Multilayer packaging film comprising a compatibilized polypropylene film

Abstract

A packaging film is disclosed, comprising a first outer film made of polypropylene, the first outer film being coupled to a second outer film also made of polypropylene. At least one of the first and second outer films contains a compatibilizer selected from the group consisting substantially of: propylene / ethylene copolymers, 1-butene-rich 1-butene / ethylene plastomers, polypropylene multiphase olefin copolymers, olefin block copolymers, hydrogenated styrene-butadiene-styrene block copolymers, ethylene propylene rubber, EPDM rubber, and combinations thereof.

Description

Technical Field

[0001] This application relates to orientation films, packaging films, and packaging products made therefrom. The orientation films contain structures and compositions designed for easy recycling. Background Technology

[0002] Packaging films are widely used in various industries for the purpose of protecting and preserving goods during storage and transportation. These films typically consist of multiple layers to provide desired properties such as strength, flexibility, and barrier properties. A common approach in the prior art has been to use polypropylene as the primary material for the outer film of packaging films. Polypropylene is known for its excellent mechanical properties, including high tensile strength and impact resistance, making it suitable for packaging applications.

[0003] Typical snack packaging consists of oriented polypropylene (OPP) based packaging film. This film is very thin, features high-gloss patterns for retail appeal, and offers excellent sealing properties. These films provide protection for snacks throughout their storage and distribution cycle. Furthermore, the films can be processed very quickly on packaging lines.

[0004] To bond the outer membrane and provide a cohesive structure, a polymer layer is typically used. Previous methods have employed various types of polymers for this purpose. For example, some existing packaging films have used polyethylene as the polymer layer because it provides good adhesion between polypropylene outer membranes.

[0005] While these prior methods have provided packaging films with excellent mechanical properties and overall performance, they still present challenges for disposal purposes. High levels of polypropylene in the structure are crucial for performance but pose significant challenges to recyclability. Replacing polypropylene with other materials, such as polyethylene or compostable polymers, only leads to undesirable results, such as unacceptable packaging integrity and packaging forming performance. Furthermore, these alternative solutions are often prohibitively expensive.

[0006] Previous approaches have not provided a comprehensive solution that combines superior packaging film performance with excellent end-of-life options. Summary of the Invention

[0007] In some aspects, the technology described herein relates to a packaging film comprising: a first outer film comprising polypropylene, the first outer film being coupled to a second outer film comprising polypropylene; wherein at least one of the first outer film and the second outer film comprises a compatibilizer selected from the group consisting substantially of: propylene / ethylene copolymers, 1-butene-rich 1-butene / ethylene plastomers, polypropylene multiphase olefin copolymers, olefin block copolymers, hydrogenated styrene-butadiene-styrene block copolymers, ethylene propylene rubber, EPDM rubber, and combinations thereof.

[0008] In some respects, the technology described herein relates to a packaging film, wherein at least one of the first outer film and the second outer film further comprises a stabilizer selected from the group consisting substantially of homogeneous branched linear ethylene polymers, heterogeneous branched linear ethylene polymers, and combinations thereof.

[0009] In some respects, the technology described herein relates to a packaging film, wherein each of the first outer film and the second outer film is independently biaxially oriented or uniaxially oriented.

[0010] In some respects, the technology described herein relates to a packaging film, wherein the first outer film comprises a first outer film composition comprising polypropylene in the range of 80% to 100% by weight, and the first outer film has a thickness in the range of 5 micrometers to 35 micrometers.

[0011] In some respects, the technology described herein relates to a packaging film, wherein the second outer film comprises a second outer film composition comprising polypropylene in the range of 80% to 100% by weight, and the second outer film has a thickness in the range of 5 micrometers to 35 micrometers.

[0012] In some respects, the technology described herein relates to a packaging film comprising a packaging film composition comprising polypropylene in the range of 30% to 90% by weight.

[0013] In some respects, the technology described herein relates to a packaging film that further includes an adhesive layer located between the first outer film and the second outer film.

[0014] In some respects, the technology described herein relates to a packaging film, wherein the adhesive layer comprises a polymer layer containing polyethylene.

[0015] In some respects, the technology described herein relates to a packaging film in which the adhesive layer comprises an adhesive.

[0016] In some respects, the technology described herein relates to a packaging film having a packaging film composition comprising, by weight, 10% to 35% of the compatibilizer.

[0017] In some respects, the technology described herein relates to a packaging film in which the compatibilizer is a propylene-rich propylene / ethylene copolymer.

[0018] In some respects, the technology described herein relates to a packaging film in which the compatibilizer is a propylene / α-olefin copolymer.

[0019] In some respects, the technology described herein relates to a packaging film in which the stabilizer is a homogeneous branched linear ethylene polymer.

[0020] In some respects, the technology described herein relates to a packaging film in which the stabilizer is an ethylene / hexene copolymer or an ethylene / octene copolymer.

[0021] In some aspects, the technology described herein relates to a packaging film suitable for recycling in a polyethylene recycling stream, the packaging film comprising: a first outer film comprising at least 50% by weight of polypropylene, the first outer film being coupled to a second outer film comprising at least 50% by weight of polypropylene; wherein at least one of the first outer film and the second outer film comprises a compatibilizer selected from the group consisting substantially of: propylene / ethylene copolymers, 1-butene-rich 1-butene / ethylene plastomers, polypropylene multiphase olefin copolymers, olefin block copolymers, hydrogenated styrene-butadiene-styrene block copolymers, ethylene propylene rubber, EPDM rubber, and combinations thereof; wherein at least one of the first outer film and the second outer film comprises a stabilizer selected from the group consisting substantially of: homogeneous branched linear ethylene polymers, heterogeneous branched linear ethylene polymers, and combinations thereof; wherein each of the first outer film and the second outer film is independently biaxially oriented or uniaxially oriented; and the packaging film comprises a packaging film composition comprising the compatibilizer in the range of 10% to 35% by weight.

[0022] In some respects, the technology described herein relates to a packaging film that further includes a barrier layer coated on the surface of a second outer film.

[0023] In some respects, the technology described herein relates to a packaging film that further includes ink located between a first outer film and a second outer film.

[0024] In some respects, the technology described herein relates to a packaging film that also has a thickness in the range of 15 micrometers to 100 micrometers.

[0025] In some respects, the technology described herein relates to a packaging film, wherein the packaging film composition comprises a first outer film and a second outer film in the range of 30% to 80% by weight.

[0026] In some respects, the technology described herein relates to a packaging film that is recyclable in a polyethylene recycling stream.

[0027] In some respects, the technology described herein relates to a packaging film in which the compatibilizer is selected from the group consisting essentially of propylene / ethylene copolymers, polypropylene multiphase olefin copolymers, ethylene propylene rubber, EPDM rubber, and combinations thereof.

[0028] In some respects, the technology described herein relates to a packaging film, wherein the first outer film comprises: a first outer layer comprising polypropylene; a second outer layer comprising polypropylene; and an inner layer connecting the first outer layer and the second outer layer; wherein a compatibilizer is contained in the inner layer.

[0029] In some respects, the technology described herein relates to a packaging film, wherein the second outer film comprises: a first outer layer comprising polypropylene; a second outer layer comprising polypropylene; and an inner layer connecting the first outer layer and the second outer layer; wherein a compatibilizer is contained in the inner layer.

[0030] In some respects, the technology described herein relates to a packaging product comprising: a packaging film and a product; wherein the packaging film is sealed to form a package, and the product is enclosed within the package.

[0031] In some aspects, the technology described herein relates to a packaged product comprising: a packaging film sealed to form a package and a product encapsulated within the package, the packaging film comprising: a first outer film comprising polypropylene, the first outer film being coupled to a second outer film comprising polypropylene; wherein the first outer film comprises a compatibilizer selected from the group consisting substantially of: propylene / ethylene copolymers, 1-butene-rich 1-butene / ethylene plastomers, polypropylene multiphase olefin copolymers, olefin block copolymers, hydrogenated styrene-butadiene-styrene block copolymers, ethylene propylene rubber, EPDM rubber, and combinations thereof.

