Elastomer Containing Multilayer Films and Manufacturing Method

Abstract

A multilayer film including at least one abuse layer. The abuse layer is a blend of one or more polyamides and an acid anhydride-grafted or maleic anhydride-grafted elastomer. The acid anhydride or maleic anhydride-grafted elastomer includes ethylene propylene diene monomer rubber, ethylene propylene copolymer, styrene-ethylene-butene-styrene, ethylene / octene copolymer, and blends thereof. Also disclosed are pouches made from the multilayer film and a method of packaging food with the multilayer film.

Description

BACKGROUND OF THE INVENTION

[0001] The subject matter disclosed herein relates to multilayer films. More particularly, it relates to multilayer films for food packaging.

[0002] Nylon has been incorporated into multilayer films to improve abuse and impact properties and to resist failure and leakage during packaging and dispensing of food products. However, even with the inclusion of nylon in the multilayer film, packaging failures are still evident. Failures can be shell body, seal, and pinhole failures that result in package leakage. In addition, nylon can become brittle, especially in cold and dry environments, which causes the film to rupture upon strain.

[0003] The foregoing discussion provides only general background information and is not intended to serve as an aid in determining the scope of the claimed subject matter. SUMMARY OF THE INVENTION

[0004] A multilayer film comprising at least one abuse layer. The abuse layer is a blend of one or more polyamides and an acid anhydride-grafted elastomer. The acid anhydride-grafted elastomer includes ethylene propylene diene monomer, ethylene propylene copolymer, styrene-ethylene-butylene-styrene, ethylene / octene copolymer, and blends thereof. Also disclosed are pouches made from the multilayer film and methods of packaging food products with the multilayer film.

[0005] An advantage that can be achieved in practicing some of the disclosed embodiments of the multilayer film is reduced impact failure.

[0006] In one exemplary embodiment, a multilayer film is disclosed. The multilayer film comprises at least one outer layer comprising at least 70 wt% of one or more ethylene / α-olefin copolymers; and at least one inner layer that is an abuse layer comprising a blend of: at least 1 wt% of an acid anhydride-grafted elastomer selected from ethylene propylene diene monomer, ethylene propylene copolymer, styrene-ethylene-butylene-styrene, ethylene / octene copolymer, and blends thereof; and at least 25 wt% of one or more polyamides; at least 5%, 10%, 20%, 30%, 40%, or 50 wt% of the multilayer film is one or more polyamides.

[0007] In another exemplary embodiment, a food packaging is disclosed. The food packaging includes food; a pouch containing the food, the pouch being made of a multilayer film, the multilayer film comprising: at least one outer layer comprising at least 70 wt% of one or more ethylene / α-olefin copolymers; and at least one inner layer as an abuse layer, the abuse layer comprising a blend of: at least 1 wt% of an acid anhydride-grafted elastomer selected from ethylene propylene diene monomer (EPDM), ethylene propylene copolymer, styrene-ethylene-butene-styrene (SEBS), ethylene / octene copolymer, and blends thereof; and at least 25 wt% of one or more polyamides; at least 5%, 10%, 20%, 30%, 40%, or 50 wt% of the multilayer film is one or more polyamides.

[0008] In another exemplary embodiment, a method of forming an article of packaging is disclosed. The method includes the steps of: a. providing a multilayer film comprising: at least one outer layer comprising at least 70 wt% of one or more ethylene / α-olefin copolymers; and at least one inner layer as an abuse layer, the abuse layer comprising a blend of: at least 1 wt% of an acid anhydride-grafted elastomer selected from ethylene propylene diene monomer (EPDM), ethylene propylene copolymer, styrene-ethylene-butene-styrene (SEBS), ethylene / octene copolymer, and blends thereof; and at least 25 wt% of one or more polyamides; at least 5%, 10%, 20%, 30%, 40%, or 50 wt% of the multilayer film is one or more polyamides; b. forming the film into a tube in a vertical form-fill-seal apparatus; c. filling the tube with food; and d. closing the tube to form a sealed pouch containing the food.

[0009] In another exemplary embodiment, a multilayer film is disclosed. The multilayer film comprises a first inner layer; two abuse layers disposed on opposite surfaces of the first inner layer, the two abuse layers comprising a blend of: at least 1 wt% of an acid anhydride-grafted elastomer selected from ethylene propylene diene monomer (EPDM), ethylene propylene copolymer, styrene-ethylene-butene-styrene (SEBS), ethylene / octene copolymer, and blends thereof; and at least 25 wt% of one or more polyamides; two adhesive layers, each disposed on the surface of the corresponding abuse layer, each adhesive layer comprising an acid anhydride-modified ethylene / α-olefin copolymer; two outer layers, each disposed on the surface of the corresponding adhesive layer, each outer layer comprising at least 70 wt% of one or more ethylene / α-olefin copolymers.

[0010] This brief description of the invention is only intended to provide a brief overview of the subject matter disclosed herein according to one or more illustrative embodiments, and is not to be used as a guide for interpreting the claims or as a guide for limiting or restricting the scope of the invention, which is defined only by the appended claims. This brief description is provided to introduce, in a simplified form, an illustrative selection of concepts that will be further described in the following detailed description. This brief description is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to assist in determining the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all of the disadvantages recited in the background. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] To be able to understand the features of the present invention, the present invention may be described in detail with reference to certain embodiments, some of which are illustrated in the drawings. However, it should be noted that the drawings illustrate only certain embodiments of the present invention and should not be considered as limiting its scope, since the scope of the present invention encompasses other equivalent embodiments. The drawings are not necessarily to scale, and the emphasis is generally on illustrating the features of certain embodiments of the present invention. In the drawings, the same reference numerals are used to denote the same components throughout the various views. Thus, for a further understanding of the present invention, reading in conjunction with the drawings, reference may be made to the following detailed description, wherein:

[0012] Figure 1 is an exemplary representative peripheral view of a package according to one embodiment;

[0013] Figure 2 is a representative cross-sectional view taken along line Figure 1 7-7;

[0014] Figure 3 is an exemplary representative peripheral view of a package according to one embodiment;

[0015] Figure 4 is a representative cross-sectional view taken along line Figure 4 5-5;

[0016] Figure 5 is a representative cross-sectional view of a multilayer film according to one embodiment; and

[0017] Figure 6 is a representative view of a vertical form-fill-seal apparatus used in an exemplary packaging method;

[0018] Figure 7 is a representative cross-sectional view of a multilayer film according to one embodiment; and

[0019] Figure 8 is a representative cross-sectional view of a lap-seal package according to one embodiment. Detailed implementation manners

[0020] Figure 1-2 and Figure 8 depicts an exemplary package according to one embodiment. A roll of material can be formed (i.e., extruded) into a tubular shape or supplied in a flat configuration and folded and sealed together along a longitudinal heat seal seam 34 (e.g., a fin seal ( Figure 2 ) or a lap seal ( Figure 8 ) arrangement) to produce a tubular shape, and then the opposite ends 38, 40 are heat sealed to enclose the package 36, such that the package can have two edges 42, 44 formed by the folded roll and two edges formed by the end seals 38, 40 to define a film upper surface 12 and a film lower surface 14.

