Laminate having multilayer films oriented in the machine direction

Abstract

This disclosure provides a laminate. In one embodiment, the laminate comprises a first mechanically oriented (1MDO) multilayer film. The 1MDO multilayer film comprises a skin layer comprising (a) (i) a skin layer (SL) first ethylene / α-olefin copolymer having a density of 0.870 g / cc to 0.920 g / cc, and (ii) an optional skin layer (SL) second ethylene / α-olefin copolymer having a density of 0.900 g / cc to 0.980 g / cc. The 1MDO multilayer film comprises (b) a first intermediate layer in direct contact with the skin layer. The first intermediate layer comprises (i) a first intermediate layer (FIL) first ethylene / α-olefin copolymer having a density of 0.940 g / cc to 0.980 g / cc, and (ii) a first intermediate layer (FIL) second ethylene / α-olefin copolymer having a density of 0.916 g / cc to 0.980 g / cc. The 1MDO multilayer film includes a (c) core layer in direct contact with the first intermediate layer (b). The core layer (c) comprises (i) a core layer (CL) first ethylene / α-olefin copolymer having a density of 0.915 g / cc to 0.980 g / cc. The 1MDO multilayer film includes a (d) second intermediate layer in direct contact with the core layer. The second intermediate layer may contain an ethylene-based polymer. The 1MDO multilayer film includes an (e) inner layer in direct contact with the second intermediate layer. The inner layer contains an ethylene-based polymer. The laminate includes a second mechanically oriented (2MDO) film and an adhesive layer between the 1MDO multilayer film and the 2MDO film.

Description

[Technical Field]

[0001] This disclosure relates to a laminate, and more specifically to a laminate comprising multilayer films oriented in the machine direction. [Background technology]

[0002] Polyolefin films are widely used in flexible packaging, both as standalone packaging and as lamination films. In efforts to improve recyclability and expand sustainability, the flexible packaging market is moving towards single-material solutions based on ethylene-based polymers (commonly referred to as "polyethylene"). As such, efforts continue to downgauge polyethylene films in search of thinner, stronger, stiffer, and lower-cost solutions for flexible packaging.

[0003] Machine-direction oriented (MDO) films are one method for downgauging polyethylene and providing the film with rigidity and optical properties. However, when oriented in the machine direction, polyethylene-based films may have weaker tear strength in the machine direction due to the unidirectional orientation. Therefore, polyethylene in films is often blended with one or more non-polyethylene resins, or polyethylene films are often laminated with another non-polyethylene film (e.g., polyethylene terephthalate, polypropylene film) to achieve the desired physical film properties. However, films containing polyethylene and non-polyethylene resins may be difficult or impossible to recycle. Similarly, oriented polypropylene laminates with a cast polypropylene structure may offer some desirable properties in packaging, but such laminates are not easily recyclable.

[0004] As a result, there is a recognized need in this technical field for polyethylene-containing laminates and MDO multilayer films that can be recycled and provide tear strength, rigidity, optical properties, and heat sealability suitable for flexible packaging applications. [Overview of the project]

[0005] This disclosure provides a laminate. In one embodiment, the laminate comprises a first machine direction oriented (1MDO) multilayer film. The 1MDO multilayer film comprises a skin layer comprising (a) (i) a skin layer (SL) of a first ethylene / α-olefin copolymer having a density of 0.870 g / cc to 0.920 g / cc, and (ii) an optional skin layer (SL) of a second ethylene / α-olefin copolymer having a density of 0.900 g / cc to 0.980 g / cc. The 1MDO multilayer film comprises (b) a first intermediate layer in direct contact with the skin layer. The first intermediate layer comprises (i) a first intermediate layer (FIL) containing a first ethylene / α-olefin copolymer having a density of 0.940 g / cc to 0.980 g / cc, and (ii) a second first intermediate layer (FIL) containing a second ethylene / α-olefin copolymer having a density of 0.916 g / cc to 0.980 g / cc. The 1MDO multilayer film comprises (c) a core layer in direct contact with the first intermediate layer (b). The core layer (c) comprises (i) a core layer (CL) containing a first ethylene / α-olefin copolymer having a density of 0.915 g / cc to 0.980 g / cc. The 1MDO multilayer film comprises (d) a second intermediate layer in direct contact with the core layer. The second intermediate layer may contain an ethylene-based polymer. The 1MDO multilayer film comprises (e) an inner layer in direct contact with the second intermediate layer. The inner layer contains an ethylene-based polymer. The laminate includes a second machine direction oriented (2MDO) film and an adhesive layer between the 1MDO multilayer film and the 2MDO film.

[0006] definition Any reference to the periodic table refers to the version published by CRC Press, Inc., 1990–1991. References to element groups in this table refer to a new notation for numbering groups.

[0007] For the purposes of U.S. patent practice, the content of any referenced patent, patent application, or publication, in particular with respect to the disclosure of definitions (to the extent that it does not conflict with any definitions specifically provided in this disclosure), is incorporated by reference in its entirety (or its corresponding U.S. version is incorporated by reference in this way).

[0008] Numerical ranges disclosed herein include all values ​​from the lower limit to the upper limit (including the lower and upper limits). In the case of ranges that include explicit values ​​(e.g., 1, or 2, or 3-5, or 6, or 7), any subrange between any two explicit values ​​is included (for example, the above range of 1-7 includes subranges such as 1-2, 2-6, 5-7, 3-7, 5-6, etc.).

