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

Patent metadata

Field	Value
Publication number	US-2016326746-A1
Application number	US-201615211085-A
Country	US
Kind code	A1
Filing date	Jul 15, 2016
Priority date	May 24, 2007
Publication date	Nov 10, 2016
Grant date	—

Abstract

Solar reflective roofing granules include a binder and inert mineral particles, with solar reflective particles dispersed in the binder. An agglomeration process preferentially disposes the solar reflective particles at a desired depth within or beneath the surface of the granules.

First claim

1 . A process for preparing solar reflective roofing granules, the process comprising:
(a) providing a binder and inert mineral particles to form a mixture; (b) forming the mixture into uncured granule bodies having an exterior surface; (c) adhering solar reflective particles to the exterior surface of the uncured granule bodies; and (d) curing the binder.

2 . A process according to claim 1 wherein the solar reflective particles are mechanically adhered to the exterior surface of the uncured granule bodies.

3 . A process according to claim 1 , further comprising mixing the solar reflective particles with a fluid carrier to form a paste and adhering the solar reflective particles to the exterior surface of the granule bodies by applying the paste to the exterior surface of the granule bodies.

4 . A process according to claim 1 further comprising sizing the uncured granules by screening.

5 . A process according to claim 1 wherein the uncured granules are heated to cure the binder.

6 . A process according to claim 1 further comprising surface treating the cured roofing granules.

7 . A process according to claim 1 wherein the inert mineral particles comprise uncalcined kaolin, the binder comprises metal silicate, and the binder is cured by heating the uncured granules at from about 500 degrees C. to 800 degrees C.

8 . A process for preparing solar reflective roofing granules, the process comprising:
(a) providing ceramic particles and solar reflective particles; (b) dispersing the ceramic particles and the solar reflective particles to form a mixture; (c) forming the mixture into uncured granules; and (d) sintering the uncured granules to form cured roofing granules.

9 . A process according to claim 8 further comprising selecting the solar reflective particles to provide at least 60 percent solar reflectance.

10 . A process according to claim 8 further comprising sizing the uncured granules by screening.

11 . A process according to claim 8 further comprising providing a sintering binder, the mixture being formed from the ceramic particles, the solar reflective particles, and the sintering binder.

12 . A process for preparing solar reflective roofing granules, the process comprising:
(a) providing ceramic particles; (b) forming the ceramic particles into uncured granule bodies having an exterior surface; (c) adhering solar reflective particles to the exterior surface of the uncured granule bodies; and (d) sintering the uncured granule bodies to form solar reflective roofing granules.

13 . A process according to claim 12 wherein the solar reflective particles are mechanically adhered to the exterior surface of the uncured granule bodies.

14 . A process according to claim 12 further comprising providing a sintering binder and mixing the sintering binder with the ceramic particles to form a mixture and subsequently forming the mixture including the ceramic particles into uncured granule bodies.

Assignees

• Certain Teed Corp

Inventors

• Shiao Ming Liang
• Hong Keith C
• Stephens Walter T

Classifications

• E04D5/12

  specially modified, e.g. perforated, with granulated surface, with attached pads · CPC title

• C04B35/64

  Burning or sintering processes (C04B33/32 takes precedence {; powder metallurgy B22F}) · CPC title

• C04B35/62821

  Titanium oxide · CPC title

• C04B33/04

  Clay; Kaolin · CPC title

• E04D1/12 Primary

  Roofing elements shaped as plain tiles or shingles, i.e. with flat outer surface (E04D1/28, E04D1/30 take precedence) · CPC title