阅读说明：本技术 具有经回收聚酰胺成分的包装膜 (Packaging film with recycled polyamide component ) 是由 K·拉蒂南 K·纳蒂南 E·A·鲁纳南 A·J·利谢夫斯基 于 2018-05-30 设计创作，主要内容包括：可以在包装膜中利用含有聚酰胺组分的多组分回收物,从而节省材料和能源两者。可以通过在回收物材料的两侧上都引入气味阻挡层来最小化或消除通常由过度加工的聚酰胺材料产生的有气味化合物的迁移。所得膜具有低气味特点并且可以用于包装感官敏感产品。(Multi-component recyclates containing a polyamide component can be utilized in packaging films, thereby saving both material and energy. Migration of odorous compounds, typically resulting from over-processed polyamide materials, can be minimized or eliminated by incorporating an odor barrier layer on both sides of the recyclate material. The resulting film has low odor characteristics and can be used to package organoleptic sensitive products.)

1. A low odor packaging film comprising:

a) an inner layer comprising a multi-component regrind,

b) a first odor barrier layer, and

c) a second odor barrier layer, wherein the second odor barrier layer,

wherein the inner layer is between the first odor barrier layer and the second odor barrier layer.

2. The low odor packaging film of claim 1 wherein the first and second odor barrier layers each comprise an oxygen transmission rate of less than 150cm when tested at 23 ℃ and 50% RH³ 25μm/m²Day material.

3. The low odor packaging film of claim 1 wherein the first odor barrier layer comprises at least one of a polyamide or an ethylene vinyl alcohol copolymer.

4. The low odor packaging film of claim 1 wherein the second odor barrier layer comprises at least one of a polyamide or an ethylene vinyl alcohol copolymer.

5. The low odor packaging film of claim 1 wherein the inner layer further comprises a compatibilizer.

6. The low odor packaging film of claim 1 wherein the inner layer further comprises an odoriferous caprolactam derivative.

7. The low odor packaging film of claim 1 wherein the multi-component recyclate comprises a polyamide and a polyolefin.

8. The low odor packaging film of claim 7 wherein the polyolefin is polyethylene or polypropylene.

9. The low odor packaging film of claim 7 wherein the multicomponent recyclate further comprises ethylene vinyl alcohol copolymer.

10. The low odor packaging film of claim 1 wherein the first and second odor barrier layers reduce the transmission of odor-causing compounds from the inner layer such that the packaging film has low odor characteristics.

11. The low odor packaging film of claim 6 wherein the first odor barrier layer and the second odor barrier layer reduce permeation of the odoriferous caprolactam derivative from the interior layer such that the packaging film has low odor characteristics.

12. The low odor packaging film of claim 1 wherein the film has a haze value of less than 30%.

13. A low odor packaging film comprising:

a) a first odor barrier layer, wherein the first odor barrier layer,

b) an inner layer comprising a polyamide, a polyolefin and a compatibilizer, an

c) A second odor barrier layer, wherein the second odor barrier layer,

wherein the inner layer is positioned between the first odor barrier layer and the second odor barrier layer.

14. The low odor packaging film of claim 13 wherein the first odor barrier layer comprises a polyamide and the second odor barrier layer comprises a polyamide.

15. The low odor packaging film of claim 13 wherein the inner layer is directly adjacent to the first odor barrier layer and the second odor barrier layer is directly adjacent to the inner layer.

16. The low odor packaging film of claim 13 further comprising:

a) a first polymeric adhesive layer between the first odor barrier layer and the inner layer, an

b) A second polymeric adhesive layer between the inner layer and the second odor barrier layer.

17. The low odor packaging film of claim 13 wherein the first and second odor barrier layers prevent permeation of odor-causing compounds from the inner layer such that the packaging film has low odor characteristics.

18. The low odor packaging film of claim 13 wherein the film is thermoformable.

19. A method of producing the low odor packaging film of claim 13 wherein the polyamide and polyolefin of the inner layer are introduced as an unseparated multicomponent recyclate.

20. A low odor packaging film comprising:

a) an inner layer comprising a recycled polyamide,

b) a first odor barrier layer, and

c) a second odor barrier layer, wherein the second odor barrier layer,

wherein the inner layer is between the first odor barrier layer and the second odor barrier layer.

Technical Field

The present disclosure relates to multilayer films of recycled polymer components containing conjunct polymers. The packaging films do not exhibit an objectionable odor and are useful for packaging organoleptically sensitive food items.

Background

The production and use of multilayer films can generate polymer waste streams. For example, some film conversion processes require trimming the edges of the film to produce a high quality film. Similarly, when producing packaging from film, a "skeleton" of trim waste may remain after production. The multicomponent nature of these films prevents them from being easily recycled in a large scale recycling process. It is often impossible or impractical to separate materials from each other. Reprocessing of unseparated material often results in low process efficiency and poor product quality due to material incompatibility. Films made using even small amounts of multicomponent polymeric waste often suffer from poor mechanical properties and appearance.

The use of various types of compatibilizing agents improves the recovery of waste materials from multilayer or multi-component films. Polymeric multicomponent films can be recovered by melt blending, whereby the compatibilizer reduces phase separation of the materials and the blend is introduced into a portion or all of the film construction by extrusion. The resulting film has appearance and physical properties suitable for some applications. However, films containing polyamides as part or all of the recycled component often exhibit strong odors that cannot be eliminated by the addition of compatibilizers. The odor may be exacerbated by certain additional components. The odor prevents the use of films with recycled ingredients for packaging of organoleptically sensitive items such as food.