[0009] Unless otherwise stated, implied by the context, or customary in the art, all parts and percentages are based on weight, and all test methods are current as of the filing date of this disclosure.

[0010] The terms “blend” or “polymer blend” as used refer to a mixture of two or more polymers. A blend may or may not be miscible (not phase-separated at the molecular level). A blend may or may not be phase-separated. A blend may or may not contain one or more domain configurations determined by transmission electron spectroscopy, light scattering, X-ray scattering, and other methods well known in the art. A blend may be influenced by the physical mixing of two or more polymers at a macro level (e.g., melt blending or formulation of resins) or at a micro level (e.g., simultaneous formation in the same reactor).

[0011] The term "composition" refers to a mixture of materials that constitute a composition, as well as reaction products and decomposition products formed from the materials of the composition.

[0012] The terms “comprising,” “including,” and “having,” and their derivatives, are not intended to exclude the existence of any additional components, processes, or procedures, whether or not they are specifically disclosed. To avoid any doubt, all compositions claimed through the use of the term “comprising” may, unless otherwise stated, include any additional additives, adjuvants, or compounds, whether or not they are polymers. In contrast, the term “essentially consisting of” excludes any other components, processes, or procedures from the scope of any prior description, except those not essential for operability. The term “consisting of” excludes any components, processes, or procedures that are not specifically described or enumerated. The term “or” refers to the enumerated members individually and in any combination, unless otherwise specified.

[0013] The terms "direct contact," "to be in direct contact," or "to be in direct contact," or similar terms, refer to a layer configuration in which the first layer is located immediately next to the second layer, and there is no intervening layer or structure between the first and second layers.

[0014] "Polyethylene" or "ethylene-based polymer" is a polymer containing more than half (over 50 mol%) of units derived from ethylene monomers. This includes polyethylene homopolymers or copolymers (meaning units derived from two or more comonomers). Common forms of polyethylene known in the art include low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), ultra-low-density polyethylene (ULDPE), single-site catalyst linear low-density polyethylene (m-LLDPE) which includes 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). The following description may help in understanding the differences between some of these different polyethylene resins.

[0015] 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 viscosity of 0.916 g / cm³. 3 ~0.935g / cm 3 It has a density within the range.

[0016] 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, pyridylamine 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 containing fewer long-chain branches than LDPEs, as further defined in U.S. Patents 5,272,236, 5,278,272, 5,582,923, and 5,733,155; homogeneously branched linear ethylene polymer compositions such as those in U.S. Patent 3,645,992; heterogeneously branched ethylene polymers such as those prepared according to the process disclosed in U.S. Patent 4,076,698; and / or blends thereof (such as those disclosed in U.S. Patents 3,914,342 or 5,854,045). LLDPEs can be produced using any type of reactor or reactor configuration via gas-phase, solution-phase, or slurry polymerization, or any combination thereof.

[0017] The term "MDPE" refers to 0.926 g / cm³ 3 ~0.935g / cm 3 This refers to polyethylene having a density of . "MDPE" is typically produced using chromium or Ziegler-Natta catalysts, or single-site catalysts including, but not limited to, substituted mono- or bis-cyclopentadienyl catalysts (typically referred to as metallocenes), geometrically constrained catalysts, pyridylamine catalysts, phosphineimine catalysts, and polyvalent aryloxyether catalysts (typically referred to as bisphenylphenoxy), and typically has a molecular weight distribution ("MWD") greater than 2.5.

[0018] The term "HDPE" generally refers to polyethylene prepared using single-site catalysts including, but not limited to, Ziegler-Natta catalysts, chromium catalysts, or substituted mono- or bis-cyclopentadienyl catalysts (typically referred to as metallocenes), geometrically constrained catalysts, pyridylamine catalysts, phosphine imine catalysts, and polyvalent aryloxy ether catalysts (typically referred to as bisphenol phenoxy), having a density of from about 0.935 g / cm 3 to a maximum of about 0.980 g / cm 3 .

[0019] The term "ULDPE" generally refers to polyethylene prepared using single-site catalysts including, but not limited to, Ziegler-Natta catalysts, chromium catalysts, or substituted mono- or bis-cyclopentadienyl catalysts (typically referred to as metallocenes), geometrically constrained catalysts, pyridylamine catalysts, phosphine imine catalysts, and polyvalent aryloxy ether catalysts (typically referred to as bisphenol phenoxy), having a density of 0.855 to 0.912 g / cm 3 . ULDPE includes, but is not limited to, polyethylene (ethylene-based) plastomers and polyethylene (ethylene-based) elastomers. Polyethylene (ethylene-based) elastomer plastomers generally have a density of 0.855 g / cm 3 to 0.912 g / cm 3 .

[0020] As used herein, the term "ethylene monomer" or "ethylene" refers to a chemical unit having two carbon atoms with a double bond therebetween and each carbon bonded to two hydrogen atoms, which polymerizes with other such chemical units to form an ethylene-based polymer composition.

[0021] A "heteroatom" is an atom other than carbon and hydrogen. A heteroatom can be a non-carbon atom from Groups IV, V, VI, and VII of the periodic table. Non-limiting examples of heteroatoms include F, N, O, P, B, S, and Si.

[0022] "Hydrocarbon" is a compound containing only hydrogen atoms and carbon atoms. "Hydrocarbonyl" (or "hydrocarbonyl group") is a hydrocarbon having a valence (typically monovalent). Hydrocarbons can have a linear structure, a cyclic structure, or a branched structure.

