Method of preparing small particle size phosphors
US6132642A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 1, 1994 |
| Grant date | Oct 17, 2000 |
| Priority date | — |
| Expiry date | Jul 1, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N33/544
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A process for preparing phosphor particles having a particle size of 1 micron or less and that are spherical in shape. Such phosphors are useful, for example, as upconverter phosphors in labels for immunoassays. The process comprises preparing a dilute solution of soluble salts of the rare earth metals in amounts required to make the desired phosphor, adding a chemical agent that releases hydroxyl ions, precipitating small spherical particles of a rare earth hydroxycarbonate compound, heating the particles in oxygen at a limited temperature to form the corresponding trioxide particles, and heating the trioxide particles in a sulfur-containing flux in the absence of oxygen at a temperature no higher than about 900.degree. C. to convert the trioxide particles to the corresponding oxysulfide phosphor particles.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.