Patent ID: 8409710
Filing Date: 2013-04-02
Classification: C08J,C08K,C08L,C09D,Y10S,Y10T

Abstract:
1. A method for producing particles comprising a core of a solid polymerization product of a polyaddable, polycondensable or polymerizable siloxane, silane, or mixture thereof and a shell of silylated fumed silica particles, where the mean particle size of the silylated fumed silica particles is smaller than the mean particle size of the core, and wherein the silylated fumed silica particles are chemically bonded to the surface of the core, the method comprising: emulsifying an oil phase comprising at least one polyaddable, polycondensable or polymerizable siloxane comprising units of the formula (1) where A R z and p are independently 0, 1, 2 or 3 or comprises a polyaddition product, condensation product or polymerization product of at least one polyaddable, polycondensable or polymerizable silane of the formula (2), where n is 1, 2, 3 or 4, R R or a plurality of such siloxanes of the formula (1) and/or silanes of the formula (2) with silylated fumed silica particles in aqueous medium, and crosslinking the polyaddable, polycondensable, or polymerizable siloxane, silane or mixture thereof to form particles having a core of solid polymer particles and having a shell of silylated fumed silica particles chemically bonded to the surface of the core.