Aligned multilayer film containing a metal layer

Abstract

This disclosure provides a film structure. In one embodiment, the film structure includes a mechanically oriented (MDO) multilayer film. The MDO multilayer film includes (a) a first outer layer (FOL) comprising (i) a first ethylene / α-olefin copolymer of the first outer layer (FOL) having a density of 0.900 g / cc to 0.920 g / cc, and (ii) an optional ethylene polymer selected from the group consisting of (1) a second ethylene / α-olefin copolymer of the FOL having a density of 0.920 g / cc to 0.980 g / cc, and (2) a third ethylene-based polymer (LDPE) of the FOL. The MDO multilayer film includes (b) a first intermediate layer (FIL) in direct contact with the first outer layer. The first intermediate layer (FIL) comprises a first ethylene / α-olefin copolymer of the FIL having a density of 0.920 g / cc to 0.980 g / cc. The MDO film multilayer includes (c) a core layer (CL) in direct contact with a first intermediate layer. The core layer (c) comprises a first ethylene-based polymer of CL having a density of 0.920 g / cc to 0.980 g / cc, and a metal layer on the first outer layer (a).

Description

[Technical Field]

[0001] This disclosure relates to an oriented multilayer film, and more specifically, to an oriented multilayer film including a metal layer. [Background technology]

[0002] Multilayer film structures containing a metal layer (i.e., metallized films formed by depositing a layer of metal and / or metal oxide on a layer of film) are widely used for packaging perishable foods and products. The thin coating provided by the metal layer improves barrier properties and reduces the permeability of liquids, gases, and / or vapors through the multilayer film.

[0003] In efforts to improve recyclability and expand sustainability, the flexible packaging market is shifting towards single-material solutions based on ethylene polymers. Because polyethylene-oriented films offer suitable optics, tensile strength, and rigidity for many flexible packaging applications, oriented films made from ethylene polymers, particularly machine-direction oriented (MDO) films, are evolving as viable substrates for use in single-material flexible packaging. However, the non-polar nature of ethylene polymers makes it difficult to apply metal layers to multilayer film structures with metal-receiving layers composed of ethylene polymers.

[0004] Therefore, in the art, there is a recognized need for oriented multilayer films made of ethylene polymers that provide (i) improved metal layer adhesion (improved bond strength) in balance with (ii) low gas and / or liquid permeability through the multilayer film. [Overview of the Initiative]

[0005] This disclosure provides a film structure. In one embodiment, the film structure includes a mechanically oriented (MDO) multilayer film. The MDO multilayer film includes (a) a first outer layer (FOL) comprising (i) a first ethylene / α-olefin copolymer having a density of 0.900 g / cc to 0.920 g / cc, and (ii) an optional ethylene polymer selected from the group consisting of (1) a second ethylene / α-olefin copolymer of the FOL having a density of 0.920 g / cc to 0.980 g / cc, and (2) a third ethylene-based polymer (LDPE) of the FOL. The MDO multilayer film includes (b) a first intermediate layer (FIL) in direct contact with the first outer layer. The first intermediate layer (FIL) comprises a first ethylene / α-olefin copolymer of the FIL having a density of 0.920 g / cc to 0.980 g / cc. The MDO multilayer film includes (c) a core layer (CL) in direct contact with the first intermediate layer. The core layer (c) comprises a first ethylene-based polymer of CL having a density of 0.920 g / cc to 0.980 g / cc, and a metal layer on the first outer layer (a).

[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 to 5, or 6 or 7), any subrange between any two explicit values ​​is included (e.g., the above range of 1 to 7 includes subranges such as 1 to 2, 2 to 6, 5 to 7, 3 to 7, 5 to 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] As used herein, the terms “blend” or “polymer blend” refer to a mixture of two or more polymers. Blends may or may not be miscible (not phase-separated at the molecular level). Blends may or may not be phase-separated. Blends may or may not contain one or more domain configurations determined by transmission electron spectroscopy, light scattering, X-ray scattering, and other methods known in the art. Blends may be made by physically mixing two or more polymers at a macro level (e.g., melt blend or compounding of resins) or at a micro level (e.g., co-formation in the same reactor).

[0011] The term "composition" refers to a mixture of materials constituting the 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 presence of any additional components, processes, or procedures, whether or not they are specifically disclosed. To avoid any doubt, all compositions claimed through the use of the term “comprising” may include any additional additives, adjuvants, or compounds, whether or not they are polymers, unless otherwise stated. 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 to operability. The term “consisting of” excludes any components, processes, or procedures not specifically described or enumerated. The term “or” refers to the enumerated members individually and in any combination, unless otherwise stated.

[0013] The terms "direct contact," "in direct contact," or "in direct contact with" 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 polymer" is a polymer containing more than a majority (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) including both linear low density resin and substantially linear low density resin, ethylene plastomer (POP) and ethylene elastomer (POE), Medium Density Polyethylene (MDPE), and High Density Polyethylene (HDPE). These polyethylene materials are generally known in the art. However, the following description may be helpful in understanding the differences among some of these different polyethylene resins.

