FIBRE-BASED PACKAGING MATERIAL WITH BARRIER LAYER AND SPECIAL MOISTURE BARRIER

A fibre-based packaging material 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, includes a fibrous material-containing substrate layer, a top layer, 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 which is deposited from a vapour phase, is made from a metal oxide, and is situated between the top layer and the substrate layer, in addition, a first polymer layer, up to at least 90% by weight of which is formed from a first polymer, and a second polymer layer, up to at least 90% by weight of which is formed from a second polymer, are arranged between the top layer and the substrate layer, wherein the first and the second polymer have different wettabilities by distilled water in accordance with DIN EN 828.

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Description

This Application claims priority in PCT application PCT/EP2023/085529 filed Dec. 13, 2023, which claims priority in German Patent Application DE 10 2022 133 081.8 filed on Dec. 13, 2022, which are incorporated by reference herein.

The present invention relates to a fiber-material-based packaging material 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 vapor permeability of less than 1.1 g/(m2·d), determined in accordance with ISO 15106-2 at 23° C. and 85% relative humidity.

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

The aforementioned barrier properties relating to oxygen permeability, also known in the technical field as “OTR” for “Oxygen Transfer Rate,” and water vapor permeability, also known in the technical field as “WVTR” for “Water Vapor Transfer Rate,” are achieved in the fiber-material-based packaging material primarily by incorporating a barrier layer of a metal oxide deposited from a vapor phase into the layer arrangement of the packaging material.

To protect the barrier layer against mechanical stress or to provide a sealable layer, a cover layer is arranged over the barrier layer. The barrier layer is therefore located between the cover layer and the substrate layer. The cover layer is formed to an extent of at least 90% by weight, based on the dry state, from a water-based dispersion of a polymer.

The fiber material-containing substrate layer is preferably a fiber fleece formed by dewatering a fiber suspension, which is compacted and dried. The fibers of the fiber material are preferably made of cellulose, wood pulp, or waste paper. The fiber material-containing substrate layer is therefore further preferably a paper layer or cardboard layer. The fiber-material-containing substrate layer is therefore generally absorbent without further treatment and absorbs liquid on contact.

BACKGROUND OF THE INVENTION

Fiber-material-based packaging materials with metallization are known from the prior art in order to provide the packaging material with a desired barrier against migration of oxygen and water vapor through the packaging material.

A disadvantage of the aforementioned metallization is its opacity and metallic sheen, which sometimes leads to the packaging material being confused with a metal foil and consequently not being fed to the recycling stream for which it is intended.

The metal oxide layer deposited from the vapor phase as a barrier layer, on the other hand, is transparent, so that its presence does not conceal or obscure the nature of the packaging material. This facilitates the correct feeding of the packaging material to the recycling stream for which it is intended.

However, metal oxide layers deposited from the vapor phase are thinner than known metallizations. In some cases, their thickness is only a quarter of that of a conventional metallization. Accordingly, the tightness of the barrier layer may be limited, especially if the fiber-material-containing substrate layer is porous and has sufficiently large pores in relation to the thickness of the metal oxide barrier layer.

Therefore, it is possible that during the application of the above-mentioned cover layer as a water-based dispersion, which is designed to prevent mechanical damage to the barrier layer or to provide a sealable layer, moisture from the applied cover layer dispersion passes through the metal oxide barrier layer and reaches the fiber material-containing substrate layer. The moisture penetrating into the substrate layer can cause it to swell, in particular if the fiber-material-containing substrate layer is a paper or cardboard layer according to a preferred embodiment, which leads to a considerable impairment of the entire packaging material formed with the substrate layer.

SUMMARY OF THE INVENTION

It is therefore the object of the present invention to further develop the above-mentioned fiber-material-based film packaging material with the fiber-material-containing substrate layer, the cover layer and the barrier layer arranged between the substrate layer and the cover layer from metal oxide deposited from the vapor phase in such a way that the above-mentioned disadvantages are mitigated or completely avoided.

The present invention solves this problem in a flat fiber-material-based packaging material of the type mentioned at the beginning by providing a first polymer layer and a second polymer layer on the packaging material between the cover layer and the substrate layer. The first polymer layer is formed to an extent of at least 90% by weight from a first polymer and the second polymer layer is formed to an extent of at least 90% by weight from a second polymer. The first and second polymers have different wettabilities with distilled water according to DIN EN 828.

The relevant layers of the fiber-material-based packaging material are also referred to briefly below as “substrate layer,” “barrier layer,” “cover layer,” “first polymer layer,” and “second polymer layer,” since the abbreviated designation is unambiguous.

