Polyethylene-containing heat seal barrier laminate

Abstract

A barrier laminate comprising polyethylene is provided that provides heat resistance and a wide sealing window. The laminate can be fully compatible with polyethylene recycling streams and can exhibit improved, maintained, or desirable properties compared to existing laminate structures that are not fully compatible with polyethylene recycling streams. The laminate includes a multilayer film, a polyethylene film, and an adhesive. The adhesive adheres the multilayer film to the polyethylene film to provide the laminate.

Description

[Technical Field]

[0001] Embodiments of this disclosure generally relate to laminates, and more specifically to laminates containing polyethylene.

[0002] Introduction Laminates incorporating polypropylene, polyamide, and polyethylene terephthalate, comprising multiple layers, are widely used in flexible packaging for consumer products. For example, a typical laminate for flexible packaging may include a biaxially oriented polypropylene (BOPP) outer printing substrate, a metallized film barrier layer, a solvent-based adhesive layer, and a polyethylene sealant layer. The combination of layers and materials can enable heat resistance for a wide sealing window, good printability, high barrier performance, and shrinkage-free sealing. However, such laminates can be difficult, if not impossible, to recycle together due to the different types of materials that are not compatible with each other. As the demand for sustainable and recyclable materials continues to grow, there remains a strong need for laminates that are easier to recycle and exhibit performance characteristics equivalent to or improved upon existing structures. [Overview of the project]

[0003] Embodiments of the present disclosure satisfy the aforementioned need by providing laminates that can be fully recyclable in the polyethylene recycling flow. The performance of the laminates of the present invention may be better than or at least equivalent to other laminates, such as laminates containing BOPP, and may allow for the use of faster packaging speeds during manufacturing. For example, in certain embodiments, the laminates may show improvement or maintenance of properties such as barrier seal performance, oxygen transmission rate (OTR), water vapor transmission rate (WVTR), heat seal initiation temperature (HSIT), heat seal strength, hot tack strength, hot tack initiation temperature, and / or shrinkage rate compared to existing laminates.

[0004] This specification discloses laminates. In embodiments, the laminate comprises (a) (1) a barrier layer containing an ethylene vinyl alcohol copolymer, and (2) a maximum peak melting temperature (T) of 100°C or less. m (b) a multilayer film comprising a sealant layer containing at least 70% by weight of an ionomer or polyethylene elastomer / plastomer of an ethylene acid copolymer having (b) a tie layer between the barrier layer and the sealant layer, and (b) 0.900~0.970 g / cm 3 (c) A polyethylene film containing an ethylene-based polymer having a density of (a) and an adhesive for bonding a multilayer film to the polyethylene film.

[0005] These and other embodiments are described in more detail in “Modes for Carrying Out the Invention.” [Brief explanation of the drawing]

[0006] [Figure 1] This is a graph showing the heat seal strength of the comparative examples and inventive examples described later. [Figure 2] This is a graph of the hot tack intensity for the comparative examples and inventive examples described later. [Modes for carrying out the invention]

[0007] The embodiments of the disclosed laminates are described in more detail below. The laminates of this disclosure can have a wide variety of applications, including, for example, pouches, self-standing pouches, pillow pouches, bulk bags, ready-made packages, sachets, and the like. However, this disclosure should not be construed as limiting the embodiments described below.

[0008] As used herein, the term “polymer” means a polymer compound prepared by polymerizing monomers, whether of the same or different types. Thus, the general term polymer encompasses the terms homopolymer (used to refer to polymers prepared from only one type of monomer) and copolymer or interpolymer. Trace amounts of impurities (e.g., catalyst residue) may be incorporated into and / or within the polymer. A polymer may be a single polymer, a polymer blend, or a polymer mixture containing a mixture of polymers formed in situ during polymerization.

[0009] As used herein, the terms “polyethylene” or “ethylene-based polymer” mean a polymer containing units derived from a majority (>50 mol%) of ethylene monomers. This includes polyethylene homopolymers or copolymers (meaning units derived from two or more comonomers). Common forms of polyethylene known in the art include low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), ultra-low-density polyethylene (ULDPE), very low-density polyethylene (VLDPE), single-site catalyst linear low-density polyethylene (m-LLDPE), which includes both linear and substantially linear low-density resins, ethylene-based plastomers (POP) and ethylene-based elastomers (POE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE). These polyethylene materials are generally known in the art. However, the following description may help in understanding the differences between some of these different polyethylene resins.

[0010] The term "LDPE" may also be referred to as "high-pressure ethylene polymer" or "highly branched polyethylene," and is defined to mean that the polymer is partially or completely homopolymerized or copolymerized in an autoclave or tubular reactor at a pressure 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 incorporated by reference). LDPE resins typically have a density of 0.916–0.935 g / cm³. 3 It has a density within the range.

[0011] The term "LLDPE" includes both resins produced using single-site catalysts, including but not limited to traditional Ziegler-Natta catalyst systems and chromium-based catalysts, as well as substituted mono- or bis-cyclopentadienyl catalysts (typically referred to as metallocenes) and geometrically constrained catalysts, phosphineimine catalysts and polyvalent aryloxyether catalysts (typically referred to as bisphenylphenoxy), and includes linear, substantially linear, or heterogeneous polyethylene copolymers or homopolymers. LLDPE contains fewer long-chain branches than LDPE and includes substantially linear ethylene polymers as further defined in U.S. Patents 5,272,236, 5,278,272, 5,582,923, and 5,733,155; homogeneously branched linear ethylene polymer compositions such as those in U.S. Patent 3,645,992; heterogeneously branched ethylene polymers such as those prepared according to the process disclosed in U.S. Patent 4,076,698; and / or blends thereof (such as those disclosed in U.S. Patents 3,914,342 or 5,854,045). LLDPE can be produced via gas-phase, solution-phase, or slurry polymerization, or any combination thereof, using any type of reactor or reactor configuration known in the art.

[0012] The term "MDPE" refers to 0.926-0.935 g / cm³ 3 This refers to polyethylene having a density of 2.5. "MDPE" is typically produced using chromium or Ziegler-Natta catalysts, or single-site catalysts including, but not limited to, substituted mono- or bis-cyclopentadienyl catalysts (typically referred to as metallocenes), geometrically constrained catalysts, phosphinimine catalysts, and polyvalent aryloxy ether catalysts (typically referred to as bisphenylphenoxy), and typically has a molecular weight distribution ("MWD") greater than 2.5.

[0013] The term "HDPE" generally 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), geometrically constrained catalysts, phosphine imine catalysts, and polyvalent aryloxy ether catalysts (typically referred to as bisphenol phenoxy), having a density of about 0.935 g / cm 3 to a maximum of about 0.980 g / cm 3 .

[0014] The term "ULDPE" generally 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), geometrically constrained catalysts, phosphine imine catalysts, and polyvalent aryloxy ether catalysts (typically referred to as bisphenol phenoxy), having a density of 0.855 - 0.912 g / cm 3 . ULDPE includes, but is not limited to, polyethylene (ethylene-based) plastomers and polyethylene (ethylene-based) elastomers.

