Process for preparing water resistant luminous pigments
US6264855A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 10, 1999 |
| Grant date | Jul 24, 2001 |
| Priority date | — |
| Expiry date | Dec 10, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2993
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A process for preparing a water resistant luminous pigment with durability, characterized in that a luminous pigment, in which an oxide matrix comprising at least one element selected from the group consisting of Mg, Ca, Sr, Ba and Zn and at least one element selected from the group consisting of B, Al, P and Ga is doped with at least one rare-earth metal element, is allowed to an acid treatment under the condition of pH of not more than 3 using at least one acidic compound selected from the group consisting of acids and acid generating compounds, and is subsequently allowed to an alkaline treatment under the condition of pH 4-9 using at least one alkaline compound selected from the group consisting of alkalis and alkali generating compounds.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.