Multilayer polyethylene films with a thin layer loaded with a mineral and ethylene copolymer

Abstract

A multilayer film includes a first outer layer, a second outer layer, and at least one inner layer positioned between the first outer layer and the second outer layer. The at least one inner layer includes: greater than or equal to 5 wt.% CaCO3 based on a total weight of the inner layer; greater than or equal to 5 wt.% of an ethylene copolymer selected from the group consisting of ethylene / butyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / methyl acrylate copolymer, and ethylene / vinyl acetate copolymer based on the total weight of the inner layer; and greater than or equal to 25 wt.% of a combination of the CaCO3 and the ethylene copolymer based on the total weight of the inner layer. The inner layer is greater than or equal to 2% and less than or equal to 40% of the total thickness of the multilayer film

Description

MULTILAYER POLYETHYLENE FILMS WITH A THIN LAYER LOADED WITH A MINERAL AND ETHYLENE COPOLYMERCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of Spanish Patent Application No. P202330543 filed June 28, 2023, the contents of which are incorporated in their entirety herein.TECHNICAL FIELD

[0002] Embodiments of the present disclosure generally relate to multilayer films, and more particularly relate to multilayer films including a thin layer comprising a mineral and ethylenebased copolymers.INTRODUCTION

[0003] Multilayer films that incorporate ethylene-based polymers, are widely used in industrial and consumer products. Such films used in industrial and consumer products often require desirable properties such as sufficient tear resistance — for example, to avoid the film from breakage during use. The combination of layers and materials can allow for good performance of the films, but there is a continued need to produce ever stronger multilayer films as well as thinner films and / or films that use less ethylene-based polymers.SUMMARY

[0004] Embodiments of the present disclosure meet one or more of the foregoing needs by providing multilayer films that exhibit desirable tear resistance and include recycle-compatible ethylene-based polymers. Higher mechanical resistance makes films more suitable for packaging applications by providing less environmental impact, higher consumer convenience, and less food waste — in the case of food packaging. However, multilayer films comprised of ethylene-based films often have lower mechanical resistance than multilayer films comprising other polymers, such as propylene, amide, and terephthalate.

[0005] The multilayer films of embodiments disclosed and described herein have improved tear resistance compared to similar multilayer films. Moreover, multilayer films according to one or more embodiments are thin multilayer films that have the same or similar tear resistance compared to thicker films. In addition, multilayer films according to embodiments use lessethylene-based polymers and are less costly to make than fdms with comparable, or lesser, tear resistance. The multilayer fdms according to embodiments disclosed herein comprise at least a first outer layer, second outer layer, and an inner layer, wherein the inner layer comprises a mineral and an ethylene-based copolymer and is less than 40% of the total thickness of the multilayer film. Without being bound by theory, among the other features, the structure of the film with a thin inner layer and a specific combination of a mineral and ethylene-based copolymer results in surprisingly desirable tear resistance and maintained or improved dart impact when compared to existing film structures.

[0006] Disclosed herein are multilayer films. In one aspect, a multilayer film comprises: a first outer layer; a second outer layer; at least one inner layer positioned between the first outer layer and the second outer layer, wherein the at least one inner layer comprises: greater than or equal to 5 wt.% CaCOs based on a total weight of the at least one inner layer; greater than or equal to 5 wt.% of an ethylene copolymer selected from the group consisting of ethylene / butyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / methyl acrylate copolymer, and ethylene / vinyl acetate copolymer based on the total weight of the at least one inner layer; greater than or equal to 25 wt.% of a combination of the CaCC and the ethylene copolymer based on the total weight of the at least one inner layer; and greater than or equal to 2% and less than or equal to 40% of the total thickness of the multilayer fdm.

[0007] These and other embodiments are described in more detail in the Detailed Description.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is a scatter plot showing Elmendorf tear in the machine direction based on the amounts of ethylene copolymer and calcium carbonate (CaCCb) in an inner layer according to embodiments disclosed and described herein;

[0009] FIG. 2 is a scatter plot showing Elmendorf tear in the cross direction based on the amounts of ethylene copolymer and CaCOs in an inner layer according to embodiments disclosed and described herein;

[0010] FIG. 3 is a scatter plot showing puncture energy based on the amounts of ethylene copolymer and CaCOs in an inner layer according to embodiments disclosed and described herein;

[0011] FIG. 4 is a scater plot showing dart impact based on the amounts of ethylene copolymer and CaCC in an inner layer according to embodiments disclosed and described herein;

[0012] FIG. 5 is a bar graph showing Elmendorf tear in the machine direction for comparative samples 7-9 and samples 12 and 13 of films according to the examples provided herein;

[0013] FIG. 6 is a bar graph showing Elmendorf tear in the cross direction for comparative samples 7-9 and samples 12 and 13 of films according to the examples provided herein;

[0014] FIG. 7 is a bar graph showing Elmendorf tear in the machine direction for comparative sample 10 and samples 14-17 of films according to the examples provided herein;

[0015] FIG. 8 is a bar graph showing Elmendorf tear in the cross direction for comparative sample 10 and samples 14-17 of films according to the examples provided herein;

[0016] FIG. 9 is a bar graph showing Elmendorf tear in the machine direction for comparative samples 11-14 and samples 18-21 of films according to the examples provided herein;

[0017] FIG. 10 is a bar graph showing Elmendorf tear in the cross direction for comparative samples 11-14 and samples 18-21 of films according to the examples provided herein;

[0018] FIG. 11 is a bar graph showing Elmendorf tear in the machine direction for comparative sample 15 and samples 22-25 of films according to the examples provided herein; and

[0019] FIG. 12 is a bar graph showing Elmendorf tear in the cross direction for comparative sample 15 and samples 22-25 of films according to the examples provided herein.DETAILED DESCRIPTION

[0020] Aspects of the disclosed multilayer films are described in more detail below. The multilayer films can have a wide variety of applications, including, for example, cast stretch films, blown films, oriented films, stretch hood films, or the like. The multilayer films are also suited for use in trash bag or trash liner, heavy duty shipping sack, mattress film, food storage, frozen food storage, fertilizer storage, silage, and grain storage applications. This disclosure, however, should not be construed to limit the embodiments set forth below as this disclosure is an illustrative implementation of the embodiments described herein.

[0021] As used herein, the term “polymer” means a polymeric compound prepared by polymerizing monomers, whether of the same or a different type. The generic term polymer thus embraces the term homopolymer (employed to refer to polymers prepared from only one type of monomer), and the term copolymer. Trace amounts of impurities (for example, catalyst residues) may be incorporated into and / or within the polymer. A polymer may be a single polymer, a polymer blend, or a polymer mixture, including mixtures of polymers that are formed in situ during polymerization.

[0022] As used herein, the term “copolymer” means a polymer formed by the polymerization reaction of at least two structurally different monomers. The term “copolymer” is inclusive of terpolymers. For example, ethylene-based copolymers, such as ethylene / butyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / methyl acrylate copolymer, and ethylene / vinyl acetate copolymer, include at least two structurally different monomers (e.g., ethylene / butyl acrylate copolymer includes copolymerized units of at least 50 wt.% ethylene monomer and butyl acrylate comonomer) and can optionally include additional monomers or functional materials or modifiers, such as acid, acrylate, or anhydride functional groups. Put another way, the copolymers described herein comprise at least two structurally different monomers, and although the copolymers may consist of only two structurally different monomers, they do not necessarily consist of only two structurally different monomers and may include additional monomers or functional materials or modifiers.