[0015] The term "LDPE" may also be referred to as "high-pressure ethylene polymer" or "highly branched polyethylene", and is defined to mean that the polymer is partially or fully homopolymerized or copolymerized in an autoclave or tubular reactor at a pressure above 14,500 psi (100 MPa) using a free radical initiator such as peroxide (see, for example, U.S. Patent No. 4,599,392, which is incorporated herein by reference). LDPE resins typically have a density within the range of 0.916 to 0.935 g / cm 3 of.

[0016] The term "LLDPE" includes both resins made using single-site catalysts including, but not limited to, traditional Ziegler-Natta catalyst systems and chromium catalysts, as well as mono- or bis-cyclopentadienyl catalysts (typically referred to as metallocenes), geometrically constrained catalysts, pyridylamine catalysts, phosphineimine catalysts, and polyvalent aryloxy ether catalysts (typically referred to as bisphenol phenoxy), and includes linear, substantially linear, or heterogeneous polyethylene copolymers or homopolymers. LLDPE contains fewer long-chain branches than LDPE and is further defined in U.S. Patent No. 5,272,236, U.S. Patent No. 5,278,272, U.S. Patent No. 5,582,923, and U.S. Patent No. 5,733,155 as substantially linear ethylene polymers, homogeneous branched linear ethylene polymer compositions such as those of U.S. Patent No. 3,645,992, heterogeneous branched ethylene polymers prepared according to the process disclosed in U.S. Patent No. 4,076,698, and / or blends thereof (such as those disclosed in U.S. Patent No. 3,914,342 or U.S. Patent No. 5,854,045). LLDPE can be made via gas phase, solution phase, or slurry polymerization, or any combination thereof, using any type of reactor or reactor configuration known in the art.

[0017] The term "MDPE" refers to polyethylene having a density of 0.926 to 0.935 g / cm 3 Typically, "MDPE" is produced using a chromium or Ziegler-Natta catalyst or using a single-site catalyst 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 aryloxy ether catalysts (typically referred to as bisphenol phenoxy) and typically has a molecular weight distribution (MWD) greater than 2.5.

[0018] The term "HDPE" generally refers to 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, phosphineimine catalysts, and polyvalent aryloxyether catalysts (typically referred to as bisphenylphenoxy), prepared at a concentration of approximately 0.935 g / cm³. 3 Super ~ maximum approx. 0.980g / cm 3 This refers to polyethylene having a certain density.

[0019] The term "ULDPE" generally refers to 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, phosphineimine catalysts, and polyvalent aryloxyether catalysts (typically referred to as bisphenylphenoxy), prepared using these catalysts in a concentration of 0.855–0.912 g / cm³. 3 This refers to polyethylene having a density of 0.855 to 0.912 g / cm³. Examples of ULDPE include, but are not limited to, polyethylene (ethylene-based) plastomers and polyethylene (ethylene-based) elastomers. Polyethylene (ethylene-based) elastomer plastomers generally have a density of 0.855 to 0.912 g / cm³. 3 It has a density of .

[0020] As used herein, the terms "ethylene monomer" or "ethylene" refer to a chemical unit having two carbon atoms with a double bond between them, and each carbon atom being 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. Heteroatoms can be non-carbon atoms from groups IV, V, VI, and VII of the periodic table. Non-restrictive examples of heteroatoms include F, N, O, P, B, S, and Si.

[0022] A hydrocarbon is a compound containing only hydrogen and carbon atoms. A hydrocarbonyl (or hydrocarbonyl group) is a hydrocarbon with a bonding value (typically monovalent). Hydrocarbons can have a linear, cyclic, or branched structure.

[0023] As used herein, “laminated structure” includes a first film structure, a second film structure, and an adhesive layer between the first and second film structures. The first and / or second film structures may be single-layer films or multi-layer films.

[0024] A "machine-oriented film" or "MDO film" is stretched (or oriented) in the machine direction with a stretch ratio of 4:1 to 12:1. MDO films are uniaxially oriented films. The stretching or orientation of the film is performed by machine-oriented rolls, via widthening or via meshing gears, thereby the film is ring-rolled or otherwise gradually stretched in the machine direction below the film's melting point.

[0025] A "multilayer structure" is a structure having two or more layers. For example, a multilayer structure may have two, three, four, five, or more layers. A multilayer structure may be described as having layers specified by letters. For example, a three-layer structure having a core layer B and two outer layers A and C may be indicated as A / B / C.

[0026] "Olefins" are unsaturated aliphatic hydrocarbons that have a carbon-carbon double bond.

