| 摘要 |
1. Object of the invention is a process for making silica particles, comprising the following steps: 1) An alkali stabilized silica sol with a particle size in the range from 8 to 250 nm is diluted to at most 30 % SiO<SUB>2</SUB> with water and/or a water-soluble organic solvent 2) A silane and/or an organic compound, selected from polyols und dicarboxylic acids, is pumped into the agitated sol of step 1, which is maintained at a temperature between 20 and 75 °C, 3) The sol of step 2 is deionized by contacting it with anion and cation exchange resins 4) The silylated, deionized sol of step 3 is dried by evaporating the water, preferably under vacuum or in an air stream, 5) optionally, the dried sol of step 4 is milled to a fine powder, whereby at least two of the steps 2), 3) and 4) may be carried out in a different order. |
