Roofing granules with high solar reflectance, roofing products with high solar reflectance,and processes for preparing same

• US 10,392,806 B2
• Filed: 10/28/2016
• Issued: 08/27/2019
• Est. Priority Date: 03/15/2010
• Status: Active Grant

• Current Assignee: Certainteed, LLC (Compagnie de Saint-Gobain SA)
• Original Assignee: CertainTeed Corp. (Compagnie De Saint-Gobain)
• Inventors: Shiao, Ming Liang, Kalkanoglu, Husnu M.
• Primary Examiner(s): Van Sell, Nathan L
• Application Number:
  US15/337,928
• Publication Number:
  US 20170051508A1
• Time in Patent Office: 1,033 Days
• CPC Class Codes: C04B 14/108 Shale, slate colliery shale C04B18/125
• CPC Class Codes: C04B 14/20 Mica; Vermiculite mechanical splitting B28D
• CPC Class Codes: C04B 14/34 Metals , e.g. ferro-silicon
• CPC Class Codes: C04B 20/1033 obtained by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: C04B 20/1051 Organo-metallic compounds; Organo-silicon compounds, e.g. bentone
• CPC Class Codes: C04B 20/1059 Pigments or precursors thereof
• CPC Class Codes: C04B 20/107 Acids or salts thereof
• CPC Class Codes: C04B 20/1085 Waterglass
• CPC Class Codes: C04B 2111/00586 Roofing materials
• CPC Class Codes: C04B 2235/3232 Titanium oxides or titanates, e.g. rutile or anatase
• CPC Class Codes: C04B 2235/349 Clays, e.g. bentonites, smectites such as montmorillonite, vermiculites or kaolines, e.g. illite, talc or sepiolite
• CPC Class Codes: C04B 2235/5292 Flakes, platelets or plates
• CPC Class Codes: C04B 2235/5296 with a defined aspect ratio, e.g. indicating sphericity spherical constituents C04B2235/528
• CPC Class Codes: C04B 2235/5427 millimeter or submillimeter sized, i.e. larger than 0,1 mm
• CPC Class Codes: C04B 2235/5463 Particle size distributions
• CPC Class Codes: C04B 2235/9661 Colour
• CPC Class Codes: C04B 33/14 Colouring matters
• CPC Class Codes: C04B 35/62695 Granulation or pelletising devices for shaping artificial aggregates from ceramic mixtures B28B1/004
• CPC Class Codes: C04B 35/62807 Silica or silicates
• CPC Class Codes: C04B 35/62884 by gas phase techniques
• CPC Class Codes: D06N 5/003 : coated with bitumen
• CPC Class Codes: E04B 1/78 : Heat insulating elements E04B1/7662 takes precedence
• CPC Class Codes: E04D 1/22 : of specified materials not covered by any one of groups E04D1/14 - E04D1/205, or of combinations of materials, where at least one is not covered by any one of groups E04D1/14 - E04D1/205
• CPC Class Codes: E04D 2001/005 : the roofing elements having a granulated surface
• CPC Class Codes: E04D 7/005 : characterised by loose or embedded gravel or granules as an outer protection of the roof covering
• CPC Class Codes: Y02A 30/254 : Roof garden systems; Roof coverings with high solar reflectance
• CPC Class Codes: Y02B 80/00 : Architectural or constructional elements improving the thermal performance of buildings
• CPC Class Codes: Y10T 428/2438 : Coated
• CPC Class Codes: Y10T 428/2991 : Coated
• CPC Class Codes: Y10T 428/2993 : Silicic or refractory material containing [e.g., tungsten oxide, glass, cement, etc.]

Abstract

A solar heat-reflective roofing product includes a base sheet, and solar heat-reflective roofing granules on top of the base sheet. The granules have a base particle with a flake-like geometry covered by a uniform coating layer. The coating layer has a thickness of at least one mil and includes a coating binder and at least one solar heat-reflective pigment. The solar heat-reflective pigment provides a solar heat reflectance of greater than 70 percent to the granules and the roofing product. Roofing products including roofing shingles and roofing membranes are described.

Claims

1. Solar heat-reflective roofing granules comprising:

a) a base particle having a flake-like geometry, an average particle size from #5 US mesh to #50 US mesh, and UV opacity greater than 70 percent

b) a uniform coating layer on the base particle, the coating layer having a thickness of at least one mil, the coating layer comprising a coating binder and at least one solar heat reflective pigment;

wherein the thickness of the coating layer does not vary by more than about 25 percent from the average coating thickness, at the 95 percent confidence interval,

wherein the roofing granules have an aspect ratio of at least 5 and a solar heat reflectance of at least 70 percent.

