Multilayer film and article comprising the same

Abstract

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

Description

TECHNICAL FIELD

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

[0002] Flexible packaging film structures are often formed from a variety of types of polymeric materials including, for example, polyethylene, polypropylene, ethylene vinyl alcohol, polyethylene terephthalate, polyamide, and the like. These materials are often combined together to achieve a balance of properties that exceeds the range achieved by a single material type. However, due to the different of these materials, the final package is often not easily recyclable. Thus, there is also a move toward mono-component structures (e.g., all-polyethylene structures) to improve the recyclability profile. For example, in the case of all-polyethylene structures, certain performance metrics (e.g., mechanical properties) would need to be enhanced to maintain the expected performance level of these structures when formed from different polymeric materials, while improving recyclability.

[0003] Generally, in designing films for packaging and other applications, an improvement in one property of the film can result in a decrease in another property of the film. For example, the use of polyethylene having a lower density can improve some mechanical properties (e.g., dart drop impact), but decrease other properties, such as secant modulus and / or barrier properties.

[0004] It would be desirable to have new multilayer films including different polyethylenes that provide an improved balance of properties. SUMMARY

[0005] The present invention provides multilayer films including a combination of polyethylene compositions and having desirable and / or improved properties. In some embodiments, the multilayer films of the present invention provide improved dart performance, while also providing higher modulus and / or higher gas barrier properties. In some embodiments, for example, the multilayer films can surprisingly include a higher density polyethylene to provide a higher overall film density, while also improving dart performance.

[0006] In one aspect, the multilayer film includes:

[0007] (a) a first polyethylene composition, the first polyethylene composition including:

[0008] (1) from 25 wt% to 37 wt% of a first polyethylene fraction having a density in the range of from 0.935 g / cm3to 0.947 g / cm3and a melt index (I2) of less than 0.1 g / 10 minutes; and 3 from 0.947 g / cm3to 0.950 g / cm3; and 3 from 0.947 g / cm3to 0.950 g / cm3; and

[0009] (2) from 63 wt% to 75 wt% of a second polyethylene fraction; and

[0010] wherein when using 13The first polyethylene composition has less than 0.10 branches per 1,000 carbon atoms when measured by C NMR, wherein the first polyethylene composition has a density of at least 0.965 g / cm 3 and wherein the first polyethylene composition has a melt index (I2) of 0.5 g / 10 min to 10 g / 10 min; and

[0011] (b) a second polyethylene composition comprising:

[0012] (1) a first polyethylene fraction having a single peak in a temperature range of 45 °C to 87 °C in an elution profile obtained by an improved comonomer composition distribution (iCCD) analysis method, wherein a first polyethylene area fraction is an area under the single peak of the first polyethylene fraction between 45 °C and 87 °C in the elution profile; and

[0013] (2) a second polyethylene fraction having a single peak in a temperature range of 95 °C to 120 °C in the elution profile obtained by the iCCD analysis method, and wherein a second polyethylene area fraction is an area under the single peak of the second polyethylene fraction between 95 °C and 120 °C in the elution profile;

[0014] wherein the second polyethylene composition has a density of 0.924 g / cm 3 to 0.936 g / cm 3 and a melt index (I2) of 0.25 g / 10 min to 2.0 g / 10 min, wherein the second polyethylene fraction area is at least 40% of the total area of the elution profile, wherein the ratio of the first polyethylene fraction area to the second polyethylene fraction area is 0.75 to 2.5, and wherein the width of the single peak of the second polyethylene fraction at 50% peak height is less than 5.0 °C;

[0015] wherein the multi-layer film comprises 40 wt% or less of the first polyethylene composition based on the total weight of the multi-layer film. In some embodiments, the first polyethylene composition and the second polyethylene composition are in different layers of the multi-layer film. In some embodiments, at least one layer of the multi-layer film comprises the first polyethylene composition and the second polyethylene composition.

[0016] In some embodiments, an outer layer of the multi-layer film comprises a third polyethylene composition comprising:

[0017] (a) a first polyethylene fraction comprising at least one peak in a temperature range from 35°C to 70°C in an elution curve obtained by a modified comonomer composition distribution (iCCD) analysis method, wherein a first polyethylene area fraction is an area from 35°C to 70°C in the elution curve, and wherein the first polyethylene fraction area comprises from 25% to 65% of a total area of the elution curve;

[0018] (b) a second polyethylene fraction comprising at least one peak in a temperature range from 85°C to 120°C in an elution curve obtained by the iCCD analysis method, wherein a second polyethylene area fraction is an area from 85°C to 120°C in the elution curve, and wherein the second polyethylene fraction area comprises at least 20% of a total area of the elution curve; and

[0019] (c) a third polyethylene fraction in a temperature range from 70°C to 85°C in an elution curve obtained by the iCCD analysis method, wherein a third polyethylene area fraction is an area from 70°C to 85°C in the elution curve, and wherein the third polyethylene fraction area comprises less than 10% of a total area of the elution curve; and

[0020] wherein the third polyethylene composition has a density from 0.880 g / cm3 3 to 0.910 g / cm3 3 , a melt index (I2) from 0.50 g / 10 min to 6.0 g / 10 min, and a zero shear viscosity ratio less than 2.0.

[0021] The present disclosure also relates to articles. In one aspect, the articles comprise any of the inventive multilayer films disclosed herein.

[0022] These and other embodiments are described in more detail in the DETAILED DESCRIPTION. BRIEF DESCRIPTION OF DRAWINGS

[0023] For the purposes of illustrating the embodiments of the present disclosure, exemplary forms are shown in the drawings; however, it is understood that the embodiments are not limited to the precise arrangements and instrumentalities shown.

[0024] Figure 1 An iCCD elution curve according to one or more embodiments described herein is schematically depicted.

[0025] Figure 2 An iCCD elution curve of a second polyethylene composition according to one or more embodiments described herein is graphically depicted. DETAILED DESCRIPTION

[0026] Unless otherwise indicated, all parts and percentages are by weight, all temperatures are in °C, and all testing methods are current methods as of the submission date of this disclosure.

[0027] The term "composition," as used herein, refers to a mixture of materials which comprises the composition, as well as reaction products and decomposition products formed from the materials of the composition.

[0028] "Polymer" means a polymeric compound prepared by polymerizing monomers, whether of the same or a different type. The generic term polymer thus includes the term homopolymer, as defined below, and the term interpolymer, as defined below. Trace impurities of the catalyst, for example, can be incorporated into and / or within the polymer. The polymer can be a single polymer, a polymer blend, or a mixture of polymers, comprising mixtures of polymers formed in situ, during polymerization.

[0029] The term "homopolymer," as used herein, means a polymer prepared from only one type of monomer, with the understanding that trace amounts of impurities can also be incorporated into the polymer structure.

[0030] The term "interpolymer," as used herein, means a polymer prepared by the polymerization of at least two different types of monomers. The generic term interpolymer, thus, includes copolymers (used to refer to polymers prepared from two different types of monomers) and polymers prepared from more than two different types of monomers.

[0031] The term "olefin-based polymer" or "polyolefin," as used herein, means a polymer that includes a majority amount of an olefin monomer, such as ethylene or propylene, in polymerized form (by weight of the polymer) and optionally can include one or more comonomers.

[0032] The term "ethylene / alpha-olefin interpolymer," as used herein, means an interpolymer that includes a majority by mole (> 50 mole %) of units derived from ethylene monomers and the remaining units derived from one or more alpha-olefins. Typical alpha-olefins used to form ethylene / alpha-olefin interpolymers are C3-C 10 olefins.

[0033] The term "ethylene / alpha-olefin copolymer," as used herein, means a copolymer that includes a majority by mole (> 50 mole %) of ethylene monomers and alpha-olefins as the only two types of monomers in polymerized form.

[0034] The term "alpha-olefin," as used herein, means an olefin having a double bond in the primary or alpha position.

[0035] "Polyethylene" or "ethylene-based polymer" shall mean a polymer that includes a major amount (> 50 mol%) of units derived from ethylene monomer. This includes polyethylene homopolymers or copolymers (meaning units derived from two or more comonomers). Common forms of polyethylene known in the art include low density polyethylene (LDPE); linear low density polyethylene (LLDPE); ultra low density polyethylene (ULDPE); very low density polyethylene (VLDPE); single-site catalyzed linear low density polyethylene, including linear and substantially linear low density resins (m-LLDPE); ethylene-based plastomers (POPs) and ethylene-based elastomers (POEs); medium density polyethylene (MDPE); and high density polyethylene (HDPE). These polyethylene materials are generally known in the art; however, the following description can be helpful in understanding the differences between some of these different polyethylene resins.

[0036] The term "LDPE" can also be referred to as "high pressure ethylene polymer" or "highly branched polyethylene" and is defined to mean that the polymer is partially or entirely homopolymerized or copolymerized in a high pressure autoclave or tubular reactor using a free radical initiator such as a peroxide at pressures higher than 14,500 psi (100 MPa) (see, for example, US 4,599,392, which is hereby incorporated by reference). LDPE resins typically have densities in the range of 0.916 g / cm3to 0.935 g / cm3. 3 3

[0037] ​​The term "LLDPE" includes both resins made using traditional Ziegler-Natta catalyst systems and chromium-based catalyst systems as well as single-site catalysts including, but not limited to, substituted mono- or bis-cyclopentadienyl catalysts (commonly known as metallocenes), constrained geometry catalysts, phosphinimine catalysts, and polyvalent aryloxo ether catalysts (commonly known as bisphenylphenoxy), and includes linear, substantially linear, or heterogeneous polyethylene copolymers or homopolymers. LLDPE includes less long chain branching than LDPE and includes substantially linear ethylene polymers, which are further defined in U.S. Patent 5,272,236, U.S. Patent 5,278,272, U.S. Patent 5,582,923, and U.S. Patent 5,733,155; homogeneously branched linear ethylene polymer compositions, such as those in U.S. Patent No. 3,645,992; heterogeneously branched ethylene polymers, such as those prepared according to the process disclosed in U.S. Patent No. 4,076,698; and / or blends thereof (such as those disclosed in US 3,914,342 or US 5,854,045). LLDPE 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.

[0038] The term "MDPE" means a polyethylene having a density from 0.926 g / cm 3 to 0.935 g / cm 3 "MDPE" is typically made using chromium or Ziegler-Natta catalysts or using single-site catalysts including, but not limited to, substituted mono- or bis-cyclopentadienyl catalysts (commonly known as metallocenes), constrained geometry catalysts, phosphinimine catalysts, and polyvalent aryloxo ether catalysts (commonly known as bisphenylphenoxy), and typically has a molecular weight distribution ("MWD") greater than 2.5.

[0039] The term "HDPE" means a polyethylene having a density greater than about 0.935 g / cm 3 and up to about 0.980 g / cm 3 "HDPE" is typically made with Ziegler-Natta catalysts, chromium catalysts, or single-site catalysts including, but not limited to, substituted mono- or bis-cyclopentadienyl catalysts (commonly known as metallocenes), constrained geometry catalysts, phosphinimine catalysts, and polyvalent catalyst aryloxo ether catalysts (commonly known as bisphenylphenoxy).

[0040] The term "ULDPE" means a polyethylene having a density from 0.855 g / cm 3 to 0.912 g / cm 3polyethylenes, which are generally made with Ziegler-Natta catalysts, chromium catalysts, or single-site catalysts, including but not limited to substituted mono- or bis-cyclopentadienyl catalysts (commonly referred to as metallocenes), constrained geometry catalysts, phosphinimine catalysts, and polyvalent catalysts (commonly referred to as bisphenylphenoxy). ULDPEs include, but are not limited to, polyethylene (ethylene-based) plastomers and polyethylene (ethylene-based) elastomers. Polyethylene (ethylene-based) elastomer plastomers generally have a density of 0.855 g / cm3 3 to 0.912 g / cm3 3 .

[0041] The terms "blend," "polymer blend," and the like mean a composition of two or more polymers. Such a blend can or can not be miscible. Such a blend can or can not be phase separated. Such blends can or can not contain one or more domain configurations, as determined by transmission electron spectroscopy, light scattering, x-ray scattering, and any other methods known in the art. A blend is not a laminate, but one or more layers of a laminate can contain a blend. Such blends can be prepared as dry blends, formed in situ (for example, in a reactor), melt blended, or using other techniques known to those skilled in the art.

[0042] As described herein, a polyethylene "fraction" refers to a portion of the total composition of the polyethylene composition. Certain polyethylene compositions described herein include at least a "first polyethylene fraction" and a "second polyethylene fraction." Some polyethylene compositions can include a "third polyethylene fraction" and a "fourth polyethylene fraction." The various fractions included in such polyethylene compositions can be quantified by their temperature ranges in elution profiles obtained by improved comonomer composition distribution (iCCD) analysis methods. Unless otherwise specified, any elution profile referred to herein is an elution profile observed by iCCD. Embodiments of such fractions will be better understood in view of the examples provided herein. Certain polyethylene compositions described herein can be referred to as "multimodal," meaning that they include at least two peaks in their elution profiles. Certain polyethylene compositions described herein can be "bimodal," meaning that there are two major peaks. Others can be described as "trimodal," meaning that there are three peaks. As used herein, "monomodal" refers to an iCCD in which a particular fraction includes only a single peak. That is, in some embodiments, the iCCD of a particular fraction can have only one region that slopes upward, followed by a region that slopes downward, to form a single peak.

[0043] The terms "comprising," "including," "having," and derivatives thereof are not intended to exclude the presence of any additional components, steps, or procedures, whether or not specifically disclosed. For the avoidance of any doubt, all compositions claimed through use of the term "comprising" may include any additional additive, adjuvant, or compound, whether polymeric or otherwise, unless stated to the contrary. In contrast, the term "consisting essentially of excludes from the scope of any subsequently recited component, step, or procedure, except those that are not essential to operability. The term "consisting of excludes any ingredient, step, or procedure not specifically recited or listed.

[0044] The present invention provides multilayer films comprising a combination of polyethylene compositions and having desirable and / or improved properties. In some embodiments, the multilayer films of the present invention provide improved dart drop performance while also providing higher modulus and / or higher gas barrier properties. In some embodiments, for example, the multilayer films can surprisingly comprise higher density polyethylene to provide a higher overall film density while also improving dart drop performance.

[0045] In one aspect, the multilayer film comprises:

[0046] (a) a first polyethylene composition comprising:

[0047] (1) 25 to 37 wt% of a first polyethylene fraction having a molecular weight of 0.935 g / cm 3 to 0.947g / cm 3 A density within the range and a melt index (I2) of less than 0.1 g / 10 minutes; and

[0048] (2) 63% to 75% by weight of a second polyethylene fraction; and

[0049] When using 13 The first polyethylene composition has less than 0.10 branches per 1,000 carbon atoms as measured by C NMR, wherein the density of the first polyethylene composition is at least 0.965 g / cm 3 , and wherein the first polyethylene composition has a melt index (I2) of 0.5 g / 10 min to 10 g / 10 min; and

[0050] (b) a second polyethylene composition comprising:

[0051] (1) a first polyethylene fraction having a single peak in a temperature range from 45 °C to 87 °C in an elution curve obtained by a modified comonomer composition distribution (iCCD) analysis method, wherein a first polyethylene area fraction is an area under the single peak of the first polyethylene fraction between 45 °C and 87 °C in the elution curve; and

[0052] (2) a second polyethylene fraction having a single peak in a temperature range from 95 °C to 120 °C in the elution curve obtained by the iCCD analysis method, and wherein a second polyethylene area fraction is an area under the single peak of the second polyethylene fraction between 95 °C and 120 °C in the elution curve;

[0053] wherein the second polyethylene composition has a density from 0.924 g / cm3 3 to 0.936 g / cm3 3 and a melt index (I2) from 0.25 g / 10 min to 2.0 g / 10 min, wherein the second polyethylene fraction area is at least 40% of the total area of the elution curve, wherein the ratio of the first polyethylene fraction area to the second polyethylene fraction area is from 0.75 to 2.5, and wherein the width of the single peak of the second polyethylene fraction at 50% peak height is less than 5.0 °C;

[0054] wherein the multilayer film comprises 40 wt% or less of the first polyethylene composition based on the total weight of the multilayer film. In some embodiments, the first polyethylene composition and the second polyethylene composition are in different layers of the multilayer film. In some embodiments, at least one layer of the multilayer film comprises the first polyethylene composition and the second polyethylene composition. Additional details regarding various embodiments of the first polyethylene composition are provided in the First Polyethylene Composition section below. Additional details regarding various embodiments of the second polyethylene composition are provided in the Second Polyethylene Composition section below.

[0055] In some embodiments, a layer comprising the first polyethylene composition further comprises from 20 ppm to 5000 ppm of a nucleating agent based on the total weight of the layer, wherein the nucleating agent comprises calcium 1,2-cyclohexane dicarboxylate or sodium 4-[(4-chlorobenzoyl)amino]benzoate.

[0056] In some embodiments, an outer layer of the multilayer film comprises a third polyethylene composition, the third polyethylene composition comprising:

[0057] (a) a first polyethylene fraction comprising at least one peak in a temperature range from 35°C to 70°C in an elution profile obtained by a modified comonomer composition distribution (iCCD) analysis method, wherein a first polyethylene area fraction is an area from 35°C to 70°C in the elution profile, and wherein the first polyethylene fraction area comprises from 25% to 65% of a total area of the elution profile;

[0058] (b) a second polyethylene fraction comprising at least one peak in a temperature range from 85°C to 120°C in an elution profile obtained by the iCCD analysis method, wherein a second polyethylene area fraction is an area from 85°C to 120°C in the elution profile, and wherein the second polyethylene fraction area comprises at least 20% of a total area of the elution profile; and

[0059] (c) a third polyethylene fraction in a temperature range from 70°C to 85°C in an elution profile obtained by the iCCD analysis method, wherein a third polyethylene area fraction is an area from 70°C to 85°C in the elution profile, and wherein the third polyethylene fraction area comprises less than 10% of a total area of the elution profile; and

[0060] wherein the third polyethylene composition has a density from 0.880 g / cm3to 0.910 g / cm3, a melt index (I2) from 0.50 g / 10 min to 6.0 g / 10 min, and a zero-shear viscosity ratio of the polyethylene composition of less than 2.0. Additional details regarding various embodiments of the third polyethylene composition are provided in the Third Polyethylene Composition section below. 3 3 to 0.910 g / cm3, a melt index (I2) from 0.50 g / 10 min to 6.0 g / 10 min, and a zero-shear viscosity ratio of the polyethylene composition of less than 2.0. Additional details regarding various embodiments of the third polyethylene composition are provided in the Third Polyethylene Composition section below.

[0061] In some further embodiments, the first polyethylene composition and the second polyethylene composition are in different layers of the film, and the layer comprising the second polyethylene composition is between an outer layer comprising the third polyethylene composition and a layer comprising the first polyethylene composition.

[0062] In some embodiments, at least one layer further comprises a linear low density polyethylene, a low density polyethylene, or a combination thereof.

[0063] In another aspect, the present application relates to articles, such as packages. In one aspect, the article comprises any of the present multilayer films disclosed herein.

[0064] First polyethylene composition

[0065] ​As discussed above, the multilayer film of the present invention comprises at least one layer comprising a first polyethylene composition having certain properties. The first polyethylene composition used in embodiments of the present invention comprises (i) 25 wt% to 37 wt% of a first polyethylene fraction having a molecular weight of 0.935 g / cm 3 to 0.947g / cm 3 and a melt index (I2) of less than 0.1 g / 10 minutes; and (ii) 63 wt% to 75 wt% of a second polyethylene composition, wherein when used 13 The first polyethylene composition has less than 0.10 branches per 1,000 carbon atoms as measured by C NMR, wherein the first polyethylene composition has a density of at least 0.965 g / cm 3 , and wherein the melt index (I2) of the first polyethylene composition is from 0.5 g / 10 min to 10 g / 10 min.

[0066] In some embodiments, the first polyethylene composition has a melt index (I2) of 2.5 g / 10 minutes or less.

[0067] In some embodiments, the first polyethylene composition comprises 25 wt% to 37 wt% of a polyethylene having a density of 0.940 g / cm 3 to 0.947g / cm 3 The first polyethylene fraction has a density of 0.970 g / cm2 and 63 wt% to 75 wt% of the first polyethylene fraction has a density of 0.970 g / cm2 3 or greater second polyethylene fraction.

