Barrier laminate

Abstract

A barrier laminate material comprising a substrate layer (1), a tie layer (2) comprising an electrospun network of fibers and a non-fibrous based sealing layer (3) adjacent to the tie layer (2) and facing the outer side of the laminate.

Description

[0001] Invention Field This invention relates to a barrier laminate material. It also relates to a packaging product comprising the barrier laminate material. Furthermore, it relates to a method for manufacturing the barrier laminate material. Background of the Invention Consumer goods, such as food products including frozen desserts, liquid and dry soup mixes, broths, sauces; palatable snacks, ready-to-eat meals, and soap bars, laundry detergents, etc., are typically packaged before consumer use. Beyond their sales purpose, depending on the consumer product, packaging provides structure and / or holds the product in place and protects it from external influences that may affect its quality, including light, water, and air. This leads to the presence of several barrier materials included in the packaging material, depending on the product's needs. Furthermore, the consumer product itself may affect the packaging material due to components such as water, fats, salts, corrosive alkaloids, etc. The packaging material often needs to resist these influences to ensure proper protection of the packaged product. For this reason, packaging materials for consumer goods are typically laminates of different materials, such as various polymer materials (plastics), and metals such as aluminum.

[0003] With increasing emphasis on environmentally friendly packaging materials, the use of non-petroleum-based base layers, such as paper, has gained attention. These non-petroleum-based base layers serve as the structural basis for, for example, barrier laminates. Clearly, base layers like paper are typically thin to allow for high flexibility, for example, during the packaging process and in the packaging line. In the case of paper, while it provides a degree of texture to the packaged consumer product, its barrier properties against external influences, such as water, are limited, and it is easily damaged upon contact with fats or water from the packaged consumer product. In this art, laminates comprising paper and petroleum-based polymers have been found to be a solution for providing barrier properties to paper materials.

[0004] Barrier laminates can be used, for example, to produce flexible packaging, such as pouches or doyies. For this purpose, barrier laminates are typically folded and self-sealed to form a pouch-like structure. Optionally, individual sheets of barrier laminate can be sealed to each other to obtain a pouch-like structure, such as a pouch or doyie. After the packaging is filled, it can be sealed in a process involving further sealing steps. To achieve this sealing step during the manufacture and sealing of the packaging, the barrier laminate includes a sealing layer. This is the layer in the barrier laminate that, when pressurized or heated, is most preferably bonded to another layer when heat is applied.

[0005] It has been recognized that one of the challenges observed in the absence of oil-barrier laminates is the seal integrity within packaging produced by flexible barrier laminates. For optimal protection of consumer products, the sealed areas within the packaging (typically located at the packaging boundaries) should not open or leak during storage and transport. Seal integrity is particularly challenging, yet crucial, when the base layer in the laminate is paper-based.

[0006] EP 3907078 A relates to a biodegradable packaging comprising a low-cost, tear-resistant, thermoformable structural layer and optional self-adhesive gas and vapor barrier layers, self-adhesive active layers, and / or layers for direct contact with the product, all based on biodegradable polymers.

[0007] Therefore, it is recognized that there is a need for a flexible barrier laminate that is, as far as possible and more preferably, completely free of petroleum-based layers and comprises a base layer and a sealing layer, which allows for the manufacture of packaged products for consumer goods and provides adequate integrity and a tight bond between the sealing layer and the base layer during use (transportation and storage). Invention Overview Surprisingly, this objective can be achieved by the present invention, which in its first aspect relates to a barrier laminate material comprising: • Basal layer (1) • Connecting layer (2), which comprises an electrospun fiber network, • A non-fibrous sealing layer (3), which is adjacent to the connecting layer (2) and faces the outside of the laminated material, The connecting layer (2) has a thickness of 1 to 30 micrometers, preferably 5 to 10 micrometers. The sealing layer (3) has a thickness of 5 to 65 micrometers, more preferably 20 to 60 micrometers, even more preferably 20 to 50 micrometers, even more preferably 30 to 45 micrometers, and most preferably 30 to 40 micrometers. None of the base layer (1), connecting layer (2) and sealing layer (3) contain petroleum-derived materials.

[0009] In a second aspect, the present invention relates to a method for providing a packaging laminate material according to the invention, the method comprising the following steps: a) Provide a base layer (1). b) Electrospinning is used to deposit fibers to form a fiber network. c) Apply a sealing layer (3) to the fiber network. d) Laminated base layer, deposited fiber network, and sealing layer. To obtain the barrier laminate material according to the present invention.

[0010] In a third aspect, the present invention relates to packaging products for packaged consumer goods, the packaging product comprising a barrier laminate according to the invention. Preferably, the packaging product is a wrapper or a bag.

[0011] In a fourth aspect, the present invention relates to a method for manufacturing the packaging product of the third aspect of the present invention.

[0012] In a fifth aspect, the present invention relates to the use of an electrospun fiber layer located between a base layer and a sealing layer for enhancing the connection between the base layer and the sealing layer, wherein the resulting barrier laminate is according to the invention.

