Barrier laminate containing an ethylene copolymer extruded web layer

Abstract

Provided are laminates comprising polyethylene and an extruded web layer. The laminates are adhesive-free and may be fully compatible with polyethylene recycle streams. They may exhibit improved, maintained, or desirable properties compared to existing laminate structures that are not fully compatible with polyethylene recycle streams. The laminates include a first film, an extruded web layer, and a second film, the extruded web layer being between the first film and a lamination layer of the second film, and the laminate is formed via extrusion lamination of the extruded web layer.

Description

[Technical Field]

[0001] Embodiments of this disclosure generally relate to laminates, and more specifically to laminates comprising polyethylene and an extruded web layer.

[0002] Introduction Laminates incorporating polypropylene, polyamide, and polyethylene terephthalate, containing multiple layers, are widely used in flexible packaging for consumer products. For example, a laminate can be formed for flexible packaging comprising a biaxially oriented polypropylene (BOPP) outer printing substrate, a polyurethane adhesive, a metallized film barrier layer, and a polyethylene sealant layer. The combination of layers and materials can enable a wide seal window, good printability, high barrier performance, and heat resistance for sealing without shrinkage. However, such laminates can be difficult to recycle together due to different types of materials that are not compatible with each other for recycling, if not impossible. As the demand for sustainable and recyclable materials continues to rise, there remains a strong need for laminates that are easier to recycle and can exhibit performance characteristics equivalent to or improved upon existing structures. [Overview of the project]

[0003] Embodiments of the present disclosure satisfy one or more of the aforementioned needs by providing laminates that can be formed by extrusion lamination and bonded to an extruded web layer containing recyclable polyethylene. In some embodiments, the laminates can be fully recyclable in polyethylene recycling flows. 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, for example, in some embodiments, may allow the use of faster packaging speeds during manufacturing. In some embodiments, the recyclable laminates may exhibit improved or maintained properties compared to existing laminates, such as bond strength, 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.

[0004] This specification discloses laminates. In one embodiment, the laminate comprises (a) a first film comprising at least 95% by weight of polyethylene, and (b) a laminate layer comprising an ethylene copolymer selected from the group consisting of (i) ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / acrylate copolymer, anhydrous-modified ethylene / acrylate copolymer, anhydrous-modified polyethylene, anhydrous-modified ethylene / vinyl acetate copolymer, polyethylene elastomer / plastomer, and combinations thereof, and (ii) a maximum peak melting temperature (T) of 108°C or less. mThe invention comprises a second film comprising: (iii) a sealant layer containing at least 70% by weight of a polymer having (iii) an ethylene vinyl alcohol copolymer; (iv) a first binder layer between the laminate layer and the barrier layer; and (v) a second binder layer between the barrier layer and the sealant layer; and (c) an extruded web layer for bonding the laminate layer of the second film to the first film, wherein the extruded web layer comprises at least one of ethylene / methyl acrylate copolymer, ethylene / butyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / vinyl trimethoxysilane copolymer, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / methacrylic acid copolymer, maleic anhydride modified polyethylene, ethylene-acid terpolymer, or ethylene / methacrylic acid / acrylate terpolymer.

[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] The following graphs show the heat seal strength of comparative examples and embodiments of the present invention discussed below. [Figure 2] The following are hot tack intensity graphs for comparative examples and embodiments of the present invention discussed below. [Modes for carrying out the invention]

[0007] The embodiments of the disclosed laminates are described in more detail below. The laminates may have a wide variety of applications, including, for example, pouches, stand-up pouches, pillow pouches, bulk bags, pre-fabricated packaging, sachets, and the like. However, this disclosure should not be construed as limiting the embodiments described below, as this disclosure is an exemplary implementation of the embodiments described herein.

[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 a polymer prepared from only one type of monomer) and copolymer or interpolymer. Trace amounts of impurities (e.g., catalyst residues) 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 term “copolymer” means a polymer formed by the polymerization reaction of at least two structurally distinct monomers. The term “copolymer” includes terpolymers. For example, ethylene copolymers, e.g., ethylene / vinyl acetate copolymers, ethylene / acrylic acid copolymers, and ethylene / acrylate copolymers contain at least two structurally distinct monomers (e.g., ethylene / vinyl acetate copolymers contain at least copolymer units of ethylene monomer and vinyl acetate monomer, ethylene / acrylic acid copolymers contain at least units of ethylene monomer and acrylic acid monomer, and ethylene / acrylate copolymers contain at least units of ethylene monomer and acrylate monomer), and may optionally contain additional monomers or functional materials or modifiers, e.g., acids, acrylates, or anhydride functional groups. In other words, the copolymers described herein contain at least two structurally distinct monomers, and copolymers may consist of only two structurally distinct monomers, but they are not necessarily composed of only two structurally distinct monomers and may contain additional monomers or functional materials or modifiers.

[0010] As used herein, the terms “polyethylene” or “ethylene-based polymer” shall 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). Unless otherwise specified, the ethylene copolymers or terpolymers disclosed herein (e.g., ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / acrylate copolymer, anhydride-modified ethylene / acrylate copolymer, anhydride-modified polyethylene, anhydride-modified ethylene / vinyl acetate copolymer, polyethylene plastomer, polyethylene elastomer, ethylene / butyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / vinyl trimethoxysilane copolymer, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / methacrylic acid copolymer, maleic anhydride-modified polyethylene, ethylene-acid terpolymer, or ethylene / methacrylic acid / acrylate terpolymer) are ethylene-based polymers.

[0011] Common forms of polyethylene known in the art include, but are not limited to, low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), ultra-low-density polyethylene (ULDPE), very low-density polyethylene (VLDPE), single-site catalyst linear low-density polyethylene (m-LLDPE) including both linear low-density resins 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 well known in the art. However, the following description may be helpful in understanding the differences between some of these different polyethylene resins.

[0012] The term “LDPE” may also be referred to as “high-pressure ethylene polymer” or “highly branched polyethylene,” but 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 herein by reference). LDPE resins typically have a density of 0.916–0.935 g / cm³. 3 It has a density within the range.

[0013] 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 mono- or bis-cyclopentadienyl catalysts (typically referred to as metallocenes), 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. LLDPEs include 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 No. 3,645,992, heterogeneously branched ethylene polymers, such as those prepared according to the process disclosed in U.S. Patent No. 4,076,698, and / or blends thereof (such as those disclosed in U.S. Patents 3,914,342 or 5,854,045). LLDPEs 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.

[0014] The term "MDPE" refers to 0.926-0.935 g / cm³ 3 "MDPE" 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), bound structure catalysts, phosphineimine catalysts, and polyvalent aryloxyether catalysts (typically referred to as bisphenylphenoxy), and typically has a molecular weight distribution ("molecular weight distribution, MWD") greater than 2.5.