[0068] The first polyethylene composition may comprise a combination of two or more embodiments as described herein.

[0069] In one embodiment, the first polyethylene composition has a 3 In some embodiments, the first polyethylene composition has a density of at least 0.968 g / cm 3 In some embodiments, the first polyethylene composition has a density of at most 0.976 g / cm 3 In some embodiments, the first polyethylene composition has a density of 0.965 g / cm 3 to 0.976g / cm 3 , for example 0.965 g / cm 3 to 0.970g / cm 3 , or 0.967 g / cm 3 to 0.969g / cm 3 , or 0.965g / cm 3 to 0.970g / cm 3density within a range. For example, the density can be a lower limit of 0.965 g / cm 3 or 0.967 g / cm 3 to an upper limit of 0.970 g / cm 3 , 0.972 g / cm 3 , 0.975 g / cm 3 , or 0.976 g / cm 3 .

[0070] The first polyethylene composition has a melt index (I2 or I2; at 190 °C / 2.16 kg) of 0.5 g / 10 min to 10 g / 10 min. For example, the melt index (I2 or I2; at 190 °C / 2.16 kg) can be a lower limit of 0.5 g / 10 min, 0.7 g / 10 min, 0.9 g / 10 min, 1.0 g / 10 min, 1.1 g / 10 min, 1.2 g / 10 min, 1.5 g / 10 min, 2 g / 10 min, 3 g / 10 min, 4 g / 10 min, or 5 g / 10 min to an upper limit of 1.5 g / 10 min, 2 g / 10 min, 2.5 g / 10 min, 3 g / 10 min, 4 g / 10 min, 5 g / 10 min, 6 g / 10 min, 7 g / 10 min, 8 g / 10 min, 9 g / 10 min, or 10 g / 10 min. In some embodiments, the first polyethylene composition has a melt index (I2) of 0.5 g / 10 min to 5 g / 10 min, or 0.5 g / 10 min to 2.5 g / 10 min, or 0.7 g / 10 min to 3 g / 10 min, or 1.0 g / 10 min to 2.0 g / 10 min, or 1.0 g / 10 min to 1.5 g / 10 min.

[0071] In some embodiments, the first polyethylene composition has a melt index ratio (I 10 / I2) of 10 or more. In some embodiments, the first polyethylene composition has a melt index ratio (I 10 / I2) of at most 17. In some embodiments, the first polyethylene composition has a melt index ratio (I 10 / I2) of 10 to 17. In some embodiments, the first polyethylene composition has a melt index ratio (I 10 / I2) of 12 to 17.

[0072] The first polyethylene composition has a low level of branching. In some embodiments, the first polyethylene composition has less than 0.10 branches per 1,000 carbon atoms when measured using 13 CNMR. In some embodiments, the first polyethylene composition has less than 0.10 branches per 1,000 carbon atoms when measured using 13The first polyethylene composition has less than 0.07 branches per 1,000 carbon atoms, as measured by C NMR. In some embodiments, when measured by C NMR, the first polyethylene composition has less than 0.05 branches per 1,000 carbon atoms. In some embodiments, when measured by C NMR, the first polyethylene composition has less than 0.03 branches per 1,000 carbon atoms. 13 The first polyethylene composition has less than 0.07 branches per 1,000 carbon atoms, as measured by C NMR. In some embodiments, when measured by C NMR, the first polyethylene composition has less than 0.05 branches per 1,000 carbon atoms. In some embodiments, when measured by C NMR, the first polyethylene composition has less than 0.03 branches per 1,000 carbon atoms. 13 The first polyethylene composition has less than 0.07 branches per 1,000 carbon atoms, as measured by C NMR. In some embodiments, when measured by C NMR, the first polyethylene composition has less than 0.05 branches per 1,000 carbon atoms. In some embodiments, when measured by C NMR, the first polyethylene composition has less than 0.03 branches per 1,000 carbon atoms.

[0073] In some embodiments, the first polyethylene composition has a low level of non- vinyl unsaturation. In some embodiments, when measured by H NMR, the first polyethylene composition has less than 25 non-vinyl unsaturations per 1 million carbons. In some embodiments, when measured by H NMR, the first polyethylene composition has less than 20 non-vinyl unsaturations per 1 million carbons. 1 In some embodiments, when measured by H NMR, the first polyethylene composition has less than 25 non-vinyl unsaturations per 1 million carbons. In some embodiments, when measured by H NMR, the first polyethylene composition has less than 20 non-vinyl unsaturations per 1 million carbons. 1 In some embodiments, when measured by H NMR, the first polyethylene composition has less than 25 non-vinyl unsaturations per 1 million carbons. In some embodiments, when measured by H NMR, the first polyethylene composition has less than 20 non-vinyl unsaturations per 1 million carbons.

[0074] Without wishing to be bound by theory, it is believed that the combination of low branching levels and low levels of non-vinyl unsaturation in the first polyethylene composition provides a greater amount of crystallinity in the first polyethylene composition, which improves its barrier properties when formed into a film.

[0075] In one embodiment, the first polyethylene composition has a ZSVR value of less than 2.0, or from 1.0 to 2.0, or from 1.2 to 1.8, or from 1.3 to 1.7.

[0076] In one embodiment, the first polyethylene composition has a molecular weight distribution, expressed as the ratio of weight average molecular weight to number average molecular weight (M w / M n ; determined by conventional GPC) in the range of 8.0 to 14.0. For example, the molecular weight distribution (M w / M n ) can be a lower limit of 8.0, 8.5, 9.0, or 9.5 to an upper limit of 10.0, 11.0, 11.5, 12.0, 12.5, 13.0, 13.5, or 14.0. In some embodiments, M w / M n is from 10.0 to 12.0.

[0077] In one embodiment, the first polyethylene composition has a number average molecular weight (M n; determined by conventional GPC) in the range of 8,000 g / mol to 20,000 g / mol. For example, the number average molecular weight can be a lower limit of 8,000 g / mol, 9,000 g / mol, 10,000 g / mol, or 11,000 g / mol to an upper limit of 12,000 g / mol, 13,000 g / mol, 15,000 g / mol, or 20,000 g / mol.

[0078] In one embodiment, the weight average molecular weight (M) of the first polyethylene composition w ; determined by conventional GPC) in the range of 100,000 g / mol to 125,000 g / mol. For example, the weight average molecular weight can be a lower limit of 100,000 g / mol, 105,000 g / mol, or 110,000 g / mol to an upper limit of 115,000 g / mol, 120,000 g / mol, or 124,000 g / mol.

[0079] In one embodiment, the z-average molecular weight (M) of the first polyethylene composition Z ; determined by conventional GPC) is at least 350,000 g / mole, such as within the range of 350,000 g / mole to 600,000 g / mole. For example, the z-average molecular weight can be a lower limit of 350,000 g / mole, 375,000 g / mole, 400,000 g / mole, 405,000 g / mole, or 410,000 g / mole to an upper limit of 420,000 g / mole, 425,000 g / mole, 450,000 g / mole, 475,000 g / mole, 500,000 g / mole, 550,000 g / mole, or 600,000 g / mole.

[0080] In one embodiment, the M of the first polyethylene composition z / M w Ratio (each as determined by conventional GPC) is greater than 3.0. In some embodiments, the M of the first polyethylene composition is greater than z / M w Ratio (each as determined by conventional GPC) is greater than 3.5. In some embodiments, M z / M w It can be 3.0 to 4.0, or in some embodiments, 3.5 to 4.5, or in some embodiments, 3.5 to 4.0.

[0081] In one embodiment, the first polyethylene composition has a ZSVR of less than 2.0 and M z / M w In another embodiment, the first polyethylene composition has a ZSVR of less than 2.0 and a Mz / M w a ratio (each as determined by conventional GPC) of greater than 3.5.

[0082] The first polyethylene composition preferably comprises an ethylene-based polymer formed in the absence of a comonomer. In some embodiments, the first polyethylene composition comprises at least 99 wt% of an ethylene-based polymer formed in the absence of a comonomer. In some embodiments, the first polyethylene composition comprises at least 99 wt% of a polymer comprising a major amount (>99 mol%) of units derived from ethylene monomer.

[0083] The first polyethylene composition comprises two polyethylene fractions.

[0084] The first polyethylene fraction has a density of 0.935 g / cm 3 to 0.947 g / cm 3 In some embodiments, the first polyethylene fraction has a density of 0.940 g / cm 3 to 0.947 g / cm 3 The first polyethylene fraction has a melt index (I2) of less than 0.1 g / 10 min. In some embodiments, the first polyethylene fraction has a melt index (I2) of 0.01 g / 10 min or more. In some embodiments, the first polyethylene fraction has a melt index of 0.05 g / 10 min to 0.1 g / 10 min. In some embodiments, the first polyethylene fraction has less than 0.10 branches per 1,000 carbon atoms when measured using 13 C NMR.

[0085] In some embodiments, the ethylene-based polymer has a density of 0.970 g / cm 3 or more. In some embodiments, the first polyethylene fraction has a density of 0.940 g / cm 3 to 0.947 g / cm 3 and the second polyethylene fraction has a density of 0.970 g / cm 3 or more. In some embodiments, the second polyethylene fraction has a melt index (I2) of at least 100 g / 10 min. In some embodiments, the second polyethylene fraction has a melt index (I2) of at least 100 g / 10 min and up to 10,000 g / 10 min or more. In some embodiments, the second polyethylene fraction has a melt index (I2) of at least 100 g / 10 min and up to 10,000 g / 10 min. In some embodiments, the second polyethylene fraction has a melt index (I2) of at least 100 g / 10 min and up to 1,000 g / 10 min.

[0086] In some embodiments, the ratio of the melt index of the second polyethylene fraction (I2) to the melt index of the first polyethylene fraction (I2) is at least 1,000.

[0087] The first polyethylene composition comprises 25 wt% to 37 wt% of the first polyethylene fraction and 63 wt% to 75 wt% of the second polyethylene composition, based on the total weight of the first polyethylene composition. In some embodiments, the first polyethylene composition comprises 30 wt% to 37 wt% of the first polyethylene fraction and 63 wt% to 70 wt% of the second polyethylene fraction, based on the total weight of the first polyethylene composition.

[0088] The following discussion focuses on the preparation of the first polyethylene composition for use in embodiments of the present application.

[0089] Polymerization

[0090] Any conventional polymerization process can be employed to produce the first polyethylene composition. Such conventional polymerization processes include, but are not limited to, slurry polymerization processes using one or more conventional reactors, for example, loop reactors, isothermal reactors, stirred tank reactors, batch reactors, and / or any combination thereof, in parallel or in series. The first polyethylene composition can be produced, for example, by solution phase polymerization processes using one or more loop reactors, isothermal reactors, and combinations thereof.

[0091] Generally, solution phase polymerization processes occur in one or more well-mixed reactors, such as one or more isothermal loop reactors and / or one or more adiabatic reactors, at temperatures in the range of 115°C to 250°C; for example, in the range of 115°C to 200°C, and at pressures in the range of 300 psi to 1,000 psi; for example, in the range of 400 psi to 750 psi, in one or more well-stirred reactors, such as one or more loop reactors. In one embodiment, in a dual reactor, the temperature in the first reactor is in the range of 115°C to 190°C (e.g., 115°C to 175°C), while the second reactor temperature is in the range of 150°C to 250°C (e.g., 130°C to 165°C). In another embodiment, in a single reactor, the temperature in the reactor is in the range of 115°C to 250°C (e.g., 115°C to 225°C).

[0092] The residence time in the solution phase polymerization process is typically in the range of 2 minutes to 30 minutes; for example, 10 minutes to 20 minutes. Ethylene, solvent, hydrogen, one or more catalyst systems, optionally one or more co-catalysts, and optionally one or more comonomers are continuously fed into one or more reactors. Exemplary solvents include, but are not limited to, isoparaffins. For example, such a solvent is commercially available under the name ISOPAR E from ExxonMobil Chemical Co., Houston, Texas. The resulting mixture of the first polyethylene composition and solvent is then removed from the reactor and the first polyethylene composition is isolated. The solvent is typically recovered via a solvent recovery unit (i.e., heat exchanger and vapor-liquid separator drum) and subsequently recycled back into the polymerization system.

[0093] In one embodiment, the first polyethylene composition can be produced by solution polymerization in a dual reactor system, for example, 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 co-catalysts can be present. In another embodiment, the first polyethylene composition can be produced by solution polymerization in a single reactor system, for example, a single loop reactor system, where ethylene is polymerized in the presence of two catalyst systems. In some embodiments, only ethylene is polymerized.

[0094] Catalyst system

[0095] Specific embodiments of catalyst systems that can be used to produce the first polyethylene compositions described herein will now be described. It should be understood that the catalyst systems of the present disclosure can be embodied in different forms and should not be interpreted as being limited to the specific embodiments set forth in the present disclosure. Rather, the embodiments are provided so that the present disclosure will be thorough and complete, and so that the embodiments will fully convey the scope of the subject matter to those skilled in the art.

[0096] The term “independently selected” is used herein to indicate that the R groups (such as R 1 , R 2 , R 3 , R 4 , and R 5 ) can be the same or different (e.g., R 1 , R 2 , R 3 , R 4 , and R 5 may all be substituted alkyl, or R 1 and R 2 may be substituted alkyl while R 3can be aryl, etc.). Use of the singular encompasses use of the plural, and vice versa (e.g., a hexane solvent encompasses a plurality of hexanes). A named R group will generally have an art-recognized structure corresponding to the R group having that name. These definitions are intended to supplement and illustrate, but not to exclude, definitions known to those skilled in the art.

[0097] The term "procatalyst" refers to a compound that has catalytic activity when combined with an activator. The term "activator" refers to a compound that chemically reacts with the procatalyst in a manner that converts the procatalyst into a catalytically active catalyst. As used herein, the terms "procatalyst" and "activator" are interchangeable terms.

[0098] When used to describe certain chemical groups containing carbon atoms, it has the form "(C x -C y )" means that the unsubstituted form of the chemical group has x 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, certain chemical groups may be substituted with one or more substituents such as RS. The parenthetical phrase "(C x -C y )" defined chemical group R S Substituted versions may contain more than y carbon atoms, depending on the number of any group R S For example, "with exactly one group R S Substituted (C1-C 40 )alkyl, wherein R S is a phenyl group (-C6H5)" may contain from 7 to 46 carbon atoms. Therefore, in general, when using "(C x -C y )" is inserted into the chemical group defined by one or more carbon-containing substituents R S When substituted, both x and y are added to the substituent R from all carbon atoms S The combined sum of the number of carbon atoms is used to determine the minimum and maximum total number of carbon atoms in a chemical group.

[0099] The term "substituted" means that at least one hydrogen atom (-H) bonded to a carbon atom or heteroatom in the corresponding unsubstituted compound or functional group is replaced by a substituent (e.g., R S ) is replaced. The term "persubstituted" means that each 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) Substitution. The term "poly-substituted" means that at least two but fewer than all of the hydrogen atoms bonded to a carbon atom or a heteroatom of the corresponding unsubstituted compound or functional group are replaced with a substituent.

[0100] The term "-H" means a hydrogen or hydrogen radical covalently bonded to another atom. "Hydrogen" and "-H" are interchangeable and have the same meaning unless explicitly specified.

[0101] The term "(C1-C 40 )alkyl" means a saturated straight chain or branched hydrocarbon radical having from 1 to 40 carbon atoms, and the term "(C1-C 40 )alkylene" means a saturated straight chain or branched hydrocarbon diradical having from 1 to 40 carbon atoms, wherein each alkyl and each alkylene is aromatic or non-aromatic, saturated or unsaturated, straight chain or branched, cyclic (including mono- and polycyclic, fused and non-fused polycyclic, including bicyclic; 3 or more carbon atoms) or acyclic, and unsubstituted or substituted with one or more R S substituents.

[0102] In the present disclosure, (C1-C 40 )alkyl can be 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 foregoing (C1-C 40 )alkyl groups has up to 20 carbon atoms (i.e., (C1-C 20 )alkyl), and in various embodiments, up to 12 carbon atoms.

[0103] The terms "(C1-C 40 )alkyl" and "(C1-C 18 )alkyl" mean a saturated straight chain or branched hydrocarbon radical having from 1 to 40 carbon atoms or from 1 to 18 carbon atoms, respectively, which is unsubstituted or substituted with one or more RS. 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 40Examples of alkyl groups are substituted (C1-C 20 )alkyl, substituted (C1-C 10 ) alkyl, trifluoromethyl and [C 45 ] alkyl. The term "[C 45 ] alkyl" (with square brackets) means that there are up to 45 carbon atoms in the group (including substituents) and are, for example, each substituted with one RS, (C 27 -C 40 )alkyl, wherein RS is (C1-C5)alkyl. Each (C1-C5)alkyl group may be methyl, trifluoromethyl, ethyl, 1-propyl, 1-methylethyl or 1,1-dimethylethyl.

[0104] The term "(C6-C 40 ) aryl" means an unsubstituted or substituted aryl group having 6 to 40 carbon atoms (one or more R S ) substituted monocyclic, bicyclic or tricyclic aromatic hydrocarbon group, at least 6 to 14 carbon atoms of the aromatic hydrocarbon group are aromatic ring carbon atoms, and the monocyclic, bicyclic or tricyclic group includes 1, 2 or 3 rings respectively; wherein 1 ring is an aromatic ring, and 2 or 3 rings are independently condensed rings or non-condensed rings, and at least one of the 2 or 3 rings is an aromatic ring. Unsubstituted (C6-C 40 Examples of aryl groups are unsubstituted (C6-C 20 )aryl; unsubstituted (C6-C 18 )aryl; 2-(C1-C5)alkyl-phenyl; 2,4-bis(C1-C5)alkyl-phenyl; phenyl; fluorenyl; tetrahydrofluorenyl; dicyclopentadienylphenyl; hexahydrodicyclopentadienylphenyl; indenyl; dihydroindenyl; naphthyl; tetrahydronaphthyl; and phenanthrene. Substituted (C6-C 40 Examples of aryl groups are substituted (C1-C 20 ) aryl; substituted (C6-C 18 )aryl; 2,4-bis[(C 20 )alkyl]-phenyl; polyfluorophenyl; pentafluorophenyl; and fluoren-9-on-1-yl.

[0105] The term "(C3-C 40 ) Cycloalkyl" means a saturated cyclic hydrocarbon group of 3 to 40 carbon atoms, which is unsubstituted or substituted by one or more R S Substituted. Other cycloalkyl groups (e.g., (C x -C y )cycloalkyl) is defined in a similar manner as having x to y carbon atoms and being unsubstituted or substituted with one or more R S Substituted. Unsubstituted (C3-C 40 Examples of cycloalkyl groups are unsubstituted (C3-C20 )cycloalkyl, unsubstituted (C3–C 10 )cycloalkyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl and cyclodecyl. Substituted (C3-C 40 Examples of cycloalkyl groups are substituted (C3-C 20 )cycloalkyl, substituted (C3-C 10 )cycloalkyl, cyclopentanone-2-yl and 1-fluorocyclohexyl.

[0106] (C1-C 40 Examples of the alkylene group include unsubstituted or substituted (C6-C 40 )arylene, (C3-C 40 )cycloalkylene and (C1-C 40 )alkylene (e.g., (C1-C 20 ) alkylene). In some embodiments, the diradicals are located on the same carbon atom (e.g., -CH2-) or on adjacent carbon atoms (i.e., 1,2-diradicals), or are separated by one, two, or more than two intervening carbon atoms (e.g., corresponding 1,3-diradicals, 1,4-diradicals, etc.). Some diradicals include α,ω-diradicals. α,ω-diradicals are diradicals with the largest carbon backbone spacing between radical carbons. (C2-C 20 Some examples of alkylene α,ω-diyl radicals include ethane-1,2-diyl (ie, -CH2CH2-), propane-1,3-diyl (ie, -CH2CH2CH2-), 2-methylpropane-1,3-diyl (ie, -CH2CH(CH3)CH2-). (C6-C 50 Some examples of arylene α,ω-diyl include phenyl-1,4-diyl, naphthalene-2,6-diyl, or naphthalene-3,7-diyl.

