Composite nanoparticles for roofing granules, roofing shingles containing such granules, and process for producing same

• US 9,540,822 B2
• Filed: 11/19/2010
• Issued: 01/10/2017
• Est. Priority Date: 11/24/2009
• Status: Active Grant

• Current Assignee: CertainTeed Corp. (Compagnie De Saint-Gobain)
• Original Assignee: CertainTeed Corp. (Compagnie De Saint-Gobain)
• Inventors: Shiao, Ming Liang, Jacobs, Gregory F., Zhou, Sean X.
• Primary Examiner(s): PENNY, TABATHA L
• Application Number:
  US12/950,460
• Publication Number:
  US 20110159240A1
• Time in Patent Office: 2,244 Days
• Field of Search: 427/212
• US Class Current: 1/1
• CPC Class Codes: A01N 59/16 Heavy metals; Compounds thereof
• CPC Class Codes: B01J 2/006 Coating of the granules without description of the process or the device by which the granules are obtained to prevent the granules sticking together B01J2/30
• CPC Class Codes: B05D 3/007 After-treatment
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C04B 2235/3284 Zinc oxides, zincates, cadmium oxides, cadmiates, mercury oxides, mercurates or oxide forming salts thereof
• CPC Class Codes: C04B 2235/3418 Silicon oxide, silicic acids, or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint glass constituents C04B2235/36
• CPC Class Codes: C04B 2235/3427 Silicates other than clay, e.g. water glass
• 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 2235/408 Noble metals
• CPC Class Codes: C04B 2235/96 Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
• CPC Class Codes: C04B 33/131 Inorganic additives
• 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

Abstract

Roofing granules are prepared by coating granule cores with a coating material including composite nanoparticles and curing the coating layer to dissolve the aggregate binder and disperse the nanoparticles in the coating.

Claims

1. A process for preparing roofing granules, the process comprising:

(a) providing granule cores;

(b) providing a coating material;

(c) coating the granule cores with the coating material to form a coating layer having an exterior surface;

(d) including composite nanoparticles in the coating layer; and

(e) curing the coating layer.

2. A process for preparing roofing granules according to claim 1 wherein the composite nanoparticles are dispersed in the coating material prior to coating the granule cores with the coating material.

3. A process for preparing roofing granules according to claim 1, the process further comprising:

(a) providing nanoparticles;

(b) providing a carrier material;

(c) coating the nanoparticles with the carrier material, the carrier material being dispersible in the coating material; and

(d) aggregating the coated nanoparticles to form green composite nanoparticles.

4. A process according to claim 3 wherein the process further comprises sizing the green composite nanoparticles to form green composite nanoparticles having a predetermined average size.

5. A process for preparing roofing granules according to claim 1 further comprising forming composite nanoparticles including nanoparticles, the nanoparticles being selected from the group comprising silver, silver oxide, copper, copper oxide, zinc, zinc oxide, and titania nanoparticles.

6. A process for preparing roofing granules according to claim 1 further comprising forming composite nanoparticles including at least one carrier material, the at least one carrier material comprising at least one metal silicate.

7. A process for preparing roofing granules according to claim 6 wherein the at least one metal silicate is sodium silicate.

8. A process for preparing roofing granules according to claim 1 further comprising forming composite nanoparticles including at least one curing agent for a predetermined coating binder.

9. A process for preparing roofing granules according to claim 8 wherein the curing agent is selected from the group consisting of kaolin clays, metal phosphates, aluminum fluoride, sodium fluorosilicates, zinc oxides, metal oxides with leachable multi-valent ions in alkaline environment and combinations thereof.

10. A process for preparing roofing granules according to claim 1 further comprises forming composite nanoparticles comprising at least one functional material.

11. A process for preparing roofing granules according to claim 10 wherein the at least one functional material is selected from the group consisting of colorant pigments, solar reflective pigments, near infrared reflective pigments, photocatalytic particles, organic biocides, inorganic biocides, and algaecides.

12. A process for preparing roofing granules according to claim 1 wherein the composite nanoparticles are applied to the exterior surface of the coating layer.

13. A process for preparing roofing granules according to claim 1, the process further comprising:

(a) providing nanoparticles;

(b) providing carrier material;

(c) dispersing the nanoparticles in the carrier material, the carrier material being dispersible in the coating material; and

(d) forming carrier particles from the carrier material including the dispersed nanoparticles, the carrier particles comprising the composite nanoparticles.

14. A process for preparing roofing granules according to claim 1, the process further comprising:

(a) providing nanoparticles;

(b) providing carrier particles having an exterior surface, the carrier particles including carrier material dispersible in the coating material; and

(c) adhering the nanoparticles to the exterior surface of the carrier particles.

15. A process for preparing roofing granules according to claim 1, the process further comprising:

(a) providing nanoparticles;

(b) providing carrier particles;

(c) mixing the nanoparticles and the carrier particles, the carrier particles including carrier material dispersible in the coating material; and

(d) aggregating the carrier particles, the nanoparticles being entrapped among the aggregated carrier particles.

16. A process for preparing roofing granules according to claim 1, the process further comprising:

(a) providing nanoparticles;

(b) providing porous carrier particles, the carrier particles including carrier material dispersible in the coating material; and

(c) entrapping the nanoparticles in the pores of the carrier particles.

17. A process for preparing roofing granules according to claim 1 further comprising forming composite nanoparticles including at least one carrier material, the at least one carrier material comprising silica.