Fibre-based packaging material with barrier layer and special moisture barrier

Abstract

A fibre-based packaging material (10) with an oxygen permeability of less than 1.1 cm³ / (m²·d·bar), determined in accordance with DIN 53380-3 at 23°C and 85% relative humidity, and with a water vapour permeability of less than 1.1 g / (m²·d), determined in accordance with ISO 15106-2 at 23°C and 85% relative humidity, comprises a fibrous material-containing substrate layer (12), a top layer (20), up to 90% by weight of which, in relation to the dry state, is formed from a water-based dispersion of a polymer, and a barrier layer (16) which is deposited from a vapour phase, is made from a metal oxide, and is situated between the top layer (20) and the substrate layer (12). In addition, a first polymer layer (14), up to at least 90% by weight of which is formed from a first polymer, and a second polymer layer (18), up to at least 90% by weight of which is formed from a second polymer, are arranged between the top layer (20) and the substrate layer (12), wherein the first and the second polymer have different wettabilities by distilled water in accordance with DIN EN 828.

Description

[0001] Fibre-based packaging material with barrier layer and special moisture barrier

[0002] Description

[0003] The present invention relates to a fiber-based packaging material with an oxygen permeability of less than 1.1 cm 3 / (m 2 d bar), determined according to DIN 53380-3 at 23°C and 85% relative humidity, and with a water vapor permeability of less than 1.1 g / (m 2 d), determined according to ISO 15106-2 at 23°C and 85% relative humidity.

[0004] The packaging material comprises a fiber-containing substrate layer, which preferably forms a base layer of the overall multi-layer packaging material.

[0005] The aforementioned barrier properties regarding oxygen permeability, also known in the specialist world as "OTR" for "Oxygen Transfer Rate", and water vapor permeability, also known in the specialist world as "WVTR" for "Water Vapor Transfer Rate", are achieved in the fiber-based packaging material primarily by incorporating a vapor-deposited barrier layer of a metal oxide into the layer arrangement of the packaging material.

[0006] To protect the base layer against mechanical stress or to provide a sealable layer, a top layer is arranged over the base layer. The base layer is thus located between the top layer and the substrate layer. The top layer consists of at least 90% by weight, based on the dry state, of a water-based polymer dispersion.

[0007] The fibrous substrate layer is preferably a fiber fleece formed by dewatering a fiber suspension, which is then compacted and dried. The fibers of the fibrous material are preferably made of cellulose, wood pulp, or waste paper. The fibrous substrate layer is therefore more preferably a paper or cardboard layer. The fibrous substrate layer is therefore generally absorbent without further treatment and absorbs liquid upon contact. Fiber-based packaging materials with a metallization are known from the prior art to provide the packaging material with a desired barrier against the migration of oxygen and water vapor through the packaging material.

[0008] The disadvantage of the metallization mentioned is its opacity and its metallic shine, which sometimes leads to the packaging material being mistaken for a metal foil and consequently not being fed into the recycling stream intended for it.

[0009] The aforementioned vapor-deposited metal oxide barrier layer, on the other hand, is transparent, so its presence does not conceal or obscure the nature of the packaging material. This facilitates the correct feeding of the packaging material into its intended recycling stream.

[0010] However, vapor-deposited metal oxide layers are thinner than conventional metallizations. In some cases, their thickness is only a quarter of that of a conventional metallization. Accordingly, the impermeability of the barrier layer may be limited, especially if the fiber-containing substrate layer is porous and has sufficiently large pores relative to the thickness of the metal oxide barrier layer.

[0011] Therefore, during the application of the above-mentioned top layer as a water-based dispersion, which is formed to prevent mechanical damage to the barrier layer or to provide a sealable layer, moisture from the applied top layer dispersion penetrates the metal oxide barrier layer and reaches the fiber-containing substrate layer. The moisture penetrating the substrate layer can cause it to swell, particularly if the fiber-containing substrate layer is a paper or cardboard layer according to a preferred embodiment, resulting in significant deterioration of the entire packaging material formed with the substrate layer.It is therefore an object of the present invention to further develop an above-mentioned fiber-based sheet-like packaging material with the fiber-containing substrate layer, the cover layer and the barrier layer arranged between the substrate layer and the cover layer made of metal oxide deposited from the vapor phase in such a way that the above-mentioned disadvantages are mitigated or completely avoided.