Disclosure of Invention

Disclosed herein are low odor multilayer films having multi-component recyclate components.

A low odor packaging film can be produced having an inner layer comprising a multi-component recyclate, a first odor barrier layer, and a second odor barrier layer. The inner layer is positioned between the first odor barrier layer and the second odor barrier layer.

The first and second odor barrier layers each can comprise an oxygen transmission rate of less than 150cm when tested at 23 ℃ and 50% RH³ 25μm/m²Day material. The first odor barrier layer may include at least one of a polyamide or an ethylene vinyl alcohol copolymer. The second odor barrier layer may include at least one of a polyamide or an ethylene vinyl alcohol copolymer.

In addition to the multi-component regrind, the inner layer may further include a compatibilizing agent. The inner layer may also include an odorous caprolactam derivative.

The multicomponent recyclate can include a polyamide and a polyolefin and can further include an ethylene vinyl alcohol copolymer. The polyolefin of the multicomponent recyclate can be polyethylene or polypropylene.

The first and second odor barrier layers of the packaging film reduce the permeation of odor-generating compounds from the inner layer, such that the packaging film has a low odor character. The first odor barrier and the second odor barrier may reduce permeation of odorous caprolactam derivatives. Packaged food items using the low-odor packaging film can have taste characteristics that are not affected by the packaging film. Additionally, the film may have a haze value of less than 30%.

Another embodiment of a low odor packaging film has a first odor barrier layer, an inner layer comprising a polyamide, a polyolefin, and a compatibilizer, and a second odor barrier layer. The first odor barrier layer may comprise a polyamide. The second odor barrier layer may include a polyamide. The inner layer is positioned between the first odor barrier layer and the second odor barrier layer. The inner layer may be directly adjacent to the first odor barrier layer, and the second odor barrier layer may be directly adjacent to the inner layer. Alternatively, the low-odor packaging film may additionally include: a first polymeric adhesive layer between the first odor barrier layer and the inner layer; and a second polymeric adhesive layer between the inner layer and the second odor barrier layer.

The polyamide and the polyolefin of the inner layer may be introduced as an unseparated multicomponent recyclate when producing the low-odor packaging film. The first and second odor barrier layers can prevent the permeation of odor-causing compounds from the inner layer, resulting in the packaging film having a low odor profile. The low odor packaging film may be thermoformable. A low odor packaging film can include an inner layer comprising recycled polyamide, a first odor barrier layer, and a second odor barrier layer. The inner layer can be between the first odor barrier layer and the second odor barrier layer.

Drawings

The disclosure may be more completely understood in consideration of the following detailed description of various embodiments of the disclosure in connection with the accompanying drawings, in which:

figure 1 is a cross-sectional view of an embodiment of a packaging film having low odor properties,

figure 2 is a cross-sectional view of an embodiment of a packaging film having low odor properties,

figure 3 is a perspective view of an embodiment of a package utilizing a packaging film having low odor properties,

FIG. 4 is a cross-sectional view of an embodiment of a package utilizing a packaging film having low odor properties, an

Fig. 5 is a process flow diagram of an embodiment of a method of producing a low odor packaging film.

The figures are not necessarily to scale. Like reference numerals used in the drawings refer to like elements. It should be understood, however, that the use of a reference number to refer to a component in a given figure is not intended to limit the component in another figure labeled with the same reference number.

The drawings illustrate some, but not all embodiments. Elements depicted in the figures are illustrative and not necessarily drawn to scale, and the same (or similar) reference numerals refer to the same (or similar) features throughout the figures.

Detailed Description

It has been found that incorporation of polyamide-containing recyclates into films can cause unpleasant odours, thereby negatively affecting the user experience. For films (especially films used in packaging), having a strong odor is generally undesirable. Without being bound by theory, it is believed that the odor from polyamide-containing recyclates can be attributed to the oxidized forms of monomers and oligomers resulting from depolymerization of the polyamide during high heat processing (such as extrusion). In particular, oxidized caprolactam can be a source of odor.

When the film is used in packaging, the odor from the outside of the package is objectionable, creating an unpleasant user experience. As the scent penetrates into the interior of the package, it becomes even more problematic, possibly causing the packaged product to become scented. The odor emanating from the package is particularly problematic for food products, as the odor may alter the taste and odor characteristics of the packaged product.

The odor becomes worse in some cases. The use of large amounts of recyclates may produce more odor. In addition, it has been found that the odor problem is exacerbated if the recyclate blend also contains ethylene vinyl alcohol copolymer. There is a continuing need to provide low odor multilayer films having polyamide-containing recycle blends.

Previously, films have been developed that incorporate odor barrier materials and layers. These membranes are designed to keep odorous compounds from migrating from one side of the membrane to the other. For example, packaging films with previously designed odor barriers can prevent packaged products from becoming contaminated with odors emanating from the environment outside the package. These films are not designed with regard to odors that may emanate from the packaging material itself. The packaging material is typically selected such that it is free of odorous compounds.

Surprisingly, the multilayer low odor films containing recyclates described herein do not exhibit objectionable odors. With the specified materials and structures, migration of odors present in one or more of the recycle layers to the outside or inside of the package can be blocked. The low odor film structures provided herein reduce or prevent odors contained in the recycle layer of a multilayer film from affecting the taste and odor characteristics of the product packaged therein. As described herein, a recycle layer may be included in a layer located between two odor barrier layers.

