Packaging material with improved oxygen barrier properties

Abstract

A packaging material comprising a base paper and at least one coating on the base paper wherein the base paper has a basis weight of at least 30 g / m and at most 90 g / m wherein the at least one coating is a starch / pectin coating comprising one or more layers, the one or more layers each comprise a mixture of starch and pectin, the mass ratio of starch to pectin in the mixture being 1000: 5 to 100: 5, and wherein the total mass of the mixture of starch and pectin in the previous one or more layers is at least 1.5 g / m and at most 12.0 g / m relative to the surface area of the starch / pectin coating actually applied to the base paper, and wherein the packaging material has an oxygen permeability through the packaging material in at least one direction of at least 1 cm / (m.d) and at most 500 cm / (m.d), measured according to ASTM D3985-17 at a relative humidity of 0% and a temperature of 23 DEG C.

Description

[0001] Invention Field

[0002] This invention relates to packaging materials made primarily from renewable raw materials and having a coating, wherein, although the amount of coating material is small, it can particularly effectively reduce the oxygen permeability of the packaging material. The invention also relates to packages derived from such packaging materials and methods for manufacturing such packaging materials.

[0003] Background and Existing Technology

[0004] In recent years, the demand for alternatives to plastic film-based packaging materials has increased dramatically due to ecological reasons. Paper has been proposed as an important alternative. While paper is superior to plastic film in terms of ecology, such as printability, comparable performance in key technical aspects can only be achieved through additional measures.

[0005] An example of this property is the barrier effect. Many packaging material applications require barrier properties against substances such as water vapor, oxygen, water, oils, and greases. For paper, this property is usually achieved through additional coatings, but there is still potential for improvement.

[0006] Especially in food packaging materials, high oxygen barrier properties are required to extend the shelf life of packaged foods. For paper, this high barrier property can typically only be achieved by applying a large amount of coating material. This increases the material consumption in manufacturing packaging materials.

[0007] Material consumption can also be reduced by using low-basis-weight paper as a starting material for packaging. However, this problem is exacerbated by the fact that such thin and lightweight paper itself has only a low barrier effect, and is usually addressed simply by coating more material.

[0008] Some coating materials that provide good oxygen barrier properties also come from non-renewable raw materials. In this case, the ecological advantages of paper over plastic film cannot be fully utilized.

[0009] Therefore, the industry needs to provide paper with coatings that reduce oxygen permeability as effectively as possible. Furthermore, the coating material should be derived from renewable raw materials. Summary of the Invention

[0010] The object of this invention is to provide packaging materials that have low basis weight, good oxygen barrier properties, and contain minimal coating material to produce this oxygen barrier property. The raw materials used should be derived from renewable sources whenever possible.

[0011] This objective is achieved by the packaging material according to claim 1, the packaging material according to claim 32, and the method of manufacturing the packaging material according to claim 33. Advantageous embodiments are provided in the dependent claims.

[0012] This objective is achieved through packaging materials comprising a base paper and at least one coating on the base paper, wherein the base paper has a basis weight of at least 30 g / m² and at most 90 g / m², and wherein the at least one coating is a starch-pectin coating comprising one or more layers, each of the one or more layers comprising a mixture of starch and pectin in a mass ratio of starch to pectin of 1000:5 to 100:5, and wherein the total mass of the starch-pectin mixture in the one or more layers is at least 1.5 g / m² and at most 12.0 g / m² relative to the area actually coated by the starch-pectin coating on the base paper. In this regard, the packaging material has an oxygen permeability of at least 1 cm³ / (m²·d) and at most 500 cm³ / (m²·d) in at least one direction, as measured according to ASTM D3985-17 at 0% relative humidity and 23°C.

[0013] The packaging material includes a base paper, which is selected to have a low basis weight. This base paper itself has a high oxygen permeability, so the oxygen permeability needs to be reduced as effectively as possible, i.e., low material consumption.

[0014] A starch-pectin coating comprising a mixture of starch and pectin is applied to a base paper. In this disclosure, the term "starch-pectin coating" is primarily used to refer to the corresponding coating, but it should not be excluded that the coating may also contain components other than starch and pectin. In the art, "coating / coating" should be understood as a manufacturing process used to apply an adhesive layer of shapeless material to the surface of an object. The corresponding coating procedure and the coating layer itself are designated as "coating / coating" in the art. Such a coating may consist of a single layer applied in a single coating step. However, a "coating" may also include several connecting layers; for example, a coating may be obtained by applying different coating compositions one after another.

[0015] In some embodiments, the starch-pectin coating of the present invention may comprise a single layer. For example, such a single layer can be obtained by coating a base paper with a coating composition comprising a mixture of starch and pectin in a mass ratio of 1000:5 to 100:5 in a coating step. In this case, the “total mass of the starch-pectin mixture” mentioned above refers only to the mass of the starch-pectin mixture in such a single-layer starch-pectin coating.

[0016] However, in the context of this disclosure, a single layer can also be obtained by coating the same coating composition onto each other in several consecutive steps. In this case, there are actually several coating procedures, but because the coating composition is the same, they generally result in layers that are indistinguishable from each other, so that in this case, in the context of this disclosure, only one layer exists. In this case, the aforementioned "total mass of the starch and pectin mixture" simply corresponds to the mass of the starch and pectin mixture in such a single layer of starch-pectin coating, even if the mixture is coated in several coating steps.

[0017] In another embodiment, the starch-pectin coating may comprise several layers, which are distinguishable from each other, each containing a mixture of starch and pectin. The mass ratio of starch to pectin in the mixture may vary among the layers, but in each of the layers, this mass ratio is required to be in the range of 1000:5 to 100:5. In this case, the aforementioned "total mass of the starch-pectin mixture" corresponds to the sum of the masses of the starch-pectin mixtures in each of the several layers of the "starch-pectin coating".

[0018] There may be additional layers or coatings that also contain starch and / or pectin, but not in the mass ratios cited; these additional layers are not included in the “one or more layers” mentioned above and therefore do not contribute to the “total mass of the starch and pectin mixture” mentioned above.

[0019] According to the inventors' findings, this starch-pectin mixture shows particular effectiveness in reducing the oxygen permeability of packaging materials, with a starch-to-pectin mass ratio of 1000:5 to 100:5 showing particular effectiveness. This is surprising because the proportion of pectin is relatively low, and the specific effect does not occur at higher or lower starch-to-pectin mass ratios. The inventors believe that pectin acts as a gelling agent and can combine with starch to effectively seal the pores in the base paper.

