BLACK TONER, AND PREPARATION THEREOF

摘要

PROBLEM TO BE SOLVED: To provide a magnetic black toner by means of polymerization method with improved productivity without deteriorating blackness of the toner and its chargeablity. SOLUTION: This toner has at least a binding resin and a coloring agent. At least a magnetic carbon black compounded particle is contained as the coloring agent. The magnetic carbon black compounded particle contains preferably a magnetic substance fine particle of 10-180 nm and a magnetic substance fine particle of 15-100 nm, and relation 1/2<=a/b<=2 is satisfied where (a) is an average particle size of the magnetic substance fine particles in the magnetic carbon black compounded particles, and (b) is an average particle size of the carbon black.