Colored roofing granules with increased solar heat reflectance, solar heat-reflective shingles, and process for producing same
View Patent ↗Solar-reflective roofing granules having deep-tone colors are formed by coating base mineral particles with a coating composition including an infrared-reflective pigment. Color is provided by a colored infrared pigment, a light-interference platelet pigment, or a metal oxide.
1. Colored infrared-reflective roofing granules comprising inert base particles coated with a cured coating composition comprising a coating binder and at least one colored, infrared-reflective pigment.
2. Colored infrared-reflective roofing granules according to claim 1 wherein the based particles have a size passing #8 mesh.
3. Colored infrared-reflective roofing granules according to claim 1 wherein the based particles have a size retained on #70 mesh.
4. Colored infrared-reflective roofing granules according to claim 1 , the colored infrared-reflective roofing granules having an L* value of less than 55.
5. Colored infrared-reflective roofing granules according to claim 1 the colored infrared-reflective roofing granules having an infrared reflectance of at least 25%.
6. Colored infrared-reflective roofing granules according to claim 1 wherein the coating composition further comprises at least one infrared-reflective functional pigment selected from the group consisting of light-interference platelet pigments including mica, light-interference platelet pigments including titanium dioxide, mirrorized silica pigments based upon metal-doped silica, and alumina.
7. Colored infrared-reflective roofing granules according to claim 1 wherein the coating composition further comprises at least one coloring material selected from the group consisting of granule coloring pigments and uv-stabilized dyes.
8. Colored infrared-reflective roofing granules comprising base particles coated with a cured coating composition comprising a coating binder and at least one colored, infrared-reflective pigment wherein the base particles comprise mineral particles coated with a cured base coating composition including a base particle binder, and at least one reflective white pigment.
9. Colored infrared-reflective roofing granules according to claim 8 wherein the based particles have a size passing #8 mesh.
10. Colored infrared-reflective roofing granules according to claim 8 wherein the based particles have a size retained on #70 mesh.
11. Colored infrared-reflective roofing granules according to claim 8 wherein the at least one reflective white pigment is selected from the group consisting of titanium dioxide, zinc oxide and zinc sulfide.
12. A bituminous roofing product comprising a substrate sheet of a fibrous material saturated with a bituminous coating material and colored, infrared-reflective roofing granules comprising base particles coated with a cured coating composition comprising a coating binder and at least one colored, infrared-reflective pigment.
13. A bituminous roofing product according to claim 12 wherein the base particles have a size passing #8 mesh.
14. A bituminous roofing product according to claim 12 wherein the base particles have a size retained on #70 mesh.
15. A bituminous roofing product according to claim 12 having an L* value of less than 55.
16. A bituminous roofing product according to claim 12 having an infrared reflectance of at least 25%.
17. A bituminous roofing product according to claim 12 wherein the coating composition further comprises at least one infrared-reflective functional pigment selected from the group consisting of light-interference platelet pigments including mica, light-interference platelet pigments including titanium dioxide, mirrorized silica pigments based upon metal-doped silica, and alumina.
18. A bituminous roofing product according to claim 12 wherein the base particles comprise mineral particles coated with a cured base coating composition including a base coating binder and at least one reflective white pigment.
19. A bituminous roofing product according to claim 12 wherein the at least one reflective white pigment is selected from the group consisting of titanium dioxide, zinc oxide and zinc sulfide.