Packaging material with improved oxygen barrier

Abstract

The invention discloses a packaging material which comprises 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, wherein the at least one coating is a starch / pectin coating comprising one or more layers each comprising a mixture of starch and pectin with a mass ratio of starch to pectin in the mixture of between 1000:5 and 100:5, wherein the total mass of the mixture of starch and pectin in the aforementioned one or more layers in relation to the surface area over which the starch / pectin coating is actually applied to the base paper is at least 1.5 g / m² and at most 12.0 g / m², and wherein the packaging material has an oxygen permeability in at least one direction through the packaging material - measured in accordance with ASTM D3985-17 at a relative humidity of 0% and a temperature of 23°C - of at least 1 cm³ / (m²×d) and at most 500 cm³ / (m²×d).

Description

[0001] PACKAGING MATERIAL WITH IMPROVED OXYGEN BARRIER

[0002] FIELD OF THE INVENTION

[0003] The invention relates to a packaging material made essentially from renewable raw materials and having a coating that allows the oxygen permeability of the packaging material to be particularly efficiently reduced despite a small amount of coating material. The invention also relates to a package made from this packaging material and a method for producing such a packaging material.

[0004] BACKGROUND AND STATE OF THE ART

[0005] For environmental reasons, there has been a significant demand in recent years to replace packaging materials based on plastic films with other materials. Paper has emerged as a significant alternative. While paper is superior to plastic films in terms of environmental aspects and, for example, printability, there are important technical properties where comparable performance can only be achieved through additional measures.

[0006] One example of such properties is barrier properties. Many packaging material applications require barrier properties, for example, against water vapor, oxygen, water, oils, and fats. In paper, such properties are typically achieved through additional coatings, although there is still room for improvement.

[0007] Especially for food packaging materials, there is a need for the packaging material to have a high barrier to oxygen penetration in order to extend the shelf life of the packaged food. Such high barriers can often only be achieved with paper by applying a large amount of coating material. This increases the material consumption in the production of the packaging material.

[0008] Material consumption can also be reduced by choosing paper with a low basis weight as the starting material for the packaging material. However, since such thin and lightweight papers have only a low barrier effect in themselves, the problem is exacerbated and can often only be remedied by coating with more material.

[0009] Some coating materials that provide a good oxygen barrier are also not derived from renewable resources. In this case, the ecological advantages of paper over plastic films cannot be fully utilized.

[0010] There is therefore a need in the industry to provide paper with a coating that reduces oxygen permeability as efficiently as possible. Furthermore, the coating material should be made from renewable raw materials.

[0011] SUMMARY OF THE INVENTION

[0012] The object of the invention is to provide a packaging material that has a low basis weight, a good oxygen barrier, and contains little coating material to create this oxygen barrier. The raw materials used should come from renewable sources as far as possible.

[0013] This object is achieved by a packaging material according to claim 1, a package according to claim 32, and a method for producing a packaging material according to claim 33. Advantageous further developments are specified in the dependent claims.

[0014] The object is achieved by 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 2 and a maximum of 90 g / m 2and wherein the at least one coating is a starch-pectin coating comprising one or more layers, each comprising a mixture of starch and pectin in a mass ratio of starch to pectin in the mixture of between 1000:5 and 100:5, and the total mass of the mixture of starch and pectin in said one or more layers, based on the area to which the starch-pectin coating is actually applied on the base paper, is at least 1.5 g / m 2 and a maximum of 12.0 g / m 2 The packaging material has an oxygen permeability 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, of ​​at least 1 cm 3 / (m 2 xd) and a maximum of 500 cm 3 / (m 2 xd).

[0015] The packaging material comprises a base paper with a low basis weight. Such base papers inherently exhibit high oxygen permeability, so there is a need to reduce oxygen permeability as efficiently as possible, i.e., with minimal material consumption.

[0016] A starch-pectin coating comprising a mixture of starch and pectin is applied to the base paper. The term "starch-pectin coating" is used in the present disclosure primarily to describe the coating in question, but is not intended to exclude the possibility that this coating also contains other components besides starch and pectin. In the art, "coating" is understood to mean a manufacturing process used to apply a firmly adhering layer of amorphous material to the surface of an object. Both the corresponding application process and the applied layer itself are referred to in the art as a "coating." Such a coating can consist of a single layer applied in a single application step.However, a “coating” can also comprise several interconnected layers, which are obtained, for example, by applying different coating compositions one after the other.

[0017] In this sense, the starch-pectin coating of the invention may, in some embodiments, comprise a single layer. Such a single layer is obtainable, for example, by applying a coating composition comprising a mixture of starch and pectin in a mass ratio of 1000:5 and 100:5 to the base paper in a single coating operation. The above-mentioned "total mass of the mixture of starch and pectin" in this case simply refers to the mass of the mixture of starch and pectin in this single layer of the starch-pectin coating.

[0018] However, a single layer within the meaning of the present disclosure can also be obtained by successively applying the same coating composition one on top of the other in several steps. In this case, although several coating processes are involved, they generally result in layers that are indistinguishable from one another due to the identical coating composition, so that in this case too, only a single layer would be present within the meaning of the present disclosure. In this case, too, the above-mentioned "total mass of the mixture of starch and pectin" simply corresponds to the mass of the mixture of starch and pectin in this single layer of the starch-pectin coating, even if the mixture was applied in several application steps.

[0019] In yet further embodiments, the "starch-pectin coating" may comprise multiple, distinguishable layers, each of which, in this case, comprises a mixture of starch and pectin. The mass ratios of starch to pectin in the mixture may vary in these multiple layers, provided, however, that this mass ratio in each of these multiple layers lies within the stated range of 1000:5 to 100:5. The above-mentioned "total mass of the mixture of starch and pectin" in this case corresponds to the sum of the masses of the respective mixture of starch and pectin in the multiple layers of the "starch-pectin coating."