[0023] As used herein, the term “ethylene-based copolymer” shall mean copolymers comprising a majority amount (>50 wt.%) of units derived from ethylene monomer and units of at least one different comonomer. Ethylene-based copolymers are ethylene-based polymers as that term is defined below. Examples of ethylene-based copolymers include ethylene / butyl acrylate copolymer (units of ethylene monomer copolymerized with units of butyl acrylate comonomer), ethylene / ethyl acrylate copolymer (units of ethylene monomer copolymerized with units of ethyl acrylate comonomer), ethylene / methyl acrylate copolymer (units of ethylene monomer copolymerized with units of methyl acrylate comonomer), and ethylene / vinyl acetate copolymer (units of ethylene monomer copolymerized with units of vinyl acetate comonomer).

[0024] As used herein, the terms “polyethylene” or “ethylene-based polymer” shall mean polymers comprising a majority amount (>50 wt.%) of units which have been derived from ethylene monomer. This includes polyethylene homopolymers and ethylene-based copolymers.Unless expressly stated otherwise, the ethylene-based copolymers disclosed herein (e.g., ethylene / butyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / methyl acrylate copolymer, and ethylene / vinyl acetate copolymer) are ethylene-based polymers.

[0025] Common forms of polyethylene known in the art include Low Density Polyethylene (LDPE); Linear Low Density Polyethylene (LLDPE); Ultra Low Density Polyethylene (ULDPE); Very Low Density Polyethylene (VLDPE); Medium Density Polyethylene (MDPE); and High Density Polyethylene (HDPE) either polymerized with a heterogeneous catalyst — such as, for example, a Ziegler-Natta type catalyst — or with a single-site catalyst. These polyethylene materials are generally known in the art; however, the following descriptions may be helpful in understanding the differences between some of these different polyethylene resins.

[0026] The term “LDPE” may also be referred to as “high pressure ethylene polymer” or “highly branched polyethylene” and is defined to mean that the polymer is partly or entirely homopolymerized or copolymerized in autoclave or tubular reactors at pressures above 14,500 psi (100 MPa) with the use of free-radical initiators, such as peroxides (see for example US 4,599,392, which is hereby incorporated by reference). LDPE resins typically have a density in the range of 0.916 to 0.935 g / cm3.

[0027] The term “LLDPE”, includes both resin made using the traditional Ziegler-Natta catalyst systems and chromium-based catalyst systems as well as single-site catalysts, including, but not limited to, substituted mono- or bis-cyclopentadienyl catalysts (typically referred to as metallocene), constrained geometry catalysts, phosphinimine catalysts & polyvalent aryloxyether catalysts (typically referred to as bisphenyl phenoxy), and includes linear, substantially linear or heterogeneous polyethylene copolymers or homopolymers. LLDPEs contain less long chain branching than LDPEs and include the substantially linear ethylene polymers which are further defined in U.S. Patent 5,272,236, U.S. Patent 5,278,272, U.S. Patent 5,582,923 and US Patent 5,733,155; the homogeneously branched linear ethylene polymer compositions such as those in U.S. Patent No. 3,645,992; the heterogeneously branched ethylene polymers such as those prepared according to the process disclosed in U.S. Patent No. 4,076,698; and / or blends thereof (such as those disclosed in US 3,914,342 or US 5,854,045). LLDPEs can be made via gas-phase, solution-phase or slurry polymerization or any combination thereof, using any type of reactor or reactor configuration known in the art.

[0028] The term “MDPE” refers to polyethylenes having densities from 0.926 to 0.935 g / cm3. “MDPE” is typically made using chromium or Ziegler-Natta catalysts or using single-site catalysts including, but not limited to, substituted mono- or bis-cyclopentadienyl catalysts (typically referred to as metallocene), constrained geometry catalysts, phosphinimine catalysts & polyvalent aryloxyether catalysts (typically referred to as bisphenyl phenoxy), and typically have a molecular weight distribution (“MWD”) greater than 2.5.

[0029] The term “HDPE” refers to polyethylenes having densities greater than about 0.935 g / cm3and up to about 0.980 g / cm3, which are generally prepared with Ziegler-Natta catalysts, chrome catalysts or single-site catalysts including, but not limited to, substituted mono- or bis- cyclopentadienyl catalysts (typically referred to as metallocene), constrained geometry catalysts, phosphinimine catalysts & polyvalent aryloxyether catalysts (typically referred to as bisphenyl phenoxy).

[0030] The term “UEDPE” refers to polyethylenes having densities of 0.855 to 0.912 g / cm3, which are generally prepared with Ziegler-Natta catalysts, chrome catalysts, or single-site catalysts including, but not limited to, substituted mono- or bis-cyclopentadienyl catalysts (typically referred to as metallocene), constrained geometry catalysts, phosphinimine catalysts & polyvalent aryloxy ether catalysts (typically referred to as bisphenyl phenoxy). UEDPEs include, but are not limited to, polyethylene (ethylene-based) plastomers and polyethylene (ethylenebased) elastomers.

[0031] As used herein, the term “inner layer” refers to a non-skin or non-outer layer of a multilayer fdm. An inner layer is an internal layer, i.e., a layer positioned between two outer layers, of a multilayer fdm. In one embodiment, an inner layer is the non-outer layer of a three-layer fdm that comprises a first outer layer and a second outer layer.

[0032] The terms “comprising,” “including,” “having,” and their derivatives, are not intended to exclude the presence of any additional component, step or procedure, whether or not the same is specifically disclosed. In order to avoid any doubt, all compositions claimed through use of the term “comprising” may include any additional additive, adjuvant, or compound, whether polymeric or otherwise, unless stated to the contrary. In contrast, the term, “consisting essentially of’ excludes from the scope of any succeeding recitation any other component, step or procedure,excepting those that are not essential to operability. The term “consisting of’ excludes any component, step or procedure not specifically delineated or listed.

[0033] Disclosed herein are multilayer films. In embodiments, the multilayer film can be an oriented film that is oriented in the machine and / or cross direction. In embodiments, the multilayer film is a blown film. In other embodiments, the multilayer film is a cast film. In further embodiments, the multilayer film is a stretch hood film.

[0034] The multilayer films according to embodiments disclosed herein comprise a first outer layer, a second outer layer, and at least one inner layer. The at least one inner layer is positioned between the first outer layer and the second outer layer. It should be understood that in embodiments, the multilayer film may comprise more than one inner layer, such as two inner layers, three inner layers, four inner layers, etc., and each inner layer may individually comprise a mineral and an ethylene-based copolymer as described herein. However, in embodiments including more than one inner layer, not every inner layer necessarily comprises a mineral and an ethylene-based copolymer as described herein, but at least one inner layer comprises a mineral and an ethylene-based copolymer as described herein. The at least one inner layer comprises a first core layer that comprises an ethylene -based copolymer selected from the group consisting of ethylene / butyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / methyl acrylate copolymer, and ethylene / vinyl acetate copolymer.

