COLORED MAGNETIC POWDER CONTAINING FLUORESCENT DYE

PROBLEM TO BE SOLVED: To obtain a colored toner powder which does not cause the quenching of fluorescence. SOLUTION: The colored magnetic powder contains a thermoplastic resin, a fluorescent dye, a magnetic material and a metallic compound giving a diamagnetic ion and it is particularly a toner powder. The metal is, e.g. Ca, Ag, Na, K, Ba, Al, Zr, Zn or Mg. The metallic compound is preferably a metallic salt and is contained in the colored powder in the range of 2-15 wt.%. The metallic compound is soluble or finely dispersible in the thermoplastic resin (or a thermoplastic resin mixture). The metallic salt is preferably the salt of Zn or Mg and an aliphatic carboxylic acid, preferably an aliphatic branched carboxylic acid, articularly having an at least 6C hydrocarbon group. Since the metallic compound is contained, the quenching of the fluorescence of the fluorescent dye is suppressed.