[0107] The term "(C1-C 40 ) alkylene refers to an unsubstituted or substituted group having 1 to 40 carbon atoms. S Substituted saturated straight or branched chain divalent groups (i.e., the divalent groups are not on ring atoms). Unsubstituted (C1-C 50 Examples of alkylene groups are unsubstituted (C1-C 20 )alkylene, including unsubstituted -CH2CH2-, -(CH2)3-, -(CH2)4-, -(CH2)5-, -(CH2)6-, -(CH2)7-, -(CH2)8-, -CH2C*HCH3, and -(CH2)4C*(H)(CH3), where "C*" represents a carbon atom from which a hydrogen atom is removed to form a secondary or tertiary alkyl group. Substituted (C1-C 50 Examples of alkylene groups are substituted (C1-C20 )alkylene, -CF2-, -C(O)- and -(CH2) 14 C(CH3)2(CH2)5- (i.e., 6,6-dimethyl-substituted n-1,20-eicosene). As mentioned previously, the two R S Can be combined to form (C1-C 18 ) alkylene, substituted (C1-C 50 Examples of the alkylene group 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.

[0108] The term "(C3-C 40 ) cycloalkylene refers to a cycloalkylene group having 3 to 40 carbon atoms which is unsubstituted or substituted with one or more R S Substituted cyclic diradicals (ie, the radicals are on ring atoms).

[0109] 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(R C )2– or –Si(R C )–, where each R C , each R N and each R P is unsubstituted (C1-C 18 )alkyl or -H. The term "heteroalkyl" refers to a molecule or molecular framework in which one or more carbon atoms are replaced by a heteroatom. 40 )heteroalkyl" means a heteroalkyl group having 1 to 40 carbon atoms, and the term "(C1-C 40 ) heteroalkylene" means a heteroalkyl diradical having from 1 to 40 carbon atoms, each heteroalkyl having one or more heteroatoms. The radical of the heteroalkyl group is located on a carbon atom or a heteroatom, and the diradical of the heteroalkyl group can be located on: (1) one or two carbon atoms, (2) one or two heteroatoms, or (3) both carbon atoms and heteroatoms. Each (C1-C 50 ) heteroalkyl and (C1-C 50 ) The heteroalkylene group may be unsubstituted or (substituted by one or more R S ) substituted, aromatic or non-aromatic, saturated or unsaturated, linear or branched, cyclic (including mono- and polycyclic, fused and non-fused polycyclic) or acyclic.

[0110] (C1-C 40 )heteroalkyl can be unsubstituted or substituted (C1-C 40 )heteroalkyl, (C1-C 40 )alkyl-O-, (C1-C 40 )alkyl-S-, (C1-C 40 )alkyl-S(O)-, (C1-C 40 )alkyl-S(O)2-, (C1-C 40 )alkyl-Si(R C )2-, (C1-C 40 )alkyl-N(R N )-, (C1-C 40 )alkyl-P(R P )-, (C2-C 40 )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.

[0111] The term “(C4-C 40 )heteroaryl” means a monocyclic, bicyclic, or tricyclic heteroaromatic hydrocarbon radical having a total number of carbon atoms from 4 to 40 and a total number of heteroatoms from 1 to 10, and is unsubstituted or substituted with (one or more R S )heteroaryl groups (e.g., typically (C4-C x )heteroaryl) are defined in an analogous manner as having from x to y carbon atoms (e.g., from 4 to 12 carbon atoms), and are unsubstituted or substituted with one or more R y )heteroaryl groups (e.g., typically (C4-C 12 )heteroaryl) are defined in an analogous manner as having from x to y carbon atoms (e.g., from 4 to 12 carbon atoms), and are unsubstituted or substituted with one or more R SSubstituted. Monocyclic heteroaromatic hydrocarbyl groups are 5- or 6-membered rings. A 5-membered ring has 5 minus h carbon atoms, where h is the number of heteroatoms and can be 1, 2, or 3; and each heteroatom can be O, S, N, or P. Examples of 5-membered ring heteroaromatic hydrocarbyl groups are pyrrol-1-yl; piperidin-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. A 6-membered ring has 6 minus h carbon atoms, where h is the number of heteroatoms and can be 1 or 2, and the heteroatoms can be N or P. Examples of 6-membered ring heteroaromatic hydrocarbyl groups are pyridin-2-yl; pyrimidin-2-yl; and pyrazin-2-yl. Bicyclic heteroaromatic hydrocarbyl groups can be fused 5,6- or 6,6-ring systems. Examples of fused 5,6-ring system bicyclic heteroaromatic hydrocarbyl groups are indol-1-yl; and benzimidazol-1-yl. Examples of fused 6,6-ring system bicyclic heteroaromatic hydrocarbyl groups are quinolin-2-yl; and isoquinolin-1-yl. Bicyclic heteroaromatic hydrocarbyl groups can be fused 5,6,5-ring systems; 5,6,6-ring systems; 6,5,6-ring systems; or 6,6,6-ring systems. 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.

[0112] The foregoing heteroalkyl groups can be saturated straight or branched chain groups containing (C1–C 50 ) carbon atoms or fewer, and one or more heteroatoms. Likewise, heteroalkylene groups can be saturated straight or branched chain diradicals containing 1 to 50 carbon atoms and one or more than one heteroatom. Heteroatoms as defined above can include Si(R C )3, Ge(R C )3, Si(R C )2, Ge(R C )2, P(R P )2, P(R P ), N(R N )2, N(R N ), N, O, OR C , S, SR C , S(O), and S(O)2, where each of the heteroalkyl and heteroalkylene groups is unsubstituted or substituted with one or more R S .

[0113] Unsubstituted (C2-C 40 Examples of heterocycloalkyl groups are unsubstituted (C2-C 20 ) heterocycloalkyl, unsubstituted (C2-C 10 ) heterocycloalkyl, aziridine-1-yl, oxetan-2-yl, tetrahydrofuran-3-yl, pyrrolidin-1-yl, tetrahydrothiophene-S,S-dioxide-2-yl, morpholin-4-yl, 1,4-dioxane-2-yl, hexahydroazepin-4-yl, 3-oxa-cyclooctyl, 5-thioxo-cyclononyl and 2-aza-cyclodecyl.

[0114] The term "halogen atom" or "halogen" refers to a free radical of a fluorine atom (F), a chlorine atom (Cl), a bromine atom (Br), or an iodine atom (I). The term "halide" refers to the anionic form of a halogen atom: fluoride ion (F-), chloride ion (Cl-), bromide ion (Br-), or iodide ion (I-).

[0115] The term "saturated" means free of carbon-carbon double bonds, carbon-carbon triple bonds, and (in heteroatom-containing groups) carbon-nitrogen, carbon-phosphorus, and carbon-silicon double bonds. S In the case of substitution, one or more double bonds and / or triple bonds may or may not be present in the substituent R S The term "unsaturated" means containing one or more carbon-carbon double bonds, carbon-carbon triple bonds and (in heteroatom-containing groups) carbon-nitrogen, carbon-phosphorus and carbon-silicon double bonds, excluding those that may be present in the substituent R S Any such double bonds may be present in the (hetero)aromatic ring (if present) or in the (hetero)aromatic ring (if present).

[0116] According to some embodiments, the catalyst system used to produce the first polyethylene composition comprises a metal-ligand complex according to formula (I):

[0117]

[0118] In formula (I), M is a metal selected from titanium, zirconium or hafnium, the metal having a formal oxidation state of +2, +3 or 4; n is 0, 1 or 2; when n is 1, X is a monodentate ligand or a bidentate ligand; when n is 2, each X is a monodentate ligand and is the same or different; the metal-ligand complex as a whole is electrically neutral; each Z is independently selected from -O-, -S-, -N(R N )-or-P(R P )-; L is (C1-C 40 )alkylene or (C1-C 40 ) heteroalkylene, wherein (C1-C 40) alkylene group has a moiety (to which L is bonded) comprising a 1-carbon atom to a 10-carbon atom main chain connecting two Z groups in formula (I), or (C1-C 40 ) heteroalkylene has a moiety comprising a 1-atom to 10-atom connecting backbone linking two Z groups in formula (I), wherein (C1-C 40 ) heteroalkylene groups wherein each of the 1-atom to 10-atom connected backbone atoms is independently a carbon atom or a heteroatom, wherein each heteroatom is independently O, S, S(O), S(O)2, Si(R C )2、Ge(R C )2、P(R C ) or N(R C ), where each R C Independently (C1-C 30 )alkyl or (C1-C 30 ) heteroalkyl; R 1 and R 8 Independently selected from the group consisting of: -H, (C1-C 40 )alkyl, (C1-C 40 ) heteroalkyl, -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 group of formula (II), formula (III) or formula (IV):

[0119]

[0120] In formulas (II), (III) and (IV), R 31-35 、R 41-48 or R 51-59 Each of which is independently selected from (C1-C 40 )alkyl, (C1-C 40 ) heteroalkyl, -Si(R C )3、-Ge(R C )3、-P(R P)2, -N=CHR 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 group having formula (II), formula (III), or formula (IV).

[0121] In formula (I), each of R 2-4 , R 5-7 , and R 9-16 is independently selected from (Ci-C 40 )hydrocarbyl, (Ci-C 40 )heterohydrocarbyl, -Si(R C )3, -Ge(R C )3, -P(R P )2, -N(R N )2, -N=CHR C , -OR C , -SR C , -NO2, -CN, -CF3, R C S(O)-, R C S(O)2-, (R C )2C=N-, R C C(O)O-, R C OC(O)-, R C C(O)N(R N )-, (R C )2NC(O)-, halogen, and -H.

[0122] In some embodiments, the first polyethylene composition is formed using a first catalyst according to formula (I) in a first reactor and a different catalyst according to formula (I) in a second reactor.

[0123] In one exemplary embodiment using dual loop reactors, the procatalyst used in the first loop is [[2,2"'-[[bis[l-methylethyl)germylene]bis(methyleno-kO)]bis[3",5,5"-tris(l,l-dimethylethyl)-5'-octyl[l,l':3',l"-terphenyl]-2'-yl-kO]](2-)]dimethylzirconium, having the chemical formula C 86 H 128 F2GeO4Zr and the following structure:

[0124]

[0125] In such embodiments, the procatalyst used in the second loop is [[2,2"'- [l,3-propanediylbis(oxy-kO)]bis[3-[2,7-bis(l,l-dimethylethyl)-9H-carbazol-9-yl]]-5'- (dimethyloctylsilyl)-3'-methyl-5-(l,l,3,3-tetramethylbutyl)[l,l]- biphenyl]-2-yl-kO]](2-)]dimethylhafnium, having the chemical formula C 107 H 154 N2O4Si2Zr and the following structure:

[0126]

[0127] In other embodiments, the procatalyst used in the second loop is [[2,2"'- [l,3-propanediylbis(oxy-kO)]bis[3-[2,7-bis(l,l-dimethylethyl)-9H-carbazol-9-yl]]-5'- (dimethyloctylsilyl)-3'-methyl-5-(l,l,3,3-tetramethylbutyl)[l,l]- biphenyl]-2-yl-kO]](2-)]dimethylhafnium, having the chemical formula C 107 H 154 N2O4Si2Hf and the following structure:

[0128]

[0129] Promoter component

[0130] The catalyst system comprising the metal-ligand complex of formula (I) can be rendered catalytically active by any technique known in the art for activating metal-based catalysts for olefin polymerization reactions. For example, the system comprising the metal-ligand complex of formula (I) can be rendered catalytically active by contacting the complex with an activating co-catalyst or combining the complex with an activating co-catalyst. Suitable activating co-catalysts for use herein include alkylaluminums; polymeric or oligomeric aluminoxanes (also known as aluminoxanes); neutral Lewis acids; and non-polymeric, non-coordinating, ion-forming compounds including the use of such compounds under oxidizing conditions. A suitable activating technique is bulk electrolysis. Combinations of one or more of the foregoing activating co-catalysts and techniques are also contemplated. The term "alkylaluminum" means a monoalkylaluminum dihydride or dihalide, a dialkylaluminum hydride or halide, or a trialkylaluminum. Examples of polymeric or oligomeric aluminoxanes include methylaluminoxane, methylaluminoxane modified with triisobutylaluminum, and isobutylaluminoxane.

[0131] Lewis acid activators (co-catalysts) include Group 13 metal compounds containing from 1 to 3 (Ci-C 20 )alkyl substituents as described herein. In one embodiment, the Group 13 metal compound is a tri((Ci-C 20 )alkyl) substituted aluminum or a tri((Ci-C 20 )alkyl)-boron compound. In other embodiments, the Group 13 metal compound is a tri(alkyl) substituted aluminum, a tri((Ci-C 20 )alkyl)-boron compound, a tri((Ci-C 10 )alkyl) aluminum, a tri((C6-C 18 )aryl) boron compound, and halogenated (including perhalogenated) derivatives thereof. In other embodiments, the Group 13 metal compound is a tri(fluoro-substituted phenyl) borane, a tri(pentafluorophenyl) borane. In some embodiments, the activating co-catalyst is a tri((Ci-C 20 )alkyl) borate (e.g., trityl tetrafluoroborate) or a tri((Ci-C 20 )alkyl) ammonium tetra((Ci-C 20 )alkyl) borane (e.g., bis(octadecyl)methylammonium tetra(pentafluorophenyl) borane). As used herein, the term "ammonium" means a nitrogen cation which is ((Ci-C 20 )alkyl)4N + , ((Ci-C 20 )alkyl)3N(H) + , ((Ci-C 20 )alkyl)2N(H)2 + , (Ci-C 20 )alkyl N(H)3 + , or N(H)4 +wherein each (C1-C4)hydrocarbyl group can be the same or different (when two or more are present). 20 )alkyl)aluminum and a halogenated tri((C6-C

[0132] Combinations of neutral Lewis acid activators (cocatalysts) include mixtures comprising a tri((C1-C4)alkyl)aluminum and a halogenated tri((C6-C 18 )aryl)borane compound, especially tris(pentafluorophenyl)borane. Other embodiments are combinations of such neutral Lewis acid mixtures with polymeric or oligomeric aluminoxanes and combinations of a single neutral Lewis acid (especially tris(pentafluorophenyl)borane) with polymeric or oligomeric aluminoxanes. The ratio of (group 4 metal-ligand complex):(tris(pentafluoro-phenylborane):(aluminoxane) [e.g., (group 4 metal-ligand complex):(tris(pentafluoro-phenylborane):(aluminoxane)] moles is from 1:1:1 to 1:10:30, in other embodiments from 1:1:1.5 to 1:5:10.

[0133] Catalyst systems comprising a metal-ligand complex of formula (I) can be activated to form an active catalyst composition by combination with one or more cocatalysts (e.g., cation-forming cocatalysts, strong Lewis acids, or combinations thereof). Suitable activating cocatalysts include polymeric or oligomeric aluminoxanes (especially methylaluminoxane) and inert, compatible, non-coordinating, ion-forming compounds. Exemplary suitable cocatalysts include, but are not limited to, modified methylaluminoxane (MMAO), bis(hydrogenated tallowalkyl)methyl tetrakis(pentafluorophenyl)borate (1 - )amine, and combinations thereof.

[0134] In some embodiments, one or more of the foregoing activating co-catalysts are used in combination with one another. One particularly preferred combination is a mixture of tri((Ci-C4)hydrocarbyl)aluminum, tri((Ci-C4)hydrocarbyl)borane or ammonium borate and an oligomeric or polymeric aluminoxane compound. The ratio of the total moles of one or more metal-ligand complexes of formula (I) to the total moles of one or more activating co-catalysts is 1 : 10,000 to 100: 1. In some embodiments, the ratio is at least 1 :5000, in some other embodiments, at least 1 : 1000; and 10: 1 or less, and in some other embodiments, 1 : 1 or less. When aluminoxane is used alone as the activating co-catalyst, preferably the moles of aluminoxane employed are at least 100 times the moles of metal-ligand complex of formula (I). In some other embodiments, when tri(pentafluorophenyl)borane is used alone as the activating co-catalyst, the ratio of the moles of tri(pentafluorophenyl)borane employed to the total moles of one or more metal-ligand complexes of formula (I) is 0.5: 1 to 10: 1, 1 : 1 to 6: 1, or 1 : 1 to 5: 1. The remaining activating co-catalyst is generally employed in a molar amount approximately equal to the total molar amount of one or more metal-ligand complexes of formula (I).

[0135] Nucleating agent

[0136] According to some embodiments, the layer comprising the first polyethylene composition in the multilayer film of the present application can further comprise a nucleating agent that is calcium 1,2-cyclohexane dicarboxylate or sodium 4-[(4-chlorobenzoyl)amino]benzoate. In some embodiments, the first polyethylene composition and the nucleating agent can be blended and provided as a polyethylene-based composition. In some embodiments, such polyethylene-based composition can be co-extruded with other layers to form a multilayer film. When such nucleating agents are used in suitable amounts and in combination with the first polyethylene composition described herein, it is believed to provide a more uniform distribution of crystals and crystal size in the polyethylene film, a more uniform melting behavior of the resulting polyethylene-based composition and films formed from the polyethylene-based composition, and one or more other improvements in the resulting film (e.g., stiffness, barrier, and / or optical properties).

[0137] In some embodiments, the nucleating agent is calcium 1,2-cyclohexane dicarboxylate. In some embodiments, the nucleating agent is sodium 4-[(4-chlorobenzoyl)amino]benzoate. In some embodiments, such polyethylene-based composition comprises both calcium 1,2-cyclohexane dicarboxylate and sodium 4-[(4-chlorobenzoyl)amino]benzoate.

[0138] Nucleating agents such as calcium 1,2-cyclohexane dicarboxylate or sodium 4-[(4- chlorobenzoyl)amino]benzoate are heterogeneous nucleating agents. The amount and type of heterogeneous nucleating agent is important in providing the desired properties. In some embodiments, the polyethylene-based composition comprises from 20 ppm to 5000 ppm of a heterogeneous nucleating agent in the form of calcium 1,2-cyclohexane dicarboxylate or sodium 4-[(4-chlorobenzoyl)amino]benzoate, the remainder being the first polyethylene composition described herein, based on the total weight of the polyethylene-based composition. In some embodiments, the polyethylene-based composition comprises from 20 ppm to 2000 ppm of calcium 1,2-cyclohexane dicarboxylate or sodium 4-[(4-chlorobenzoyl)amino]benzoate, the remainder being the first polyethylene composition described herein, based on the total weight of the polyethylene-based composition. In some embodiments, the polyethylene-based composition comprises from 500 ppm to 2000 ppm of calcium 1,2-cyclohexane dicarboxylate or sodium 4-[(4-chlorobenzoyl)amino]benzoate, the remainder being the first polyethylene composition described herein, based on the total weight of the polyethylene-based composition.

[0139] In some embodiments, the heterogeneous nucleating agent can be provided with a fatty acid metal salt such as zinc stearate, zinc palmitate, and mixtures thereof. Based on the commercial preparation of zinc stearate, some zinc palmitate can also be present because commercial stearic acid typically contains a significant amount of palmitic acid. In some such embodiments, the polyethylene-based composition comprises from 45 ppm to 1000 ppm of at least one of zinc stearate and zinc palmitate, based on the total weight of the polyethylene-based composition. In some embodiments, the polyethylene-based composition comprises from 50 to 700 ppm of zinc stearate and / or zinc palmitate, based on the total weight of the polyethylene-based composition. In some embodiments, the polyethylene-based composition comprises from 85 to 600 ppm of zinc stearate and / or zinc palmitate, based on the total weight of the polyethylene-based composition.

[0140] One non-limiting example of a calcium 1,2-cyclohexane dicarboxylate that can be used in embodiments of the present application is Hyperform HPN-20E from Milliken Chemical, Spartanburg, South Carolina. Hyperform HPN-20E comprises 60 to 70 weight percent calcium 1,2-cyclohexane dicarboxylate and 30 to 40 weight percent zinc stearate / zinc palmitate. In some embodiments, the polyethylene-based composition comprises 20 to 5000 ppm of Hyperform HPN-20E, based on the total weight of the polyethylene-based composition. In some embodiments, the polyethylene-based composition comprises 20 to 2000 ppm of Hyperform HPN-20E, based on the total weight of the polyethylene-based composition.