[0015] As used herein, the term "polyethylene elastomer / plastomer" means a substantially linear or linear ethylene / α-olefin copolymer containing a homogeneous short-chain branch distribution containing units derived from ethylene and at least one C3-C 10 α-olefin comonomer, or at least one C4-C8 α-olefin comonomer, or at least one C6-C8 α-olefin comonomer. The polyethylene elastomer / plastomer has a density of 0.865 g / cm 3 , or 0.870 g / cm 3 , or 0.880 g / cm 3 , or 0.890 g / cm 3 to 0.900 g / cm 3 , or 0.902 g / cm 3 , or 0.904 g / cm 3, or 0.909 g / cm³ 3 , or 0.910 g / cm³ 3 It has a density up to [value]. Non-limiting examples of polyethylene elastomers / plastomers include AFFINITY® plastomers and elastomers (available from The Dow Chemical Company), EXACT® plastomers (available from ExxonMobil Chemical), Tafmer (available from Mitsui), Nexlene® (available from SK Chemicals Co.), and Lucene® (available from LG Chem Ltd.).

[0016] The terms “comprising,” “including,” and “having,” and their derivatives, are not intended to exclude the existence of any additional components, processes, or procedures, whether or not they are specifically disclosed. To avoid any doubt, all compositions claimed through the use of the term “comprising” may include any additional additives, adjuvants, or compounds, whether polymeric or otherwise, unless otherwise stated. In contrast, the term “consisting essentially of” excludes any other components, processes, or procedures from the scope of any subsequent description, except those not essential to operability. The term “consisting of” excludes any components, processes, or procedures not specifically described or listed.

[0017] Laminated multilayer film The laminates disclosed herein include multilayer films. Multilayer films according to embodiments disclosed herein include a barrier layer, a sealant layer, and a tie layer, the tie layer being located between the barrier layer and the sealant layer. For example, a multilayer film according to embodiments disclosed herein may have an A / B / C structure in which A is a barrier layer, B is a tie layer, and C is a sealant layer. In a further embodiment, the multilayer film further includes an outer layer and a second tie layer, the second tie layer being located between the outer layer and the barrier layer. For example, a multilayer film according to embodiments disclosed herein may have an A / B / C / D / E structure in which A is an outer layer, B is a second tie layer, C is a barrier layer, D is a tie layer, and E is a sealant layer. In such an embodiment, the second tie layer B may have the same composition as tie layer D, or it may have a different composition.

[0018] Barrier layer of multilayer film The multilayer film of the laminate includes a barrier layer.

[0019] In some embodiments, the barrier layer of the multilayer film may be located adjacent to or near the tie layer described below and may be the outermost layer of the multilayer film. In other embodiments, the outer layer described below is part of the multilayer film and is the outermost layer of the multilayer film, and the second tie layer, also described below, is located between the outer layer and the barrier layer. The barrier layer according to the embodiments disclosed herein comprises ethylene vinyl alcohol copolymer (EVOH).

[0020] In embodiments, the EVOH in the barrier layer has an ethylene content of 20–50 mol%. Sub-ranges and individual values ​​of the 20–50 mol% ethylene content are all disclosed and included herein. For example, in embodiments, the EVOH in the barrier layer has an ethylene content of 20–50 mol%, or 22–45 mol%, or 25–40 mol%. Those skilled in the art will understand that the ethylene content of the EVOH may contribute to lower or higher OTR of the laminates disclosed herein (i.e., generally, lower ethylene content results in lower achievable OTR values). Those skilled in the art will understand that barrier layers containing EVOH with lower ethylene content may be suitable for flexible bottle and tube applications, while barrier layers containing EVOH with higher ethylene content may enable easier processing, long-term operational stability, and flexibility (flex crack resistance) such as thermoformability in packaging types.

[0021] Examples of commercially available EVOH that can be used in barrier layers include, for example, EVAL® H171B (38 mol% ethylene content) and EVAL® F171B (32 mol% ethylene content), which are commercially available under the name EVAL® from Kuraray Co., Ltd. (Tokyo, Japan).

[0022] Multilayer films can be of various thicknesses. In this embodiment, the barrier layer is 5-25% of the total thickness of the multilayer film.

[0023] multilayer film sealant layer The multilayer film of the laminate includes a sealant layer.

[0024] The sealant layer of the multilayer film contains at least 70% by weight of (meth)acrylic acid copolymer ionomer (also referred herein as "ethylene acid copolymer ionomer") or polyethylene elastomer / plastomer, based on the total weight of the sealant layer. All individual values ​​and partial ranges of at least 70% by weight are disclosed herein and included. For example, in embodiments, the sealant layer may contain at least 70% by weight, at least 80% by weight, at least 90% by weight, at least 95% by weight, at least 99% by weight, at least 99.5% by weight, or 70% to 100% by weight, 75% to 99% by weight, 80% to 95% by weight, or 90% to 95% by weight of ethylene acid copolymer ionomer or polyethylene elastomer / plastomer, based on the total weight of the sealant layer.

[0025] The sealant layer of the multilayer film has a maximum peak melting temperature (T) of 100°C or less. m The sealant layer contains at least 70% by weight of an ionomer or polyethylene elastomer / plastomer of an ethylene acid copolymer having a maximum peak melting temperature (T) in the range of 100°C or less, 98°C or less, 96°C or less, 94°C or less, or 92°C or less, or 70°C to 100°C, 70°C to 95°C, 75°C to 100°C, or 75°C to 95°C. m ) has a maximum peak melting temperature (T m ) can be measured according to the DSC test method described below.

[0026] In some embodiments, the sealant layer has a maximum peak melting temperature (T) of 100°C or less. m The sealant layer contains at least 70% by weight of polyethylene elastomer / plastomer having ). In such embodiments, the polyethylene elastomer / plastomer of the sealant layer is 0.865 to 0.910 g / cm³ 3 It can have a density in the range of 0.865~0.910 g / cm³. 3All individual values ​​and partial ranges of the density are disclosed and included herein. For example, polyethylene elastomers / plastomers have a density of 0.865 to 0.910 g / cm³. 3 , 0.865~0.900 g / cm³ 3 , 0.865~0.890 g / cm³ 3 , 0.865~0.880 g / cm³ 3 , 0.865~0.870 g / cm³ 3 , 0.870~0.910 g / cm³ 3 , 0.870~0.900 g / cm³ 3 , 0.870~0.890 g / cm³ 3 , 0.870~0.880 g / cm³ 3 , 0.880~0.910 g / cm³ 3 , 0.880~0.900 g / cm³ 3 , 0.880~0.890 g / cm³ 3 , 0.890~0.910 g / cm³ 3 , 0.890~0.900 g / cm³ 3 , or 0.900~0.910 g / cm³ 3 It may have a density within that range.

[0027] In embodiments in which the sealant layer comprises a polyethylene elastomer / plastomer, the polyethylene elastomer / plastomer may have a melt index (I2) in the range of 0.50 to 20 g / 10 min (g / 10 min). All individual values ​​and partial ranges of the melt index (I2) of 0.50 to 20 g / 10 min are disclosed and included herein. For example, the polyethylene elastomer / plastomer may have a melt index (I2) from a lower limit of 0.50, 1.0, 2.0, 5.0, 10.0, 15, or 18 g / 10 min to an upper limit of 1.0, 2.0, 5.0, 10.0, 15, 18, 19, or 20 g / 10 min.

[0028] Examples of commercially available polyethylene elastomers / plastomers that can be used in sealant layers include those marketed under the name AFFINITY® by The Dow Chemical Company (Midland, MI), such as AFFINITY®VP 8770G1, AFFINITY®PF7266, AFFINITY®PL 1881G, and AFFINITY®PF1140G.