[0021] The package 36 has a heat seal 28 between and connecting the film upper surface 12 and the film lower surface 14 in a selected heat seal zone 16 to enclose the package space 20. The heat seal operation for forming the heat seal 28 uses a heat seal unit operation, such as any one of conduction sealing, impulse sealing, ultrasonic sealing, and dielectric sealing. For example, a heat seal machine having a heated seal platen (i.e., bar) contacts and compresses two films to heat seal them together for a sufficient length of time such that heat is transferred from the heated seal platen to soften at least a portion of the films (e.g., the seal layer of the films) such that they can fuse together to produce the heat seal 28.

[0022] Figure 3-4 Describes an exemplary package according to one embodiment, where the film is folded and heat sealed along three edges 16 to produce a closed package 30 (e.g., a sachet or bag) having heat seals along three edges and a folded edge 32 defining a fourth edge between the film upper surface 12 and the film lower surface 14. The package 30 has a heat seal 28 between and connecting the film upper surface 12 and the film lower surface 14 in a selected edge 16 to enclose the package space 20. The heat seal operation for forming the heat seal 28 uses a heat seal unit operation, such as any one of conduction sealing, impulse sealing, ultrasonic sealing, and dielectric sealing. For example, a heat seal machine having a heated seal platen (i.e., bar) contacts and compresses two films to heat seal them together for a sufficient length of time such that heat is transferred from the heated seal platen to soften at least a portion of the films (e.g., the seal layer of the films) such that they can fuse together to produce the heat seal 28.

[0023] Other exemplary packages are contemplated, such as but not limited to a top roll adhered to a tray, a top roll adhered to a bottom roll, and a cover film over a tray.

[0024] Now turning to Figure 5, depicts a cross-sectional view of a multilayer film according to an embodiment. The multilayer film contains two outer layers 51, 57 that serve as heat-sealing layers. Adhesive layers 52, 56 bond the two outer layers 51, 57 to abuse layers 53, 55 respectively. A barrier layer 54 is disposed between the two abuse layers 53 and 55. In the embodiment, additional adhesive layers are used between the barrier layer 54 and the abuse layers 53 and 55.

[0025] If both surfaces of a layer are directly adhered to other layers of the film, the layer can be an "inner layer" of the film. If a layer forms the outer surface of the film, the layer can be an "outer layer" of the film. An "outer layer" is the outer layer of the film that is or is intended to be adjacent to the space outside the package containing the film. An "inner layer" of the film is the outer layer of the film that is or is intended to be adjacent to the space inside the package containing the film. A sealant layer is the outer layer of the film that is adapted to facilitate heat-sealing of the film to itself or to another object (such as another film). A sealant layer can also be an inner layer of the film. Any of the inner, outer, exterior, interior, and sealant layers can be a modified layer as described herein.

[0026] As used herein, "polyethylene" refers to ethylene homopolymers or copolymers.

[0027] An ethylene / α-olefin copolymer is a copolymer of ethylene and one or more α-olefins, which copolymer has ethylene as the major molar percentage content. In some embodiments, the comonomer includes one or more C3-C20 α-olefins, such as C4-C12 or C4-C8 α-olefins. α-olefins include, but are not limited to, 1-butene, 1-hexene, 1-octene, and mixtures thereof.

[0028] The ethylene / α-olefin copolymer includes one or more of the following: 1) high density polyethylene, such as having a density greater than 0.94 g / cm 3 , 2) medium density polyethylene, such as having a density of 0.93 - 0.94 g / cm 3 , 3) linear medium density polyethylene, such as having a density of 0.926 - 0.94 g / cm 3 , 4) low density polyethylene, such as having a density of 0.915 - 0.939 g / cm 3 , 5) linear low density polyethylene, such as having a density of 0.915 - 0.935 g / cm 3 , 6) very low or ultra-low density polyethylene, such as having a density below 0.915 g / cm 3 , and homogeneous ethylene / α-olefin copolymers. Homogeneous ethylene / α-olefin copolymers include those having a density less than any of the following: 0.925, 0.922, 0.92, 0.917, 0.915, 0.912, 0.91, 0.907, 0.905, 0.903, 0.9, and 0.86 g / cm 3Unless otherwise indicated, all densities herein are measured according to ASTM D1505.

[0029] In an embodiment, the multilayer film is asymmetric. The multilayer film may have at least and / or at most 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 layers. In an embodiment, the multilayer film uses microlayers. The thickness of the multilayer film may be at least and / or at most any of the following: 1, 1.5, 2, 4, 6, 8, 10, 12 mils. In an embodiment, each layer of the multilayer film may independently have at least and / or at most any of the following thicknesses: 0.25, 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 7, 8, and 10 mils.

[0030] At least one outer layer is a sealant layer. The sealant layer can include more than one polyamide, such as a blend of polyamides, for example, two polyamides, at least two polyamides, three polyamides, and at least three polyamides. The sealant layer can include any of the following amounts of the first polyamide (based on the weight of the sealant layer): at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, and ranges between any of these aforementioned values ​​(e.g., 60-80%).

[0031] The sealant layer can include any of the following amounts of the second polyamide (based on the weight of the sealant layer): less than 60%, less than 50%, less than 40%, less than 30%, less than 20%, less than 10% and less than 5% and ranges between any of these foregoing values ​​(e.g., 20-40%).

[0032] In embodiments, the sealant layer may include any of the following amounts of the third polyamide (based on the weight of the sealant layer): less than 60%, less than 50%, less than 40%, less than 30%, less than 20%, less than 10% and less than 5% and ranges between any of these foregoing values ​​(e.g., 20-40%).

[0033] Each of the first, second and third polyamides of the sealant layer can be selected from any of the polyamides or ethylene / α-olefin copolymers described herein, such as low density polyethylene, linear low density polyethylene, ethylene / α-olefin copolymers, ethylene / butene copolymers, ethylene / hexene copolymers, ethylene / octene copolymers, ethylene / C4-8 α-olefin copolymers.

[0034] In an embodiment, the melting point of the sealant layer is less than any of the following values: 220 °C, 210 °C, 200 °C, 190 °C, and 180 °C; and the melting point of the sealant layer can be at least any of the following values: 120 °C, 130 °C, 140 °C, and 150 °C. In this application, the melting point of all polymers, resins, or film layers mentioned refers to the melting peak temperature of the main melting phase of the polymer, resin, or layer determined by differential scanning calorimetry according to ASTM D-3418.

[0035] In an embodiment where the sealant layer contains an amorphous material, the seal layer may not clearly show a melting point. The glass transition temperature of the seal layer can be less than any of the following values and can be within the range between any of the following values: 125 °C, 120 °C, 110 °C, 100 °C, 90 °C, 80 °C, 70 °C, 60 °C, and 50 °C; the relative humidity measured can be any of the following values: 100%, 75%, 50%, 25%, and 0%. In this application, the glass transition temperature of all polymers, resins, or film layers mentioned refers to the characteristic temperature at which a glassy or amorphous polymer becomes flexible, as determined by differential scanning calorimetry (DSC) according to ASTM D-3417.