[0013] Barrier laminates comprising a substrate and an electrospun layer have been described in the art. Furthermore, barrier laminates comprising a sealing layer are known. The inventors are unaware of any barrier laminate comprising a sealing layer, in which enhanced interlayer adhesion has been recognized following the introduction of an electrospun bonding layer. Attached Figure Description

[0014] Figure 1 A schematic diagram of the fiber electrospinning process is shown. Invention Details The barrier laminate of the present invention comprises three layers. It includes a base layer (1), a non-fiber-based sealing layer (3), and a connecting layer (2) containing a fiber network located between the base layer and the sealing layer. It has been found that the electrospun connecting layer results in significantly enhanced interlayer sealing performance, where the thickness of individual layers is relevant. An advantage of this approach is that it provides a barrier laminate in which the risk of individual layer delamination is reduced. Layer delamination is particularly likely to pose a risk in cellulose fiber-based barrier laminates, especially when the barrier laminate is used in packaging products containing, for example, consumer goods, and is therefore subjected to forces, for example, during material cutting or tearing during the opening of such packaging. It also allows the barrier laminate to be independent of other petroleum-derived barrier laminates. These materials are preferably not present in the base layer, connecting layer, and sealing layer, and more preferably not in the barrier laminate itself.

[0016] The barrier laminate is flexible. It can generally be easily bent without compromising its integrity. The laminate is not rigid. The barrier laminate typically comprises 3 to 7 layers, preferably 3 to 6 layers, more preferably 4 to 6 layers, and most preferably 5 or 6 layers. Preferably, on one side of the barrier laminate containing the sealing layer (3) (typically facing the packaged product during use), the barrier laminate consists of 3 layers: a base layer (1), a connecting layer (2), and a sealing layer (3). On the other side of the base layer (typically facing the outside world during use), one or two other layers, such as an ink layer (4) and a varnish layer (5), may preferably be deposited.

[0017] basal layer The barrier laminate comprises a base layer (1). The base layer is preferably a cellulose fiber-based layer. More preferably, the base layer is paper-based or paperboard-based, most preferably paper-based, and most preferably paper. The flexible barrier laminate preferably comprises one or two layers in total, but preferably one paper layer in total. Paper typically contains cellulose fibers.

[0018] The cellulose fiber-based layer preferably includes paper, or more preferably has a basis weight of 40 to 100 g / m². 2 Between 50 and 90 g / m 2 Even more preferred is 50 to 80 g / m 2 The optimal value is 50 to 70 g / m³. 2 The paper. This provides suitable rigidity for the final packaged product to contain consumer goods, such as wrapping paper or pouches, which can then be properly transported on a packaging line, such as on rollers.

[0019] Considering the aim of providing a barrier laminate material with a minimal environmental impact, it is likely preferable that the amount of paper present is greater than 80% by weight based on the total weight of the barrier laminate material, more preferably greater than 85% by weight. Preferably, paper fibers account for greater than 80% by weight based on the total weight of the barrier laminate material, more preferably greater than 85% by weight. It is likely preferable that the amount of total polymer, such as plastic, is less than 20% by weight based on the weight of the barrier laminate material, preferably less than 15% by weight. It can be, for example, 9 to 20% by weight, more preferably 11 to 15% by weight. A paper content exceeding 80% by weight is generally considered to meet the recyclability standards of many countries.

[0020] Alternatively, the barrier layer can be polymer-based. The polymer is not petroleum-derived. Besides environmental impacts, several petroleum-derived polymers result in fragile or rigid base layers, such as polypropylene terephthalate or polyethylene terephthalate, and have been found less suitable for providing flexible barrier laminates. Suitable polymers for use as base layers are preferably selected from polyhydroxyalkanoates (PHAs), polyvinyl alcohol, polylactic acid, and mixtures thereof. PHA-based base layers are the most preferred in this group. These are not derived from petroleum (unlike polyvinyl alcohol) and are relatively easy to compost (unlike polylactic acid, which cannot be home composted). PHA preferably contains poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) or poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH). When the base layer is polymer-based, it is preferred to contain poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) or poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH), more preferably poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) or poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH). However, a cellulose fiber-based, preferably paper-based, base layer is more preferred than a polymer-based base layer, and preferably the base layer is cellulose fiber-based, more preferably paper-based.

[0021] Connection layer A connecting layer (2) exists between the base layer and the sealing layer (3). The connecting layer is preferably deposited directly on the base layer (1). Preferably, the connecting layer (2) is the only barrier layer present on the side of the base layer (1) where the connecting layer is applied. Preferably, the connecting layer and the sealing layer are the only layers located on the side of the base layer where the connecting layer is located. Preferably, there is only one connecting layer comprising a fiber network. It may be preferable that no further barrier layer exists on the side of the base layer where the sealing layer (3) is not located (i.e., the environmentally facing side).