[0032] In some respects, the technology described herein relates to a packaging product, wherein the packaging is in the form of a pillow-shaped package, the pillow-shaped package including two end seals and seams, the seams being formed as fin seals or as overlapping seals. Attached Figure Description

[0033] A more complete understanding of this disclosure can be achieved by considering the following detailed description of various embodiments taken in conjunction with the accompanying drawings. The drawings illustrate some, but not all, of the embodiments. Elements depicted in the drawings are illustrative and not necessarily drawn to scale, and throughout the drawings, the same (or similar) reference numerals denote the same (or similar) features.

[0034] Figure 1 This is a cross-sectional view of an embodiment of the packaging film as described herein.

[0035] Figure 2 This is a cross-sectional view of an embodiment of the outer membrane as described herein.

[0036] Figure 3 This is a cross-sectional view of an embodiment of the packaging film as described herein.

[0037] Figure 4 This is a perspective view of an embodiment of the packaging product as described herein.

[0038] The accompanying drawings illustrate some, but not all, of the embodiments. The elements depicted in the drawings are illustrative and not necessarily drawn to scale, and throughout the drawings, the same (or similar) reference numerals denote the same (or similar) features. Detailed Implementation

[0039] This disclosure includes a description of packaging films and their use in manufacturing packaging for packaged products. The inventors have surprisingly discovered that, through the unique film structure and formulation discussed herein, commonly used BOPP / BOPP laminates as an economical solution for snack packaging can be recycled in polyethylene recycling streams. Compared to currently used BOPP / BOPP snack packaging structures, the new structure strategically improves recyclability while maintaining appearance, barrier properties, low cost, ease of production, and packaging line speed.

[0040] Currently, snack packaging using oriented polypropylene laminates presents significant end-of-life disposal challenges. Potentially technically suitable polypropylene recycling streams for flexible packaging have not yet been well-developed and are therefore unreliable. In some countries, current structures are not recyclable by any existing methods, and efforts to convert these structures into compostable / biodegradable solutions have not been successful. The end-of-life option for current structures is typically waste logistics. Other structural options that could potentially avoid waste logistics, such as those made using compostable materials, have not yet reached sufficient performance and / or cost to make these solutions viable for the packaging industry. This paper presents a pioneering solution that incorporates nearly identical performance to current solutions (…). Right now (Appearance, barrier properties, operability, heat resistance) but now capable of being accepted by a wider range of recycled polyethylene streams. As will be fully discussed in this article, the introduction of polymer layers containing compatibilizers and optionally stabilizers allows for advancements in this previously unknown type of packaging.

[0041] The packaging films described in this article contain a significant proportion ( Right now Polypropylene (greater than 20%, 30%, 40%, 50%, or 60%). Polypropylene is immiscible with polyethylene, and therefore its addition to polyethylene recycling streams, including melt-incorporated and blended polymer materials, is generally unacceptable. The inventors' research has yielded a surprising effect: by introducing specific compatibilizers into the structure, packaging film structures containing a significant proportion of polypropylene can be recycled in polyethylene recycling streams.

[0042] The properties of immiscible polymer blends depend on factors such as the droplet size of the dispersed (minor) phase and interfacial adhesion. Larger droplet sizes result in reduced light scattering, decreasing the blend's transparency. Low interfacial adhesion reduces strength properties and promotes cavitation during deformation operations such as thermoforming and uniaxial or biaxial stretching. Immiscible polymers can lead to less than ideal appearance and / or mechanical properties in articles made from such blends. To improve transparency and strength, it is generally desirable to maintain a stable distribution of small droplets within the multiphase polymer blend.

[0043] When thermodynamically immiscible polymers are blended in a mixing device and the elongation stress exceeds the elastic limit of the secondary polymer fractions, these secondary fractions break down into droplets, which become the dispersed phase of the multiphase system. The mixing device can utilize moving elements (…). For example (extruder), or it can be a stationary type (extruder). For example (static mixer).

[0044] The deformation and breakup of viscous droplets in a flow field are controlled by the capillary number (Ca). The capillary number compares the relative strength of viscous stress (which tends to cause droplet elongation) and interfacial stress (the surface tension effect that tends to cause droplet spherical shape). When the capillary number reaches a critical value, viscous stress dominates, and the interfacial stress is not large enough to prevent droplet breakup. That is, surface tension is no longer able to maintain a spherical droplet, so the droplet elongates and eventually breaks up into smaller units.

[0045] Because smaller droplets create more interfaces, increasing the interfacial area, droplet breakup increases the system's free energy. As the polymer blend leaves the strongly mixed zone of the mixing apparatus (i.e., entering a region of lower elongation stress), droplet collisions lead to coalescence, reducing the total interfacial area and consequently lowering the system energy. Therefore, some of the transparency and strength benefits provided by strong mixing are lost. To minimize coalescence and maintain small droplets, compatibilizers are used to influence polymer interactions at the phase interfaces. Successful compatibilizers exhibit affinity for both phases. These affinityes can be chemical (…). For example Maleic anhydride-modified compatibilizer reacts with amine functional groups in polymer droplets ( For example Dow Retain 3000 used in PE / polyamide systems), or physical ( For example The compatibilizer chain becomes entangled with the droplet and / or the continuous phase ( For example (PE / PP block copolymers used in PE / PP systems). Ideally, compatibilizers prevent the aggregation of dispersed droplets and maintain a stable multiphase polymer system.

[0046] As used herein, the term "recyclable" is intended to indicate that the film can be transformed into a new, useful article by means of reprocessing in a polyethylene recycling stream. Reprocessing may involve washing, separation, melting, and molding, as well as many other steps. Typically, when plastic packaging is reprocessed, the material is mechanically shredded into small pieces and then melted to be reshaped into a new product. If multiple incompatible materials are present in the packaging, interactions occur during reprocessing, resulting in gelling, brittle materials, poor appearance, and products that are generally unusable or of poor quality. The use of the term "recyclable" indicates that these disadvantages are generally not present. Qualification for recyclable materials is not regulated by any particular agency but may be obtained from specific groups such as the Association of Plastic Recyclers (APR) and How2Recycle™ in the United States, or Recyclass and CEFLEX in Europe. The recyclable films disclosed herein are suitable for "store drop-off" recycling streams. These streams may accept: 100% polyethylene bags, wraps, and films; bags, wraps, and films very close to 100% polyethylene; and polyethylene-based carrier packaging approved by How2Recycle (with or without compatibilizer technology). Introducing recyclable membranes into any of these recycling pathways through reprocessing should not require additional compatibilizers. As used herein, the term "polyethylene recycling stream" refers to an industrial process of reprocessing from which the product can be reformulated into a new product. Polyethylene recycling streams can be dedicated to polyethylene (PE)... Right now , a blend of polyethylene recycled stream or polyolefin.

[0047] The packaging film disclosed herein may be free of materials that contaminate polyethylene recycled streams. In particular, the packaging film may be free of polyamide (PA), ethylene vinyl alcohol copolymer (EVOH), and / or metal foil (…). Right now (Aluminum foil with a thickness greater than 5 micrometers). In some packaging films, polymers (such as PA and EVOH) may be present, but at low levels, such as less than 5% by weight of the entire packaging film.

[0048] As used herein, the term "membrane" refers to a web constructed of one or more layers and / or membranes, all of which are adjacent to and connected to each other. A membrane can be described as having a thickness that is insignificant compared to its length and width. A membrane has two primary surfaces whose areas are defined by its length and width. As used herein, the term "layer" refers to a building block of a membrane. A layer may have a composition of a single material type or a homogeneous blend of materials. A layer may be a single polymer, a blend of materials within a single polymer type, or a blend of various polymers, may contain metallic materials, and may have additives. A layer may be continuous with the membrane, or it may be discontinuous or patterned. A layer has a thickness (z direction) that is insignificant compared to its length and width (xy direction), and is therefore defined as having two primary surfaces whose areas are defined by the length and width of the layer. A layer may have sublayers. As used herein, the term "sublayer" refers to a homogeneous layer within a layer. As used herein, a polymer layer may have a composition of a single material type or a homogeneous blend of materials. A layer can be a single polymer, a blend of materials within a single polymer type, or a blend of various polymers, and may contain metallic materials and additives. A layer can be continuous with the film, or it can be discontinuous or patterned. Compared to its length and width (xy direction), a layer has a negligible thickness (z direction) and is therefore defined as having two main surfaces whose area is defined by the layer's length and width. An outer layer is a layer that connects to another layer only at one of its main surfaces. In other words, one main surface of the outer layer is exposed. An inner layer is a layer that connects to another layer at both of its main surfaces. In other words, the inner layer lies between two other layers.

