Laminate having longitudinally oriented multilayer film

Abstract

The present disclosure provides a laminate. In an embodiment, the laminate includes a first longitudinal oriented (1MDO) multilayer film. The 1MDO multilayer film comprises (a) a skin layer comprising: (i) a skin layer (SL) first ethylene / alpha-olefin copolymer having a density of from 0.870 g / cc to 0.920 g / cc; and (ii) optionally a skin layer (SL) second ethylene / alpha-olefin copolymer having a density of from 0.900 g / cc to 0.980 g / cc. The 1MDO multilayer film includes: (b) a first intermediate layer in direct contact with the skin layer. The first intermediate layer comprises: (i) a first intermediate layer (FIL) first ethylene / a-olefin copolymer having a density of from 0.940 g / cc to 0.980 g / cc; and (ii) a first intermediate layer (FIL) second ethylene / alpha-olefin copolymer having a density of from 0.916 g / cc to 0.980 g / cc. The 1MDO multilayer film comprises (c) a core layer in direct contact with the first intermediate layer (b). The core layer (c) comprises: (i) a core layer (CL) first ethylene / alpha-olefin copolymer having a density of from 0.915 g / cc to 0.980 g / cc. The 1MDO multilayer film comprises (d) a second intermediate layer in direct contact with the core layer. The second intermediate layer comprises an ethylene-based polymer. The 1MDO multilayer film includes (e) an inner layer in direct contact with the second intermediate layer. The inner layer comprises an ethylene-based polymer. The laminate includes a second machine direction oriented (2MDO) film and an adhesive layer between the 1MDO multilayer film and the 2MDO film.

Description

Technical Field

[0001] The present disclosure relates to laminates, and more particularly to laminates comprising multilayer films oriented in a machine direction. Background Art

[0002] Polyolefin films are widely used in flexible packaging, both as stand-alone packaging and as laminated films. In an effort to improve recyclability and extend sustainability, the flexible packaging market is moving toward single-material solutions based on ethylene-based polymers (commonly referred to as "polyethylene"). As a result, efforts to downgauge polyethylene films continue in search of thinner, tougher, stiffer, and lower-cost solutions for flexible packaging.

[0003] Longitudinally oriented (MDO) film is a method for thinning polyethylene and providing rigidity and optical properties to film. However, when oriented in the longitudinal direction, due to unidirectional orientation, the tear strength of the film based on polyethylene in the longitudinal direction can be weakened. Therefore, the polyethylene in the film is often blended with one or more non-polyethylene resins, or the polyethylene film is often laminated with another non-polyethylene film (for example, polyethylene terephthalate, polypropylene film) to achieve the desired physical film properties. However, the film of the cladding polyethylene resin and the non-polyethylene resin may be difficult or impossible to recycle. Similarly, although the oriented polypropylene laminate with cast polypropylene structure can provide some desired properties in packaging, this type of laminate is not easy to recycle.

[0004]

[0006] Thus, there is a recognized need in the art for laminates and MDO multilayer films comprising polyethylene that can be recycled and provide suitable tear strength, stiffness, optics, and heat sealability for flexible packaging applications. Summary of the invention

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

[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 the 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 in contact with" or "in direct contact with..." or similar terms refer to a layer configuration whereby a first layer is positioned 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 (greater than 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). 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). The density of LDPE resins is typically 0.916 g / cm 3 Up to 0.935g / cm 3 within the range.

[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 via gas phase, solution phase, or slurry polymerization, or any combination thereof, using any type of reactor or reactor configuration.

[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 with a density of 0.935 g / cm 3 Up to about 0.980g / 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 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-based 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 multilayer film.

