Method for preparing silica glass

Abstract From the Canadian patent

This invention relates to a method for preparing a silica glass by the sol-gel method. The silica glass obtained has particular utility as a silicon substrate for a photomask, a preform for an optical fiber a support tube, a, jacket tube, a silicon bar or other optical member. The method involves the steps of (a) preparing a first solution containing fine particle silica by hydrolyzing silicon alkoxide with a basic reagent (b) preparing a second, solution containing fine particle silica by hydrolyzing silicon alkoxide with an acid reagent, (c) mixing said first and second solutions in a predetermined mixing ratio to obtain a sol solution (d) gelling said sol, solution to a wet gel (e) …