[0023] As used herein, a "laminate" includes a first film structure, a second film structure, and an adhesive layer between the first film structure and the second film structure. The first film structure and / or the second film structure can be a single-layer film or a multilayer film.

[0024] A "machine direction oriented film" or "MDO film" is a film stretched (or oriented) in the machine direction at a draw ratio of 4:1 to 12:1. An MDO film is a uniaxially oriented film. The stretching or orientation of the film is performed by a machine direction orientation roll, via a width expansion, or via meshing gears, whereby the film is ring-rolled or otherwise gradually stretched in the machine direction below the melting point of the film.

[0025] A "multilayer structure" is a structure having two or more layers. For example, a multilayer structure can have 2, 3, 4, 5, or more layers. A multilayer structure can be described as having layers designated by letters. For example, a three-layer structure having a core layer B and two outer layers A and C can be shown as A / B / C.

[0026] "Olefin" is an unsaturated aliphatic hydrocarbon having a carbon-carbon double bond.

[0027] An "olefin polymer" (alternatively referred to as "polyolefin") is a polymer that contains (based on the total amount of polymerizable monomers) a majority molar percentage of polymerized olefin monomers and optionally can contain at least one comonomer. Non-limiting examples of olefin polymers include ethylene polymers and propylene polymers.

[0028] As used herein, the terms “polymer” or “polymer material” refer to compounds prepared by polymerizing monomers, whether of the same or different types, providing multiple and / or repeating “units” or “mer units” that constitute the polymer in a polymeric form. Thus, the general term polymer encompasses the term homopolymer, which is typically used to refer to polymers prepared from only one type of monomer, and the term copolymer, which is typically used to refer to polymers prepared from at least two types of monomers. It also encompasses all forms of copolymers, such as random and block. The terms “ethylene / α-olefin polymer” and “propylene / α-olefin polymer” refer to the aforementioned copolymers and one or more additional polymerizable α-olefin monomers prepared by polymerizing ethylene or propylene, respectively. Polymers are often referred to as being “made from” one or more specific monomers, “based on” a specific monomer or type of monomer, or “containing” a specific monomer content, but it should be noted that in this context, the term “monomer” is understood to refer to the polymerized residue of a specific monomer and not to the non-polymerized species. In general, polymers in this specification are referred to as "units," which are the polymerized forms of the corresponding monomers.

[0029] A “propylene polymer” (replaceable with “polypropylene”) is a polymer containing more than 50 mol percent of polymerized propylene monomer (based on the total amount of polymerizable monomers) and may optionally contain at least one comonomer. Propylene polymers include propylene homopolymers and propylene copolymers (meaning units derived from propylene and one or more comonomers). The terms “propylene polymer” and “polypropylene” may be used interchangeably. A non-limiting example of a propylene polymer (polypropylene) is at least one C2 or C4-C2 polymer. 10This is a propylene / α-olefin copolymer having an α-olefin comonomer. [Modes for carrying out the invention]

[0030] This disclosure provides a laminate. In one embodiment, the laminate is The present invention comprises a first mechanically oriented multilayer (1MDO) film bonded to a second mechanically oriented (2MDO) film. The 1MDO multilayer film comprises (a) a skin layer ("SL"), (b) a first intermediate layer ("FIL"), (c) a core layer ("CL"), (d) a second intermediate layer ("SIL"), and (e) an interior layer ("IL"). The skin layer (a) comprises (i) an SL first ethylene / α-olefin copolymer having a density of 0.870 g / cc to 0.920 g / cc, and (ii) an optional SL second ethylene / α-olefin copolymer having a density of 0.900 g / cc to 0.980 g / cc. The first intermediate layer (b) is in direct contact with the skin layer (a), and the first intermediate layer (b) contains (i) a FIL first ethylene / α-olefin copolymer having a density of 0.940 g / cc to 0.980 g / cc, and (ii) a FIL second ethylene / α-olefin copolymer having a density of 0.916 g / cc to 0.980 g / cc. The core layer (c) is in direct contact with the first intermediate layer (b). The core layer (c) contains (i) a CL first ethylene / α-olefin copolymer having a density of 0.900 g / cc to 0.920 g / cc. The second intermediate layer (d) is in direct contact with the core layer (c). The second intermediate layer (d) contains an ethylene-based polymer. The inner layer (e) is in direct contact with the second intermediate layer (d). The inner layer (e) contains an ethylene-based polymer.

[0031] It is understood that while a 1MDO film is oriented in the machine direction, it can also be further oriented in the transverse (or lateral) direction and may be a biaxially oriented film.

[0032] Each of the following terms and their respective abbreviations are used interchangeably: skin layer (or SL), first intermediate layer (or FIL), core layer (or CL), second intermediate layer (or SIL), and inner layer (or IL). Each ethylene polymer (and / or each ethylene / α-olefin copolymer) is a hydrocarbon. The ethylene polymers disclosed herein are identified by position, i.e., by the film layer in which the ethylene polymer resides. It is understood that an ethylene polymer present in the first layer (i.e., present in the skin layer or SL) may or may not be the same ethylene polymer present in the second layer (i.e., present in the core layer or CL). The term “different” means, with respect to an ethylene polymer (or ethylene / α-olefin copolymer), that the ethylene polymer has at least one property or property value that is not similar to the corresponding property in another ethylene polymer. Non-limiting examples of ethylene polymer (or ethylene / α-olefin copolymer) properties include comonomer type, comonomer amount, density, melt index, and / or melt temperature. For example, a first ethylene / α-olefin copolymer that is "different" from the second ethylene / α-olefin copolymer may have a density value that is not similar to that of the second ethylene / α-olefin copolymer.