[0036] In an embodiment, the sealant layer comprises a blend of one or more relatively high melting point polyamides or ethylene / α-olefin copolymers with one or more relatively low melting point polyamides or ethylene / α-olefin copolymers. The sealant layer can contain at least any of the following amounts of such a blend, based on the weight of the sealant layer: 70%, 80%, 90%, and 95%. The melting point of the relatively high melting point polyamide or ethylene / α-olefin copolymer can be at least any of the following values: 210 °C, 215 °C, 220 °C, 225 °C, 230 °C, 235 °C, 240 °C, 245 °C, 250 °C, 255 °C, 260 °C, 265 °C, 270 °C, 275 °C, 280 °C, 285 °C, 290 °C, 295 °C, and 300 °C; and can be within the range between any of the foregoing values (e.g., 235 - 280 °C). Representative relatively high melting point polyamides can include nylon-6, nylon-6,6, nylon-6 / 6,6, nylon-6,10, nylon-6,12, nylon-6 / 6,T, nylon-MXD,6, nylon-4,6, nylon-6,9, and nylon-6,6, / 6,10 (with less than 10% or more than 60% of nylon-6,6 in the copolymer).

[0037] The melting point of a relatively low melting point polyamide or ethylene / α-olefin copolymer can be less than any of the following values: 210 °C, 200 °C, 190 °C, 180 °C, 170 °C, 160 °C, 150 °C, 140 °C, 130 °C, 120 °C, 110 °C, and 100 °C. Representative relatively low melting point polyamides or ethylene / α-olefin copolymers can include low density polyethylene, linear low density polyethylene, ethylene / α-olefin copolymers, ethylene / butene copolymers, ethylene / hexene copolymers, ethylene / octene copolymers, ethylene / C4-8 α-olefin copolymers, nylon-6 / 12, nylon-12, nylon-12,T, nylon-6 / 6,9, nylon-11, and nylon-6,6, / 6,10 (with 10% to 60% nylon-6,6 in the copolymer).

[0038] In a polyamide blend of a relatively high melting point polyamide or ethylene / α-olefin copolymer and a relatively low melting point polyamide or ethylene / α-olefin copolymer, the amount of the relatively high melting point polyamide or ethylene / α-olefin copolymer can be at least any of the following amounts, can be less than any of the following amounts, and can be within the range between any of the following amounts (based on the weight of the blend): 1%, 5%, 10%, 10%, 20%, 30%, 40%, and 50%. In a blend of a relatively high melting point polyamide or ethylene / α-olefin copolymer and a relatively low melting point polyamide or ethylene / α-olefin copolymer, the amount of the relatively low melting point polyamide or ethylene / α-olefin copolymer can be at least any of the following amounts, can be less than any of the following amounts, and can be within the range between any of the following amounts (based on the weight of the blend): 50%, 60%, 70%, 80%, 90%, 95%, and 99%.

[0039] In an embodiment, the sealant layer can comprise a blend comprising two or more relatively low melting point polyamides or ethylene / α-olefin copolymers. The sealant layer can comprise at least any of the following amounts of such a blend, based on the weight of the sealant layer: 50%, 60%, 70%, 80%, 90%, and 95%.

[0040] The sealant layer can comprise one or more amorphous polyamides, for example, nylon-6,I / 6,T. The sealant layer can comprise an amorphous polyamide in an amount that is at least any of the following values, at most any of the following values, and within the range between any of the following values (based on the weight of the sealant layer): 20%, 30%, 40%, 50%, 60%, 70%, and 80%.

[0041] The thickness of the sealant layer can be selected to provide sufficient material to achieve a strong thermally sealed bond, yet not be so thick as to have an unacceptable level of negative impact on the characteristics of the film. The thickness of the sealant layer can be at least any one of the following values: 0.05 mil, 0.1 mil, 0.15 mil, 0.2 mil, 0.25 mil, 0.3 mil, 0.35 mil, 0.4 mil, 0.45 mil, 0.5 mil, and 0.6 mil. The thickness of the sealant layer can be less than any one of the following values: 5 mil, 4 mil, 3 mil, 2 mil, 1 mil, 0.7 mil, 0.5 mil, and 0.3 mil. The thickness of the sealant layer as a percentage of the total thickness of the film can be less than any one of the following values: 50%, 40%, 30%, 25%, 20%, 15%, 10%, and 5%; and can be in a range between any of the foregoing values (e.g., 10% to 30%).

[0042] The adhesive layer refers to an inner film layer that adheres two layers to each other. In an embodiment, the adhesive layer includes a modified polyolefin, such as a modified ethylene-vinyl acetate copolymer, or a modified heterogeneous or homogeneous ethylene / α-olefin copolymer, including but not limited to anhydride-grafted linear low density polyethylene, anhydride-grafted low density polyethylene, anhydride-grafted high density polyethylene, anhydride-grafted ethylene-vinyl acetate copolymer, or a modified elastomer, including anhydride-grafted ethylene propylene diene monomer, anhydride-grafted ethylene propylene copolymer, anhydride-grafted ethylene / octene copolymer, and anhydride-grafted styrene-ethylene-butene-styrene, maleic anhydride-grafted linear low density polyethylene, maleic anhydride-grafted low density polyethylene, maleic anhydride-grafted high density polyethylene, maleic anhydride-grafted ethylene-vinyl acetate copolymer, or a modified elastomer, including maleic anhydride-grafted ethylene propylene diene monomer, maleic anhydride-grafted ethylene propylene copolymer, maleic anhydride-grafted ethylene / octene copolymer, and maleic anhydride-grafted styrene-ethylene-butene-styrene. In an embodiment, the adhesive layer includes at least 0.5, 1.0, 1.5, 2.0, 2.5, or 3.0 weight % of the polymer found in the adjacent layer. In an embodiment, the graft level of the anhydride-grafted or maleic anhydride-grafted polymer is less than 3 weight %.

[0043] The abuse layer is a film that can resist abrasion, puncture, and / or other potential causes of reduced packaging integrity and / or potential causes of reduced packaging appearance quality. The abuse layer is a blend comprising a polyamide and an acid anhydride-grafted or maleic anhydride-grafted elastomer. Representative polyamides include, but are not limited to, nylon 6, nylon 6 / 6, amorphous nylon, nylon 6,6 / 6, nylon 6 / 6,6, nylon 6 / 12, nylon 12, and combinations thereof. In some embodiments, the abuse layer may comprise additional polymers. In an embodiment, the polyamide in the abuse layer accounts for 50-99%, 55-98%, 60-97%, 65-96%, 70-95% by weight of the abuse layer. In an embodiment, the polyamide in the abuse layer accounts for at least 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, and 99% by weight of the abuse layer. In an embodiment, the polyamide accounts for 55-95% by weight of the abuse layer.

[0044] In an embodiment, the acid anhydride-grafted elastomer is a maleic anhydride-grafted elastomer. The maleic anhydride-grafted elastomer is selected from ethylene propylene diene monomer rubber, ethylene propylene copolymer, styrene-ethylene-butene-styrene, ethylene / octene copolymer, and blends thereof. In an embodiment, the maleic anhydride-grafted elastomer in the abuse layer accounts for at least 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10% by weight of the abuse layer. In an embodiment, the maleic anhydride-grafted elastomer in the abuse layer accounts for no more than 50%, 45%, 40%, 35%, 30% by weight of the abuse layer. In an embodiment, the maleic anhydride-grafted elastomer in the abuse layer accounts for between 1-50%, 2-40%, 3-30%, 4-20%, 5-15% by weight of the abuse layer.

