Glass useful as either photosensitive glass or opaline foam glass
US4703019A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 9, 1986 |
| Grant date | Oct 27, 1987 |
| Priority date | — |
| Expiry date | May 9, 2006 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03C11/00
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The invention relates to a photosensitive and heat-sensitive glass which is composed of 25-70 mol % of Al.sub.2 O.sub.3 and/or Ga.sub.2 O.sub.3, 30-75 mol % of at least one of CaO, BaO, SrO and MgO and 0-40 mol % of an auxiliary component which is at least one of SiO.sub.2, GeO.sub.2, B.sub.2 O.sub.3 and P.sub.2 O.sub.5. The glass is produced by melting a batch mixture of powdery raw materials. By exposure to UV rays the glass colors in yellowish brown, and the color does not fade by termination of the exposure. Bleaching of the colored glass is accomplished by heating for a short time at about 150.degree.-300.degree. C. Coloration and bleaching can be repeated without deterioration. The same glass turns into an opaline foam glass, which presents a very attractive appearance, by heat treatment at a temperature above the softening temperature. This change is irreversible. The foams created in the glass matrix are usually tens of microns in diameter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.