torque at low frequencies. The second SS experiment is performed at a high applied frequency of 100 rad / s. This is to ensure that the selected applied strain fits well within the linear viscoelastic region of the polymer so that the oscillatory rheological measurement does not induce a structural change in the polymer during the test. In addition, a time sweep (TS) experiment is performed at a low applied frequency of 0.1 rad / s at the selected strain (as determined by the SS experiment) to check the stability of the sample during the test.

[0206] Storage modulus (or modulus of elasticity), loss modulus (or viscosity) (G”), complex modulus (G * )), complex viscosity (η *) and tanδ (the ratio of the loss modulus to the storage modulus, G’ / G’) were obtained as a function of frequency (ω) at a given temperature (e.g., 190 °C).

[0207] ASTM D1922 MD (Machine Direction) and CD (Cross Direction) Elmendorf Tear Type B The Elmendorf tear test uses an Elmendorf type tear tester to determine the average force to propagate a tear through a specified length of plastic film or non-rigid sheet after the tear has been initiated.

[0208] After manufacturing the film from the sample to be tested, the film was conditioned at 23 °C (±2 °C) and 50% relative humidity (±5) for at least 40 hours according to ASTM standards. The standard test conditions were 23 °C (±2 °C) and 50% (±5) relative humidity according to ASTM standards.

[0209] The force in grams required to propagate a tear in the film or sheet specimen was measured using a precisely calibrated pendulum device. In the test, the pendulum acts under gravity and swings in an arc, tearing the specimen from a pre-cut slit. The specimen is held on one side by the pendulum and on the opposite side by a fixed member. The energy loss by the pendulum is indicated by a pointer or an electronic scale. The scale reading is a function of the force required to tear the specimen.

[0210] The shape of the sample specimen used in the Elmendorf tear test was a "constant radius shape" as defined in ASTM D1922. The test was typically performed on specimens cut from both the MD and CD directions of the film. Prior to the test, the thickness of the film specimen was measured at the center of the sample. A total of 15 specimens were tested for each film direction, and the average tear strength and average thickness were reported. The average tear strength was normalized with respect to the average thickness.

[0211] MD and CD 1% and 2% Secant Moduli according to ASTM D882 The MD (machine direction) and CD (cross direction) secant modulus of the film were determined in accordance with ASTM D882. The reported secant modulus values were the average of five measurements.

[0212] Puncture strength The puncture test determines the film's resistance to probe penetration at standard low speed and a single test speed. The puncture test method is based on ASTM D5748. After film production, the film was conditioned at 23 °C (±2 °C) and 50% relative humidity (±5) for at least 40 hours in accordance with ASTM standards. The standard test conditions are 23 °C (±2 °C) and 50% (±5) relative humidity in accordance with ASTM standards. Puncture was measured on a tensile testing machine. Square specimens were cut from the sheet to a size of 6 inches × 6 inches. The specimens were clamped in a circular specimen holder with a diameter of 4 inches, and the puncture probe was pushed into the center of the clamped film at a crosshead speed of 10 inches / min. The internal test method conforms to ASTM D5748 with one modification. This method differed from the method of ASTM D5748 in that the probe used was a ground steel ball with a diameter of "0.5 inches" on a "0.25 inches" support (instead of the pear-shaped probe with a diameter of 0.75 inches specified in D5748).

[0213] To prevent damage to the test fixture, a maximum travel length of "7.7 inches" was provided. There was no gauge length, and before the test, the probe was positioned as close as possible to the specimen without touching it. A single thickness measurement was taken at the center of the specimen. For each specimen, the maximum force, force at break, penetration distance, and energy to break were determined. A total of five specimens were tested to determine the average puncture value. The puncture probe was cleaned with "Kimwipe" after use on each specimen.

Examples

[0214] The following examples illustrate the features of the present disclosure and are not intended to limit the scope of the present disclosure. In the following experiments, the performance of embodiments of the multimodal polyethylene composition described herein was analyzed.

[0215] Example 1: Preparation of Multimodal Polyethylene Composition 1 Multimodal polyethylene composition 1, described according to one or more embodiments of the detailed description, was prepared by a method using the catalysts and reactors described below.

