Toner, method for forming image, and image forming apparatus

摘要

A toner includes toner base particles containing at least a binder resin, a coloring agent, and a release agent; and alumina fine particles whose phase angle (θ) is |80°| or less at an alternating current frequency of 1 to 10 kHz in an alternating current impedance method.

主权项

1. A toner comprising: toner base particles containing at least a binder resin, a coloring agent, and a release agent, wherein the toner base particles have a volume-average particle size (D50) of 2.0 to 12.0 μm and are obtained by phase inversion emulsification; and alumina fine particles whose phase angle (θ) is |80°| or less at an alternating current frequency of 1 to 10 kHz in an alternating current impedance method, wherein, an amount of the alumina fine particles added to 100 parts of tone base particles is 0.5 to 2.0 parts by mass, and wherein the alumina fine particles are obtained by vaporizing or by pyrolyzing ammonium dawsonite, wherein the binder resin is composed of a polyester resin, wherein the polyester resin has: a weight-average molecular weight of 30,000 or more; a ratio of weight-average molecular weight to number-average molecular weight is 12 or more; an area ratio of a component having a molecular weight of 600,000 to a total is 0.3% or more; and an area ratio of a component having a molecular weight of 10,000 or less to the total is 20 to 80%.