[0020] There may be additional layers or coatings which may also contain starch and / or pectin, but not in the stated mass ratio; however, these additional layers do not count as the above-mentioned 'one or more layers' and therefore do not contribute to the stated 'total mass of the mixture of starch and pectin'.

[0021] According to the inventors' findings, such a mixture of starch and pectin has proven particularly effective in reducing the oxygen permeability of the packaging material, with a starch-pectin mass ratio between 1000:5 and 100:5 proving particularly effective. This is surprising given that the proportion of pectin is relatively small, and the special effect does not occur at higher or lower mass ratios of starch and pectin. The inventors assume that the pectin acts as a gelling agent and, in combination with the starch, can thus efficiently seal the pores of the base paper.

[0022] The term "mixture" is to be understood broadly and is present when the starch and pectin are applied together in a coating composition to the base paper. There are no special requirements regarding the homogeneity of the mixture in the applied coating or in the coating composition used; it is sufficient to process the starch and pectin in the manner recommended by the manufacturer for application as a coating material.

[0023] The amount of starch and pectin applied to the base paper as part of the starch-pectin coating is relatively small compared to the achieved reduction in oxygen permeability. Since the oxygen permeability of the base paper can vary widely and the base paper can also have other coatings that influence oxygen permeability, the specific amount of starch and pectin depends significantly on how high the oxygen permeability is before the application of the starch-pectin coating and what oxygen permeability the packaging material is ultimately intended to have. According to the inventors' findings, however, the oxygen permeability can be reduced particularly efficiently using a mixture of starch and pectin in the mass ratio according to the invention, so that relatively little material is required to achieve a significant reduction in oxygen permeability.The oxygen permeability required by the packaging material depends on the specific application. The interval proposed here is well suited for packaging materials for food, but also for packaging materials for other goods that require protection from oxygen.

[0024] 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 / m 2 and a maximum of 80 g / m 2 and particularly preferably at least 35 g / m 2 and a maximum of 70 g / m 2The basis weight can be measured according to ISO 536:2019 and is the basis weight of the base paper immediately before the starch-pectin coating is applied. A base paper with a higher basis weight is more favorable in terms of barrier effect and mechanical properties, but the material consumption is also higher, so the basis weight should be kept as low as possible. With the starch-pectin coating according to the invention, it is possible to achieve low oxygen permeability at a low basis weight with a small applied amount of the starch-pectin mixture.

[0025] The base paper preferably comprises cellulose fibers, with the cellulose fibers particularly preferably being formed from pulp fibers or regenerated cellulose fibers or a mixture thereof. The pulp fibers are most preferably obtained from softwood, in particular 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 recycled paper pulp, or are a mixture of pulp fibers from several of these sources.

[0026] The pulp fibers can be bleached or unbleached, or they can be a mixture of bleached and unbleached pulp fibers in any ratio, since, apart from the color, they are practically equivalent in their technical performance in packaging materials. For ecological reasons, the proportion of unbleached pulp fibers can be higher, preferably at least 50% and at most 100%, particularly preferably at least 70% and at most 100%, each based on the mass of the pulp fibers.

[0027] The regenerated cellulose fibers are most preferably fibrillatable regenerated cellulose fibers. Such fibers are sold, for example, under the name Lyocell. The proportion of cellulose fibers is preferably at least 55% and at most 100%, particularly preferably at least 70% and at most 99%, based in each case on the mass of the base paper.

[0028] The base paper preferably comprises 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. The filler can contribute to the barrier effect and influence the optical properties of the base paper, for example, opacity, whiteness, or color.

[0029] Preferably, the proportion of filler is at least 1% and at most 45%, most preferably at least 2% and at most 30%, based on the mass of the base paper.

[0030] The base paper may contain further additives to influence certain properties of the base paper, for example sizing agents such as alkyl ketene dimers, alkenyl succinic anhydrides or resin sizes.

[0031] Preferably, the base paper is calendered. Calendering increases smoothness, thereby improving the homogeneity of the starch-pectin coating, and it densifies the base paper, thus reducing oxygen permeability.

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

[0033] The starch is preferably selected from the group consisting of corn starch, potato starch, cassava starch, yam starch, rice starch, degraded starch, or mixtures of two or more of these starches. The starch is particularly preferably a degraded starch, most preferably a dextrin. If the starch-pectin coating comprises multiple layers, different starches of the aforementioned types can also be used in different layers.

[0034] The pectin is preferably a pectin obtained from one or more plants selected from the group consisting of citrus fruits, apples, oranges, rose hips, cherries, or carrots. More preferably, at least 80% of the pectin is obtained from citrus fruits, based on its mass. If the starch-pectin coating comprises several layers, different pectins of the aforementioned pectins can be used in different layers. The pectin is preferably a pectin with a degree of esterification of at least 65% and at most 80%, particularly preferably of at least 69% and at most 75%. The degree of esterification influences gel formation, and according to the inventors' findings, degrees of esterification in the preferred and particularly preferred intervals have proven particularly favorable.