[0216] An ethylene-1-octene bimodal copolymer sample was produced using a liquid full-solution polymerization process in a series double-reactor configuration such as that shown in Figure 2. For the production of this sample, the first reactor was a continuous stirred tank reactor (CSTR) and the second reactor was a loop reactor (LR). Each reactor feed contained a recycle solvent (consisting of Isopar E, ethylene, 1-octene, and hydrogen), as well as fresh ethylene, 1-octene, and hydrogen. The recycle solvent, ethylene, and 1-octene were measured using industry-standard Coriolis flowmeter technology, and the hydrogen flow rate was measured using an industry-standard thermal mass flowmeter. An industry-standard rising-stem plug valve was used to control the flow of each reactor feed component. A unique digital control system (DCS) automatically manipulated the position of each rising-stem plug valve to control the mass flow rate of each reactant to its target value.

[0217] A single industry-standard positive displacement pump technology was used to deliver the recycle solvent pressure to each reactor. The recycle solvent flow to each reactor was metered to maintain the Isopar E to polymer production ratio described in the following table. The ethylene pressure was supplied using industry-standard gas compressor technology. A single compressor was used to supply the ethylene feed to both reactors. The ethylene to each reactor was metered to maintain the Isopar E to ethylene ratio described in the following table. Ethylene was combined with the recycle solvent downstream of both the recycle solvent flow meter and the 1-octene feed injection location. The 1-octene pressure was delivered using industry-standard positive displacement pump technology. The 1-octene flow to the reactor system was metered to maintain the 1-octene to ethylene ratio shown in Table 1 below. The entire 1-octene reactor system feed was injected into the first reactor feed downstream of the recycle solvent metering system. No fresh 1-octene was injected with the second reactor feed. The hydrogen supply pressure was delivered from a gas cylinder at 1,500 psig. The hydrogen to production ratio target for each reactor was automatically manipulated by the DCS to maintain the respective reactor solution viscosity at target. The hydrogen to production ratio target was converted to a hydrogen flow rate, and the DCS manipulated the position of a pneumatic stem plug valve to control the flow rate to the target value. The hydrogen to production ratio and solution viscosity targets for each reactor are shown in the following table. Hydrogen was mixed with the ethylene gas downstream of the ethylene flow controller. For the first reactor, the combined gas flow was mixed with the combined liquid flow downstream of the 1-octene injection point into the recycle solvent, and for the second reactor, the combined gas flow was combined with the liquid flow downstream of the recycle solvent flow control device.

[0218] The combined feed streams to each reactor were passed through separate heat exchanger systems and cooled to the target feed temperature shown in the following table. From the heat exchanger systems, the flows were directed to each reactor where they were injected into the polymerization liquid. The feed pressure was not directly controlled. The control point was the reactor pressure. Thus, the measured feed pressure was a result of the pressure drop within the feed system for a given total flow rate.

[0219] The pressure required to inject each catalyst component into each reactor was delivered using industry-standard positive displacement pump technology. The flow rate was measured using a Coriolis flow meter. Each component was pumped and metered separately. The catalyst complex was injected into the reactor separately from the cocatalyst. Cocatalyst 2 (MMAO) was combined with cocatalyst 1 downstream of the flow meter for cocatalyst 1, and the combined stream was injected into the reactor through a second injector. As a result of this configuration, the catalyst complex in each reactor was activated in the polymerization solution.

[0220] The flow of the catalyst complex to each reactor was manipulated by the DCS to control the ethylene conversion to the values shown in Table 1 below. The flows of cocatalyst 1 and cocatalyst 2 were manipulated to maintain a constant molar ratio of each component to the catalyst, and those values are also listed in the table. As a result, by controlling the target cocatalyst-to-catalyst ratio, automatic adjustment of each component flow for each adjustment of the catalyst complex flow was effected. The 1-octene conversion was not directly controlled. Instead, the 1-octene conversion resulted from the selected catalyst complex and its relative reactivity of ethylene to 1-octene corresponding to the ethylene conversion set point and the selected reactor temperature as described in the table. In addition to the recycled and fresh feeds injected into the second reactor, unreacted ethylene, 1-octene, and hydrogen were present in the first reactor effluent injected into the second reactor.