[0049] As used herein, the term "packaging film" refers to a film that can be shaped into packaging. Packaging films can be flexible. Flexible packaging films can be bent or flexed into a shape and then bonded to themselves or other packaging components to form a cavity and generally maintain its shape. A product can be contained within said cavity. Packaging films can form an airtight seal and provide oxygen and / or moisture barrier properties. Packaging films can be flexible. Flexible packaging films can be bent or flexed into a shape and then bonded to themselves or other packaging components to form a cavity and generally maintain its shape. A product can be contained within said cavity. Packaging films can form an airtight seal and provide oxygen and / or moisture barrier properties. Packaging films have two outer surfaces defined by length and width ( Right now (One outer surface and one inner surface).

[0050] Figure 1A cross-sectional view of an embodiment of packaging film 102 is shown, the packaging film including a first outer film 104, a second outer film 106, and an adhesive layer 108 connecting the first outer film 104 to the second outer film 106. The adhesive layer 108 is located between the first outer film 104 and the second outer film 106. The adhesive layer 108 can be in direct contact with the first outer film 104, such as... Figure 1 As shown in the diagram. The adhesive layer 108 can directly contact the second outer membrane 106, as... Figure 1 As shown in the diagram, the first outer film 104, the second outer film 106, and the adhesive layer 108 may be completely co-extended with each other. In other embodiments of the packaging film, one or more additional intermediate layers may be present between the outer layer and the adhesive layer. For example, a thin primer may be applied to the surface of the first outer film to aid in the adhesion of the adhesive layer to the first outer film.

[0051] The first outer membrane can be an outer layer, and it can be an outermost layer. As used herein, the term "outer layer" refers to one or more layers of the membrane on any of its main surfaces. Right now A layer that is not between two other layers of the film. As used herein, the term “outer layer” is used to describe a film, layer, or surface located in an outer layer position such that when the film is used in a packaging application, it is in or near the surrounding environment.

[0052] The second outer membrane can be an outer layer or an inner layer. As used herein, the term "inner" is used to describe a membrane, layer, or surface located in the outer layer position such that when the membrane is used in a packaging application, it is located at or near the packaged product.

[0053] Each of the first and second outer membranes may contain polypropylene. The composition of the first and second outer membranes may independently range from 50% to 100%, 60% to 100%, 70% to 100%, 80% to 100%, or 90% to 100% polypropylene by weight. The first outer membrane may contain at least 80% or at least 90% polypropylene. The second outer membrane may contain at least 80% or at least 90% polypropylene. The composition of polypropylene should be understood to include any polymer or copolymer containing more than 50% propylene bonds. Right now The weight of polypropylene (a copolymer rich in propylene). For example, the weight of polypropylene will include homopolymer polypropylene and atactic polypropylene copolymer.

[0054] If the composition of the first or second outer membrane comprises less than 100% polypropylene, the remainder may be a polyolefin, such as polyethylene. The composition of the first and / or second outer membrane may include one or more compatibilizers disclosed herein. The composition of the first and / or second outer membrane may include one or more stabilizers disclosed herein.

[0055] The first outer membrane and / or the second outer membrane can be transparent or opaque. The first outer membrane and / or the second outer membrane can be white due to added pigments (such as titanium dioxide particles) or cavitation.

[0056] As described herein, the first and second outer films can be oriented. Orientation can be the result of uniaxial orientation (longitudinal or transverse) or biaxial orientation (longitudinal and transverse) stretching of the film, thereby increasing the longitudinal and / or transverse dimensions and subsequently reducing the thickness of the material. Biaxial orientation can be imparted to the film simultaneously or continuously. The film is stretched in either or both directions at a temperature just below the melting temperature of the polymer in the film. In this way, stretching “orients” the polymer chains, thereby altering the physical properties of the film. Simultaneously, stretching thins the film. The resulting oriented film is thinner and can exhibit significant changes in mechanical properties such as toughness, heat resistance, stiffness, tear strength, and barrier properties. Orientation is typically achieved through double-bubble or triple-bubble processes, through tenter frame processes, or through MDO processes using heated rollers. Typical blown film processes do impart some stretch to the film, but not enough to be considered oriented as described herein. Oriented films can be heat-set after orientation ( Right now Annealing) allows for further transformation of the membrane ( Right now During printing or lamination, or during the use of the laminate or packaging film ( Right now The dimensions are relatively stable under the elevated temperature conditions that may be experienced during heat sealing.

[0057] In some embodiments of the packaging film, the first outer film is biaxially oriented. In some embodiments of the packaging film, the first outer film is uniaxially oriented. In some embodiments of the packaging film, the first outer film is a biaxially oriented polypropylene film. In some embodiments of the packaging film, the second outer film is biaxially oriented. In some embodiments of the packaging film, the second outer film is uniaxially oriented. In some embodiments of the packaging film, the second outer film is a biaxially oriented polypropylene film. In some embodiments of the packaging film, both the first and second outer films are biaxially oriented polypropylene films.

[0058] The first outer membrane may have a thickness greater than 4, 5, 6, 7, 8, 9 or 10 micrometers, 104T (see [reference]). Figure 1The first outer film may have a thickness of 104T less than 50, 45, 40, 35, 30, or 25 micrometers. For example, the first outer film may have a thickness of 104T in the range of 5 to 35 micrometers. The second outer film may have a thickness of 106T greater than 4, 5, 6, 7, 8, 9, or 10 micrometers. The combined thickness of the first and second outer films (104T plus 106T) may be greater than 50%, 60%, 70%, or 80% of the thickness of the packaging film.

[0059] In some embodiments, the first outer film and / or the second outer film may include a surface suitable for printing. The surface may contain ethylene content (…). Right now (by blending ethylene polymers into polypropylene or by propylene-ethylene copolymers), and can be corona treated for easy printing of markings. Right now The application of ink. The surface of the printed film can be oriented toward the polymer layer or toward the exposed surface of the packaging film. The film on which ink is applied should have good dimensional stability under elevated temperature and tension.

[0060] In some embodiments, the first outer film and / or the second outer film may include a heat-sealable surface. The film surface may contain a C4 / C3 / C2 terpolymer having a low initial sealing temperature and excellent sealing properties. The surface of the film intended for heat sealing is ideally oriented to be exposed at the surface of the packaging film. During heat sealing, the heat-sealable surface may seal against itself or another surface (such as the opposite side of the packaging film).

[0061] In some embodiments, the first outer film and / or the second outer film may include a surface having a cold-seal adhesive applied in a pattern consistent with the seal to be formed in the final packaged product. As used herein, "cold-seal adhesive" refers to a material that has the ability to form a strong bond with itself when pressure is applied, but can also be applied to a substrate and rolled up as a dry film for storage without such bonding. Therefore, the adhesive must be sufficiently deformable to form a bond only when pressure is applied, but rigid enough to resist bonding with the substrate during storage. Such adhesives are well known and used in a variety of applications, including as envelope sealants and in food packaging where heat application for bonding is not appropriate. The film on which the cold-seal adhesive is applied can be formulated to adhere well to the adhesive, while the film on the opposite side of the packaging film can be formulated to resist bonding. Right now (Through release additives or coatings).

[0062] The term "adhesive layer" refers to a layer placed on one or more layers to facilitate adhesion between that layer and another surface. Preferably, the adhesive layer is positioned between two layers of a multilayer film to bond the two layers ( Right now The outer and inner films maintain their proper positions relative to each other and prevent undesirable delamination. Unless otherwise indicated, the adhesive layer can have any suitable composition that provides the desired level of adhesion to one or more surfaces in contact with the adhesive layer material. The adhesive layer may contain an adhesive (applied by an adhesive lamination process) Right now It can be a single-component, two-component, solvent-based, solvent-free, water-based, etc., or composed of the adhesive. The adhesive layer can be a polymer layer containing polyethylene applied by an extrusion lamination process.