[0035] A first aspect is a multilayer film comprising: a first outer layer; a second outer layer; at least one inner layer positioned between the first outer layer and the second outer layer, wherein the at least one inner layer comprises: greater than or equal to 5 wt.% CaCC based on a total weight of the at least one inner layer; greater than or equal to 5 wt.% of an ethylene copolymer selected from the group consisting of ethylene / butyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / methyl acrylate copolymer, and ethylene / vinyl acetate copolymer based on the total weight of the at least one inner layer; greater than or equal to 25 wt.% of a combination of the CaCOs and the ethylene copolymer based on the total weight of the at least one inner layer; and greater than or equal to 2% and less than or equal to 40% of the total thickness of the multilayer fdm.

[0036] A second aspect includes a multilayer fdm of the first aspect, wherein the at least one inner layer comprises greater than or equal to 40 wt.% of a combination of the CaCC and the ethylene copolymer based on the total weight of the at least one inner layer.

[0037] A third aspect includes a multilayer fdm of any of the preceding aspects, wherein the at least one inner layer comprises greater than or equal to 15 wt.% of CaCC based on the total weight of the at least one inner layer.

[0038] A fourth aspect includes a multilayer fdm of any of the preceding aspects, wherein the at least one inner layer comprises greater than or equal to 15 wt.% of the ethylene copolymer based on the total weight of the at least one inner layer.

[0039] A fifth aspect includes a multilayer fdm of any of the preceding aspects, wherein an amount of CaCOs and ethylene copolymer in the at least one inner layer satisfies the following inequality:where y is the amount of ethylene copolymer in wt.% and x is the amount of CaC'Os in wt.% based on the total weight of the at least one inner layer.

[0040] A sixth aspect includes a multilayer fdm of any of the preceding aspects, wherein an amount of CaCOs and ethylene copolymer in the at least one inner layer satisfies the following inequality:where y is the amount of ethylene copolymer in wt.% and x is the amount of CaC'Os in wt.% based on the total weight of the at least one inner layer.

[0041] A seventh aspect includes a multilayer fdm of any of the preceding aspects, wherein the at least one inner layer further comprises an ethylene-based polymer.

[0042] An eighth aspect includes the multilayer fdm of the seventh aspect, wherein the at least one inner layer comprises the ethylene-based polymer in an amount that is less than or equal to 75 wt.% based on the total weight of the at least one inner layer.

[0043] A ninth aspect includes a multilayer film of any of the preceding aspects, wherein the multilayer film has greater than or equal to 12% and less than or equal to 400% improvement in Elmendorf Tear in the cross-direction compared to a multilayer film having equivalent outer layer compositions and thickness but does not comprise the CaCC and the ethylene copolymer in an inner layer.

[0044] A tenth aspect includes a multilayer film of any of the preceding aspects, wherein the multilayer film has greater than or equal to 13% and less than or equal to 400% improvement in Elmendorf Tear in the machine-direction compared to a multilayer film having equivalent outer layer compositions and thickness but does not comprise the CaCOs and the ethylene copolymer in an inner layer.

[0045] An eleventh aspect includes a multilayer film of any of the preceding aspects, wherein the multilayer film has a thickness that is greater than or equal to 25 microns and less than or equal to 100 microns.

[0046] A twelfth aspect includes a multilayer film of any of the preceding aspects, wherein the at least one inner layer comprises greater than or equal to 5% and less than or equal to 30% of the thickness of the multilayer film.

[0047] A thirteenth aspect includes a multilayer film of any of the preceding aspects, wherein the inner layer comprises greater than or equal to 5% and less than or equal to 10% of the thickness of the multilayer film.

[0048] A fourteenth aspect includes a multilayer film of any of the preceding aspects, wherein at least one of the first outer layer and the second outer layer comprises EEDPE, EDPE, UEDPE, MDPE, HDPE, and combinations thereof.

[0049] A fifteenth aspect includes a multilayer film of any of the preceding aspects, wherein the first out layer and the second outer layer comprise greater than or equal to 60% and less than or equal to 98% of the total thickness of the multilayer film.

[0050] A multilayer film of the present disclosure can comprise a combination of two or more aspects as described herein.

[0051] First Outer Payer and Second Outer Payer of Multilayer Film

[0052] The first outer layer and the second outer layer of the multilayer film are not particularly limited. The first outer layer and the second outer layer can have the same polymer composition or different polymer composition. In embodiments, the first outer layer and the second outer layer have a thickness that is greater than or equal to 60% of the total thickness of the multilayer film, such as greater than or equal to 65% of the total thickness of the multilayer film, greater than or equal to 65% of the total thickness of the multilayer film, greater than or equal to 70% of the total thickness of the multilayer film, greater than or equal to 75% of the total thickness of the multilayer film, greater than or equal to 80% of the total thickness of the multilayer film, greater than or equal to 85% of the total thickness of the multilayer film, greater than or equal to 90% of the total thickness of the multilayer film, or greater than or equal to 95% of the total thickness of the multilayer film.

[0053] In embodiments, the first outer layer and the second outer layer each comprise a polyethylene having a density less than 0.950 g / cc and a melt index (E) of less than 7 g / 10 min. All individual values and subranges less than or equal to 0.950 g / cm3are included and disclosed herein; for example, the density of the polyethylene can be from a lower limit of 0.870 g / cm3to an upper limit of 0.940, 0.935, 0.925, 0.920 or 0.915 g / cm3. All individual values and subranges between 0.870 and 0.950 g / cm3are included and disclosed herein. All individual values and subranges of a melt index (I2) of less than 7 g / 10 min are disclosed and included herein. For example, the melt index (I2) of the polyethylene can be less than 6 g / 10 min, less than 5 g / 10 min, less than 4 g / 10 min, less than 3 g / 10 min, less than 2 g / 10 min, or less than 1 g / 10 min.

[0054] In embodiments, the first outer layer and / or the second outer layer comprise an ethylene-based polymer such as an ULDPE, LLDPE, LDPE, MDPE, or HDPE. For example, in embodiments, the first outer layer and / or the second outer layer comprise an ULDPE, LLDPE, an LDPE, or a blend thereof.

[0055] In embodiments where the first outer layer and / or the second outer layer comprise an TTDPE, the TTDPE can have a density less than or equal to 0.935 g / cm3. All individual values and subranges less than or equal to 0.935 g / cm3are included and disclosed herein; for example, the density of the linear low density polyethylene can be from a lower limit of 0.870 g / cm3to an upper limit of 0.928, 0.925, 0.920 or 0.915 g / cm3. All individual values and subranges between 0.870 and 0.930 g / cm3are included and disclosed herein.

[0056] Polyethylenes that are suited for use in the first outer layer and / or second outer layer of embodiments of the present invention include, without limitation, ultra-low density polyethylene (ULDPE), low density polyethylene (LDPE), polyethylene plastomer / elastomer, linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), high density polyethylene (EIDPE), other ethylene -based polymers (e.g., enhanced polyethylene) having a density less than 0.980 g / cm3, olefin block copolymers, and combinations thereof. Various commercially available polyethylenes are contemplated for use as polyolefins in embodiments disclosed herein. Examples of commercially available ULDPE that can be used in embodiments of the present invention include ATTANE™ ultra low density polyethylene commercially available from The Dow Chemical Company. Examples of commercially available LLDPE that can be used in embodiments of the present invention include DOWLEX™ linear low density polyethylene commercially available from The Dow Chemical Company. Examples of other commercially available ethylene-based polymers that can be used in embodiments include those available from The Dow Chemical Company under the names INNATE™.