[0022] The connecting layer comprises a fiber network. The fiber network is electrospun. The fibers in the fiber network preferably have a diameter (shortest dimension) between 250 and 1000 nanometers, more preferably between 300 and 700 nanometers, and most preferably between 300 and 500 nanometers. The fiber diameter can be examined, for example, by a microscope, such as an (electron) microscope known in the art.

[0023] The bonding layer preferably has a concentration of 1 to 30 g / m 2 Preferably 2 to 20 g / m 2 Even more preferred is 2 to 12 g / m 2 The density is 10 to 20 g / m³. 2The density is likely preferred. The thickness of the bonding layer is 1 to 18 micrometers, preferably 4 to 15 micrometers, and more preferably 5 to 10 micrometers. This width can be readily inspected using methods common in the art, such as those known to those skilled in the art, such as microscopes or diameter gauges.

[0024] The material in the connecting layer is preferably not petroleum-derived. The barrier layer may contain filler particles, for example, to improve barrier performance. The connecting layer preferably contains one or more materials selected from polyhydroxyalkanoates (PHAs), silk fibroin, alcohol-soluble glutenin, chitin polysaccharides, phenolic polymers, and mixtures thereof. In this invention, the preferred polyhydroxyalkanoate is selected from polyhydroxybutyrate (PHB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH), and mixtures thereof. In this invention, the preferred silk fibroin is silk. In this invention, the preferred alcohol-soluble glutenin is zein. In this invention, the preferred chitin polysaccharide is chitin from shellfish and chitin from mushrooms. In this invention, the preferred phenolic polymer is lignin. More preferably, the connecting layer contains PHA, silk fibroin, or alcohol-soluble glutenin. Even more preferably, the connecting layer comprises one or more selected from polyhydroxybutyrate (PHB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH), filaments, zein, and mixtures thereof. PHB may result in a relatively high layer thickness, which may not be preferred. It may be preferred that the PHB layer is absent. Most preferably, the connecting layer comprises one or more selected from poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH), filaments, zein, and mixtures thereof.

[0025] electrospinning The bonding layer is typically an electrospun layer of deposited fibers. Electrospinning is a known deposition technique for depositing fibers onto a substrate. It is commonly used in pharmaceutical applications, such as the manufacture of filters. Typical deposition techniques involve heating the material to be deposited, for example, to melt it. It has been found that, in the case of this invention, several non-petroleum-derived natural materials cannot be melted and are therefore difficult to deposit, and can be deposited in the form of fibers using electrospinning. In this way, barrier laminates with enhanced interlayer sealing strength can be produced while allowing the barrier laminate to be biodegradable. In the case of cellulose fiber-based, particularly paper-based, barrier laminates, electrospinning allows the material to be deposited without negatively impacting the quality of the cellulose-based fiber layer: since coatings are traditionally applied to a substrate using disperse coating, this can cause the substrate to dry out when the solvent used in the disperse coating is absorbed, and this can damage the cellulose fiber-based substrate, whereas in the electrospinning process, the fibers are deposited as any solvent evaporates during deposition, leaving the substrate unaffected.

[0026] Electrospinning is a known fiber manufacturing technique that produces nonwoven fiber mats. This technique utilizes electrical charge to draw in a charged jet of polymer solution and deposit dry fibers onto a negatively charged collector. Polymers such as polyhydroxyalkanoates (PHAs) and proteins such as silk fibroin and zein can be electrospinned. These polymers are dissolved in a solvent and loaded into a syringe; during electrospinning, the solvent evaporates, leaving dry fibers. The process is essentially as follows: Figure 1 As depicted. As is known in the art, electrospinning parameters, including the distance to the collector, voltage, and flow rate, can be adjusted, which will allow for adjustment of the fiber diameter. In the case of this invention, a diameter of 250-1000 nm, but particularly preferably 300-700 micrometers, has proven to be optimal, especially in the case of a cellulose fiber-based, preferably paper-based, substrate layer, because this diameter results in optimal barrier properties to accommodate the inherent pores present in the substrate material.

[0027] Furthermore, the thickness of the connecting layer can be adjusted by increasing the spinning time of the fibers, thereby allowing for a higher fiber density deposition, preferably neither too thin nor too thick. The preferred deposition thickness of the fiber layer is between 10 and 55 micrometers, preferably between 15 and 25 micrometers. This is not necessarily the thickness observed in the final packaging laminate of the present invention, as a third layer will be deposited on this electrospun connecting layer, which preferably involves compression and produces the final thickness of the connecting layer as mentioned earlier herein. In the case of the present invention, for optimal sealing, a “random” orientation of the fibers during deposition is preferred (e.g., relative to “aligned” deposition).

[0028] When describing the manufacturing method of the present invention, the electrospinning process will be further explained.

[0029] sealing layer The barrier laminate includes a sealing layer. The sealing layer is preferably a heat-sealing layer. The heat-sealing layer is preferably a layer not made of petroleum-derived materials.

[0030] Preferably, the sealing layer (3) comprises a material selected from polyhydroxyalkanoates (PHA), heat-sealable cellulose, polymers derived from biomass, and protein membranes. Preferably, the sealing layer contains PHA, more preferably PHA.