[0063] The packaging film can be assembled by any known series of conversion operations, including but not limited to blown film extrusion, cast film extrusion, orientation, metallization, printing, lamination, extrusion lamination, and slitting. Specifically, the second outer film may be metallized, the first outer film may be printed, and the adhesive layer may be extruded and laminated between the first and second outer films.

[0064] Because the first and second outer films constitute the majority of the packaging film, and because both have high polypropylene content, or even 100% polypropylene, the overall composition of the packaging film contains a very high level of polypropylene. The packaging film composition may contain more than 30%, 40%, 50%, or 60% polypropylene by weight. Alternatively, the packaging film composition may contain less than 90% or 80% polypropylene by weight. For example, the packaging film composition may contain polypropylene in the range of 30% to 90% by weight. Despite the very high level of polypropylene, the packaging film may still be suitable for recycling in polyethylene recycling streams due to the composition of the outer films as described herein.

[0065] At least one of the first and second outer membranes contains a compatibilizer. In general applications, a compatibilizer is any material that, when added to a multiphase polymer blend, reduces the tendency of the dispersed phase in the blend to coalesce. The average dispersed phase droplet size in a blend containing a compatibilizer will be smaller than the droplet size in a blend without a compatibilizer. The theoretical function of the compatibilizer used in the system described herein is to allow the polypropylene component to be more easily blended into the polyethylene matrix during the melt and blending process of the recycling process. During the melt and blending of the polymer, the polypropylene is more uniformly distributed, resulting in smaller fractions, so that the resulting blend has virtually no defects such as gelation during film extrusion. The compatibilizer minimizes the impact of entrained polypropylene on the physical properties of the polyethylene matrix and the resulting film.

[0066] As used herein, at least one of the first outer membrane and the second outer membrane may contain at least one compatibilizer selected from the list of propylene / ethylene copolymers, 1-butene-rich 1-butene / ethylene plastomers, polypropylene multiphase olefin copolymers, olefin block copolymers, hydrogenated styrene-butadiene-styrene block copolymers, ethylene propylene rubber, EPDM rubber, and combinations thereof.

[0067] Preferably, the compatibilizer has a composition comprising both propylene and ethylene. In some embodiments of the packaging film, the polymer layer comprises at least one compatibilizer selected from the list of propylene / ethylene copolymers, polypropylene multiphase olefin copolymers, ethylene propylene rubber, EPDM rubber, and combinations thereof. In some embodiments of the packaging film, the polymer layer comprises at least one compatibilizer selected from propylene / ethylene copolymers and polypropylene multiphase olefin copolymers. In some embodiments, the compatibilizer may be a propylene-rich copolymer (… Right now (More than 50% of the bonds are propylene).

[0068] Propylene / ethylene copolymers can be propylene / α-olefin copolymers. Examples of propylene-rich propylene / ethylene copolymers include elastomers (such as Dow Versify™ 3401 or 3300 and ExxonMobil Vistamaxx 6102 and 6202) and plasmons (such as Dow Versify™ 3000).

[0069] Propylene-ethylene copolymers can be propylene-rich propylene / ethylene / butene terpolymers. Examples of propylene-rich propylene / ethylene / butene terpolymers include Lyondell Bassell Adsyl 5C 30F and 7416 XCP.

[0070] Examples of 1-butene-rich 1-butene / ethylene copolymers include Mitsui TAFMER BL3110 or BL3450.

[0071] The polypropylene multiphase olefin copolymers described herein preferably have a polypropylene matrix (55% to 90% by weight) and an elastomer (10% to 45% by weight), such as ethylene / propylene copolymers or C4 to C10 α-olefin copolymers.

[0072] Olefin block copolymers can be polypropylene-based olefin block copolymers, such as Dow INTUNE™, or can have alternating blocks with rigid and elastomeric segments, such as Dow INFUSE™.

[0073] Olefin block copolymers can be triblock or multiblock.

[0074] Examples of hydrogenated styrene-butadiene-styrene block copolymers (SEBS) include resins available in the Kraton CirKular+™ product line.

[0075] Ethylene propylene rubber (EPR) as described herein preferably has a polyethylene component (50% to 80% by weight) and polypropylene (20% to 50% by weight), such as a random rubber copolymer of ethylene and propylene. Examples of ethylene propylene rubber (EPR) include Versalis Dutral® CO 034 or CO 038.

[0076] Examples of ethylene propylene diene monomer (EPDM) rubber include ExxonMobil Vistalon™ and Dow NORDEL™.

[0077] The packaging film composition may contain more than 6%, 8%, 10%, 12%, or 14% compatibilizer by weight. The packaging film composition may contain less than 40%, 35%, or 30% compatibilizer by weight. For example, the packaging film composition may contain compatibilizer in the range of 10% to 35% by weight.

[0078] At least one of the first and second outer layers may contain a stabilizer. The theoretical function of the stabilizer is to counteract the negative effects of incompatibility in the blended olefins (polyethylene and polypropylene). The stabilizer may “build back” or otherwise improve the physical properties of the blend to produce a higher quality film containing recycled blends. As used herein, “stabilizer” refers to a homogeneous branched linear ethylene polymer or a heterogeneous branched linear ethylene polymer. The stabilizer may be a homogeneous branched linear ethylene / α-olefin copolymer, such as an ethylene / hexene copolymer or an ethylene / octene copolymer.

[0079] Examples of polymers that can be used as stabilizers include C6-mLLDPE, C6-LLDPE, C8-LLDPE, C8-ULDPE, and C8 plastomers. Examples of homogeneous branched linear ethylene polymers include ENGAGE™ grades 8100, 8180, and 8200 (C8 elastomers) available from Dow; Exact™ 0210 (C8 plastomer) from ExxonMobil; TAFMER™ grades from Mitsui; and Queo™ grades from Borealis. Examples of heterogeneous branched linear ethylene polymers include DOWLEX 3010 and ATTANE grades available from Dow.

[0080] As used in this article, the phrase "homogeneous polymer" refers to polymerization products with significant variations in both molecular weight and compositional distribution. Right nowTypical polymers, for example, are prepared using conventional Ziegler-Natta catalysts. Heterogeneous polymers can be used in the various layers of the membranes used in this invention. Although there are a few exceptions (such as the TAFMER™ linear homogeneous ethylene and α-olefin copolymer produced by Mitsui using a Ziegler-Natta catalyst), heterogeneous polymers generally contain a relatively wide variety of chain lengths and comonomer percentages.

[0081] As used herein, the phrase "homogeneous polymer" refers to a polymerization product with a relatively narrow molecular weight distribution and a relatively narrow compositional distribution. Homogeneous polymers differ structurally from heterogeneous polymers because they exhibit a relatively uniform sequence of comonomers within the chain, a mirror image of the sequence distribution across all chains, and a similarity in chain length. Right now Narrower molecular weight distribution. Furthermore, homogeneous polymers are typically prepared using metallocene or other single-site type catalysts instead of Ziegler-Natta catalysts.

