PRODUCTION OF SINGLE BODY OF SILICA GLASS BY USING SOL-GEL METHOD

PROBLEM TO BE SOLVED: To solve the problem that the efficient production is not possible as the gelatinization process of sol is repeated and that cracks are liable to be formed at drying time even if the sol dispersion process is executed by dividing the process to primary and secondary processes with the conventional process for production. SOLUTION: The primary sol is formed by mixing 100wt.% silica-contg. powder of a high concn. and 100 to 300wt.% water. The pH of the primary sol is adjusted to a range of 9 to 11 and the primary sol is dried. The dried primary sol is heat treated at >=600 deg.C and the secondary sol is formed by mixing the heat treated primary sol with 100 to 200wt.% deionized water. The secondary sol is gelatinized in a metal mold. The secondary sol is subjected to drying, heat treating and sintering, by which the single body of the silica glass is obtd.