Barrier laminate comprising an extruded web layer of an ethylene copolymer

Abstract

The present invention provides laminates comprising polyethylene and an extruded web layer. The laminates can be adhesionless and fully compatible with polyethylene recycle streams. They can exhibit improved, sustained, 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, wherein the extruded web layer is positioned between the laminate layers of the first film and the second film, and the laminate is formed via extrusion lamination of the extruded web layer.

Description

Technical Field

[0001] The embodiments disclosed herein generally relate to laminates, and more specifically to laminates comprising polyethylene and an extruded mesh layer. Background Technology

[0002] Laminates incorporating polypropylene, polyamide, and polyethylene terephthalate contain multiple layers and are widely used in flexible packaging for consumer products. For example, laminates for flexible packaging can be formed comprising an outer printing substrate of biaxially oriented polypropylene (BOPP), a polyurethane-based adhesive, a metallized barrier layer, and a polyethylene sealant layer. The combination of layers and materials can allow for heat resistance, good printability, high barrier performance, and a seal without shrinkage in wide-sealed windows. However, such laminates may be difficult (if not impossible) to recycle together because different types of materials are not recyclably compatible with each other. As the demand for sustainable and recyclable materials continues to rise, there remains a strong need for laminates that are easier to recycle and exhibit performance characteristics comparable to or improved upon existing structures. Summary of the Invention

[0003] Embodiments of this disclosure satisfy one or more of the aforementioned requirements by providing laminates that can be formed via extrusion lamination and bonded to an extruded web layer comprising recyclable polyethylene. In some embodiments, the laminates may be fully recyclable in a polyethylene recycling stream. The laminates of the present invention may have better performance than or at least comparable to other laminates (such as laminates comprising BOPP), and may, for example, allow for faster packaging speeds during manufacturing in some embodiments. In some aspects, recyclable laminates may exhibit improved or maintained properties, such as bond strength, oxygen permeability (OTR), water vapor transmission rate (WVTR), heat seal initiation temperature (HSIT), heat seal strength, hot tack strength, hot tack initiation temperature, and / or shrinkage, when compared to existing laminates.

[0004] This document discloses a laminate. In one aspect, the laminate comprises (a) a first film comprising at least 95% by weight polyethylene; and (b) a second film comprising: (i) a laminate layer comprising an ethylene copolymer selected from the group consisting of: 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 elastomer / plasticizer, and combinations thereof; and (ii) a sealant layer comprising at least 70% by weight of a maximum peak melt temperature (T0). m(iii) a polymer with a temperature of 108°C or lower; (iv) a barrier layer comprising an ethylene-vinyl alcohol copolymer; (v) a first adhesive layer located between the laminated layer and the barrier layer; and (v) a second adhesive layer located between the barrier layer and the sealant layer; and (c) adhering the laminated layer of the second film to an extruded mesh layer of the first film, the extruded mesh layer comprising at least one of the following: ethylene / methyl acrylate copolymer, ethylene / butyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / vinyltrimethoxysilane 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 implementation schemes are described in more detail in the specific embodiments. Attached Figure Description

[0006] Figure 1 The diagram below shows the heat seal strength of the comparative examples and embodiments of the present invention.

[0007] Figure 2 The following are comparative examples and embodiments of the present invention, showing the thermal viscous strength diagrams. Detailed Implementation

[0008] The disclosed laminates are described in more detail below. Laminates can have a wide variety of applications, including, for example, bags, stand-up pouches, pillowcases, bulk bags, pre-manufactured packaging, pouches, etc. However, this disclosure should not be construed as limiting the embodiments set forth below, as it is an illustrative description of the embodiments described herein.

[0009] As used herein, the term "polymer" refers to a polymeric compound prepared by polymerizing monomers of the same or different types. Therefore, the general term polymer encompasses the term homopolymer (used to refer to a polymer prepared from only one type of monomer) and the terms copolymer or interpolymer. Trace impurities (e.g., catalyst residues) may be incorporated into and / or within a polymer. A polymer can be a single polymer, a polymer blend, or a mixture of polymers comprising a mixture of polymers formed in situ during polymerization.

[0010] As used herein, the term "copolymer" refers to a polymer formed by the polymerization of at least two monomers with different structures. The term "copolymer" includes terpolymers. For example, ethylene copolymers (such as ethylene / vinyl acetate copolymers, ethylene / acrylic acid copolymers, and ethylene / acrylate copolymers) contain at least two monomers with different structures (e.g., an ethylene / vinyl acetate copolymer contains copolymer units of at least ethylene monomers and vinyl acetate monomers; an ethylene / acrylic acid copolymer contains units of at least ethylene monomers and acrylic acid monomers; and an ethylene / acrylate copolymer contains units of at least ethylene monomers and acrylate monomers) and may optionally contain additional monomers or functional materials or modifiers, such as acid, acrylate, or anhydride functional groups. In other words, copolymers described herein contain at least two monomers with different structures, and although copolymers may consist of only two monomers with different structures, they do not necessarily consist of only two monomers with different structures and may contain additional monomers or functional materials or modifiers.

[0011] As used herein, the terms "polyethylene" or "ethylene-based polymer" should mean a polymer comprising a majority amount (>50 mol%) of units derived from ethylene monomers. This includes polyethylene homopolymers and copolymers (meaning units derived from two or more comonomers). Unless otherwise explicitly stated, the ethylene copolymers or terpolymers disclosed herein (e.g., ethylene / vinyl acetate copolymers, ethylene / acrylic acid copolymers, ethylene / acrylate copolymers, anhydride-modified ethylene / acrylate copolymers, anhydride-modified polyethylene, anhydride-modified ethylene / vinyl acetate copolymers, polyethylene plastomers, polyethylene elastomers, ethylene / butyl acrylate copolymers, ethylene / ethyl acrylate copolymers, ethylene / vinyltrimethoxysilane copolymers, ethylene / vinyl acetate copolymers, ethylene / acrylic acid copolymers, ethylene / methacrylic acid copolymers, maleic anhydride-modified polyethylene, ethylene-acid terpolymers, or ethylene / methacrylic acid / acrylate terpolymers) are ethylene-based polymers.

[0012] 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-point catalytic linear low-density polyethylene, including linear and substantially linear low-density resins (m-LLDPE); 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 to understand the differences between some of these different polyethylene resins.

[0013] The term "LDPE" can also be referred to as "high-pressure ethylene polymer" or "highly branched polyethylene," and it is defined as meaning that the polymer is partially or completely homopolymerized or copolymerized in an autoclave or tubular reactor at pressures above 14,500 psi (100 MPa) using a free radical initiator (such as peroxide) (see, for example, US 4,599,392, which is hereby incorporated herein by reference). The density of LDPE resin is typically around 0.916 g / cm³. 3 Up to 0.935 g / cm 3 Within the range.

[0014] The term "LLDPE" encompasses two resins prepared using conventional Ziegler-Natta catalyst systems and chromium-based catalyst systems, as well as single-site catalysts (including, but not limited to, substituted mono- or dicyclopentadienyl catalysts (commonly referred to as metallocenes), confined geometry catalysts, phosphine imine catalysts, and polyvalent aryloxy ether catalysts (commonly referred to as diphenylphenoxys), and comprising linear, substantially linear, or heterogeneous polyethylene copolymers or homopolymers. LLDPE contains less long-chain branching than LDPE and includes substantially linear ethylene polymers 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; non-homogeneously 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 in US 3,914,342 or US 4,076,698). (Those disclosed in 5,854,045). LLDPE can be prepared by gas-phase, solution-phase, or slurry polymerization, or any combination thereof, using any type of reactor or reactor configuration known in the art.

[0015] The term "MDPE" refers to a material with a density of 0.926 g / cm³. 3 Up to 0.935 g / cm 3 Polyethylene. "MDPE" is typically prepared using chromium or Ziegler-Natta catalysts or using single-point catalysts, including but not limited to substituted mono- or di-cyclopentadienyl catalysts (commonly known as metallocenes), restricted geometry catalysts, phosphine imine catalysts, and polyvalent aryloxy ether catalysts (commonly known as bisphenylphenoxy), and typically has a molecular weight distribution ("MWD") greater than 2.5.

