Thermally conductive lamp reflector

• US 6,827,470 B2
• Filed: 08/28/2002
• Issued: 12/07/2004
• Est. Priority Date: 08/31/2001
• Status: Expired due to Term

• Current Assignee: Ticona Polymers, Inc. (Celanese Corporation)
• Original Assignee: Cool Options, Inc.
• Inventors: Sagal, E. Mikhail, McCullough, Kevin A., Miller, James D.
• Primary Examiner(s): Husar, Stephen
• Assistant Examiner(s): Zeade, Bertrand
• Application Number:
  US10/229,557
• Publication Number:
  US 20030043586A1
• Time in Patent Office: 832 Days
• Field of Search: 362/341, 362/255, 362/256, 362/373, 362/294, 362/345, 362/296, 524/404
• 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 liquid crystal polymer matrix and about 20% to about 70% by volume of a thermally conductive PITCH-based carbon fiber.

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

3. 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.

4. 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 liquid crystal polymer matrix, ii) about 25% to about 60% by volume of a first thermally conductive filter 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, wherein the first thermally conductive material is PITCH-based carbon fiber.

5. The lamp reflector of claim 4, wherein the reflector has a thermal conductivity of greater than 22 W/m°

K.

6. The lamp reflector of claim 4, wherein the metallized layer includes aluminum.

7. The lamp reflector of claim 4, 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.

8. 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, said shell including about 30% to about 80% by volume of a liquid crystal polymer matrix and about 20% to about 70% by volume of a thermally conductive PITCH-based carbon fiber; and

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

9. The method of claim 8, wherein the metallized material is aluminum.

10. The method of claim 8, wherein a protective layer including a compound selected from the group consisting of polysiloxanes, acrylics, and silicon dioxide is coated over the metallized layer.