Layerable laminated packaging material, packaging container comprising the laminated packaging material, and method of manufacturing and recycling the material and container

Abstract

A delaminable laminated packaging material (10) for packaging liquid or semi-liquid food products, comprising as a layer sequence layers: an outermost protective material layer (16); a base layer (11) of paper or paperboard or other cellulosic based material; a peelable adhesive coating (12) comprising a water-dispersible polymer selected from the group consisting of ethylene-vinyl acetate copolymer, acrylic copolymer, styrene-butadiene copolymer and ethylene-vinyl alcohol copolymer, coated on the inner surface of the base layer (11); an intermediate adhesive layer (13); a gas barrier layer (14) adhered to the peelable adhesive coating (12) by the intermediate adhesive layer (13); and an innermost liquid-tight material layer (19); wherein the peelable adhesive coating (12) has an adhesive strength to the intermediate adhesive layer (13) of 10 to 30 N / m. Also described are packaging containers comprising the material and methods of manufacturing the material and containers.

Description

Technical Field

[0001] This invention relates to a delaminate packaging material (also referred to herein as a “packaging laminate”) comprising a gas barrier layer, particularly intended for use in liquid cardboard food packaging; a method for manufacturing the laminated packaging material; a packaging container comprising the laminated packaging material; a method for manufacturing the packaging container; and a method for recycling the laminated packaging material or container. Background Technology

[0002] Single-use packaging containers for liquid foods are typically manufactured from cardboard or rigid cardboard-based packaging laminates. One common type of such container is marketed under the trademark Tetra Brik Aseptic®, primarily for the aseptic packaging of liquid foods such as milk, juice, etc., which are marketed for long-term environmental storage. The packaging material in this known container is typically a laminate comprising a base layer or core layer of paper, cardboard, or other fibrous material, and an outer liquid-tight layer of thermoplastic. To ensure the container is airtight, particularly oxygen-tight, for purposes such as aseptic packaging and packaging milk or juice, the laminate in these containers typically includes at least one additional layer, most commonly aluminum (Al) foil.

[0003] On the inner side of the laminate, that is, the side intended to face the filled food contents of the container produced from the laminate, there is an innermost layer applied to the aluminum foil. This innermost layer may consist of one or more partial layers containing a heat-sealable thermoplastic polymer, such as an adhesive polymer and / or a polyolefin. Similarly, on the outer side of the base layer, there is an outermost heat-sealable polymer layer. As mentioned above, these layers are also liquid-tight.

[0004] Packaging containers are typically manufactured using modern high-speed packaging machines that form, fill, and seal packages from rolls or pre-made packaging material blanks. Packaging containers can thus be produced by reforming rolls of laminated packaging material into tubes; that is, by welding the innermost and outermost heat-sealable thermoplastic polymer layers together, joining the two longitudinal edges of the roll with an overlapping joint. The tube is filled with the intended liquid food, and is subsequently separated into individual packages by repeatedly performing lateral seals on the tube at predetermined intervals below the liquid level of the contents. The packages are separated from the tubes by cutting along the lateral seals, and the desired geometry, typically a cuboid shape, is achieved by folding along indentations prepared in the packaging material.

[0005] The main advantage of this continuous tube-forming, filling, and sealing packaging method concept is that the roll material can be continuously sterilized before tube formation, thus providing the possibility of aseptic packaging methods—a method in which both the liquid contents to be filled and the packaging material itself have reduced bacteria—and the filled packaging containers are produced under clean conditions, allowing the filled packages to be stored for extended periods even at ambient temperatures without the risk of microbial growth in the filled product. As mentioned above, another important advantage of the Tetra Brik® type packaging method is the possibility of continuous high-speed packaging, which has a significant impact on cost efficiency.

[0006] Packaging containers for sensitive liquid foods (such as milk or juice) can also be produced from sheet preforms or preforms of the laminated packaging material of the present invention. Packaging is produced from tubular preforms folded into flat packaging laminates by first constructing the preform into an open tubular capsule, wherein one open end of the capsule is closed by folding and heat-sealing an integral end plate. The thus closed capsule is filled with the relevant food (e.g., juice) through its open end, and subsequently closed by further folding and heat-sealing the corresponding integral end plate. An example of packaging containers produced from sheet and tubular preforms is the conventional so-called gable-top packaging. Packaging of this type with a molded top and / or a screw cap made of plastic also exists.

[0007] The aforementioned type of packaging laminate is typically produced through the following process: joining a roll of paper or paperboard to a pre-formed aluminum roll, which is bonded to the paper or paperboard roll with good adhesive strength by means of a thermoplastic adhesive layer (adhesive or binder) extruded between the rolls. These rolls are then coated with a thin layer of polyethylene, which is extruded onto both sides of the roll to form the outer liquid-tight plastic layer of the packaging laminate.

[0008] In this way, the packaging laminate can have good integrity and internal bonding or adhesive strength, which is a key prerequisite for producing mechanically robust and structurally stable packaging from the packaging laminate. Typically, the internal adhesive strength is at least 60 N / m, for example, at least 100 N / m, as discussed in the applicant's WO2017 / 089506.

[0009] In recent years, most food packaging container manufacturers have worked to meet the recyclability and sustainability standards promoted by national governments and other institutions, such as the European Union. These efforts aim to provide a future of carton-based packaging containers that are made more from renewable packaging materials and have a higher degree of recyclability, thereby reducing waste and pollution.

[0010] The aluminum foil layer in packaging laminates provides superior gas barrier properties compared to most other gas barrier materials. Conventional aluminum foil-based packaging laminates for aseptic packaging of liquid foods remain the most cost-effective packaging material available on the market today in terms of their performance level.

[0011] However, alternative barrier materials to aluminum foil are needed to further reduce the carbon footprint. The thickness of aluminum foil barrier layers used in liquid cardboard food packaging is typically 5 to 9 µm, with approximately 6 µm being the most common.

[0012] Any alternative material to foil-based materials should be cost-effective in terms of raw materials, have comparable food preservation performance, a reduced carbon footprint, and be relatively less complex in converting the material into finished packaging laminates.

[0013] Efforts to develop non-aluminum foil materials for cardboard packaging of liquid foods generally favor the development of pre-formed films or sheets with high barrier properties, or the combination of several separate barrier materials in multilayer films or sheets. Such films or sheets would replace aluminum foil barrier materials in conventional laminated packaging materials and would be further adaptable to conventional processes for laminating and manufacturing laminated packaging materials.

[0014] With increasing demands for sustainable materials, polymeric barrier materials derived from fossil sources have become less of a focus. Therefore, there remains a need to investigate thin barrier coating types—aqueous dispersion coatings and vapor-deposited coatings—that are negligible in recycling and pose very few problems in an economy based on material recycling and renewable (non-fossil) materials. These coatings are applied to substrates that do not typically provide significant barrier properties on their own. Dispersed polymer coatings are typically 1 to 2 µm thick, while vapor-deposited barrier coatings are as thin as less than 0.5 µm, for example, 10 to 100 nm, 15 to 80 nm, or 20 to 50 nm. Various such coatings have been developed over the years and incorporated into multilayer packaging material structures in pursuit of improved overall performance. Typical materials used for vapor-deposited barrier coatings are aluminum, alumina, and silicon oxide. Such gas barrier layers are discussed, for example, in the applicant's WO2013 / 041469 and WO2023 / 186448.