[0029] In this embodiment, the sealant layer has a maximum peak melting temperature (T) of 100°C or less. m The ionomer of the ethylene acid copolymer contains ) a monovalent or divalent cation source, which may include formate, acetate, hydroxide, nitrate, carbonate, and bicarbonate. In embodiments, the ionomer of the ethylene acid copolymer may be treated with one or more cations or cation sources, which may include magnesium, sodium, zinc, or combinations thereof.

[0030] In the embodiment, the ethylene content of the ionomer of the ethylene acid copolymer is greater than 50% by weight or greater than 60% by weight, based on the total weight of the ionomer of the ethylene acid copolymer. For example, the ethylene content of the ionomer of the ethylene acid copolymer may be 50% to 95% by weight, 50% to 90% by weight, 50% to 85% by weight, or 60% to 80% by weight, based on the total weight of the ionomer of the ethylene acid copolymer.

[0031] In the embodiment, the ionomer of ethylene acid copolymer has a melt index (I2) of 0.1 g / 10 min to 16 g / 10 min, 3 g / 10 min to 13 g / 10 min, 3.5 g / 10 min to 10 g / 10 min, or 5 g / 10 min to 8 g / 10 min. A commercially available ionomer of ethylene acid copolymer is available from The Dow Chemical Company (Midland, MI) under the name SURLYN®.

[0032] In addition to the ionomer or polyethylene elastomer / plastomer of the ethylene acid copolymer, the sealant layer may, in embodiments, further include at least one additional polymer and / or at least one additive. For example, the at least one additional polymer may be selected from the group consisting of polyethylene, ethylene vinyl acetate, ethylene acrylic acid, or a combination thereof, in an amount of less than 30% by weight of the sealant layer. The at least one additive may be selected from the group consisting of antioxidants, UV light stabilizers, heat stabilizers, slip agents, antiblocking agents, antistatic agents, pigments or colorants, processing aids, crosslinking catalysts, flame retardants, fillers, foaming agents, or a combination thereof, in an amount of less than 30% by weight of the sealant layer.

[0033] In this embodiment, the sealant layer has a maximum peak melting temperature (T) of 108°C or lower. m The sealant layer further comprises polyethylene having 0.930 g / cm³. For example, in the embodiment, the sealant layer further comprises linear low-density polyethylene (LLDPE). The linear low-density polyethylene has a density of 0.930 g / cm³. 3 It may have the following density: 0.930 g / cm³ 3 All of the following individual values ​​and subranges are included and disclosed herein. For example, the density of linear low-density polyethylene is 0.870 g / cm³. 3 From the lower limit, 0.928, 0.925, 0.920, or 0.915 g / cm³ 3 It may be up to the upper limit of 0.870~0.930 g / cm³. 3 All individual values ​​and subranges of are disclosed and included herein.

[0034] The maximum peak melting temperature (T) of 108°C or less that can be used in sealant layers is 108°C or less. m Examples of commercially available polyethylenes having ) include, for example, those sold by The Dow Chemical Company under the name ELITE®AT, including ELITE®AT 6202 and ELITE®AT 6410.

[0035] In some embodiments, the sealant layer is at least 10 micrometers thick, or at least 15 micrometers thick, or at least 20 micrometers thick. In further embodiments, the sealant layer is 25-60% of the total thickness of the multilayer film.

[0036] Tie layer of multilayer film The laminated multilayer film includes a tie layer between the barrier layer and the sealant layer. The tie layer can bond the barrier layer to the sealant layer.

[0037] In the embodiment, the tie layer comprises an adhesive resin selected from the group consisting of anhydride-grafted ethylene polymers, ethylene acid copolymers, and ethylene vinyl acetate. Examples of anhydride-grafted portions, but not limited to, maleic anhydride, citraconic anhydride, 2-methylmaleic anhydride, 2-chloromaleic anhydride, 2,3-dimethylmaleic anhydride, bicyclo[2,2,1]-5-heptene-2,3-dicarboxylic acid anhydride and 4-methyl-4-cyclohexene-1,2-dicarboxylic acid anhydride, bicyclo(2.2.2)octa-5-ene-2,3-dicarboxylic acid anhydride, and lo-octahydronaphthalene-2 Examples include 3-dicarboxylic acid anhydrides, 2-oxa-1,3-diketospiro(4.4)nona-7-ene, bicyclo(2.2.1)hepta-5-ene-2,3-dicarboxylic acid anhydride, tetrahydrophthalic acid anhydride, norbom-5-ene-2,3-dicarboxylic acid anhydride, nadic acid anhydride, methylnadic acid anhydride, hymic acid anhydride, methylhymic acid anhydride, and x-methyl-bicyclo(2.2.1)hepta-5-ene-2,3-dicarboxylic acid anhydride. In one embodiment, the anhydride grafted portion contains maleic anhydride.

[0038] In the embodiment, the tie layer contains anhydrous modified linear low-density polyethylene. In the embodiment, the anhydrous modified linear low-density polyethylene is 0.860 g / cm³ 3 ~0.935g / cm 3 It has a density in the range of 0.860 g / cm³. 3 ~0.935g / cm 3All individual values ​​and subranges are disclosed and included herein. For example, anhydrous modified linear low-density polyethylene is 0.875 g / cm³. 3 ~0.935g / cm 3 , 0.900 g / cm³ 3 ~0.925g / cm 3 , 0.910 g / cm³ 3 ~0.935g / cm 3 , 0.910 g / cm³ 3 ~0.925g / cm 3 , 0.915 g / cm³ 3 ~0.935g / cm 3 , or 0.920 g / cm³ 3 ~0.930g / cm 3 It may have a density in the range of . In the embodiment, the anhydrous modified linear low-density polyethylene has a melt index (I2) of 0.1 g / 10 min to 50 g / 10 min, or 0.5 g / 10 min to 20 g / 10 min, or 1.0 g / 10 min to 10 g / 10 min.

[0039] In embodiments, the tie layer contains 0 to 100% by weight of anhydrous modified linear low-density polyethylene, based on the total weight of the tie layer. All individual values ​​and partial ranges of 0 to 100% by weight are disclosed and included herein. For example, in embodiments, the tie layer may contain 10 to 90% by weight, 20 to 80% by weight, 30 to 70% by weight, or 40 to 60% by weight of anhydrous modified linear low-density polyethylene, based on the total weight of the tie layer.

[0040] Examples of commercially available anhydrous modified linear low-density polyethylenes that can be used in the embodiment include BYNEL® Series 4100 resins such as BYNEL® 41E710 and BYNEL® 41E687, available from The Dow Chemical Company (Midland, MI).

[0041] In the embodiment, the tie layer further comprises at least one of linear low-density polyethylene, low-density polyethylene, medium-density polyethylene, or high-density polyethylene. For example, in the embodiment, the tie layer is 0.945 g / cm³ 3~0.970g / cm 3 It further contains high-density polyethylene having a density in the range of 0.945 g / cm³. 3 ~0.970g / cm 3 All individual values ​​and subranges are disclosed and included herein. For example, high-density polyethylene is 0.945 g / cm³. 3 ~0.965g / cm 3 , 0.950 g / cm³ 3 ~0.970g / cm 3 , 0.950 g / cm³ 3 ~0.965g / cm 3 , 0.955 g / cm³ 3 ~0.970g / cm 3 , 0.955 g / cm³ 3 ~0.965g / cm 3 , or 0.955 g / cm³ 3 ~0.965g / cm 3 It may have a density within that range.

