Packaging material with enhanced barrier action.

Description

1 / 27 Packaging material with enhanced barrier action. FIELD OF THE INVENTION

[0001] The present invention relates to a packaging material that can extend the minimum shelf life of the products packaged therein, particularly food, by ensuring that the variation in barrier properties on the surface of the packaging material is particularly low. The invention also relates to a method for producing such packaging material. TECHNICAL BACKGROUND AND STATE OF THE ART

[0002] For ecological reasons, there has been a great demand in recent years for the replacement of plastic film-based packaging materials with other materials. Paper has emerged as a significant alternative. Although paper is superior to plastic films in terms of ecological aspects and, for example, printability, there are important technical properties where comparable performance can only be achieved through additional measures.

[0003] One example of such properties is barrier action. Many packaging material applications require barrier properties, for example, against water vapor, oxygen, water, oils and fats. In paper, these properties are usually achieved through additional coatings, although there is still potential for improvement.

[0004] Strict quality requirements must be met, especially for food packaging materials. Packaged food products undergo shelf-life testing, in which the food products are examined for changes in taste or color, aging processes such as oxidation, and other properties under different climatic and storage conditions. These tests determine the minimum shelf life guaranteed by the manufacturer. Petition 870250087372, dated 09 / 26 / 2025, page 10 / 59 2 / 27 Extending the minimum shelf life is desirable simply because it can reduce food waste.

[0005] Among other things, the shelf life of food is determined by the permeability of the packaging material to oxygen or water vapor, so attempts are made to create the strongest possible barrier in the paper. This usually requires a large amount of material or coating materials, which makes recycling these packaging materials difficult.

[0006] There is therefore a need in the industry to further improve the barrier properties of packaging materials so that the products packaged in them have a longer shelf life. SUMMARY OF THE INVENTION

[0007] The objective of the invention is to provide a packaging material that can extend the shelf life of the product packaged in it without having to accept significant disadvantages in the ecological aspects of the packaging material.

[0008] This objective is achieved by a packaging material according to claim 1, a package according to claim 1 and a method for producing a packaging material according to claim 33. Further advantageous developments are specified in the dependent claims.

[0009] The objective is achieved by a packaging material comprising a base paper and a first and a second coating, wherein the base paper has a basis weight of at least 30 g / m2 and at most 90 g / m2, and wherein the first coating is located between the base paper and the second coating, forms a barrier against oxygen penetration and comprises a polymer with hydroxyl groups, wherein the hydroxyl groups of the polymer are at least partially cross-linked, and wherein the second coating is applied directly Petition 870250087372, dated 09 / 26 / 2025, page 11 / 59 3 / 27 closely related to the first coating, forms a barrier against water vapor penetration and comprises a polymer and a wax, wherein the packaging material, on the side where the first and second coatings are applied, has a Bekk smoothness of at least 800 s and at most 20,000 s, and wherein the average water vapor permeability M of the packaging material is at least 2.0 g / (m2χ 24 h) and at most 100.0 g / (m2 χ 24 h), and the following formula applies to the standard deviation s of the water vapor permeability s <M· (0,15 + 0,1 · e-0-003^2), em que a permeabilidade média ao vapor de água M e o desvio padrão s da permeabilidade ao vapor de água em g / (m2 χ 24 h) devem ser inseridos na fórmula e são determinados por medição de acordo com a norma ISO 2528:2017 a uma umidade relativa de 85% e uma temperatura de 23°C em 10 posições selecionadas aleatoriamente e não sobrepostas do material de embalagem na mesma direção através do material de embalagem.

[0010] One way to increase the shelf life of packaged products is to reduce the average water vapor permeability of the packaging material to the lowest possible value. However, this requires more lining material and therefore generates more effort and higher costs.

[0011] A key finding of the inventors is that the minimum shelf life of a packaged product does not depend solely on the average water vapor permeability. In fact, the maximum expected water vapor permeability of the packaging material must be taken into account when determining the minimum shelf life, since the manufacturer of the packaged product must guarantee the minimum shelf life. According to the inventors' findings, the minimum shelf life can be extended by reducing the variation in water vapor permeability. This reduces the maximum expected water vapor permeability, even with the Petition 870250087372, dated 09 / 26 / 2025, page 12 / 59 4 / 27 same average permeability to water vapor, and the minimum shelf life of the packaged product can be extended.

[0012] An essential aspect of the present invention is, therefore, the reduction of the standard deviation of the water vapor permeability of the packaging material. For this reason, upper limits for this standard deviation are provided above and in the subsequent description as a function of the average water vapor permeability. A lower limit for the standard deviation of water vapor permeability is not defined in the patent claims; instead, in the sense of the present invention, it is fundamentally desired that it be as small as possible. However, there are technical limitations to the lower limit, which, to the inventors' knowledge, may be around 0.1 g / (m2χ 24 h). However, exploring the technically attainable lower limit of the standard deviation of water vapor permeability is not the objective of the present invention. Therefore, for the definition of the present invention, only the upper limit of the standard deviation of water vapor permeability is decisive.

[0013] The average water vapor permeability M of the packaging material of the invention may – depending on the intended use – be between 2.0 g / (m2 χ 24 h) and 100.0 g / (m2 χ 24 h), where the preferred ranges will be defined in more detail below. Within this range, at least for the higher water vapor permeabilities, the coefficient of variation, i.e., the quotient between the standard deviation and the average value of the water vapor permeability, should not exceed 15%.

[0014] However, for lower values ​​of the average water vapor permeability M, higher coefficients of variation, up to 25%, are acceptable within the scope of the invention. The formula determined purely empirically for the upper limit of the standard deviation ensures a smooth transition between these ranges. Petition 870250087372, dated 09 / 26 / 2025, page 13 / 59 5 / 27

[0015] It should be noted that the variation in water vapor permeability is significantly greater for conventional packaging materials based on coated base papers. For example, the standard deviation of water vapor permeability for a commercially available packaging paper with a water vapor and grease barrier (BAG WG BA 4762 barrel from Mitsubishi HiTec Paper Europe), which is used as a comparative example for the embodiments described in more detail below, is 10 g / (m2χ 24 h) with an average water vapor permeability M of 35 g / (m2 χ 24 h), whereas for the packaging material according to the invention according to the formula given above, the standard deviation in this average water vapor permeability is below a value of 5.3 g / (m2 χ 24 h).

[0016] To achieve low variation in water vapor permeability, the inventors recognized that a combination of measures in the composition of the packaging material and its manufacturing process is necessary, especially if the ecological aspects of the packaging material are to be taken into consideration.

[0017] The packaging material according to the invention comprises a base paper. The basis weight of the base paper must be low to limit the material used. However, base papers with low basis weight are less homogeneous than base papers with high basis weight, which is why the variation in barrier properties is greater for packaging materials comprising such base papers.

[0018] To achieve the desired effect, the base paper has a first and a second coating. The first coating is located between the base paper and the second coating. It creates a barrier against oxygen penetration and comprises a polymer that has hydroxyl groups. A first fundamental aspect to achieve Petition 870250087372, dated 09 / 26 / 2025, page 14 / 59 6 / 27 A low variation in water vapor permeability is due to the fact that the hydroxyl groups of the polymer are cross-linked. This creates a surface particularly favorable to the application of the second coating, which forms the barrier against water vapor penetration.