[0025] "Machine direction oriented film" or "MDO film" is a film stretched (or oriented) in the machine direction at 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 orienting 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] "Multilayer structure" refers to 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 olefin-based polymers include ethylene-based polymers and propylene-based 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. The general term also covers all forms of copolymers, such as random copolymers, block copolymers, etc. The terms "ethylene / α-olefin polymer" and "propylene / α-olefin polymer" represent 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 generally 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 % polypropylene 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 (polypropylene) 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 laminate. In an embodiment, the laminate comprises

[0032] A first machine direction oriented (1MDO) multilayer film, the 1MDO multilayer film being attached to a second machine direction oriented (2MDO) film. The 1MDO multilayer film comprises: (a) a skin layer ("SL"), (b) a first intermediate layer ("FIL"), (c) a core layer ("CL"), (d) a second intermediate layer ("SIL"), and (e) an inner layer ("IL"). The skin layer (a) comprises: (i) a SL first ethylene / α-olefin copolymer having a density of 0.870 g / cc to 0.920 g / cc; and (ii) an optional SL second ethylene / α-olefin copolymer having a density of 0.900 g / cc to 0.980 g / cc. The first intermediate layer (b) is in direct contact with the skin layer (a), and the first intermediate layer (b) comprises: (i) a first ethylene / α-olefin copolymer of FIL having a density of 0.940 g / cc to 0.980 g / cc; and (ii) a second ethylene / α-olefin copolymer of FIL having a density of 0.916 g / cc to 0.980 g / cc. The core layer (c) is in direct contact with the first intermediate layer (b). The core layer (c) comprises: (i) a first ethylene / α-olefin copolymer of CL having a density of 0.900 g / cc to 0.920 g / cc. The second intermediate layer (d) is in direct contact with the core layer (c). The second intermediate layer (d) comprises an ethylene-based polymer. The inner layer (e) is in direct contact with the second intermediate layer (d). The inner layer (e) comprises an ethylene-based polymer.

[0033] Although the 1MDO film is oriented in the machine direction, it is understood that the 1MDO film can be further oriented in the transverse (or cross) direction and be a biaxially oriented film.

[0034] Each of the following terms and corresponding abbreviations may be used interchangeably: skin layer (or SL), first intermediate layer (or FIL), core layer (or CL), second intermediate layer (or SIL), and inner layer (or IL). Each ethylene-based polymer (and / or each ethylene / α-olefin copolymer) is a hydrocarbon. The ethylene-based polymers disclosed herein are identified by location, i.e., by the film layer in which the ethylene-based polymer resides. It should be understood that the ethylene-based polymer present in the first layer (i.e., present in the skin layer or SL) may or may not be the same as the ethylene-based polymer present in the second layer (i.e., present in the core layer or CL). When referring to an ethylene-based polymer (or ethylene / α-olefin copolymer), the term "different from" indicates that the ethylene-based polymer has at least one property or property value that is different from the corresponding property in another ethylene-based polymer. Non-limiting examples of properties of ethylene-based polymers (or ethylene / α-olefin copolymers) 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.

[0035] In an embodiment, the comonomer of the ethylene / α-olefin copolymer is C3-C 12 α-olefins, or C4-C 10 In yet another embodiment, the comonomer is butene, hexene or octene.

[0036] 1. The first MDO multilayer film

[0037] The laminate includes a 1MDO multilayer film, and the 1MDO multilayer film includes a skin layer (a). The skin layer (a) is the outermost layer of the laminate. The skin layer (a) can be a sealing layer. The skin layer (a) contains: (i) a SL first ethylene / α-olefin copolymer; (ii) an optional SL second ethylene / α-olefin copolymer; and (iii) an optional additive. The density of the SL first ethylene / α-olefin copolymer is 0.870 g / cc to 0.920 g / cc, or 0.900 g / cc to 0.920 g / cc. The melt index of the SL first ethylene / α-olefin copolymer can be 0.5 g / 10 min to 1.5 g / 10 min, and the melt temperature can be 55° C. to 125° C., or 120° C. to 125° C. When present, the SL second ethylene / α-olefin copolymer may have a density of 0.900 g / cc to 0.980 g / cc, or 0.920 g / cc to 0.980 g / cc, or 0.900 g / cc to 0.935 g / cc, or 0.900 g / cc to 0.920 g / cc, a melt index of 0.5 g / 10 min to 1.5 g / 10 min, and a melt temperature of 95° C. to 135° C., or 95° C. to 105° C., or 120° C. to 135° C. In an embodiment, the skin layer (a) comprises: 50 wt% to 80 wt%, or 50 wt% to 70 wt%, or 55 wt% to 65 wt% of the SL first ethylene / α-olefin copolymer, and 50 wt% to 20 wt%, or 50 wt% to 30 wt%, or 40 wt% to 30 wt% of the SL second ethylene / α-olefin copolymer. The weight percentages are based on the total weight of the skin layer (a). It is understood that the weight percentages of the skin layer (a) total 100 weight percent. With respect to the film layer weight percentages, it is further understood that for each existing layer disclosed herein, the weight percentages total 100 weight percent.

