Solar Heat Responsive Exterior Surface Covering

• US 20100225988A1
• Filed: 05/18/2010
• Published: 09/09/2010
• Est. Priority Date: 07/07/2006
• Status: Active Grant

• Current Assignee: CertainTeed Corp. (Compagnie De Saint-Gobain)
• Original Assignee: CertainTeed Corp. (Compagnie De Saint-Gobain)
• Inventors: Jacobs, Gregory F., Hong, Keith C., Kalkanoglu, Husnu M., Shiao, Ming Liang
• Granted Patent: US 8,017,224 B2
• Time in Patent Office: Days
• US Class Current: 359/267
• CPC Class Codes: B44F 1/10 Changing, amusing, or secret pictures
• CPC Class Codes: C09D 5/26 Thermosensitive paints
• CPC Class Codes: E04D 5/10 by making use of compounded or laminated materials, e.g. metal foils or plastic films coated with bitumen
• CPC Class Codes: Y02B 80/00 Architectural or constructional elements improving the thermal performance of buildings
• CPC Class Codes: Y10T 428/24372 Particulate matter
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 428/31678 Of metal

Abstract

An exterior surface covering has a colored outer layer that transmits infrared radiation and an inner layer with a thermochromic pigment that absorbs heat at low temperature and reflects at high temperatures. The outer layer conceals the color change of the thermochromic pigment.

Claims

1. An exterior surface covering comprising:

(a) an outer layer having a transmission coefficient of at least 50 percent for electromagnetic radiation in the wavelength rage from 700 nanometers to 2500 nanometers; and

(b) an inner layer having a reflectance for electromagnetic radiation in the wavelength range from 700 nanometers to 2500 nanometers, the reflectance being dependent on a variable parameter, the reflectance varying by a factor of at least 0.5 as the parameter is varied over a predetermined range.

2. An exterior surface covering according to claim 1 wherein the reflectance increases with an increase in the parameter over the predetermined range of the parameter.

3. An exterior surface covering according to claim 1 wherein the outer layer is colored.

4. An exterior surface covering according to claim 1 wherein the variable parameter is temperature.

5. An exterior surface covering according to claim 4 wherein the inner layer comprises at least one thermochromic substance selected from the group consisting of thermochromatic colorants, thermochromatic polymers, composite thermochromatic pigments, chromogenic thermotropic gels, vanadium oxides, polythiophene polymers, liquid crystals, spirobenzopyrans, spironaphthoxazines, chromenes, fulgides, and diarylethenes.

6. An exterior surface covering according to claim 4 wherein the reflectance varies from less than 0.2 to greater than 0.25 when the temperature varies from less than 20 degrees C. to greater than 30 degrees C.

7. An exterior surface covering according to claim 1 wherein the variable parameter is the strength of an applied electric field and the inner layer comprises an electrochromic substance.

8. An exterior surface covering according to claim 7 wherein the reflectance varies from less than 0.2 to greater than 0.25 when the strength of the applied electric field exceeds a predetermined field strength.

19. Roofing granules coated with an exterior surface covering according to claim 1.

20. An asphalt shingle with an exterior surface coated with an exterior surface covering according to claim 1.

21. A bituminous sheet-roofing product with an exterior surface covering with an exterior surface coating according to claim 1.

9. An exterior surface covering comprising:

(a) an outer colored layer having a transmission coefficient of at least 50 percent for electromagnetic radiation in the wavelength rage from 700 nanometers to 2500 nanometers;

(b) a middle layer having a transmission coefficient for electromagnetic radiation in the wavelength range from 700 nanometers to 2500 nanometers, the transmission coefficient being dependent on a variable parameter, the transmission coefficient varying by a factor of at least 0.5 as the parameter is varied over a predetermined range; and

(c) an inner layer having a reflectance of at least 40 percent for electromagnetic radiation in the wavelength range from 700 nanometers to 2500 nanometers.

10. An exterior surface covering according to claim 9 wherein the transmission coefficient of the middle layer increases with an increase in the parameter over the predetermined range of the parameter.

11. An exterior surface covering according to claim 10 wherein the variable parameter is temperature.

12. An exterior surface covering according to claim 11 wherein the middle layer comprises at least one thermochromic substance selected from the group consisting of thermochromatic colorants, thermochromatic polymers, composite thermochromatic pigments, chromogenic thermotropic gels, vanadium oxides, polythiophene polymers, liquid crystals, spirobenzopyrans, spironaphthoxazines, chromenes, fulgides, and diarylethenes.

13. An exterior surface covering according to claim 10 wherein the transmission coefficient of the middle layer varies from less than 0.4 to greater than 0.5 when the temperature varies from less than 20°

C. to greater than 30°

C.

14. An exterior surface covering according to claim 9 wherein the variable parameter is the strength of an applied electric field and the middle layer comprises an electrochromic substance.

15. An exterior surface covering according to claim 14 wherein the transmission coefficient of the middle layer varies from less than 0.4 to greater than 0.5 when the strength of the applied electric field exceeds a predetermined electric field strength.

22. Roofing granules coated with an exterior surface covering according to claim 9.

23. An asphalt shingle with an exterior surface covered with an exterior surface covering according to claim 9.

24. A bituminous sheet-roofing product with an exterior surface covered with an exterior surface covering according to claim 9.

16. An exterior surface covering comprising:

(a) an outer colored layer having a transmission coefficient of at least 50 percent for electromagnetic radiation in the wavelength rage from 700 nanometers to 2500 nanometers;

(b) a middle layer having a transmission coefficient for electromagnetic radiation in the wavelength range from 700 nanometers to 2500 nanometers, the transmission coefficient being dependent on a variable parameter, the transmission coefficient varying by a factor of at least 0.5 as the parameter is varied over a predetermined range; and

(c) an inner layer having an absorption coefficient at least 60 percent for electromagnetic radiation in the wavelength range from 700 nanometers to 2500 nanometers.

17. An exterior surface covering according to claim 16 wherein the variable parameter is the strength of an applied electric field and the middle layer comprises an electrochromic substance.

18. An exterior surface covering according to claim 17 wherein the transmission coefficient of the middle layer varies from greater than 0.5 to less than 0.4 when the strength of the applied electric field exceeds a predetermined electric field strength.

25. Roofing granules coated with an exterior surface covering according to claim 16.

26. An asphalt shingle with an exterior surface covered with an exterior surface covering according to claim 16.

27. A bituminous sheet roofing product with an exterior surface covered with an exterior surface covering according to claim 16.