NONMAGNETIC ONE-COMPONENT TONER

PROBLEM TO BE SOLVED: To ensure a low minimum fixing temperature, a wide offsetting temperature range, good fixing characteristics, superior electrostatic chargeability and good image characteristics by incorporating a specified boron-containing compound as a negative charge type charge controlling agent and an ethylene- propylene copolymer having a specified melting point. SOLUTION: The nonmagnetic one-component toner contains at least a polyester resin, a colorant, a charge controlling agent of the formula and an ethylene- propylene copolymer having 125-140 deg.C melting point. In the formula, R1-R4 are each H or an optionally substituted hydrocarbon and may be the same or different, X+ is a cation, preferably R1-R4 are each phenyl and X+ is K+. The molecular weight of the ethylene-propylene copolymer is preferably 2,000-30,000, the amount of the copolymer is preferably 0.05-10 pts.wt. based on 100 pts.wt. polyester resin and the amount of the charge controlling agent is preferably 0.1-5 pts.wt. based on 100 pts.wt. polyester resin.