[0020] The term "mixture" should be interpreted broadly, referring to any situation where starch and pectin are applied together as a coating composition to base paper. There are no particular requirements regarding the uniformity of the mixture in the coated layer or the coating composition used, as long as the starch and pectin are processed in a manner recommended by the manufacturer for use as a coating material.

[0021] The amount of starch and pectin coated onto the base paper as components of the starch-pectin coating is relatively low relative to the resulting reduction in oxygen permeability. Since the oxygen permeability of the base paper can vary over a wide range, and since there can be additional coatings on the base paper to influence oxygen permeability, the specific content of starch and pectin essentially depends on the oxygen permeability prior to coating the starch-pectin coating and the desired oxygen permeability of the packaging material. However, according to the inventors' findings, a mixture of starch and pectin in the mass ratio according to the invention can particularly effectively reduce oxygen permeability, requiring relatively little material to achieve a significant reduction in oxygen permeability.

[0022] The required oxygen permeability of packaging materials depends on the specific coating. The interval range according to the invention is ideally suited for food packaging materials, but also suitable for other packaging materials that require protection from oxygen.

[0023] The packaging material according to the invention comprises a base paper, wherein the base paper preferably has a basis weight of at least 35 g / m² and at most 80 g / m², particularly preferably at least 35 g / m² and at most 70 g / m². The weight can be measured according to ISO 536:2019, and the basis weight of the base paper can be measured directly before applying the starch-pectin coating. A base paper with a higher basis weight is more advantageous considering barrier effects and mechanical properties, but material consumption is also higher; therefore, the lowest possible basis weight should be chosen. The starch-pectin coating according to the invention achieves low oxygen permeability by coating a low amount of a mixture of starch and pectin.

[0024] The base paper preferably comprises cellulose fibers, particularly preferably formed from pulp fibers or fibers derived from regenerated cellulose, or mixtures thereof. The pulp fibers are more particularly preferably derived from coniferous wood, especially spruce, pine, or fir; deciduous wood, especially beech, birch, or eucalyptus; hemp, flax, jute, ramie, kenaf, kapok, coconut, Manila hemp, sisal, bamboo, cotton, or fine-stemmed needlegrass; or waste paper pulp; or mixtures of pulp fibers from several of these sources.

[0025] The pulp fibers can be bleached or unbleached, or a mixture of bleached and unbleached pulp fibers in any mixing ratio, as they are virtually identical in technical performance for packaging materials, except for color. For ecological reasons, a higher proportion of unbleached pulp fibers can be selected relative to the mass of the pulp fibers, preferably at least 50% and at most 100%, particularly preferably at least 70% and at most 100%.

[0026] More particularly preferred is that the fiber derived from regenerated cellulose is a fibrillable fiber derived from regenerated cellulose. For example, such a fiber is marketed under the name Lyocell.

[0027] Preferably, the proportion of cellulose fibers relative to the mass of the base paper is at least 55% and at most 100%, particularly preferably at least 70% and at most 99%.

[0028] The base paper preferably contains fillers. Particularly preferably, the fillers are selected from kaolin, talc, calcium carbonate, magnesium carbonate, magnesium oxide, magnesium hydroxide, aluminum oxide, aluminum hydroxide, titanium dioxide, or mixtures thereof. Fillers can contribute to the barrier effect and can also affect the optical properties of the base paper, such as opacity, brightness, or color.

[0029] Preferably, the filler content is at least 1% and at most 45% relative to the mass of the base paper, and particularly preferably at least 2% and at most 30%.

[0030] To influence certain properties of the base paper, the base paper may contain other additives, such as sizing agents, alkyl ketone dimers, alkenyl succinic anhydride, or resin sizing agents.

[0031] Preferably, the base paper is calendered. Calendering improves smoothness, thereby improving the uniformity of the starch-pectin coating, and compresses the base paper, reducing oxygen permeability.

[0032] According to the present invention, a starch-pectin coating comprising a mixture of starch and pectin is applied to a base paper.

[0033] Preferably, the starch is selected from corn starch, potato starch, tapioca starch, yam starch, rice starch, degraded starch, or a mixture of two or more of these starches. Particularly preferred is degraded starch, and even more particularly preferred is dextrin. If the starch-pectin coating comprises several layers, different starches may be used in the different layers.

[0034] Preferably, the pectin is derived from one or more plants selected from citrus fruits, apples, oranges, rosehips, cherries, or carrots. Particularly preferably, up to 80% by weight of the pectin is derived from citrus fruits. If the starch-pectin coating comprises several layers, different starches may be used in each layer.

[0035] Preferably, the pectin has an esterification degree of at least 65% and at most 80%, particularly preferably at least 69% and at most 75%. Preferably, the esterification degree has an influence on gel formation, and according to the inventors' research, the preferred and particularly preferred ranges of esterification degree have been found to be particularly advantageous.

[0036] Preferably, the total mass of the starch and pectin mixture in one or more layers of the starch-pectin coating on the packaging material is at least 2.0 g / m² and at most 10.0 g / m², particularly preferably at least 2.0 g / m² and at most 8.0 g / m², relative to the actual area covered by the starch-pectin coating. Coatings or layers in multilayer coatings on packaging materials containing starch or pectin but not mixtures thereof, or coatings or layers in multilayer coatings on packaging materials containing starch and pectin at a different mass ratio than described above, are not included in the total mass. The amount of starch and pectin mixture required to achieve a certain oxygen permeability depends particularly on the initial oxygen permeability of the base paper, additional coatings on the packaging material, and the required oxygen permeability of the packaging material. Based on the inventors' findings, a large amount of base paper and packaging material can be covered within the inventive, preferred, and particularly preferred range.

[0037] The mass ratio of starch to pectin in a starch-pectin mixture is crucial and can only vary within certain limits. Preferably, the mass ratio of starch to pectin in one or more layers of a starch-pectin coating is between 1000:15 and 100:4, particularly preferably between 100:1 and 100:3. These ranges, and the ranges according to the invention, are understood to include limits. The inventors have discovered that oxygen permeability can be minimized if the mass ratio of starch to pectin is about 100:2. These mass ratios are not taken into account for coatings on packaging materials containing either starch or pectin but not mixtures thereof.

