Tie layers comprising olefin block copolymer and multilayer films incorporating same

Abstract

A multilayer film may includes a first layer, a second layer, and a tie layer disposed between the first layer and the second layer wherein the tie layer includes at least one ethylene-based polymer, functionalized polyethylene having 0.900 to 0.925 g / cm3 and a melt index (I2) of 0.5 to 10.0 dg / min (190 °C / 2.16 kg), wherein the functionalized polyethylene comprises a polyethylene grafted with ethylenically unsubstituted dicarboxylic acid or derivative thereof, and an olefin block copolymer having a density of 0.860 to 0.900 g / cm3, a melt index (I2) of 0.5 to 5.0 dg / min (190 °C / 2.16 kg), and a melting temperature of at least 115 °C, and the first layer includes at least one polyolefin; and the second layer includes at least one polar polymer.

Description

TIE LAYERS COMPRISING OLEFIN BLOCK COPOLYMER AND MULTILAYER FILMS INCORPORATING SAMECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 627,385 filed January 31, 2024, the contents of which are incorporated in their entirety herein.TECHNICAL FIELD

[0002] The present disclosure generally relates to tie layers effective at higher temperatures and specifically relate to multilayer films that utilizes these tie layers to maintain adhesion between a polyolefin layer and a polar layer at higher temperatures.BACKGROUND

[0003] Specialty multilayer films serve multiple applications and market segments across the food, specialty packaging, infrastructure, and transportation industries. These multilayer films may include tie layers to adhere dissimilar layers, for example, polyolefin layers and polar layers, within the multilayer film. The tie layers strongly adhere to the layers on each side of the tie layer, thus helping bind together those layers in the multilayer film.

[0004] However, conventional tie layers are often unable to withstand at high temperatures (i.e. temperatures of at least 100 °C), which may result in poor adhesion and delamination of the film. Therefore, a need exists for improved tie layers that resist delamination at high temperatures.SUMMARY

[0005] Embodiments of the present disclosure address these needs by utilizing a tie layer comprising an olefin block copolymer that delivers superior adhesion enhancement at higher temperatures to multilayer films. The olefin block copolymer will not only deliver enhanced solid handling during pellet transportation, but also provide improved heat resistance for high- temperature applications such as hot water pipes or retort packages.

[0006] In one embodiment, a multilayer film comprises a first layer, a second layer, and a tie layer disposed between the first layer and the second layer wherein the tie layer includes at least one ethylene-based polymer, functionalized polyethylene having 0.900 to 0.925 g / cm3and a melt index (h) of 0.5 to 10.0 dg / min (190 °C / 2.16 kg), wherein the functionalized polyethylene comprises a polyethylene grafted with ethylenically unsubstituted dicarboxylic acid or derivative thereof, and an olefin block copolymer having a density of 0.860 to 0.900 g / cm3, a melt index (I2) of 0.1 to 5.0 dg / min (190 °C / 2.16 kg), and a melting temperature of at least 115 °C. The first layer may include at least one polyolefin. The second layer may include at least one polar polymer.

[0007] According to one or more embodiments of the present disclosure, an article may be produced from the above multilayer films.

[0008] According to one or more embodiments of the present disclosure, a tie layer formulation may include at least one ethylene -based polymer, functionalized polyethylene having 0.860 to 0.970 g / cm3and a melt index (I2) of 0.5 to 10.0 dg / min (190 °C / 2.16 kg), wherein the functionalized polyethylene comprises a polyolefin grafted with ethylenically unsubstituted dicarboxylic acid or derivative thereof, and an olefin block copolymer having a density of 0.860 to 0.900 g / cm3, a melt index (I2) of 0.1 to 5.0 dg / min (190 °C / 2.16 kg), and a melting temperature of at least 115 °C.

[0009] Additional features and advantages will be set forth in the detailed description that follows and, in part, will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments described herein, including the detailed description which follows in addition to the claims.

[0010] It is to be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter.DETAILED DESCRIPTION

[0011] DEFINITIONS

[0012] As used in this disclosure, the term “polymer” may refer to a polymeric compound prepared by polymerizing monomers, whether of the same or a different type. The generic term polymer thus embraces the term “homopolymer,” usually employed to refer to polymers prepared from only one type of monomer as well as “copolymer,” which refers to polymers prepared from two or more different monomers. The term “interpolymer,” as used herein, refers to a polymer prepared by the polymerization of at least two different types of monomers. The generic term interpolymer thus includes copolymers, and polymers prepared from more than two different types of monomers, such as terpolymers.