[0015] Recycling is also an important consideration. While good integrity and internal bond or adhesive strength of packaging laminates are both desirable and necessary for producing packaging with excellent mechanical strength and structural stability, these are also important when it comes to being able to recycle as much of the individual material in used packaging laminates as possible and to reuse these individual materials by recycling and reusing them in the purest possible form. For example, there has long been a need in the art to be able to recycle the fibrous component (its paper or paperboard portion) of packaging laminates, but due to the strong adhesive bond between the paper or paperboard layers and adjacent layers, it has proven difficult to separate these layers from each other without significant loss due to fibers adhering to the plastic after separation processing.

[0016] The applicant’s WO97 / 16312 discloses a layerable packaging material in which paper is adhered to adjacent layers by a water-soluble polymer such as starch or polyvinyl alcohol.

[0017] International Paper Company’s US5587204 discloses a recyclable paperboard composite material in which a paperboard substrate is coated with a highly hydrolyzed polyvinyl alcohol adhesive layer and a polyethylene polymer layer is bonded to the polyvinyl alcohol layer.

[0018] Sumimoto's JP2022073824 discloses a layerable packaging material comprising a paper portion and a laminated portion, and having a release layer on the surface of the paper. This release layer is composed of a butene glycol-vinyl alcohol copolymer or polyvinyl alcohol.

[0019] Dai Nippon Printing Co., Ltd.'s JP2000128144 discloses a layerable packaging material comprising a paper layer and a gas barrier layer, bonded by hot melt extrusion of an intermediate adhesive layer of LDPE or an adhesive resin layer of ethylene methyl methacrylate or other acrylic polymers.

[0020] Dai Nippon Printing Co., Ltd.'s JP2000203564 discloses a layerable packaging material comprising a paper layer and a gas barrier layer bonded together by two release layers (e.g., a polyester or polyurethane resin and an ethylene-vinyl acetate copolymer, respectively). The release layers are printed on the gas barrier layer and adhered to the paper layer by extrusion lamination of an adhesive resin layer.

[0021] Constantia Pirk GmbH & Co. KG's WO2021 / 164913 discloses a recyclable paper packaging laminate consisting of a paper layer and a barrier film attached to the paper layer by a hydrophilic adhesive layer, wherein the side of the paper layer facing the barrier film is uncoated.

[0022] There remains a need to develop a packaging laminate that, while exhibiting good integrity and cohesion between its layers, is easily delaminated manually, thus facilitating sorting for recycling and reuse without excessive material loss. On the other hand, premature delamination, such as in the filling machine, should be avoided. The fibrous components (paper or paperboard) and polymeric components (optionally including aluminum) of the packaging laminate should be reusable in the purest possible form. Summary of the Invention

[0023] In a first aspect, the present invention relates to a layerable laminated packaging material for packaging liquid or semi-liquid foods, comprising layers as a layer sequence: Outermost protective material layer; The bulk layer of paper, paperboard, or other cellulose-based materials; A peelable adhesive coating comprising a water-dispersible polymer selected from ethylene-vinyl acetate copolymer, acrylic copolymer, styrene-butadiene copolymer and ethylene-vinyl alcohol copolymer, coated on the inner surface of the substrate layer; Intermediate bonding layer; A gas barrier layer, which is bonded to the peelable adhesive coating via the intermediate adhesive layer; and Innermost liquid-tight material layer; The adhesive strength between the peelable adhesive coating and the intermediate adhesive layer is 10 to 30 N / m.

[0024] It should be understood that the adhesive strength within and between other layers of the laminated packaging material must be significantly higher, for example, above 100 N / m, to avoid delamination in incorrect layers. This includes the Z-axis strength of the base layer (i.e., the strength perpendicular to the plane of the base layer).

[0025] In a preferred embodiment, the gas barrier layer comprises aluminum foil, and the adhesive strength between the peelable adhesive coating and the intermediate adhesive layer is 15 to 30 N / m, preferably 15 to 25 N / m.

[0026] In an alternative preferred embodiment, the gas barrier layer comprises a barrier substrate and a barrier material layer, and the adhesive strength between the peelable adhesive coating and the intermediate adhesive layer is 15 to 20 N / m.

[0027] The laminated packaging material may include at least one laminated opening, wherein the opening in the base layer is covered by other layers of the laminated packaging material.

[0028] Preferably, the laminated packaging material provides oxygen barrier properties and water vapor barrier properties.

[0029] Preferably, the oxygen permeability of the laminated packaging material at 1 atm, 21% O2, 23°C, and 50% RH is 10 cm. 3 / (m 2 • 24h) or lower, for example, 1.0cm 3 / (m 2 • 24h) or lower, for example 0.5cm 3 / (m 2 • 24h) or less, more preferably 0.4cm 3 / (m 2 • 24h) or less, preferably 0.3cm 3 / (m 2 • 24h) or lower.

[0030] In a second aspect, the present invention relates to a method for manufacturing a delaminated packaging material for packaging liquid or semi-liquid foods, the delaminated packaging material optionally comprising, as described above, specified layers, and the method comprising the following steps: The peelable adhesive coating of the substrate layer is laminated to the gas barrier layer via the intermediate adhesive layer through melt extrusion; and Apply the outermost and innermost material layers.

[0031] In a third aspect of the invention, a packaging container comprising the above-described laminated packaging material is provided.

[0032] According to one embodiment, the packaging container is at least partially made of the laminated packaging material of the present invention, and according to a further embodiment, it is entirely made of the laminated packaging material.

[0033] In a fourth aspect of the invention, a method for manufacturing the packaging container is provided.

[0034] In a fifth aspect, a method for recycling the packaging material or container is provided, comprising repulping the laminated packaging material or a portion thereof.

[0035] All features described in connection with any aspect of the invention may be used in conjunction with any other aspect of the invention. Detailed Implementation

[0036] By using the term "long-term storage" in this invention, it is meant that the packaging container should be able to maintain the quality of the packaged food, i.e., its nutritional value, hygiene and safety, and taste, under environmental conditions for at least one or two months, for example, at least three months, preferably longer, for example, six months, for example, twelve months or longer.

[0037] The term "package integrity" generally refers to the tightness of packaging, that is, the resistance of the packaging container to leakage or breakage. This term includes the packaging's resistance to the invasion of microorganisms (such as bacteria, dirt, and other substances) that can spoil filled food and shorten its intended shelf life.

[0038] A major contribution to the integrity of packaging derived from laminated packaging materials lies in the strong internal adhesion between adjacent layers. Another contribution comes from the inherent resistance of the material layers to defects such as pinholes and cracks, and yet another from the strength of the sealing joints through which the materials are sealed together during the formation of the packaging container. Regarding the laminated packaging materials themselves, integrity performance therefore primarily concerns the adhesion of each laminate layer to its adjacent layers, and the quality of each material layer. Regarding the sealing of the packaging, integrity primarily concerns the quality of the sealing joints.

[0039] The term "liquid or semi-liquid food" generally refers to foods with a liquid content, including foods with high viscosity such as sauces, pastes, and soups, and optionally, foods that may contain food chunks. Dairy products and milk, soy, rice, grains and seed-containing beverages or liquids, fruit juices, syrups, non-carbonated beverages, energy drinks, sports drinks, coffee or tea beverages, coconut water, alcohol, soups, crushed tomatoes, sauces (such as pasta sauce), and olive oil are some examples of non-restricted foods under consideration.

[0040] The term "aseptic" in relation to packaging materials and containers refers to conditions under which microorganisms are eliminated, inactivated, or killed. Examples of microorganisms are bacteria and spores. Aseptic processes are typically used when products are aseptically packaged in containers. To maintain sterility throughout the shelf life of the packaging, packaging integrity performance is, of course, very important. For the long shelf life of filled foods, it may be even more important for the packaging to have barrier properties against gases and vapors (such as oxygen) to maintain its original flavor and nutritional value, such as its vitamin C content.