[0038] The starch-pectin coating may contain other substances. In addition to the starch and pectin mixture, the starch-pectin coating preferably additionally contains microfibrillated cellulose (MFC), microcrystalline cellulose (MCC), nanofibrillated cellulose (NFC), or nanocrystalline cellulose (NCC), or mixtures thereof. Particularly preferably, in each of one or more layers of the starch-pectin coating, the total mass of microfibrillated cellulose, microcrystalline cellulose, nanofibrillated cellulose, and / or nanocrystalline cellulose is at least 1% and at most 10%, particularly preferably at least 2% and at most 8%, of the mass of starch in the starch-pectin mixture. According to the inventors, the addition of microfibrillated cellulose, microcrystalline cellulose, nanofibrillated cellulose, or nanocrystalline cellulose produces a surprising synergistic effect with pectin, thereby significantly reducing oxygen permeability without increasing the coating amount. Therefore, in this preferred variant of the packaging material according to the invention, the oxygen permeability through the packaging material in at least one direction is at least 1 cm³ / (m²·d) and at most 150 cm³ / (m²·d), as measured according to ASTM D3985-17 at 0% relative humidity and 23°C.

[0039] The starch-pectin coating can be applied to the entire surface or a portion of the surface of one side of the base paper. Preferably, the starch-pectin coating covers at least 70% and at most 100%, particularly preferably at least 90% and at most 100%, of the surface of one side of the base paper. For some applications, oxygen barrier properties are required only on a portion of the surface of the packaging material; in this case, the starch-pectin coating covers at least 5% and at most 30% of the surface of one side of the base paper. In other applications, particularly high oxygen barrier properties may be required. For these applications, the starch-pectin coating is preferably applied to both sides of the base paper, wherein the above-mentioned amount, mass ratio, and surface area ratio are applied to the coating on each of the two sides.

[0040] The base paper itself may also include one or more additional coatings. These one or more additional coatings are preferably applied to one side of the base paper, which is also intended for starch-pectin coating, but they may also be applied to the other side or both sides of the base paper.

[0041] In a preferred embodiment of the packaging material according to the invention, the base paper includes at least one additional coating applied to the side of the base paper intended for coating a starch-pectin coating. In this preferred embodiment, the additional coating contains starch but not pectin, and the mass of starch in this additional coating is at least 1.0 g / m² and at most 5.0 g / m² relative to the area covered by this additional coating. This indicates that the condition of this additional coating being "pectin-free" preferably also includes the case where the additional coating contains trace amounts of pectin, particularly trace amounts of 1‰ or less of the starch mass.

[0042] In a preferred embodiment of the packaging material according to the invention, the base paper further includes at least two additional coatings applied to the side of the base paper intended for coating a starch-pectin coating. However, in this preferred embodiment, the first additional coating contains starch but not pectin, and the mass of starch in this first additional coating is at least 1.0 g / m² and at most 4.0 g / m² relative to the area covered by this first additional coating.

[0043] Furthermore, in this preferred embodiment, the second additional coating comprises starch, kaolin, and a crosslinking agent, particularly preferably glyoxal, but without pectin, wherein the mass of starch is at least 50% and at most 85% of the mass of the second additional coating, the mass of kaolin is at least 10% and at most 40% of the mass of the second additional coating, and the mass of the crosslinking agent is at least 1% and at most 5% of the mass of the second additional coating, and the mass of the second additional coating relative to the area covered by the second additional coating is at least 1.0 g / m² and at most 3.0 g / m².

[0044] The inventors' experiments have shown that these additional coatings can further enhance the oxygen permeability reduction effect of the starch-pectin mixture. Therefore, in this preferred variant of the packaging material according to the invention, the oxygen permeability through the packaging material in at least one direction is at least 1 cm³ / (m²·d) and at most 100 cm³ / (m²·d), as measured according to ASTM D3985-17 at 0% relative humidity and 23°C.

[0045] The packaging material according to the invention has oxygen barrier properties. Preferably, generally, the oxygen permeability (OTR) through the packaging material in at least one direction, measured according to ASTM D3985-17 at 0% relative humidity and 23°C, is at least 3 cm³ / (m²·d) and at most 400 cm³ / (m²·d), and particularly preferably at least 5 cm³ / (m²·d) and at most 200 cm³ / (m²·d).

[0046] Another advantage of the packaging material according to the invention is its particularly low oxygen barrier properties even at high relative humidity. Preferably, the oxygen permeability (OTR) through the packaging material in at least one direction, measured according to ASTM D3985-17 at 50% relative humidity and 23°C, is at least 2 cm³ / (m²·d) and at most 50 cm³ / (m²·d), and particularly preferably at least 3 cm³ / (m²·d) and at most 40 cm³ / (m²·d).

[0047] The packaging material according to the invention can have advantageous water absorption properties. Preferably, at least one side of the packaging material has Cobb... 60 The value is at least 5 g / m² and at most 35 g / m², particularly preferably at least 10 g / m² and at most 30 g / m². Cobb can be measured according to ISO 535:2023. 60 value.

[0048] Mechanical properties are important for packaging materials. Despite the low basis weight of the base paper, the packaging material according to the invention preferably has a tensile strength of at least 20 N / 15 mm and at most 100 N / 15 mm in at least one direction. The packaging material according to the invention preferably has an elongation at break of at least 1% and at most 5% in at least one direction. Tensile strength and elongation at break can be measured according to ISO 1924-2:2008.

[0049] The burst strength of the packaging material is also important. Preferably, the burst strength of the packaging material according to the invention, on the side with the starch-pectin coating, is at least 100 kPa and at most 250 kPa. The burst strength can be measured according to ISO 2758:2014.

[0050] The ecological advantages of packaging materials stem from the raw materials used to manufacture the packaging materials according to the present invention. For ecological reasons, it is advantageous if the packaging materials do not contain certain materials.

[0051] Therefore, preferably, the packaging material according to the invention does not include metal foil or plastic film made from mineral oil. Metal foil and plastic film can form excellent oxygen barrier properties, but their disposal is a fundamental advantage of the invention.

[0052] Preferably, at least 90% and particularly preferably at least 95% of the organic mass of the packaging material is formed from renewable raw materials. In the case of this invention, raw materials are renewable if the consumed raw materials can be replaced by natural processes within a relatively short period of time. Cellulose fibers, pulp fibers, starch, pectin, as well as microfibrillated cellulose and nanofibrillated cellulose, and microcrystalline cellulose and nanocrystalline cellulose from sources commonly used in the industry are considered renewable raw materials in this case, while mineral oil-based products that will only be naturally replaced after millions of years are not renewable raw materials. Organic matter should be understood as a substance formed in a chemical sense by organic compounds. For example, cellulose fibers, pulp fibers, starch, or pectin form part of organic matter, while fillers or pigments such as kaolin, talc, calcium carbonate, magnesium carbonate, magnesium oxide, magnesium hydroxide, alumina, aluminum hydroxide, and titanium dioxide are not considered organic matter.

