Formulation And Printability Of A Rare Earth Flourescence Anti-Falsification Ink

The fluorescent ink printed on the stocks is invisible in the visible light. Pictures and texts printed with the ink can prevent being forged through scanning and duplicating. So the anti-counterfeit fluorescent ink is paid more attention by people, a new type of ink was proposed in this paper which consisted of rare earth complexes and ultraviolet (UV) curing resins. The conclusions can be used to the anti-counterfeit printing of negotiable securities, commodity packaging, valid certificate and so on, and it is of profound social and economic significance, and also has definite pushing effect to the innovation and development of anti-counterfeit printing.According to the thermodynamic balance theory, the rare earth complexes fluorescent agent was synthesized in-situ in UV-curing resin (Bisphenol A oxygen acrylic acid resin), in which complexation reaction happened between grinds and rare earth ions in EA, and complexes granule are composed. And according to the fluorescence synergistic effect mechanism, cheap inert doped lanthanide ions were added to the rare earth complexes, which was useful to reduce the cost of the ink.The results indicated : 1) The fluorescent agent well overcome the limitation such as flocculating, depositing and poorly dispersing, when the rare earth complexes is grinded and dispersed in UV-curing resin. 2) When certain lanthanide ions (La³⁺, Gd³⁺, Y³⁺ ) are appended in this solution, and then it enhanced the fluorescence intensity of the complexes of Tb-Ssal-TOPO synthesized. The ink has higher color purity and stronger fluorescence intensity for it's linear fluorescence spectrum emission, and that surmounted the disadvantage of organic fluorescent agent, such as low fluorescence intensity, poisonous and poor dispersing, and the same time, the ink has the advantage of UV-curing ink, such as, speedy drying, environment protecting, and improving production efficiency.