초록 ▼

A multi-layer sheet for forming an expanded foam container, the multi-layer sheet including a first layer of an expanded foam material including a first polyolefin-based material including at least one polypropylene-based polymer and a second layer of an unexpected material including a second polyol

A multi-layer sheet for forming an expanded foam container, the multi-layer sheet including a first layer of an expanded foam material including a first polyolefin-based material including at least one polypropylene-based polymer and a second layer of an unexpected material including a second polyolefin-based material including at least one polypropylene-based polymer that is co-extruded, extrusion coated, or laminated on a first side of the first layer.

대표청구항 ▼

1. A co-extruded sheet comprising an extrusion having at least a first layer of an expanded foam material comprising a blend of a first high melt strength homopolymer or copolymer of polypropylene including long chain branching and having a melt strength of at least 20 cN and a second high melt stre

1. A co-extruded sheet comprising an extrusion having at least a first layer of an expanded foam material comprising a blend of a first high melt strength homopolymer or copolymer of polypropylene including long chain branching and having a melt strength of at least 20 cN and a second high melt strength homopolymer or copolymer of polypropylene, and a second layer of an unexpanded material comprising a third high melt strength homopolymer or copolymer of polypropylene having a melt strength of at least 20 cN, wherein the co-extruded sheet has a density of less than about 12.5 lb/ft3. 2. The co-extruded sheet of claim 1 wherein the second high melt strength homopolymer or copolymer of polypropylene, the third high melt strength homopolymer or copolymer of polypropylene or both comprise a homopolymer or copolymer of polypropylene that is not cross-linked and does not include long chain branching. 3. The co-extruded sheet of claim 2 wherein the second high melt strength homopolymer or copolymer of polypropylene, the third high melt strength homopolymer or copolymer of polypropylene or both have a melting point of about 155-170° C. 4. The co-extruded sheet of claim 2 wherein the second high melt strength homopolymer or copolymer of polypropylene, the third high melt strength homopolymer or copolymer of polypropylene or both have a flexural modulus of at least 1400 MPa. 5. The co-extruded sheet of claim 2 wherein the second high melt strength homopolymer or copolymer of polypropylene, the third high melt strength homopolymer or copolymer of polypropylene or both have a melt flow rate in the range of 0.1-18 g/10 min. at 230° C. and 2.16 kg load. 6. The co-extruded sheet of claim 2 wherein the second high melt strength homopolymer or copolymer of polypropylene, the third high melt strength homopolymer or copolymer of polypropylene or both have a tensile strain of at least 70%. 7. The co-extruded sheet of claim 2 wherein the second high melt strength homopolymer or copolymer of polypropylene, the third high melt strength homopolymer or copolymer of polypropylene or both comprise an ethylene-propylene block copolymer. 8. The co-extruded sheet of claim 2 wherein the second high melt strength homopolymer or copolymer of polypropylene, the third high melt strength homopolymer or copolymer of polypropylene or both have a weight average molecular weight or number average molecular weight of at least 300,000 g/mol. 9. The co-extruded sheet of claim 1 wherein the second high melt strength homopolymer or copolymer of polypropylene, the third high melt strength homopolymer or copolymer of polypropylene or both comprise a homopolymer or copolymer of polypropylene that includes long chain branching. 10. The co-extruded sheet of claim 9 wherein the third high melt strength homopolymer or copolymer of polypropylene comprises a polypropylene-based block co-polymer or a polypropylene homopolymer. 11. The co-extruded sheet of claim 9 wherein the first high melt strength homopolymer or copolymer of polypropylene, the second high melt strength homopolymer or copolymer of polypropylene, the third high melt strength homopolymer or copolymer of polypropylene, or all three have a melting point of about 155-175° C. 12. The co-extruded sheet of claim 9 wherein the first high melt strength homopolymer or copolymer of polypropylene, the second high melt strength homopolymer or copolymer of polypropylene, the third high melt strength homopolymer or copolymer of polypropylene, or all three have a flexural modulus of at least 1400 MPa. 13. The co-extruded sheet of claim 9 wherein the first high melt strength homopolymer or copolymer of polypropylene, the second high melt strength homopolymer or copolymer of polypropylene or both have a melt flow rate in the range of 0.1-6 g/10 min. at 230° C. and 2.16 kg load. 14. The co-extruded sheet of claim 9 wherein the first high melt strength homopolymer or copolymer of polypropylene, the second high melt strength homopolymer or copolymer of polypropylene or both have a melt strength of at least 25 cN. 15. The co-extruded sheet of claim 9 wherein the first high melt strength homopolymer or copolymer of polypropylene, the second high melt strength homopolymer or copolymer of polypropylene, the third high melt strength homopolymer or copolymer of polypropylene, or all three have a polydispersity index (PDI) of at least 8. 