Mineral surfaced asphalt-based roofing products with encapsulated healing agents and methods of producing the same
An asphalt-based sheet roofing material includes capsules on its upper surface. When struck, as by hailstones, the capsules break to release a film forming fluid that spreads over the surface to heal the damage created by the hailstones.
1. An asphalt-based sheet roofing material comprising a bituminous binder and having an exterior upper surface, the exterior upper surface being provided with a plurality of capsules partially embedded in the exterior upper surface, the capsules having an outer shell and an inner cavity, the outer shell being susceptible to being ruptured by mechanical impact, the outer shell having enough strength to endure the manufacturing operation of shingle making and normal foot traffic without rupture, the outer shell being weak enough to be broken upon impact of hail stones, the inner cavity being provided with at least one functional material.
2. A roofing material according to claim 1 wherein the at least one functional material comprises a liquid composition, the liquid composition being film forming.
3. A roofing material according to claim 1 wherein the at least one functional material comprises at least one solvent component, the bituminous binder being soluble in the at least one solvent component of the functional material.
4. A roofing material according to claim 1 wherein the functional material comprises at least one pigment.
5. A roofing material according to claim 1 wherein the functional material comprises at least one biocide.
6. A roofing material according to claim 1 wherein the functional material is selected from the group consisting of adhesives, adhesion promoters, coating compositions, asphalt-based emulsions, and plasticizers.
7. A roofing material according to claim 6 wherein the coating composition is an asphalt-based coating composition.
8. A roofing material according to claim 1 , the outer shell of the capsules being formed from a shell-forming material, the shell-forming material having a compressive strength greater than 100 psi and less than 30,000 psi.
9. A roofing material according to claim 1 wherein the outer shell is formed from a material selected from the group consisting of glass, ceramic materials, and polymeric materials.
10. A roofing material according to claim 1 wherein the outer shell of the capsules comprises a capsule binder and at least one pigment.
11. A roofing material according to claim 10 wherein the at least one pigment is a solar reflective pigment.
12. A roofing material according to claim 2 wherein the upper surface being further provided with a plurality of roofing granules and the portion of the upper surface that is provided with capsules being coextensive with the portion of the upper surface that is provided with roofing granules.
13. A roofing material according to claim 1 wherein the capsules have an average size that is smaller than the average size of the roofing granules.
14. A roofing material according to claim 1 wherein the capsules range in size from about U.S. mesh #18 to U.S. mesh #50.