[0035] Preferably, 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, based on the area to which the starch-pectin coating is actually applied, is at least 2.0 g / m 2 and a maximum of 10.0 g / m 2 , particularly preferably at least 2.0 g / m 2 and a maximum of 8.0 g / m 2This total mass does not include coatings or layers of a multi-layer coating on the packaging paper that contain starch or pectin but not a mixture thereof, or that contain starch and pectin in a different mass ratio than that stated above. The amount of the mixture of starch and pectin required to achieve a certain oxygen permeability depends, among other things, on the initial oxygen permeability of the base paper, other coatings on the packaging material, and the desired oxygen permeability of the packaging material. According to the inventors' findings, a broad spectrum of base papers and packaging materials can be covered with the amount in the inventive, preferred, and particularly preferred intervals.

[0036] The mass ratio of starch to pectin in the starch-pectin mixture is essential and can only vary within certain limits. Preferably, the mass ratio of starch to pectin in the one or more layers of the starch-pectin coating is between 1000:15 and 100:4, and particularly preferably between 100:1 and 100:3. These intervals and the interval according to the invention are to be understood as inclusive of the limits. The inventors have found that oxygen permeability can be minimized if the mass ratio of starch to pectin is approximately 100:2. These mass ratios do not include coatings on the packaging paper that contain starch or pectin but not a mixture thereof.

[0037] The starch-pectin coating may contain additional substances. Preferably, in addition to the mixture of starch and pectin, the starch-pectin coating additionally comprises microfibrillated cellulose (MFC), microcrystalline cellulose (MCC), nanofibrillated cellulose (NFC), or nanocrystalline cellulose (NCC), or a mixture thereof. Particularly preferably, the combined mass of microfibrillated cellulose, microcrystalline cellulose, nanofibrillated cellulose, and / or nanocrystalline cellulose amounts to at least 1% and at most 10%, most preferably at least 2% and at most 8%, of the mass of the starch in the mixture of starch and pectin in the respective layer of said one or more layers of the starch-pectin coating.According to the inventors' findings, the addition of microfibrillated, microcrystalline, nanofibrillated, or nanocrystalline cellulose produces a surprising synergistic effect with the pectin, allowing oxygen permeability to be reduced even further without increasing the application rate. Therefore, in this preferred variant of the packaging material according to the invention, the oxygen permeability 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, is at least 1 cm². 3 / (m 2 xd) and a maximum of 150 cm 3 / (m 2 xd).

[0038] The starch-pectin coating can be applied to the entire surface or part of the surface of one side of the base paper. Preferably, the starch-pectin coating is applied to at least 70% and at most 100%, particularly preferably to at least 90% and at most 100% of the surface of one side of the base paper. For some applications, an oxygen barrier is only required on part of the surface of the packaging material; in this case, the starch-pectin coating is preferably applied to at least 5% and at most 30% of the surface of one side of the base paper. In other applications, a particularly high oxygen barrier may be desired. For these applications, the starch-pectin coating is preferably applied to both sides of the base paper, with the above-mentioned application quantities, mass ratios, and area proportions applying separately to the coating on each of the two sides.

[0039] The base paper itself may also comprise one or more additional coatings. These one or more additional coatings are preferably applied to the side of the base paper that is also intended for the starch-pectin coating, but they can also be applied to the other side or to both sides of the base paper.

[0040] In a preferred embodiment of the packaging material according to the invention, the base paper comprises at least one further coating applied to the side of the base paper intended for application of the starch-pectin coating. In this preferred embodiment, the further coating comprises starch but no pectin, and the mass of starch in this further coating, based on the area to which this further coating is applied, is at least 1.0 g / m 2 and a maximum of 5.0 g / m 2The statement that this further coating contains "no pectin" preferably also includes cases in which the further coating contains small traces of pectin, in particular traces amounting to 1% or less of the mass of the starch. In a preferred embodiment of the packaging material according to the invention, the base paper comprises at least two further coatings applied to that side of the base paper which is intended for the application of the starch-pectin coating. In this preferred embodiment, a first of the further coatings comprises starch but no pectin, and the mass of the starch in this first of the further coatings, based on the area to which this first of the further coatings is applied, is at least 1.0 g / m 2 and a maximum of 4.0 g / m 2 .

[0041] Furthermore, in this preferred embodiment, a second of the further coatings comprises starch, kaolin and a crosslinking agent, 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 crosslinking agent is at least 1% and at most 5% of the mass of the second of the further coatings and the mass of the second of the further coatings based on the area to which this second of the further coatings is applied is at least 1.0 g / m 2 and a maximum of 3.0 g / m 2 .

[0042] The inventors' experiments show that these additional coatings further enhance the reducing effect of the starch and pectin mixture on oxygen permeability. Therefore, in this preferred variant of the packaging material according to the invention, the oxygen permeability 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, is at least 1 cm 3 / (m 2 xd) and a maximum of 100 cm 3 / (m 2 xd).

[0043] The packaging material according to the invention has a barrier against oxygen. Preferably, the oxygen transmission rate (OTR) 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, is generally at least 3 cm 3 / (m 2 xd) and a maximum of 400 cm 3 / (m2 xd) and particularly preferably at least 5 cm 3 / (m 2 xd) and a maximum of 200 cm 3 / (m 2 xd).

[0044] A further advantage of the packaging material according to the invention is that the barrier to oxygen is particularly low, even at higher air humidity. Preferably, the oxygen transmission rate (OTR) in at least one direction through the packaging material, measured according to ASTM D3985-17 at a relative humidity of 50% and a temperature of 23°C, is at least 2 cm 3 / (m 2 xd) and a maximum of 50 cm 3 / (m 2 xd) and particularly preferably at least 3 cm 3 / (m 2 xd) and a maximum of 40 cm 3 / (m 2 xd). The packaging material according to the invention can have a favorable water absorption capacity. Preferably, the Cobbeo value of at least one side of the packaging material is at least 5 g / m2 and a maximum of 35 g / m 2 , particularly preferably at least 10 g / m 2 and a maximum of 30 g / m 2 The Cobbeo value can be measured according to ISO 535:2023.