[0057] Inner Layer of Multilayer Film

[0058] The multilayer film comprises at least one inner layer positioned between the first outer layer and the second outer layer. In embodiments, the multilayer film comprises one inner layer and in other embodiments, the multilayer film comprises more than one inner layer, such as two inner layers, three inner layers, four inner layers, etc. The at least one inner layer comprises greater than greater than or equal to 5 wt.% CaCOs based on the total weight of the at least one inner layer, and the at least one inner layer comprises greater than or equal to 5 wt.% of an ethylene copolymer selected from the group consisting of ethylene / butyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / methyl acrylate copolymer, and ethylene / vinyl acetate copolymer, based on the total weight of the at least one inner layer. In total, the at least one inner layer comprises greater than or equal to 25 wt.% of a combination of the CaCCh and the ethylene copolymer based on the total weight of the at least one inner layer.

[0059] In embodiments, the multilayer film comprises greater than or equal to 10 wt.%, such as greater than or equal to 15 wt.%, greater than or equal to 20 wt.%, greater than or equal to 25 wt.%, greater than or equal to 30 wt.%, greater than or equal to 35 wt.%, greater than or equal to 40 wt.%, or greater than or equal to 45 wt.% CaCCh based on the total weight of the at least one inner layer. In one or more embodiments, the at least one inner layer comprises greater than orequal to 5 wt.% and less than or equal to 70 wt.% CaCC based on the total weight of the at least one inner layer, such as greater than or equal to 10 wt.% and less than or equal to 65 wt.% CaCC based on the total weight of the at least one inner layer, greater than or equal to 15 wt.% and less than or equal to 60 wt.% CaCOs based on the total weight of the at least one inner layer, greater than or equal to 20 wt.% and less than or equal to 55 wt.% CaCOs based on the total weight of the at least one inner layer, greater than or equal to 25 wt.% and less than or equal to 50 wt.% CaCC based on the total weight of the at least one inner layer, or greater than or equal to 30 wt.% and less than or equal to 45 wt.% CaCC based on the total weight of the at least one inner layer.

[0060] The CaCOs may, in embodiments, have a particle size diameter D50 that is less than or equal to 2.0 pm, such as less than or equal to 1.7 pm, less than or equal to 1.5 pm, less than or equal to 1.2 pm, less than or equal to 1.0 pm, or less than or equal to 0.7 pm.

[0061] In embodiments, the at least one inner layer comprises greater than or equal to 10 wt.%, such as greater than or equal to 15 wt.%, greater than or equal to 20 wt.%, greater than or equal to 25 wt.%, greater than or equal to 30 wt.%, greater than or equal to 35 wt.%, greater than or equal to 40 wt.%, or greater than or equal to 45 wt.% of an ethylene copolymer selected from the group consisting of ethylene / butyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / methyl acrylate copolymer, and ethylene / vinyl acetate copolymer based on the total weight of the at least one inner layer. In one or more embodiments, the at least one inner layer comprises greater than or equal to 5 wt.% and less than or equal to 80 wt.% of the ethylene copolymer based on the total weight of the at least one inner layer, such as greater than or equal to 15 wt.% and less than or equal to 70 wt.% of the ethylene copolymer based on the total weight of the at least one inner layer, greater than or equal to 25 wt.% and less than or equal to 60 wt.% of ethylene copolymer based on the total weight of the at least one inner layer, or greater than or equal to 35 wt.% and less than or equal to 50 wt.% of ethylene copolymer based on the total weight of the at least one inner layer.

[0062] In embodiments, the ethylene copolymer selected from the group consisting of ethylene / butyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / methyl acrylate copolymer, or ethylene / vinyl acetate copolymer of the at least one inner layer has a density of from 0.900 g / cc to 0.950 g / cc. All individual values and subranges of from 0.900 g / cc to 0.950 g / cc are disclosed and included herein. For example, the ethylene-based copolymer of the firstcore layer can have a density of from 0.900 g / cc to 0.945 g / cc, from 0.905 g / cc to 0.945 g / cc, from 0.910 g / cc to 0.945 g / cc or from 0.920 g / cc to 0.945 g / cc.

[0063] In embodiments, the ethylene copolymer selected from the group consisting of ethylene / butyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / methyl acrylate copolymer, or ethylene / vinyl acetate copolymer of the at least one inner layer has a melt index (I2) of less than 5 g / 10 min. All individual values and subranges of less than 5 g / 10 min are disclosed and included herein. For example, the ethylene-based copolymer can have a melt index (I2) of less than 5 g / 10 min, less than 4 g / 10 min, less than 3 g / 10 min, less than 2 g / 10 min, or less than 1 g / 10 min.

[0064] In embodiments, the ethylene / vinyl acetate copolymer comprises from 9 to 28 wt.% vinyl acetate comonomer, based on the total weight of the ethylene / vinyl acetate copolymer. All individual values and subranges of from 9 to 28 wt.% are disclosed and included herein. For example, the ethylene / vinyl acetate copolymer can comprise from 10 to 25 wt.%, from 12 to 23 wt.%, or from 15 to 20 wt.% of vinyl acetate comonomer, based on total weight of the ethylene / vinyl acetate copolymer.

[0065] In embodiments, the ethylene / butyl acrylate copolymer, ethylene / ethyl acrylate copolymer, or ethylene / methyl acrylate copolymer comprises from 15 to 30 wt.% acrylate comonomer, based on total weight of the ethylene / acrylate-based copolymer. All individual values and subranges of from 15 to 30 wt.% are disclosed and included herein. For example, the ethylene / butyl acrylate copolymer, ethylene / ethyl acrylate copolymer, or ethylene / methyl acrylate copolymer can contain from 15 to 28 wt.% or 15 to 26 wt.% acrylate comonomer.

[0066] Examples of commercially available ethylene / butyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / methyl acrylate copolymer, and ethylene / vinyl acetate copolymer that can be used in embodiments of the present invention include polymers under the name ELVALOY™ and ELVAX™ commercially available from The Dow Chemical Company.

[0067] In embodiments, the at least one inner layer comprises greater than or equal to 25 wt.% of a combination of the CaCOs and the ethylene copolymer selected from the group consisting of ethylene / butyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / methyl acrylate copolymer, and ethylene / vinyl acetate copolymer based on the total weight of the at least one inner layer, such as greater than or equal to 30 wt.%, greater than or equal to 35 wt.%, greater than orequal to 40 wt.%, greater than or equal to 45 wt.%, greater than or equal to 50 wt.%, greater than or equal to 55 wt.%, greater than or equal to 60 wt.%, greater than or equal to 65 wt.%, greater than or equal to 70 wt.%, greater than or equal to 75 wt.%, greater than or equal to 80 wt.%, greater than or equal to 85 wt.%, greater than or equal to 90 wt.%, or greater than or equal to 95 wt.% of a combination of the CaC'Os and the ethylene copolymer based on the total weight of the at least one inner layer. In one or more embodiments, the at least one inner layer comprises greater than or equal to 25 wt.% and less than or equal to 100 wt.%, such as greater than or equal to 30 wt.% and less than or equal to 95 wt.%, greater than or equal to 35 wt.% and less than or equal to 90 wt.%, greater than or equal to 40 wt.% and less than or equal to 85 wt.%, greater than or equal to 45 wt.% and less than or equal to 80 wt.%, greater than or equal to 50 wt.% and less than or equal to 75 wt.%, or greater than or equal to 55 wt.% and less than or equal to 70 wt.% of a combination of the CaCOs and the ethylene copolymer based on the total weight of the at least one inner layer.

