High-purity quartz powder, process for producing the same, and glass molding
AssigneeMitsubishi Chemical Corporation
InventorsYoshio Katsuro, Keiji Yamahara, Takashi Yamaguchi, Yutaka Mori
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Abstract
Subjects for the invention are to obtain a quartz powder having a high purity and high quality and a process for producing the same and to obtain a glass molding formed by melting and molding the powder and extremely reduced in bubble inclusion. The invention provides a quartz powder, preferably a synthetic quartz powder obtained by the sol-gel method, which, upon heating from room temperature to 1,700° C., generates gases in which the amount of CO is 300 nl/g or smaller and the amount of CO2 is 30 nl/g or smaller.
Claims19
A process for producing a synthetic quartz powder which comprises hydrolyzing an alkoxysilane to obtain a silica gel having an average particle diameter of from 10 to 500 μm and bringing said silica gel into contact with at least one of helium and hydrogen gas at a temperature of from 400° C. to 1,300° C., wherein before or after said bringing said silica gel into contact with at least one of helium and hydrogen gas, said silica gel is heat-treated at a temperature of 1,000° C. or higher for from 10 to 50 hours in an oxygen-containing atmosphere, and
- wherein said synthetic quartz powder, upon heating from room temperature to 1,700° C., generates gases in which the amount of CO is 300 nl/g or smaller and the amount of CO2 is 30 nl/g or smaller.
A process for producing a synthetic quartz powder which comprises hydrolyzing an alkoxysilane to obtain a silica gel having an average particle diameter of from 10 to 500 μm and bringing said silica gel into contact with at least one of helium and hydrogen gas at a temperature of from 400° C. to 1,300° C. wherein before or after said bringing said silica gel into contact with at least one of helium and hydrogen gas, said silica gel is heat-treated at a temperature of 1,000° C. or higher for from 10 to 50 hours in an oxygen-containing atmosphere, wherein said silica gel is brought into contact with pure helium.
Dependencies are inferred from the claim text.