[0013] “Blend”, “polymer blend” and like terms mean a composition of two or more polymers. Such a blend may or may not be miscible. Such a blend may or may not be phase separated. Such a blend may or may not contain one or more domain configurations, as determined from transmission electron spectroscopy, light scattering, x-ray scattering, and any other method known in the art. Blends are not laminates, but one or more layers of a laminate may contain a blend. Such blends can be prepared as dry blends, formed in situ (e.g., in a reactor), melt blends, or using other techniques known to those of skill in the art.

[0014] As used in this disclosure, the term “polyethylene” or “ethylene -based polymer” may refer to polymers comprising greater than 50% by mole of units which have been derived from ethylene monomer. This includes polyethylene homopolymers or copolymers (meaning units derived from two or more comonomers). Common forms of ethylene-based polymer known in the art include low density polyethylene (TDPE); linear low density polyethylene (TTDPE); ultra low density polyethylene (ULDPE); very low density polyethylene (VLDPE); single-site catalyzed linear low density polyethylene, including both linear and substantially linear low density resins (m-LLDPE); medium density polyethylene (MDPE); and high density polyethylene (HDPE).

[0015] As used in this disclosure, the term “polypropylene” or “polypropylene -based polymer” may refer to polymers comprising greater than 50% by mole of units, which have been derived from polypropylene monomer. This includes polypropylene homopolymers or copolymers (meaning units derived from two or more comonomers).

[0016] The term “functionalized polyethylene” means a polyethylene incorporating at least one functional group in its polymer structure. Exemplary functional groups may include, for example,ethylenically unsaturated mono- and di-functional carboxylic acids, ethylenically unsaturated mono- and di-functional carboxylic acid anhydrides, salts thereof and esters thereof. Such functional groups can be grafted to an ethylene homopolymer or an ethylene / a-olefin interpolymer, or it may be copolymerized with ethylene and an optional additional comonomer to form an interpolymer of ethylene, the functional comonomer and optionally other comonomer(s).

[0017] As used herein, the term “polyolefin” refers to any polymerized olefin, which can be linear, branched, cyclic, aliphatic, aromatic, substituted, or unsubstituted. Polyolefin includes olefin homopolymer and olefin copolymers. Specific examples include ethylene homopolymer, propylene homopolymer, butene homopolymer, ethylene alpha-olefin copolymers, and the like, propylene / alpha-olefin copolymer, butene / alpha-olefin copolymer and the like.

[0018] The term “LLDPE”, includes both resin made using the traditional Ziegler-Natta catalyst systems and chromium-based catalyst systems as well as single-site catalysts, including, but not limited to, bis -metallocene catalysts (sometimes referred to as “m- LLDPE”), constrained geometry catalysts (CGC), and molecular catalysts. Resins include linear, substantially linear, or heterogeneous polyethylene copolymers or homopolymers. LLDPEs contain less long chain branching than LDPEs and includes the 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 US Patent 5,733,155; the homogeneously branched linear ethylene polymer compositions such as those in U.S. Patent No. 3,645,992; the 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). The LLDPEs can be made via gasphase, solution-phase or slurry polymerization or any combination thereof, using any type of reactor or reactor configuration known in the art.

[0019] Low density polyethylene (LDPE) refers polyethylene having a density from about 0.910 to 0.940 g / cm3produced in radical polymerization reactions under high pressure such that branching occurs and non-linear polyethylene is formed.

[0020] High density polyethylene (HDPE) refers to polyethylene having a density from about 0.940 usually to about 0.970 g / cm3.

[0021] The term "olefin block copolymer" refers to a copolymerized polymer of ethylene or propylene with a-olefins, wherein the copolymer comprises a plurality of repeating unit blocks or segments that are distinguishable from one another as they differ in at least one of their physical or chemical properties; for example, the content (mole fraction) of the repeating units derived from ethylene (or propylene) and the a-olefins, respectively, a degree of crystallization, a density, or a melting temperature.

[0022] The term "polar polymer" refers to a polymer formed from at least one monomer that comprises at least one heteroatom, such as oxygen (O), nitrogen (N), phosphorus (P) or sulfur (S).

