High melt-strength polyethylene containing ultra-high molecular weight polyethylene components

Abstract

The film comprises a polyethylene multimodal resin. The polyethylene multimodal resin comprises the polymerization reaction product of ethylene and at least one alpha-olefin copolymer. The polyethylene multimodal resin has a melt strength (MS) ≥ X1 / I2 + y, where X1 is equal to 3.9, y is equal to 1.4, I2 is the melt index of the copolymer, and MS is the melt strength in cN units. The film comprises a normalized dart strength (DS) (DS ≥ 9,876 - 10,512 (ρ)) greater than or equal to the density of the polyethylene multimodal resin multiplied by 9,876 minus 10,512, where the normalized DS is measured in grams (g) according to ASTM 1709 Method A and divided by the film thickness in mill units.

Description

[Technical Field]

[0001] (Cross-reference of related applications) This application claims the benefits of U.S. Provisional Application No. 63 / 510,774, filed on 28 June 2023, the contents of which are incorporated herein by reference in their entirety.

[0002] (Field of Invention) The embodiments described herein generally relate to films having high melt strength, and more specifically to films produced from high melt strength polyethylene resins having ultra-high molecular weight components. [Background technology]

[0003] High melt strength is an advantageous property in polyethylene resins because it improves the processability of the material. Low-density polyethylene (LDPE) produced by radical processes typically exhibits high melt strength, but LDPE resins generally have poor mechanical properties. In contrast, linear low-density polyethylene (LLDPE) produced via solution or gas-phase processes typically has poor melt strength but excellent mechanical properties. To address LLDPE and the problems surrounding it, and to improve the processability of LLDPE resins, a certain amount of LDPE is typically blended into LLDPE. Unfortunately, the addition of LDPE results in a significant decrease in the mechanical properties of the resulting blend compared to the excellent performance of LLDPE resin. [Overview of the Initiative]

[0004] Conventional films produced from a blend of LLDPE and LDPE resins have higher melt strength, but the addition of LDPE reduces the mechanical properties of the film compared to films produced from conventional LLDPE resin.

[0005] Melt strength and processability are correlated properties of polyethylene resin. Generally, higher melt strength provides polyethylene resin with improved processability.

[0006] In addition, conventional polyethylene resins produced by conventional processes typically exhibit a trade-off between the resin's mechanical properties and melt strength. For example, conventional radical processes, which are known to be hazardous, typically produce low-density polyethylene (LDPE) with high melt strength but insufficient mechanical properties. In contrast, linear low-density polyethylene (LLDPE) produced via solution or gas-phase processes typically has insufficient melt strength but excellent mechanical properties.

[0007] Therefore, to increase processability and improve the processability and melt strength of LLDPE resin, some amount of LDPE can typically be blended with LLDPE. Unfortunately, the addition of LDPE results in a decrease in the mechanical properties of the resulting blend compared to pure LLDPE resin.

[0008] Therefore, a film is needed that offers both high processability and high dirt strength when compared to a blend of LLDPE and UHMWPE.

[0009] Embodiments of the present disclosure include a film comprising a polyethylene multimodal resin. The polyethylene multimodal resin comprises a polymerization reaction product of ethylene and at least one alpha-olefin copolymer. The polyethylene multimodal resin comprises a melt strength (MS) ≥ X1 / I2 + y, where X1 is equal to 3.9, y is equal to 1.4, I2 is the melt index of the copolymer measured according to ASTM 1238 at 2.16 kg and 190°C, and MS is the melt strength in cN units (Rheotens apparatus, 190°C, 2.4 mm / s²). 2 120mm from die exit to wheel center, extrusion speed 38.2s -1(Capillary die with length 30 mm, diameter 2 mm, and incidence angle 180°), the film contains a normalized dart strength (dart strength, DS) (DS ≥ 9,876 - 10,512 (ρ)) greater than or equal to the density of polyethylene multimodal resin, and DS is measured according to ASTM 1709.

[0010] In some embodiments, the film comprises a polyethylene multimodal resin. The polyethylene multimodal resin comprises a polymerization reaction product of ethylene and at least one alpha-olefin copolymer. In one or more embodiments, the polyethylene multimodal resin may have a melt strength (MS) ≥ x / I² + y, where x is equal to 3.9, y is equal to 1.4, I² is the melt index of the copolymer measured according to ASTM 1238 at 2.16 kg and 190°C, and MS is the melt strength in cN units (Rheotens apparatus, 190°C, 2.4 mm / s²). 2 120mm from die exit to wheel center, extrusion speed 38.2s -1 (Capillary die with length 30 mm, diameter 2 mm, and incidence angle 180°). In various embodiments, the film contains normalized machine direction (MD) tear of more than 85 gf / mil, and the MD tear is measured according to ASTM D1922-15.

[0011] These and their embodiments will be described in more detail in the following embodiments for carrying out the invention, in conjunction with the accompanying drawings. [Brief explanation of the drawing]

[0012] The following “Modes for Carrying Out the Invention” of specific embodiments of this disclosure will be best understood in conjunction with the following drawings, in which similar structures are shown with similar reference numerals. [Figure 1] A schematic diagram of a reactor system useful for producing polyethylene, according to one or more embodiments described herein, is shown. [Figure 2]This graph shows the melt strength as a function of melt flow (I2) for the examples and comparative examples described herein, including blends of LLDPE and HDPE and single resin polymers. [Figure 3] This is a graphical representation of the normalized dirt strength as a function of density for the examples and comparative examples described herein, including blends of LLDPE and HDPE and single resin polymers. [Modes for carrying out the invention]

[0013] Herein, specific embodiments of the present application are described. These embodiments are provided to ensure that the present disclosure is detailed and complete and to fully convey the scope of the claimed subject matter to those skilled in the art.

[0014] The term "polymer" refers to polymer compounds prepared by polymerizing monomers, whether of the same or different types. Therefore, the general term "polymer" typically includes the term "homopolymer," which refers to polymers prepared from only one type of monomer, and the term "copolymer," which refers to polymers prepared from two or more different types of monomers. As used herein, the term "interpolymer" refers to polymers prepared by polymerizing at least two different types of monomers. Therefore, the general term "interpolymer" includes copolymers or polymers prepared from more than two different types of monomers, such as terpolymers.

[0015] "Polyethylene" or "ethylene polymer" means a polymer containing units derived from more than 50 mol% of ethylene monomers. This includes ethylene homopolymers or copolymers (meaning units derived from two or more comonomers). Common forms of ethylene polymers known in the art include low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), ultra-low-density polyethylene (ULDPE), very low-density polyethylene (VLDPE), single-site catalyst linear low-density polyethylene (m-LLDPE) including both linear low-density resins and substantially linear low-density resins, medium-density polyethylene (MDPE), and high-density polyethylene (HDPE).

[0016] As used herein, the term “composition” refers to a mixture of materials comprising the composition, as well as reaction products and decomposition products formed from the materials of the composition.

[0017] As used herein, the terms “polypropylene” or “propylene polymer” refer to polymers that constitute units derived from more than 50 mol% of propylene monomer in their polymerized form. This includes propylene homopolymers, random copolymer polypropylenes, impact copolymer polypropylenes, propylene / α-olefin copolymers, and propylene / α-olefin copolymers.

[0018] The term "LDPE" is also sometimes referred to as "high-pressure ethylene polymer" or "highly branched polyethylene," and is defined as a polymer that is partially or completely homopolymerized or copolymerized in an autoclave or tubular reactor at a pressure exceeding 14,500 psi (100 MPa) using a free radical initiator such as a peroxide (see, for example, U.S. Patent No. 4,599,392, which is incorporated herein by reference in its entirety). LDPE resins typically have a viscosity of 0.916 g / cm³. 3 ~0.940g / cm 3 It has a density within the range.

[0019] The term "LLDPE" includes resins produced using the Ziegler-Natta catalyst system, as well as resins produced using single-site catalysts, including but not limited to bismetallocene catalysts (sometimes referred to as "m-LLDPE"), phosphine imines, and geometrically constrained catalysts, and resins produced using post-metallocene molecular catalysts, including but not limited to bis(biphenylphenoxy) catalysts (also referred to as polyvalent aryloxy ether catalysts). LLDPE includes linear, substantially linear, or heterogeneous ethylene copolymers or homopolymers. LLDPE includes substantially linear ethylene polymers containing fewer long-chain branches than LDPE and further defined in U.S. Patents 5,272,236, 5,278,272, 5,582,923 and 5,733,155, which are incorporated herein by reference in their entirety; uniformly branched linear ethylene polymer compositions such as those in U.S. Patent 3,645,992, which are incorporated herein by reference in their entirety; heterogeneously branched ethylene polymers such as those prepared according to the process disclosed in U.S. Patent 4,076,698, which are incorporated herein by reference in their entirety; and blends thereof (such as those disclosed in U.S. Patents 3,914,342 and 5,854,045, which are incorporated herein by reference in their entirety). LLDPE resins can be produced by gas-phase, solution-phase, or slurry polymerization, or any combination thereof, using any type of reactor or reactor configuration known in the art.

[0020] The term "selective MDPE" is defined as 0.924 g / cm³, as will be described in more detail later herein. 3 ~0.936 g / cm³ 3 This refers to polyethylene having a certain density.

[0021] The term "HDPE" refers to polyethylene prepared using single-site catalysts including, but not limited to, Ziegler-Natta catalysts, chromium catalysts, or substituted mono- or bis-cyclopentadienyl catalysts (typically referred to as metallocenes), constrained geometry catalysts, phosphinimine catalysts, and polyvalent aryloxy ether catalysts (typically referred to as bisphenol phenoxy) having a density of 0.935 g / cm 3 to a maximum of 0.980 g / cm 3 .

[0022] The term "ULDPE" refers to polyethylene prepared using single-site catalysts including, but not limited to, Ziegler-Natta catalysts, chromium catalysts, or substituted mono- or bis-cyclopentadienyl catalysts (typically referred to as metallocenes), constrained structure catalysts, phosphine imine catalysts, and polyvalent aryloxy ether catalysts (typically referred to as bisphenol phenoxy) having a density of 0.855 g / cm 3 to 0.912 g / cm 3 . ULDPE includes, but is not limited to, polyethylene (ethylene-based) plastomers and polyethylene (ethylene-based) elastomers. Polyethylene (ethylene-based) elastomer plastomers generally have a density of 0.855 g / cm 3 to 0.912 g / cm 3 .

