Tosoh Corporation

Nippon Silica Glass Co., Ltd.

Yushiharu Funakoshi

Koji Tsukuma

Hiroya Nagata

Yoshikazu Kikuchi

Emiko Abe

Kouichi Ono

Kenji Kamo

The high-purity, opaque quartz glass containing 3.times.10.sup.6 -9.times.10.sup.6 of closed cells having an average size of 20-40 .mu.m per 1 cm.sup.3, a ratio of closed cells having sizes of 100 .mu.m or more to the whole of cells being 1% or less, thereby showing 5% or less of linear transmittance for near infrared rays (.lambda.=900 nm) at a thickness of 1 mm is produced by compacting amorphous silica powder having an average particle size of 0.5-10 .mu.m, in which each of impurities selected from Li, Na, K, Fe, Ti and Al is 1 ppm or less, if any, and sintering the resultant green body at 1730.degree.-1850.degree. C.

High-purity, opaque quartz glass, method for producing same and use

Growing community of inventors

Yamagata, Japan

Yushiharu Funakoshi