Electric incandescent and discharge lamps having doped quartz glass envelopes
US5680010A · kind A · utility
6Cited by
8References
24Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 5, 1996 |
| Grant date | Oct 21, 1997 |
| Priority date | — |
| Expiry date | Feb 5, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03C2203/10
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Soft quartz glass having low viscosity and a low thermal coefficient of expansion, high electrical insulation capability and free from release of contaminants, when used as a bulb of an incandescent lamp or as an envelope in an arc vessel of a discharge lamp, is a quartz glass made of ultra-pure quartz (SiO.sub.2), for example having a purity of 99.99 mol-%, doped with stoichiometric compounds of alkaline earth oxides with boron oxide, optionally also with a small quantity of Al.sub.2 O.sub.3 in an overall quantity of the doping substance of between about 0.05% to 0.8%, by weight.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.