Paperboard structure with at least one barrier coating layer

Patent metadata

Field	Value
Publication number	US-12152346-B2
Application number	US-202217689041-A
Country	US
Kind code	B2
Filing date	Mar 8, 2022
Priority date	Feb 19, 2018
Publication date	Nov 26, 2024
Grant date	Nov 26, 2024

Abstract

A paperboard structure that includes a paperboard substrate which includes a first major side and a second major side along with at least one barrier coating layer on the first major side. The barrier coating layer(s) may include a binder and a pigment, wherein the binder has a glass transition temperature of at least 20° C., wherein a ratio of the binder to the pigment is at least about 1:2 by weight.

First claim

What is claimed is:

1. A paperboard structure comprising:
a paperboard substrate comprising a first major side and a second major side opposed from said first major side; and
at least one barrier coating layer on said first major side, wherein said barrier coating layer comprises a binder and a pigment, and wherein said binder has a glass transition temperature of at least 20° C., wherein said pigment comprises at least one of clay and CaCO 3 , wherein a ratio of said binder to said pigment is about 1:2 to about 9:1 by weight, wherein said barrier coating layer defines an outermost surface of said paperboard structure, and wherein said barrier coating layer is heat sealable,
wherein the paperboard structure has a repulpability of at least 80 percent.

2. The paperboard structure of claim 1 wherein said glass transition temperature is at least 25° C.

3. The paperboard structure of claim 1 wherein said glass transition temperature is at least 30° C.

4. The paperboard structure of claim 1 wherein a ratio of said binder to said pigment is about 1:1 to about 4:1 by weight.

5. The paperboard structure of claim 1 wherein said binder comprises at least one of styrene-acrylate, styrene-butadiene rubber, ethylene acrylic acid, polyvinyl acetate, and polyester dispersion.

6. The paperboard structure of claim 1 wherein said pigment comprises clay and CaCO 3 .

7. The paperboard structure of claim 1 wherein at least 60 percent by weight of the pigment is comprised of particles having a particle size less than 2 microns.

8. The paperboard structure of claim 1 wherein at least 80 percent by weight of said pigment is comprised of particles having a particle size less than 2 microns.

9. The paperboard structure of claim 1 wherein said pigment comprises at least one of:
a coarse ground CaCO 3 with a particle size of about 60% less than 2 microns;
a fine ground CaCO 3 with a particle size of about 90% less than 2 microns; and
a fine ground CaCO 3 with a mean particle diameter size of about 0.4 microns.

10. The paperboard structure of claim 1 providing a 30-minute water Cobb test of less than about 20 g/m 2 .

11. The paperboard structure of claim 1 providing a blocking rate of less than 3 at 40° C. and at 60 psi in a 24-hour period.

12. The paperboard structure of claim 1 further comprising a base coat layer between said paperboard substrate and said barrier coating layer.

13. The paperboard structure of claim 12 wherein said base coat layer comprises a binder and a pigment.

14. The paperboard structure of claim 1 further comprising a second barrier coating layer on said second major side.

15. The paperboard structure of claim 1 wherein said paperboard substrate has a caliper ranging from about 4 points to about 30 points.

16. The paperboard structure of claim 15 wherein said caliper ranges from about 13 points to about 18 points.

17. The paperboard structure of claim 1 wherein said paperboard substrate has a basis weight of about 85 to about 250 pounds per 3,000 square feet.

18. The paperboard structure of claim 1 further comprising a second barrier coating layer on said first major side.

19. The paperboard structure of claim 18 providing a 30-minute water Cobb test of less than 6 g/m 2 .

20. The paperboard structure of claim 18 providing a 30-minute hot water Cobb test of less than 15 g/m 2 .

21. The paperboard structure of claim 18 providing a 30-minute hot coffee Cobb test of less than 15 g/m 2 .

22. The paperboard structure of claim 18 providing a blocking rate of less than 3 at 50° C. and at 60 psi in a 24-hour period.

23. The paperboard structure of claim 1 wherein the paperboard structure has a repulpability of at least 85 percent.

24. The paperboard structure of claim 1 wherein the paperboard structure has a repulpability of at least 90 percent.

25. The paperboard structure of claim 1 wherein the paperboard structure has a repulpability of at least 95 percent.

26. The paperboard structure of claim 1 wherein the at least one barrier coating layer on said first major side is a single barrier coating.

27. The paperboard structure of claim 1 wherein the at least one barrier coating layer on said first major side includes a plurality of barrier coatings, wherein each barrier coating layer includes said binder having a glass transition temperature of at least 20° C.

28. A method for manufacturing a paperboard structure comprising:
preparing a barrier coating composition comprising a binder and a pigment, wherein said binder, when dried, has a glass transition temperature of at least 20° C., wherein said pigment comprises at least one of clay and CaCO 3 , wherein a ratio of said binder to said pigment is about 1:2 to about 9:1 by weight; and
applying said barrier coating composition to a paperboard substrate to form a first barrier coating layer, wherein said barrier coating layer defines an outermost surface of said paperboard structure, and wherein said barrier coating layer is heat sealable,
wherein the paperboard structure has a repulpability of at least 80 percent.

29. The method of claim 28 further comprising applying a second barrier coating composition over said first barrier coating layer to form a second barrier coating layer.

30. The method of claim 28 further comprising drying said barrier coating composition.

Assignees

• Westrock Mwv Llc

Inventors

• Pang Jiebin
• Melton Natasha G
• Parker Steven
• Krug Teresa

Classifications

• D21H19/38

  characterised by the pigments · CPC title

• D21H19/56

  Macromolecular organic compounds or oligomers thereof obtained by reactions only involving carbon-to-carbon unsaturated bonds · CPC title

• D21H21/16 Primary

  Sizing or water-repelling agents · CPC title

• D21H23/22

  Addition to the formed paper · CPC title

• D21H19/822

  two superposed coatings, both being pigmented · CPC title