[0045] Mechanical properties are important for a packaging material. Despite the low basis weight of the base paper, the packaging material according to the invention preferably has a tensile strength in at least one direction of at least 20 N / 15 mm and at most 100 N / 15 mm 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. The tensile strength and elongation at break can be measured according to ISO 1924-2:2008.

[0046] The burst strength of a packaging material is also important. Preferably, the packaging material according to the invention has a burst strength of at least 100 kPa and at most 250 kPa on the side bearing the starch-pectin coating. The burst strength can be measured according to ISO 2758:2014.

[0047] The ecological advantages of the packaging material arise from the raw materials used to manufacture the packaging material according to the invention. For ecological reasons, it is advantageous if the packaging material does not contain certain materials.

[0048] The packaging material according to the invention therefore preferably does not comprise metal foil or plastic film made from mineral oils. Metal foils and plastic films can form excellent barriers against oxygen, but it is a significant advantage of the invention that they can be omitted.

[0049] Preferably, at least 90%, particularly preferably at least 95%, of the organic mass of the packaging material is formed from renewable raw materials. For the purposes of this invention, raw materials are renewable if the replacement of the consumed raw material is possible through natural processes within a relatively short period of time. Cellulose fibers, pulp fibers, starch, pectin, as well as micro- and nanofibrillated cellulose and micro- and nanocrystalline cellulose from sources commonly used in industry are considered renewable raw materials in this sense, whereas mineral oil-based products, which are only replaced naturally after millions of years, are not renewable raw materials. Organic mass is understood to mean the mass formed by compounds that are organic in the chemical sense.For example, cellulose fibers, pulp fibers, starch or pectin are part of the organic matter, while fillers or pigments such as kaolin, talc, calcium carbonate, magnesium carbonate, magnesium oxide, magnesium hydroxide, aluminum oxide, aluminum hydroxide, titanium dioxide are not part of the organic matter.

[0050] In a preferred embodiment of the packaging material according to the invention, one or more further coatings can be applied to the packaging material on one or both sides of the packaging material, particularly preferably coatings which form a barrier against the penetration of water, water vapor, fats or oils and very particularly preferably one or more coatings which form a barrier against the penetration of water or water vapor.

[0051] In a preferred embodiment of the packaging material according to the invention, the packaging material is printed on at least one side.

[0052] The packaging material according to the invention is particularly well suited for packaging solid foodstuffs. A further aspect of the invention therefore also relates to packaging. A package according to the invention comprises the packaging material according to the invention, a solid foodstuff, and preferably a protective gas, wherein the solid foodstuff is packaged in the packaging material, and the solid foodstuff is preferably selected from the group consisting of rice, sugar, pasta, chocolate, chocolate bars, nuts, muesli, cheese, pastries, meat products, coffee, tea, tobacco, or tobacco products. "Protective gas" means that the proportion of oxygen in the gas contained in the package accounts for less than 15% of the volume of the gas contained in the package.

[0053] A further aspect of the invention relates to a method by which a packaging material can be produced, in particular according to one of the above-mentioned embodiments. The method according to this aspect of the invention comprises steps A to C.

[0054] A - Providing a base document,

[0055] B - applying one or more coating compositions to at least one side of the base paper,

[0056] 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 / m 2 and a maximum of 90 g / m 2and 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 the respective mixture is between 1000:5 and 100:5 and the total mass of the mixture of starch and pectin, based on the area to which the mixture is applied to the base paper after drying in step C, is at least 1.5 g / m 2 and a maximum of 12.0 g / m 2 and wherein the packaging material after step C has an oxygen permeability 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, of ​​at least 1 cm 3 / (m 2 xd) and a maximum of 500 cm 3 / (m 2 xd).

[0057] According to the process of the invention, only one coating composition containing a mixture of starch and pectin in a mass ratio of between 1000:5 and 100:5 can be applied in step B, optionally in several successive application steps. In this case, the "total mass of the mixture of starch and pectin" is the mass of the mixture in this one coating composition.

[0058] In other embodiments, in step B, several coating compositions may be applied successively, which differ from one another, but each contain a mixture of starch and pectin in a respective mass ratio that also lies in the interval of 1000:5 and 100:5. In this case, the "total mass of mixture of starch and pectin" is the sum of the masses of the respective mixtures applied as a respective component of the multiple coating compositions.

[0059] Preferably, the provision of the base paper in step A comprises producing the base paper on a paper machine, particularly preferably a Fourdrinier paper machine.

[0060] Preferably, the base paper from step A has a basis weight of at least 35 g / m 2 and a maximum of 80 g / m 2 and particularly preferably at least 35 g / m 2 and a maximum of 70 g / m 2 .

[0061] The base paper from step A preferably comprises cellulose fibers, with the cellulose fibers particularly preferably being formed from pulp fibers or regenerated cellulose fibers or a mixture thereof. The pulp fibers are most preferably obtained from softwood, in particular 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 recycled paper pulp, or are a mixture of pulp fibers from several of these sources.

[0062] The fibers of regenerated cellulose are most preferably fibrillatable fibers of regenerated cellulose.

[0063] The proportion of cellulose fibers is preferably at least 55% and at most 100%, particularly preferably at least 70% and at most 99%, in each case based on the mass of the base paper from step A. The base paper from step A preferably comprises 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.

[0064] Preferably, the proportion of filler is at least 1% and at most 45%, most preferably at least 2% and at most 30%, based on the mass of the base paper from step A.

[0065] Preferably, providing the base paper in step A comprises calendering the base paper.

