| 摘要 |
Provided are a toner base particle having a core-shell structure, which comprise: a core particle containing at least a binder resin and a colorant; and as a shell, a resin fine particle containing at least a release agent and attaching to the surface of the core particle, wherein when out of TEM images of a cross-section of said toner base particle, a cross-sectional image where a long diameter of the cross-section is 80% or more of a volume median diameter (Dv) of said toner base particle is image-processed and an approximate ellipse having an area corresponding to 84.6% of a cross-sectional area of said toner base particle is delineated inside of said cross-section, a mass of the release agent contained outside of an approximate oval sphere obtained by rotating said approximate ellipse around the major axis thereof is from 50 to 100% of a mass of all release agents in said toner base particle, and a shape factor of said toner base particle is 150 or more, and an electrostatic image developing toner obtained by externally adding an external additive to the toner base particle. |
