TONER AND TWO-COMPONENT DEVELOPER

摘要

Provided are a toner and a two-component developer each of which: shows a small fluctuation in charge quantity and a small fluctuation in image density even under a high-temperature and high-humidity environment; and does not cause any member contamination even after endurance and hence can stably output an image. The toner and the two-component developer each have a feature in that positively chargeable strontium titanate fine particles are added to toner particles having fixed thereto negatively chargeable silica fine particles.

主权项

1. A toner, comprising:
toner particles each containing a binder resin, a wax, and a coloring agent; and silica fine particles A and strontium titanate fine particles B present on surfaces of the toner particles, wherein: the silica fine particles A have a number-average particle diameter (D1) of 60 nm or more and 300 nm or less; when
a coverage rate of the surfaces of the toner particles with the silica fine particles A is defined as a coverage rate X (%) anda coverage rate with the silica fine particles A fixed to the surfaces of the toner particles is defined as a coverage rate Y (%), the coverage rate X is 20% or more and 95% or less, and a ratio [coverage rate Y/coverage rate X] of the coverage rate Y to the coverage rate X is 0.75 or more; the silica fine particles A are negatively chargeable; and the strontium titanate fine particles B are positively chargeable.