16. The co-extruded sheet of claim 1 wherein the first layer comprises at least one nucleating agent and at least one blowing agent. 17. The co-extruded sheet of claim 1 wherein the second layer includes at least one additive to increase an opacity of the second layer. 18. The co-extruded sheet of claim 1 wherein the second layer is about 1-2 mils (0.02-0.05 mm) thick. 19. The co-extruded sheet of claim 1, further comprising a third layer co-extruded, extrusion coated, or laminated on a side of the first layer opposite the second layer. 20. The co-extruded sheet of claim 19 wherein the third layer comprises an unexpanded material comprising a fourth high melt strength homopolymer or copolymer of polypropylene that is not cross-linked and does not include long chain branching. 21. The co-extruded sheet of claim 20 wherein the third layer comprises an unexpanded material comprising a fourth high melt strength homopolymer or copolymer of polypropylene that includes long chain branching. 22. The co-extruded sheet of claim 1 wherein the first high melt strength homopolymer or copolymer of polypropylene of the first layer is different than the third high melt strength homopolymer or copolymer of polypropylene of the second layer. 23. The co-extruded sheet of claim 22 wherein the third high melt strength homopolymer or copolymer of polypropylene has a higher melt flow rate than the first high melt strength homopolymer or copolymer of polypropylene. 24. The co-extruded sheet of claim 1 wherein the co-extruded sheet is an extrusion coating. 25. An expanded foam container comprising: a peripheral wall having an interior surface defining an interior cavity, an upper end defining an upper opening to the interior cavity and a lower end, opposite the upper end, defining a lower opening to the interior cavity; anda bottom wall closing the lower opening, the bottom wall comprising a floor having an upper surface defining a bottom of the interior cavity and a lower surface;wherein at least the sleeve comprises a co-extruded sheet having at least a first layer of an expanded foam material comprising a blend of a first high melt strength homopolymer or copolymer of polypropylene including long chain branching and having a melt strength of at least 20 cN and a second high melt strength homopolymer or copolymer of polypropylene, and a second layer of an unexpanded material comprising a third high melt strength homopolymer or copolymer of polypropylene having a melt strength of at least 20 cN;wherein the co-extruded sheet has a density of less than about 12.5 lb/ft3. 26. The expanded foam container according to claim 25 wherein the container comprises a cup. 27. The expanded foam container according to claim 26 wherein the upper end terminates in a rolled lip. 28. The expanded foam container according to claim 27 wherein the peripheral wall further comprises a stacking element having at least a portion located below the rolled lip. 29. The expanded foam container according to claim 28 wherein the stacking element comprises a shoulder in the peripheral wall, with the shoulder located below the rolled lip. 30. The expanded foam container according to claim 29 wherein the stacking element comprises a generally vertical portion of the peripheral wall between the rolled lip and the shoulder. 31. The expanded foam container according to claim 30 wherein the peripheral wall comprises-a-tapered portion extending from the shoulder to the bottom wall. 32. The expanded foam container according to claim 31 wherein the generally vertical portion has a taper that is less than the tapered portion. 33. The expanded foam container according to claim 25 wherein the bottom wall is formed separately from the peripheral wall. 34. The expanded foam container of claim 25 wherein the second high melt strength homopolymer or copolymer of polypropylene, the third high melt strength homopolymer or copolymer of polypropylene or both comprise a homopolymer or copolymer of polypropylene that is not cross-linked and does not include long chain branching. 35. The expanded foam container of claim 34 wherein the second high melt strength homopolymer or copolymer of polypropylene, the third high melt strength homopolymer or copolymer of polypropylene or both have a melting point of about 155-170° C. 36. The expanded foam container of claim 34 wherein the second high melt strength homopolymer or copolymer of polypropylene, the third high melt strength homopolymer or copolymer of polypropylene or both have a flexural modulus of at least 1400 MPa. 37. The expanded foam container of claim 34 wherein the second high melt strength homopolymer or copolymer of polypropylene, the third high melt strength homopolymer or copolymer of polypropylene or both have a melt flow rate in the range of 0.1-18 g/10 min. at 230° C. and 2.16 kg load. 38. The expanded foam container of claim 34 wherein the second high melt strength homopolymer or copolymer of polypropylene, the third high melt strength homopolymer or copolymer of polypropylene or both have a tensile strain of at least 70%. 