| 摘要 |
<p>Europium compounds represented by the general formula (1) and water-base ink compositions containing the same: <CHEM> Äwherein X is an optionally substituted aromatic or heterocyclic group: Y is a fluorohydrocarbon group having 1 to 10 carbon atoms: Z1 to Z3 are each independently a hydrophilicity-imparting group: R1 to R3 are each a direct bond or a divalent hydrocarbon or heterocyclic group which may be substituted: n1 to n3 are each independently an integer of 0 to 2: and m1 to m3 are each independently an integer of 1 to 3, with the proviso that all of n1 to n3 must not be 0Ü. The compounds and the ink compositions are excellent in stability and safety, and emit red light by irradiation with ultraviolet light though they are substantially invisible in the visible light region. Thus, they are useful for prints which are to be read by a system having a sensor reading function with the need for hidden letters or security markings.</p> |