[0041] The term "bulk layer" generally refers to the thickest layer or the layer with the most material in a multilayer laminate, which contributes the most to the mechanical properties and dimensional stability of the laminate and the packaging containers folded from it, such as cardboard or hardboard.

[0042] The term “outer layers” is used herein to refer to the layers outside the peelable adhesive coating (including the substrate layer and the outermost layer, and generally at least partially peelable adhesive coating), while the term “inner layers” is used to refer to the layers inside the peelable adhesive coating (including the gas barrier layer and the innermost layer, and any remaining peelable adhesive coating).

[0043] The term "polyethylene" (PE) refers to a polymer containing approximately 90 to 100 mol% ethylene monomer.

[0044] The term "polypropylene" (PP) refers to a homopolymer or copolymer of PP, such as a polymer containing about 90 to 100 mol% propylene monomer.

[0045] Low-density polyethylene (LDPE) has a density of 917 to 930 kg / m³. 3 It is typically polymerized solely from ethylene monomers and has a branched polymer chain structure (on about 2% of the carbon atoms), resulting in a less compact molecular packing and lower crystallinity. Consequently, its density is lower than that of linear polyethylene, such as linear low-density polyethylene (LLDPE) or high-density polyethylene (HDPE).

[0046] The term "linear low-density polyethylene" (or "LLDPE") encompasses all linear low-density polyethylenes, including "ZN-LLDPE" polymerized via Ziegler-Natta type catalysts and "m-LLDPE" polymerized via so-called "constrained geometry" or "single-site" catalysts (e.g., metallocene catalysts), as well as other linear low-density polyethylenes. ZN-LLDPE and m-LLDPE are typically produced by copolymerizing ethylene monomers with C4-C8, more preferably C6-C8 α-olefin alkylene monomers, in the presence of a metallocene catalyst. Comonomer contents of 1 to 10 mol%, and preferably 8 to 10 mol%, are typical. LLDPEs have a significant number of short branches. Due to the lack of long-chain branching, they differ structurally from conventional LDPEs. LLDPE polymers typically have a narrower molecular weight distribution than conventional LDPEs (especially for m-LLDPEs) and significantly different rheological properties.

[0047] High-density polyethylene (HDPE) has a density of 930 to 970 kg / m³. 3 Typical comonomer content is as high as 2 mol%. Branch-free processes are ensured by selecting appropriate catalysts (e.g., Zn catalysts) and reaction conditions.

[0048] The term "ethylene vinyl acetate copolymer" (also known as "EVA", "EVAc" and "PEVA") refers to a copolymer of ethylene and vinyl acetate.

[0049] The term "dispersion coating" (also known as "liquid-film coating") herein refers to a coating technique in which an aqueous or substantially aqueous dispersion, suspension, emulsion, or solution of a polymer is applied to the surface of a substrate layer (typically in the form of a continuous roll), which, upon drying, forms a solid, substantially non-porous film. The term "dispersion" therefore also encompasses any solution, suspension, emulsion, or solution or mixture thereof capable of providing such a coating upon drying. Aqueous dispersions may contain suspended or emulsified fine polymer particles and can therefore be latexes. The term "water-dispersible" includes polymers capable of forming aqueous dispersions and, preferably, coatings that are redispersible in water.

[0050] Adhesive strength (also referred to herein as “peeling strength”) was measured according to ASTM D903-98 at 180° using a 15 mm wide strip and a speed of 50 mm / min. The inner layer was peeled while the outer layer was held in place.

[0051] The term "delaminable" includes laminated packaging materials that can be manually separated into inner and outer layers (as defined above).

[0052] "Repulping" refers to the mechanical treatment of materials in water to provide a pulp containing fibrous components and water, as well as an optional coarse residue portion of non-fibrous materials.

[0053] "Fiber yield" refers to the weight percentage (wt%) of the matrix layer recovered as fiber content in the pulp.

[0054] matrix layer The paper or paperboard matrix layer used in this invention typically has a thickness of about 100 µm to about 600 µm and a g / m² of about 100 to 500 g / m³. 2 (gsm)(preferably about 200 to 300 g / m) 2The surface weight of the substrate can be any type of paper or cardboard with suitable packaging quality. In the laminated packaging material of this invention, the purpose of the matrix layer is to provide dimensional stability, stiffness, and rigidity to the packaging container, for example, for use in wet and humid conditions and / or for storing liquids and wet (heavy) foods. For larger packages, a cardboard thickness of 400 to 500 µm is preferred. For partial packages of 150 to 350 mL in size, a flexural stiffness of 80 mN is preferred.

[0055] In use, the inner surface of the substrate layer is coated with a peelable adhesive coating. Preferably, this surface is fibrous and uncoated without any prior coating (e.g., clay coating). The outer surface may be clay-coated, which facilitates the delamination of the outermost layer.

[0056] Peelable adhesive coating The peelable adhesive coating comprises a water-dispersible polymer selected from ethylene-vinyl acetate copolymers, acrylic copolymers, styrene-butadiene copolymers, and ethylene-vinyl alcohol copolymers. In a preferred embodiment, the peelable adhesive coating comprises a water-dispersible polymer selected from ethylene-vinyl acetate copolymers and ethylene-vinyl alcohol copolymers.

[0057] The most preferred material is an ethylene-vinyl acetate copolymer. Preferably, the peelable adhesive coating comprises a majority of the EVAc copolymer, and more preferably, substantially comprises the EVAc copolymer. In a preferred embodiment, the peelable adhesive coating consists of an EVAc copolymer.

[0058] Preferably, the ethylene comonomer content of the EVAc copolymer is 35 to 65 mol, more preferably 45 to 65 mol.

[0059] Suitable acrylic copolymers include ethylene-acrylic copolymers such as ethylene (meth)acrylic acid copolymers and ethylene (meth)acrylic acid ester copolymers, as well as styrene-acrylic acid copolymers.

[0060] When using ethylene-vinyl alcohol copolymer (EVOH), it is preferable that it contains only a small amount of mol% ethylene monomer, such as the dispersible coating Exceval™ EVOH from Kuraray, such as Exceval HR3010™.

[0061] Preferably, the peelable adhesive coating is at a concentration of 0.5 to 3 g / m 2 The amount present is preferably 0.5 to 2.5 g / m³. 2 For example, 1g / m 2 or 2g / m 2 (Dry weight). Below 0.5 or 1 g / m³ 2 At this point, the substrate surface may not be adequately covered. (Higher than 3g / m³)2 At that time, coverage did not improve significantly, and costs increased.

[0062] Preferably, the water-dispersible polymer is applied in a dispersed coating. It is suitably applied in an aqueous form, such as an aqueous emulsion or latex. Suitably, the solid content is 35 to 65 wt%, preferably 40 to 60 wt%, for example, 55 wt%. An emulsifier such as polyvinyl alcohol (PVOH) may be present to stabilize the emulsion.

[0063] The preferred grade of EVAc is Aquence BG 9031 from Henkel, Germany.

[0064] Gas barrier layer In a first preferred embodiment, the gas barrier layer is aluminum foil.

[0065] In a second preferred embodiment, the gas barrier layer is a multilayer gas barrier layer comprising a barrier substrate (e.g., a barrier substrate film) and a barrier material layer.

[0066] The barrier substrate preferably comprises a polymer, more preferably a polyolefin such as polypropylene or polyethylene. Typical polyolefin films can be made primarily of PE or PP, such as HDPE. This is advantageous for recycling because laminated packaging materials typically contain additional PE or PP layers, and also to ensure compatibility with adjacent PE or PP layers, an adhesive polymer bonding layer (as described below) is not required. EVOH (e.g., containing 30 to 40 mol% ethylene) can also be used.