[0045] The acid anhydride-grafted or maleic anhydride-grafted elastomer is dispersed throughout the abuse layer as discrete particles. In an embodiment, the acid anhydride-grafted or maleic anhydride-grafted elastomer is discrete and distinct spherical particles having an average area size less than 3.00, 2.50, 2.00, 1.75, 1.50, 1.25, 1.00, 0.75, or 0.50 microns. The area size is determined by measuring the diameter (by the long axis or the short axis) of the cross-section of the area in the film. Using stereology, representative film samples are collected and a statistically significant number of particles are examined. The diameter of the elliptical area is determined by multiplying the average diameter (d 平均 ) of the cross-section of the cut area by the long axis or the short axis by 4 / π, as defined by the following equation:

[0046] Area size = (4 / π)d 平均

[0047] In an embodiment, the graft level of the anhydride-grafted or maleic anhydride-grafted elastomer is at least 0.1 wt%. In an embodiment, the graft level of the anhydride-grafted or maleic anhydride-grafted elastomer is between 0.1% and 3.0 wt%. In an embodiment, the graft level of the anhydride-grafted or maleic anhydride-grafted elastomer is between 0.5% and 2.0 wt%.

[0048] In an embodiment, the anhydride-grafted or maleic anhydride-grafted elastomer can be crosslinked, partially crosslinked, or non-crosslinked. In an embodiment, the anhydride-grafted or maleic anhydride-grafted elastomer is crosslinked by copolymerization with a crosslinking monomer having two or more double bonds.

[0049] As used herein, the term "elastomer" refers to a material that can be repeatedly stretched (at least three times) to at least twice its initial length at room temperature and substantially retract to its initial dimensions. The density of the elastomer as used herein is less than 0.920 g / cc. In an embodiment, the density of the elastomer is from 0.850 g / cc to 0.920 g / cc.

[0050] The barrier layer comprises one or more barrier components. Useful barrier components include, but are not limited to: ethylene / vinyl alcohol copolymers, polyacrylonitrile, polyvinylidene chloride, and polyamides such as nylon-MXD,6 (with or without nanocomposites), nylon-MXD,6 / MXD,I.

[0051] The ethylene content of the ethylene / vinyl alcohol copolymer can be, for example, between 20 wt% and 45 wt%, between 25% and 35%, and 32 wt%. The ethylene / vinyl alcohol copolymer can include saponified or hydrolyzed ethylene / vinyl acetate copolymers, such as those with a degree of hydrolysis of at least 50%, preferably at least 85%.

[0052] The thickness and composition of the additional layer comprising the barrier component can be sufficient to impart an oxygen transmission rate of the film incorporating the barrier layer not exceeding any of the following values: 150, 100, 50, 45, 40, 35, 30, 25, 20, 15, 10, and 5 cubic centimeters (at standard temperature and pressure) / square meter / day / 1 atm oxygen pressure differential, measured at 0% relative humidity and 23°C. All references to oxygen transmission rate in this application are measured under these conditions according to ASTM D-3985.

[0053] The additional layer can comprise at least any of the following amounts of the barrier component: 50%, 60%, 70%, 80%, 90%, and 100%, based on the weight of the additional layer comprising the barrier component. The thickness of the additional layer can be any of the following: 0.05 - 6 mils, 0.05 - 4 mils, 0.1 - 3 mils, and 0.12 - 2 mils.

[0054] In an embodiment, any layer and / or any polyamide resin or blend can contain an effective amount of one or more nucleating agents. The effective amount and type of nucleating agent are known to those skilled in the art.

[0055] Additional layers or the layers described herein can further include one or more additives useful for packaging films, such as antiblocking agents, slip agents, antifogging agents, colorants, pigments, dyes, fragrances, antimicrobial agents, heat stabilizers, meat preservatives, antioxidants, fillers, radiation stabilizers, antistatic agents, oxygen scavengers, and odor scavengers.

[0056] Polyamide

[0057] Useful polyamides include those of the type that can be formed by the polycondensation of one or more diamines with one or more diacids and / or those of the type that can be formed by the polycondensation of one or more amino acids. Useful polyamides include aliphatic polyamides and aliphatic / aromatic polyamides.

[0058] Representative aliphatic diamines for preparing polyamides include those having the following formula:

[0059] H2N(CH2) n NH2

[0060] where n is an integer value from 1 to 16. Representative examples include trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, octamethylenediamine, decamethylenediamine, dodecamethylenediamine, hexadecamethylenediamine. Representative aromatic diamines include p-phenylenediamine, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenylethane. Representative alkylated diamines include 2,2-dimethylpentamethylenediamine, 2,2,4-trimethylhexamethylenediamine, and 2,4,4-trimethylpentamethylenediamine. Representative cycloaliphatic diamines include diaminodicyclohexylmethane. Other useful diamines include heptamethylenediamine, nonamethylenediamine, etc.

[0061] Representative diacids for preparing polyamides include dicarboxylic acids, which can be represented by the following general formula:

[0062] HOOC--Z--COOH

[0063] where Z represents a divalent aliphatic group containing at least 2 carbon atoms. Representative examples include adipic acid (i.e., hexanedioic acid), sebacic acid, octadecanedioic acid, pimelic acid, suberic acid, azelaic acid, dodecanedioic acid, and glutaric acid. The dicarboxylic acid can be an aliphatic acid or an aromatic acid, such as isophthalic acid and terephthalic acid.

[0064] The polycondensation reaction product of one or more of the above diamines and one or more of the above diacids can form useful polyamides. Representative polyamides of the type that can be formed by the polycondensation of one or more diamines and one or more diacids include aliphatic polyamides such as poly(hexamethylene adipamide) ("nylon-6,6"), poly(hexamethylene sebacamide) ("nylon-6,10"), poly(heptamethylene pimelamide) ("nylon-7,7"), poly(octamethylene suberamide) ("nylon-8,8"), poly(nonamethylene adipamide) ("nylon-6,9"), poly(nonamethylene nonamide) ("nylon-9,9"), poly(nonamethylene sebacamide) ("nylon-10,9"), poly(tetramethylene diamine-co-oxalic acid) ("nylon-4,2"), the polyamide of dodecanedioic acid and hexamethylenediamine ("nylon-6,12"), and the polyamide of dodecamethylenediamine and dodecanedioic acid ("nylon-12,12").

[0065] Representative aliphatic / aromatic polyamides include poly(tetramethylene diamine-co-isophthalic acid) ("nylon-4,I"), poly(isophthaloyl hexamethylene diamine) ("nylon-6,I"), poly(terephthaloyl 2,2,2-trimethylhexamethylene diamine), poly(adipoyl m-xylylenediamine) ("nylon-MXD,6"), poly(adipoyl p-xylylenediamine), poly(terephthaloyl hexamethylene diamine), poly(terephthaloyl dodecanediamine), and polyamide-MXD,I.