[0031] Preferably, PHA is selected from polyhydroxybutyrate (PHB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH), and mixtures thereof. Heat-sealable cellulose is known in the art and can preferably be regenerated cellulose (e.g., Natureflex). TM The biomass-derived polymers used for heat sealing are known in the art and preferably contain polysaccharides such as chitosan, starch, or mixtures thereof, preferably starch or a starch-based coating. The protein used for heat sealing preferably includes zein. Preferably, the sealing layer comprises a material preferably selected from polyhydroxybutyrate (PHB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH), regenerated cellulose, polysaccharides such as chitosan or starch, zein, and mixtures thereof, preferably composed of such materials. More preferably, the sealing layer comprises a material selected from polyhydroxybutyrate (PHB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH), and mixtures thereof, even more preferably composed of such materials. Even more preferably, the sealing layer comprises one or more of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH), and mixtures thereof, more preferably composed of them.

[0032] The thickness of the sealing layer is preferably 5 to 65 µm, more preferably 20 to 60 µm, more preferably 20 to 50 µm, even more preferably 30 to 45 µm, and most preferably 30 to 40 µm. The density of the sealing layer is preferably 10 to 50 g / cm³. 2 Preferably 20 to 50 g / cm 2 The optimal value is 30 to 40 g / cm³. 2 .

[0033] The sealing layer (3) is directly connected to the connecting layer (2).

[0034] Additional layer Preferably, the base layer (1) and the connecting layer (2) are in direct contact, and the latter is preferably deposited directly on the base layer to obtain optimal sealing strength. Alternatively, it may be preferred that a pre-coating be present between the base layer (1) and the connecting layer (2), but this is not necessary. If present, the pre-coating is preferably made from a non-petroleum-derived material. Preferred pre-coatings may be selected from starch, zein, protein, cellulose, clay, and mixtures thereof. Clay-based pre-coatings are most preferred. The pre-coating may preferably have a thickness of 1 to 5 gsm, preferably 1.5 to 4 gsm. As those skilled in the art know, the pre-coating can be suitably applied using dispersion or extrusion coating. It may be preferred that no pre-coating be present between the base layer and the barrier layer, for example, for better results.

[0035] In addition to the base layer, the connecting layer, and the sealing layer, the barrier laminate of the present invention may also include an ink layer (4). The barrier laminate is used to protect consumer products (7). In this respect, it also provides communication functions to consumers who will purchase the consumer products, typically through information printed on a base (e.g., paper), including information about ingredients, attractive artwork, and advertisements. Therefore, the barrier laminate preferably includes an ink layer (4). This ink layer is preferably attached to the base layer (1). It is probably preferred to apply a primer between the paper layer and the ink layer. Suitable primers are known to those skilled in the art. It is probably preferred that the primer is non-petroleum-based. The ink layer is preferably directly attached to the base layer (1) and is generally oriented towards the outside of the barrier laminate (e.g., when applied in consumer product packaging), that is, the side of the barrier laminate that will come into contact with the consumer product to be packaged, that is, the side of the paper on which the sealing layer (3) is located.

[0036] For example, to protect the ink layer, the barrier laminate material preferably includes a protective layer (5) on top of the ink layer. The protective layer typically faces the outside world. It is typically located opposite the product-facing side of the laminate material (e.g., when applied in consumer packaging) and opposite the side where the sealing layer of the laminate material is located. The protective layer (5) may be an overprinted varnish (OPV), which is well known to those skilled in the art, and the varnish chosen depends on the intended use of the barrier laminate material of the present invention. For example, the OPV may be selected from conventional offset letterpress varnishes, acrylic varnishes, UV varnishes, and gravure varnishes. The OPV may be a water-based polymer formulation or a solvent-based polymer formulation. The protective layer (5) is typically deposited directly on the ink layer (4), preferably in direct contact with the ink layer. The protective layer faces the outside of the barrier laminate material, typically the side opposite to the side intended to face or be facing the consumer product to be packaged, i.e., typically the side opposite to the side of the paper where the sealing layer is located. The ink layer and the protective layer (e.g., the OPV) are not referred to as “barrier layer” in the sense used in this specification.

[0037] The thickness of the protective layer (5) is preferably between 0.5 and 3 micrometers, and more preferably between 1 and 2 micrometers.

[0038] Preferably, there are a total of three layers on the "product side," i.e., the side where the sealing layer is located, including the base layer. Therefore, preferably, there are no other layers between the sealing layer and the base layer except for the connecting layer. Preferably, there are no other layers on top of the sealing layer (3). It is probably preferred that only one barrier layer exists in the barrier laminate of the present invention, i.e., a barrier layer containing electrospun fibers (preferably composed of electrospun fibers). Preferably, there is no second or additional barrier layer on the side of the base layer facing the environment (5), i.e., the side opposite to the side where the barrier layer (2) exists. Preferably, there are no metal layers or metal oxide layers in the barrier laminate. It is probably preferred that no plasma treatment is performed on any of the materials used in the barrier laminate.