[0068] According to one or more embodiments, the at least one inner layer comprises an amount of CaCOs and ethylene copolymer selected from the group consisting of ethylene / butyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / methyl acrylate copolymer, or ethylene / vinyl acetate copolymer that satisfies the following inequality:where y is the amount of the ethylene copolymer in wt.% and x is the amount of CaC'Os in wt.% based on the total weight of the at least one inner layer. As will be explained in more detail below, it has been found that when the above inequality is satisfied, the tear resistance of the multilayer film improves by at least 30% compared to multilayer films that do not comprise CaCOs and the ethylene copolymer in an inner layer.

[0069] According to one or more embodiments, the at least one inner layer comprises an amount of CaCOs and ethylene copolymer selected from the group consisting of ethylene / butyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / methyl acrylate copolymer, or ethylene / vinyl acetate copolymer that satisfies the following inequality:2400where y is the amount of the ethylene copolymer in wt.% and x is the amount of CaC'Os in wt.% based on the total weight of the at least one inner layer. As will be explained in more detail below, it has been found that when the above inequality is satisfied, the tear resistance of the multilayer film improves by at least 50% compared to multilayer films that do not comprise CaC'Os and the ethylene copolymer in an inner layer.

[0070] In embodiments, in addition to the CaCOs and ethylene copolymer selected from the group consisting of ethylene / butyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / methyl acrylate copolymer, or ethylene / vinyl acetate copolymer, the at least one inner layer further comprises an ethylene -based polymer such as an ULDPE, LLDPE, LDPE, MDPE, HDPE, or a combination thereof.

[0071] The ethylene-based polymer is, in embodiments, present in the at least one inner layer in amounts less than or equal to 75 wt.%, such as less than or equal to 70 wt.%, less than or equal to 65 wt.%, less than or equal to 60 wt.%, less than or equal to 55 wt.%, less than or equal to 50 wt.%, less than or equal to 45 wt.%, less than or equal to 40 wt.%, less than or equal to 35 wt.%, less than or equal to 30 wt.%, less than or equal to 25 wt.%, less than or equal to 20 wt.%, less than or equal to 15 wt.%, or less than or equal to 10 wt.%, less than or equal to 5 wt.% based on the total weight of the at least one inner layer. In embodiments, the ethylene-based polymer is present in the at least one inner layer in amounts greater than or equal to 0 wt.% and less than or equal to 75 wt.%, such as greater than or equal to 5 wt.% and less than or equal to 70 wt.%, greater than or equal to 10 wt.% and less than or equal to 65 wt.%, greater than or equal to 15 wt.% and less than or equal to 60 wt.%, greater than or equal to 20 wt.% and less than or equal to 55 wt.%, greater than or equal to 25 wt.% and less than or equal to 50 wt.%, or greater than or equal to 30 wt.% and less than or equal to 45 wt.% based on the total weight of the at least one inner layer.

[0072] According to embodiments, the multilayer film has a thickness that is greater than or equal to 25 microns (pm) and less than or equal to 100 pm, such as greater than or equal to 30 pm and less than or equal to 95 pm, greater than or equal to 35 pm and less than or equal to 90 pm, greater than or equal to 40 pm and less than or equal to 85 pm, greater than or equal to 45 pm and less than or equal to 80 pm, greater than or equal to 50 pm and less than or equal to 75 pm, greater than or equal to 55 pm and less than or equal to 70 pm, or greater than or equal to 60 pm and less than or equal to 65 pm.

[0073] The at least one inner layer comprises, according to embodiments, greater than or equal to 2% and less than or equal to 40% of the total thickness of the multilayer fdm, such as greater than or equal to 5% and less than or equal to 30% of the total thickness of the multilayer fdm, greater than or equal to 5% and less than or equal to 25% of the total thickness of the multilayer fdm, greater than or equal to 5% and less than or equal to 20% of the total thickness of the multilayer fdm, greater than or equal to 5% and less than or equal to 15% of the total thickness of the multilayer fdm, greater than or equal to 5% and less than or equal to 10% of the total thickness of the multilayer fdm, greater than or equal to 10% and less than or equal to 30% of the total thickness of the multilayer fdm, greater than or equal to 15% and less than or equal to 30% of the total thickness of the multilayer fdm, or greater than or equal to 20% and less than or equal to 30% of the total thickness of the multilayer fdm.

[0074] Additives

[0075] It should be understood that any of the foregoing layers can further comprise one or more additives as known to those of skill in the art such as, for example, antioxidants, ultraviolet light stabilizers, thermal stabilizers, slip agents, antiblock agents, antistatic agents, pigments or colorants, processing aids, crosslinking catalysts, flame retardants, fdlers and foaming agents. For example, in embodiments, the first outer layer and the second outer layer each comprise an antiblock agent.

[0076] Multilayer Films

[0077] Multilayer films disclosed herein can be produced using techniques known to those of skill in the art based on the disclosure herein. For example, the multilayer fdm may be produced by coextrusion. The formation of coextruded multilayer films is known in the art and applicable to the present disclosure. Coextrusion systems for making multilayer films employ at least two extruders feeding a common die assembly. The number of extruders is dependent upon the number of different materials or polymers comprising the coextruded fdm. For example, a five-layer coextrusion may require up to five extruders although less may be used if two or more of the layers are made of the same materials or polymers.

[0078] The multilayer fdm disclosed and described herein, in various embodiments, can have several desirable properties. Without being bound by any theory, the specific structure of themultilayer film, including the at least one inner layer comprising the CaCOs and specific ethylene copolymer, can result in the multilayer film having high tear resistance properties.

[0079] In embodiments, the multilayer film has a machine direction Elmendorf tear resistance greater than or equal to 1700 grams (g), such as greater than or equal to 2000 g, greater than or equal to 2500 g, greater than or equal to 3000 g, greater than or equal to 3500 g, greater than or equal to 4000 g, greater than or equal to 4500 g, or greater than or equal to 5000 g. In one or more embodiments, the multilayer film has a machine direction Elmendorf tear resistance greater than or equal to 1700 g and less than or equal to 5500 g, such as greater than or equal to 2000 g and less than or equal to 5500 g, greater than or equal to 2250 g and less than or equal to 5500 g, greater than or equal to 2500 g and less than or equal to 5500 g, greater than or equal to 2750 g and less than or equal to 5500 g, greater than or equal to 3000 g and less than or equal to 5500 g, greater than or equal to 3250 g and less than or equal to 5500 g, greater than or equal to 3500 g and less than or equal to 5500 g, greater than or equal to 3750 g and less than or equal to 5500 g, greater than or equal to 4000 g and less than or equal to 5500 g, greater than or equal to 4250 g and less than or equal to 5500 g, greater than or equal to 4500 g and less than or equal to 5500 g, greater than or equal to 4750 g and less than or equal to 5500 g, greater than or equal to 3500 g and less than or equal to 5000 g, greater than or equal to 3500 g and less than or equal to 4750 g, greater than or equal to 3500 g and less than or equal to 4500 g, greater than or equal to 3500 g and less than or equal to 4250 g, or greater than or equal to 3500 g and less than or equal to 4000 g. Machine direction tear resistance can be measured in accordance with ASTM DI 922-09.

