| 摘要 |
PURPOSE:To easily produce the title large-sized silica glass without cracks, etc., by hydrolyzing silicon alkoxide or its polycondensation product with an amine as catalyst to form a silica sol, gelating the sol, and drying and sintering the gel. CONSTITUTION:Silicon alkoxide shown by the general formula, Si(OR)4, (where R is an alkyl group) and/or its polycondensation product are hydrolyzed by adding water, a solvent such as alcohols, and an amine as catalyst. The obtained sol is then charged in a vessel, and heated at from room temp. to about 70 deg.C to gelate the sol. The gel is dried at a temp. higher than room temp. to obtain a dry gel. The strength of the dry gel is increased by using the strongly basic amine as catalyst, and a monolithic gel wherein the generation of cracks, crazes, etc., is prevented can be obtained irrespective of its size and shape. The dry gel is subsequently sintered in an appropriate atmosphere to form silica glass. |