[0066] Representative polyamides of the type that can be formed by the polycondensation of one or more amino acids include poly(4-aminobutyric acid) ("nylon-4"), poly(6-aminohexanoic acid) ("nylon-6" or "poly(caprolactam)"), poly(7-aminoheptanoic acid) ("nylon-7"), poly(8-aminooctanoic acid) ("nylon-8"), poly(9-aminononanoic acid) ("nylon-9"), poly(10-aminodecanoic acid) ("nylon-10"), poly(11-aminoundecanoic acid) ("nylon-11"), and poly(12-aminododecanoic acid) ("nylon-12").

[0067] Representative copolyamides include copolymers based on combinations of monomers used to prepare any of the foregoing polyamides, such as nylon-4 / 6, nylon-6 / 9, caprolactam / adipic acid hexamethylene diamine copolymer (“nylon-6,6 / 6”), adipic acid hexamethylene diamine / caprolactam copolymer (“nylon-6 / 6,6”), adipic acid trimethylene diamine / sebacic acid hexamethylene diamine copolymer (“nylon-trimethyl 6,2 / 6,2”), adipic acid hexamethylene diamine-sebacic acid hexamethylene diamine-caprolactam copolymer (“nylon-6,6 / 6,9 / 6”), adipic acid hexamethylene diamine / isophthalic acid hexamethylene diamine (“nylon-6,6 / 6,I”), adipic acid hexamethylene diamine / terephthalic acid hexamethylene diamine (“nylon-6,6 / 6,T”), nylon-6,T / 6,I, nylon-6 / MXD,T / MXD,I, nylon-6,6 / 6,10, and nylon-6,I / 6,T.

[0068] The term “copolymer” as used in this application refers to a polymer derived from two or more types of monomers and includes terpolymers and the like. Conventional nomenclature typically lists the main components of the copolymer before the slash (“ / ”) in the name of the copolymer; however, in this application, the component listed before the slash is not necessarily the main component unless specifically indicated as such. For example, unless this application specifically states the contrary, “nylon-6 / 6,6” and “nylon-6,6 / 6” can be considered to refer to the same type of copolyamide.

[0069] The polyamide copolymer may include the most prevalent polymer unit in the copolymer (e.g., adipic acid hexamethylene diamine as the polymer unit in the copolymer nylon-6,6 / 6), the mole percentage of which is in the range of any of the following: at least 50%, at least 60%, at least 70%, at least 80%, and at least 90%, and in the range between any of the foregoing values (e.g., 60% to 80%); and may include the second most prevalent polymer unit in the copolymer (e.g., caprolactam as the polymer unit in the copolymer nylon-6,6 / 6), the mole percentage of which is in any of the following ranges: less than 50%, less than 40%, less than 30%, less than 20%, less than 10%, and in the range between any of the foregoing values (e.g., 20 - 40%).

[0070] Useful polyamides include those polyamides that are approved by a regulatory agency (such as the U.S. Food and Drug Administration) for direct contact with food and / or for use in food packaging films under the desired conditions of use.

[0071] For outer layer measurements, the gloss of the film (i.e., specular gloss) can be at least about and / or at most about any of the following values: 40, 50, 60, 63, 65%, 70, 75, 80, 85, 90, and 95%. These numbers represent the ratio of the light reflected from the sample to the initial amount of light incident on the sample at a specified angle. All "gloss" values mentioned in this application are in accordance with ASTM D2457 (45° angle), which is incorporated herein by reference in its entirety.

[0072] Haze is a measure of the transmitted light scattered more than 2.5° from the axis of the incident light. Haze of the outer surface of the film is measured according to the method of ASTM D 1003, which is incorporated herein by reference in its entirety. All "haze" values mentioned in this application are in accordance with this standard. The haze of the film can be no higher than any of the following values: 20%, 15%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, and 1%. After placing a representative film sample in a conventional oven at an air temperature of 204.4 °C for two hours, either the first film and / or the second film can have any of these haze values.

[0073] The first film and / or the second film can be transparent (at least in the non-printed areas) such that the packaged article is visible through the film. As used herein, "transparent" means that the material transmits incident light, with negligible scattering and low absorption, such that an object (e.g., a packaged food or printing) can be clearly seen through the material under typical unaided viewing conditions (i.e., the intended use conditions of the material). The transparency (i.e., clarity) of the film can be at least any of the following values: 20%, 25%, 30%, 40%, 50%, 65%, 70%, 75%, 80%, 85%, and 95%, as measured according to ASTM D1746. All "transparency" values mentioned in this application are in accordance with this standard.

[0074] Either the first film and / or the second film can have a heat-shrinkable property. For example, the free shrinkage of the film measured at 104.4 °C in at least one direction (i.e., longitudinal or transverse) or in each of two directions (longitudinal and transverse) can be at least any one of the following: 3%, 7%, 10%, 15%, 20%, 25%, 30%, 40%, 50%, 55%, 60%, and 65%. Additionally, when measured at any one of 37.8 °C, 48.9 °C, 60.0 °C, 71.1 °C, 85.0 °C, 87.8 °C, 93.3 °C, and 98.9 °C, any free shrinkage of the film in at least one direction (longitudinal or transverse) or in each of two directions (longitudinal and transverse) can be at least any one of the listed shrinkage values. Unless otherwise specified, each mention of free shrinkage in this application refers to the free shrinkage determined by measuring the percentage change in the size of a 10 cm × 10 cm specimen when subjected to a selected heat (i.e., exposure at a certain temperature) according to ASTM D-2732.

[0075] The multilayer film can be manufactured by thermoplastic film-forming methods known in the art (e.g., tubular or blown film extrusion, coextrusion, extrusion coating, flat film extrusion, annular film extrusion). Combinations of these methods can also be employed. For example, the film can be prepared using either the "double bubble" or "triple bubble" extrusion method.

[0076] In an embodiment, the multilayer film can be oriented or non-oriented. For example, to enhance the optical properties, strength, and durability of the film, the film can be oriented longitudinally (i.e., in the machine direction) or transversely, or biaxially (i.e., in two directions). For example, the film can be oriented in one direction (longitudinal or transverse) or in both directions at at least any one of the following ratios: 2:1, 2.5:1, 2.7:1, 3:1, 3.5:1, and 4:1. The film can be oriented in one direction (longitudinal or transverse) or in both directions at no more than any one of the following ratios: 10:1, 9:1, 8:1, 7:1, 6:1, 5:1, and 4:1. If the film is oriented, it can be heat-set or annealed after orientation to reduce the heat-shrinkable property to a desired level or to help obtain a desired crystalline state of the film. For example, the first film and / or the second film can be prepared using a tenter frame method.

[0077] In an embodiment, the multilayer film is partially or fully crosslinked. To effect crosslinking, the film, one or more layers of the film, are treated with high energy electrons at an appropriate radiation dose. In an embodiment, an electron accelerator introduces the radiation dose, where the dose level is determined by standard dosimetry methods. It will be understood that other accelerators, such as Van der Graaf generators or resonant transformers, can be used. The radiation is not limited to electrons from an accelerator, as any ionizing radiation can be used. In an embodiment, the radiation dose of high energy electrons is at most 140 kGreys, in the range of 10 - 120 kGreys, in the range of 20 - 100, or in the range of 30 - 80 kGreys. In an embodiment, irradiation is carried out before orientation. In an embodiment, irradiation is carried out after orientation.