Referring now to the drawings, one embodiment of a low odor packaging film 10 is shown in FIG. 1. The inner layer 22 is polymer-based and contains, inter alia, a multi-component recyclate blend. The recyclate blend contains at least polyamide and polyolefin. The inner layer 22 is located between the first odor barrier 32 and the second odor barrier 42. As shown in fig. 1, the inner layer 22 may be directly adjacent to the first and second odor barrier layers. However, in some embodiments, one or more intervening layers may be present.

Another embodiment of a low odor packaging film 10 is shown in fig. 2. Likewise, the inner layer 22 is located between the first odor barrier 32 and the second odor barrier 42. In this embodiment, there is a first 34 and second 44 polymeric adhesive layer, respectively, located between the odor barrier layers 32 and 42, respectively, and the inner layer 22 is present.

Fig. 3 and 4 illustrate an exemplary embodiment of a packaged product 70 utilizing the low odor packaging film 10. In fig. 3, the packaging film 10 is sealed to itself or a different packaging film to form a bag or pouch that encloses and encloses a product 72. In fig. 4, the packaging film 10 is in the form of a shaped tray holding the products 72, the tray plus products being enclosed within an outer wrapper component. The outer package component may or may not be an embodiment of the present disclosure.

Fig. 5 is a process flow diagram of one embodiment of a method 100 for producing a low odor packaging film. The process represents a typical coextrusion technique for combining several layers of polymeric material. In this process, the polyamide material is introduced into two extruders 200 and 220 where the material is melted and mixed with any other components that may be added. Similarly, an unseparated multi-component regrind material is introduced into the extruder 210. The molten polymer is fed from the extruder into an extrusion die 300 where the materials are combined in a layered format such that unseparated multi-component recyclate material is between the polyamide material streams. The polyamide fed into the extruder 200 becomes the odor barrier. The unseparated multi-component regrind fed into layer 210 becomes the inner layer. The polyamide fed into extruder 220 becomes the odor barrier. The layered material is extruded into a film 400 having the general structure of odor barrier layer/inner layer/odor barrier layer. In an alternative process embodiment, the materials of the two odor barrier layers may be fed from the same extruder, split before entering the feedblock to form a multilayer film.

As used herein, the term "film" is a material having a very high ratio of length or width to thickness. The film has two major surfaces defined by a length and a width. Films generally have good flexibility and can be used in a variety of applications, including flexible packaging. The membrane may also have a thickness or material composition such that the membrane is semi-rigid or rigid. The films described herein are constructed of various polymeric materials, but may also contain other materials, such as metal or paper. The film may be described as a single layer or as multiple layers.

As used herein, the term "layer" refers to the thickness of material within a film having a relatively consistent formulation. The layer may be of any type of material including polymeric, cellulosic and metallic or blends thereof. A given polymer layer may consist of a single polymer type or a blend of polymers and may be accompanied by additives. A given layer may be combined or joined to other layers to form a film. A layer may be partially or completely continuous as compared to an adjacent layer or film. A given layer may be partially or completely coextensive with an adjacent layer. The layer may contain sublayers.

As used herein, "inner layer" refers to a layer of the film structure that does not reside on either major exterior surface of the film. The inner layer may consist of a single layer or may be multilayered.

As used herein, the term "derivative" means a chemical substance that is structurally related to another substance and that can be derived from it in theory. When applicable to some embodiments, the odor-generating compound is theoretically a fragment of the polyamide copolymer that has been degraded by the recovery process. The odorous caprolactam derivative, as applicable in some embodiments, is a caprolactam molecule that has been oxidized during prolonged high temperature exposure.

As used herein, "EVOH" refers to an ethylene vinyl alcohol copolymer, EVOH is otherwise referred to as a saponified or hydrolyzed ethylene vinyl alcohol copolymer and refers to a vinyl alcohol copolymer having an ethylene comonomer. EVOH is commonly used in multilayer packaging films to provide an oxygen barrier. EVOH copolymers typically used in packaging applications comprise about 24 to 48 mole% ethylene. EVOH may be blended with other materials to modify properties, but is typically used as the single component of the barrier layer. EVOH is typically incorporated into the inner layers of the multilayer film.

The term "polyamide" refers to high molecular weight polymers having amide linkages (- -CONH- -) n occurring along the molecular chain and includes "nylon" resins, which are well known polymers having a number of uses, including utility as packaging films, bags and shells. Examples of nylon polymeric resins for food packaging and processing include: nylon 66, nylon 610, nylon 66/610, nylon 6/66, nylon 11, nylon 6, nylon 66T, nylon 612, nylon 12, nylon 6/12, nylon 6/69, nylon 46, nylon 6-3-T, nylon MXD-6, nylon MXDI, nylon 12T, and nylon 61/6T disclosed in 21CFR § 177.1500. Examples of polyamides include nylon homopolymers and copolymers, such as nylon homopolymers and copolymers selected from the group consisting of: nylon 4,6 (poly (tetramethylene adipamide)), nylon 6 (polycaprolactam, nylon 6,6 (poly (hexamethylene adipamide)), nylon 6,9 (poly (hexamethylene nonanediamide)), nylon 6,10 (poly (hexamethylene sebacamide)), nylon 6,12 (poly (hexamethylene dodecanediamide)), nylon 6/12 (poly (caprolactam-co-dodecanediamide)), nylon 6,6/6 (poly (hexamethylene adipamide-co-caprolactam)), nylon 66/610 (e.g., made by condensation of a mixture of nylon 66 salt and nylon 610 salt), nylon 6/69 resin (e.g., made by condensation of epsilon-caprolactam, hexamethylene diamine, and azelaic acid), nylon 11 (polyundecane bridge) lactam), Nylon 12 (polylaurolactam) and copolymers or mixtures thereof. The polyamide is preferably chosen from nylon compounds approved for the production of articles intended for processing, handling and packaging of food.