[0221] The solution viscosity was not directly measured. Instead, the frictional pressure loss was measured and the viscosity of the polymer solution was calculated using the Fanning equation. To calculate the viscosity, the pipe dimensions, total mass flow rate, density, and pressure drop across a pipe of known dimensions (inner diameter, surface roughness, and length) must be known. An industry-standard Coriolis flow meter was used to measure both the mass flow rate and density of the reactor effluent. An industry-standard diaphragm-type differential pressure transmitter was used to measure the pressure drop across a pipe of known dimensions. The viscosity was then calculated by inserting the above measurements into the rearranged Fanning equation, which is solved to obtain the viscosity, according to the following equation.

[0222]

Equation

[0223] For each reactor, the DCS manipulated the hydrogen-to-production ratio, converted this to a hydrogen flow rate target, and controlled the solution viscosity to the target shown in Table 1.

[0224] The multimodal polyethylene composition 1 was prepared using a bis-biphenylphenoxy catalyst as described above. A bis-biphenylphenoxy catalyst complex having the structure described and shown above can be activated by combination with one or more cocatalysts, such as a cation-forming cocatalyst, a strong Lewis acid, or a combination. Suitable activating cocatalysts include polymeric or oligomeric aluminoxanes, particularly methylaluminoxane, and inert, compatible noncoordinating ion-forming compounds. Exemplary suitable cocatalysts include modified methyl aluminoxane (MMAO), bis(hydrogenated tallow alkyl)methyltetrakis(pentafluorophenyl)borate(1<->)amine (i.e., [HNMe(C 18 H 37 )2][B(C6F5)4] and combinations thereof, but are not limited thereto.

[0225] The multimodal polyethylene composition 1 was produced using two different catalyst complexes from the bis-biphenylphenoxy family. A first reactor fraction was produced using catalyst A and a second reactor fraction was produced using catalyst B. Both catalysts contain a hafnium metal center (M) and the structures are shown as follows.

[0226]

Chemical formula

[0227] The catalyst is activated by contacting a metal ligand complex with bis(hydrogenated tallow alkyl)methyltetrakis(pentafluorophenyl)borate(1-) amine (cocatalyst 1) and MMAO (cocatalyst 2) activation cocatalysts, and their structures are shown as follows.

[0228]

Chemical formula

[0229] For the first reactor, the heat of polymerization was removed by the adiabatic temperature rise of the solvent and reactants from the feed to the reactor temperature. For the second reactor, part of the heat was also removed by the adiabatic temperature rise of the reactants and solvent from the feed to the reactor temperature. The remaining heat of polymerization was removed non-adiabatically from the second reactor using a heat exchanger in the loop reactor. The target temperatures of each reactor are shown in the following table.

[0230] Polymer split is defined as the weight % of the polymer produced in each reactor. During the production of the multimodal polyethylene composition 1, the polymer split was not directly controlled. Instead, the target polymer split was achieved by controlling the feed rate of the reactants and the ethylene conversion rate in each reactor to the targets shown in Table 1. Together with the selected catalyst complex and its reactivity ratio of ethylene to 1-octene, the above determine the amount of polymer produced and the density of its fractions.

[0231] To ensure that the overall polymer density reaches the target described in the following table, fine adjustments were made to the 1-octene to ethylene ratio. To decrease the polymer density, the 1-octene to ethylene ratio was increased to increase the 1-octene flow rate to the reactor. To increase the polymer density, the ratio of 1-octene to ethylene was decreased, resulting in a smaller 1-octene flow rate to the reactor.

[0232] As described above, the polymer viscosity was controlled by manipulating the hydrogen-to-polymer production ratio. To decrease the polymer viscosity, the hydrogen-to-polymer ratio was increased to increase the hydrogen flow rate into the reactor. To increase the polymer viscosity, the hydrogen-to-polymer ratio was decreased to decrease the hydrogen flow rate into the reactor.

