Paperboard structure with at least one barrier coating layer

Patent metadata

Field	Value
Publication number	US-11299855-B2
Application number	US-201916267865-A
Country	US
Kind code	B2
Filing date	Feb 5, 2019
Priority date	Feb 19, 2018
Publication date	Apr 12, 2022
Grant date	Apr 12, 2022

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 hinder and a pigment, wherein said binder has a glass transition temperature of at least 20° C., wherein a ratio of said hinder to said pigment is at least 1:2 by weight, wherein at least 60 percent by weight of the pigment is comprised of particles having a particle size less than 2 microns, wherein the paperboard structure is heat-sealable when coated with a single layer of said barrier coating layer, and 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 1:2 to 9:1 by weight.

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

6. 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.

7. The paperboard structure of claim 1 wherein said pigment comprises clay.

8. The paperboard structure of claim 1 wherein said pigment comprises CaCO 3 .

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

10. The paperboard structure of claim 1 wherein at least 70 percent by weight of the pigment is comprised of particles having a particle size less than 2 microns.

11. 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.

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

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

14. 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.

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

16. The paperboard structure of claim 15 wherein said base coat layer comprises a binder and a pigment.

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

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

19. The paperboard structure of claim 18 wherein said caliper ranges from 13 points to 18 points.

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

21. The paperboard structure of claim 1 having a repulpability of at least 85 percent.

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

23. The paperboard structure of claim 1 providing a 30-min water Cobb test of less than 6 g/m 2 .

24. The paperboard structure of claim 22 providing a 30-minute hot water Cobb test of less than 15 g/m 2 .

25. The paperboard structure of claim 22 providing a 30-minute hot coffee Cobb test of less than 15 g/m 2 .

26. The paperboard structure of claim 22 providing a 30-minute hot coffee Cobb test of less than 10 g/m 2 .

27. The paperboard structure of claim 22 providing a 30-minute hot coffee Cobb test of less than 8 g/m 2 .

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

29. A method for manufacturing a paperboard structure comprising:
preparing a harrier coating composition comprising a binder and a pigment, wherein said binder, when dried, has a glass transition temperature of at least 20° C., wherein a ratio of said binder to said pigment is at least 1:2 by weight, wherein at least 60 percent by weight of the pigment is comprised of particles having a particle size less than 2 microns; and
applying a single layer of said barrier coating composition to a paperboard substrate to form a first barrier coaling layer, wherein said paperboard structure is heat-sealable after application of a single layer of said harrier coating composition, and wherein said paperboard structure has a repulpability of at least 80 percent.

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

31. The method of claim 29 further comprising drying said barrier coating composition.

32. The method of claim 29 further comprising applying a base coating to a first major side of the paperboard substrate.

Assignees

• Westrock Mwv Llc

Inventors

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

Classifications

• D21H19/385

  Oxides, hydroxides or carbonates · CPC title

• D21H19/38

  characterised by the pigments · CPC title

• D21H21/16 Primary

  Sizing or water-repelling agents · CPC title

• D21H19/84 Primary

  on both sides of the substrate · CPC title

• D21H19/60

  Polyalkenylalcohols; Polyalkenylethers; Polyalkenylesters · CPC title