Polyamides are used in films for food packaging and other applications because of their unique physical and chemical properties. The polyamide may be used alone (i.e., a single layer biaxially oriented polyamide web) or in a composite structure mixed with or coated with other polymers. Polyamides are selected as materials for improving the temperature resistance, abrasion resistance, puncture strength and/or barrier properties of the film. The properties of the polyamide-containing film can be modified by selecting various variables including copolymer selection, conversion methods (e.g., coextrusion, lamination, and coating), and post-conversion processing (such as orientation). The polyamide layer is often combined with layers containing materials belonging to other polymer families, such as polyolefins, polymeric binders and barrier polymers, to produce films suitable for specific applications. It is not uncommon for packaging films to contain blends or combinations of layers that include polymers from many families.

The terms "polymeric adhesive layer," "adhesive layer," or "tie layer" refer to a layer or material that is placed in or on one or more layers to facilitate the adhesion of the layer to another surface. Preferably, an adhesive layer is positioned between two layers of the multilayer film to maintain the two layers in position relative to each other and prevent unwanted delamination. Unless otherwise indicated, the adhesive layer can have any suitable composition that provides a desired level of adhesion to one or more surfaces in contact with the adhesive layer material. Optionally, an adhesive layer disposed between the first and second layers in the multilayer film may include components of both the first and second layers to facilitate simultaneous adhesion of the adhesive layer to both the first and second layers on opposite sides of the adhesive layer.

The term "oxygen transmission rate" (OTR) is defined herein as the amount of oxygen that will pass through a material in a given period of time. OTR may be defined for a specific oxygen barrier material and is typically used in units of cm when measured at defined temperature and humidity³ 25μm/m²Days or the like are defined as upper and/or lower limits. The oxygen barrier material useful for the odor barrier layer may have an OTR value of less than 150cm when tested at 23 ℃ and 50% RH³ 25μm/m²And (5) day.

In addition, OTR may be defined for multilayer films. The OTR of a multilayer film is the result of the sequential contribution of each layer within the film. The OTR of a multilayer film is typically used in units of cm when measured at defined temperatures and humidity³/m²Days or the like are defined as upper and/or lower limits. The multilayer film useful as a low odor packaging film may have an OTR value of about 0.001 to 200cm at 80% R.H. and 23 ℃ over 24 hours³/m². Oxygen transmission rate may be measured according to ASTM D-3985-81, incorporated by reference.

As used herein, the term "recyclate" or "recycled" refers to a polymer-based material that has been previously formed into a product (e.g., a film) by an extrusion process that is used to form an extruded layer of the film. The recyclate can be subjected to other processing steps, such as granulation, between the extrusion step in which the initial product is formed and the extrusion step in which the recyclate is now used. A "multicomponent recyclate" presents more than one type of polymer, which may be derived from a single previous product (such as a multilayer film) or from more than one previous product.

For a given recycle, the materials of the initial polymer product may not be substantially separated, such that any materials that may have been in separate layers of the initial film remain together in the bonding layer and are now intermixed or mixed or blended in the individual layers of the current film. This type of recycle is referred to herein as "unseparated multicomponent recycle".

As used herein, "odor barrier material" or "odor barrier layer" refers to a material or layer of a film that has the property of blocking or slowing the transmission of odorous compounds. Traditionally, odor barriers have been used to prevent compounds from penetrating through a membrane containing the compound to one side of the membrane. As used herein, odor barriers are used in combination (at least two odor barriers) to contain odorous compounds within the membrane. Migration of odorous compounds incorporated into the multilayer film as part of the recyclate-containing inner layer out of the film at both major surfaces is prevented or significantly blocked. The odor barrier material has the property of slowing the migration of oxidized caprolactam such that a product packaged within the multilayer film will not have odor or flavor characteristics that are significantly affected by odor.

As used herein, "polyolefin" refers to a polyethylene homopolymer, a polyethylene copolymer, a polypropylene homopolymer, or a polypropylene copolymer.

As used herein, "polyethylene" refers to a polymer that includes vinyl bonds. The polyethylene can be a homopolymer, copolymer, or interpolymer. The polyethylene copolymer or interpolymer may comprise other types of polymers (i.e., non-polyethylene polymers). The polyethylene may have functional groups incorporated by grafting or other means. Polyethylenes include, but are not limited to, Low Density Polyethylene (LDPE), Linear Low Density Polyethylene (LLDPE), Medium Density Polyethylene (MDPE), Ultra Low Density Polyethylene (ULDPE), High Density Polyethylene (HDPE), Cyclic Olefin Copolymer (COC), ethylene vinyl acetate copolymer (EVA), ethylene acrylic acid copolymer (EAA), ethylene methacrylic acid copolymer (EMAA), neutralized ethylene copolymer (such as ionomer), and maleic anhydride grafted polyethylene (MAHgPE).