[0080] In embodiments, the multilayer film has an improved Elmendorf tear in the machine direction that is greater than or equal to 13% and less than or equal to 400% compared to a multilayer film that does not comprise the CaCOs and the ethylene copolymer in the at least one inner layer, such as greater than or equal to 30% and less than or equal to 400%, greater than or equal to 45% and less than or equal to 375%, greater than or equal to 60% and less than or equal to 350%, greater than or equal to 75% and less than or equal to 300%, greater than or equal to 90% and less than or equal to 250%, greater than or equal to 105% and less than or equal to 200%, or greater than or equal to 120% and less than or equal to 180% compared to a multilayer film having equivalent outer layer compositions and thickness but does not comprise the CaCOs and the ethylene copolymer in an inner layer.

[0081] As used herein, “compared to a multilayer fdm having equivalent outer layer compositions and thickness but does not comprise the CaCCh and the ethylene copolymer in an inner layer” means that the comparative fdm has the same number and thickness of layers as the fdm comprising CaCOs and ethylene copolymer in its inner layer. Moreover, the comparative fdm as the same composition in its first outer layer and second outer layer as the fdm comprising CaCOs and ethylene copolymer in its inner layer. However, the inner layer of the comparative fdm does not comprise CaCOs and ethylene copolymer.

[0082] Likewise, in embodiments, the multilayer fdm has an Elmendorf cross direction tear resistance that is greater than or equal to 2000 g, such as greater than or equal to 2250 g, greater than or equal to 2500 g, greater than or equal to 2750 g, greater than or equal to 3000 g, greater than or equal to 3250 g, greater than or equal to 3500 g, greater than or equal to 3750 g, greater than or equal to 4000 g, greater than or equal to 4250 g, greater than or equal to 4500 g, greater than or equal to 4750 g, greater than or equal to 5000 g. In one or more embodiments, the multilayer fdm has an Elmendorf cross direction tear resistance that is greater than or equal to 2000 g and less than or equal to 5500 g, such as greater than or equal to 2250 g and less than or equal to 5500 g, greater than or equal to 2500 g and less than or equal to 5500 g, greater than or equal to 2750 g and less than or equal to 5500 g, greater than or equal to 3000 g and less than or equal to 5500 g, greater than or equal to 3250 g and less than or equal to 5500 g, greater than or equal to 3500 g and less than or equal to 5500 g, greater than or equal to 3750 g and less than or equal to 5500 g, greater than or equal to 4000 g and less than or equal to 5500 g, greater than or equal to 4250 g and less than or equal to 5500 g, greater than or equal to 4500 g and less than or equal to 5500 g, greater than or equal to 4750 g and less than or equal to 5500 g, greater than or equal to 3500 g and less than or equal to 5250 g, greater than or equal to 3500 g and less than or equal to 5000 g, greater than or equal to 3500 g and less than or equal to 4750 g, greater than or equal to 3500 g and less than or equal to 4500 g, greater than or equal to 3500 g and less than or equal to 4250 g, or greater than or equal to 3500 g and less than or equal to 4000 g. Cross direction tear resistance can be measured in accordance with ASTM DI 922-09.

[0083] The multilayer fdm of one or more embodiments has an improved Elmendorf tear in the cross direction that is greater than or equal to 12% and less than or equal to 200% compared to a multilayer fdm that does not comprise the CaCOs and the ethylene copolymer in the at least one inner layer, such as greater than or equal to 15% and less than or equal to 185%, greater than or equal to 30% and less than or equal to 170%, greater than or equal to 45% and less than orequal to 155%, greater than or equal to 60% and less than or equal to 140%, greater than or equal to 75% and less than or equal to 125%, or greater than or equal to 90% and less than or equal to 110% compared to a multilayer fdm that does not comprise the CaC'Os and the ethylene copolymer in the at least one inner layer.

[0084] In embodiments, the multilayer fdm has a dart impact of greater than or equal to 800 g, such as greater than or equal to 850 g, greater than or equal to 900 g, greater than or equal to 950 g, greater than or equal to 1000 g, greater than or equal to 1050 g, greater than or equal to 1100 g, greater than or equal to 1150 g, greater than or equal to 1200 g, greater than or equal to 1250 g, or greater than or equal to 1300 g, where dart impact is measured according to ISO 7765- 1 / 1998. In one or more embodiments, the multilayer fdm has a dart impact that is greater than or equal to 800 g and less than or equal to 1400 g, such as greater than or equal to 850 g and less than or equal to 1350 g, greater than or equal to 900 g and less than or equal to 1300 g, greater than or equal to 950 g and less than or equal to 1250 g, greater than or equal to 1000 g and less than or equal to 1200 g, or greater than or equal to 1050 g and less than or equal to 1150 g.

[0085] In embodiments, the multilayer fdm has a puncture energy that is greater than or equal to 5.0 joules (J), such as greater than or equal to 5.5 J, greater than or equal to 6.0 J, greater than or equal to 6.5 J, or greater than or equal to 7.0 J, where the puncture is measured by ASTM D5748-95. In one or more embodiments, the multilayer fdm has a puncture energy that is greater than or equal to 5.0 J and less than or equal to 7.5 J, such as greater than or equal to 5.5 J and less than or equal to 7.5 J, greater than or equal to 6.0 J and less than or equal to 7.5 J, greater than or equal to 6.5 J and less than or equal to 7.5 J, greater than or equal to 7.0 J and less than or equal to 7.5 J, greater than or equal to 5.0 J and less than or equal to 7.0 J, or greater than or equal to 5.5 J and less than or equal to 6.5 J.

[0086] Articles

[0087] Embodiments disclosed and described herein also provide articles including any of the multilayer fdms described herein. Examples of such articles can include wraps, packages, flexible packages, pouches, and sachets. For example, in one or more embodiments, the multilayer fdm disclosed and described herein is a heavy-duty shipping sack. Articles of the embodiments can be formed from the multilayer fdms disclosed herein using techniques known to those of skill in the art in view of the teachings herein.

[0088] TEST METHODS

[0089] Density

[0090] Density is measured in accordance with ASTM D792, and expressed in grams / cm3(g / cm3or g / cc).

[0091] Melt Index (I2 and 110)

[0092] Melt index (I2) is measured in accordance with ASTM D-1238 at 190 °C at 2.16 kg. The values for melt indices are reported in g / 10 min, which corresponds to grams eluted per 10 minutes.

[0093] Tear Resistance in Cross Direction and Machine Direction (MD)

[0094] Tear resistance of the example multilayer fdms is measured in both the machine direction (MD) and cross direction (CD) in accordance with ASTM DI 922-09. The ASTM DI 922-09 standard determines the average force to propagate tearing in the machine and cross direction through a specified length of plastic film after the tear has been started.

[0095] Dart Impact

[0096] Dart Impact is measured according to ISO 7765-1, Standard Test Methods for Determination of Impact Resistance of Plastic Film by the Free-Falling Dart Test Method, Method A. Method A employs a dart with a 38 mm ± mm diameter hemispherical head dropped from a height of 0.66 m ± 0.01 m. This test method can be used for films whose impact resistances require masses of about 0.05 kg to about 2 kg to fracture them. Results expressed in grams (g).