[0078] Figure 6 Illustrate a vertical form fill and seal apparatus for use in a packaging method according to the present invention. Schematically illustrate a vertical form fill and seal apparatus 60. The apparatus 60 uses a multilayer film 61 as described herein. The product 62 to be packaged is supplied to the apparatus 60 from a source (not shown) or other conventional means, and a predetermined quantity of the product 62 reaches the upper end portion of a forming tube 64 from the source via a hopper 63. A package is formed in the lower portion of the apparatus 60, and a flexible sheet material 61 forming a bag or package is fed from a roll 71 onto certain forming rods (not shown), wound around the forming tube 64, and provided with a longitudinal seal 67 by a longitudinal heat sealing device 66, resulting in the formation of a vertically sealed tube 68. An end sealing bar 65 operates to close and seal horizontally across the lower end of the vertically sealed tube 68 to form a pouch 70, which is then immediately packaged with the product 62. As illustrated, a film drive belt 72 is powered and guided by rolls to advance the vertically sealed tube 68 and the pouch 70 a predetermined distance, after which the end sealing bar 65 closes and simultaneously seals horizontally across the lower end of the vertically sealed tube 68, and simultaneously seals horizontally across the upper end of the sealed pouch 69 to form the product packaged in the sealed pouch 69. Then the next pouch 70 thereon is filled with a metered quantity of the product 62, advanced, and so on. Conventionally, an end sealing bar is also incorporated with a cutting knife (not shown), which operates to cut the lower sealed pouch 69 from the bottom of the upstream pouch 70.

[0079] In the packaging method, in an embodiment, a vertical form, fill, and seal machine forms, fills, and seals at least 15 packages per minute. In another embodiment, the vertical form, fill, and seal machine forms, fills, and seals 15 - 45 packages per minute with substantially no film burn-through at the seal. In an embodiment, the product is a food product containing a liquid, including but not limited to macaroni and cheese, mashed potatoes, diced vegetables, diced fruit, eggs, soup, gravy, sauce, whole meat, diced meat, rice, cereal, pasta without sauce, partially cooked pasta, pasta / sauce blend, whole vegetables, fruit filling, puree, ground meat, or combinations thereof.

[0080] Turning now to Figure 7 , a cross-sectional view of a multilayer film according to an embodiment is depicted. The multilayer film contains two outer layers 51, 57 that serve as heat-sealing layers. Adhesive layers 52, 56 bond the two outer layers 51, 57 to abuse layers 53, 55, respectively. An adhesive layer 58 is disposed between the two abuse layers 53 and 55. In an embodiment, additional adhesive layers are used between the barrier layer 54 and the abuse layers 53 and 55. Examples

[0081] The following examples are provided to further illustrate and explain various embodiments of the invention and should not be construed as limiting in any way. Unless otherwise indicated, all parts and percentages are by weight.

[0082] The following abbreviations may be used:

[0083] LDPE is low-density polyethylene with a melting point of 110 °C and is available from ExxonMobile under the trade name LDPE LD 102.LC.

[0084] LLDPE is linear low-density polyethylene with a melting point of 114 °C and is available from ExxonMobile under the trade name Exceed 4518PA.

[0085] MA-LLDPE is maleic anhydride-modified linear low-density polyethylene with a melting point of 122 °C and is available from Westlake Chemical under the trade name GT4408.

[0086] MA-VLDPE is maleic anhydride-modified very low-density polyethylene with a melting point of 124 °C and is available from LyondellBasell under the trade name Plexar PX3216.

[0087] MA-EOC is maleic anhydride-modified ethylene / octene copolymer with a melting point of 52 °C and is available from DuPont under the trade name Fusabond N598.

[0088] PA-6 is nylon-6 with a melting point of 220 °C and is available from BASF Corporation under the trade name Ultramid B40.

[0089] PA-6 / 66 is nylon-6 / 66 with a melting point of 193 °C and is available from BASF under the trade name Ultramid C40.

[0090] MDPE is medium density polyethylene with a melting point of 125 °C and is available from Dow under the trade name Dowlex 2037.

[0091] EVOH is ethylene / vinyl acetate copolymer with a melting point of 187 °C and is available from CCP under the trade name EV2951F.

[0092] Antifogging agents are additives that prevent or reduce the condensation of small droplets of water on the surface of a packaging film. Such additives act as mild wetting agents that exude to the surface of the packaging film and reduce the surface tension of water, thereby causing the water to spread into the continuous film. Examples of antifogging agents are mono-fatty acid derivatives of glycerol (such as glycerol monostearate) and polyglycerol mono-fatty acid derivatives (such as polyglycerol monostearate). The mono-fatty acid derivatives of glycerol and the polyglycerol mono-fatty acid derivatives can be used alone or in combination as the antifogging agent of the present invention.

[0093] Processing aids include, but are not limited to, fluoropolymers / polyethylene.

[0094] Preparation of sample films

[0095] Films with a thickness of 4 mils were prepared by the circular casting coextrusion method to have the compositions shown in the following table.

[0096] Sample film 1 (comparison)

[0097]

[0098] Sample film 2

[0099]

[0100] Sample film 3

[0101]

[0102] Sample film 4

[0103]

[0104] Sample film 5

[0105]

[0106] Sample film 6

[0107]

[0108] Sample film 7

[0109]

[0110] Sample film 8

[0111]

[0112] Sample film 9

[0113]

[0114] Sample film 10

[0115]

[0116] Impact test

[0117] Samples films 1 - 6 were tested in accordance with ASTM D3763 - 08 to measure the film's performance at impact speeds and rate sensitivity to impact. The tests were conducted at least one week after film manufacture. The results are presented in Table A below.

[0118] Table A

[0119]

[0120] Preparation of packages

[0121] Samples films 1 - 6 were formed into pouches using an Onpack 3002 vertical form - fill - and - seal machine. The end - seal temperature was 140 °C and the time was 0.8 seconds. The end - seal was a five - rib seal. The center "lap" seal was at 145 °C for 0.7 seconds. Each pouch was 380 mm in length and 240 mm in width. The pouches were filled with approximately 6 pounds of water at a water temperature between 21 - 25.5 °C. The packages were produced in a room at a temperature of 18 - 25 °C. Sample film 1 was formed into sample pouch 1. Sample film 2 was formed into sample pouch 2. Sample film 3 was formed into sample pouch 3. Sample film 4 was formed into sample pouch 4. Sample film 5 was formed into sample pouch 5. Sample film 6 was formed into sample pouch 6.

[0122] Immediate drop test

[0123] Within at least 10 minutes of the pouch generating fill water, the "drop test" of the package is completed using the following procedure. In a room with a temperature between 18 - 25 °C, place the pouches individually on the platform of a Lansmont drop tester. Place the pouches face up with the lap seal. Each pouch is dropped once from a height of 6 feet, and the failure mode is recorded. Squeeze each pouch by hand to detect failure. If the pouch survives the fall without damage that would cause water leakage, the fall is recorded as a "pass". If the pouch ruptures within the body of the package, which would cause a crack or hole in the film, this failure is termed a "body" failure. Small leaks within the body of the pouch will cause pinholes or needle holes, which are recorded as "pinhole" failures. Failure of the film at either end of the pouch along the bottom of the five-rib seal is recorded as a "seal" failure. The results of the immediate drop test are shown in Table B below.