[0023] EMBODIMENTS

[0024] Reference will now be made in detail to embodiments of multilayer fdms including a first layer, a second layer, and a tie layer disposed between the first layer and the second layer wherein the tie layer includes at least one ethylene-based polymer, functionalized polyethylene having 0.860 to 0.970 g / cm3and a melt index (E) of 0.5 to 10.0 dg / min (190 °C / 2.16 kg), wherein the functionalized polyethylene comprises a polyethylene grafted with ethylenically unsubstituted dicarboxylic acid or derivative thereof, and an olefin block copolymer having a density of 0.860 to 0.900 g / cm3, a melt index (I2) of 0.1 to 5.0 dg / min (190 °C / 2.16 kg), and a melting temperature of at least 115 °C. The first layer may include at least one polyolefin. The second layer may include at least one polar polymer.

[0025] Various compositions are considered suitable for the ethylene-based polymer. In one or more embodiments, the ethylene-based polymer may include linear low density polyethylene (EEDPE), a low density polyethylene (EDPE), a high density polyethylene (HDPE), an ethylene vinyl acetate copolymer, and an ethylene alkyl acrylate copolymer.

[0026] In embodiments, the ethylene-based polymer may have a melt index (I2) of from 0.5 to 10.0 dg / min as measured according to ASTM D-1238 (190 °C / 2.16 kg). In embodiments, the ethylene-based polymer may have a melt index of from 0.5 to 10.0 dg / min, from 0.5 to 5.0 dg / min, from 0.5 to 2.5 dg / min, 1.0 to 10.0 dg / min, from 1.0 to 5.0 dg / min, or from 1.0 to 2.5 dg / min. In further embodiments, the ethylene-based polymer may have a density from 0.900 to 0.925 g / cm3,from 0.905 to 0.925 g / cm3, from 0.910 to 0.925 g / cm3, from 0.915 to 0.925 g / cm3, from 0.900 to 0.920 g / cm3, from 0.905 to 0.920 g / cm3, from 0.910 to 0.920 g / cm3, or from 0.915 to 0.920 g / cm3.

[0027] In one or more embodiments, the tie layer may include from 40 weight percent (wt.%) to 90 wt.% ethylene based polymer. In some embodiments, the tie layer may comprises from 40 to 90 wt.%, from 45 to 90 wt.%, from 50 to 90 wt.%, from 55 to 90 wt.%, from 60 to 90 wt.%, from 65 to 90 wt.%, from 40 to 85 wt.%, from 45 to 85 wt.%, from 50 to 85 wt.%, from 55 to 85 wt.%, from 60 to 85 wt.%, from 65 to 85 wt.%, from 40 to 80 wt.%, from 45 to 80 wt.%, from 50 to 80 wt.%, from 55 to 80 wt.%, from 60 to 80 wt.%, from 65 to 80 wt.%, from 40 to 75 wt.%, from 45 to 75 wt.%, from 50 to 75 wt.%, from 55 to 75 wt.%, from 60 to 75 wt.%, from 65 to 75 wt.%, from 40 to 70 wt.%, from 45 to 70 wt.%, from 50 to 70 wt.%, from 55 to 70 wt.%, from 60 to 70 wt.%, or from 65 to 70 wt.% ethylene based polymer.

[0028] Various compositions are considered suitable for the functionalized polyethylene. The functionalized polyethylene may be a polyethylene grafted with ethylenically unsubstituted dicarboxylic acid or derivative thereof. The ethylenically unsubstituted dicarboxylic acid or derivative thereof may be selected from maleic anhydride, itaconic anhydride, maleic acid diesters, fumaric diesters, maleic acid monoesters or fumaric acid monoesters, esters of Ci to C4 alcohols, maleic acid, itaconic acid, fumaric acid, or mixtures thereof. For example, the functionalized polyethylene may include maleic anhydride grafted linear low density polyethylene, maleic anhydride grafted high density polyethylene, maleic anhydride grafted polyolefin elastomer, maleic anhydride grafted plastomer, or combinations thereof.

[0029] The functionalized polyethylene may have a melt index of from 0.5 to 10.0 dg / min as measured according to ASTM D-1238 (190 °C / 2.16 kg). In embodiments, the functionalized polyethylene may have a melt index of from 0.5 to 10.0 dg / min, from 0.5 to 5.0 dg / min, from 0.5 to 2.5 dg / min, 1.0 to 10.0 dg / min, from 1.0 to 5.0 dg / min s, or from 1.0 to 3.5 dg / min.

