Oriented multilayer film comprising metal layers

Abstract

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

Description

Technical Field

[0001] The present disclosure relates to oriented multilayer films, and more particularly to oriented multilayer films including a metal layer. Background Art

[0002] Multilayer film structures including a metal layer (i.e., a metallized film formed by depositing a metal and / or metal oxide layer onto a film layer) are widely used for packaging perishable foods and products. The thin coating provided by the metal layer improves barrier properties and reduces liquid, gas and / or vapor permeation through the multilayer film.

[0003] To improve recyclability and expand sustainability, the flexible packaging market is moving toward single-material solutions based on vinyl polymers. Oriented films made from vinyl polymers (and in particular machine direction oriented (MDO) films) are developing as viable substrates for single-material flexible packaging because polyethylene-based oriented films offer optics, tensile strength, and stiffness suitable for many flexible packaging applications. However, the non-polar nature of vinyl polymers makes it difficult to apply metal layers to multilayer film structures having metal receptive layers composed of vinyl polymers.

[0004] Thus, there is a recognized need in the art for oriented multilayer films composed of vinyl polymers that provide (i) improved metal layer adhesion (improved bond strength) balanced with (ii) low gas and / or low liquid permeation through the multilayer film. Summary of the invention

[0005] The present disclosure provides a film structure. In one embodiment, the film structure includes a machine direction oriented (MDO) multilayer film. The MDO multilayer film includes (a) a first outer layer (FOL), which includes (i) a FOL first ethylene / α-olefin copolymer with a density of 0.900g / cc to 0.920g / cc, and (ii) an optional vinyl polymer selected from the group consisting of the following items: (1) a FOL second ethylene / α-olefin copolymer with a density of 0.920g / cc to 0.980g / cc; and (2) a FOL third vinyl polymer (LDPE). The MDO multilayer film includes (b) a first intermediate layer (FIL) in direct contact with the first outer layer. The first intermediate layer (FIL) includes a FIL first ethylene / α-olefin copolymer with a density of 0.920g / cc to 0.980g / 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 CL first vinyl polymer 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

[0007] Any reference to the Periodic Table of the Elements is to the Periodic Table as published by CRC Press, Inc., 1990-1991. A group of elements in this table is referred to by a new notation for numbering the groups.

[0008] For purposes of U.S. patent practice, the contents of any referenced patent, patent application, or publication are incorporated by reference in their entirety (or their equivalent U.S. versions are incorporated by reference), particularly with respect to disclosure of definitions (to the extent not inconsistent with any definitions specifically provided in this disclosure).

[0009] The numerical range disclosed herein includes all values ​​from the lower limit to the upper limit, and includes the lower limit and the upper limit. For a range containing clear values ​​(e.g., 1 or 2, or 3 to 5, or 6, or 7), any sub-range between any two clear values ​​is included (e.g., the above range 1 to 7 includes 1 to 2; 2 to 6; 5 to 7; 3 to 7; 5 to 6; etc.).

[0010] Unless stated to the contrary, implicit from 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.

[0011] The term "blend" or "polymer blend" as used refers to a mixture of two or more polymers. A blend may be miscible or immiscible (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, as determined by transmission electron spectroscopy, light scattering, x-ray scattering, and other methods known in the art. A blend may be achieved by physically mixing two or more polymers at a macroscopic level (e.g., melt blending resins or compounding) or a microscopic level (e.g., simultaneously formed in the same reactor).

[0012] The term "composition" refers to a mixture of materials comprising the composition, as well as reaction products and decomposition products formed from the materials of the composition.

[0013] The terms "comprising," "including," "having," and their derivatives are not intended to exclude the presence of any additional components, steps, or procedures, whether or not these components, steps, or procedures are specifically disclosed. For the avoidance of any doubt, all compositions claimed through the use of the term "comprising" may include any additional additives, adjuvants, or compounds, whether in polymeric form or otherwise, unless stated to the contrary. Conversely, the term "consisting essentially of excludes any other components, steps, or procedures (except those that are not essential to operability) from the scope of any subsequent statements. The term "consisting of" excludes any components, steps, or procedures that are not specifically described or listed. Unless otherwise stated, the term "or" refers to the listed members individually and in any combination.

[0014] The term “direct contact” or “directly contacts” or “is in direct contact with” or similar terms refers to a layer configuration in which a first layer is positioned immediately adjacent to a second layer and there are no intervening layers or structures between the first and second layers.

[0015] "Polyethylene" or "ethylene-based polymer" is a polymer comprising a majority amount (>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 catalyzed linear low density polyethylene, including both linear and substantially linear low density resins (m-LLDPE); ethylene-based plastomers (POPs) and ethylene-based elastomers (POEs); medium density polyethylene (MDPE); and high density polyethylene (HDPE). These polyethylene materials are generally known in the art; however, the following description may help understand the differences between some of these different polyethylene resins.

[0016] The term "LDPE" may also be referred to as "high pressure ethylene polymer" or "highly branched polyethylene" and is defined to mean a polymer that is partially or completely homopolymerized or copolymerized in an autoclave or tubular reactor at pressures above 14,500 psi (100 MPa) using a free radical initiator such as a peroxide (see, e.g., U.S. Pat. No. 4,599,392, which is hereby incorporated by reference). LDPE resins typically have a molecular weight of 0.916 g / cm 3 Up to 0.935g / cm 3 density within the range of .