[0066] Preferably, the starch in the respective mixture of starch and pectin in the coating composition in step B is selected from the group consisting of corn starch, potato starch, cassava starch, yam starch, rice starch, degraded starch, or mixtures of two or more of these starches. The starch is particularly preferably a degraded starch, most preferably a dextrin.

[0067] Preferably, the pectin in the respective mixture of starch and pectin in the coating composition in step B is a pectin obtained from one or more plants selected from the group consisting of citrus fruits, apples, oranges, rose hips, cherries, or carrots. The pectin is particularly preferably obtained from citrus fruits.

[0068] Preferably, the pectin in the respective mixture of starch and pectin in the respective coating composition in step B is a pectin with a degree of esterification of at least 65% and at most 80%, particularly preferably of at least 69% and at most 75%.

[0069] Preferably, the total mass of the mixture of starch and pectin after drying in step C, based on the area to which the respective mixture was actually applied in step B, is at least 2.0 g / m 2 and a maximum of 10.0 g / m 2 , particularly preferably at least 2.0 g / m 2 and a maximum of 8.0 g / m 2 .

[0070] Preferably, the mass ratio of starch to pectin in the respective mixture of starch and pectin in the respective coating composition in step B is between 1000:15 and 100:4, and preferably between 100:1 and 100:3. These intervals and the interval according to the invention are to be understood as inclusive. Preferably, the respective coating composition in step B, in addition to the mixture of starch and pectin, additionally comprises microfibrillated cellulose, microcrystalline cellulose, nanofibrillated cellulose, or nanocrystalline cellulose, or a mixture thereof.Particularly preferably, the mass of microfibrillated cellulose, microcrystalline cellulose, nanofibrillated cellulose and / or nanocrystalline cellulose taken together is at least 1% and at most 10%, very particularly preferably at least 2% and at most 8%, of the mass of the starch in the respective mixture of starch and pectin in the respective coating composition in step B. In this particularly preferred variant of the process according to the invention, the oxygen permeability of the packaging material after step C 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, is at least 1 cm. 3 / (m 2 xd) and a maximum of 150 cm 3 / (m 2 xd).

[0071] Preferably, the respective coating composition in step B comprises the mixture of starch and pectin, as well as water. Particularly preferably, the solids content of the respective coating composition from step B is at least 10% and at most 40%, particularly preferably at least 15% and at most 35%, in each case based on the mass of the coating composition.

[0072] Preferably, at least one of the coating compositions in step B has a viscosity at 45°C of at least 300 cP and at most 3000 cP, more preferably of at least 500 cP and at most 2500 cP.

[0073] In a preferred embodiment of the process according to the invention, the application of the one or more coating compositions in step B comprises application in a film press, a size press, a jet coater, a gravure coater, a counter-rotating gravure coater or a bar coater.

[0074] In a preferred embodiment of the process according to the invention, the drying in step C comprises drying by means of hot air, by means of microwave radiation, by means of infrared radiation or by means of contact with at least one heated drying cylinder or by means of a combination of these processes.

[0075] In a preferred embodiment of the method according to the invention, the provision of the base paper in step A comprises applying at least one further coating composition to that side of the base paper to which the one or more coating compositions from step B are applied in step B, and the additional subsequent drying of the base paper.

[0076] In a particularly preferred embodiment of this method, the further coating composition comprises starch and water but no pectin and is applied in such an amount that after additional drying, the mass of starch in this further coating, based on the area to which this further coating is applied, is at least 1.0 g / m 2 and a maximum of 5.0 g / m 2 amounts.

[0077] In a preferred embodiment of the method according to the invention, the provision of the base paper in step A comprises the application of at least two further coating compositions to that side of the base paper to which the one or more coating compositions from step B are applied in step B, and the additional drying after each application of a further coating composition.

[0078] In a particularly preferred embodiment of this method, a first of the further coating compositions comprises starch and water but no pectin and is applied in such an amount that after drying of the first of the further coating compositions, the mass of the starch from the first of the further coating compositions, based on the area to which the first of the further coating compositions is applied, is at least 1.0 g / m 2 and a maximum of 4.0 g / m 2 amounts.

[0079] Furthermore, in this particularly preferred embodiment, a second of the further coating compositions comprises water, starch, kaolin and a crosslinking agent, most 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 crosslinking agent is at least 1% and at most 5%, each based on the mass of the solids in the second of the further coating compositions, and the second of the further coating compositions is applied in such an amount that after drying of the second of the further coating compositions, the mass of the solids from the second of the further coating compositions, based on the area to which this second of the further coating compositions is applied, is at least 1.0 g / m 2 and a maximum of 3.0 g / m 2 amounts.

[0080] In this particularly preferred variant of the process according to the invention, the oxygen permeability of the packaging material after step C 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, is at least 1 cm 3 / (m 2 xd) and a maximum of 100 cm 3 / (m 2 xd). DESCRIPTION OF PREFERRED EMBODIMENTS AND COMPARISON WITH NON-INVENTION EMBODIMENTS

[0081] In the following, some preferred embodiments of the packaging material according to the invention and the method according to the invention are described by way of example, and packaging materials not according to the invention are illustrated as comparative examples.

[0082] Two base papers Pi and P2 were used to produce the embodiments according to the invention and the comparative examples not according to the invention.

[0083] According to step A of the process according to the invention, a first base paper Pi comprising a mixture of pulp fibers from hardwoods and softwoods and titanium dioxide was prepared by production on a paper machine. The amount of titanium dioxide was approximately 1% of the mass of the base paper Pi, with the remainder consisting essentially of the pulp fibers. The base paper Pi also contained a resin size as a sizing agent. The base paper Pi had a basis weight according to ISO 536:2019 of approximately 40 g / m² 2 .

