PAPER PACKAGING MATERIAL WITH IMPROVED RESUSPENDABILITY OF CELLULOSIC FIBRES

Abstract

The patent application relates to a paper-based packaging material with a carrier paper and a first coating arranged indirectly on at least one side of the carrier paper, wherein the first coating is a barrier layer and has an increased diffusion resistance to at least one substance selected from a group comprising fluid, gas, air, oxygen, carbon dioxide, nitrogen, inert gas, odorant, aromatic substance, water vapor, liquid, water, water-fat emulsion, fat, oil, mineral oil, and edible oil, odorant, flavorant, water vapor, liquid, water, water-fat emulsion, grease, oil, mineral oil, and edible oil individually or in combination, wherein the first coating is disposed between the carrier paper and a visually perceptible surface coating and directly contacts the surface coating. Furthermore, the invention relates to a package made of such a paper-based packaging material and a method of manufacturing the same.

Claims

1. A paper-based, recyclable packaging material, having a carrier paper and a first coating arranged indirectly on at least one side of the carrier paper, wherein the first coating representing at least one substance selected from a group comprising fluid, gas, air, oxygen, carbon dioxide, nitrogen, inert gas, odorant, aromatic substance, water vapour, liquid, water, water-fat emulsion, grease, oil, mineral oil (MOSH (Mineral Oil Saturated Hydrocarbons), MOAH (Mineral Oil Aromatic Hydrocarbons), POSH (Polyolefinic Saturated Hydrocarbons)) and edible oil, individually or in combination, has an increased diffusion resistance compared to paper, characterised in that the first coating is disposed between the carrier paper and a visually perceptible surface coating and directly contacts the surface coating.

2. The paper-based packaging material according to claim 1, characterized in that the first coating is a barrier layer and this is selected from a group comprising PVDC, PVOH, modified PVOH, acrylate, biopolymers, casein, starch, thermoplastic starch, sugar, cellulose, carboxymethyl cellulose, cellulose ether, xanthan, carrageenan, polypeptides, proteins, gelatine, pectin, guaran, chitin derivatives, chitosan derivatives (in particular N-carboxymethylchitosan), dextran, gluten, hyaluronic acid, polyhydroxyalkanoate-based water-soluble polymer, ionomers, polyurethane, polyacrylic acid, hydrophilic polyacrylate, polyacrylamide (in particular N-(2-hydroxypropyl)methacrylamide), polymethacrylic acid, copolymers of acrylic acid and/or metacrylic acid and their esters, polysulfonic acid, polyamine, amino resin, polyimine, polybetaine, polyethylene oxide, polyethylene glycol, homo-polyvinylpyrrolidone (in particular poly-N-vinylpyrrolidone), vinyl-pyrrolidones (in particular vinyl-pyrrolidone/vinyl laurate copolymers, vinyl-pyrrolidone/vinyl imidazole and vinyl-pyrrolidone/vinyl caprolactam), polyvinyl alcohol, polyvinyl alcohol/ethylene-vinyl alcohol copolymers, butenediol-vinyl alcohol copolymer (BVOH), acetalised polyvinyl alcohol, polyvinyl acetal, polyester, polyethyleneimine, quaternary ammonium compounds, polyoxazoline, polyphosphate, carboxypolymethylene, polyvinyl methyl ether, maleic anhydride and polyacrylamide, in each case individually, as a mixture and/or as copolymers.

3. The paper-based packaging material according to claim 2, characterized in that the carrier paper has, on the second side opposite the first coating, a second coating which does not cover this side of the carrier paper over its entire surface, wherein the second coating being a sealable coating.

4. The paper-based packaging material according to claim 2, characterised in that the optically perceptible surface coating on the side opposite the barrier layer is covered at least in sections, over the entire surface, by a protective layer.

5. The paper-based packaging material according to claim 2, characterized in that the second coating covers at most 50% of one side of the carrier paper.

6. The paper-based packaging material according to claim 1, characterized in that the paper-based packaging material has a water permeation rate at 50° C. of at least 90 g/m.sup.2-day.

7. A packaging, characterised in that it comprises a paper-based packaging material according to claim 1.

8. The package according to claim 7, characterised in that the second coating is arranged on an inner side of the package.

9. A method for producing a paper-based packaging material, characterized by the steps of: providing a carrier paper, providing a first coating composition suitable for producing a barrier layer having an increased diffusion resistance to at least one substance selected from a group comprising fluid, gas, air, oxygen, carbon dioxide, nitrogen, inert gas, odorant, flavorant, water vapor, liquid, water, water-fat emulsion, grease, oil, mineral oil, and edible oil individually or in combination, applying the first coating comprising the first coating composition to one side of the carrier paper, providing a surface coating composition, applying the surface coating composition directly to the first coating.

10. The method for producing a paper-based packaging material according to patent claim 9, characterized in that the carrier paper, before and/or after the application of the first coating to a first side, is provided on the second side opposite the first side with a second coating composition which does not cover this second side of the carrier paper over the entire surface.

Description

EXAMPLE 1

Heat-Sealable Paper-Based Packaging Material

[0064] Layer Sequence: [0065] a) Surface coating, [0066] b) Barrier layer, basis weight>1 g/m.sup.2, comprising three-dimensional cross-linked silicone-containing powder (particle size<1 μm), [0067] c) Kraft paper, basis weight>40 g/m.sup.2, [0068] d) Partially applied heat-seal lacquer, basis weight (in the coated sections)>3 g/m.sup.2,

[0069] The heat-sealing lacquer of layer d), which is only partially applied, allows water to wet the kraft paper (layer c)) in the non-coated areas and to dissolve cellulose fibres out of it during recycling. The extremely flexible surface coating cannot be damaged or destroyed by liquid (for example water, oil or grease) diffusing through the kraft paper (layer c)) when used as packaging due to the barrier layer b). Instead of the heat-sealing lacquer, a heat-sealing coating with a thickness of more than 5 μm could also be used. If the cold sealability of the sealing layer is desired, the heat seal lacquer applied only in sections could be replaced by a cold seal lacquer applied in sections, for example with a thickness of more than 3 μm.