By providing additional polymer layers between the substrate layer and the cover layer, whose respective polymers have different wettabilities with respect to water—distilled water is only referred to as the reference liquid or “reference water” in consideration of the cited DIN standard—the migration of moisture, i.e. water, from the cover layer applied as a water-based dispersion through the barrier layer into the fiber material can be prevented or reduced to a very considerable extent. Water-based dispersions are usually even formed with distilled water, so that the reference liquid for determining the wettability and the liquid base of the dispersion of the cover layer during application are even identical. Even if water other than distilled water is used to prepare the top layer dispersion, the relevant wettability of the respective polymer will only differ negligibly from the wettability with distilled water.

In the present application, the application of layers as a dispersion is mentioned in various contexts. The application as a dispersion actually refers to the process of application. In all other respects, 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.

When the present application refers to “solvent,” this solvent is mentioned in contrast to the water also mentioned. “Solvent” within the meaning of the present application is therefore a liquid suitable for forming a polymer dispersion which is not water.

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 a surface of the respective material. Materials for which the contact angle of the water is greater than 90° are considered hydrophobic. Materials with small contact angles are considered hydrophilic. As a general rule, the wettability of the material under consideration decreases as the contact angle increases.

In the following it is to be assumed that the first polymer has a better wettability with 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.

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

Since the second polymer should be less wettable by distilled water, the second polymer preferably exhibits a contact angle measured in accordance with DIN EN 828 of more than 45° when wetted by distilled water. If the contact angle specified here as the lower limit is smaller 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. Preferably, the contact angle when the second polymer is wetted is greater than 60°, particularly preferably greater than 75°.

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

Since the first polymer layer is more easily wettable by water than the second polymer layer, it is preferable that it is located as far away as possible from the cover layer or with an intermediate arrangement of as many further layers as possible between it and the cover layer. This can be achieved by design by arranging the first polymer layer between the substrate layer and the barrier layer. In this way, at least the barrier layer is always located between the substrate layer and the first polymer layer. Furthermore, the first polymer layer can form a smoother surface for the deposition of a metal oxide barrier layer thereon than the fiber-material-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.

Preferably, the first polymer layer is the polymer layer closest to the substrate layer on that side of the substrate layer on which the barrier layer is arranged. 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 printing ink and the first polymer layer can therefore be applied directly to the printed ink.

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 may comprise two partial polymer layers or be formed from two partial polymer layers.

If 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.

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 be particularly preferably arranged between the first polymer layer and the barrier layer.

Alternatively, the second polymer layer can be applied and formed as a solvent-based dispersion of the second polymer. Then, 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 one or at least one further partial polymer layer can be applied and formed as a solvent-based dispersion.

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.

The first polymer may 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, with the same layer thickness, increase the oxygen barrier layer in particular and consequently reduce the oxygen permeability of the packaging material disproportionately.

The second polymer can be a polyolefin and/or a polyester. This applies in particular if 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 may be a polyolefin or a polyester.

The first and second polymer layers are formed to an extent of at least 90% by weight from the first polymer and the second polymer, respectively, to ensure that the polymer layers have the wetting properties of the first and second polymers, respectively. At least one layer of the first and second polymer layers, preferably both layers, may be formed to an extent of at least 95% by weight, particularly preferably at least 99% by weight, from the first and second polymers, respectively.

The polymer of the cover layer may comprise or be an acrylic copolymer and/or a polyolefin and/or an ethylene vinyl acetate copolymer and/or a biopolymer. Biopolymers such as polylactic acid, polyhydroxyalkanoates, starch polymers or, in general, polymers with cellulose or starch as starting materials are suitable, to name just a few examples.

For a particularly resource-saving but at the same time effective formation of the first polymer layer, this can be formed with an application weight of 1.0 to 5.0 g/m2, measured in the dry state, in particular with an application weight of 1.5 to 3.5 g/m2.

For the same reason, the second polymer layer can be formed with an application weight of 0.5 to 3.0 g/m2 (measured in dry condition), in particular with an application weight of 1.0 to 2.5 g/m2.

The fiber-material-based film packaging material discussed here can be part of a packaging layer material comprising further layers. However, the cover layer is preferably a layer exposed to the environment. The ink application mentioned above as a preferred further development can also be applied to the side of the substrate layer facing away from the barrier layer. One or more further layers may be applied to the ink application, for example a protective lacquer layer to protect the ink application from external influences and/or a sealable polymer layer, in particular a polyolefin layer.