2. Solar heat-reflective roofing granules according to claim 1, wherein the roofing granules have an aspect ratio of at least 7.

3. Solar heat-reflective granules according to claim 1, the base particles having UV opacity greater than 80 percent.

4. Solar heat-reflective granules according to claim 3, the base particles having UV opacity greater than 90 percent.

5. Solar heat-reflective roofing granules according to claim 1, wherein the coating layer has a thickness of at least 2 mils.

6. Solar heat-reflective roofing granules according to claim 1, wherein the base particles are selected from the group consisting of naturally occurring rocks with low solar reflectance in the range around 8 to 15 percent.

7. Solar heat-reflective roofing granules according to claim 1, wherein the coating binder is selected from the group consisting of metal silicates, fluoropolymers, metal phosphates, silica coating binders, and sol-gel coating binders, polysiloxanes, silicones, polyurethanes and polyacrylates.

8. Solar heat-reflective roofing granules according to claim 1, wherein the at least one solar heat-reflective pigment is selected from the group consisting of titanium dioxide, calcium carbonate, zinc oxide, lithopone, zinc sulphide, white lead, glass microspheres, glass microbubbles, microvoid pigments, and synthetic polymeric opacifiers.

9. Solar heat-reflective roofing granules according to claim 1, which have (a*²+b*²)^1/2 less than 6.

10. Solar heat-reflective roofing granules according to claim 1, wherein the coating binder is selected from the group consisting of metal silicates, metal phosphates, silica coating binders, and sol-gel coating binders.

11. A solar heat-reflective roofing product according to claim 1, having a solar reflectance of greater than 70%.

12. A solar heat-reflective roofing product according to claim 1, further comprising a plurality of second granules disposed on the base sheet in interstices between the solar heat-reflective roofing granules.

13. A solar heat-reflective roofing product according to claim 1, wherein the coating binder is a metal silicate.

25. Solar heat-reflective roofing granules according to claim 1, wherein the thickness of the coating layer does not vary by more than about 10 percent from the average coating thickness, at the 95 percent confidence interval.

14. A solar heat-reflective roofing product comprising:

a) a base sheet, and

b) solar heat-reflective roofing granules laying flat on top of the base sheet, the granules comprising;

1) a base particle having a flake-like geometry, an average particle size from #5 US mesh to #50 US mesh, and UV opacity greater than 70 percent,

2) a uniform coating layer on the base particle, the coating layer having a thickness of at least one mil, the coating layer comprising a coating binder and at least one solar heat-reflective pigment;

wherein the granules have an aspect ratio of at least 5 and a solar reflectance of at least 70 percent, and

wherein the thickness of the coating layer does not vary by more than about 25 percent from the average coating thickness, at the 95 percent confidence interval.

15. A solar heat-reflective roofing product according to claim 14 wherein the granules cover at least 85 percent of the surface area of the base sheet.

16. A solar heat-reflective roofing product according to claim 15 wherein the granules cover at least 90 percent of the surface area of the base sheet.

17. A solar heat-reflective roofing product according to claim 16 wherein the granules cover at least 95 percent of the surface area of the base sheet.

18. A solar heat-reflective roofing product according to claim 14, wherein the roofing granules particles have an aspect ratio of at least 7.

19. A solar heat-reflective roofing product according to claim 15, the base particles having UV opacity greater than 80 percent.

20. A solar heat-reflective roofing product according to claim 19, the base particles having UV opacity greater than 90 percent.

21. A solar heat-reflective roofing product according to claim 14, wherein the coating layer has a thickness of at least 2 mils.

22. A solar heat-reflective roofing product according to claim 14, wherein the base particles are formed from a suitable material by an extrusion or casting process.

23. A solar heat-reflective roofing product according to claim 14, wherein the coating binder is selected from the group consisting of metal silicates, fluoropolymers, metal phosphates, silica coating binders, and sol-gel coating binders, polysiloxanes, silicones, polyurethanes and polyacrylates.

24. A solar heat-reflective roofing product according to claim 14, wherein the at least one solar heat-reflective pigment is selected from the group consisting of titanium dioxide, calcium carbonate, zinc oxide, lithopone, zinc sulphide, white lead, glass microspheres, glass microbubbles, microvoid pigments, and synthetic polymeric opacifiers.

26. A solar heat-reflective roofing product according to claim 14, wherein the thickness of the coating layer does not vary by more than about 10 percent from the average coating thickness, at the 95 percent confidence interval.

27. A solar heat-reflective roofing product according to claim 14, wherein the coating binder is selected from the group consisting of metal silicates, metal phosphates, silica coating binders, and sol-gel coating binders.