[0016] The term "HDPE" refers to a material with a density greater than approximately 0.935 g / cm³. 3 And at most about 0.980 g / cm 3Polyethylene is generally prepared using Ziegler-Natta catalysts, chromium catalysts, or single-point catalysts (including but not limited to substituted mono- or di-cyclopentadienyl catalysts (commonly known as metallocenes), confined geometry catalysts, phosphine imine catalysts, and polyvalent aryloxy ether catalysts (commonly known as bisphenylphenoxy).

[0017] The term "ULDPE" refers to a material with a density of 0.855 g / cm³. 3 Up to 0.912 g / cm 3 Polyethylene, which is generally prepared using Ziegler-Natta catalysts, chromium catalysts, or single-site catalysts (including but not limited to substituted mono- or di-cyclopentadienyl catalysts (commonly known as metallocenes), confined geometry catalysts, phosphine imine catalysts, and polyvalent catalysts (commonly known as bisphenylphenoxys)). ULDPE includes, but is not limited to, polyethylene (ethylene-based) plasmons and polyethylene (ethylene-based) elastomers.

[0018] As used herein, the terms "polyethylene elastomer / plasticizer" or ethylene-based plasticizer (POP) and ethylene-based elastomer (POE) should mean including units derived from ethylene and units derived from at least one C3-C 10 A substantially linear or linear ethylene / α-olefin copolymer containing homogeneously short-chain branched units of α-olefin comonomers, or at least one C4-C8 α-olefin comonomer, or at least one C6-C8 α-olefin comonomer. The density of the polyethylene elastomer / plastic is 0.865 g / cm³. 3 or 0.870 g / cm 3 or 0.880 g / cm 3 or 0.890 g / cm 3 Up to 0.900 g / cm 3 or 0.902 g / cm 3 or 0.904 g / cm 3 or 0.909 g / cm 3 or 0.910 g / cm 3 Non-limiting examples of polyethylene elastomers / plastics include AFFINITY. TM Plastics and elastomers (available from The Dow Chemical Company), EXACT TM plasmid (available from ExxonMobil Chemical), Tafmer (available from Mitsui), Nexlene TM (Available from SK Chemicals Co.) and Lucene TM(Available from LG Chem Ltd.)

[0019] The terms "comprising," "including," "having," and their derivatives are not intended to exclude the presence of any additional components, steps, or procedures, whether or not such components, steps, or procedures are specifically disclosed. For the avoidance of any doubt, unless stated otherwise, all compositions claimed using the term "comprising" may include any additional additives, adjuvants, or compounds, whether polymerized or otherwise. In contrast, the term "substantially composed of" excludes any other components, steps, or procedures from any subsequently listed scope, except those that are not essential for operability. The term "composed of" excludes any ingredients, steps, or procedures not specifically described or listed.

[0020] This document discloses a laminate. The laminate according to the embodiments disclosed herein includes a first film, a second film, and an extruded mesh layer, wherein the second film includes a laminate layer, and the extruded mesh layer adheres the laminate layer of the second film to the first film to form a laminate.

[0021] The first membrane of the laminate

[0022] The laminates disclosed herein include a first membrane. The first membrane, according to an embodiment disclosed herein, is adhered to a laminated layer of a second membrane (also described below) via an extruded web layer (described below). Based on the total weight of the first membrane, the first membrane according to an embodiment disclosed herein contains at least 95% by weight polyethylene. This document includes and discloses all individual values ​​and subranges for at least 95% by weight polyethylene. For example, the first membrane may contain at least 95 wt%, at least 96 wt%, at least 97 wt%, at least 98 wt%, or at least 99 wt% of polyethylene based on the total weight of the first membrane; or the first membrane may contain 95 wt% to 100 wt%, 96 wt% to 100 wt%, 97 wt% to 100 wt%, 98 wt% to 100 wt%, 99 wt% to 100 wt%, 95 wt% to 99 wt%, 95 wt% to 98 wt%, 95 wt% to 97 wt%, 95 wt% to 96 wt%, 96 wt% to 99 wt%, 96 wt% to 98 wt%, 96 wt% to 97 wt%, 97 wt% to 99 wt%, 97 wt% to 98 wt%, or 98 wt% to 99 wt% of polyethylene based on the total weight of the first membrane.

[0023] There are no particular limitations on the first film of the laminate, except that it contains at least 95% polyethylene by weight. For example, in some embodiments, the first film may comprise a single layer or multiple layers. In some embodiments, the first film may be an oriented film oriented in the longitudinal and / or transverse directions. In some embodiments, the first film is a blown film. In other embodiments, the first film is a cast film.

[0024] In some implementations, the first membrane contains a density of 0.900 g / cm³. 3 Up to 0.970 g / cm 3 Ethylene-based polymers. This document discloses and includes 0.900 g / cm³. 3 Up to 0.970 g / cm 3 All individual values ​​and sub-ranges of density. For example, the density of ethylene-based polymers can be 0.900 g / cm³. 3 Up to 0.970 g / cm 3 0.910 g / cm 3 Up to 0.957 g / cm 3 0.920g / cm 3 Up to 0.947 g / cm 3 0.920g / cm 3 Up to 0.937 g / cm 3 0.920g / cm 3 Up to 0.930 g / cm 3 Or 0.920 g / cm 3 Up to 0.927 g / cm 3 .

[0025] In some embodiments, the melt index (I2) of the ethylene-based polymer of the first membrane can be from 0.1 g / 10 min to 10 g / 10 min, or from 0.5 g / 10 min to 8 g / 10 min, or from 0.5 g / 10 min to 5 g / 10 min.

[0026] In some embodiments, the ethylene-based polymer of the first membrane may comprise at least 50% by weight of the first membrane, based on the total weight of the first membrane. This document discloses and includes all individual values ​​and sub-ranges of at least 50% by weight. For example, the ethylene-based polymer may comprise at least 50% by weight, at least 75% by weight, at least 90% by weight, at least 99% by weight, or at least 99.9% by weight of the first membrane, based on the total weight of the first membrane.

[0027] In addition to ethylene-based polymers, in some embodiments, the first membrane may also contain at least one other polymer, and the at least one other polymer may be selected from the group consisting of: ultra-low density polyethylene, low density polyethylene, polyethylene elastomer / plasticizer, ethylene vinyl alcohol copolymer (EVOH), ethylene vinyl acetate copolymer, ethylene acrylic acid copolymer, or combinations thereof, in an amount less than 5% by weight of the first membrane.

[0028] In some embodiments, the first film is a longitudinally 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 can 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, based on the teachings herein, other techniques known to those skilled in the art (such as a double-bubble orientation process) can be used to biaxially oriented the first film. Typically, using a tenter frame sequential biaxial orientation process, the tenter frame is incorporated as part of an extrusion production line. After extrusion from a flat die, the film is cooled on cooling rollers and immersed in a water bath filled with room temperature water. The cast film is then conveyed onto a series of rollers with different rotational speeds to achieve stretching in the longitudinal direction. There are several pairs of rollers in the MD stretching section of the production line, and said pairs of rollers are all oil-heated. The pairs of rollers are used sequentially as preheating rollers, stretching rollers, and rollers for relaxation and annealing. The temperature of each pair of rollers is controlled individually. After stretching in the longitudinal direction, the film web is conveyed to a tenter frame hot air oven with heating zones for stretching in the transverse direction. The first few zones are used for preheating, the following zones are used for stretching, and the final zone is used for annealing.

[0029] In some embodiments, the first membrane may be a single-layer TF-BOPE membrane comprising an ethylene-based polymer. In other embodiments, the first membrane comprises at least two layers. For example, in some embodiments, the first membrane may be a multilayer TF-BOPE membrane comprising three layers (e.g., an A / B / C structure, which is a TF-BOPE membrane made by co-extruding three layers using a single ethylene-based polymer resin). Embodiments of the first membrane may include, for example, an adhesive layer, a sealant layer, or a barrier layer. In some embodiments, the first membrane includes a barrier layer comprising an ethylene vinyl alcohol copolymer.

