Aqueous colloidal dispersion based on at least a lanthanide compound and a complexing agent a process for its preparation and use thereof
US7495033B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 21, 2000 |
| Grant date | Feb 24, 2009 |
| Priority date | — |
| Expiry date | Nov 21, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2004/64
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
An aqueous colloidal dispersion of at least one lanthanide compound and a complexing agent with a pK (cologarithm of the dissociation constant of the complex formed by the complexing agent and the lanthanide cation) or more than 2.5. The dispersion can also include a compound of at least one other element selected from groups IVa, Va, VIIa, VIIa, VIII, Ib and IIb of the periodic table. A process for preparing the dispersion starts by forming an aqueous mixture comprising at least one lanthanide salt, optionally a salt of one of the elements mentioned, and the complexing agent. A base is added to the mixture, which is heated to obtain the dispersion. Methods that use the dispersion are also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.