[0015] The term "HDPE" refers to polyethylene having a density of about 0.935 g / cm 3 to a maximum of about 0.980 g / cm 3 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).

[0016] The term "ULDPE" refers to polyethylene having a density of 0.855 - 0.912 g / cm 3 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). ULDPE includes, but is not limited to, polyethylene (ethylene-based) plastomers and polyethylene (ethylene-based) elastomers.

[0017] As used herein, the terms "polyethylene elastomer / plastomer" or ethylene-based plastomer (POP) and ethylene-based elastomer (POE) mean substantially linear or linear ethylene / α-olefin copolymers containing a homogeneous short-chain branch distribution containing units derived from ethylene and units derived from 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 / cm³ 3 , or 0.904 g / cm³ 3 , or 0.909 g / cm³ 3 , or 0.910 g / cm³ 3 It has a density of . 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.).

[0018] The terms “comprising,” “including,” and “having,” and their derivatives, are not intended to exclude the presence of any additional components, processes, or procedures, whether or not they are specifically disclosed. To avoid any doubt, all compositions claimed through the use of the term “comprising” may 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.

[0019] This specification discloses laminates. Laminates according to embodiments disclosed herein include a first film, a second film, and an extruded web layer, wherein the second film includes a laminate layer, and the extruded web layer adheres the laminate layer of the second film to the first film to form a laminate.

[0020] The first film of the laminate The laminates disclosed herein include a first film. The first film according to the embodiments disclosed herein is bonded to a laminate of a second film (described later) via an extruded web layer (described later). The first film according to the embodiments disclosed herein contains at least 95% by weight of polyethylene, based on the total weight of the first film. All individual values ​​and partial ranges relating to at least 95% by weight of polyethylene are included and disclosed herein. For example, the first film may contain at least 95% by weight, at least 96% by weight, at least 97% by weight, at least 98% by weight, or at least 99% by weight of polyethylene, based on the total weight of the film, or the first film may contain 95-100% by weight, 96-100% by weight, 97-100% by weight, 98-100% by weight, 99-100% by weight, 95-99% by weight, 95-98% by weight, 95-97% by weight, 95-96% by weight, 96-99% by weight, 96-98% by weight, 96-97% by weight, 97-99% by weight, 97-98% by weight, or 98-99% by weight of polyethylene, based on the total weight of the first film.

[0021] The first film of the laminate is not particularly limited, except that it contains at least 95% by weight of polyethylene. For example, in some embodiments, the first film may consist of a single layer or multiple layers. In some embodiments, the first film may be an oriented film oriented in the mechanical direction and / or transverse direction. In some embodiments, the first film is an inflation film. In some embodiments, the first film is a cast film.

[0022] In some embodiments, the first film has a density of 0.900 to 0.970 g / cm². 3 It may contain ethylene-based polymers having a density of 0.900 to 0.970 g / cm³. 3 All individual values ​​and subranges of 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 .

[0023] In some embodiments, the ethylene polymer of the first film may have 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.

[0024] In some embodiments, the ethylene polymer of the first film may constitute at least 50% by weight of the first film, based on the total weight of the first 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 first film, based on the total weight of the first film.

[0025] In addition to ethylene-based polymers, in some embodiments the first film may further contain at least one additional polymer, the at least one additional polymer, in an amount of less than 5% by weight of the first film, selected from the group consisting of ultra-low density polyethylene, low density polyethylene, polyethylene elastomer / plastomer, ethylene vinyl alcohol copolymer (EVOH), ethylene vinyl acetate copolymer, ethylene acrylic acid copolymer, or a combination thereof.

[0026] In some embodiments, the first film is a machine-oriented film. In other embodiments, the first film is biaxially oriented. In such embodiments, the first film may be a biaxially oriented polyethylene (BOPE) film. In some embodiments where the first film is a BOPE film, the BOPE film may be biaxially oriented using a tenter frame sequential biaxial orientation process and may be referred to as tenter frame biaxially oriented polyethylene (TF-BOPE). Such techniques are generally known to those skilled in the art. In other embodiments, the first film may be biaxially oriented using other techniques known to those skilled in the art, such as a double-cell orientation process, based on the teachings herein. Generally, using a tenter frame sequential biaxial orientation process, the tenter frame is incorporated as part of the 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. The cast film is then passed over a series of rollers having different rotational 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.

[0027] In some embodiments, the first film may be a single-layer TF-BOPE film comprising an ethylene-based polymer. In other embodiments, the first film comprises at least two layers. For example, in some embodiments, the first film may be a multilayer TF-BOPE film comprising three layers (e.g., an A / B / C structured TF-BOPE film produced by co-extruding three layers using a single ethylene-based polymer resin). Embodiments of the first film may include, for example, a binding layer, a sealant layer, or a barrier layer. In some embodiments, the first film includes a barrier layer comprising an ethylene vinyl alcohol copolymer.

[0028] In some embodiments, the first film can be oriented in the machine direction with a stretch ratio of 2:1 to 6:1, or alternatively, with a stretch ratio of 3:1 to 5:1. In embodiments, the first film can be oriented with a stretch ratio of 2:1 to 9:1, or alternatively, with a stretch ratio of 3:1 to 8:1.

[0029] In some embodiments, for example, depending on the end use, the first film may be corona-treated or printed using techniques known to those skilled in the art before or after extrusion lamination onto the second film.

[0030] The first film can have various thicknesses, for example, depending on the number of layers. For example, in some embodiments, the first film can have a thickness of 10 to 200 microns, or 10 to 100 microns, or 10 to 50 microns, or 15 to 25 microns.

[0031] The second film of the laminate The laminate disclosed herein includes a second film. The second film according to the embodiments disclosed herein includes a laminate layer, a barrier layer, a sealant layer, a first binding layer, and a second binding layer.

[0032] Second film lamination layer The second film of the laminate includes a laminate layer. The laminate layer is an outer layer of the second film that functions as a functional layer or bonding layer, which is bonded to the first film (described above) via an extruded web layer (described below) when forming the laminate. The laminate layer according to the embodiments disclosed herein assists or enables the high bonding strength of the extruded web layer and prevents delamination from the second film.

[0033] In some embodiments, the laminated layer of the second film includes an ethylene copolymer selected from the group consisting of ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / acrylate copolymer, anhydrous-modified ethylene / acrylate copolymer, anhydrous-modified polyethylene, anhydrous-modified ethylene / vinyl acetate copolymer, polyethylene elastomer / plastomer, and combinations thereof.

