Roofing shingles, tiles and shakes
The present disclosure relates generally to roofing elements and methods for making them. In one embodiment, the disclosure provides a roofing element in the form of a roofing shingle that includes a body of a foamed cured cross-linked polymer, the body having a top surface and a bottom surface, the body extending substantially in a plane and having a thickness in the range of 0.5 mm to 35 mm; and a layer of weather-resistant roofing granules disposed on and adhered at the top surface of roofing element. The roofing element can be made by providing a body of wet foamed curable composition, and allowing the curable composition to cure to provide the body of foamed cured cross-linked polymer.
1. A method for preparing a roofing element in the form of a roofing shingle, shake or tile extending substantially in a plane, the roofing element having a top surface,
the roofing element comprising:
a body of a foamed cured cross-linked polymer, the body having a top surface at the top surface of the roofing element and a bottom surface, the body extending substantially in the plane and having a thickness in the range of 2 mm to 35 mm; and
a layer of weather-resistant roofing granules disposed on and adhered at the top surface of the roofing element,
wherein the shingle, shake or tile has an asphalt content of less than about 5 wt %,
the method comprising:
foaming a curable composition by physically incorporating air therein to provide a foamed curable composition, the foamed curable composition being adapted to provide the foamed cured cross-linked polymer upon curing, the foamed curable composition having a wet foam density of about 0.1 to about 1.0 g/mL;
providing a wet body of the foamed curable composition;
disposing the granules at a top surface of the wet body of foamed curable composition; and then
allowing the wet body of foamed curable composition to cure to provide the body of foamed cured cross-linked polymer having the granules adhered to the top surface thereof.
2. The method of claim 1 , wherein the foamed curable composition has a filler dispersed therein.
3. The method of claim 1 , wherein the physical incorporation comprises beating or whipping.
4. The method of claim 1 , wherein the physical incorporation is performed in two steps, with a first step at a higher speed and a second step at a slower speed.
5. The method of claim 1 , wherein the foaming the curable composition is performed at a first condition at a first turbulence and a second condition at a second turbulence lower than the first turbulence.
6. The method of claim 1 , wherein forming the wet body of foamed curable composition comprises coating one or both sides of a support sheet with the foamed curable composition.
7. The method of claim 6 , wherein the support sheet is a fibrous mat, a fiberglass mat, a roofing felt, or a fibrous mat of metallic strands, of polymeric fibers, of glass fibers, or of a combination thereof.
8. The method of claim 1 , wherein the wet body of the foamed curable composition is allowed to cure at ambient temperature.
9. The method of claim 1 , wherein the wet body of the foamed curable composition is allowed to cure at a temperature of in the range of 60° C. to 200° C.
10. The method of claim 1 , wherein the wet body of foamed curable composition has a wet foam density in the range of 0.15 to 1.0 g/mL.
11. The method of claim 1 , further comprising disposing weather-resistant granules to a top surface of the wet body of the foamed curable composition to provide the wet roofing element precursor; and allowing the wet body of the foamed curable composition to cure to provide the roofing element such that the roofing granules are embedded in and adhered to the top surface of the foamed polymer body.
12. The method of claim 1 , further comprising disposing an adhesive on a top surface of the wet body of the foamed curable composition, then disposing granules on the adhesive, then allowing the wet body and the adhesive to cure such that the roofing granules are adhered to the top surface of the foamed polymer body by the adhesive.
13. The method of claim 1 , further comprising disposing a polymer film at the top surface of the body of the wet foamed curable composition, or at the top surface of the body of foamed cured cross-linked composition, then disposing an adhesive on the polymer film, then disposing roofing granules on the adhesive, then allowing the adhesive to cure.
14. The method of claim 1 , wherein the body of foamed cured cross-linked polymer is in the form of a substantially closed-cell foam.
15. The method of claim 1 , wherein the roofing element has an asphalt content of less than 1 wt %.
16. The method of claim 1 , wherein the body of foamed cured cross-linked polymer has a void volume, and wherein no more than 10% of the void volume is formed by foam cells having a longest dimension in excess of 100 microns.
17. The method of claim 1 , wherein the polymer of the body of foamed cured cross-linked polymer is a poly(meth)acrylate-based polymer, a polyurethane/acrylate hybrid polymer, a polyurethane, a polyvinylidine difluoride or a copolymer thereof.
18. The method of claim 1 , wherein the polymer of the body of foamed cured cross-linked polymer is a poly(meth)acrylate-based polymer or a polyurethane/acrylate hybrid polymer.
19. The method of claim 2 , wherein the filler comprises stucco, dolomite, sand, glass powder, magnesium oxide, magnesium hydroxide, aluminum trihydrate; talc; kaolin, barium sulfate or wollastonite.
20. The method of claim 2 , wherein the filer comprises calcium carbonate.