[0082] More specifically, homogeneous ethylene and α-olefin copolymers can be characterized by one or more methods known to those skilled in the art, such as molecular weight distribution (Mw / Mn), compositional distribution width index (CDBI), narrow melting point range, and single melting point behavior. Molecular weight distribution (Mw / Mn), also known as polydispersity, can be determined by gel permeation chromatography. The homogeneous ethylene and α-olefin copolymers used in this invention typically have a (Mw / Mn) of less than 2.7; preferably from about 1.9 to about 2.5; more preferably from about 1.9 to about 2.3. Such homogeneous ethylene and α-olefin copolymers will typically have a compositional distribution width index (CDBI) greater than about 70%. CDBI is defined as the content of comonomers being 50% of the median total molar comonomer content (…). Right now The composition distribution width index (CDBI) is the weight percentage of copolymer molecules within the range of 50% (plus or minus 50%). The CDBI of linear polyethylene without comonomers is defined as 100%. The composition distribution width index (CDBI) is determined via temperature elution fractionation (TREF) technology. CDBI determination clearly distinguishes between homogeneous copolymers used in this invention (e.g., narrow composition distributions assessed by CDBI values ​​typically greater than 70%) and commercially available VLDPEs that typically have wide composition distributions assessed by CDBI values ​​typically less than 55%. The CDBI of copolymers can be readily calculated from data obtained using techniques known in the art (e.g., temperature elution fractionation as described, for example, in Wild et al., J. Poly. Sci. Poly. Phys. Ed., Vol. 20, p.441 (1982)). Preferably, homogeneous ethylene and α-olefin copolymers have a CDBI greater than about 70%. Right now CDBI is approximately 70% to 99%. Typically, it is associated with "homogeneous copolymers" (…). Right nowCompared to polymers with a CDBI of less than 55%, the homogeneous ethylene and α-olefin copolymers in the multilayer films of the present invention also exhibit a relatively narrow melting point range. Preferably, the homogeneous ethylene and α-olefin copolymers exhibit substantially single melting point characteristics, having a peak melting point (Tm) of about 60°C to about 110°C, as determined by differential scanning calorimetry (DSC). Preferably, the homogeneous copolymer has a DSC peak Tm of about 80°C to about 105°C. As used herein, the phrase "substantially single melting point" means that, as determined by DSC analysis, at least about 80% by weight of the material corresponds to a single Tm peak at a temperature in the range of about 60°C to about 110°C, and substantially no substantial fraction of the material has a peak melting point exceeding about 115°C. The reported melting information is second melting data. Right now The sample was heated to a temperature below its critical range at a programmed rate of 10°C / min. The sample was then reheated at a programmed rate of 10°C / min (second melting). The presence of a higher melting peak is detrimental to film properties such as haze and reduces the chance of a meaningful reduction in the final film's sealing temperature.

[0083] Homogeneous ethylene and α-olefin copolymers can typically be prepared by copolymerizing ethylene with any one or more α-olefins. Preferably, the α-olefin is a C4-C2 α-monoolefin, more preferably a C4-C8 α-monoolefin. Even more preferably, the α-olefin comprises at least one member selected from butene-1, hexene-1, and octene-1. Right now 1-Butene, 1-hexene, and 1-octene, respectively. Most preferably, the α-olefin comprises octene-1 and / or a blend of hexene-1 and butene-1.

[0084] As used herein, the phrase "ethylene and α-olefin copolymer" refers to heterogeneous materials such as linear low-density polyethylene (LLDPE), linear medium-density polyethylene (LMDPE), and very low-density and ultra-low-density polyethylene (VLDPE and ULDPE); and homogeneous polymers such as metallocene-catalyzed EXACT™ linear homogeneous ethylene and α-olefin copolymer resins available from Exxon, unit-point AFFFNITY™ linear homogeneous ethylene and α-olefin copolymer resins available from Dow, and TAFMER™ linear homogeneous ethylene and α-olefin copolymer resins available from Mitsui. All these materials typically comprise copolymers of ethylene with one or more comonomers selected from C4 to C10 α-olefins (such as butene-1, hexene-1, octene-1, etc.), wherein the molecules of said copolymers contain long chains with relatively few side-chain branches or crosslinking structures. Heterogeneous ethylene and α-olefin copolymers, commonly referred to as LLDPE, typically have a density of about 0.915 g / cm³. 3Approximately 0.930 g / cm³ 3 Within this range, heterogeneous ethylene and α-olefin copolymers, commonly referred to as LMDPE, typically have a density of about 0.930 g / cm³. 3 To approximately 0.945 g / cm 3 Within this range, while those copolymers typically identified as VLDPE or ULDPE have a density of less than about 0.915 g / cm³. 3 .

[0085] Either the first outer membrane or the second outer membrane can be a monolayer having a homogeneous composition, which includes a compatibilizer and / or a stabilizer.

[0086] Either the first outer membrane or the second outer membrane may comprise two or more layers, and compatibilizers and stabilizers (if present) may be present in any one or more layers. The outer membrane may have 3, 4, 5, 6, 7, 8, 9, or 10 layers. The outer layers may contain an odd number of layers, and the composition and thickness of these layers may form a palindromic sequence, such as ABA, ABCBA, or ABCDCBA, where each letter represents a layer with the same composition and thickness.

[0087] Figure 2 An embodiment of the outer film 204 is shown. In packaging film embodiments, the outer film 204 may represent a first outer film, a second outer film, or both. The outer film 204 includes a first layer 210, a second layer 212, and a third layer 214. The second layer 212 is located between the first layer 210 and the third layer 214 and is adjacent to the first and third layers. In other embodiments of the outer film, an intermediate layer may exist between the second layer 212 and any or both of the first layer 210 and the third layer 214.

[0088] The first layer of the outer film may be located on the outer surface of the packaging film. The first layer of the outer film may be formulated to facilitate printing or metallization on its surface. The first layer may be formulated for heat sealing. The first layer may contain a polypropylene copolymer, such as a C4-C3-C2 terpolymer. The first layer may contain a polypropylene homopolymer. The first layer may have a composition comprising 90% to 100% polypropylene by weight.

[0089] The third layer may be located on the inner surface of the outer film and may include other parts for reinforcement and packaging film. Right now A composition for bonding (other outer films or adhesive layers). The third layer of the outer film may be formulated to be easily printed or metallized on its surface. The third layer may contain a polypropylene copolymer. The third layer may have a composition comprising 90% to 100% polypropylene by weight.

[0090] The second layer is located between the first and third layers. The second layer may have a composition of more than 25%, 50%, 60%, 70%, 80%, or 90% polyethylene by weight. The second layer may include compatibilizers and / or stabilizers. In some embodiments, the first and third layers do not contain compatibilizers and / or stabilizers.

[0091] In addition to the first outer film, the second outer film, and the adhesive layer, some embodiments of the packaging film may include additional layers such as inks, adhesives, primers, barrier materials, etc. For example, Figure 3 A cross-sectional view of an embodiment of packaging film 302 is shown, which includes a first outer film 304, a second outer film 306, an adhesive layer 308, ink 316 on the surface of the first outer film 304, and a metallization layer 318 on the surface of the second outer film 306. As used herein, "ink" refers to ink applied to a film by common conversion processes such as flexographic printing or rotary gravure printing. Right now The markings are printed on the surface of the outer film (the first outer film), but the application process is not limited to this. Ink 316 has a polymer matrix and pigments for coloring. Inks are typically applied in various colors in a pattern to create graphics and / or information on the packaging film. Figure 3 In this configuration, ink 316 is reverse-printed on the inner surface of the first outer film 304 and is visible through the first outer film 304. In an alternative embodiment, the ink may be applied to the outer surface of the first outer film, i.e., the outer surface of the packaging film.

[0092] As used herein, the terms “metallization layer,” “metallization,” or “metal coating” (which forms a metallization layer upon application) refer to a coating that can be applied to one or both surfaces of a film by any known method, such as sputtering, vacuum deposition, or electroplating (all of which are within the definition of a “metallized” film and involve some action or method of “depositing” a continuous layer of metal, metal oxide, or metal alloy onto a surface of a polymer substrate). The metal used can vary, but aluminum, zinc, gold, silver, or suitable alloys thereof are preferred, with aluminum or aluminum-containing alloys being particularly preferred. As those skilled in the art will recognize, while the metal coating consists primarily of the specified metal (such as aluminum), certain amounts of other additives may be present to improve various physical and optical properties of the deposited metal layer. In some cases, pure aluminum (or the metal of choice) may be used. Other additives may be used in small amounts, making aluminum (or the metal of choice) the main component. Vacuum deposition is the preferred method for metallization in terms of processing and cost trends. The preferred value for the average thickness of the metal coating layer is in the range of about 1.0 to 100 nanometers, with the preferred average thickness in the range of about 3 to 25 nanometers. (1 micrometer equals 10 -7 Meter, 1 nanometer equals 10 -8(meters.) In any case, the thickness of the metal coating is preferably less than the thickness of the polymer substrate deposited thereon, and preferably substantially less than the thickness of the substrate. The metal used can vary, but aluminum, zinc, gold, silver or suitable alloys thereof are preferred, with aluminum or aluminum-containing alloys being particularly preferred. As those skilled in the art will recognize, although the metal coating is primarily composed of the specified metal (such as aluminum), certain amounts of other additives may be present to improve various physical and optical properties of the deposited metal layer. In some cases, pure aluminum (or the metal of choice) may be used. Other additives may be used in small amounts, making aluminum (or the metal of choice) the main component. Vacuum deposition is the preferred method for metallization in terms of processing and cost trends. The preferred value for the average thickness of the metal coating layer is in the range of about 1.0 to 100 nanometers, with the preferred average thickness in the range of about 3 to 25 nanometers. (1 micrometer equals 10 -7 Meter, 1 nanometer equals 10 -8 (meters.) In any case, the thickness of the metal coating is preferably less than the thickness of the polymer substrate deposited thereon, and preferably substantially less than the thickness of the substrate.

