Expanded polytetrafluoroethylene (ePTFE)-reinforced perfluoroelastomers (FFKM)

• US 20030211264A1
• Filed: 05/09/2002
• Published: 11/13/2003
• Est. Priority Date: 05/09/2002
• Status: Abandoned Application

• Current Assignee: W. L. Gore & Associates (W.L. Gore & Associates)
• Original Assignee: W. L. Gore & Associates (W.L. Gore & Associates)
• Inventors: Egres, Ronald Gene Jr., Farnsworth, Ted Ray
• Application Number:
  US10/142,350
• Publication Number:
  US 20030211264A1
• Time in Patent Office: Days
• US Class Current: 428/36.9
• CPC Class Codes: B32B 25/00 Layered products comprising a layer of natural or synthetic rubber fibrous or filamentary layer made of a natural or synthetic rubber B32B5/02; particulate layer made of a natural or synthetic rubber B32B5/16; foamed layer made of a natural or synthetic rubber B32B5/18
• CPC Class Codes: B32B 25/08 of synthetic resin
• CPC Class Codes: B32B 5/18 characterised by features of a layer of foamed material
• CPC Class Codes: C08L 2205/02 containing two or more polymers of the same C08L -group
• CPC Class Codes: C08L 2205/16 Fibres; Fibrils
• CPC Class Codes: C08L 2666/04 Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof
• CPC Class Codes: C08L 27/18 Homopolymers or copolymers or tetrafluoroethene
• CPC Class Codes: Y10T 428/139 Open-ended, self-supporting conduit, cylinder, or tube-type article
• CPC Class Codes: Y10T 428/218 Aperture containing

Abstract

A reinforced elastomer composite is disclosed comprising expanded polytetrafluoroethylene (ePTFE) and an FFKM polymer that preferably comprises monomer units of TFE and PAVE. At least a portion of the reinforced elastomer composite is substantially non-permeable. Further disclosed are methods of making the reinforced elastomer composites, and articles made therefrom.

Claims

1. A reinforced elastomer composite comprising expanded polytetrafluoroethylene (ePTFE) having a node and fibril microstructure defining a plurality of interconnected passages and pathways to form a continuous matrix, and a polymer comprising monomer units of TFE and PAVE substantially filling a portion of said passages and pathways, at least a portion of the composite being substantially non-permeable.

2. A reinforced elastomer composite of claim 1, wherein the ePTFE comprises a preformed structure.

3. A reinforced elastomer composite of claim 1, wherein the ePTFE comprises a scaffold.

4. A reinforced elastomer composite of claim 1, wherein the PAVE monomer units are PMVE.

5. A reinforced elastomer composite of claim 4, wherein the polymer comprises between about 20 and 80% by weight TFE and between about 80 and 20% by weight PMVE.

6. A reinforced elastomer composite of claim 4, wherein the polymer comprises between about 30 and 70% by weight TFE and between about 70 and 30% by weight of PMVE.

7. A reinforced elastomer composite of claim 1, wherein the polymer is amorphous.

8. A reinforced elastomer composite as defined in claim 1, wherein the polymer further comprises a crosslinking monomer.

9. A reinforced elastomer composite as defined in claim 1, further comprising a curing agent.

10. A reinforced elastomer composite as defined in claim 1, wherein the polymer is crosslinked.

11. A reinforced elastomer composite as defined in claim 1, further comprising at least one additional layer.

12. An article comprising

a reinforced elastomer composite comprising

a polymer comprising TFE and PAVE, and

a scaffold of porous ePTFE,

the polymer substantially filling a portion of the pores, and

wherein at least a portion of the reinforced elastomer composite is substantially non-permeable.

13. An article of claim 12, said reinforced elastomer composite further comprising an elastomer-rich section on a portion of the composite.

14. An article of claim 12, further comprising at least one additional material.

15. An article of claim 14, wherein the at least one additional material is selected from ePTFE-reinforced FFKM composite, an elastomer, and an ePTFE layer.

16. An article of claim 15 wherein the elastomer is a TFE/PMVE elastomer.

17. An article of claim 12 wherein PAVE is PMVE.

18. An article of claim 12 wherein the article comprises a gasket.

19. An article of claim 12 wherein the article comprises a fuel cell gasket.

20. An article of claim 12 wherein the article comprises an o-ring.

21. An article of claim 12 wherein the article comprises a flexible hinge.

22. An article of claim 12 wherein the article comprises a tube.

23. An article of claim 22 wherein the tube is peristaltic pump tube.

24. An article of claim 12 wherein the article comprises a tube liner.

25. An article of claim 12 wherein the article comprises a release film.

26. An article of claim 12 wherein the article comprises a diaphragm.

27. A method of making a substantially non-permeable article comprising the steps of:

(a) providing a scaffold of expanded polytetrafluoroethylene (ePTFE) having a microstructure defining a plurality of interconnected passages and pathways to form a continuous matrix;

(b) providing an emulsion of a polymer comprising TFE and PAVE;

(c) dispensing said emulsion onto said scaffold, said emulsion imbibing into at least a portion of said passages and pathways of said scaffold to render the article substantially non-permeable.

28. The method of claim 27 wherein said emulsion has a solids content of about 10 to 70%.

29. The method of claim 27 wherein PAVE is PMVE.

30. The method of claim 29, wherein said emulsion has a solids content of about 50% to 70% by weight of the polymer comprising TFE and PMVE.

31. The method of claim 29, wherein said emulsion has a solids content of about 60% by weight or greater of the polymer comprising TFE and PMVE.

32. The method of claim 29, wherein the polymer comprises between about 20 and 80% by weight TFE and between about 80 and 20% by weight PMVE.

33. The method of claim 29, wherein the polymer comprises between about 30 and 70% by weight TFE and between about 70 and 30% by weight PMVE.

34. The method of claim 27 further comprising the step of drying said substantially non-permeable article.

35. The method of claim 27 wherein the polymer further comprises a crosslinking monomer.

36. The method of claim 27 wherein the polymer further comprises a curing agent.

37. The method of claim 27 further comprising crosslinking the polymer comprising TFE and PAVE.

38. The method of claim 27 wherein the emulsion further comprises an emulsifying agent.

39. The method of claim 27 further comprising allowing the emulsion to imbibe into substantially all of the passages and pathways of the scaffold.

40. A method of forming an ePTFE-reinforced FFKM polymer composite comprising providing a scaffold of porous ePTFE and an aqueous emulsion of a TFE/PAVE copolymer, substantially filling the pores with the polymer, and rendering at least a portion of the composite substantially non-permeable.