Compostable paperboard with oil, grease, and moisture resistance

Patent metadata

Field	Value
Publication number	US-9670621-B2
Application number	US-201615230896-A
Country	US
Kind code	B2
Filing date	Aug 8, 2016
Priority date	Feb 11, 2015
Publication date	Jun 6, 2017
Grant date	Jun 6, 2017

Abstract

A coated paperboard is disclosed which includes a coating containing substantially no fluorochemical or wax, exhibiting good resistance to oil and grease, no tendency toward blocking, the coated paperboard being fully repulpable as well as compostable.

First claim

The invention claimed is:

1. A coated paperboard, comprising:
a paperboard substrate;
a coating in contact with the paperboard substrate, the coating comprising binder and pigment, the coating containing substantially no fluorochemical or wax;
wherein the coated paperboard has a caliper of at least 0.010″;
wherein the coated paperboard provides barrier properties to at least one of oil, grease, and moisture; and
wherein the coated paperboard is compostable according to the ASTM D6868-11 standard for compostability.

2. The coated paperboard of claim 1 , wherein the coated paperboard has a caliper of at least 0.012″.

3. The coated paperboard of claim 1 , wherein the binder to pigment ratio in the coating is between 25 to 40 parts binder per 100 parts pigment, by weight.

4. The coated paperboard of claim 3 , wherein the binder to pigment ratio in the coating is between 30 to 35 parts binder per 100 parts pigment, by weight.

5. The coated paperboard of claim 1 , wherein the binder comprises a synthetic polymer including (i) a non-biodegradable component and (ii) a natural biodegradable component.

6. The coated paperboard of claim 5 , wherein the binder further comprises (iii) an additional natural biodegradable component.

7. The coated paperboard of claim 6 , wherein the additional biodegradable component (iii) is at least one of polysaccharide and protein.

8. The coated paperboard of claim 6 , wherein the additional biodegradable component (iii) comprises between 1 to 7 parts starch per 100 parts pigment, by weight.

9. The coated paperboard of claim 1 , wherein the 3M kit test value is at least 3.

10. The coated paperboard of claim 1 , wherein the coated paperboard has a 30-minute oil Cobb test of at most 20 grams per square meter.

11. The coated paperboard of claim 1 , wherein the coated paperboard is repulpable to the extent that after repulping the percentage accepts is at least 99%.

12. The coated paperboard of claim 11 , wherein the percentage accepts is at least 99.9%.

13. The coated paperboard of claim 1 , wherein the coating weight is 5 to 12 lbs per 3000 ft 2 .

14. The coated paperboard of claim 13 , wherein the coating is applied in two passes for a total coat weight of 5 to 12 lbs per 3000 ft 2 .

15. The coated paperboard of claim 1 , having no tendency toward blocking after being held for 24 hours at 50° C. at a pressure of 100 psi.

16. The coated paperboard of claim 1 , wherein the pigment comprises at least one of a clay and calcium carbonate.

17. A method of treating paperboard, the method comprising:
providing a paperboard substrate;
applying to the paperboard substrate a coating comprising binder and pigment, and containing substantially no fluorochemical or wax;
wherein the binder comprises starch;
wherein the coated paperboard has a caliper of at least 0.010″;
wherein the coated paperboard is compostable according to the ASTM D6868-11 standard for compostability;
wherein the coated paperboard has a 3M kit test value of at least 3; and
wherein the coated paperboard is repulpable to the extent that after repulping the percentage accepts is at least 99%.

18. The method of claim 17 , wherein the coated paperboard has a caliper of at least 0.012″.

19. The method of claim 17 , wherein the binder to pigment ratio in the coating is between 25 to 40 parts binder per 100 parts pigment, by weight.

20. The method of claim 17 , wherein the coating is applied by a device selected from the group consisting of a blade coater, curtain coater, air knife coater, rod coater, film coater, short-dwell coater, spray coater, and metering film size press.

Assignees

• Westrock Mwv Llc

Inventors

• Pang Jiebin
• Melton Natasha G

Classifications

• D21H23/48 Primary

  Curtain coaters · CPC title

• D21H23/32

  by contacting paper with an excess of material, e.g. from a reservoir or in a manner necessitating removal of applied excess material from the paper (D21H23/66 takes precedence; removing excess material D21H25/08) · CPC title

• D21H19/385

  Oxides, hydroxides or carbonates · CPC title

• D21H19/822

  two superposed coatings, both being pigmented · CPC title

• D21H21/16

  Sizing or water-repelling agents · CPC title