摘要 |
Surface-modified silica prepared by a pyrogenic method is obtained by placing a silica, prepared by a pyrogenic method, in a known mixing apparatus, spraying it with a chemical compound from the group CHF2-CF2-O-(CH2)3-Si(OCH3)3 CF3-CHF-CF2-O-(CH2)3-Si(OCH3)3 C4F9-CH2-CH2-Si(OCH3)3 C6F13-CH2-CH2-Si(OCH3)3 with thorough mixing, carrying out further mixing and heating the resulting mixture over a relatively long period. |