[0038] The laminate comprises a 1MDO multilayer film, the 1MDO multilayer film comprising a first intermediate layer (b). The first intermediate layer (b) is in direct contact with the skin layer (a). The first intermediate layer (b) comprises: (i) a FIL first ethylene / α-olefin copolymer, (ii) a FIL second ethylene / α-olefin copolymer, and (iii) an optional additive. The FIL first ethylene / α-olefin copolymer is different from the FIL second ethylene / α-olefin copolymer. The density of the FIL first ethylene / α-olefin copolymer is 0.940 g / cc to 0.980 g / cc, or 0.940 g / cc to 0.950 g / cc. The melt index of the FIL first ethylene / α-olefin copolymer may be 0.5 g / 10 min to 1.5 g / 10 min, and the melt temperature may be 125° C. to 135° C., or 125° C. to 130° C. The first intermediate layer (b) also contains: (ii) a FIL second ethylene / α-olefin copolymer, the density of the FIL second ethylene / α-olefin copolymer is 0.916 g / cc to 0.980 g / cc, or 0.940 g / cc to 0.980 g / cc, or 0.960 g / cc to 0.980 g / cc. The melt index of the FIL second ethylene / α-olefin copolymer may be 0.5 g / 10 min to 1.5 g / 10 min, and the melt temperature may be 125° C. to 135° C., or 130° C. to 135° C. In an embodiment, the first intermediate layer comprises 40 wt % to 80 wt %, or 50 wt % to 70 wt %, or 50 wt % to 60 wt % of the FIL first ethylene / α-olefin copolymer, and 60 wt % to 20 wt %, or 50 wt % to 30 wt %, or 50 wt % to 40 wt % of the FIL second ethylene / α-olefin copolymer. The weight percentages are based on the total weight of the first intermediate layer.

[0039] The laminate comprises a 1MDO multilayer film, the 1MDO multilayer film comprising 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) an optional additive. The density of the CL first ethylene / α-olefin copolymer is 0.915 g / cc to 0.980 g / cc, or 0.900 g / cc to 0.920 g / cc, or 0.910 g / cc to 0.920 g / cc. The melt index of the CL first ethylene / α-olefin copolymer may be 0.5 g / 10 min to 1.5 g / 10 min, and the melt temperature may be 120° C. to 135° C., or 120° C. to 125° C.