[0034] In some embodiments, the laminated layer contains ethylene-vinyl acetate copolymer, and the ethylene-vinyl acetate copolymer is present in a concentration of 0.930-0.980 g / cm³. 3 It can have a density in the range of 0.930~0.980 g / cm³. 3 All individual values ​​and partial ranges of the density of ethylene / vinyl acetate copolymer are disclosed and included herein, for example, 0.930 to 0.980 g / cm³. 3 , 0.935~0.970 g / cm³ 3 , 0.935~0.950 g / cm³ 3 , 0.935~0.945 g / cm³ 3 , or 0.940~0.945 g / cm³ 3 It can have a density within that range.

[0035] In some embodiments in which the laminated layer contains an ethylene-vinyl acetate copolymer, the ethylene / vinyl acetate copolymer can have a melt index (I2) of 0.1 g / 10 min to 500 g / 10 min, or 0.2 g / 10 min to 400 g / 10 min, or 0.5 g / 10 min to 100 g / 10 min, or 0.1 to 30 g / 10 min, or 0.1 to 10 g / 10 min.

[0036] In some embodiments in which the laminated layer comprises an ethylene / vinyl acetate copolymer, the ethylene / vinyl acetate copolymer may have a vinyl acetate content of 5 to 50% by weight, based on the total weight of the ethylene / vinyl acetate copolymer. All individual values ​​and partial ranges of the 5% to 50% by weight vinyl acetate content are disclosed and included herein. For example, in some embodiments, the ethylene / vinyl acetate copolymer may have a vinyl acetate content of 5 to 10% by weight, 10 to 30% by weight, or 30 to 50% by weight, based on the total weight of the ethylene / vinyl acetate copolymer.

[0037] An example of a commercially available ethylene / vinyl acetate copolymer that can be used in laminated layers is ELVAX® 470 (containing 18% vinyl acetate by weight), available from The Dow Chemical Company, Midland, MI.

[0038] In some embodiments where the laminated layer contains an ethylene / acrylate copolymer, the ethylene / acrylate copolymer is present in a concentration of 0.925 to 0.955 g / cm³. 3 It can have a density in the range of 0.925~0.955 g / cm³. 3 All individual values ​​and partial ranges of the density of the ethylene / acrylate copolymer are disclosed and included herein, for example, 0.925 to 0.955 g / cm³. 3 , 0.925~0.945 g / cm³ 3 , 0.930~0.955 g / cm³ 3 , 0.930~0.945 g / cm³ 3 , 0.935~0.955 g / cm³ 3 , or 0.935~0.945 g / cm³ 3 It can have a density within that range.

[0039] In some embodiments in which the laminated layer contains an ethylene / acrylate copolymer, the ethylene / acrylate copolymer 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.

[0040] Examples of commercially available ethylene / acrylate copolymers that can be used in laminated layers include, for example, those sold under the name BYNEL® by The Dow Chemical Company (Midland, MI), including BYNEL® 22E780 adhesive resin and BYNEL® 22E757 adhesive resin.

[0041] In some embodiments, the laminated layer includes a polyethylene elastomer / plastomer, and the polyethylene elastomer / plastomer is present in a concentration of 0.865 to 0.910 g / cm³. 3 It can have a density in the range of 0.865~0.910 g / cm³. 3 All individual values ​​and partial ranges of the density are disclosed and included herein, for example, polyethylene elastomer / plastomer is 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 , 0.870~0.910 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.

[0042] In embodiments in which the laminated layer includes 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 subranges of the melt index of 0.50 to 20 g / 10 min are disclosed herein and include, for example, that the polyethylene elastomer / plastomer may have a melt index (I2) in the lower limit of 0.50, 1.0, 2.0, 5.0, 10.0, 15, or 18 g / 10 min to the upper limit of 1.0, 2.0, 5.0, 10.0, 15, 18, 19, or 20 g / 10 min.

[0043] Examples of commercially available polyethylene plastomers / elastomers that can be used in laminated layers include, for example, 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.

[0044] In some embodiments, the laminate further comprises at least one of linear low-density polyethylene, low-density polyethylene, medium-density polyethylene, or high-density polyethylene. In such embodiments, the laminate may comprise up to 50% by weight of at least one of linear low-density polyethylene, low-density polyethylene, medium-density polyethylene, or high-density polyethylene.

[0045] Barrier layer of the second film The second film of the laminate includes a barrier layer.

[0046] In some embodiments, the barrier layer of the second film may be located adjacent to or near the first binding layer (described later) and the lamination layer (described above). The barrier layer according to the embodiments disclosed herein comprises ethylene vinyl alcohol copolymer (EVOH).

[0047] In some embodiments, the EVOH in the barrier layer has an ethylene content of 20–50 mol%. All sub-ranges and individual values ​​of the 20–50 mol% ethylene content are disclosed and included herein. For example, in some 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, the lower the ethylene content, the lower the achievable OTR value). Those skilled in the art will also understand that barrier layers containing EVOH with lower ethylene content may be suitable for flexible bottle and tube applications, and barrier layers containing EVOH with higher ethylene content may enable packaging types requiring flexibility (bend crack resistance), such as easier processing, long-term run-through stability, and thermoformability.

[0048] 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 sold under the name EVAL by Kuraray Co., Ltd. (Tokyo, Japan).

[0049] The second film can have various thicknesses. In some embodiments, the barrier layer is 5-25% of the total thickness of the second film.

[0050] Second film sealant layer The second film of the laminate includes a sealant layer.

[0051] The sealant layer of the second film has a maximum peak melting temperature (T) of 108°C or lower. mThe sealant layer contains at least 70% by weight of a polymer having ). The sealant layer can act as an inner surface of the laminate and, for example, can provide a method for sealing packaging around a packaged product. The composition of the sealant layer can affect the ability of the laminate layer and the sealant layer to obtain high seal bonding strength at lower sealing temperatures. In some embodiments, the sealant layer is at least 10 microns thick. In further embodiments, the sealant layer is 25-60% of the total thickness of the multilayer film.

[0052] The sealant layer of the second film contains at least 70% by weight of polymer, based on the total weight of the sealant layer. All individual values ​​and partial ranges of at least 70% by weight are disclosed and included herein. For example, in some 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 polymer, based on the total weight of the sealant layer.

[0053] The sealant layer of the second film has a maximum peak melting temperature (T) of 108°C or lower. m The polymer comprises at least 70% by weight of a polymer having ) . All individual values ​​and partial ranges below 108°C are disclosed and included herein. For example, in some embodiments, the polymer of the sealant layer has a maximum peak melting temperature (T) in the range of 108°C or less, 106°C or less, 104°C or less, 102°C or less, 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 108°C, 70°C to 100°C, 70°C to 95°C, 75°C to 108°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.

[0054] In some embodiments, the polymer in the sealant layer has a maximum peak melting temperature (T) of 108°C or lower. mThe sealant layer comprises or consists of a polyethylene elastomer / plastomer having ) . In such embodiments, the polyethylene elastomer / plastomer of the sealant layer has a density of 0.865 to 0.910 g / cm³ 3 It can have a density in the range of 0.865~0.910 g / cm³. 3 All individual values ​​and partial ranges of the density are disclosed and included herein, for example, polyethylene elastomer / plastomer is 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.