[0067] Other possible polymers are polyesters (e.g., polyethylene terephthalate, PET) and polyamides (PA). However, these may require the use of a bonding layer of adhesive polymer to ensure compatibility with adjacent layers containing polyolefins, as described below.

[0068] The polymer barrier substrate film can be non-oriented, but is preferably uniaxially oriented (MO) or biaxially oriented (BO). Preferred barrier substrate film materials include MO polyethylene (MOPE), BO polyethylene (BOPE), and BO polypropylene (BOPP).

[0069] Appropriately, the thickness of the barrier substrate is 10 to 30 µm, more preferably 15 to 25 µm, for example 20 µm.

[0070] The barrier substrate film can be a multilayer film and may include a core layer and a skin layer.

[0071] Suitable, the barrier substrate film is provided with a relatively much thinner skin layer of a vinyl alcohol-based polymer (e.g., EVOH or PVOH) or polyamide, which may also be oriented. The skin layer is preferably applied together with the core layer by co-extrusion, but can alternatively be dispersed and coated onto the core layer. Such films are called "high surface energy" (HSE) films because the skin layer allows the barrier material layers to adhere well. The skin layer typically also provides some oxygen barrier properties.

[0072] The barrier material layer is preferably formed by vapor deposition, dispersion coating, or liquid film coating.

[0073] Thin vapor-deposited layers are typically only nanometer-thick, i.e., on the order of nanometers, for example, 1 to 500 nm (50 to 5000 Å), preferably 1 to 200 nm, more preferably 1 to 100 nm, and most preferably 1 to 50 nm.

[0074] In a preferred embodiment, the barrier material layer comprises a metal, metal oxide, silicon oxide, amorphous carbon, or diamond-like carbon (DLC), and is preferably vapor-deposited. Such barrier material layers typically provide barrier properties against both oxygen and water vapor. Preferred such barrier materials are aluminum, alumina, and silicon oxide. The oxides may be non-stoichiometric.

[0075] Vapor-deposited metal layers (also referred to herein as “metallised layers”) are preferred. Generally, oxide coatings are more brittle than metallised coatings and are less suitable for incorporation into packaging materials via lamination. Metallised layers typically do possess mechanical properties suitable for lamination, but generally offer lower oxygen barrier properties. A suitable optical density is at least 1.5, preferably at least 1.8.

[0076] The vapor-deposited barrier material layer is preferably applied by physical vapor deposition (PVD) or chemical vapor deposition (CVD), such as by plasma-enhanced chemical vapor deposition (PECVD). PVD is commonly used for metallization layers, but is also suitable for metal oxide and silicon oxide layers. Typically, aluminum metallization layers inherently have a thin surface portion composed of aluminum oxide due to the nature of the metallization coating process used. Silicon oxide and DLC coatings can be applied, for example, by a PECVD process. Preferably, a hydrocarbon gas, such as acetylene or methane, is used as the process gas in the plasma to produce the DLC coating.

[0077] Preferred embodiments of the gas barrier layer are aluminum-metallized BOPP (met-BOPP) and aluminum-metallized oriented polyethylene (metOPE). A preferred gas barrier layer material is Metallyte 16MM883 from Jindal Films.

[0078] When a gas barrier layer comprises a barrier substrate and a barrier material layer, it can be arranged in the laminated packaging material with the barrier material layer facing the substrate layer (CFL, coating facing the laminate) or the barrier layer facing the innermost layer (CFI, coating facing inward). CFL is preferred, especially when the barrier substrate comprises a polyolefin, to ensure compatibility with the innermost layer.

[0079] In a third preferred embodiment, the gas barrier layer comprises a gas barrier polymer layer, such as PA or EVOH. This can be in the form of a pre-formed film or a layer co-extruded with a suitable adhesive polymer linker layer, as described below, preferably on both sides. It may be a five-layer co-extruded inner layer structure, such as an intermediate adhesive layer / linker layer / EVOH / linker layer / innermost layer.

[0080] Intermediate adhesive layer The gas barrier layer is bonded to the substrate layer via an intermediate adhesive layer (preferably a thermoplastic polymer) that is a peelable adhesive coating. According to one embodiment, the intermediate adhesive layer comprises a polyolefin, such as PE or PP. The same thermoplastic polyolefin-based materials listed below for the outermost and innermost layers, particularly polyethylene such as LDPE, are also suitable for the intermediate adhesive layer. In a preferred embodiment, the intermediate adhesive layer is composed of LDPE.

[0081] Intermediate adhesive layers can typically be 10 to 25 µm or 12 to 25 g / m 2 The total amount applied is preferably 15 to 23 g / m³. 2 For example, 15 to 20 g / m 2 .

[0082] Other layers of laminated packaging materials The outermost and innermost thermoplastic polymer layers typically do not provide significant (recognizable) barrier properties against migrating gas molecules or small molecules. Their purpose is to provide direct barrier against water or other liquids penetrating into the cellulose matrix material and other sensitive layers, and to act as a sterile barrier, maintaining packaging integrity to protect the contents inside the package, and preferably being heat-sealable.

[0083] The outermost layer may be a protective polymer layer or coating to prevent dirt and moisture from reaching the interior of the laminate, such as a polymer layer, for example a thermoplastic polymer layer. Preferably, this layer is liquid-tight.

[0084] The thermoplastic suitable for both the outermost and innermost layers is a polyolefin, such as a homopolymer or copolymer of polyethylene and polypropylene, preferably polyethylene, and more preferably polyethylene from the group consisting of LDPE, LLDPE, m-LLDPE, and blends or copolymers thereof. According to one embodiment, the outermost layer is LDPE, while the innermost layer is a blend of m-LLDPE and LDPE (also referred to herein as “mPE”) to obtain optimal lamination and heat-sealing properties. In a preferred embodiment, the innermost layer comprises 50 to 90 wt% mLLDPE and 10 to 50 wt% LDPE, for example, 70 wt% mLLDPE and 30 wt% LDPE. However, lower proportions of mLLDPE, such as 10 to 50 wt% (e.g., 30 wt%) of this blend, are also contemplated. A suitable LDPE grade is 19N730 from Ineos. A suitable blend grade of mLLDPE and LDPE is Elite 5800G from Dow.

[0085] In an alternative implementation, both the outermost and innermost layers comprise PP. This is suitable when heat resistance is required, such as if the packaging container will undergo heat treatment.

[0086] The outermost layer is preferably transparent. This allows any printed decorative patterns applied to the outer surface of the substrate layer to be seen. This is useful for informing observers of, for example, the contents of the packaging, the packaging brand, and other relevant consumer information in retail facilities and / or food stores.

[0087] The outermost layer is typically 5 to 20 µm (e.g., 10 to 15 µm) or 5 to 15 g / m 2 (e.g., 8 to 15 g / m) 2 The thickness of the innermost layer can be 10 to 50 µm or 10 to 50 g / m. 2 (e.g., 15 to 45 g / m) 2 The range is applied. The innermost layer may include two or more sublayers with different compositions.

[0088] The outermost and / or innermost layers are preferably applied by extrusion coating. However, the innermost layer may be applied in the form of a pre-formed oriented or non-oriented film.

[0089] In an alternative preferred embodiment, the outermost layer can be applied in a lower amount (e.g., 6 to 8 g / m²). 2 (Dry weight) disperse coating to provide a protective rather than a strongly liquid-tight coating. This improves recyclability by reducing the polymer content of the outer layer.