[0023] The terms “blend” and “polymer blend” refer to a composition of two or more polymers. Such a blend may or may not be miscible. Such a blend may or may not be phase-separated. Such a blend may or may not contain one or more domain configurations, as determined by transmission electron spectroscopy, light scattering, X-ray scattering, and any other method known in the art. A blend is not a laminate, but one or more layers of a laminate may contain a blend. Such a blend may be prepared as a dry blend, and may be formed in situ (e.g., in a reactor), as a molten blend, or by other techniques known to those skilled in the art.

[0024] The term "multimodal" refers to a polymer produced from multiple polymer fractions, each polymer fraction being produced by a different catalyst in a different reaction environment. Multimodal polymers may include bimodal polymers having two polymer fractions, trimodal ethylene polymers having three polymer fractions, or polymers having more than three polymer fractions.

[0025] "Multilayer structure" or "multilayer film" means any structure having two or more layers. For example, a multilayer structure (e.g., a film) may have two, three, four, five, six, seven, or more layers. A multilayer structure may be described as having layers specified by letters. For example, a three-layer structure designated as A / B / C may have a core layer (B) and two outer layers (A) and (C).

[0026] The terms “comprising,” “including,” and “having,” and their derivatives, are not intended to exclude the presence of any additional components, processes, or procedures, whether or not they are specifically disclosed. To avoid any doubt, all compositions claimed through the use of the term “comprising” may, unless otherwise specified, include any additional additives, adjuvants, or compounds, whether polymeric or otherwise. In contrast, the term “consisting essentially of” excludes any other components, processes, or procedures from the scope of any subsequent description, except those not essential to operability. The term “consisting of” excludes any components, processes, or procedures not specifically described or listed.

[0027] Embodiments of the present disclosure include a film comprising a polyethylene multimodal resin. The polyethylene multimodal resin comprises a polymerization reaction product of ethylene and at least one alpha-olefin copolymer. The polyethylene multimodal resin comprises a melt strength (MS) ≥ X1 / I2 + y, where X1 is equal to 3.9, y is equal to 1.4, I2 is the melt index of the copolymer measured according to ASTM 1238 at 2.16 kg and 190°C, and MS is the melt strength in cN units (Rheotens apparatus, 190°C, 2.4 mm / s²). 2 120mm from die exit to wheel center, extrusion speed 38.2s -1 (Capillary die with length 30 mm, diameter 2 mm, and incidence angle 180°), the film contains a dart strength (DS) greater than or equal to the density of polyethylene multimodal resin (DS ≥ 9,876 - 10,512 (ρ)), and DS is measured according to ASTM 1709 using dart type A.

[0028] In some embodiments, the film comprises a polyethylene multimodal resin. The polyethylene multimodal resin comprises a polymerization reaction product of ethylene and at least one alpha-olefin copolymer. In one or more embodiments, the polyethylene multimodal resin may have a melt strength (MS) ≥ X / I² + y, where x is equal to 3.9, y is equal to 1.4, I² is the melt index of the copolymer measured according to ASTM 1238 at 2.16 kg and 190°C, and MS is the melt strength in cN units (Rheotens apparatus, 190°C, 2.4 mm / s²). 2 120mm from die exit to wheel center, extrusion speed 38.2s -1 (Capillary die with length 30 mm, diameter 2 mm, and incidence angle 180°). In various embodiments, the film contains normalized machine direction (MD) tear of more than 85 gf / mil, and the MD tear is measured according to ASTM D1922-15.

[0029] In one or more embodiments, the multimodal resin does not include additional polymer resins added by a post-reactoral blending method. Blending methods include, but are not limited to, dry blending, melt processing, or a combination thereof.

[0030] According to the embodiment, the polyethylene multimodal resin composition may have a melt strength (MS) that satisfies the following formula 1.

[0031]

number

[0032] In Equation 1, x is equal to 3.9, y is equal to 1.4, and I2 is the melt index of the copolymer measured according to ASTM 1238 at 2.16 kg and 190°C. According to one or more embodiments, a multimodal ethylene copolymer composition may have a melt strength of at least 5 centiNewtons (cN). Further embodiments include multimodal ethylene copolymer compositions with concentrations of 5cN to 50cN, 5cN to 45cN, 5cN to 40cN, 5cN to 35cN, 5cN to 30cN, 5cN to 25cN, 5cN to 20cN, 5cN to 15cN, 5cN to 10cN, 10cN to 50cN, 10cN to 45cN, 10cN to 40cN, 10cN to 35cN, 10cN to 30cN, 10cN to 25cN, 10cN to 20cN, 10cN to 15cN, 15cN to 50cN, 15cN to 45cN, 15cN to 40cN, 15cN to 35cN, and 15cN to 30cN. It had a melt strength of 15cN~25cN, 15cN~20cN, 20cN~50cN, 20cN~45cN, 20cN~40cN, 20cN~35cN, 20cN~30cN, 20cN~25cN, 25cN~50cN, 25cN~45cN, 25cN~40cN, 25cN~35cN, 25cN~30cN, 30cN~50cN, 30cN~45cN, 30cN~40cN, 30cN~35cN, 35cN~50cN, 35cN~45cN, 35cN~40cN, 40cN~50cN, 40cN~45cN, or 45cN~50cN.

[0033] In the embodiment, the polyethylene multimodal resin, when determined by dynamic mechanical analysis, has a viscosity of 6 or less, which is the ratio (V) between the viscosity measured at 0.1 radians / second and 190°C and the viscosity measured at 100 radians / second and 190°C. 0.1 / V 100 ) may have. In some embodiments, polyethylene multimodal resins have a viscosity ratio V less than 5, 6-1, 6-2, 6-3, 6-4, 6-5, 5-1, 5-2, 5-3, 5-4, 4-1, 4-2, 4-3, 3-1, 3-2, or 2-1, as determined by dynamic mechanical analysis. 0.1 / V 100 It may have.

[0034] In one or more embodiments, the polyethylene multimodal resin may have a melt index (I2) of 0.50 g / 10 min (g / 10 min) to 10.0 g / 10 min when measured according to ASTM D-1238 at 190°C and 2.16 kg. In one or more embodiments, the multimodal ethylene copolymer composition may have a melt index (I2) of 0.50 g / 10 min (g / 10 min) to 10.0 g / 10 min when measured according to ASTM D-1238 at 190°C and 2.16 kg. When measured according to D-1238, the following values ​​were observed: 0.5g / 10 min to 10.0g / 10 min, 0.5g / 10 min to 9.0g / 10 min, 0.5g / 10 min to 8.0g / 10 min, 0.5g / 10 min to 7.0g / 10 min, 0.5g / 10 min to 6.0g / 10 min, 0.5g / 10 min to 5.0g / 10 min, 0.5g / 10 min to 4.0g / 10 min, 0.5g / 10 min to 3.0g / 10 min, 0.5g / 10 min to 2.0g / 10 min, 0.5g / 10 min to 1.0g / 10 min, 1.0g / 10 min to 1 0.0g / 10 minutes, 1.0g / 10 minutes ~ 9.0g / 10 minutes, 1.0g / 10 minutes ~ 8.0g / 10 minutes, 1.0g / 10 minutes ~ 7.0g / 10 minutes, 1.0g / 10 minutes ~ 6.0g / 10 minutes, 1.0g / 10 minutes ~ 5.0g / 10 minutes, 1.0g / 10 minutes 10 minutes ~ 4.0g / 10 minutes, 1.0g / 10 minutes ~ 3.0g / 10 minutes, 1.0g / 10 minutes ~ 2.0g / 10 minutes, 2.0g / 10 minutes ~ 10.0g / 10 minutes, 2.0g / 10 minutes ~ 9.0g / 10 minutes, 2.0g / 10 minutes ~ 8.0g / 10 minutes, 2 .0g / 10 minutes ~ 7.0g / 10 minutes, 2.0g / 10 minutes ~ 6.0g / 10 minutes, 2.0g / 10 minutes ~ 5.0g / 10 minutes, 2.0g / 10 minutes ~ 4.0g / 10 minutes, 2.0g / 10 minutes ~ 3.0g / 10 minutes, 3.0g / 10 minutes ~ 10.0g / 10 minutes, 3.0g / 10 minutes~9.0g / 10 minutes, 3.0g / 10 minutes~8.0g / 10 minutes, 3.0g / 10 minutes~7.0g / 10 minutes, 3.0g / 10 minutes~6.0g / 10 minutes, 3.0g / 10 minutes~5.0g / 10 minutes, 3.0g / 10 minutes~4. 0g / 10 minutes, 4.0g / 10 minutes ~ 10.0g / 10 minutes, 4.0g / 10 minutes ~ 9.0g / 10 minutes, 4.0g / 10 minutes ~ 8.0g / 10 minutes, 4.0g / 10 minutes ~ 7.0g / 10 minutes, 4.0g / 10 minutes ~ 6.0g / 10 minutes, 4.0g / 1 0 minutes~5.0g / 10 minutes, 5.0g / 10 minutes~10.0g / 10 minutes, 5.0g / 10 minutes~9.0g / 10 minutes, 5.0g / 10 minutes~8.0g / 10 minutes, 5.0g / 10 minutes~7.0g / 10 minutes, 5.0g / 10 minutes~6.0g / 10 minutes, 6.The melt index (I2) may be in the following ranges: 0g / 10 min to 10.0g / 10 min, 6.0g / 10 min to 9.0g / 10 min, 6.0g / 10 min to 8.0g / 10 min, 6.0g / 10 min to 7.0g / 10 min, 7.0g / 10 min to 10.0g / 10 min, 7.0g / 10 min to 9.0g / 10 min, 7.0g / 10 min to 8.0g / 10 min, 8.0g / 10 min to 10.0g / 10 min, 8.0g / 10 min to 9.0g / 10 min, 9.0g / 10 min to 10.0g / 10 min, or any combination of these ranges.

[0035] In the embodiment, the film contains a normalized dirt strength (DS) (DS ≥ 9,876 - 10,512 (ρ)) greater than or equal to the density of polyethylene multimodal resin multiplied by 9,876 minus 10,512, where the normalized DS is measured in grams (g) according to ASTM 1709 Method A and divided by the film thickness in mills.