[0055] In some embodiments in which the polymer of the sealant layer includes or consists of 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 of 0.50 to 20 g / 10 min are disclosed herein and included, for example, the polyethylene elastomer / plastomer may have a melt index 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.

[0056] Examples of commercially available polyethylene elastomers / plastomers that can be used in sealant layers include, for example, 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.

[0057] In some embodiments, the polymer in the sealant layer has a maximum peak melting temperature (T) of 108°C or lower. m The material comprises or consists of an ionomer of an ethylene (meth)acrylic acid copolymer (also referred to herein as "ionomer of ethylene acid copolymer") having ). The cation source of the ionomer of the ethylene acid copolymer may be a monovalent or divalent cation source, including formates, acetates, hydroxides, nitrates, carbonates, and dicarbonates. In some embodiments, the ionomer of the ethylene acid copolymer was treated with one or more cations or cation sources, which may include magnesium, sodium, zinc, or combinations thereof.

[0058] In some embodiments, 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.

[0059] In some embodiments, the ionomers of ethylene acid copolymers have melt indices (I2) of 0.1 g / 10 min to 16 g / 10 min, 0.5 g / 10 min to 16 g / 10 min, 2 g / 10 min to 16 g / 10 min, 3 g / 10 min to 13 g / 10 min, 0.5 g / 10 min to 6 g / 10 min, 3.5 g / 10 min to 10 g / 10 min, or 5 g / 10 min to 8 g / 10 min. Commercially available ionomers of ethylene acid copolymers include those available from The Dow Chemical Company (Midland, MI) under the name SURLYN®.

[0060] In some embodiments, the polymer in the sealant layer has a maximum peak melting temperature (T) of 108°C or lower. m It contains or consists of polyethylene having ). For example, in some embodiments, the polymer of the sealant layer may contain or consist of linear low-density polyethylene (LLDPE). 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 Lower limit ~0.928, 0.925, 0.920, or 0.915 g / cm³ 3 This could be the upper limit: 0.870~0.930 g / cm³ 3 All individual values ​​and subranges of are included and disclosed herein.

[0061] Examples of commercially available polyethylenes that can be used in sealant layers include those sold by The Dow Chemical Company under the name ELITE® AT, such as ELITE® AT6202 and ELITE® AT6410.

[0062] Highest peak melting temperature (T) below 108℃ mIn addition to at least 70% by weight of a polymer having ), the sealant layer may, in some 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. For example, the at least one additive may be selected from the group consisting of antioxidants, UV stabilizers, heat stabilizers, slip agents, anti-tack 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.

[0063] First and second bonding layers of the second film The second film includes a first binder layer between the laminate and the barrier layer. The first binder layer can bond the barrier layer to the laminate. The second film also includes a second binder layer between the barrier layer and the sealant layer. The second binder layer can bond the barrier layer to the sealant layer. The first binder layer and the second binder layer may have the same polymer composition or different polymer compositions.

[0064] In some embodiments, the first binder layer and / or the second binder layer includes an adhesive resin selected from the group consisting of an anhydride-grafted ethylene-based polymer, an ethylene / acrylate copolymer, an ethylene acid copolymer, and an ethylene / vinyl acetate copolymer. Examples of the anhydride grafting moiety include, but are not limited to, maleic anhydride, citraconic anhydride, 2-methylmaleic anhydride, 2-chloromaleic anhydride, 2,3-dimethylmaleic anhydride, bicyclo[2,2,1]-5-heptene-2,3-dicarboxylic anhydride and 4-methyl-4-cyclohexene-1,2-dicarboxylic anhydride, bicyclo(2.2.2)oct-5-ene-2,3-dicarboxylic anhydride, lo-octahydronaphthalene-2,3-dicarboxylic anhydride, 2-oxa-1,3-diketospiro(4.4)nona-7-ene, bicyclo(2.2.1)hepta-5-ene-2,3-dicarboxylic anhydride, tetrahydrophthalic anhydride, norborn-5-ene-2,3-dicarboxylic anhydride, nadic anhydride, methyl nadic anhydride, himic anhydride, methyl himic anhydride, and x-methyl-bicyclo(2.2.1)hepta-5-ene-2,3-dicarboxylic anhydride. In one embodiment, the anhydride graft moiety includes maleic anhydride.

[0065] In some embodiments, the first binder layer and / or the second binder layer includes at least one of an anhydride-modified linear low density polyethylene, a linear low density polyethylene, a low density polyethylene, a medium density polyethylene, or a high density polyethylene. For example, in some embodiments, the first binder layer and / or the second binder layer includes an anhydride-modified linear low density polyethylene. In some embodiments, the anhydride-modified linear low density polyethylene has a density in the range of 3 ~0.935 g / cm 3 . All individual values and subranges of 3 ~0.935 g / cm 3 are disclosed and included herein. For example, the anhydride-modified linear low density polyethylene has a density in the range of 3 ~0.935 g / cm 3, 0.900 g / cm 3 ~0.925 g / cm 3 , 0.910 g / cm 3 ~0.935 g / cm 3 , 0.910 g / cm 3 ~0.925 g / cm 3 , 0.915 g / cm 3 ~0.935 g / cm 3 , or can have a density in the range of 0.920 g / cm 3 ~0.930 g / cm 3 In some embodiments, the anhydride-modified linear low-density polyethylene can 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.

[0066] In some embodiments, the first binder layer and / or the second binder layer comprises 0 to 100 wt% of the anhydride-modified linear low-density polyethylene based on the total weight of the binder layer in which the anhydride-modified linear low-density polyethylene is present. All individual values and subranges from 0 to 100 wt% are disclosed and included herein. For example, in some embodiments, the first binder layer and / or the second binder layer can comprise 10 to 90 wt%, 20 to 80 wt%, 30 to 70 wt%, or 40 to 60 wt% of the anhydride-modified linear low-density polyethylene based on the total weight of the binder layer in which the anhydride-modified linear low-density polyethylene is present.

[0067] Examples of commercially available anhydride-modified linear low-density polyethylenes that can be used in embodiments include BYNEL (trademark) Series 4100 resins such as BYNEL (trademark) 41E710 and BYNEL (trademark) 41E687 available from The Dow Chemical Company (Midland, MI).

[0068] In some embodiments, the first binding layer and / or the second binding layer comprises at least one of linear low-density polyethylene, low-density polyethylene, medium-density polyethylene, or high-density polyethylene. For example, in some embodiments, the first binding layer and / or the second binding layer comprises 0.945 g / cm³ 3 ~0.970g / cm 3 Contains high-density polyethylene having a density in the range of 0.945 g / cm³. 3 ~0.970g / cm 3 All individual values ​​and partial ranges of 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.

