Nanocomposite dielectrics

• US 6,762,237 B2
• Filed: 06/10/2002
• Issued: 07/13/2004
• Est. Priority Date: 06/08/2001
• Status: Expired due to Fees

• Current Assignee: Eikos, Inc.
• Original Assignee: Eikos, Inc.
• Inventors: Arthur, David J., Glatkowski, Paul J.
• Primary Examiner(s): Wyrozebski, Katarzyna
• Application Number:
  US10/165,306
• Publication Number:
  US 20030008123A1
• Time in Patent Office: 764 Days
• Field of Search: 524/495, 524/496, 523/218
• US Class Current: 524/496
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C08K 2201/011 Nanostructured additives
• CPC Class Codes: C08K 7/24 inorganic
• CPC Class Codes: H05K 1/162 incorporating printed capacitors
• CPC Class Codes: Y10S 977/753 with polymeric or organic binder
• CPC Class Codes: Y10T 428/249931 Free metal or alloy fiber
• CPC Class Codes: Y10T 428/249948 Fiber is precoated

Abstract

The present invention relates to a novel nanocomposite dielectric comprising a polymer matrix and a plurality of carbon nanotubes dispersed therein. A method for increasing a dielectric constant of a polymer matrix, as well as a laminate and mobile antenna comprising the novel dielectric are also disclosed.

Claims

1. A nanocomposite dielectric comprising a polymer matrix and a plurality of carbon nanotubes dispersed therein, wherein a metal coating is deposited on a surface of said dielectric.

2. The nanocomposite dielectric of claim 1, wherein said plurality of carbon nanotubes are single walled carbon nanotubes.

3. The nanocomposite dielectric of claim 1, wherein said plurality of carbon nanotubes are multi-walled carbon nanotubes.

4. The nanocomposite dielectric of claim 1, wherein said plurality of carbon nanotubes are a mixture of single walled and multi-walled nanotubes.

5. The nanocomposite dielectric of claim 1, wherein said polymer matrix is selected from the group consisting of epoxy resins, cyanate ester resins, polyimides, silicones, polybutadiene resins, fluoropolymers, urethanes, acrylics, polycarbonate, polypropylene, polyethylene, polyesters and mixtures thereof.

6. The nanocomposite dielectric of claim 1, wherein said plurality of carbon nanotubes are oriented parallel to an electric field of the Nanocomposite.

7. The nanocomposite dielectric of claim 1, wherein the metal coating increases conductivity.

8. The nanocomposite dielectric of claim 1, wherein said metallic coating is selected from the group consisting of silver, gold, copper, nickel, aluminum and mixtures thereof.

9. The nanocomposite dielectric of claim 1, wherein said nanotubes are present at a concentration below a percolation threshold of said nanocomposite dielectric.

10. The nanocomposite dielectric of claim 1, wherein said nanotubes are mixed with a conductive filler selected from the group consisting of silver particles, nickel coated graphite, metallic coated glass beads, metallic coated hollow glass or ceramic spheres, copper particles, stainless steel fibers, carbon black, gold particles, aluminum particles and mixtures thereof.

11. The nanocomposite dielectric of claim 1, wherein said nanotubes are mixed with inorganic dielectric particles to increase the volume resistivity of said dielectric.

12. The nanocomposite dielectric of claim 1, wherein an organic molecule is adsorbed or covalently bonded to a surface of said nanotubes to improve dispersion or increase the volume resistivity of said dielectric.

13. The nanocomposite dielectric of claim 1, wherein said dielectric has a volume resistivity greater than 10⁸ ohm-cm.

14. The nanocomposite dielectric of claim 1, wherein said dielectric has a volume resistivity greater than 10¹² ohm-cm.

15. The nanocomposite dielectric of claim 1, wherein said dielectric has a dielectric constant greater than 4.

16. The nanocomposite dielectric of claim 1, wherein said dielectric has a dielectric constant greater than 10.

17. The nanocomposite dielectric of claim 1, wherein said dielectric has a dielectric constant greater than 40.

18. The nanocomposite dielectric of claim 1, wherein said dielectric has a dielectric constant greater than 100.

19. The nanocomposite dielectric of claim 1, wherein said dielectric has a dielectric loss less than 0.05.

20. The nanocomposite dielectric of claim 1, wherein said dielectric has a dielectric loss less than 0.02.

21. The nanocomposite of claim 1, wherein said dielectric has a dielectric breakdown strength greater than 1,000 volts/mil.