Preferably, the oxygen permeability of the packaging material is less than 1.0 cm3/(m2·d·bar), particularly preferably less than 0.85 cm3 /(m2·d·bar), determined in accordance with 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/(m2·d), particularly preferably less than 0.85cm3 /(m2·d·bar), determined in accordance with ISO 15106-2 at 23° C. and 85% relative humidity.

The items defined below are of particular interest for the present application. The features of the items are accompanied by the reference signs in the following figure description:

    • Item 1: A fiber-material-based packaging material (10; 110; 210) 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 vapor permeability of less than 1.1 g/(m2·d), determined in accordance with ISO 15106-2 at 23° C. and 85% relative humidity, comprising a fiber-material-containing substrate layer (12; 112; 212), a cover layer (20; 120; 220) formed to an extent of at least 90 wt.-%, based on the dry state, from a water-based dispersion of a polymer, and a barrier layer (16; 116; 216) of a metal oxide deposited from a vapor phase, which is located between the cover layer (20; 120; 220) and the substrate layer (12; 112; 212),
      • wherein, in addition, a first polymer layer (14; 114; 214), which is formed to an extent of at least 90% by weight from a first polymer, and a second polymer layer (18; 118; 218a, 218b), which is formed to an extent of at least 90% by weight from a second polymer, are arranged between the cover layer (20; 120; 220) and the substrate layer (12; 112; 212), wherein the first and second polymers have different wettabilities when wetted by distilled water according to DIN EN 828.
    • Item 2: Fiber-material-based packaging material (10; 110; 210) according to item 1, further characterized in that the fiber-material-containing substrate layer (12; 112; 212) is a paper or cardboard layer.
    • Item 3: Fiber-material-based packaging material (10; 110; 210) according to item 1 or 2, further characterized in that the first polymer, when wetted by distilled water, exhibits a contact angle of less than 90°, preferably less than 75°, particularly preferably less than 60°, measured in accordance with DIN EN 828, and in that the second polymer, when wetted by distilled water, exhibits a contact angle of more than 45°, preferably more than 75°, particularly preferably more than 90°, measured in accordance with DIN EN 828. preferably greater than 60°, particularly preferably greater than 75%.
    • Item 4: Fiber-material-based packaging material (10; 110; 210) according to item 3, further refined in that the second polymer, when wetted by distilled water, exhibits a contact angle of more than 90° as measured according to DIN EN 828.
    • Item 5: Fiber-material-based packaging material (10; 110; 210) according to one of the preceding items,
      • further refined 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).
    • Item 6: Fiber-material-based packaging material (110; 210) according to one of the preceding items,
      • further refined 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).
    • Item 7: Fiber-material-based packaging material (110; 210) according to items 5 and 6,
      • further refined 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).
    • Item 8: Fiber-material-based packaging material (10; 210) according to one of the preceding items,
      • further refined 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).
    • Item 9: Fiber-material-based packaging material (10; 110; 210) according to one of the preceding items, further refined in that the first polymer is a vinyl alcohol-based polymer.
    • Item 10: Fiber-material-based packaging material (110; 210) according to one of the preceding items, incorporating at least one of items 6 and 7, further refined in that the second polymer is a polyolefin.
    • Item 11: Fiber-material-based packaging material (10; 210) according to one of the preceding items, incorporating item 8, further refined in that the second polymer is a polyolefin or a polyester.
    • Item 12: Fiber-material-based material (10; 110; 210) according to one of the preceding items,
      • further refined 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.
    • Item 13: Fiber-material-based packaging material (10; 110; 210) according to one of the preceding items,
      • further refined in that the first polymer layer (14; 114; 214) is formed with an application weight of 1.0 to 5.0 g/m2, measured in the dry state.
    • Item 14: Fiber-material-based packaging material (10; 110; 210) according to one of the preceding items,
      • further refined in that the second polymer layer (18; 118; 218a, 218b) is formed with an application weight of 0.5 to 3.0 g/m2, measured in the dry state.
    • Item 15: Fiber-material-based packaging material (10; 110; 210) according to one of the preceding items,
      • further refined in that the metal oxide of the barrier layer (16; 116; 216) is aluminum oxide or silicon oxide.

These and other objects, aspects, features and advantages of the invention will become apparent to those skilled in the art upon a reading of the Detailed Description of the invention set forth below taken together with the drawings which will be described in the next section.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may take physical form in certain parts and arrangement of parts, a preferred embodiment of which will be described in detail and illustrated in the accompanying drawings which forms a part hereof and wherein:

FIG. 1 a first embodiment of a film packaging material according to the invention in cross-section,

FIG. 2 a second embodiment of a film packaging material according to the invention in cross-section, and

FIG. 3 a third embodiment of a film packaging material according to the invention in cross-section.