[0019] To obtain low variation in water vapor permeability, the base paper already provided with the first coating can be calendered according to the process described below. This smooths the surface and prepares it even better for the application of the second coating, which represents another essential aspect of the invention. It was surprisingly found that calendering after the application of the first coating and before the application of the second coating significantly contributes to reducing the variation in water vapor permeability.

[0020] In packaging material, calendering between the application of the first and second coatings results in a high level of smoothness, which is still detectable after the application of the second coating or, if present, the application of additional coatings. In the final product, this manifests as a Bekk smoothness of at least 800 s on the side where the first and second coatings are applied, which is significantly higher than in comparative examples from the prior art, where the Bekk smoothness of the coated side is only 400 s or less. The second coating is applied over the first, and, according to the inventors' findings, it is important that the second coating be applied directly over the first to take advantage of the surface optimized by the first coating and calendering. The second coating forms a barrier against water vapor penetration and is composed of a polymer and a wax.Through these measures and the composition of the second coating, which represents another essential aspect of the invention, the coating is particularly homogeneous and the variation in vapor permeability is minimized. Petition 870250087372, dated 09 / 26 / 2025, page 15 / 59 7 / 27 water can be significantly reduced. The lower variance in water vapor permeability results in a lower expected maximum water vapor permeability, so the packaged product manufacturer can assume a more favorable value when determining shelf life and can ensure a longer shelf life.

[0021] The packaging material according to the invention comprises a base paper, wherein the base paper has a basis weight of at least 30 g / m2 and at most 90 g / m2, preferably at least 35 g / m2 and at most 80 g / m2, and particularly preferably at least 40 g / m2 and at most 70 g / m2. The basis weight can be measured according to ISO 536:2019. A base paper with a higher basis weight is more advantageous in terms of homogeneity, barrier action and mechanical properties, but the material consumption is also higher, therefore the basis weight should be as low as possible. With the method according to the invention, it is possible to obtain a low variation in water vapor permeability, even with a particularly low basis weight, which results in a significant advantage of the packaging material according to the invention. The ranges according to the invention and preferred ranges allow the best possible combination of material consumption and low variation in water vapor permeability.

[0022] The base paper preferably comprises cellulose fibers, with the cellulose fibers being particularly preferably formed from cellulose fibers or regenerated cellulose fibers or a mixture thereof. The cellulose fibers are preferably obtained from softwood, in particular red spruce, pine or fir; from hardwood, in particular beech, birch or eucalyptus; from hemp, flax, jute, ramie, kenaf, kapok, coconut, abaca, sisal, bamboo, cotton or esparto grass; or from residual paper pulp, or are a mixture of cellulose fibers from several of these sources. Petition 870250087372, dated 09 / 26 / 2025, page 16 / 59 8 / 27

[0023] Regenerated cellulose fibers are preferably fibrillable regenerated cellulose fibers. Such fibers are sold, for example, under the name Lyocell.

[0024] Preferably, the percentage of cellulose fibers is at least 55% and at most 100% based on the mass of the base paper, particularly preferably at least 60% and at most 95%.

[0025] The base paper preferably comprises a filler. The filler is particularly preferably selected from the group consisting of kaolin, talc, calcium carbonate, magnesium carbonate, magnesium oxide, magnesium hydroxide, aluminum oxide, aluminum hydroxide, titanium dioxide or a mixture thereof. More preferably, the base paper comprises kaolin, as this can contribute to the barrier action of the base paper.

[0026] Preferably, the freight agent percentage is at least 5% and at most 45%, more preferably at least 10% and at most 40%, based on the mass of the base paper.

[0027] Preferably, the base paper is calendered. This allows for a simple increase in smoothness and improves the uniformity of the first and second coatings. Calendering of the base paper should be distinguished from calendering after the application of the first coating.

[0028] Preferably, the base paper on the side where the first and second coatings are applied, but before the first and second coatings are applied, has a Bekk smoothness, measured according to ISO 5627:1995, of at least 600 and at most 10,000 s, more preferably at least 800 and at most 6,000 s. In addition to polymer crosslinking in the first coating and calendering between the application of the first and second coatings, the smoothness of the base paper can help reduce variation. Petition 870250087372, dated 09 / 26 / 2025, page 17 / 59 9 / 27 of water vapor permeability, which is why this is an additional feature of the base paper that can further enhance the inventive effect.

[0029] Preferably, the base paper on the side where the first and second coatings are applied, but before the application of the first and second coatings, has a contact angle with water, measured with a 4 μl drop after 0.1 s, of at least 30° and at most 70°, particularly preferably at least 40° and at most 65°. This range of contact angles is particularly favorable for the application of the first coating.

[0030] Preferably, the base paper on the side where the first and second coatings are applied, but before the first and second coatings are applied, has a specific water absorption capacity of at least 0.1 and at most 0.7, particularly preferably at least 0.2 and at most 0.5. The specific water absorption capacity is the quotient between the water absorption capacity, determined by the Cobb60 value, according to ISO 535:2014, in g / m2, and the basis weight, measured according to ISO 536:2019, in g / m2. It expresses the water absorption capacity independently of the basis weight.

[0031] The first coating creates a barrier against oxygen penetration and, for this purpose, comprises a polymer with hydroxyl groups, some of which are cross-linked. Preferably, the polymer is selected from the group consisting of starch, starch derivatives, polyvinyl alcohol, modified polyvinyl alcohol, carbohydrates, modified carbohydrates, or mixtures thereof. The cross-linking of the polymer's hydroxyl groups can be achieved by various cross-linking agents, for example, by glyoxal or ammonium zirconium carbonate, so that the first coating preferably comprises glyoxal or ammonium zirconium carbonate. Petition 870250087372, dated 09 / 26 / 2025, page 18 / 59 10 / 27

[0032] Preferably, the first coating is applied over the entire surface, or at least over 90% or more of the surface on one side of the base paper.

[0033] Preferably, the amount of polymer in the first coating, based on the area to which the polymer is actually applied, is at least 0.2 g / m2 and at most 5.0 g / m2, particularly preferably at least 0.5 g / m2 and at most 4.0 g / m2.

[0034] In a preferred embodiment, at least one additional coating comprising a barrier material and a filler may be applied between the base paper and the first coating, the barrier material of this additional coating being selected from the group consisting of starch, acrylic acid polymers, modified acrylic acid polymers, styrene-acrylate copolymers and mixtures thereof. The filler of this additional coating is preferably an inorganic pigment, and more preferably alumina (AbO3> or talc). This additional coating prevents the first layer from penetrating deeply into the base paper structure. This allows for the creation of a good barrier against oxygen penetration with less material in the first layer.

[0035] Particularly preferably, the additional coating is applied over the entire surface or at least over 90% or more of the surface on one side of the base paper and, more preferably, is applied directly onto the base paper.

[0036] Particularly preferably, the mass of the additional coating, based on the area to which it is actually applied, is at least 0.2 g / m2 and at most 4.0 g / m2, particularly preferably at least 0.5 g / m2 and at most 2.5 g / m2.

[0037] The second coating creates a barrier against the penetration of water vapor and comprises a polymer and a wax. Preferably, the polymer of the second coating is selected from Petition 870250087372, dated 09 / 26 / 2025, p. 19 / 59 11 / 27 group consisting of styrene-butadiene copolymers, carboxylated styrene-butadiene copolymers, styrene-acrylate copolymers, acrylic copolymers, acrylic polymers, ethylene-acrylic acid copolymers, vinyl acetate-acrylic acid copolymers, acrylic acid-maleic acid copolymers, methacrylic acid polymers, methyl methacrylate and polyurethane polymers, and mixtures thereof. Preferably, the wax of the second coating is selected from the group consisting of vegetable waxes, animal waxes, mineral oil-based waxes, polymer waxes, semi-synthetic waxes and synthetic waxes, and mixtures thereof. The wax is, particularly preferably, a paraffin wax.