[0012] The present invention achieves this objective with a sheet-like, fiber-based packaging material of the type mentioned above by additionally arranging a first polymer layer and a second polymer layer between the cover layer and the substrate layer. The first polymer layer is composed of at least 90% by weight of a first polymer, and the second polymer layer is composed of at least 90% by weight of a second polymer. The first and second polymers have different wettabilities by distilled water according to DIN EN 828.

[0013] The relevant layers of the fiber-based packaging material are hereinafter referred to as "substrate layer", "barrier layer", "cover layer", "first polymer layer" and "second polymer layer", since even the abbreviated designation is unambiguous.

[0014] By providing additional polymer layers between the substrate layer and the top layer, whose respective polymers exhibit different wettability with respect to water (distilled water is mentioned as the reference liquid or reference water only with regard to the cited DIN standard), the migration of moisture, i.e., water, from the top layer applied as a water-based dispersion through the barrier layer into the fiber-containing substrate layer can be prevented or significantly reduced. Water-based dispersions are typically even formed with distilled water, so that the reference liquid for determining wettability and the liquid base of the dispersion of the top layer are even identical during application.Even if a water other than distilled water is used to provide the top layer dispersion, the relevant wettability of the respective polymer will differ only to a negligible extent from the wettability by distilled water.

[0015] In this application, the application of layers as a dispersion is discussed in various contexts. Application as a dispersion actually refers to the application process. In all other aspects, the layers are discussed in their dried or dry and solidified final state, i.e., when the dispersion-forming water or a solvent used instead of water has evaporated.

[0016] When the present application refers to "solvent," this solvent is used in contrast to the also mentioned water. "Solvent" within the meaning of the present application is therefore a liquid suitable for forming a polymer dispersion that is not water.

[0017] The DIN EN 828 standard specified here measures the wettability of a material by distilled water according to generally accepted scientific principles, based on the contact angle formed by a defined drop of water on the surface of the material in question. Materials with a water contact angle greater than 90° are considered hydrophobic. Materials with small contact angles are considered hydrophilic. Generally, the wettability of the material in question decreases with increasing contact angles.

[0018] In the following, we assume that the first polymer has better wettability by distilled water than the second polymer. According to DIN EN 828, this means that the contact angle of a drop of distilled water is smaller when wetting the first polymer than when wetting the second polymer.

[0019] In principle, it is advantageous if the first polymer is not hydrophobic, i.e., when wetted with distilled water, it has a contact angle of less than 90°, measured according to DIN EN 828. Since better wettability than the second polymer is more easily achievable the lower the contact angle occurring when wetting with distilled water, the first polymer, according to DIN EN 828, preferably has a contact angle of less than 75°, particularly preferably less than 60°, when wetting with distilled water. The contact angle of a drop of distilled water when wetting the first polymer, according to DIN EN 828, can also be significantly below 60° and can, for example, be in an angle range of 0 to 30°.

[0020] Since the second polymer is said to be less readily wettable by distilled water, the second polymer preferably exhibits a contact angle of more than 45° when wetted by distilled water, measured in accordance with DIN EN 828. If the contact angle specified here as the lower limit is smaller in magnitude than the contact angle specified as the upper limit in connection with the first polymer, it should also be noted that the contact angle when the first polymer is wetted by distilled water is smaller than when the second polymer is wetted by distilled water. The contact angle when the second polymer is wetted is preferably more than 60°, particularly preferably more than 75°.

[0021] Particularly good results in preventing water migration from the water-based dispersion of the subsequent top layer through the barrier layer into the fiber-containing substrate layer were achieved with a second polymer that is hydrophobic. Therefore, the second polymer preferably exhibits a contact angle of more than 90° when wetted with distilled water, measured according to DIN EN 828.