 DESCRIPTION OF PREFERRED EMBODIMENTS

Referring now to the drawings wherein the showings are for the purpose of illustrating preferred and alternative embodiments of the invention only and not for the purpose of limiting the same, FIG. 1 shows a first embodiment of a film packaging material according to the invention in cross-section and is generally designated by 10. It comprises, as a fiber-material-based substrate layer 12, a paper layer with a preferred basis weight of between 40 g/m2 and 200 g/m2 . The paper layer as the fiber-material-based substrate layer 12 may be a layer of coated or uncoated paper.

A first polymer layer 14 with polyvinyl alcohol as a preferred first polymer in water-based dispersion is applied to one side of the substrate layer 12. In the first embodiment shown, 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/m2, preferably of about 3.5 g/m2. 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.

Polyvinyl alcohol absorbs water and is therefore easily wettable by water, including distilled water.

A barrier layer 16, preferably of aluminum oxide, is deposited on the first polymer layer 14 by vacuum vapor deposition. The barrier layer 16, which is less than 1 μm thick, in particular less than 0.5 μm thick, forms an excellent barrier layer for reducing the oxygen permeability and water vapor permeability of the packaging material 10.

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, there is no risk of the solvent-based dispersion impairing the first polymer layer 14 made of polyvinyl alcohol.

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

The layer arrangement consisting of the first polymer layer 14, barrier layer 16, and 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 thereof facing away from the barrier layer 16. The cover layer 20 is therefore also a polymer layer, for example made of an acrylic copolymer.

The second polymer layer 18 is applied with an application weight in the range of 0.5 g/m2 to 3.0 g/m2, preferably with an application weight of 2.0 g/m2.

The packaging material 10 of the first embodiment has an oxygen permeability of 1.0 cm3/(m2·d·bar), determined in accordance with DIN 53380-3 at 23° C. and 85% relative humidity, and has a water vapor permeability of 1.0 g/(m2·d), determined in accordance with ISO 15106-2 at 23° C. and 85% relative humidity.

FIG. 2 shows a second embodiment of a packaging material according to the invention in cross-section. The second embodiment will only be described below insofar as it differs from the first embodiment. Components and component sections that are identical and functionally identical to those in the first embodiment are designated by the same reference numerals in the second embodiment, but increased by the number 100. For the rest, reference is made to the description of the first embodiment for an explanation of the second embodiment.

The second embodiment is intended, among other things, to illustrate 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 consequently carry an ink coating 122. The first polymer layer 114 can be applied to this ink coating as a water-based dispersion of polyvinyl alcohol.

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 not applied as a solvent-based dispersion of the second polymer, but as a water-based dispersion of the second polymer. The second polymer is therefore preferably a polyolefin in the second embodiment. The application weight of the second polymer layer 118 corresponds to that in the first embodiment.

Consequently, the aluminum oxide barrier layer 116 is deposited from the vapor phase in a vacuum onto the second polymer layer 118.

The cover layer 120 still forms a layer exposed to the environment of the packaging material 110.

FIG. 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. Components and component sections that are identical and functionally identical to those in the first embodiment are designated by the same reference numerals in the third embodiment, but increased by the number 200. For the rest, reference is made to the description of the first and second embodiments for an explanation of the second embodiment.

The third embodiment of the packaging material 210 corresponds to a combination of the first two embodiments, wherein, for the sake of simplicity, no printing ink is applied as in the first embodiment.

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

The second polymer layer 218 is formed by two partial polymer layers in the third embodiment. 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.

As in the second embodiment, the second polymer layer 218 also comprises 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 on the latter.

The packaging material 10 and 210 of the first and third embodiments may also have an ink application layer, for example to apply consumer information to the packaging material. As in the second embodiment, an ink application layer may be applied to the substrate layer 12 or 212 between the substrate layer 12 or 212 and the first polymer layer 14 or 214, or/and to the aluminum oxide barrier layer 216. 212 between the substrate layer 12 or 212 and the first polymer layer 14 or 214, or/and on the surface of the substrate layer 12 or 212 facing away from the barrier layer 16 or 216.

In the third embodiment, each partial polymer layer 218a and 218b may have the application weight specified in the first and second embodiments for the second polymer layer 18 or 118, respectively. Alternatively, the two partial polymer layers 218a and 218b may together have the application weight specified in the first and second embodiments for the second polymer layer 18 and 118, respectively.

