Encapsulated compositions
View Patent ↗A capsule having a reactive chemical enclosed in the hollow interior thereof, and at least one coating in direct contact with and surrounding the reactive chemical, wherein the coating is a heat-cured thermosetting synthetic resin. The capsule can also include a second coating which is in direct contact with and surrounds the heat-cured thermosetting synthetic resin. The reactive chemical is not reactive with, soluble in or a solvent for the coating, or coatings, which surround the reactive chemical in the hollow interior of the capsule. The coating material is not soluble in water, but is permeable to water.
1. A capsule having a hollow interior,
said capsule consisting of a water-soluble, particulate reactive chemical enclosed in said hollow interior by a wall which is permeable to water, but which is not water soluble;
said wall is comprised of a first coating
wherein
said first coating is a heat-cured first chemical composition whereby said capsule having said first coating is dry, flowable and not sticky; and
wherein
said first chemical composition is selected from the group consisting of phenolic, epoxy and melamine thermosetting synthetic resins.
2. The capsule of claim 1 wherein said thermosetting resin is a phenolic resin.
3. The capsule of claim 2 wherein said phenolic resin is the reaction product of phenol and formaldehyde.
4. The capsule of claim 1 wherein said thermosetting resin is an epoxy resin.
5. The capsule of claim 4 wherein said epoxy resin is the reaction product of epichlorohydrin, bisphenol A and diethylenetriamine.
6. The capsule of claim 1 wherein said thermosetting resin is a melamine resin.
7. The capsule of claim 6 wherein said melamine resin is the reaction product of melamine, formaldehyde and methanol.
8. The capsule of claim 1 further comprising a second coating, wherein the interior of said first coating is in direct contact with said reactive chemical in said hollow interior of said capsule, the exterior of said first coating is in direct contact with the interior of said second coating and said second coating is a second chemical composition different from said first chemical composition wherein said second chemical composition is a polyurethane-vinyl polymer dispersion prepared by the simultaneous polymerization of a vinyl monomer and chain extension of an isocyanate-terminated polyurethane prepolymer in the presence of water.
9. The capsule of claim 8 wherein said thermosetting resin is a phenolic resin.
10. The capsule of claim 9 wherein said phenolic resin is the reaction product of phenol and formaldehyde.
11. The capsule of claim 8 wherein said thermosetting resin is an epoxy resin.
12. The capsule of claim 11 wherein said epoxy resin is the reaction product of epichlorohydrin, bisphenol A and diethylenetriamine.
13. The capsule of claim 8 wherein said thermosetting resin is a melamine resin.
14. The capsule of claim 13 wherein said melamine resin is the reaction product of melamine, formaldehyde and methanol.
15. The capsule of claim 1 further comprising a second coating, wherein the interior of said first coating is in direct contact with said reactive chemical in said hollow interior of said capsule, the exterior of said first coating is in direct contact with the interior of said second coating and said second coating is a second chemical composition different from said first chemical composition wherein said second chemical composition is a partially hydrolyzed acrylic polymer cross-linked with one of an aziridine prepolymer or a carbodiimide.
16. The capsule of claim 15 wherein said thermosetting resin is a phenolic resin.
17. The capsule of claim 16 wherein said phenolic resin is the reaction product of phenol and formaldehyde.
18. The capsule of claim 15 wherein said thermosetting resin is an epoxy resin.
19. The capsule of claim 18 wherein said epoxy resin is the reaction product of epichlorohydrin, bisphenol A and diethylenetriamine.
20. The capsule of claim 15 wherein said thermosetting resin is a melamine resin.
21. The capsule of claim 20 wherein said melamine resin is the reaction product of melamine, formaldehyde and methanol.