| 摘要 |
PURPOSE:To obtain a quartz glass excellent in ultraviolet ray absorptivity, small in the damage by ultraviolet ray and solarization and high in visible ray transmissivity by incorporating a specific quantity of transition metal ele ment and aluminum in the quartz glass and controlling the concn. of OH group to a specific range. CONSTITUTION:A soot body is formed by flame hydrolysis of a silicon compound. The soot body, into which the transition metal element and an aluminum compound is doped in the state of aq. solution, is dried at 100-200 deg.C and, if necessary, after heated at about 1000 deg.C to adjust the water content, transparently vitrified by electric heating fusion method. The vitrified product is, after cooled, heated at 900-1300 deg.C for 10-100hr to execute virtual temp. setting treatment. The obtained quartz glass contains 100-10000wt.ppm transition metal element and 100-10000wt.ppm aluminum, is 30-2000wt.ppm in OH group concn. and has <=1% ultraviolet transmissivity in 200nm wavelength, >=85% visible ray transmissivity in 600nm wavelength and 900-1300 deg.C virtual temp. |
