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EP-4735350-A1 - PACKAGING MATERIAL

EP4735350A1EP 4735350 A1EP4735350 A1EP 4735350A1EP-4735350-A1

Abstract

A compostable and eco-sustainable multi-layer packaging material comprising: - a paper layer 1 and a barrier layer (3, 5) on one or both sides of the paper layer, wherein, said barrier layer comprises from 51 to 99% wt., preferably 90-10% wt., more preferably 95–98% wt. of a polymeric component selected from the group consisting of a polyhydroxyalkanoate polymer or copolymer, proteins from milk, fungi or legumes, polylactic acid, polybutylene succinate or polybutylene succinate copolymers, thermoplastic blends of starch and aliphatic polyesters, chitosan, carrageenan, pectin alginates and lipids and mixtures thereof and from 49 to 1% wt., preferably 1-10% wt., more preferably 2-5% wt. of a filler selected from the group consisting of layered double hydroxides, nanocellulose, silicates and clays, preferably phyllosilicates, and mixtures thereof, the percentage by weight being referred to 100 parts by weight of the polymeric component and the filler.

Inventors

  • ZULIANI, Luca
  • ROMANO, Igor

Assignees

  • SOREMARTEC S.A.

Dates

Publication Date
20260506
Application Date
20240627

Claims (18)

  1. 1. A multi-layer packaging material comprising: a paper layer 1 and a barrier layer (3, 5) on one or both sides of the paper layer, wherein, said barrier layer comprises from 51 to 99% wt., preferably 90-10% wt., more preferably 95-98% wt. of a polymeric component selected from the group consisting of a polyhydroxyalkanoate polymer or copolymer, proteinaceous materials selected from proteins from milk, proteins from fungi or proteins from legumes, or gelatin, polylactic acid, polybutylene succinate or polybutylene succinate copolymers, polybutylene adipate terephthalate, thermoplastic blends of starch and aliphatic polyesters, chitosan, carrageenan, pectin, alginates and lipids and mixtures thereof and from 49 to 1% wt., preferably 1-10% wt., more preferably 2-5% wt. of a filler selected from the group consisting of layered double hydroxides, nanocellulose, silicates and clays, preferably phyllosilicates, and mixtures thereof, the percentage by weight being referred to 100 parts by weight of the polymeric component and the filler.
  2. 2. The packaging material of claim 1, wherein said barrier layer (3) is extrusion coated or laminated onto the paper layer (1).
  3. 3. The packaging material of claim 1 or 2, wherein said barrier layer is on both sides of the paper layer (1).
  4. 4. The packaging material of claim 1, wherein said barrier layer (5) is obtained by applying and drying a lacquer comprising said polymeric component and filler in water or in a solvent vehicle.
  5. 5. The packaging material of claim 4, wherein said barrier layer (5), obtained from a lacquer is on both sides of the paper layer (1).
  6. 6. The packaging material of claim 1, comprising a barrier layer (3) according to claim 2 on one side of the paper layer and a barrier layer (5) according to claim 4 on the other side of the paper layer (1).
  7. 7. The packaging material of claim 3, comprising an additional barrier layer (5) according to claim 4, above one or both the laminated or extrusion coated barrier coating layers.
  8. 8. The packaging material according to claims 3 or 7 wherein said laminated or extrusion coated barrier layer (3) is heat sealable and wherein the polymeric component is selected from the group consisting of a polyhydroxyalkanoate polymer or copolymer, polybutylene succinate, polybutylene adipate terephthalate (PBAT) and polylactic acid and mixtures thereof and the filler is selected from a layered double hydroxide and nanocellulose.
  9. 9. The packaging material according to claim 3 or 7, wherein said laminated or extrusion coated barrier layer (3) is heat sealable and wherein the polymeric component is selected from the group consisting of a proteinaceous material selected from milk, fungal and pea proteins, gelatin and mixture thereof and said filler is selected from the group consisting of hydrotalcite, nanocellulose, silicates and clays and mixtures thereof.
  10. 10. The packaging material according to claim 8 wherein said barrier layer comprises from 50 to 85% wt., preferably 50 to 70% wt., of a polyhdyroxyalkanoate (PHA), from 20 to 40% wt. of polybutylenesuccinate (PBS) or polylactic acid and mixtures thereof, and from 0,5 to 3% wt. of nanocellulose, preferably CNC and optionally up to 9,5% wt. conventional additives, wherein the sum of the wt. percentages is 100%.
  11. 11. The polymeric material according to claim 8, wherein said laminated or extrusion coated barrier layer comprises from 50 to 60% wt. of a polyhdyroxyalkanoate (PHA), from 20 to 30% wt. of polybutylenesuccinate (PBS) or polylactic acid and mixtures thereof, from 0,5 to 10% wt. of dispersed hydrotalcite or hydrotalcite-like minerals and optionally from 5 to 9,5% wt. of conventional additive, the sum of said percentages being 100% wt.
  12. 12. The packaging material according to any of the preceding claim further comprising a primer layer applied to one or both sides of the paper layer in between the surface of the paper layer and said barrier coating layer ((3), (5)).
  13. 13. The packaging material according to any of the preceding claims, further comprising an external ink printed layer (11).
  14. 14. The packaging material according to any of the preceding claims, comprising a heat- sealable layer (7) a as surface layer.
  15. 15. The packaging material according to claim 14, wherein said heat sealable layer (7) comprises a polymeric component selected from the group consisting of polyhydroxyalkanoate, polybutylenesuccinate and polybutylene adipate terephtalate and does not include a filler.
  16. 16. The packaging material according to any of claims 1 to 13 comprising as a surface layer a cold sealable layer (9) formulated from a latex suspension, optionally including additives or pigments.
  17. 17. The packaging material according to claim 16 comprising as a surface layer a coating of a release varnish.
  18. 18. The packaging material according to any of claims 1 to 17 wherein said paper layer is a film having a weight of from 35 to less than 120 g/m2 or is a sheet having a weight of from 120 to 400 g/m2.