[0141] One non-limiting example of a sodium 4-[(4-chlorobenzoyl)amino]benzoate that can be used in embodiments of the present application is Hyperform HPN 210M from Milliken Chemical, Spartanburg, South Carolina.

[0142] In some embodiments, the calcium 1,2-cyclohexane dicarboxylate or sodium 4-[(4-chlorobenzoyl)amino]benzoate (and the fatty acid metal salt (e.g., zinc stearate and / or zinc palmitate), when also included) can be provided as a masterbatch by blending it with a carrier resin prior to combination with the first polyethylene composition described herein. In some such embodiments, the carrier resin is a polyethylene having a melt index (I2) of 1 to 12 grams / 10 minutes. In some embodiments in which the calcium 1,2-cyclohexane dicarboxylate and zinc stearate / palmitate are provided as a masterbatch, the masterbatch comprises 2 to 4 weight percent calcium 1,2-cyclohexane dicarboxylate and zinc stearate / zinc palmitate, based on the total weight of the masterbatch. In one embodiment, the carrier resin is a high density polyethylene homopolymer having a narrow molecular weight distribution with a density of 0.965 and a melt index (I2) of 8 to 9 grams / 10 minutes. In some embodiments, the masterbatch can also comprise other additives. Depending on the total amount of additives included, the masterbatch can comprise 85 to 98 weight percent carrier resin, based on the total weight of the masterbatch.

[0143] Other nucleating agents that can be used in some embodiments of the present application include those disclosed in U.S. Patent Publication Nos. 2015 / 0087758, 2015 / 0087759, and 2015 / 0086736, which are hereby incorporated by reference herein. In some embodiments, the polyethylene-based composition comprises from 20 ppm to 5000 ppm of such nucleating agent, based on the total weight of the polyethylene-based composition. In some embodiments, the polyethylene-based composition comprises from 20 ppm to 2000 ppm of such nucleating agent, based on the total weight of the polyethylene-based composition.

[0144] Second polyethylene composition

[0145] As discussed above, the multilayer film of the present application comprises at least one layer comprising a second polyethylene composition having certain properties. In some embodiments, the layers in the multilayer film of the present application comprise both a first polyethylene composition and a second polyethylene composition. In other embodiments, the first polyethylene composition and the second polyethylene composition are in different layers.

[0146] The second polyethylene composition used in embodiments of the present application comprises (1) a first polyethylene fraction having a single peak in an elution profile obtained by an improved comonomer composition distribution (iCCD) analysis method in the temperature range from 45 °C to 87 °C, wherein the first polyethylene area fraction is the area under the single peak of the first polyethylene fraction in the elution profile between 45 °C and 87 °C, and (2) a second polyethylene fraction having a single peak in an elution profile obtained by the iCCD analysis method in the temperature range from 95 °C to 120 °C, and wherein the second polyethylene area fraction is the area under the single peak of the second polyethylene fraction in the elution profile between 95 °C and 120 °C. The second polyethylene composition has a density from 0.924 g / cm3to 0.936 g / cm3and a melt index (I2) from 0.25 g / 10 min to 2.0 g / 10 min, wherein the second polyethylene fraction area is at least 40% of the total area of the elution profile, wherein the ratio of the first polyethylene fraction area to the second polyethylene fraction area is from 0.75 to 2.5, and wherein the width of the single peak of the second polyethylene fraction at 50% peak height is less than 5.0 °C. 3 to 0.936 g / cm3. 3 to 2.0 g / 10 min, wherein the second polyethylene fraction area is at least 40% of the total area of the elution profile, wherein the ratio of the first polyethylene fraction area to the second polyethylene fraction area is from 0.75 to 2.5, and wherein the width of the single peak of the second polyethylene fraction at 50% peak height is less than 5.0 °C.

[0147] In one or more embodiments, the second polyethylene composition can have a density from 0.924 g / cm3 3 to 0.936 g / cm3. 3 to 0.936 g / cm3. 3to 0.931 g / cm 3 , 0.924 g / cm 3 to 0.928 g / cm 3 , 0.927 g / cm 3 to 0.931 g / cm 3 or 0.929 g / cm 3 to 0.933 g / cm 3 According to further embodiments, the second polyethylene composition can have a density of 0.924 g / cm 3 to 0.928 g / cm 3 , 0.928 g / cm 3 to 0.932 g / cm 3 , 0.932 g / cm 3 to 0.936 g / cm 3 or any combination of these ranges.

[0148] In one or more embodiments, the second polyethylene composition can have a melt index (I2) of 0.25 g / 10 min to 2.0 g / 10 min, such as 0.5 g / 10 min to 1.2 g / 10 min. For example, in one or more embodiments, the second polyethylene composition can have a melt index (I2) of 0.25 g / 10 min to 0.5 g / 10 min, 0.5 g / 10 min to 0.7 g / 10 min, 0.7 g / 10 min to 0.9 g / 10 min, 0.59 g / 10 min to 1.1 g / 10 min, 1.1 g / 10 min to 1.3 g / 10 min, 1.3 g / 10 min to 1.5 g / 10 min, 1.5 g / 10 min to 1.7 g / 10 min, 1.7 g / 10 min to 2.0 g / 10 min, or any combination of these ranges. According to further embodiments, the second polyethylene composition can have a melt index (I2) of 0.65 to 1.05.

[0149] According to embodiments, the second polyethylene composition can have a molecular weight distribution, expressed as the ratio of weight average molecular weight to number average molecular weight (Mw / Mn), in the range of 2.5 to 8.0. For example, the second polyethylene composition can have a molecular weight distribution of 2.5 to 3.0, 3.0 to 3.5, 3.5 to 4.0, 4.0 to 4.5, 4.5 to 5.0, 5.0 to 5.5, 5.5 to 6.0, 6.0 to 6.5, 6.5 to 7.0, 7.0 to 7.5, 7.5 to 8.0, or any combination of these ranges. In further embodiments, the second polyethylene composition can have a molecular weight distribution of 3.0 to 5.0. As presently described, the molecular weight distribution can be calculated according to gel permeation chromatography (GPC) techniques as described herein.

[0150] According to one or more additional embodiments, the second polyethylene composition can have a zero shear viscosity ratio of less than 3.0. For example, the second polyethylene composition can have a zero shear viscosity ratio of less than 2.9, less than 2.8, less than 2.7, less than 2.6, less than 2.5, less than 2.4, less than 2.3, less than 2.2, less than 2.1, less than 2.0, less than 1.9, less than 1.8, less than 1.7, less than 1.6, less than 1.5, less than 1.4, less than 1.3, less than 1.2, or even less than 1.1. In one or more embodiments, the second polyethylene composition can have a zero shear viscosity ratio of at least 1.0.

[0151] Referring to the depicted iCCD distribution, Figure 1 A sample iCCD distribution 100 is schematically depicted along with a cumulative weight fraction curve 200. Figure 1 Several features of the iCCD curve of the second polyethylene composition discussed in detail herein are generally depicted, such as the first fraction, the second fraction, the half-peak width, and the like. Thus, Figure 1 may be used as a reference with respect to the disclosure relating to the iCCD curve provided herein. Specifically, a first fraction 102 and a second fraction 106 are depicted. The first fraction 102 has a peak 104 and the second fraction 106 has a peak 108. Each fraction has a half-peak width 110 and a half-peak width 112. It should be understood that, Figure 1 The curve of

[0152] In one or more embodiments, the first polyethylene fraction of the second polyethylene composition can have a single peak in the elution curve obtained by iCCD in the temperature range of 45°C to 87°C. In one or more embodiments, the single peak of the first polyethylene fraction can be in the temperature range of 60°C to 85°C, such as 70°C to 85°C. Without being bound by theory, it is believed that in at least some embodiments of the second polyethylene composition, where a dual reactor design is used for polymerization, there can be a combination of crystalline domains of higher density and amorphous domains of lower density. Impact strength is primarily controlled by the amorphous region or the tie concentration connecting adjacent lamellae. When the density is less than 0.910 g / cc, the relative tie chain concentration is estimated to be relatively large. The peak of the first polymer fraction in the composition disclosed herein can be in the temperature range of 60°C to 85°C, which can provide a greater tie chain concentration to obtain functional benefits, such as improved toughness.

[0153] It should be understood that the peak in the first or second polyethylene fraction may not be formed by a local minimum in the corresponding polyethylene fraction at a defined temperature boundary. That is, the peak must be a peak within the entire spectral range, rather than a peak formed by a threshold temperature of the polyethylene fraction. For example, if there is a single peak in the polyethylene fraction, followed by a single valley (upward slope, then downward slope, then upward slope), then there will be only a single peak in such a polyethylene fraction.

[0154] In one or more embodiments, the second polyethylene fraction can have a single peak in the elution curve obtained by iCCD in the temperature range of 95° C. to 120° C. A temperature range of 95° C. to 120° C. for the second polyethylene fraction can be desirable because the low molecular weight, high density component at 95° C. to 120° C. can allow the polyethylene to achieve a higher overall density while maintaining a lower density fraction, as described by the ratio of the two fractions.

[0155] In one or more embodiments, the width of the single peak of the second polyethylene fraction at 50% peak height may be less than 5.0° C., less than 4° C., or even less than 3° C. Typically, a smaller temperature range at 50% peak height corresponds to a "sharper" peak. Without being bound by any particular theory, it is believed that the "sharper" or "narrower" peak is a characteristic caused by the molecular catalyst and indicates that the comonomer incorporation on the higher density fraction is minimized, thereby enabling a higher density separation between the two fractions.

[0156] In one or more embodiments, the second polyethylene composition may have a local minimum in the elution curve obtained by iCCD within a temperature range of 80° C. to 90° C. The local minimum may fall between the peaks of the first polyethylene fraction and the second polyethylene fraction.

[0157] In the embodiments described herein, the first polyethylene fraction area is the area under the single peak of the first polyethylene fraction between 45°C and 87°C in the elution curve. Similarly, the second polyethylene fraction area is the area under the single peak of the second polyethylene fraction between 95°C and 120°C in the elution curve. The first polyethylene fraction area and the second polyethylene fraction area can generally correspond to the total relative mass of each polymer fraction in the polyethylene composition, respectively. Generally speaking, the polyethylene fraction area in the iCCD curve can be determined by integrating the iCCD curve between specified starting and ending temperatures.

[0158] 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 may be at least 10° C. For example, the difference between the single peak of the second polyethylene fraction and the single peak of the first polyethylene fraction may be at least 12° C., 14° C., 16° C., 18° C., or even at least 20° C.

[0159] In one or more embodiments, the first polyethylene fraction area can 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 area can comprise 40% to 65%, such as 42% to 58%, 43% to 45%, 45% to 47%, 53% to 55%, or 55% to 57% of the total area of the elution profile.

[0160] According to one or more embodiments, the second polyethylene fraction area can comprise at least 25% of the total area of the elution profile (e.g., at least 30%, at least 35%, or even at least 40% of the total area of the elution profile). For example, the first polyethylene fraction area can comprise 20% to 50%, 27% to 31%, or 41% to 48% of the total area of the elution profile.

[0161] According to some embodiments, the ratio of the first polyethylene fraction area to the second polyethylene fraction area can be 0.75 to 2.5 (such as 0.75 to 1.0, 1.0 to 1.25, 1.25 to 1.5, 1.5 to 1.75, 1.75 to 2.0, 2.0 to 2.25, 2.25 to 2.5, or any combination of these ranges).

[0162] In one or more embodiments, the second polyethylene composition is formed from the polymerization of ethylene and a comonomer, such as a C3-C12 olefin. Contemplated comonomers include C6-C9 olefins, such as 1-octene and 1-hexene. In one or more embodiments, the comonomer is 1-octene.

[0163] In one or more embodiments, the difference between the unimodal of the second polyethylene fraction and the unimodal of the first polyethylene fraction can be at least 10 °C, at least 12.5 °C, at least 15 °C, at least 17.5 °C, or even at least 20 °C.

[0164] In one or more embodiments, the first polyethylene fraction can have a melt index (I2) of 0.01 g / 10 min to 0.18 g / 10 min. For example, according to one or more embodiments, the first polyethylene fraction can have a melt index (I2) of 0.01 g / 10 min to 0.03 g / 10 min, 0.03 g / 10 min to 0.05 g / 10 min, 0.05 g / 10 min to 0.07 g / 10 min, 0.07 g / 10 min to 0.09 g / 10 min, 0.09 g / 10 min to 0.11 g / 10 min, 0.11 g / 10 min to 0.13 g / 10 min, 0.13 g / 10 min to 0.15 g / 10 min, 0.15 g / 10 min to 0.18 g / 10 min, or any combination of these ranges.

[0165] In one or more embodiments, the second polyethylene fraction can have a melt index (I2) of 1 g / 10 minutes to 10,000 g / 10 minutes. For example, according to one or more embodiments, the second polyethylene fraction can have a melt index (I2) of 10 g / 10 minutes to 1,000 g / 10 minutes, 20 g / 10 minutes to 800 g / 10 minutes, 1 g / 10 minutes to 100 g / 10 minutes, 100 g / 10 minutes to 1,000 g / 10 minutes, 1,000 g / 10 minutes to 10,000 g / 10 minutes, or any combination of these ranges.

[0166] In one or more embodiments, the second polyethylene fraction can have a weight average molecular weight of less than or equal to 120,000 g / mol, such as 20,000 g / mol to 120,000 g / mol or 40,000 g / mol to 65,000 g / mol. In further embodiments, the second polyethylene fraction can have a weight average molecular weight of 20,000 g / mol to 40,000 g / mol, 40,000 g / mol to 60,000 g / mol, 60,000 g / mol to 80,000 g / mol, 80,000 g / mol to 100,000 g / mol, 100,000 g / mol to 120,000 g / mol, or any combination of these ranges. The molecular weight of the polyethylene fraction can be calculated based on GPC results, as described below.

[0167] According to further embodiments, the second polyethylene composition can have a Dow Rheology Index of less than or equal to 5, such as less than or equal to 4, less than or equal to 3, less than or equal to 2, or even less than or equal to 1.

[0168] In one or more embodiments, the second polyethylene composition can 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 Ti02or CaC03), opacifiers, nucleating agents, processing aids, pigments, primary antioxidants, secondary antioxidants, UV stabilizers, anticaking agents, slip agents, slip agents, flame retardants, antimicrobial agents, odor-reducing agents, antifungal agents, and combinations thereof. The total weight of such additives included in the second polyethylene composition can be about 0.1% to about 10%, based on the weight of the second polyethylene composition including such additives.

[0169] Polymerization

[0170] Any conventional polymerization process can be employed to produce the second polyethylene composition described herein. Such conventional polymerization processes include, but are not limited to, slurry polymerization processes using one or more conventional reactors, for example, loop reactors, isothermal reactors, stirred tank reactors, batch reactors, and / or any combination thereof, in parallel or in series. The polyethylene composition can be produced, for example, via a solution phase polymerization process using one or more loop reactors, isothermal reactors, and combinations thereof.

[0171] Generally, the solution phase polymerization process can be conducted at temperatures ranging from 115 °C to 250 °C (e.g., 115 °C to 210 °C) and pressures ranging from 300 psi to 1,000 psi (e.g., 400 psi to 800 psi) in one or more well-mixed reactors, for example, one or more isothermal loop reactors or one or more adiabatic reactors. In one embodiment, in a dual reactor, the temperature in the first reactor ranges from 115 °C to 190 °C (e.g., 160 °C to 180 °C), while the second reactor temperature ranges from 150 °C to 250 °C (e.g., 180 °C to 220 °C). In other embodiments, in a single reactor, the temperature in the reactor ranges from 115 °C to 250 °C (e.g., 115 °C to 225 °C).

[0172] The residence time in the solution phase polymerization process can range from 2 to 30 minutes (e.g., 5 to 25 minutes). Ethylene, solvent, hydrogen, one or more catalyst systems, optionally one or more co-catalysts, and optionally one or more comonomers are continuously fed into the one or more reactors. Exemplary solvents include, but are not limited to, isoparaffins. For example, such a solvent is commercially available from ExxonMobil Chemical Co., Houston, Texas, under the name ISOPAR E. The resulting mixture of polyethylene composition and solvent is then removed from the reactor and the polyethylene composition is isolated. The solvent is typically recovered via a solvent recovery unit (i.e., heat exchangers and vapor-liquid separator drums) and subsequently recycled back into the polymerization system.

[0173] In some embodiments, the second polyethylene composition can be produced by solution polymerization in a dual reactor system, for example, 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 co-catalysts can be present. In another embodiment, the second polyethylene composition can be produced by solution polymerization in a single reactor system, for example, a single loop reactor system, where ethylene is polymerized in the presence of two catalyst systems. In some embodiments, only ethylene is polymerized.

[0174] Catalyst system

[0175] The same catalyst system described in connection with the production of the first polyethylene composition can be used to produce the polyethylene composition of the second composition. As described in the Examples section, the first and second polyethylene compositions are produced by different processes such that the resulting polyethylene compositions have different properties as described herein.

[0176] Multilayer film

[0177] The multilayer film of the present application comprises both the first polyethylene composition and the second polyethylene composition. In some embodiments, the layers in the multilayer film of the present application comprise both the first polyethylene composition and the second polyethylene composition. In other embodiments, the first polyethylene composition and the second polyethylene composition are in different layers.

[0178] In some embodiments of the multilayer film of the present application, the multilayer film can comprise the first polyethylene composition in more than one layer, while in other embodiments, the first polyethylene composition is provided in a single layer. The multilayer film comprises 40 wt% or less of the first polyethylene composition, based on the total weight of the multilayer film. In some embodiments, the multilayer film comprises at least 20 wt% of the first composition, based on the total weight of the multilayer film. In some embodiments, the multilayer film comprises from 20 wt% to 40 wt% of the first polyethylene composition, based on the total weight of the multilayer film. For example, the multilayer film can comprise from 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, or 30 wt% to 31 wt%, 32 wt%, 33 wt%, 34 wt%, 35 wt%, 36 wt%, 37 wt%, 38 wt%, 39 wt%, or 40 wt% of the first polyethylene composition, based on the total weight of the multilayer film. In some embodiments, the multilayer film comprises from 30 wt% to 40 wt% of the first polyethylene composition, based on the total weight of the multilayer film.

[0179] The amount of the second polyethylene composition used in the films of the present application can depend on a number of factors, including, for example, other layers in the film, the desired properties of the film, the end-use application of the film, and the like. In some embodiments, the multilayer film comprises 20 wt% to 80 wt% of the second polyethylene composition, based on the total weight of the multilayer film. For example, the multilayer film can comprise 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, or 30 wt% to 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt%, or 80 wt% of the second polyethylene composition, based on the total weight of the multilayer film. In some embodiments, the multilayer film comprises 20 wt% to 70 wt% of the second polyethylene composition, based on the total weight of the multilayer film.

[0180] The number of layers in the film can depend on a number of factors, including, for example, the desired properties of the film, the desired thickness of the film, the contents of other layers of the film, the end-use application of the film, the equipment available to make the film, and the like. In various embodiments, the multilayer films of the present application can comprise up to 2 layers, 3 layers, 4 layers, 5 layers, 6 layers, 7 layers, 8 layers, 9 layers, 10 layers, or 11 layers. In some embodiments, the multilayer film is a five-layer film. In some embodiments, the multilayer film is a three-layer film.