[0038] The second coating is applied directly over the first coating and is preferably applied over the entire surface or at least over 90% or more of the surface on one side of the base paper.

[0039] Preferably, the combined mass of polymer and wax in the second coating, based on the area in which the polymer and wax are actually applied, is at least 1.0 g / m2 and at most 10.0 g / m2, particularly preferably at least 2.0 g / m2 and at most 8.0 g / m2.

[0040] The packaging material may have additional coatings applied to the second coating. Such coatings may preferably serve to protect the first and second coatings, improve printability, make the packaging material heat-sealable or create additional barriers, for example, against the penetration of water, oils or fats.

[0041] Between the application of the first and second coatings, the base paper coated with the first coating is calendered according to the process explained below to increase its smoothness and Petition 870250087372, dated 09 / 26 / 2025, page 20 / 59 12 / 27 Prepare the surface as thoroughly as possible for the application of the second coating. This high level of smoothness is maintained even after the application of the second coating or, if present, additional coatings.

[0042] The packaging material according to the invention therefore has, on the side where the first, second and optionally other coatings are applied, a Bekk smoothness of at least 800 s and at most 20,000 s, preferably of at least 1,000 s and at most 10,000 s, and particularly preferably of at least 1,500 s and at most 8,000 s. The Bekk smoothness can be measured in accordance with ISO 5627:1995.

[0043] The barrier properties of the packaging material can also be characterized by Gurley air permeability. Preferably, the Gurley air permeability, measured according to ISO 5636-5:2013, is at least 20,000 s⁻¹ in at least one direction through the packaging material, and particularly preferably at least 35,000 s⁻¹. With correspondingly good barrier properties, the air permeability may be so low, i.e., the value of the Gurley air permeability may be so high, that it cannot be measured or cannot be measured within a reasonable period of time. In this case, the packaging material may be considered airtight according to this nomenclature, which represents a particularly preferred embodiment of the packaging material according to the invention.

[0044] To characterize the variance of the barrier properties of the packaging material according to the invention, the average water vapor permeability and the standard deviation of the water vapor permeability are used. The average water vapor permeability M and the standard deviation s of the water vapor permeability of the packaging material are determined by measurement according to the standard. Petition 870250087372, dated 09 / 26 / 2025, page 21 / 59 13 / 27 ISO 2528:2017 at a relative humidity of 85% and a temperature of 23 °C in 10 randomly selected and non-overlapping positions on the packaging material in the same direction through the packaging material.

[0045] The packaging material according to the invention has an average water vapor permeability M of at least 2.0 g / (m2 x 24 h) and at most 100.0 g / (m2 χ 24 h), preferably at least 5.0 g / (m2 χ 24 h) and at most 50.0 g / (m2 χ 24 h) and particularly preferably at least 5.0 g / (m2 χ 24 h) and at most 40.0 g / (m2 χ 24 h).

[0046] In a preferred embodiment, the formula for the average water vapor permeability M and the standard deviation s of the water vapor permeability s <m· (0,12 + 0,1 ·e-0,003^2),

[0047] wherein the average water vapor permeability M and the standard deviation s of water vapor permeability in g / (m2 χ 24 h) must be entered into the formula and are determined by measurement in accordance with ISO 2528:2017 at a relative humidity of 85% and a temperature of 23°C at 10 randomly selected and non-overlapping positions of the packaging material in the same direction through the packaging material. In this preferred embodiment, the coefficient of variation of water vapor permeability is at most 12% for higher water vapor permeabilities and at most 22% for lower water vapor permeabilities.

[0048] In a particularly preferred embodiment, the formula applies to the average water vapor permeability M and the standard deviation s of the water vapor permeability s <m· (0,10 + 0,1 · e-θ,θθ3·^2),

[0049] where the average water vapor permeability M and the desPetição 870250087372, dated 09 / 26 / 2025, page 22 / 59 14 / 27 standard values ​​of water vapor permeability in g / (m2χ 24 h) must be entered into the formula and are determined by measurement in accordance with ISO 2528:2017 at a relative humidity of 85% and a temperature of 23°C at 10 randomly selected and non-overlapping positions of the packaging material in the same direction through the packaging material. In this particularly preferred embodiment, the coefficient of variation of water vapor permeability is at most 10% at higher water vapor permeabilities and at most 20% at lower water vapor permeabilities.

[0050] The packaging material according to the invention preferably has an oxygen permeability in at least one direction through the packaging material, measured in accordance with DIN 53380-3:1998-07 at a relative humidity of 0% and a temperature of 23 °C, of ​​at least 1 ml / (m2xdx100 kPa) and at most 500 ml / (m2xdx100 kPa), particularly preferably of at least 5 ml / (m2xdx100 kPa) and at most 400 ml / (m2xdx100 kPa).

[0051] The packaging material according to the invention may already have favorable barrier properties without additional coatings, but these can be further improved by additional coatings.

[0052] Preferably, the water absorption capacity, expressed as a Cobb300 value and measured in accordance with ISO 535:2014 on the side where the first and second coatings are applied, is at least 0 g / m2 and at most 10 g / m2 and particularly preferably at least 0 g / m2 and at most 5 g / m2.

[0053] Preferably, the barrier against the penetration of oils or greases, expressed as a Kit value and measured according to TAPPI T559-cm12 on the side where the first and second coatings are applied, is at least 8 and at most 12, particularly preferably at least 9 and at most 12. Petition 870250087372, dated 09 / 26 / 2025, page 23 / 59 15 / 27

[0054] The packaging material according to the invention is particularly suitable as packaging for foods that require high barrier properties from the packaging material. This applies not only to foods, but also to other products that need to be protected against oxygen or water vapor, for example, electronic components or electronic parts, or particularly hygroscopic products such as kitchen towels or hygiene products.

[0055] A package according to the invention therefore comprises a packaging material according to any of the previous embodiments, in which rice, sugar, pasta, chocolate, chocolate bars, nuts, muesli, cheese, sweets, meat products, coffee, tea, electronic components, kitchen towels or hygiene articles are packaged in the packaging material.

[0056] A further aspect of the invention relates to a method by which a packaging material according to any of the embodiments mentioned above can be produced. The method according to this aspect of the invention comprises steps A to D.