[0233] Water was injected into the reactor effluent to stop the polymerization reaction. The stoichiometric amount of water relative to the total of the three catalyst components was sufficient to neutralize the catalyst and stop its activity, but a 20% molar excess was used to ensure complete hydrolysis and deactivation of the catalyst.

[0234] An antioxidant was injected into the reactor effluent to protect the polymer from oxidation in the devolatilization section of the plant, as well as during storage and subsequent processing in the converter equipment. The antioxidant package for each experiment was mixed with a solvent in a mechanically stirred container. An industry-standard positive displacement pump was used to provide the supply pressure for injecting the slurry package into the reactor effluent. The flow rate was metered using Coriolis technology at a rate to produce the antioxidant concentration in the polymer as shown in the following table.

[0235] After stopping the reaction and adding the protective antioxidant package, steam was passed through the heat exchanger to raise the stream temperature in preparation for polymer separation. A rising-stem plug valve located downstream of the heat exchanger was automatically operated (by the DCS) to control the liquid-full reactor system pressure to the values listed in the following table. After passing through the reactor pressure control valve, the solvent and unreacted ethylene, 1-octene, and hydrogen were separated from the polymer using standard solution polymerization devolatilization / separation techniques.

[0236] After separating the volatile components from the non-volatile ethylene-1-octene copolymer in the devolatilization system, the mass flow rate of the stream was measured using standard Coriolis flowmeter technology. The composition of the stream without the polymer was measured using conventional gas chromatography technology. Using this stream information together with the feed stream information, the conversion rates of ethylene and 1-octene were calculated as shown in the following equation:

[0237] [Number]

[0238] Polymer plaques for density analysis were prepared using ASTM D4703. The density of each polymer sample shown in the following table was measured using ASTM D792. The melt index and melt flow ratio (I 10 / I2) of the polymer were measured using ASTM D1238. The density and melt index values of the first reactor and the second reactor are model estimates. The overall density, melt index, and melt flow ratio are measurements of the bimodal polymer.

[0239] [Table 1]

[0240] The polyethylene composition 1 was analyzed by iCCD. The data obtained from the iCCD test of the polyethylene composition 1 are shown in Table 2. Table 2 shows the iCCD data including the regions 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).

[0241] [Table 2]

[0242] Example 2: Comparative polyethylene composition A The comparative polyethylene composition A was generally a bimodal polyethylene composition prepared using the catalyst system and process provided for preparing the first composition of the invention in International Publication No. WO 2015 / 200743.

[0243] Example 3: Analysis of polyethylene composition 1 and comparative composition A The polyethylene composition 1 of Example 1 and the comparative polyethylene composition A were analyzed by iCCD. The data generated from the iCCD tests of both samples (the polyethylene composition 1 of Example 1 and the comparative polyethylene composition A) are provided in Table 3. Table 3 provides additional data for each sample of the comparative polyethylene composition A and the polyethylene composition 1, including the bulk density, melt index, ZSVR, and the ratio of the molecular weight of the first fraction to the overall molecular weight. These properties were measured based on the test methods described herein.

[0244] [Table 3]

[0245] Example 4: Preparation of Comparative Films A - F and Film 1 Table 4 identifies the commercially available polyethylene compositions of the comparative polyethylene compositions B - E.

[0246] [Table 4]

[0247] In this example, one film containing the polyethylene composition 1 and six comparative films were prepared. The overall thickness of each was 70 μm. Layer A of each film was 20% of the overall film thickness, each layer B was 60% of the overall film thickness, and each layer C was 20% of the overall film thickness. Table 5 provides the materials for generating each of the film samples of Example 4, and Table 6 summarizes the extrusion conditions used to produce the comparative films A - F and Film 1.

[0248] [Table 5]

[0249] [Table 6]

[0250] Example 5: Analysis of Comparative Films A - F and Film 1. To compare the performance of Film 1 and Comparative Films A - F, puncture force, puncture resistance, puncture elongation, puncture energy, dirt - drop impact resistance, average Elmendorf CD tear strength, and average Elmendorf MD tear strength were measured according to the above - mentioned test methods. The results of the puncture characteristics and dirt - drop impact resistance of Film 1 and Comparative Films A - F are shown in Table 7.