[0042] In embodiments where high-density polyethylene is present, the high-density polyethylene in the tie layer is composed of ethylene and C3-C 12 It may be a copolymer with a comonomer. In embodiments, the tie layer further comprises 0 to 90% by weight of high-density polyethylene based on the total weight of the tie layer. All individual values ​​and partial ranges of 0 to 90% by weight are disclosed and included herein. For example, in embodiments, the tie layer may comprise 10 to 90% by weight, 20 to 80% by weight, 30 to 70% by weight, or 40 to 60% by weight of high-density polyethylene based on the total weight of the tie layer. In embodiments, the melt index (I2) of the high-density polyethylene may be 0.3 to 10.0 g / 10 min, 0.3 to 7.0 g / 10 min, 0.3 to 5.0 g / 10 min, 0.3 to 4.0 g / 10 min, 0.3 to 3.0 g / 10 min, 0.3 to 2.0 g / 10 min, or 0.3 to 1.5 g / 10 min, or 0.5 to 1.0 g / 10 min.

[0043] Examples of commercially available high-density polyethylene that can be used in the Thai layer include those sold by The Dow Chemical Company (Midland, MI) under the names ELITE® 5960G1 and DOWLEX® 2006G.

[0044] Outer layer and second tie layer of multilayer film In this embodiment, the multilayer film may include an outer layer and a second tie layer, the second tie layer being located between the outer layer and the barrier layer.

[0045] According to embodiments disclosed herein, the outer layer of the multilayer film comprises polyethylene. In embodiments, the polyethylene of the outer layer is 0.900 to 0.970 g / cm³. 3 It has a density of 0.900~0.970 g / cm³. 3 All individual values ​​and subranges are disclosed and included herein. For example, polyethylene is 0.900 to 0.970 g / cm³. 3 , 0.910~0.957 g / cm³ 3 , 0.920~0.947 g / cm³ 3 , 0.920~0.937 g / cm³ 3 , 0.920~0.930 g / cm³ 3 , or 0.920~0.927 g / cm³ 3 It may have a density of .

[0046] In this embodiment, the outer polyethylene layer has a melt index of 0.1 g / 10 min to 10 g / 10 min, or 0.5 g / 10 min to 8 g / 10 min, or 0.5 g / 10 min to 5 g / 10 min.

[0047] In embodiments, the outer polyethylene constitutes at least 50% by weight of the outer layer, based on the total weight of the outer layer. All individual values ​​and partial ranges of at least 50% by weight are disclosed and included herein. For example, polyethylene may constitute at least 50%, at least 75%, at least 90%, at least 99%, or at least 99.9% by weight of the outer layer, based on the total weight of the outer layer.

[0048] In addition to polyethylene, the outer layer may, in embodiments, further contain at least one additional polymer, the at least one additional polymer being selected from the group consisting of ultra-low density polyethylene, low density polyethylene, polyethylene elastomer / plastomer, ethylene vinyl acetate, ethylene acrylic acid, or a combination thereof, in an amount of less than 50% by weight of the outer layer.

[0049] In this embodiment, the multilayer film further includes a second tie layer between the outer layer and the barrier layer. The second tie layer can bond the outer layer to the barrier layer.

[0050] In the embodiment, the second tie layer comprises an adhesive resin selected from the group consisting of anhydride-grafted ethylene polymers, ethylene acid copolymers, and ethylene vinyl acetate. Examples of anhydride-grafted portions include, but are not limited to, maleic anhydride, citraconic anhydride, 2-methylmaleic anhydride, 2-chloromaleic anhydride, 2,3-dimethylmaleic anhydride, bicyclo[2,2,1]-5-heptene-2,3-dicarboxylic acid anhydride and 4-methyl-4-cyclohexene-1,2-dicarboxylic acid anhydride, bicyclo(2.2.2)octa-5-ene-2,3-dicarboxylic acid anhydride, and lo-octahydronaphthalene-2 Examples include 3-dicarboxylic acid anhydrides, 2-oxa-1,3-diketospiro(4.4)nona-7-ene, bicyclo(2.2.1)hepta-5-ene-2,3-dicarboxylic acid anhydride, tetrahydrophthalic acid anhydride, norbom-5-ene-2,3-dicarboxylic acid anhydride, nadic acid anhydride, methylnadic acid anhydride, hymic acid anhydride, methylhymic acid anhydride, and x-methyl-bicyclo(2.2.1)hepta-5-ene-2,3-dicarboxylic acid anhydride. In one embodiment, the anhydride grafted portion contains maleic anhydride.

[0051] In the embodiment, the second tie layer contains anhydrous modified linear low-density polyethylene. In the embodiment, the anhydrous modified linear low-density polyethylene is 0.860 g / cm³ 3 ~0.935g / cm 3has a density in the range of 0.860 g / cm 3 ~0.935 g / cm 3 All individual values and sub-ranges are disclosed and included herein. For example, the anhydride-modified linear low-density polyethylene has a density in the range of 0.875 g / cm 3 ~0.935 g / cm 3 e.g., 0.900 g / cm 3 ~0.925 g / cm 3 e.g., 0.910 g / cm 3 ~0.935 g / cm 3 e.g., 0.910 g / cm 3 ~0.925 g / cm 3 e.g., 0.915 g / cm 3 ~0.935 g / cm 3 or e.g., 0.920 g / cm 3 ~0.930 g / cm 3 In embodiments, the anhydride-modified linear low-density polyethylene may have a melt index (I2) of 0.1 g / 10 min to 50 g / 10 min, or 0.5 g / 10 min to 20 g / 10 min, or 1.0 g / 10 min to 10 g / 10 min.

[0052] In embodiments, the second tie layer comprises from 0 to 100 wt% of an anhydride-modified linear low-density polyethylene, based on the total weight of the second tie layer. All individual values and sub-ranges from 0 to 100 wt% are disclosed and included herein. For example, in embodiments, the second tie layer may comprise from 10 to 90 wt%, from 20 to 80 wt%, from 30 to 70 wt%, or from 40 to 60 wt% of an anhydride-modified linear low-density polyethylene, based on the total weight of the second tie layer.

[0053] Examples of commercially available anhydride-modified linear low-density polyethylenes that can be used in embodiments include BYNEL™ Series 4100 resins such as BYNEL™ 41E710 and BYNEL™ 41E687 available from The Dow Chemical Company (Midland, MI).

[0054] In the embodiment, the second tie layer further comprises at least one of linear low-density polyethylene, low-density polyethylene, medium-density polyethylene, or high-density polyethylene. For example, in the embodiment, the second tie layer is 0.945 g / cm³ 3 ~0.970g / cm 3 It further contains high-density polyethylene having a density in the range of 0.945 g / cm³. 3 ~0.970g / cm 3 All individual values ​​and subranges are disclosed and included herein. For example, the high-density polyethylene of the second tie layer is 0.945 g / cm³. 3 ~0.965g / cm 3 , 0.950 g / cm³ 3 ~0.970g / cm 3 , 0.950 g / cm³ 3 ~0.965g / cm 3 , 0.955 g / cm³ 3 ~0.970g / cm 3 , 0.955 g / cm³ 3 ~0.965g / cm 3 , or 0.955 g / cm³ 3 ~0.965g / cm 3 It may have a density within that range.