[0057] A - provide a basic role,

[0058] B - apply a first coating composition to at least one side of the base paper to produce a first coating,

[0059] C - calendering coated base paper from step B,

[0060] D - Apply a second coating composition directly over the first coating to create a second coating,

[0061] wherein the base paper in step A has a basis weight of at least 30 g / m2 and at most 90 g / m2, and

[0062] wherein the first coating of step B forms a barrier against oxygen penetration and comprises a polymer with Petition 870250087372, dated 09 / 26 / 2025, page 24 / 59 16 / 27 hydroxyl groups, wherein the hydroxyl groups of the polymer are at least partially crosslinked in step B, and

[0063] wherein the calendering in step C is carried out in such a way that the packaging material after step D has a Bekk smoothness of at least 800 s and at most 20,000 s on the side where the first coating in step B and the second coating in step D were applied, and

[0064] wherein the second coating of step D forms a barrier against water vapor penetration and comprises a polymer and a wax, and

[0065] where the average water vapor permeability M of the packaging material after step D is at least 2.0 g / (m2χ 24 h) and at most 100.0 g / (m2 χ 24 h), and the following formula applies to the standard deviation s of the water vapor permeability s <m· (0,15 + 0,1 · e-0-003^2), em que a permeabilidade média ao vapor de água m e o desvio padrão s da g (m2 χ 24 h) devem ser inseridos na fórmula por meio medição acordo com norma iso 2528:2017 uma umidade relativa 85% temperatura 23°c 10 posições selecionadas aleatoriamente não sobrepostas do material embalagem mesma direção através embalagem.

[0066] According to the inventors' findings, the combination of crosslinking the polymer of the first coating in step B and calendering in step C can prepare the surface of the coated base paper for the application of the second coating in step D, so that the variation in water vapor permeability is reduced. This is possible even if the base paper in step A has a low basis weight.

[0067] Preferably, the supply of base paper in step A Petition 870250087372, dated 09 / 26 / 2025, page 25 / 59 17 / 27 comprises the production of base paper on a paper machine, particularly preferably a Fourdrinier paper machine.

[0068] Preferably, the base paper in step A has a basis weight of at least 35 g / m2 and at most 80 g / m2 and particularly preferably at least 40 g / m2 and at most 70 g / m2.

[0069] Preferably, the base paper in step A comprises cellulose fibers, the cellulose fibers being particularly preferably formed from cellulose fibers or regenerated cellulose fibers or a mixture thereof. The cellulose fibers are obtained, in a very particularly preferred manner, from softwood, in particular red spruce, pine or fir; from hardwood, in particular beech, birch or eucalyptus; from hemp, flax, jute, ramie, kenaf, kapok, coconut, abaca, sisal, bamboo, cotton or esparto grass; or from residual paper pulp, or are a mixture of cellulose fibers from several of these sources.

[0070] Regenerated cellulose fibers are preferably fibrillable regenerated cellulose fibers.

[0071] Preferably, the percentage of cellulose fibers is at least 55% and at most 100% based on the mass of the base paper in step A, particularly preferably at least 60% and at most 95%.

[0072] The base paper in step A preferably comprises a filler. More preferably, the filler is selected from the group consisting of kaolin, talc, calcium carbonate, magnesium carbonate, magnesium oxide, magnesium hydroxide, aluminum oxide, aluminum hydroxide, titanium dioxide, or a mixture thereof. More preferably, the base paper in step A comprises kaolin.

[0073] Preferably, the freight forwarder percentage is at least 5% and at most 45%, more preferably at least Petition 870250087372, dated 09 / 26 / 2025, page 26 / 59 18 / 27 10% and at most 40%, based on the mass of the base paper in step A.

[0074] Preferably, the process according to the invention comprises a calendering step of the base paper from step A between step A and step B. Particularly preferably, during calendering, the base paper passes through at least one opening between the cylinders in which a line load agent of at least 20 kN / m and at most 800 kN / m acts on the base paper.

[0075] Preferably, immediately before step B, the base paper on the side intended for the application of the first coating in step B has a Bekk smoothness, measured in accordance with ISO 5627:1995, of at least 600 and at most 1500 s, particularly preferably of at least 800 and at most 1200 s.

[0076] Preferably, the first coating composition in step B comprises the first coating polymer, a crosslinking agent and a solvent, wherein particularly preferably the crosslinking agent is glyoxal or ammonium zirconium carbonate and / or wherein the solvent is preferably water.

[0077] Preferably, the polymer of the first coating composition is selected from the group consisting of starch, starch derivatives, polyvinyl alcohol, modified polyvinyl alcohol, carbohydrates, modified carbohydrates or mixtures thereof.

[0078] Preferably, the application of the first coating composition in step B comprises application in a film press or sizing press on a paper machine or other coating device integrated into the paper machine or in a separate coating device and further drying of the first coating composition.

[0079] Preferably, the first coating composition in step B is applied over the entire surface or at least 90% or more of the surface on one side of the base paper. Petition 870250087372, dated 09 / 26 / 2025, page 27 / 59 19 / 27

[0080] Preferably, between stage A and stage B, an additional coating comprising a barrier material and a filler may be applied, wherein the barrier material of this additional coating is selected from the group consisting of starch, acrylic acid polymers, modified acrylic acid polymers, styrene-acrylate copolymers and mixtures thereof. The filler of this additional coating is preferably an inorganic pigment, being alumina (AbO3) or talc. The additional coating is preferably applied over the entire surface or at least over 90% or more of the surface of the base paper, the additional coating preferably being applied directly onto the base paper.

[0081] Preferably, in stage C, the calendering of the coated base paper of stage B comprises passing through at least one and at most 14, particularly preferably at least 4 and at most 12 openings between the roll cylinders, wherein in at least one of the openings between the roll cylinders the coated base paper of stage B is subjected to a line load of at least 20 kN / m and at most 800 kN / m, particularly preferably at least 40 kN / m and at most 600 kN / m.

[0082] Preferably, calendering in step C is carried out in such a way that the packaging material after step D exhibits, on the side where the first coating of step B and the second coating of step D were applied, a Bekk smoothness of at least 1000 and at most 10000 s, and more preferably of at least 1500 and at most 8000 s. Bekk smoothness can be measured in accordance with ISO 5627:1995.

[0083] Preferably, the second coating composition in step D comprises the polymer and wax of the second coating and a solvent, wherein the solvent is particularly preferably water. Petition 870250087372, dated 09 / 26 / 2025, page 28 / 59 20 / 27

[0084] Preferably, the second coating polymer is selected from the group consisting of styrene-butadiene copolymers, carboxylated styrene-butadiene copolymers, styrene-acrylate copolymers, acrylic copolymers, acrylic polymers, ethylene-acrylic acid copolymers, vinyl acetate-acrylic acid copolymers, acrylic acid-maleic acid copolymers, methacrylic acid polymers, methyl methacrylate polymers and polyurethane and mixtures thereof, and the second coating wax is selected from the group consisting of vegetable waxes, animal waxes, mineral oil-based waxes, polymer waxes, semi-synthetic waxes and synthetic waxes and mixtures thereof. Particularly preferably, the second coating wax is a paraffin wax.

[0085] Preferably, the application of the second coating composition in step D comprises application in a counter-rotating gravure coating machine, a roller coating machine or a curtain coating machine and drying of the second coating composition.

[0086] Preferably, the second coating composition in step D is applied over the entire surface or at least over 90% or more of the surface on one side of the base paper.

[0087] The average water vapor permeability M and the standard deviation s of the water vapor permeability of the packaging material after step D are determined by measurement in accordance with ISO 2528:2017 at a relative humidity of 85% and a temperature of 23°C at 10 randomly selected and non-overlapping positions in the packaging material in the same direction through the packaging material.

[0088] The packaging material according to step D preferably has an average water vapor permeability M of at least 5.0 g / (m2χ 24 h) and at most 50.0 g / (m2χ 24 h) and particularly preferably at least 5.0 g / (m2 χ 24 h) and at most Petition 870250087372, dated 09 / 26 / 2025, p. 29 / 59 21 / 27 40.0 g / (m2χ 24 h).