[0030] In some embodiments, the first membrane may be stretched in the longitudinal direction at a stretch ratio of 2:1 to 6:1, or alternatively at a stretch ratio of 3:1 to 5:1. In other embodiments, the first membrane may be stretched in the transverse direction at a stretch ratio of 2:1 to 9:1, or alternatively at a stretch ratio of 3:1 to 8:1.

[0031] In some implementations, depending on the end-use application, the first film may be corona-treated, plasma-treated, or printed using techniques known to those skilled in the art before or after extrusion lamination to the second film.

[0032] The first membrane can have various thicknesses, depending on, for example, the number of layers. For example, in some embodiments, the first membrane can have a thickness of 10 micrometers to 200 micrometers, or alternatively 10 micrometers to 100 micrometers, or alternatively 10 micrometers to 50 micrometers, or alternatively 15 micrometers to 25 micrometers.

[0033] The second membrane of the laminate

[0034] The laminates disclosed herein include a second membrane. According to the embodiments disclosed herein, the second membrane includes a laminate layer, a barrier layer, a sealant layer, a first adhesive layer, and a second adhesive layer.

[0035] The second membrane laminate

[0036] The second film of the laminate includes a laminated layer. The laminated layer is the outer layer of the second film, acting as a functional or adhesive layer, and is adhered to the first film (as described above) via an extruded web layer (described below) during the formation of the laminate. The laminated layer according to the embodiments disclosed herein contributes to or enables the extruded web layer to have high adhesive strength to prevent delamination from the second film.

[0037] In some embodiments, the laminate of the second membrane comprises an ethylene copolymer selected from the group consisting of: 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 elastomer / plasticizer, and combinations thereof.

[0038] In some embodiments where the laminate comprises an ethylene / vinyl acetate copolymer, the density of the ethylene / vinyl acetate copolymer can be 0.930 g / cm³. 3 Up to 0.980 g / cm 3 Within the scope. This article discloses and includes 0.930 g / cm. 3 Up to 0.980 g / cm 3 All individual values ​​and sub-ranges of density; for example, the density of ethylene / vinyl acetate copolymer can be as low as 0.930 g / cm³. 3 Up to 0.980 g / cm 3 0.935g / cm 3 Up to 0.970 g / cm 3 0.935g / cm 3 Up to 0.950 g / cm 30.935g / cm 3 Up to 0.945 g / cm 3 Or 0.940 g / cm 3 Up to 0.945 g / cm 3 Within the range.

[0039] In some embodiments where the laminate comprises an ethylene / vinyl acetate copolymer, the melt index (I2) of the ethylene / vinyl acetate copolymer is 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 g / 10 min to 30 g / 10 min, or 0.1 g / 10 min to 10 g / 10 min.

[0040] In some embodiments where the laminate 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. This document discloses and includes all individual values ​​and sub-ranges of the vinyl acetate content from 5% to 50% by weight. For example, in some embodiments, the ethylene / vinyl acetate copolymer may have a vinyl acetate content of 5% to 10%, 10% to 30%, or 30% to 50% by weight, based on the total weight of the ethylene / vinyl acetate copolymer.

[0041] Examples of commercially available ethylene / vinyl acetate esters that can be used in laminates include ELVAX, available from Dow Chemical Company, Midland, Michigan. TM 470 (18% by weight vinyl acetate content).

[0042] In some embodiments where the laminate comprises an ethylene / acrylate copolymer, the density of the ethylene / acrylate copolymer can be 0.925 g / cm³. 3 Up to 0.955 g / cm 3 Within the scope. This document discloses and includes 0.925 g / cm³. 3 Up to 0.955 g / cm 3 All individual values ​​and sub-ranges of density; for example, the density of ethylene / acrylate copolymers can be in the range of 0.925 g / cm3 to 0.955 g / cm3, 0.925 g / cm3 to 0.945 g / cm3, 0.930 g / cm3 to 0.955 g / cm3, 0.930 g / cm3 to 0.945 g / cm3, 0.935 g / cm3 to 0.955 g / cm3, or 0.935 g / cm3 to 0.945 g / cm3.

[0043] In some embodiments where the laminate comprises an ethylene / acrylate copolymer, the melt index (I2) of the ethylene / acrylate copolymer can be from 0.1 g / 10 min to 50 g / 10 min, or from 0.5 g / 10 min to 20 g / 10 min, or from 1.0 g / 10 min to 10 g / 10 min.

[0044] Commercially available examples of ethylene / acrylate copolymers that can be used in laminates include those available from Dow Chemical Company (Midland, Michigan) under the name BYNEL. TM Those obtained through commercial purchases, including, for example, BYNEL TM 22E780 adhesive resin and BYNEL TM 22E757 adhesive resin.

[0045] In some embodiments where the laminate comprises a polyethylene elastomer / plasticizer, the density of the polyethylene elastomer / plasticizer can be 0.865 g / cm³. 3 Up to 0.910 g / cm 3 Within the scope. This article discloses and includes 0.865 g / cm. 3 Up to 0.910 g / cm 3 All individual values ​​and sub-ranges of density; for example, the density of polyethylene elastomers / plastics can be from 0.865 g / cm³ to 0.910 g / cm³, 0.865 g / cm³ to 0.900 g / cm³, 0.865 g / cm³ to 0.890 g / cm³, 0.865 g / cm³ to 0.880 g / cm³, 0.870 g / cm³ to 0.910 g / cm³, 0.870 g / cm³ to 0.900 g / cm³, 0.870 g / cm³ to 0.900 g / cm³, 0.870 g / cm³ to 0.91 ... The ranges are 0.890 g / cm3 to 0.870 g / cm3 to 0.880 g / cm3, 0.880 g / cm3 to 0.910 g / cm3, 0.880 g / cm3 to 0.900 g / cm3, 0.880 g / cm3 to 0.890 g / cm3, 0.890 g / cm3 to 0.910 g / cm3, 0.890 g / cm3 to 0.900 g / cm3, or 0.900 g / cm3 to 0.910 g / cm3.

[0046] In embodiments where the laminate comprises a polyethylene elastomer / plastic, the melt index (I2) of the polyethylene elastomer / plastic is in the range of 0.50 g / 10 min to 20 g / 10 min. This document discloses and includes all individual values ​​and sub-ranges of the melt index from 0.50 g / 10 min to 20 g / 10 min; for example, the melt index (I2) of the polyethylene elastomer / plastic can be from an upper limit of 0.50 g / 10 min, 1.0 g / 10 min, 2.0 g / 10 min, 5.0 g / 10 min, 10.0 g / 10 min, 15 g / 10 min, or 18 g / 10 min to a lower limit of 1.0 g / 10 min, 2.0 g / 10 min, 5.0 g / 10 min, 10.0 g / 10 min, 15 g / 10 min, 18 g / 10 min, 19 g / 10 min, or 20 g / 10 min.

[0047] Commercially available examples of polyethylene plastomers / elastomers that can be used in laminates include those available from Dow Chemical Company (Midland, Michigan) under the name AFFINITY™, including, for example, AFFINITY. TM VP 8770G1, AFFINITY TM PF7266, AFFINITY TM PL 1881G and AFFINITY TM PF1140G.

[0048] 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.

[0049] The barrier layer of the second membrane

[0050] The second membrane of the laminate includes a barrier layer.

[0051] In some embodiments, the barrier layer of the second membrane may be positioned close to or adjacent to the first adhesive layer (described below) and the laminate layer (described above). The barrier layer according to the embodiments disclosed herein comprises an ethylene vinyl alcohol copolymer (EVOH).

[0052] In some embodiments, the ethylene content of the EVOH in the barrier layer is from 20 mol% to 50 mol%. All sub-ranges and individual values ​​of the ethylene content from 20 mol% to 50 mol% are disclosed herein. For example, in some embodiments, the ethylene content of the EVOH in the barrier layer is from 20 mol% to 50 mol%, or from 22 mol% to 45 mol%, or from 25 mol% to 40 mol%. Those skilled in the art will understand that the ethylene content of the EVOH can contribute to a lower and higher OTR (i.e., generally, the lower the ethylene content, the lower the achievable OTR value) of the laminates disclosed herein. Those skilled in the art will also understand that barrier layers containing EVOH with a lower ethylene content are suitable for flexible bottle and tube applications, and barrier layers containing EVOH with a higher ethylene content allow for easier handling, long-term operational stability, and packaging types requiring flexibility (flexible crack resistance), such as thermoforming.