[0027] An "olefin polymer" (interchangeably referred to as "polyolefin") is a polymer that contains a majority by weight percent of polymerizable olefin monomers (based on the total amount of polymerizable monomers) and may optionally 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 polymerized 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 “made from” one or more specified monomers, “based on” a specified monomer or type of monomer, or “containing” a specified monomer content, but it should be noted that in this context, the term “monomer” is understood to refer to the polymerized residue of a specified monomer and not to a non-polymerized species. In general, polymers as used herein are referred to in terms of "units," which are the polymerized forms of the corresponding monomers.

[0029] A "propylene polymer" (replaceable with "polypropylene") is a polymer containing more than 50 mole percent polymerized propylene monomer (based on the total amount of polymerizable monomers) and optionally containing 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. 10 This is a propylene / α-olefin copolymer having an α-olefin comonomer. [Modes for carrying out the invention]

[0030] This disclosure provides a film structure. In one embodiment, the film structure comprises a mechanically oriented (MDO) multilayer film and a metal layer. The MDO multilayer film comprises (a) a first outer layer ("FOL"). The first outer layer (a) comprises (i) a first ethylene / α-olefin copolymer of FOL having a density of 0.900 g / cc to 0.920 g / cc, and (ii) (1) a second ethylene / α-olefin copolymer of FOL having a density of 0.920 g / cc to 0.980 g / cc, (2) a third ethylene-based polymer of FOL, and (3) an optional ethylene-based polymer selected from combinations thereof. The MDO multilayer film comprises (b) a first intermediate layer ("FIL") in direct contact with the first outer layer. The first intermediate layer (b) comprises a first ethylene / α-olefin copolymer of FIL having a density of 0.920 g / cc to 0.980 g / cc. The MDO multilayer film includes (c) a core layer ("CL") in direct contact with a first intermediate layer (b). The core layer (c) contains a first ethylene / α-olefin copolymer of CL having a density of 0.920 g / cc to 0.980 g / cc. The metal layer is located on the first outer layer (a).

[0031] While a 1MDO film is oriented in the machine direction, it is understood that a 1MDO film may be further oriented in the transverse (or intersecting) direction and may be a biaxially oriented film.

[0032] The following terms and their respective abbreviations are used interchangeably: the first outer layer (or FOL), the first intermediate layer (or FIL), the core layer (or CL), the second intermediate layer (or SIL), the second outer layer (or SOL), the first sublayer, the second sublayer, and the skin layer (SL). In certain embodiments, each ethylene polymer (and / or each ethylene / α-olefin copolymer) is a hydrocarbon. The ethylene polymers disclosed herein are identified by their position, i.e., by the film layer in which the ethylene polymer is present. It is understood that the 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 from” when referring to an ethylene polymer (or ethylene / α-olefin copolymer) indicates that the ethylene polymer has at least one property or property value that is different from 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. By way of example, a second ethylene / α-olefin copolymer “different from” a first ethylene / α-olefin copolymer may have a density value that is different from the density value of the second ethylene / α-olefin copolymer.

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

[0034] 1. MDO multilayer film The film structure comprises an MDO multilayer film having a first outer layer (a). The first outer layer (a) is the outermost layer of the MDO multilayer film before the metal layer is applied. The first outer layer (a) is in direct contact with the metal layer. The first outer layer (a) comprises (i) a first ethylene / α-olefin copolymer of FOL, (ii) (1) a second ethylene / α-olefin copolymer of FOL, (2) a third ethylene-based polymer of FOL, (3) an optional ethylene-based polymer selected from a combination of (1) and (2), and (iii) an optional additive. The first ethylene / α-olefin copolymer of FOL has a density of 0.900 g / cc to 0.920 g / cc. In one embodiment, the first ethylene / α-olefin copolymer of FOL has a melt index of 0.2 g / 10 min to 3.0 g / 10 min, or 0.2 g / 10 min to 3 g / 10 min, and a melt temperature of 95°C to 125°C, or 95°C to 125°C.

[0035] In one embodiment, the first outer layer (a) comprises (i) a first ethylene / α-olefin copolymer of FOL having a density of 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 125°C, or 95°C to 125°C, and the first outer layer (a) also comprises (ii) (1) a second ethylene / α-olefin copolymer of FOL, and (iii) an optional additive. The first ethylene / α-olefin copolymer of FOL is different from the second ethylene / α-olefin copolymer of FOL, which has a density of 0.920 g / cc to 0.980 g / cc, or 0.935 g / cc to 0.980 g / cc. In one embodiment, the second ethylene / α-olefin copolymer of FOL has 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 135°C. In further embodiments, the outer layer (a) comprises 50% to 100% by weight, or 50% to 90% by weight, or 60% to 90% by weight, or 85% by weight, a first ethylene / α-olefin copolymer of FOL having a density of 0.900 g / cc to 0.920 g / cc and a melting temperature of 95°C to 125°C or 105°C to 110°C, and 50% to 0% by weight, or 50% to 10% by weight, or 40% to 10% by weight, or 15% by weight, a second ethylene / α-olefin copolymer of FOL having a density of 0.935 g / cc to 0.980 g / cc and a melting temperature of 125°C to 135°C or 130°C to 135°C. The weight percentages are based on the total weight of the first outer layer (a).

