| 摘要 |
PURPOSE:To obtain quartz glass having a small OH group content, high purity and high viscosity at a high temp. by gelatinating a sol liq. obtd. by hydrolyzing alkoxysilane, thereafter by drying and by sintering to make transparent glass. CONSTITUTION:The gel soln. obtd. by hydrolyzing alkoxysilane contg. 20-100mol% tetramethoxysilane in the presence of acidic or basic catalyst, as occasion demands, is added with <=5wt.% NH4Cl to the amt. of silica and thereafter gelatinated by heating at 30-60 deg.C. Then, the gel is dried by heating at 50-200 deg.C and thereafter sintered at 1,000-1,600 deg.C at 10-100 deg.C/hr the rate of heating for 2-100hr to obtain sintered compact contg. 20-100% crystalline silica content. Then, the sintered compact is heated above the stabilization temp. of crystalline silica to make transparent glass and the quartz glass having 0-200ppm OH group content and >=10<10> poise viscosity at 1,400 deg.C. |