[0053] Examples of commercially available EVOH that can be used in barrier layers include those commercially available from Kuraray Co., Ltd. (Tokyo, Japan) under the name EVAL, including, for example, EVAL H171B (38 mol% ethylene content) and EVAL F171B (32 mol% ethylene content).

[0054] Various thicknesses are envisioned for the second membrane. In some embodiments, the barrier layer comprises 5% to 25% of the total thickness of the second membrane.

[0055] The sealant layer of the second membrane

[0056] The second membrane of the laminate includes a sealant layer.

[0057] The sealant layer of the second membrane contains at least 70% by weight of the highest peak melt temperature (T). m The polymer is 108°C or lower. The sealant layer can act as the inner surface of the laminate and, for example, provide a way of sealing the packaging around the product. The composition of the sealant layer can affect the ability of the laminate and the sealant layer to achieve high seal bond strength at lower sealing temperatures. In some embodiments, the sealant layer is at least 10 micrometers thick. In other embodiments, the sealant layer is 25% to 60% of the total thickness of the second film.

[0058] Based on the total weight of the sealant layer, the sealant layer of the second membrane comprises at least 70 wt% of the polymer. This document discloses and includes all individual values ​​and sub-ranges of at least 70 wt%. For example, in some embodiments, based on the total weight of the sealant layer, the sealant layer may comprise at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, at least 99 wt%, at least 99.5 wt%, or 70 wt% to 100 wt%, 75 wt% to 99 wt%, 80 wt% to 95 wt%, or 90 wt% to 95 wt% of the polymer.

[0059] The sealant layer of the second membrane contains at least 70% by weight of the highest peak melt temperature (T). m The polymer is 108°C or lower. This document discloses and includes all individual values ​​and sub-ranges of 108°C or lower. For example, in some embodiments, the highest peak melt temperature (T0) of the polymer in the sealant layer is... m The values ​​are 108°C or lower, 106°C or lower, 104°C or lower, 102°C or lower, 100°C or lower, 98°C or lower, 96°C or lower, 94°C or lower, or 92°C or lower, 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, where the highest peak melting temperature (T) is [not specified]. m It can be measured according to the DSC test method described below.

[0060] In some embodiments, the polymer of the sealant layer contains the highest peak melt temperature (T0). m The sealant layer is a polyethylene elastomer / plastic composite or composed thereof, heated to 108°C or lower. In such embodiments, the density of the polyethylene elastomer / plastic composite in the sealant layer can be 0.865 g / cm³. 3 Up to 0.910 g / cm 3 Within the scope. This article discloses and includes 0.865 g / cm. 3 Up to 0.910 g / cm 3 All individual values ​​and sub-ranges of density; for example, the density of polyethylene elastomer / plastic can be as low as 0.865 g / cm³. 3 Up to 0.910 g / cm 3 0.865g / cm 3 Up to 0.900 g / cm 3 0.865g / cm 3 Up to 0.890 g / cm 3 0.865g / cm 3 Up to 0.880 g / cm 3 0.865g / cm 3 Up to 0.870 g / cm 30.870 g / cm 3 Up to 0.910 g / cm 3 0.870 g / cm 3 Up to 0.900 g / cm 3 0.870 g / cm 3 Up to 0.890 g / cm 3 0.870 g / cm 3 Up to 0.880 g / cm 3 0.880 g / cm 3 Up to 0.910 g / cm 3 0.880 g / cm 3 Up to 0.900 g / cm 3 0.880 g / cm 3 Up to 0.890 g / cm 3 0.890 g / cm 3 Up to 0.910 g / cm 3 0.890 g / cm 3 Up to 0.900 g / cm 3 Or 0.900g / cm 3 Up to 0.910 g / cm 3 Within the range.

[0061] In some embodiments where the polymer of the sealant layer comprises or is composed of a polyethylene elastomer / plastic, the melt index (I2) of the polyethylene elastomer / plastic can be in the range of 0.50 g / 10 min to 20 g / 10 min. This document discloses and includes all individual values ​​and sub-ranges of the melt index from 0.50 g / 10 min to 20 g / 10 min; for example, the melt index of the polyethylene elastomer / plastic can be from an upper limit of 0.50 g / 10 min, 1.0 g / 10 min, 2.0 g / 10 min, 5.0 g / 10 min, 10.0 g / 10 min, 15 g / 10 min, or 18 g / 10 min to a lower limit of 1.0 g / 10 min, 2.0 g / 10 min, 5.0 g / 10 min, 10.0 g / 10 min, 15 g / 10 min, 18 g / 10 min, 19 g / 10 min, or 20 g / 10 min.

[0062] Commercially available examples of polyethylene elastomers / plasticizers that can be used in sealant layers include those commercially available from Dow Chemical Company (Midland, Michigan) under the name AFFINITY™, including, for example, AFFINITY. TM VP8770G1, AFFINITY TM PF7266, AFFINITY TMPL 1881G and AFFINITY TM PF1140G.

[0063] In some embodiments, the polymer of the sealant layer contains the highest peak melt temperature (T0). m The ionomer is an ionomer of ethylene (meth)acrylic acid copolymer (also referred to herein as "ionomer of ethylene-acrylic acid copolymer") or composed thereof at 108°C or lower. The cation source for the ionomer of ethylene-acrylic acid copolymer can be a monovalent or divalent cation source, including formate, acetate, hydroxide, nitrate, carbonate, and bicarbonate. In some embodiments, the ionomer of ethylene-acrylic acid copolymer may have been treated with one or more cations or cation sources, which may include magnesium, sodium, zinc, or combinations thereof.

[0064] In some embodiments, the ethylene content of the ionomer of the ethylene-acrylic acid copolymer is greater than 50% by weight or greater than 60% by weight, based on the total weight of the ionomer. For example, the ethylene content of the ionomer of the ethylene-acrylic acid copolymer can 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.

[0065] In some embodiments, the melt index (I2) of the ionomer of the ethylene glycol copolymer is 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 glycol copolymers include those named SURLYN. TM Those were purchased from Dow Chemical Company (Midland, Michigan).

[0066] In some embodiments, the polymer of the sealant layer contains the highest peak melt temperature (T0). m The sealant layer is made of polyethylene at or below 108°C. For example, in some embodiments, the polymer of the sealant layer may comprise or be composed of linear low-density polyethylene (LLDPE). The density of linear low-density polyethylene may be less than or equal to 0.930 g / cm³. 3 This document includes and discloses values ​​less than or equal to 0.930 g / cm³. 3 All individual values ​​and sub-ranges; for example, the density of linear low-density polyethylene can range from a lower limit of 0.870 g / cm³. 3 Up to the upper limit of 0.928 g / cm 3 0.925g / cm3 0.920g / cm 3 Or 0.915g / cm 3 This document includes and discloses 0.870 g / cm³. 3 With 0.930 g / cm 3 All individual values ​​and subranges between.

[0067] Commercially available examples of polyethylene that can be used in sealant layers include those from Dow Chemical Company under the name ELITE. TM Those obtained through AT's commercial purchases, including, for example, ELITE TM AT 6202 and ELITE TM AT 6410.

[0068] In addition to at least 70% by weight of the highest peak melting temperature (T) m In addition to polymers that are 108°C or lower, in some embodiments, the sealant layer may also contain at least one additional polymer and / or at least one additive. For example, at least one additional polymer may be selected from the group consisting of polyethylene, ethylene vinyl acetate, ethylene acrylate, or combinations thereof, in an amount less than 30% by weight of the sealant layer. And, for example, at least one additive may be selected from the group consisting of antioxidants, UV stabilizers, heat stabilizers, slip agents, anti-blocking agents, antistatic agents, pigments or colorants, processing aids, crosslinking catalysts, flame retardants, fillers, foaming agents, or combinations thereof, in an amount less than 30% by weight of the sealant layer.

