Sustainable cellulosic structures for barrier applications

Patent metadata

Field	Value
Publication number	US-2024262085-A1
Application number	US-202418430752-A
Country	US
Kind code	A1
Filing date	Feb 2, 2024
Priority date	Feb 6, 2023
Publication date	Aug 8, 2024
Grant date	—

Abstract

A cellulosic substrate includes a first major side and a second major side opposed from the first major side, a single polyolefin aqueous polymer dispersion barrier layer on the first major side of the cellulosic substrate, and at least one non-polyolefin aqueous polymer dispersion coating layer between the single polyolefin aqueous polymer dispersion barrier layer and the first major side of the cellulosic substrate.

First claim

What is claimed is:

1 . A cellulosic structure comprising:
a cellulosic substrate comprising a first major side and a second major side opposed from the first major side; a single polyolefin aqueous polymer dispersion barrier layer on the first major side of the cellulosic substrate; and at least one non-polyolefin aqueous polymer dispersion coating layer between the single polyolefin aqueous polymer dispersion barrier layer and the first major side of the cellulosic substrate.

2 . The cellulosic structure of claim 1 wherein the single polyolefin aqueous polymer dispersion barrier layer comprises a polyolefin binder.

3 . The cellulosic structure of claim 2 wherein the single polyolefin aqueous polymer dispersion barrier layer further comprises a pigment.

4 . The cellulosic structure of claim 3 wherein the pigment comprises clay.

5 . The cellulosic structure of claim 3 wherein the pigment comprises clay, wherein a clay content in the pigment is at least 50% by weight.

6 . The cellulosic structure of claim 3 wherein the pigment comprises calcium carbonate, wherein the calcium carbonate content is less than 2% by weight.

7 . The cellulosic structure of claim 3 wherein a ratio of the polyolefin binder to the pigment is at least 1 to 2.

8 . The cellulosic structure of claim 1 wherein the single polyolefin aqueous polymer dispersion barrier layer has a coat weight, on a dry basis, of at least about 0.5 lb/3000 ft 2 .

9 . The cellulosic structure of claim 1 wherein the at least one non-polyolefin aqueous polymer dispersion coating layer comprises a non-polyolefin binder.

10 . The cellulosic structure of claim 9 wherein the non-polyolefin binder comprises a blend of soft binder having a glass transition temperature of less than 25° C. and hard binder having a glass transition temperature of more than 25° C.

11 . The cellulosic structure of claim 9 wherein the at least one non-polyolefin aqueous polymer dispersion coating layer further comprises a pigment.

12 . The cellulosic structure of claim 11 wherein the pigment comprises at least one of a clay and a calcium carbonate.

13 . The cellulosic structure of claim 11 wherein a ratio of the non-polyolefin binder to the pigment is at most 1 to 2.

14 . The cellulosic structure of claim 1 wherein the at least one non-polyolefin aqueous polymer dispersion coating layer comprises multiple non-polyolefin aqueous polymer dispersion coating layers.

15 . The cellulosic structure of claim 1 wherein the non-polyolefin aqueous polymer dispersion coating layer has a coat weight, on a dry basis, of at least about 0.5 lb/3000 ft 2 .

16 . The cellulosic structure of claim 1 wherein the second major side is uncoated.

17 . The cellulosic structure of claim 1 further comprising a barrier layer on the second major side.

18 . The cellulosic structure of claim 1 further comprising a single polyolefin aqueous polymer dispersion barrier layer on the second major side of the cellulosic substrate.

19 . The cellulosic structure of claim 1 further comprising a single polyolefin aqueous polymer dispersion barrier layer on the second major side of the cellulosic substrate and at least one non-polyolefin aqueous polymer dispersion coating layer between the single polyolefin aqueous polymer dispersion barrier layer and the second major side of the cellulosic substrate.

20 . The cellulosic structure of claim 1 having a 30-minute-water-Cobb rating of at most about 20 g/m 2 .

21 . The cellulosic structure of claim 1 having a water vapor transmission rate of less than 500 grams per square meter per day at 38° C./90% RH.

22 . The cellulosic structure of claim 1 having a 3M kit test value is at least 7.

23 . The cellulosic structure of claim 1 having a blocking rating of 2.0 or less.

24 . The cellulosic structure of claim 1 wherein the cellulosic structure is repulpable to an extent that after repulping a percentage of accepts is at least 50%.

25 . A container comprising the cellulosic structure of claim 1 .

Assignees

• Westrock Mwv Llc

Inventors

• Pang Jiebin
• Ramesh Natarajan S
• Drucker Taylor A

Classifications

• D21H19/58

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

• D21H19/40

  siliceous, e.g. clays · CPC title

• D21H19/385

  Oxides, hydroxides or carbonates · CPC title

• B32B2439/00

  Containers; Receptacles · CPC title

• B32B2325/00

  Polymers of vinyl-aromatic compounds, e.g. polystyrene · CPC title