[0022] Since the first polymer layer is more easily wetted by water than the second polymer layer, it is preferred if the second polymer layer is arranged as far away as possible from the cover layer or with as many additional layers as possible between it and the cover layer. This can be achieved structurally by arranging the first polymer layer between the substrate layer and the barrier layer. This means that at least the barrier layer is always located between the substrate layer and the first polymer layer. Moreover, the first polymer layer can form a smoother surface for the deposition of a metal oxide barrier layer thereon than the fiber-containing substrate layer, so that the barrier effect of the metal oxide barrier layer also increases if it is not deposited directly on the substrate layer, but on an intermediate polymer layer, such as the first polymer layer.

[0023] Preferably, the first polymer layer on the side of the substrate layer on which the barrier layer is arranged is the polymer layer closest to the substrate layer. The first polymer layer can be applied directly to the substrate layer. Since the barrier layer is transparent, the surface of the substrate layer located on the side of the barrier layer can be printed by applying a printing ink, and thus the first polymer layer can be applied directly to the printing ink.

[0024] The second polymer layer can generally be arranged between the substrate layer and the barrier layer and / or between the barrier layer and the cover layer. The second polymer layer can comprise two partial polymer layers or be formed from two partial polymer layers.

[0025] When the second polymer layer is arranged between the substrate layer and the barrier layer, it is preferably located between the first polymer layer and the barrier layer. This also applies to a partial polymer layer of the second polymer layer. The barrier layer is then deposited on the polymer material of the second polymer layer. Since the second polymer layer or one of its partial polymer layers is applied to the first polymer layer, an even smoother surface can be provided for the deposition of the metal oxide barrier layer thereon.

[0026] For example, the second polymer layer or a partial polymer layer thereof can be applied as a water-based dispersion. Then, the second polymer layer or a partial polymer layer thereof can preferably be arranged between the substrate layer and the barrier layer, and can particularly preferably be arranged between the first polymer layer and the barrier layer.

[0027] Alternatively, the second polymer layer can be applied and formed as a solvent-based dispersion of the second polymer. If the second polymer layer is formed by at least two or exactly two partial polymer layers, all or both partial polymer layers can be applied and formed as a solvent-based dispersion, or one or at least one partial polymer layer can be applied and formed as a water-based dispersion and another or at least one further partial polymer layer can be applied and formed as a solvent-based dispersion.

[0028] The second polymer layer or partial polymer layer thereof applied as a solvent-based dispersion is preferably arranged between the barrier layer and the cover layer.

[0029] The first polymer can be a vinyl alcohol-based polymer, such as ethylene-vinyl alcohol copolymer or polyvinyl alcohol. Of these, polyvinyl alcohol is preferred as the first polymer. Compared to other polymers, vinyl alcohol-based polymers, in a layer arrangement such as that of the packaging material discussed here, primarily increase the oxygen barrier at the same layer thickness and consequently disproportionately reduce the oxygen permeability of the packaging material.

[0030] The second polymer can be a polyolefin and / or a polyester. This applies in particular when the second polymer layer comprises two partial polymer layers. If the second polymer layer or a partial polymer layer thereof is applied as a water-based dispersion of the second polymer, the second polymer is preferably a polyolefin, in particular polyethylene or polypropylene. If the second polymer layer or a partial polymer layer thereof is applied as a solvent-based dispersion of the second polymer, the second polymer can be a polyolefin or a polyester.

[0031] The first and second polymer layers are formed from at least 90 wt.% of the first polymer and the second polymer, respectively, to ensure that the polymer layers exhibit the wetting properties of the first and second polymers, respectively. At least one layer of the first and second polymer layers, preferably both layers, can preferably be formed from at least 95 wt.%, particularly preferably at least 99 wt.%, of the first and second polymers, respectively.

[0032] The polymer of the cover layer can comprise or be an acrylic copolymer, a polyolefin, an ethylene-vinyl acetate copolymer, or a biopolymer. Possible biopolymers include polylactic acid, polyhydroxyalkanoates, starch polymers, or generally polymers with cellulose or starch as starting materials, to name just a few examples.

[0033] For a particularly resource-saving, but at the same time effective formation of the first polymer layer, this can be applied with a coating weight of 1.0 to 5.0 g / m 2 be designed, in particular with an application weight of 1.5 to 3.5 g / m 2 .

[0034] For the same reason, the second polymer layer can be applied with a coating weight of 0.5 to 3.0 g / m 2 be designed, in particular with an application weight of 1.0 to 2.5 g / m 2 .

