Method of producing a packaging material for a retortable package

Patent metadata

Field	Value
Publication number	US-10899119-B2
Application number	US-201716312829-A
Country	US
Kind code	B2
Filing date	Jun 21, 2017
Priority date	Jun 23, 2016
Publication date	Jan 26, 2021
Grant date	Jan 26, 2021

Abstract

The disclosure relates to a packaging material for a retortable package provided with decorative artwork, the packaging material having a pigment-coated paperboard material layer and outer, heat-resistant plastic coatings. In order to improve the printability of the paperboard layer, the surface of the coated paperboard layer intended for printing has a pigment coating composition comprising a pigment mixture, a binder and a zirconium based crosslinking agent, wherein the pigment mixture comprises at least 40 wt % calcium carbonate and at least 10 wt % clay.

First claim

What is claimed is:

1. A retortable packaging material that is formed, filled with contents and sealed to produce a retortable package that is subsequently co-sterilized together with the content by being subjected to heat treatment at elevated temperature, the retortable packaging material including a layer of a coated paperboard material, which is further laminated to outermost layers of plastics, wherein the coated paperboard material comprises a base board having a top side provided with a pigment coating to form a surface for printing, the top side of the base board coated with the pigment coating being printed with a decorative artwork of printing ink, the pigment coating comprising a pigment mixture, at least one binder and a zirconium-based cross-linker, wherein the pigment mixture comprises at least 40 wt-% calcium carbonate and at least 10 wt-% clay.

2. The retortable packaging material according to claim 1 , wherein the coat weight of the pigment coating on the top side is 5-30 g/m 2 .

3. The retortable packaging material according to claim 1 , wherein the pigment mixture amounts to 75-95% of the dry weight of the pigment coating.

4. The retortable packaging material according to claim 1 , wherein the at least one binder amounts to 10-20% of the dry weight of the pigment coating.

5. The retortable packaging material according to claim 1 , wherein the zirconium-based cross-linker amounts to 0.3-3% of the dry weight of the pigment coating.

6. The retortable packaging material according to claim 1 , wherein a pre-coating layer comprising pigment and a binder is provided between the top side of the base board and the pigment coating forming the surface for printing.

7. The retortable packaging material according to claim 1 , wherein the base board is hydrophobized from a sizing agent treatment.

8. The retortable packaging material according to claim 1 , wherein the pigment mixture comprises at least 50 wt. % calcium carbonate and at least 15 wt. % clay.

9. The retortable packaging material according to claim 1 , wherein the at least one binder is/are selected from the group consisting of co-polymers, acrylic resins, polyvinyl acetate, polyvinyl alcohol, proteins, and polysaccharides.

10. The retortable packaging material according to claim 1 , wherein the pigment mixture comprises at least 60 wt. % calcium carbonate, the at least one binder is an acrylic co-polymer and amounts to 12-18% of the dry weight of the pigment coating and the pigment coating comprises an acrylic rheology modifier.

11. The retortable packaging material according to claim 1 , wherein the at least one binder is a styrene/acrylate co-polymer.

12. The retortable packaging material according to claim 1 , wherein the zirconium-based cross-linker is a zirconium carbonate.

13. The retortable packaging material according to claim 1 , further comprising at least one layer serving as a gas barrier.

14. The packaging material according to claim 1 , further comprising at least one aluminium foil layer serving as a gas barrier.

15. The packaging material according to claim 1 , wherein the zirconium-based cross-linker is a ammonium zirconium carbonate or potassium zirconium carbonate.

16. The retortable packaging material according to claim 1 , wherein the pigment coating further comprises at least one rheology modifier.

17. The retortable packaging material according to claim 16 , wherein the at least one rheology modifier amounts to 0.05-2.0% of the dry weight of the pigment coating.

18. The retortable packaging material according to claim 16 , wherein the at least one rheology modifier is carboxy methyl cellulose (CMC) or an acrylic co-polymer.

19. A retortable package produced from the retortable packaging material according to claim 1 .

20. A method for producing a packaging material including a coated paperboard material as defined in claim 1 , comprising applying a pigment coating composition on a top side of a base board, wherein the pigment coating composition comprises a pigment mixture, at least one binder and a zirconium-based cross-linker, the pigment mixture comprising at least 40 wt % calcium carbonate and at least 10 wt % clay, and the method further comprising applying outermost layers of plastics.

21. A method according to claim 20 , further comprising providing the coated paperboard material with a decorative artwork by a printing technique.

22. A method according to claim 20 , wherein the coated paperboard material is laminated to a layer serving as a gas barrier layer, such as an aluminium foil.

Assignees

• Tetra Laval Holdings & Finance

Inventors

• Lindstedt Mikael
• Larsson Johan
• Tufvesson Helena
• Karlsson Anders

Classifications

• B32B15/12 Primary

  of paper or cardboard · CPC title

• B32B2307/718

  Weight, e.g. weight per square meter · CPC title

• B32B27/32

  comprising polyolefins {(comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30)} · CPC title

• B32B2307/7244

  Oxygen barrier · CPC title

• B32B27/36

  comprising polyesters · CPC title