Paper packaging film with multilayer barrier film

Abstract

The present disclosure relates to a paper packaging film and a method for making the same, wherein the overall composition comprises at least 80% by weight of a paper component and at most 5% by weight of non-compostable material, and the paper packaging film can be easily recycled by repulping while maintaining high performance packaging properties, including improved barrier performance and high speed operation on packaging equipment.

Description

[Technical Field]

[0001] This disclosure relates to a paper-based packaging film and a method for producing the same. Embodiments of this disclosure relate to a paper-based packaging film containing 80% by weight or more of the same material. [Background technology]

[0002] The goal of increasing the recyclability of paper-based packaging films becomes difficult when attempting to create packaging films with improved barrier properties. Traditionally, barrier properties in paper-based packaging films are improved by forming polymer multilayer films. Multilayer films contain multiple layers specific to forming the barrier layer. As performance requirements increase, the number or thickness of layers in the multilayer film increases, and the percentage of paper content decreases, which works against the recyclability of the structure.

[0003] In many cases, when high performance is required for paper packaging films, a relatively large amount of additional non-paper material is added to the paper packaging film (e.g., structures with improved barrier properties). To maintain the recyclability of paper packaging films, the thickness and / or weight of the paper components are increased to achieve the paper content required to designate the packaging material as "recyclable." This additional paper thickness / weight can be problematic in that it can cause processing problems on the packaging forming equipment due to the increased bulk of the packaging film. Often, increased film thickness and stiffness slow down the line speed because it becomes more difficult to pull the film through the forming collar. Also, increased paper weight can make sealing the packaging film more difficult because it absorbs more heat from the sealing bar and / or prevents even pressure distribution.

[0004] Without negating the associated advantages of state-of-the-art systems, there is a need for paper-based packaging films with high barrier properties suitable for both recycling and composting. [Overview of the Initiative]

[0005] Embodiments of the present disclosure relate to a flexible paper packaging film that has improved barrier properties and superior sealing performance while maintaining recyclability in paper recycling processes. The paper packaging film comprises paper components, a barrier layer, a compostable polymer, and a minimum amount of non-compostable material (i.e., a minimum amount of non-paper and non-compostable polymer material). The paper packaging film has the advantage of providing at least two end-of-life options: (1) a paper recycling (repulping) process and / or (2) a composting process.

[0006] In some embodiments, the overall composition of the paper packaging film includes 80% or more by weight, 85% or more by weight, 90% or more by weight, or 95% or more by weight of paper components.

[0007] In some embodiments, the paper packaging film contains 5% by weight or less of non-compostable material.

[0008] In some embodiments, the paper component is 30 g / m². 2 ~360g / m 2 It has a basis weight within the range.

[0009] In some embodiments, the paper packaging film comprises a multilayer barrier film attached to a paper component. In some embodiments, the paper packaging film comprises an adhesive layer for attaching the multilayer barrier film to the paper component. In some embodiments, the combined thickness of the multilayer barrier film and the adhesive layer is 10 μm or less. In some embodiments, the combined thickness is in the range of 4 μm to 8 μm.

[0010] In some embodiments, the multilayer barrier film comprises a transfer substrate and a barrier layer deposited thereon by physical vapor deposition (PVD). In some embodiments, the transfer substrate comprises a heat seal layer and, optionally, a lacquer layer.

[0011] In some embodiments, the heat-sealing layer comprises a non-stretched film. In some embodiments, the heat-sealing layer comprises a compostable polymer. In some embodiments, the heat-sealing layer comprises one or more of polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), polyhydroxyalkanoate (PHA), and / or polyvinyl alcohol (PVOH).

[0012] In some embodiments, the heat-sealing layer has a thickness in the range of 2 μm to 10 μm, including all values and sub-ranges therebetween. In some embodiments, the heat-sealing layer has a thickness in the range of 2 μm to 8 μm, or in the range of 2 μm to 6 μm. In some embodiments, the heat-sealing layer is directly connected to the barrier layer.

[0013] In some embodiments, the transfer substrate further comprises a lacquer layer. The lacquer layer may be disposed between the barrier layer and the heat-sealing layer. In some embodiments, the lacquer layer comprises one or more of polyurethane (PU), polyvinyl alcohol (PVOH), and / or ethylene vinyl alcohol (EVOH). In some embodiments, the lacquer layer has a thickness in the range of 1 μm to 2 μm.

[0014] In some embodiments, the barrier layer comprises one or more of a metal, a metal oxide, and / or an inorganic oxide. In some embodiments, the barrier layer comprises one or more of aluminum (Alu), aluminum oxide (AlOx), and / or silicon oxide (SiOx).

[0015] Another embodiment is directed to a method of manufacturing a paper packaging film. In some embodiments, the method includes coating a base web, which is a multilayer barrier film and has a thickness in the range of 6 μm to 50 μm, forming an intermediate structure by attaching the multilayer barrier film to a paper component by a lamination process, and removing the base web from the intermediate structure to obtain a paper packaging film.

[0016] In some embodiments, a single transfer operation includes attaching the multilayer barrier film to the paper component and removing the base web from the intermediate structure. In some embodiments, the attachment of the multilayer barrier film to the paper component and the removal of the base web from the intermediate structure are performed as separate operations.

[0017] The base film may be a stretched film (uniaxial or biaxially stretched) or an unstretched film (i.e., an unstretched inflation film or cast film). In some embodiments, the base web includes one or more of stretched polyethylene (OPE) film, stretched polyethylene terephthalate (OPET) film, stretched polypropylene (OPP) film, and / or stretched polyamide (OPA) film.

[0018] In some embodiments, the coating of the base web includes forming a transfer substrate on the base web and forming a barrier layer on the transfer substrate by physical vapor deposition (PVD), wherein the combination of the barrier layer and the transfer substrate forms a multilayer barrier film.