[0017] The term "LLDPE" includes those produced using conventional Ziegler-Natta catalyst systems. catalyst system) and a chromium-based catalyst system and a single-site catalyst (including but not limited to substituted mono- or dicyclopentadienyl catalysts (commonly referred to as metallocenes), constrained geometry catalysts, pyridylamine catalysts, phosphinimine catalysts, and polyvalent aryloxyether catalysts (commonly referred to as bisphenylphenoxy) and comprises linear, substantially linear or heterogeneous polyethylene copolymers or homopolymers. LLDPE contains less long chain branching than LDPE and includes substantially linear ethylene polymers, which are further defined in U.S. Pat. No. 5,272,236, U.S. Pat. No. 5,278,272, U.S. Pat. No. 5,582,923 and U.S. Pat. No. 5,733,155; homogeneously branched linear ethylene polymer compositions such as those in U.S. Pat. No. 3,645,992; heterogeneously branched ethylene polymers such as those prepared according to the process disclosed in U.S. Pat. No. 4,076,698; and / or blends thereof (such as U.S. Pat. No. 3,914,342 or U.S. Pat. No. 5,733,155). 5,854,045). LLDPE can be made by gas phase, solution phase or slurry polymerization, or any combination thereof, using any type of reactor or reactor configuration known in the art.

[0018] The term "MDPE" refers to a polyethylene with a density of 0.926 g / cm 3 Up to 0.935g / cm 3 "MDPE" is typically produced using chromium or Ziegler-Natta catalysts or using single-site catalysts, including but not limited to substituted mono- or bis-cyclopentadienyl catalysts (commonly referred to as metallocenes), constrained geometry catalysts, pyridylamine catalysts, phosphinimine catalysts, and polyvalent aryloxyether catalysts (commonly referred to as bisphenylphenoxy), and typically has a molecular weight distribution ("MWD") greater than 2.5.

[0019] The term "HDPE" refers to a polyethylene having a density greater than about 0.935 g / cm 3 and at most about 0.980 g / cm 3 The polyethylene is generally prepared using a Ziegler-Natta catalyst, a chromium catalyst or a single-site catalyst (including but not limited to substituted mono- or bis-cyclopentadienyl catalysts (commonly referred to as metallocenes), constrained geometry catalysts, pyridylamine catalysts, phosphinimine catalysts and polyvalent catalysts aryloxyether catalysts (commonly referred to as bisphenylphenoxy).

[0020] The term "ULDPE" refers to a polyethylene with a density of 0.855 g / cm 3 Up to 0.912g / cm 3Polyethylene (ULDPE) is generally prepared using Ziegler-Natta catalysts, chromium catalysts or single-site catalysts (including but not limited to substituted mono- or di-cyclopentadienyl catalysts (commonly known as metallocenes), constrained geometry catalysts, pyridylamine catalysts, phosphinimine catalysts and multivalent catalysts (commonly known as bisphenylphenoxy). ULDPE includes but is not limited to polyethylene (based on ethylene) plastomers and polyethylene (based on ethylene) elastomers. Polyethylene (based on ethylene) elastomer plastomers generally have a molecular weight of 0.855 g / cm 3 Up to 0.912g / cm 3 density.

[0021] 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, wherein the chemical unit is polymerized with other such chemical units to form an ethylene polymer composition.

[0022] A "heteroatom" is an atom other than carbon or hydrogen. A heteroatom can be a non-carbon atom from Group IV, Group V, Group VI, and Group VII of the periodic table. Non-limiting examples of heteroatoms include: F, N, O, P, B, S, and Si.

[0023] A "hydrocarbon" is a compound containing only hydrogen and carbon atoms. A "hydrocarbon group" (or "hydrocarbon group") is a hydrocarbon having a valence (usually a single valence). A hydrocarbon may have a straight chain structure, a cyclic structure, or a branched structure.

[0024] As used herein, "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 may be a single film or a multi-layer film.

[0025] "Machine direction oriented film" or "MDO film" is a film stretched (or oriented) in the machine direction with a stretch ratio of 4:1 to 12:1. MDO film is a uniaxially oriented film. Stretching or orientation of the film is performed by machine direction orientation rolls, via tentering, or via intermeshing gears whereby the film is ring rolled, or otherwise incrementally stretched in the machine direction and below the melting point of the film.

[0026] A "multilayer structure" is a structure having more than one layer. For example, a multilayer structure may have two, three, four, five or more layers. A multilayer structure may be described as having layers represented by letters. For example, a three-layer structure having a core layer B and two outer layers A and C may be designated A / B / C.

[0027] An "olefin" is an unsaturated aliphatic hydrocarbon having a carbon-carbon double bond.

[0028] "Olefin-based polymers" (interchangeably referred to as "polyolefins") are polymers containing a majority weight % polymerized olefin monomer (based on the total amount of polymerizable monomers) and optionally may contain at least one comonomer. Non-limiting examples of olefinic polymers include vinyl polymers and propylene polymers.