[0040] In an embodiment, the core layer (c) comprises: (i) a first ethylene / α-olefin copolymer of Cl, (ii) a second ethylene / α-olefin copolymer of CL, and (iii) an optional additive. The first ethylene / α-olefin copolymer of CL is different from the second ethylene / α-olefin copolymer of CL. The density of the first ethylene / α-olefin copolymer of CL is from 0.915 g / cc to 0.980 g / cc, or from 0.900 g / cc to 0.920 g / cc, or from 0.910 g / cc to 0.920 g / cc, and the melt index may be from 0.5 g / 10 min to 1.5 g / 10 min, and the melt temperature is from 120°C to 135°C, or from 120°C to 125°C. The core layer (c) also contains: (ii) a second ethylene / α-olefin copolymer of CL. The density of the CL second ethylene / α-olefin copolymer is 0.940 g / cc to 0.980 g / cc, or 0.940 g / cc to 0.950 g / cc, and the melt index may be 0.5 g / 10 min to 1.5 g / 10 min, and the melt temperature is 125° C. to 135° C., or 125° C. to 130° C. In another embodiment, the core layer (c) comprises 10 wt % to 50 wt %, or 10 wt % to 40 wt %, or 20 wt % to 40 wt % of the CL first ethylene / α-olefin copolymer, and 90 wt % to 50 wt %, or 90 wt % to 60 wt %, or 80 wt % to 60 wt % of the CL second ethylene / α-olefin copolymer. The weight percentages are based on the total weight of the core layer (c).

[0041] The laminate comprises a 1MDO multilayer film, the 1MDO multilayer film comprising a second intermediate layer (d). The second intermediate layer (d) is in direct contact with the core layer (c). The second intermediate layer (d) comprises: (i) one or more ethylene-based polymers, and (ii) optional additives. The second intermediate layer (d) may comprise: (i) a SIL first ethylene / α-olefin copolymer, (ii) an optional SIL second ethylene / α-olefin copolymer, and (iii) optional additives.

[0042] In an embodiment, the second intermediate layer (d) comprises: (i) a SIL first ethylene / α-olefin copolymer, (ii) a SIL second ethylene / α-olefin copolymer, and (iii) optional additives. The density of the SIL first ethylene / α-olefin copolymer is 0.900 g / cc to 0.920 g / cc, or 0.910 g / cc to 0.920 g / cc, and the melt index may be 0.5 g / 10 min to 1.5 g / 10 min, and the melt temperature is 120° C. to 125° C. The second intermediate layer (d) also contains (ii) a SIL second ethylene / α-olefin copolymer. The density of the SIL second ethylene / α-olefin copolymer is greater than or equal to 0.940 g / cc to 0.980 g / cc, or 0.940 g / cc to 0.950 g / cc, and the melt index may be 0.5 g / 10 min to 1.5 g / 10 min, and the melt temperature is 125° C. to 135° C., or 125° C. to 130° C. In another embodiment, the second intermediate layer (d) comprises 10 wt % to 50 wt %, or 20 wt % to 40 wt %, or 30 wt % to 40 wt % of the SIL first ethylene / α-olefin copolymer, and 90 wt % to 50 wt %, or 80 wt % to 60 wt %, or 70 wt % to 60 wt % of the SIL second ethylene / α-olefin copolymer. The weight percentage is based on the total weight of the second intermediate layer (d). In another embodiment, the composition of the second intermediate layer (d) is the same or equivalent to the composition of the core layer (c).

[0043] The laminate comprises a 1MDO multilayer film, and the 1MDO multilayer film comprises an inner layer (e). The inner layer (e) is interfaced with the adhesive layer. The inner layer (e) comprises: (i) (one or more) ethylene-based polymers and (ii) optional additives. The inner layer (e) may comprise: (i) IL first ethylene / α-olefin copolymer, (ii) optional IL second ethylene / α-olefin copolymer and (iii) optional additives. The density of the IL first ethylene / α-olefin copolymer is 0.940 g / cc to 0.980 g / cc.

[0044] In an embodiment, the inner layer (e) comprises: (i) IL first ethylene / α-olefin copolymer, (ii) IL second ethylene / α-olefin copolymer, and (iii) optional additives. The density of the IL first ethylene / α-olefin copolymer is 0.940g / cc to 0.980g / cc, or 0.960g / cc to 0.980g / cc, and the melt index may be 0.5g / 10min to 1.5g / 10min, and the melt temperature is 130°C to 135°C. The inner layer (e) also includes IL second ethylene / α-olefin copolymer. The density of the IL second ethylene / α-olefin copolymer is 0.900g / cc to 0.920g / cc, or 0.910g / cc to 0.920g / cc, and the melt index may be 0.5g / 10min to 1.5g / 10min, and the melt temperature is 95°C to 125°C, or 120°C to 125°C. In another embodiment, inner layer (e) comprises 50 wt % to 90 wt %, or 60 wt % to 80 wt %, or 65 wt % to 75 wt % of the first ethylene / alpha-olefin copolymer of IL, and 50 wt % to 10 wt %, or 40 wt % to 20 wt %, or 35 wt % to 25 wt % of the second ethylene / alpha-olefin copolymer of IL. The weight percentages are based on the total weight of inner layer (e).