[0036] The film may contain a normalized dart strength (DS) of 9,876 minus 10,512 multiplied by the density of the polyethylene multimodal resin (DS ≥ 9,876 - 10,512(ρ)), where the normalized DS is measured in grams (g) according to ASTM 1709 Method A and divided by the film thickness in mills. The relationship between this normalized dart strength and the density of the polyethylene multimodal resin is shown in Figure 3. The normalized DS of the film may be 15 to 1000 g / mill or 20 to 1000 g / mill.

[0037] In some embodiments, the film contains a dirt strength greater than 800 g when measured according to ASTM 1709 Method A using dirt type A. In one or more embodiments, the dirt strength is greater than 900 g, greater than 1000 g, or greater than 1200 g. In various embodiments, the film contains a dirt strength of 800 g to 5000 g. In some embodiments, the film contains a dirt strength of 800g-2000g, 800g-1800g, 800g-1600g, 800g-1500g, 800g-1200g, 800g-1000g, 800g-900g, 850g-2000g, 850g-1800g, 850g-1600g, 850g-1500g, 850g-1200g, 850g-1000g, 850g-900g, 900g-2000g, 900g-1800g, 900g-1600g, 900g-1500g, 900g-1200g, or 900g-1000g.

[0038] In one or more embodiments, the film includes normalized machine direction (MD) tear of greater than 85 gf / mil, where the MD tear is measured according to ASTM D1922-15. In some embodiments, the film includes normalized MD tear of greater than 90 gf / mil, greater than 100 gf / mil, greater than 120 gf / mil, greater than 150 gf / mil, or greater than 200 gf / mil. In various embodiments, the film includes normalized MD tear of 85 gf / mil to 1000 gf / mil, 85 gf / mil to 500 gf / mil, 85 gf / mil to 400 gf / mil, 85 gf / mil to 300 gf / mil, 85 gf / mil to 200 gf / mil, 85 gf / mil to 100 gf / mil, 90 gf / mil to 500 gf / mil, 90 gf / mil to 400 gf / mil, 90 gf / mil to 300 gf / mil, 90 gf / mil to 200 gf / mil, or 90 gf / mil to 100 gf / mil.

[0039] In various embodiments, the polyethylene multimodal resin has a melt flow ratio greater than 5 (I 10 / I2) may have. In some embodiments, the polyethylene multimodal resin has a melt flow ratio greater than 7. In some embodiments, the polyethylene multimodal resin has a melt flow ratio greater than 5-10. In some embodiments, the polyethylene multimodal resin has a melt flow ratio of 5-9, 5-8, 5-7, 5-6, 6-10, 6-9, 6-8, 6-7, 7-10, 7-9, 7-8, 8-10, 8-9, or 9-10.

[0040] In some embodiments, the polyethylene multimodal resin has a density of 0.900 to 0.975 g / cc or 0.910 to 0.930 g / cc. In various embodiments, the polyethylene multimodal resin has a density of 0.0915 to 0.950 or 0.0900 to 0.950, and in one or more embodiments, the polyethylene multimodal resin has a density of 0.0915 to 0.930.

[0041] In one or more embodiments, the polyethylene multimodal resin has a density of 0.918 g / cc or more, a melt strength of at least 7 cN, and a melt flow ratio greater than 5 (I 10 The film has / I2) and possesses a dirt strength exceeding 300g.

[0042] In some embodiments, the polyethylene multimodal resin has a density of 0.910 to 0.930 g / cc, a melt strength of at least 7 cN, and a melt flow ratio of 5 to 10 (I 10 The film has / I2) and possesses a dirt strength exceeding 800g.

[0043] In various embodiments, the polyethylene multimodal resin has a melt strength of at least 7 cN, and the film has a mechanical tear strength greater than 85 gf / mil, as measured according to ASTM D1922-15.

[0044] In one or more embodiments, the polyethylene multimodal resin has a melt strength of at least 8 cN and a rheology ratio of 6 or less V 0.1 / V 100The film has a dirt strength of over 800g, V 0.1 V is the viscosity of an ethylene-based polymer at 190°C with an angular frequency of 0.1 radians / second. 100 This is the viscosity of an ethylene-based polymer at 190°C with an angular frequency of 100 radians / second.

[0045] In the embodiment, the polyethylene multimodal resin has an overall density of 0.918 to 0.925 g / cc, a melt strength of 6 cN or more, and a (Mz / Mw) ratio of 2 or more, where Mz is the Z-average molecular weight and Mw is the weight-average molecular weight, and is measured according to gel permeation chromatography.

[0046] It should be understood that polyethylene multimodal resin may further contain one or more additives known to those skilled in the art, such as plasticizers, stabilizers including viscosity stabilizers, hydrolysis stabilizers, primary and secondary antioxidants, UV absorbers, antistatic agents, dyes, pigments, or other colorants, inorganic fillers, flame retardants, lubricants, reinforcing agents such as glass fibers and flakes, synthetic (e.g., aramid) fibers or pulp, forming agents or foaming agents, processing aids, slip additives, anti-tack agents such as silica or talc, release agents, tackifying resins, or two or more combinations thereof. Inorganic fillers such as calcium carbonate may also be incorporated into the blend. In some embodiments, polyethylene multimodal resin may contain up to 5 weight percent of such additional additives based on the total weight of each layer. All individual values ​​and sub-ranges from 0% by weight to 5% by weight are included and disclosed herein, for example, the total amount of additives in the first, second, or third layer may be 0.5% to 5% by weight, 0.5% to 4% by weight, 0.5% to 3% by weight, 0.5% to 2% by weight, 0.5% to 1% by weight, 1% to 5% by weight, 1% to 4% by weight, 1% to 3% by weight, 1% to 2% by weight, 2% to 5% by weight, 2% to 4% by weight, 2% to 3% by weight, 3% to 5% by weight, 3% to 4% by weight, or 4% to 5% by weight, based on the total weight of each layer. The incorporation of additives can be carried out by any known process, such as dry blending, extrusion of a mixture of various components, or conventional masterbatch technology.

[0047] Polyethylene multimodal resin can be blended with low-density polyethylene (LDPE) resin to produce polyethylene blends. Low-density polyethylene may have a melt index of 0.1 g / 10 min to 10.0 g / 10 min when measured according to ASTM D1238 at a load of 2.16 kg and a temperature of 190 °C. Low-density polyethylene may have a melt index of 0.1 g / 10 min to 5.0 g / 10 min, or 0.5 g / 10 min to 5.0 g / 10 min, or 0.5 g / 10 min to 2.0 g / 10 min. Low-density polyethylene (LDPE) may have a melt index of 0.910 to 0.930 g / cc or 0.915 g / cm³ when measured according to ASTM D792. 3 ~0.930g / cm 3 LDPE has a density of 0.910 g / cm³. 3 ~0.925g / cm 3 , or 0.915 g / cm³ 3 ~0.930g / cm 3 It could be that density.

[0048] In one or more embodiments, the film of the present disclosure may be a single-layer film.

[0049] The multilayer films of this disclosure can have a variety of thicknesses. The thickness of the film may depend on a number of factors, including, for example, the number of layers in the film, the composition of the layers in the multilayer film, the desired properties of the film, the desired end use of the film, and the manufacturing process of the film. In embodiments, the film may have a thickness of less than 205 micrometers (μm or micron). In this embodiment, the multilayer film may have a thickness of 15 μm to 205 μm, 20 μm to 180 μm, 15 μm to 180 μm, 15 μm to 160 μm, 15 μm to 140 μm, 15 μm to 120 μm, 15 μm to 100 μm, 15 μm to 80 μm, 15 μm to 60 μm, 15 μm to 40 μm, 20 μm to 160 μm, 20 μm to 140 μm, 20 μm to 120 μm, 20 μm to 100 μm, 20 μm to 80 μm, 20 μm to 60 μm, or 20 μm to 40 μm.

[0050] Multilayer film Embodiments of this disclosure include multilayer films. In some embodiments, the multilayer film may comprise two, three, four, or five layers, or even seven, nine, eleven, thirteen or more layers. The number of layers in the multilayer film may depend on a number of factors, including, for example, the composition of each layer of the multilayer film, the desired properties of the multilayer film, the end use of the multilayer film, and the manufacturing process of the multilayer film. As described in more detail herein, embodiments of the multilayer film may comprise a barrier layer, one or more outer layers as described later herein, and one or more subskin layers. The one or more subskin layers may comprise selected medium-density polyethylene (MDPE) as detailed below herein. The selected MDPE in the one or more subskin layers may have the same or different compositions.

[0051] The multilayer film may be, for example, a three-layer film designated as A / B / C or A / B / A, or the multilayer film may be a five-layer film designated as A / B / C / D / E, where the first layer may be designated as (A), the second layer as (B), the third layer as (C), the fourth layer as (D), and the fifth layer as (E). In embodiments, layer (C) may be referred to as the “intermediate layer” or “core layer”. In embodiments, layer (C) may be a barrier layer, as described later in this disclosure. In embodiments, one or both of layers (A) and (E) may be outer layers, as described later in this disclosure. In embodiments, one or both of layers (B) and (D) may be subskin layers, as described later in this disclosure.

[0052] In one or more embodiments, the film further comprises a low-density polyethylene (LDPE) resin layer. In one or more embodiments, the low-density polyethylene may have a melt index of 0.1 g / 10 min to 10.0 g / 10 min when measured according to ASTM D1238 at a load of 2.16 kg and a temperature of 190 °C. In embodiments, the low-density polyethylene may have a melt index of 0.1 g / 10 min to 5.0 g / 10 min, or 0.5 g / 10 min to 5.0 g / 10 min, or 0.5 g / 10 min to 2.0 g / 10 min.

[0053] In some embodiments, low-density polyethylene (LDPE) has a density of 0.910–0.930 g / cc or 0.915 g / cm³ when measured according to ASTM D792. 3 ~0.930g / cm 3 It can have a density from having a density of . In another embodiment, LDPE has a density of 0.910 g / cm³. 3 ~0.925g / cm 3 , or 0.915 g / cm³ 3 ~0.930g / cm 3 It is possible.

