| 摘要 |
PURPOSE:To mass-produce a quartz glass having excellent optical property by heating a dry gel obtained from an alkyl-silicate as raw material. CONSTITUTION:The dry gel, which is produced from the alkyl-silicate as the raw material by the sol-gel method, is allowed to desorb the physically adsorbed water by heating in atmosphere at >=300 deg.C and at the same time a residual carbon compd. is removed in the form of CO2. Next, the dry gel is set in a vacuum furnace, and is vetrified by heating at 700-1,450 deg.C in decompression atmosphere, and then is heated and maintained at 1,500-2,200 deg.C for a specified time. Thereby the inclusion or flaw is eliminated and the quartz glass having optically high purity is obtained. |