[0019] In some embodiments, attaching a multilayer barrier film to a paper component includes placing an adhesive layer between the multilayer barrier film and the paper component.

[0020] In other embodiments, a method for manufacturing a paper packaging film includes manufacturing a base web and a heat seal layer by co-extrusion molding; depositing a barrier layer on the heat seal layer by physical vapor deposition (PVD); attaching the barrier layer to a paper component by a lamination process to form an intermediate structure; and removing the base web from the intermediate structure to expose the heat seal layer and obtain a paper packaging film. [Brief explanation of the drawing]

[0021] This disclosure may be better understood by considering the following detailed description of various embodiments of this disclosure in relation to the accompanying drawings.

[0022] [Figure 1] Figure 1 illustrates a process flow diagram of a method for manufacturing paper packaging film according to one or more embodiments.

[0023] [Figure 2] Figure 2 illustrates a process flow diagram of a method for manufacturing paper packaging film according to one or more embodiments.

[0024] [Figure 3] Figures 3, 4, and 5 are schematic cross-sectional views of the film structure in the intermediate process of forming paper packaging film. [Figure 4] Same as above. [Figure 5] Same as above.

[0025] [Figure 6] Figures 6 and 7 are schematic cross-sectional views of an embodiment of the final paper packaging film. [Figure 7] Same as above.

[0026] The drawings are illustrative but do not represent all embodiments. The elements shown in the drawings are illustrative and not necessarily to exact scale, and the same (or similar) reference numbers represent the same (or similar) features throughout the drawings. [Modes for carrying out the invention]

[0027] This specification provides a paper-based packaging film that overcomes the shortcomings of conventionally available films. The paper-based packaging film of this disclosure is uniquely designed to achieve a key combination of 1) recyclability (high paper content), 2) ease of packaging material processing, and 3) high barrier performance. Furthermore, this unique combination of layers and materials results in an overall high paper content and thin thickness, enabling excellent runability (i.e., high-speed running) in packaging equipment.

[0028] As described herein, the “whole composition” of a paper packaging film refers to all materials contained therein. The whole composition of a paper packaging film may contain 80% or more, 85% or more, 90% or more, or 95% or more by weight of paper components. The whole composition of a paper packaging film may contain 99% or less, 98% or less, 97% or less, or 96% or less by weight of paper components. For example, the whole composition of a paper packaging film may contain paper components in the range of 85% to 98% by weight (including all values ​​and partial ranges in between). The whole composition of a paper packaging film may contain 5% or less, 4% or less, 3% or less, 2% or less, or 1% or less by weight of non-compostable materials. The whole composition of a paper packaging film may contain compostable materials that are not paper components (e.g., compostable polymers). The overall composition of the paper packaging film may contain compostable materials that are not paper components in amounts of 15% by weight or less, 10% by weight or less, 5% by weight or less, 4% by weight or less, 3% by weight or less, 2% by weight or less, or 1% by weight or less. For example, the overall composition of the paper packaging film may contain 90% by weight of paper components, 5% by weight of compostable polymer, and 5% of non-compostable material. In another example, the overall composition of the paper packaging film may contain 80% to 95% by weight of paper components, 5% to 20% by weight of compostable polymer, and 5% by weight or less of non-compostable material.

[0029] The paper packaging films described herein include a multilayer barrier film attached to a paper component. In some embodiments, the entire multilayer barrier film is attached to the paper component. As used herein, the term “entirely” means, for example, that 1% or less or 0.5% or less of the multilayer barrier film is not attached to the paper component. In some embodiments, a portion of the multilayer barrier film is attached to the paper component. As described herein, the fact that a portion of the multilayer barrier film is attached to the paper component means that the multilayer barrier film remains attached to the paper component at least partially, and that the multilayer barrier film remains attached to the paper component without being damaged during manufacturing / processing. Furthermore, the multilayer barrier film has a spread that is partially or completely identical to that of the paper component.

[0030] Paper packaging films may include additional layers. These combinations of materials can be described as multilayer films (e.g., structures or laminates). The term “layer” as used herein refers to a component of a film. In other words, a film consists of one or more layers. A layer is a structure of a single type of material or a homogeneous mixture of materials. A layer may be a single polymer, a mixture of materials within a single polymer type, or a mixture of various polymers. A layer may contain metallic materials and may have additives. Layers may be continuous with the film, or they may be discontinuous or patterned. Both layers and the film have a relatively small thickness (in the z direction) compared to their respective length and width (in the x and y directions).

[0031] As used herein, the term “compostable” refers to materials that can be decomposed and biodegraded under industrial and household composting conditions (12 weeks at 58°C or 26 weeks at 21°C, respectively), and that meet industrial composting standards, e.g., EN 13432-2000, ASTM D6400 “Standard Specification for Labeling of Plastics Designed to be Aerobically Composted in Municipal or Industrial Facilities” or ASTM D6868 “Standard Specification for Labeling of End Items that Incorporate Plastics and Polymers as Coatings or Additives with Paper and Other Substrates Designed to be Aerobically Composted in Municipal or Industrial Facilities” and household composting standards, e.g., AS-5810-2010 NF T51800, e.g., polymers, layers, films, packaging materials. Compostable polymers include, but are not limited to, polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), and / or polyvinyl alcohol (PVOH).

[0032] As used herein, “PLA polymer” or “PLA” refers to a polylactic acid-based compostable polymer. Commercial examples of PLA polymer are available from Total Corbion and NatureWorks. A layer of film containing PLA may contain at least 50% by weight, at least 75% by weight, or at least 95% by weight of PLA polymer.

