POLYSILSESQUIOXANE COMPOSITIONS AND PROCESS
First Claim
1. A non-porous microparticle of polyorganosilsesquioxane containing an entrapped optical agent whereby the surface of the particle is essentially free of optical agents.
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Accused Products
Abstract
Composite particles comprised of an optical agent(s) entrapped in a non-porous microparticle of polyorganosilsesquioxane to yield discrete microparticles, are provided. The optical agent is fully encapsulated in the interior of the silsesquioxane particle to impart optical properties that include absorption and emission in the ultraviolet and visible spectrum respectively, without otherwise interfering with the surface chemistry or surface properties of the particle. The use of these novel microparticles in a cosmetic or pharmaceutical composition provides a change in the optical appearance of the skin by either changing the apparent tone or hue, making the skin appear lighter, softer, or by photoluminescent brightening and/or by novel color sculpting under various light conditions.
31 Citations
27 Claims
- 1. A non-porous microparticle of polyorganosilsesquioxane containing an entrapped optical agent whereby the surface of the particle is essentially free of optical agents.
- 17. A personal care, cosmetic or pharmaceutical composition comprising about 0.1% to about 75% by weight of a plurality of non-porous microparticles of polyalkylsilsesquioxane containing an entrapped optical agent, whereby the surface of the plurality of microparticles is essentially free of optical agent, wherein the alkyl group in said polyalkylsilsesquioxane is selected from methyl, ethyl, propyl, butyl or phenyl radicals, either singly or in any combination thereof in combination with a cosmetically or pharmaceutically acceptable inert carrier or diluent.
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23. A process to produce a plurality of non-porous microparticles of polyorganosilsesquioxane containing an entrapped optical agent, whereby the surface of the plurality of microparticles is essentially free of optical agent, which comprises the steps of:
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a) hydrolyzing and condensing an alkyltrialkoxysilane in water in the presence of about 0.001% to about 2% by weight of optical agent, with about 0% to about 1% by weight suspending agent, with about 0% to about 2% by weight a surface tension modifier and an acid or base catalyst to form spherical particles; b) purifying the spherical particles by washing them from about 1 to up to about 10 times and; c) optionally, drying the particles at elevated temperatures to cure them to a highly cross-linked state;
wherein, weight % is in reference to the initial weight of silane charged and;
the alkyl groups in said alkyltrialkoxysilane can be the same or different, selected from methyl, ethyl, propyl, butyl or phenyl radicals. - View Dependent Claims (24, 25, 26)
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Specification