[0039] Packaging products and packaged consumer goods In a further aspect, the present invention relates to flexible packaging products for packaging consumer goods, the packaging product comprising the flexible barrier laminate of the present invention. The packaging product comprises a sealed flexible barrier laminate of the present invention, wherein multiple barrier laminates are sealed together, or one barrier laminate is folded and sealed together, wherein corresponding sealing layers (3) face each other. As will be understood by those skilled in the art, the boundaries of the resulting packaging product, such as a pouch or wrapping paper, are typically sealed together. Sealing is preferably performed by heat sealing.

[0040] The packaged product can be in the form of a flow-wrap, pillow bag, gusseted bag, stand-up pouch, diaper bag, tetrahedral bag, quattro seal bag, or sac. The packaged product can contain consumer goods. Typical consumer goods packaged using the flexible barrier laminate of the present invention are preferably selected from frozen desserts, broths, soups, sauces, coffee, tea, supplements, vitamins, electrolyte powders, laundry detergents, skin cleansing products, skin care products, and hair care products. In particular, it is preferred that the packaged product be a sac or wrapping paper. Wrapping paper can be used, for example, to wrap soap bars, frozen dessert products, or condiments such as broths or flavor concentrates.

[0041] The present invention also relates to packaged consumer products, wherein the consumer products are packaged in packaged products comprising the flexible barrier laminate of the present invention.

[0042] Manufacturing method In a further aspect, the present invention relates to a method for manufacturing the barrier laminate material of the present invention. The method includes the following steps: a) Provide the base layer (1).

[0043] b) Electrospinning is used to deposit fibers to form a fiber network. c) Apply a sealing layer (3) to the fiber network. d) Laminated fiber network and sealing layer, To produce the barrier laminate material according to the invention.

[0044] The preferred embodiments described in the context of the first aspect of the invention are applicable to the second and other aspects of the invention with the necessary modifications.

[0045] Barrier laminates can be produced in conventional electrospinning equipment, such as the EF500 electrospinning system from Ske Research Equipment. In step a) of the method of the present invention, a base layer is provided. (See reference...) Figure 1 The substrate layer described above, relating to the first aspect of the invention, is typically located in the collector of the device, such as a collecting plate, and is generally negatively charged. For optimal results, it may be advantageous to apply a low pressure (“vacuum”) under the substrate layer. The material to be spun, such as a polymer or protein, is dissolved in a solvent. The solvent is then loaded into the device, for example, a syringe.

[0046] The materials described in the first aspect of the invention are spun to form a fibrous network, the forming layer of which is typically on top of a base layer. Solvents for dissolving the materials to be spun, such as polymers, are known in the art. For example, polyhydroxyalkanoates (such as PHBV or PHBH) are preferably dissolved in a mixture of 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP), DMSO, and water (8:1:1), wherein the PHA is suitably dissolved by stirring at a preferred temperature of 50°C, for example, overnight, followed by the addition of dimethyl sulfoxide and water by stirring at room temperature. Zeadin is dissolved by stirring in ethanol / deionized water (80% / 20%) at room temperature. Silk fibroin, such as fibroin, is dissolved in formic acid.

[0047] A solution containing the fiber-forming material (polymer, polysaccharide, protein) is typically fed into a charged jet using a Taylor cone. The charge attracts the charged jet containing the polymer solution and deposits the fibers onto a collector. In this way, a nonwoven fiber mat is produced and deposited on a substrate layer. The fibers can be deposited using a needle-based electrospinning system, or (preferably) a needle-free electrospinning system.

[0048] As is known in the art, the fiber diameter can be appropriately adjusted by changing electrospinning parameters, including voltage, flow rate, distance to the collector, and collector rotation speed. The thickness of the resulting fiber mat can be adjusted by increasing the fiber deposition time to collect a thicker mat; the longer the fiber spun, the higher the density of the deposited fiber.

[0049] The fiber network deposited in step b) of this method preferably has a thickness of 10 to 60 micrometers, more preferably 12 to 35 micrometers. PHA, particularly PHB, PHBV, or PHBH, preferably PHBV or PHBH pads, are preferably deposited to a thickness of 10 to 30 micrometers, more preferably 15 to 25 micrometers. Pads of silk fibroin (e.g., silk protein) are preferably deposited to a thickness of 10 to 30 micrometers, more preferably 15 to 20 micrometers. Pads of alcohol-soluble gluten, preferably zein, are preferably deposited to a thickness between 10 and 30 micrometers, more preferably between 10 and 15 micrometers. Pads of polysaccharides, preferably chitosan (including deacetylated chitosan), are preferably deposited to a thickness of 10 to 60 micrometers, more preferably 12 to 35 micrometers. Pads of phenolic polymers (e.g., lignin) are preferably deposited to a thickness between 10 and 60 micrometers, more preferably between 12 and 35 micrometers.

