| 摘要 |
PURPOSE:To obtain a developer having excellent flowability and electrostatic chargeability by specifying the grain size and shape coefft. of a toner and the relation between shape coeffts. of the toner and carriers, thereby forming the two-component developer consisting of the toner and carrier. CONSTITUTION:The toner of the two-component developer consisting of the toner and the carrier is spheroidized by reducing the grain size of the toner to a small grain size of <=14mum in order to obtain a high-grade image. Further, the shape coefft. SF expressed by the equation II [the max. length is the average value of the max. length of a projection image, the area is the average value of the projection area of the particle] is specified to <=150 to improve the flowability. On the other hand, the shape coeffts. St, SFt of the toner and the shape coefft. Sc of the carrier expressed by the equation I [the outside circumference is the outside circumference of the projection image of the particle and the area is a projection area] satisfy the equation III, by which the rise of the toner is expedited and the sufficient electrostatic quantity is obtd.; in addition, the toner splashing is decreased. The developer having the excellent flowability and electrostatic chargeability is thus obtd. by using the small-sized spherical toner. |