[0053] In a preferred embodiment of the packaging material according to the invention, one or more additional coatings may be applied to one or both sides of the packaging material, particularly preferably forming a barrier coating that prevents the penetration of water, water vapor, fat or grease, and more particularly preferably forming one or more coatings that prevent the penetration of water or water vapor.

[0054] In a preferred embodiment of the packaging material according to the invention, the packaging material is printed on at least one side.

[0055] The packaging material according to the invention is particularly suitable for packaging solid food products. Therefore, another aspect of the invention relates to packaging products. A packaging product according to the invention comprises the packaging material according to the invention, a solid food product, and preferably a protective gas, wherein the solid food product is packaged in the packaging material, and preferably, the solid food product is selected from rice, sugar, pasta, chocolate, chocolate bars, nuts, muesli, cheese, pastries, meat, coffee, tea, tobacco, or tobacco products. In this respect, "protective gas" means that the proportion of oxygen in the gas present in the packaging product is less than 15% of the volume of the gas present in the packaging product.

[0056] Another aspect of the invention relates to a method by which packaging material, particularly according to one of the foregoing embodiments, can be manufactured. The method according to this aspect of the invention comprises steps A through C.

[0057] A – Provides base paper, B – Apply one or more coating compositions to at least one side of the base paper. C – Dry the coated base paper from step B. The base paper in step A has a basis weight of at least 30 g / m² and at most 90 g / m², and Each of the one or more coating compositions from step B comprises a mixture of starch and pectin, wherein the mass ratio of starch to pectin in each mixture is from 1000:5 to 100:5, and the total mass of the starch and pectin mixture is at least 1.5 g / m² and at most 12.0 g / m² relative to the area on the base paper coated with the mixture after drying in step C. Following step C, the packaging material, measured according to ASTM D3985-17 at 0% relative humidity and 23°C, has an oxygen permeability of at least 1 cm³ / (m²·d) and at most 500 cm³ / (m²·d) through the packaging material in at least one direction.

[0058] According to the method of the invention, in step B, only one coating composition is applied, and where appropriate, in several successive coating steps, the coating composition comprises a mixture of starch and pectin in a mass ratio of 1000:5 to 100:5. In this case, "the total mass of the starch and pectin mixture" refers to the mass of the mixture in the one coating composition.

[0059] In other embodiments, several coating compositions may be applied sequentially in step B. These coating compositions are different from each other, but each contains a mixture of starch and pectin in a respective mass ratio, which is also within the range of 1000:5 to 100:5. In this case, the "total mass of the starch and pectin mixture" is the sum of the masses of the mixtures coated as components of the several coating compositions.

[0060] Preferably, the provision of the base paper in step A includes manufacturing the base paper on a paper machine, particularly preferably a Fourdrinier paper machine.

[0061] Preferably, the base paper from step A has a basis weight of at least 35 g / m² and at most 80 g / m², particularly preferably at least 35 g / m² and at most 70 g / m².

[0062] The base paper from step A preferably comprises cellulose fibers, particularly preferably formed from pulp fibers or fibers derived from regenerated cellulose, or mixtures thereof. The pulp fibers are more preferably derived from coniferous wood, especially spruce, pine, or fir; deciduous wood, especially beech, birch, or eucalyptus; hemp, flax, jute, ramie, kenaf, kapok, coconut, Manila hemp, sisal, bamboo, cotton, or fine-stemmed needlegrass; or waste paper pulp; or a mixture of pulp fibers from several of these sources.

[0063] Particularly preferred is that the fiber derived from regenerated cellulose is a fibrillable fiber derived from regenerated cellulose.

[0064] Preferably, the proportion of each cellulose fiber relative to the mass of the base paper from step A is at least 55% and at most 100%, particularly preferably at least 70% and at most 99%.

[0065] The base paper from step A preferably contains fillers. Particularly preferably, the fillers are selected from kaolin, talc, calcium carbonate, magnesium carbonate, magnesium oxide, magnesium hydroxide, aluminum oxide, aluminum hydroxide, titanium dioxide, or mixtures thereof.

[0066] Preferably, the filler content is at least 1% and at most 45% relative to the mass of the base paper from step A, and particularly preferably at least 2% and at most 30%.

[0067] Preferably, the provision of the base paper in step A includes calendering the base paper.

[0068] Preferably, the starch in the respective starch-pectin mixtures of the coating compositions in step B is selected from corn starch, potato starch, tapioca starch, yam starch, rice starch, degraded starch, or mixtures of two or more of these starches. Particularly preferred is that the starch is degraded starch, and more particularly preferred is dextrin.

[0069] Preferably, the pectin in the respective starch-pectin mixtures of the coating compositions in step B is derived from one or more plants selected from citrus fruits, apples, oranges, rosehips, cherries, or carrots. Particularly preferably, the pectin is derived from citrus fruits.

[0070] Preferably, the pectin in the respective starch and pectin mixtures of the coating compositions in step B is pectin with an esterification degree of at least 65% and at most 80%, particularly preferably at least 69% and at most 75%.

[0071] Preferably, after drying in step C, the total mass of the starch and pectin mixture is at least 2.0 g / m² and at most 10.0 g / m², particularly preferably at least 2.0 g / m² and at most 8.0 g / m², relative to the area actually coated by each mixture in step B.

[0072] Preferably, the mass ratio of starch to pectin in the respective starch-pectin mixtures of the coating compositions in step B is from 1000:15 to 100:4, and more preferably from 100:1 to 100:3. These ranges and the ranges according to the invention are understood to include limits.

[0073] In addition to the starch and pectin mixture, each coating composition in step B preferably additionally contains microfibrillated cellulose, microcrystalline cellulose, nanofibrillated cellulose, or nanocrystalline cellulose, or mixtures thereof. Particularly preferably, in step B, the total mass of microfibrillated cellulose, microcrystalline cellulose, nanofibrillated cellulose, and / or nanocrystalline cellulose is at least 1% and at most 10%, more particularly preferably at least 2% and at most 8% of the mass of starch in the respective starch and pectin mixture of each coating composition. In this particularly preferred variant of the method according to the invention, after step C, the oxygen permeability of the packaging material in at least one direction is at least 1 cm³ / (m²·d) and at most 150 cm³ / (m²·d), as measured according to ASTM D3985-17 at 0% relative humidity and 23°C.

[0074] Preferably, each coating composition in step B comprises a mixture of starch and pectin and water. Particularly preferably, the solids content of each coating composition in step B is at least 10% and at most 40% by mass of the coating composition, and particularly preferably at least 15% and at most 35%.

[0075] Preferably, at least one of the coating compositions in step B has a viscosity of at least 300 cP and at most 3000 cP, particularly preferably at least 500 cP and at most 2500 cP, at 45°C.

