Flexure endurant composite elastomer compositions

• US 6,451,396 B1
• Filed: 12/03/1998
• Issued: 09/17/2002
• Est. Priority Date: 02/13/1998
• Status: Expired due to Term

• Current Assignee: W. L. Gore & Associates (W.L. Gore & Associates)
• Original Assignee: Gore Enterprise Holdings Incorporated (W.L. Gore and Associates)
• Inventors: Zumbrum, Michael Allen, Muller, Jason William
• Primary Examiner(s): Dye, Rena L.
• Assistant Examiner(s): Miggins, Michael C.
• Application Number:
  US09/204,429
• Publication Number:
  US 20020031628A1
• Time in Patent Office: 1,384 Days
• Field of Search: 428/422, 428/421, 428/36.91, 428/448, 428/35.7, 428/447
• US Class Current: 428/36.91
• CPC Class Codes: B32B 25/08 of synthetic resin
• CPC Class Codes: B32B 5/32 at least two layers being foamed and next to each other
• CPC Class Codes: Y10S 277/945 Containing fluorine
• CPC Class Codes: Y10S 277/946 PTFE
• CPC Class Codes: Y10T 428/1352 Polymer or resin containing [i.e., natural or synthetic]
• CPC Class Codes: Y10T 428/1372 Randomly noninterengaged or randomly contacting fibers, filaments, particles, or flakes
• CPC Class Codes: Y10T 428/1376 Foam or porous material containing
• CPC Class Codes: Y10T 428/139 Open-ended, self-supporting conduit, cylinder, or tube-type article
• CPC Class Codes: Y10T 428/1393 Multilayer [continuous layer]
• CPC Class Codes: Y10T 428/218 Aperture containing
• CPC Class Codes: Y10T 428/249953 Composite having voids in a component [e.g., porous, cellular, etc.]
• CPC Class Codes: Y10T 428/249955 Void-containing component partially impregnated with adjacent component
• CPC Class Codes: Y10T 428/3154 Of fluorinated addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31544 Addition polymer is perhalogenated
• CPC Class Codes: Y10T 428/31663 As siloxane, silicone or silane

Abstract

A flexure endurant composition of an elastomer reinforced with a continuous phase of microporous, expanded polytetrafluoroethylene (ePTFE) having a ratio of elastomer to PTFE of approximately 1:1 to 50:1 on a volume basis. The composite is prepared by a coating process and the final articles are prepared by molding or vulcanizing. Such materials can be used to fabricate pump tubing, pump diaphragms, gaskets, bellows and other mechanical devices.

Claims

1. A composite tube comprising:

a plurality of expanded PTFE layers having a node and fibril structure, wherein the expanded PTFE layers are impregnated with at least one elastomer,

and layers of elastomer,

wherein the impregnated layers are adhered together by the layers of elastomer and wherein the ratio of the thickness of an elastomer layer to the thickness of an impregnated expanded PTFE layer is 6.5;

1 or less.

2. The composite tube of claim 1, wherein the tube has a diameter of elongation of less than 35% of the original diameter when subjected to 125 psi internal pressure at 25°

C.

3. The tube of claim 2 wherein the ratio of wall thickness to inside diameter is less than 0.25.

4. The composite of claim 1, wherein said at least one elastomer and the layers of elastomer each independently comprise a silicone, a urethane, a nitrile rubber, a styrene-butadiene rubber, a chloroprene, a phosphazene, a fluoroelastomer, a perfluoroelastomer, a perfluoro polyether elastomer or combinations thereof.

5. The composite tube of claim 1, wherein said at least one elastomer and the layers of elastomer each independently comprise an organosilicone.

6. The composite tube of claim 1, wherein said at least one elastomer and the layers of elastomer each independently comprise a methyl silicone, a phenyl silicone, a fluorosilicone, or combinations thereof.

7. The composite tube of claim 1, wherein said at least one elastomer and the layers of elastomer each independently comprise a fluoroelastomer, a perfluoroelastomer, a perluoro polyether elastomer, or combinations thereof.

8. The composite tube of claim 1, wherein the volume ratio of elastomer to expanded PTFE is at least 4:

1.

9. The composite tube of claim 1, wherein said expanded PTFE includes at least one filler.

10. The composite tube of claim 1, wherein said at least one filler is fumed silica, colloidal silica, carbon black, or combinations thereof.

11. The composite tube of claim 1, wherein said expanded PTFE layers include a plasma treatment.

12. The composite tube of claim 1, wherein said expanded PTFE layers have a silane coupling agent treatment thereon.

13. The composite tube of claim 1, wherein the tube can be continuously operated in a peristaltic pump for at least 100 hours at 200 rpm at room temperature at a pressure of at least 30 psi.

14. A composite tube comprising

at least 31 layers of expanded PTFE having a node and fibril structure, wherein the expanded PTFE layers are impregnated with at least one organosilicone elastomer,

and layers of elastomer,

wherein said impregnated layers are adhered together by the layers of organosilicone elastomer, and wherein the ratio of the thickness of an organosilicone elastomer layer to the thickness of an impregnated expanded PTFE layer is 6.5:

1 or less.

15. The composite tube of claim 14, wherein said expanded PTFE further comprises fumed silica filler.

16. The tube of claim 14, wherein the tube is non-contaminating, steam sterilizable and can be continuously operated in a peristaltic pump for at least 100 hours at 200 rpm at room temperature at a pressure of at least 30 psi.

17. A composite tube comprising:

a plurality of expanded PTFE membrane layers having a microstructure of nodes interconnected by fibrils, the microstructure of the expanded PTFE layers impregnated with at least one elastomer, and

layers of elastomer,

wherein the impregnated expanded PTFE layers are adhered together by the layers of elastomer, and wherein the ratio of thickness of a layer of elastomer to the thickness of an impregnated expanded PTFE layer is 6.5;

1.

18. A composite tube comprising

at least 31 layers of expanded PTFE membrane having a microstructure of nodes interconnected by fibrils, wherein the layers are impregnated with at least one organosilicone elastomer, and

layers of organosilicone elastomer, wherein the impregnated expanded PTFE membrane layers are adhered together by the layers of organosilicone elastomer, wherein the ratio of thickness of a layer of organosilicone elastomer to the thickness of an impregnated expanded PTFE membrane layer is 6.5:

1 or less.