[0251] [Table 7]

[0252] As shown in Table 7, Film 1 showed higher puncture characteristics (puncture force, puncture resistance, puncture elongation, and puncture energy) than all of the other Comparative Film samples A - F. For Films D and E, which utilized comparative polyethylene compositions having the closest density to the polyethylene composition of the present disclosure, Film 1 showed excellent puncture characteristics as well as dirt - drop impact resistance (Method B).

[0253] It will be apparent that modifications and changes can be made without departing from the scope of the disclosure as defined in the appended claims. More specifically, although some aspects of the disclosure are identified herein as preferred or particularly advantageous, it is contemplated that the disclosure is not necessarily limited to these aspects. The invention described in the original claims of the present application is appended below. [1] A polyethylene composition comprising: a first polyethylene fraction region within a temperature range of 45°C to 80°C of an elution profile by an improved comonomer composition distribution (iCCD) analysis method; and a second polyethylene fraction region within a temperature range of 80°C to 95°C of the elution profile by an ICCD analysis method, wherein the second polyethylene fraction region comprises at least 5% of the total area of the elution profile; and a third polyethylene fraction region within a temperature range of 95°C to 120°C of the elution profile by an ICCD analysis method, wherein the third polyethylene fraction region comprises at least 25% of the total area of the elution profile, wherein a ratio of the first polyethylene fraction region to the second polyethylene fraction region is 6 to 15; the polyethylene composition has a density of 0.910 g / cm 3 to 0.924 g / cm 3 and a melt index (I 2 ) of 0.1 g / 10 min to 0.5 g / 10 min. [2] The polyethylene composition according to [1], having a molecular weight distribution represented as a ratio (Mw / Mn) of the weight average molecular weight to the number average molecular weight within a range of 2.0 to 5.0. [3] The polyethylene composition according to [1] or [2], having a zero shear viscosity ratio of 3 to 6. [4] The polyethylene composition according to any one of [1] to [3], wherein a ratio of the molecular weight of the first polyethylene fraction to the molecular weight of the second polyethylene fraction is 0.75 to 1.50. [5] The polyethylene composition according to any one of [1] to [4], wherein the third polyethylene fraction comprises a peak, and a width of the peak at 50% peak height is 2°C to 10°C. [6] The polyethylene composition according to any one of [1] to [5], wherein the first polyethylene fraction region comprises 45% to 60% of the total area of the elution profile. [7] The polyethylene composition according to any one of [1] to [6], wherein the second polyethylene fraction region comprises 5% to 15% of the total area of the elution profile. [8] The third polyethylene fraction region contains 25% to 50% of the total area of the elution profile, and is the polyethylene composition according to any one of [1] to [7]. [9] The polyethylene composition has a tandelta ratio of 2.0 to 5.0 when measured using the DMS frequency sweep test method at 0.1 rad / sec per 500 rad / sec, and is the polyethylene composition according to any one of [1] to [8].

[10] The polyethylene composition has a tandelta of 1.0 to 6.0 when measured using the DMS frequency sweep test method at 0.1 rad / sec and 190 °C, and is the polyethylene composition according to any one of [1] to [9].

[11] A polyethylene composition, a first polyethylene fraction region within the temperature range of 45 °C to 80 °C of the elution profile by an improved comonomer composition distribution (iCCD) analysis method, and a second polyethylene fraction region within the temperature range of 80 °C to 95 °C of the elution profile by the ICCD analysis method, wherein the second polyethylene fraction region contains at least 5% of the total area of the elution profile, and is the second polyethylene fraction region, a third polyethylene fraction region within the temperature range of 95 °C to 120 °C of the elution profile by the ICCD analysis method, wherein the third polyethylene fraction region contains at least 25% of the total area of the elution profile, and is the third polyethylene fraction region, and includes the polyethylene composition has a density of 0.910 g / cm 3 ~0.924 g / cm 3 and a melt index (I 2 ) of 0.1 g / 10 min to 0.5 g / 10 min, and has a molecular weight distribution represented as the ratio (Mw / Mn) of the weight average molecular weight to the number average molecular weight within the range of 2.0 to 5.0, and is the polyethylene composition.

