Patent ID: 8399093
Filing Date: 2013-03-19
Classification: B82Y,C01P,C08K,C09C,C09D,G03G,Y10T

Abstract:
1. A process for preparing surface-modified silicon dioxide particles with a mean particle diameter of at most 100 nm, the process comprising: (I) high-pressure grinding of a predispersion comprising (A1) initial surface-modified silicon dioxide particles which (A1a) are at least partly aggregated, (A1b) are bonded to a surface-modifying component via Si—O—Si bonds, and (A1c) comprise reactive groups on their surface after the grinding, (A2) an organosilicon compound which has (A2a) a silicon-carbon bond and (A2b) a functional group which react with the reactive groups to form a covalent Si—O—Si bond, and (A3) an organic, volatile solvent, to form a dispersion; and (II) removing a liquid phase of the dispersion by spray drying, to obtain the surface-modified silicon dioxide particles with the mean particle diameter of at most 100 nm, wherein a proportion of the organic, volatile solvent (A3) in the predispersion is from 60 to 98% by weight.