Rare-earth borate and its precursor, preparation processes and use of borate as luminophore
US6238593A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 2, 1998 |
| Grant date | May 29, 2001 |
| Priority date | — |
| Expiry date | Dec 2, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K11/7797
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The present invention relates to a rare-earth borate, to a precursor thereof, to processes for their preparation and to the use of this borate as a luminophore. The rare-earth borate and the precursor thereof are characterized in that they are in the form of cubic, parallelepipedal or spherical particles and in that they have a dispersion index of not more than 0.8. According to one embodiment of the invention, the borate is a red luminophore. The process for the preparation of the precursor is characterized in that a rare-earth carbonate or hydroxycarbonate is reacted with boric acid, the reaction medium being in the form of an aqueous solution. The borate is obtained by calcination of the precursor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.