Process for production of pure transparent quartz
US5665133A · kind A · utility
21Cited by
4References
5Claims
0Family size
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Key dates
| Filing date | Oct 10, 1995 |
| Grant date | Sep 9, 1997 |
| Priority date | — |
| Expiry date | Oct 10, 2015 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03C2203/10
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Pure transparent quartz glass is provided by molding powdery amorphous silica into an article, converting the molded powdery amorphous silica into crystalline silica of high-temperature type cristobalite structure, and then fusing the crystalline silica, the quartz glass containing impurities respectively at a content of not higher than 1 ppm, and an OH group at a content of not higher than 20 ppm, and having a viscosity of 10.sup.12.0 poise or more at 1200.degree. C. The quartz glass is transparent and has high purity, and is excellent in high temperature viscosity characteristics. The quartz glass can be produced at a low cost.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.