[0030] In further embodiments, the functionalized polyethylene may have a density from 0.860 to 0.970 g / cm3, from 0.870 to 0.970 g / cm3, from 0.880 to 0.970 g / cm3, from 0.890 to 0.970 g / cm3, from 0.900 to 0.970 g / cm3, from 0.905 to 0.970 g / cm3, from 0.910 to 0.970 g / cm3, from 0.915 to 0.970 g / cm3, from 0.860 to 0.960 g / cm3, from 0.870 to 0.960 g / cm3, from 0.880 to 0.960 g / cm3, from 0.890 to 0.960 g / cm3, from 0.900 to 0.960 g / cm3, from 0.905 to 0.960 g / cm3, from 0.910 to0.960 g / cm3, from 0.915 to 0.960 g / cm3, from 0.860 to 0.950 g / cm3, from 0.870 to 0.950 g / cm3, from 0.880 to 0.950 g / cm3, from 0.890 to 0.950 g / cm3, from 0.900 to 0.950 g / cm3, from 0.905 to 0.950 g / cm3, from 0.910 to 0.950 g / cm3, from 0.915 to 0.950 g / cm3, from 0.860 to 0.940 g / cm3, from 0.870 to 0.940 g / cm3, from 0.880 to 0.940 g / cm3, from 0.890 to 0.940 g / cm3, from 0.900 to 0.940 g / cm3, from 0.905 to 0.940 g / cm3, from 0.910 to 0.940 g / cm3, from 0.915 to 0.940 g / cm3, from 0.860 to 0.930 g / cm3, from 0.870 to 0.930 g / cm3, from 0.880 to 0.930 g / cm3, from 0.890 to 0.930 g / cm3, from 0.900 to 0.930 g / cm3, from 0.905 to 0.930 g / cm3, from 0.910 to 0.930 g / cm3, from 0.915 to 0.930 g / cm3, from 0.860 to 0.920 g / cm3, from 0.870 to 0.920 g / cm3, from 0.880 to 0.920 g / cm3, from 0.890 to 0.920 g / cm3, from 0.900 to 0.920 g / cm3, from 0.905 to 0.920 g / cm3, from 0.910 to 0.920 g / cm3, or from 0.915 to 0.920 g / cm3. .

[0031] In some embodiments, the functionalized polyethylene may be grafted with 0.1 to 3.0 wt.%, such as from 0.1 to 3.0 wt.%, from 0.5 to 3.0 wt.%, from 0.8 to 3.0 wt.%, from 0.1 to 2.5 wt.%, from 0.5 to 2.5 wt.%, 0.8 to 2.5 wt.%, from 0.1 to 2.0 wt.%, from 0.5 to 2.0 wt.%, or from 0.8 to 2.0 wt.% ethylenically unsubstituted dicarboxylic acid or derivative thereof, for example, maleic anhydride.

[0032] In one or more embodiments, the tie layer may include from 5 wt.% to 30 wt.% functionalized polyethylene. In one or more embodiments, the tie layer may include from 5 wt.% to 30 wt.%, from 8 wt.% to 30 wt.%, from 10 wt.% to 30 wt.%, from 12 wt.% to 30 wt.%, from 5 wt.% to 25 wt.%, from 8 wt.% to 25 wt.%, from 10 wt.% to 25 wt.%, from 12 wt.% to 25 wt.%, from 5 wt.% to 20 wt.%, from 8 wt.% to 20 wt.%, from 10 wt.% to 20 wt.%, or from 12 wt.% to 20 wt.% functionalized polyethylene.

[0033] Various compositions are considered suitable for the olefin block copolymer. In one or more embodiments, the olefin block copolymer may be an ethylene copolymer-based elastomer with a C3 to C20 hydrocarbon comonomer such as 1 -butene, 1 -hexene, or 1 -octene. For example, the olefin block copolymer may include an ethylene / C3-Ci2-alpha-olefin copolymer. Without being bound by theory, it is believed that using an ethylene based polymer, a functionalized polyethylene, and an ethylene copolymer-based block copolymer may improve adhesion at higher temperatures compared to tie layers that include combinations of ethylene based polymers and propylene based polymers.