[0055] In embodiments where high-density polyethylene is present, the high-density polyethylene in the second tie layer contains ethylene and C3-C3. 12 It may be a copolymer with a comonomer. In embodiments, the second tie layer contains 0 to 90% by weight of high-density polyethylene based on the total weight of the second tie layer. All individual values ​​and partial ranges of 0 to 90% by weight are disclosed and included herein. For example, in embodiments, the second tie layer may contain 10 to 90% by weight, 20 to 80% by weight, 30 to 70% by weight, or 40 to 60% by weight of high-density polyethylene based on the total weight of the second tie layer. In the embodiment, the high-density polyethylene of the second tie layer may have a melt index (I2) of 0.3 to 10.0 g / 10 min, 0.3 to 7.0 g / 10 min, 0.3 to 5.0 g / 10 min, 0.3 to 4.0 g / 10 min, 0.3 to 3.0 g / 10 min, 0.3 to 2.0 g / 10 min, or 0.3 to 1.5 g / 10 min, or 0.5 to 1.0 g / 10 min.

[0056] Examples of commercially available high-density polyethylene that can be used for the second tie layer include those sold by The Dow Chemical Company (Midland, MI) under the names ELITE® 5960G1 and DOWLEX® 2006G.

[0057] glue The laminate includes an adhesive for bonding the multilayer film described above to the polyethylene film described below. The adhesive is applied to the outermost layer of the multilayer film (for example, a barrier layer in one embodiment or an outer layer in another embodiment) and acts as an adhesive layer, allowing the multilayer film to be bonded to the polyethylene film described below.

[0058] In the embodiments, the adhesive is a solvent-based adhesive, a solvent-free adhesive, or a water-based adhesive. Examples of commercially available adhesives that can be used in the embodiments include those available from The Dow Chemical Company (Midland, MI) under the names ADCOTE®, MOR-FREE®, and ROBOND®.

[0059] Laminated polyethylene film The laminates disclosed herein include a polyethylene film. The polyethylene film according to the embodiments disclosed herein is bonded to the barrier layer or outer layer of a multilayer film via the adhesive described above. The polyethylene film has a density of 0.900 to 0.970 g / cm³. 3 It contains an ethylene-based polymer having a density of [density].

[0060] In this embodiment, the ethylene-based polymer in the polyethylene film is 0.900 to 0.970 g / cm³. 3 It has a density of 0.900~0.970 g / cm³. 3 All individual values ​​and partial ranges are disclosed and included herein. For example, ethylene polymers are 0.900 to 0.970 g / cm³. 3 , 0.910~0.957 g / cm³ 3, 0.920~0.947 g / cm³ 3 , 0.920~0.937 g / cm³ 3 , 0.920~0.930 g / cm³ 3 , or 0.920~0.927 g / cm³ 3 It may have a density of .

[0061] In this embodiment, the ethylene-based polymer has a melt index (I2) of 0.1 g / 10 min to 10 g / 10 min, or 0.5 g / 10 min to 8 g / 10 min, or 0.5 g / 10 min to 5 g / 10 min.

[0062] In embodiments, the ethylene polymer constitutes at least 50% by weight of the polyethylene film, based on the total weight of the polyethylene film. All individual values ​​and partial ranges of at least 50% by weight are disclosed and included herein. For example, the ethylene polymer may constitute at least 50%, at least 75%, at least 90%, at least 99%, or at least 99.9% by weight of the polyethylene film, based on the total weight of the polyethylene film.

[0063] In addition to the ethylene-based polymer, the polyethylene film may, in some embodiments, further contain at least one additional polymer, the at least one additional polymer being selected from the group consisting of a second ethylene-based polymer, polyethylene elastomer / plastomer, ethylene vinyl acetate, ethylene acrylic acid, or a combination thereof. For example, the polyethylene film may contain 0.958 g / cm². 3 The mixture may further contain at least 20% by weight of a second ethylene-based polymer having the above density.

[0064] The polyethylene film may be a multilayer film or a single-layer film. In one embodiment, the polyethylene film is a single-layer film. In another embodiment, the polyethylene film comprises at least two layers. Embodiments of the polyethylene film may include, for example, a tie layer, a sealant layer, or a barrier layer. In one embodiment, the polyethylene film further comprises a barrier layer containing ethylene vinyl alcohol copolymer (EVOH).

[0065] In some embodiments, the polyethylene film is a stretched film. In some embodiments, the polyethylene film is a film stretched in the mechanical direction. In such embodiments, the polyethylene film may be a mechanically stretched (MDO) polyethylene film. In other embodiments, the polyethylene resin is biaxially stretched. In such embodiments, the polyethylene film may be a biaxially stretched polyethylene (BOPE) film. In embodiments where the polyethylene film is BOPE, the BOPE may be biaxially stretched using a tenter-frame sequential biaxial stretching process and may be referred to as tenter-frame biaxially stretched polyethylene (TF-BOPE). Such techniques are generally known to those skilled in the art. In other embodiments, the polyethylene film may be biaxially stretched using other techniques known to those skilled in the art, such as a double-cell stretching process, based on the teachings herein. Generally, in a tenter-frame sequential biaxial stretching process, the tenter frame is incorporated as part of a multilayer co-extrusion line. After extrusion from a flat die, the film is cooled on a cooling roll and immersed in a water bath filled with room temperature water. Next, the cast film is passed over a series of rollers with different rotation speeds to achieve stretching in the machine direction. The MD stretching segment of the production line has several pairs of rollers, all of which are oil heated. The pairs of rollers operate sequentially as preheating rollers, stretching rollers, and rollers for relaxation and annealing. The temperature of each pair of rollers is controlled separately. After stretching in the machine direction, the film web is passed through a tenter-frame hot air furnace with heating zones to perform stretching in the transverse direction. The first few zones are for preheating, followed by stretching zones, and then a final zone for annealing.

[0066] In the embodiment, the polyethylene film has a transverse stretch ratio greater than its stretch ratio in the mechanical direction, and the polyethylene film has a ratio of at least 2:1 between the elongation at break in the mechanical direction and the elongation at break in the transverse direction. In the embodiment, the polyethylene film may exhibit an elongation at break in the mechanical direction that is at least twice, at least five times, at least eight times, or at least ten times greater than the elongation at break in the transverse direction, when measured according to ASTM D882.

[0067] In embodiments, the polyethylene film may be stretched in the machine direction at a stretch ratio of 2:1 to 6:1 or at a stretch ratio of 3:1 to 5:1. In embodiments, the polyethylene film may be stretched transversely at a stretch ratio of 2:1 to 9:1 or at a stretch ratio of 3:1 to 8:1. In embodiments, the polyethylene film is stretched in the machine direction at a stretch ratio of 2:1 to 6:1 and transversely at a stretch ratio of 2:1 to 9:1.

[0068] In the embodiment, for example, depending on the end use, the polyethylene film may be corona-treated or printed using techniques known to those skilled in the art before or after bonding to a multilayer film.

[0069] The multilayer films and polyethylene films disclosed herein may have various thicknesses, for example, depending on the number of layers. For example, in the embodiments, the multilayer film or polyethylene film may have a thickness of 10 to 200 micrometers or 15 to 100 micrometers.