[0033] In one embodiment, the comonomer of the ethylene / α-olefin copolymer is C3-C 12 α-olefin, or C4~C 10 The comonomer is an α-olefin or a C4-C8 α-olefin. In further embodiments, the comonomer is butene, hexene, or octene.

[0034] 1. First MDO multilayer film The laminate comprises a 1MDO multilayer film including a skin layer (a). The skin layer (a) is the outermost layer of the laminate. The skin layer (a) may be a sealing layer. The skin layer (a) comprises (i) SL-1 ethylene / α-olefin copolymer, (ii) an optional SL-2 ethylene / α-olefin copolymer, and (iii) an optional additive. The SL-1 ethylene / α-olefin copolymer has a density of 0.870 g / cc to 0.920 g / cc, or 0.900 g / cc to 0.920 g / cc. The SL-1 ethylene / α-olefin copolymer may have a melt index of 0.5 g / 10 min to 1.5 g / 10 min, and a melt temperature of 55°C to 125°C, or 120°C to 125°C. If present, the SL-2 ethylene / α-olefin copolymer may have a density of 0.900 g / cc to 0.980 g / cc, or 0.920 g / cc to 0.980 g / cc, or 0.900 g / cc to 0.935 g / cc, or 0.900 g / cc to 0.920 g / cc, a melt index of 0.5 g / 10 min to 1.5 g / 10 min, and a melt temperature of 95°C to 135°C, or 95°C to 105°C, or 120°C to 135°C. In one embodiment, the skin layer (a) comprises 50% to 80% by weight, or 50% to 70% by weight, or 55% to 65% by weight of an SL-first ethylene / α-olefin copolymer, and 50% to 20% by weight, or 50% to 30% by weight, or 40% to 30% by weight of an SL-second ethylene / α-olefin copolymer. The weight percentages are based on the total weight of the skin layer (a). It is understood that the weight percentages correspond to 100% by weight for the skin layer (a). It is further understood that, relative to the film layer weight percentages, the weight percentages correspond to 100% by weight for each subsequent layer disclosed herein.

[0035] The laminate comprises a 1MDO multilayer film including a first intermediate layer (b). The first intermediate layer (b) is in direct contact with the skin layer (a). The first intermediate layer (b) comprises (i) FIL first ethylene / α-olefin copolymer, (ii) FIL second ethylene / α-olefin copolymer, and (iii) an optional additive. The FIL first ethylene / α-olefin copolymer is different from the FIL second ethylene / α-olefin copolymer. The FIL first ethylene / α-olefin copolymer has a density of 0.940 g / cc to 0.980 g / cc, or 0.940 g / cc to 0.950 g / cc. The FIL first ethylene / α-olefin copolymer may have a melt index of 0.5 g / 10 min to 1.5 g / 10 min, and a melt temperature of 125°C to 135°C, or 125°C to 130°C. The first intermediate layer (b) also contains (ii) FIL second ethylene / α-olefin copolymer, which has a density of 0.916 g / cc to 0.980 g / cc, or 0.940 g / cc to 0.980 g / cc, or 0.960 g / cc to 0.980 g / cc. The FIL second ethylene / α-olefin copolymer may have a melt index of 0.5 g / 10 min to 1.5 g / 10 min and a melt temperature of 125°C to 135°C, or 130°C to 135°C. In one embodiment, the first intermediate layer comprises 40% to 80% by weight, or 50% to 70% by weight, or 50% to 60% by weight of a first FIL ethylene / α-olefin copolymer, and 60% to 20% by weight, or 50% to 30% by weight, or 50% to 40% by weight of a second FIL ethylene / α-olefin copolymer. The weight percentages are based on the total weight of the first intermediate layer (b).

[0036] The laminate comprises a 1MDO multilayer film including a core layer (c). The core layer (c) is in direct contact with a first intermediate layer (b). The core layer (c) comprises (i) CL first ethylene / α-olefin copolymer, (ii) an optional CL second ethylene / α-olefin copolymer, and (iii) an optional additive. The CL first ethylene / α-olefin copolymer has a density of 0.915 g / cc to 0.980 g / cc, or 0.900 g / cc to 0.920 g / cc, or 0.910 g / cc to 0.920 g / cc. The CL first ethylene / α-olefin copolymer may have a melt index of 0.5 g / 10 min to 1.5 g / 10 min and a melt temperature of 120°C to 135°C, or 120°C to 125°C.

[0037] In one embodiment, the core layer (c) comprises (i) CL first ethylene / α-olefin copolymer, (ii) CL second ethylene / α-olefin copolymer, and (iii) an optional additive. CL first ethylene / α-olefin copolymer is different from CL second ethylene / α-olefin copolymer. CL first ethylene / α-olefin copolymer may have a density of 0.915 g / cc to 0.980 g / cc, or 0.900 g / cc to 0.920 g / cc, or 0.910 g / cc to 0.920 g / cc, a melt index of 0.5 g / 10 min to 1.5 g / 10 min, and a melt temperature of 120°C to 135°C, or 120°C to 125°C. The core layer (c) also contains (ii) CL second ethylene / α-olefin copolymer. The CL second ethylene / α-olefin copolymer may have a density of 0.940 g / cc to 0.980 g / cc, or 0.940 g / cc to 0.950 g / cc, a melt index of 0.5 g / 10 min to 1.5 g / 10 min, and a melt temperature of 125°C to 135°C, or 125°C to 130°C. In further embodiments, the core layer (c) comprises 10% to 50% by weight, or 10% to 40% by weight, or 20% to 40% by weight of the CL first ethylene / α-olefin copolymer, and 90% to 50% by weight, or 90% to 60% by weight, or 80% to 60% by weight of the CL second ethylene / α-olefin copolymer. The weight percentages are based on the total weight of the core layer (c).