[0054] It should be understood that any of the aforementioned layers may further contain one or more additives known to those skilled in the art, such as plasticizers, stabilizers including viscosity stabilizers, hydrolysis stabilizers, primary and secondary antioxidants, ultraviolet absorbers, antistatic agents, dyes, pigments, or other colorants, inorganic fillers, flame retardants, lubricants, reinforcing agents such as glass fibers and flakes, synthetic (e.g., aramid) fibers or pulp, forming agents or foaming agents, processing aids, slip additives, anti-tack agents such as silica or talc, release agents, tackifying resins, or two or more combinations thereof. Inorganic fillers such as calcium carbonate and analogues may also be incorporated into one or more of the first layer, the second layer, the third layer, and combinations thereof. In some embodiments, each layer may contain up to 5 weight percent of such additional additives based on the total weight of each layer. All individual values ​​and sub-ranges from 0% by weight to 5% by weight are included and disclosed herein, for example, the total amount of additives in the first, second, or third layer may be 0.5% to 5% by weight, 0.5% to 4% by weight, 0.5% to 3% by weight, 0.5% to 2% by weight, 0.5% to 1% by weight, 1% to 5% by weight, 1% to 4% by weight, 1% to 3% by weight, 1% to 2% by weight, 2% to 5% by weight, 2% to 4% by weight, 2% to 3% by weight, 3% to 5% by weight, 3% to 4% by weight, or 4% to 5% by weight, based on the total weight of each layer. The incorporation of additives can be carried out by any known process, such as dry blending, extrusion of a mixture of various components, or conventional masterbatch technology.

[0055] The multilayer films of this disclosure may have a variety of thicknesses. The thickness of the multilayer film may depend on a number of factors, including, for example, the number of layers in the multilayer film, the composition of the layers in the multilayer film, the desired properties of the multilayer film, the desired end use of the film, and the manufacturing process of the multilayer film. In embodiments, the multilayer film may have a thickness of less than 205 micrometers (μm or micron). In this embodiment, the multilayer film may have a thickness of 15 μm to 205 μm, 20 μm to 180 μm, 15 μm to 180 μm, 15 μm to 160 μm, 15 μm to 140 μm, 15 μm to 120 μm, 15 μm to 100 μm, 15 μm to 80 μm, 15 μm to 60 μm, 15 μm to 40 μm, 20 μm to 160 μm, 20 μm to 140 μm, 20 μm to 120 μm, 20 μm to 100 μm, 20 μm to 80 μm, 20 μm to 60 μm, or 20 μm to 40 μm.

[0056] process In embodiments, polyethylene multimodal resins may be produced via a solution polymerization process. In embodiments, the process for producing a polyethylene multimodal resin may involve contacting at least two olefin monomers in a solution polymerization reactor system in the presence of a catalyst system comprising at least one low molecular weight catalyst and at least one high molecular weight catalyst.

[0057] In embodiments, the solution polymerization reactor system may include one or more reactors. In embodiments, the solution polymerization reactor system may be a double reactor system. In embodiments including a double reactor system, the solution polymerization reactor system may include a first reactor and a second reactor. Such a solution polymerization process may involve using, for example, one or more conventional reactors, such as loop reactors, isothermal reactors, adiabatic reactors, fluidized bed gas-phase reactors, stirred-tank reactors, and batch reactors, for example, in parallel, in series, or in any combination thereof.

[0058] In embodiments, ethylene and at least one olefin monomer may be polymerized in the presence of a catalyst to produce the polyethylene multimodal resin described herein. The olefin monomer may be an α-olefin comonomer. Typically, an α-olefin monomer has 20 or fewer carbon atoms. For example, an α-olefin comonomer may have 3 to 10 carbon atoms or 3 to 8 carbon atoms. Exemplary α-olefin comonomers include, but are not limited to, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, and 4-methyl-1-pentene. For example, one or more α-olefin comonomers may be selected from the group consisting of propylene, 1-butene, 1-hexene, and 1-octene, or alternatively, from the group consisting of 1-hexene and 1-octene. In embodiments, the α-olefin comonomer and process solvent may be purified using molecular sieves before being introduced into the solution polymerization reactor system. A solvent, monomer, comonomer, and hydrogen can be combined and supplied to a solution polymerization reactor system. Examples of solvents include, but are not limited to, isoparaffins. For example, such solvents are commercially available from ExxonMobil Chemical under the name ISOPAR(trademark)E. In some embodiments, the combined feed can be at a controlled temperature of 5°C–50°C, 5°C–25°C, 5°C–10°C, 10°C–50°C, 10°C–25°C, or 25°C–50°C.

[0059] Method for producing the film described herein Various methodologies are contemplated for producing the films of this disclosure. In one or more embodiments, the process for producing a multilayer film may include extrusion of a cast film or extrusion of an inflated film.

[0060] In some embodiments, the process for manufacturing the film may include forming inflation film bubbles. In some embodiments, the inflation film bubbles may be multilayer inflation film bubbles. According to this embodiment, the multilayer inflation film bubbles may further include at least five, seven, nine, or more layers, which may be bonded to one another.

[0061] In embodiments of the inflation film process, an extruded film from an extrusion die may be formed (inflated) and pulled upwards in a tower up to the nip. The film can then be wound onto a core. Before winding the film onto the core, the ends of the film may be cut and folded using a folding device. This makes it difficult to separate the layers of film, which can be important for general transport applications or for heavy-duty transport sack applications.

[0062] In further embodiments, inflation film bubbles may be formed via an inflation film extrusion line having a length-to-diameter ("L / D") ratio of 30:1. In some embodiments, the extrusion line may have a blow-up ratio of 1–5, 1–3, 2–5, or 2–3. In some embodiments, the extrusion line may utilize a die with internal bubble cooling. In some embodiments, the die gap may be 1 millimeter (mm)–5 mm, 1 mm–3 mm, 2 mm–5 mm, or 2 mm–3 mm.

[0063] In some embodiments, the extrusion molding line may utilize a film thickness gauge scanner. In some embodiments, the multilayer film thickness can be maintained between 15 μm and 115 μm during the extrusion molding process. In embodiments, the multilayer film thickness can be maintained between 15 μm and 100 μm, 15 μm and 75 μm, 15 μm and 50 μm, 15 μm and 25 μm, 25 μm and 115 μm, 25 μm and 100 μm, or 100 μm and 115 μm.

[0064] In some embodiments, the multilayer inflation film bubble formation process may be carried out at a temperature of 350 to 500°F or 375 to 475°F. The output speed may be 5 lb / h / in to 25 lb / h / in, 5 lb / h / in to 20 lb / h / in, 5 lb / h / in to 15 lb / h / in, 5 lb / h / in to 10 lb / h / in, 10 lb / h / in to 25 lb / h / in, 10 lb / h / in to 20 lb / h / in, 10 lb / h / in to 15 lb / h / in, 15 lb / h / in to 25 lb / h / in, or 20 lb / h / in to 25 lb / h / in.

[0065] Description of the inflation film line; line 1 A 2-mil inflation film was fabricated using a single-layer Dr. Collin inflation film line. This line featured a 30mm screw diameter 30:1 L / D single-screw extruder equipped with a grooved feed zone. The annular die had a diameter of 60mm and used a double-lip air-ring cooling system. The die lip gap was 2mm, and the blow-up ratio (BUR) was 2.0. The flattening width was approximately 48cm. The frost line height was 5-6 inches. The total output was 5-8 kg / hour. The melting temperature was 200-220°C, and the die temperature was set to 225°C.

[0066] Description of inflation film line: Line 2 A gravimetric feeder fed the resin compound into a Labtech LTE20-32 twin-screw extruder at a rate of 15 pounds / hour. From the extruder, the resin compound was transported to a 2-inch diameter die with a 1.0 mm gap. The Labtech feed throat was set to 193°C, and the rest of the barrel, transport section, and die temperature were set and maintained at 215°C. Pressurized ambient air was used to inflate the film bubble to a blow-up ratio of 2.5. A dual-lip air ring driven by a variable-speed blower was used for all experiments. The frost line height (FLH) was maintained between 8.8 and 10.8 inches. The film thickness was targeted at 2 mils and controlled within ±15% by adjusting the nip roller speed. The film was wound onto a roll.

[0067] Goods Embodiments of the present disclosure also relate to articles such as packages formed from the multilayer films of the present disclosure. Such packages may be formed from any of the multilayer films of the present disclosure as described herein. The multilayer films of the present disclosure are particularly useful in articles where good tear strength and dirt strength are desired.

[0068] Examples of such articles include flexible packaging, pouches, self-standing pouches, and ready-made packaging or pouches.

[0069] Various methods for manufacturing embodiments of articles from multilayer films disclosed herein will be well known to those skilled in the art.

[0070] Catalyst system Specific embodiments of catalyst systems that may be used in one or more embodiments to produce the polyethylene compositions described herein are described herein. It should be understood that the catalyst systems of this disclosure may be embodied in different forms and should not be construed as being limited to the specific embodiments described herein. Rather, the embodiments are provided so that this disclosure is detailed and complete and fully conveys the scope of the subject matter to those skilled in the art.

[0071] The term "procatalyst" refers to a compound that exhibits catalytic activity when combined with an activator. The term "activator" refers to a compound that chemically reacts with a procatalyst to convert it into a catalytically active catalyst. As used herein, the terms "co-catalyst" and "activator" are interchangeable.

[0072] When used to describe a chemical group containing a specific carbon atom, "(C x ~C y A parenthetical expression in the form of ")" means that the unsubstituted form of the chemical group has x carbon atoms to y carbon atoms, including x and y. For example, (C1~C 40 ) Alkyl is an alkyl group having 1 to 40 carbon atoms in its unsubstituted form. In some embodiments and general structures, certain chemical groups are R S It may be replaced by one or more substituents such as (C x ~C y The chemical group R defined using ) S The substitution version is any base R S Depending on the identity, it may contain more than y carbon atoms. For example, "R S Strictly speaking, one group R is phenyl (-C6H5). S Replaced with (C1~C 40 )alkyl can contain 7 to 46 carbon atoms. Therefore, generally, the parenthetical "(C x ~C y A substituent R, defined using ")", contains one or more carbon atoms in the chemical group. SWhen substituted by, the minimum and maximum total number of carbon atoms in the chemical group is such that both x and y contain all carbon atoms of substituent R. S It is determined by adding up the total number of carbon atoms from each origin.