[0069] In embodiments in which high-density polyethylene is present in the first and / or second binding layer, the high-density polyethylene is composed of ethylene and C3-C 12It can be a copolymer with a comonomer. In some embodiments, the first binder layer and / or the second binder layer contains 0 to 90% by weight of high-density polyethylene, based on the total weight of the binder layer in which the high-density polyethylene is present. All individual values ​​and partial ranges of 0 to 90% by weight are disclosed and included herein. For example, in some embodiments, the binder 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 binder layer in which the high-density polyethylene is present. In some embodiments, the melt index (I2) of high-density polyethylene can be 0.3-10.0 g / 10 min, 0.3-7.0 g / 10 min, 0.3-5.0 g / 10 min, 0.3-4.0 g / 10 min, 0.3-3.0 g / 10 min, 0.3-2.0 g / 10 min, or 0.3-1.5 g / 10 min, or 0.5-1.0 g / 10 min.

[0070] Examples of commercially available high-density polyethylene that can be used as a binding layer include those sold by The Dow Chemical Company (Midland, MI) under the names ELITE® 5960G1, ELITE® AT 6900, and DOWLEX® 2006G.

[0071] Extruded web layer The laminate also includes an extruded web layer. The extruded web layer adheres the laminate of the second film to the first film. In particular, the extruded web layer can be formed via an extruded laminate, where the extruded material or molten polymer stream exiting the extruded die is extruded between the first film and the laminate of the second film so that the extruded web layer adheres the laminate to the first film. The laminate can be formed by passing the first film and the second film having the extruded web layer between a pair of rollers.

[0072] In some embodiments, the extruded web layer comprises at least one of the following: ethylene / methyl acrylate copolymer, ethylene / butyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / vinyl trimethoxysilane copolymer, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / methacrylic acid copolymer, maleic anhydride-modified polyethylene, ethylene-acid terpolymer, or ethylene / methacrylic acid / acrylate terpolymer. In other embodiments, the extruded web layer comprises at least one of the following: ethylene / methyl acrylate copolymer, ethylene / methacrylic acid / acrylate terpolymer, or ethylene / vinyl acetate copolymer.

[0073] In some embodiments, the polymer of the extruded web layer has a peak melting temperature (T) in the range of 105°C or below, 104°C or below, 103°C or below, 102°C or below, 101°C or below, 100°C or below, 98°C or below, 96°C or below, or 94°C or below, or 70°C to 105°C, 70°C to 100°C, 70°C to 95°C, 75°C to 105°C, 75°C to 100°C, or 75°C to 95°C. m ) has a maximum peak melting temperature (T m The highest peak melting temperature (T) below 105°C can be measured according to the DSC test method described below. Although not bound by any theory, m The use of polymers having ) allows for lower coating temperatures (below 250°C) compared to conventional LDPE extruded web layers (290-310°C), improves adhesion, and prevents shrinkage or wrinkling when the laminate is formed.

[0074] Examples of ethylene / methyl acrylate copolymers suitable for use in extruded web layers include ELVALOY® AC 12024S acrylate copolymer, commercially available from Dow Chemical Company (Midland, MI). Examples of ethylene / methacrylic acid / acrylate copolymers suitable for use in extruded web layers include NUCREL® N0427HS, commercially available from Dow Chemical Company (Midland, MI). Examples of ethylene / vinyl acetate copolymers suitable for use in extruded web layers include ELVAX® 3180 ethylene vinyl acetate copolymer, commercially available from Dow Chemical Company (Midland, MI).

[0075] additives It should be understood that any of the aforementioned layers, including the extruded web layer and the film layer, may further contain one or more additives known to those skilled in the art, such as antioxidants, UV stabilizers, heat stabilizers, slip agents, anti-tack agents, antistatic agents, pigments or colorants, processing aids, crosslinking catalysts, flame retardants, fillers, and foaming agents. For example, in some embodiments, the sealant layer of the second film contains at least one of a slip agent or an anti-tack agent.

[0076] Laminate The laminate of the present invention can have several desirable properties in various embodiments. In some embodiments, the laminate has a thickness of 50 to 150 microns, or 75 to 125 microns, or 90 to 110 microns.

[0077] In some embodiments, the laminates of the present invention contain, based on the total weight of the laminate, at least 90% by weight of an ethylene-based polymer, or at least 95% by weight of an ethylene-based polymer, or at least 99% by weight of an ethylene-based polymer, or at least 99.5% by weight of an ethylene-based polymer. Since the laminates in some embodiments contain at least 90% by weight of an ethylene-based polymer, they can be adapted to polyethylene recycling flows.

[0078] In some embodiments, the laminates of the present invention do not include laminating adhesives (solvent-based or aqueous laminating adhesives such as those commercially available from The Dow Chemical Company under trade names MOR-FREE® (a solvent-free laminating adhesive based on polyurethane technology), ADCOTE® (a solvent-based laminating adhesive having a two-component polyurethane system), and ROBOND® (a water-based adhesive having a one- or two-component acrylic copolymer)). As used herein, the term “laminating adhesive” refers to a liquid suspension or emulsion of a chemical substance (e.g., polyurethane or polyacrylate) for bonding two surfaces, which is applied using a conventional dry laminator or solvent-free laminating coating apparatus to coat a first substrate with the laminating adhesive, dry to form an adhesive layer, and then bring into contact with a second substrate by pressure to form an immediate bond, followed by curing to form a laminate. As used herein, the term “laminating adhesive” does not include “extruded web layers” (i.e., layers formed by extrusion lamination in which an extruded material or molten polymer stream exiting an extrusion die is extruded between films). The extruded web layers described herein can be formed by extrusion lamination without requiring drying of the solvent or water through a drying tunnel and subsequent curing conditions. The extruded web layers can form a bond between a first film and a second film by utilizing (along with heat and pressure) polar-polar interactions between the polymer of the film and the ethylene copolymer(s) of the extruded web layer.

[0079] The laminate of the present invention may have one or more of the following characteristics: a bonding strength of at least 2.00 N / 25 mm and 3.00 cm 3 / day / m 2 Less than OTR, 5.50g / day / m² 2 WVTR less than 100°C, heat seal initiation temperature of 5N less than 110°C, seal strength of at least 7.0N / 25mm at 120°C, hot tack initiation of 1N less than 85°C, hot tack strength of at least 2.00N / 25mm at 110°C, and zero percent (0%) shrinkage at temperatures in the range of 70°C to 120°C.

[0080] Goods Embodiments of the present invention also provide articles formed from any of the laminates of the present invention described herein. Examples of such articles include packaging, flexible packaging, pouches, and sachets. In some embodiments, the packaging of the present invention may include liquids, powders, food products, or other items. Articles and packaging of the present invention may be formed from the laminates disclosed herein using techniques known to those skilled in the art in consideration of the teachings herein.

