PHOTOSTIMULATED LUMINESCENT COMPOUND Russian patent published in 2023 - IPC C09K11/55 C09K11/78 C09K11/80 B42D25/36 

FIELD: chemical industry.

SUBSTANCE: invention can be used for visual authentication as part of the marking of a valuable document, which is a banknote, a security form, a label, an excise and postage stamp, a payment and identification document, as well as a passport and a travel document. The luminescent compound has the effect of photostimulated luminescence, which consists in the appearance, after removal of the exciting radiation in the wavelength range of 250-450 nm, of a visually observed glow in the spatial region of the action of the stimulating radiation with a wavelength of 700-1600 nm, the decay time of which after the cessation of the stimulating radiation is 0.1-10 s. The luminescent compound is a powder with an average particle size of 0.1-50 mcm and has a chemical composition corresponding to the empirical formula (Sr_1-x-y-z-wEu_xDy_yLn_zMe_w)₄Al₁₄O₂₅ or (Sr_1-x-y-z-wEu_xDy_yLn_zMe_w)Al₂O₄ where Ln is an element from the series Tm, Lu; Me is an element from the series Mg, Ca, Er, Nd, Ce, La, Gd, Zr, Nb, Ta; 0.001≤X≤0.05; 0.001≤Y≤0.005; 0.0001≤Z≤0.03; 0.0001≤W≤0.6.

EFFECT: increased security of a valuable document.

6 cl, 2 dwg, 9 tbl, 8 ex