[0073] The term "substituted" means that at least one hydrogen atom (-H) bonded to a carbon or heteroatom of the corresponding unsubstituted compound or functional group is a substituent (e.g., R S This means that all hydrogen atoms (H) bonded to the carbon or heteroatom of the corresponding unsubstituted compound or functional group are replaced by substituents (e.g., R S This means that the atoms are replaced by the substituents. The term "polysubstituted" means that at least two, but fewer than all, hydrogen atoms bonded to the carbon or heteroatom of the corresponding unsubstituted compound or functional group are replaced by the substituents.

[0074] The term "-H" refers to hydrogen or a hydrogen radical covalently bonded to another atom. "Hydrogen" and "-H" are interchangeable and mean the same thing unless otherwise specified.

[0075] "halogen atom", "halogen", "halide", "saturated", "unsaturated", "C1~C 50 ) Hydrocarbyl, (C1~C 50 )alkyl", (C1~C 18 )alkyl", (C6~C 50 )Arial," (C3~C 50 )Cycloalkyl", (C1~C 50 )alkylene", "heteroatom", and "(C1~C 50 ")heteroalkyl" is defined as described in publication number 2020185494(A1).

[0076] According to some embodiments, the catalyst system for producing the polyethylene composition comprises a metal-ligand complex according to formula (I).

[0077] [ka]

[0078] In formula (I), M is a metal selected from titanium, zirconium, or hafnium, the metal is in a formal oxidation state of +2, +3, or +4, n is 0, 1, or 2, if n is 1, X is a monodentate or bidentate ligand, if n is 2, each X is a monodentate ligand, the same or different, the metal-ligand complex is charge-neutral overall, and each Z is independently -O-, -S-, or -N(R) N )-, or -P(R P )- is selected from, and L is (C1~C 40 ) Hydrocarbylene or (C1~C 40 ) is a heterohydrocarbylene, (C1~C 40 Hydrocarbylene has a portion containing a linker skeleton of 1 to 10 carbon atoms that connects the two Z groups in formula (I) (to which L is bonded), or (C1 to C 40 ) Heterohydrocarbylene has a portion containing a linker skeleton of 1 to 10 atoms that connects the two Z groups in formula (I), (C1 to C 40 Each of the 1 to 10 atoms in the linker skeleton of heterohydrocarbylene is independently a carbon atom or a heteroatom, and each heteroatom is independently O, S, S(O), S(O)2, Si(R) C )2, Ge(R C )2, P(R C ), or N(R C ) and independently, each R C (C1~C 30 ) Hydrocarbyl or (C1~C 30 ) is a heterohydrocarbyl, R 1 and R 8 These are independently -H, (C1~C 40 ) Hydrocarbyl, (C1~C 40 ) Heterohydrocarbyl, -Si(R C )3, -Ge(R C )3, -P(R P )2, -N(RN ) 2. -OR C , -SR C , -NO2, -CN, -CF3, R C S(O)-, R C S(O)2-, (R C )2C=N-, R C C(O)O-, R C OC(O)-, R C C(O)N(R N )-, (R N )2NC(O)-, halogen, and a radical having formula (II), formula (III), or formula (IV).

[0079]

Chemical formula

[0080] In formula (II), (III), and (IV), each of R 31~35 , R 41~48 , or R 51~59 is independently (C1-C 40 ) hydrocarbyl, (C1-C 40 ) heterohydrocarbyl, -Si(R C )3, -Ge(R C )3, -P(R P )2, -N(R N )2, -N=CHR C , -OR C , -SR C , -NO2, -CN, -CF3, R C S(O)-, R C S(O)2-, (R C )2C=N-, R C C(O)O-, R C OC(O)-, R C C(O)N(R N )-, (R N )2NC(O)-, halogen, or -H, provided that at least one of R 1 or R 8 is a radical having formula (II), formula (III), or formula (IV).<​​In formula (I), R 2~4 , R 5~7 , and R 9~16 Each of these is independent of (C1~C 40 ) Hydrocarbyl, (C1~C 40 ) Heterohydrocarbyl, -Si(R C )3, -Ge(R C )3, -P(R P )2, -N(R N )2, -N=CHR C , -OR C , -SR C -NO2, -CN, -CF3, R C S(O)-, R C S(O)2-, (R C )2C=N-, R C C(O)O-, R C OC(O)-, R C C(O)N(R N )-, (R C ) Selected from 2NC(O)-, halogen, and -H.

[0082] In some embodiments, the multimodal base resin 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.

[0083] [ka]

[0084] Co-catalyst components A catalyst system comprising the metal-ligand complex of formula (I) may be catalytically activated by any technique well known in the art for activating metal catalysts in olefin polymerization reactions. For example, a system comprising the metal-ligand complex of formula (I) may be catalytically activated by contacting the complex with an activating co-catalyst or by combining the complex with an activating co-catalyst. Suitable activating co-catalysts for use herein include alkylaluminum, polymers or oligomeric alumoxanes (also known as aluminoxanes), neutral Lewis acids, and nonpolymers, non-coordinating, ion-forming compounds (including the use of such compounds under oxidizing conditions). A preferred activation technique is bulk electrolysis. Combinations of one or more of the aforementioned activating co-catalysts and techniques are also contemplated. The term "alkylaluminum" means monoalkylaluminum dihydride or monoalkylaluminum dihalide, dialkylaluminum hydride or dialkylaluminum halide, or trialkylaluminum. Examples of polymeric or oligomeric almoxanes include methyl almoxane, triisobutylaluminum-modified methyl almoxane, and isobutyl almoxane.

[0085] Lewis acid activators (co-catalysts) are provided in the form of 1 to 3 (C1-C) as described herein. 20 )Includes a group 13 metal compound containing a hydrocarbyl substituent.In one embodiment, the group 13 metal compound is tri((C1~C 20 )hydrocarbyl) substituted aluminum or tri((C1~C 20 The compound is a tri(hydrocarbyl)-boron compound. In the embodiment, the group 13 metal compound is tri((C1~C 20 )hydrocarbyl)-boron compounds, tri((C1~C 10 )Alkyl) Aluminum, Tri((C6~C 18The aryl)boron compounds and their halogenated (including perhalated) derivatives. In further embodiments, the Group 13 metal compound is tris(fluorosubstituted phenyl)borane, tris(pentafluorophenyl)borane. In some embodiments, the activation co-catalyst is tris((C1~C 20 ) Hydrocarbyl borate (e.g., trityltetrafluoroborate) or tri((C1~C 20 ) Hydrocarbyl ammonium tetra((C1~C 20 (Hydrocarbyl)borane (e.g., bis(octadecyl)methylammoniumtetrakis(pentafluorophenyl)borane). As used herein, the term "ammonium" means ((C1-C 20 ) Hydrocarbyl 4N + , ((C1~C 20 ) Hydrocarbyl 3N(H) + , ((C1~C 20 )hydrocarbyl)2N(H)2 + , (C1~C 20 ) Hydrocarbyl N(H)3 + , or N(H)4 + This refers to nitrogen cations, and each (C1~C 20 ) If two or more hydrocarbyl molecules are present, they may be the same or different.

[0086] A combination of neutral Lewis acid activators (co-catalysts) is tri((C1~C4)alkyl)aluminum and halogenated tri((C6~C 18Examples include mixtures containing aryl)boron compounds, particularly combinations with tris(pentafluorophenyl)borane. Embodiments include combinations of such neutral Lewis acid mixtures with polymers or oligomeric almoxanes, and combinations of a single neutral Lewis acid, particularly tris(pentafluorophenyl)borane, with polymers or oligomeric almoxanes. The molar ratio of (metal-ligand complex):(tris(pentafluorophenylborane):(almoxane) [e.g., Group 4 metal-ligand complex):(tris(pentafluorophenylborane):(almoxane)] is 1:1:1 to 1:10:30, and in embodiments, 1:1:1.5 to 1:5:10.

[0087] A catalyst system containing a metal-ligand complex of formula (I) can be activated to form an activated catalyst composition in combination with one or more co-catalysts, such as a cation-forming co-catalyst, a strong Lewis acid, or a combination thereof. Suitable activation co-catalysts include polymers or oligomers of aluminoxanes, particularly methylaluminoxanes, and inert, miscible, non-coordinating, and ion-forming compounds. Examples of suitable co-catalysts include modified methylaluminoxane (MMAO), bis(hydrogenated tulose alkyl)methyl, and tetrakis(pentafluorophenyl)borate (1 - Examples include, but are not limited to, amines and combinations thereof.

[0088] In some embodiments, one or more of the aforementioned activation co-catalysts are used in combination with each other. Particularly preferred combinations are mixtures of tri((C1-C4)hydrocarbyl)aluminum, tri((C1-C4)hydrocarbyl)borane, or ammonium borate with an oligomer or polymer-almoxane compound. The ratio of the total number of moles of one or more metal-ligand complexes of formula (I) to the total number of moles of one or more activation co-catalysts is 1:10,000 to 100:1. In some embodiments, this ratio is at least 1:5000, in some embodiments at least 1:1000 and 10:1 or less, and in some embodiments 1:1 or less. When an almoxane is used alone as an activation co-catalyst, the number of moles of the almoxane used is preferably at least 100 times the number of moles of the metal-ligand complex of formula (I). When tris(pentafluorophenyl)borane is used alone as an activation co-catalyst, in some embodiments, the number of moles of tris(pentafluorophenyl)borane used relative to the total number of moles of one or more metal-ligand complexes of formula (I) is 0.5:1 to 10:1, 1:1 to 6:1, or 1:1 to 5:1. The remaining activation co-catalyst is generally used in a molar amount approximately equal to the total number of moles of one or more metal-ligand complexes of formula (I).