[0035] The sheet-like, fiber-based packaging material discussed here can be part of a packaging layer material comprising additional layers. Preferably, however, the cover layer is a layer exposed to the environment. The printing ink coating mentioned above as a preferred development can also be applied to the side of the substrate layer facing away from the barrier layer. One or more additional layers can be applied to the printing ink coating, such as a protective varnish layer to protect the printing ink coating from external influences and / or a sealable polymer layer, in particular a polyolefin layer.

[0036] Preferably, the oxygen permeability of the packaging material is less than 1 .0 cm 3 / (m 2 d bar), particularly preferably less than 0.85 cm 3 / (m 2d bar), determined according to DIN 53380-3 at 23°C and 85% relative humidity. Additionally or alternatively, the water vapor permeability of the packaging material is less than 1.0 g / (m 2 d), particularly preferably less than 0.85 cm 3 / (m 2 d bar), determined according to ISO 15106-2 at 23°C and 85% relative humidity. The following defined objects (Ggs) are of particular interest for this application. The features of the objects are accompanied by the reference numerals of the following figure description:

[0037] Ggs1 : Fibre-based packaging material (10; 110; 210) with an oxygen permeability of less than 1.1 cm 3 / (m 2 d bar), determined according to DIN 53380-3 at 23°C and 85% relative humidity, and with a water vapor permeability of less than 1.1 g / (m 2d), determined according to ISO 15106-2 at 23°C and 85% relative humidity, comprising a fibrous substrate layer (12; 112; 212), a cover layer (20; 120; 220) formed to at least 90% by weight, based on the dry state, from a water-based dispersion of a polymer and a vapor-deposited base layer (16; 116; 216) made of a metal oxide, which is located between the cover layer (20; 120; 220) and the substrate layer (12; 112; 212), wherein additionally between the cover layer (20; 120; 220) and the substrate layer (12; 112; 212) there is a first polymer layer (14; 114; 214), which is formed to at least 90% by weight from a first polymer, and a second Polymer layer (18; 118; 218a, 218b) which is formed of at least 90 wt.% of a second polymer, wherein the first and the second polymer have different wettabilities according to DIN EN 828 by distilled water.

[0038] Ggs2: Fibre-based packaging material (10; 110; 210) according to item 1, further developed in that the fibre-containing substrate layer (12; 112; 212) is a paper or cardboard layer.

[0039] Ggs3: Fibre-based packaging material (10; 110; 210) according to item 1 or 2, further developed in that the first polymer, when wetted by distilled water, exhibits a contact angle measured according to DIN EN 828 of less than 90°, preferably of less than 75°, particularly preferably of less than 60°, and in that the second polymer, when wetted by distilled water, exhibits a contact angle measured according to DIN EN 828 of more than 45°, preferably of more than 60°, particularly preferably of more than 75°.

[0040] Ggs4: Fibre-based packaging material (10; 110; 210) according to item 3, further developed in that the second polymer, when wetted by distilled water, shows a contact angle of more than 90° measured according to DIN EN 828.

[0041] Ggs5: Fibre-based packaging material (10; 110; 210) according to one of the preceding objects, further developed in that the first polymer layer (14; 114; 214) is arranged between the substrate layer (12; 112; 212) and the barrier layer (16; 116; 216).

[0042] Ggs6: Fibre-based packaging material (110; 210) according to one of the preceding objects, further developed in that the second polymer layer (118; 218b) is arranged as a water-based dispersion of the second polymer between the substrate layer (112; 212) and the barrier layer (116; 216).

[0043] Ggs7: Fibre-based packaging material (110; 210) according to

[0044] Articles 5 and 6, further developed in that the second polymer layer (118; 218b) is arranged as a water-based dispersion of the second polymer between the first polymer layer (114; 214) and the barrier layer (116; 216).

[0045] Ggs8: Fibre-based packaging material (10; 210) according to one of the preceding objects, further developed in that the second polymer layer (18; 218a) is arranged as a solvent-based dispersion of the second polymer between the barrier layer (16; 216) and the cover layer (20; 220).

[0046] Ggs9: Fibre-based packaging material (10; 110; 210) according to one of the preceding objects, further developed in that the first polymer is a vinyl alcohol-based polymer.