[0089] In a preferred embodiment, the formula for the average water vapor permeability M and the standard deviation s of the water vapor permeability of the packaging material after step D is s <m· (0,12 + 0,1 ·e-0,003^2), em que a permeabilidade média ao vapor de água m e o desvio padrão s da g (m2 χ 24 h) devem ser inseridos na fórmula.

[0090] In a particularly preferred embodiment, the formula for the average water vapor permeability M and the standard deviation s of the water vapor permeability of the packaging material after step D is s <m· (0,10 + 0,1 ·e-0,003·^2), em que a permeabilidade média ao vapor de água m e o desvio padrão s da g (m2 χ 24 h) devem ser inseridos na fórmula.DESCRIPTION OF A PREFERRED EMBODIMENT AND COMPARISON WITH AN EMBODIMENT THAT DOES NOT CONFORM TO THE INVENTION

[0091] A preferred embodiment of the packaging material according to the invention and the method according to the invention are described below, as well as a packaging material not in accordance with the invention as a comparative example.

[0092] According to step A of the process according to the invention, a base paper with a basis weight of 55 g / m2, according to ISO 536:2109, was produced on a Fourdrinier paper machine, consisting of a mixture of cellulose fibers from noble and soft woods and kaolin as a filler. The amount of filler was 5% of the mass of the base paper, the remainder being composed of cellulose fibers. Petition 870250087372, dated 09 / 26 / 2025, page 30 / 59 22 / 27

[0093] The base paper was calendered in an opening between the cylinders with a line load of 40 kN / m and had a Bekk smoothness according to ISO 5627:1995 of 1070 s on the side intended for subsequent coating in steps B and D. The contact angle of this side was measured with a 4 pl drop of water after 0.1 s and was 55°.

[0094] The Cobb60 value on the side to be coated was measured according to ISO 535:2014 and was 21.6 g / m2, resulting in a specific water absorption capacity of 21.6 / 55.0 = 0.393.

[0095] A first coating composition, composed of A coating of 74% water and 26% solids was applied to the entire surface of this base paper, according to step B. The solids consisted of 36% by weight of modified polyvinyl alcohol, 63% by weight of alumina, and 1% by weight of glyoxal as a crosslinking agent. The coated base paper was then dried. The amount of coating applied was 2.5 g / m².

[0096] In the subsequent step C of the process according to the invention, the coated base paper from step B was calendered in a calender with 4 openings between the roller cylinders at a line load agent of 40 kN / m and a temperature of 105°C to prepare the surface for the application of the second coating composition.

[0097] In step D of the process according to the invention, a second coating composition, comprising a styrene-butadiene copolymer, a paraffin wax and water, was applied directly over the first coating across the entire surface and dried. The amount of styrene-butadiene copolymer and wax applied together was approximately 6.0 g / m2.

[0098] The Bekk smoothness of the packaging material thus obtained was determined in accordance with ISO 5627:1995 on the side where the first and second coatings were applied and a value of 1200 s was obtained. Petition 870250087372, dated 09 / 26 / 2025, page 31 / 59 23 / 27

[0099] The Gurley air permeability of the packaging material was determined according to ISO 5636-5:2013. However, the air permeability was too low to be meaningfully measured, so the packaging material can be considered practically airtight.

[0100] The Cobb300 value of the packaging material was determined in accordance with ISO 535:2014 from the side where the first and second coatings were applied and a value <0.1 g / m2 was obtained.

[0101] The value of the packaging material kit was determined according to TAPPI T559-cm12 from the side where the first and second coatings were applied and a value of 12 was obtained.

[0102] The oxygen permeability of the packaging material was measured according to DIN 53380-3:1998-07 at a relative humidity of 0% and a temperature of 23°C and a value of 200 ml / (m2xdx100 kPa) was obtained.

[0103] The water vapor permeability of the packaging material was measured according to ISO 2528:2017 at a relative humidity of 85% and a temperature of 23°C twice at 10 randomly selected and non-overlapping positions in the same direction through the packaging material. Individual values ​​are shown in g / (m2 x 24 h) in Table 1, with column A1 containing the values ​​from the first series of 10 measurements and column A2 containing the values ​​from the second series of 10 measurements. The MW, SD, and CoV rows show the mean (MW) in g / (m2 x 24 h), the standard deviation (SD) in g / (m2 x 24 h), and the coefficient of variation (CoV) in %.

[0104] The packaging material thus obtained has - despite the relatively small quantities of coatings applied - excellent water vapor permeability of only about 15 g / (m2 x 24 h) and a very low standard deviation of permeability to Petition 870250087372, dated 09 / 26 / 2025, p. 32 / 59 24 / 27 water vapor of only 2.5 g / (m2χ 24 h), thus falling below the upper limit of the standard deviation of 3.0 g / (m2 χ 24 h) provided by the formula for this average water vapor permeability.

[0105] In comparison, the paper sold under the name Barricote BAG WG BA 4762 by Mitsubishi HiTec Paper Europe, as a packaging paper with a water vapor and grease barrier, with a basis weight of 49 g / m², exhibits an average water vapor permeability at a temperature of 23°C and a relative humidity of 85% of 35 g / (m² χ² 24 h) and a standard deviation of 10 g / (m² χ² 24 h). The standard deviation of water vapor permeability is therefore significantly greater than the upper limit for the standard deviation of 5.3 g / (m² χ² 24 h) predicted in the formula for this average water vapor permeability.

[0106] According to the inventors' knowledge, the additional and unusual calendering step between the application of the first and second coating is important for the exceptionally advantageous behavior of the packaging material according to the invention, which, in addition to providing low variation in water vapor permeability, also manifests itself in the claimed smoothness of the finished packaging material.

[0107] To demonstrate this, another packaging material with identical composition was produced in the same manner, with the only difference being that calendering was omitted in step C. The water vapor permeability of this packaging material (not according to the invention) was also measured according to ISO 2528:2017 at a relative humidity of 85% and a temperature of 23 °C twice at 10 randomly selected and non-overlapping positions in the same direction through the packaging material. The individual values ​​are presented in g / (m2 χ 24 h) in Table 1, with column B1 containing the values ​​from the first series of 10 measurements and column B2 containing the values ​​from the second series of 10 measurements. The rows MW, Petition 870250087372, dated 09 / 26 / 2025, page 33 / 59 25 / 27 SD and CoV show the mean (MW) in g / (m2χ 24 h), the standard deviation (SD) in g / (m2 χ 24 h), and the coefficient of variation (CoV) in %. Table 1 - Water vapor permeability of the packaging material according to the invention (A1, A2) and of the packaging material not according to the invention (B1, B2) A1 A2 B1 B2 1 15.4 18.9 25.8 19.3 2 19.9 14.2 34.2 29.9 3 14.7 18.4 32.4 21.9 4 15.9 11.0 27.4 26.2 5 16.0 15.5 26.0 23.3 6 11.4 15.6 35.5 28.8 7 14.1 15.0 25.1 25.5 8 15.1 15.1 34.3 34.0 9 17.9 11.4 22.8 19.4 10 16.0 13.4 25.8 30.9 MW 15.64 14.85 28.91 25.92 SD 2.24 2.57 4.66 4.99 CoV 14.32 17.29 16.13 19.25

[0108] From Table 1 it can be observed that the comparative example (B1, B2), not in accordance with the invention, already represents a significant improvement over the commercially available product BAG WG BA 4762, both in terms of the water vapor permeability itself and in terms of the standard deviation and coefficient of variation. However, it can also be observed that the additional calendering step C can significantly reduce the average water vapor permeability from approximately 27 g / (m2 χ 24 h) to approximately 15 g / (m2 χ 24 h). This does not require any additional lining material, which is already an advantage of the invention. Furthermore, Table 1 shows that the standard deviation of the water vapor permeability of Petition 870250087372, dated 09 / 26 / 2025, page 34 / 59 26 / 27 water for the packaging material according to the invention (A1, A2) is about 2.5 g / (m2χ 24 h) and is significantly lower than that of the non-inventive packaging material (B1, B2) with more than 4.5 g / (m2 χ 24 h).