[0070] additives It should be understood that either the aforementioned layers of the multilayer film or the polyethylene film may further contain one or more additives known to those skilled in the art, such as antioxidants, UV stabilizers, heat stabilizers, slip agents, antiblocking agents, antistatic agents, pigments or colorants, processing aids, crosslinking catalysts, flame retardants, fillers, and foaming agents. For example, in embodiments, the sealant layer of the multilayer film contains at least one of slip agents or antiblocking agents.

[0071] Laminate As described above, the polyethylene film is bonded to the outermost layer of the multilayer film (for example, a barrier layer in one embodiment or an outer layer in another embodiment), and the combination of the multilayer film and the polyethylene film provides a laminate.

[0072] The laminate of the present invention may have several desirable properties. For example, the laminate of the present invention may have one or more of the following properties: 6.75 cm 3 / day / m 2 OTR less than 4.50g / day / m² 2 WVTR less than 97°C; heat seal initiation temperature at 5N below 97°C; seal strength at 120°C at least 10.0N / 25mm; hot tack initiation at 1N below 83°C; hot tack strength at 110°C at least 0.30N; and zero percent (0%) shrinkage rate in the temperature range of 70°C to at least 110°C.

[0073] In this embodiment, the laminate has a sealing window of at least 40°C.

[0074] In one embodiment, the laminate of the present invention comprises, based on the total weight of the laminate, at least 90% by weight of polyethylene, or at least 95% by weight of polyethylene, or at least 99% by weight of polyethylene, or at least 99.5% by weight of polyethylene, or at least 99.9% by weight of polyethylene.

[0075] Goods Embodiments of the present invention also provide articles formed from the laminates described herein. Examples of such articles include packages, flexible packages, and pouches. In embodiments, the packages of the present invention may contain liquids, powders, food products, or other items. Articles and packages of the present invention may be formed from the laminates disclosed herein using techniques known to those skilled in the art, taking into consideration the teachings herein.

[0076] Test method density Density was measured according to ASTM D792, in grams / cm³. 3 (g / cm 3 It is represented as ).

[0077] Melt Index (I2) The melt index (I2) is measured at 190°C and 2.16 kg according to ASTM D-1238. The value is reported as g / 10 min, corresponding to the grams dissolved per 10 minutes.

[0078] Oxygen transmission rate (OTR) Oxygen permeability (OTR) is measured according to ASTM D3985. The sample is stored at 23°C, 0% RH, and 50 cm³. 2 Test with the following sample size. The value should be measured in cm. 3 / day / m 2 I will report it.

[0079] Water vapor transmission rate (WVTR) Water vapor transmission rate (WVTR) is measured according to ASTM F1249. The sample is subjected to 37.8°C, 100% RH, and 50 cm³. 2 Test with the following sample size. The value should be expressed as g / day / m². 2 I will report it.

[0080] Hot tack initiation and hot tack intensity The hot tack test was conducted using a J&B Hot Tack Tester 4000 with a seal width of 25 mm, a dwell time of 0.5 seconds, and a seal pressure of 0.275 N / mm². 2The hot tack is performed at 40 psi and a tensile speed of 200 mm / s. The start of the hot tack is reported as the lowest temperature (°C) required to reach a force of 1 Newton. The hot tack strength is measured in Newtons per 25 mm (N / 25 mm).

[0081] Heat seal initiation temperature and seal strength To determine the heat seal initiation temperature (HSIT) and seal strength, the sample was sealed using a J&B Hot Tack 4000 tester. The sample width was 25 mm, the residence time for sealing was 0.5 seconds, and the sealing pressure was 0.275 N / mm². 2 The heat-sealed specimens are conditioned for 24 hours, and then measured at a tensile speed of 500 mm / min using a Zwick tensile testing machine equipped with a 200 N load cell. HSIT is reported as the lowest temperature (°C) required to reach a force of 5 Newtons. The seal strength value is reported in N / 25 mm.

[0082] contraction rate The shrinkage rate (%) is obtained by measuring the length and width of the sealed area in both the MD and TD directions after heat-sealing the films together, and calculating the percentage change compared to the width of the seal bar, which can be 1 mm to 15 mm. A standard heat sealing machine, including a PULSA impulse sealer or a J&B hot tack tester, may be used, as long as the machine has an accurate and adjustable temperature controller. Sealing conditions include jaw pressure (40 to 80 psi or 0.275 to 0.552 N / mm²). 2 This includes a residence time (0.1-1.5 seconds) and a seal temperature (60-150°C) window, which depend on the packaging speed. Typical conditions for a high-speed packaging machine are 40 psi (0.275 N / mm²). 2 ) are the jaw pressure and the residence time of 0.5 seconds.

[0083] Maximum peak melting temperature (Tm) Differential scanning calorimetry (DSC) is used to measure the melting and crystallization behavior of polymers over a wide temperature range. For example, this analysis is performed using a TA Instruments Q1000DSC equipped with an RCS (Refrigerated Cooling System) and an autosampler. The instrument is first calibrated using a software calibration wizard. The baseline is obtained by heating the cell from -80°C to 280°C with no sample placed in the aluminum DSC dish. Then, a sapphire standard is used according to the instructions of the calibration wizard. Next, 1-2 milligrams (mg) of fresh indium sample is analyzed by heating the standard sample to 180°C, cooling it to 120°C at a cooling rate of 10°C / min, and then keeping the standard sample isothermal at 120°C for 1 minute. The standard sample is then heated from 120°C to 180°C at a heating rate of 10°C / min. The indium standard sample is then subjected to the heat of fusion (H f It is determined that the saturation point is 28.71 ± 0.50 joules / gram (J / g) and the melting onset temperature is 156.6°C ± 0.5°C. Next, the test sample is analyzed using a DSC instrument.

[0084] During the test, a nitrogen purge gas flow rate of 50 mL / min is used. Each sample is melted and pressurized at approximately 175°C to form a thin film, and then the molten sample is air-cooled to room temperature (approximately 25°C). A film sample is formed by pressurizing 0.1 to 0.2 grams of the sample at 175°C and 1,500 psi for 30 seconds, creating a film with a thickness of 0.1 to 0.2 mils. A 3 to 10 mg, 6 mm diameter test piece is extracted from the cooled polymer, weighed, placed in a light (approximately 50 mg) aluminum pan, and crimped and sealed. Analysis is then performed to determine its thermal properties.

[0085] The thermal behavior of the sample is determined by raising and lowering the sample temperature to create a heat flow versus temperature profile. First, to remove the thermal history, the sample is rapidly heated to 180°C and held isothermally for 5 minutes. Next, the sample is cooled to -40°C at a cooling rate of 10°C / min and held isothermally at -40°C for 5 minutes. Then, the sample is heated to 150°C at a heating rate of 10°C / min (this is the "second heating" slope). The cooling curve and the second heating curve are recorded. The cooling curve is analyzed by setting a baseline endpoint from the start of crystallization to -20°C. The heating curve is analyzed by setting a baseline endpoint from -20°C to the end of melting. The value to be obtained is the highest peak melting temperature (T m ), peak crystallization temperature (T c ), starting crystallization temperature (Tc start), heat of fusion (H f )(Joules per gram), and the degree of crystallinity of PE % = ((H f The crystallinity percentage for the polyethylene sample was calculated using ((Hf) / (292J / g))×100, and the crystallinity percentage for the polypropylene sample was calculated using ((Hf) / 165J / g))×100. Heat of fusion (H f The peak melting temperature and the highest peak melting temperature are reported from the second thermal curve. The peak crystallization temperature and the onset crystallization temperature are determined from the cooling curve. [Examples]

[0086] The following embodiments are illustrative of the features of the present disclosure and are not intended to limit the scope of the present disclosure.