[0089] Continuous solution polymerization reaction: Setting 1 The raw materials (ethylene, 1-octene) and process solvent (SBP 100 / 140, a high-purity isoparaffin solvent with a narrow boiling point range, commercially available from Shell Chemicals) are purified using molecular sieves before being introduced into the reaction environment. Hydrogen is supplied into the pressurized cylinder as high-purity grade and is not further purified. The reactor monomer feed (ethylene) stream is pressurized to a pressure higher than 525 psig reaction pressure via a mechanical compressor. The solvent and comonomer (1-octene) feeds are pressurized to a pressure higher than 525 psig reaction pressure via a mechanical positive displacement pump. MMAO-3A, ​​commercially available from AkzoNobel, was used as an impurity scavenger. Individual catalyst components (pro-catalyst and co-catalyst) are manually batch diluted to specific component concentrations with the purified solvent (SBP 100 / 140), and, if necessary, 4 equivalents of triethylaluminum are added to the pro-catalyst solution, and they are pressurized to a pressure higher than 525 psig reaction pressure. The co-catalyst is [HNMe(C)], which is commercially available from Boulder Scientific. 18 H 37 )2][B(C6F5)4] was used in a 1.2 molar ratio relative to the pro catalyst. All reaction feed flows were measured using a mass flow meter and controlled independently by a computer-automated valve control system.

[0090] Continuous solution polymerization is carried out in a 5-liter (L) continuously stirred-tank reactor (CSTR). In some cases, the reaction was carried out in two such reactors connected either in series or in parallel. The reactors independently control all fresh solvent, monomer, comonomer, hydrogen, and catalyst component feeds. The combined feed of solvent, monomer, comonomer, and hydrogen to the reactor is temperature-controlled somewhere between 5°C and 50°C, typically 25°C or 50°C. The fresh comonomer feed to the polymerization reactor is supplied together with the solvent feed. The fresh solvent feed is typically controlled by each injector receiving half of the total fresh feed volume flow rate. The co-catalyst is supplied to the pro-catalyst component based on a calculated specific molar ratio (1.2 molar equivalents). Immediately after each fresh injection point, the feed stream is mixed with the contents of the circulating polymerization reactor using a static mixing element. The effluent (containing solvent, monomer, comonomer, hydrogen, catalyst components, and molten polymer) from the polymerization reactor is routed through the first reactor loop and through a control valve (which maintains the pressure in the first reactor at a specified target). As the stream exits the reactor, it is brought into contact with water to halt the reaction. In addition, various additives such as antioxidants may be added at this point. The stream is then passed through another set of static mixing elements to uniformly disperse the catalyst killer and additives.

[0091] Following the addition of additives, the effluent (containing solvent, monomers, comonomers, hydrogen, catalyst components, and molten polymer) passed through a heat exchanger to raise the stream temperature in preparation for the separation of the polymer from other lower-boiling point reaction components. The stream was then placed into a two-stage separation and defoliation system, where the polymer was separated from the solvent, hydrogen, and unreacted monomers and comonomers. The separated and defoliated polymer molten material was pumped through a die specially designed for underwater pelletization, cut into uniform solid pellets, dried, and transferred to storage boxes.

[0092] Continuous solution polymerization reaction: Setting 2 Before introducing them into the reaction environment, all raw materials (monomers and comonomers) and the process solvent (high-purity isoparaffin solvent with a narrow boiling point range, Isopar-E) are purified using molecular sieves. Hydrogen is supplied under pressure as a high-purity grade and is not purified further. The monomer feed stream to the reactor is pressurized to exceed the reaction pressure via a mechanical compressor. The solvent and comonomer feed streams are pumped to a pressure higher than the reaction pressure. Individual catalyst components are manually batch-diluted with the purified solvent and pressurized to exceed the reaction pressure. All reaction feed streams are measured using mass flowmeters and controlled independently by a computer-automated valve control system.

[0093] Two reactor systems are used in a series configuration. The first reactor is a continuous solution polymerization reactor consisting of a liquid-filled, adiabatic, continuously stirred tank reactor (CSTR). All fresh solvent, monomers, comonomers, hydrogen, and catalyst component feeds can be independently controlled. All fresh feed streams to the second reactor (solvent, monomers, comonomers, and hydrogen) are temperature-controlled to maintain a single solution phase by passing the feed streams through a heat exchanger. All fresh feeds to the second polymerization reactor are injected into the reactor at a single location. Catalyst components are injected into the second polymerization reactor separately from the fresh feeds. The supply of primary catalyst components is computer-controlled to maintain the monomer conversion rate of the reactor at a specific value. Co-catalyst components are supplied based on their molar ratio to the primary catalyst component. Mixing in the second reactor is provided by a stirrer. The effluent from the first polymerization reactor (containing solvent, monomer, comonomer, hydrogen, catalyst components, and polymer) flows out of the first reactor loop and is added to the second reactor separately from the fresh feed and the catalyst feed components.

[0094] The second reactor is a continuous solution polymerization reactor consisting of a liquid-filled, non-adiabatic, isothermal, circulating, loop reactor that mimics a continuous stirred-tank reactor (CSTR) for heat removal. All fresh solvent, monomer, comonomer, hydrogen, and catalyst component feeds are independently controlled. All fresh feed streams to the first reactor (solvent, monomer, comonomer, and hydrogen) are temperature-controlled to maintain a single solution phase by passing the feed streams through a heat exchanger. All fresh feeds to the first polymerization reactor are injected into the reactor at two locations, with approximately equal reactor volumes between each injection point. Fresh feed is controlled by each injector, receiving half of the total fresh feed flow rate. Catalyst components are injected into the polymerization reactor separately from the fresh feeds. Primary catalyst component feeding is computer-controlled to maintain the reactor monomer conversion rate at a specific value and to produce polymers with desired MI, density, and melt strength. Co-catalyst components are supplied based on their molar ratio to the primary catalyst component. Immediately after the injection point of each first reactor feed, the feed stream is mixed with the contents of a circulating polymerization reactor having a static mixing element. The contents of the first reactor are continuously circulated through a heat exchanger, which plays a role in removing most of the reaction heat, at the temperature of the coolant side, which plays a role in maintaining an isothermal reaction environment at a specific temperature. The circulation around the first reactor loop is provided by a pump.

[0095] The second reactor effluent enters a zone where a suitable reagent (water) is added and reacts with it to deactivate the effluent. The addition of antioxidants may also occur at this same point. Following catalyst deactivation and additive addition, the reactor effluent enters a devolving system where the polymer is removed from the non-polymer stream. The isolated polymer molten material is pelletized and collected. The non-polymer stream passes through various devices that separate most of the ethylene removed from the system. Most of the solvent and unreacted comonomers are recycled back into the reactor after passing through a purification system. Small amounts of solvent and comonomers are purged from the process.

[0096] Reactor flow feed data flow corresponding to the values ​​in Table 3. The data is presented to take into account the complexity of the solvent recycling system and to allow for easier processing of the reaction system as a through-flow diagram.

[0097] Procedure for compounding resin The compounding process was performed using a Thermo micro-16 twin-screw compounding machine. Samples were compounded specifically for processing films in an inflation film line and for testing using analytical techniques such as GPC (Gel Permeation Chromatography) and rheological measurements. The compounding process was carried out under carefully controlled conditions to ensure optimal results. Specific temperature zones were set on the Micro-16 extruder: Zone 1 was approximately 140°C, Zone 2 approximately 150°C, Zone 3 approximately 160°C, Zone 4 approximately 170°C, Zone 5 approximately 180°C, Zone 6 approximately 180°C, Zone 7 approximately 205°C, Zone 8 approximately 205°C, Zone 9 approximately 212°C, and Zone 10 approximately 200°C. The die temperature was maintained at approximately 180°C. The extruder was operated at 400 rpm. The extruder was operated at a speed of 2.7 pounds / hour.

[0098] Description of the inflation film line; line 1 A 2-mil inflation film was fabricated using a single-layer Dr. Collin inflation film line. This line featured a 30mm screw diameter 30:1 L / D single-screw extruder equipped with a grooved feed zone. The annular die had a diameter of 60mm and used a double-lip air-ring cooling system. The die lip gap was 2mm, and the blow-up ratio (BUR) was 2.0. The flattening width was approximately 48cm. The frost line height was 5-6 inches. The total output was 5-8 kg / hour. The melting temperature was 200-220°C, and the die temperature was set to 225°C.

[0099] Description of inflation film line: Line 2 A gravimetric feeder fed the resin compound into a Labtech LTE20-32 twin-screw extruder at a rate of 15 pounds / hour. From the extruder, the resin compound was transported to a 2-inch diameter die with a 1.0 mm gap. The LTE feed throat was set to 193°C, and the rest of the barrel, transport section, and die temperature were set and maintained at 215°C. Pressurized ambient air inflated the film bubbles to a blow-up ratio of 2.5. A dual-lip air ring driven by a variable-speed blower was used in all experiments. The frost line height (FLH) was maintained between 8.8 and 10.8 inches. The film thickness was targeted at 2 mils and controlled within ±15% by adjusting the nip roller speed. The film was wound onto rolls.

[0100] Test method The test method includes the following:

[0101] Melt Index Melt index I2 (or I2) and I 10 (or I10) were measured at 190°C and under loads of 2.16 kg and 10 kg, respectively, according to ASTM D-1238 (Method B). These values ​​were reported in units of g / 10 min. Fractions of polymer samples were determined by collecting the product polymer from the reactor producing that particular fraction or portion of the polymer composition. For example, the first polyethylene fraction could be recovered from the reactor producing the lower-density, higher-molecular-weight component of the polymer composition. The polymer solution was dried under vacuum before melt index measurement.

[0102] density Samples for density measurement were prepared according to ASTM D4703. Within one hour of sample pressurization, measurements were performed according to ASTM D792, Method B.

[0103] Turbidity Prior to testing, the samples are conditioned at 23 (±2)°C and 50 (±10)% RH for a minimum of 40 hours according to ASTM D618 (Procedure A).

[0104] Haze is measured using a 6-inch x 6-inch test specimen cut from a film sheet. Thickness is measured at the center of the specimen. The specimen is placed in the haze port of the BYK Hazegard-I tester, and the haze is measured according to ASTM D1003. Typically, 10 replicates are measured, and the mean and standard deviation are reported.

[0105] Elmendorf MD tear MD tear was measured according to ASTM D-1922. The force (in grams) required to propagate the tear across the film specimen was measured using an Elmendorf Tear tester. Acting on by gravity, the pendulum oscillated in an arc, tearing the specimen through a pre-cut slit. The tear propagated transversely. The specimen was conditioned at the pre-test temperature for a minimum of 40 hours.