As used herein, "polypropylene" refers to a polymer derived from propylene monomers. The polypropylene may be a homopolymer, copolymer or interpolymer. The polypropylene copolymer or interpolymer may comprise other types of polymers (i.e., non-polypropylene polymers). The polypropylene may have functional groups incorporated by grafting or other means. Polypropylenes include, but are not limited to, propylene-ethylene copolymers, ethylene-propylene copolymers, and maleic anhydride grafted polypropylenes (mahgpps).

As used herein, "odor-generating compound" refers to a migrating molecule that may be present within the inner layer of the membrane. The presence of these compounds may be due to the conditions present during extrusion which may promote depolymerization of the polymer. Alternatively, the compound may be a derivative of a monomer present in the polymer from the polymerization process (i.e., caprolactam is present in nylon-6). In either case, the compounds are theoretically oxidized derivatives of relatively small molecules. In any case, the compound is detectable by smell or taste.

Polymeric materials are typically subjected to high heat when formed and formed into useful products (i.e., extruded). The recycled polymer is repeatedly subjected to high heat and excessive shear stress events, which can lead to degradation of the polymer. Under these conditions, oxidation may occur, and in particular, oxidation may occur of any monomers and oligomers that may be the result of depolymerization of the polymer or that remain from the original polymerization of the polymer. Oxidized material may be generated as a result of repeated extrusion processes. Polyamides and especially nylon-6 can be particularly easily produced with odor-generating compounds, especially odorous caprolactam derivatives (i.e., oxidized caprolactam).

Without being bound by theory, the odor generated during the reprocessing of the recovered polyamide is generally due to oxidized caprolactam. The odor-generating material may be oxidized caprolactam or similar monomers or oligomers that are present in nylon-6 due to incomplete polymerization. Alternatively, the odor-generating material may be oxidized components that are the result of depolymerized fragments of the polyamide resulting from the over-processing.

Some embodiments of the low odor packaging film have an inner layer comprising a recycled polyamide material. The inner layer may have a material that is a multi-component recyclate. The inner layer can have material that is an unseparated multi-component recyclate. The multicomponent recyclate can contain a polyamide and a polyolefin. The inner layer may comprise more than 5%, 10%, 20%, 40%, 60% or 80% recyclate. The inner layer may comprise 100% recyclate. The inner layer may comprise at least 1%, 5%, 10%, 15%, 20% or 25% polyamide. The inner layer may comprise at least 50% polyamide.

As a result of the use of recycled polymers, particularly multi-component recycled materials, the inner layer of the film also includes odor-causing compounds, particularly odoriferous caprolactam derivatives. These odor-generating compounds can be transient in nature such that they readily travel through the non-blocking polymeric structure and are emitted from the film. If the film is used as a packaging material, odors from the outside and the inside may be objectionable. The odor emanating from the interior of the film may even impart off-flavors and off-flavors to the product packaged therein. By using the required membrane structure, the compounds that generate odor can be contained within the membrane, thereby eliminating any problems. By using the films disclosed herein, the packaged food product can have odor and taste characteristics that are not affected by the film. By using the recycle-containing low-odor films disclosed herein, the taste characteristics of the food product can be similar to the taste characteristics after packaging in a similarly formulated film without recycle. By using the recycle-containing low-odor films disclosed herein, the odor profile of a food product can be similar to the odor profile after packaging in a similarly formulated film without recycle.

The multicomponent recyclate may also contain ethylene vinyl alcohol copolymer (EVOH). It has been found that extrusion of multi-component recyclates comprising both polyamide and EVOH tend to exhibit very high odor levels. In this case, it is even more valuable to produce the film in the manner described herein. By using an odor barrier layer on each side of the layer containing recyclates, the value of the recyclates can be optimized while still producing a low odor membrane that can be used in applications requiring low odor.

The inner layer of some embodiments may also contain a compatibilizing agent. The compatibilizer may be introduced as part of the recycle or may be added to the inner layer as a separate component. Any compatibilizer known in the art may be used as an adjunct to make the components of the inner layer a more homogeneous blend.

A compatibilizing agent may be added to the recycle to help homogenize the material blend. Compatibilizers are functional additives that can be added to a blend of incompatible materials to help obtain a blend with improved mechanical properties. Incompatible materials may be from recycle blends or other sources. Blends of incompatible materials often have insufficient properties to meet end-use applications. Functional additives can improve this compatibility. The general principle of compatibilization is to reduce the interfacial energy between two polymers to increase adhesion. The addition of a polymeric compatibilizer also typically results in finer dispersion and a more regular and stable morphology. Additive for foodThe addition of a compatibilizer generally improves mechanical properties and appearance properties. Examples of useful compatibilizing agents areE226 (available from DuPont)^TMObtained) andOE825 (available from Arkema).

The inner layer may also contain a polymeric binder material. In particular, if the inner layer is directly adjacent to the odor barrier layer, the polymeric binder material in the inner layer may aid in interlayer adhesion. Alternatively, the polymeric adhesive may be in an intermediate layer between the inner layer and the odor barrier layer. Depending on the chemical composition of the inner layer and odor barrier layer, and also depending on the interlayer adhesion performance criteria for the application, the film may not require any polymeric adhesive component.

The polymer binder may include a polyolefin copolymer having a maleic anhydride grafting function. In some embodiments, the polymeric binder is a maleic anhydride grafted polyethylene (MAHgPE) polymer having a melt index of 0.5 g/10 min to 10 g/10 min.