[0109] The standard deviation is, on average, smaller for the packaging material according to the invention (A1, A2) than for the improved but not yet inventive packaging material (B1, B2). The upper limit for the standard deviation specified in the formula is exceeded only by the packaging material of the comparative example (B1, B2), because it is not in accordance with the invention, although it has other characteristics of the invention in a combination that, as far as the inventors know, is not previously known in the state of the art and in itself already represents an improvement over the state of the art.

[0110] It is remarkable and surprising how significant the difference is in terms of water vapor permeability and its variance between the packaging materials (A1, A2) and (B1, B2), considering that the comparative example (B1, B2) uses all the other characteristics of the packaging material (A1, A2) according to the invention, including the calendering step of the base paper, which was also present in the comparative example (B1, B2), but by itself in this configuration is obviously not sufficient to achieve an inventive combination of water vapor permeability and its standard deviation.

[0111] This treatment manifests itself in the finished packaging material – in addition to reducing the variation in water vapor permeability – also in the increase in Bekk smoothness, which was determined to be 1200 s on the coated side of the manufacturing material according to an invention (A1, A2) in accordance with ISO 5627:1995. The comparison example (B1, B2), on the other hand, had a Bekk smoothness on the coated side of only 720 s. This demonstrates that this smoothness is indeed a Petition 870250087372, dated 09 / 26 / 2025, page 35 / 59 27 / 27 suitable structural parameter to characterize the packaging material according to the invention.

[0112] If, for the determination of the expiration date, a value for water vapor permeability is used that is exceeded in less than 1% of cases, then this value, assuming a normal distribution, is approximately 22 g / (m2χ 24 h) for the packaging material according to the invention (A1, A2) and approximately 42 g / (m2 χ 24 h) for the previously unknown, very similar, but not inventive packaging material (B1, B2), and is therefore almost twice as high. This shows that products packaged in the packaging material according to the invention can have a longer shelf life without increasing material consumption or impairing the recyclability of the packaging material. Petition 870250087372, dated 09 / 26 / 2025, p. 36 / 59

Claims

1 / 14 CLAIMS 1. Packaging material, characterized in that it comprises a base paper and a first and a second coating, wherein the base paper has a basis weight of at least 30 g / m2 and at most 90 g / m2, wherein the first coating - between the base paper and the second coating - forms a barrier against the penetration of oxygen and - comprises a polymer with hydroxyl groups, the hydroxyl groups of the polymer being at least partially crosslinked, and wherein the second coating - is applied directly to the first coating - forms a barrier against the penetration of water vapor and - is a polymer and a wax, wherein the packaging material, on the side where the first and second coatings are applied, has a Bekk smoothness of at least 800 and at most 20.000 s, and where the average water vapor permeability M of the packaging material is at least 2.0 g / (m2 χ 24 h) and at most 100.0 g / (m2 χ 24 h), and the following formula applies to the standard deviation s of the water vapor permeability s <M· (0,15 + 0,1 · e-0-003^2), em que a permeabilidade média ao vapor de água M e o desvio padrão s da permeabilidade ao vapor de água em g / (m2 χ 24 h) devem ser inseridos na fórmula e devem ser determinados por medição de acordo com a norma ISO 2528:2017 a uma umidade relativa de 85% e a uma temperatura de 23 °C em 10 posições selecionadas aleatoriamente e não sobrepostas do material de embalagem na mesma direção através do material de embalagem.

2. Packaging material, according to claim 1, Petition 870250087372, dated 09 / 26 / 2025, p. 37 / 59 2 / 14, characterized in that the base paper has a basis weight of at least 35 g / m2 and at most 80 g / m2 and, preferably, at least 40 g / m2 and at most 70 g / m2.

3. Packaging material, according to claim 1 or 2, characterized in that the base paper comprises cellulose fibers, wherein the cellulose fibers are preferably formed from cellulose fibers or regenerated cellulose fibers or a mixture thereof.

4. Packaging material, according to claim 3, characterized in that the cellulose fibers are obtained from softwood, in particular red spruce, pine or fir; from hardwood, in particular beech, birch or eucalyptus; from hemp, flax, jute, ramie, kenaf, kapok, coconut, abaca, sisal, bamboo, cotton or esparto grass; or from residual paper pulp, or are a mixture of cellulose fibers from several of these sources.

5. Packaging material according to claim 3, characterized in that the regenerated cellulose fibers are fibrillable regenerated cellulose fibers.

6. Packaging material, according to any one of claims 3 to 5, characterized in that the percentage of cellulose fibers is at least 55% and at most 100%, preferably at least 60% and at most 95%, in each case based on the mass of the base paper.

7. Packaging material, according to any of the preceding claims, characterized in that the base paper comprises a filler, wherein said filler is preferably selected from the group consisting of kaolin, talc, calcium carbonate, magnesium carbonate, magnesium oxide, magnesium hydroxide, aluminum oxide, aluminum hydroxide, titanium dioxide or a mixture thereof, wherein the percentage of filler is preferably at least 5% and at most 45%, particularly preferably at least 10% and at most 40%, in each case based on the mass of the base paper.

8. Packaging material, according to any of the preceding claims, characterized in that the base paper is calendered.

9. Packaging material, according to any of the preceding claims, characterized in that the base paper has, on the side where the first and second coatings are applied, before the application of the first and second coatings, a Bekk smoothness, measured in accordance with ISO 5627:1995, of at least 600 and at most 10,000 s, preferably at least 800 and at most 6,000 s.

10. Packaging material, according to any of the preceding claims, characterized in that the base paper has, on the side where the first and second coatings are applied, before the application of the first and second coatings, a contact angle with water of at least 30° and at most 70°, preferably at least 40° and at most 65°, wherein the contact angle should be measured with a 4 pl drop after 0.1 s.

11. Packaging material, according to any of the preceding claims, characterized in that the base paper has, on the side where the first and second coatings are applied, before the application of the first and second coatings, a specific water absorption capacity of at least 0.1 and at most 0.7, preferably at least 0.2 and at most 0.5, wherein the specific water absorption capacity corresponds to the quotient between the water absorption capacity determined as the Cobb60 value according to ISO 535:2014 in g / m2 and the basis weight of the base paper measured according to ISO 536:2019 in Petition 870250087372, dated 26 / 09 / 2025, page 39 / 59 4 / 14 g / m2.

12. Packaging material, according to any of the preceding claims, characterized in that the polymer of the first coating, which has hydroxyl groups and whose hydroxyl groups are partially cross-linked, is selected from the group consisting of starch, starch derivatives, polyvinyl alcohol, modified polyvinyl alcohol, carbohydrates, modified carbohydrates or mixtures thereof.

13. Packaging material, according to any of the preceding claims, characterized in that the first coating comprises glyoxal or ammonium zirconium carbonate.