[0038] The laminate comprises a 1MDO multilayer film including a second intermediate layer (b). The second intermediate layer (d) is in direct contact with the core layer (c). The second intermediate layer (d) comprises (i) one or more ethylene-based polymers and (ii) an optional additive. The second intermediate layer (d) may comprise (i) a SIL first ethylene / α-olefin copolymer, (ii) an optional SIL second ethylene / α-olefin copolymer, and (iii) an optional additive.

[0039] In one embodiment, the second intermediate layer (d) comprises (i) SIL first ethylene / α-olefin copolymer, (ii) SIL second ethylene / α-olefin copolymer, and (iii) an optional additive. The SIL first ethylene / α-olefin copolymer may have a density of 0.900 g / cc to 0.920 g / cc or 0.910 g / cc to 0.920 g / cc, a melt index of 0.5 g / 10 min to 1.5 g / 10 min, and a melt temperature of 120°C to 125°C. The second intermediate layer (d) also contains (ii) SIL second ethylene / α-olefin copolymer. The SIL second ethylene / α-olefin copolymer may have a density of 0.940 g / cc or more to 0.980 g / cc, or 0.940 g / cc to 0.950 g / cc, a melt index of 0.5 g / 10 min to 1.5 g / 10 min, and a melt temperature of 125°C to 135°C, or 125°C to 130°C. In further embodiments, the second intermediate layer (d) comprises 10% to 50% by weight, or 20% to 40% by weight, or 30% to 40% by weight of the SIL first ethylene / α-olefin copolymer, and 90% to 50% by weight, or 80% to 60% by weight, or 70% to 60% by weight of the SIL second ethylene / α-olefin copolymer. The weight percentages are based on the total weight of the second intermediate layer (d). In further embodiments, the composition of the second intermediate layer (d) is the same as or identical to the composition of the core layer (c).

[0040] The laminate comprises a 1MDO multilayer film including an inner layer (e), which is the interface with the adhesive layer. The inner layer (e) comprises (i) one or more ethylene-based polymers and (ii) an optional additive. The inner layer (e) may comprise (i) IL 1 ethylene / α-olefin copolymer, (ii) an optional IL 2 ethylene / α-olefin copolymer, and (iii) an optional additive. The IL 1 ethylene / α-olefin has a density of 0.940 g / cc to 0.980 g / cc.

[0041] In one embodiment, the inner layer (e) comprises (i) IL first ethylene / α-olefin copolymer, (ii) IL second ethylene / α-olefin copolymer, and (iii) an optional additive. The IL first ethylene / α-olefin copolymer may have a density of 0.940 g / cc to 0.980 g / cc, or 0.960 g / cc to 0.980 g / cc, a melt index of 0.5 g / 10 min to 1.5 g / 10 min, and a melt temperature of 130°C to 135°C. The inner layer (e) also comprises IL second ethylene / α-olefin copolymer. The IL second ethylene / α-olefin copolymer may have a density of 0.900 g / cc to 0.920 g / cc, or 0.910 g / cc to 0.920 g / cc, a melt index of 0.5 g / 10 min to 1.5 g / 10 min, and a melt temperature of 95°C to 125°C, or 120°C to 125°C. In further embodiments, the inner layer (e) comprises 50% to 90% by weight, or 60% to 80% by weight, or 65% to 75% by weight of the IL first ethylene / α-olefin copolymer, and 50% to 10% by weight, or 40% to 20% by weight, or 35% to 25% by weight of the IL second ethylene / α-olefin copolymer. The weight percentages are based on the total weight of the inner layer (e).

[0042] The 1MDO multilayer film includes a skin layer (a), which is the outermost layer of the laminate and may be a sealing layer. An intermediate layer (b) is located between the skin layer (a) and the core layer (c), and is in direct contact with them. The core layer (c) is located between the first intermediate layer (b) and the second intermediate layer (d), and is in direct contact with them. The second intermediate layer (d) is located between the core layer (c) and the inner layer (e), and is in direct contact with them. The inner layer (e) is the outermost layer of the MDO multilayer film and is the interface with the adhesive layer. The MDO1 multilayer film has a thickness of 10 to 50 microns, or 15 to 40 microns, or 20 to 30 microns, or 25 microns. Each layer in the 1MDO multilayer film may contain only or consist solely of one or more ethylene-based polymers (and optionally selected additives). In one embodiment, the 1MDO multilayer film contains at least 95% by weight, or at least 97% by weight, or at least 99% by weight of an ethylene-based polymer, based on the total weight of the 1MDO multilayer film. In further embodiments, the 1MDO multilayer film consists of or is essentially an ethylene-based polymer (and an optional additive).