[0076] In a preferred embodiment of the method according to the invention, applying one or more coatings in step B includes coating in a film press, a sizing machine, a jet coater, a gravure coater, a reverse gravure coater, or a bar coater.

[0077] In a preferred embodiment of the method according to the invention, drying in step C includes drying with hot air, drying with microwave radiation, drying with infrared radiation, or drying by contact with at least one heated drying cylinder, or a combination of these methods.

[0078] In a preferred embodiment of the method according to the invention, the provision of the base paper in step A includes applying at least one additional coating composition to one or more coating compositions of step B on the side of the base paper that has been coated in step B, and additional subsequent drying of the base paper.

[0079] In a particularly preferred embodiment of the method, the additional coating composition comprises starch and water but not pectin, and is applied in such an amount that, after additional drying, the mass of starch in the additional coating is at least 1.0 g / m² and at most 5.0 g / m² relative to the area already coated by the additional coating.

[0080] In a preferred embodiment of the method according to the invention, the provision of the base paper in step A includes coating at least two additional coating compositions onto the side of the base paper that has been coated with one or more coating compositions in step B, and additional drying after each coating of the additional coating compositions.

[0081] In a particularly preferred embodiment of the method, the first additional coating composition comprises starch and water but not pectin, and is applied in an amount such that, after drying the first additional coating composition, the mass of starch from the first additional coating composition is at least 1.0 g / m² and at most 4.0 g / m² relative to the area already coated by the first additional coating composition. Furthermore, in this particularly preferred embodiment, the second additional coating composition comprises water, starch, kaolin, and a crosslinking agent, more particularly preferably glyoxal, but excluding pectin, wherein the starch comprises at least 50% and at most 85% by mass, the kaolin comprises at least 10% and at most 40% by mass, and the crosslinking agent comprises at least 1% and at most 5% by mass, each relative to the mass of solids in the second additional coating composition, and the second additional coating composition is applied in an amount such that, after drying the second additional coating composition, the mass of solids in the second additional coating composition relative to the area coated by the second additional coating composition is at least 1.0 g / m² and at most 3.0 g / m².

[0082] In this particularly preferred variant of the method according to the invention, after step C, the oxygen permeability of the packaging material in at least one direction is at least 1 cm³ / (m²·d) and at most 100 cm³ / (m²·d), as measured according to ASTM D3985-17 at 0% relative humidity and 23°C.

[0083] Description of preferred embodiments and comparison with embodiments not conforming to the present invention

[0084] Some preferred embodiments of the packaging materials and methods according to the invention will be described below by way of examples and packaging materials that do not conform to the invention, with comparative examples shown.

[0085] Two types of base paper, P1 and P2, are used to manufacture exemplary embodiments according to the present invention and comparative examples that do not conform to the present invention.

[0086] According to step A of the method of the present invention, a first base paper P1 comprising a mixture of pulp fibers from deciduous and coniferous trees and titanium dioxide is provided by manufacturing a first base paper P1 on a paper machine. The amount of titanium dioxide is about 1% of the mass of the base paper P1; the remaining mass is substantially formed by the pulp fibers. The base paper P1 also contains a resin sizing agent as a sizing agent.

[0087] According to ISO 536:2019, the basis weight of P1 base paper is approximately 40 g / m².

[0088] Furthermore, according to step A of the method of the present invention, a second preliminary base paper comprising a mixture of pulp fibers from deciduous and coniferous wood and titanium dioxide is produced on a paper machine. The amount of titanium dioxide is about 3% of the mass of the base paper P2, with the remaining mass formed substantially by the pulp fibers of the base paper P2 and subsequent coating.

[0089] The base paper P2 also contains alkyl ketene dimers as sizing agents.

[0090] According to a preferred embodiment of the method of the present invention, in step A for providing base paper P2, two additional coating compositions are applied to the preliminary base paper. The first additional coating composition consists of water and oxidized starch, and is applied to the entire surface in an amount such that after drying the first additional coating composition, approximately 2.5 g / m² of oxidized starch remains on the base paper. The second additional coating composition contains water and 67% oxidized starch, 30% kaolin, and 3% glyoxal as solid materials, each relative to the mass of the solid materials, and is applied in an amount such that after drying the second additional coating composition, approximately 2.0 g / m² of solid material remains on the finished base paper P2.

[0091] According to ISO 536:2019, the basis weight of P2 base paper is approximately 38.5 g / m².

[0092] Furthermore, in step B of the method according to the invention, base papers P1 and P2 are coated with different coating compositions, wherein, for an exemplary embodiment of the invention, the coating compositions consist of water, starch, pectin, and optionally microfibrillated cellulose.

[0093] For manufactures that do not conform to the comparative examples of the present invention, the coating compositions are applied in the same manner, but they consist only of water, starch, and optionally microfibrillated cellulose, and therefore do not contain pectin.

[0094] In step C of the method according to the invention, the coated base paper is dried, and thus a packaging material according to the invention and not according to the invention is obtained.

[0095] Oxygen permeability according to an exemplary embodiment of the invention and a comparative example not conforming to the invention were measured according to ASTM D3985-17 at 0% relative humidity and 23°C.

[0096] Table 1 contains (“BP”), the composition of the coating applied in step B, the coating amount (“W”) (g / m²), and the oxygen permeability (“OTR”) (cm³ / (m²·d)). Exemplary embodiments according to the invention are represented by Ax-y, while embodiments not conforming to the invention are represented by Zx-y, where x and y are each natural numbers. In Table 1, “Pec” refers to pectin, and “MFC” refers to microfibrillated cellulose. Pectin and microfibrillated cellulose are each given as a percentage of the starch mass relative to the coating composition of step B.

[0097] Table 1 - Data from exemplary embodiments of the present invention and comparative examples not conforming to the present invention.

[0098] A comparison of packaging material Z1-1, which does not conform to the present invention, with a set of exemplary embodiments A1-1, A1-2, and A1-3 according to the present invention shows that, for a comparable coating amount, the addition of 1%, 2%, or 3% pectin relative to the mass of starch can reduce the oxygen permeability from 628 cm³ / (m²·d) in Z1-1 to about 400 cm³ / (m²·d) to about 530 cm³ / (m²·d) in A1-1, A1-2, and A1-3. Therefore, these examples demonstrate the advantageous role of pectin in the mass range of starch to pectin from about 100:1 to about 100:3.

