Pre-water-based suspension alumina coated phosphor treatment process
US5151215A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 9, 1991 |
| Grant date | Sep 29, 1992 |
| Priority date | — |
| Expiry date | Dec 9, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K11/595
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A method for eliminating carbonaceous contaminants and preventing the hydration/solubilization of the alumina protective coating of a phosphor is described. The method involves the heating a fluidized alumina coated phosphor in a fluidized bed at a temperature and for a period of time sufficient to preclude adversely affecting the protective oxide coating on the phosphor during subsequent water-based suspension processing without detrimentally altering the phosphor. After heating the fluidized phosphor is cooled and then added to a water-based suspension. The conditions for treating a manganese activated zinc silicate phosphor having a protective alumina coating are heating the fluidized phosphor at a temperature between about 700.degree. C. and about 850.degree. C. for a period of time from about 15 minutes to about 20 hours. A fluorescent lamp containing the phosphor prepared by the above described method is also described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.