[0036] In one embodiment, the first outer layer (a) comprises (i) a first ethylene / α-olefin copolymer of FOL having a density of 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 125°C or 105°C to 110°C, and the first outer layer (a) also comprises (ii) (2) a third ethylene-based polymer of FOL which is LDPE having a density of 0.918 g / cc to 0.930 g / cc and a melt temperature of 105°C to 115°C. The first ethylene / α-olefin copolymer of FOL is different from the third ethylene-based polymer of FOL. In a further embodiment, the first outer layer (a) is (i) 50% to 100% by weight, or 50% to 90% by weight, or 60% to 90% by weight, or 85% by weight, of a first ethylene / α-olefin compound of FOL having a density of 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 125°C or 105°C to 110°C. The polymer comprises (ii)(2) 50% to 0% by weight, or 50% to 10% by weight, or 40% to 10% by weight, or 15% by weight, a third ethylene-based polymer of FOL having a density of 0.910 g / cc to 0.930 g / cc, a melt index of 0.2 g / 19 min to 3.0 g / 10 min, or 0.5 g / 10 min to 1.5 g / 10 min, and a melt temperature of 105°C to 115°C. The weight percentages are based on the total weight of the first outer layer (a).

[0037] The film structure comprises an MDO multilayer film having a first intermediate layer (b). The first intermediate layer (b) is in direct contact with the first outer layer (a). The intermediate layer (b) comprises (i) FIL ethylene / α-olefin copolymer, (ii) an optional second FIL ethylene / α-olefin copolymer, and (iii) an optional additive. The first FIL ethylene / α-olefin copolymer has a density of 0.920 g / cc to 0.980 g / cc, or 0.935 g / cc to 0.980 g / cc.

[0038] In one embodiment, the first intermediate layer (b) comprises (i) 90% to 100% by weight, or 100% by weight, of a first ethylene / α-olefin copolymer of FIL having a density of 0.935 g / cc to 0.980 g / cc, or 0.940 g / cc to 0.980 g / cc, or 0.940 g / cc to 0.950 g / cc, and a melting temperature of 125°C to 135°C or 125°C to 129°C. The weight percentage is based on the total weight of the intermediate layer (b).

[0039] In one embodiment, the first intermediate layer (b) comprises a first ethylene / α-olefin copolymer of FIL and a second ethylene / α-olefin copolymer of FIL. The first ethylene / α-olefin copolymer of FIL is different from the second ethylene / α-olefin copolymer of FIL. In one embodiment, the first intermediate layer (b) comprises (i) 60% to 90% by weight, or 60% to 80% by weight, or 70% by weight, of a first ethylene / α-olefin copolymer of FIL having a density of 0.935 g / cc to 0.980 g / cc, or 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, or less than 0.5 g / 10 min to 1.0 g / 10 min, and a melt temperature of 125°C to 135°C or 125°C to 129°C. The first intermediate layer comprises (ii) 40% to 10% by weight, or 40% to 20% by weight, or 30% by weight, of a second ethylene / α-olefin copolymer of FIL. In one embodiment, the second ethylene / α-olefin copolymer of FIL has a density of 0.935 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, a melt index of 0.5 g / 10 min to 1.5 g / 10 min or 1.0 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. The weight percentage is based on the total weight of the first intermediate layer (b).

[0040] The film structure comprises an MDO multilayer film having a core layer (c). The core layer (c) is in direct contact with a first intermediate layer (b). The core layer (c) comprises (i) a first ethylene / α-olefin copolymer of CL, (ii) an optional second ethylene / α-olefin copolymer of CL, and (iii) an optional additive. In one embodiment, the core layer (c) comprises 90% to 100% by weight, or 100% by weight, of a first ethylene / α-olefin copolymer of CL having a density of 0.920 g / cc to 0.980 g / cc, or 0.935 g / cc to 0.980 g / cc, or 0.940 g / cc to 0.950 g / cc, a melt index of 0.2 g / 10 min to 2.0 g / 10 min, 0.5 g / 10 min to 1.5 g / 10 min, or less than 0.5 g / 10 min to 1.0 g / 10 min, and a melt temperature of 125°C to 135°C or 125°C to 129°C. The weight percentages are based on the total weight of the core layer (c).

[0041] In one embodiment, the film structure includes an MDO multilayer film having a first sublayer (d1). The first sublayer (d1) is in direct contact with the core layer (c). The first sublayer (d1) comprises one or more ethylene-based polymers.

