Coating compositions for roofing granules, dark colored roofing granules with increased solar heat reflectance, solar heat-reflective shingles, and process for producing the same

• US 8,491,985 B2
• Filed: 03/18/2009
• Issued: 07/23/2013
• Est. Priority Date: 03/31/2008
• Status: Active Grant

• Current Assignee: CertainTeed Corp. (Compagnie De Saint-Gobain)
• Original Assignee: CertainTeed Corp. (Compagnie De Saint-Gobain)
• Inventors: Kalkanoglu, Husnu M., McShea, Thomas, Shiao, Ming Liang
• Primary Examiner(s): Le, Hoa (Holly)
• Application Number:
  US12/933,144
• Publication Number:
  US 20110008622A1
• Time in Patent Office: 1,588 Days
• US Class Current: 428/143
• CPC Class Codes: C04B 12/04 Alkali metal or ammonium silicate cements ; Alkyl silicate cements; Silica sol cements; Soluble silicate cements alkali metal silicates per se, their preparation C01B33/32; ammonium silicates per se, their preparation C01C1/00
• CPC Class Codes: C04B 14/042 Magnesium silicates, e.g. talc, sepiolite
• CPC Class Codes: C04B 14/045 Alkali-metal containing silicates, e.g. petalite waterglass C04B12/04
• CPC Class Codes: C04B 14/048 Granite
• CPC Class Codes: C04B 14/06 Quartz; Sand
• CPC Class Codes: C04B 14/062 Microsilica, e.g. colloïdal silica preparing microsilica slurries or suspensions C04B18/148
• CPC Class Codes: C04B 14/10 Clay sepiolite C04B14/042; grog C04B18/025
• CPC Class Codes: C04B 14/20 Mica; Vermiculite mechanical splitting B28D
• CPC Class Codes: C04B 14/285 Marble
• CPC Class Codes: C04B 14/303 Alumina
• CPC Class Codes: C04B 14/305 Titanium oxide, e.g. titanates
• CPC Class Codes: C04B 14/308 Iron oxide
• CPC Class Codes: C04B 14/309 Copper oxide or solid solutions thereof
• CPC Class Codes: C04B 14/34 Metals , e.g. ferro-silicon
• CPC Class Codes: C04B 18/141 Slags
• CPC Class Codes: C04B 18/16 from building or ceramic industry
• CPC Class Codes: C04B 20/0076 characterised by the grain distribution
• CPC Class Codes: C04B 20/008 Micro- or nanosized fillers, e.g. micronised fillers with particle size smaller than that of the hydraulic binder colloidal silica C04B14/062 ; silica fume C04B18/146
• CPC Class Codes: C04B 20/1059 Pigments or precursors thereof
• CPC Class Codes: C04B 20/1062 Metals
• CPC Class Codes: C04B 20/107 : Acids or salts thereof
• CPC Class Codes: C04B 20/1085 : Waterglass
• CPC Class Codes: C04B 2103/54 : Pigments; Dyes
• CPC Class Codes: C04B 2111/00586 : Roofing materials
• CPC Class Codes: C04B 2111/80 : Optical properties, e.g. transparency or reflexibility
• CPC Class Codes: C04B 22/126 : Fluorine compounds, e.g. silico-fluorine compounds
• CPC Class Codes: C04B 28/04 : Portland cements
• CPC Class Codes: C04B 28/26 : Silicates of the alkali metals
• CPC Class Codes: C04B 41/5018 : with fluorine compounds
• CPC Class Codes: C04B 41/5024 : Silicates C04B41/5022 takes precedence; silico-fluorides C04B41/5018
• CPC Class Codes: C04B 41/524 : Multiple coatings, comprising a coating layer of the same material as a previous coating layer
• CPC Class Codes: C04B 7/02 : Portland cement
• CPC Class Codes: C09D 1/00 : Coating compositions, e.g. paints, varnishes or lacquers, based on inorganic substances
• 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: Y02W 30/91 : Use of waste materials as fillers for mortars or concrete
• CPC Class Codes: Y10T 428/24372 : Particulate matter
• CPC Class Codes: Y10T 428/24413 : Metal or metal compound
• CPC Class Codes: Y10T 428/24421 : Silicon containing
• CPC Class Codes: Y10T 428/252 : Glass or ceramic [i.e., fired or glazed clay, cement, etc.] [porcelain, quartz, etc.]
• CPC Class Codes: Y10T 428/259 : Silicic material
• 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.]
• CPC Class Codes: Y10T 428/2995 : Silane, siloxane or silicone coating
• CPC Class Codes: Y10T 428/31 : Surface property or characteristic of web, sheet or block

Abstract

Dark colored roofing granules include an inert base particle coated with a composition including a metal silicate, a non-clay latent heat reactant, and a dark colored but solar reflective prigment.

