Packaging materials with enhanced thermal-insulating performance

1. A packaging material comprising:

(A) a paper-based substrate including a first surface and a second surface; and

(B) a thermal-insulating composition on the first surface of the substrate, wherein the thermal-insulating composition comprises, based on total weight of the composition:

(a) filler in an amount of 10% to 70% by weight;

(b) organic binder in an amount of 15% to 70% by weight; and

(c) plasticizer.

2. The packaging material of claim 1 , wherein the filler comprises, based on total weight of the filler:

(i) inorganic filler in an amount of 0% to 90% by weight; and

(ii) organic filler in an amount of 10% to 100% by weight.

3. The packaging material of claim 1 , wherein the filler comprises, based on total weight of the filler:

(i) inorganic filler in an amount of 40% to 90% by weight; and

(ii) organic filler in an amount of 10% to 60% by weight.

4. The packaging material of claim 1 , wherein the thermal-insulating composition is applied onto the substrate in a form of coalesced droplets, longitudinally-extending sinuous strands, or combinations thereof.

5. The packaging material of claim 1 , wherein the thermal-insulating composition further comprises borax.

6. The packaging material of claim 1 , wherein the thermal-insulating composition comprises sodium silicate in an amount of 1% to 15% by weight based on total weight of the composition.

7. The packaging material of claim 1 , wherein the thermal-insulating composition comprises corn fibers as the filler in an amount of 0.5% to 1% by weight based on total weight of the composition.

8. The packaging material of claim 1 , wherein the filler comprises insulating particles selected from the group consisting of ceramic air-containing particles, pearlite particles, and combinations thereof.

9. The packaging material of claim 1 , wherein the organic binder includes a member selected from the group consisting of styrene-butadiene polymer, an acrylic-styrene butadiene polymer, starch, polyvinyl alcohol, polyvinyl acetate, and combinations thereof.

10. The packaging material of claim 1 , wherein the plasticizer comprises 0.5% to 10% by weight of the composition.

11. The packaging material of claim 1 , characterized by a thickness of the thermal-insulating composition in a range of 0.05 mm to 5 mm.

12. The packaging material of claim 1 , wherein the thermal-insulating composition has a pseudoplasticity index in a range of 0.03 to 0.5.

13. The packaging material of claim 1 , wherein the thermal-insulating composition has a low shear viscosity in a range of 2,000 to 50,000 cps, and a high shear viscosity in a range of 100 to 5,000 cps.

14. The packaging material of claim 1 , characterized by a porosity of the paper-based substrate in a range 20 to 150 Gurley units.

15. The packaging material of claim 1 , wherein the material is able to hold pressure in a range of 0.1 kgf/cm 2 to 1.0 kgf/cm 2 .

16. A beverage cup including the packaging material of claim 1 .

17. The packaging material of claim 1 , wherein the filler comprises particles having an irregular shape.

18. The packaging material of claim 1 further comprising a paper-based top layer, the thermal-insulating composition being positioned between the first surface of the paper-based substrate and the paper-based top layer.

19. The packaging material of claim 18 further comprising a moisture barrier layer positioned on the paper-based top layer.

20. A beverage cup including the packaging material of claim 19 .

21. The packaging material of claim 18 further comprising: a first moisture barrier layer positioned on the paper-based top layer, and a second moisture barrier layer positioned on the second surface of the paper-based substrate.

22. The packaging material of claim 18 , characterized by a porosity of the paper-based top layer in a range 20 to 150 Gurley units.

23. The packaging material of claim 18 , wherein the paper-based substrate and the top composition have a combined thickness associated therewith, and the thermal-insulating composition has a thickness associated therewith, and wherein the thickness of the thermal-insulating composition is in a range of 20-100% of the combined thickness of the paper-based substrate and the top layer.

24. The packaging material of claim 23 , wherein the thermal-insulating composition provides space for separating the paper-based substrate and the top layer.

25. A beverage cup including the packaging material of claim 18 .

26. The packaging material of claim 1 , wherein the thermal-insulating composition comprises no more than 20% by weight of starch binder based on total weight of the thermal-insulating composition.

27. The packaging material of claim 26 , wherein the starch binder comprises, based on total weight of the starch binder:

(i) gelatinized starch in an amount of 10% to 50% by weight, and

(ii) ungelatinized starch in an amount of 50% to 90% by weight.

28. The packaging material of claim 26 , wherein the starch binder comprises, based on total weight of the starch binder:

(i) gelatinized starch in an amount of 0% to 70% by weight, and

(ii) ungelatinized starch in an amount of 30% to 100% by weight.

29. The packaging material of claim 26 , wherein the starch binder comprises, based on total weight of the starch binder:

(i) gelatinized starch in an amount of 50% to 100% by weight, and

(ii) ungelatinized starch in an amount of 0% to 50% by weight.

30. The packaging material of claim 1 , wherein the thermal-insulating composition comprises at least 20% by weight of starch binder based on total weight of the composition.

31. The packaging material of claim 30 , wherein the starch binder comprises, based on total weight of the starch binder:

(i) gelatinized starch in an amount of 10% to 50% by weight, and

(ii) ungelatinized starch in an amount of 50% to 90% by weight.

32. The material of claim 1 , wherein the thermal-insulating composition comprises ungelatinized starch and sodium silicate.

33. The packaging material of claim 32 , wherein the thermal-insulating composition comprises, based on total weight of the composition:

(i) ungelatinized starch in an amount of 5% to 32% by weight, and

(ii) sodium silicate in an amount of 1% to 15% by weight.

34. The packaging material of claim 1 , wherein the thermal-insulating composition comprises cellulosic solids as the filler in an amount of 2% to 50% by weight based on total weight of the composition.

35. The packaging material of claim 34 , wherein a particle size of the cellulosic solids is more than 100 microns.

36. The packaging material of claim 34 , wherein the cellulosic solids includes a member selected from the group consisting of cellulosic fibers, wood flour, wood dust, gluten feed, and combinations thereof.

37. The packaging material of claim 36 , wherein the cellulosic fiber is characterized by a length of no greater than 2 mm and an aspect ratio of no greater than 25:1.

38. The packaging material of claim 1 , wherein the thermal-insulating composition includes a void structure.

39. The packaging material of claim 38 , wherein the void structure comprises air space between at least some of the filler, the organic binder, and the plasticizer.

40. A beverage cup including the packaging material of claim 38 .

41. The packaging material of claim 1 , wherein the thermal-insulating composition is positioned on the first surface in a random pattern.

42. A beverage cup including the packaging material of claim 41 .

43. The packaging material of claim 1 , wherein the thermal-insulating composition comprises a foam.

44. The packaging material of claim 43 , wherein the foam is mechanically-induced.

45. The packaging material of claim 43 , wherein the foam comprises a mechanically-whipped latex.

46. The packaging material of claim 43 , wherein the foam comprise an emulsion polymer binder and a foam stabilizer.

47. A beverage cup including the packaging material of claim 43 .