[0033] As used herein, “PBAT polymer” or “PBAT” is a poly(butylene adipate-co-terephthalate)-based compostable biopolymer. Commercial examples of PBAT biopolymers are available from, but are not limited to, many suppliers, such as Mitsubishi, Novamont, Jiangsu Torise Biomaterials Co., and BASF. A film layer containing PBAT may contain at least 50% by weight, at least 75% by weight, or at least 95% by weight of PBAT polymer.

[0034] As used herein, the term “non-compostable” refers to materials that are not compostable (i.e., materials that cannot be decomposed and biodegraded under industrial and household composting conditions (12 weeks at 58°C or 26 weeks at 21°C, respectively)). In paper packaging films, examples of layers that may contain non-compostable materials include, but are not limited to, adhesive layers, barrier layers, and / or lacquer layers. Examples of non-compostable materials include, but are not limited to, polyolefins, EVOH, SiOx, vapor-deposited metals, inks, and / or overlacquers.

[0035] All layers and films described herein have two opposing main surfaces defined by the xy plane. As used herein, the term “outer layer” means one or more layers of a film that lie on any of the main surfaces of the film, i.e., layers that are not between two other layers of the film. A film has an outer surface that is on the outside of the packaging material in which it is used. When formed into packaging material, the outer surface of the film is exposed to the environment. A film has an inner surface that is on the inside of the packaging material in which it is used. When formed into packaging material, the inner surface is used to form a seal and is exposed to the packaged product.

[0036] One or more layers or films of a paper packaging material may have partially or completely identical extents to one another.

[0037] As used herein, the term “adjacent” means that objects, such as layers of a film, are in close proximity to one another, with or without intervening materials, such as an adhesive layer. As used herein, the terms “directly adjacent,” “directly connected,” or “directly in contact” mean that objects are in contact with one another without any intervening materials.

[0038] All layers and films can be manufactured by any suitable method known to those skilled in the art. Layers and films can be manufactured by co-extrusion, curtain coating, and multi-station lacquering.

[0039] There are several challenges in the paper conversion process and the formation of layers / films on paper components. Vacuum coating of paper materials is problematic because the water content of the paper causes gas release during the vacuum process. Furthermore, fibers released from the paper contaminate the vacuum pump. Packaging paper is usually considerably thicker than film, typically over 40 μm, while polymer films are typically between 10 μm and 20 μm thick. Therefore, PVD coating paper is highly inefficient in batch vacuum deposition processes.

[0040] The surface of paper components is not ideal for vacuum deposition of a high-quality barrier layer; even the smoothest paper surfaces are not flat enough to achieve a defect-free PVD coating. Normal suction of paper causes cracks in the PVD layer. Furthermore, combining a PVD layer on top of paper is not ideal for flexural crack resistance.

[0041] A typical process for applying a PVD barrier layer to paper components involves applying a primer coating to the paper before the PVD coating. If the primer coating is hydrosensitive, such as EVOH, the coating will readily absorb water through the paper components, causing them to expand and subsequently crack in the PVD layer. By placing the PVD layer between the laminated adhesive layer facing the paper components and the EVOH support layer, the support layer is protected from excessive moisture and expansion by the PVD layer, thereby preventing cracking of the PVD layer as well. PVD coating on primer-coated paper is inefficient and suffers from the same problems that occur with PVD coating on uncoated paper.

[0042] The method for manufacturing paper packaging films described herein advantageously preserves the barrier function of the multilayer barrier film of the paper packaging film and shields the multilayer barrier film from the adverse effects of the paper conversion process.

[0043] Figure 1 illustrates a process flow diagram of Method 100 for producing a paper packaging film according to one or more embodiments. Method 100 includes coating a base web with a multilayer barrier film (operation 102), attaching the multilayer barrier film to a paper component by a lamination process to form an intermediate structure (operation 104), and removing the base web from the intermediate structure to obtain a paper packaging film (operation 106). In some embodiments, a single transfer operation includes attaching the multilayer barrier film to the paper component (operation 104) and removing the base web from the intermediate structure (operation 106).

[0044] In some embodiments, in operation 102, the coating of the base web includes forming a transfer substrate on the base web and forming a barrier layer on the transfer substrate by physical vapor deposition (PVD).

[0045] In some embodiments, attaching the multilayer barrier film to the paper component in operation 104 includes placing an adhesive layer between the multilayer barrier film and the paper component.

[0046] In some embodiments, the second paper component is attached to the paper packaging film by a second lamination process. In specific embodiments where the paper packaging film has a paper component and a second paper component, the paper component is attached to the top surface of the multilayer barrier film by an adhesive layer. In specific embodiments where the paper packaging film has a paper component and a second paper component, the second paper component is attached to the bottom surface of the multilayer barrier film by placing an adhesive layer between the bottom surface of the multilayer barrier film and the second paper component.

[0047] In specific embodiments, the second paper component may have the same or similar properties as the “paper component” described herein. In specific embodiments, the second lamination process may have the same or similar properties as the “lamination process” described herein, or may require the same process conditions.

[0048] Figure 2 illustrates a process flow diagram of Method 150 for producing a paper packaging film according to one or more embodiments. Method 150 includes producing a base web and a transfer substrate by co-extrusion (operation 152), depositing a barrier layer on a heat seal layer by physical vapor deposition (PVD) (operation 154), attaching the barrier layer to a paper component by a lamination process to form an intermediate structure (operation 156), and removing the base web from the intermediate structure to obtain a paper packaging film having a heat seal layer on its surface (operation 158). Separation occurs between the base web and the heat seal layer in operation 158. The co-extruded transfer substrate includes a heat seal layer. The co-extruded transfer substrate may include other layers, such as a lacquer layer.

[0049] In some embodiments, a single transfer operation includes attaching a barrier layer to a paper component by a lamination process to form an intermediate structure (operation 156) and removing the base web from the intermediate structure (operation 158).