[0029] As used herein, the term "polymer" or "polymeric material" refers to a compound prepared by polymerizing monomers, whether monomers of the same type or different types, which provide multiple and / or repeating "units" or "monomer units" constituting the polymer in a polymerized form. Therefore, the general term polymer covers the term homopolymer, which is usually used to refer to polymers prepared from only one type of monomer, and the term copolymer, which is usually used to refer to polymers prepared from at least two types of monomers. It also covers all forms of copolymers, such as random copolymers, block copolymers, etc. The terms "ethylene / α-olefin polymer" and "propylene / α-olefin polymer" refer to copolymers prepared by polymerizing ethylene or propylene and one or more additional polymerizable α-olefin monomers, respectively, as described above. It should be noted that although polymers are often referred to as "made of" one or more specified monomers, "based on" a specified monomer or monomer type, "containing" a specified monomer content, etc., in this context, the term "monomer" should be understood to refer to the polymerized residue of the specified monomer rather than the unpolymerized substance. In general, polymers are referred to herein as "units" based on the polymerized form of the corresponding monomers.

[0030] "Propylene-based polymers" (interchangeably referred to as "polypropylene") are polymers containing greater than 50 mole percent polymerized propylene monomer (based on the total amount of polymerizable monomers) and optionally may contain at least one comonomer. Propylene-based polymers include propylene homopolymers and propylene copolymers (meaning units derived from propylene and one or more comonomers). The terms "propylene-based polymers" and "polypropylene" are used interchangeably. Non-limiting examples of propylene-based polymers (polypropylenes) are polypropylenes having at least one C2 or C4-C 10 Propylene / α-olefin copolymers with α-olefin comonomers. DETAILED DESCRIPTION

[0031] The present disclosure provides a film structure. In one embodiment, the film structure includes a machine direction oriented (MDO) multilayer film and a metal layer. The MDO multilayer film includes (a) a first outer layer ("FOL"). The first outer layer (a) comprises (i) a FOL first ethylene / α-olefin copolymer having a density of 0.900 g / cc to 0.920 g / cc, and (ii) an optional vinyl polymer selected from (1) a FOL second ethylene / α-olefin copolymer having a density of 0.920 g / cc to 0.980 g / cc, (2) a FOL third vinyl polymer, and (3) a combination thereof. The MDO multilayer film includes (b) a first intermediate layer ("FIL") in direct contact with the first outer layer. The first intermediate layer (b) comprises a FIL first ethylene / α-olefin copolymer 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 (b). The core layer (c) comprises a CL first ethylene / α-olefin copolymer having a density of 0.920 g / cc to 0.980 g / cc. The metal layer is on the first outer layer (a).

[0032] Although the 1 MDO film is oriented in the machine direction, it is understood that the 1 MDO film can be further oriented in the transverse (or cross) direction and be a biaxially oriented film.

[0033] Each of the following terms and corresponding abbreviations are used interchangeably: first outer layer (or FOL), first intermediate layer (or FIL), core layer (or CL), second intermediate layer (or SIL), second outer layer (or SOL), first layer (FSL), second layer (SSL) and skin layer (SL). In one embodiment, each vinyl polymer (and / or each ethylene / α-olefin copolymer) is a hydrocarbon. The vinyl polymers disclosed herein are identified by location, i.e., by the film layer in which the vinyl polymer resides. It should be understood that the vinyl polymer present in the first layer (i.e., present in the skin layer or SL) may be the same as or different from the vinyl polymer present in the second layer (i.e., present in the core layer or CL). The term "different from" when it refers to a vinyl polymer (or ethylene / α-olefin copolymer) means that the vinyl polymer has at least one property or property value that is different from the corresponding property in another vinyl polymer. Non-limiting examples of vinyl 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" a second ethylene / α-olefin copolymer may have a density value that is different from the density value of the second ethylene / α-olefin copolymer.

[0034] In one embodiment, the comonomer of the ethylene / α-olefin copolymer is C3-C 12 α-olefins, or C4-C10 α-olefin, or C4-C8 α-olefin. In another embodiment, the comonomer is butene, hexene or octene.

[0035] 1.MDO multilayer film

[0036] The film structure includes 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 thereto. The first outer layer (a) directly interfaces with the metal layer. The first outer layer (a) comprises (i) a FOL first ethylene / α-olefin copolymer, (ii) an optional vinyl polymer selected from (1) a FOL second ethylene / α-olefin copolymer, (2) a FOL third vinyl polymer, (3) a combination of (1) and (2), and (iii) optional additives. The density of the FOL first ethylene / α-olefin copolymer is from 0.900 g / cc to 0.920 g / cc. In one embodiment, the melt index of the FOL first ethylene / α-olefin copolymer is from 0.2 g / 10 min to 3.0 g / 10 min or from 0.2 g / 10 min to 3 g / 10 min, and the melt temperature is from 95° C. to 125° C. or from 95° C. to 125° C.