[0097] Puncture Energy

[0098] This method is based on ASTM D5748-95 and is intended to determine the resistance of a film to the penetration of a probe at a standard low rate, a single test velocity. Performed at standard conditions imparts a biaxial stress that is representative of the type of stress encountered in many product end-use applications. The maximum force, force at break, penetration distance, and energy to break are determined.EXAMPLES

[0099] The following examples illustrate the embodiments of the present disclosure but are not intended to limit the scope of embodiments.

[0100] Example 1

[0101] Samples of multilayer fdms according to embodiments disclosed and described as well as comparative samples of multilayer fdms were produced according to the compositions provided in Table 1 below. Each of the multilayer fdms had a thickness of 100 pm where the inner layer comprises 10% of the thickness, the first outer layer comprises 45% of the thickness, and the second out layer comprises 45% of the thickness. The first and second outer layers in each of the samples and comparative samples comprises 85 wt.% DOWEEX™ GM8090 manufactured by the Dow Chemical Company and 15 wt.% EDPE 310E manufactured by the Dow Chemical Company. The fdms in the examples were formed on a blown multilayer machine.

[0102] Table 1

[0103] In these samples, the source of CaCC is Granic 422 (“Granic” in Table 1), which is manufactured by GCR Group and comprises 80 wt.% CaCOs; “ethylene copolymer” is EEVAEOY™ AC manufactured by the Dow Chemical Company; “GM8090” is DOWEEX™GM8090 LDPE manufactured by the Dow Chemical Company; and “LDPE 310E” is a LDPE manufactured by the Dow Chemical Company.

[0104] The Elmendorf tear in the machine direction and the cross direction, puncture energy, and dart impact of each of the samples shown in Table 1 were measured according to the measurement standards described herein. The results of these measurements are provided in Table 2 below.

[0105] Table 2

[0106] As shown in Table 2, the samples provide significantly improved Elmendorf tear in the machine direction and cross direction while also increasing puncture energy and dart impact performance.

[0107] Using the data provided in Table 2, the results can be plotted an analyzed to determine the amounts of CaCOs and ethylene copolymer in the inner layer that will provide the best results. FIG. 1 is a plot of the Elmendorf tear in the machine direction with wt.% of ethylene copolymer along the y-axis and wt.% of CaCOs along the x-axis; FIG. 2 is a plot of the Elmendorf tear in the cross direction with wt.% of ethylene copolymer along the y-axis and wt.% of CaCOs along the x-axis; FIG. 3 is a plot of the puncture energy with wt.% of ethylene copolymer along the y-axisand wt.% of CaCOs along the x-axis; and FIG. 4 is a plot of the dart impact with wt.% of ethylene copolymer along the y-axis and wt.% of CaCC along the x-axis.

[0108] Analysis of the plots in FIG. 1 to FIG. 4 shows that when the following inequality is met, there is at least a 30% increase in Elmendorf tear in the machine direction and the cross direction without significantly sacrificing the puncture energy or dart impact of the inner layer:1280 y > -16 + x + 16 where y is the amount of ethylene copolymer in wt.% and x is the amount of CaCOs in wt.% based on the total weight of the at least one inner layer.

[0109] Similarly, an analysis of the plots in FIG. 1 to FIG. 4 shows that when the following inequality is met, there is at least a 50% increase in Elmendorf tear in the machine direction and the cross direction without significantly sacrificing the puncture energy or dart impact of the inner layer:2400where y is the amount of ethylene copolymer in wt.% and x is the amount of CaCOs in wt.% based on the total weight of the at least one inner layer.

[0110] Example 2

[0111] Example 2 was designed to show the efficacy of multilayer films according to embodiments disclosed and described herein at thin film gauges, such as 25 pm. Table 3 provides the composition of the inner layers for each of the samples. In each sample, the inner layer comprises 10 wt.% of the total weight of the multilayer film, the first outer layer comprises 45 wt.% of the total weight of the multilayer film, and the second outer layer comprises 45 wt.% of the total weight of the multilayer film. Each of the first outer layer and the second outer layer comprise 85 wt.% GM8090 and 15 wt.% LDPE 310E based on the total weight of the first outer layer or the second outer layer, respectively. Each film had a total thickness of 25 pm.

[0112] Table 3

[0113] The Elmendorf tear in the machine direction and the cross direction, puncture energy, and dart impact of each of the samples shown in Table 3 were measured according to the measurement standards described herein. The results of these measurements are provided in Table 4 below.

[0114] Table 4

[0115] As shown in Table 4, the samples provide improved Elmendorf tear in the machine direction and cross direction without sacrificing puncture energy or dart impact performance of the multilayer films have a thin gauge of only 25 pm. The results shown in Table 4 are provided in bar graphs in FIG. 5, which shows Elmendorf tear in the machine direction, and in FIG. 6, which shows Elmendorf tear in the cross direction. In each of FIG. 5 and FIG. 6, the Elmendorf tear is provided on the y-axis. This example shows that thin films according to embodiments, which cost less and use less ethylene-based polymers, still have good tear, dart, and puncture properties.

[0116] Example 3

[0117] Example 3 was designed to show the efficacy of multilayer films according to embodiments disclosed and described herein at different inner layer thicknesses. Comparative sample 9 was a 5-layer film having a total thickness of 100 pm, where each layer was made from 85 wt.% GM8090 and 15 wt.% LDPE 310E. Multilayer film samples 14-17 included a first outerlayer and a second outer layer made from 85 wt.% GM8090 and 15 wt.% LDPE 310E based on the individual weight of the first outer layer or the second outer layer, respectively. Each of the multilayer film samples 14-17 had inner layers made from 25 wt.% Granic 422 (20 wt.% CaCOs) and 75 wt.% ethylene copolymer (ELVALOY™ AC) based on the total weight of the inner layer. Each of the multilayer film samples 14-17 had a total thickness of 100 pm.

[0118] Table 5 provides the percentage of the multilayer film thickness that is comprised of the inner layer, where the remainder of the thickness is evenly distributed between the first outer layer and the second outer layer. Table 5 also provides the Elmendorf tear in the cross direction, Elmendorf tear in the machine direction, puncture energy, and dart impact of each sample.

[0119] Table 5

[0120] As shown in Table 5, the each of the samples provide improved Elmendorf tear in the machine direction and cross direction without sacrificing puncture energy or dart impact performance compared to the film of comparative sample 9. Table 4 also shows the best results for Elmendorf tear in either the cross direction or the machine direction are achieved at inner layer thicknesses from 5% to 10%. The results shown in Table 5 are provided in bar graphs in FIG. 7, which shows Elmendorf tear in the machine direction, and in FIG. 8, which shows Elmendorf tear in the cross direction. In each of FIG. 7 and FIG. 8, the Elmendorf tear is provided on the y-axis.