[12] A film containing the polyethylene composition according to any one of [1] to

[11] .

[13] The film is a single-layer film, and is the film according to

[12] .

[14] The film is a multilayer film, and is the film according to

[12] .

[15] One or more layers of the multilayer film contain the polyethylene composition, and is the film according to

[14] .

Claims

**Claim 1** A polyethylene composition comprising: a first polyethylene fraction region within a temperature range of 45°C to 80°C of an elution profile by an improved comonomer composition distribution (iCCD) analysis method, wherein the first polyethylene fraction region comprises 45% to 60% of the total area of the elution profile; a second polyethylene fraction region within a temperature range of 80°C to 95°C of the elution profile by the iCCD analysis method, wherein the second polyethylene fraction region comprises 5% to 15% of the total area of the elution profile; a third polyethylene fraction region within a temperature range of 95°C to 120°C of the elution profile by the iCCD analysis method, wherein the third polyethylene fraction region comprises 25% to 50% of the total area of the elution profile, and a ratio of the first polyethylene fraction region to the second polyethylene fraction region is 6 to 15; The polyethylene composition has a density of 0.910 g / cm ３ to 0.924 g / cm ３ , and a melt index (I ２ ) of 0.1 g / 10 min to 0.5 g / 10 min, and the polyethylene composition is bimodal having peaks in the first polyethylene fraction region and the third polyethylene fraction region; a polyethylene composition. **Claim 2** The polyethylene composition according to claim 1, having a molecular weight distribution represented as a ratio (Mw / Mn) of the weight average molecular weight to the number average molecular weight within a range of 2.0 to 5.

0. **Claim 3** The polyethylene composition according to claim 1 or 2, having a zero shear viscosity ratio of 3 to 6. **Claim 4** The polyethylene composition according to any one of claims 1 to 3, wherein a ratio of the molecular weight of the first polyethylene fraction to the molecular weight of the second polyethylene fraction is 0.75 to 1.

50. **Claim 5** The polyethylene composition according to any one of claims 1 to 4, wherein the third polyethylene fraction contains a peak, and a width of the peak at 50% peak height is 2°C to 10°C. **Claim 6** The polyethylene composition according to any one of claims 1 to 5, having a tandelta ratio of 2.0 to 5.0 when measured using a DMS frequency swap test method at 0.1 rad / sec with respect to 500 rad / sec. **Claim 7** The polyethylene composition according to any one of claims 1 to 6, having a tandelta of 1.0 to 6.0 when measured using the DMS frequency swap test method at 0.1 rad / sec and 190 °C.

8. A polyethylene composition, A first polyethylene fraction region within a temperature range of 45 °C to 80 °C of the elution profile by an improved comonomer composition distribution (iCCD) analysis method, wherein the first polyethylene fraction region comprises 45% to 60% of the total area of the elution profile, a first polyethylene fraction region, A second polyethylene fraction region within a temperature range of 80 °C to 95 °C of the elution profile by the iCCD analysis method, wherein the second polyethylene fraction region comprises 5% to 15% of the total area of the elution profile, a second polyethylene fraction region, A third polyethylene fraction region within a temperature range of 95 °C to 120 °C of the elution profile by the iCCD analysis method, wherein the third polyethylene fraction region comprises 25% to 50% of the total area of the elution profile, a third polyethylene fraction region, and The polyethylene composition has a density of 0.910 g / cm ３ to 0.924 g / cm ３ , a melt index (I ２ ) of 0.1 g / 10 min to 0.5 g / 10 min, and a molecular weight distribution represented as the ratio (Mw / Mn) of the weight average molecular weight to the number average molecular weight within the range of 2.0 to 5.0, The polyethylene composition is bimodal having peaks in the first polyethylene fraction region and the third polyethylene fraction region Polyethylene composition.

9. A film comprising the polyethylene composition according to any one of claims 1 to 8.

10. The film according to claim 9, wherein the film is a single-layer film.

11. The film according to claim 9, wherein the film is a multilayer film.

12. The film according to claim 11, wherein one or more layers of the multilayer film comprise the polyethylene composition.

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