[0050] The method described herein is advantageous in that, when removing the base web from the intermediate structure (operation 158), the PVD-deposited barrier layer remains attached to the heat-seal layer (and ultimately to the paper component) without damage. In specific embodiments, the PVD-deposited barrier layer is advantageously attached to the heat-seal layer (and ultimately to the paper component) once the base web is completely removed from the intermediate structure (operation 158).

[0051] Advantageously, the method described herein allows each layer added to the paper component to be extremely thin. By utilizing a PVD barrier layer, attaching a multilayer barrier film to the paper component by laminating adhesive and removing the base film results in extremely thin adhesive, barrier, and heat-seal layers (and lacquer layers, if present), thus reducing the overall material content. In this way, the paper packaging film remains recyclable due to its high paper component content and also benefits from high-performance barrier and sealing layers.

[0052] Figures 3, 4, and 5 are schematic cross-sectional views of the film structure in an intermediate step of forming the paper packaging film shown in Figure 6. Figure 7 is a schematic cross-sectional view of another embodiment of the paper packaging film. The paper packaging films illustrated in Figures 6 and 7 may be formed by Method 100 and / or Method 150.

[0053] Figure 3 illustrates a transfer substrate 203 on a base web 250. The base web 250 includes one or more of the following: stretched polyethylene (OPE) film, stretched polyethylene terephthalate (OPET) film, stretched polypropylene (OPP) film, and / or stretched polyamide (OPA) film.

[0054] In the exemplary embodiment shown in Figure 3, the transfer substrate 203 comprises a heat seal layer 204 and a lacquer layer 205. In some embodiments, the heat seal layer 204 includes an unstretched film. In some embodiments, the heat seal layer 204 includes a compostable polymer. In some embodiments, the heat seal layer 204 includes one or more of polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), and / or polyvinyl alcohol (PVOH).

[0055] Figure 4 illustrates the result of operation 156 of method 150 applied to the film of Figure 3, in which a barrier layer 206 is deposited on a transfer substrate 203 comprising a heat seal layer 204 and a lacquer layer 205. The transfer substrate 203 and the barrier layer 206 deposited on the transfer substrate 203 form a multilayer barrier film 202. In some embodiments, the heat seal layer 204 is directly bonded to the barrier layer 206 such that there is no intervening element / layer / film between the heat seal layer 204 and the barrier layer 206 (i.e., the lacquer layer 205 is absent).

[0056] Figure 5 illustrates the results of operation 104 of method 100 and operation 156 of method 150, in which a multilayer barrier film 202 with the structure shown in Figure 4 is attached to a paper component 210 to form an intermediate structure. In some embodiments, in operation 104, attaching the multilayer barrier film 202 to the paper component 210 includes placing an adhesive layer 208 between the multilayer barrier film 202 and the paper component 210.

[0057] Figure 6 illustrates the results of operation 106 of method 100 and operation 158 of method 150, in which the base web 250 is removed from the intermediate structure (shown in Figure 5) to expose the heat seal layer 204 and obtain a paper packaging film 200.

[0058] Figure 7 illustrates a schematic cross-sectional view of a paper packaging film 200' having a transfer substrate 203. In one or more embodiments, the transfer substrate 203 comprises a single layer. In some embodiments, the transfer substrate 203 comprises a heat seal layer having the same or similar properties as the heat seal layer 204. In the embodiment illustrated in Figure 7, there is a barrier layer 206 deposited on the transfer substrate 203 by physical vapor deposition (PVD), and the transfer substrate 203 and the barrier layer 206 define a multilayer barrier film 202. Figure 7 also illustrates an adhesive layer 208 between the multilayer barrier film 202 and a paper component 210.

[0059] Each of the layers / films illustrated in Figures 3-7 has a thickness measured in the z direction. In some embodiments, the heat seal layer 204 has a thickness 204A in the range of 2 μm to 10 μm. In some embodiments, the heat seal layer 204 has a thickness 204A in the range of 2 μm to 8 μm, or in the range of 2 μm to 6 μm. In some embodiments, the lacquer layer 205 has a thickness 205A in the range of 1 μm to 2 μm. In some embodiments, the transfer substrate 203 comprising the heat seal layer 204 and the lacquer layer 205 has a thickness in the range of 3 μm to 12 μm. In some embodiments, the base web 250 has a thickness 250A in the range of 6 μm to 50 μm.

[0060] In some embodiments, the combined thickness of the multilayer barrier film 202 and the adhesive layer 208 is 10 μm or less. In some embodiments, the combined thickness is in the range of 4 μm to 8 μm.

[0061] Referring again to the paper component, the paper component is an outer layer of the paper packaging film that is positioned on the outer surface of the paper packaging film. In some embodiments, the paper component includes additional components, such as ink or overlacquer, adjacent to or on the outer surface of the paper component. These additional components may cover part or all of the outer surface.

[0062] "Paper components" may be any type of paper that can be processed in a paper recycling (repulping) process. As used herein, the term "paper components" may also refer to the amount of cellulose fibers in the paper components. For example, paper components may contain cellulose fibers or be essentially made of cellulose fibers. As used in this context, "essentially made of" means that the entire composition of the paper components contains 95% or more, 98% or more, 99% or more, 99.9% or more, or 100% cellulose fibers. In some cases, paper components may contain up to 20% by weight of mineral fillers and, accordingly, 80% or more by weight of cellulose fibers.

[0063] Therefore, in embodiments in which the entire composition of the paper packaging film contains 80% or more by weight, 85% or more by weight, 90% or more by weight, or 95% or more by weight of paper components, the entire composition of the paper packaging film contains 80% or more by weight, 85% or more by weight, 90% or more by weight, or 95% or more by weight of cellulose fibers.

