METHOD OF PRODUCING INORGANIC LUMINESCENT COMPOUND WITH GIVEN FRACTIONAL COMPOSITION Russian patent published in 2021 - IPC C09K11/77 C09K11/84 B42D25/36 B42D25/21 

FIELD: optics.

SUBSTANCE: invention can be used in production of materials having specified optical and physical properties and intended for authenticity control of valuable documents. To produce material based on inorganic luminescent compound of rare-earth metals, charge is prepared, solid-phase synthesis, washing and milling of finished product. Solid-phase synthesis is carried out in two steps. At the first stage, a complex is synthesized, containing a group II element of the periodic table, selected from Mg, Ca, Zn, Sr, element III of the group of the periodic table from the range of lanthanides Er, Yb, Tm, Ho; element IV of the group of the periodic table, selected from Ti, Si, Zr, Ge. At the second step, the end product is synthesized. Ground product is fractionated using track membranes by tangential filtration. Size of not less than 90 % of the particles of the obtained material is a given value selected within interval 0.1–50 mcm.

EFFECT: invention enables to obtain an efficient inorganic luminescent substance with a given fractional composition for incorporation into paper, plastic, composite materials, printing inks and ink-jet compositions.

3 cl, 1 ex