[0090] As described above, the bonding layer can exist within the laminated packaging material, particularly between the intermediate adhesive layer and the gas barrier layer and / or between the gas barrier layer and the innermost layer. Such bonding layers can comprise adhesive thermoplastic polymers, such as modified polyolefins, mostly based on LDPE or LLDPE copolymers or graft copolymers with functionalized monomer units (such as carboxyl or glycidyl functional groups, such as (meth)acrylic acid monomers or maleic anhydride (MAH) monomers, i.e., EAA or ethylene-methacrylic acid copolymers (EMAA)), ethylene-(meth)acrylic acid glycidyl ester copolymers (EG(M)A), or MAH-grafted polyethylene (MAH-g-PE). Other examples of such modified polymers or adhesive polymers are so-called ionomers or ionomer polymers. A preferred EEA bonding layer material is Primacor 3540 from the SK Group of South Korea.

[0091] Specifically, the innermost layer can be bonded to the gas barrier layer via a connecting layer (e.g., ethylene-acrylic acid copolymer (EAA)), which is preferably co-extruded with the innermost layer. This is particularly suitable for the first and third embodiments of the gas barrier layer (aluminum foil and gas barrier polymer). However, as mentioned above, it can also be applied to the second embodiment (a multilayer gas barrier layer with a barrier substrate and a barrier material layer), wherein the material facing the innermost layer is incompatible with the innermost layer. For example, a mLLDPE adhesive layer can be used to bond the BOPP barrier substrate to the innermost layer, as discussed in WO2023 / 186448.

[0092] The bonding layer is typically 3 to 8 g / m 2 Apply the thickness.

[0093] Methods for manufacturing laminated packaging materials A method for manufacturing a layerable laminated packaging material includes laminating a peelable adhesive coating of a base layer to a gas barrier layer via an intermediate adhesive layer, and applying an outermost and innermost material layer.

[0094] Optionally, the method further includes an initial step of coating the inner surface of the substrate layer with an aqueous dispersion or solution containing an ethylene-vinyl acetate copolymer to form a dry, peelable adhesive coating. A drying step may be performed.

[0095] The method may further include the steps of printing and / or indenting the substrate layer after coating the inner surface of the substrate layer with a peelable adhesive coating and before laminating the peelable adhesive coating onto the gas barrier layer.

[0096] The intermediate adhesive layer appropriately bonds the base layer to the gas barrier layer through melt extrusion lamination, that is, between the roll of material coated with the base layer and the roll of material coated with the gas barrier layer, and simultaneously presses these three layers together while advancing them through the lamination roll gap, thereby providing a laminated structure.

[0097] The lamination temperature (i.e., the extrusion melt temperature of the molten curtain) can be adjusted to achieve the desired level of adhesion between the peelable adhesive coating and the intermediate adhesive layer. Typically, this temperature will be 10-15°C lower than the typical lamination temperature for the intermediate adhesive layer at the corresponding speed on the lamination line (e.g., 311°C for LDPE), thereby reducing adhesive strength. Preferably, particularly when the intermediate adhesive layer is LDPE, the lamination temperature is 310°C or lower. Preferably, it is at least 290°C.

[0098] In a preferred embodiment, the substrate layer and the gas barrier layer are laminated, followed by the application of the innermost layer and then the outermost layer (or less preferably, the outermost layer is applied first, followed by the innermost layer). The former sequence is called "LID," where L = substrate layer laminated to gas barrier layer; I = innermost layer applied to gas barrier layer; D (decorative) = outermost layer applied to substrate layer. The latter, less preferred alternative is called "LDI." Alternatively, the substrate layer may initially be bonded to the outermost layer before being laminated to the gas barrier layer. This sequence is called "DLI."

[0099] Packaging containers and methods for manufacturing packaging containers Packaging containers can be made from rolls of delaminated packaging material or from blanks of delaminated packaging material, as discussed in more detail below; various possible shapes of containers are shown.

[0100] According to a further embodiment, the packaging container formed from the laminated packaging material can be partially sealed, filled with liquid or semi-liquid food, and subsequently sealed by sealing the packaging material to itself, optionally in combination with a plastic opening or the top portion of the packaging. Induction heat sealing is preferred for laminated packaging materials containing an aluminum foil barrier layer or other suitable materials. Ultrasonic heat sealing is another possible alternative.

[0101] Layering Delaminated packaging materials are preferably designed for manual delamination by the consumer at the peelable adhesive coating to separate the outer layer (including the base layer) from the inner layer (including the intermediate adhesive layer and gas barrier layer). Typically, delamination is performed on the packaging container after use and before it is ready for recycling. The inner layer can be sent directly to the polymer / polyolefin recycling stream, for example, via a polymer recycling bin.

[0102] Recycling of laminated packaging materials or packaging containers In a further embodiment, the present invention relates to a method for recycling the as-described delaminated packaging material or packaging container, comprising repulping the laminated packaging material or a portion thereof. Repulping packaging containers typically requires more time to achieve a given fiber yield compared to repulping flat laminated packaging material.

[0103] Repulping can be performed only on the outer layers from the peelable adhesive coating outwards (including the base layer but excluding the gas barrier layer), after delamination, or on the entire laminated packaging material, including the inner layers, without initial delamination. Repulping is preferably performed only on the outer layers. Repulping can be performed without dry cutting (also known as shredding or fragmentation) of the laminated packaging material. This is particularly advantageous for undelaminated materials (e.g., packaging containers) to reduce the possibility that fragmentation of the inner layers could leave the material retained in the fibrous pulp; for the same reason, reducing fragmentation of the outermost layer is also advantageous. Appropriately, 15 wt% of dry packaging containers are mixed with water.

[0104] Alternatively, the laminated packaging material or its outer layer can be first dry-cut into small pieces or strips.

[0105] The material to be repulped is appropriately fed into a conventional pulper and mechanically treated by agitation in hot water at 40-600°C. This releases and redisperses the peelable adhesive coating, thus separating the fibers from the inner layer (if present) without fiber adhesion and associated with the plastic surface. The outermost layer will also separate from the fibers, although the separation may not be entirely complete due to the absence of the peelable adhesive coating. The fibers and water form a pulp. The pulp can then be physically separated from the inner layer (if present) and the outermost "coarse" portion.

[0106] In a preferred embodiment, the fiber yield after 30 minutes of repulping is at least 97 wt%, more preferably at least 99 wt%. These fiber yields can be achieved after 20 minutes, or after 15 or 10 minutes.

[0107] Examples and descriptions of preferred implementation schemes In the following description, preferred embodiments of the invention will be illustrated with reference to the accompanying drawings, wherein: Figure 1a A cross-section of a layerable laminated packaging material according to a first embodiment of the present invention is schematically shown, comprising an aluminum foil gas barrier layer.

[0108] Figure 1b A cross-section of a layerable laminated packaging material according to a second embodiment of the present invention is schematically shown, comprising a metallized multilayer gas barrier layer.

[0109] Figures 2a-2c The production process is illustrated schematically. Figure 1a Methods for laminating packaging materials.

[0110] Figures 3a-3d A typical example of a liquid cardboard packaging container produced from the laminated packaging material of Figure 1 is shown.

[0111] Figure 4 This demonstrates the principle of how such liquid cardboard packaging containers are manufactured from laminated packaging materials in a continuous, roll-fed forming, filling, and sealing process.

[0112] Figure 5 The chart shows how the available fiber yield changes over time using a repulping example of the material.

[0113] Figure 6 This schematically illustrates consumers'... Figure 1a The laminated packaging materials are layered.

[0114] Example An example of a layerable laminated packaging material having an outermost / substrate / peelable adhesive coating / intermediate adhesive layer / gas barrier layer / connecting layer / innermost layer structure was prepared.