[0099] The same effect can also be observed with packaging material Z3-1 (not conforming to the present invention) and with base paper P2 according to embodiments A3-1, A3-2, and A3-3 of the present invention. Due to the additional coating on base paper P2, the oxygen permeability of packaging material Z3-1 (coated only with starch) (164 cm³ / (m²·d) is already low; however, the addition of 1% to 3% pectin relative to the mass of starch shows a further reduction of at least 20% in oxygen permeability in exemplary embodiments A3-1, A3-2, and A3-3 of the present invention, and a particularly significant reduction of 75% for exemplary embodiment A3-2. Therefore, these comparisons demonstrate that a starch to pectin mass ratio of 100:2 is particularly preferred. Surprisingly, a small amount of pectin has such a significant effect on oxygen permeability, and this effect occurs only within a relatively narrow range of starch to pectin mass ratios.

[0100] Further examples demonstrate the additional specific effects of combining microfibrillated cellulose with pectin. For packaging materials Z2-1 and Z2-2 that do not conform to the present invention, starch and 2% or 4% (relative to the mass of starch) of microfibrillated cellulose were coated onto a base paper P1. In this respect, an oxygen permeability of approximately 200 cm³ / (m²·d) was obtained. By adding 2% or 3% pectin relative to the mass of starch, oxygen permeability of 80 cm³ / (m²·d) or 33 cm³ / (m²·d) was obtained with a smaller coating amount in exemplary embodiments A2-1 and A2-2 according to the present invention. Since the pectin is combined with the microfibrillated cellulose, the oxygen permeability can be reduced by almost 85%. This effect is stronger than in other similar embodiments A1-2 according to the present invention and demonstrates an additional synergistic effect between pectin and microfibrillated cellulose.

[0101] The combination of pectin and microfibrillated cellulose also showed remarkable effects on the base paper P2. For packaging materials Z4-1 and Z4-2 that do not conform to the present invention, starch and 2% or 4% microfibrillated cellulose (relative to the mass of starch) were coated onto the base paper P2. In this respect, oxygen permeability of approximately 118 cm³ / (m²·d) or 85 cm³ / (m²·d) was obtained, respectively. By adding 2% or 3% pectin relative to the mass of starch, despite the lower coating amount, oxygen permeability of only 21 cm³ / (m²·d) or only 56 cm³ / (m²·d) was obtained in exemplary embodiments A4-1 and A4-2 according to the present invention. Therefore, in exemplary embodiment A4-1, compared to Z4-2, the oxygen permeability can be reduced by approximately 75% due to the combination of pectin and microfibrillated cellulose, while in embodiment A4-1, less than half the amount of coating material is required. These examples provide evidence of the remarkable synergistic effect between pectin and microfibrillated cellulose, and further demonstrate that a starch to pectin mass ratio of 100:2 is found to be particularly preferred.

[0102] The ecological advantages of the exemplary embodiments of the present invention automatically derive from the raw materials used. At least 95% of the organic quality of all exemplary embodiments of the present invention is composed of renewable raw materials.

[0103] Regarding other properties, such as mechanical properties, optical properties, printability, and additional blocking effects, exemplary embodiments of the invention are well-suited for coating food packaging, thus enabling the manufacture of food packaging without any difficulty.

Claims

1. Packaging material, comprising a base paper and at least one coating on the base paper, wherein the base paper has a basis weight of at least 30 g / m2and at most 90 g / m2, wherein the at least one coating is a starch-pectin coating, which comprises one or more layers, each comprising a mixture of starch and pectin, the mass ratio of starch to pectin in the mixture being 1000:5 to 100:5, wherein the total mass of the mixture of starch and pectin in the one or the plurality of layers is at least 1.5 g / m2and at most 12.0 g / m2per area actually coated with the starch- pectin coating on the base paper, and wherein the packaging material has an oxygen permeability of at least 1 cm3 / (m2-d) and at most 500 cm3 / (m2-d) in at least one direction through the packaging material, measured according to ASTM D3985-17 at a relative humidity of 0% and a temperature of 23 °C.

2. Packaging material according to claim 1, wherein the base paper has a basis weight of at least 35 g / m2and at most 80 g / m2, preferably at least 35 g / m2and at most 70 g / m2.

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

4. Packaging material according to claim 3, wherein the pulp fibers are derived from coniferous wood, in particular spruce, pine or fir; deciduous wood, in particular beech, birch or eucalyptus; hemp, flax, jute, ramie, kenaf, kapok, coconut, abaca, sisal, bamboo, cotton or esparto; or waste paper pulp; or are a mixture of pulp fibers from several of these sources.

5. Packaging material according to claim 3 or 4, wherein in the pulp fibers at least 50% and at most 100%, preferably at least 70% and at most 100%, by mass of each are unbleached.

6. Packaging material according to claim 3 or 5, wherein the fibers from regenerated cellulose are fibrillatable fibers from regenerated cellulose.

7. Packaging material according to any one of claims 3 to 6, wherein the proportion of the cellulose fibers each relative to the mass of the base paper is at least 55% and at most 100%, preferably at least 70% and at most 99%.

8. Packaging material according to any one of the preceding claims, wherein the base paper comprises a filler, wherein 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, wherein the proportion of the filler each relative to the mass of the base paper is preferably at least 1% and at most 45%, particularly preferably at least 2% and at most 30%.

9. Packaging material according to any one of the preceding claims, wherein the base paper is calendered.

10. The packaging material according to any one of the preceding claims, wherein the starch is selected from corn starch, potato starch, tapioca starch, yam starch, rice starch, a degraded starch or a mixture of two or more of these starches.

11. The packaging material according to any one of the preceding claims, wherein the starch is a degraded starch, preferably a dextrin.

12. The packaging material according to any one of the preceding claims, wherein the pectin is a pectin derived from one or more plants selected from citrus fruits, apples, oranges, rose hips, cherries or carrots, wherein preferably at most 80% by mass of the pectin is derived from citrus fruits.

13. The packaging material according to any one of the preceding claims, wherein the pectin is a pectin having a degree of esterification of at least 65% and at most 80%, preferably at least 69% and at most 75%.

14. The packaging material according to any one of the preceding claims, wherein the total mass of the mixture of starch and pectin in the one or more layers of the starch-pectin coating on the packaging material is at least 2.0 g / m2and at most 10.0 g / m2, preferably at least 2.0 g / m2and at most 8.0 g / m2, relative to the area actually coated by the starch-pectin coating.

15. The packaging material according to any one of the preceding claims, wherein the mass ratio of starch to pectin in the mixture of starch and pectin in the one or more layers of the starch-pectin coating is 1000:15 to 100:4, preferably 100:1 to 100:3, respectively.

