| abstract |
Disclosed is a blue luminous ink composition comprising a luminous compound represented by the formula: n n n wherein R 1 is a group selected from the group consisting of a hydrogen atom, an alkyl group having from 1 to 4 carbon atoms, an alkoxyl group having from 1 to 4 carbon atoms and a halogen atom, R is a group selected from the group consisting of a fluorine-comprising alkyl group having from 1 to 20 carbon atoms, a substituted or unsubstituted alkyl group having from 1 to 4 carbon atoms, a substituted or unsubstituted aralkyl group having from 7 to 10 carbon atoms and a substituted or unsubstituted aryl group having from 6 to 12 carbon atoms, M is a two-valent or three-valent metal, provided rare-earth metal and alkaline earth metal (IIa group) are eliminated, and n is an integer of 2 or 3. The blue luminous ink composition exhibits satisfactory emission intensity under ultraviolet irradiation. |