[0045] The 1MDO multilayer film includes a skin layer (a), which is the outermost layer of the laminate and may be a sealant. The intermediate layer (b) is located between the skin layer (a) and the core layer (c) and is in direct contact with them. The core layer (c) is located between the first intermediate layer (b) and the second intermediate layer (d) and is in direct contact with them. The second intermediate layer (d) is located between the core layer (c) and the inner layer (e) and is in direct contact with them. The inner layer (e) is the outermost layer of the MDO multilayer film and is interfaced with the adhesive layer. The MDO1 multilayer film has a thickness of 10 microns to 50 microns, or 15 microns to 40 microns, or 20 microns to 30 microns, or 25 microns. Each layer in the 1MDO multilayer film may contain only one or more ethylene-based polymers (and optional additives), or only consist of one or more ethylene-based polymers (and optional additives). In an embodiment, the 1MDO multilayer film comprises at least 95 wt%, or at least 97 wt%, or at least 99 wt% ethylene-based polymer, based on the total weight of the 1MDO multilayer film. In another embodiment, the 1MDO multilayer film consists of or consists essentially of ethylene-based polymer (and optional additives).

[0046] 2. Second MDO membrane

[0047] The laminate includes a second longitudinally oriented (2MDO) film. The 2MDO film can be a monolayer film or a multilayer film. When the 2MDO film is a multilayer film, the 2MDO film can have two, or three, or four, or five, or six, or seven, or eight, or nine, or more layers. Although the 2MDO film is oriented in the longitudinal direction, it should be understood that the 2MDO film can be further oriented in the transverse (or cross) direction and is a biaxially oriented film.

[0048] In an embodiment, the 2MDO film is a multilayer film and includes an outermost layer (interchangeably referred to as "ol") comprising (i) a 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; (ii) an optional second ethylene / α-olefin copolymer; and (iii) optional additives. The laminate includes an adhesive layer between and in direct contact with the inner layer (e) of the 1MDO multilayer film and the outermost layer of the 2MDO multilayer film.

[0049] In an embodiment, the 2MDO film is a multilayer film and includes an outermost layer (ol), an outer middle layer (interchangeably referred to as "om") in direct contact with the outermost layer (ol), a middle layer (interchangeably referred to as "ml") in direct contact with the outer middle layer (om), an inner middle layer (interchangeably referred to as "im") in direct contact with the middle layer (ml), and an inner layer (interchangeably referred to as "in") in direct contact with the inner middle layer (im). The 2MDO multilayer film has an unblocked layer configuration ol / om / ml / im / in or a blocked layer configuration ol / om / ml / im / in / in / im / ml / om / ol. Each layer in the 2MDO multilayer film may comprise only one or more ethylene-based polymers (and optional additives), or consist only of one or more ethylene-based polymers (and optional additives). In an embodiment, the 2MDO film comprises at least 95 wt%, or at least 97 wt%, or at least 99 wt% of an ethylene-based polymer, based on the total weight of the 2MDO film. In an embodiment, the 2MDO film consists of or consists essentially of an ethylene-based polymer (and optional additives).The 2MDO multilayer film has a thickness of 10 microns to 50 microns, or 15 microns to 40 microns, or 20 microns to 30 microns, or 25 microns.