[0047] Ggs10: Fibre-based packaging material (110; 210) according to one of the preceding items, including at least one of items 6 and 7, further developed in that the second polymer is a polyolefin.

[0048] Ggs11 : Fibre-based packaging material (10; 210) according to one of the preceding objects, including object 8, further developed in that the second polymer is a polyolefin or a polyester.

[0049] Ggs12: Fiber-based packaging material (10; 110; 210) according to one of the preceding objects, further developed in that the polymer of the cover layer (20; 120; 220) comprises an acrylic copolymer and / or a polyolefin and / or an ethylene-vinyl acetate copolymer or is a biopolymer.

[0050] Ggs13: Fibre-based packaging material (10; 110; 210) according to one of the preceding objects, further developed in that the first polymer layer (14; 114; 214) has a coating weight - to be measured in the dry state - of 1.0 to 5.0 g / m 2 is trained.

[0051] Ggs14: Fibre-based packaging material (10; 110; 210) according to one of the preceding objects, further developed in that the second polymer layer (18; 118; 218a, 218b) has a coating weight - to be measured in the dry state - of 0.5 to 3.0 g / m 2 is trained.

[0052] Ggs15: Fibre-based packaging material (10; 110; 210) according to one of the preceding objects, further developed in that the metal oxide of the barrier layer (16; 116; 216) is aluminium oxide or silicon oxide.

[0053] The present invention will be explained in more detail below with reference to the accompanying drawings. It shows:

[0054] Fig. 1 shows a first embodiment of a flat packaging material according to the invention in cross section,

[0055] Fig. 2 shows a second embodiment of a flat packaging material according to the invention in cross section, and

[0056] Fig. 3 shows a third embodiment of a flat packaging material according to the invention in cross section.

[0057] Figure 1 shows a first embodiment of a sheet-like fiber-based packaging material according to the invention in cross-section and is generally designated 10. It comprises, as fiber-based substrate layer 12, a paper layer with a preferred basis weight of between 40 g / m 2 and 200 g / m 2 . The paper layer as the fiber-based substrate layer 12 may be a layer of coated or uncoated paper.

[0058] On one side of the substrate layer 12, a first polymer layer 14 is applied with polyvinyl alcohol as a preferred first polymer in a water-based dispersion. In the illustrated first embodiment, the water-based dispersion of polyvinyl alcohol is applied directly to the substrate layer 12. The first polymer layer 14 has an application weight of 1.0 to 5.0 g / m 2 , in the preferred case of about 3.5 g / m 2 The first polymer layer 14 not only forms a smoother surface on the side of the substrate layer 12 to which it is applied than the substrate layer 12 itself, but also significantly reduces the oxygen permeability of the packaging material 10 as a whole.

[0059] Polyvinyl alcohol absorbs water and is therefore easily wettable by water, even distilled water.

[0060] A barrier layer 16, preferably made of aluminum oxide, is deposited onto the first polymer layer 14 by vacuum vapor deposition. The barrier layer 16, with a thickness of less than 1 μm, in particular less than 0.5 μm, forms an excellent barrier layer for reducing the oxygen permeability and water vapor permeability of the packaging material 10.

[0061] A second polymer layer 18 comprising a second polymer as a solvent-based dispersion is applied to the barrier layer 16, i.e., to the side of the barrier layer 16 facing away from the first polymer layer 14. Since the solvent-based dispersion of the second polymer layer 18 does not contain water, the application of the solvent-based dispersion poses no risk of impairing the first polymer layer 14 made of polyvinyl alcohol.

[0062] The second polymer of the second polymer layer 18 is less easily wettable by distilled water than the polyvinyl alcohol of the first polymer layer 14. In the first exemplary embodiment shown, the second polymer can be a polyolefin, such as polypropylene or polyethylene, or a polyester, such as polyethylene terephthalate.

[0063] The layer arrangement comprising the first polymer layer 14, the barrier layer 16, and the second polymer layer 18 is protected against external mechanical influences by a cover layer 20, which is preferably applied as a water-based dispersion of a polymer to the second polymer layer 18, more precisely to the side facing away from the barrier layer 16. The cover layer 20 is therefore also a polymer layer, for example, made of an acrylic copolymer.