[0064] In some embodiments, the basis weight of the paper component is 30 g / m². 2 ~360g / m 2 It is within the range, including all values ​​and subranges within that range, and 30 g / m 2 ~100g / m 2 Within the range of 30g / m 2 ~70g / m 2This includes the range of [specific range]. Because additional components are minimized, the paper components can be made lighter while maintaining easy recyclability. Examples of paper components useful for paper packaging films include, but are not limited to, kraft paper, parchment, and bleached paper. Paper components may or may not be coated (i.e., clay coated). Examples of papers commonly used in packaging that would be acceptable for the paper packaging films described herein include machine-glazed bleached kraft paper (MGBK), single-sided clay-coated paper (C1S), and double-sided clay-coated paper (C2S), but less common papers with improved mechanical or barrier properties through the use of special fibers or additives may also be part of the paper packaging films described herein. Clay-coated paper can contain a coating of up to 15 gsm, resulting in a significant proportion of latex being applied. This means that clay-coated paper is generally not considered compostable unless the latex used is a compostable polymer. In embodiments in which the paper components are coated, the entire composition of the paper components has 95% or more, 98% or more, 99% or more, 99.9% or more, or 100% cellulose fibers.

[0065] As used herein, the term “basis weight” is used to refer to the amount of material by weight present in a given area of ​​a film or layer. Typically, the defined area is square meters, but any area can be used. The area is defined by the length-width (i.e., xy direction) of the film or layer. A material having a given thickness (z direction) and density will have a specific weight when covering a defined area (i.e., square meters). Because the density of paper can vary considerably, basis weight is a commonly used measure of paper weight. In other words, measuring the thickness of paper in the z direction can be difficult. Materials applied to discontinuous layers, such as patterned materials, can be defined by basis weight. In the case of patterns, basis weight refers to the amount of material by weight present when covering a defined area. In the film processing industry, basis weight is commonly used to measure the weight of materials, such as paper and patterned materials.

[0066] In some embodiments, the paper packaging film comprises a multilayer barrier film attached to a paper component. In some embodiments, the paper packaging film comprises an adhesive layer for attaching the multilayer barrier film to the paper component.

[0067] In some embodiments, the multilayer barrier film comprises a transfer substrate and a barrier layer deposited thereon by physical vapor deposition (PVD). In some embodiments, the transfer substrate comprises a heat seal layer and, optionally, a lacquer layer.

[0068] In some embodiments, the transfer substrate further comprises a lacquer layer. In some embodiments, the lacquer layer comprises one or more of polyurethane (PU), polyvinyl alcohol (PVOH), and / or ethylene vinyl alcohol (EVOH).

[0069] In some embodiments, the barrier layer comprises one or more of a metal, a metal oxide, and / or an inorganic oxide. In some embodiments, the barrier layer comprises one or more of aluminum oxide (AlOx) and / or silicon oxide (SiOx). The barrier layer can reduce the permeation of oxygen, moisture, or both oxygen and moisture.

[0070] The barrier material may be multilayered and may include different layers of the barrier material. The barrier material may be a mixture of multiple barrier materials.

[0071] In some embodiments, a paper packaging film comprising the multilayer barrier film described herein has an average oxygen transmission rate (OTR) value measured according to ASTM F1927 using conditions of 1 atmosphere, 23 °C, and 50% RH of 5 cm 3 / m 2 / day or less, 1 cm 3 / m 2 / day or less, or 0.5 cm 3 / m 2 / day or less. In some embodiments, a paper packaging film comprising a barrier material coated on a polymer film has an average water vapor transmission rate (MVTR) value (sometimes referred to as water vapor transmission rate (WVTR)) measured according to ASTM F1249 using conditions of 1 atmosphere, 38 °C, and 90% RH of 1 g / m 2 / day or less.

[0072] The paper packaging film may include an adhesive layer that bonds the paper component to the barrier material. The adhesive layer may be in direct contact with the paper component. The adhesive layer may be in direct contact with the multilayer barrier film. The adhesive layer may be applied by any known means of web-to-web lamination, such as dry bond lamination, wet bond lamination, or heat lamination. The adhesive layer may have a dry basis weight (i.e., after solvent removal) between 0.5 g / m 2 ~4.0 g / m 2 .

[0073] Embodiments of the present disclosure have the advantage of providing a paper packaging film comprising a water-sensitive adhesive layer. As used herein, the term “water-sensitive” means that, upon prolonged exposure to or immersion in liquid water, the adhesive layer loses its adhesive and / or tackiness, thereby allowing the paper components to be peeled (separated) from the rest of the paper packaging film structure during the repulping process. Examples of materials that can be used for the adhesive layer between the paper components and the multilayer barrier film include, but are not limited to, latex / casein mixtures, starch, sugar derivatives, cellulose, amino resins, (poly)acrylates, polyvinyl alcohol (PVOH), polyvinyl acetate, polyacrylic acid, maleic acid-modified ethylene copolymer, methylcellulose, carboxymethylcellulose, carboxy-functional polyester, polyethylene succinate, polybutylene succinate, ionomer, or hydrophilic polyurethane.

[0074] As described above, the paper packaging film may also contain ink placed on the outer surface of the paper packaging film. The type and amount of ink can be changed within the limits of complying with local paper recycling guidelines.

[0075] Paper packaging films can be advantageously used to form packaging materials. In this specification, the term “packaging material” is used to mean an article capable of containing an object (i.e., a product), which is formed by joining one or more paper packaging films or other packaging components together, either by themselves or to each other, thereby forming the internal space of the packaging material. “Packaged product” means one or more packaging components forming an hermetically sealed packaging material and the product within it. As used herein, hermetically sealed packaging material refers to a sealed or sealed packaging material that is completely closed and inherently airtight. Hermetically sealed packaging materials are typically stored for periods exceeding several days, and the integrity of the packaging material must be maintained. Integrity of the packaging material includes a consistent appearance, maintenance of barrier properties, maintenance of laminated bonding, and maintenance of the seal.

