摘要 |
PROBLEM TO BE SOLVED: To obtain the subject fluorescent pigment having a coloring capacity and a sufficiently high concealing property, capable of recording characters, numbers, marks, patterns, or the like, even by using it singly and excellent in light fastness by coupling a specific diazo component with a specific coupling component. SOLUTION: This azo-based fluorescent pigment is obtained by coupling a diazo component of formula I or II X, Y are each methyl, methoxy or ethoxy; Z is NHCOA [A is a (substituted) aromatic ring] or NHA} with a coupling component of formula III or IV [L is a halogen or an ester; (n) is 0-4; M is CONHA or NH(CO)2; (m) is 0, 1]. |