[0069] The first adhesive layer and the second adhesive layer of the second membrane

[0070] The second membrane includes a first adhesive layer between the laminate and the barrier layer. The first adhesive layer can adhere the barrier layer to the laminate. The second membrane also includes a second adhesive layer between the barrier layer and the sealant layer. The second adhesive layer can adhere the barrier layer to the sealant layer. The first adhesive layer and the second adhesive layer may have the same polymer composition or different polymer compositions.

[0071] In some embodiments, the first adhesive layer and / or the second adhesive layer comprises an adhesive resin selected from the group consisting of an anhydride-grafted ethylene-based polymers, ethylene / acrylate copolymers, ethylene-acrylic acid copolymers, and ethylene / vinyl acetate copolymers. Examples of anhydride-grafted portions may include, but are not limited to, maleic anhydride, citrate 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, and o-octahydronaphthalene-2,3-dicarboxylic acid. Anhydride, 2-oxa-1,3-diketospiro(4,4)non-7-ene, bicyclo(2.2.1)hept-5-ene-2,3-dicarboxylic anhydride, tetrahydrophthalic anhydride, norbornen-5-ene-2,3-dicarboxylic anhydride, nadic anhydride, methylnadic anhydride, norbornen enediic anhydride, methyl norbornen enediic anhydride, and x-methyl-bicyclo(2.2.1)hept-5-ene-2,3-dicarboxylic anhydride. In one embodiment, the anhydride graft portion comprises maleic anhydride.

[0072] In some embodiments, the first adhesive layer and / or the second adhesive layer comprises at least one of the following: anhydride-modified linear low-density polyethylene, linear low-density polyethylene, low-density polyethylene, medium-density polyethylene, or high-density polyethylene. For example, in some embodiments, the first adhesive layer and / or the second adhesive layer comprises anhydride-modified linear low-density polyethylene. In some embodiments, the density of the anhydride-modified linear low-density polyethylene is 0.860 g / cm³. 3 Up to 0.935 g / cm 3 Within the scope. This document discloses and includes 0.860 g / cm. 3 Up to 0.935 g / cm 3 All individual values ​​and sub-ranges; for example, the density of anhydride-modified linear low-density polyethylene can be as low as 0.875 g / cm³. 3 Up to 0.935 g / cm 3 0.900g / cm 3 Up to 0.925 g / cm 3 0.910 g / cm 3 Up to 0.935 g / cm 3 0.910 g / cm 3 Up to 0.925 g / cm 3 0.915g / cm 3 Up to 0.935 g / cm 3 Or 0.920 g / cm 3 Up to 0.930 g / cm 3Within the range. In some embodiments, the melt index (I2) of the anhydride-modified linear low-density polyethylene is 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.

[0073] In some embodiments, the first and / or second adhesive layers comprise 0% to 100% by weight of anhydride-modified linear low-density polyethylene, based on the total weight of the adhesive layers in which anhydride-modified linear low-density polyethylene is present. All individual values ​​and sub-ranges from 0% to 100% by weight are disclosed and included herein. For example, in some embodiments, the first and / or second adhesive layers may comprise 10% to 90%, 20% to 80%, 30% to 70%, or 40% to 60% by weight of anhydride-modified linear low-density polyethylene, based on the total weight of the adhesive layers in which anhydride-modified linear low-density polyethylene is present.

[0074] Examples of commercially available anhydride-modified linear low-density polyethylene that can be used in implementations include BYNEL, which is commercially available from Dow Chemical Company (Midland, Michigan). TM Series 4100 resin, such as BYNEL TM 41E710 and BYNEL TM 41E687.

[0075] In some embodiments, the first adhesive layer and / or the second adhesive layer comprises at least one of the following: linear low-density polyethylene, low-density polyethylene, medium-density polyethylene, or high-density polyethylene. For example, in some embodiments, the first adhesive layer and / or the second adhesive layer comprises materials with a density of 0.945 g / cm³. 3 Up to 0.970 g / cm 3 High-density polyethylene within the specified range. This document discloses and includes 0.945 g / cm³. 3 Up to 0.970 g / cm 3 All individual values ​​and sub-ranges; for example, the density of high-density polyethylene can be as low as 0.945 g / cm³. 3 Up to 0.965 g / cm 3 0.950g / cm 3 Up to 0.970 g / cm 3 0.950g / cm 3 Up to 0.965 g / cm 3 0.955g / cm 3 Up to 0.970 g / cm 3 0.955g / cm 3 Up to 0.965 g / cm 3Or 0.955g / cm 3 Up to 0.965 g / cm 3 Within the range.

[0076] In embodiments where high-density polyethylene is present in the first adhesive layer and / or the second adhesive layer, the high-density polyethylene may be ethylene and C3-C4. 12 A copolymer of comonomers. In some embodiments, the first and / or second adhesive layers comprise 0% to 90% by weight of high-density polyethylene based on the total weight of the adhesive layer in which high-density polyethylene is present. All individual values ​​and sub-ranges from 0% to 90% by weight are disclosed and included herein. For example, in some embodiments, the adhesive 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 adhesive layer in which high-density polyethylene is present. In some embodiments, the melt index (I2) of high-density polyethylene can be 0.3 g / 10 min to 10.0 g / 10 min, 0.3 g / 10 min to 7.0 g / 10 min, 0.3 g / 10 min to 5.0 g / 10 min, 0.3 g / 10 min to 4.0 g / 10 min, 0.3 g / 10 min to 3.0 g / 10 min, 0.3 g / 10 min to 2.0 g / 10 min, or 0.3 g / 10 min to 1.5 g / 10 min, or 0.5 g / 10 min to 1.0 g / 10 min.

[0077] Commercially available examples of high-density polyethylene that can be used in adhesive layers include those available from Dow Chemical Company (Midland, Michigan) under the name ELITE. TM 5960G1, ELITE TM AT 6900 and DOWLEX TM Those obtained through a 2006G commercial purchase.

[0078] Extruded web

[0079] The laminate also includes an extrusion mesh layer. The extrusion mesh layer adheres the laminated layers of the second film to the first film. Specifically, the extrusion mesh layer can be formed via extrusion lamination, wherein an extrudate or molten polymer stream exiting the extrusion die is extruded between the laminated layers of the first and second films, such that the extrusion mesh layer adheres the laminated layers to the first film. The laminate can be formed by passing the first and second films together with the extrusion mesh layer between a pair of rollers.

[0080] 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 / vinyltrimethoxysilane 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.

[0081] In some implementations, the highest peak melt temperature (Tm) of the polymer in the extruded web layer is... m The values ​​are 105°C or lower, 104°C or lower, 103°C or lower, 102°C or lower, 101°C or lower, 100°C or lower, 98°C or lower, 96°C or lower, or 94°C or lower, 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, where the highest peak melting temperature (T) is [not specified]. m It can be measured according to the DSC test method described below. Unbound by any theory, it has a maximum peak melt temperature (T0.05) of 105°C or lower compared to conventional LDPE extruded webs (290°C-310°C). m The use of polymers allows for lower coating temperatures (less than 250°C), enhances adhesion, and prevents shrinkage or wrinkling during the formation of the laminate.

[0082] Examples of ethylene / methyl acrylate copolymers suitable for extruded webs include ELVALOY. TM AC 12024S acrylate copolymer is commercially available from Dow Chemical Company (Midland, Michigan). Examples of ethylene / methacrylic acid / acrylate terpolymers suitable for extrusion webs include NUCREL. TM N0427HS is commercially available from Dow Chemical Company (Midland, Michigan). Examples of ethylene / vinyl acetate copolymers suitable for extruded webs include ELVAX. TM 3180 Ethylene-vinyl acetate copolymer is commercially available from Dow Chemical Company (Midland, Michigan).

[0083] additive

[0084] It should be understood that any of the aforementioned layers, including the extruded web layer and the film layer, further includes one or more additives known to those skilled in the art, such as antioxidants, UV stabilizers, heat stabilizers, slip agents, anti-blocking 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 includes at least one of a slip agent or an anti-blocking agent.

