ALKALI-EARTH METAL SILICATE BASED LUMINOPHORES AND METHOD OF IMPROVING LONG-TERM STABILITY THEREOF Russian patent published in 2014 - IPC C09K11/02 

FIELD: chemistry.

SUBSTANCE: disclosed is a luminophore with improved long-term stability, which absorbs radiation in a first wavelength range and emits radiation in a second wavelength range different from the first range, formed in form of grains and contains as a matrix an activator-doped alkali-earth metal silicate of general chemical formula EA_xSi_yO_z, where EA is formed by one or more alkali-earth metals and the condition x, y, z>0 applies, characterised by that the surface of the grains is chemically modified such that at least parts of the surface are formed by a chemical compound of general formula EA_uZ₂. Z is formed by anions which are capable of chemically bonding with cations of EA and have one or more of the following chemical formulae: SO₄ ^2-, PO₄ ^3-, CO₃ ^2-, C₂O₄ ^2-, SiO₃ ^2-, SiH₆ ^2-, where u denotes the ion charge of anions of Z. Also disclosed is a method of improving long-term stability of alkali-earth metal silicate based luminophores.

EFFECT: chemical compound formed on the surface of luminophore grains due to chemical modification through low solubility protects the luminophore from moisture, enabling long-term stability thereof.

8 cl, 3 dwg