[0042] In one embodiment, the first sublayer (d1) comprises (i) a first ethylene / α-olefin copolymer of FSL, (ii) an optional second ethylene / α-olefin copolymer of FSL, and (iii) an optional additive. The first ethylene / α-olefin copolymer of FSL is different from the second ethylene / α-olefin copolymer of FSL. The first sublayer (d1) comprises (i) 60% to 100% by weight, or 60% to 90% by weight, or 60% to 80% by weight, or 70% by weight of the first ethylene / α-olefin copolymer of FSL. In one embodiment, the first ethylene / α-olefin copolymer of FSL has a density of 0.935 g / cc to 0.980 g / cc, or 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 or less than 0.5 g / 10 min to 1.0 g / 10 min, and a melt temperature of 125°C to 129°C. The first sublayer (d) comprises (ii) 40% to 0% by weight, or 40% to 10% by weight, or 40% to 20% by weight, or 30% by weight, of the second ethylene / α-olefin copolymer of FSL. In one embodiment, the second ethylene / α-olefin copolymer of FSL has a density of 0.935 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, a melt index of 0.5 g / 10 min to 1.5 g / 10 min or greater than 1.0 g / 10 min to 1.5 g / 10 min, and a melt temperature of 130°C to 135°C. The weight percentage is based on the total weight of the first sublayer (d1). In a further embodiment, the composition of the first sublayer (d1) is the same as the composition of the first intermediate layer (b).

[0043] In one embodiment, the first sublayer (d1) comprises 90% to 100% by weight, or 100% by weight, maleic anhydride-functionalized ethylene copolymer. The maleic anhydride-functionalized ethylene copolymer has a density of 0.870 g / cc to 0.940 g / cc or 0.870 g / cc to 0.89 g / cc, and a melt index of 1.0 g / 10 min to 3.0 g / 10 min or 2.0 g / 10 min to 3.0 g / 10 min.

[0044] In one embodiment, the MDO multilayer film includes additional sublayers (d2), (d3), (d4), and (d5), and optionally, additional sublayers. Each sublayer contains an ethylene-based polymer and optionally an additive. In a further embodiment, one of the sublayers (d2), (d3), (d4), and (d5) contains ethylene vinyl alcohol (EVOH), and the remaining sublayers each contain an ethylene-based polymer.

[0045] In one embodiment, the film structure comprises an MDO multilayer film having a skin layer (e). The skin layer (e) is in direct contact with one of the sublayers (d1), (d2), (d3), (d4), or (d5). The skin layer (e) comprises (i) a first ethylene / α-olefin copolymer of SL, (ii) an optional second ethylene / α-olefin copolymer of SL, and (iii) an optional additive.

[0046] In one embodiment, the skin layer (e) is in direct contact with the sublayer (d1). The skin layer (e) contains (i) 50% to 0% by weight, or 50% to 10% by weight, or 40% to 20% by weight, or 30% by weight of a first ethylene / α-olefin copolymer of SL. In one embodiment, the first ethylene / α-olefin copolymer of SL has a density of 0.900 g / cc to 0.920 g / cc, a melt index of 0.5 g / 10 min to 1.5 g / 10 min, or less than 0.5 g / 10 min to 1.0 g / 10 min, and a melt temperature of 95°C to 125°C or 105°C to 110°C. The skin layer (e) contains (ii) 50% to 100% by weight, or 50% to 90% by weight, or 60% to 80% by weight, or 70% by weight of a second ethylene / α-olefin copolymer of SL. In one embodiment, the second ethylene / α-olefin copolymer of SL has a density of 0.935 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, a melt index of 0.5 g / 10 min to 1.5 g / 10 min or greater than 1.0 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. The first ethylene / α-olefin of SL is different from the second ethylene / α-olefin of SL. Weight percentages are based on the total weight of the skin layer (e).

[0047] In one embodiment, skin layer (e) is in direct contact with one of the sublayers other than (d1), namely (d2), or (d3), or (d4), or (d5). Skin layer (e) comprises 90% to 100% by weight (and optional additives), or 100% by weight, of a first ethylene / α-olefin copolymer of SL having a density of 0.935 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, a melt index of 0.5 g / 10 min to 1.5 g / 10 min, or greater than 1.0 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. The weight percentages are based on the total weight of the second skin layer (e).

[0048] 2. Additives Each layer in the MDO 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 additive(s) may be present in amounts greater than 0% to 5% by weight, or 0.01% to 4% by weight, or 0.01% to 3% by weight, or 0.01% to 2.0% by weight, or 0.01% to 1.0% by weight, or 0.05% to 1.0% by weight of the MDO multilayer film layer. The weight percentage is based on the total weight of each film layer containing the additive.

[0049] 3. Metal layer The MDO multilayer film includes a metal layer. The metal layer is located on a first outer layer (a) and is in direct contact with the first outer layer (a). In one embodiment, the first outer layer (a) is subjected to plasma treatment before metal / metal oxide deposition to improve metal adhesion.

[0050] Non-limiting examples of plasma treatment techniques include solution spraying, spinning, coating, or the addition of hydrophilic additives to film structures. For example, hydrophilic treatment can be applied via plasma treatment, where the film structure is exposed to an atmospheric plasma containing an inert gas and a substance having polar groups, which may be vaporized or aerosolized and, upon exposure to dielectric barrier discharge, forms free radicals. Atmospheric plasma systems and methods are generally described in U.S. Patent No. 5,433,786, the disclosure of which is incorporated herein by reference.