[0050] 3. Additives

[0051] Each layer in the 1MDO multilayer film and / or the 2MDO 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 one or more additives total greater than 0% to 5% by weight, or 0.01% to 4% by weight, or 0.05% to 3% by weight, or 0.01% to 1.0% by weight, or 0.05% to 1.0% by weight of the MDO multilayer film layer. The weight % is based on the total weight of the corresponding film layer containing the one or more additives.

[0052] 4. Adhesive layer

[0053] The laminate comprises an adhesive layer. The adhesive layer is between the inner layer (e) of the 1MDO multilayer film and the outermost layer (ol) of the 2MDO multilayer film, so that the adhesive layer is in direct contact with the inner layer (e) and in direct contact with the outermost layer (ol). The adhesive layer adheres the 1MDO film or otherwise attaches it to the 2MDO film. Non-limiting examples of suitable adhesive materials for adhesive layer include solvent-based adhesives, solvent-free adhesives, aqueous adhesives, polyurethane, epoxy resins, acrylic acid, extruded polyethylene, etc. In an embodiment, the laminate comprises an adhesive layer consisting of a polyurethane adhesive. The adhesive may be solvent-free, aqueous or solvent-based. In addition, the adhesive may be a part or two-part formulation. The two parts crosslink or otherwise combine the 1MDO multilayer film with the 2MDO film. The coating weight of the adhesive layer is 1 gram per square meter (gsm) to 5gsm.

[0054] As used herein, the term "heat sealing conditions" refers to providing two separate laminates arranged so that the two skin layers (a) are opposite to each other and in contact with each other (hereinafter interchangeably referred to as "the first skin layer (a) is in contact with the second skin layer (a)"). The two laminates are placed between opposing heat sealing bars, and the heat sealing bars are moved toward each other, thereby sandwiching the two laminates to apply heat and pressure to the two laminates so that the opposing skin layers (a) contact, melt and form a heat seal or weld, thereby attaching the two laminates together. The heat seal includes a suitable structure and mechanism for moving the sealing bars toward and away from each other in order to perform the heat sealing procedure. The heat sealing conditions further include applying 2.5Kg / cm2 of heat to the two laminates at a temperature ranging from 85°C to 130°C in increments of 5°C ("sealing temperature") in accordance with ASTM F88. 2The heat seal strength is reported as the average peak load (in Kg / 25mm) for each corresponding temperature.

[0055] In an embodiment, the laminate forms a heat seal strength of greater than or equal to 0.3 Kg / 25 mm, or 0.3 Kg / 25 mm to 0.8 Kg / 25 mm, or 0.5 Kg / 25 mm to 0.8 Kg / 25 mm, under heat sealing conditions of sealing pressure, 0.5 second dwell time, and 95° C. sealing temperature. In an embodiment, the laminate comprises at least 95 wt%, or at least 97 wt%, or at least 99 wt% of the ethylene-based polymer, based on the total weight of the laminate.

[0056] Test Method

[0057] density Measured according to ASTM D792, Method B. Results are expressed in grams per cubic centimeter (g / cc or g / cm 3 ) as the unit to report.

[0058] Heat seal initiation temperature and seal strength To determine the heat seal initiation temperature (HSIT) and seal strength, the samples were sealed by a heat sealing device with opposing sealing jaws. The sample width was 25 mm, the dwell seal time for a thickness of less than 100 microns was 0.5 seconds, and the sealing pressure was 2.5 kg / cm 2 The heat seal samples were conditioned for 24 hours and then measured using a tensile machine equipped with a 100N load cell and a tensile speed of 500mm / min. HSIT is reported as the minimum temperature in degrees Celsius for obtaining a seal strength force of 0.3 Newton (0.3Kg). Seal strength values ​​are reported in Kg / 25mm.

[0059] Heat seal strength Heat seal strength or seal strength was measured according to ASTM F88. The values ​​are reported in Kg / 25mm.

[0060] Melt Index (I2 or MI) is measured according to ASTM D-1238 at 190°C under 2.16 kg. Values ​​are reported in g / 10 min, which corresponds to grams eluted per 10 minutes.