While considerable emphasis has been placed on the preferred embodiments of the invention illustrated and described herein, it will be appreciated that other embodiments, and equivalences thereof, can be made and that many changes can be made in the preferred embodiments without departing from the principles of the invention. Furthermore, the embodiments described above can be combined to form yet other embodiments of the invention of this application. Accordingly, it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

Claims

1-14. (canceled)

15. A fiber-material-based packaging material comprising a

fiber-material-containing substrate layer, a cover layer, and a barrier layer of a metal oxide, which is deposited from a vapor phase and is located between the cover layer and the substrate layer,
wherein additionally a first polymer layer, which is formed to an extent of at least 90% by weight from a first polymer, and a second polymer layer, which is formed to an extent of at least 90% by weight from a second polymer, are arranged between the cover layer and the substrate layer, the first and the second polymer having different wettabilities according to DIN EN 828 by distilled water, the contact angle of a drop of distilled water being smaller when the first polymer is wetted than when the second polymer is wetted, wherein the first polymer layer is arranged between the substrate layer and the barrier layer,
wherein the second polymer layer is arranged as a water-based dispersion of the second polymer between the first polymer layer and the barrier layer or/and is arranged as a solvent-based dispersion of the second polymer between the barrier layer and the cover layer, wherein the second polymer layer is formed with an application weight—to be measured in the dry state—of 0.5 to 3.0 g/m2, wherein the barrier layer is deposited on the first polymer layer or is deposited on the polymer material of the second polymer layer, wherein the cover layer is formed to an extent of at least 90 % by weight, based on the dry state, from a water-based dispersion of a polymer, and wherein the fiber-material-based packaging material has an oxygen permeability of less than 1.1 cm3 /(m2·d·bar), determined according to DIN 53380-3 at 23° C. and 85% relative humidity, and having a water vapor permeability of less than 1.1 g/(m2·d), determined according to ISO 15106-2 at 23° C. and 85% relative humidity.

16. The fiber-material-based packaging material according to claim 15, wherein the fiber-material-containing substrate layer is a paper or cardboard layer.

17. The fiber-material-based packaging material according to claim 16, wherein the first polymer, when wetted by distilled water, exhibits a contact angle, measured according to DIN EN 828, of less than 90°, and the second polymer, when wetted by distilled water, exhibits a contact angle, measured according to DIN EN 828, of more than 45°.

18. The fiber-material-based packaging material according to claim 15, wherein the first polymer, when wetted by distilled water, exhibits a contact angle, measured according to DIN EN 828, of less than 60°, and the second polymer, when wetted by distilled water, exhibits a contact angle, measured according to DIN EN 828, of more than 60°.

19. The fiber-material-based packaging material according to claim 15, wherein the first polymer, when wetted by distilled water, exhibits a contact angle, measured according to DIN EN 828, of less than 90°, and the second polymer, when wetted by distilled water, exhibits a contact angle, measured according to DIN EN 828, of more than 45°.

20. The fiber-material-based packaging material according to claim 19, wherein the second polymer exhibits a contact angle of more than 90° when wetted by distilled water, measured according to DIN EN 828.

21. The fiber-material-based packaging material according to claim 15, wherein the first polymer is a vinyl alcohol-based polymer.

22. The fiber-material-based packaging material according to claim 15, wherein the second polymer is a polyolefin.

23. The fiber-material-based packaging material according to claim 15, wherein the second polymer is a polyolefin or a polyester.

24. The fiber-material-based packaging material according to claim 15, wherein the polymer of the cover layer comprises an acrylic copolymer or/and a polyolefin or/and an ethylene vinyl acetate copolymer or is a biopolymer.

25. The fiber-material-based packaging material according to claim 15, wherein the first polymer layer is formed with an application weight—to be measured in the dry state—of 1.0 to 5.0g/m2.

26. The fiber-material-based packaging material according to claim 15, wherein the metal oxide of the barrier layer is aluminum oxide or silicon oxide.

Patent History
Publication number: 20260201647
Type: Application
Filed: Dec 13, 2023
Publication Date: Jul 16, 2026
Inventors: Martin Schmölz (Oberthingau), Bastian Bäuerlein (Obergünzburg)
Application Number: 19/137,941
Classifications
International Classification: D21H 19/82 (20060101); B65D 65/40 (20060101); D21H 19/12 (20060101); D21H 19/22 (20060101); D21H 21/14 (20060101); D21H 27/10 (20060101);