[0051] A metal (and / or metal oxide) is deposited on the first outer layer (a) of the MDO multilayer film. Non-limiting procedures by which the metal / metal oxide can be applied to the first outer layer (a) include vapor deposition (chemical or physical) or vacuum metallization. With respect to vacuum metallization, the metal source is evaporated in a vacuum environment, and as the film passes through a vacuum chamber, the metal vapor condenses on the surface of the film to form a thin layer. Non-limiting examples of metals suitable for the metal layer include aluminum (Aluminum, Al), silicon (Si), zinc (Zinc, Zn), gold (Au), silver (Ag), copper (Cu), nickel (Nickel, Ni), chromium (Cr), germanium (Ge), selenium (Se), titanium (Ti), tin (Sn), their oxides, and combinations thereof. The metal layer has a thickness of 10-60 nanometers (nm), or 15-60 nm, or 10-45 nm, or 15-45 nm, or 15-40 nm. The bonding strength of the metal layer to the first outer layer (a) (referred to as interchangeable metal bonding) is 1.5 N / 25 mm or more, or 1.5 N / 25 mm to 12.0 N / 25 mm, or 2.5 N / 25 mm to 10.0 N / 25 mm, or 2.7 N / 25 mm to 9.0 N / 25 mm, or 3.0 N / 25 mm to 8.5 N / 25 mm.

[0052] In one embodiment, the metal layer is formed from aluminum and / or an aluminum oxide (e.g., Al2O3), and the metal layer has a thickness of 10 nm to 60 nm, or 15 nm to 60 nm, or 10 nm to 45 nm, or 15 nm to 45 nm, or 15 nm to 40 nm.

[0053] In one embodiment, the film structure has a thickness of 20 to 30 microns, or 25 microns. The first outer layer (a), (i) A first ethylene / α-olefin copolymer of FOL having a density of 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 125°C, or 105°C to 110°C, or 110°C to 125°C, or 120°C to 125°C, (ii) 40% by weight to 10% by weight, or 30% by weight to 10% by weight, (1) A second ethylene / α-olefin copolymer of FOL having a density of 0.935 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 125°C to 135°C or 130°C to 135°C, or (2) A first outer layer (a) comprising another ethylene polymer selected from the third ethylene polymer of FOL, which is low-density polyethylene, The first intermediate layer (b), (i) A first ethylene / α-olefin copolymer of FIL having a density of 0.935 g / cc to 0.980 g / cc, and optionally, (ii) A first intermediate layer (b) comprising a second ethylene / α-olefin copolymer of FIL having a density of 0.935 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 or greater than 1.0 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, The core layer (c), i) A core layer (c) comprising a primary ethylene / α-olefin copolymer of CL with a melt index of 0.935 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 or less than 0.5 g / 10 min to 1.0 g / 10 min, and a melt temperature of 125°C to 135°C or 125°C to 129°C, One or more optional sublayers (d1), (d2), (d3), (d4), (d5), The skin layer (e), (i) A skin layer (e) comprising a first ethylene / α-olefin copolymer of SL having a density of 0.935 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 or greater than 1.0 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, The metal layer has a thickness of 10 nm to 60 nm and contains a metal selected from aluminum, aluminum oxide, and combinations thereof. The film structure has one, some, or all of the following characteristics: (1) 0.1 cm 3 / m 2 Sun~120cm 3 / m 2 / day, or 0.5cm 3 / m 2 / day~115cm 3 / m 2 / day, or 0.7cm 3 / m 2 / day~110cm 3 / m 2 / day OTR value, and / or (2) 0.1 g / m 2 / day~2.5g / m 2 / day, or 0.2g / m³ 2 / day~2.0g / m 2 / day, or 0.3g / m³ 2 / day ~1.9g / m 2 WVTR value per day, and / or (3) Metal bonding values ​​of 2.5N / 25mm to 10N / 25mm, or 2.7N / 25mm to 9.0N / 25mm, or 3.0N / 25mm to 8.5N / 25mm.

[0054] In one embodiment, the MDO 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 MDO multilayer film.

[0055] In one embodiment, the MDO multilayer film consists solely of ethylene-based polymers (excluding the metal layer).

[0056] Test method Density is measured according to ASTM D792, Method B. Results are reported in grams per cubic centimeter (g / cc).

[0057] The melting index (I2) is measured at 190°C using 2.16 kg according to ASTM D-1238. The value is reported as g / 10 min, corresponding to the grams eluted per 10 minutes.

[0058] Melting temperature. Differential scanning calorimetry (DSC) measurements were performed using a differential scanning calorimeter. The sample (approximately 3 mg) was loaded into an aluminum calorimeter dish and heated from approximately 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.

