Patent ID: 8518620

Claim:
A magnetic toner comprising magnetic toner base particles each containing at least a binder resin and magnetic iron oxide, wherein: (i) the binder resin contains a polyester unit; (ii) the toner has a weight average particle size (D4) of 5.0 to 9.0 μm; (iii) the toner has a true specific gravity of 1.34 to 1.56 g/cm 3 ; (iv) the toner has a saturated magnetization of 20 to 35 Am 2 /kg in a magnetic field of 796 kA/m; (v) the toner contains 60 number % or more of toner having a circularity of 0.93 or more; and (vi) a dielectric loss tangent (tan δ) of the toner at 100 kHz satisfies the following formula (I): (tan δ H −tan δ L )/tan δ L <0.20 (1) wherein tan δ H represents a dielectric loss tangent of the toner at a glass transition temperature (° C.)+10° C. and tan δ L represents a dielectric loss tangent of the toner at the glass transition temperature (° C.)−10° C.