Reduced-VOC and non-VOC blowing agents for making expanded and extruded thermoplastic foams

Patent metadata

Field	Value
Publication number	US-9453090-B2
Application number	US-201414196716-A
Country	US
Kind code	B2
Filing date	Mar 4, 2014
Priority date	Sep 3, 2004
Publication date	Sep 27, 2016
Grant date	Sep 27, 2016

Abstract

Process for producing a thermoplastic polymer foam article includes preparing an expandable polymeric formulation comprising a thermoplastic polymer and a blowing agent blend, forming the formulation into an expandable bead, and expanding the expandable bead to form a thermoplastic polymer foam article. The blowing agent blend includes methyl formate, hydrocarbon, and either carbon dioxide or 1,1,1,2-tetrafluoroethane (HFC-134a). The blowing agent blend has a higher effective volatility than that of methyl formate alone. A thermoplastic polymer foam article prepared by a process is also provided.

First claim

What is claimed is:

1. A process for producing a thermoplastic polymer foam article comprising:
preparing an expandable polymeric formulation comprising a thermoplastic polymer and a blowing agent blend, the blowing agent blend comprising methyl formate, hydrocarbon, and either carbon dioxide or 1,1,1,2-tetrafluoroethane (HFC-134a), the blowing agent blend comprising about 6 to about 53 weight percent of the methyl formate and having a higher effective volatility than that of methyl formate alone;
forming the formulation into an expandable bead; and
expanding the expandable bead to form a thermoplastic polymer foam article that is substantially free of a gas barrier resin.

2. The process of claim 1 , wherein the expandable beads are formed by a process selected from the group consisting of (a), (b), and (c):
a. (i) melting the thermoplastic polymer;
(ii) mixing an effective amount of the blowing agent blend in the thermoplastic polymer to define a mixture; and
(iii) extruding the mixture into a low temperature zone to form the expandable bead;

b. dissolving an effective amount of the blowing agent blend into the thermoplastic polymer;
c. synthesizing the thermoplastic polymer in the presence of the blowing agent blend.

3. The process of claim 1 , wherein the article has a density less than about 15 lb/ft 3 .

4. The process of claim 1 , wherein the article is foamed beads.

5. The process of claim 1 , wherein the article is a sheet.

6. The process of claim 1 , wherein the article is a board.

7. The process of claim 1 , further comprising fusing together the foamed beads to form a substantially closed-cell, dimensionally stable thermoplastic polymer foam structure.

8. The process of claim 7 , wherein the structure is a sheet.

9. The process of claim 7 , wherein the structure is a board.

10. The process of claim 1 , wherein the hydrocarbon contains two to five carbon atoms.

11. The process of claim 10 , wherein the hydrocarbon contains four or five carbon atoms.

12. The process of claim 11 , wherein the hydrocarbon is isobutane.

13. The process of claim 11 , wherein the hydrocarbon is isopentane.

14. The process of claim 11 , wherein the hydrocarbon is cyclopentane.

15. The process of claim 1 , wherein the blowing agent blend comprises about 19 to about 85 weight percent of the hydrocarbon.

16. The process of claim 1 , wherein the blowing agent blend comprises about 7 to about 17 weight percent of carbon dioxide.

17. The process of claim 1 , wherein the blowing agent blend comprises about 19 to about 85 weight percent of the hydrocarbon, and about 7 to about 17 weight percent of carbon dioxide.

18. The process of claim 1 , wherein the blowing agent blend comprises about 23 to about 31 weight percent of methyl formate.

19. The process of claim 1 , wherein the blowing agent blend comprises about 19 to about 24 weight percent of the hydrocarbon.

20. The process of claim 1 , wherein the blowing agent blend comprises about 49 to about 53 weight percent of 1,1,1,2-tetrafluoroethane (HFC-134a).

21. The process of claim 1 , wherein the blowing agent blend comprises about 23 to about 31 weight percent of methyl formate, about 19 to about 24 weight percent of the hydrocarbon, and about 49 to about 53 weight percent of 1,1,1,2-tetrafluoroethane (HFC-134a).

22. A thermoplastic polymer foam article prepared by a process comprising:
preparing an expandable polymeric formulation comprising a thermoplastic polymer and a blowing agent blend, the blowing agent blend comprising methyl formate, hydrocarbon, and either carbon dioxide or 1,1,1,2-tetrafluoroethane (HFC-134a), the blowing agent blend comprising about 6 to about 53 weight percent of the methyl formate and having a higher effective volatility than that of methyl formate alone;
forming the formulation into an expandable bead; and
expanding the expandable bead to form a thermoplastic polymer foam article that is substantially free of a gas barrier resin.

23. The thermoplastic polymer foam article of claim 22 , wherein the article has a density less than about 15lb/ft 3 .

24. The thermoplastic polymer foam article of claim 22 , wherein the article is foamed beads.

25. The thermoplastic polymer foam article of claim 22 , wherein the article is a sheet.

26. The thermoplastic polymer foam article of claim 22 , wherein the article is a board.

27. The thermoplastic polymer foam article of claim 22 , wherein the hydrocarbon contains two to five carbon atoms.

28. The thermoplastic polymer foam article of claim 27 , wherein the hydrocarbon contains four or five carbon atoms.

29. The thermoplastic polymer foam article of claim 28 , wherein the hydrocarbon is isobutane.

30. The thermoplastic polymer foam article of claim 28 , wherein the hydrocarbon is isopentane.

31. The thermoplastic polymer foam article of claim 28 , wherein the hydrocarbon is cyclopentane.

32. The thermoplastic polymer foam article of claim 22 , wherein the blowing agent blend comprises about 19 to about 85 weight percent of the hydrocarbon.

33. The thermoplastic polymer foam article of claim 22 , wherein the blowing agent blend comprises about 7 to about 17 weight percent of carbon dioxide.

34. The thermoplastic polymer foam article of claim 22 , wherein the blowing agent blend comprises about 19 to about 85 weight percent of the hydrocarbon, and about 7 to about 17 weight percent of carbon dioxide.

35. The thermoplastic polymer foam article of claim 22 , wherein the blowing agent blend comprises about 23 to about 31 weight percent of methyl formate.

36. The thermoplastic polymer foam article of claim 22 , wherein the blowing agent blend comprises about 19 to about 24 weight percent of the hydrocarbon.

37. The thermoplastic polymer foam article of claim 22 , wherein the blowing agent blend comprises about 49 to about 53 weight percent of 1,1,1,2-tetrafluoroethane (HFC-134a).

38. The thermoplastic polymer foam article of claim 22 , wherein the blowing agent blend comprises about 23 to about 31 weight percent of methyl formate, about 19 to about 24 weight percent of the hydrocarbon, and about 49 to about 53 weight percent of 1,1,1,2-tetrafluoroethane (HFC-134a).

Assignees

• Pactiv LLC
• Univ Columbia

Inventors

• Handa Y Paul
• Francis Gary A
• Castner Glenn C
• Zafar Mohammad

Classifications

• C08J2201/03

  Extrusion of the foamable blend · CPC title

• C08J2203/142

  Halogenated saturated hydrocarbons, e.g. H3C-CF3 · CPC title

• C08J9/127

  Mixtures of organic and inorganic blowing agents · CPC title

• C08J2203/12

  Organic compounds only containing carbon, hydrogen and oxygen atoms, e.g. ketone or alcohol · CPC title

• C08J9/146

  only fluorine as halogen atoms · CPC title