[0085] Layers

[0086] In various embodiments, the layered compound of the present invention may have several desired properties. In some embodiments, the layered compound has a thickness between 50 micrometers and 150 micrometers, or alternatively between 75 micrometers and 125 micrometers, or alternatively between 90 micrometers and 110 micrometers.

[0087] In some embodiments, based on the total weight of the laminate, the laminates of the present invention comprise at least 90% by weight of a polyethylene-based polymer, or at least 95% by weight of a polyethylene-based polymer, or at least 99% by weight of a polyethylene-based polymer, or at least 99.5% by weight of a polyethylene-based polymer, or at least 99.9% by weight of a polyethylene-based polymer. Because in some embodiments the laminates comprise at least 90% by weight of an ethylene-based polymer, they are compatible with polyethylene recycling streams.

[0088] In some embodiments, the laminates of the present invention do not conform to laminating adhesives (e.g., solvent-based or water-based laminating adhesives, such as those marketed under the trade name MOR-FREE). TM (solvent-free laminating adhesives based on polyurethane technology), ADCOTE TM (Solvent-based laminating adhesives with a two-component polyurethane system), ROBOND TM(Water-based adhesives having one or two components of an acrylic copolymer) those commercially available from Dow Chemical Company. As used herein, the term "laminate adhesive" refers to a liquid suspension or emulsion of a chemical substance (e.g., polyurethane or polyacrylate) used to bond two surfaces, applied using conventional dry laminators or solvent-free laminators to coat a first substrate with the laminate adhesive, dry to form an adhesive layer, and contact with a second substrate under pressure to form an immediate bond, followed by curing to form a laminate. As used herein, the term "laminate adhesive" does not include "extruded web" (i.e., a layer formed via extrusion lamination, wherein extrudate or molten polymer stream exiting an extrusion die is extruded between membranes). The extruded web described herein can be formed via extrusion lamination without requiring solvent or water drying through a drying tunnel and subsequent curing conditions. The extruded web can utilize the polar-polar interactions (as well as heat and pressure) between the polymer of the membrane and the ethylene copolymer of the extruded web to form a bond between the first and second membranes.

[0089] The laminate of the present invention may have one or more of the following properties: a bond strength of at least 2.00 N / 25 mm; less than 3.00 cm. 3 / day / m 2 OTR; less than 5.50g / day / m 2 WVTR; heat seal initiation temperature of less than 110°C at 5N; seal strength of at least 7.0N / 25mm at 120°C; heat tack initiation of less than 85°C at 1N; heat tack strength of at least 2.00N / 25mm at 110°C; and zero percentage (0%) shrinkage at temperatures ranging from 70°C to 120°C.

[0090] Products

[0091] Embodiments of the present invention also provide articles formed from any of the laminates of the present invention described herein. Examples of such articles may include packaging, flexible packaging, bags, and pouches. In some embodiments, the packaging of the present invention may include liquids, powders, food, or other articles. In view of the teachings herein, the articles and packaging of the present invention can be formed from the laminates disclosed herein using techniques known to those skilled in the art.

[0092] Methods for manufacturing layered compounds

[0093] The laminates of the present invention can be manufactured based on the teachings disclosed herein using methods known to those skilled in the art. For example, a method for manufacturing a laminate as disclosed herein may include: (a) providing a first film comprising at least 95% by weight polyethylene; (b) providing a second film comprising: (i) a laminate layer comprising an ethylene copolymer selected from the group consisting of: 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 elastomer / plasticizer, and combinations thereof; (ii) a sealant layer comprising at least 70% by weight of the highest peak melt temperature (T0). m (iii) a polymer at 108°C or lower; (iv) a barrier layer comprising an ethylene-vinyl alcohol copolymer; (v) a first adhesive layer located between the laminated layer and the barrier layer; and (v) a second adhesive layer located between the barrier layer and the sealant layer; and (c) extruding a web layer comprising a polymer between the laminated layers of the first and second films, the polymer comprising at least one of the following: ethylene / methyl acrylate copolymer, ethylene / butyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / vinyltrimethoxysilane 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 and second films together with the extruded web layer between a pair of rollers to form a laminate.

[0094] In an embodiment of the method for manufacturing a laminate, which includes the step of passing a first and a second film together with an extruded web 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.

[0095] Test methods

[0096] density

[0097] Density was measured according to ASTM D792 and expressed in grams per cubic centimeter. 3 (g / cm 3 )express.

[0098] Melt index (I2)

[0099] Melt index (I2) was measured at 190°C and 2.16 kg according to ASTM D-1238. Values ​​are reported in g / 10 min, corresponding to the number of grams eluted per 10 min.

[0100] Oxygen permeability (OTR)

[0101] Oxygen permeability (OTR) was measured using a Mocon Ox-Tran 2 / 21 according to ASTM D3985. The sample was dried at 23°C, 100% O2 gas, 0% RH, and 50 cm⁻¹. 2 Tested at sample size. Values ​​are expressed in cm. 3 / day / m 2 Report.

[0102] Water vapor transmission rate (WVTR)

[0103] Water vapor transmission rate (WVTR) was measured using a Mocon Permatran-W 3 / 34 & 3 / 60 according to ASTM F1249. The samples were subjected to temperatures of 37.8°C, 100% RH, and 50 cm⁻¹. 2 Tested at sample size. Values ​​are expressed in g / day / m³. 2 Report.

[0104] Hot tack initiation and hot tack strength

[0105] Hot tack testing was conducted using a J&B Hot Tack Tester 4000, with a seal width of 25 mm, a sealing time of 0.5 s, and a sealing pressure of 0.275 N / mm². 2 (40psi) and the hot tack pull speed is 200mm / s. Hot tack initiation is reported as the minimum temperature in degrees Celsius at which 1 Newton force is achieved. Hot tack strength is measured in Newtons / 25mm (N / 25mm).

[0106] Heat sealing starting temperature and sealing strength

[0107] To determine the heat seal initiation temperature (HSIT) and seal strength, samples were sealed using a J&B Hot Tack 4000 tester. The sample width was 25 mm, the residence time was 0.5 seconds, and the sealing pressure was 0.275 N / mm². 2 The heat-sealed sample was conditioned for 24 hours and then measured using a Zwick tensile tester equipped with a 200N pressure sensor at a tensile speed of 500 mm / min. HSIT is reported as the minimum temperature at which 5 Newtons of force is achieved in degrees Celsius. Seal strength is reported in N / 25 mm.

[0108] Shrinkage

[0109] Shrinkage (%) is obtained by measuring the length and width of the sealed area in the longitudinal (MD) and transverse (TD) directions after the films are heat-sealed together and calculating the percentage change compared to the width of the sealing strip, which can range from 1 mm to 15 mm. Standard heat-sealing machines (including PULSA pulse sealers or J&B heat seal testers) with accurate and adjustable temperature controllers can be used. Sealing conditions include jaw pressure (40-80 psi or 0.275-0.552 N / mm). 2 The dwell time (0.1-1.5 seconds) and sealing temperature (60-150°C) window are also relevant, depending on the packaging speed, with typical conditions for high-speed packaging machines being a jaw pressure of 40 psi (0.275 N / mm). 2 The dwell time is 0.5 seconds.

[0110] Bond strength

[0111] Bond strength was measured using a Zwick tensile testing machine at a tensile speed of 250 mm / min and with a 25 mm wide strip. The tensile testing machine is equipped with a clamp (sample held in a T-shape) to hold the ends of partially delaminated or partially peeled samples in place before they are pulled apart. The upper clamp, connected to the crosshead, is driven in the tensile direction to measure the required force or bond strength between two adjacent layers of a multilayer sample. The maximum and average force results were calculated from five measurements and recorded in Newtons (N / 25 mm strip).