[0034] The olefin block copolymer may have a melt index (I2) of from 0.1 to 5.0 dg / min (190 °C / 2.16 kg). The olefin block copolymer may have a melt index (l2)of from 0.1 to 5.0 dg / min, from 0.1 to 4.0 dg / min, from 0.1 to 3.0 dg / min, from 0.1 to 2.0 dg / min, from 0.1 to 1.5 dg / min, from 0.5 to 5.0 dg / min, from 0.5 to 4.0 dg / min, from 0.5 to 3.0 dg / min, from 0.5 to 2.0 dg / min, or from 0.5 to 1.5 dg / min. The olefin block copolymer may have a melting temperature of at least 115 °C, at least 116 °C, at least 117 °C, or at least 118 °C. Without being bound by theory, it is believed that using olefin block copolymers with a melting temperature of greater than 115 °C may improve adhesion performance and improved delamination resistance of the tie layer at high temperature (i.e. temperatures of at least 100 °C).

[0035] The olefin block copolymer may have a density of from 0.860 to 0.900 g / cm3, such as from 0.860 to 0.900 g / cm3, from 0.860 to 0.895 g / cm3, from 0.860 to 0.890 g / cm3, from 0.860 to 0.885 g / cm3, from 0.860 to 0.880 g / cm3, 0.865 to 0.900 g / cm3, such as from 0.865 to 0.900 g / cm3, from 0.865 to 0.895 g / cm3, from 0.865 to 0.890 g / cm3, from 0.865 to 0.885 g / cm3, or from 0.865 to 0.880 g / cm3.

[0036] In one or more embodiments, the tie layer may include from 5 wt.% to 30 wt.% olefin block copolymer. In one or more embodiments, the tie layer may include from 5 wt.% to 30 wt.%, from 8 wt.% to 30 wt.%, from 10 wt.% to 30 wt.%, from 12 wt.% to 30 wt.%, from 5 wt.% to 25 wt.%, from 8 wt.% to 25 wt.%, from 10 wt.% to 25 wt.%, from 12 wt.% to 25 wt.%, from 5 wt.% to 20 wt.%, from 8 wt.% to 20 wt.%, from 10 wt.% to 20 wt.%, or from 12 wt.% to 20 wt.% olefin block copolymer.

[0037] In one or more embodiments, the tie layer may have an anhydride content of from 0.08 to 0.35 wt.%, such as from 0.08 to 0.35 wt.%, from 0.10 to 0.35 wt.%, from 0.08 to 0.30 wt.%, from 0.10 to 0.30 wt.%, from 0.08 to 0.25 wt.%, or from 0.10 to 0.25 wt.%, based on the total weight of the tie layer.

[0038] In various embodiments, a first layer of multilayer film includes at least one polyolefin.In one or more embodiments, the polyolefin may include an ethylene-based polymer.

[0039] In various embodiments, a second layer of the multilayer film includes least one polar polymer. The polar polymer may include polyamide, ethylene vinyl alcohol (EVOH), polyvinylalcohol (PVOH), thermal plastic starch (TPS), thermoplastic polyurethane (TPU), or combinations thereof.

[0040] ARTICLES

[0041] The multilayer films described herein may be co-extruded multilayer films. In one or more embodiments, an article may be produced from the multilayer films described herein. The articles may include laminates. The articles may include wires, pipes, tubing, or food packaging.

[0042] ADDITIVES

[0043] It should be understood that any of the foregoing layers can further comprise one or more additives as known to those of skill in the art such as, for example, antioxidants, ultraviolet light stabilizers, thermal stabilizers, slip agents, antiblock agents, antistatic agents, pigments or colorants, processing aids, crosslinking catalysts, flame retardants, fillers and foaming agents. The layer may contain any amounts of such additives, such as from 0 wt. % to 10 wt. %, from 0 wt. % to 5 wt. %, from 0 wt. % to 1 wt. %, from 0 wt. % to 0.1 wt. %, from 0 wt. % to 0.001 wt. %, or any subset thereof, based on a weight of the layer.

[0044] TEST METHODS

[0045] Melt index was measured according to ASTM D1238 and / or ISO 1133, under selected conditions of temperature (T) and load (L), noted as MI (T(°C) / L(kg)) and expressed in units of gram per 10 minutes or simplified to dg / min. Conditions used are (190 °C / 2.16 kg) so the melt index is also referred to as “I2”.