[0061] Melt temperatureDifferential 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 a nitrogen atmosphere. The sample was exposed to a complete heating and cooling cycle to remove any thermal history prior to measurement.

[0062] The embodiments of the present disclosure are offered by way of example and not limitation.

[0063] Example

[0064] The materials used in the comparative samples (CS) and the inventive examples (IE) are provided in Table 1.

[0065] Table 1 - Materials

[0066]

[0067]

[0068] *-Non-limiting example of ethylene / α-olefin copolymer identified by layer and number.

[0069] Fabrication of MDO membranes

[0070] 1. The first MDO multilayer film (heat-sealable MDO film)

[0071] Two multilayer films were produced on a Windmoller & Holscher coextrusion apparatus, each with a layer configuration a / b / c / d / e and a layer ratio of 1 / 1 / 1 / 1 / 1. The two heat-sealable MDO films were designated "MDO-PE (HS-1)" and "MDO-PE (HS-2)", as shown in Table 2 below.

[0072] Table 2

[0073]

[0074] Wt% - based on the total weight of each corresponding layer

[0075] The original thickness of each primary multilayer film IE1 and IE2 (pre-oriented) was 125 μm. In the MDO unit roll, each primary multilayer film was stretched at a stretch ratio of 5:1 at a preheating temperature of 100°C to 110°C, a stretching temperature of 110°C to 115°C, an annealing temperature of 105°C to 110°C, a cooling roll temperature of 80°C to 85°C and 40°C to 45°C to produce an MDO multilayer film (1MDO) having a final thickness of 25 μm (yield: 1000 kg / hr).

[0076] 2. Second MDO film (printed film)

[0077] For the production of the second MDO film, a Windmoller & Holscher 5-layer blown coextrusion unit produced a closed multilayer film having a layer configuration ol / om / ml / im / in / in / im / ml / om / ol and layer ratios 1 / 1 / 1 / 1 / 1 / 2 / 1 / 1 / 1 / 1 as shown in Table 3A below.

[0078] Table 3A Closing membrane, layer configuration ol / om / m / im / in / in / im / ml / om / ol

[0079] layer 3A membrane structure formulation ("MDO Blocked A") (ol) Outer layer <![CDATA[100% ELITE TM AT6900 (or 100% of 5960G1)]]> (om) outer middle layer <![CDATA[100% of ELITE5940ST (or 100% of DOWLEX TM 2038.68)]]> (ml) Middle layer 70% Elite 5940ST + 30% Elite 5400G (im) inner middle layer 100% Elite 5940ST (in)Inner layer <![CDATA[80% AFFINITY TM EG8100G + 20% AFFINITY TM 1880G]]>

[0080] The weight percentages are based on the total weight of each corresponding layer.

[0081] A Windmoller & Holscher 5-layer blown coextrusion apparatus produced an unoccluded multilayer film having a layer configuration o / om / m / im / i and a layer ratio of 1 / 1 / 1 / 1 / 1 as shown in Table 3B below.

[0082] Table 3B Unblocked membrane, layer configuration ol / om / ml / im / in

[0083] layer 3B membrane structure formulation ("MDO unblocked B") (ol) Outer layer <![CDATA[100% ELITE TM AT6900 (or 100% ELITE TM 5960G1)]]> (om) outer middle layer <![CDATA[100% of ELITE5940ST (or 100% of DOWLEX TM 2038.68)]]> (ml) Middle layer 70% Elite 5940ST + 30% Elite 5400G (im) inner middle layer 100% Elite 5940ST (in)Inner layer <![CDATA[100% ELITE TM AT6900 (or 100% ELITE TM 5960G1)]]>

[0084] The weight percentages are based on the total weight of each corresponding layer.