[0050] In a preferred embodiment, the electrospinning in step b) comprises electrospinning, preferably electroblowing. Electroblowing is a technique already known in the art. In this context, it has the advantage of increased production volume compared to conventional electrospinning. The fiber coating can be deposited at a higher rate, and more fibers can be deposited in a shorter time.

[0051] It is likely preferable to electrospin at least two materials simultaneously in step b). For example, it may be preferable to spin a mixture of filament and PHBV. It has been found that mixtures of filament and PHBV have proven to be optimal for reducing vapor permeability of the laminate.

[0052] In step c) of the method, a sealing layer is applied to the bonding layer. The sealing layer faces outward of the laminate material, meaning no additional layer is deposited on it. When a barrier laminate is applied to a packaged product, the sealing layer typically faces inward of the packaged product, i.e., the product-facing side of the packaged product.

[0053] During step c) or after the sealing layer is applied in step c), lamination step d) is performed. In the lamination step, the composite material obtained after step c) and typically includes a base layer, a connecting layer, and a sealing layer is laminated to form a barrier laminate material.

[0054] Lamination typically involves applying pressure and heat treatment. Lamination is preferably carried out in a hot laminator.

[0055] Pressure is preferably applied to the sealing layer. In this case, the sealing layer is typically located on top of the bonding layer. Pressure is preferably applied while the bonding layer has not completely cooled, preferably while it is still hot, ensuring it is still in the molten stage, to ensure adhesion to promote sealant adhesion. Pressure is suitably applied using a hot press. The pressure is suitably applied at a force between 1 and 10 tons, preferably between 3 and 5 tons. The application of pressure results in compression of the bonding layer. Preferably, pressure is applied to result in a bonding layer density of 1 to 50 g / m³. 2 Preferably 1 to 30 g / m 2 Preferably 5 to 15 g / m 2 The resulting thickness of the bonding layer is preferably 1 to 30 micrometers, more preferably 4 to 15 micrometers, and even more preferably 5 to 10 micrometers. Pressure is preferably applied under heating, and more preferably at a temperature of 140 to 160°C. Heat is typically applied by pressure plates within a hot press. Heat is preferably applied to the top and bottom of the laminated structure.

[0056] When the ink layer (4) is applied as part of the barrier laminate material, it is typically applied after step c), preferably to the substrate layer, as previously described. After the ink layer is applied, a protective layer (5) may be applied on the ink layer.

[0057] Therefore, the present invention further relates to barrier laminates manufactured by the method of the present invention.

[0058] The present invention also relates to a method for manufacturing a packaged product according to the invention, the method comprising the following steps: a) Provide the base layer (1).

[0059] b) Electrospinning is used to deposit fibers to form a fiber network. c) Apply a sealing layer (3) to the fiber network. d) Laminate the resulting composite material comprising a base layer, a fiber network, and a sealing layer. To form a barrier laminate material; e) Forming a packaged product containing barrier laminate material; f) The barrier laminate is sealed by connecting portions of the barrier laminate, wherein the corresponding sealing layers are sealed together; To form packaged products.

[0060] Preferably, the method further includes the step of filling the packaged product obtained in step e) with consumer goods.

[0061] Heat sealing is typically used for sealing in step f). The sealing conditions used are preferably in the temperature range of 120-200°C. Pressure is typically applied during the sealing step, preferably in the range of 2 to 4 bar. The sealing time is preferably 0.2 to 1 second.

[0062] use Surprisingly, a significant improvement in interlayer seal strength was found by using an electrospun bonding layer located between the base layer and the sealing layer in the barrier laminate. In this way, the sealing layer is reliably secured to the base layer, such as a paper layer, and does not peel off while containing the product during use, ensuring structural integrity and preventing the packaged product from breaking or failing.

[0063] In this regard, it is likely preferable that the water vapor transmission rate of the barrier laminate at 23°C and 50% RH is less than 20 g / m³. 2 / day, preferably less than 10 g / m 2 / day, or even better, below 5 g / m 2 / day. The maximum interlayer bond strength is preferably between 1 and 5 N, more preferably between 1.25 and 4 N.

[0064] Therefore, the present invention relates to the use of an electrospun bonding layer in a barrier laminate according to the invention, wherein the bonding layer is deposited between a base layer and a sealing layer to enhance interlayer adhesion. More specifically, the present invention relates to the use of an electrospun fiber network in a bonding layer of a flexible barrier laminate for enhancing interlayer adhesion, wherein the bonding layer is deposited between a base layer and a sealing layer.

[0065] The barrier laminate material comprises: • Basal layer (1) • A connecting layer containing an electrospun fiber network (2). • A non-fibrous sealing layer (3), which is adjacent to another layer (2) and faces the outside of the laminate, The thickness of the connecting layer (2) is 1 to 30 micrometers, preferably 5 to 10 micrometers. The thickness of the sealing layer (3) is preferably 5 to 65 micrometers, more preferably 20 to 60 micrometers, more preferably 20 to 50 micrometers, more preferably 30 to 45 micrometers, and most preferably 30 to 40 micrometers. Preferably, the base layer (1), the other layers (2) and the sealing layer (3) do not contain petroleum-derived materials.