[0043] 2. Second MDO film The laminate includes a second mechanically oriented (2MDO) film. The 2MDO film may be a single-layer film or a multilayer film. When the 2MDO is a multilayer film, it may have two, three, four, five, six, seven, eight, or nine or more layers. While the 2MDO film is oriented mechanically, it is understood that the 2MDO film may be further oriented transversely (or laterally) and may be a biaxially oriented film.

[0044] In one embodiment, the 2MDO film is a multilayer film comprising (i) a first ethylene / α-olefin copolymer (ol) having a density of 0.935 g / cc to 0.980 g / cc or 0.940 g / cc to 0.980 g / cc, (ii) an optional second ethylene / α-olefin copolymer (ol), and (iii) an optional additive (ol) (replaceable as "ol"). The laminate comprises an adhesive layer located between the inner layer (e) of the 1MDO multilayer film and the outermost layer of the 2MDO multilayer film, and in direct contact with them.

[0045] In one embodiment, the 2MDO film is a multilayer film comprising an outermost layer (ol), an outer middle layer in direct contact with the outer layer (ol) (replaceably referred to as "om"), a middle layer in direct contact with the outer middle layer (om) (replaceably referred to as "ml"), an inner middle layer in direct contact with the middle layer (ml) (replaceably referred to as "im"), and an inner layer in direct contact with the inner middle layer (im) (replaceably referred to as "in"). The 2MDO multilayer film has an unblocked layer configuration ol / om / ml / im / in or a blocked layer configuration ol / om / ml / im / in / in / im / ml / om / ol. Each layer in the 2MDO multilayer film may contain only or consist of one or more ethylene-based polymers (and optionally selected additives). In one embodiment, the 2MDO film contains at least 95% by weight, or at least 97% by weight, or at least 99% by weight of ethylene-based polymers, based on the total weight of the 2MDO film. In one embodiment, the 2MDO film consists of or is essentially an ethylene-based polymer (and an optional additive). The 2MDO multilayer film has a thickness of 10 to 50 microns, or 15 to 40 microns, or 20 to 30 microns, or 25 microns.

[0046] 3. Additives Each layer in a 1MDO multilayer film and / or a 2MDO multilayer film may contain one or more optional additives. Non-limiting examples of suitable additives include antioxidants such as IRGANOX 1010 and IRGAFOS 168 (commercially available from BASF), UV absorbers, antistatic agents, pigments, dyes, nucleating agents, fillers, lubricants, flame retardants, plasticizers, polymer processing aids (PPAs), lubricants, stabilizers, smoke suppressants, viscosity modifiers, surface modifiers, and antiblocking agents. If present, the additives correspond to MDO multilayer film layers of greater than 0% to 5% by weight, or 0.01% to 4% by weight, or 0.05% to 3% by weight, or 0.01% to 1.0% by weight, or 0.05% to 1.0% by weight. The weight percentage is based on the total weight of each film layer containing the additive.

[0047] 4.Adhesive layer The laminate includes an adhesive layer. The adhesive layer is located between the inner layer (e) of the 1MDO multilayer film and the outermost layer (ol) of the 2MDO multilayer film, such that the adhesive layer is in direct contact with the inner layer (e) and the outermost layer (ol). The adhesive layer bonds or otherwise adheres the 1MDO film to the 2MDO film. Non-limiting examples of adhesive materials suitable for the adhesive layer include solvent-based adhesives, solvent-free adhesives, water-based adhesives, polyurethane, epoxy, acrylic, and extruded polyethylene. In one embodiment, the laminate includes an adhesive layer composed of a polyurethane adhesive. The adhesive may be solvent-free, water-based, or solvent-based. Furthermore, the adhesive may be a one- or two-part formulation. The two parts crosslink or otherwise bond the 1MDO multilayer film to the 2MDO film. The adhesive layer has a coating weight of 1 gm to 5 gsm.

[0048] As used herein, the term “heat sealing conditions” assumes that two separate laminates are positioned such that two skin layers (a) face each other and are in contact with each other (hereinafter interchangeably referred to as “first skin layer (a) in contact with second skin layer (a)”). The two laminates are positioned between opposing heat seal bars, which are moved toward each other, sandwiching the two laminates and applying heat and pressure to the two laminates so that the opposing skin layers (a) come into contact, melt, form a heat seal, or weld together to attach the two laminates. The heat sealing includes structures and mechanisms suitable for moving the seal bars toward and away from each other in order to carry out the heat sealing procedure. The heat sealing conditions, according to ASTM F88, apply 2.5 kg / cm³ to the two laminates at a temperature in the range of 85°C to 130°C in 5°C increments ("seal temperature") for a residence time of 0.5 seconds ("residence"). 2 This further includes applying a pressure ("seal pressure"). The heat seal strength is reported as the average peak load (Kg / 25mm) for each respective temperature.

[0049] In one embodiment, the laminate forms a heat seal having a heat seal strength of 0.3 kg / 25 mm or more, or 0.3 to 0.8 kg / 25 mm, or 0.5 to 0.8 kg / 25 mm, under heat seal conditions of seal pressure, residence time of 0.5 seconds, and seal temperature of 95°C. In one embodiment, the laminate contains at least 95% by weight, or at least 97% by weight, or at least 99% by weight of an ethylene-based polymer, based on the total weight of the laminate.

[0050] Test method Density is measured according to ASTM D792, Method B. The result is expressed in grams per cubic centimeter (g / cc or g / cm³). 3 ) will be reported.