[0046] The melting temperature (Tm) of different polymers was measured by differential scanning calorimetry (DSC) with a heat / cool / heat method, where the reported Tm was the peak temperature determined from the second heat based on ASTM D3418.

[0047] Density measurements were performed on test specimen from compression-molded plaques prepared according to ASTM D4703. Measurements were made within one hour of sample pressing, according to ASTM D792, Method B, within one hour of sample pressing.

[0048] A bonding strength was measured using a T peel test according to ASTM F904 at the speed of 10 inches per minute. An extension between 1 inch to 4 inches were recorded for average S-P mean peel strength.

[0049] Examples

[0050] The following Examples are offered by way of illustration and are presented in a manner such that one skilled in the art should recognize are not meant to be limiting to the present disclosure as a whole or to the appended claims.

[0051] The following compositions listed in Table 1 were used in the Examples below.Table 1: Chemical Compositions

[0052] EXAMPLE 1

[0053] Example tie layers were prepared according to the formulations shown in Table 2. Different formulations of tie resins were compounded through a 25 mm diameter co-rotating, intermeshing twin-screw extruder. The extruder was configured with 12 barrels (48 L / D). The extruder was equipped with “loss-in-weight feeders,”. All the raw materials were fed through the main feed port. Nitrogen at 10 SCFH was used to purge first barrel section to maintain an inert atmosphere and minimize oxidation. A two-hole die strand pelletization process were used. Cooling water temp was at 13 °C. A run rate of 20 Ibs / hr and a screw speed of 300 rpm was used. Barrel 1 was water cooled, Barrels 2-3 were maintained at 130-180 °C, Barrels 4-11 were maintained at 220 °C. The compounded formulations were then co-extruded with HDPE and EVOH to fabricate the multilayer blown films.Table 2: Example Tie Layer Formulations

[0054] A 3 -layer blown film coextrusion trial was performed with a Brampton 3 -layer stack plate die with 3 -inch diameter opening and 60 mils. Three extruders from American Kuhne all have 1.25 inch diameter and each extruder has 4 heat / cool zones. The outer layer extruder was used for HDPE and a barrel temperature profile was 185 °C / 210 °C / 235 °C / 235 °C; the middle layer extruder was used for the tie resin and a barrel temperature profile was 185 °C / 210 °C / 235°C / 235°C; and inner layer extruder was used for EVOH with a temperature profile was 210 °C / 235 °C / 235 °C / 235 °C. A structure of (2 mil HDPE - 0.5 mil tie - 1 mil EVOH) was made for all example tie layer resins. The HDPE was SCLAIR® 99K and the EVOH was Soarnol™ DC3203F. All three extruders were set up at 225 °C with a frost line height of 7 inches.

[0055] The resulting multilayer films were delaminated by a score / stretch method, where a razor blade was applied to score the surface on the EVOH layer and film was stretched to separate the EVOH layer from tie - HDPE layer. After 1 inch of the EVOH film was separated, the EVOH and the tie - HDPE layer were taped around and strengthened before being used as peel tabs on an Instron instrument for a peel test. T peel test (ASTM F904) was applied at the speed of 10 inches per minute and an extension between 1 inch to 4 inches were recorded for average “S-P mean peel strength”. The tests were conducted for each sample both immediately after production (referred to as “Green Bonding”) and after one week. The results were as shown in Table 3.Table 3: Results of the T Peel Test

[0056] Examples IE1-IE3, which all utilized olefin block copolymers all showed the green bonding peel strength (average peak load) over 15 Newtons per inch(N / inch), whereas examples CE1-CE3, which did not utilize olefin block copolymer had peel strength of less than 13 N / inch. After 1-week, all samples experienced an increase of peel strength, but examples IE1-IE3 all showed peel strength more than 24 N / inch whereas examples CE1-CE3 all had a peel strength of less than 20 N / inch.

[0057] The subject matter of the present disclosure has been described in detail and by reference to specific embodiments. It should be understood that any detailed description of acomponent or feature of an embodiment does not necessarily imply that the component or feature is essential to the particular embodiment or to any other embodiment. Further, it should be apparent to those skilled in the art that various modifications and variations can be made to the described embodiments without departing from the spirit and scope of the claimed subject matter.