[0115] This example relates to a first embodiment. It includes an Al foil gas barrier layer and has the following structure: 12gsm LDPE / paperboard / 2gsm EVAc (coated onto paperboard) / 20gsm LDPE / 6.3µm Al foil / 6gsm EAA / 19gsm blend of 70wt% mL LDPE and 30wt% LDPE The cardboard matrix layer is CLC / C Duplex BK from Billerud, Sweden, with a bending stiffness of 80mN and a basis weight of 200g / m³. 2 Only the outer surface is coated with clay, while the inner surface is an uncoated fibrous surface.

[0116] The EVAc in the peelable adhesive coating is Aquence BG9031 (premixed aqueous emulsion, 55wt% solids) from Henkel, Germany.

[0117] The LDPE in the outermost and middle adhesive layers is 19N730 from Ineos.

[0118] The innermost mPE blend is from Dow's Elite 5800G.

[0119] The EAA in the connection layer is Primacor 3540 from SK Group in South Korea.

[0120] The following is how laminated packaging materials are formed.

[0121] The EVAc emulsion is dispersed and coated onto the non-clay coated fibrous inner surface of the cardboard, dried in a hot air convection dryer, and wound onto a reel.

[0122] Unwind the EVAc-coated cardboard roll, print and provide embossing lines on its outer surface for subsequent folding to align with the printed decoration, and then rewind it onto the reel.

[0123] LID lamination is then performed. Therefore, the EVAc-coated paperboard and Al foil are laminated with LDPE at a melt curtain temperature of approximately 303°C and a speed of 100 m / min. The connecting layer and the innermost layer are co-extruded onto the inner surface of the Al foil, and then the outermost layer is extruded onto the outer surface of the paperboard.

[0124] An alternative predictive example relates to a second embodiment. It includes a multilayer gas barrier layer (barrier material layer / barrier substrate film); and has the following structure: 12gsm LDPE / paperboard / 2gsm EVAc (coated on paperboard) / 20gsm LDPE / Metallyte 16MM883 / 6gsm LLDPE / 19gsm blend of 70wt% mL LDPE and 30wt% LDPE The gas barrier layer of Metallyte 16MM883 from Jindal Films is a BOPP film with a metallized coating (16µm thickness, 2.8 optical density).

[0125] The other materials and the methods for forming laminated packaging materials are the same as in the example.

[0126] The gas barrier layer is oriented CFL, meaning the metallized coating faces the cardboard substrate layer and the BOPP film faces the innermost layer.

[0127] Laminated packaging materials of the example (TBA) and its variants were tested using different amounts of peelable adhesive coating (0.5–2 gsm) and different intermediate adhesive layer lamination temperatures. Adhesion strength was tested. The results are shown in Tables 1–2. Table 1 Table 2 - Results of Selected Examples "Low adhesion" means delamination on the intended layer, but there is a risk of premature delamination.

[0128] "Good adhesion" means that the desired layer can be delaminated; it is easy to delaminate manually.

[0129] "High adhesion" means that the delamination is partially or completely in the wrong layer (usually within the matrix layer).

[0130] Therefore, good delamination results were obtained using a 1gsm peelable adhesive coating. For the predictive example of the second embodiment, a lower level of adhesion is expected.

[0131] The adhesive strength increases with increasing lamination temperature.

[0132] In variants of the Al foil (TBA) material, which uses ethylene-vinyl alcohol copolymer Exceval™ HR3010 as an example of a peelable adhesive coating, the application of the intermediate adhesive layer at different lamination temperatures was tested, and the results are shown in Table 3: Table 3 Therefore, low-temperature lamination with an intermediate adhesive layer at 297°C provided the best delamination results; the results at 303°C were acceptable, but high-temperature lamination at 311°C did not provide acceptable delamination due to excessive adhesive strength.

[0133] No fibers were observed on the inner layer when the laminated packaging material was manually separated.

[0134] Repulping tests were conducted on laminated and delaminated packaging materials in the Kadant Auto Lab Pulper, a pulper that simulates commercial batch pulpers used for used beverage cardboard. A 9% dry-weight aqueous solution was used at 43°C. The material was cut into 5x5cm pieces before repulping. The pulp was passed through a bottom plate with 10mm diameter holes, retaining coarse residue.

[0135] Compare the following items: Example of fully laminated Al foil (TBA) packaging material (“300 Full PM”) Example of a layered Al foil (TBA) packaging material, outer layer discarded, inner layer discarded (“300 No inside”). Referencing Tetra Brick Aseptic Laminated Packaging Material, without EVAc Peelable Adhesive Coating (“TBA / jl 80mN”).

[0136] The laminate is re-pulped for 30 minutes. The inner layer (if present) separates from the outer layer, forming the polymer-aluminum moiety. EVAc is redispersed in water. The outermost LDPE layer separates from the matrix layer.

[0137] To determine fiber yield, 25 sheets of 5x5cm laminated packaging material were processed and sampled periodically until a fiber yield close to 100% was achieved. For example, for 300 Full PM, samples were taken at 10, 15, and 20 minutes after hand washing of the material mixture, and the fiber content was calculated based on the weight of known polymer-aluminum standard sheets (while taking into account small fibers lost from the recycled fiber stream in the wash liquid, which were captured as screen residue in the Somerville screen).

[0138] The results are shown in Figure 5 And in Table 4 below. Table 4 For fully laminated packaging materials, the fiber yield was tested to reach a threshold of 97% after 15 minutes. It is expected that the fiber yield of the packaging containers will also reach the 97% threshold after 20 minutes.

[0139] Fully laminated packaging material repulped faster than the reference laminated packaging material (20 minutes). The delaminated outer layer repulped faster than the fully laminated packaging material (10 minutes). The polymer-aluminum portion (inner layer) was found to contain less than 1 wt% fiber, and the outermost LDPE layer contained less than 2 wt% fiber. No increase in breakage of the polymer-aluminum portion was observed compared to the initial sheet.

[0140] In addition, regarding the attached diagram: exist Figure 1a The image shows a cross-section of a laminated packaging material 10 for liquid cardboard packaging, wherein the laminated packaging material includes a cardboard base layer 11 with a bending strength of 80 mN and a basis weight of approximately 200 g / m². 2 The base layer 11 has a clay coating on its outer surface and an uncoated fibrous inner surface. The laminated packaging material 10 further includes a polyolefin outer liquid-tight and heat-sealable layer 16 applied to the outside of the base layer 11, facing the exterior of the packaging container produced from the laminated packaging material. Layer 16 is transparent to show a printed decorative pattern 17 applied to the outside of the cardboard base layer.

[0141] The outer 16 layer of polyolefin is conventional heat-sealable low-density polyethylene (LDPE), but may also include other similar polymers, including LLDPE. It has a density of approximately 12 g / m³. 2 The amount applied.

[0142] The substrate layer 11 is coated with a dispersed peelable adhesive coating 12 of ethylene-vinyl acetate copolymer on its fibrous inner surface. The peelable adhesive coating 12 has a coating density of approximately 2 g / m². 2 Apply the amount of (dry weight).

[0143] The peelable adhesive coating 12 is bonded to the barrier layer 14 of a 6.3µm thick aluminum foil via an intermediate adhesive layer 13 of LDPE. The intermediate adhesive layer has a strength of approximately 20g / m². 2 The amount applied.

[0144] Barrier layer 14 is bonded to the innermost layer 19 on its inner side by a co-extruded connecting layer 18 of EAA, with EAA at approximately 6 g / m 2 The amount applied.

[0145] The innermost liquid-tight and heat-sealable layer 19 is arranged facing the interior of the packaging container made of laminated packaging material, meaning layer 19 will be in direct contact with the packaged product. This innermost layer 19 will form a robust lateral heat seal for the liquid packaging container made of laminated packaging material, which comprises a blend of LDPE and m-LLDPE. It has a density of approximately 19 g / m³. 2 The amount applied.