[0051] Heat seal initiation temperature and seal strength. To determine the heat seal initiation temperature (HSIT) and seal strength, the sample is sealed using a heat sealing device with opposing seal jaws. The sample width is 25 mm, the residence seal time is 0.5 seconds for thicknesses less than 100 microns, and the seal pressure is 2.5 kg / cm². 2 The heat-sealed sample is allowed to set for 24 hours, and then measured using a tensile machine equipped with a 100N load cell at a tensile speed of 500 mm / min. HSIT is reported as the minimum temperature in degrees Celsius required to obtain a seal strength of 0.3 Newtons (0.3 kg). The seal strength value is reported in kg / 25 mm.

[0052] Heat seal strength. Heat seal strength, or seal strength, was measured according to ASTM F88. Values ​​are reported in kg / 25 mm.

[0053] The melt index (I2 or MI) 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.

[0054] Melting temperature. Differential scanning calorimetry (DSC) measurements were performed using a differential scanning calorimeter. The sample (approximately 3 mg) was placed in an aluminum calorimeter and heated from -40°C to 150°C under a nitrogen atmosphere at a heating rate of 10°C / min. The sample was subjected to one complete heating and cooling cycle to remove any thermal history before measurement.

[0055] Examples of the present disclosure are provided, but are not limited to, examples of the present disclosure. [Examples]

[0056] Table 1 shows the materials used in the comparative sample (CS) and the invention's example (IE).

[0057] [Table 1] * - Non-limiting examples of ethylene / α-olefin copolymers identified by layer and number.

[0058] Production of MDO films 1. First MDO multilayer film (heat-sealable MDO film) Two multilayer films, each having a layer configuration a / b / c / d / e and a layer ratio of 1 / 1 / 1 / 1 / 1, were fabricated using a Windmoller & Holscher co-extrusion device. The two heat-sealable MDO films are referred to as "MDO-PE(HS-1)" and "MDO-PE(HS-2)" as shown in Table 2 below.

[0059] [Table 2] Weight % - Based on the total weight of each layer.

[0060] The original thickness (before orientation) of each primary multilayer film IE1 and IE2 was 125 microns. Each primary multilayer film was stretched on an MDO unit roller with a stretching ratio of 5:1, at a preheating temperature of 100°C to 110°C, a stretching temperature of 110°C to 115°C, an annealing temperature of 105°C to 110°C, and cooling roll temperatures of 80°C to 85°C and 40°C to 45°C to produce an MDO multilayer film (1MDO) with a final thickness of 25 microns (production: 1000 kg / hour).

[0061] 2. Second MDO film (print film) For the production of the second MDO film, the Windmoller & Holscher 5-layer blow co-extrusion device produced blocked multilayer films having a layer configuration of ol / om / ml / im / in / in / im / ml / om / ol and a layer ratio of 1 / 1 / 1 / 1 / 2 / 1 / 1 / 1 / 1, as shown in Table 3A below.

[0062] [Table 3] Weight percentage based on the total weight of each layer

[0063] The Windmoller & Holscher 5-layer blow co-extrusion device produced unblocked multilayer films with layer configurations o / om / m / im / i and layer ratios 1 / 1 / 1 / 1 / 1, as shown in Table 3B below.

[0064] [Table 4] Weight percentage based on the total weight of each layer

[0065] The original thickness of each primary multilayer film 3A and 3B was 130 microns. Each primary film was stretched on an MDO unit roller at a stretching ratio of 6.5:1, with a preheating temperature of 105°C to 110°C, a stretching temperature of 110°C to 120°C, an annealing temperature of 105°C to 120°C, and cooling roll temperatures of 80°C to 85°C and 40°C to 45°C to produce an MDO multilayer film with a final thickness of 20 microns (2MDO). MDO multilayer film 3A (from Table 3A) is a blocked film (hereinafter, "MDO Block A"). MDO multilayer film 3B (from Table 3B) is an unblocked film (hereinafter, "MDO Unblocked B").

[0066] 3. Manufacturing of the laminate Laminates were prepared using solvent-free (SF) and solvent-based (SB) lamination processes by applying K-Bar coating and using a hot-roll laminator, with SF adhesive MORFREE® 899A / C99 and SB adhesive ADCOTE® 545EA / COREACTANT F.

[0067] [Table 5]

[0068] Each of IE1 to IE8 unexpectedly possesses a seal strength exceeding 0.3 kg / 25 mm at a low heat seal initiation temperature (95°C). A heat seal strength of 0.3 kg / 25 mm at 95°C is suitable for many flexible packaging applications. Each of IE1 to IE8 is composed solely of polyethylene (no polypropylene) and is compatible with polyethylene recycling streams. CS1 and CS2 each contain polypropylene (BOPP, or biaxially oriented polypropylene) or cast polypropylene (CPP), and CS1 / CS2 are not readily recyclable.

[0069] This disclosure is not limited to the embodiments and examples contained herein, but is particularly intended to include some embodiments and modified forms of those embodiments, including combinations of elements of different embodiments, to the extent that they fall within the scope of the following claims.