The inner layer may have any thickness. Preferably, the inner layer may be between 0.01% and 50% or between 0.1% and 25% or between 1% and 15% of the thickness of the entire packaging film structure. The inner layer may have a thickness greater than 0.1 microns, 1 micron, or 10 microns.

The membrane has a first odor barrier layer and a second odor barrier layer positioned on opposite sides of the inner layer. In this way, the multi-component regrind in the inner layer is between the first and second odor barrier layers. The odour barrier layer and the inner layer may be in direct contact with each other, or an intermediate layer may be present. Either or both of the first and second odor barrier layers may be positioned on the exterior surface of the membrane, or additional layers may be positioned exterior (i.e., closer to one of the major surfaces of the membrane) to one or both of the odor barrier layers.

The odour barrier layer comprises a material that will substantially slow down or prevent the permeation of any odour-producing compounds from the inner layer of the membrane. In this way, the odor is trapped within the membrane between the odor barrier layers, and the membrane has low odor characteristics. The odor characteristics of the low odor film are similar to packaging films having the same composition except that there is no recyclate ingredient. The odor barrier material may have any general composition including polymeric materials, metals, inorganics, or combinations thereof. The polymeric odor barrier material may be any material that provides a barrier to odorous compounds including, but not limited to, polyesters, polyamides, or Cyclic Olefin Copolymers (COCs). Metals that may be used for the odor barrier include, but are not limited to, thin aluminum foil, vacuum deposited metal coatings, and transparent metal oxides. Inorganics include, but are not limited to, exfoliated nanoclays.

Odor barrier materials that may be used in the odor barrier layer include odor barrier materials that are generally considered good oxygen barrier materials because these barrier materials are similar and similar in nature. From this perspective, materials that can be used for the odor barrier material include EVOH, polyvinylidene chloride (PVdC) copolymers, polyamide copolymers, aluminum oxide or silicon oxide coatings, aluminum alloy foils, vacuum deposited metals, exfoliated clay substrates, and any other material commonly used in high barrier packaging structures for the purpose of oxygen transmission blocking. Preferably, the odor barrier layer comprises a polyamide or EVOH copolymer.

When tested at 23 ℃ and 50% RH Using ASTM F1927-14 (Standard Test Method for determining Oxygen Transmission Rate, Permeability, and permeation at Controlled Relative Humidity Through a Barrier material Using a Coulomb Detector (Permeability and Permeability at Controlled Relative Humidity) the Oxygen Transmission Rate of an odor Barrier material may be less than 150cm when tested at 23 ℃ and 50% RH³25μm/m²And (5) day. Some embodiments may utilize oxygen transmission rates of less than 125, 100, 80, 60, 40, 20, 10, 5, 2, or 1cm when tested at 23 ℃ and 50% RH³ 25μm/m²A natural odor barrier material.

The odor barrier material may be blended with other components as may be required for other processing requirements, performance characteristics, or economic value. The odor barrier layer can have any necessary thickness as long as the layers function as needed to prevent odor migration. The odor barrier layer may be split into multiple layers, such as polyamide/polymeric binder/polyamide, that effectively act together to block odor migration. The odor barrier layers may have the same or different compositions.

Odor absorbers may be used within the multilayer film. However, the addition of conventional odor absorbers may deteriorate the transparency and mechanical properties of the film. The use of the absorbent is preferably restricted.

The low odor film comprising the recyclate component and at least two odor barrier layers may also include other layers necessary for the application in which the film is used. For example, films for packaging may have an exterior layer with abuse-resistant or special appearance properties. Layers and materials may be required throughout the film to make the film structure suitable for thermoforming. Inks, pigments, or other materials may be added to the film structure for graphics improvement, light blocking, or to meet other requirements. In some embodiments, additional layers or materials may be added to enhance the moisture barrier properties of the film.

The low odor film may be opaque, translucent, or transparent to visible light. In many cases, it is desirable that the film be transparent so that the product packaged in the film is clearly visible. Haze is the scattering of light as it passes through a transparent material, resulting in poor visibility and/or glare. Preferably, the Haze level of the low odor film will be less than 30% when measured according to ASTM D1003 (Haze and luminescence Transmission of Transparent Plastics) method B. The haze level may be less than 50%, 40%, 30%, 25%, 20%, 15%, 10% or even 5%.

In many embodiments, the low odor film needs to be heat sealable, particularly when the film is to be used in packaging applications. Heat sealing requires that portions of the film structure (i.e., the outer layers) be heat resistant and that portions of the film structure (i.e., the sealant layers) be capable of forming a strong seal with another packaging component. Sealable films are widely documented and may be any known formulation and structural combination to produce the heat seal required for the application. Alternatively, the outer layer of the film may be formulated for other types of sealing, such as ultrasonic sealing.

The films described herein may be produced by any means known. The layers of the described structure can be produced and combined by a multilayer coextrusion process. All, some, or none of the layers may be combined by coextrusion. Layers and materials may be added to the film structure by adhesive lamination, extrusion coating, vacuum metallization, solution coating, or printing. Other known processes may be utilized in producing the final film structure so long as the spirit of the embodiments disclosed herein is met (i.e., including recyclates in the inner layer of the film using the odor barrier layer to achieve the low odor character film).

