| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing synthetic quartz glass capable of introducing fluorine into a porous glass body at a low temperature of ≤400°C, and adjusting stably the finally obtained fluorine concentration in the synthetic quartz glass to be ≥1,000 ppm mass. <P>SOLUTION: This method for manufacturing synthetic quartz glass includes processes for: (a) forming the porous glass body by depositing and growing on a base material, quartz glass particulate obtained by subjecting a glass forming raw material to flame hydrolysis; (b) obtaining the porous glass body containing fluorine by holding the porous glass body in a fluorine simple substance (F<SB POS="POST">2</SB>)-containing atmosphere having a pressure of P<SB POS="POST">b1</SB>and a temperature of ≤400°C in a reaction tank, and by holding it under the condition of the pressure of P<SB POS="POST">b2</SB>which is lower than the pressure of P<SB POS="POST">b1</SB>and the temperature of ≤400°C in the reaction tank; and (c) obtaining a transparent glass body containing fluorine by heating the porous glass body containing fluorine up to a transparent-vitrification temperature in a vitrifying furnace. <P>COPYRIGHT: (C)2012,JPO&INPIT |