[0037] In one embodiment, the first outer layer (a) comprises (i) a FOL first ethylene / α-olefin copolymer 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) further comprises (ii) (1) a FOL second ethylene / α-olefin copolymer, and (iii) optional additives. The FOL first ethylene / α-olefin copolymer is different from the FOL second ethylene / α-olefin copolymer. The FOL second 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. In one embodiment, the FOL second ethylene / a-olefin copolymer has a melt index from 0.5 g / 10 min to 1.5 g / 10 min and a melt temperature from 125°C to 135°C or from 125°C to 135°C. In another embodiment, outer layer (a) comprises 50 wt% to 100 wt%, or 50 wt% to 90 wt%, or 60 wt% to 90 wt%, or 85 wt% of a FOL first ethylene / α-olefin copolymer having a density of 0.900 g / cc to 0.920 g / cc and a melt temperature of 95° C. to 125° C. or 105° C. to 110° C., and 50 wt% to 0 wt%, or 50 wt% to 10 wt%, or 40 wt% to 10 wt%, or 15 wt% of a FOL second ethylene / α-olefin copolymer having a density of 0.935 g / cc to 0.980 g / cc 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 first outer layer (a).

[0038] In one embodiment, the first outer layer (a) comprises (i) a FOL first ethylene / α-olefin copolymer 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) further comprises (ii) (2) a FOL third ethylene polymer having a density of 0.918 g / cc to 0.930 g / cc and a melt temperature of 105° C. to 115° C., which is LDPE. The FOL first ethylene / α-olefin copolymer is different from the FOL third ethylene polymer. In another embodiment, the first outer layer (a) comprises (i) 50 wt% to 100 wt%, or 50 wt% to 90 wt%, or 60 wt% to 90 wt%, or 85 wt% of a first ethylene / α-olefin copolymer 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 (ii) (2) 50 wt% to 0 wt%, or 50 wt% to 10 wt%, or 40 wt% to 10 wt%, or 15 wt% of a FOL third vinyl polymer 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).

[0039] The film structure includes 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) a FIL ethylene / α-olefin copolymer, (ii) an optional FIL second ethylene / α-olefin copolymer, and (iii) an optional additive. The density of the FIL first ethylene / α-olefin copolymer is 0.920 g / cc to 0.980 g / cc or 0.935 g / cc to 0.980 g / cc.

[0040] In one embodiment, the first intermediate layer (b) comprises (i) 90 wt% to 100 wt% or 100 wt% of a FIL first ethylene / α-olefin copolymer 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 melt temperature of 125° C. to 135° C. or 125° C. to 129° C. The wt% is based on the total weight of the intermediate layer (b).

[0041] 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) 60wt% to 90wt% or 60wt% to 80wt% or 70wt% of a density of 0.935g / cc to 0.980g / cc, or 0.940g / cc to 0.980g / cc, or 0.940g / cc to 0.950g / cc, a melt index of 0.5g / 10min to 1.5g / 10min or 0.5g / 10min to less than 1.0g / 10min, and a melt temperature of 125°C to 135°C or 125°C to 129°C of the first ethylene / α-olefin copolymer of FIL. The first intermediate layer comprises (ii) 40wt% to 10wt% or 40wt% to 20wt% or 30wt% of the FIL second ethylene / α-olefin copolymer. In one embodiment, the density of the FIL second ethylene / α-olefin copolymer is 0.935g / cc to 0.980g / cc, or 0.940g / cc to 0.980g / cc, or 0.960g / cc to 0.980g / cc, a melt index of 0.5g / 10min to 1.5g / 10min or 1.0g / 10min to 1.5g / 10min, and a melt temperature of 125°C to 135°C or 130°C to 135°C. The weight % is based on the total weight of the first intermediate layer (b).

[0042] The film structure comprises an MDO multilayer film having a core layer (c). The core layer (c) is in direct contact with the first intermediate layer (b). The core layer (c) comprises (i) a CL first ethylene / α-olefin copolymer, (ii) an optional CL second ethylene / α-olefin copolymer, and (iii) optional additives. In one embodiment, the core layer (c) comprises 90 wt% to 100 wt% or 100 wt% of a CL first ethylene / α-olefin copolymer 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 0.5 g / 10 min to less than 1.0 g / 10 min, and a melt temperature of 125° C. to 135° C. or 125° C. to 129° C. The wt% is based on the total weight of the core layer (c).

[0043] In one embodiment, the film structure comprises an MDO multilayer film having a first layer (d1). The first layer (d1) is in direct contact with the core layer (c). The first layer (d1) comprises one or more vinyl polymers.

[0044] In one embodiment, the first layer (d1) comprises (i) FSL first ethylene / α-olefin copolymer, (ii) optional FSL second ethylene / α-olefin copolymer, and (iii) optional additives. The FSL first ethylene / α-olefin copolymer is different from the FSL second ethylene / α-olefin copolymer. The first layer (d1) comprises (i) 60 wt% to 100 wt%, or 60 wt% to 90 wt%, or 60 wt% to 80 wt%, or 70 wt% of the FSL first ethylene / α-olefin copolymer. In one embodiment, the FSL first ethylene / α-olefin copolymer 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 0.5 g / 10 min to less than 1.0 g / 10 min, and a melt temperature of 125° C. to 129° C. The first layer (d) comprises (ii) 40 wt% to 0 wt%, or 40 wt% to 10 wt%, or 40 wt% to 20 wt%, or 30 wt%% of the FSL second ethylene / α-olefin copolymer. In one embodiment, the density of the FSL second ethylene / α-olefin copolymer is from 0.935 g / cc to 0.980 g / cc, or from 0.940 g / cc to 0.980 g / cc, or from 0.960 g / cc to 0.980 g / cc, a melt index of from 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 from 130° C. to 135° C. The weight percent is based on the total weight of the first layer (d1). In another embodiment, the composition of the first layer (d1) is the same as the composition of the first intermediate layer (b).

