| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide silica having a large pore volume and specific surface area, controlled pore properties, a low total content of unnecessary metal impurities and also excellent heat and water resistances, etc. <P>SOLUTION: The silica has the following properties: (a) a pore volume of the silica is >1.6 to 3 ml/g; (b) a specific surface area of the silica is 100-1,000 m<SP>2</SP>/g; (c) a mode pore diameter (D<SB>max</SB>) of the silica is≥5 nm; (d) a value of Q<SP>4</SP>/Q<SP>3</SP>in a solid-state Si-NMR (nuclear magnetic resonance) spectrum of the silica is≥1.2; (e) the silica is amorphous; and (f) a total content of metal impurities in the silica is≤100 ppm. <P>COPYRIGHT: (C)2003,JPO</p> |
