| 摘要 |
PURPOSE:To obtain dry gel having low bulk density without causing cracking or breaking when optical glass is produced by a sol-gel method, by mixing a metallic alkoxide with a solvent whose b.p. is higher than that of water and water. CONSTITUTION:A metallic alkoxide such as Si(OCH3)4 is mixed with a solvent whose b.p. is higher than that of water and water to prepare silica sol, this silica sol is allowed to stand, and the resulting gel is dried to obtain dry gel. Optical glass is produced by sintering the dry gel. By this method, the dry gel having low bulk density is obtd. without causing cracking or breaking, so transparent silica glass is produced without causing cracking or breaking by sintering the dry gel. The solvent whose b.p. is higher than that of water may be 1-C4H9OH, 1-C5H11OH, 1-C6H13OH or C6H5CH3. The solvent may be used in combination with CH3OH or C2H5OH as a conventional solvent. |