[0045] In one embodiment, the first layer (d1) comprises 90 wt% to 100 wt% or 100 wt% of 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.

[0046] In one embodiment, the MDO multilayer film comprises additional sublayers (d2), (d3), (d4) and (d5) and optionally additional sublayers. Each sublayer comprises a vinyl polymer and optional additives. In another embodiment, one of the sublayers (d2), (d3), (d4) and (d5) comprises ethylene vinyl alcohol (EVOH), and the remaining sublayers each comprise a vinyl polymer.

[0047] 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 SL first ethylene / α-olefin copolymer, (ii) an optional SL second ethylene / α-olefin copolymer, and (iii) optional additives.

[0048] In one embodiment, the skin layer (e) is in direct contact with the sublayer (d1). The skin layer (e) comprises (i) 50 wt% to 0 wt%, or 50 wt% to 10 wt%, or 40 wt% to 20 wt%, or 30 wt% of the SL first ethylene / α-olefin copolymer. In one embodiment, the density of the SL first ethylene / α-olefin copolymer is 0.900 g / cc to 0.920 g / cc, the melt index is 0.5 g / 10 min to 1.5 g / 10 min or 0.5 g / 10 min to less than 1.0 g / 10 min, and the melt temperature is 95°C to 125°C or 105°C to 110°C. The skin layer (e) comprises (ii) 50% to 100 wt%, or 50 wt% to 90 wt%, or 60 wt% to 80 wt%, or 70 wt% of the SL second ethylene / α-olefin copolymer. In one embodiment, the density of the SL second ethylene / α-olefin copolymer is from 0.935 g / cc to 0980 g / cc, or from 0.940 g / cc to 0.980 g / cc, or from 0.960 g / cc to 0.980 g / cc, the melt index is from 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 the melt temperature is from 125° C. to 135° C. or from 130° C. to 135° C. The SL first ethylene / α-olefin is different from the SL second ethylene / α-olefin. The weight percentages are based on the total weight of the skin layer (e).

[0049] In one embodiment, the skin layer (e) is in direct contact with the sublayer other than (d1), i.e., one of (d2), or (d3), or (d4), or (d5). The skin layer (e) comprises 90 wt% to 100 wt% (and optional additives) or 100 wt% of the SL first ethylene / α-olefin copolymer, 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 % is based on the total weight of the second skin layer (e).

[0050] 2. Additives

[0051] Each layer in the MDO multilayer film may include 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, slip agents, flame retardants, plasticizers, polymer processing aids (PPA), lubricants, stabilizers, smoke suppressants, viscosity control agents, surface modifiers, and antiblocking agents. When present, the amount of the additive is greater than 0 wt% to 5 wt%, or 0.01 wt% to 4 wt%, or 0.01 wt% to 3 wt%, or 0.01 wt% to 2.0 wt%, or 0.01 wt% to 1.0 wt%, or 0.05 wt% to 1.0 wt% of the MDO multilayer film layer. The weight % is based on the total weight of the corresponding film layer containing the additive.

[0052] 3. Metal layer

[0053] The MDO multilayer film includes a metal layer. The metal layer is on the first outer layer (a) and the metal layer directly contacts the first outer layer (a). In one embodiment, the first outer layer (a) is exposed to a plasma treatment before the metal / metal oxide deposition to improve metal adhesion.

[0054] Non-limiting examples of plasma treatment techniques include solution spraying, spin coating, coating, or adding hydrophilic additives to the film structure. For example, the hydrophilic treatment can be applied via plasma treatment, wherein the film structure is exposed to an atmospheric plasma that contains an inert gas and a substance with polar groups, and which can be evaporated or made into an aerosol, and which forms free radicals when exposed to a dielectric barrier discharge. Atmospheric plasma systems and methods are generally described in U.S. Pat. No. 5,433,786, the disclosure of which is incorporated herein by reference.

[0055] The metal (and / or metal oxide) is deposited on the first outer layer (a) of the MDO multilayer film. Non-limiting procedures for applying the metal / metal oxide to the first outer layer (a) include vapor deposition (chemical or physical) or vacuum metallization. For vacuum metallization, the metal source evaporates in a vacuum environment, and when 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 suitable metals for the metal layer include aluminum (Al), silicon (Si), zinc (Zn), gold (Au), silver (Ag), copper (Cu), nickel (Ni), chromium (Cr), germanium (Ge), selenium (Se), titanium (Ti), tin (Sn), their oxides, and combinations thereof. The thickness of the metal layer is 10 nanometers to 60 nanometers (nm), or 15nm to 60nm, or 10nm to 45nm, or 15nm to 45nm, or 15nm to 40nm. The bonding strength of the metal layer to the first outer layer (a) (interchangeably referred to as metal adhesion) is greater than or equal to 1.5 N / 25 mm, 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.

