Method of coating yttrium vanadate phosphors with Al.sub.2 O.sub.3
US4979893A · kind A · utility
7Cited by
13References
4Claims
0Family size
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Key dates
| Filing date | Feb 21, 1989 |
| Grant date | Dec 25, 1990 |
| Priority date | — |
| Expiry date | Feb 21, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J61/72
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The lumen maintenance of fluorescent lamps containing yttrium vanadate phosphors is markedly improved by the presence of a protective oxide layer for the phosphor. The protective oxide layer is produced by evaporating aluminum isopropoxide, in a vacuum, over phorphor particles forming a continuous aluminum isopropoxide over the phosphor particles. The isopropoxide coating is subsequently oxidized by lehring the phosphor at a temperature from about 500.degree. C. to 625.degree. C. forming an alumina coating on the phosphor particles.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.