Compositions: ceramic – Ceramic compositions – Glass compositions – compositions containing glass other than...
Patent
1998-12-03
2000-10-17
Group, Karl
Compositions: ceramic
Ceramic compositions
Glass compositions, compositions containing glass other than...
C03C 306
Patent
active
061331783
ABSTRACT:
A high-purity transparent silica glass containing Fe, Na and K impurities each in an amount of 0.01-0.3 ppm, and an OH group in an amount of 0-3 ppm; among the Fe impurities, the content of metallic Fe having a valency of +0 being not larger than 0.1 ppm. This transparent silica glass exhibits, even when it is maintained at 900-1,400.degree. C. for at least 20 hours, an extinction coefficient of not larger than 0.009 at a wavelength of 400 nm, and does not become colored as visually examined. The silica glass is made by a process wherein powdery silica filled in a mold cavity is melted at 1,700.degree. C. or higher, characterized in that the melting is conducted in a graphite mold having a porous high-purity graphite layer provided on the mold inner surface so that the filled silica is not contacted with the mold; said porous layer having a bulk density of 0.1-1.5 g/cm.sup.3, and the content of each of Fe, Na and K impurities in the porous layer being not larger than 1 ppm.
REFERENCES:
patent: 4113844 (1978-09-01), Tokimoto, et al.
patent: 5349456 (1994-09-01), Iwanaga et al.
patent: 5665133 (1997-09-01), Orii et al.
patent: 5729090 (1998-03-01), Scott et al.
patent: 5977000 (1999-11-01), Sato et al.
Akiyama Tomoyuki
Hashimoto Shinkichi
Kikuchi Yoshikazu
Segawa Hideaki
Tsukuma Koji
Group Karl
Nippon Silica Glass Co., Ltd.
Tosoh Corporation
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