[0146] Figure 1b Laminated packaging materials correspond to Figure 1a In addition to its gas barrier layer 14 and connecting layer 18. Figure 1b The gas barrier layer 14 is a multilayer gas barrier layer comprising a biaxially oriented polypropylene barrier substrate film 14a, which is vacuum-deposited with an aluminum barrier material layer 14b. The barrier substrate film 14a faces the innermost layer (CFL). The connecting layer 18 is mLLDPE.

[0147] Figure 2a It shows the manufacturing process. Figure 1a As part of the process of laminating packaging material 10, a base layer 11 is dispersedly coated with a peelable adhesive coating 12. This step can be performed at the site of a paperboard supplier. The roll 11 of paper or paperboard is obtained from... Figure 2a The hopper reel on the left is guided in the direction of the arrow to the dispersion coating station at position 20, where a conventional roller coating device 21 is used to coat one side of the roll 11 with a thin layer of an aqueous emulsion of ethylene-vinyl acetate copolymer, the emulsion having a solid content of 55%.

[0148] Due to the high moisture content of the dispersion composition, a significant amount of moisture on the coated substrate roll 11 needs to be thermally dried and evaporated to form a continuous layer. Drying is carried out using a hot air convection dryer 22, which allows moisture to evaporate and be removed from the substrate surface via air convection. The substrate temperature is maintained at a constant 60 to 80°C as it passes through the dryer. Alternatively, particularly at high speeds, drying can be partially aided by a combination of infrared (IR) lamp radiant heat and hot air convection drying.

[0149] Optionally, the coated substrate roll 11 can be fed into a conversion line for printing and / or creasing (these steps are not shown).

[0150] Figure 2b A portion of the lamination process for manufacturing the laminated packaging material 10 of FIG1 is shown, wherein a coated substrate layer 11 is laminated onto a gas barrier layer 14.

[0151] The peelable adhesive coating 12 of the substrate layer 11 is laminated to the gas barrier layer 14 via an intermediate adhesive layer 13 of LDPE. The intermediate adhesive layer 13 is formed by molten extrusion of a thin polymer melt curtain 26 from a die 25 between rolls containing the peelable adhesive coating 12 and the gas barrier layer 14, thereby laminating the substrate layer 11 and the gas barrier layer 14 to each other. Simultaneously, all three layers pass through a roll gap 23 between a pressure roller and a cooling roller, cooling the laminated material 24 to properly cure the extruded LDPE intermediate adhesive layer 13. The lamination temperature is approximately 300°C.

[0152] The resulting pre-laminated plate 24 is fed into a roll for intermediate storage or directly used for subsequent lamination operations.

[0153] exist Figure 2c In this process, the resulting pre-laminated sheet 24 of the substrate layer 11 and gas barrier layer 14 is fed into a further lamination step, or directly from... Figure 2b The lamination operation, or from the joint and unwinding of the intermediate storage reel.

[0154] The uncoated inner surface of the gas barrier layer 14 is joined at the cooling roll gap 27 to the molten polymer curtain 27a of the connecting layer 18 and the innermost layer 19, which are co-extruded from the extruder feed block and the die 27b.

[0155] Subsequently, the pre-laminated plate 24, now coated with the connecting layer 18 and the innermost layer 19 on its inner side, passes through the second extruder feed block and die 28b and the lamination roll gap 28, where the molten polymer curtain 28a of the outermost layer 16 of the laminated packaging material 10 is bonded and coated onto the other side of the pre-laminated plate, namely the unlaminated side of the base layer 11. This forms the final laminated packaging material 29; 10, which is ultimately wound onto a storage reel, not shown. This step sequence is LID. These two co-extrusion steps at the lamination roll gaps 27 and 28 can alternatively be performed in the reverse order (LDI) as two consecutive steps, and can be performed in a manner similar to... Figure 2b The lamination roller gap 23 shown is used before or after laminating two rolls of material (DIL or IDL).

[0156] The substrate layer 11 may be provided with pores (not shown), which are overlapped and laminated with other layers of the laminated packaging material 10 to form pre-laminated pores.

[0157] Figure 3aAn embodiment of a packaging container 30a produced from the laminated packaging material 10 according to the invention is shown. This packaging container is particularly suitable for beverages, sauces, soups, etc. Typically, the volume of such packaging is about 100 to 1000 mL. It can be of any construction, but is preferably brick-shaped, with longitudinal and transverse seals 31a and 32a, and an opening device 33 optionally located above a pre-laminated hole (not shown). In another embodiment (not shown), the packaging container can be formed as a wedge. To obtain this "wedge shape," only the bottom portion of the packaging is folded, such that the transverse heat seal of the bottom is hidden under triangular flaps, which are folded and sealed at the bottom of the packaging. The transverse seal of the top portion remains unfolded. In this way, the partially folded packaging container is still easy to handle and is dimensionally stable enough to be placed on a grocery store shelf or any flat surface.

[0158] Figure 3b An alternative example of a packaging container 30b produced from an alternative laminated packaging material 10 according to the invention is shown. This alternative laminated packaging material is thinner by having a thinner paper matrix layer, and therefore its dimensional stability is insufficient to form a parallelepiped or wedge-shaped packaging container, and it will not fold into shape after the lateral seal 32b. The packaging container will remain a pillow-shaped capsule container and will be dispensed and sold in this form.

[0159] Figure 3c A roof-type package 30c is shown, which is formed by folding laminated packaging material 10 from pre-cut sheets or blanks. Optionally, opening devices and / or pre-laminated holes (not shown) may be present. Flat-top packages can also be formed from similar material blanks.

[0160] Figure 3d A bottle-shaped package 30d is shown, which is a combination of a sleeve 34 and a top 35 formed from a pre-cut blank of the laminated packaging material 10 of the present invention, the top being formed by injection molding of plastic and joining it with an opening device such as a screw cap. This type of packaging is exemplified by products under the trade name Tetra Pak. ® (Tetra Top ® Sales. These specific packages are formed by attaching a molded top 35 having an opening device that attaches in the closed position to a tube sleeve 34 of laminated packaging material, sterilizing the bottle-top capsule thus formed, filling it with food, and finally folding it to form the bottom of the package and sealing it.

[0161] Figure 4The principle described in the introduction of this application is illustrated, in which a roll of packaging material is formed into a tube 41, and an overlapping joint 43 is formed by overlapping the longitudinal edges 42, 42' of the roll and heat-sealing them together. The tube is continuously filled 44 with liquid food to be filled, and the tube is divided into individual filled packages by repeatedly performing double transverse seals 45 at predetermined intervals below the liquid level of the filled contents in the tube. The packages 46 are separated by cutting between the double transverse seals (top seal and bottom seal) and finally shaped into the desired geometry by folding along indentation lines prepared in the material.

[0162] After use, the materials in the packaging can be easily separated into their individual components using existing technology and equipment, and recycled and reused in a very pure form.

[0163] The inner (polymer-based) and outer (fiber-based) layers of the laminated packaging material of the packaging container can be separated by the consumer after use, or when the packaging container is discarded and sorted for recycling at an appropriate time. Appropriately, the outer layer goes to UBC (Used Beverage Cardboard) for recycling, while the inner layer is placed in the polymer recycling bin by the consumer. Figure 6 This shows what happens when peeling manually. Figure 1a The separation of the laminated packaging material between the peelable adhesive coating layer 12 and the intermediate adhesive layer 13. The outward peeling force applied by the consumer's thumb is schematically shown at point 60 of the separation layer.

[0164] However, the entire laminated packaging material can be recycled. The fiber content of the packaging container (the paper or cardboard in the matrix layer of the laminated packaging material) is particularly recyclable and can be reused in an extremely clean form using a pulper as described in the example.

