Compostable paperboard with oil, grease, and moisture resistance

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.