[0093] In some embodiments, the metallization layer 318 may be replaced by another functional coating. The coating may be a barrier layer, such as, but not limited to, coated EVOH, coated PVOH, SiOx, AlOx, etc. The coating may also have another function, such as adhesion (…). Right now Primer).

[0094] The packaging film can have a thickness greater than 15, 20, or 25 micrometers, 102T (see [reference]). Figure 1 The packaging film may have a thickness of less than 150, 125, 100, or 90 micrometers. For example, the packaging film may have a thickness of 102T in the range of 15 to 100 micrometers.

[0095] Packaging films can be used to form packaged products. As used herein, the term "packaged product" refers to one or more packaging components that form an airtight, sealed package. Right nowPackaging film, two packaging films, trays, zippers, etc.) and the product therein. As used herein, the terms “airtight,” “airtight seal,” or “airtight” refer to a completely closed and substantially airtight sealed or sealed package. Airtight packages are typically required to maintain storage and package integrity for a period of more than several days. Package integrity includes a consistent appearance, maintaining barrier properties, maintaining lamination adhesion, and maintaining a seal. As used herein, the term “package” refers to an article of article formed from packaging components, such as packaging film, having a cavity capable of holding the product. Packages can be airtight and can provide protection for the product during storage and distribution. When formed into a package, the inner surface of the packaging film ( Right now The inner surface (i.e., the first outer film or outer layer) is exposed to the product cavity, while the outer surface (i.e., the first outer film or outer layer) is exposed to the surrounding environment. The packaging can be hermetically sealed and can provide protection for the product during storage and distribution. When formed into packaging, the inner surface of the packaging film (i.e., the second outer film or inner layer) is exposed to the product cavity, while the outer surface (i.e., the first outer film or outer layer) is exposed to the surrounding environment. Right now The second outer membrane or inner surface is exposed to the product cavity, while the outer surface ( Right now The first outer membrane or outer surface is exposed to the surrounding environment.

[0096] Packaging can take any form, and the packaging film can form the entire package or be combined with other packaging components to form a package.

[0097] Figure 4 An embodiment of packaged product 420 is shown. Packaged product 420 is a package containing a product (not shown) formed entirely of packaging film 402, in the form of a pillow-shaped package. Packaging film 402 wraps around the product in a generally tubular configuration, wherein the longitudinal edges are sealed to each other at a seam 424 extending along the length of the package. Seam 424 may be a fin seal or an overlap seal. As used herein, the term "fin seal" refers to a seam that includes bonding the inner surface of the packaging film to itself. Fin seals typically protrude from the package, but may also be folded flat against the outer surface of the package. Fin seals typically protrude from the package, but may also be folded flat against the outer surface of the package. As used herein, the term "overlap seal" refers to a seam that includes bonding the inner surface of one edge of the packaging film ( Right now The inner layer and the second outer film are bonded to the outer surface of the other edge of the packaging film. Right nowThe seam of the outer layer (first outward-oriented film). The edges of the packaging film overlap and are bonded together. The edges of the packaging film overlap and are bonded together. End seal 422 closes each end of the tube, thereby creating a cavity in which the product is held. As used herein, the term "end seal" refers to a seal located at the end of the packaging, running transversely from one side of the packaging to the other, bonding the inner surface of the packaging film to itself. In the manufacture of the packaging, the end seal is oriented transversely ( Right now The end seals are arranged between the packages (perpendicular to the longitudinal direction), and each package is typically cut at or near the end seal, so that the final package has an end seal at each end. During packaging manufacturing, the end seals are arranged transversely (perpendicular to the longitudinal direction). Right now The packages are arranged between each other (perpendicular to the longitudinal direction), and each package is typically cut at or near the end seal, so that the final package has an end seal at each end. The end seal 422 can be formed by heat sealing, which will seal the inner surface ( Right now The inner layer and the second outer membrane are bonded to themselves.

[0098] Products enclosed in packaging made of packaging film are not limited. The products can be of a type that benefits from the moisture-proof, oxygen-proof, or light-proof protection provided by the packaging film. Examples of products include food items such as potato chips, crackers, snacks, cereals, dry powders, sweets, candies, or nut butters. Examples of products include cosmetics such as loose powder, facial tissues, or detergents. Examples of products include household / industrial products such as cleaning wipes, powdered cleaners, or pet food.

[0099] Predictive instances The following illustrative examples are presented to aid in understanding the disclosed packaging film, but are not intended to limit this disclosure. Additional features may be added to these illustrative examples.

[0100] In a first preliminary example of the packaging film, the first outer film is a transparent biaxially oriented polypropylene film having a thickness of approximately 18 micrometers and containing a compatibilizer. The first outer film is printed such that ink is located on the surface of the first outer film. The second outer film is a transparent biaxially oriented polypropylene film, which is heat-sealable and has a thickness of approximately 18 micrometers. The second outer film is metallized. The first and second outer films are joined by co-extrusion lamination to form a white polyethylene polymer layer, thereby producing the following structure: first outer film with compatibilizer / ink / white polyethylene polymer laminate layer / metallized layer / second outer film.

[0101] In a second preliminary example of the packaging film, the first outer film is a transparent biaxially oriented polypropylene film with a thickness of approximately 18 micrometers and containing a compatibilizer and a stabilizer. The first outer film is printed such that ink is located on the surface of the first outer film. The second outer film is a transparent biaxially oriented polypropylene film, heat-sealable and with a thickness of approximately 18 micrometers, and also contains a compatibilizer and a stabilizer. The second outer film is metallized. The first and second outer films are joined by co-extrusion lamination to form a white polyethylene polymer layer, thereby producing the following structure: first outer film with compatibilizer and stabilizer / ink / white polyethylene polymer laminate / metallized layer / second outer film with compatibilizer and stabilizer.

[0102] In a first preliminary example of the packaging, a vertical forming, filling, and sealing machine is used to form the first preliminary example of the packaging film into a pillow-shaped package and fill it with potato chips. The package has an overlapping seal style that extends along the length of the package and end seals at each end. The package is then opened and emptied. Right now After being disposed of by consumers, the items can be recycled in the store's disposal stream, which is designed for use with polyethylene bags and similar items.

[0103] Work examples The following examples and comparative studies are intended to aid in understanding this disclosure and are not intended to limit or restrict its scope.

[0104] Three biaxially oriented films were prepared to test the performance of films with added compatibilizers and / or stabilizers. Each film had a structure of 10% surface layer / 80% core layer / 10% surface layer, with all surface layers composed of polypropylene copolymers. Each film was prepared to a thickness of approximately 70 ga (approximately 18 micrometers). The core layer composition is shown in Table 1.

[0105] Table 1: Core Composition of Biaxially Oriented Films These films were then simulated as typical packaging film laminates: biaxially oriented film / 10 lb polyethylene laminate (PEL) / biaxially oriented film, where the two orientation films were identical, thus obtaining simulated laminates. Simulated comparative laminate 1 has the structure of comparative film 1 / PEL / comparative film 1. Simulated example laminate 2 has the structure of example film 1 / PEL / example film 1. Simulated example laminate 3 has the structure of example film 3 / PEL / example film 3. Each packaging film laminate has a composition containing approximately 66% polypropylene by weight. For the simulation, each BOPP film and extruded laminated simulated film were prepared, shredded separately, then combined, melted, mixed, and granulated in the correct proportions.