[0084] Also according to step A of the inventive process, a second preliminary base paper comprising a mixture of pulp fibers from hardwoods and softwoods and titanium dioxide was produced on a paper machine. The amount of titanium dioxide was approximately 3% of the mass of base paper P2, with the remainder of the mass being essentially formed by the pulp fibers and the subsequent coatings of base paper P2. Base paper P2 also contained alkyl ketene dimer as a sizing agent.

[0085] According to a preferred embodiment of the process according to the invention, in step A, two further coating compositions were applied to the preliminary base paper to provide the base paper P2. A first further coating composition consisted of water and an oxidized starch and was applied over the entire surface in such an amount that, after drying, this first of the further coating compositions amounted to approximately 2.5 g / m 2 oxidized starch remained on the base paper. A second coating composition contained water and, as solids, 67% oxidized starch, 30% kaolin, and 3% glyoxal, each based on the mass of solids, and was applied over the entire surface in such a quantity that, after drying, this second coating composition contained approximately 2.0 g / m 2 of the solids remaining on the finished base paper P2.

[0086] The base paper P2 had a basis weight according to ISO 536:2019 of approximately 38.5 g / m 2 . Subsequently, according to step B of the process according to the invention, various coating compositions were applied to the base papers Pi and P2, wherein for the exemplary embodiments according to the invention the coating compositions consisted of water, starch, pectin and optionally microfibrillated cellulose.

[0087] For the production of the comparative examples not according to the invention, coating compositions were applied in the same way, but they consisted only of water, starch and optionally microfibrillated cellulose, i.e. they did not contain any pectin.

[0088] According to step C of the process according to the invention, the coated base papers were dried and thus packaging materials according to the invention and non-according to the invention were obtained.

[0089] The oxygen permeability of the inventive embodiments and the non-inventive comparative examples was measured according to ASTM D3985-17 at a relative humidity of 0% and a temperature of 23°C.

[0090] Table 1 contains the base papers (“BP”), the components of the coating applied in step B, the applied quantity (“W”) of the coating in g / m 2 and the oxygen permeability (“OTR”) in cm 3 / (m 2 xd). The inventive embodiments are designated by Ax-y, and the non-inventive embodiments are designated by Zx-y, where x and y are each natural numbers. In Table 1, "Pec" means pectin and "MFC" means microfibrillated cellulose. Pectin and microfibrillated cellulose are each given as a percentage based on the mass of the starch in the coating composition from step B.

[0091] Table 1 - Data of embodiments according to the invention and comparative examples not according to the invention

[0092] A comparison of the non-inventive packaging material Z1-1 with the group of inventive embodiments A1-1, A1-2 and A1-3 shows that with a comparable application quantity of the coating, the addition of 1%, 2% or 3% pectin, based on the mass of starch, leads to a reduction in the oxygen permeability of 628 cm 3 / (m 2 xd) at Z1-1 to about 400 cm 3 / (m 2 xd) up to about 530 cm 3 / (m 2 xd) can be achieved with A1-1, A1-2, and A1-3. These examples demonstrate the beneficial effect of pectin in a starch-to-pectin mass ratio of approximately 100:1 to approximately 100:3.

[0093] The same effect can also be seen in the base paper P2 using the non-inventive packaging material Z3-1 and the inventive embodiments A3-1, A3-2, and A3-3. Due to the additional coatings on the base paper P2, the oxygen permeability of the non-inventive packaging material Z3-1, coated only with starch, is 164 cm 3 / (m 2xd) Although already low, the addition of 1% to 3% pectin, based on the mass of the starch, shows a further reduction in oxygen permeability of at least 20% in the inventive embodiments A3-1, A3-2, and A3-3, and in particular a dramatic reduction of 75% in the embodiment A3-2, so that from these comparisons a mass ratio of starch to pectin of 100:2 proves to be particularly preferred. It is surprising that a small proportion of pectin has such a significant effect on oxygen permeability and that the effect only occurs within a relatively narrow range of the mass ratio of starch to pectin.

[0094] Further examples demonstrate the additional special effect of microfibrillated cellulose in combination with pectin. For the non-inventive packaging materials Z2-1 and Z2-2, starch and 2% and 4% microfibrillated cellulose, respectively, based on the mass of the starch, were applied to the base paper Pi. Oxygen permeabilities of around 200 cm 3 / (m 2 xd). By adding 2% or 3% pectin, based on the mass of starch, an oxygen permeability of 80 cm 3 / (m 2 xd) or 33 cm 3 / (m 2xd). The pectin, in combination with the microfibrillated cellulose, can thus reduce oxygen permeability by almost 85%. This effect is stronger than in the otherwise similar inventive embodiment A1-2 and demonstrates that there is an additional synergistic effect between the pectin and the microfibrillated cellulose.

[0095] This surprising effect of the combination of pectin and microfibrillated cellulose can also be observed for base paper P2. For the non-inventive packaging materials Z4-1 and Z4-2, starch and 2% and 4% microfibrillated cellulose, respectively, based on the mass of the starch, were applied to base paper P2. Oxygen permeabilities of 118 cm were achieved. 3 / (m 2 xd) or 85 cm 3 / (m 2xd). By adding 2% or 3% pectin, based on the mass of starch, an oxygen permeability of only 21 cm is achieved despite the lower application amount in the inventive embodiments A4-1 and A4-2 3 / (m 2 xd) or only 56 cm 3 / (m 2 xd). In Example A4-1, the pectin in combination with the microfibrillated cellulose can reduce the oxygen permeability by approximately 75% compared to Example A4-2, whereby in Example A4-1, less than half the coating material is required. These examples surprisingly demonstrate the synergistic effect between the pectin and the microfibrillated cellulose and show that, once again, a starch to pectin mass ratio of 100:2 proves to be particularly preferred.

