| abstract |
The present invention relates to an ink composition containing: a trivalent rare earth ion-containing rare earth complex selected from the group consisting of Eu3 +, Tb3 +, Sm3 +, Yb3 +, Nd3 +, Er3 +, Pr3 +, Ho3 +, Tm3 +, Dy3 +, Ce3 + and Gd3 +, and at least one organic ligand selected from a β-diketone ligand, a carboxylic acid ligand, a phosphine oxide ligand and an aromatic heterocyclic ligand containing nitrogen; and a long-lasting luminescent material having a remanence time greater than or equal to 1 second after stopping exposure to excitation light. |