[0059] Metal layer bonding. The bonding strength (or "bond strength" or "metal bond") of the metal layer to the first outer layer (layer (a)) of each MDO multilayer film is measured as follows: Each film structure is heat-sealed to a 100-micron film ("EAA film") made from ethylene acrylic acid copolymer with an acrylic acid content of approximately 7%, with the metal layer of the film structure in contact with the EAA film. The film structure and EAA film are heat-sealed by placing the film between the upper jaw at 110°C and the lower jaw at 70°C, with the upper jaw in contact with the EAA film and the lower jaw in contact with the film structure. The jaws are brought into contact with the EAA film and film structure for 20 seconds under a pressure of 5 bar. After aging for 24 hours at room temperature, the metal bond strength (bond strength) is then measured using an Instron 5567 tensile tester by measuring T-peel at a test speed of 12 inches / min using a 100 N load cell. The average value is reported as the metal adhesion strength (bonding strength) between the first outer layer (a) of the MDO multilayer film and the metal layer, and the result is reported as Newtons per 25 mm (N) or N / 25 mm.

[0060] Optical density test method. Measure the optical density of the film using a densitometer. Mark the sample at 10 equally spaced points across its width, with the metal side facing up. Place the densitometer in diffusion mode and set to light transmittance. Test the sample with the metal side facing up. Special care should be taken when handling the material to avoid scratches, pinholes, etc. US standard number PH2-19-1959 provides the basis for the concept of diffuse optical density.

[0061] Oxygen transmission rate (OTR). Oxygen transmission rate (OTR) is measured according to ASTM D3985. The sample is placed at 23°C, 0% relative humidity (RH), and 50 cm². 2 Test with the following sample size. Value in cm 3 / day / m 2 I will report it.

[0062] Water vapor transmission rate (WVTR). The water vapor transmission rate (WVTR) is measured according to ASTM F1249. The sample is subjected to 37.8°C, 100% RH, and 50 cm³. 2 Test with the following sample size. Value g / day / m 2 I will report it.

[0063] Examples of the present disclosure are provided, but are not limited to, examples of the present disclosure. [Examples]

[0064] Table 1 shows the materials used in the comparative sample (CS) and the example of the present invention (IE).

[0065] [Table 1]

[0066] 1. Fabrication of MDO multilayer film Five co-extruded multilayer films (comparative sample (CS)1, CS2, and innovative example (IE)IE3, IE4, and IE5) each had a primary film thickness of 125 microns. Each multilayer film was stretched 5.5 times using a HOSOKAWA ALPINE blow film line equipped with an MDO in-line stretching unit to obtain an MDO multilayer film with a thickness of 25 microns. The layer configuration / composition and layer volume percentage of each multilayer film CS1, CS2, IE3, IE4, and IE5 are provided in the following Tables 2A to 2E.

[0067] [Table 2] Weight percentages (if shown) are based on the total weight of each layer.

[0068] [Table 3] Weight percentages (if shown) are based on the total weight of each layer.

[0069] [Table 4] Weight percentages (if shown) are based on the total weight of each layer.

[0070] [Table 5] Weight percentages (if shown) are based on the total weight of each layer.

[0071] [Table 6] Weight percentages (if shown) are based on the total weight of each layer.

[0072] 2. Manufacturing of film structures having a metal layer Each MDO multilayer film (CS1, CS2, IE3, IE4, IE5) is subjected to plasma treatment. Following the plasma treatment, an aluminum metal layer is applied to the first outer layer (a) of each MDO multilayer film CS1, IE2, IE3, and IE4.

[0073] In Table 3 below, each film structure has an MDO multilayer film and an aluminum metal layer having the following optical density values: CS1 3.3, CS2 3.4, IE3 2.4, IE4 2.8, and IE5 2.8. The aluminum metal layer is in direct contact with the first outer layer (a) of each MDO multilayer film.

[0074] [Table 7] Weight percentages (if shown) are based on the total weight of each layer.

[0075] Examples IE3, IE4, and IE5 of the present invention each unexpectedly exhibited excellent OTR (0.1cm). 3 / m 2 Sun~120cm 3 / m 2 ( / day) and excellent WVTR (0.1g / m²) 2 / day~2.5g / m 2 It exhibits a ( / day) characteristic and simultaneously provides strong metal bonding (2.5N / 25mm~10N / 25mm).

[0076] This disclosure is not limited to the embodiments and examples contained herein, but is specifically 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. A film structure, The invention includes a mechanically oriented (MDO) multilayer film, and the mechanically oriented (MDO) multilayer film is (a) The first outer layer (FOL), (i) A first ethylene / α-olefin copolymer of FOL having a density of 0.900 g / cc to 0.920 g / cc, (ii) (1) A second ethylene / α-olefin copolymer of FOL having a density of 0.920 g / cc to 0.980 g / cc, and (2) A first outer layer (FOL) comprising an optional ethylene polymer selected from the group consisting of a third ethylene polymer (LDPE) of FOL, (b) A first intermediate layer (FIL) in direct contact with the first outer layer, comprising a first ethylene / α-olefin copolymer of FIL having a density of 0.920 g / cc to 0.980 g / cc, (c) A core layer (CL) in direct contact with the first intermediate layer, comprising a first ethylene polymer of CL having a density of 0.920 g / cc to 0.980 g / cc, and A film structure comprising a core layer (CL) including a metal layer on the first outer layer (a).