[0058] It is noted that one or more of the following claims utilize the term “wherein” as a transitional phrase. For the purposes of defining the present technology, it is noted that this term is introduced in the claims as an open-ended transitional phrase that is used to introduce a recitation of a series of characteristics of the structure and should be interpreted in like manner as the more commonly used open-ended preamble term “comprising.”

[0059] It should be understood that where a first component is described as “comprising” a second component, it is contemplated that, in embodiments, the first component “consists” or “consists essentially of’ that second component. It should further be understood that where a first component is described as “comprising” a second component, it is contemplated that, in embodiments, the first component comprises at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or even at least 99% that second component (where % can be weight % or molar %).

[0060] It is also noted that recitations herein of “at least one” component, element, etc., should not be used to create an inference that the alternative use of the articles “a” or “an” should be limited to a single component, element, etc.

Claims

CLAIMS1. A multilayer film comprising a first layer, a second layer, and a tie layer disposed between the first layer and the second layer wherein: the tie layer comprises: at least one ethylene-based polymer; functionalized polyethylene having 0.860 to 0.970 g / cm3and a melt index (I2) of 0.5 to 10.0 dg / min (190 °C / 2.16 kg), wherein the functionalized polyethylene comprises a polyethylene grafted with ethylenically unsubstituted dicarboxylic acid or a derivative thereof; and an olefin block copolymer having a density of 0.860 to 0.900 g / cm3, a melt index (I2) of 0.1 to 5.0 dg / min (190 °C / 2.16 kg), and a melting temperature of at least 115 °C; and the first layer comprises at least one polyolefin; and the second layer comprises at least one polar polymer.

2. The multilayer film of claim 1, wherein the ethylene-based polymer comprises linear low density polyethylene having a density of 0.900 to 0.925 g / cm3and a melt index (I2) of 0.5 to 10.0 dg / min as determined according to ASTM D1238 (2.16 kg, 190 °C).

3. The multilayer film of claim 1, wherein the ethylene-based polymer comprises linear low density polyethylene, low density polyethylene, high density polyethylene, ethylene vinyl acetate copolymer, ethylene alkyl acrylate copolymer, or combinations thereof.

4. The multilayer film of any one of claims 1 to 3, wherein the functionalized polyethylene comprises polyethylene grafted with ethylenically unsubstituted dicarboxylic acid or derivative thereof.

5. The multilayer film of claim 4, wherein the functionalized polyethylene is grafted with 0.1 to 3.0 wt.% maleic anhydride.

6. The multilayer film of any one of claims 1 to 5, wherein the functionalized polyethylene comprises a polyethylene having a melt index (I2) of 0.5 to 10 dg / min (190 °C / 2.16 kg) and a density of 0.900 to 0.965 g / cc.85883-WO-PCT / DOW 85883 WO157. The multilayer film of any one of claims 1 to 6, wherein the ethylenically unsubstituted dicarboxylic acid or derivative thereof is selected from the group consisting of maleic anhydride, itaconic anhydride, maleic acid diesters, fumaric diesters, maleic acid monoesters or fumaric acid monoesters, esters of Ci to C4 alcohols, maleic acid, itaconic acid, fumaric acid, or mixtures thereof.

8. The multilayer film of any one of claims 1 to 7, wherein the ethylenically unsubstituted dicarboxylic acid or derivative thereof comprises maleic anhydride.

9. The multilayer film of any one of claims 1 to 8, wherein the olefin block copolymer comprises an ethylene / C3-Ci2-alpha-olefin copolymer.

10. The multilayer film of any one of claims 1 to 9, wherein the polar polymer of the second layer comprises polyamide, EVOH, PVOH, TPS, TPU, or combinations thereof.

11. The multilayer film of any one of claims 1 to 10, wherein the tie layer comprises: from 40 to 90 wt.% ethylene-based polymer; from 5 to 30 wt.% functionalized polyethylene; and from 5 to 30 wt.% olefin block copolymer.

12. An article comprising the multilayer film of any one of claims 1 to 11.

13. The article of claim 12, wherein the article is a laminate.

14. A formulation comprising: at least one ethylene-based polymer; functionalized polyethylene having 0.860 to 0.970 g / cm3and a melt index (I2) of 0.5 to 10.0 dg / min (190 °C / 2.16 kg), wherein the functionalized polyethylene comprises a polyolefin grafted with ethylenically unsubstituted dicarboxylic acid or derivative thereof; and an olefin block copolymer having a density of 0.860 to 0.900 g / cm3, a melt index

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