[0106] To test recyclability, a simulated packaging film laminate (granules) was blended with a similarly granulated control polyethylene film (65 wt% MDPE, 20 wt% HDPE, 15 wt% LDPE) at a 50:50 ratio. These blended granules were then processed into 2-mil thick films using a blown film process. Comparative test film 1 was prepared using comparative laminate 1, example test film 2 was prepared using example laminate 2, and test film 3 was prepared using example laminate 3. An additional comparative test film 4 was prepared using 100% control polyethylene film through melt mixing, granulation, and film production.

[0107] These test films were then tested to compare their physical properties. The results of these tests are shown in Table 2. Impact strength is the dart impact strength, measured using ASTM D7192 with a 0.75-inch radius probe, a speed of 10.63 ± 0.02 ft / sec, and a weight of 10.55 lbs. MD and TD tear data are Elmendorf tear strengths, measured according to ASTM D1922 using a 200 g pendulum for MD and a 1,600 g pendulum for TD.

[0108] Table 2: Recyclability Analysis of Added Compatibilizers By comparing the data from Comparative Test Film 1 and Comparative Test Film 4, it is evident that adding standard BOPP film (Comparative Film 1) to the packaging film is detrimental, significantly reducing impact strength, MD tear, and TD tear. Adding compatibilizers to the oriented films (Example Test Films 2 and 3 compared to Comparative Test Film 1) showed improvements in impact strength, MD tear, and TD tear. The increase in impact strength and the decrease in tear properties indicate more easily recyclable films (Example Films 2 and 3).

[0109] The foregoing detailed description includes reference to the accompanying drawings, which form part of the detailed description. The drawings schematically illustrate specific embodiments in which the invention can be practiced. These embodiments, also referred to herein as “examples,” are described in sufficient detail to enable those skilled in the art to practice the invention. Combinations of embodiments may be made, other embodiments may be adopted, or structural and logical changes may be made without departing from the scope of the invention. Therefore, the following detailed description should not be construed as limiting. However, before such detailed description of the invention, it should be understood that the invention is not limited to the specific variations set forth, and changes are certainly possible.

[0110] Various changes may be made to the described invention without departing from its true spirit and scope, and equivalents may be substituted. Furthermore, numerous modifications may be made to adapt particular circumstances, materials, composition, processes, process actions, or steps to the objectives, spirit, or scope of the invention. All such modifications are intended to fall within the scope of this disclosure.

[0111] Unless otherwise stated, the words and phrases appearing in this document have their ordinary meanings as understood by those skilled in the art. Such ordinary meanings can be obtained by referring to their usage in the art and by consulting general and scientific dictionaries. The following explanations of certain terms are intended to be illustrative rather than exhaustive. These terms have their ordinary meanings as assigned by usage in the art, in addition to the following explanations.

[0112] The use of phrases such as "an embodiment" or "an aspect" in the specification indicates that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment.

[0113] Furthermore, when describing a particular feature, structure, or characteristic in conjunction with an implementation scheme, it should be assumed that the influence of such feature, structure, or characteristic on other implementation schemes is within the knowledge of a person skilled in the art, whether or not it is explicitly described.

[0114] As used herein, the term “and / or” means any one item, any combination of items, or all items associated with that term. As used herein, unless the context clearly specifies otherwise, the singular forms “a,” “an,” and “the” include plural references. As used herein, the terms “comprising,” “for example,” “such as,” etc., are used illustratively and are not intended to limit the invention. As used herein, the terms “preferred” and “preferred” refer to embodiments of the invention that provide certain benefits in certain contexts. However, other embodiments may also be preferred in the same or other contexts. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable and is not intended to exclude other embodiments from the scope of the invention.

[0115] It should be understood that although the terms first, second, etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element, without departing from the teachings of this disclosure.

[0116] Implementation Scheme 1: A packaging film comprising: a first outer film comprising polypropylene, the first outer film being coupled to a second outer film comprising polypropylene; wherein at least one of the first outer film and the second outer film comprises a compatibilizer selected from the group consisting substantially of: propylene / ethylene copolymers, 1-butene-rich 1-butene / ethylene plastomers, polypropylene multiphase olefin copolymers, olefin block copolymers, hydrogenated styrene-butadiene-styrene block copolymers, ethylene propylene rubber, EPDM rubber, and combinations thereof.

[0117] Implementation Scheme 2: The packaging film of Implementation Scheme 1, wherein at least one of the first outer film and the second outer film further comprises a stabilizer selected from the group consisting substantially of homogeneous branched linear ethylene polymers, heterogeneous branched linear ethylene polymers, and combinations thereof.

[0118] Implementation Scheme 3: The packaging film of Implementation Scheme 1 or 2, wherein each of the first outer film and the second outer film is independently biaxially oriented or uniaxially oriented.

[0119] Implementation Scheme 4: A packaging film of any one of Implementation Schemes 1 to 3, wherein the first outer film comprises a first outer film composition comprising polypropylene in the range of 80% to 100% by weight, and the first outer film has a thickness in the range of 5 micrometers to 35 micrometers.

[0120] Implementation Scheme 5: The packaging film of Implementation Scheme 4, wherein the second outer film comprises a second outer film composition comprising polypropylene in the range of 80% to 100% by weight, and the second outer film has a thickness in the range of 5 micrometers to 35 micrometers.

[0121] Implementation Scheme 6: A packaging film of any one of Implementation Schemes 1 to 5, wherein the packaging film comprises a packaging film composition comprising polypropylene in the range of 30% to 90% by weight.

[0122] Implementation Scheme 7: The packaging film of any one of Implementation Schemes 1 to 6 further includes an adhesive layer located between the first outer film and the second outer film.

[0123] Implementation Scheme 8: The packaging film of Implementation Scheme 7, wherein the adhesive layer comprises a polymer layer containing polyethylene.

[0124] Implementation Scheme 9: The packaging film of Implementation Scheme 7, wherein the adhesive layer comprises an adhesive.

[0125] Implementation Scheme 10: A packaging film of any one of Implementation Schemes 1 to 9, wherein the packaging film has a packaging film composition comprising the compatibilizer in the range of 10% to 35% by weight.

[0126] Implementation Scheme 11: A packaging film of any one of Implementation Schemes 1 to 10, wherein the compatibilizer is a propylene-rich propylene / ethylene copolymer.

[0127] Implementation Scheme 12: A packaging film of any one of Implementation Schemes 1 to 11, wherein the compatibilizer is a propylene / α-olefin copolymer.

[0128] Implementation Scheme 13: The packaging film of Implementation Scheme 2, wherein the stabilizer is a homogeneous branched linear ethylene polymer.

[0129] Implementation Scheme 14: The packaging film of Implementation Scheme 13, wherein the stabilizer is an ethylene / hexene copolymer or an ethylene / octene copolymer.

[0130] Implementation Scheme 15: A packaging film suitable for recycling in a polyethylene recycling stream, the packaging film comprising: a first outer film comprising at least 50% by weight of polypropylene, the first outer film being coupled to a second outer film comprising at least 50% by weight of polypropylene; wherein at least one of the first outer film and the second outer film comprises a compatibilizer selected from the group consisting substantially of: propylene / ethylene copolymers, 1-butene-rich 1-butene / ethylene plastomers, polypropylene multiphase olefin copolymers, olefin block copolymers, hydrogenated styrene-butadiene-styrene block copolymers, ethylene propylene rubber, EPDM rubber, and combinations thereof; wherein at least one of the first outer film and the second outer film comprises a stabilizer selected from the group consisting substantially of: homogeneous branched linear ethylene polymers, heterogeneous branched linear ethylene polymers, and combinations thereof; wherein each of the first outer film and the second outer film is independently biaxially oriented or uniaxially oriented; and the packaging film comprises a packaging film composition comprising the compatibilizer in the range of 10% to 35% by weight.

[0131] Implementation Scheme 16: The packaging film of any one of Implementation Schemes 1 to 15, further comprising a barrier layer coated on the surface of the second outer film.