[0081] Method for manufacturing a laminate The laminates of the present invention can be manufactured by methods known to those skilled in the art based on the teachings disclosed herein. For example, a method for manufacturing the laminates disclosed herein is to (a) provide a first film comprising at least 95% by weight of polyethylene, and (b) a laminate layer comprising (i) an ethylene copolymer selected from the group consisting of ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / acrylate copolymer, anhydrous-modified ethylene / acrylate copolymer, anhydrous-modified polyethylene, anhydrous-modified ethylene / vinyl acetate copolymer, polyethylene elastomer / plastomer, and combinations thereof, and (ii) a maximum peak melting temperature (T) of 108°C or less. mThe present invention provides a second film comprising: (iii) a sealant layer containing at least 70% by weight of a polymer having (iii) an ethylene vinyl alcohol copolymer; (iv) a first binder layer between the laminate layer and the barrier layer; and (v) a second binder layer between the barrier layer and the sealant layer; (c) extruding a web layer containing a polymer between the laminate layer of the first film and the second film, wherein the polymer comprises at least one of ethylene / methyl acrylate copolymer, ethylene / butyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / vinyl trimethoxysilane copolymer, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / methacrylic acid copolymer, maleic anhydride modified polyethylene, ethylene-acid terpolymer, or ethylene / methacrylic acid / acrylate terpolymer; and (d) passing the first film and the second film having the extruded web layer between a pair of rollers to form a laminate.

[0082] In embodiments of a method for manufacturing a laminate, which includes the step of passing a first film and a second film having an extruded web layer between a pair of rollers to form a laminate, the pair of rollers forming the laminate may include heated pressure rollers and / or embossing rollers.

[0083] Test method density Density was measured according to ASTM D792, in grams / cm³. 3 (g / cm 3 It is represented as ).

[0084] Melt Index (I2) The melt index (I2) is measured at 190°C using 2.16 kg according to ASTM D-1238. The value is reported as g / 10 min, corresponding to the grams eluted per 10 minutes.

[0085] Oxygen transmission rate (OTR) Oxygen permeability (OTR) is measured according to ASTM D3985 using Mocon Ox-Tran2 / 21. The sample is dried at 23°C, 100% O2 gas, 0% RH, and 50 cm³. 2 Test with the following sample size. Value in cm 3 / day / m 2 I will report it.

[0086] Water vapor transmission rate (WVTR) Water vapor transmission rate (WVTR) is measured according to ASTM F1249 using Mocon Permatran-W3 / 34 and 3 / 60. The sample is heated at 37.8°C, 100% RH, and 50 cm². 2 Test with the following sample size. Value g / day / m 2 I will report it.

[0087] Hot tack initiation and hot tack intensity The hot tack test was conducted with a seal width of 25 mm, a dwell time of 0.5 seconds, and a load of 0.275 N / mm². 2 The test is performed using a J&B Hot Tack Tester 4000 at a sealing pressure of 40 psi and a hot tack tensile speed of 200 mm / sec. The start of the hot tack is reported as the minimum temperature in degrees Celsius required to reach a force of 1 Newton. The hot tack strength is measured in Newtons per 25 mm (N / 25 mm).

[0088] 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 Hottack 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 sample is allowed to set for 24 hours, and then measured using a Zwick tensile machine equipped with a 200N load cell at a tensile speed of 500 mm / min. HSIT is reported as the minimum temperature in degrees Celsius required to reach a force of 5 Newtons. The seal strength value is reported in N / 25mm.

[0089] contraction Shrinkage (%) is obtained by measuring the length and width of the sealed area in both the machine direction (MD) and the transverse direction (TD) 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. Standard heat sealing machines, including PULSA impulse sealers or J&B hot tack testers, can be used, provided that 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 window for dwell time (0.1-1.5 seconds) and seal temperature (60-150°C), which depends on the packaging speed. Typical conditions for high-speed packaging machines are 40 psi (0.275 N / mm²). 2 ) are the jaw pressure and the residence time of 0.5 seconds.

[0090] Bonding strength The joint strength is measured using a Zwick tensile tester with a tensile speed of 250 mm / min and a 25 mm wide strip. The tensile testing machine is equipped with a gripper holder (which holds the sample in a T-shape) to hold both ends of a partially delaminated or partially detached sample and then pull them apart. The upper gripper connected to the crosshead is driven in the tensile direction to measure the required force or joint strength between two adjacent layers of the multilayer sample. The results of the maximum and average forces are calculated from five measurements and recorded in Newtons (N / 25 mm strip).

[0091] 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 the software calibration wizard. A baseline is obtained by heating the cell from -80°C to 280°C with no sample in the aluminum DSC pan. 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. Then, the standard sample is heated from 120°C to 180°C at a heating rate of 10°C / min. The indium standard sample then undergoes fusion (H₂ f It is determined that the saturation point is 28.71 ± 0.50 joules / gram (J / g) and the onset of melting is 156.6°C ± 0.5°C. The test sample is then analyzed using a DSC instrument.

[0092] During the test, the nitrogen purge gas flow rate used is 50 ml / min. Each sample is melted and compressed 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 pressing a 0.1-0.2 gram sample at 175°C, 1,500 psi, and for 30 seconds, creating a film with a thickness of 0.1-0.2 mils. A 3-10 mg, 6 mm diameter test piece is extracted from the cooled polymer, weighed, placed in a light aluminum pan (approximately 50 mg), and sealed by pressing. Next, analysis is performed to determine its thermal properties.

[0093] The thermal behavior of the sample is determined by raising and lowering the sample temperature to create a heat flow versus temperature profile. First, the sample is rapidly heated to 180°C and held isothermally for 5 minutes to remove its thermal history. 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" gradient). The cooling curve and the second heating curve are recorded. The cooling curve is analyzed by setting the baseline endpoint from the start of crystallization to -20°C. The thermal curve is analyzed by setting the baseline endpoint from -20°C to the end of melting. The determined value is the highest peak melting temperature (T m ), maximum peak crystallization temperature (T c ), starting crystallization temperature (Tc start), heat of fusion (H f The crystallinity percentage of the polyethylene sample was calculated using (Hf) / (292J / g) × 100, and the crystallinity percentage of 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.

[0094] Several embodiments of the present invention will be described in detail in the following examples. [Examples]

[0095] Materials and films used The laminates of the examples discussed below contained the following materials.

[0096] 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).

[0097] DOW (trademark) LDPE450E, 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).

[0098] BYNEL(trademark)22E780, 0.94g / cm 3 An ethylene / acrylate copolymer resin commercially available from The Dow Chemical Company (Midland, MI), having a density and a melt index (I2) of 2 g / 10 min.