Description

Packaging Material The present invention relates to a multi-layer paper-based packaging material, particularly for use in packaging confectionary products, comprising a paper layer and at least a barrier coating layer. Barrier coatings are required and widely used in food packaging to preserve the food organoleptic properties. Barrier properties for flexible packaging materials, particularly for a confectionary product, include a low permeability to 02 and water vapor, as well as low permeability to volatile aroma compounds and low light permeability. Particularly, for packaging materials for use in the packaging of confectionary products it is desirable to achieve an oxygen transmission rate (OTR) lower than 100 or preferably lower than 0.1 cc/m2 24h, measured at 23 °C at 40-50% RH and a water vapor transmission rate (WVTR) lower than 10 or preferably lower than 0.1 g/m2 24 h at 38°C at 90% RH. Currently used solutions to obtain the desirable barrier properties for the packaging of confectionary products include lamination with a polyolefin film (PE, PP, PET) coupled with metallization or the use of a barrier coating layer including clay and polymeric components. There is however a need for paper-based packaging materials that are eco-sustainable, allowing the paper-based packagings to be compostable and/or easily recyclable. Moreover, there is a need for packaging materials that combine the required barrier properties and the eco-sustainability properties, with mechanical properties that allow their use in modem highspeed packaging machines such as for instance flow-pack and flow-wrap machines and twist-wrap machines. Particularly desirable as mechanical properties are tensile strength and resistance to pierce, which can be also represented with the bursting strength leveraging the T403 analytical method. The purpose of the invention is to provide a multi-layer paper-based packaging material that combines the above-mentioned requirements. Summary of the invention In view of the above-mentioned purpose, the subject-matter of the invention is a multi-layer packaging material as defined in the appended claims. The dependent claims relate to preferred embodiments of the invention. Further characteristics and advantages of the packaging material of the invention will become clear from the detailed description that follows, made with reference to the attached drawings, provided by way of non-limiting example. Brief description of the drawings In the attached drawings: - Fig. 1 is a schematic sectional representation showing the layout of a plurality of embodiments (a) to (g) of the packaging material, wherein a surface layer of the multi-layer structure has heat sealing properties; - Fig. 2 is a schematic sectional representation showing the layout of a plurality of embodiments (a) to (g), wherein the multi-layer structure includes a surface layer having cold sealing properties, and - Fig. 3 is a schematic sectional representation of a plurality of exemplified embodiments (a) to (e); and - Fig. 4 is a schematic sectional representation of a plurality of exemplified embodiments (a) to (e). In the annexed drawings, the reference numerals indicate the following structural features: 1 paper layer (substrate) 3 barrier layer, extrusion coated or laminated onto the paper layer 1; 5 barrier layer coating the paper layer 1 or the barrier layer 3, obtained by applying a lacquer; 7 optional layer, obtained by applying a heat sealable lacquer; 9 optional continuous or discontinuous cold sealable layer (also indicated CS in the drawings); 11 optional continuous or discontinuous printed layer; 13 optional layer obtained from a release varnish; 15 extrusion coated layer consisting of a PHA. Detailed description of the invention The invention relates to packaging materials having a multi-layer structure and comprising a paper-based layer 1, that generally constitutes the core layer of the packaging material, and at least a barrier layer 3, 5 comprising or obtained from sustainable and/or natural materials suitable to provide packagings that are compostable and that achieve higher scorings in the recyclability certification tests. The terms “paper layer” or “paper-based layer” is intended to mean a layer comprising or consisting essentially of cellulose fibers and includes paperboard and cardboard. The wording, used in the present description, relating to the use of a material "comprising" cellulose or cellulose fibers or "consisting essentially of cellulose or cellulose fibers" does not exclude the presence of additives, for example of the type conventionally used in the production of paper or additives functional for obtaining barrier effects to gases and liquids or for improving the mechanical properties. For example, such terms include the case where the material comprises from 70 to 99.9% by weight of cellulose fibers on an anhydrous basis, preferably from 90 to 99.9% by weight and from 0.1 to 30% by weight on an anh