[0076] Products may be any kind of food, beverage, medicine or other medical aid, nutritional supplement, consumer goods, or industrial product. Products may be liquid in nature. Examples of products include, but are not limited to, condiments such as ketchup, mustard, mayonnaise, or spices, puddings, yogurts, cheese sauces, nut butters, jams / jelly, dairy or non-dairy creams, guacamole, applesauce, pureed baby food, infant formula, nutritional drinks / shakes, beverage or supplement concentrates, cough syrups, fish oil, lotions, ointments / ointments, personal care products, soaps / detergents, or solvents.

[0077] As described above, the product may be essentially a fluid or may have a fluid component. The product may be aqueous (i.e., containing water as a medium or main component) or oily (i.e., containing oil as a medium or main component). The paper packaging films described herein may be particularly useful for accommodating acidic products for long storage periods (days, weeks, or months) while minimizing barrier loss. The product may have a pH of less than 7, less than 6, less than 5, less than 4, or less than 3.

[0078] The packaged products disclosed herein include packaging materials formed from at least one paper packaging film and, optionally, other components. In some embodiments of the packaged products, the entire packaging material is formed from a single paper packaging film that is folded and sealed in itself (i.e., a flow wrap or stick pack configuration).

[0079] In each product being packaged, the first side of the paper packaging film faces away from the product and is exposed to the external environment, while the second side of the compostable multilayer film faces the product and is exposed to the product and the internal environment. The paper components may face away from the product being packaged and be on or near the first side. The second side may include a heat-seal layer.

[0080] The paper packaging films disclosed herein are particularly useful for products to be packaged in small sizes, such as 6 inches x 9 inches, 5 inches x 7 inches, 5 inches x 5 inches, 3 inches x 3 inches, and 3 inches x 2 inches, because these types of packaging materials are difficult to collect and / or separate for recycling. Small packaging materials and components may be better suited to compostable end-of-life solutions rather than recyclable ones.

[0081] The paper packaging films disclosed herein are particularly useful for forms and / or types of products that are packaged, where a significant amount of product residue remains in the packaging after consumer use. The packaged product may have a form or structure that prevents / prohibits complete removal of the product. The packaged product may have a form or structure that prevents / prohibits cleaning the packaging after use. The packaged product may have a tendency to stick or adhere to the packaging. In such cases, the packaging should not be recycled because the product residue contaminates the recycling process. In such cases, composting is an excellent solution because the product residue may facilitate the decomposition process.

[0082] In some embodiments of the products to be packaged, a paper packaging film is sealed inside another paper packaging film (i.e., a sachet structure). In some embodiments of the products to be packaged, the paper packaging film is a lid component that seals onto a molded container, such as a cup or tray. Packaging including components that do not conform to the paper packaging films disclosed herein may also be compostable, such that the entire package is compostable. In some embodiments, the packaging includes components that are not compostable but can be separated from the compostable portion for proper disposal.

[0083] The heat-seal layer of a paper packaging film may have a composition that enables the formation of an airtightly sealed packaging material. In some embodiments, the heat-seal layer includes an unstretched film (i.e., the heat-seal layer is part of the unstretched film). In some embodiments, the heat-seal layer includes a compostable polymer. In some embodiments, the heat-seal layer includes one or more of polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), and / or polyvinyl alcohol (PVOH).

[0084] A heat seal layer allows two or more surfaces to be bonded by applying both heat and pressure. Heat sealing is a well-known and commonly used process for creating packaging materials and is well known to those skilled in the art. While not bound by theory, during heat sealing, the heat seal layer softens upon heating, enabling the formation of a heat seal bond. Raising the temperature of the sealable material requires transferring heat throughout the paper packaging film, and since paper components often absorb much of the heat, it is advantageous for the heat sealable material to soften and seal at a relatively low temperature. A lower seal onset temperature (SIT) allows for faster packaging line speeds. For example, some embodiments of paper packaging films may include heat sealable materials exhibiting SITs of 110°C or less, 100°C or less, or 90°C or less. Possible heat sealable materials include, but are not limited to, acrylic copolymers, PET, PE, PP, or hot melt (wax-based).

[0085] The heat seal layer is applied to a thickness that allows for hermetically sealed sealing. In some embodiments, the heat seal layer is 1 g / m². 2 or more, or 3g / m² 2 The coating may be applied with the above basis weight. In another embodiment, the heat seal layer is 8 g / m². 2 Below, 9g / m 2 The following, or 10g / m 2 The following basis weights may be used for coating. For example, the heat seal layer may have a basis weight of approximately 1 g / m².2 ~about 10g / m 2 Within the range of approximately 3g / m 2 ~approximately 9g / m 2 It may be within the range of [a certain limit].

[0086] The present disclosure will now be described with reference to the following examples. [Examples]

[0087] Examples

[0088] Example 1 is a theoretical experiment based on the paper packaging film described above. Example 1 uses 67 g / m². 2 It can be manufactured by laminating the paper components onto a multilayer barrier film. The multilayer barrier film has a density of 1.3 g / m². 2 This can be manufactured by applying a PVOH-based barrier lacquer layer to a 12 μm polyester film. The lacquer may be applied in such a way that its adhesion to the polyester film is reduced, for example, by not including an adhesion promoter in the lacquer layer. After lacquering, 50 mg / m² of adhesive is applied to the PVOH-based barrier lacquer layer. 2 SiOx can be coated with SiOx. The SiOx coating layer has a density of 3 g / m². 2 It may be laminated to paper with a suitable adhesive layer to form an intermediate structure. After removing the 12 μm polyester film, the weight is 67 g / m². 2 / / Adhesive 3g / m 2 / / SiOx coating 0.05g / m 2 / / PVOH coating 1.3g / m 2 A paper packaging film having the structure is obtained. The paper packaging film of Example 1 has a composition that is approximately 94% by weight of paper components and approximately 4% by weight of non-compostable materials.

