Heat sealable barrier paperboard

Patent metadata

Field	Value
Publication number	US-2022154410-A1
Application number	US-202117464395-A
Country	US
Kind code	A1
Filing date	Sep 1, 2021
Priority date	Feb 27, 2017
Publication date	May 19, 2022
Grant date	—

Abstract

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

First claim

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

• D21J1/08 Primary

  Impregnated or coated fibreboard · CPC title

• D21H19/12 Primary

  applied as a solution using water as the only solvent, e.g. in the presence of acid or alkaline compounds · CPC title

• D21H19/40 Primary

  siliceous, e.g. clays · CPC title

• D21H19/82

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

• D21H19/58

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