[0099] ELVAX® 3180 ("ELVAX"), maximum peak melting temperature of 70°C (T m ), 0.95 g / cm³ 3 Ethylene / vinyl acetate copolymer, commercially available from The Dow Chemical Company (Midland, MI), having a density and a melt index (I2) of 25 g / 10 min.

[0100] 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).

[0101] EVAL H171B, 1.17 g / cm³ 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).

[0102] SURLYN(trademark) 1707, maximum peak melting temperature 92°C (T m ), 0.95 g / cm³ 3An 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).

[0103] AFFINITY (trademark) PF7266, maximum peak melting temperature 76℃ (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.

[0104] NUCREL(TM) N0427HS (“NUCREL”), 0.94g / cm 3 An ethylene / methacrylic acid / acrylate terpolymer with a density and a melt index (I2) of 27 g / 10 min, commercially available from The Dow Chemical Company (Midland, MI).

[0105] ELVALOY (trademark) AC12024S ("ELVALOY"), maximum peak melting temperature of 88°C (T m ), 0.944 g / cm³ 3 An ethylene / methyl acrylate copolymer having a density and a melt index (I2) of 20 g / 10 min, commercially available from The Dow Chemical Company (Midland, MI).

[0106] AFFINITY (trademark) PL 1881G, maximum peak melting temperature at 100℃ (T m ), 0.904 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 1.0 g / 10 min.

[0107] POLYBATCH CE505 is a slip masterbatch sold commercially by Lyondell Basell (Houston, TX).

[0108] POLYBATCH AB5 is a non-stick masterbatch commercially available from Lyondell Basell (Houston, TX).

[0109] CONPOL 13B is a non-stick masterbatch commercially available from The Dow Chemical Company (Midland, MI).

[0110] CONPOL (trademark) 20S1 is a slip masterbatch commercially available from The Dow Chemical Company (Midland, MI).

[0111] ADCOTE (trademark) 545S / co-reactant F854 is a solvent-based two-component polyurethane adhesive commercially available from The Dow Chemical Company (Midland, MI).

[0112] A BOPP substrate ("BOPP"), a printable biaxially oriented propylene film processed with 36 dynes and having a thickness of 2 microns and a gauge of 18 microns, for printing.

[0113] The film is a 25-micron thick, 5-layer multilayer film made of a PE base material ("PE"), consisting of (1) 100% ELITE® 5960G1, (2) 100% ELITE® 5960G1, (3) 100% ELITE® 5960G1, (4) 100% ELITE® 5960G1, and (5) 100% DOW® LDPE 450E, with (1) ELITE® 5960G1 oriented towards the outside of the laminate. The film is formed on a Collin 5-layer cast co-extrusion line using four extruders, configuration: A / B / C / B / D, layer ratio: 1 / 1 / 1 / 1 / 1, melting temperature of 250-260°C for each extruder, slot dies with coat hanger shape, total throughput of 8 kg / hour, and line speed of 21.5 m / min.

[0114] Laminates referred to as Examples 1-6 and Comparative Examples 1-6 of the present invention are formed with a "PRINT-WEB-ABCBD" configuration. "PRINT" corresponds to a PE substrate (first film) in the Examples of the present invention and to a BOPP substrate in the Comparative Examples. "ABCBD" corresponds to a 5-layer multilayer film (second film), where "A" is the laminate layer, "B" is the binding layer, "C" is the barrier layer, and "D" is the sealant layer. The "ABCBD" 5-layer multilayer film is formed on a Collin 5-layer blow co-extrusion line with the following parameters: target film thickness: 55 microns, extruder: 4 extruders, layer configuration: A / B / C / B / D, additives: layer A = 5000 ppm anti-tack agent and layer D = 5000 ppm slip and 5000 ppm anti-tack agent, layer ratio: 18.2% / 13.65% / 18.2% / 13.65% / 36.4%, BUR: 3.0, layer thickness (μm): 10 / 7.5 / 10 / 7.5 / 20, and lay-flat width (mm): 235. The "web" corresponds to the extruded web layer in which the polymer extruded is extruded between the "PRINT" film and the "ABCBD" film via extrusion lamination. For the extrusion lamination process, the film was corona treated to approximately 40-42 dynes with corona power of 2KW. The initial extruder conditions for the extruded web layer are set as follows: extruder temperature: 120 / 140 / 170 / 170°C, joint / adapter: 170 / 170°C, die: 170°C. The final processing extrusion lamination conditions are as follows: screw speed 16 rpm, melting temperature 200°C, line speed 6 m / min, and air gap 100 mm. The target thickness of the extruded web layer is 20 microns (or 20 gsm). The extruded web layer is extruded between the "PRINT" film and the "ABCBD" film, and the resulting structure is passed through a pair of rollers to form a laminate.

[0115] Comparative Examples 7 and 8 were not formed by extrusion lamination using an extruded web layer, but instead by hot roll lamination using a lamination adhesive. In these examples, the "PRINT" substrate was laminated to layer "A" of a multilayer film using ADCOTE® 545S / co-reactant F854 applied at a coating weight of 3 to 3.5 gsm. The examples were cured at room temperature (25°C) for 2 days, and the hot roll lamination process was carried out on ChemInstruments#007416 at a temperature of 75°C, a pressure of 60 psi, and a speed of 1.66 m / min.

[0116] Table 1 below provides examples of laminates, Examples 1-6 of the present invention, and the structures and compositions of Comparative Examples 1-8.

[0117] [Table 1] * In addition to 96% BYNEL™ 22E780, layer A contains 4% CONPOL™ 13B. ** In addition to 80% AFFINITY (trademark) PF 7266, layer D contains 10% POLYBATCH (registered trademark) CE505. and includes 10% POLYBATCH® AB5. *** In addition to 93.5% SURLYN™ 1707, layer D contains 4% CONPOL™ 13B and 2.5% CONPOL™ 20S1.

[0118] The thickness, oxygen permeability (OTR), water vapor permeability (WVTR), and bond strength of the laminate were measured. Table 2 provides the results. The examples of the present invention maintain OTR and WVTR values ​​and have bond strengths that are generally equivalent to or higher than those of comparative examples that are not suitable for polyethylene recycling flows. Furthermore, those skilled in the art will understand that the OTR of the laminate can be adjusted depending on the thickness of the barrier layer and the 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).

[0119] [Table 2] * The comparative example BOPP film was a printed BOPP in which the printing ink side was laminated to a 5-layer film using a solvent-based lamination adhesive. Therefore, the bonding strength was measured along the printing ink side of the BOPP relative to the 5-layer film.

