| 摘要 |
PURPOSE:To produce quartz glass without striae in three directions, by dispersing silica fine particles in a hydrolyzate solution of an alkyl silicate, drying the resultant gel, heating the dried gel and vitrifying the formed glass (precursor) body. CONSTITUTION:An acidic catalyst is added to hydrolyze an alkyl silicate (e.g., ethyl silicate) and silica fine powder is then added to the resultant hydrolyzate solution obtained by the hydrolysis, sufficiently stirred and dispersed to form a sol. Aqueous ammonia is added to adjust the sol to pH3-6 and the resultant gel is dried to provide a dry gel, which is then heated in an atmosphere of O2/N2 and heated under reduced pressure of <=1Torr or in an He atmosphere at 1300-1500 deg.C to close pores and afford a glass (precursor) body. The obtained glass (precursor) body is subsequently heated at 1500-2200 deg.C and kept for a constant time. |
