发明名称 |
Process for making hydrophobic silica with reduced surface area under neutral conditions |
摘要 |
The present invention is hydrophobic silica gels having a reduced surface area and a method for their preparation under neutral conditions. The method comprises two steps, where in the first step the pH of a mixture comprising a silica hydrosol and colloidal silica is adjusted with a base to within a range of pH 3 to pH 6 to facilitate formation of a silica hydrogel having incorporated therein colloidal silica. In the second step the silica hydrogel is contacted with an organosilicon compound in the presence of a catalytic amount of a strong acid to effect hydrophobing of the silica hydrogel to form a hydrophobic silica gel having a surface area within a range of about 100 m2/g to 450 m2/g in the dry state. In a preferred process the hydrophobic silica gel is contacted with a sufficient quantity of a water-immiscible organic solvent to convert the hydrophobic silica hydrogel into a hydrophobic silica organogel. A water soluble compound of cerium or iron may be added during conduct of the second step to improve heat stability of the hydrophobic silica gel.
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申请公布号 |
US5942590(A) |
申请公布日期 |
1999.08.24 |
申请号 |
US19980022282 |
申请日期 |
1998.02.11 |
申请人 |
DOW CORNING CORPORATION |
发明人 |
BURNS, GARY THOMAS;DENG, QIN;HAHN, JAMES RICHARD;REESE, CLIFFORD CARLTON |
分类号 |
C01B33/159;C01B33/16;C09C1/30;(IPC1-7):C08G77/00 |
主分类号 |
C01B33/159 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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