Thermally conductive lamp reflector

• US 20030043586A1
• Filed: 08/28/2002
• Published: 03/06/2003
• Est. Priority Date: 08/31/2001
• Status: Active Grant

• Current Assignee: Ticona Polymers, Inc. (Celanese Corporation)
• Original Assignee: Cool Options, Inc.
• Inventors: Sagal, E. Mikhail, Miller, James, McCullough, Kevin A.
• Granted Patent: US 6,827,470 B2
• Time in Patent Office: Days
• US Class Current: 362/341
• CPC Class Codes: F21S 41/321 the reflector being a surface of revolution or a planar surface, e.g. truncated
• CPC Class Codes: F21S 41/37 characterised by their material, surface treatment or coatings
• CPC Class Codes: F21S 45/48 with means for conducting heat from the inside to the outside of the lighting devices, e.g. with fins on the outer surface of the lighting device
• CPC Class Codes: F21V 29/505 of reflectors
• CPC Class Codes: F21V 7/24 characterised by the material
• CPC Class Codes: H01J 5/16 Optical or photographic arrangements structurally combined with the vessel

Abstract

A thermally conductive lamp reflector is provided that dissipates heat from a light source within the reflector. The reflector assembly includes a shell having a metallized layer on its surface. The shell is made from a composition including about 30% to about 80% by volume of a base polymer matrix and about 20% to about 70% by volume of a thermally conductive filler material. The reflector has a thermal conductivity of greater than 3 W/m° K and preferably greater than 22 W/m° K. The reflectors can be used in automotive headlamps, flashlights, and other lighting fixtures. A method of forming the lamp reflector is also provided.

Claims

1. A thermally conductive lamp reflector having a thermal conductivity of greater than 3 W/m°

K, comprising;

a shell having a surface; and

a metallized layer on the surface of the shell;

said shell including about 30% to about 80% by volume of a polymer matrix and about 20% to about 70% by volume of a thermally conductive filler material.

2. The lamp reflector of claim 1, wherein the metallized layer includes aluminum.

3. The lamp reflector of claim 1, wherein the polymer matrix includes a thermoplastic or thermosetting polymer.

4. The lamp reflector of claim 3, wherein the polymer matrix includes a thermoplastic polymer selected from the group consisting of polycarbonate, polyethylene, polypropylene, acrylics, vinyls, and fluorocarbons.

5. The lamp reflector of claim 3, wherein the polymer matrix includes a thermosetting polymer selected from the group consisting of elastomers, epoxies, polyesters, polyimides, and acrylonitriles.

6. The lamp reflector of claim 1, wherein the polymer matrix includes a liquid crystal polymer.

7. The lamp reflector of claim 1, wherein the filler material is selected from the group consisting of aluminum, alumina, copper, magnesium, brass, carbon, silicon nitride, aluminum nitride, boron nitride, zinc oxide, glass, mica, and graphite.

8. The lamp reflector of claim 7, wherein the filler material is in the form of particles.

9. The lamp reflector of claim 8, wherein the particles have an average particle size of 15 μ

m.

10. The lamp reflector of claim 7, wherein the filler material is in the form of fibers.

11. The lamp reflector of claim 1, wherein a protective layer including a compound selected from the group consisting of polysiloxanes, acrylics, and silicon dioxide is coated over the metallized layer.

12. A thermally conductive lamp reflector having a thermal conductivity of greater than 3 W/m°

K, comprising;

a shell having a surface; and

a metallized layer on the surface of the shell;

said shell including;

i) about 30% to about 60% by volume of a polymer matrix, ii) about 25% to about 60% by volume of a first thermally conductive filler material having an aspect ratio of 10;

1 or greater, and iii) about 10% to about 15% by volume of a second thermally conductive filler material having an aspect ratio of 5;

1 or less.

13. The lamp reflector of claim 12, wherein the reflector has a thermal conductivity of greater than 22 W/m°

K.

14. The lamp reflector of claim 12, wherein the metallized layer includes aluminum.

15. The lamp reflector of claim 12, wherein the polymer matrix includes a thermoplastic or thermosetting polymer.

16. The lamp reflector of claim 12, wherein the polymer matrix includes a liquid crystal polymer.

17. The lamp reflector of claim 12, wherein the first thermally conductive filler material includes carbon fiber having an aspect ratio of about 50:

1, and the second thermally conductive filler material includes boron nitride particles having an aspect ratio of about 4;

1.

18. A method of forming a thermally conductive lamp reflector having a thermal conductivity of greater than 3 W/m°

K, comprising the steps of;

molding a shell, having an inner surface, and including about 30% to about 80% by volume of a polymer matrix and about 20% to about 70% by volume of a thermally conductive filler material; and

depositing a layer of metallized material on the inner surface of the shell.

19. The method of claim 18, wherein the metallized material is aluminum.

20. The method of claim 18, wherein the polymer matrix includes a thermoplastic or thermosetting polymer.

21. The method of claim 20, wherein the polymer matrix includes a thermoplastic polymer selected from the group consisting of polycarbonate, polyethylene, polypropylene, acrylics, vinyls, and fluorocarbons.

22. The method of claim 20, wherein the polymer matrix includes a thermosetting polymer selected from the group consisting of elastomers, epoxies, polyesters, polyimides, and acrylonitriles.

23. The method of claim 18, wherein the polymer matrix includes a liquid crystal polymer.

24. The method of claim 18, wherein the filler material is selected from the group consisting of aluminum, alumina, copper, magnesium, brass, carbon, silicon nitride, aluminum nitride, boron nitride, zinc oxide, glass, mica, and graphite.

25. The method of claim 24, wherein the filler material is in the form of particles.

26. The method of claim 25, wherein the particles have an average particle size of 15 μ

m.

27. The method of claim 24, wherein the filler material is in the form of fibers.

28. The method of claim 18, wherein a protective layer including a compound selected from the group consisting of polysiloxanes, acrylics, and silicon dioxide is coated over the metallized layer.