[0121] Example 4

[0122] Example 4 was designed to show the efficacy of a variation of outer layer densities and polymer architecture. As shown in Table 6, comparative sample 10 was a five-layer film where each layer was made from 100 wt.% GM8090, which has a melt index (h) of 1.00 g / 10 min and a density of 0.916 g / cm3; comparative sample 11 was a five-layer film where each layer was madefrom 100 wt.% DOWLEX™ SL2103G manufactured by the Dow Chemical Company, which has a melt index (E) of 0.70 g / 10 min and a density of 0.917 g / cm3; comparative sample 12 was a five-layer film where each layer was made from 100 wt.% INNATE™ ST50 manufactured by the Dow Chemical Company, which has a melt index (I2) of 0.85 g / 10 min and a density of 0.918 g / cm3; and comparative sample 13 was a five-layer film where each layer was made from 100 wt.% ATTANE™ SL4102G manufactured by the Dow Chemical Company, which has a melt index (I2) of 1.00 g / 10 min and a density of 0.905 g / cm3. Each of the films of comparative samples 10-13 had a total thickness of 100 pm.

[0123] Table 6 also shows the compositions of multilayer film samples 18-21, which each have an inner layer made from 30 wt.% Granic 422 (24 wt.% CaCOs) and 70 wt.% ethylene copolymer (EEVAEOY™ AC). The multilayer film of samples 18-21 also included a first outer layer and a second outer layer corresponding to the polymers used in the films of comparative samples 11-14, as shown in Table 6. The thickness of the multilayer films of samples 18-21 comprised 45% of a first outer layer, 10% of an inner layer, and 45% of a second outer layer. Each of the multilayer films of samples 18-21 had a total thickness of 100 pm.

[0124] Table 6

[0125] The Elmendorf tear in the machine direction and the cross direction, puncture energy, and dart impact of each of the samples shown in Table 6 were measured according to the measurement standards described herein. The results of these measurements are provided in Table 7 below.

[0126] Table 7

[0127] As shown in Table 7, the multilayer film samples 18-21 provide improved Elmendorf tear in the machine direction and cross direction with a minimal decrease in puncture energy and a slight increase in dart impact performance compared to corresponding films of comparative samples 11-14. The results shown in Table 7 are provided in bar graphs in FIG. 9, which shows Elmendorf tear in the machine direction, and in FIG. 10, which shows Elmendorf tear in the cross direction. In each of FIG. 9 and FIG. 10, the Elmendorf tear is provided on the y-axis.

[0128] Example 5

[0129] Example 5 was designed to show the efficacy of using different ethylene copolymers in the inner layer. As shown in Table 8, comparative sample 14 was a five-layer film where each layer was made from 100 wt.% GM8090 having a total thickness of 100 pm. Multilayer films of samples 22-25 each comprised a first outer layer and a second outer layer made from 85 wt.% GM8090 and 15 wt.% EDPE 310E, and an inner layer comprising Granic 422 and either an ethylene / acrylate copolymer (EEVAEOY™ AC) or an ethylene / acetate copolymer (EEVAX™ 3182 manufactured by the Dow Chemical Company) in the amounts shown in Table 8. The multilayer films of samples 22-25 each had a total thickness of 100 pm comprised of 45% of the first outer layer, 10% of the inner layer, and 45% of the second outer layer based on the total thickness of the multilayer film.

[0130] Table 8

[0131] The Elmendorf tear in the machine direction and the cross direction, puncture energy, and dart impact of each of the samples shown in Table 8 were measured according to the measurement standards described herein. The results of these measurements are provided in Table 9 below.

[0132] Table 9

[0133] As shown in Table 9, the multilayer fdm samples 22-25 provide improved Elmendorf tear in the machine direction and cross direction without sacrificing puncture energy or dart impact performance compared to corresponding film of comparative sample 14. The results shown in Table 9 are provided in bar graphs in FIG. 11, which shows Elmendorf tear in the machine direction, and in FIG. 12, which shows Elmendorf tear in the cross direction. In each of FIG. 11 and FIG. 12, the Elmendorf tear is provided on the y-axis.

[0134] Every document cited herein, if any, including any cross-referenced or related patent or application and any patent application or patent to which this application claims priority or benefit thereof, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaningor definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.

[0135] While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.

Claims

CLAIMS1. A multilayer film comprising: a first outer layer; a second outer layer; at least one inner layer positioned between the first outer layer and the second outer layer, wherein the at least one inner layer comprises: greater than or equal to 5 wt.% CaCOs based on a total weight of the at least one inner layer; greater than or equal to 5 wt.% of an ethylene copolymer selected from the group consisting of ethylene / butyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / methyl acrylate copolymer, and ethylene / vinyl acetate copolymer based on the total weight of the at least one inner layer; greater than or equal to 25 wt.% of a combination of the CaC'Os and the ethylene copolymer based on the total weight of the at least one inner layer; and greater than or equal to 2% and less than or equal to 40% of a total thickness of the multilayer fdm.

2. The multilayer fdm of claim 1, wherein the at least one inner layer comprises greater than or equal to 40 wt.% of a combination of the CaCOs and the ethylene copolymer based on the total weight of the at least one inner layer.

3. The multilayer fdm of any of the preceding claims, wherein the at least one inner layer comprises greater than or equal to 15 wt.% of CaC'Os based on the total weight of the at least one inner layer.

4. The multilayer film of any of the preceding claims, wherein the at least one inner layer comprises greater than or equal to 15 wt.% of the ethylene copolymer based on the total weight of the at least one inner layer.

5. The multilayer fdm of any of the preceding claims, wherein an amount of CaC'Os and ethylene copolymer in the at least one inner layer satisfies the following inequality:1280where y is an amount of ethylene copolymer in wt.% and x is an amount of CaCC in wt.% based on the total weight of the at least one inner layer.

6. The multilayer fdm of any of the preceding claims, wherein an amount of CaCOs and ethylene copolymer in the at least one inner layer satisfies the following inequality:where y is an amount of ethylene copolymer in wt.% and x is an amount of CaCC in wt.% based on the total weight of the at least one inner layer.

7. The multilayer film of any of the preceding claims, wherein the at least one inner layer further comprises an ethylene-based polymer.

8. The multilayer film of claim 7, wherein the at least one inner layer comprises the ethylene-based polymer in an amount that is less than or equal to 75 wt.% based on the total weight of the at least one inner layer.

9. The multilayer film of any of the preceding claims, wherein the multilayer film has greater than or equal to 12% and less than or equal to 400% improvement in Elmendorf Tear in a cross-direction compared to a multilayer film having equivalent outer layer compositions and thickness but does not comprise the CaCOs and the ethylene copolymer in an inner layer.

10. The multilayer film of any of the preceding claims, wherein the multilayer film has greater than or equal to 13% and less than or equal to 400% improvement in Elmendorf Tear in a machine-direction compared to a multilayer film having equivalent outer layer compositions and thickness but does not comprise the CaCOs and the ethylene copolymer in an inner layer.

11. The multilayer film of any of the preceding claims, wherein the multilayer film has a thickness that is greater than or equal to 25 microns and less than or equal to 100 microns.

12. The multilayer film of any of the preceding claims, wherein the at least one inner layer comprises greater than or equal to 5% and less than or equal to 30% of the thickness of the multilayer film.

13. The multilayer film of any of the preceding claims, wherein the at least one inner layer comprises greater than or equal to 5% and less than or equal to 10% of the thickness of the multilayer film.

14. The multilayer film of any of the preceding claims, wherein at least one of the first outer layer and the second outer layer comprises TTDPE, TDPE, ULDPE, VLDPE, MDPE, HDPE, and combinations thereof.

15. The multilayer film of any of the preceding claims, wherein the first outer layer and the second outer layer comprise greater than or equal to 60% and less than or equal to 98% of a total thickness of the multilayer film.

Images