Heat sealable barrier paperboard

Patent metadata

Field	Value
Publication number	US-11542665-B2
Application number	US-202117464395-A
Country	US
Kind code	B2
Filing date	Sep 1, 2021
Priority date	Feb 27, 2017
Publication date	Jan 3, 2023
Grant date	Jan 3, 2023

Abstract

An aqueous coated paperboard is disclosed which exhibits good barrier properties and anti-blocking behavior and is heat sealable.

First claim

The invention claimed is:

1. A paperboard comprising:
a substrate having a first side and an opposing second side; and
a layer applied on the first side as an aqueous coating forming an outer surface for the first side, wherein the aqueous coating comprises:
a pigment blend; and
a binder having a glass transition temperature above 20° C.,
wherein a ratio of the binder to the pigment blend is at least 1 part binder per 1 part pigment blend, by weight,
wherein the layer is heat sealable,
wherein the paperboard has a blocking rating below 4, and
wherein the paperboard is at least 90% repulpable.

2. The paperboard of claim 1 wherein the binder comprises styrene-acrylate.

3. The paperboard of claim 1 wherein the glass transition temperature is above 30° C.

4. The paperboard of claim 1 wherein the glass transition temperature is above 35° C.

5. The paperboard of claim 1 further comprising a printable coating on the second side.

6. The paperboard of claim 1 wherein the ratio of the binder to the pigment blend is at least 1.25:1 by weight.

7. The paperboard of claim 1 wherein the ratio of the binder to the pigment blend is at least 1.5:1 by weight.

8. The paperboard of claim 1 wherein a heat seal formed between the first side and the second side, when made with a sealing bar at 350° F. (177° C.) and 50 psi (345 kPa) for 1.5 seconds, provides adhesion to the extent of 80% or greater fiber tear.

9. The paperboard of claim 1 exhibiting no fiber tear after being held under 100 psi (689 kPa) pressure at 50° C. for 24 hours.

10. The paperboard of claim 1 wherein the aqueous coating has a dry weight from 6 to 15 lb/3000 ft 2 (9.8-24.5 g/m 2 ).

11. The paperboard of claim 1 wherein the aqueous coating has a dry weight from 8 to 12 lb/3000 ft 2 (13.1-19.6 g/m 2 ).

12. The paperboard of claim 1 wherein the aqueous coating is applied in two coats.

13. The paperboard of claim 1 wherein the substrate comprises at least one of solid bleached sulfate and natural kraft board.

14. The paperboard of claim 1 providing a 2-minute water Cobb test of less than 5 g/m 2 .

15. The paperboard of claim 1 providing a 30-minute water Cobb test of less than 60 g/m 2 .

16. The paperboard of claim 1 providing a 30-minute oil Cobb test of less than 1 g/m 2 .

17. The paperboard of claim 1 providing a water vapor transmission rate of less than 900 g/m 2 .

18. The paperboard of claim 1 having a 3M Kit test rating of at least 7.

19. The paperboard of claim 1 being at least 95% repulpable.

20. The paperboard of claim 1 wherein the pigment blend comprises clay and calcium carbonate, and wherein a ratio of the clay to the calcium carbonate is about 1:1.

Assignees

• Westrock Mwv Llc

Inventors

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

Classifications

• D21H19/58

  Polymers or oligomers of diolefins, aromatic vinyl monomers or unsaturated acids or derivatives thereof · CPC title

• D21H27/10

  Packing paper (packaging materials of special type or form B65D65/38) · CPC title

• D21H19/40 Primary

  siliceous, e.g. clays · CPC title

• D21H19/385

  Oxides, hydroxides or carbonates · CPC title

• D21H19/82

  superposed {(D21H19/84 takes precedence)} · CPC title