To provide a toner for electrostatic image development having excellent charge stability independently of colorant concentration by properly regulating value for electric conductivity obtained in consideration of not only the surfaces of toner particles but the interiors.
The toner for electrostatic image development contains at least a binder resin and a colorant, wherein the colorant has been refined with a refining apparatus 1, e.g., using a hydrophilic fluid and a supercritical fluid. An electric conductivity St (μS/cm) of a toner extract and a concentration C (wt.%) of the colorant contained in the toner satisfy expression: St<-2C+80 (where 5≤C≤15), wherein the toner extract is obtained by mixing an organic solvent capable of dissolving or swelling the binder resin with the toner, mixing the toner mixed organic solvent with ion-exchanged water, and removing the organic solvent from the resulting mixed solution.
SHIBAI YASUHIRO
TSUBAKI YORIHISA
Takeshi Sugiyama
Minetarou Hirose