Hollow silica particles, compositions comprising them and methods for making same
View Patent ↗Methods for making comprising hollow silica particles from a composition comprising a silicon-containing compound selected from the group consisting of tetraalkoxysilanes, trialkyloxysilanes and derivatives thereof, dialkoxysilanes and derivatives thereof, alkoxysilanes and derivatives thereof, silicone oligomers, oligomeric silsesquioxanes and silicone polymers distributed over a polymer template core that is eliminated from the particle in a two-stage heating process. The particles of the present invention have a substantially uniform particle size and exhibit low permeability to liquids.
1. A method of making a cosmetic composition comprising a hollow, low permeable silica particle, comprising the step of adding: a colorant; a cosmetically-suitable decamethylcyclopentylsiloxane carrier, and a plurality of hollow silica particles comprising a silicon-containing compound selected from the group consisting of tetraalkoxysilanes, trialkyloxysilanes and derivatives thereof, dialkoxysilanes and derivatives thereof, alkoxysilanes and derivatives thereof, silicone oligomers, oligomeric silsesquioxanes and silicone polymers, said hollow silica particles having an average particle size of 500 nm; wherein said hollow silica particles have a shell thickness from about 15 to about 25 nm and are spherical and 90% to 100% of a particle sample of 50 to 100 mg floats in decamethylcyclopentyl siloxane for a time period of at least 30 days.
2. The method of claim 1 , further comprising a plurality of coatings, each coating having a constant thickness.
3. The method of claim 1 , wherein said hollow silica particle comprises an outer surface functionalized with a material comprising organosilyl groups.
4. The method of claim 1 , wherein said hollow silica particle comprises an outer surface functionalized by reacting said surface with hexamethyldisilazane.
5. The method of claim 1 , wherein said hollow silica particle further comprises a chemical functionality selected from the group consisting of olefins, esters, amines, acids, epoxides, alcohols, and mixtures thereof.
6. The method of claim 1 , wherein said at least one coating comprises a metallic formulation.
7. The method of claim 6 , wherein said metallic formulation comprises a material selected from the group consisting of copper-containing compounds, silver-containing compounds, gold-containing compounds, and mixtures thereof.
8. The method of claim 1 , wherein said colorant is selected from the group consisting of pigments and dyes.
9. The method of claim 1 , wherein said hollow silica-containing particle is present in an amount of from about 0.01% to about 90% by weight of the composition.
10. The method of claim 1 , wherein said hollow silica-containing particle is present in an amount of from about 0.02% to about 50% by weight of the composition.
11. A cosmetic composition comprising a hollow, low permeable silica particle made according to the method of claim 1 .