The recyclate is most easily incorporated into the inner layer of the film structure by extrusion. The recyclate can be introduced in the form of chopped film, pellets, or any other format as it is fed into the extruder for melting and mixing. Other components may be added to the inner layer while melting and mixing. These other components may include a compatibilizer or a polymeric binder material. Any other material may be added to the inner layer. The inner layer can include greater than 25%, 30%, 35%, 40%, 45%, or 50% of the recyclate blend. The inner layer may comprise 5%, 10%, 15% or 20% of a compatibilizing agent. The inner layer may comprise greater than 1%, 2%, 5%, 10%, 15%, 20% or 25% polyamide.

Film production may include other processes to enhance the functionality or overall quality of the film. For example, as is known, the film may be subjected to electron beam irradiation to crosslink some of the components in the film. The film may have one or more layers scored by mechanical or high energy (laser) means. The resulting film may have any type of properties, including high slip, low slip, high gloss, matte finish, heat shrinkage, thermoformability, high hardness, low hardness, lap sealability, easy-open, reclosable, etc., as long as the spirit of the embodiments described herein is not hindered.

In some cases, the multilayer films described herein are used as packaging materials. The films disclosed herein may be used independently to create a package or may be combined with other package components. In either case, the package may be hermetically sealed around the product for protection. The multilayer films described herein may be used as packaging components such as trays, liners, zippers, and the like.

The product packaged in the low odor packaging film may be, but is not limited to, a food item, including a dry or liquid product, a personal care item, a pet food, a medical product, a pharmaceutical, a first aid item, a nutritional aid, or a beverage. The packaging may take any number of forms, including a pouch, bag, tray/cover, flip-top, box, or bottle. The packaged product may be a single serving or may have multiple servings. The package may have additional features such as a zipper for reclosing.

The product packaged in the low-odor packaging film is advantageously unaffected in odor or taste. As disclosed herein, the effect of a low odor packaging film containing a recyclate component on the packaging of a product therein is not significantly different from the effect of a similar packaging film without the recyclate component on the product. Packaging films are used to protect products therein throughout the packaging, storage, distribution, retail, and consumer use periods. Due to this long-term relationship between the product and the packaging, the packaging may have some effect on the product. However, the films disclosed herein do not have a negative impact on the product packaged therein due to the recycle components, especially when the impact relates to odor or taste characteristics. The food product has a similar taste before and after exposure to the low-odor film.

The product packaged in the packaging film may be negatively affected by the smell of the package in several ways. Odours can emanate from the packaging film and even before the package is opened, can be objectionable to users of the packaged product. Odors that are noticeable from outside the package (especially in a retail environment) are generally avoided. The odor may emanate from the packaging film to the interior of the package, thereby causing an objectionable odor to the internal environment of the package (i.e., the headspace) and/or the product within the package. The odor from within the package may be particularly strong when leaving the package when the user opens the package. When the product inside is intended to be consumed or otherwise used by a person or pet, odors inside the package should be avoided. If the odors are objectionable, they may negatively impact the user experience of the product.

It should also be noted that the concepts discussed herein may be applied to other multi-layer packaging components other than films. For example, the packaging component may be blow molded, compression molded, or injection molded and may also benefit from the use of an odor barrier layer to improve the application of recycled components therein.

Examples and data

The following examples are provided for illustrative purposes only and are not intended to limit the scope of the claims in any way. Indeed, various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description and following examples and fall within the scope of the appended claims.

Coextruded films of the formulations listed in tables 1 and 2 were produced for testing purposes. The produced film was subjected to various odor analyses, thermoforming and physical tests.

Example 1 represents the low odor packaging film disclosed herein. Multilayer test films were produced using a standard blown film coextrusion process. In this embodiment of the low odor packaging film, the first odor barrier layer of the film is comprised of a single layer of nylon-6 with standard slip and anti-blocking additives. The first odor barrier layer is also the exterior surface of the produced packaging film.

The inner layer of example 1 consisted of a single layer containing industrial recycle, ULDPE, 10% polymeric binder and 4% compatibilizer. The industrial recyclates are derived from multilayer packaging films comprising a polyamide layer, a polyethylene layer, an EVOH layer and a polymeric adhesive layer. The industrial recycle was regranulated prior to use in the film of example 1. The inner layer is positioned directly adjacent to the first odor barrier layer.

As shown in table 1, a second odor barrier layer was positioned directly adjacent to the inner layer, consisting of two layers of nylon-6 separated by a polymeric adhesive layer. The remainder of the structure of example 1 can be seen in table 1. Reference a, produced in the same manner as example 1, but without any industrial recyclates, is also shown in table 1.

Table 1: test film formulations

Samples of the films of example 1 and reference a were thermoformed into a deep-draw packaging configuration using heat and vacuum applied on a Multivac packager. When the films were thermoformed, both films were observed to exhibit good formation and good appearance. The addition of industrial recyclates has no detrimental effect on the packaging film.

Odor panels were assembled to evaluate example 1 using reference a for comparison. A film sample was cut from the produced web and placed in a 500ml Erlenmeyer glass cylinder. The entire container was covered with foil to protect the sample from light and to prevent any odors from escaping. The odor panel was carried out in a manner similar to DIN 10955 standard. The odor panel of 6 people was unable to distinguish any odor differences between the test film (example 1) and the reference film (reference a).

The films of comparative 1 and reference B were produced to demonstrate the necessity of an odor barrier layer on both sides of the inner layer containing recyclate. As shown in table 2, the industrial recyclate was included in layer 4 of comparative example 1.