[0089] The paper packaging film of Example 1 was used as a packaging film and had a density of 1.5 g / m². 2It can be lacquered with a heat-seal layer and / or a lacquer layer. The heat-seal layer can be added in a pattern that minimizes the level of non-composted material, keeping it below 5%.

[0090] Example 2 is a theoretical experimental example based on the paper packaging film described above. Example 2 can be manufactured by first co-extruding a 20 μm polyethylene / 6 μm amorphous PLA / 4 μm PVOH multilayer film. In the second step, the PE / aPLA / PVOH film is coated with 50 mg / m² of PVOH on the PVOH surface. 2 The film is coated with SiOx. Finally, the SiOx-coated surface of the film is laminated to paper (67 gsm) with a suitable adhesive, and the PE layer is removed. The final structure of the paper packaging film is 67 g / m² paper. 2 / / Adhesive 3g / m 2 / / SiOx coating 0.05g / m 2 / / PVOH coating 3.0g / m 2 / / / Amorphous PLA heat seal layer 7.5g / m² 2 The paper packaging film of Example 2 has a composition that comprises about 83% by weight of paper components and about 4% by weight of non-compostable materials.

[0091] Example 3 is a theoretical experimental example based on the paper packaging film described above. Example 3 can be manufactured by first co-extruding a 25 μm polyethylene / 8 μm amorphous PLA multilayer film. In the second step, the PE / aPLA film is coated with 50 mg / m² of aPLA on the aPLA surface. 2 The film is coated with SiOx. Finally, the SiOx-coated surface of the film is laminated to paper (67 gsm) with a suitable adhesive, and the PE layer is removed. The final structure of the paper packaging film is 67 g / m² paper. 2 / / Adhesive 3g / m 2 / / SiOx coating 0.05g / m 2 / / Amorphous PLA heat seal layer 10.0 g / m 2The paper packaging film of Example 3 has a composition that comprises about 84% by weight of paper components and about 4% by weight of non-compostable materials.

[0092] Examples 4, 5, and 6 are paper packaging films manufactured by the processes disclosed herein. The films were manufactured by co-extruding a base web and a heat seal layer (i.e., a transfer substrate), depositing an aluminum PVD layer (negligible in weight) as a barrier layer on the heat seal layer, laminating it onto a paper component, and removing the base web. The structures of the manufactured films are shown in Table 1. [Table 1]

[0093] Embodiments:

[0094] Embodiment 1: A paper packaging film comprising paper components attached to a multilayer barrier film containing a compostable polymer, wherein the overall composition of the paper packaging film comprises 80% by weight or more of paper components and 5% by weight or less of non-compostable material.

[0095] Embodiment 2: The paper component is 30 g / m². 2 ~360g / m 2 A paper packaging film according to Embodiment 1, having a basis weight within the range.

[0096] Embodiment 3: A paper packaging film according to any one of embodiments 1 to 2, further comprising an adhesive layer for attaching a multilayer barrier film to a paper component.

[0097] Embodiment 4: A paper packaging film according to any one of Embodiments 1 to 3, wherein the multilayer barrier film comprises a transfer substrate and a barrier layer formed thereon by physical vapor deposition (PVD).

[0098] Embodiment 5: A paper packaging film according to any one of embodiments 1 to 4, wherein the transfer substrate comprises a heat-seal layer.

[0099] Embodiment 6: A paper packaging film according to any one of Embodiments 1 to 5, wherein the heat-seal layer includes a non-stretched film.

[0100] Embodiment 7: A paper packaging film according to any one of embodiments 1 to 6, wherein the heat-seal layer contains a compostable polymer.

[0101] Embodiment 8: A paper packaging film according to any one of Embodiments 1 to 7, wherein the compostable polymer is selected from the group consisting of polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), and polyhydroxyalkanoate (PHA).

[0102] Embodiment 9: A paper packaging film according to any one of embodiments 5 to 8, wherein the heat-seal layer has a thickness in the range of 2 μm to 10 μm.

[0103] Embodiment 10: A paper packaging film according to any one of embodiments 5 to 9, wherein the heat-seal layer is directly connected to the barrier layer.

[0104] Embodiment 11: A paper packaging film according to any one of embodiments 5 to 10, wherein the transfer substrate further comprises a lacquer layer, the lacquer layer comprising one or more of polyurethane (PU), polyvinyl alcohol (PVOH), and / or ethylene vinyl alcohol (EVOH).

[0105] Embodiment 12: A paper packaging film according to Embodiment 11, wherein the lacquer layer has a thickness in the range of 1 μm to 2 μm.

[0106] Embodiment 13: A paper packaging film according to any one of embodiments 4 to 12, wherein the barrier layer comprises one or more metals, metal oxides, and / or inorganic oxides.

[0107] Embodiment 14: The paper packaging film according to Embodiment 13, wherein the barrier layer comprises one or more of aluminum oxide (AlOx) and / or silicon oxide (SiOx).

[0108] Embodiment 15: A paper packaging film according to any one of Embodiments 5 to 14, wherein the combined thickness of the multilayer barrier film and the adhesive layer is 10 μm or less.

[0109] Embodiment 16: A paper packaging film according to Embodiment 15, wherein the combined thickness is in the range of 4 μm to 8 μm.