22. The nanocomposite of claim 1, wherein said dielectric has a dielectric breakdown strength greater than 15,000 volts/mil.

23. The nanocomposite of claim 1, wherein said dielectric has a dielectric breakdown strength greater than 20,000 volts/mil.

24. A laminate comprising a nanocomposite dielectric of claim 1.

25. A mobile antenna comprising a nanocomposite dielectric of claim 1.

43. The laminate of claim 24, wherein a metal layer is bonded to at least one side of the dielectric.

44. The laminate of claim 24, wherein said laminate is incorporated into a multilayer circuit structure to form an embedded capacitor.

45. The laminate of claim 24, wherein said dielectric is reinforced with glass fabric.

46. The laminate of claim 24, wherein said dielectric is greater than 0.002 mm thick.

47. The laminate of claim 24, wherein said metal layer is copper foil.

48. The mobile antenna of claim 46, wherein a dielectric constant of said dielectric increases as size of said antenna decreases.

26. A high energy density (HED) capacitor comprising a dielectric material comprising a polymer matrix and a plurality of carbon nanotubes substantially dispersed therein, wherein a metal coating is deposited on a surface of said capacitor.

27. The high energy density (HED) capacitor of claim 26, wherein said plurality of carbon nanotubes are single walled carbon nanotubes.

28. The high energy density (HED) capacitor of claim 26, wherein said plurality of carbon nanotubes are multi-walled carbon nanotubes.

29. The high energy density (HED) capacitor of claim 26, wherein said plurality of carbon nanotubes are a mixture of single walled and multi-walled nanotubes.

30. The high energy density (HED) capacitor of claim 26, wherein said polymer matrix is selected from the group consisting of epoxy resins, cyanate ester resins, polyimides, silicones, polybutadiene resins, fluoropolymers, urethanes, acrylics, polycarbonate, polypropylene, polyethylene, polyesters and mixtures thereof.

31. The high energy density (HED) capacitor of claim 26, wherein said plurality of carbon nanotubes are oriented parallel to an electric field of the nanocomposite.

32. The high energy density (HED) capacitor of claim 26, wherein a metal coating is deposited on the surface of said nanotubes to increase conductivity of said nanotubes.

33. The high energy density (HED) capacitor of claim 26, wherein said nanotubes are present at a concentration below a percolation threshold of said nanocomposite dielectric.

34. A circuit comprising a high energy density (HED) capacitor of claim 26.

35. A method for increasing a dielectric constant of a polymer matrix, comprising dispersing a plurality of carbon nanotubes in said polymer matrix to form a nanocomposite dielectric, wherein a metal coating is deposited on a surface of said polymer matrix, and measuring the dielectric constant of said nanocomposite dielectric.

36. The method of claim 35, wherein said plurality of carbon nanotubes are single walled carbon nanotubes.

37. The method of claim 35, wherein said plurality of carbon nanotubes are multi-walled carbon nanotubes.

38. The method of claim 35, wherein said plurality of carbon nanotubes are a mixture of single walled and multi-walled nanotubes.

39. The method of claim 35, wherein said polymer matrix is selected from the group consisting of epoxy resins, cyanate ester resins, polyimides, silicones, polybutadiene resins, fluoropolymers, urethanes, acrylics, polycarbonate, polypropylene, polyethylene, polyesters and mixtures thereof.

40. The method of claim 35, wherein said plurality of carbon nanotubes are oriented parallel to an electric field of the nanocomposite.

41. The method of claim 35, wherein a metal coating is deposited on the surface of said nanotubes to increase conductivity of said nanotubes.

42. The method of claim 35, wherein said nanotubes are present at a concentration below a percolation threshold of said nanocomposite dielectric.