[0112] Peak melting temperature (Tm)

[0113] Differential scanning calorimetry (DSC) was used to measure the melting and crystallization behavior of polymers over a wide temperature range. For example, this analysis was performed using a TA Instruments Q1000DSC equipped with a refrigerated cooling system (RCS) and an autosampler. The instrument was first calibrated using the software calibration wizard. A baseline was first obtained by heating the individual cells from -80°C to 280°C, with no sample in the DSC aluminum dish. Then, a sapphire standard was used as instructed by the calibration wizard. Next, a fresh indium sample of 1 to 2 mg was analyzed by heating the standard sample to 180°C, cooling it to 120°C at a cooling rate of 10°C / min, and then holding the standard sample isothermally at 120°C for 1 minute. The standard sample was then heated from 120°C to 180°C at a heating rate of 10°C / min. Then, the indium standard sample was determined to have a heat of fusion (Hf) of 28.71 ± 0.50 J / g and an initial melt temperature of 156.6 °C ± 0.5 °C. The sample was then analyzed using a DSC instrument.

[0114] During testing, a nitrogen purge flow of 50 ml / min was used. Each sample was melt-pressed into a thin film at approximately 175 °C; the molten sample was then cooled to room temperature (approximately 25 °C). Film samples were formed by pressing 0.1 to 0.2 g of sample at 1,500 psi for 30 seconds to form a film with a thickness of 0.1 to 0.2 mils. 3–10 mg of sample with a diameter of 6 mm was extracted from the cooled polymer, weighed, placed in a light aluminum dish (approximately 50 mg), and capped. Analysis was then performed to determine its thermal properties.

[0115] The thermal behavior of a sample was determined by generating a heat flow versus temperature curve through steep inclines and declines in sample temperature. First, the sample was rapidly heated to 180°C and held isothermally for five minutes to remove its thermal history. Next, the sample was cooled to -40°C at a cooling rate of 10°C / min and held isothermally at -40°C for five minutes. Then, the sample was heated to 150°C at a heating rate of 10°C / min (this is the "second heating" homogenization). The cooling and heating curves were recorded. The cooling curve was analyzed by setting a baseline endpoint from the start of crystallization to -20°C. The heating curve was analyzed by setting a baseline endpoint from -20°C to the end of melting. The measured value is the peak melting temperature (T0). m ), highest peak crystallization temperature (T) c ), initial crystallization temperature (T) c The initial melting temperature (Hf) and heat of fusion (in Joules per gram) are used to calculate the crystallinity % of polyethylene samples using the following formulas: Crystallinity % for PE = ((Hf) / (292 J / g)) × 100, and the crystallinity % for polypropylene samples using the following formula: Crystallinity % for PP = ((Hf) / 165 J / g)) × 100. The heat of fusion (Hf) and the highest peak melting temperature are reported from the second thermal curve. The highest peak crystallization temperature and the initial crystallization temperature are determined based on the cooling curve.

[0116] Some embodiments of the present invention will now be described in detail in the following examples.

[0117] Example

[0118] Materials and membranes used

[0119] The following materials are included in the example layered compounds discussed below.

[0120] ELITE TM 5960G1 is a reinforced polyethylene resin with a density of 0.962 g / cm³. 3 It has a melt index (I2) of 0.85 g / 10 min and is commercially available from Dow Chemical Company (Midland, Michigan).

[0121] DOW TM LDPE 450E is a low-density polyethylene with a density of 0.923 g / cm³. 3 It has a melt index (I2) of 2.0 g / 10 min and is commercially available from Dow Chemical Company (Midland, Michigan).

[0122] BYNEL TM 22E780 is an ethylene / acrylate copolymer resin with a density of 0.94 g / cm³. 3 Furthermore, the melt index (I2) is 2 g / 10 min, and it is commercially available from Dow Chemical Company (Midland, Michigan).

[0123] ELVAX TM 3180 ("ELVAX") is an ethylene / vinyl acetate copolymer with a maximum peak melting temperature (T0). m The temperature is 70℃, and the density is 0.95 g / cm³. 3 It has a melt index (I2) of 25 g / 10 min and is commercially available from Dow Chemical Company (Midland, Michigan).

[0124] BYNEL TM 41E710 is a linear low-density polyethylene with a density of 0.922 g / cm³. 3 It has a melt index (I2) of 2.7 g / 10 min and is commercially available from Dow Chemical Company (Midland, Michigan).

[0125] EVALH171B is a 38 mol% ethylene-vinyl alcohol copolymer with a density of 1.17 g / cm³. 3 Furthermore, the melt index (I2) is 1.7 g / 10 min, and it is commercially available from Kuraray Corporation (Tokyo, Japan).

[0126] SURLYN TM 1707 is an ionomer of ethylene glycol copolymer neutralized with a sodium cation source, and its highest peak melting temperature (T) m The temperature is 92℃ and the density is 0.95 g / cm³. 3 It has a melt index (I2) of 0.9 g / 10 min and is commercially available from Dow Chemical Company (Midland, Michigan).

[0127] AFFINITY TM PF 7266 is a polyethylene elastomer / plasticizer with a maximum peak melt temperature (T0). m The temperature is 76℃, and the density is 0.885 g / cm³. 3 It has a melt index (I2) of 2.5 g / 10 min and is commercially available from Dow Chemical Company (Midland, Michigan).

[0128] NUCREL TM N0427HS ("NUCREL") is an ethylene / methacrylic acid / acrylate terpolymer with a density of 0.94 g / cm³. 3 It has a melt index (I2) of 27 g / 10 min and is commercially available from Dow Chemical Company (Midland, Michigan).

[0129] ELVALOY TM AC12024S ("ELVALOY") is an ethylene / methyl acrylate copolymer with a maximum peak melting temperature (T0). m The temperature is 88℃, and the density is 0.944 g / cm³. 3 It has a melt index (I2) of 20 g / 10 min and is commercially available from Dow Chemical Company (Midland, Michigan).

[0130] AFFINITY TM PL 1881G is a polyethylene elastomer / plasticizer with a maximum peak melting temperature (T0). m The temperature is 100℃, and the density is 0.904 g / cm³. 3 It has a melt index (I2) of 1.0 g / 10 min and is commercially available from Dow Chemical Company (Midland, Michigan).

[0131] POLYBATCH CE505 is a lubricating masterbatch that is commercially available from LyondellBasell (Houston, TX).

[0132] POLYBATCH AB5 is an anti-blocking masterbatch that is commercially available from LyondellBasell (Houston, Texas).

[0133] CONPOL TM 13B is an anti-blocking masterbatch, commercially available from Dow Chemical Company (Midland, Michigan).

[0134] CONPOL TM 20S1 is a lubricating fluid masterbatch that is commercially available from Dow Chemical Company (Midland, Michigan).

[0135] ADCOTE TM 545S / Co-reactant F854 is a solvent-based two-component polyurethane adhesive commercially available from Dow Chemical Company (Midland, Michigan).

[0136] BOPP substrate (“BOPP”) is a printed biaxially oriented film that is treated with 36 dynes and has an 18-micron specification and a 2-micron printing thickness.

[0137] PE substrate ("PE") is a multilayer five-layer film with a thickness of 25 micrometers and a layer structure: (1) 100% ELITE TM 5960G1; (2) 100% ELITE TM 5960G1; (3) 100% ELITE TM 5960G1; (4) 100% ELITE TM 5960G1; (5) 100% DOW TM LDPE 450E, of which (1) ELITE TM 5960G1 points to the outer side of the laminate. Films are formed on a Collin 5-layer casting co-extrusion production line with 4 extruders, configuration: A / B / C / B / D; layer ratio: 1 / 1 / 1 / 1 / 1; melt temperature of each extruder: 250-260℃; through a hanger-shaped die; total throughput: 8 kg / h; linear velocity: 21.5 m / min.