Claims

1. A coating composition comprising:

a metal silicate;

at least one non-clay latent heat reactant, the at least one non-clay latent heat reactant comprising from about 3 to 15 weight percent of the coating composition of aluminum fluoride, from about 0.5 to 5 weight percent of the coating composition of sodium silicofluoride, and from about 0.5 to 5 weight percent of the coating composition of Portland cement; and

at least one pigment having high solar reflectance, wherein the at least one pigment is selected from the group consisting of solar reflective pigments having an L* less than 30 and a solar reflectance of at least 20 percent.

2. A coating composition according to claim 1 wherein the at least one non-clay latent heat reactant comprise from about 5 to 11 weight percent of the coating composition of aluminum fluoride, from about 1.5 to 3 weight percent of the coating composition of sodium silicofluoride, and from about 1.5 to 3 weight percent of the coating composition of Portland cement.

3. A coating composition according to claim 1 wherein the metal silicate is selected from the group consisting of ammonium silicate, sodium silicate, potassium silicate and lithium silicate.

4. A substrate coated with the coating composition of claim 1.

5. A coated substrate according to claim 4 wherein the coated substrate has an L* less than about 30 and a solar reflectance of at least about 20 percent.

6. A coated substrate according to claim 5 wherein the coated substrate comprises an architectural material.

7. Dark colored, solar reflective roofing granules, the roofing granules comprising:

(a) an inert base particle;

(b) at least one coating layer, the at least one coating layer formed from a silicate coating composition comprising

a metal silicate coating binder comprising a metal silicate and at least one non-clay latent heat reactant; and

at least one pigment having high solar reflectance;

the at least one solar reflective pigment being selected to provide roofing granules having an L* less than 30 and solar reflectance of at least 20 percent.

8. Roofing granules according to claim 7 wherein the at least one non-clay latent heat reactant is selected from the group consisting of Portland cement, aluminum fluoride, ammonium silicofluoride, alkali metal silicofluorides, and alkaline earth metal silicofluorides.

9. Roofing granules according to claim 8 wherein the at least one non-clay latent heat reactant comprises Portland cement, aluminum fluoride and at least one alkali metal silicofluoride.

10. Roofing granules according to claim 9 wherein the at least one alkali metal silicofluoride is sodium silicofluoride.

11. Roofing granules according to claim 10 wherein the at least one non-clay latent heat reactant comprises from about 3 to 15 weight percent of the coating composition of aluminum fluoride, from about 0.5 to 5 weight percent of the coating composition of sodium silicofluoride, and from about 0.5 to 5 weight percent of the coating composition of Portland cement.

12. Roofing granules according to claim 11 wherein the at least one non-clay latent heat reactant comprises from about 5 to 11 weight percent of the coating composition of aluminum fluoride, from about 1.5 to 3 weight percent of the coating composition of sodium silicofluoride, and from about 1.5 to 3 weight percent of the coating composition of Portland cement.

13. Roofing granules according to claim 7, the roofing granules comprising at least two coating layers formed from the silicate coating composition.

14. Roofing granules according to claim 7 wherein the metal silicate is selected from the group consisting of ammonium silicate, sodium silicate, potassium silicate and lithium silicate.

15. Roofing granules according to claim 7 wherein the at least one solar reflective pigment is selected from the group consisting of solar reflective pigments having an L* less than 30 and a solar reflectance of least 20 percent.

16. Roofing shingles comprising dark colored, solar reflective roofing granules, each roofing granule comprising:

(a) an inert base particle;

(b) at least one coating layer, the at least one coating layer formed from a coating composition comprising

a metal silicate coating binder comprising an alkali metal silicate and at least one non-clay latent heat reactant; and

at least one pigment having high solar reflectance;

the at least one solar reflective pigment being selected to provide roofing granules having an L* less than 30 and solar reflectance of at least 20 percent.