[0066] Preferably, the base layer, the bonding layer, and the sealing layer do not contain any petroleum-derived materials. Preferably, the barrier laminate does not contain any petroleum-derived materials except for an optional protective layer (5), an optional ink primer, an optional ink layer, and an optional pre-coating layer between the base layer and the bonding layer. More preferably, the barrier laminate does not contain any petroleum-derived materials except for the optional protective layer (5), the optional ink primer, and the optional ink layer (4). Most preferably, the barrier laminate does not contain any petroleum-derived materials.

[0067] The invention will now be illustrated by way of the following non-limiting embodiments.

[0068] Example Example 1 The paper-based flexible packaging material according to the present invention is prepared using the following method.

[0069] Dissolve fibrous materials using the following parameters: Silk fibroin: Silk fibroin was dissolved in pure formic acid to obtain a membrane, which was then dissolved in formic acid at 8% w / v for 20 minutes at room temperature with mechanical stirring.

[0070] Zeatin: Zeatin was dissolved in 80% v / v ethanol and 20% deionized water for 1 hour at room temperature with mechanical stirring. The final concentration of zeatin in the resulting solution was 29% by weight.

[0071] PHBV: The polymer was dissolved overnight at 50°C with magnetic stirring in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP). In the morning, the solution was removed from the heat source and allowed to return to room temperature. A mixture of dimethyl sulfoxide (DMSO) and deionized water (1:1, v / v) was added under magnetic stirring for 20 minutes to obtain an 8:1:1 HFIP:DMSO:H₂O mixture and a final concentration of 7.5 wt% PHBV in the solvent. The solution was then ready for electrospinning.

[0072] Paper sheets with weights of 65, 78, and 90 gsm were placed in a collector measuring 210 mm × 297 mm. No vacuum was applied.

[0073] Four different electrospun fiber coatings were prepared. A solution chamber was loaded with dissolved polymer, and a voltage was applied to the spinneret, causing the polymer to deposit from the spinneret. The difference in charge caused the polymer solution to generate fibers, which were projected onto paper in a collector. As the fibers traveled to the collector, the solvent carrier of the polymer evaporated. When the target fiber pad thickness was reached, the coated paper was removed from the electrospinning apparatus. The target pad thickness was set to 20 µm before heat compression.

[0074] Electrospinning parameters: Fibers with a uniform diameter were obtained using electrospinning and deposited with a “random” (as opposed to “aligned”) fiber orientation. No spray droplets or other artifacts were produced. For this purpose, the polymer concentration, distance from the collector, voltage, spinneret speed / polymer flow rate, and collector speed are shown in Table 1.

[0075] Table 1: Optimization of electrospinning parameters for polymer / protein fibers to produce stable and uniform fibers in a needleless electrospinning system.

[0076] The fibers spun under the above conditions have the following characteristics, as shown in Table 2:

[0077] Table 2: Fiber properties of polymers / proteins spun onto paper.

[0078] The PHBH sealing layer (non-electrostatic spinning) is applied onto the barrier layer. Therefore, the base layer, sealing layer, and bonding layer are laminated together using a manual hydraulic press and the conditions shown in Table 3.

[0079] Table 3. Lamination conditions used to produce 3-layer laminated materials for further characterization.

[0080] The lamination of the barrier laminate produced barrier laminates with the specifications shown in Table 4.

[0081] Table 4. Thickness and weight of the bonding layer (fiber pad) and sealing layer in samples after lamination steps including compression.

[0082] = PHBV in CE A is not electrospun; it is a dispersion coated as a comparative example.

[0083] =Silk fibroin and PHBV are simultaneously applied to layers on top of each other through electrospinning. Water vapor transmission rate (WVTR) measurements recorded at 23°C and 50% RH were performed using a MOCON AQUATRAN 3WVTR analyzer in accordance with ASTM F3288-18, employing a Coulometric P2O5 sensor.

[0084] Interlayer adhesion measurements were performed under environmental conditions using Instron, in accordance with ASTM F88.

[0085] WVTR:

[0086] Table 5: WVTR of three-layer laminates at 23℃ and 50% RH All structures of the present invention showed acceptable results at 23°C and 50% RH. Example 3 showed results below 5 g / m³. 2The highest WVTR decreases at the optimal value per day.

[0087] Interlayer bond strength:

[0088] Table 6: Interlayer Bond Strength When compared with the case in which no bonding layer was applied by electrospinning (Comparative Example A), all Examples 1-3 showed improved interlayer adhesion.

[0089] Example 2 The following describes embodiments of the barrier laminate material according to the present invention.

[0090] This proposed structure is the final construct that will enter the flexible bag production line for product manufacturing. Here, before the product is filled, the construct undergoes another heating step to seal the outer edge of the bag. The sealing conditions used are preferably in the temperature range of 120-200°C, the pressure range of 2-4 bar, and the time range of 0.5-1 second. The sealing layer (3) in this construct forms a seal around and contains the product (6).