[0138] The laminates named Examples 1-6 and Comparative Examples 1-6 of the present invention are formed with a "printed layer-mesh-ABCBD" structure. "Printed layer" corresponds to the PE substrate (first film) of the present invention and the BOPP substrate of the comparative examples. "ABCBD" corresponds to a five-layer multilayer film (second film), wherein "A" is a laminating layer, "B" is an adhesive layer, "C" is a barrier layer, and "D" is a sealant layer. A five-layer "ABCBD" multilayer film was formed on a Collin 5-layer blow molding co-extrusion line with the following parameters: target film thickness: 55 micrometers; extruders: 4 extruders; layer configuration: ABCBD; additives: layer A = 5000 ppm antiblocking agent, and layer D = 5000 ppm lubricant and 5000 ppm antiblocking 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 plane width (mm): 235. The "mesh" corresponds to the extruded mesh layer, where the polymer extrudate is extruded via extrusion lamination between the "printed layer" and the "ABCBD" film. For the extrusion lamination process, the film was corona treated with a corona power of 2 kW to approximately 40-42 dynes. The extruder start-up conditions for the extruded mesh layer are set as follows: Extruder temperature: 120 / 140 / 170 / 170℃; Joint / connector: 170 / 170℃; Die: 170℃. The final extrusion lamination conditions are as follows: Melt temperature 200℃, screw speed 16 rpm, linear speed 6 m / min, air gap 100 mm. The target extruded mesh layer thickness is 20 micrometers (or 20 gsm). The extruded mesh layer is extruded between the "printed layer" and the "ABCBD" film, and the resulting structure passes through a pair of rollers to form a laminate.

[0139] Comparative Examples 7 and 8 were not formed by extrusion lamination with an extruded web, but rather by hot roller lamination with a laminating adhesive. For these embodiments, ADCOTE was applied at a coating weight of 3-3.5 gsm. TM 545S / co-reactant F854 is used to laminate the “printed layer” substrate onto layer “A” of the multilayer film. The example is cured at room temperature (25°C) for two days and then hot-rolled on ChemInstruments #007416 at 75°C, 60 psi pressure and 1.66 m / min speed.

[0140] Table 1 below provides the structure and composition of the layered compound examples, Examples 1-6 of the present invention, and Comparative Examples 1-8.

[0141] Table 1 - Structure and Composition of Layered Compounds

[0142]

[0143]

[0144] *Except for 96% BYNEL TM In addition to 22E780, Layer A contains 4% CONPOL TM 13B.

[0145] **Besides 80% AFFINITY TM In addition to PF 7266, layer D contains 10%. CE505 and 10% AB5.

[0146] *** 93.5% SURLYN TM In addition to 1707, layer D contains 4% CONPOL TM 13B and 2.5% CONPOL TM 20S1.

[0147] The thickness of the laminate, oxygen permeability (OTR), water vapor transmission rate (WVTR), and bond strength of the embodiments were measured. Table 2 provides the results. The embodiments of the present invention maintain OTR and WVTR values ​​and generally have bond strength comparable to or higher than that of the comparative examples, which are incompatible with polyethylene recycle flow. Furthermore, those skilled in the art will understand that the OTR of the laminate can be adjusted based on the thickness of the barrier layer and the ethylene content of the EVOH (i.e., generally, a thicker barrier layer or a lower ethylene content results in a lower achievable OTR value).

[0148] Table 2 - Thickness, Bond Strength, OTR and WVTR

[0149]

[0150] *The BOPP film used for the comparative example is a printed BOPP, wherein the printing ink side is laminated to the five-layer film using a solvent-based laminating adhesive, and thus the bond strength is measured from the printing ink side of the BOPP to the five-layer film.

[0151] Measure the heat seal initiation temperature (HSIT), heat seal strength, and hot tack initiation temperature and hot tack strength at 1 Newton. Figure 1 The heat seal strength curves of comparative examples 1, 3, 5 and 7 and embodiments 1, 3 and 5 of the present invention are shown. Figure 2 The thermal viscous strength curves of Comparative Examples 2, 4, 6, and 8 and Examples 2, 4, and 6 of the present invention are shown. Table 3 provides the results for the comparative examples and the examples of the present invention, wherein AFFINITY TM PF 7266 is part of the sealant layer / D layer. Table 4 provides results for comparative examples and embodiments of the present invention, wherein SURLYN TM1707 is part of the sealant layer / D layer. From Tables 3 and 4, embodiments of the invention demonstrate ideal or maintained low hot tack onset temperature and low HSIT. Embodiments of the invention also achieve desired, maintained, or improved seal strength performance.

[0152] Table 3 - HSIT, sealing strength, hot tack initiation, and heat resistance of Comparative Examples 1, 3, 5, and 7 and Examples 1, 3, and 5 of the present invention. Viscosity .

[0153]

[0154] Table 4 - HSIT, sealing strength, hot tack initiation, and heat resistance of Comparative Examples 2, 4, 6, and 8 and Examples 2, 4, and 6 of the present invention. Viscosity .

[0155]

[0156] *Not measured.

[0157] The shrinkage rate (%) of the heat-sealed area of ​​the embodiments was measured at 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, and 130°C. No embodiments showed shrinkage rates at 70°C, 80°C, 90°C, 100°C, 110°C, or 120°C in either the longitudinal (MD) or transverse (TD) direction. The shrinkage rates (%) of the embodiments are reported in Table 5. Although some embodiments of the invention show shrinkage at 130°C compared to comparative examples, the performance of the embodiments of the invention is equivalent to or similar to that of the comparative examples in a temperature range of approximately 70°C–120°C, providing a wide heat-sealing window of at least 50°C.

[0158] Table 5 - Shrinkage values ​​of embodiments and comparative examples of the present invention

[0159]

[0160] *Sealing strip dimensions: 0.5cm (MD direction) × 2.5cm (TD direction).

[0161] Unless expressly excluded or otherwise limited, every document cited herein (if any), including any cross-referenced or related patent or application and any patent application or patent claiming priority or benefit to this application, is hereby incorporated in its entirety by reference. No reference to any document acknowledges it as prior art to any invention disclosed or claimed herein, or as teaching, indicating, or disclosing any such invention, alone or in combination with any other referenced document. Furthermore, in the event of any conflict between the meaning or definition of any term in this document and the meaning or definition of the same term in any document incorporated by reference, the meaning or definition given to the term in this document shall prevail.

[0162] While specific embodiments of the invention have been described and illustrated, it will be apparent to those skilled in the art that many other changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, it is intended that all such changes and modifications falling within the scope of the invention be covered in the appended claims.

Claims

1. A layered compound comprising: (a) A first membrane comprising at least 95% by weight polyethylene; (b) a second membrane, the second membrane comprising: (i) A laminate comprising an ethylene copolymer selected from the group consisting of: 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 elastomer / plasticizer, and combinations thereof; (ii) A sealant layer, wherein the sealant layer contains at least 70% by weight of the highest peak melt temperature T. m Polymers with a temperature of 108°C or lower; (iii) A barrier layer comprising an ethylene vinyl alcohol copolymer; (iv) a first adhesive layer, wherein the first adhesive layer is located between the laminate and the barrier layer; and (v) a second adhesive layer, the second adhesive layer being located between the barrier layer and the sealant layer; and (c) Adhere the laminate of the second film to the extruded web layer of the first film, the extruded web layer comprising at least one of the following: ethylene / methyl acrylate copolymer, ethylene / butyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / vinyltrimethoxysilane copolymer, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / methacrylic acid copolymer, maleic anhydride modified polyethylene, ethylene-acid terpolymer, ethylene / methacrylic acid / acrylate terpolymer. The laminates therein do not contain laminating adhesives.

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

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

4. The laminate according to claim 1 or 2, wherein the laminate further comprises at least one of the following: linear low-density polyethylene, medium-density polyethylene, and high-density polyethylene.

5. The laminate according to claim 1 or 2, wherein the polymer in the sealant layer has a peak melting temperature T. m Ionomers of ethylene-based copolymers at 100°C or lower, or polyethylene elastomers / plastics.

6. The laminate according to claim 1 or 2, wherein the ethylene copolymer of the laminate is an ethylene / acrylate copolymer.

7. The laminate according to claim 1 or 2, wherein the first membrane is a longitudinally oriented membrane.

8. The laminate according to claim 1 or 2, wherein the first membrane is a biaxially oriented membrane.

9. The layered compound according to claim 1 or 2, wherein the thickness of the layered compound is between 50 micrometers and 150 micrometers.

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