Microcapsules having an envelope composed essentially of silsesquioxane homopolymers or copolymers
AssigneeMicrocapsules Technologies
InventorGerard Daniel HABAR
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Abstract
A microcapsule having a reservoir that includes a core containing at least one active principle, the core being surrounded by a polymer shell, is presented. The polymer shell contains 50% to 100% by weight of a silsesquioxane compound with respect to the total weight of the shell. A process for the manufacture of the microcapsules is also presented. The microcapsules containing active principles can be used in cosmetic products.
Claims20
A process for the manufacture of reservoir microcapsules, said microcapsules comprising a core of at least one active principle surrounded by a polymer shell, said polymer shell comprising 50% to 100% by weight of a silsesquioxane compound with respect to the total weight of said shell, the process comprising:
- dispersing at least one hydrophilic active principle in an organic continuous phase, so as to form a water-in-oil emulsion or dispersion;
- introducing into the organic phase (i) a precursor of the silsesquioxane polymer compound, and (ii) a poly(ethyl)silicate that is insoluble in water in the hydrolyzed state;
- hydrolyzing and polymerizing said precursor in situ in or on contact with the aqueous phase of the water-in-oil emulsion or dispersion, so as to form a silsesquioxane homopolymer or copolymer, wherein said polymerizing is carried out at a pH of less than 6.
The process according to claim 6, wherein said polymerizing begins at an initial pH between 3 to 5, and proceeds at a lower pH up to the end of the polymerization reaction of from 1 to 4.
The process according to claim 14, wherein the one or more silane carries a cationic charge.
Dependencies are inferred from the claim text.