[0110] Embodiment 17: A paper packaging film according to any one of Embodiments 1 to 16, wherein the entire composition of the paper packaging film comprises 85% by weight or more of paper components and 5% by weight or less of non-compostable materials.

[0111] Embodiment 18: A method for producing a paper packaging film, the method comprising: coating a base web having a thickness in the range of 6 μm to 50 μm with a multilayer barrier film containing a compostable polymer; attaching the multilayer barrier film to a paper component by a lamination process to form an intermediate structure; and removing the base web from the intermediate structure to obtain a paper packaging film, wherein the overall composition of the paper packaging film comprises 80% by weight or more of paper components and 5% by weight or less of non-compostable material.

[0112] Embodiment 19: The method according to Embodiment 18, wherein a single transfer operation includes attaching the multilayer barrier film to the paper components and removing the base web from the intermediate structure.

[0113] Embodiment 20: The method according to any one of embodiments 18 and 19, wherein the base web comprises one or more of stretched polyethylene (OPE) film, stretched polyethylene terephthalate (OPET) film, stretched polypropylene (OPP) film, and / or stretched polyamide (OPA) film.

[0114] Embodiment 21: The method according to any one of Embodiments 18 to 20, wherein the coating of the base web comprises forming a transfer substrate on the base web and forming a barrier layer on the transfer substrate by physical vapor deposition (PVD), and the combination of the barrier layer and the transfer substrate forms a multilayer barrier film.

[0115] Embodiment 22: The method according to any one of embodiments 18 to 21, wherein attaching a multilayer barrier film to a paper component includes arranging an adhesive layer between the multilayer barrier film and the paper component.

[0116] Embodiment 23: The method according to Embodiment 21, wherein the transfer substrate comprises a heat seal layer and, optionally, a lacquer layer.

[0117] Embodiment 24: The method according to Embodiment 23, wherein the heat seal layer includes an unstretched film.

[0118] Embodiment 25: The method according to any one of embodiments 23 to 24, wherein the heat-seal layer contains a compostable polymer.

[0119] Embodiment 26: The method according to any one of Embodiments 23 to 25, wherein the heat-seal layer comprises one or more of polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), polyhydroxyalkanoate (PHA), polyethylene vinyl alcohol (EVOH), and / or polyvinyl alcohol (PVOH).

[0120] Embodiment 27: The method according to any one of embodiments 23 to 26, wherein the heat seal layer has a thickness in the range of 2 μm to 10 μm.

[0121] Embodiment 28: The method according to any one of embodiments 23 to 27, wherein the heat seal layer is directly connected to the barrier layer.

[0122] Embodiment 29: The method according to Embodiment 23, wherein the transfer substrate further comprises a lacquer layer, the lacquer layer comprising one or more of polyurethane (PU), polyvinyl alcohol (PVOH), and / or ethylene vinyl alcohol (EVOH).

[0123] Embodiment 30: The method according to any one of embodiments 21 to 29, wherein the barrier layer comprises one or more aluminum oxide (AlOx) and / or silicon oxide (SiOx).

[0124] Embodiment 31: The method according to any one of Embodiments 18 to 30, wherein the entire composition of the paper packaging film comprises 85% by weight or more of paper components and 5% by weight or less of non-compostable materials.

[0125] Embodiment 32: A method for manufacturing a paper packaging film, the method comprising: manufacturing a base web and a heat seal layer by co-extrusion molding; forming a barrier layer on the heat seal layer by physical vapor deposition (PVD); attaching the barrier layer to paper components by a lamination process to form an intermediate structure; and removing the base web from the intermediate structure to expose the heat seal layer and obtain a paper packaging film, wherein the overall composition of the paper packaging film contains 80% by weight or more of paper components.

[0126] Embodiment 33: A paper packaging film comprising a multilayer barrier film including a transfer substrate and a barrier layer formed by physical vapor deposition (PVD), and an adhesive layer for attaching paper components to the multilayer barrier film, wherein the transfer substrate comprises a heat seal layer, the heat seal layer having a thickness in the range of 2 μm to 8 μm, the barrier layer containing one or more of metal, aluminum oxide (AlOx) and / or silicon oxide (SiOx), and the overall composition of the paper packaging film contains 85% by weight or more of paper components.

[0127] Embodiment 34: A paper packaging film according to Embodiment 33, wherein the heat-seal layer contains a compostable polymer.

[0128] Embodiment 35: A paper packaging film according to any one of embodiments 33 to 34, wherein the heat-seal layer includes a non-stretched film.

[0129] Embodiment 36: A paper packaging film according to any one of embodiments 33 to 35, wherein the heat-seal layer comprises one or more of polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), and / or polyvinyl alcohol (PVOH).

Claims

1. Paper packaging film, A multilayer barrier film comprising a transfer substrate and a barrier layer formed by physical vapor deposition (PVD), The film comprises an adhesive layer for attaching paper components to the multilayer barrier film, The transfer substrate comprises a heat seal layer, and the heat seal layer has a thickness in the range of 2 μm to 8 μm. The barrier layer comprises one or more of a metal, aluminum oxide (AlOx), and / or silicon oxide (SiOx). The entire composition of the paper packaging film comprises 85% by weight or more and 99% by weight or less of the paper component, A paper-based packaging film in which the heat-seal layer contains a compostable polymer.

2. The paper packaging film according to claim 1, wherein the heat-seal layer includes a non-stretched film.

3. The paper packaging film according to claim 1, wherein the heat-seal layer comprises one or more of polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), polyhydroxyalkanoate (PHA), and / or polyvinyl alcohol (PVOH).

4. The paper packaging film according to claim 1, wherein the combined thickness of the multilayer barrier film and the adhesive layer is in the range of 4 μm to 10 μm.

Images