[0181] In addition to the first polyethylene composition and the second polyethylene composition, one or more layers of the multilayer film can also comprise other polymers. For example, in some embodiments, in addition to the first polyethylene composition and the second polyethylene composition described above, one or more layers of the multilayer film can also comprise a low density polyethylene (LDPE) or a linear low density polyethylene (LLDPE). For example, LDPE can be included in some layers to facilitate processing. In some embodiments in which LDPE is used in the film, the LDPE can comprise 1 wt% to less than 50 wt% of the LDPE, based on the total weight of the multilayer film. In some embodiments, the multilayer film can comprise 1 wt% to 30 wt% of the LDPE, based on the total weight of the film. In some embodiments, the multilayer film can comprise 20 wt% to 30 wt% of the LDPE, based on the total weight of the film. Examples of commercially available LDPE that can be used in some embodiments of the present application include LDPE available from The Dow Chemical Company, such as DOW LDPE 132I, DOW LDPE 203M, DOW LDPE 586A, DOW LDPE 230N, and AGILITY LDPE 1000. TM DOW LDPE 132I, DOW LDPE 203M, DOW LDPE 586A, DOW LDPE 230N, and AGILITY LDPE 1000. TM DOW LDPE 132I, DOW LDPE 203M, DOW LDPE 586A, DOW LDPE 230N, and AGILITY LDPE 1000. TM DOW LDPE 132I, DOW LDPE 203M, DOW LDPE 586A, DOW LDPE 230N, and AGILITY LDPE 1000. TM DOW LDPE 132I, DOW LDPE 203M, DOW LDPE 586A, DOW LDPE 230N, and AGILITY LDPE 1000. TM1021. In some embodiments where LLDPE is used in the film, the LLDPE can comprise from 1 wt% to less than 50 wt% of the LDPE, based on the total weight of the multilayer film. In some embodiments, the multilayer film can comprise from 20 wt% to 50 wt% of the LLDPE, based on the total weight of the film. Examples of commercially available LLDPE that can be used in some embodiments of the present application include LLDPE available from The Dow Chemical Company, such as DOWLEX TM GM 8051F, DOWLEX TM GM 8051G, DOWLEX TM GM 8051, DOWLEX TM GM 8070, DOWLEX TM TG 2085B, INNATE TM ST50, ELITE TM NG5400B, ELITE TM NG5401B, ELITE TM 5400G, and ELITE TM 5401G.

[0182] In some embodiments, one outer layer of the multilayer film is a sealant layer. The sealant layer can be used to form an article or package by adhering the film to another film, laminate, or itself using the sealant layer. Thus, the sealant layer is the outermost layer of the multilayer film.

[0183] In some embodiments, the sealant layer can comprise any resin known to one of ordinary skill in the art to be useful as a sealant layer.

[0184] In some embodiments, the sealant layer can comprise one or more ethylene-based polymers having a density from 0.890 g / cm3 3 to 0.925 g / cm3 3 and a melt index (I2) from 0.1 g / 10 min to 2.0 g / 10 min. In further embodiments, the ethylene-based polymer of the sealant film (or sealant layer) can have a density from 0.900 g / cm3 3 to 0.925 g / cm3 3 or from 0.910 g / cm3 3 to 0.925 g / cm3 3 Additionally, the ethylene-based polymer of the sealant film (or sealant layer) can have a melt index (I2) from 0.1 g / 10 min to 2.0 g / 10 min or from 0.1 g / 10 min to 1.5 g / 10 min. Various commercially available polyethylenes are considered suitable for use in the sealant film. Suitable commercially available examples can include ELITE TM 5400G, ELITETM 5401B and various AFFINITY TM polyolefin plastomers (e.g., AFFINITY TM 1888, AFFINITY TM 1140 and AFFINITY TM 1146), each of which is available from The Dow Chemical Company (Midland, MI).

[0185] In other embodiments, the sealant layer of the multilayer film can include additional ethylene-based polymers, for example, polyolefin plastomers, LDPE, LLDPE, and the like. The LDPE of the sealant film or sealant layer can generally include any LDPE known to those skilled in the art, including, for example, DOW TM LDPE 132I and DOW TM LDPE 586A. In embodiments using polyolefin plastomers, the polyolefin plastomers can have a melt index (I2) of 0.2 g / 10 min to 5 g / 10 min or 0.5 g / 10 min to 2.0 g / 10 min. Further, the polyolefin plastomers can have a density of 0.890 g / cm3to 0.920 g / cm3or 0.900 g / cm3 3 to 0.910 g / cm3. 3 Various commercially available polyolefin plastomers are believed to be suitable for use in the sealant film. Suitable examples include AFFINITY TM PL 1881G, AFFINITY TM PL 1888G, AFFINITY TM PF 1140G, and AFFINITY TM PF 1146G. In embodiments where the sealant layer includes LLDPE, the LLDPE can generally include any LLDPE known to those skilled in the art, including, for example, those commercially available from The Dow Chemical Company, such as DOWLEX TM NG2045B, DOWLEX TM TG2085B, DOWLEX TM GM 8051, DOWLEX TM GM 8070, DOWLEX TM GM 8085, and DOWLEX TM 5056G. Another example of an ethylene-based polymer that can be included is an INNATE 3 polyethylene resin having a density of 0.918 g / cm3 TM or less, available as INNATE TMST50 and INNATE TM TH60 is commercially available from The Dow Chemical Company.

[0186] In some embodiments, the sealant layer comprises a density of 0.900 g / cm 3 to 0.925g / cm 3 and a blend of an ethylene-based polymer and a polyolefin plastomer having a melt index (I2) of 0.1 g / 10 min to 2.0 g / 10 min. For example, in some embodiments, such a blend may include ELITE TM 5400G or ELITE TM 5401B and AFFINITY TM PL1881G. As another example, in some embodiments, such blends may include INNATE TM ST50 and AFFINITY TM PL1881G.

[0187] In some embodiments, the sealant layer comprises a blend of LLDPE and a polyolefin plastomer. For example, in some embodiments, such a blend may comprise DOWLEX TM NG 2045B or DOWLEX TM GM 8051 and AFFINITY TM PL1881G.

[0188] In some embodiments, the sealant layer comprises a blend of LLDPE and LDPE. For example, in some embodiments, such a blend may comprise DOWLEX TM NG 2045B or DOWLEX TM GM 8051 and DOW as LDPE TM LDPE 132I or DOW TM LDPE 586A. In some such embodiments, the amount of LDPE is 30 wt% or less based on the weight of the sealant layer.

[0189] In some embodiments, the sealant layer comprises a blend of a polyolefin plastomer and LDPE. For example, in some embodiments, such a blend may comprise AFFINITY TM PL 1881G, AFFINITY TM PL 1888G, AFFINITY TM PF 1140G and AFFINITY TM PF 1146G and DOW as LDPE TMLDPE 132I or DOW TM LDPE 586A. In some such embodiments, the amount of LDPE is 30 wt.% or less, based on the weight of the sealant layer.

[0190] In some embodiments, it can be particularly advantageous to use a third polyethylene composition (or sealant resin) in the sealant layer. For example, in some embodiments, the third polyethylene composition (or sealant resin) can provide a low heat seal initiation temperature (similar to a polyolefin plastomer), but with less bubble obstruction relative to a polyolefin plastomer having an equivalent heat seal initiation temperature. The third polyethylene composition (sealant resin) is further described below.

[0191] It will be appreciated that in some embodiments, any of the layers within the film can further include one or more additives known to those skilled in the art (in addition to the additives described above for the polyethylene-based compositions), such as antioxidants, ultraviolet light stabilizers, heat stabilizers, slip agents, anti-blocking agents, pigments or colorants, processing aids, crosslinking catalysts, flame retardants, fillers, and blowing agents.

[0192] In some embodiments, the multilayer film is formed primarily of polyethylene. According to some embodiments of the present application, because it is polyethylene-based, the multilayer film of the present application can be incorporated into an article that is primarily (if not substantially or entirely) composed of polyethylene, in order to provide an article that is more easily recyclable. For example, in addition to other advantages that can be provided by the use of such polymers, a multilayer film that primarily includes polyethylene also has improved recyclability. For example, in some embodiments, the multilayer film is composed entirely of ethylene-based polymers, in addition to additives. In some embodiments, the multilayer film can include 90% by weight ethylene-based polymers, or in some embodiments, 95% by weight ethylene-based polymers, or in some embodiments, 99% by weight ethylene-based polymers, or in some embodiments, 99.9% by weight ethylene-based polymers, or in some embodiments, 100% by weight ethylene-based polymers, based on the total weight of the multilayer film.

[0193] The multilayer film can have a variety of thicknesses, depending on, for example, the number of layers, the intended use of the film, and other factors. In some embodiments, the total thickness of such multilayer films is less than 200 micrometers, or in some embodiments, less than 150 micrometers, or in some embodiments, less than 120 micrometers. In some embodiments, the multilayer films of the present application have a total thickness of 30 micrometers to 200 micrometers, or 30 micrometers to 150 micrometers, or 30 micrometers to 120 micrometers.

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

[0195] The multilayer films of the present application can exhibit one or more desirable properties. For example, in some embodiments, the multilayer films can exhibit desirable dart impact values, secant modulus, barrier properties, and / or other properties. In particular, in some embodiments, the multilayer films of the present application can surprisingly exhibit a good balance of dart impact (toughness) versus secant modulus when compared to multilayer films having the same overall density. Further, in some embodiments, the increased density of the multilayer films of the present application can also improve the barrier properties of the multilayer films.

[0196] In one exemplary embodiment, the multilayer film of the present application is a three layer film in which the first polyethylene composition is in the core layer as described herein, and in which the two outer layers comprise the second polyethylene composition as described herein.

[0197] In another exemplary embodiment, the multilayer film of the present application is a three layer film having a layer arrangement of A / B / C, in which the A layer is a sealant layer (as described above), in which the B layer comprises the first polyethylene composition as described herein, and in which the C layer comprises the second polyethylene composition as described herein. In further embodiments, the A layer comprises the third polyethylene composition as described herein.

[0198] In another exemplary embodiment, the multilayer film of the present application is a five layer film having a layer arrangement of A / B / C / B / D, in which the A layer is a sealant layer (as described above), in which the B layer comprises the second polyethylene composition as described herein, in which the C layer comprises the first polyethylene composition as described herein, and in which the D layer comprises a linear low density polyethylene. In further embodiments, the A layer comprises the third polyethylene composition as described herein.

[0199] In another exemplary embodiment, the multilayer film of the present application is a five layer film having a layer arrangement of A / B / C / C / B, in which the A layer is a sealant layer (as described above), in which the B layer comprises the second polyethylene composition as described herein, and in which the C layer comprises the first polyethylene composition as described herein. In further embodiments, the A layer comprises the third polyethylene composition as described herein.

[0200] In another example embodiment, the multilayer film of the present application is a five- layer film having a layer arrangement of A / B / C / B / D, where the A layer is a sealant layer (as described above), where the B layer comprises a first polyethylene composition as described herein, where the C layer comprises a second polyethylene composition as described herein, and where the D layer comprises a linear low density polyethylene. In further embodiments, the A layer comprises a third polyethylene composition as described herein.

[0201] In another example embodiment, the multilayer film of the present application is a five- layer film having a layer arrangement of A / B / C / B / C, where the A layer is a sealant layer (as described above), where the B layer comprises a second polyethylene composition as described herein, and where the C layer comprises a first polyethylene composition as described herein. In further embodiments, the A layer comprises a third polyethylene composition as described herein.

[0202] In another example embodiment, the multilayer film of the present application is a five- layer film having a layer arrangement of A / B / A / B / A, where the A layer comprises a second polyethylene composition as described herein, and where the B layer comprises a first polyethylene composition as described herein.

[0203] Third polyethylene composition (sealant resin)

[0204] As described above, in some embodiments, the multilayer film of the present application includes an outer layer that is a sealant layer comprising a third polyethylene composition. In some embodiments, the third polyethylene composition comprises (a) a first polyethylene fraction comprising at least one peak in a temperature range from 35°C to 70°C in an elution profile obtained by a modified comonomer composition distribution (iCCD) analysis method, where a first polyethylene area fraction is an area from 35°C to 70°C in the elution profile, and where the first polyethylene fraction area comprises from 25% to 65% of a total area of the elution profile; (b) a second polyethylene fraction comprising at least one peak in a temperature range from 85°C to 120°C in an elution profile obtained by the iCCD analysis method, where a second polyethylene area fraction is an area from 85°C to 120°C in the elution profile, and where the second polyethylene fraction area comprises at least 20% of the total area of the elution profile; and (c) a third polyethylene fraction in a temperature range from 70°C to 85°C in an elution profile obtained by the iCCD analysis method, where a third polyethylene area fraction is an area from 70°C to 85°C in the elution profile, and where the third polyethylene fraction area comprises less than 10% of the total area of the elution profile. The third polyethylene composition can have a density from 0.880 g / cm3to 0.910 g / cm3, a melt index (I2) from 0.1 g / 10 min to 2.0 g / 10 min, and a melt strength from 10 cN to 25 cN. 3 to 0.910 g / cm3 3A density of 0.50 g / 10 min to 6.0 g / 10 min, a melt index (I2) of 0.50 g / 10 min to 6.0 g / 10 min, and a zero shear viscosity ratio of the third polyethylene composition of less than 2.0.

[0205] In one or more embodiments, the density of the third polyethylene composition may be 0.880 g / cm 3 to 0.910g / cm 3 For example, embodiments of the third polyethylene composition may have a density within the following ranges: 0.880 g / cm 3 to 0.908g / cm 3 , 0.880g / cm 3 to 0.906g / cm 3 , 0.880g / cm 3 to 0.904g / cm 3 , 0.880g / cm 3 to 0.902g / cm 3 、0.880g / cm 3至 0.900g / cm 3 , 0.900g / cm 3 to 0.908g / cm 3 , 0.900g / cm 3 to 0.906g / cm 3 , 0.900g / cm 3 to 0.904g / cm 3 , 0.900g / cm 3 to 0.902g / cm 3 , 0.902g / cm 3 to 0.910g / cm 3 , 0.902g / cm 3 to 0.908g / cm 3 , 0.902g / cm 3 to 0.906g / cm 3 , 0.902g / cm 3 to 0.904g / cm 3 , 0.904g / cm 3 to 0.910g / cm 3 、0.904g / cm 3 to 0.908g / cm 3 , 0.904g / cm 3 to 0.906g / cm 3 , 0.906g / cm 3 to 0.910g / cm 3 , 0.906g / cm 3 to 0.908g / cm3 0.908 g / cm3 3 0.908 g / cm3 3 0.908 g / cm3, or a combination of these ranges.

[0206] In one or more embodiments, the third polyethylene composition can have a melt index (I2) of 0.50 g / 10 min to 6.0 g / 10 min. For example, in one or more embodiments, the third polyethylene composition can have a melt index (I2) within the following ranges: 0.5 g / 10 min to 5.0 g / 10 min, 0.5 g / 10 min to 4.0 g / 10 min, 0.5 g / 10 min to 3.0 g / 10 min, 0.5 g / 10 min to 2.0 g / 10 min, 0.5 g / 10 min to 1.0 g / 10 min, 1.0 g / 10 min to 6.0 g / 10 min, 1.0 g / 10 min to 5.0 g / 10 min, 1.0 g / 10 min to 4.0 g / 10 min, 1.0 g / 10 min to 3.0 g / 10 min, 1.0 g / 10 min to 2.0 g / 10 min, 2.0 g / 10 min to 6.0 g / 10 min, 2.0 g / 10 min to 5.0 g / 10 min, 2.0 g / 10 min to 4.0 g / 10 min, 2.0 g / 10 min to 3.0 g / 10 min, 3.0 g / 10 min to 6.0 g / 10 min, 3.0 g / 10 min to 5.0 g / 10 min, 3.0 g / 10 min to 4.0 g / 10 min, 4.0 g / 10 min to 6.0 g / 10 min, 4.0 g / 10 min to 5.0 g / 10 min, 5.0 g / 10 min to 6.0 g / 10 min, or a combination of these ranges.

[0207] According to embodiments, the third polyethylene composition can have a molecular weight distribution, expressed as the ratio of weight average molecular weight to number average molecular weight (Mw / Mn), in the range of 2.0 to 6.0. For example, the third polyethylene composition can have a molecular weight distribution within the following ranges: 2.0 to 5.5, 2.0 to 5.0, 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 6.0, 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, or 5.5 to 6.0, or a combination of these ranges. As presently described, the molecular weight distribution can be calculated according to gel permeation chromatography (GPC) techniques as described herein.

[0208] According to one or more additional embodiments, the third polyethylene composition can have a zero shear viscosity ratio of less than 2.0. For example, the third polyethylene composition can have a zero shear viscosity ratio of less than 1.9, less than 1.8, less than 1.7, less than 1.6, less than 1.5, less than 1.4, less than 1.3, less than 1.2, or even less than 1.1. In one or more embodiments, the third polyethylene composition can have a zero shear viscosity ratio of at least 1.0. In embodiments, the third polyethylene composition can have a zero shear viscosity ratio in a range from 1.0 to 2.0, 1.0 to 1.8, 1.0 to 1.6, 1.0 to 1.4, 1.0 to 1.2, 1.2 to 2.0, 1.2 to 1.8, 1.2 to 1.6, 1.2 to 1.4, 1.4 to 2.0, 1.4 to 1.8, 1.4 to 1.6, 1.6 to 2.0, 1.6 to 1.8, or 1.8 to 2.0.

[0209] Tan delta refers to the closeness of a material to a perfectly elastic solid (where d = 0°, tan delta = 0) or a perfectly Newtonian liquid (where d = 90°, tan delta ~ infinity). Thus, the lower the value of tan delta, the more elastic the material. Tan delta is a function of long chain branching (LCB) and molecular weight distribution (MWD) at the same overall molecular weight. The greater the value of tan delta, the lower the LCB. In embodiments, the third polyethylene composition can have a tan delta in a range from 10 to 100, 10 to 90, 10 to 80, 10 to 70, 10 to 60, 10 to 50, 10 to 40, 10 to 30, 10 to 20, 20 to 100, 20 to 90, 20 to 80, 20 to 70, 20 to 60, 20 to 50, 20 to 40, 20 to 30, 30 to 100, 30 to 90, 30 to 80, 30 to 70, 30 to 60, 30 to 50, 30 to 40, 40 to 100, 40 to 90, 40 to 80, 40 to 70, 40 to 60, 40 to 50, 50 to 100, 50 to 90, 50 to 80, 50 to 70, 50 to 60, 60 to 100, 60 to 90, 60 to 80, 60 to 70, 70 to 100, 70 to 90, 70 to 80, 80 to 100, 80 to 90, or 90 to 100 at 0.1 radian / second and 190 °C.

[0210] The third polyethylene composition can include at least a first polyethylene fraction and a second polyethylene fraction. Embodiments can include a third polyethylene fraction and a fourth polyethylene fraction. The various fractions included in the third polyethylene composition can be defined by their temperature ranges in an elution profile by improved comonomer composition distribution (iCCD) analysis methods. Embodiments of such fractions will be better understood in view of the examples provided herein.

[0211] Generally, the first fraction can include at least one peak within the temperature range of the first fraction. The second fraction can include at least one peak within the temperature range of the second fraction. The fourth fraction can include at least one peak within the temperature range of the fourth fraction. The first polyethylene area fraction, the second polyethylene fraction, the third polyethylene fraction, and the fourth polyethylene fraction can each include a portion of the total mass of the third polyethylene composition.

[0212] In one or more embodiments, one or more of the first polyethylene fraction, the second polyethylene fraction, and the fourth polyethylene fraction can have a unimodal peak.

[0213] It is understood that the peak in one or more of the first polyethylene fraction, the second polyethylene fraction, and the fourth polyethylene fraction can not be formed by a local minimum of the respective polyethylene fraction at a defined temperature boundary. That is, the peak must be a peak across the entire spectral range, and not a peak formed by a threshold temperature of the polyethylene fraction. For example, if there is a single peak in a polyethylene fraction, followed by a single valley (an upward slope, followed by a downward slope, followed by an upward slope), then there will only be a single peak in such a polyethylene fraction.

[0214] In one or more embodiments, the first polyethylene fraction can be the area in the elution profile from 35 °C to 70 °C. In further embodiments, the first polyethylene fraction can be the area of the elution profile in the temperature range of 35 °C to 60 °C, 35 °C to 50 °C, 40 °C to 70 °C, 40 °C to 60 °C, 40 °C to 50 °C, 50 °C to 70 °C, 50 °C to 60 °C, 60 °C to 70 °C, or any combination of temperature ranges in the elution profile obtained by iCCD.

[0215] According to one or more embodiments, the first polyethylene fraction area can be at least 25% of the total area of the elution profile (e.g., at least 30%, at least 40%, at least 50%, or even at least 60% of the total area of the elution profile). For example, the first polyethylene fraction area can be 25% to 65%, 25% to 55%, 25% to 45%, 25% to 35%, 35% to 65%, 35% to 55%, 35% to 45%, 45% to 65%, 45% to 55%, 55% to 65%, or any combination of the total area of the elution profile.