[0056] In one embodiment, the metal layer is formed of aluminum and / or aluminum oxide (e.g., Al2O3), and the thickness of the metal layer is 10nm to 60nm, or 15nm to 60nm, or 10nm to 45nm, or 15nm to 45nm, or 15nm to 40nm.

[0057] In one embodiment, the film structure has a thickness of 20 microns to 30 microns or 25 microns and comprises

[0058] A first outer layer (a), the first outer layer comprising

[0059] (i) 60 wt% to 90 wt%, or 70 wt% to 90 wt% of a FOL first ethylene / α-olefin copolymer 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 a melt temperature of 120°C to 125°C, and

[0060] (ii) 40 wt% to 10 wt% or 30 wt% to 10 wt% of another vinyl polymer,

[0061] Selected from

[0062] (1) Density is 0.935 g / cc to 0.980 g / cc or 0.960 g / cc to 0.980 g / cc, melt index

[0063] The number is 0.5 g / 10 min to 1.5 g / 10 min, and the melt temperature is 125°C to 135°C

[0064] or a FOL second ethylene / α-olefin copolymer at 130°C to 135°C, or

[0065] (2) FOL third vinyl polymer, the FOL third vinyl polymer is a low density

[0066] Polyethylene;

[0067] A first intermediate layer (b), the first intermediate layer comprising

[0068] (i) a FIL first ethylene / α-olefin copolymer having a density of 0.935 g / cc to 0.980 g / cc, and optionally

[0069] (ii) 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

[0070] The FIL second ethylene / α-olefin having a melt temperature 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.

[0071] hydrocarbon copolymers;

[0072] A core layer (c), the core layer comprising

[0073] (i) 0.935 g / cc to 0.980 g / cc or 0.940 g / cc to 0.950 g / cc with a melt index of 0.5 g / 10

[0074] min to 1.5g / 10min or 0.5g / 10min to less than 1.0g / 10min, and the melt temperature

[0075] A first ethylene / α-olefin copolymer having a CL temperature of 125° C. to 135° C. or 125° C. to 129° C.;

[0076] one or more optional sublayers (d1), (d2), (d3), (d4), (d5);

[0077] The epidermis (e), which contains

[0078] (i) Density of 0.935 g / cc to 0.980 g / cc or 0.960 g / cc to 0.980 g / cc, melt index

[0079] The SL first ethylene / α-olefin having a melt temperature 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.

[0080] hydrocarbon copolymers;

[0081] a metal layer having a thickness of 10 nm to 60 nm and comprising a metal selected from the group consisting of aluminum, aluminum oxide, and combinations thereof; and

[0082] A membrane structure having one, some or all of the following properties

[0083] (1) 0.1 cm 3 / m 2 Day to 120cm 3 / m 2 / day, or 0.5cm 3 / m 2 / day to 115cm 3 / m 2 / sky,

[0084] or 0.7cm 3 / m 2 / day to 110cm 3 / m 2 / day OTR value, and / or

[0085] (2) 0.1 g / m 2 / day to 2.5g / m 2 / day, or 0.2g / m 2 / day to 2.0g / m 2 / day, or 0.3g / m 2 /

[0086] Day to 1.9g / m 2 / day WVTR value, and / or

[0087] (3) Metal adhesion value of 2.5 N / 25 mm to 10 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.

[0088] In one embodiment, the MDO multilayer film comprises at least 95 wt%, or at least 97 wt%, or at least 99 wt% of the vinyl polymer, based on the total weight of the MDO multilayer film.

[0089] In one embodiment, the MDO multilayer film consists solely of vinyl polymers (except for the metal layer).

[0090] Test Method

[0091] density Measured according to ASTM D792, Method B. Results are reported in grams per cubic centimeter (g / cc).

[0092] Melt Index (I2) Measured according to ASTM D-1238 at 190°C and 2.16 kg. Values ​​are reported in g / 10 min, which corresponds to grams eluted per 10 minutes.

[0093] Melt temperature. Differential Scanning Calorimetry (DSC) measurements were performed on a differential scanning calorimeter. The sample (about 3 mg) was loaded into an aluminum calorimetry pan and heated from -40°C to 150°C at a heating rate of 10°C / min under an argon atmosphere. The sample was exposed to a complete heating and cooling cycle to remove any thermal history prior to measurement.