[0120] The heat seal onset temperature (HSIT), heat seal strength, hot tack onset temperature at 1 Newton, and hot tack strength were measured. Figure 1 shows the heat seal strength curves for Comparative Examples 1, 3, 5, and 7, and Examples 1, 3, and 5 of the present invention. Figure 2 shows the hot tack strength curves for Comparative Examples 2, 4, 6, and 8, and Examples 2, 4, and 6 of the present invention. Table 3 provides the results for the comparative examples and examples of the present invention, where AFFINITY® PF7266 is part of the sealant layer / layer D. Table 4 provides the results for the comparative examples and examples of the present invention, where SURLYN® 1707 is part of the sealant layer / layer D. From Tables 3 and 4, the examples of the present invention show desirable or maintained low hot tack onset temperatures and low HSIT. The examples of the present invention also modestly achieve desirable, maintained, or improved seal strength performance.

[0121] [Table 3]

[0122] [Table 4] * Not measured

[0123] The shrinkage rate (%) of the heat-sealed area of ​​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, 110°C, or 120°C in the mechanical direction (MD) or transverse or lateral direction (TD). The shrinkage (%) results for the examples are reported in Table 5. Some of the examples of the present invention show shrinkage at 130°C compared to the comparative examples, but the examples of the present invention can function equivalently or similarly to the comparative examples in the temperature range of about 70°C to 120°C, which shows a wide heat-sealed window of at least 50°C.

[0124] [Table 5] * Seal bar dimensions: 0.5cm (MD direction) x 2.5cm (TD direction).

[0125] All documents cited herein, including any cross-referenced or related patents or applications, and any patent applications or patents to which this application claims priority or benefit, are incorporated herein by reference in their entirety unless expressly excluded or otherwise limited. No reference to any document constitutes prior art relating to any invention disclosed or claimed herein, nor does it teach, 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.

[0126] While 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. The invention described in the original claims of this application is listed below. [1] A laminate, (a) A first film comprising at least 95% by weight of polyethylene, (b) (i) A laminated layer comprising an ethylene copolymer selected from the group consisting of ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / acrylate copolymer, anhydrous-modified ethylene / acrylate copolymer, anhydrous-modified polyethylene, anhydrous-modified ethylene / vinyl acetate copolymer, polyethylene elastomer / plastomer, and combinations thereof. (ii) Highest peak melting temperature (T) below 108°C m A sealant layer containing at least 70% by weight of a polymer having ) (iii) A barrier layer containing ethylene vinyl alcohol copolymer, (iv) A first bonding layer between the laminated layer and the barrier layer, (v) A second bonding layer between the barrier layer and the sealant layer, A second film including, (c) An extruded web layer for adhering the laminated layer of the second film to the first film, wherein the extruded web layer comprises at least one of the following: ethylene / methyl acrylate copolymer, ethylene / butyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / vinyl trimethoxysilane copolymer, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / methacrylic acid copolymer, maleic anhydride modified polyethylene, ethylene-acid terpolymer, or ethylene / methacrylic acid / acrylate terpolymer, A laminate containing the above. [2] The laminate according to [1], wherein each of the first binding layer and the second binding layer comprises at least one of anhydrous modified linear low-density polyethylene, linear low-density polyethylene, low-density polyethylene, medium-density polyethylene, or high-density polyethylene. [3] The laminate according to [1] or [2], wherein the extruded web layer comprises at least one of ethylene / methyl acrylate copolymer, ethylene / methacrylic acid / acrylate terpolymer, or ethylene / vinyl acetate copolymer. [4] The laminate according to any one of [1] to [3], wherein the laminate further comprises at least one of linear low-density polyethylene, medium-density polyethylene, or high-density polyethylene. [5] The polymer in the sealant layer is an ionomer of an ethylene acid copolymer, or has a maximum peak melting temperature of 100°C or less (T m A laminate according to any one of [1] to [4], which is a polyethylene elastomer / plastomer having ). [6] The laminate according to any one of [1] to [5], wherein the ethylene copolymer of the laminate layer is an ethylene / acrylate copolymer. [7] The laminate according to any one of [1] to [6], wherein the first film is a film oriented in the machine direction. [8] The laminate according to any one of [1] to [7], wherein the first film is a biaxially oriented film. [9] The laminate according to any one of [1] to [8], wherein the laminate has a thickness of 50 to 150 microns.

[10] The laminate according to any one of [1] to [9], wherein the laminate does not contain a laminating adhesive.

Claims

1. It is a laminate, (a) A first film containing at least 95% by weight of polyethylene, (b) (i) A laminated layer containing an ethylene copolymer selected from the group consisting of ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / acrylate copolymer, anhydrous-modified ethylene / acrylate copolymer, anhydrous-modified polyethylene, anhydrous-modified ethylene / vinyl acetate copolymer, polyethylene elastomer or plastomer, and combinations thereof. (ii) Highest peak melting temperature (T) below 108°C ｍ A sealant layer containing at least 70% by weight of a polymer having ) (iii) Barrier layer containing ethylene vinyl alcohol copolymer, (iv) A first bonding layer between the laminated layer and the barrier layer, (v) A second bonding layer between the barrier layer and the sealant layer, A second film including, (c) An extruded web layer for adhering the laminated layer of the second film to the first film, wherein the extruded web layer comprises at least one of the following: ethylene / methyl acrylate copolymer, ethylene / butyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / vinyl trimethoxysilane copolymer, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / methacrylic acid copolymer, maleic anhydride modified polyethylene, ethylene-acid terpolymer, or ethylene / methacrylic acid / acrylate terpolymer, A laminate containing the above.

2. The laminate according to claim 1, wherein each of the first binding layer and the second binding layer comprises at least one of anhydrous modified linear low-density polyethylene, linear low-density polyethylene, low-density polyethylene, medium-density polyethylene, or high-density polyethylene.

3. The laminate according to claim 1 or 2, wherein the extruded web layer comprises at least one of ethylene / methyl acrylate copolymer, ethylene / methacrylic acid / acrylate terpolymer, or ethylene / vinyl acetate copolymer.

4. The laminate according to any one of claims 1 to 3, wherein the laminate further comprises at least one of linear low-density polyethylene, medium-density polyethylene, or high-density polyethylene.

5. The polymer in the sealant layer is an ionomer of an ethylene acid copolymer, or has a maximum peak melting temperature (T) of 100°C or lower. ｍ A laminate according to any one of claims 1 to 4, which is a polyethylene elastomer or plastomer having ).

6. The laminate according to any one of claims 1 to 5, wherein the ethylene copolymer in the laminate is an ethylene / acrylate copolymer.

7. The laminate according to any one of claims 1 to 6, wherein the first film is a film oriented in the machine direction.

8. The laminate according to any one of claims 1 to 7, wherein the first film is a biaxially oriented film.

9. The laminate according to any one of claims 1 to 8, wherein the laminate has a thickness of 50 to 150 microns.

10. The laminate according to any one of claims 1 to 9, wherein the laminate does not contain a laminating adhesive.

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