[0216] In one or more embodiments, the first polyethylene fraction can have at least one peak in the elution profile obtained by iCCD in a temperature range of 35°C to 70°C. In one or more embodiments, the first polyethylene fraction can have at least one peak in a temperature range of 35°C to 60°C, 35°C to 50°C, 40°C to 70°C, 40°C to 60°C, 40°C to 50°C, 50°C to 70°C, 50°C to 60°C, 60°C to 70°C, or any combination of temperature ranges in the elution profile obtained by iCCD.

[0217] The temperature range of the first polyethylene fraction (35°C to 70°C) can be desirable because it can correspond to the low density component of the third polyethylene composition. In embodiments, the low density component can provide a low hot tack initiation temperature, a hot seal initiation temperature, or both. Thus, increasing the first polyethylene fraction, which can include the low density component, can thereby decrease the hot tack initiation temperature, the hot seal initiation temperature, or both, and improve the hot tack strength and hot tack window of the third polyethylene composition.

[0218] In one or more embodiments, the second polyethylene fraction can be the area in the elution profile from 85°C to 120°C. In further embodiments, the second polyethylene fraction can be the area in the elution profile in a temperature range of 85°C to 110°C, 85°C to 100°C, 85°C to 90°C, 90°C to 120°C, 90°C to 110°C, 90°C to 100°C, 100°C to 120°C, 100°C to 110°C, 110°C to 120°C, or any combination of temperature ranges in the elution profile obtained by iCCD.

[0219] According to one or more embodiments, the second polyethylene fraction area can be at least 20% of the total area of the elution profile (e.g., at least 30%, at least 35%, at least 40, or at least 45% of the total area of the elution profile). For example, the second polyethylene fraction area can be 20% to 60%, 20% to 50%, 20% to 40%, 20% to 30%, 30% to 60%, 30% to 50%, 30% to 40%, 40% to 60%, 40% to 50%, 50% to 60%, or any combination of the total area of the elution profile.

[0220] In one or more embodiments, the second polyethylene fraction can have at least one peak in the elution profile obtained by iCCD in a temperature range of 85°C to 120°C. In one or more embodiments, the second polyethylene fraction can have at least one peak in a temperature range of 85°C to 110°C, 85°C to 100°C, 85°C to 90°C, 90°C to 120°C, 90°C to 110°C, 90°C to 100°C, 100°C to 120°C, 100°C to 110°C, 110°C to 120°C, or any combination of temperature ranges in the elution profile obtained by iCCD.

[0221] The temperature range of the second polyethylene fraction (85 °C to 120 °C) can be desirable as it can correspond to the high density component. In embodiments, increasing the high density component can increase the overall density of the third polyethylene composition. Thus, increasing the second polyethylene fraction can thereby increase the high density component and provide a polyethylene composition having a higher overall density. Further, increasing the second polyethylene fraction can increase the cohesiveness of the third polyethylene composition. Without being bound by theory, it is believed that larger crystals are formed in the high density fraction, which provides a rough surface. The rough surface can reduce the contact area and thus increase the cohesiveness of the third polyethylene composition.

[0222] In one or more embodiments, the third polyethylene composition can have a local minimum in the elution profile obtained by iCCD in the temperature range of 65 °C to 85 °C. The local minimum can fall between the peak of the first polyethylene fraction and the peak of the second polyethylene fraction.

[0223] In one or more embodiments, the third polyethylene area fraction can be the area in the elution profile from 70 °C to 85 °C. In further embodiments, the third polyethylene fraction can be the area of the elution profile in the temperature range of 70 °C to 80 °C, 70 °C to 75 °C, 75 °C to 85 °C, 75 °C to 80 °C, 80 °C to 85 °C, or any combination of ranges in the elution profile obtained by iCCD.

[0224] According to one or more embodiments, the third polyethylene fraction area can be less than 10% of the total area of the elution profile (e.g., less than 8%, less than 6%, or less than 4% of the total area of the elution profile). For example, the third polyethylene fraction area can be 4% to 10%, 4% to 8%, 4% to 6%, 6% to 10%, 6% to 8%, 8% to 10%, or any combination of ranges of the total area of the elution profile.

[0225] In the embodiments described herein, the third polyethylene area fraction can be the area in the elution profile from 70 °C to 85 °C. In one or more embodiments, the third polyethylene area fraction can be the area of the elution profile in the range of 70 °C to 85 °C, 70 °C to 80 °C, 70 °C to 75 °C, 75 °C to 85 °C, 75 °C to 80 °C, 80 °C to 85 °C, or any combination of ranges in the elution profile obtained by iCCD.

[0226] It can be desirable to minimize the third polyethylene fraction in the temperature range of 70 °C to 85 °C, otherwise this would shift the higher density component from the second polyethylene fraction to a lower temperature range within the elution profile. Without being bound by theory, it is believed that shifting the high density component to a lower temperature range within the elution profile would prevent the third polyethylene composition from obtaining the desired cohesiveness.

[0227] In one or more embodiments, the fourth polyethylene area fraction can be the area in the elution profile from 20 °C to 35 °C. In further embodiments, the fourth polyethylene fraction can be the area in the elution profile obtained by iCCD in the temperature range of 20 °C to 30 °C, 20 °C to 25 °C, 25 °C to 35 °C, 25 °C to 30 °C, 30 °C to 35 °C, or any combination thereof.

[0228] According to one or more embodiments, the fourth polyethylene fraction area can be less than 35% (e.g., less than 30%, less than 20%, less than 10%, less than 5%, or even less than 2% of the total area of the elution profile). For example, the fourth polyethylene fraction area can be from 0% to 35%, 0% to 20%, 0% to 10%, 0% to 5%, 5% to 35%, 5% to 20%, 5% to 10%, 10% to 35%, 10% to 20%, 20% to 35%, or any combination of the total area of the elution profile.

[0229] In the embodiments described herein, the fourth polyethylene area fraction is the area in the elution profile under at least one peak of the fourth polyethylene fraction in the range of 20 °C to 35 °C. In one or more embodiments, the fourth polyethylene fraction can have at least one peak in the temperature range of 20 °C to 30 °C, 20 °C to 25 °C, 25 °C to 35 °C, 25 °C to 30 °C, 30 °C to 35 °C, or any combination thereof in the elution profile obtained by iCCD.

[0230] It can be desirable to minimize the fourth polyethylene fraction in the temperature range of 20 °C to 35 °C. Without being bound by theory, it is believed that a high content of the fourth polyethylene portion prevents the third polyethylene composition from obtaining the desired adhesion.

[0231] In one or more embodiments, the third polyethylene composition can have a local minimum in the temperature range of 30 °C to 40 °C in the elution profile obtained by iCCD. The local minimum can fall between the peak of the fourth polyethylene fraction and the peak of the first polyethylene fraction.

[0232] It will be appreciated that two or more polyethylene fractions can overlap one another. In one or more embodiments, the first polyethylene area fraction and the fourth polyethylene area fraction can overlap.

[0233] In one or more embodiments, the third polyethylene composition is formed from the polymerization of ethylene and a comonomer, such as a C3–C12 olefin. Contemplated comonomers include C6–C9 olefins, such as 1-octene and 1-hexene. In one or more embodiments, the comonomer is 1-octene.

[0234] In one or more embodiments, the first polyethylene fraction can have a weight average molecular weight of less than or equal to 225,000 g / mol, for example, 30,000 g / mol to 225,000 g / mol, 60,000 g / mol to 150,000 g / mol, or 90,000 g / mol to 120,000 g / mol, or any combination of these ranges. The molecular weight of the polyethylene fraction can be calculated based on iCCD results, as described below.

[0235] In one or more embodiments, the second polyethylene fraction can have a weight average molecular weight of less than or equal to 225,000 g / mol, for example, 25,000 g / mol to 225,000 g / mol, 50,000 g / mol to 150,000 g / mol, 75,000 g / mol to 125,000 g / mol, or any combination of these ranges. The molecular weight of the polyethylene fraction can be calculated based on iCCD results, as described below.

[0236] In embodiments, the ratio of the molecular weight of the first polyethylene area fraction to the molecular weight of the total area of the elution profile is 0.5 to 1.5. In embodiments, the ratio can be 0.5 to 1.5, 0.5 to 1.0, or 1.0 to 1.5.

[0237] Polymerization

[0238] Any conventional polymerization process can be employed to produce the third polyethylene composition. Such conventional polymerization processes include, but are not limited to, gas phase polymerization processes, slurry polymerization processes, solution polymerization processes using one or more conventional reactors, for example, loop reactors, isothermal reactors, stirred tank reactors, tubular reactors, plug flow reactors, batch reactors, and / or any combination thereof, in parallel or in series. The third polyethylene composition can be produced, for example, by a solution phase polymerization process using one or more loop reactors, isothermal reactors, and combinations thereof.

[0239] Generally, the solution phase polymerization process can be conducted at temperatures ranging from 115 °C to 250 °C (e.g., 115 °C to 210 °C) and pressures ranging from 300 psi to 3,000 psi (e.g., 400 psi to 800 psi) in one or more well-mixed reactors, for example, one or more isothermal loop reactors or one or more adiabatic reactors. In one embodiment, in a dual reactor, the temperature in the first reactor ranges from 115 to 190 °C (e.g., 150 °C to 180 °C), while the second reactor temperature ranges from 150 °C to 250 °C (e.g., 180 °C to 220 °C). In another embodiment, in a single reactor, the temperature in the reactor ranges from 115 °C to 250 °C (e.g., 115 °C to 225 °C).

[0240] The residence time in the solution phase polymerization process is typically in the range of 2 to 30 minutes (e.g., 5 to 25 minutes). Ethylene, solvent, hydrogen, one or more catalyst systems, optionally one or more co-catalysts, and optionally one or more comonomers are continuously fed into one or more reactors. Exemplary solvents include, but are not limited to, isoparaffins. For example, such solvents are commercially available from ExxonMobil Chemical Co., Houston, Texas under the name ISOPAR E. The resulting mixture of the third polyethylene composition and solvent is then removed from the reactor and the polyethylene composition is isolated. The solvent is typically recovered via a solvent recovery unit (i.e., heat exchanger and vapor-liquid separator drum) and subsequently recycled back into the polymerization system.

[0241] In some embodiments, the third polyethylene composition can be produced via solution polymerization in a dual reactor system (e.g., dual loop reactor system) where ethylene is polymerized in the presence of one or more catalyst systems and one or more comonomers. In some embodiments, only ethylene is polymerized. Additionally, one or more co-catalysts can be present. In another embodiment, the third 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 and one or more comonomers.

[0242] Catalyst system

[0243] The same catalyst systems described in connection with the production of the first polyethylene composition can be used to produce the polyethylene composition of the second composition. As described in the Examples section, the first polyethylene composition and the second polyethylene composition are prepared differently such that the resulting polyethylene compositions have different properties as described herein.

[0244] Article

[0245] Embodiments of the present application also relate to articles, such as laminates and packages, formed from or incorporating the oriented multilayer polyethylene films of the present application (or from laminates incorporating such films). Such packages can be formed from any of the films or laminates described herein.

[0246] Examples of such articles can include flexible packages, pouches, stand-up pouches, and pre-made packages or pouches. In some embodiments, the oriented multilayer polyethylene films or laminates of the present application can be used for food packaging. Examples of food that can be included in such packaging include meat, cheese, grains, nuts, juice, sauces, pet food, and the like. Such packaging can be formed using techniques known to those skilled in the art based on the teachings herein and based on the particular use of the packaging (e.g., the type of food, the amount of food, etc.).

[0247] Embodiments of the articles of the present application can also be a laminate comprising the multilayer film of the present application. In some embodiments, the multilayer film according to embodiments of the present application can be laminated to another film. The other film in such embodiments can be a polyethylene sealant film, polyethylene terephthalate, polypropylene, or polyamide. The polyethylene sealant film can be a monolayer film or a multilayer film (e.g., comprising greater than 90 wt% of an ethylene-based polymer, or greater than 95 wt% of an ethylene-based polymer, or greater than 99 wt% of an ethylene-based polymer) formed substantially of polyethylene, which when heated as part of a laminate structure, can seal the laminate to another film, another laminate, or itself. Any polyethylene sealant film known to one of ordinary skill in the art based on the teachings herein can be used. When the other film comprises polyethylene terephthalate, polypropylene, or polyamide, the entire film can be formed of polyethylene terephthalate, polypropylene, or polyamide, or the film comprises at least one layer comprising polyethylene terephthalate, polypropylene, or polyamide. The film comprising polyethylene terephthalate, polypropylene, or polyamide for such embodiments based on the teachings herein can be selected by one of ordinary skill in the art.

[0248] Laminates according to embodiments of the present application can be formed using techniques known to one of ordinary skill in the art based on the teachings herein. For example, the multilayer film can be laminated to another film using an adhesive. Various adhesive compositions are believed to be suitable for use as the adhesive for preparing the laminate. These adhesives can include polyurethanes, epoxies, acrylics, and the like. In one embodiment, the laminate can include an adhesive layer comprising a polyurethane adhesive. The polyurethane adhesive can be solventless, aqueous, or solvent-based. Further, the polyurethane adhesive can be a two-part formulation. The weight or thickness of the adhesive layer can depend on a variety of factors including, for example, the desired thickness of the laminate, the type of adhesive used, and other factors. In some embodiments, the adhesive layer is applied to up to 5.0 g / m2 2 , or 1.0 g / m 2 to 4.0 g / m 2 , or 2.0 g / m 2 to 3.0 g / m 2 .

[0249] Laminates according to some embodiments of the present application can also be formed by extrusion lamination.

[0250] Test methods

[0251] The following analytical methods were used to describe various aspects of the present application unless otherwise indicated herein:

[0252] Melt index

[0253] Melt Index, I2(or I2) and I10 10 (or I10) are measured according to ASTM D-1238 (Method B) at 190 °C and under 2.16 kg and 10 kg load, respectively. Values are reported in g / 10 min.

[0254] Density

[0255] Samples for density measurement are prepared according to ASTM D4703. Measurements are made according to ASTM D792, Method B within one hour of pressing the sample.

[0256] Conventional gel permeation chromatography (conventional GPC)

[0257] A GPC-IR high temperature chromatographic system from PolymerChar (Valencia, Spain) was equipped with a Precision Detector (Amherst, MA), a 2-angle laser light scattering detector Model 2040, an IR5 infra-red detector, and a 4-capillary viscometer, both from PolymerChar. Data collection was performed using PolymerChar Instrument Control software and data collection interface. The system was equipped with an online solvent degassing device and pumping system from Agilent Technologies (Santa Clara, CA).

[0258] The injection temperature was controlled at 150 °C. The columns used were three 10- micron “Mixed-B” columns from Polymer Laboratories (Shropshire, UK). The solvent used was 1,2,4-trichlorobenzene. Samples were prepared at a concentration of 0.1 grams of polymer in 50 milliliters of solvent. Both the chromatographic solvent and the sample preparation solvent each contained “200 ppm butylated hydroxy toluene (BHT)”. Both solvent sources were sparged with nitrogen. The ethylene-based polymer samples were gently stirred at 160 degrees C for three hours. The injection volume was “200 microliters” and the flow rate was “1 mL / min”. The GPC column set was calibrated by running 21 “narrow molecular weight distribution” polystyrene standards. The molecular weight (MW) range of the standards was 580 g / mol to 8,400,000 g / mol, and the standards were contained in six “cocktail” mixtures. The individual cocktail mixtures had at least a decade separation of molecular weight. The cocktail mixtures were purchased from Polymer Laboratories. The polystyrene standards were prepared at “0.025 g in 50 mL of solvent” for molecular weights equal to or greater than 1,000,000 g / mol and “0.050 g in 50 mL of solvent” for molecular weights less than 1,000,000 g / mol.

[0259] The polystyrene standards were dissolved at 80°C with gentle agitation for 30 minutes. The narrow standards mix was run first and followed in order of decreasing highest molecular weight component to minimize degradation. Equation 1 was used to convert the polystyrene standard peak molecular weights to polyethylene molecular weights (as described by Williams and Ward, J. Polym. Sci, Polym. Letters, 6, 621 (1968):

[0260] Mpolyethylene = A x (Mpolystyrene) B (Equation 1),

[0261] where M is the molecular weight, A is equal to 0.4316 and B is equal to 1.0.

[0262] The number average molecular weight (Mn(conv gpc)), weight average molecular weight (Mw-conv gpc), and z average molecular weight (Mz(conv gpc)) were calculated according to Equations 2-4 below.

[0263]

[0264]

[0265]

[0266] In Equations 2 to 4, RV is the column retention volume (linear interval) collected in "points per second", IR is the IR detector signal in volts from the IR5 measurement channel of the GPC instrument, and M PE is the polyethylene equivalent MW determined from Equation 1. Data calculations were performed using "GPC One software (version 2.013H)" from PolymerChar.

[0267] Creep zero shear viscosity measurement method

[0268] Zero-shear viscosity was obtained by creep testing, which was performed on an AR G2 stress controlled rheometer (TA Instruments; New Castle, Del) using 25 mm diameter parallel plates at 190 °C. The rheometer oven was set to the test temperature for at least 30 minutes before zeroing the fixtures. At the test temperature, a compression molded sample disk was inserted between the plates and allowed to equilibrate for five minutes. The upper plate was then lowered 50 pm (instrument setting) above the desired test gap (1.5 mm). Any excess material was trimmed off and the upper plate was lowered to the desired gap. The measurement was conducted under a nitrogen purge at a flow rate of 5 L / min. The default creep time was set to two hours. Each sample was compression molded into a “2 mm thick x 25 mm diameter” circular plate at 177 °C under air at a pressure of 10 MPa for five minutes. The sample was then removed from the press and placed on the bench top to cool.

[0269] A constant low shear stress of 20 Pa was applied to all samples to ensure that the steady state shear rate was low enough to be in the Newtonian region. For the samples in this study, the resulting steady state shear rate was in the range of 10 -3 s -1 to 10 -4 s -1 . Steady state was determined by linear regression of all data in the last 10% time window of the plot of “log(J(t)) vs log(t)”, where J(t) is the creep compliance and t is the creep time. If the slope of the linear regression was greater than 0.97, then steady state was considered to have been reached and the creep test was stopped. In all cases for this study, the slope met the criteria within one hour. The steady state shear rate was determined from the slope of the linear regression of all data points in the last 10% time window of the plot of “e vs t”, where e is the strain. The zero-shear viscosity was determined from the ratio of the applied stress to the steady state shear rate.

[0270] To determine if the sample degraded during the creep test, a small amplitude oscillatory shear test from 0.1 rad / s to 100 rad / s was performed on the same sample before and after the creep test. The complex viscosity values of the two tests were compared. If the difference in viscosity values was greater than 5% at 0.1 rad / s, then the sample was considered to have degraded during the creep test and the results were discarded.

[0271] Zero shear viscosity ratio (ZSVR)

[0272] The zero-shear viscosity ratio (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 at an equivalent average molecular weight. According to the equation:

[0273] ZSVR = η 0B / η0L = η 0B / (2.29 -15 X Mwt 3.65 )

[0274] ZSV values were obtained from the creep test at 190°C by the method described above. As described above, Mwt was determined using conventional gel permeation chromatography. A correlation between ZSV and molecular weight of linear polyethylene was established based on a series of linear polyethylene reference materials. Lower ZSVR indicates a lower level of long chain branching.

[0275] Use 13 C NMR for branching measurement

[0276] Sample preparation

[0277] Samples were prepared by adding about 2.7 g of a 50 / 50 mixture of tetrachloroethane-d2 / o-dichlorobenzene containing 0.025 M Cr(AcAc)3 to 0.20 g to 0.30 g of sample in a Norell 1001-7 10 mm NMR tube. Oxygen was removed by purging the tube with N2for 1 minute. The sample was dissolved and homogenized by heating the tube and its contents to 120°C to 140°C using a heating block and a vortexer. Each sample was inspected visually to ensure homogeneity. Thoroughly mixed samples were not allowed to cool before insertion into a heated NMR sample changer and / or NMR probe.

