Process for preparing neutral-aged hydrophobic organosilicate-modified silica gels and hydrophobic organosilicate-modified silica gels prepared therefrom
The present invention is neutral-aged hydrophobic organosilicate-modified silica gels and a method for their preparation. The method comprises three steps, where in the first step an organosilicate-modified silica hydrosol is contacted with a strong mineral acid at a pH less than 1 to form an organo...
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Zusammenfassung: | The present invention is neutral-aged hydrophobic organosilicate-modified silica gels and a method for their preparation. The method comprises three steps, where in the first step an organosilicate-modified silica hydrosol is contacted with a strong mineral acid at a pH less than 1 to form an organosilicate-modified silica hydrogel. In the second step the organosilicate-modified silica hydrogel is aged at a pH within a range of pH 3.5 to pH 8. In the third step the neutral-aged organosilicate-modified silica hydrogel is contacted with an organosilicon compound in the presence of a catalytic amount of a strong acid to effect hydrophobing of the organosilicate-modified silica hydrogel to form a hydrophobic organosilicate-modified silica hydrogel having a surface area within a range of 100 m2/g to 750 m2/g in the dry state. In a preferred process the hydrophobic organosilicate-modified silica hydrogel is contacted with a sufficient quantity of a water-immiscible organic solvent to convert the hydrophobic organosilicate-modified silica hydrogel into a hydrophobic organosilicate-modified silica organogel. |
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