| 摘要 |
<p>PROBLEM TO BE SOLVED: To ensure a proper quantity of electric charges by rapid build-up of electrostatic charge, to suppress excess toner fogging to a photoreceptor and to prevent the stain of a white ground part of printed matter by incorporating a specified negative charge type electrostatic charge controlling agent and an ethylene-propylene copolymer having a specified melting point as toner components. SOLUTION: The nonmagnetic one-component toner contains at least a polyester resin, a colorant, a metal-containing azo compound as an electrostatic charge controlling agent and an ethylene-propylene copolymer having 125-140 deg.C melting point. The average particle diameter of toner particles is 4-20μm, preferably 5-12μm. The molecular weight of the ethylene-propylene copolymer is 2,000-30,000, preferably 5,000-25,000, further preferably 7,000-25,000. A preferred amount of the copolymer is 0.05-10 pts.wt., in particular 0.1-6 pts.wt. based on 100 pts.wt. bonding resin.</p> |