[0106] The normalized Elmendorf MD tear value is calculated by dividing the Elmendorf MD tear value by the film thickness.

[0107] ASTM D1709 Dirt Drop The film dart drop test determines the energy required to break a plastic film under specified conditions of impact from a free-falling dart. The test result is expressed as the energy of the impactor falling from a specified height that would result in the breakage of 50% of the test specimen.

[0108] After the film is produced, it is conditioned at 23°C (±2°C) and 50% RH (±5) for at least 40 hours according to ASTM standards. The standard test conditions are 23°C (±2°C) and 50% RH (±5) according to ASTM standards.

[0109] Test results are reported by Method A, using a 1.5-inch diameter dart head and a drop height of 26 inches. The thickness of the specimen is measured at the center of the specimen, and the specimen is then secured in an annular specimen holder with an inner diameter of 5 inches. The dart is loaded at the center, above the specimen, and released by either a pneumatic or electromagnetic mechanism.

[0110] The test is conducted according to the "staircase" method. If a sample is damaged, a new sample is tested with the dart weight reduced by a known fixed amount. If the sample is not damaged, a new sample is tested with the dart weight increased by a known amount. After 20 test specimens have been tested, the number of damaged specimens is determined. If this number is 10, the test is completed. If this number is less than 10, the test is continued until 10 damages are recorded. If this number is greater than 10, the test is continued until the total number of undamaged specimens is 10. The dart drop strength is determined from these data according to ASTM D1709 and expressed in grams as a Type A dart drop impact. All samples analyzed were 2 mils thick.

[0111] The normalized dirt is determined by dividing the dirt value by the film thickness.

[0112] Instrumented Dirt Impact Prior to testing, the samples are conditioned at 23 (±2)°C and 50 (±10)% RH for a minimum of 40 hours according to ASTM D618 (Procedure A).

[0113] Instrumented dart impact is measured on a 6-inch by 6-inch square specimen. The IDI dart test is based on ASTM D7192. The film thickness is measured at the center of the specimen, and the film is then clamped to obtain an unsupported test area with a diameter of 3 inches. The film is struck by an impactor at the center of the specimen, perpendicular to the plane of the film. The impactor consists of a stainless steel plunger rod with a diameter of 12.7 ± 0.13 mm, with hemispherical ends of the same diameter, which are polished to a mirror finish. The impactor strikes the film specimen at 3.3 m / s with sufficient energy so that the velocity reduction at the end of the test is less than 20%. From the force-displacement curve, the peak force, energy to the peak force, displacement at the peak force, total displacement, and total energy are reported. Typically, 10 replicates are measured, and the mean and standard deviation of the results are reported.

[0114] Melt strength Melt strength tests were performed using either a Rheotester 2000 or Rheograph 25 capillary rheometer paired with a Rheotens Model 71.97, all manufactured by Gottfert. The dies used in the tests had a diameter of 2 mm, a length of 30 mm, and an incidence angle of 180 degrees. Each test was typically performed at an isothermal temperature of 190°C.

[0115] During the test, pelletized samples were loaded into a capillary barrel and allowed to equilibrate at the test temperature for 10 minutes. A piston in the barrel then applied a constant force to the molten sample to achieve an apparent wall shear rate of 38.16 s⁻¹, and the molten material was extruded through the die at an exit velocity of approximately 9.7 mm / s. Located 100 mm below the die exit, the extruded material was guided through a pair of rheotens wheels, both of which were accelerated at a constant velocity of 2.4 mm / s², and the response of the extruded material to the applied tensile force was measured. Note that the rheotens wheel pair was serrated and spaced 0.4 mm apart. The results of this test were recorded using the RtensEvaluations2007 Excel macro to plot the force against the rheotens wheel velocity. For analysis, the force at which fracture occurred in the molten material was referred to as the molten strength of the material, and the corresponding rheotens wheel velocity at fracture was considered the tensile limit.

[0116] Gel permeation chromatography (GPC) The chromatography system consisted of a PolymerChar GPC-IR (Valencia, Spain) high-temperature GPC chromatograph equipped with an internal IR5 infrared detector (IR5), and a 4-capillary viscometer (DV) coupled to a Precision Detectors (now Agilent Technologies) Model 2040 2-angle laser scattering (LS) detector. A 15-degree angle was used for all absolute light scattering measurements. The autosampler oven compartment was set to 160°C, and the column and detector compartments were set to 150°C. The columns used were four Agilent "Mixed A" 30 cm, 20 micron linear mixed-bed columns. The chromatography solvent used was 1,2,4-trichlorobenzene containing 200 ppm butylated hydroxytoluene (BHT). The solvent source was spurged with nitrogen. The injection volume used was 200 microliters, and the flow rate was 1.0 milliliter / minute.

[0117] The total plate count of the GPC column set was performed using decane introduced into the blank sample via a micropump controlled by the PolymerChar GPC-IR system. The plate count of the chromatography system should be greater than 18,000 for four Agilent "Mixed A" 30 cm² 20 micron linear mixed-bed columns.

[0118] The sample was prepared semi-automatically using PolymerChar's "Instrument Control" software, with a target weight of 2 mg / ml. The solvent (containing 200 ppm BHT) was added to a vial with a pre-nitrogen-spurged septum cap via a PolymerChar high-temperature autosampler. The sample was dissolved at 160°C for 2 hours under "low-speed" shaking.

[0119] To monitor deviations over time, a flow rate marker (decane) was introduced into each sample via a micropump controlled by the PolymerChar GPC-IR system. Using this flow rate marker (FM), the pump flow rate (nominal flow rate) for each sample was linearly corrected by matching the RV (RV(FM sample)) of each decane peak in the sample with the RV (RV(FM calibrated)) of the calibrated decane peak in the narrow standard material. It was assumed that any temporal change in the decane marker peak corresponds to a linear shift in the flow rate (effective flow rate) over the entire run. After calibrating the system based on the flow rate marker peaks, the effective flow rate (relative to the narrow standard calibration) was calculated using Equation 1. The processing of the flow rate marker peaks was performed via PolymerChar GPCOne® software. An acceptable flow rate correction is required so that the effective flow rate is within ±0.5% of the nominal flow rate. Effective flow rate = Nominal flow rate * (RV(Calibrated FM) / RV(FM Sample))(Equation 2)

[0120] Regarding the determination of viscometer and light scattering detector offsets from an IR5 detector, a systematic method for determining multiple detector offsets was developed by Balke, Mourey et al. (Mourey and Balke, Chromatography Polym. Chpt 12, (1992)) (Balke, Thitiratsakul, Lew, Cheung, Mourey, Chromatography Polym. Chpt 13, (1992)). Using PolymerChar GPCOne™ software, the results of triple detector log(MW and IV) obtained from linear homopolymer polyethylene standard materials (3.5>Mw / Mn>2.2) with molecular weights in the range of 115,000 to 125,000 g / mol were optimized to the results of narrow standard column calibration obtained from a narrow standard material calibration curve.

[0121] Absolute molecular weight data was obtained using PolymerChar GPCOne® software in a format consistent with that published by Zimm (Zimm, BH, J. Chem. Phys., 16, 1099 (1948)) and Kratochvil (Kratochvil, P., Classical Light Scattering from Polymer Solutions, Elsevier, Oxford, NY (1987)). The total injection concentration used in determining the molecular weight was obtained from the mass detector area and mass detector constant derived from one of the following: a suitable linear polyethylene homopolymer or a polyethylene standard material with a known weight-average molecular weight. The molecular weight calculated (using GPCOne®) was obtained using the light scattering constant derived from one or more of the polyethylene standards described below, and the refractive index concentration coefficient, dn / dc, of -0.104. Generally, the mass detector response (IR5) and light scattering constant (determined using GPCOne®) should be determined from linear reference materials having a molecular weight greater than approximately 50,000 g / mol. Calibration of the viscometer (determined using GPCOne®) can be achieved using the method described by the manufacturer, or alternatively, by using published values ​​of a suitable linear reference material such as Standard Reference Material (SRM) 1475 (available from the National Institute of Standards and Technology (NIST)). The specific viscosity area (DV) and injected mass for the calibration standard are used to calculate the viscometer constant (obtained using GPCOne®) related to its intrinsic viscosity. The chromatographic concentration is assumed to be low enough to eliminate the second viral coefficient effect (concentration effect on molecular weight).

[0122] Absolute weight average molecular weight (MW) (Abs)) is obtained (using GPCOne®) from a light scattering (LS) area integrated chromatogram (factored by the light scattering constant) divided by the mass recovered from the mass constant and mass detector (IR5) area. The molecular weight and intrinsic viscosity response are linearly extrapolated (using GPCOne®) at the chromatographic end where the signal-to-noise ratio is low. The other respective moments are Mn (Abs) and Mz (Abs) This is calculated according to the following equations 8-10.

[0123]

number

[0124] DMS frequency sweep For preparation, the test specimen was first placed in a 3.10 mm thick, 1.5 inch diameter chase and compressed using a Carver Hydraulic Press (Model #4095.4NE2003) at a pressure of 25,000 lbs at 190°C for 6.5 minutes. After cooling to room temperature, the specimen was removed and awaited rheological testing.

[0125] DMS (dynamic mechanical spectroscopy) frequency sweeps are performed using 25 mm parallel plates at frequencies in the ranges of 0.01 to -100 rad / s, 0.1 to 100 rad / s, and 0.1t to 500 rad / s at 150°C, 190°C, and 230°C, respectively. The test gap separating the plates is 1.8 mm, and a strain satisfying linear viscoelastic conditions, typically 10%, is used. Each test was performed in a nitrogen atmosphere under isothermal conditions. To begin the DMS test, the rheometer oven is first equilibrated at the desired test temperature for at least 30 minutes, after which the sample is loaded into the test shape. The sample is then equilibrated in the closed oven for 1 minute. Next, the test gap is set to 1.8 mm, and the sample is allocated 5 minutes to relax the resulting normal force. The oven is then quickly opened, and the sample is trimmed to ensure no bulging is present. The oven is then closed again, and the DMS measurement is started. During the test, the shear modulus (G'), viscosity coefficient (G") and complex viscosity ( * ) Measure.

