| 摘要 |
A developer material includes base particles that contain at least a binder resin and a colorant, and an external additive that covers the surface of the base particles. The developer material has a mean volume particle diameter in the range of 3.9-6.1 μm, and includes pulverized base particles of an external additive. The external additive has a mean particle diameter in the range of 30-110 nm, the external additive being in an amount in the range of 1.0-3.0 weight parts based on 100 weight parts of the base particles. The external additive covers a surface of the base particles, a surface area of the base particles being covered with said external additive, the surface area being in the range of 30.6-58.6% of a total surface area of the base particles.
|