[0278] Data acquisition parameters

[0279] Data were collected using a Bruker 600 MHz spectrometer equipped with a Bruker 10 mm multi-nuclear high-temperature CryoProbe. Data were acquired with 1280 transients per data file, a 7.8 second pulse repetition delay, a 90 degree flip angle, and reverse gated decoupling at a sample temperature of 120°C. All measurements were made on non-spinning samples in lock mode. The sample was allowed to thermally equilibrate before data were acquired. 13 C NMR chemical shift internal reference to EEE triads at 30.0 ppm. Data were processed into a spectrum, appropriate peaks were integrated (to quantify branching), and then one or more peak integrations were used or an average was taken of total branches per 1000C. If no branching was detected, the limit of detection for the spectrum was calculated using the integration of peaks such as chain end induced peaks and signal to noise.

[0280] Use 1 H NMR for unsaturation measurement

[0281] A stock solution (3.26 g) was added to 0.10 g to 0.13 g of polymer sample in a 10 mm NMR tube. The stock solution was a mixture of tetrachloroethane-d2 (TCE) and perchloroethylene (50:50, w:w) with 0.001 M Cr 3+ or 100% TCE with 0.001 M Cr 3+ The solution in the tube was purged with N2for 5 minutes to reduce the amount of oxygen. The sample was dissolved at 120 °C to 140 °C with periodic vortex mixing. Each 1 H NMR analysis was performed on a Bruker AVANCE 600 MHz spectrometer at 120 °C with a 10 mm cryoprobe.

[0282] Two experiments were performed to measure unsaturation: one control experiment and one double pre-saturation experiment. For the control experiment, the data was processed with an exponential window function with a 0.7 Hz line broadening. The signal from residual 1 H from TCE was set to 100, and the integrals (I 总 ) from about -0.5 ppm to 3 ppm were used as the signal for the entire polymer in the control experiment. The total number of carbons in the polymer, NC, was calculated as follows in Equation 1A:

[0283] NC= I 总计 / 2 (Equation 1A).

[0284] For the double pre-saturation experiment, the data was processed with an exponential window function with a 0.7 Hz line broadening, and the baseline was corrected from about 7 ppm to 4 ppm. The signal from residual 1 H from TCE was set to 100, and the corresponding integrals (I 亚乙烯基 , I 三取代 , I 乙烯基 , and I 乙烯叉 ) for unsaturation were integrated. It is well known that NMR spectroscopy can be used to determine polyethylene unsaturation, for example, see Busico, V. et al., Macromolecules, 2005, 38, 6988. The numbers of vinylidene, tri-substituted, vinyl, and vinylidene unsaturation units were calculated as follows:

[0285] N 亚乙烯基 = I 亚乙烯基 / 2 (Equation 2A),

[0286] N 三取代 = I 三取代 (Equation 3A),

[0287] N 乙烯基 = I 乙烯基 / 2 (Equation 4A),

[0288] N 乙烯叉= I 乙烯叉 / 2 (Equation 5A).

[0289] The unsaturation units per 1,000 total carbon (i.e., all polymer carbon including main chain and branch) is calculated as follows:

[0290] N 亚乙烯基 / 1,000 C = (N 亚乙烯基 / NC) * 1,000 (Equation 6A),

[0291] N 三取代 / 1,000 C = (N 三取代 / NC) * 1,000 (Equation 7A),

[0292] N 乙烯基 / 1,000 C = (N 乙烯基 / NCH2) * 1,000 (Equation 8A),

[0293] N 乙烯叉 / 1,000 C = (N 乙烯叉 / NC) * 1,000 (Equation 9A).

[0294] For residual proton from TCE-d2 1 H signals, the chemical shift reference value was set to 6.0 ppm. The control was run with ZG pulse, NS = 16, DS = 2, AQ = 1.82 s, D1 = 14 s (where D1 is the relaxation delay). The double pre-saturation experiment was run with a modified pulse sequence with O1P = 1.354 ppm, O2P = 0.960 ppm, NS = 50, AQ = 1.82 s, D1 = 1 s (where D1 is the pre-saturation time), D13 = 13 s (where D13 is the relaxation delay).

[0295] Improved method for comonomer content distribution analysis (iCCD)

[0296] An improved method for comonomer content analysis (iCCD) was developed in 2015 (Cong and Parrott et al., WO2017040127A1). The iCCD test was performed with a Crystallization Elution Fractionation instrument (CEF) (PolymerChar, Spain) equipped with an IR-5 detector (PolymerChar, Spain) and a two-angle light scattering detector model 2040 (Precision Detectors, now Agilent Technologies). A 5 cm or 10 cm (length) X ¼” (ID) stainless steel guard column packed with 20-27 micron glass (MoSCi Corporation, USA) was installed just before the IR-5 detector in the detector oven. 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 (previously used to dry ODCB solvent). The CEF instrument was equipped with an autosampler with N2 sweep function. ODCB was bubbled with dry nitrogen (N2) for one hour before use. Sample preparation was performed with the autosampler at a concentration of 4 mg / ml (unless otherwise specified) at 160 °C for 1 hour with shaking. The injection volume was 300 μΐ. The temperature profile for iCCD was: crystallization from 105 °C to 30 °C at 3 °C / min, thermal equilibration at 30 °C for 2 minutes (including solubles fraction elution time set to 2 minutes), elution from 30 °C to 140 °C at 3 °C / min. The flow rate during crystallization was 0.0 milliliter / minute. The flow rate during elution was 0.50 mL / min. Data were collected at one data point per second.

[0297] The iCCD column was packed with Bright 7GNM8-NiS (Nippon Chemical Industrial Co.) in a 15 cm (length) X ¼” (ID) stainless steel tube. Column packing and conditioning were performed with slurry method according to the reference (Cong, R.; Parrott, A.; Hollis, C; Cheatham, M. WO2017040127A1). The final pressure of TCB slurry packing was 150 bar.

[0298] Column temperature calibration was performed by using a mixture of a reference material linear homopolymer polyethylene (with zero comonomer content, melt index (I2) of 1.0, polydispersity Mw / Mn of about 2.6 by conventional gel permeation chromatography at 1.0 mg / ml) with eicosane (2 mg / ml) in ODCB. The iCCD temperature calibration consisted of four steps: (1) calculation of a delay volume, which was defined as the measured peak elution temperature of eicosane minus a temperature offset between 30.00 °C; (2) subtraction of the temperature offset of the elution temperature from the iCCD raw temperature data. It should be noted that this temperature offset is a function of experimental conditions, such as elution temperature, elution flow rate, etc.; (3) creation of a linear calibration line, converting the elution temperature in the range of 30.00 °C to 140.00 °C such that the linear homopolymer polyethylene reference had a peak temperature at 101.0 °C and eicosane had a peak temperature at 30.0 °C; (4) linear extrapolation of the elution temperature below 30.0 °C according to the reference (Cerk and Cong et al., US 9,688,795) by using a 3 °C / minute elution heating rate for the soluble fraction measured isothermally at 30 °C.

[0299] A comonomer content versus elution temperature relationship for the iCCD was constructed by using 12 reference materials (ethylene homopolymers and ethylene-octene random copolymers made with single-site metallocene catalysts with 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 the previously specified 4 mg / mL. The reported elution peak temperatures were linearly fit to the linear equation y = -6.3515x + 101.00, where y represents the elution temperature of the iCCD and x represents the octene mole %, and R 2 was 0.978.

[0300] The molecular weight of the polymer and the molecular weight of the polymer fractions were determined directly from the LS detector (90 degree angle) and the concentration detector (IR-5) according to the Rayleigh-Gans-Debys approximation (Striegel and Yau, Modern Size Exclusion Liquid Chromatogram, pages 242 and 263) by assuming a shape factor of 1 and all virial coefficients equal to zero. The integration window was set to integrate the entire chromatogram in the elution temperature (temperature calibration specified above) range of 23.0 °C to 120 °C.

[0301] The molecular weight (Mw) was calculated from the iCCD including the following four steps:

[0302] (1) Measure the bias between detectors. The bias is defined as the geometric volume offset between the LS detector and the concentration detector. It is calculated as the difference in elution volume (mL) of the polymer peak between the concentration detector and the LS chromatogram. This is converted to a temperature bias by using the elution heat rate and the elution flow rate. The polydispersity M of linear high-density polyethylene (with zero comonomer content and a melt index (I2) of 1.0) was measured by conventional gel permeation chromatography. w / M n The same experimental conditions as the normal iCCD method described above were used, except for the following parameters: crystallization from 140°C to 137°C at 10°C / min, 1 minute of thermal equilibrium at 137°C as the soluble fraction elution time, 7 minutes of soluble fraction (SF) time, and elution from 137°C to 142°C at 3°C / min. The flow rate during crystallization was 0.0 ml / min. The flow rate during elution was 0.80 ml / min. The sample concentration was 1.0 mg / ml.

[0303] (2) Prior to integration, each LS data point in the LS chromatogram was shifted to correct for inter-detector bias.

[0304] (3) Integrate the baseline-subtracted LS and concentration chromatograms over the entire elution temperature range of step (1). The MW detector constant is calculated by using known MW HDPE samples in the range of 100,000 to 140,000 MW and the area ratio of the LS and concentration integrated signals.

[0305] (4) The Mw of the polymer was calculated by using the ratio of the integrated light scattering detector (90 degree angle) to the concentration detector and using the MW detector constant.

[0306] The calculation of the half-peak width is defined as the temperature difference between the front temperature and the back temperature at half the maximum peak height. The front temperature at half the maximum peak height is searched from 35.0°C forward, while the back temperature at half the maximum peak height is searched from 119.0°C backward.

[0307] Dynamic shear rheology

[0308] The samples were compression molded in air at 190°C under a pressure of 25,000 pounds for 6.5 minutes, after which the plaques were cooled on a laboratory bench. The thickness of the plaques was approximately 3 mm. Constant temperature frequency sweep measurements were performed on an ARES strain controlled parallel plate rheometer (TA Instruments) equipped with 25 mm parallel plates under a nitrogen purge. For each measurement, the rheometer was thermally equilibrated for at least 30 minutes before the gap was zeroed. The sample was placed on the plates and allowed to melt at 190°C for five minutes. The plates were then brought close to 2 mm, the sample trimmed, and the test was then started. The method was additionally built in with a five minute delay to allow for temperature equilibration. The experiments were performed at 190°C over a frequency range of 0.1 rad / s-100 rad / s at five points per decade. The strain amplitude was constant at 10%. The stress response was analyzed in terms of amplitude and phase, from which the storage modulus (G'), loss modulus (G"), complex modulus (G*), dynamic complex viscosity (η*), and tan δ (or tan δ) were calculated.

[0309] Water vapor transmission rate

[0310] Water vapor transmission rate or "WVTR" is measured according to ASTM E-398 at 37°C and 90% relative humidity.

[0311] Oxygen transmission rate

[0312] Oxygen transmission rate or "OTR" is measured according to ASTM D3985 using a Mocon Oxtran OTR test system at 100% oxygen content, 85% relative humidity and a temperature of 23°C.

[0313] Dart drop impact

[0314] After film preparation, the films were conditioned at 23°C (+ / -2°C) and 50% RH (+ / -5) for at least 40 hours according to ASTM standards.According to ASTM standards, standard testing conditions are 23°C (+ / -2°C) and 50% RH (+ / -5).

[0315] The sample thickness is measured at the center of the sample, and the sample is then clamped by a ring sample holder with an inner diameter of 5 inches. A dart is loaded over the center of the sample and released by a pneumatic or electromagnetic mechanism.

[0316] The test is performed according to the 'Step' method. If the sample fails, a new sample is tested with the dart weight reduced by a known and fixed amount. If the sample does not fail, a new sample is tested with the dart weight increased by a known amount. After testing 20 samples, the number of failures is determined. If this number is 10, the test is complete. If the number is less than 10, the test continues until 10 failures are recorded. If the number is greater than 10, the test continues until the sum of non-failures is 10. The dart drop impact value is determined from these data according to ASTM D1709 and is expressed in grams. Test results in the examples are reported by Method A (Type A dart drop impact).

[0317] The terms "dart drop impact" and "dart impact" are used synonymously herein to refer to this test method.

[0318] Secant modulus (2%)

[0319] The secant modulus at 2% strain is measured according to ASTM D882-12 on the Instron Universal Tester in the machine direction (MD) and cross direction (CD).

[0320] Some embodiments of the application will now be described in detail in the following Examples.

[0321] Examples

[0322] First polyethylene composition

[0323] The following are examples of first polyethylene compositions that can be used in embodiments of the multilayer films of the present application. First polyethylene composition 1 was prepared according to the following process and based on the reaction conditions reported in Table 1.

[0324] All feedstocks (ethylene monomer) and process solvents (narrow boiling high purity isoparaffin solvent, Isopar-E) were purified with molecular sieves prior to introduction into the reaction environment. Hydrogen was supplied at a high purity grade and was not further purified. The reactor monomer feed stream was pressurized to greater than reaction pressure via a mechanical compressor. The solvent feed was pressurized to greater than reaction pressure via a pump. The individual catalyst components were manually batch diluted to the prescribed component concentrations with purified solvent and pressurized to greater than reaction pressure. All reaction feed streams were measured with mass flow meters and independently controlled with a computer automated valve control system.

[0325] The continuous solution polymerization reactor consists of two liquid filled non-adiabatic isothermal loop reactors mimicking a continuous stirred tank reactor (CSTR) with heat removal. All fresh solvent, monomer, hydrogen, and catalyst component feeds to each reactor can be independently controlled. The temperature of the total fresh feed stream (solvent, monomer, and hydrogen) into each reactor is controlled by passing the feed stream through a heat exchanger. The total fresh feed to each polymerization reactor is injected into the reactor at two locations with approximately equal reactor volume between each injection location. The fresh feed into the first reactor is typically controlled to receive half of the total fresh feed mass flow rate at each injector. The fresh feed to the second reactor in series is typically controlled to maintain half of the total ethylene mass flow rate near each injector, and this injector typically has less than half of the total fresh feed mass flow rate into the second reactor due to unreacted ethylene from the first reactor entering the second reactor adjacent to the low pressure fresh feed.

[0326] The catalyst / co-catalyst components for each reactor are injected into the polymerization reactor through specially designed injection plugs. Each catalyst / co-catalyst component is injected into the reactor at the same relative location separately with no contact time prior to the reactor. The computer controls the primary catalyst component to maintain the individual reactor monomer conversion at the specified target. The co-catalyst components are fed based on the calculated specified molar ratio to the primary catalyst component.

[0327] The catalyst used in the first reactor is [[2,2”'-[[bis[l-methylethyl)germylene]bis(methylenoxy-κO)]bis[3”,5,5”-tris(l,l-dimethylethyl)-5'-octyl[l,l':3',l”-terphenyl]-2'-yl-κO]](2-)]dimethylzirconium, with the chemical formula C 86 H 128 F2GeO4Zr and the following structure (“Catalyst 1”):

[0328]

[0329] The catalyst used in the second reactor is [[2,2”'-[l,3-propanediylbis(oxy-κO)]bis[3-[2,7-bis(l,l-dimethylethyl)-9H-carbazol-9-yl]]-5'-(dimethyloctylsilyl)-3'-methyl-5-(l,l,3,3-tetramethylbutyl)[l,l]- biphenyl]-2-yl-κO]](2-)]dimethylzirconium, with the chemical formula C 107 H 154 N2O4Si2Zr and the following structure (“Catalyst 2”):

[0330]

[0331] Immediately following each reactor feed injection point, the feed streams are mixed with the circulating polymer reactor contents using static mixing elements. The contents of each reactor are continuously circulated through a heat exchanger responsible for removing the majority of the heat of reaction, and where the temperature on the coolant side is responsible for maintaining an isothermal reaction environment at the specified reactor temperature. Circulation around each reactor loop is provided by a pump.

[0332] The effluent from the first polymerization reactor (containing solvent, monomer, hydrogen, catalyst components, and molten polymer) exits the first reactor loop and passes through a control valve responsible for controlling the pressure of the first reactor at the specified target and is injected into a similarly designed second polymerization reactor. The final effluent from the second polymerization reactor enters a zone where it is deactivated by the addition of and reaction with a suitable reagent (water). At this same reactor exit point, additional additives are added for polymer stabilization. This final effluent stream passes through another set of static mixing elements to facilitate catalyst deactivation and additive dispersion.

[0333] After catalyst deactivation and addition of additives, the reactor effluent enters a devolatilization system where the polymer is removed from the non-polymer stream. The isolated polymer melt is pelletized and collected. The non-polymer stream passes through various equipment that separates the majority of the ethylene removed from the system. The majority of the solvent is recycled back into the reactor after passing through a purification system. A small amount of solvent is purged from the process. The first polyethylene composition 1 is stabilized with a small (ppm) amount of stabilizers.

[0334] The polymerization conditions for the first polyethylene composition 1 are shown in Table 1. As shown in Table 1, co-catalyst 1 (bis(hydrogenated tallow alkyl)methyltetrakis(pentafluorophenyl)borate (1-)amide) and co-catalyst 2 (modified methylaluminoxane (MMAO)) were each used as co-catalysts for catalyst 1 and catalyst 2.

[0335] The first polyethylene composition 2 was prepared using the same catalyst system as polyethylene composition 1 and using the same process with comparable reaction conditions.

[0336] Other properties of the first polyethylene composition 1 and the first polyethylene composition 2 were measured using the test methods described above and are reported in Table 2. The first polyethylene fraction refers to the polyethylene component from the first reactor and the second polyethylene fraction refers to the polyethylene component from the second reactor.

[0337] Table 1

[0338]

[0339]

[0340] Table 2

[0341]

[0342]

[0343] The limit of detection for this measurement is <3.

[0344] **Target

[0345] Density of the first polyethylene fraction of the first polyethylene composition 1, the total first polyethylene composition 1, and the total first polyethylene composition 2 was measured as described in the Test Methods section above. The density of the first polyethylene fraction of the first polyethylene composition 2 was the target value. The density of the second polyethylene fraction was calculated using the following blend rule:

[0346]

[0347] Other properties of the first polyethylene composition 1 and the first polyethylene composition 2 were evaluated and reported in Table 3.

[0348] Table 3

[0349]

[0350] The first polyethylene composition 1 can be dry blended with Hyperform HPN-20E nucleating agent (Milliken Chemical) provided in a masterbatch to result in different final loadings of HPN-20e nucleating agent (“HPN-20E”). One example of a masterbatch containing HPN-20E includes 3 wt% HPN-20E, 1.5 wt% silica, 0.5 wt% hydrotalcite, 5 wt% antioxidant, and 90 wt% carrier resin. The carrier resin can be a high density polyethylene homopolymer with a narrow molecular weight distribution having a density of 0.965 g / cm3and a melt index (I2) of 8.0 g / 10 min. Hyperform HPN-20E includes about 66 wt% calcium 1,2-cyclohexane dicarboxylate and about 34 wt% zinc stearate / zinc palmitate. This masterbatch formed with Hyperform HPN-20E nucleating agent will be referred to as “nucleating agent masterbatch”. 3 The limit of detection for this measurement is <3.

[0344] **Target

[0345] Density of the first polyethylene fraction of the first polyethylene composition 1, the total first polyethylene composition 1, and the total first polyethylene composition 2 was measured as described in the Test Methods section above. The density of the first polyethylene fraction of the first polyethylene composition 2 was the target value. The density of the second polyethylene fraction was calculated using the following blend rule:

[0346]

[0347] Other properties of the first polyethylene composition 1 and the first polyethylene composition 2 were evaluated and reported in Table 3.

[0348] Table 3

[0349]

[0350] The first polyethylene composition 1 can be dry blended with Hyperform HPN-20E nucleating agent (Milliken Chemical) provided in a masterbatch to result in different final loadings of HPN-20e nucleating agent (“HPN-20E”). One example of a masterbatch containing HPN-20E includes 3 wt% HPN-20E, 1.5 wt% silica, 0.5 wt% hydrotalcite, 5 wt% antioxidant, and 90 wt% carrier resin. The carrier resin can be a high density polyethylene homopolymer with a narrow molecular weight distribution having a density of 0.965 g / cm3and a melt index (I2) of 8.0 g / 10 min. Hyperform HPN-20E includes about 66 wt% calcium 1,2-cyclohexane dicarboxylate and about 34 wt% zinc stearate / zinc palmitate. This masterbatch formed with Hyperform HPN-20E nucleating agent will be referred to as “nucleating agent masterbatch”.