[0124] Table B

[0125]

[0126] The free shrink test is used to evaluate the unrestricted linear thermal shrinkage of thin plastic films for packaging applications. ASTM D2732 is used to determine free shrinkage. The water bath temperature used is 85 °C. Readings are taken once the film is produced ("as produced") and after the film has aged for 7 days. The results from the thermal shrinkage test are shown in Table C below.

[0127] Table C

[0128] Sample film 7 Production Aged for 7 days Longitudinal direction 14% 13.5% Transverse direction 5.3% 8.75%

[0129] The appearance characteristics of Films 1 - 6 are shown in Table D below.

[0130] Table D

[0131] Sample Transmittance (%) Haze (%) Glossiness 1 93.0 7.8 96.3 2 92.2 9.3 90.2 3 91.8 11.4 91.8 4 92.4 10.0 96.3 5 92.8 9.5 95.0 6 92.4 9.9 93.5 8 93.7 9.5 76.0 9 91.9 11.8 73.0 10 91.2 13.3 70.4

[0132] This written description uses examples to disclose the invention, including the best mode, and also enables those skilled in the art to practice the invention, including making and using any device or system and performing any incorporated methods. The patentable scope of the invention is defined by the claims and may include other examples that occur to those skilled in the art. If such other examples have structural elements that are not different from the literal language of the claims, or if they include equivalent structural elements that are not materially different from the literal language of the claims, then such other examples are intended to be within the scope of the claims.

[0133] Component listing:

[0134] 12 - Upper surface of the film

[0135] 14 - Lower surface of the film

[0136] 16 - Edge

[0137] 20 - Packaging space

[0138] 28 - Heat seal

[0139] 30 - Packaging

[0140] 32 - Folding edge

[0141] 34 - Heat seal seam

[0142] 36 - Packaging

[0143] 38 - End seal

[0144] 40 - End seal

[0145] 42 - Edge

[0146] 44 - Edge

[0147] 51 - Outer layer

[0148] 52 - Adhesive layer

[0149] 53 - Abuse layer

[0150] 54 - Barrier layer

[0151] 55 - Abuse layer

[0152] 56 - Adhesive layer

[0153] 57 - Outer layer

[0154] 58 - Adhesive layer

[0155] 60 - Instrument

[0156] 61 - Multilayer film

[0157] 62 - Product

[0158] 63 - Funnel

[0159] 64 - Forming tube

[0160] 65 - End seal rod

[0161] 66 - Heat sealing equipment

[0162] 67 - Longitudinal seal

[0163] 68 - Vertically sealed tube

[0164] 69 - Sachet

[0165] 70 - Sachet

[0166] 71 - Roller

[0167] 72 - Film drive belt.

Claims

1. A multilayer film, the multilayer film comprising: At least one outer layer, the outer layer comprising at least 70% by weight of one or more ethylene / α-olefin copolymers; And at least one inner layer as an abuse layer, the abuse layer comprising a blend of: At least 1% by weight of a maleic anhydride-grafted ethylene / octene copolymer having a grafting level between 0.5 - 2.0% by weight; and At least 25% by weight of one or more polyamides; Wherein at least 5% by weight of the multilayer film is one or more polyamides; the multilayer film has a haze of no more than 20% measured according to ASTM D1003, and a gloss of at least 90 measured according to ASTM D 2457.

2. The multilayer film according to claim 1, wherein at least 10% by weight of the multilayer film is one or more polyamides.

3. The multilayer film according to claim 1, wherein at least 20% by weight of the multilayer film is one or more polyamides.

4. The multilayer film according to claim 1, wherein at least 30% by weight of the multilayer film is one or more polyamides.

5. The multilayer film according to claim 1, wherein at least 40% by weight of the multilayer film is one or more polyamides.

6. The multilayer film according to claim 1, wherein at least 50% by weight of the multilayer film is one or more polyamides.

7. The multilayer film according to claim 1, wherein the outer layer is a sealant layer comprising linear low density polyethylene.

8. The multilayer film according to claim 7, wherein the linear low density polyethylene of the outer layer comprises a blend of linear low density ethylene / hexene copolymer and linear low density ethylene / octene copolymer.

9. The multilayer film according to any one of the preceding claims, wherein the abuse layer comprises at least 3% of the maleic anhydride-grafted ethylene / octene copolymer.

10. The multilayer film according to any one of claims 1 - 8, wherein the abuse layer comprises at least 5% of the maleic anhydride-grafted ethylene / octene copolymer.

11. The multilayer film according to any one of claims 1 - 8, wherein the multilayer film further comprises an inner layer, and the inner layer is a barrier layer disposed between the outer layer and the abuse layer, and the oxygen transmission rate of the multilayer film does not exceed 150 cubic centimeters per square meter per day per 1 atmosphere oxygen pressure difference, measured according to ASTM D-3985 at 0% relative humidity and 23°C.

12. The multilayer film according to claim 11, wherein the barrier layer comprises at least 50% by weight of ethylene / vinyl alcohol copolymer or polyvinylidene chloride.

13. The multilayer film according to any one of claims 1-8, wherein the one or more polyamides of the abuse layer are selected from nylon-6,6; nylon-6,10; nylon-7,7; nylon-8,8; nylon-6,9; nylon-9,9; nylon-10,9; nylon-4,2; nylon-6,12; nylon-12,12; nylon-4,I; nylon-6,I; poly(2,2,2-trimethylhexamethylene terephthalamide), nylon-MXD,6; poly(p-xylylene adipamide); poly(hexamethylene terephthalamide); poly(dodecamethylene terephthalamide); polyamide-MXD,I; nylon-4; nylon-6; nylon-7; nylon-8; nylon-9; nylon-10; nylon-11; nylon-12; nylon-4 / 6; nylon-6 / 9; nylon-6,6 / 6; nylon-6 / 6,6; nylon-trimethyl 6,2 / 6,2; nylon-6,6 / 6,9 / 6; nylon-6,6 / 6,I; nylon-6,6 / 6,T; nylon-6,T / 6,I; nylon-6 / MXD,T / MXD,I; nylon-6,6 / 6,10; nylon-6,I / 6,T; and blends thereof.

14. The multilayer film according to any one of claims 1-8, wherein the one or more polyamides of the abuse layer are selected from nylon-4; nylon-6; nylon-7; nylon-8; and blends thereof.

15. The multilayer film according to any one of claims 1-8, wherein the one or more polyamides of the abuse layer comprise at least 50% of nylon-4; nylon-6; nylon-7; nylon-8; and blends thereof.

16. The multilayer film according to claim 15, wherein the one or more polyamides of the abuse layer comprise at least 70% of nylon-4; nylon-6; nylon-7; nylon-8; and blends thereof.

17. The multilayer film according to any one of claims 1-8, wherein the free shrinkage of the multilayer film in any direction is less than 30%, measured according to ASTM D 2732.