Claims

1. Flexible barrier laminate material, comprising: • Base layer (1), wherein the base layer is paper-based or paperboard-based, • Connecting layer (2), which comprises an electrospun fiber network, • A non-fibrous sealing layer (3), which is adjacent to the connecting layer (2) and faces the outside of the laminated material. The connecting layer (2) has a thickness of 1 to 30 micrometers, preferably 5 to 10 micrometers. The sealing layer (3) preferably has a thickness of 5 to 65 micrometers, more preferably 20 to 60 micrometers, more preferably 20 to 50 micrometers, more preferably 30 to 45 micrometers, and most preferably 30 to 40 micrometers. Preferably, the base layer (1), the connecting layer (2), and the sealing layer (3) do not contain petroleum-derived materials.

2. The barrier laminate material according to any one of the preceding claims, wherein the density of the connecting layer (2) is 5 to 50 g / m³. 2 Preferably 5 to 30 g / m 2 Preferably 10 to 20 g / m 2 .

3. The barrier laminate material according to any one of the preceding claims, wherein the base layer is paper or paperboard.

4. The barrier laminate material according to any one of the preceding claims, wherein the fibers in the fiber network of the connecting layer (2) have a diameter of 250 to 1000 nanometers, preferably 300 to 700 nanometers, and most preferably 300 to 500 nanometers.

5. The barrier laminate material according to any one of the preceding claims, wherein the connecting layer (2) is not petroleum-based and comprises one or more materials selected from polyhydroxyalkanoates, silk fibroin, alcohol-soluble glutenin, chitin polysaccharides, phenolic polymers and mixtures thereof.

6. The barrier laminate according to claim 5, wherein the connecting layer is composed of one or more materials selected from polyhydroxyalkanoates, silk fibroin, alcohol-soluble glutenin, chitin polysaccharides, phenolic polymers, and mixtures thereof.

7. The barrier laminate material according to claim 5 or 6, wherein the polyhydroxyalkanoate is selected from polyhydroxybutyrate (PHB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH), wherein the silk fibroin is silk protein, wherein the alcohol-soluble glutenin is zein, wherein the chitin polysaccharide is chitosan, and wherein the phenolic polymer is lignin.

8. The barrier laminate material according to any one of the preceding claims, wherein the pre-coating layer (3) is present between the base layer (1) and the connecting layer (2), preferably clay-based.

9. The barrier laminate material according to any one of the preceding claims, wherein the sealing layer (3) comprises polyhydroxyalkanoate (PHA), preferably polyhydroxybutyrate (PHB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) or poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH), which can heat-seal cellulose or polymers derived from biomass as well as protein and lipid membranes.

10. The barrier laminate material according to any one of claims 1 to 8, wherein the sealing layer (3) comprises a compound selected from polyhydroxybutyrate (PHB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH), heat-sealable cellulose, polysaccharide, starch, zein, lipid membrane, chitosan, and mixtures thereof.

11. The barrier laminate material according to any one of the preceding claims, wherein only one layer comprises electrospun fibers.

12. A method of providing a packaging laminate material according to any one of the preceding claims, the method comprising the steps of: a) Providing a base layer (1), wherein the base layer is paper-based or paperboard-based, b) Electrospinning is used to deposit fibers to form a fiber network. c) Apply a sealing layer (3) to the fiber network. d) A composite material comprising the base layer, the fiber network, and the sealing layer. To obtain the barrier laminate material according to any one of claims 1 to 11.

13. The method according to any one of claims 11 to 12, wherein at least two materials are electrospun simultaneously in step b).

14. A flexible packaging product for packaging consumer goods, the packaging product comprising a barrier laminate according to any one of claims 1 to 11, wherein the barrier laminate is sealed, wherein multiple pieces of the barrier laminate are sealed together, or one piece of the barrier laminate is folded and sealed together, wherein the respective sealing layers (3) face each other, preferably wherein the packaging product is a wrapping paper or a bag.

15. The use of electrospun fiber networks in the bonding layer of a flexible barrier laminate to enhance interlayer adhesion, wherein the bonding layer is deposited between a base layer and a sealing layer. The barrier laminate material comprises: • Base layer (1), wherein the base layer is paper-based or paperboard-based, • A connecting layer containing an electrospun fiber network (2). • A non-fibrous sealing layer (3), which is adjacent to the other layer (2) and faces the outside of the laminated material, The connecting layer (2) has a thickness of 1 to 30 micrometers, preferably 5 to 10 micrometers. The sealing layer (3) preferably has a thickness of 5 to 65 micrometers, more preferably 20 to 60 micrometers, more preferably 20 to 50 micrometers, more preferably 30 to 45 micrometers, and most preferably 30 to 40 micrometers. Preferably, the base layer (1), the other layers (2) and the sealing layer (3) do not contain petroleum-derived materials.

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