[0351] In preparing the multilayer films in the following examples, the same catalyst system as used for polyethylene composition 1 and polyethylene composition 2 was used and the same process and comparable reaction conditions were used to prepare the first polyethylene composition so that the first polyethylene composition had properties consistent with polyethylene composition 2. This first polyethylene composition was melt blended with a nucleated masterbatch to provide a target loading of 750 ppm of Hyperform HPN-20E nucleating agent. The first polyethylene composition 3 referred to in the formation of the inventive films and comparative films hereinafter should be understood to be this first polyethylene composition combined with the nucleated masterbatch having a target loading of 750 ppm of Hyperform HPN-20E.

[0352] Second polyethylene composition

[0353] The following are examples of second polyethylene compositions that can be used in the embodiments of the inventive multilayer films.

[0354] The second polyethylene compositions 1 to 5 described according to one or more embodiments of the detailed description were prepared by the following methods and using the following catalysts and reactors.

[0355] All feedstocks (monomers and comonomers) and process solvents (narrow boiling high purity isoparaffin solvent, Isopar-E) were purified with molecular sieves prior to introduction into the reaction environment. Hydrogen was supplied at a high purity grade and was not further purified. Reactor monomer feed streams were pressurized to greater than reaction pressure via a mechanical compressor. Solvent and comonomer feeds were pressurized to greater than reaction pressure via pumps. Individual catalyst components were manually batch diluted with purified solvent and pressurized to greater than reaction pressure. All reaction feed streams were measured with mass flow meters and independently controlled with a computer automated valve control system.

[0356] The two reactor system is used in a series configuration. Each continuous solution polymerization reactor consists of a liquid filled non-adiabatic isothermal loop reactor that mimics a continuously stirred tank reactor (CSTR) with heat removal. All fresh solvent, monomer, comonomer, hydrogen, and catalyst component feeds can be independently controlled. The total fresh feed stream (solvent, monomer, comonomer, and hydrogen) to each reactor is temperature controlled to maintain a single solution phase by passing the feed stream through a heat exchanger. The total fresh feed to each polymerization reactor is injected into the reactor at two locations with approximately equal reactor volume between each injection location. The fresh feed is controlled with each injector receiving half of the total fresh feed mass flow. The catalyst component is injected into the polymerization reactor through an injection insertion tube. The primary catalyst component feed is computer controlled to maintain each reactor monomer conversion at the specified target. The cocatalyst component is fed based on the calculated specified molar ratio to the primary catalyst component. Immediately following each reactor feed injection location, the feed stream is mixed with the circulating polymerization reactor contents with a static mixing element. The contents of each reactor are continuously circulated through a heat exchanger which is responsible for removing the majority of the reaction heat and where the temperature on the coolant side is responsible for maintaining an isothermal reaction environment at the specified temperature. Circulation around each reactor loop is provided by a pump.

[0357] In the dual series reactor configuration, the effluent from the first polymerization reactor (containing solvent, monomer, comonomer, hydrogen, catalyst components, and polymer) exits the first reactor loop and is added to the second reactor loop.

[0358] The second reactor effluent enters a zone where it is deactivated by the addition of and reaction with a suitable reagent (water). At this same reactor exit location, other additives are added to stabilize the polymer (typical antioxidants suitable for use in stabilized in extrusion and film manufacturing processes such as 3,5-di-tert-butyl-4-hydroxyhydrocinnamic acid octadecyl ester, tetrakis(methylene(3,5-di-tert-butyl-4-hydroxyhydrocinnamate))methane, and tris(2,4-di-tert-butyl-phenyl)phosphite).

[0359] After the catalyst is deactivated and the additives are added, the reactor effluent enters a devolatilization system where the polymer is removed from the non-polymer stream. The isolated polymer melt is pelletized and collected. The non-polymer stream passes through various equipment that separates the majority of the ethylene removed from the system. The majority of the solvent and unreacted comonomer are recycled back to the reactor after passing through a purification system. A small amount of solvent and comonomer are purged from the process.

[0360] The polymerization conditions for the second polyethylene compositions 1 to 5 are shown in Table 4. Table 5 shows the catalysts referred to in Table 4.

[0361] Table 4

[0362]

[0363]

[0364]

[0365] Table 5

[0366]

[0367] The second polyethylene composition 6 described according to one or more embodiments of the detailed description is prepared by the following method and utilizing the following catalyst and reactors.

[0368] All feedstocks (monomers and comonomers) and process solvents (narrow boiling high purity isoparaffin solvent, Isopar-E) are purified with molecular sieves prior to introduction into the reaction environment. Hydrogen is supplied at a high purity grade and is not further purified. Reactor monomer feed streams are pressurized to greater than reaction pressure via a mechanical compressor. Solvent and comonomer feeds are pressurized to greater than reaction pressure via pumps. Individual catalyst components are manually batch diluted with purified solvent and pressurized to greater than reaction pressure. All reaction feed streams are measured with mass flow meters and independently controlled with a computer automated valve control system.

[0369] Two reactor systems are used in a parallel configuration. Each continuous solution polymerization reactor consists of a liquid filled non-adiabatic isothermal circulating loop reactor that mimics a continuously stirred tank reactor (CSTR) with heat removal. All fresh solvent, monomer, comonomer, hydrogen, and catalyst component feeds can be independently controlled. The total fresh feed stream (solvent, monomers, comonomer, and hydrogen) to each reactor is temperature controlled by passing the feed stream through a heat exchanger to maintain a single solution phase. The total fresh feed to each polymerization reactor is injected into the reactor at two locations with approximately equal reactor volume between each injection location. Fresh feed is controlled with half of the total fresh feed mass flow rate being received by each injector. Catalyst components are injected into the polymerization reactor through specially designed injection lances. The primary catalyst component feed is computer controlled to maintain each reactor monomer conversion at the specified target. The cocatalyst component is fed based on the calculated specified molar ratio to the primary catalyst component. Immediately following each reactor feed injection location, the feed streams are mixed with the circulating polymerization reactor contents with static mixing elements. The contents of each reactor are continuously circulated through a heat exchanger that is responsible for removing the majority of the reaction heat, and where the temperature of the coolant side is responsible for maintaining an isothermal reaction environment at the specified temperature. Circulation around each reactor loop is provided by a pump.

[0370] The effluent streams from the first and second polymerization reactors are combined prior to any additional processing. This final combined reactor effluent enters a zone where it is deactivated by the addition of and reaction with a suitable agent (water). At this same reactor exit location, other additives are added to stabilize the polymer (typical antioxidants suitable for use during extrusion and blown film manufacture such as 3,5-di-tert-butyl-4-hydroxyhydrocinnamic acid octadecyl ester, tetrakis(methylene(3,5-di-tert-butyl-4-hydroxyhydrocinnamate))methane, and tris(2,4-di-tert-butyl-phenyl)phosphite).

[0371] After the catalyst is deactivated and the additives are added, the reactor effluent enters a devolatilization system where the polymer is removed from the non-polymer stream. The separated polymer melt is pelletized and collected. The non-polymer stream passes through various equipment that separates the majority of the ethylene removed from the system. The majority of the solvent and unreacted comonomer are recycled back into the reactor after passing through a purification system. A small amount of solvent and comonomer are purged from the process.

[0372] The polymerization conditions for the second polyethylene composition 6 are provided in Table 6. Table 5 shows the catalysts referenced in Table 6.

[0373] Table 6

[0374]

[0375]

[0376] The second polyethylene compositions 1, 3, 5, and 6 were analyzed by iCCD. The iCCD data for the second polyethylene composition 5 is provided in Figure 2 Additional data generated from the iCCD testing of these samples is provided in Tables 7A and 7B. Specifically, Tables 7A and 7B include an analysis of the iCCD data, including the area for each of the first polyethylene fraction and the second polyethylene fraction (45 °C to 87 °C and 95 °C to 120 °C). Additional data for these samples is also provided, including the overall density, melt index, and weight average molecular weight in the second PE fraction. These properties are based on a monolayer blown film consisting entirely of the respective polyethylene sample.

[0377] Table 7A

[0378]

[0379] Table 7B

[0380]

[0381] Inventive films 1 to 3 and comparative films A to C

[0382] The inventive film 1 and comparative films A-C were prepared as three-layer (A / B / A) coextruded films as follows. The inventive film 1 and comparative films A-C had the following structure:

[0383] Table 8

[0384]

[0385] Inventive films 1 and comparative films A to C

[0386] The inventive film 1 and comparative films A-C were prepared as three-layer (A / B / A) coextruded films as follows. The inventive film 1 and comparative films A-C had the following structure:

[0387] Table 9

[0388]

[0389] The films were produced using a Dr. Collin 3-layer coextruded blown film line. The line consisted of three 25:1 L / D single screw extruders equipped with a fluted feed zone. The screw diameter of the two outer layer (A layer) extruders was 25 mm, while the screw diameter of the inner layer (formed by the B layer) extruder was 30 mm. The melt temperature was 190-210 °C. The die diameter was 80 mm, and the die gap was 1.8 mm. The blow-up ratio was 2.5:1. The output rate was 22.42 kg / h. The temperature profile was 190 °C / 210 °C / 220 °C / 235 °C / 235 °C / 235 °C / 235 °C. The nominal thickness of each film was 90 microns, with a layer distribution of A (33%) / B (34%) / A (33%).

[0390] Dart impact, 2% secant modulus in the machine direction, water vapor transmission rate, and oxygen transmission rate were measured using the methods described above. The results are shown in Table 10.

[0391] Table 10

[0392]

[0393] As shown in Table 10, the combination of the first polyethylene composition and the second polyethylene composition provides a unique combination of stiffness (secant modulus) and toughness (dart impact). Additionally, the inclusion of the first polyethylene composition having a high density provides a significant improvement in water vapor transmission rate and oxygen transmission rate.

[0394] Inventive films 2 to 3and comparative films D to E

[0395] The inventive films 2-3 and comparative films D-E were five-layer (A / B / C / D / E) coextruded films prepared as follows. Inventive films 2 and comparative films D-F had the following structure:

[0396] Table 11

[0397]

[0398]

[0399] The films were produced using a Dr. Collin 5-layer coextrusion blown film line. The line consisted of five 25:1 L / D single screw extruders equipped with a fluted feed zone. The screw diameter of the two outer layer (A and E layer) extruders was 30 mm, while the screw diameter of the inner layer (B to D layer) extruders was 25 mm. The melt temperature was 190-210 °C. The die diameter was 80 mm and the die gap was 1.8 mm. The blow up ratio was 2.5:1. The output rate was 22.42 kg / h. The temperature profile was 190 °C / 210 °C / 220 °C / 235 °C / 235 °C / 235 °C / 235 °C. The nominal thickness of each film was 90 microns with the layer distribution as specified in Table 11.

[0400] Dart impact, 2% secant modulus in the machine direction, water vapor transmission rate, and oxygen transmission rate were measured using the methods described above. The results are shown in Table 12.

[0401] Table 12

[0402]

[0403] As shown in Table 12, the combination of the first polyethylene composition and the second polyethylene composition provides a unique combination of stiffness (secant modulus) and toughness (dart impact), particularly when the second polyethylene composition is present in an amount of 20 wt% or more. Furthermore, a good balance of stiffness (secant modulus) and toughness (dart impact) is achieved when the amount of the first polyethylene composition is below 40 wt%. For example, in comparative film E, the first polyethylene composition is present in 50 wt% and the dart impact value is significantly lower.

[0404] Other inventive examples

[0405] As described above, in some embodiments, the multilayer films of the present application include an outer layer that is a sealant layer comprising a third polyethylene composition. For example, in the inventive films described above, one of the outer layers (e.g., layer A) can be a sealant layer comprising a third polyethylene composition. Embodiments of the third polyethylene composition can be prepared as follows.

[0406] The third polyethylene compositions 1 to 3 described according to one or more embodiments of the detailed description can be prepared by the following method and utilizing the following catalyst and reactor.

[0407] All feedstocks (monomers and comonomers) and process solvents (narrow boiling high purity isoparaffin solvent, Isopar-E) were purified with molecular sieves prior to introduction into the reaction environment. Hydrogen was supplied at a high purity grade and was not further purified. The reactor monomer feed stream was pressurized above the reaction pressure by a mechanical compressor. The solvent and comonomer feeds were pressurized to greater than the reaction pressure via pumps. The individual catalyst components were manually batch diluted with purified solvent and pressurized to greater than the reaction pressure. All reaction feed streams were measured with mass flow meters and independently controlled with a computer automated valve control system.

[0408] A dual reactor system was used. Each continuous solution polymerization reactor used a liquid filled non-adiabatic isothermal loop reactor that mimicked a continuously stirred tank reactor (CSTR) with heat removal. All fresh solvent, monomer, comonomer, hydrogen, and catalyst component feeds could be independently controlled. The total fresh feed stream (solvent, monomer, comonomer, and hydrogen) to each reactor was temperature controlled by passing the feed stream through a heat exchanger to maintain a single solution phase. The total fresh feed to each polymerization reactor was injected into the reactor at two locations with approximately equal reactor volume between each injection location. The fresh feeds were controlled such that each injector received half of the total fresh feed mass flow rate. The catalyst components were injected into the polymerization reactor through injection lances. The catalyst feeds were computer controlled to maintain each reactor monomer conversion at the specified target. The cocatalyst component was fed into the procatalyst component based on the calculated specified molar ratio. The feed streams were mixed with the circulating polymerization reactor contents with static mixing elements immediately following each reactor feed injection location. The contents of each reactor were continuously circulated through a heat exchanger that was responsible for removing the majority of the reaction heat and where the temperature of the coolant side was responsible for maintaining an isothermal reaction environment at the specified temperature. Circulation around each reactor loop was provided by pumps.

[0409] The effluent from the first polymerization reactor (containing solvent, monomer, comonomer, hydrogen, catalyst components, and polymer) exited the first reactor loop and was added to the second reactor loop.

[0410] The second reactor effluent enters a zone where it is deactivated by the addition of and reaction with a suitable reagent (water). At this same reactor exit location, other additives are added to stabilize the polymer (typical antioxidants used in the extrusion and film manufacturing process for stabilization such as 3,5-di-tert-butyl-4-hydroxyhydrocinnamic acid octadecyl ester, tetrakis(methylene(3,5-di-tert-butyl-4-hydroxyhydrocinnamate))methane, and tris(2,4-di-tert-butyl-phenyl)phosphite).

[0411] After catalyst deactivation and addition of additives, the reactor effluent enters a devolatilization system where the polymer is removed from the non-polymer stream. The isolated polymer melt is pelletized and collected. The non-polymer stream passes through various equipment that separates the majority of the ethylene removed from the system. The majority of the solvent and unreacted comonomer are recycled back to the reactor after passing through a purification system. A small amount of solvent and comonomer are purged from the process.

[0412] The reactor stream feed data stream corresponds to the values used in Table 13. The data is presented such that the complexity of the solvent recycle system is taken into account and the reaction system can be handled more simply as a once through flow diagram. Table 14 shows the catalyst referenced in Table 13.

[0413] Table 13

[0414]

[0415]

[0416] Table 14

[0417]

[0418]

[0419] Third polyethylene compositions 1 to 3 were analyzed by iCCD. The data generated from the iCCD test for all samples (third polyethylene compositions 1 to 3) are provided in Table 15A and Table 15B. Specifically, Table 15A includes the analysis of the iCCD data at temperature increments of 5 °C.

[0420] Table 15A

[0421] Sample ID 25℃–70℃ 70℃–85℃ 85℃–120℃ Third polyethylene composition 1 60.29％ 3.15％ 36.56％ Third polyethylene composition 2 60.15％ 2.70％ 37.16％ Third polyethylene composition 3 59.55％ 4.65％ 35.80％

[0422] Table 15B further describes the iCCD data to include the area of the individual polyethylene fractions (25 °C - 35 °C, 35 °C - 70 °C, 70 °C - 85 °C, and 85 °C - 120 °C).

[0423] Table 15B

[0424]

[0425] Table 16 provides additional data for the third polyethylene compositions 1 to 3, including bulk density, melt index, ZSVR, and ratio of first fraction molecular weight to total molecular weight. These properties were measured based on the test methods described herein.

[0426] Table 16

[0427]

[0428] As previously described in the present disclosure, tan delta refers to the closeness of a material to a perfectly elastic solid (where d = 0°, tan delta = 0) or a material to a perfectly Newtonian liquid (where d = 90°, tan delta ~ infinity). Thus, the lower the value of tan delta, the more elastic the material. Tan delta is a function of LCB and MWD at the same total molecular weight. A higher value of tan delta indicates lower LCB.

[0429] Table 17

[0430]

Claims

1. A multilayer film comprising: (a) a first polyethylene composition comprising: (1) 25 to 37 wt% of a first polyethylene fraction having a molecular weight of 0.935 g / cm 3 to 0.947g / cm 3 A density within the range and a melt index I2 of less than 0.1 g / 10 minutes; and (2) 63% to 75% by weight of a second polyethylene fraction; and When using 13 The first polyethylene composition has less than 0.10 branches per 1,000 carbon atoms as measured by C NMR, wherein the density of the first polyethylene composition is at least 0.965 g / cm 3 , and wherein the first polyethylene composition has a melt index I2 of 0.5 g / 10 min to 10 g / 10 min; and (b) a second polyethylene composition comprising: (1) a first polyethylene fraction having a single peak in a temperature range of 45° C. to 87° C. in an elution curve obtained by an improved comonomer composition distribution iCCD analysis method, wherein a first polyethylene area fraction is an area under the single peak of the first polyethylene fraction between 45° C. and 87° C. in the elution curve; and (2) a second polyethylene fraction having a single peak in the temperature range of 95° C. to 120° C. in the elution curve obtained by the iCCD analysis method, and wherein the second polyethylene area fraction is the area under the single peak of the second polyethylene fraction between 95° C. and 120° C. in the elution curve; The second polyethylene composition has a thickness of 0.924 g / cm 3 to 0.936g / cm 3 and a melt index I2 of 0.25 g / 10 min to 2.0 g / 10 min, wherein the area of ​​the second polyethylene fraction accounts for at least 40% of the total area of ​​the elution curve, wherein the ratio of the area of ​​the first polyethylene fraction to the area of ​​the second polyethylene fraction is 0.75 to 2.5, and wherein the width of the single peak of the second polyethylene fraction at 50% peak height is less than 5.0°C; wherein the multilayer film comprises 40 wt% or less of the first polyethylene composition based on the total weight of the multilayer film, wherein the first polyethylene composition is present in at least one layer of the multilayer film, and wherein the second polyethylene composition is present in at least one layer of the multilayer film.

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

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

4. The multilayer film of claim 1 or claim 2, wherein the outer layer of the film comprises a third polyethylene composition comprising: (a) a first polyethylene fraction, which comprises at least one peak in a temperature range of 35°C to 70°C in an elution curve obtained by an improved comonomer composition distribution iCCD analysis method, wherein the first polyethylene area fraction is the area from 35°C to 70°C in the elution curve, and wherein the area of ​​the first polyethylene fraction accounts for 25% to 65% of the total area of ​​the elution curve; (b) a second polyethylene fraction comprising at least one peak in a temperature range of 85°C to 120°C in an elution curve obtained by an iCCD analysis method, wherein the second polyethylene area fraction is the area from 85°C to 120°C in the elution curve, and wherein the second polyethylene fraction area accounts for at least 20% of the total area of ​​the elution curve; and (c) a third polyethylene fraction, said third polyethylene fraction being within a temperature range of 70° C. to 85° C. in an elution curve obtained by an iCCD analysis method, wherein the third polyethylene area fraction is the area from 70° C. to 85° C. in the elution curve, and wherein the third polyethylene fraction area accounts for less than 10% of the total area of ​​the elution curve; and The third polyethylene composition has a 0.880 g / cm 3 to 0.910g / cm 3 The invention discloses a composite material comprising a first embodiment of the present invention and a second embodiment of the present invention. The first embodiment comprises a first embodiment of the present invention and a second embodiment of the present invention. The first embodiment comprises a first embodiment of the present invention and a second embodiment of the present invention.

5. The multilayer film of claim 4, wherein the first polyethylene composition and the second polyethylene composition are in different layers of the film, and wherein the layer comprising the second polyethylene composition is between the outer layer comprising the third polyethylene composition and the layer comprising the first polyethylene composition.

6. The multilayer film of claim 1 or claim 2, wherein at least one layer further comprises linear low density polyethylene, low density polyethylene, or a combination thereof.

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

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