[0087] Polymer / film used The following materials were included in the laminate of the example described later.

[0088] ELITE (trademark) 5960G, 0.962g / cm 3 A reinforced polyethylene resin with a density of 0.85 g / 10 min and a melt index (I2), commercially available from The Dow Chemical Company (Midland, MI).

[0089] ELITE(TM) 5960G1, 0.962g / cm 3 A reinforced polyethylene resin with a density of 0.85 g / 10 min and a melt index (I2), commercially available from The Dow Chemical Company (Midland, MI).

[0090] ELITE(TM) 5940ST, 0.941g / cm 3 A reinforced polyethylene resin with a density of 0.8 g / 10 min and a melt index (I2), commercially available from The Dow Chemical Company (Midland, MI).

[0091] ELITE(TM) 5400G, 0.916g / cm 3 A reinforced polyethylene resin with a density and a melt index (I2) of 1.0 g / 10 min, commercially available from The Dow Chemical Company (Midland, MI).

[0092] ELITE(TM) 5400GS, 0.916g / cm 3 A reinforced polyethylene resin with a density and a melt index (I2) of 1.0 g / 10 min, commercially available from The Dow Chemical Company (Midland, MI).

[0093] DOW(trademark)LDPE 450E, 0.923g / cm 3 A low-density polyethylene resin with a density of 2.0 g / 10 min and a melt index (I2), commercially available from The Dow Chemical Company (Midland, MI).

[0094] BYNEL(TM)41E710, 0.922g / cm 3 An anhydrous modified linear low-density polyethylene resin, commercially available from The Dow Chemical Company (Midland, MI), having a density of 2.7 g / 10 min and a melt index (I2).

[0095] EVAL(trademark) H171B, 1.17g / cm 3 A 38 mol% ethylene vinyl alcohol copolymer with a density and a melt index (I2) of 1.7 g / 10 min, commercially available from Kuraray Co., Ltd. (Tokyo, Japan).

[0096] SURLYN(trademark) 1707, maximum peak melting temperature 92°C (T m ), 0.95 g / cm³ 3 An ionomer of ethylene acid copolymer having a density and a melt index (I2) of 0.9 g / 10 min, neutralized with a sodium cation source commercially available from The Dow Chemical Company (Midland, MI).

[0097] AFFINITY (trademark) PF 7266, maximum peak melting temperature of 76°C (T m ), 0.885 g / cm³ 3 A polyethylene elastomer / plastomer commercially available from The Dow Chemical Company (Midland, MI), having a density and a melt index (I2) of 2.5 g / 10 min.

[0098] ADCOTE (trademark) 545S / Co-reactant F is a solvent-based two-component polyurethane adhesive commercially available from The Dow Chemical Company (Midland, MI).

[0099] INNATE(TM) ST70, 0.926g / cm 3 A precision packaging resin with a density of 0.85 g / 10 min and a melt index (I2), commercially available from The Dow Chemical Company (Midland, MI).

[0100] POLYBATCH® CE505 is a slip masterbatch commercially available from Lyondell Basell (Houston, TX).

[0101] POLYBATCH® AB5 is a commercially available anti-blocking masterbatch from Lyondell Basell (Houston, TX).

[0102] CONPOL (trademark) 13B is an anti-blocking masterbatch commercially available from The Dow Chemical Company (Midland, MI).

[0103] CONPOL (trademark) 20S1 is a slip masterbatch commercially available from The Dow Chemical Company (Midland, MI).

[0104] TF-BOPE substrate 20, a biaxially oriented linear low-density polyethylene film stretched to a thickness of 20 micrometers by a tenter frame with a stretch ratio of 3 to 5 times in the longitudinal direction and 7 to 9 times in the transverse direction. Linear low-density polyethylene is 0.926 g / cm³ 3 It has a density and a melt index (I2) of 1.7 g / 10 min, and is commercially available from The Dow Chemical Company (Midland, MI) under the name INNATE® XUS 59910.08.

[0105] TF-BOPE substrate 40, a biaxially oriented linear low-density polyethylene film stretched to a thickness of 40 micrometers by a tenter frame, with a stretch ratio of 3 to 5 times in the longitudinal direction and 7 to 9 times in the transverse direction. The linear low-density polyethylene has a density of 0.926 g / cm³. 3 It has a density and a melt index (I2) of 1.7 g / 10 min, and is commercially available from The Dow Chemical Company (Midland, MI) under the name INNATE® XUS 59910.08.

[0106] MDO substrate, a mechanically oriented multilayer 5-ply polyethylene film with a thickness of 25 micrometers. The MDO substrate includes ELITE® 5960G, ELITE® 5940 ST, INNATE® ST70, and ELITE® 5400 GS.

[0107] A multilayer 5-layer film with an HDPE substrate, a thickness of 25 micrometers, and the following layer structure: (1) 100% ELITE® 5960G1; (2) 100% ELITE® 5960G1; (3) 100% ELITE® 5960G1; (4) 100% ELITE® 5960G1; (5) 100% DOW® LDPE 450E. The film is manufactured on a Collin 5-layer flow-co-extrusion line equipped with four extruders, with the following composition: A / B / C / B / D; layer ratio: 1 / 1 / 1 / 1 / 1; melting temperature of each extruder: 250~260°C o C; Slot die with coat hanger shape; Total throughput: 8 kg / hour; Line speed: 21.5 m / min.

[0108] A printed biaxially oriented propylene film made from a BOPP substrate, treated with 36 dynes, and having a gauge of 18 micrometers.

[0109] The laminates named Invention Examples 1-8 and Comparative Examples 1-2 are formed in a PRINT-ABCBD configuration, where "PRINT" corresponds to TF-BOPE substrate 20, TF-BOPE substrate 40, MDO substrate, or HDPE substrate in the Invention Examples, or to BOPP substrate in the Comparative Examples, and "ABCBD" corresponds to a 5-layer multilayer film. For each example, the "PRINT" substrate is laminated to layer "A" of the multilayer film using ADCOTE® 545S / Co-reactant F applied at a coating weight of 3-3.5 gsm. The examples are cured at room temperature (25°C) for 2 days, and a hot roll lamination process is performed on ChemInstruments#007416 at a temperature of 75°C, a pressure of 60 psi, and a speed of 1.66 m / min.

[0110] Five-layer multilayer films for each of the inventive example and comparative example are formed on a Collin five-layer blown co-extrusion line using the following parameters: Target film thickness: 55 μm; Extruders: 4 extruders; Layer configuration: A / B / C / B / D; Layer ratio: 2 / 1.5 / 2 / 1.5 / 4; Layer thickness (μm): 10 / 7.5 / 10 / 7.5 / 20; Die diameter (mm): 50; Blow-up ratio (BUR): 3.0; Lay flat width (mm): 235; Total throughput: 8 kg / hour; Line speed: 5.4 m / min; Melting temperatures of extruders A, B, C, and D: 174°C, 191°C, 197°C, and 177°C, respectively.

[0111] Table 1 below provides the structure and composition of examples of laminates, namely Invention Examples 1-8 and Comparative Examples 1-2.