16. The packaging material according to any one of the preceding claims, wherein the mixture of starch and pectin additionally comprises microfibrillated cellulose (MFC), microcrystalline cellulose (MCC), nanofibrillated cellulose (NFC), nanocrystalline cellulose (NCC) or a mixture thereof.

17. The packaging material according to claim 16, wherein in each of the one or more layers of the starch-pectin coating, the mass of microfibrillated cellulose, microcrystalline cellulose, nanofibrillated cellulose and / or nanocrystalline cellulose is at least 1% and at most 10%, preferably at least 2% and at most 8%, of the mass of the starch in the mixture of starch and pectin.

18. The packaging material according to claim 17, having an oxygen permeability through the packaging material in at least one direction of at least 1 cm3 / (m2·d) and at most 150 cm3 / (m2·d) measured according to ASTM D3985-17 at a relative humidity of 0% and a temperature of 23 °C.

19. The packaging material according to any one of the preceding claims, wherein the starch- pectin coating is coated on at least 70% and at most 100%, preferably at least 90% and at most 100%, of the area of one side of the base paper.

20. The packaging material according to any one of claims 1 to 18, wherein the starch-pectin coating is coated on at least 5% and at most 30% of the area of one side of the base paper.

21. The packaging material according to any one of the preceding claims, comprising at least one further coating applied to the side of the base paper intended for coating with the starch-pectin coating, wherein the further coating comprises starch but no pectin, and the mass of the starch in the further coating is at least 1.0 g / m2and at most 5.0 g / m2per area of the further coating applied.

22. The packaging material according to any one of claims 1 to 20, comprising at least two further coatings applied to the side of the base paper intended for coating with the starch-pectin coating, wherein a first of the further coatings comprises starch but no pectin, and the mass of the starch in the first further coating is at least 1.0 g / m2and at most 4.0 g / m2per area of the first further coating applied, and wherein a second of the further coatings comprises starch, kaolin and a crosslinking agent, preferably glyoxal, but no pectin, wherein the mass of the starch is at least 50% and at most 85% of the mass of the second further coating, the mass of the kaolin is at least 10% and at most 40% of the mass of the second further coating, and the mass of the crosslinking agent is at least 1% and at most 5% of the mass of the second further coating, and wherein the mass of the second further coating is at least 1.0 g / m2and at most 3.0 g / m2per area of the second further coating applied.

23. The packaging material according to claim 22, wherein the oxygen permeability through the packaging material in at least one direction is at least 1 cm3 / (m2d) and at most 100 cm3 / (m2d) measured according to ASTM D3985-17 at a relative humidity of 0% and a temperature of 23 °C.

24. The packaging material according to any one of claims 1 to 21, wherein the oxygen permeability through the packaging material in at least one direction is at least 3 cm3 / (m2d) and at most 400 cm3 / (m2d), and preferably at least 5 cm3 / (m2d) and at most 200 cm3 / (m2d), measured according to ASTM 21-17 at a relative humidity of 0% and a temperature of 23 °C.

25. The packaging material according to any one of the preceding claims, wherein the oxygen permeability through the packaging material in at least one direction is at least 2 cm3 / (m2d) and at most 50 cm3 / (m2d), and preferably at least 3 cm3 / (m2d) and at most 40 cm3 / (m2d), measured according to ASTM D3985-17 at a relative humidity of 50% and a temperature of 23 °C.

26. The packaging material according to any one of the preceding claims, wherein the Cobb 60 value of at least 5 g / m2and at most 35 g / m2, preferably at least 10 g / m2and at most 30 g / m2.​ 27. The packaging material according to any one of the preceding claims having a tensile strength in at least one direction of at least 20 N / 15 mm and at most 100 N / 15 mm.

28. The packaging material according to any one of the preceding claims having an elongation at break of at least 1 % and at most 5 %.

29. The packaging material according to any one of the preceding claims, wherein the burst strength of the side where the starch-pectin coating is located is at least 100 kPa and at most 250 kPa.

30. The packaging material according to any one of the preceding claims, which is free of metal foils and free of plastic films made from mineral oil.

31. The packaging material according to any one of the preceding claims, wherein at least 90 %, preferably at least 95 % of the organic mass of the packaging material is formed by renewable raw materials.

32. A package comprising the packaging material according to any one of the preceding claims, a solid food and preferably a protective gas, wherein the solid food is packaged in the packaging material, wherein the solid food is preferably selected from rice, sugar, pasta, chocolate, chocolate bars, nuts, muesli, cheese, pastries, meat, coffee, tea, tobacco or a tobacco product.

33. A method of manufacturing a packaging material, comprising the steps A to C: A - providing a base paper, B - applying one or more coating compositions to at least one side of the base paper, C - drying the coated base paper from step B, wherein the base paper in step A has a basis weight of at least 30 g / m2and at most 90 g / m2, and wherein the one or more coating compositions from step B each comprise a mixture of starch and pectin, and the mass ratio of starch to pectin in each mixture is 1000:5 to 100:5, wherein the total mass of the mixture or mixtures of the mixture of starch and pectin is at least 1.5 g / m2and at most 12.0 g / m2relative to the area on the base paper to which the mixture or mixtures has or have been applied after drying in step C, and wherein after step C, the packaging material has an oxygen permeability of at least 1 cm3 / (m2d) and at most 500 cm3 / (m2d) through the packaging material in at least one direction, measured according to ASTM D3985-17 at a relative humidity of 0 % and a temperature of 23 °C.

34. The method according to claim 33, wherein the providing of the base paper in step A comprises manufacturing the base paper on a paper machine, preferably the paper machine is a Fourdrinier paper machine.

35. The method according to claim 33 or 34, wherein the base paper from step A has a basis weight of at least 35 g / m2and at most 80 g / m2, preferably at least 35 g / m2and at most 70 g / m2.

36. The method according to any one of claims 33 to 35, wherein the base paper from step A comprises cellulose fibers, wherein the cellulose fibers are preferably formed by pulp fibers or fibers from regenerated cellulose or a mixture thereof.

37. The method according to claim 36, wherein the pulp fibres are derived from coniferous wood, in particular spruce, pine or fir; deciduous wood, in particular beech, birch or eucalyptus; hemp, flax, jute, ramie, kenaf, kapok, coconut, abaca, sisal, bamboo, cotton or esparto; or waste paper pulp; or are a mixture of pulp fibres from several of these sources.

38. The method according to claim 36, wherein the fibres from regenerated cellulose are fibrillatable fibres from regenerated cellulose.

39. The method according to any one of claims 36 to 38, wherein the proportion of the cellulose fibres each relative to the mass of the base paper from step A is at least 55% and at most 100%, preferably at least 70% and at most 99%.