14. Packaging material, according to any of the preceding claims, characterized in that the first coating is applied over the entire surface, or at least 90% or more of the surface on one side of the base paper.

15. Packaging material, according to any of the preceding claims, characterized in that the amount of polymer in the first coating, based on the area to which the polymer is effectively applied, is at least 0.2 g / m2 and at most 5.0 g / m2, preferably at least 0.5 g / m2 and at most 4.0 g / m2.

16. Packaging material, according to any of the preceding claims, characterized in that at least one additional coating comprising a barrier material and a filler is applied between the base paper and the first coating, wherein the barrier material of the additional coating is selected from the group consisting of starch, acrylic acid polymers, modified acrylic acid polymers, styrene-acrylate copolymers and mixtures thereof. Petition 870250087372, dated 09 / 26 / 2025, p. 40 / 59 5 / 14 17. Packaging material according to claim 16, characterized in that the filler of this additional coating is an inorganic pigment, preferably alumina (AbO3) or talc.

18. Packaging material, according to any one of claims 16 or 17, characterized in that the additional coating is applied over the entire surface or at least over 90% or more of the surface of one side of the base paper, wherein the additional coating is preferably applied directly to the base paper.

19. Packaging material, according to any one of claims 16 to 18, characterized in that the mass of the additional coating, based on the area on which it is effectively applied, is at least 0.2 g / m2 and at most 4.0 g / m2, preferably at least 0.5 g / m2 and at most 2.5 g / m2.

20. Packaging material, according to any of the preceding claims, characterized in that the polymer of the second coating is selected from the group consisting of styrene-butadiene copolymers, carboxylated styrene-butadiene copolymers, styrene-acrylate copolymers, acrylic copolymers, acrylic polymers, ethylene-acrylic acid copolymers, vinyl acetate-acrylic acid copolymers, acrylic-maleic acid copolymers, methacrylic acid polymers, methyl methacrylate and polyurethane polymers and mixtures thereof.

21. Packaging material, according to any of the preceding claims, characterized in that the wax of the second coating is selected from the group consisting of vegetable waxes, animal waxes, mineral oil-based waxes, polymer waxes, semi-synthetic waxes and synthetic waxes and mixtures thereof, wherein the wax is preferably a paraffin wax. Petition 870250087372, dated 09 / 26 / 2025, p. 41 / 59 6 / 14 22. Packaging material, according to any of the preceding claims, characterized in that the second coating is applied over the entire surface or at least over 90% or more of the surface of one side of the base paper.

23. Packaging material, according to any of the preceding claims, characterized in that the mass of polymer and wax in the second coating, considered together, based on the area in which the polymer and wax are actually applied, is at least 1.0 g / m2 and at most 10.0 g / m2, particularly preferably at least 2.0 g / m2 and at most 8.0 g / m2.

24. Packaging material, according to any of the preceding claims, characterized in that it has a Bekk smoothness of at least 1000 and at most 10,000 s, and preferably of at least 1500 and at most 8000 s, on the side where the first coating, the second coating and, optionally, other coatings are applied.

25. Packaging material, according to any of the preceding claims, characterized in that the air permeability according to Gurley, measured in accordance with ISO 5636-5:2013, in at least one direction through the packaging material is at least 20,000 s, preferably at least 35,000 s.

26. Packaging material, according to any of the preceding claims, characterized in that it has an average water vapor permeability M of at least 5.0 g / (m2 χ 24 h) and at most 50.0 g / (m2 χ 24 h) and, preferably, of at least 5.0 g / (m2 χ 24 h) and at most 40.0 g / (m2 χ 24 h).

27. Packaging material, according to any of the preceding claims, characterized in that the formula s applies to the average water vapor permeability M and the standard deviation s of the water vapor permeability. <M · (0,12 + 0,1 · e-0,003^2) em que a permeabilidade média ao vapor de água M e o desvio padrão s da permeabilidade ao vapor de água em g / (m2 x 24 h) devem ser inseridos na fórmula.

28. Packaging material, according to any of the preceding claims, characterized in that the formula s applies to the average water vapor permeability M and the standard deviation s of the water vapor permeability. <M · (0,10 + 0,1 · e-0,003·^2) em que a permeabilidade média ao vapor de água M e o desvio padrão s da permeabilidade ao vapor de água em g / (m2 χ 24 h) devem ser inseridos na fórmula.

29. Packaging material, according to any of the preceding claims, characterized in that it has an oxygen permeability in at least one direction through the packaging material, measured in accordance with DIN 533803:1998-07 at a relative humidity of 0% and a temperature of 23 °C, of ​​at least 1 ml / (m2xdx100 kPa) and at most 500 ml / (m2xdx100 kPa), particularly preferably of at least 5 ml / (m2xdx100 kPa) and at most 400 ml / (m2xdx100 kPa).

30. Packaging material, according to any of the preceding claims, characterized in that its water absorption capacity, expressed as a Cobb300 value and measured in accordance with ISO 535:2014 from the side where the first and second coatings are applied, is at least 0 g / m2 and at most 10 g / m2, and preferably at least 0 g / m2 and at most 5 g / m2.

31. Packaging material, according to any of the preceding claims, characterized in that a barrier against the penetration of oils or fats, expressed as a Kit value and measured according to TAPPI T559-cm12 on the side where the first and second coatings are applied, is at least 8 and at most 12, preferably at least 9 and at most 12.

32. Packaging material, according to any of the preceding claims, characterized in that rice, sugar, noodles, chocolate, chocolate bars, nuts, muesli, cheese, sweets, meat products, coffee, tea, electronic components, kitchen towels or hygiene articles are packaged in the packaging material.

33. Method for producing a packaging material, as defined in any one of claims 1 to 31, characterized in that it comprises the following steps A to D: A - providing a base paper, B - applying a first coating composition to at least one side of the base paper to produce a first coating, C - calendering the coated base paper from step B, D - applying a second coating composition directly onto the first coating to create a second coating, wherein the base paper in step A has a basis weight of at least 30 g / m2 and at most 90 g / m2, and wherein the first coating of step B forms a barrier against oxygen penetration and comprises a polymer with hydroxyl groups, wherein the hydroxyl groups of the polymer are at least partially crosslinked in step B, and wherein the calendering in step C is carried out so that the packaging material after step D has a smoothness DE Bekk de Petição 870250087372, dated 26 / 09 / 2025, pág.44 / 59 9 / 14 at least 800 if at most 20,000 s on the side where the first coating in step B and the second coating in step D were applied, and where the second coating of step D forms a barrier against water vapor penetration and comprises a polymer and a wax, and where the average water vapor permeability M of the packaging material after step D is at least 2.0 g / (m2 χ 24 h) and at most 100.0 g / (m2 χ 24 h), and the following formula applies to the standard deviation s of the water vapor permeability s <M· (0,15 + 0,1 · e-0-003^2), em que a permeabilidade média ao vapor de água M e o desvio padrão s da permeabilidade ao vapor de água em g / (m2 χ 24 h) devem ser inseridos na fórmula e são determinados por medição de acordo com a norma ISO 2528:2017 a uma umidade relativa de 85% e a uma temperatura de 23 °C em 10 posições selecionadas aleatoriamente e não sobrepostas do material de embalagem na mesma direção através do material de embalagem.

34. Method according to claim 33, characterized in that the supply of the base paper in step A comprises the production of the base paper on a paper machine, particularly preferably a Fourdrinier paper machine.