[0064] The second polymer layer 18 has an application weight in the range of 0.5 g / m 2 up to 3.0 g / m 2 applied, preferably with an application weight of 2.0 g / m2 .

[0065] The packaging material 10 of the first embodiment has an oxygen permeability of 1.0 cm 3 / (m 2 d bar), determined according to DIN 53380-3 at 23°C and 85% relative humidity, and has a water vapor permeability of 1.0 g / (m 2 d) determined according to ISO 15106-2 at 23°C and 85% relative humidity.

[0066] Figure 2 shows a second embodiment of a packaging material according to the invention in cross-section. The second embodiment will be described below only insofar as it differs from the first embodiment. Identical and functionally identical components and component sections as in the first embodiment are provided with the same reference numerals in the second embodiment, but increased by the number 100. For an explanation of the second embodiment, reference is made to the description of the first embodiment.

[0067] The second embodiment is intended to clarify, among other things, that the first polymer layer 114 does not necessarily have to be applied directly to the substrate layer 112, but that the substrate layer 112 can, for example, be printed and thus bear a printing ink coating 122. The first polymer layer 114 can be applied to this printing ink coating as a water-based dispersion of polyvinyl alcohol.

[0068] Furthermore, in the second embodiment, the second polymer layer 118 is formed between the first polymer layer 114 and the barrier layer 116 made of aluminum oxide. In the second embodiment, the second polymer layer 118 is applied not as a solvent-based dispersion of the second polymer, but as a water-based dispersion of the second polymer. Therefore, in the second embodiment, the second polymer is preferably a polyolefin. The application weight of the second polymer layer 118 corresponds to that in the first embodiment.

[0069] Consequently, the aluminum oxide base layer 116 is deposited from the vapor phase in vacuum onto the second polymer layer 118.

[0070] The cover layer 120 still forms a layer exposed to the surroundings of the packaging material 110.

[0071] Figure 3 shows a third embodiment of a packaging material according to the invention in cross-section. The third embodiment will be described below only insofar as it differs from the first embodiment. Identical and functionally equivalent components and component sections as in the first embodiment are provided with the same reference numerals in the third embodiment, but with the number 200 added. For an explanation of the second embodiment, reference is made to the description of the first and second embodiments.

[0072] The third embodiment of the packaging material 210 corresponds to a combination of the first two embodiments, wherein, for ease of illustration, no printing ink application is provided as in the first embodiment.

[0073] The substrate layer 212 and the first polymer layer 214 correspond to the substrate layers 12 and 112, respectively, and the first polymer layers 14 and 114, respectively, of the first and second embodiments, respectively. Likewise, the aluminum oxide barrier layer 216 corresponds to the barrier layers 16 and 116, respectively, of the first and second embodiments, respectively.

[0074] In the third embodiment, the second polymer layer 218 is formed by two partial polymer layers. As in the first embodiment, the second polymer layer 218 comprises a partial polymer layer 218a provided as a solvent-based dispersion of polyolefin or polyester between the barrier layer 216 and the cover layer 220. The second polymer layer 218 also comprises, as in the second embodiment, a partial polymer layer 218b applied as a water-based dispersion of polyolefin between the first polymer layer 214 and the barrier layer 216. The aluminum oxide barrier layer 216 was deposited onto the latter.

[0075] The packaging materials 10 and 210 of the first and third embodiments, respectively, can also comprise an ink application layer, for example, to apply consumer information to the packaging material. As in the second embodiment, an ink application layer can be applied to the substrate layer 12 or 212, respectively, between the substrate layer 12 or 212 and the first polymer layer 14 or 214, respectively, or / and to the surface of the substrate layer 12 or 212 facing away from the barrier layer 16 or 216.

[0076] In the third embodiment, each partial polymer layer 218a and 218b can individually have the coating weight specified in the first and second embodiments for the second polymer layer 18 and 118, respectively. Alternatively, the two partial polymer layers 218a and 218b can jointly have the coating weight specified in the first and second embodiments for the second polymer layer 18 and 118, respectively.

