Sol-gel method for making ultra-low expansion glass
US4786618A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 29, 1987 |
| Grant date | Nov 22, 1988 |
| Priority date | — |
| Expiry date | May 29, 2007 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03C2203/24
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Ultra-low thermal expansion TiO.sub.2 --SiO.sub.2 glasses are prepared using a sol-gel process wherein a stable alkali silicate solution comprising colloidal TiO.sub.2 and having a pH above 9 is gelled to form a semisolid silicate gel, the gel comprising homogeneously dispersed colloidal TiO.sub.2 but being essentially free of agglomerated TiO.sub.2 particles, washing the gel with aqueous media to remove alkali therefrom, and finally drying and consolidating the gel to a clear, void-free TiO.sub.2 --SiO.sub.2 glass which is substantially free of compositional inhomogeneities and has a thermal expansion coefficient below that of pure fused silica.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.