POSITIVE CHARGE TYPE TONER

摘要

PROBLEM TO BE SOLVED: To obtain a positive charge type toner that stably ensures good image characteristics over a long period of time by using a bonding resin containing a styrene copolymer and having a specified acid value and a charge controlling agent containing a specified imidazole derivative. SOLUTION: The toner contains at least a bonding resin, a colorant and a charge controlling agent. The bonding resin contains a styrene copolymer and has 0.5-50 mgKOH/g acid value. The charge controlling agent contains an imidazole derivative of formula I or II. In the formula I, R1, R3 and R4 are each H, alkyl, aryl or the like or halogen and R2 is H, alkyl or the like. In the formula II, R5 is H, alkyl which may have a substituent or the like or halogen, R6 is H, alkyl, aryl or the like, R7 is H, alkyl, aryl or the like or halogen and Ar is an aromatic residue and may be condensed with another imidazole unit.