18. The multilayer film according to any one of claims 1-8, further comprising an adhesive layer disposed between the outer layer and the abuse layer, the adhesive layer comprising at least 80 wt% of maleic anhydride-grafted linear low density polyethylene.

19. The multilayer film according to any one of claims 1-8, wherein the total thickness of the multilayer film does not exceed 12 mils.

20. The multilayer film according to claim 18, wherein the total thickness of the multilayer film does not exceed 10 mils.

21. The multilayer film according to claim 18, wherein the total thickness of the multilayer film does not exceed 8 mils.

22. The multilayer film according to claim 18, wherein the total thickness of the multilayer film does not exceed 6 mils.

23. The multilayer film according to claim 18, wherein the total thickness of the multilayer film does not exceed 4 mils.

24. The multilayer film according to claim 18, wherein the total thickness of the multilayer film does not exceed 1.5 mils.

25. The multilayer film according to claim 18, wherein the total thickness of the multilayer film does not exceed 1 mil.

26. The multilayer film according to any one of claims 1-8, wherein the maleic anhydride-grafted ethylene / octene copolymer is dispersed as distinct spherical particles in the abuse layer and has an average area size less than 3.00 microns according to the following formula: Area size = (4 / π)d 平均 The diameter is measured by taking the average diameter (d 平均 ) of the region spanning the major or minor axis.

27. The multilayer film according to any one of claims 1-8, wherein the multilayer film comprises: i. at least one outer layer that is a first outer layer, the first outer layer comprising a blend of linear low density polyethylene and low density polyethylene; ii. a first adhesive layer that directly adheres to the at least one outer layer on one side and the abuse layer on the other side, the first adhesive layer comprising maleic anhydride-modified linear low density polyethylene; iii. an inner layer that directly adheres to the abuse layer on one side and a second abuse layer on the other side; iv. a second abuse layer that comprises a blend of: at least 1 wt% of a maleic anhydride-grafted elastomer selected from ethylene propylene diene monomer, ethylene propylene copolymer, styrene-ethylene-butene-styrene, ethylene / octene copolymer, and blends thereof; and at least 25 wt% of one or more polyamides; v. a second adhesive layer that directly adheres to the second abuse layer on one side and a second outer layer on the other side, the second adhesive layer comprising maleic anhydride-modified linear low density polyethylene; and vi. a second outer layer comprising a blend of linear low density polyethylene and low density polyethylene.

28. A food package, which comprises: food; a pouch containing the food, the pouch being made of a multilayer film that comprises: at least one outer layer, the outer layer comprising at least 70 wt% of one or more ethylene / α-olefin copolymers; and at least one inner layer that is an abuse layer, the abuse layer comprising a blend of: at least 1 wt% of a maleic anhydride-grafted ethylene / octene copolymer having a graft level between 0.5-2.0 wt%; and at least 25 wt% of one or more polyamides; wherein at least 5 wt% of the multilayer film is one or more polyamides; the multilayer film has a haze of no more than 20% as measured according to ASTM D1003, and a gloss of at least 90 as measured according to ASTM D 2457.

29. The food package according to claim 27, wherein at least 10 wt% of the multilayer film is one or more polyamides.

30. The food package according to claim 27, wherein at least 20 wt% of the multilayer film is one or more polyamides.

31. The food package according to claim 27, wherein at least 30 wt% of the multilayer film is one or more polyamides.

32. The food package according to claim 27, wherein at least 40 wt% of the multilayer film is one or more polyamides.

33. The food package according to claim 27, wherein at least 50 wt% of the multilayer film is one or more polyamides.

34. A method of forming an article for packaging, the method comprising the following steps: a) Provide a multilayer film, the multilayer film comprising: i. At least one outer layer, the outer layer comprising at least 70% by weight of one or more ethylene / α-olefin copolymers; ii. And at least one inner layer as an abuse layer, the abuse layer comprising a blend of: At least 1% by weight of a maleic anhydride-grafted ethylene / octene copolymer having a graft level between 0.5 - 2.0% by weight; and At least 25% by weight of one or more polyamides; iii. At least 5% by weight of the multilayer film is one or more polyamides; the multilayer film has a haze of no more than 20% measured according to ASTM D1003, and a gloss of at least 90 measured according to ASTM D 2457; b) Form the film into a tube in a vertical form-fill-seal apparatus; c) Fill the tube with food; and d) Seal the tube to form a sealed pouch containing the food.

35. The method according to claim 33, wherein at least 10% by weight of the multilayer film is one or more polyamides.

36. The method according to claim 33, wherein at least 20% by weight of the multilayer film is one or more polyamides.

37. The method according to claim 33, wherein at least 30% by weight of the multilayer film is one or more polyamides.

38. The method according to claim 33, wherein at least 40% by weight of the multilayer film is one or more polyamides.

39. The method according to claim 33, wherein at least 50% by weight of the multilayer film is one or more polyamides.

40. A multilayer film, the multilayer film comprising: a) A first inner layer; b) Two abuse layers disposed on opposite surfaces of the first inner layer, the two abuse layers comprising a blend of: i. At least 1% by weight of a maleic anhydride-grafted ethylene / octene copolymer having a graft level between 0.5 - 2.0% by weight; and ii. At least 25% by weight of one or more polyamides; c) Two adhesive layers, each disposed on the surface of a corresponding abuse layer, each adhesive layer comprising a maleic anhydride-modified ethylene / α-olefin copolymer; and d) Two outer layers, each disposed on the surface of a corresponding adhesive layer, each outer layer comprising at least 70% by weight of one or more ethylene / α-olefin copolymers, wherein the multilayer film has a haze of no more than 20% measured according to ASTM D1003, and a gloss of at least 90 measured according to ASTM D 2457.

41. The multilayer film according to claim 39, wherein the first inner layer is an adhesive layer comprising a maleic anhydride-modified ethylene / α-olefin copolymer.

42. The multilayer film according to claim 39, wherein the first inner layer is a barrier layer, and the oxygen transmission rate of the multilayer film does not exceed 150 cubic centimeters per square meter per day per 1 atmosphere oxygen pressure difference, measured according to ASTM D-3985 at 0% relative humidity and 23°C.

43. The multilayer film according to claim 39, wherein the two abuse layers comprise: i. The maleic anhydride-grafted ethylene / octene copolymer between 1 - 50% by weight; and ii. one or more polyamides of at least 50% by weight.

44. The multilayer film according to claim 42, wherein the amount of the maleic anhydride grafted ethylene / octene copolymer is between 2 and 40% by weight.

45. The multilayer film according to claim 42, wherein the amount of the maleic anhydride grafted ethylene / octene copolymer is between 3 and 30% by weight.

46. The multilayer film according to claim 42, wherein the amount of the maleic anhydride grafted ethylene / octene copolymer is between 4 and 20% by weight.

47. The multilayer film according to claim 42, wherein the amount of the maleic anhydride grafted ethylene / octene copolymer is between 5 and 15% by weight.

48. The multilayer film according to claim 42, wherein the amount of the one or more polyamides is at least 60% by weight.

49. The multilayer film according to claim 42, wherein the amount of the one or more polyamides is at least 70% by weight.

50. The multilayer film according to claim 42, wherein the amount of the one or more polyamides is at least 80% by weight.

Images