[0094] Metal layer adhesion . The adhesion strength (or "bonding strength" or "metal adhesion") of the metal layer to the first outer layer (layer (a)) of each MDO multilayer film was measured as follows. Each film structure was heat sealed to a 100 micron film made of an ethylene acrylic acid copolymer having an acrylic acid content of about 7% ("EAA film"), wherein the metal layer of the film structure was in contact with the EAA film. The film structure and the EAA film were heat sealed by placing the film between an upper jaw at 110°C and a lower jaw at 70°C, wherein the upper jaw was in contact with the EAA film and the lower jaw was in contact with the film structure. The jaws were in contact with the EAA film and the film structure for 20 seconds at a pressure of 5 bars. After aging for 24 hours at room temperature, the metal adhesion strength (or bonding strength) was then measured using an Instron 5567 tensile machine by measuring T-peel with a load cell of 100N at a test speed of 12 inches / minute. The average value is reported as the metal adhesion strength (or bond strength) between the first outer layer (a) of the MDO multilayer film and the metal layer, where the results are reported in Newtons (N) / 25 mm or N / 25 mm.

[0095] Optical density test method. Densitometer instruments are used to measure the optical density of films. Mark the sample at 10 evenly spaced intervals across the width with the metal side facing up. Place the densitometer in diffuse mode and set for visible light transmittance. Test the sample with the metal side facing up. Take extreme care when handling the material to avoid scratches, pinholes, etc. American Standard No. PH2-19-1959 provides the basis for the concept of diffuse optical density.

[0096] Oxygen Transmission Rate (OTR).The oxygen transmission rate (OTR) was measured according to ASTM D3985. The samples were placed at 23°C, 0% relative humidity (RH), 50 cm 2 Sample size tested. Values ​​in cm 3 / day / m 2 Report.

[0097] Water Vapor Transmission Rate (WVTR). The water vapor transmission rate (WVTR) was measured according to ASTM F1249. The samples were placed at 37.8°C, 100% RH and 50 cm 2 The sample size is tested. The value is expressed in g / day / m 2 Report.

[0098] The embodiments of the present disclosure are offered by way of example and not limitation.

[0099] Example

[0100] The materials used in the comparative samples (CS) and the inventive examples (IE) are provided in Table 1.

[0101] Table 1 – Materials

[0102]

[0103] 1. Fabrication of MDO multilayer membranes

[0104] Five coextruded multilayer films - comparative sample (CS) 1, CS2, inventive 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 blown film production line with an MDO online 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 corresponding Tables 2A to 2E.

[0105] Table 2A CS1-MDO Multilayer Film - 25 Micron Thickness

[0106] CS1 First outer layer (a) – 10% 90% 6900 + 10% 5400GS First intermediate (b) - 20% 5940ST Core layer (c) 10% 5400GS Bonding layer - 10% <![CDATA[BYNEL TM 41E687B]]> Barrier - 10% T101B Bonding layer - 10% <![CDATA[BYNEL TM 41E687B]]> First layer (d1) - 10% 5400GS Second layer (d2) - 10% 5940ST Epidermis (e) - 10% 6900

[0107] Weight percentage based on the total weight of each layer (where indicated)

[0108] Table 2B CS2-MDO Multilayer Film - 25 Micron Thickness

[0109] CS2 First outer layer (a) - 15% 92% ADSYL 3C30FHP +8% BYNEL 22E780 First intermediate (b) - 12.5% 5940ST-75%+PL 1880G-25% Core layer (c) - 12.5% 5940ST-75%+PL 1880G-25% First layer (d1) - 7% 5400GS Second layer (d2) - 6% 5400GS Third layer (d3) - 7% 5400GS Fourth layer (d4) - 12.5% 5940ST Fifth layer (d5) - 12.5% 5940ST Epidermis (e) - 15% 6900

[0110] Weight percentage based on the total weight of each layer (where indicated)

[0111] Table 2C IE3-MDO Multilayer Film - 25 micron thickness

[0112]

[0113]

[0114] Weight percentage based on the total weight of each layer (where indicated)

[0115] Table 2D IE4-MDO Multilayer Film - 25 micron thickness

[0116] IE4 First outer layer (a) - 14% 85% ELITE AT 6410 + 15% ELITE AT 6900 First intermediate layer (b) - 21% 30% 6900 + 70% 5940ST Core layer (c) - 30% 5940ST First layer (d1) – 24.5% 30% 6900 + 70% 5940ST Epidermis (e) - 10.5% 30%ELITE AT 6410+70%6900

[0117] Weight percentage based on the total weight of each layer (where indicated)

[0118] Table 2E IE5-MDO Multilayer Film - 25 micron thickness

[0119] IE5 First outer layer (a) - 11% 80% ELITE AT 6410 + 20% LDPE 2MI First intermediate layer (b) - 16% 5940ST Core layer (c) – 8% 5940ST First layer (d1) – 9% 69B1003.00 Second layer (d2) – 8% J171B Third layer (d3) - 9% 69B1003.00 Fourth layer (d4) - 12% 5940ST Fifth layer (d5) - 11% 6900 Epidermis (e) - 16% 6900

[0120] Weight percentage based on the total weight of each layer (where indicated)

[0121] 2. Fabrication of membrane structures with metal layers

[0122] Each MDO multilayer film (CS1, CS2, IE3, IE4, IE5) was subjected to a plasma treatment. After the plasma treatment, a metal layer of aluminum metal was applied to the first outer layer (a) of each MDO multilayer film CS1, IE2, IE3 and IE4.

[0123] 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. For each MDO multilayer film, the aluminum metal layer is in direct contact with the first outer layer (a).

