Method of making composite borosilicate glass articles
US4244721A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jan 31, 1979 |
| Grant date | Jan 13, 1981 |
| Priority date | — |
| Expiry date | Jan 31, 1999 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03C23/008
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A method for producing a glass article which comprises melting and forming a preshaped glass article having a composition in the phase separable regions of the alkali-boro-silicate or alkali-boro-germania-silicate systems, inducing the article to phase separate, leaching out a silica-poor phase from the surface layers only to form a structure having porous surface layers surrounding a solid region of substantially the original glass composition, washing this structure with an organic media which dissolves oxides of boron and other leaching reaction products, drying and heating to collapse the outer porous structure to form a glass having a silica-rich surface layer surrounding a solid region having substantially the original glass composition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.