METAL POLYMER COMPOSITE WITH ENHANCED VISCOELASTIC AND THERMAL PROPERTIES

• US 20090314482A1
• Filed: 02/09/2006
• Published: 12/24/2009
• Est. Priority Date: 02/09/2006
• Status: Abandoned Application

• Current Assignee: Tundra Composites, LLC.
• Original Assignee: Wild River Consulting Group, LLC
• Inventors: Heikkila, Kurt E.
• Application Number:
  US12/278,633
• Publication Number:
  US 20090314482A1
• Time in Patent Office: Days
• US Class Current: 165/185
• CPC Class Codes: C08K 3/08 Metals
• CPC Class Codes: C09K 5/14 Solid materials, e.g. powdery or granular

Abstract

The invention relates to a metal polymer composite having properties that are enhanced or increased in the composite. Such properties include viscoelastic character, color, magnetism, thermal conductivity, electrical conductivity, density, improved malleability and ductility and thermoplastic or injection molding properties.

Claims

1. A metal and polymer viscoelastic composite comprising:

(a) a metal particulate, the particle size such that less than 5 wt % of the particulate is less than about 10 microns, the particulate in an amount of about 45 to about 95 vol % of the composite; and

(b) a polymer phase comprising about 5 to about 55 vol % of the composite,

wherein the viscoelastic composite, when subject to a deforming force, exhibits a characteristic stress and strain curve with a yield stress maximum A at an ε

_A, a lower yield stress minimum B at an ε

_B, a second yield stress maximum and an initiation of failure C at ε

_C and a 0 strain failure D at ε

_D, the ε

_D of the composite greater than 10% and each ε

represents an increase in % strain.

2. The composite of claim 1 wherein the stress point A is greater than 0.2 MPa.

3. The composite of claim 1 wherein the stress point B is less than 60 MPa.

4. The composite of claim 1 wherein the stress point C is greater than 0.2 MPa.

5. The composite of claim 1 wherein the metal particulate comprises a volume packing greater than 45 vol %.

6. The composite of claim 1 wherein the metal particulate comprises a volume packing greater than 54 vol %.

7. The composite of claim 1 wherein the polymer is a halogen containing polymer having a density of greater than 1.3 gm-cm⁻

3.

8. The composite of claim 1 wherein the composite comprises an interfacial modifier material comprising about 0.0005 to about 2 wt % of the composite;

9. The composite of claim 1 wherein the composite comprises an interfacial modifier material comprising about 0.0005 to about 1 wt % of the composite;

10. The composite of claim 1 wherein the metal particulate comprises a metal having a particle size distribution ranging from about 10 to 70 microns.

11. The composite of claim 7 wherein the metal particulate comprises a metal having at least 5 wt.-% with a particle size ranging from about 70 to 250 microns.

12. The composite of claim 4 wherein the polymer comprises a fluoropolymer having a density greater than 1.7 gm-cm⁻

3.

13. The composite of claim 1 wherein the metal particulate has an excluded volume about 20% to about 55 volume-% and the metal is present in an amount of about 95 to 96 wt.-%.

14. The composite of claim 2 wherein the stress point A is at about 1-10 MPa.

15. The composite of claim 3 wherein the stress point B is at about 1-10 MPa.

16. The composite of claim 4 wherein the stress point C is at about 1 to 10 MPa.

17. The composite of claims 1 wherein the metal particulate comprises at least about 10 wt.-% of particulate in the range of about 70 to 250 microns and at least 5 wt % of the particulate is in the range of about 250 microns or greater.

18. The composite of claim 1 wherein the polymer comprises a fluoropolymer with a density of about 1.8 gm-cm⁻

3.

19. The composite of claim 1 wherein the metal comprises tungsten.

20. A heat transfer structure comprising:

(a) a heat source;

(b) a heat transfer layer; and

(c) a heated structure;

wherein the heat transfer layer comprises a metal and polymer viscoelastic composite comprising a metal particulate having a particle size such that less than 5% of the particulate is less than about 10 microns, the particulate in an amount of about 45 to about 95 vol % of the composite;

a polymer phase comprising about 5 to about 55 vol % of the composite; and

an interfacial modifier comprising about 0.005 to about 2 wt % of the composite; and

the transfer layer has a thermal conductivity of greater than about than about 1 W-M<sup>−

1</sup>K<sup>−

1</sup>.

21. The thermal structure of claim 20 wherein the thermal conductivity ranges from about 50 to about 175 W-M⁻

°

K<sup>−

1</sup>.

22. The thermal structure of claim 20 wherein the thermal conductivity is 75 to 155 W-M⁻

1K<sup>−

1</sup>.

23. The thermal structure of claim 20 wherein the thermal conductivity is about 87 to 105 W-M⁻

1°

K<sup>−

1</sup>.

24. The structure of claim 20 wherein the useful operating range of the composition is from about −

50°

C. to about +130°

C.

25. The thermal structure of claim 20 wherein the metal particulate comprises a circularity of greater than 14 and a density greater than 5-21 gm-cm⁻

3.

26. The thermal structure of claim 20 wherein the composite density is greater than 8-12 gm-cm⁻

3.

27. The thermal structure of claim 20 wherein the polymer is a halogen containing polymer having a density of greater than 1.7 gm-cm⁻

3.

28. The thermal structure of claim 20 wherein the composite comprises about 5 wt.-% of a colorant.

29. The thermal structure of claim 28 wherein the colorant comprises a pigment, a dye, a fluorescent dye or mixtures thereof.

30. The thermal structure of claim 20 wherein the metal particulate comprises tungsten having a particle size distribution ranging from about 10 to 70 microns.

31. The thermal structure of claim 20 wherein the metal particulate comprises tungsten having at least 5 wt.-% with a particle size ranging from about 70 to 250 microns.

32. The thermal structure of claim 20 wherein the polymer comprises a fluoropolymer.

33. The thermal structure of claim 20 wherein the metal particulate has an excluded volume about 20% to about 55 volume-% and the metal is present in an amount of about 70 to 95 wt.-%.

34. The thermal structure of claim 20 wherein the metal particulate comprises at least about 10 wt.-% of particulate in the range of about 70 to 250 microns and at least 5 wt % of the particulate is in the range of about 250 microns or greater.

35. The thermal structure of claim 20 wherein the polymer comprises a fluoropolymer.

36. The thermal structure of claim 20 wherein the metal comprises tungsten.

37. The thermal structure of claim 20 wherein the metal particulate comprises bismuth having at least 5 wt.-% with a particle size ranging from about 70 to 250 microns.

38. The thermal structure of claim 20 wherein the metal particulate comprises a ferrous metal having at least 5 wt.-% with a particle size ranging from about 70 to 250 microns.

39. The thermal structure of claim 38 wherein the metal particulate comprises stainless steel.