[0124] Table 3 – Membrane structure properties

[0125]

[0126] Weight percentage based on the total weight of each layer (where indicated)

[0127] Examples IE3, IE4, and IE5 of the present invention each unexpectedly exhibited excellent OTR (0.1 cm 3 / m 2 Day to 120cm 3 / m 2 / day) and excellent WVTR (0.1g / m 2 / day to 2.5g / m 2 / day) while providing strong metal adhesion (2.5N / 25mm to 10N / 25mm).

[0128] It is particularly intended that the present disclosure is not limited to the embodiments and descriptions contained herein, but includes modifications of those embodiments including parts of the embodiments and combinations of elements of different embodiments as appear within the scope of the following claims.

Claims

1. A membrane structure, comprising: A machine direction oriented (MDO) multilayer film comprising (a) a first outer layer (FOL), the first outer layer comprising (i) a FOL first ethylene / α-olefin copolymer having a density of 0.900 g / cc to 0.920 g / cc, and (ii) an optional vinyl polymer selected from the group consisting of: (1) a FOL second ethylene / α-olefin copolymer having a density from 0.920 g / cc to 0.980 g / cc; as well as (2) FOL third vinyl polymer (LDPE); (b) a first intermediate layer (FIL), the first intermediate layer being in direct contact with the first outer layer, the first intermediate layer (FIL) comprising a FIL first ethylene / α-olefin copolymer having a density of 0.920 g / cc to 0.980 g / cc; (c) a core layer (CL) directly contacting the first intermediate layer, the core layer comprising a CL first vinyl polymer having a density of 0.920 g / cc to 0.980 g / cc; and A metal layer is on the first outer layer (a).

2. The film structure according to claim 1, wherein the first outer layer (a) comprises (i) 50 wt% to 100 wt% of said FOL first ethylene / α-olefin copolymer having a density of 0.900 g / cc to 0.920 g / cc and a melt temperature of 95°C to 125°C, and (ii) 50 wt% to 0 wt% of said FOL second ethylene / α-olefin copolymer having a density of 0.940 g / cc to 0.980 g / cc and a melt temperature of 125°C to 135°C, the wt% based on the total weight of the first outer layer (a).

3. The film structure according to claim 1, wherein the first outer layer (a) comprises (i) 50 wt% to 100 wt% of said FOL first ethylene / α-olefin copolymer having a density of 0.900 g / cc to 0.920 g / cc and a melt temperature of 95°C to 125°C, and (ii) 50 wt% to 0 wt% of the FOL third vinyl polymer, the FOL third vinyl polymer is a low density polyethylene.

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

5. The film structure according to any one of claims 1 to 3, wherein the first intermediate layer comprises (i) 60 wt% to 90 wt% of the FIL first ethylene / α-olefin copolymer having a density of 0.935 g / cc to 0.980 g / cc and a melt temperature of 125°C to 135°C; and (ii) 40 to 10 wt% of a FIL second ethylene / α-olefin copolymer having a density of 0.940 to 0.980 g / cc and a melt temperature of 125 to 135°C, and the weight % 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 wt% to 100 wt% of a CL first ethylene / α-olefin copolymer having a density greater than or equal to 0.935 g / cc to 0.980 g / cc and a melt temperature of 125°C to 135°C, the weight % being 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), the first sublayer (d1) comprising a vinyl polymer.

8. The film structure of any one of claims 1 to 7, comprising a skin layer (e), the skin layer comprising the SK first ethylene / α-olefin copolymer 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, their oxides and combinations thereof. 10 . The film structure of 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 thickness of the metal layer is 10 nm to 60 nm.

12. The film structure according to any one of claims 1 to 11, wherein the film structure comprises a first outer layer (a), the first outer layer comprising (i) 70 wt% to 90 wt% of said FOL first ethylene / α-olefin copolymer having a density of 0.900 g / cc to 0.920 g / cc, and (ii) 30 wt% to 10 wt% of another vinyl polymer selected from the group consisting of: (1) said FOL second ethylene / α-olefin copolymer having a density of 0.935 g / cc to 0.980 g / cc and a melt temperature of 125° C. to 135° C., and (2) the third vinyl polymer of FOL, wherein the third vinyl polymer of FOL is low density polyethylene; The first intermediate layer (b), the first intermediate layer comprises (i) a first ethylene / α-olefin copolymer of the FIL having a density of 0.935 g / cc to 0.980 g / cc; The core layer (c) comprises (i) said CL first ethylene / α-olefin copolymer having a density of 0.935 g / cc to 0.980 g / cc; one or more optional sublayers; The epidermal layer (SL) comprises (i) a SL first ethylene / α-olefin copolymer having a density of 0.935 g / cc to 0.980 g / cc; the metal layer, the metal layer comprising a metal selected from the group consisting of aluminum, aluminum oxide, and combinations thereof; and The membrane structure has (1) 0.1 cm 3 / m 2 / day up to 120cm 3 / m 2 OTR value per day, (2) 0.1 g / m 2 / day to 2.5g / m 2 / day WVTR value, and (3) Metal adhesion values ​​of 2.5 N / 25 mm to 10 N / 25 mm.

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