[0165] In the preferred embodiment, various advantages are achieved: Compared to conventional laminated packaging materials that do not include a peelable adhesive coating, using full-length laminated packaging materials enables faster repulping because the coating is released to expose the fibrous inner surface of the base material.

[0166] This is further improved when the laminated packaging material is separated into layers (i.e., separated into layers of a complete laminate) before recycling, and then only the outer layer is repulped, as the fibrous inner surface of the matrix material is initially exposed. The inner layer goes directly into the polymer / polyolefin recycling stream, saving time, energy, and water in the repulping step.

[0167] Good purity of the recycled materials was achieved, with the purity of the stratified fiber portion being >90%, the polymer portion being >99% (coated barrier substrate embodiment), and the polymer-aluminum portion also being >98% pure (Al foil gas barrier layer embodiment). The outermost layer also had a purity of >98wt%.

[0168] During the repulping of the complete laminated packaging material, breakage of the inner and outermost layers is avoided. Small fragments are undesirable as they could remain in the fiber pulp.

[0169] When a polyethylene barrier substrate is used with its orientation toward the innermost layer (CFL), the use of adhesive polymer bonding layers in laminated packaging materials can be avoided, and the barrier substrate can be recycled along with the other PE layers (intermediate adhesive layer, innermost layer) in the delaminated inner layer portion.

[0170] Packaging containers can be formed using a standard filling machine.

[0171] Finally, it should be noted that the present invention is not limited to the embodiments shown and described above, but can be varied within the scope of the claims.

[0172] List of reference numerals in the attached diagram: 10. Layerable and laminated packaging materials 11 Matrix layer 12 Peelable adhesive coating 13 Intermediate Adhesive Layer 14 barrier layers 14a barrier substrate film 14b barrier material layer 16 Outermost layer 18 connection layers 19 Innermost layer 20 Coating Stations 21 Coating apparatus 22 Hot Air Dryer 23 roll gap 24-Laminated Material 25 mold heads 26 Molten Polymer Curtain 27 roll gap 27a Molten Polymer Curtain 27b mold block 28 roll gap 28a Molten Polymer Curtain 28b mold head 29-layer packaging material 30a Packaging Container 30b capsule-shaped container 30c gable packaging 30d bottle packaging 31a Longitudinal seal 31b Longitudinal seal 32a Lateral Seal 32b transverse seal 33 Opening equipment 34 sleeve 35 Top 41 tubes 42,42' roll edge 43 Overlapping Joint 44 tube filling 45 Double Lateral Seal 46 packs 60 peel strength

Claims

1. A layerable laminated packaging material (10) for packaging liquid or semi-liquid foods, comprising layers as a layer sequence: Outermost protective material layer (16); A base layer of paper or paperboard or other cellulose-based material (11); A peelable adhesive coating (12) comprising a water-dispersible polymer selected from ethylene-vinyl acetate copolymer, acrylic copolymer, styrene-butadiene copolymer and ethylene-vinyl alcohol copolymer is coated on the inner surface of the substrate layer (11); Intermediate adhesive layer (13); A gas barrier layer (14), which is bonded to the peelable adhesive coating (12) via the intermediate adhesive layer (13); and Innermost liquid-tight material layer (19); in, The bond strength between the peelable adhesive coating (12) and the intermediate adhesive layer (13) is 10 to 30 N / m.

2. The layerable laminated packaging material (10) according to claim 1, wherein the water-dispersible polymer is an ethylene-vinyl acetate copolymer.

3. The delaminated packaging material (10) according to claim 1 or claim 2, wherein the peelable adhesive coating (12) is applied at a concentration of 0.5 to 3 g / m³. 2 The quantity exists.

4. The layerable laminated packaging material (10) according to any one of claims 1 to 3, wherein the intermediate adhesive layer (13) comprises a polyolefin, preferably polyethylene, more preferably LDPE.

5. The layerable laminated packaging material (10) according to any one of the preceding claims, wherein the gas barrier layer (14) comprises aluminum foil, and the adhesive strength of the peelable adhesive coating (12) to the intermediate adhesive layer (13) is preferably 15 to 30 N / m, more preferably 15 to 25 N / m.

6. The delaminated packaging material (10) according to any one of claims 1 to 3, wherein the gas barrier layer (14) comprises a barrier substrate and a barrier material layer, and the bond strength between the peelable adhesive coating (12) and the intermediate adhesive layer (13) is preferably 15 to 20 N / m.

7. The layerable laminated packaging material (10) according to claim 6, wherein the barrier material layer comprises a metal, a metal oxide, or silicon oxide.

8. The layerable laminated packaging material (10) according to claim 6 or claim 7, wherein the barrier substrate comprises an oriented polyolefin, preferably oriented polyethylene or oriented polypropylene, and optionally has a skin layer of ethylene alcohol polymer or polyamide.

9. The layerable laminated packaging material (10) according to any one of claims 6 to 8, wherein the gas barrier layer (14) is arranged such that the barrier material layer faces the substrate layer (11) and the barrier substrate faces the innermost layer.

10. The layerable laminated packaging material (10) according to any one of claims 1 to 4, wherein the gas barrier layer (14) comprises a gas barrier polymer layer selected from polyamide and ethylene-vinyl alcohol copolymer.

11. A method of manufacturing a delaminated packaging material (10) optionally according to any one of the preceding claims, the delaminated packaging material (10) being used for packaging liquid or semi-liquid food products, the delaminated packaging material (10) comprising layers as a layer sequence: Outermost protective material layer (16); A base layer of paper or paperboard or other cellulose-based material (11); A peelable adhesive coating (12) comprising a water-dispersible polymer selected from ethylene-vinyl acetate copolymer, acrylic copolymer, styrene-butadiene copolymer and ethylene-vinyl alcohol copolymer is coated on the inner surface of the substrate layer (11); Intermediate adhesive layer (13); Gas barrier layer (14); and Innermost liquid-tight material layer (19); The method includes the following steps: The peelable adhesive coating (12) of the substrate layer (11) is laminated to the gas barrier layer (14) via the intermediate adhesive layer (13) by melt extrusion; and Apply the outermost material layer (16) and the innermost material layer (19).

12. The method of claim 11, further comprising an initial step of coating the inner surface of the substrate layer (11) with an aqueous dispersion or solution containing the water-dispersible polymer to form a dried peelable adhesive coating (12).

13. The method according to claim 11 or claim 12, further comprising the steps of printing and / or indenting the substrate layer (11) after the inner surface of the substrate layer (11) has the peelable adhesive coating (12) and before laminating the peelable adhesive coating (12) onto the gas barrier layer (14).

14. The method according to any one of claims 11 to 13, wherein laminating the peelable adhesive coating (12) of the substrate layer (11) onto the gas barrier layer (14) is performed at an extrusion melt temperature of 310°C or lower, and wherein preferably the intermediate adhesive layer (13) is LDPE.

15. A packaging container (30a; 30b; 30c; 30d) comprising the delaminated packaging material (10) as defined in any one of claims 1 to 10.

16. A method for manufacturing a packaging container (30a; 30b; 30c; 30d) according to claim 15 from a roll of the delaminated packaging material (10) or from a blank of the delaminated packaging material (10).

17. A method for recycling the packaging container (30a; 30b; 30c; 30d) according to claim 15 or the laminated packaging material (10) according to any one of claims 1 to 10, comprising repulping the laminated packaging material (10) or a portion thereof.

18. The method of claim 17, wherein after the inner layer is delaminated at the peelable adhesive coating (12), the outer layer of the delaminated laminated packaging material (10) is re-slurryed.

Images