40. The method according to any one of claims 33 to 39, wherein the base paper from step A comprises a filler, wherein the filler is preferably selected from the group consisting of kaolin, talc, calcium carbonate, magnesium carbonate, magnesium oxide, magnesium hydroxide, aluminium oxide, aluminium hydroxide, titanium dioxide or mixtures thereof.

41. The method according to claim 40, wherein the proportion of the filler each relative to the mass of the base paper from step A is at least 1% and at most 45%, preferably at least 2% and at most 30%.

42. The method according to any one of claims 33 to 41, wherein the step of providing the base paper in step A comprises calendering the base paper.

43. The method according to any one of claims 33 to 42, wherein the starch in the starch and pectin mixture each in the coating composition in step B is selected from the group consisting of corn starch, potato starch, tapioca starch, yam starch, rice starch, degraded starch or a mixture of two or more of these starches, wherein the starch is preferably a degraded starch, preferably dextrin.

44. The method according to any one of claims 33 to 43, wherein the pectin in the starch and pectin mixture each in the coating composition is a pectin derived from one or more plants selected from the group consisting of citrus fruits, apples, oranges, rose hips, cherries or carrots.

45. The method according to any one of claims 33 to 44, wherein the pectin in the starch and pectin mixture each in the coating composition in step B is a pectin having a degree of esterification of at least 65% and at most 80%, preferably at least 69% and at most 75%.

46. The method according to any one of claims 33 to 45, wherein the total mass of the starch and pectin mixture after drying in step C is at least 2.0 g / m2and at most 10.0 g / m2, preferably at least 2.0 g / m2and at most 8.0 g / m2, relative to the area to which the mixture or the mixtures have actually been applied in step B.

47. The method according to any one of claims 33 to 46, wherein the mass ratio of starch to pectin in the respective mixture of starch and pectin in the respective coating composition in step B is from 1000:15 to 100:4, and preferably from 100:1 to 100:

3.

48. The method of any one of claims 33 to 47, wherein, In addition to the mixture of starch and pectin, in step B the respective coating composition additionally comprises microfibrillated cellulose, microcrystalline cellulose, nanofibrillated cellulose or nanocrystalline cellulose or mixtures thereof.

49. The method according to claim 48, wherein in step B the mass of microfibrillated cellulose, microcrystalline cellulose, nanofibrillated cellulose and / or nanocrystalline cellulose is at least 1% and at most 10%, preferably at least 2% and at most 8% of the mass of the starch in the mixture of starch and pectin in the respective coating composition, wherein after step C the packaging material has an oxygen permeability of at least 1 cm³ / (m²·d) and at most 150 cm³ / (m²·d) in at least one direction through the packaging material measured according to ASTM D3985-17 at a relative humidity of 0% and a temperature of 23 °C.

50. The method according to any one of claims 32 to 48, wherein the respective coating composition in step C comprises the mixture of starch and pectin and water, wherein the solids content of the coating composition from step B is each preferably at least 10% and at most 40%, particularly preferably at least 15% and at most 35% relative to the mass of the respective coating composition.

51. The method according to any one of claims 33 to 50, wherein at least one of the coating compositions in step B has a viscosity of at least 300 cP and at most 3000 cP, preferably at least 500 cP and at most 2500 cP at 45 °C.

52. The method according to any one of claims 33 to 51, wherein the coating of the coating in step B comprises coating in a film press, a size press, a jet coater, a gravure coater, an inverse gravure coater or a rod coater.

53. The method according to any one of claims 33 to 52, wherein the provision of the base paper in step A comprises coating at least one further coating composition to the one or more coating compositions from step B on the one side of the base paper in step B, and an additional subsequent drying of the base paper.

54. The method according to claim 53, wherein the further coating composition contains starch and water, but does not comprise pectin, and is coated in an amount such that after the additional drying the mass of the starch in the further coating is at least 1.0 g / m² and at most 5.0 g / m² relative to the area of the further coating coated.

55. The method according to any one of claims 33 to 52, wherein the providing of the base paper in step A comprises coating at least two further coating compositions to the side of the base paper to which the coating composition from step B is coated in step B, and additional drying of the further coating compositions after each coating, wherein a first of the further coating compositions preferably comprises starch and water, but no pectin, and is coated in an amount such that, after drying of the first further coating composition, the mass of the starch from the first further coating composition is at least 1.0 g / m2and at most 4.0 g / m2per area of the first further coating composition coated, and wherein a second of the further coating compositions preferably comprises water, starch, kaolin, and a crosslinker, more particularly preferably glyoxal, but no pectin, wherein the mass of the starch is at least 50% and at most 85%, the mass of the kaolin is at least 10% and at most 40%, and the mass of the crosslinker is at least 1% and at most 5%, each relative to the mass of the solid material in the second further coating composition, and and wherein the second further coating composition is preferably coated in an amount such that, after drying of the second further coating composition, the mass of the solid material in the second further coating composition is at least 1.0 g / m2and at most 3.0 g / m2per area of the second further coating composition coated, wherein the oxygen permeability of the packaging material in at least one direction, measured according to ASTM D3985-17 at a relative humidity of 0% and a temperature of 23 °C, is preferably at least 1 cm3 / (m2d) and at most 100 cm3 / (m2d) after step C.

55. The method according to any one of claims 33 to 52, wherein the providing of the base paper in step A comprises coating at least two further coating compositions to the side of the base paper to which the coating composition from step B is coated in step B, and additional drying of the further coating compositions after each coating, wherein a first of the further coating compositions preferably comprises starch and water, but no pectin, and is coated in an amount such that, after drying of the first further coating composition, the mass of the starch from the first further coating composition is at least 1.0 g / m2and at most 4.0 g / m2per area of the first further coating composition coated, and wherein a second of the further coating compositions preferably comprises water, starch, kaolin, and a crosslinker, more particularly preferably glyoxal, but no pectin, wherein the mass of the starch is at least 50% and at most 85%, the mass of the kaolin is at least 10% and at most 40%, and the mass of the crosslinker is at least 1% and at most 5%, each relative to the mass of the solid material in the second further coating composition, and and wherein the second further coating composition is preferably coated in an amount such that, after drying of the second further coating composition, the mass of the solid material in the second further coating composition is at least 1.0 g / m2and at most 3.0 g / m2per area of the second further coating composition coated, wherein the oxygen permeability of the packaging material in at least one direction, measured according to ASTM D3985-17 at a relative humidity of 0% and a temperature of 23 °C, is preferably at least 1 cm3 / (m2d) and at most 100 cm3 / (m2d) after step C.

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