Patent ID: 8785095

Claim:
A toner for developing an electrostatic charge image, the toner comprising: a toner particle comprising a binder resin, a colorant, and a releasing agent; and an external additive disposed on the surface of the toner particle, the external additive comprising: sol-gel silica particles having an average sphericity value in a range of from about 0.8 to about 0.97, a Braunauer-Emmett-Teller (BET) specific surface area of about 30 m 2 /g to about 70 m 2 /g, and an average primary particle diameter in a range of from about 10 nm to less than 80 nm, wherein the sphericity value is a ratio between a shortest diameter and a longest diameter of each of the sol-gel particles and a ratio of the number of sol-gel silica particles having a sphericity value of less than about 0.97 to the total number of the sol-gel silica particles is at least about 50%; hydrophobically surface-treated fumed silica particles having average primary particle diameters in a range of from about 7 nm to about 50 nm; and hydrophobically surface-treated titanium dioxide particles having average primary particle diameters in a range of from about 10 nm to about 50 nm, wherein a (D84v/D16v) 1/2 value of the sol-gel silica particles is in a range of from about 1.7 to about 2.3, in which D16v is a particle diameter at which a cumulative percentage of 16% is attained, and D84v is a particle diameter at which a cumulative percentage of 84% is attained, in a cumulative volume distribution of the sol-gel silica particles as measured by the Coulter method.