[0096] The ecological advantages of the inventive embodiments arise automatically from the raw materials used. All inventive embodiments consisted of at least 95% of their organic mass from renewable raw materials.

[0097] With regard to other properties, such as mechanical properties, optical properties, printability and additional barrier effects, the embodiments according to the invention are well suited for use as packaging for food, so that packaging for food can be produced therefrom without difficulty.

Claims

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 / m 2 and a maximum of 90 g / m 2 wherein the at least one coating is a starch-pectin coating comprising one or more layers, each comprising a mixture of starch and pectin in a mass ratio of starch to pectin in the mixture of between 1000:5 and 100:5, wherein the total mass of the mixture of starch and pectin in said one or more layers, based on the area to which the starch-pectin coating is actually applied on the base paper, is at least 1.5 g / m 2 and a maximum of 12.0 g / m 2and wherein the packaging material has an oxygen permeability 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, of ​​at least 1 cm 3 / (m 2 xd) and a maximum of 500 cm 3 / (m 2 xd).

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

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 regenerated cellulose fibers or a mixture thereof.

4. Packaging material according to claim 3, wherein the cellulose fibers are obtained from coniferous wood, in particular 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 waste paper pulp, or are a mixture of cellulose fibers from several of these sources. 5- Packaging material according to claim 3 or 4, in which a proportion of at least 50% and at most 100%, preferably at least 70% and at most 100%, of said cellulose fibres, in each case based on their mass, is unbleached.

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

7. Packaging material according to one of claims 3 to 6, in which the proportion of cellulose fibres is at least 55% and at most 100%, preferably at least 70% and at most 99%, in each case based on the mass of the base paper.

8. Packaging material according to one of the preceding claims, in which the base paper comprises filler, wherein said 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 filler is preferably at least 1% and at most 45%, particularly preferably at least 2% and at most 30%, in each case based on the mass of the base paper.

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

10. Packaging material according to one of the preceding claims, wherein said starch is selected from the group consisting of corn starch, potato starch, cassava starch, yam starch, rice starch, degraded starch or mixtures of two or more of these starches.

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

12. Packaging material according to one of the preceding claims, wherein said pectin is a pectin obtained from one or more plants selected from the group consisting of citrus fruits, apples, oranges, rose hips, cherries or carrots, wherein the pectin is preferably obtained from citrus fruits to an extent of at least 80% by mass. 13- Packaging material according to one of the preceding claims, wherein said pectin is a pectin having a degree of esterification of at least 65% and at most 80%, preferably of at least 69% and at most 75%.

14. Packaging material according to 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, based on the area to which the starch-pectin coating is actually applied, is at least 2.0 g / m 2 and a maximum of 10.0 g / m 2 , preferably at least 2.0 g / m 2 and a maximum of 8.0 g / m 2 amounts.

15. Packaging material according to one of the preceding claims, wherein the ratio of the mass of starch and pectin in the mixture of starch and pectin in the one or more layers of the starch-pectin coating is in each case between 1000:15 and 100:4, preferably between 100:1 and 100:

3.

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

17. Packaging material according to claim 16, wherein the mass of microfibrillated cellulose, microcrystalline cellulose, nanofibrillated cellulose and / or nanocrystalline cellulose taken together 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 layer of said one or more layers of the starch-pectin coating.

18. Packaging material according to claim 17, the oxygen permeability of which 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, is at least 1 cm 3 / (m 2 xd) and a maximum of 150 cm 3 / (m 2 xd).

19. Packaging material according to one of the preceding claims, wherein the starch-pectin coating is applied to at least 70% and at most 100%, preferably to at least 90% and at most 100% of the area of ​​one side of the base paper.

20. Packaging material according to one of claims 1 to 18, wherein the starch-pectin coating is applied to at least 5% and at most 30% of the area of ​​one side of the base paper.

21. Packaging material according to one of the preceding claims, which comprises at least one further coating applied to that side of the base paper which is intended for the application of the starch-pectin coating, wherein the further coating comprises starch but no pectin and the mass of the starch in this further coating, based on the area to which this further coating is applied, is at least 1.0 g / m 2 and a maximum of 5.0 g / m 2 amounts.

22. Packaging material according to one of claims 1 to 20, which comprises at least two further coatings applied to that side of the base paper which is intended for the application of the starch-pectin coating, wherein a first of the further coatings comprises starch but no pectin and the mass of the starch in this first of the further coatings, based on the area to which this first of the further coatings is applied, is at least 1.0 g / m 2 and a maximum of 4.0 g / m 2and 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%, the mass of the kaolin is at least 10% and at most 40% and the mass of the crosslinking agent is at least 1% and at most 5% of the mass of the second of the further coatings, and wherein the mass of the second of the further coatings, based on the area to which this second of the further coatings is applied, is at least 1.0 g / m 2 and a maximum of 3.0 g / m 2 amounts.

23. Packaging material according to claim 22, wherein the oxygen permeability 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, is at least 1 cm 3 / (m 2 xd) and a maximum of 100 cm 3 / (m 2 xd).