EXAMPLE 2

Heat-Sealable Paper-Based Packaging Material With Printing

[0070] Layer Sequence: [0071] a) Optional topcoat, basis weight>1 g/m.sup.2, [0072] b) Printing ink, [0073] c) Barrier layer, basis weight>1 g/m.sup.2, comprising three-dimensional cross-linked silicone-containing powder (particle size<1 μm), [0074] d) Kraft paper, basis weight>40 g/m.sup.2, [0075] e) Partially applied heat-seal lacquer, basis weight (in the coated sections)>3 g/m.sup.2.

[0076] The optional topcoat according to a) can also be used to adapt the properties of the surface to special requirements with regard to its mattness, gloss, haptic or improved friction. Again, the only partially applied heat-seal lacquer allows solvent access to the carrier paper (layer d)) during recycling.

EXAMPLE 3

Extrusion-Coated Paper-Based Packaging Material With Printing

[0077] Layer Sequence: [0078] a) Printing ink (partial) [0079] b) Hydrolysable lacquer<3 g/m.sup.2 [0080] c) Kraft paper basis weight>50 g/m.sup.2, coated on one side, paper coating inwards [0081] d) Extrusion primer (e.g. PBS)>3 g/m.sup.2 [0082] e) PVOH>5 g/m.sup.2 [0083] f) Extrusion top layer (e.g. PBS)>3 g/m.sup.2 [0084] g) Heat-sealable lacquer,>5 g/m.sup.2 optionally with barrier properties against water vapour (e.g. ionomer-based lacquer)

EXAMPLE 4

Heat-Sealable, Double-Sided Hydrolysable, Paper-Based Packaging Material With Printing

[0085] Layer Sequence: [0086] a) Printing ink (partial) [0087] b) Hydrolysable lacquer<3 g/m.sup.2 [0088] c) Kraft paper basis weight>40 g/m.sup.2, coated on one side, paper coating inwards [0089] d) Hydrolysable lacquer<3 g/m.sup.2 [0090] e) Heat-sealable lacquer,>5 g/m.sup.2 optionally with barrier properties against water vapour (e.g. ionomer-based lacquer)

EXAMPLE 5

Heat-Sealable, Double-Sided Hydrolysable, Metallised, Paper-Based Packaging Material With Printing

[0091] Layer Sequence: [0092] a) Aluminium metallisation [0093] b) Hydrolysable lacquer<3 g/m.sup.2 [0094] c) Kraft paper basis weight>40 g/m.sup.2, coated on one side, paper coating inwards [0095] d) Hydrolysable lacquer<3 g/m.sup.2 [0096] e) Heat-sealable lacquer,>5 g/m.sup.2 optionally with barrier properties against water vapour (e.g. ionomer-based lacquer)

EXAMPLE 6

Heat-Sealable, Paper-Based Packaging Laminate

[0097] Layer Sequence: [0098] a) Kraft paper basis weight>40 g/m.sup.2 [0099] b) Glue or adhesive (laser perforated if necessary) [0100] c) Aluminium metallisation [0101] d) Hydrolysable lacquer<3 g/m.sup.2 [0102] e) Kraft paper basis weight>40 g/m.sup.2, coated on one side, paper coating inwards [0103] f) Hydrolysable lacquer<3 g/m.sup.2 [0104] g) Heat-sealable lacquer,>5 g/m.sup.2 optionally with barrier properties against water vapour (e.g. ionomer-based lacquer)

EXAMPLE 7

Heat-Sealable, Channel-Perforated, Paper-Based Packaging Material With Surface Coating

[0105] Layer Sequence: [0106] a) Full surface coating<2 g/m.sup.2 perforated with channels [0107] b) Printing ink (partial) [0108] c) Water-soluble primer<2 g/m.sup.2 (e.g. cellulose derivative) perforated with channels [0109] d) Kraft paper basis weight>40 g/m.sup.2, coated on one side, paper coating inwards [0110] e) Full-surface barrier lacquer (e.g. stryrene acrylate-based)>5 g/m.sup.2 [0111] f) Partial cold seal lacquer

EXAMPLE 8

Heat-Sealable, Channel-Perforated, Paper-Based Packaging Material With Surface Coating

[0112] Layer Sequence: [0113] a) Paraffin wax based hotmelt (partial) [0114] b) Printing ink (partial) [0115] c) Water-soluble primer<2 g/m.sup.2 (e.g. cellulose derivative) perforated with channels [0116] d) Kraft paper basis weight>40 g/m.sup.2, coated on one side, paper coating inwards [0117] e) Full-surface barrier lacquer (e.g. stryrene acrylate-based)>5 g/m.sup.2 [0118] f) Paraffin wax based hotmelt (partial)

[0119] The applicant reserves the right to claim all features disclosed in the application documents as essential to the invention, provided they are individually or in combination new compared to the prior art. Furthermore, it is pointed out that the individual figures also describe features which may be advantageous in themselves. The skilled person immediately recognises that a certain feature described in a figure can also be advantageous without adopting further features from this figure. Furthermore, the skilled person recognises that advantages can also result from a combination of several features shown in individual figures or in different figures.