Photoluminescent security ink for continous ink-jet printing

Abstract

The present invention provides a photoluminescent security ink for continuous ink-jet printing, wherein said ink has a viscosity of about 1.5 mPas to about 6 mPas at 25°C, and comprises: a) from about 4 wt-% to about 6 wt-% of uncapped NaXi-yzF4YbyZz nanoparticles; b) from about 1.5 wt-% to about 10 wt-% of a dispersing agent; c) from about 80 wt-% to about 90 wt-% of an organic solvent; and d) from about 0.1 wt-% to about 1 wt-% of a conductive salt, as well as a process for producing said ink, and a process for manufacturing a photoluminescent security feature on an article, or a value document, with said ink.