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 natural 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.
|
申请公布号 |
CA2280901(A1) |
申请公布日期 |
1998.08.27 |
申请号 |
CA19982280901 |
申请日期 |
1998.02.18 |
申请人 |
DOW CORNING CORPORATION |
发明人 |
HAHN, JAMES R.;REESE, CLIFFORD C.;DENG, QIN;BURNS, GARY T. |
分类号 |
C01B33/159;C01B33/16;C09C1/30;(IPC1-7):C01B33/159 |
主分类号 |
C01B33/159 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|