35. Method according to claim 33 or 34, characterized in that the base paper in step A has a basis weight of at least 35 g / m2 and at most 80 g / m2 and, preferably, at least 40 g / m2 and at most 70 g / m2.

36. Method, according to any one of claims 33 to 35, characterized in that the base paper in step A comprises cellulose fibers, wherein said cellulose fibers are Petition 870250087372, dated 09 / 26 / 2025, page 45 / 59 10 / 14 particularly preferably formed from pulp fibers or regenerated cellulose fibers or a mixture thereof.

37. A method according to claim 36, characterized in that the cellulose fibers are obtained from softwood, in particular red spruce, pine or fir; from hardwood, in particular beech, birch or eucalyptus; from hemp, flax, jute, ramie, kenaf, kapok, coconut, abaca, sisal, bamboo, cotton or spartan grass; or from residual paper pulp, or are a mixture of cellulose fibers from several of these sources.

38. Method according to claim 36, characterized in that the regenerated cellulose fibers are fibrillable regenerated cellulose fibers.

39. Method, according to any one of claims 36 to 38, characterized in that the percentage of cellulose fibers is at least 55% and at most 100% based on the mass of the base paper in step A, and preferably at least 60% and at most 95%.

40. A method according to any one of claims 33 to 39, characterized in that the base paper in step A comprises a filler, said filler preferably being selected from the group consisting of kaolin, talc, calcium carbonate, magnesium carbonate, magnesium oxide, magnesium hydroxide, aluminum oxide, aluminum hydroxide, titanium dioxide or a mixture thereof, wherein the percentage of filler is preferably at least 5% and at most 45%, particularly preferably at least 10% and at most 40%, based on the mass of the base paper in step A.

41. Method, according to any one of claims 33 to 40, characterized in that the method comprises a calendering step of the base paper of step A between step A and Petition 870250087372, dated 09 / 26 / 2025, page 46 / 59 11 / 14 step B.

42. Method, according to claim 41, characterized in that the base paper, during calendering between stage A and stage B, passes through at least one opening between the cylinders in which a line load of at least 20 kN / m and at most 800 kN / m acts on the base paper.

43. Method, according to any one of claims 33 to 42, characterized in that the base paper immediately before step B on the side intended for the application of the first coating in step B has a Bekk smoothness, measured in accordance with ISO 5627:1995, of at least 600 if at most 1500 s, preferably at least 800 if at most 1200 s.

44. Method, according to any one of claims 33 to 43, characterized in that the first coating composition in step B comprises the first coating polymer, a crosslinking agent and a solvent, wherein the crosslinking agent is preferably glyoxal or ammonium zirconium carbonate and / or wherein the solvent is preferably water.

45. A method according to any one of claims 33 to 44, characterized in that the polymer of the first coating is selected from the group consisting of starch, starch derivatives, polyvinyl alcohol, modified polyvinyl alcohol, carbohydrates, modified carbohydrates, or mixtures thereof.

46. ​​Method, according to any one of claims 33 to 45, characterized in that the application of the first coating composition in step B comprises application in a film press or sizing press on a paper machine or other coating device integrated into the paper machine or in a separate coating device and further drying of the first coating composition. Petition 870250087372, dated 09 / 26 / 2025, pp. 47 / 59 12 / 14 47. Method, according to any one of claims 33 to 46, characterized in that the first coating composition in step B is applied over the entire surface or at least 90% or more of the surface of one side of the base paper.

48. A method according to any one of claims 33 to 47, characterized in that between step A and step B an additional coating comprising a barrier material and a filler is applied, wherein the barrier material of said additional coating is selected from the group consisting of starch, acrylic acid polymers, modified acrylic acid polymers, styrene-acrylate copolymers and mixtures thereof, and wherein said filler of said additional coating is an inorganic pigment, in particular alumina (Al2O3) or talc.

49. Method according to claim 48, characterized in that the additional coating is applied over the entire surface or at least over 90% or more of the surface of one side of the base paper, wherein the additional coating is preferably applied directly to the base paper.

50. Method, according to any one of claims 33 to 49, characterized in that in step C the calendering of the coated base paper of step B comprises passing through at least one and at most 14, preferably at least 4 and at most 12 openings between cylinders, wherein, in at least one of the openings between cylinders, the coated base paper of step B is subjected to a line load of at least 20 kN / m and at most 800 kN / m, preferably at least 40 kN / m and at most 600 kN / m.

51. Method, according to any one of claims 33 to 50, characterized in that the calendering in step C is carried out so that the packaging material after step D has, Petition 870250087372, dated 09 / 26 / 2025, page 48 / 59 13 / 14 on the side where the first coating in step B and the second coating in step D were applied, a Bekk smoothness of at least 1000 if at most 10,000 s, and preferably at least 1500 if at most 8000 s.

52. Method, according to any one of claims 33 to 51, characterized in that the second coating composition in step D comprises the polymer and wax of the second coating and a solvent, wherein the solvent is preferably water.

53. A method according to any one of claims 33 to 52, characterized in that the polymer of the second coating is selected from the group consisting of styrene-butadiene copolymers, carboxylated styrene-butadiene copolymers, styrene-acrylate copolymers, acrylic copolymers, acrylic polymers, ethylene-acrylic acid copolymers, vinyl acetate-acrylic acid copolymers, acrylic acid-maleic acid copolymers, methacrylic acid polymers, methyl methacrylate and polyurethane polymers and mixtures thereof; and the wax of the second coating is selected from the group consisting of vegetable waxes, animal waxes, mineral oil-based waxes, polymeric waxes, semi-synthetic waxes and synthetic waxes and mixtures thereof, wherein said wax of the second coating is preferably a paraffin wax.

54. Method, according to any one of claims 33 to 53, characterized in that the application of the second coating composition in step D comprises application in a counter-rotating etching machine, a roller coater or a curtain coater and drying of the second coating composition.

55. Method, according to any of the claims Petition 870250087372, dated 09 / 26 / 2025, pp. 49 / 59 14 / 14 33 to 54, characterized in that the second coating composition in step D is applied over the entire surface or at least over 90% or more of the surface on one side of the base paper.

56. Method according to any one of claims 33 to 55, characterized in that the packaging material after step D has an average water vapor permeability M of at least 5.0 g / (m2 χ 24 h) and at most 50.0 g / (m2 χ 24 h) and preferably at least 5.0 g / (m2 χ 24 h) and at most 40.0 g / (m2 χ 24 h).

57. Method, according to any one of claims 33 to 56, characterized in that the formula s is applied to the average water vapor permeability M and the standard deviation s of the water vapor permeability of the packaging material after step D. <M · (0,12 + 0,1 · e-0,003^2) em que a permeabilidade média ao vapor de água M e o desvio padrão s da permeabilidade ao vapor de água em g / (m2 χ 24 h) devem ser inseridos na fórmula.

58. Method, according to any one of claims 33 to 56, characterized in that the formula s is applied to the average water vapor permeability M and the standard deviation s of the water vapor permeability of the packaging material after step D. <M · (0,10 + 0,1 · e-0,003·^2) em que a permeabilidade média ao vapor de água M e o desvio padrão s da permeabilidade ao vapor de água em g / (m2 χ 24 h) devem ser inseridos na fórmula. Petição 870250087372, de 26 / 09 / 2025, pág. 50 / 59