Claims

1. It is a laminate, (a) (i) A first ethylene / α-olefin copolymer of a skin layer (SL) having a density of 0.870 g / cc to 0.920 g / cc, (ii) A skin layer comprising an optional skin layer (SL) having a density of 0.900 g / cc to 0.980 g / cc, and a second ethylene / α-olefin copolymer, (b) A first intermediate layer that is in direct contact with the skin layer, (i) A first intermediate layer (FIL) having a density of 0.940 g / cc to 0.980 g / cc, (ii) A first intermediate layer (FIL) having a density of 0.916 g / cc to 0.980 g / cc, comprising a second ethylene / α-olefin copolymer, (c) A core layer that is in direct contact with the first intermediate layer (b), (i) A core layer (CL) having a density of 0.915 g / cc to 0.980 g / cc, containing a first ethylene / α-olefin copolymer, and a core layer (c) (d) A second intermediate layer in direct contact with the core layer, comprising an ethylene-based polymer, (e) A first mechanically oriented (1MDO) multilayer film comprising an inner layer that is in direct contact with the second intermediate layer and contains an ethylene polymer, A second mechanically oriented (2MDO) film, A laminate comprising an adhesive layer between the 1 MDO multilayer film and the 2 MDO film.

2. The skin layer (a) is (i) 50% to 80% by weight of the SL first ethylene / α-olefin copolymer having a density of 0.870 g / cc to 0.920 g / cc and a melting temperature of 55°C to 125°C, (ii) The laminate according to claim 1, comprising 50% to 20% by weight of the SL second ethylene / α-olefin copolymer having a density of 0.900 g / cc to 0.920 g / cc and a melting temperature of 95°C to 105°C, wherein the weight percentage is based on the total weight of the skin layer (a).

3. The first intermediate layer (b) is (i) The FIL first ethylene / α-olefin copolymer having a density of 0.940 g / cc to 0.950 g / cc and a melting temperature of 125°C to 129°C, (ii) The laminate according to claim 1 or 2, comprising the FIL second ethylene / α-olefin copolymer having a density of 0.955 g / cc to 0.980 g / cc and a melting temperature of 130°C to 135°C.

4. The core layer (c) is (i) 10% to 50% by weight of the CL first ethylene / α-olefin copolymer having a density of 0.900 g / cc to 0.920 g / cc and a melting temperature of 120°C to 125°C, (ii) A laminate according to any one of claims 1 to 3, comprising 90% to 50% by weight of the CL second ethylene / α-olefin copolymer having a density of 0.940 g / cc to 0.980 g / cc and a melting temperature of 125°C to 130°C, wherein the weight percentage is based on the total weight of the core layer (c).

5. The laminate according to any one of claims 1 to 4, wherein the second intermediate layer (d) comprises a second intermediate layer (SIL) first ethylene-based polymer having a density of 0.900 g / cc to 0.920 g / cc.

6. The laminate according to any one of claims 1 to 5, wherein the inner layer (e) comprises an ethylene / α-olefin copolymer of the first inner layer (IL) having a density of 0.940 g / cc to 0.980 g / cc.

7. The aforementioned 1MDO multilayer film is (a) (i) 50% to 80% by weight of the SL first ethylene / α-olefin copolymer having a density of 0.870 g / cc to 0.920 g / cc, (ii) comprising 50% to 20% by weight of the SL second ethylene / α-olefin copolymer having a density of 0.900 g / cc to 0.920 g / cc, wherein the weight % is based on the total weight of the skin layer (a), (b) A first intermediate layer that is in direct contact with the skin layer, (i) The FIL first ethylene / α-olefin copolymer having a density of 0.940 g / cc to 0.980 g / cc, (ii) A first intermediate layer comprising the FIL second ethylene / α-olefin copolymer having a density of 0.916 g / cc to 0.980 g / cc, (c) The core layer that is in direct contact with the first intermediate layer, (i) The CL first ethylene / α-olefin copolymer having a density of 0.900 g / cc to 0.920 g / cc, (ii) comprising a CL second ethylene / α-olefin copolymer having a density of 0.940 g / cc to 0.980 g / cc, wherein the weight % of the core layer (c) is based on the total weight of the core layer, (d) The second intermediate layer in direct contact with the core layer, comprising an ethylene polymer, (e) The laminate according to any one of claims 1 to 6, comprising an inner layer which is in direct contact with the second intermediate layer and which comprises an ethylene polymer.

8. The 2MDO film is a multilayer film and includes an outermost layer (ol) containing a first ethylene / α-olefin copolymer having a density of 0.935 g / cc to 0.980 g / cc. The laminate according to any one of claims 1 to 7, wherein the adhesive layer is in direct contact with the inner layer (e) of the 1 MDO multilayer film and the outermost layer (ol) of the 2 MDO multilayer film.

9. The aforementioned 2MDO multilayer film is The outermost layer (ol) and, An outer intermediate layer (om) that is in direct contact with the outer layer, The aforementioned outer middle layer (om) and the middle layer (ml) in direct contact with it, The inner middle layer (im) is in direct contact with the aforementioned middle layer (ml), The laminate according to claim 8, comprising an inner layer (in) in direct contact with the inner middle layer (im).

10. The laminate according to claim 9, wherein the 2MDO multilayer film is composed of only one or more ethylene-based polymers.

11. The laminate according to any one of claims 1 to 10, wherein the 1MDO multilayer film is composed of only one or more ethylene-based polymers.

12. The first skin layer (a) is in contact with the second skin layer (a), The invention includes a heat seal between the first skin layer (a) and the second skin layer (a), and The heat seal is 2.5 kg / cm². ２ The laminate according to any one of claims 1 to 11, having a heat seal strength of 0.3 kg / 25 mm or more under heat seal conditions of a sealing pressure, residence time of 0.5 seconds, and sealing temperature of 95°C.

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