[0126] All DMS frequency tests are performed using either an ARES-G2 or DHR-3 rheometer (both manufactured by TA Instruments). Data analysis is performed via TA Instruments TRIOS software. [Examples]

[0127] The following examples illustrate the features of the present disclosure, but are not intended to limit the scope of the present disclosure. The performance of embodiments of the multilayer films described herein was analyzed in the following experiments.

[0128] Polyethylene compositions 1 to 4, described in accordance with one or more embodiments of "Modes for Carrying Out the Invention," were prepared using a catalyst and reactor by the method described below.

[0129] As shown in Figure 1, the two reactor systems are used in a series configuration. Each continuous solution polymerization reactor consists of a liquid-filled, non-adiabatic, isothermal circulating loop reactor that replicates a continuous stirred tank reactor (CSTR) that removes heat. All fresh solvent, monomer, comonomer, hydrogen, and catalyst component feeds are independently controlled. All fresh feed flows to each reactor (solvent, monomer, comonomer, and hydrogen) are temperature-controlled to maintain a single solution phase by passing the feed flows through a heat exchanger. All fresh feeds to each polymerization reactor are injected into the reactor at two locations, with approximately equal reactor volumes between each injection point. The fresh feed is controlled by each injector, which receives half of the total fresh feed flow rate. Catalyst components are injected into the polymerization reactor through injection stingers. The main catalyst component feed is computer-controlled to maintain the monomer conversion rate in each reactor at a specific target value. Co-catalyst components are supplied based on a calculated, specified molar ratio to the primary catalyst component. Immediately after the injection point of each reactor feed, the feed stream is mixed with the contents of a circulating polymerization reactor having a static mixing element. The contents of each reactor are passed through a heat exchanger, which plays a role in removing most of the reaction heat, and the coolant side temperature plays a role in maintaining an isothermal reaction environment at a specific temperature, and the contents are continuously circulated. Circulation around each reactor loop is provided by a pump.

[0130] In a double series reactor configuration, the effluent from the first polymerization reactor (containing solvent, monomer, comonomer, hydrogen, catalyst components, and polymer) exits the first reactor loop and is added to the second reactor loop.

[0131] The second reactor effluent enters a zone where a suitable reagent (water) is added and reacts with it to deactivate the effluent. At this same reactor outlet location, other additives are added to stabilize the polymer (typical antioxidants suitable for stabilization during extrusion and film processing).

[0132] Following catalyst deactivation and additive addition, the reactor effluent enters a devolving system where the polymer is removed from the non-polymer stream. The isolated polymer molten material is pelletized and collected. The non-polymer stream passes through various devices that separate most of the ethylene removed from the system. Most of the solvent and unreacted comonomers are recycled back into the reactor after passing through a purification system. Small amounts of solvent and comonomers are purged from the process.

[0133] The reactor flow feed data flow corresponding to the values ​​in Table 1 used to generate the examples is graphically shown in Figure 1. The data is presented to account for the complexity of the solvent recycling system and to allow for easier processing of the reaction system as a through-flow diagram.

[0134] [Table 1] Co-catalyst A is [HN(CH3)(C 18 H 37 )2] + [B(C6F5)] - That is the case.

[0135] [Table 2]

[0136] [Table 3]

[0137] MMAO-7 is commercially available from Nouryon.

[0138] The polymers produced by the reaction conditions listed in Tables 1-3 were formed into films. The films were prepared as described in the above descriptions of the inflation film lines for lines 1 and 2. As shown in Table 4 below, the films were compounded from PE resin produced in continuous reactor 2 as described in the previously provided procedure.

[0139] [Table 4]

[0140] [Table 5]

[0141] [Table 6]

[0142] [Table 7] NM - Not measured. * "Thick" means thickness. ** The dirt track is a standardized dirt track.

[0143] The data summarized in Table 7 shows that Examples I4, I7-I12 provide melt strength values ​​equivalent to those of LDPE and LLDPE blends, and offer better dirt A. As mentioned above, LLDPE resin is added to increase the dirt strength of the film, but the resin generally reduces the processability of the resin. In Examples I4, I7-I12, processability is maintained and dirt strength increases even without the addition of LLDPE resin.

[0144] The films of Examples I4 and I7-I12 have higher melt strength and higher dirt strength than LLDPE resin (Examples C17-C20).

[0145] The resins of Comparative Examples C23 to C25 are LDPE resins containing a high molecular weight component. The high molecular weight component (approximately 10% by weight of the resin according to GPC) can increase the physical properties of the resin while maintaining the processability of the LDPE resin. The films of Examples I4, I7 to I12 have higher dirt strength than LDPE and Comparative Examples C23 to C25, but their processability is only slightly lower.

[0146] The comparative polymers in Table 3 are similar to the LDPE resins of Comparative Examples C23-C25, but do not contain high molecular weight components. The films of Examples I4, I7-I12 do not have high molecular weight components, and therefore have higher dirt strength than LDPE. In comparison, the processability and melt strength are similar to those of the comparative polymers. Specifically, Examples I4, I7-I12 have a melt strength of 10.4 cN, while the comparative polymers have melt strengths of 3.7, 10.4, 10.1, and 4.5 cN, respectively.

[0147] The film of Example I2 has a dirt strength comparable to that of Comparative Example C19, which has a dirt strength of 459 g. In contrast, the resins of Examples I1 and I2 have much higher melt strengths compared to Comparative Examples C19 and C18 and C20. Example I1 has a melt strength of 10.4 cN, and Example I2 has a melt strength of 10.1 cN. Comparative Example C19 has a melt strength of 4.1 cN, Comparative Example C18 has a melt strength of 4.1 cN, and Comparative Example C20 has a melt strength of 4.9 cN. The film was able to have a dirt strength comparable to that of LLDPE resin, and its processability was improved.

[0148] Figure 2 is a graph of the melt strength of embodiments of the present invention as a function of melt index (I2). Generally, as I2 decreases, the melt strength increases. Unexpectedly, polymer resins have higher melt strengths for their I2 than expected. The line drawn in the graph of Figure 2, defined by the equation in the figure, distinguishes embodiments of the present invention, and embodiments of the present invention have a melt strength above this line.

[0149] Figure 3 is a graphical representation of the normalized dart intensity of embodiments of the present invention as a function of density. Generally, normalized dart intensity decreases as density increases. However, embodiments of the present invention do not correlate with general expectations. Embodiments of the present invention have higher normalized dart intensity than expected, considering their respective densities. The line drawn by the equation in the figure distinguishes embodiments of the present invention, and embodiments of the present invention have normalized dart intensity above this line.

Claims

1. A film containing polyethylene multimodal resin, The polyethylene multimodal resin comprises a polymerization reaction product of ethylene and at least one alpha-olefin copolymer, and the polyethylene multimodal resin has a melt strength (MS) ≥ X １ / I ２ +y is included, where X １ However, y is equal to 3.9, and y is equal to 1.4, I ２ However, the melt index of the copolymer measured at 2.16 kg and 190°C according to ASTM 1238, where MS is the melt strength in cN units (Rheotens apparatus, 190°C, 2.4 mm / s). ２ 120 mm from die exit to wheel center, extrusion speed 38.2 s －１ (A capillary die with a length of 30 mm, a diameter of 2 mm, and an incidence angle of 180°) The film comprises a normalized dirt strength (DS) (DS ≥ 9,876 - 10,512 (ρ)) greater than or equal to the density of the polyethylene multimodal resin multiplied by 9,876 - 10,512, wherein the normalized DS is measured in grams (g) according to ASTM 1709 Method A and divided by the film thickness in mill units.

2. A film containing polyethylene multimodal resin, The polyethylene multimodal resin includes a polymerization reaction product of ethylene and at least one alpha-olefin copolymer, and the polyethylene multimodal resin includes a melt strength (MS) ≧ x / I ２ + y), where x is equal to 3.9, y is 1.4 or more, and I ２ is the melt index of the copolymer measured according to ASTM 1238 at 2.16 kg and 190 °C, and MS is the melt strength in cN units (Rheotens apparatus, 190 °C, 2.4 mm / s ２ , 120 mm from the die exit to the center of the wheel, extrusion speed 38.2 s －１ , length 30 mm, diameter 2 mm, and capillary die with an incident angle of 180°) The film comprises a normalized mechanical direction (MD) tear of more than 190 gf / mil, wherein the MD tear is measured according to ASTM D1922-15.

3. The film according to claim 1 or 2, wherein the film is a single-layer film.

4. The film according to any one of claims 1 to 3, wherein the film further comprises a layer of low-density polyethylene resin having a density of 0.910 to 0.930 g / cc.

5. The film according to any one of claims 1 to 4, wherein the polyethylene multimodal resin has a density of 0.900 to 0.975 g / cc.

6. The film according to any one of claims 1 to 5, wherein the polyethylene multimodal resin has a density of 0.910 to 0.930 g / cc.

7. The polyethylene multimodal resin has a density of 0.918 g / cc or more, a melt strength of at least 7 cN, and a melt flow ratio greater than 5 (I １０ / I ２ The film according to any one of claims 1 to 6, wherein the film has a dirt strength of more than 150 g / mil.

8. The polyethylene multimodal resin has a density of 0.910 to 0.930 g / cc, a melt strength of at least 7 cN, and a melt flow ratio of 5 to 10 (I １０ / I ２ The film according to any one of claims 1 to 7, wherein the film has a dirt strength of more than 400 g / mil.

9. The film according to any one of claims 1 to 8, wherein the polyethylene multimodal resin has a melt strength of at least 7 cN, and the film has a mechanical tear strength greater than 85 gf / mil as measured according to ASTM D1922-15.

10. The polyethylene multimodal resin has a melt strength of at least 8 cN and a rheology ratio V of 6 or less. ０．１ / V １００ The film has a dirt strength of over 800g, and V ０．１ However, this is the viscosity of an ethylene-based polymer at 190°C with an angular frequency of 0.1 radians / second, and V １００ The film according to any one of claims 1 to 9, wherein the viscosity of the ethylene-based polymer at 190°C with an angular frequency of 100 radians / second.

11. The film according to any one of claims 1 to 10, wherein the polyethylene multimodal resin has an overall density of 0.918 to 0.925 g / cc or a melt strength of 6 cN or more.

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