[0112] [Table 1] * In addition to 80% AFFINITY® PF 7266, layer D contains 10% POLYBATCH® CE505 and 10% POLYBATCH® AB5. ** In addition to 93.5% SURLYN® 1707, layer D contains 4% CONPOL® 13B and 2.5% CONPOL® 20S1.

[0113] The thickness, oxygen permeability (OTR), and water vapor permeability (WVTR) of the examples were measured. Table 2 shows the results. Laminates with BOPP substrates are known to exhibit slightly better WVTR properties than comparable polyethylene laminates. Comparative Examples 1 and 2 containing BOPP substrates perform as well as or better than Inventive Examples 1-8 in terms of OTR and WVTR, but are not suitable for polyethylene recycling flows. Those skilled in the art will understand that the OTR of a laminate can be adjusted depending on the thickness and ethylene content of the EVOH in the barrier layer (i.e., generally, the thicker the barrier layer or the lower the ethylene content, the lower the achievable OTR value). As stated above, the Inventive Examples are non-limiting examples and are not intended to limit the scope of this disclosure, and multilayer films according to embodiments of the present invention may include a barrier layer containing EVOH with an ethylene content of 20-50 mol%.

[0114] [Table 2]

[0115] The heat seal start temperature (HSIT), seal strength, hot tack start temperature at 1 Newton, and hot tack strength at 110°C were measured. Figure 1 shows the heat seal strength curves for Comparative Example 1 and Invention Examples 1, 3, 5, and 7. Figure 2 shows the hot tack strength curves for Comparative Example 2 and Invention Examples 2, 4, 6, and 8. Tables 3 and 4 describe the results. The shrinkage rate (%) for the examples was measured at 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, and 130°C. None of the examples showed shrinkage at 70°C, 80°C, 90°C, 100°C, or 110°C in the machine direction (MD) or the transverse or lateral direction (TD). The shrinkage rate (%) results for the examples from 70°C to 130°C are reported in Table 5.

[0116] Examples 1, 3, 5, and 7 have comparable, or in embodiments improved, HSIT, seal strength, hot tack onset, and hot tack strength compared to Comparative Example 1. Similarly, Examples 2, 4, 6, and 8 have comparable, or in embodiments improved, HSIT, seal strength, hot tack onset, and hot tack strength compared to Comparative Example 2. The examples exhibit desirable or maintained low hot tack onset temperatures and low HSIT, and in embodiments achieve maintained or improved seal strength performance. The examples have comparable heat resistance and sealing performance to the comparative examples in a temperature range of 70°C to at least 120°C, and therefore have a sealing window of at least 40°C, or about 50°C.

[0117] [Table 3]

[0118] [Table 4]

[0119] [Table 5] * Seal bar dimensions: 0.5cm (MD direction) x 2.5cm (TD direction).

[0120] All documents referenced herein, including any cross-referenced or related patents or applications, and any patent applications or patents to which this application claims priority or interest, are incorporated herein by reference in their entirety unless expressly excluded or otherwise limited. No citation of any document constitutes prior art relating to any invention disclosed or claimed herein, nor does it imply, suggest, or disclose such invention, either alone or in any combination with any other reference. Furthermore, if any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in any document incorporated by reference, the meaning or definition assigned to that term in this document shall prevail.

[0121] Although specific embodiments of the present invention have been illustrated and described, it will be apparent to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, the appended claims are intended to encompass all such changes and modifications that fall within the scope of the invention. This application also relates to the following aspects. (1) It is a laminate, (a) (1) A barrier layer containing ethylene vinyl alcohol copolymer, (2) A sealant layer comprising at least 70% by weight of an ionomer or polyethylene elastomer / plastomer of an ethylene acid copolymer having a maximum peak melting temperature (Tm) of 100°C or less, and (3) Tie layer between the barrier layer and the sealant layer A multilayer film including, (b) 0.900~0.970 g / cm³ 3 A polyethylene film containing an ethylene-based polymer having a density of, (c) an adhesive for bonding the multilayer film to the polyethylene film, A laminate containing the above. (2) The aforementioned multilayer film has a density of 0.900 to 0.970 g / cm². 3 The laminate according to (1), further comprising an outer layer containing polyethylene having a density of , and a second tie layer between the outer layer and the barrier layer. (3) The laminate according to (1) or (2), wherein the polyethylene film is a stretched film. (4) The laminate according to (1) to (3) above, wherein the polyethylene film is a biaxially oriented film. (5) The laminate according to (1) to (3) above, wherein the polyethylene film is a mechanically oriented film. (6) The polyethylene film has a density of 0.958 g / cm². 3 The laminate according to (1) to (5) above, further comprising at least 20% by weight of a second ethylene-based polymer having the above density. (7) The laminate according to (1) to (6), wherein the polyethylene film further comprises a barrier layer containing an ethylene vinyl alcohol copolymer. (8) The barrier layer of the multilayer film is 5-25% of the total thickness of the multilayer film. The laminate described in (1) to (7) above. (9) The laminate according to (1) to (8), wherein the sealant layer has a thickness of at least 10 micrometers. (10) The laminate according to (1) to (9), wherein the sealant layer is 25 to 60% of the total thickness of the multilayer film. (11) The laminate according to (1) to (10), wherein the tie layer comprises anhydrous modified linear low-density polyethylene and at least one of linear low-density polyethylene, low-density polyethylene, medium-density polyethylene, or high-density polyethylene. (12) The laminate according to (1) to (11) above, wherein the adhesive includes a solvent-based adhesive, a solvent-free adhesive, or a water-based adhesive.

Claims

1. It is a laminate, (a) (1) A barrier layer containing ethylene vinyl alcohol copolymer, (2) Maximum peak melting temperature (T) below 100°C ｍ A sealant layer comprising at least 70% by weight of an ionomer or polyethylene elastomer / plastomer of an ethylene acid copolymer having, (3) Tie layer between the barrier layer and the sealant layer A multilayer film including, (b) 0.900-0.970g / cm ３ A polyethylene film containing an ethylene-based polymer having a density of, (c) an adhesive for bonding the multilayer film to the polyethylene film, The polyethylene film is a stretched film, and the laminate does not shrink at 70°C to 110°C in the mechanical direction (MD) or the transverse or horizontal direction (TD). Laminated structure.

2. The aforementioned multilayer film has a density of 0.900 to 0.970 g / cm². ３ The laminate according to claim 1, further comprising an outer layer containing polyethylene having a density of , and a second tie layer between the outer layer and the barrier layer.

3. The laminate according to claim 1 or 2, wherein the polyethylene film is a biaxially oriented film.

4. The laminate according to claim 1 or 2, wherein the polyethylene film is a mechanically stretched film.

5. The polyethylene film has a concentration of 0.958 g / cm². ３ The laminate according to any one of claims 1 to 4, further comprising at least 20% by weight of a second ethylene-based polymer having the above density.

6. The laminate according to any one of claims 1 to 5, wherein the polyethylene film further comprises a barrier layer containing an ethylene vinyl alcohol copolymer.

7. The laminate according to any one of claims 1 to 6, wherein the barrier layer of the multilayer film is 5 to 25% of the total thickness of the multilayer film.

8. The laminate according to any one of claims 1 to 7, wherein the sealant layer has a thickness of at least 10 micrometers.

9. The laminate according to any one of claims 1 to 8, wherein the sealant layer is 25 to 60% of the total thickness of the multilayer film.

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