[0085] The original thickness of each primary multilayer film 3A and 3B was 130 microns. In the MDO unit roll, each primary film was stretched at a stretch ratio of 6.5:1 at a preheating temperature of 105°C to 110°C, a stretching temperature of 110°C to 120°C, an annealing temperature of 105°C to 120°C, a cooling roll temperature of 80°C to 85°C and 40°C to 45°C to produce a final thickness of 20 microns MDO multilayer film (2MDO). MDO multilayer film 3A (from Table 3A) is a closed film (hereinafter referred to as "MDO closed A"). MDO multilayer film 3B (from Table 3B) is an unclosed film (hereinafter referred to as "MDO unclosed B").

[0086] 3. Fabrication of Laminated Body

[0087] By using K-bar coating and hot roll laminator, using SF adhesive MORFREE TM 899A / C99, SB adhesive-ADCOTE TM 545EA / COREACTANT F adhesive, laminates prepared using solvent-free (SF) and solvent-based (SB) lamination methods.

[0088] Table 4 - Seal strength of laminated structures at different temperatures (in Kg / 25mm)

[0089]

[0090] Each of IE1 to IE8 unexpectedly has a seal strength greater than 0.3 Kg / 25 mm at a low heat seal initiation temperature (95°C). A heat seal strength of 0.3 Kg / 25 mm at 95°C is suitable for many flexible packaging applications. Each of IE1 to IE8 consists only of polyethylene (no polypropylene) and is compatible with polyethylene recycle streams. CS1 and CS2 each contain polypropylene (BOPP, or biaxially oriented polypropylene) or cast polypropylene (CPP), and CS1 / CS2 are not easily recyclable.

[0091] 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 laminate, comprising: A first machine direction oriented (1MDO) multilayer film, the 1MDO multilayer film comprising (a) a skin layer, the skin layer comprising (i) a skin layer (SL) first ethylene / α-olefin copolymer having a density of 0.870 g / cc to 0.920 g / cc, and (ii) an optional skin layer (SL) second ethylene / α-olefin copolymer having a density from 0.900 g / cc to 0.980 g / cc; (b) a first intermediate layer, the first intermediate layer being in direct contact with the epidermis layer, the first intermediate layer comprising (i) a first intermediate layer (FIL) first ethylene / α-olefin copolymer having a density of 0.940 g / cc to 0.980 g / cc, and (ii) a first intermediate layer (FIL) second ethylene / α-olefin copolymer having a density from 0.916 g / cc to 0.980 g / cc; (c) a core layer, the core layer being in direct contact with the first intermediate layer (b), the core layer (c) comprising (i) a core layer (CL) first ethylene / α-olefin copolymer having a density of 0.915 g / cc to 0.980 g / cc; (d) a second intermediate layer, the second intermediate layer being in direct contact with the core layer, the second intermediate layer comprising an ethylene-based polymer; (e) an inner layer, the inner layer being in direct contact with the second intermediate layer, the inner layer comprising an ethylene-based polymer; a second machine direction oriented (2MDO) film; as well as An adhesive layer is between the 1MDO multi-layer film and the 2MDO film.

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

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

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

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

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

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

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

9. The laminate according to claim 8, wherein the 2MDO multilayer film comprises The outermost layer (ol); an outer middle layer (om), the outer middle layer being in direct contact with the outer layer (ol); a middle layer (ml), said middle layer being in direct contact with said outer middle layer (om); an inner intermediate layer (im), the inner intermediate layer being in direct contact with the intermediate layer (ml); and An inner layer (in), the inner layer is in direct contact with the inner intermediate layer (im).

10. The laminate of claim 9, wherein the 2MDO multilayer film consists solely of one or more ethylene-based polymers.

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

12. The laminate according to any one of claims 1 to 11, comprising: a first epidermal layer (a), the first epidermal layer being in contact with the second epidermal layer (a); A heat seal, the heat seal is between the first skin layer (a) and the second skin layer (a); and the heat seal is at 2.5 kg / cm 2 The heat sealing strength under heat sealing conditions of sealing pressure, 0.5 second dwell time and 95° C. sealing temperature is greater than or equal to 0.3 kg / 25 mm.

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