[0132] Implementation Scheme 17: The packaging film of any one of Implementation Schemes 1 to 16 further includes ink located between the first outer film and the second outer film.

[0133] Implementation Scheme 18: The packaging film of any one of Implementation Schemes 1 to 17 further has a thickness in the range of 15 micrometers to 100 micrometers.

[0134] Implementation Scheme 19: A packaging film of any one of Implementation Schemes 15 to 18, wherein the packaging film composition comprises, by weight, the first outer film and the second outer film in the range of 30% to 80%.

[0135] Implementation Scheme 20: The packaging film of any one of Implementation Schemes 1 to 19, wherein the packaging film is recyclable in the polyethylene recycling stream.

[0136] Implementation Scheme 21: A packaging film of any one of Implementation Schemes 1 to 20, wherein the compatibilizer is selected from the group consisting substantially of: propylene / ethylene copolymers, polypropylene multiphase olefin copolymers, ethylene propylene rubber, EPDM rubber, and combinations thereof.

[0137] Implementation Scheme 22: A packaging film of any one of Implementation Schemes 1 to 21, wherein the first outer film comprises: a first outer layer comprising polypropylene; a second outer layer comprising polypropylene; and an inner layer connecting the first outer layer and the second outer layer; wherein the compatibilizer is contained in the inner layer.

[0138] Implementation Scheme 23: A packaging film of any one of Implementation Schemes 1 to 22, wherein the second outer film comprises: a first outer layer comprising polypropylene; a second outer layer comprising polypropylene; and an inner layer connecting the first outer layer and the second outer layer; wherein the compatibilizer is contained in the inner layer.

[0139] Implementation Scheme 24: A packaged product comprising: a packaging film of any one of Implementation Schemes 1 to 23, and a product; wherein the packaging film is sealed to form a package, and the product is enclosed within the package.

[0140] Implementation Scheme 25: A packaged product comprising: a packaging film sealed to form a package and a product encapsulated within the package, the packaging film comprising: a first outer film comprising polypropylene, the first outer film being coupled to a second outer film comprising polypropylene; wherein the first outer film comprises a compatibilizer selected from the group consisting substantially of: propylene / ethylene copolymers, 1-butene-rich 1-butene / ethylene plastomers, polypropylene multiphase olefin copolymers, olefin block copolymers, hydrogenated styrene-butadiene-styrene block copolymers, ethylene propylene rubber, EPDM rubber, and combinations thereof.

[0141] Implementation Scheme 26: The packaging product of Implementation Scheme 24 or 26, wherein the packaging is in the form of a pillow-shaped package, the pillow-shaped package including two end seals and seams, the seams being formed as fin-shaped seals or as overlapping seals.

Claims

1. A packaging film comprising: A first outer membrane comprising polypropylene, the first outer membrane being connected to a second outer membrane comprising polypropylene; At least one of the first outer membrane and the second outer membrane contains a compatibilizer selected from the group consisting substantially of: propylene / ethylene copolymers, 1-butene-rich 1-butene / ethylene plastomers, polypropylene multiphase olefin copolymers, olefin block copolymers, hydrogenated styrene-butadiene-styrene block copolymers, ethylene propylene rubber, EPDM rubber, and combinations thereof.

2. The packaging film according to claim 1, wherein at least one of the first outer film and the second outer film further comprises a stabilizer selected from the group consisting substantially of homogeneous branched linear ethylene polymers, heterogeneous branched linear ethylene polymers, and combinations thereof.

3. The packaging film according to claim 1, wherein each of the first outer film and the second outer film is independently biaxially oriented or uniaxially oriented.

4. The packaging film of claim 1, wherein the first outer film comprises a first outer film composition comprising polypropylene in the range of 80% to 100% by weight, and the first outer film has a thickness in the range of 5 micrometers to 35 micrometers.

5. The packaging film of claim 4, wherein the second outer film comprises a second outer film composition comprising polypropylene in the range of 80% to 100% by weight, and the second outer film has a thickness in the range of 5 micrometers to 35 micrometers.

6. The packaging film of claim 1, wherein the packaging film comprises a packaging film composition comprising polypropylene in the range of 30% to 90% by weight.

7. The packaging film according to claim 1, further comprising an adhesive layer located between the first outer film and the second outer film.

8. The packaging film of claim 7, wherein the adhesive layer comprises a polymer layer comprising polyethylene.

9. The packaging film of claim 7, wherein the adhesive layer comprises an adhesive.

10. The packaging film of claim 1, wherein the packaging film comprises a packaging film composition comprising, by weight, the compatibilizer in the range of 10% to 35%.

11. The packaging film according to claim 1, wherein the compatibilizer is a propylene-rich propylene / ethylene copolymer.

12. The packaging film according to any one of claims 1 to 11, wherein the compatibilizer is a propylene / α-olefin copolymer.

13. The packaging film according to claim 2, wherein the stabilizer is a homogeneous branched linear ethylene polymer.

14. The packaging film according to claim 13, wherein the stabilizer is an ethylene / hexene copolymer or an ethylene / octene copolymer.

15. A packaging film suitable for recycling in a polyethylene recycling stream, said packaging film comprising: A first outer membrane comprising at least 50% by weight of polypropylene, the first outer membrane being coupled to a second outer membrane comprising at least 50% by weight of polypropylene; At least one of the first outer membrane and the second outer membrane contains a compatibilizer selected from the group consisting substantially of: propylene / ethylene copolymers, 1-butene-rich 1-butene / ethylene plastomers, polypropylene multiphase olefin copolymers, olefin block copolymers, hydrogenated styrene-butadiene-styrene block copolymers, ethylene propylene rubber, EPDM rubber, and combinations thereof. At least one of the first outer membrane and the second outer membrane contains a stabilizer selected from the group consisting essentially of homogeneous branched linear ethylene polymers, heterogeneous branched linear ethylene polymers, and combinations thereof. Each of the first outer membrane and the second outer membrane is independently biaxially or uniaxially oriented; and The packaging film comprises a packaging film composition, the packaging film composition comprising the compatibilizer in the range of 10% to 35% by weight.

16. The packaging film of claim 15, further comprising a barrier layer coated on the surface of the second outer film.

17. The packaging film according to claim 1, further comprising ink located between the first outer film and the second outer film.

18. The packaging film according to claim 1, further comprising a thickness in the range of 15 micrometers to 100 micrometers.

19. The packaging film of claim 1, wherein the packaging film composition comprises, by weight, the first outer film and the second outer film in the range of 30% to 80%.

20. The packaging film of claim 1, wherein the packaging film is recyclable in the polyethylene recycling stream.

21. The packaging film according to claim 1, wherein the compatibilizer is selected from the group consisting substantially of: propylene / ethylene copolymers, polypropylene multiphase olefin copolymers, ethylene propylene rubber, EPDM rubber, and combinations thereof.

22. The packaging film according to claim 1, wherein the first outer film comprises: The first outer layer comprises polypropylene; The second outer layer comprises polypropylene; and The inner layer connecting the first outer layer and the second outer layer; The compatibilizer is contained in the inner layer.

23. The packaging film according to claim 1, wherein the second outer film comprises: The first outer layer comprises polypropylene; The second outer layer comprises polypropylene; and The inner layer connecting the first outer layer and the second outer layer; The compatibilizer is contained in the inner layer.

24. A packaged product comprising: The packaging film according to claim 1, and the product; The packaging film is sealed to form a package, and the product is encapsulated within the package.

25. A packaged product comprising: A packaging film for sealing to form a package and a product encapsulated within the package, the packaging film comprising: A first outer membrane comprising polypropylene, the first outer membrane being connected to a second outer membrane comprising polypropylene; The first outer membrane contains a compatibilizer selected from the group consisting substantially of: propylene / ethylene copolymers, 1-butene-rich 1-butene / ethylene plastomers, polypropylene multiphase olefin copolymers, olefin block copolymers, hydrogenated styrene-butadiene-styrene block copolymers, ethylene propylene rubber, EPDM rubber, and combinations thereof.

26. The packaging product according to claim 24, wherein the packaging is in the form of a pillow-shaped package, the pillow-shaped package including two end seals and a seam, the seam being formed as a fin-shaped seal or an overlapping seal.

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