The structure of comparative 1 contained a layer of nylon-6, a layer of polymer binder and a layer of MDPE, all of which were outside of the recycle layer. The layer located inside the recyclate contains EVA and LLDPE and is free of odour barrier materials.

The material of reference B was produced in the same manner as comparative 1. Reference B has a similar construction and formulation but no recyclates, polymeric binders and compatibilizer materials as shown in table 2.

Table 2: test film formulations

The odor test was again completed as described above using comparative 1 as the test film and reference B as the reference film. The odor panel compares the test films using the following rating system:

the average score given for comparative 1 compared to reference B was 2.29, indicating that the film with only one odor barrier layer had a significantly different odor and may not be acceptable for applications where low odor is important.

Examples

Reference throughout this specification to "one embodiment," "certain embodiments," "one or more embodiments," or "an embodiment" means that a particular feature, structure, material, or characteristic described in connection with the embodiment is included in at least one possible embodiment. Thus, the appearances of the phrases such as "in one or more embodiments," "in certain embodiments," "in one embodiment," or "in an embodiment" in various places throughout this specification are not necessarily referring to the same embodiment. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments.

Example A: a low odor packaging film comprising:

an inner layer comprising a multi-component regrind,

a first odor barrier layer, and

a second odor barrier layer, wherein the second odor barrier layer,

wherein the inner layer is between the first odor barrier layer and the second odor barrier layer.

Example B: the low odor packaging film of any other embodiment, wherein the first odor barrier layer and the second odor barrier layer each comprise an oxygen transmission rate of less than 150cm when tested at 23 ℃ and 50% RH³ 25μm/m²Day material.

Example C: the low odor packaging film of any other embodiment, wherein the first odor barrier layer comprises at least one of a polyamide or an ethylene vinyl alcohol copolymer.

Example D: the low odor packaging film of any other embodiment, wherein the second odor barrier layer comprises at least one of a polyamide or an ethylene vinyl alcohol copolymer.

Example E: the low odor packaging film of any other embodiment, wherein the inner layer further comprises a compatibilizing agent.

Example F: the low odor packaging film of any other embodiment, wherein the inner layer further comprises an odorous caprolactam derivative.

Example G: the low odor packaging film of any other embodiment, wherein the multi-component recyclate comprises a polyamide and a polyolefin.

Example H: a low odor packaging film according to any other claim wherein the polyolefin is polyethylene or polypropylene.

Example I: the low odor packaging film of any other embodiment, wherein the multicomponent recyclate further comprises ethylene vinyl alcohol copolymer.

Example J: the low odor packaging film of any other embodiment, wherein the first and second odor barrier layers reduce the transmission of odor-generating compounds from the inner layer such that the packaging film has low odor characteristics.

Example K: the low odor packaging film of any other embodiment, wherein the first odor barrier layer and the second odor barrier layer reduce permeation of the odoriferous caprolactam derivative from the interior layer such that the packaging film has low odor characteristics.

Example L: the low odor packaging film of any other embodiment, wherein the film has a haze value of less than 30%.

Example M: a low odor packaging film comprising: a first odor barrier layer; an inner layer comprising a polyamide, a polyolefin, and a compatibilizer; and a second odor barrier layer, wherein the inner layer is positioned between the first and second odor barrier layers.

Example N: the low odor packaging film of embodiment M wherein the first odor barrier layer comprises a polyamide and the second odor barrier layer comprises a polyamide.

Example O: the low odor packaging film of any other embodiment, wherein the inner layer is directly adjacent to the first odor barrier layer and the second odor barrier layer is directly adjacent to the inner layer.

Example P: the low odor packaging film of embodiment M, further comprising: a first polymeric adhesive layer between the first odor barrier layer and the inner layer; and a second polymeric adhesive layer positioned between the inner layer and the second odor barrier layer.

Example Q: the low odor packaging film of any other embodiment, wherein the first odor barrier layer and the second odor barrier layer prevent transmission of odor-causing compounds from the multi-component recyclate layer such that the packaging film has low odor characteristics.

Example R: the low odor packaging film of any other embodiment, wherein the film is thermoformable.

Example S: a method of producing the low odor packaging film of any of embodiments M, N, O, P or R wherein the polyamide and the polyolefin of the inner layer are introduced as an unseparated multi-component recycle.

Example T: a low odor packaging film comprising: an inner layer comprising a recycled polyamide; a first odor barrier layer; and a second odor barrier layer, wherein the inner layer is between the first odor barrier layer and the second odor barrier layer.

Unless otherwise indicated, all numbers expressing dimensions, quantities, ranges, limitations, and physical and other properties used in the application are to be understood as being modified in all instances by the term "about". Accordingly, unless expressly indicated to the contrary, the numerical parameters set forth in this application are approximations that can vary depending upon the desired properties sought to be obtained by one of ordinary skill in the art using the teachings disclosed herein without undue experimentation.

The disclosed description, examples, embodiments and figures are illustrative only and should not be construed as limiting. The invention includes the disclosed description, examples, embodiments and figures; but are not limited to, such descriptions, examples, embodiments, or figures. As briefly described above, the reader should assume that features of one disclosed embodiment can also be applied to all other disclosed embodiments, unless explicitly indicated to the contrary. Modifications and other embodiments will be apparent to those of ordinary skill in the packaging arts, and all such modifications and other embodiments are intended and considered to be within the scope of the present invention.