Light reflectant surface and method for making and using same

• US 5,596,450 A
• Filed: 01/06/1995
• Issued: 01/21/1997
• Est. Priority Date: 01/06/1995
• Status: Expired due to Term

• Current Assignee: W. L. Gore & Associates (W.L. Gore & Associates)
• Original Assignee: W. L. Gore & Associates (W.L. Gore & Associates)
• Inventors: Minor, Raymond B., McGregor, Gordon L., Hannon, Gregory E.
• Primary Examiner(s): Callahan, Timothy P.
• Assistant Examiner(s): KIM, JUNG H
• Application Number:
  US08/369,850
• Time in Patent Office: 746 Days
• Field of Search: 359/599, 359/515, 362/341, 428/315.5, 428/311.1, 428/314.7, 521/142, 526/242, 526/250, 526/255
• US Class Current: 359/599
• CPC Class Codes: B29K 2027/18 PTFE, i.e. polytetrafluorethene , e.g. ePTFE, i.e. expanded polytetrafluorethene
• CPC Class Codes: C08J 2327/18 Homopolymers or copolymers of tetrafluoroethylene
• CPC Class Codes: C08J 5/18 Manufacture of films or sheets
• CPC Class Codes: C08L 27/18 Homopolymers or copolymers or tetrafluoroethene
• CPC Class Codes: F21S 41/37 characterised by their material, surface treatment or coatings
• CPC Class Codes: F21V 7/24 characterised by the material
• CPC Class Codes: F21V 7/28 characterised by coatings
• CPC Class Codes: G02B 1/04 made of organic materials, e.g. plastics G02B1/08 takes precedence
• CPC Class Codes: G02B 5/0247 by means of voids or pores
• CPC Class Codes: G02B 5/0284 used in reflection
• CPC Class Codes: G02F 1/133504 Diffusing, scattering, diffracting elements associated to illuminating devices G02F1/133606
• CPC Class Codes: G02F 1/133553 Reflecting elements associated to illuminating devices G02F1/133605

Abstract

The present invention is an improved material and method for use for providing diffuse reflectivity of light. By employing an expanded polytetrafluoroethylene (PTFE) comprising a microstructure of polymeric nodes and fibrils, the material of the present invention demonstrates exceptional diffuse reflectivity across a wide spectrum of visible and infrared light. Additionally, the material of the present invention provides many properties that have been previously unavailable in highly diffuse reflective material, including a high degree of malleability, moldability and flexibility, and effective reflectivity even at relatively thin cross-sections.

Claims

1. A method of providing improved diffuse reflectivity of light comprising

providing a reflectant material comprising an expanded polytetrafluoroethylene having polymeric nodes interconnected by fibrils defining microporous voids therein;

mounting the reflectant material to cause light energy to reflect off it;

whereby the reflectant material provides diffuse reflectivity with greater than 99% of visible light with a wavelength between at least 400 to 700 nm striking the reflectant material reflecting from the material.

2. The method of claim 1 that further comprises

providing as the reflectant material a flexible sheet of expanded polytetrafluoroethylene, allowing the reflectant material to be readily formed into different shapes;

and

forming the reflective material to provide a non-planar reflective surface.

3. The method of claim 2 that further comprises

providing as the reflectant material a material having a thickness between 0.5 mm and 3 mm.

4. The method of claim 1 that further comprises

providing as the reflectant material a material having a thickness between 0.5 mm and 3 mm.

5. The method of claim 1 that further comprises

employing the reflectant material as a light reflectant panel.

6. The method of claim 1 that further comprises

employing the reflectant material as a light reflectant material within a laser.

7. The method of claim 1 that further comprises

employing the reflectant material as a reflectant standard.

24. The method of claim 1 that further comprises providing an expanded polytetrafluoroethylene that is biaxially expanded.

27. The method of claim 1 that further comprises providing the reflectant material with a thickness of between 0.5 and 6.2 mm.

8. A method of providing improved diffuse reflectivity of light comprising

providing a reflectant material comprising an expanded polytetrafluoroethylene having polymeric nodes interconnected by fibrils defining microporous voids therein;

mounting the reflectant material to cause light energy to reflect off it;

whereby the reflectant material provides diffuse reflectivity with greater than 90% of visible light with a wavelength between at least 400 to 700 nm striking the reflectant material reflecting from the material.

9. The method of claim 8 that further comprises

forming the flexible reflectant material to provide a non-planar reflective surface.

10. The method of claim 8 that further comprises

providing as the reflectant material a material having a thickness between 0.5 mm and 3 mm.

11. The method of claim 8 that further comprises

employing the reflectant material as a light reflectant panel.

12. The method of claim 8 that further comprises

employing the reflectant material as light reflectant material within a laser.

13. The method of claim 8 that further comprises

employing the reflectant material as a reflectant standard.

16. The method of claim 8 that further comprises

providing a reflectant material with a diffuse reflectivity of greater than 96%.

17. The method of claim 8 that further comprises

providing a reflectant material with a diffuse reflectivity of greater than 97%.

18. The method of claim 8 that further comprises

providing a reflectant material with a diffuse reflectivity of greater than 98%.

19. The method of claim 8 that further comprises

providing a reflectant material with a diffuse reflectivity of greater than 99%.

20. The method of claim 8 that further comprises

providing a reflectant material with a diffuse reflectivity of greater than 96% in a range of light wavelength of 400 to 700 nm.

21. The method of claim 8 that further comprises

providing a reflectant material with a diffuse reflectivity of greater than 97% in a range of light wavelength of 400 to 700 nm.

22. The method of claim 8 that further comprises

providing a reflectant material with a diffuse reflectivity of greater than 98% in a range of light wavelength of 400 to 700 nm.

23. The method of claim 8 that further comprises

providing a reflectant material with a diffuse reflectivity of greater than 99% in a range of light wavelength of 400 to 700 nm.

25. The method of claim 8 that further comprises providing an expanded polytetrafluoroethylene that is biaxially expanded.

28. The method of claim 8 that further comprises providing the reflectant material with a thickness of between 0.5 and 6.2 mm.

29. The method of claim 8 that further comprises providing a reflectant material that is flexible so as to allow the material to be readily formed into various shapes.

30. The method of claim 8 that further comprises providing a reflectant material that provides a diffuse reflectivity of greater than 95% of the visible light striking the reflectant material.

31. The method of claim 30 that further comprises providing a reflectant material that is flexible so as to allow the material to be readily formed into various shapes.

14. A method of providing improved diffuse reflectivity of light comprising

providing a reflectant material comprising an expanded polytetrafluoroethylene having polymeric nodes interconnected by fibrils defining microporous voids therein, the reflectant material being of a thickness of less than 1 mm;

mounting the reflectant material to cause light energy to reflect off it;

whereby the reflectant material provides diffuse reflectivity of greater than 95% of visible light with a wavelength between at least 400 to 700 nm striking the reflectant material reflecting from the material.

15. The method of claim 14 that further comprises

providing as the reflectant material a flexible sheet of expanded polytetrafluoroethylene, allowing the reflectant material to be readily formed into different shapes;

and

forming the reflective material to provide a non-planar reflective surface.

26. The method of claim 14 that further comprises providing an expanded polytetrafluoroethylene that is biaxially expanded.