39. The expanded foam container of claim 34 wherein the second high melt strength homopolymer or copolymer of polypropylene, the third high melt strength homopolymer or copolymer of polypropylene or both comprise an ethylene-propylene block copolymer. 40. The expanded foam container of claim 34 wherein the second high melt strength homopolymer or copolymer of polypropylene, the third high melt strength homopolymer or copolymer of polypropylene or both have a weight average molecular weight or number average molecular weight of at least 300,000 g/mol. 41. The expanded foam container of claim 25 wherein the second high melt strength homopolymer or copolymer of polypropylene, the third high melt strength homopolymer or copolymer of polypropylene or both comprise a homopolymer or copolymer of polypropylene that includes long chain branching. 42. The expanded foam container of claim 41 wherein the third high melt strength homopolymer or copolymer of polypropylene comprises a polypropylene-based block co-polymer or a polypropylene homopolymer. 43. The expanded foam container of claim 41 wherein the first high melt strength homopolymer or copolymer of polypropylene, the second high melt strength homopolymer or copolymer of polypropylene, the third high melt strength homopolymer or copolymer of polypropylene, or all three have a melting point of about 155-175° C. 44. The expanded foam container of claim 41 wherein the first high melt strength homopolymer or copolymer of polypropylene, the second high melt strength homopolymer or copolymer of polypropylene, the third high melt strength homopolymer or copolymer of polypropylene, or all three have a flexural modulus of at least 1400 MPa. 45. The expanded foam container of claim 41 wherein the first high melt strength homopolymer or copolymer of polypropylene, the second high melt strength homopolymer or copolymer of polypropylene or both have a melt flow rate in the range of 0.1-6 g/10 min. at 230° C. and 2.16 kg load. 46. The expanded foam container of claim 41 wherein the first high melt strength homopolymer or copolymer of polypropylene, the second high melt strength homopolymer or copolymer of polypropylene or both have a melt strength of at least 25 cN. 47. The expanded foam container of claim 41 wherein the first high melt strength homopolymer or copolymer of polypropylene, the second high melt strength homopolymer or copolymer of polypropylene, the third high melt strength homopolymer or copolymer of polypropylene, or all three have a polydispersity index (PDI) of at least 8. 48. The expanded foam container of claim 25 wherein the first layer comprises at least one nucleating agent and at least one blowing agent. 49. The expanded foam container of claim 25 wherein the second layer includes at least one additive to increase an opacity of the second layer. 50. The expanded foam container of claim 25 wherein the second layer is about 1-2 mils (0.02-0.05 mm) thick. 51. The expanded foam container of claim 25, wherein the co-extruded sheet further comprises a third layer co-extruded, extrusion coated, or laminated on a side of the first layer opposite the second layer. 52. The expanded foam container of claim 51 wherein the third layer comprises an unexpanded material comprising a fourth high melt strength homopolymer or copolymer of polypropylene that is not cross-linked and does not include long chain branching. 53. The expanded foam container of claim 51 wherein the third layer comprises an unexpanded material comprising a fourth high melt strength homopolymer or copolymer of polypropylene that includes long chain branching. 54. The expanded foam container of claim 25 wherein the first high melt strength homopolymer or copolymer of polypropylene of the first layer is different than the third high melt strength homopolymer or copolymer of polypropylene of the second layer. 55. The expanded foam container of claim 54 wherein the third high melt strength homopolymer or copolymer of polypropylene has a higher melt flow rate than the first high melt strength homopolymer or copolymer of polypropylene. 56. The expanded foam container of claim 25 wherein the co-extruded sheet is an extrusion coating. 57. The expanded foam container of claim 25 wherein the second layer is extrusion coated on a first side of the first layer. 58. A co-extruded sheet comprising: a first extrudate layer of an expanded foam material comprising a blend of a first high melt strength homopolymer or copolymer of polypropylene including long chain branching and having a melt strength of at least 20 cN and a second high melt strength homopolymer or copolymer of polypropylene; anda second extrudate layer of an unexpanded material comprising a third high melt strength homopolymer or copolymer of polypropylene having a melt strength of at least 20 cN;wherein the first and second extrudate layers are in overlying relationship and wherein the co-extruded sheet has a density of less than about 12.5 lb/ft3. 59. The co-extruded sheet of claim 58 wherein the co-extruded sheet is an extrusion coating.