WATER-RESISTANT FLUORESCENT PIGMENT AND FLUORESCENT INK BASED THEREON Russian patent published in 2008 - IPC C09K11/80 

FIELD: chemistry.

SUBSTANCE: water-resistant fluorescent pigment is an oxide matrix based on aluminium oxide and, at least, one of the following elements: Mg, Са, Sr, Ва, Zn, Mn, Si, В, Р, Ga, activated with, at least, single rare earth element, treated with a mixture of salts from the following group: Na₃PO₄, Na₂HPO₄, (NH₄)₂HPO₄, Ca₃(PO₄)₂, with acids from the following group: HCl, H₂SO₄, HNO₃, pH not exceeding 4 at the end of treatment. Oxide matrix may be of formula MO-SiO₂Al₂O₃:R, where М stands for, at least, a single metal from the following group: Ca, Sr, Ba, Mg, Zn; R stands for, at least, a single element from the following group: Dy, Nd, Eu, Tm, Tb, Y, Yb; MAl₂O₄:R, where М stands for, at least, a single metal from the following: Ca, Sr, Mg, Ba, while R stands for, at least, a single element from the following: Dy, Nd, Eu, Tm, Tb, Y, Yb; MAlO₄:R, where М stands for, at least, a single metal from the following: Sr, Ca, Ba; R stands for, at least, a single element from the following group: Dy, Nd, Eu, Tm, Tb, Y, Yb. Ink contains the said fluorescent pigment and thickening agent.

EFFECT: water-resistant at room or elevated temperature, fluorescent properties being retained.

5 cl, 5 tbl, 57 ex