The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 28, 2006
Filed:
Dec. 28, 2000
Kunio Sugiyama, Tokyo, JP;
Shuichi Tada, Tokyo, JP;
Jinichi Omi, Tokyo, JP;
Tadahiro Nakada, Tokyo, JP;
Hiroshi Morita, Tokyo, JP;
Masaki Kusuhara, Tokyo, JP;
Hiroyuki Watanabe, Tokyo, JP;
Hirofumi Uehara, Tokyo, JP;
Keiko Sanpei, Tokyo, JP;
Kunio Sugiyama, Tokyo, JP;
Shuichi Tada, Tokyo, JP;
Jinichi Omi, Tokyo, JP;
Tadahiro Nakada, Tokyo, JP;
Hiroshi Morita, Tokyo, JP;
Masaki Kusuhara, Tokyo, JP;
Hiroyuki Watanabe, Tokyo, JP;
Hirofumi Uehara, Tokyo, JP;
Keiko Sanpei, Tokyo, JP;
M. Watanabe & Co., Ltd., Tokyo, JP;
Asahi Denka Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
A hydrous silica gel is dehydrated by freezing, thawing, and removing water separated by thawing, thereby yielding silica particles. In addition, the silica particles thus formed is washed and fired, thereby producing a synthetic quartz glass power. A water glass is dealkalized, an oxidizing agent and an acid are added, the mixture thus formed is passed through a hydrogen type cation exchange resin, the aqueous silica solution thus formed is then gelled, and the gelled material is then washed and fired, thereby producing a synthetic quartz powder. Silica is sequentially held for a predetermined time at each temperature range of 150 to 400° C., 500 to 700° C., and 1,100 to 1,300° C., thereby producing a quartz glass.