Claims

Claims Fibre-based packaging material (10; 110; 210) with an oxygen permeability of less than 1.1 cm 3 / (m 2 d bar), determined according to DIN 53380-3 at 23°C and 85% relative humidity, and with a water vapor permeability of less than 1.1 g / (m 2d), determined according to ISO 15106-2 at 23°C and 85% relative humidity, comprising a fibrous substrate layer (12; 112; 212), a cover layer (20; 120; 220) formed to at least 90% by weight, based on the dry state, from a water-based dispersion of a polymer, and a barrier layer (16; 116; 216) deposited from a vapor phase and made of a metal oxide, which is located between the cover layer (20; 120; 220) and the substrate layer (12; 112; 212), wherein additionally between the cover layer (20; 120; 220) and the substrate layer (12; 112; 212) there is a first polymer layer (14; 114; 214), which is formed to at least 90% by weight from a first polymer, and a second polymer layer (18; 118; 218a, 218b), which contain at least 90 wt.-% of a second polymer, wherein the first and the second polymer have different wettabilities according to DIN EN 828 by distilled water, wherein the contact angle of a drop of distilled water when wetting the first polymer is smaller than when wetting the second polymer, characterized in that the first polymer layer (14; 114; 214) is arranged between the substrate layer (12; 112; 212) and the backing layer (16; 116; 216), and that the second polymer layer (18; 118; 218a, 218b) is arranged between the first polymer layer (14; 114; 214) and the backing layer (16; 116; 216) and / or between the backing layer (16; 116; 216) and the cover layer (20; 120; 220) Fibre-based packaging material (10; 110; 210) according to claim 1, characterized in that the fibre-containing substrate layer (12; 112; 212) is a paper or cardboard layer. Fibre-based packaging material (10; 110; 210) according to claim 1 or 2, characterized in that the first polymer, when wetted by distilled water, exhibits a contact angle measured according to DIN EN 828 of less than 90°, preferably less than 75°, particularly preferably less than 60°, and in that the second polymer, when wetted by distilled water, exhibits a contact angle measured according to DIN EN 828 of more than 45°, preferably more than 60°, particularly preferably more than 75°. Fibre-based packaging material (10; 110; 210) according to claim 3, characterized in that the second polymer, when wetted by distilled water, exhibits a contact angle measured according to DIN EN 828 of more than 90°.Fibre-based packaging material (110; 210) according to one of the preceding claims, characterized in that the second polymer layer (118; 218b) is arranged as a water-based dispersion of the second polymer between the substrate layer (112; 212) and the backing layer (116; 216). Fibre-based packaging material (110; 210) according to claim 5, characterized in that the second polymer layer (118; 218b) is arranged as a water-based dispersion of the second polymer between the first polymer layer (114; 214) and the backing layer (116; 216). Fibre-based packaging material (10; 210) according to one of the preceding claims, characterized in that the second polymer layer (18; 218a) is arranged as a solvent-based dispersion of the second polymer between the barrier layer (16; 216) and the cover layer (20; 220). Fiber-based packaging material (10; 110; 210) according to one of the preceding claims, characterized in that the first polymer is a vinyl alcohol-based polymer. Fiber-based packaging material (110; 210) according to one of the preceding claims, including at least one of claims 5 and 6, characterized in that the second polymer is a polyolefin. Fiber-based packaging material (10; 210) according to one of the preceding claims, including claim 7, characterized in that the second polymer is a polyolefin or a polyester. Fiber-based packaging material (10; 110; 210) according to one of the preceding claims, characterized in that the polymer of the cover layer (20; 120; 220) comprises an acrylic copolymer and / or a polyolefin and / or an ethylene-vinyl acetate copolymer or is a biopolymer.Fibre-based packaging material (10; 110; 210) according to one of the preceding claims, characterized in that the first polymer layer (14; 114; 214) has an application weight - measured in the dry state - of 1.0 to 5.0 g / m. 2 Fibre-based packaging material (10; 110; 210) according to one of the preceding claims, characterized in that the second polymer layer (18; 118; 218a, 218b) is formed with a coating weight - measured in the dry state - of 0.5 to 3.0 g / m 2 is trained. Fibre-based packaging material (10; 110; 210) according to one of the preceding claims, characterized in that the metal oxide of the barrier layer (16; 116; 216) is aluminium oxide or silicon oxide.

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