2. The first outer layer (a) is (i) A first ethylene / α-olefin copolymer of FOL having a density of 0.900 g / cc to 0.920 g / cc and a melting temperature of 95°C to 125°C, (ii) The film structure according to claim 1, comprising 50% by weight to 0% by weight of a second ethylene / α-olefin copolymer of the FOL having a density of 0.940 g / cc to 0.980 g / cc and a melting temperature of 125°C to 135°C, wherein the weight % is based on the total weight of the first outer layer (a).

3. The first outer layer (a) is (i) A first ethylene / α-olefin copolymer of FOL having a density of 0.900 g / cc to 0.920 g / cc and a melting temperature of 95°C to 125°C, (ii) The film structure according to claim 1, comprising 50% to 0% by weight of a third ethylene polymer of the FOL, which is low-density polyethylene.

4. The film structure according to any one of claims 1 to 3, wherein the first intermediate layer (b) comprises 90% to 100% by weight of the first ethylene / α-olefin copolymer of the FIL having a density of 0.935 g / cc to 0.980 g / cc and a melting temperature of 125°C to 135°C, and the weight percentage is based on the total weight of the intermediate layer (b).

5. The first intermediate layer is (i) A first ethylene / α-olefin copolymer of FIL having a density of 0.935 g / cc to 0.980 g / cc and a melting temperature of 125°C to 135°C, (ii) A film structure according to any one of claims 1 to 3, comprising 40% to 10% by weight of a second ethylene / α-olefin copolymer of FIL having a density of 0.940 g / cc to 0.980 g / cc and a melting temperature of 125°C to 135°C, wherein the weight percentage is based on the total weight of the first intermediate layer (b).

6. The film structure according to any one of claims 1 to 5, wherein the core layer (c) comprises 90% to 100% by weight of the first ethylene / α-olefin copolymer of CL having a density of 0.935 g / cc or more and 0.980 g / cc and a melting temperature of 125°C to 135°C, and the weight percentage is based on the total weight of the core layer (c).

7. The film structure according to claim 6, comprising a first sublayer (d1) in direct contact with the core layer (c), wherein the first sublayer (d1) comprises an ethylene-based polymer.

8. A film structure according to any one of claims 1 to 7, comprising a skin layer (e) containing a first ethylene / α-olefin copolymer of SK having a density of 0.935 g / cc to 0.980 g / cc.

9. The film structure according to any one of claims 1 to 8, wherein the metal layer is in direct contact with the first outer layer (a), and the metal layer comprises a metal selected from the group consisting of Al, Si, Zn, Au, Ag, Cu, Ni, Cr, Ge, Se, Ti, Sn, oxides thereof, and combinations thereof.

10. The film structure according to claim 9, wherein the metal layer comprises a component selected from the group consisting of Al metal, Al oxide, and combinations thereof.

11. The film structure according to any one of claims 1 to 10, wherein the metal layer has a thickness of 10 nanometers to 60 nanometers.

12. The aforementioned film structure The first outer layer (a), (i) 70% to 90% by weight of the first ethylene / α-olefin copolymer of FOL having a density of 0.900 g / cc to 0.920 g / cc, and (ii) 30% to 10% by weight, (1) A second ethylene / α-olefin copolymer of FOL having a density of 0.935 g / cc to 0.980 g / cc and a melting temperature of 125°C to 135°C, (2) The first outer layer (a) comprises another ethylene polymer selected from the group consisting of a third ethylene polymer of FOL which is low-density polyethylene, The first intermediate layer (b), (i) The first intermediate layer (b) comprising the first ethylene / α-olefin copolymer of FIL having a density of 0.935 g / cc to 0.980 g / cc The core layer (c), (i) The core layer (c) comprising the first ethylene / α-olefin copolymer of CL having a density of 0.935 g / cc to 0.980 g / cc One or more optional sublayers, The skin layer (SL), (i) A skin layer (SL) comprising a first ethylene / α-olefin copolymer of SL having a density of 0.935 g / cc to 0.980 g / cc, The metal layer comprises a metal selected from the group consisting of aluminum, aluminum oxide, and combinations thereof, The aforementioned film structure (1) 0.1 cm ３ / m ２ Sun~120cm ３ / m ２ OTR value per day, (2) 0.1 g / m ２ / day ~ 2.5g / m ２ The WVTR value per day, and (3) The film structure according to any one of claims 1 to 11, having a metal adhesion value of 2.5 N / 25 mm to 10 N / 25 mm.

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