24. Packaging material according to one of claims 1 to 21, wherein the oxygen permeability 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, is at least 3 cm 3 / (m 2 xd) and a maximum of 400 cm 3 / (m 2 xd) and preferably at least 5 cm 3 / (m 2 xd) and a maximum of 200 cm 3 / (m 2 xd). 25- Packaging material according to one of the preceding claims, wherein the oxygen permeability in at least one direction through the packaging material, measured according to ASTM D3985-17 at a relative humidity of 50% and a temperature of 23°C, is at least 2 cm 3 / (m 2 xd) and a maximum of 50 cm 3 / (m 2 xd) and preferably at least 3 cm 3 / (m 2 xd) and a maximum of 40 cm 3 / (m 2 xd).

26. Packaging material according to one of the preceding claims, the Cobböo value of at least one side of the packaging material is at least 5 g / m 2 and a maximum of 35 g / m 2 , preferably at least 10 g / m 2 and a maximum of 30 g / m 2 amounts.

27. Packaging material according to 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. Packaging material according to one of the preceding claims, having an elongation at break of at least 1% and at most 5%.

29. Packaging material according to one of the preceding claims, having a bursting strength of the side on which the starch-pectin coating is located of at least 100 kPa and at most 250 kPa.

30. Packaging material according to one of the preceding claims, which does not contain metal foil or plastic film made from mineral oils.

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

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

33. A process for producing a packaging material comprising steps A to C: A - Providing a base document, 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 / m 2 and a maximum of 90 g / m 2 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 the respective mixture is between 1000:5 and 100:5, wherein the total mass of the mixture of starch and pectin, based on the area to which the mixture or the respective mixtures are applied to the base paper after drying in step C, is at least 1.5 g / m 2 and a maximum of 12.0 g / m 2 and wherein the packaging material after step C has an oxygen permeability 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, of ​​at least 1 cm 3 / (m 2 xd) and a maximum of 500 cm 3 / (m 2 xd).

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

35. A process according to claim 33 or 34, wherein the base paper from step A has a basis weight of at least 35 g / m 2 and a maximum of 80 g / m 2 , preferably at least 35 g / m 2 and a maximum of 70 g / m 2 has.

36. A process 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 regenerated cellulose fibers or a mixture thereof.

37. A process according to claim 36, wherein the pulp fibers are obtained from coniferous wood, in particular 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 waste paper pulp, or are a mixture of pulp fibers from several of these sources.

38. The method of claim 36, wherein the regenerated cellulose fibers are fibrillatable regenerated cellulose fibers. 39- Process according to one of claims 36 to 38, in which the proportion of cellulose fibres is at least 55% and at most 100%, preferably at least 70% and at most 99%, in each case based on the mass of the base paper from step A.

40. A method according to any one of claims 33 to 39, wherein the base paper from step A comprises filler, wherein the 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.

41. Process according to claim 40, wherein the proportion of filler is at least 1% and at most 45%, preferably at least 2% and at most 30%, in each case based on the mass of the base paper from step A.

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

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

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

46. ​​A method according to any one of claims 33 to 45, wherein the total mass of the mixture of starch and pectin after drying in step C relative to the area to which the mixture or the respective mixtures are actually applied in step B was or were at least 2.0 g / m 2 and a maximum of 10.0 g / m 2 , preferably at least 2.0 g / m 2 and a maximum of 8.0 g / m 2 amounts.

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

3.

48. A process according to any one of claims 33 to 47, wherein the respective coating composition in step B comprises, in addition to the mixture of starch and pectin, microfibrillated cellulose, microcrystalline cellulose, nanofibrillated cellulose or nanocrystalline cellulose or a mixture thereof.

49. A method according to claim 48, wherein the mass of microfibrillated cellulose, microcrystalline cellulose, nanofibrillated cellulose and / or nanocrystalline cellulose taken together 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 in step B, wherein the oxygen permeability of the packaging material after step C 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, is at least 1 cm 3 / (m 2 xd) and a maximum of 150 cm 3 / (m 2 xd).

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

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

52. A method according to any one of claims 33 to 51, wherein the application of the coating in step B comprises application in a film press, a size press, a jet coater, an engraver coater, a counter-rotating engraver coater or a bar coater.

53. A method according to any one of claims 33 to 52, wherein providing the base paper in step A comprises applying at least one further coating composition to that side of the base paper to which the one or more coating compositions from step B are applied in step B, and additionally subsequently drying the base paper.

54. A method according to claim 53, wherein the further coating composition comprises starch and water but no pectin and is applied in an amount such that after additional drying the mass of starch in this further coating, based on the area to which this further coating is applied, is at least 1.0 g / m 2 and a maximum of 5.0 g / m 2 amounts.

55. A method according to any one of claims 33 to 52, wherein the provision of the base paper in step A comprises applying at least two further coating compositions to that side of the base paper to which the coating composition from step B is applied in step B and additional drying after each application of a further coating composition, wherein a first of the further coating compositions preferably comprises starch and water but no pectin and is applied in such an amount that after drying of the first of the further coating compositions, the mass of the starch from the first of the further coating compositions, based on the area to which the first of the further coating compositions is applied, is at least 1.0 g / m 2 and a maximum of 4.0 g / m 2and wherein a second of the further coating compositions preferably comprises water, starch, kaolin and a crosslinking agent, most 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 crosslinking agent is at least 1% and at most 5%, each based on the mass of the solids in the second of the further coating compositions, and wherein the second of the further coating compositions is preferably applied in such an amount that after drying of the second of the further coating compositions, the mass of the solids from the second of the further coating compositions, based on the area to which this second of the further coating compositions is applied, is at least 1.0 g / m 2 and a maximum of 3.0 g / m 2 amounts, wherein the oxygen permeability of the packaging material after step C 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, is preferably at least 1 cm 3 / (m 2 xd) and a maximum of 100 cm 3 / (m 2 xd).

Images