Toner

摘要

A magnetic toner contains magnetic toner particles and silica fine particles. The magnetic toner has a thermal conductivity in the range of 0.230 to 0.270 W/(m·K). Primary particles of the silica fine particles have a number-average particle diameter (D1) in the range of 5 to 20 nm. The coverage X1 of the magnetic toner surface by the silica fine particles ranges from 40% to 75% by area as determined using an X-ray photoelectron spectrometer (ESCA). The diffusion index (X1/X2) satisfies the following formula:
Diffusion index≧−0.0042×X1+0.62wherein X2 denotes the theoretical coverage of the magnetic toner surface by the silica fine particles.

主权项

1. A magnetic toner comprising:
magnetic toner particles, each of which contains
a binder resin,a magnetic material anda release agent; and silica fine particles, wherein the magnetic toner has a thermal conductivity in the range of 0.230 to 0.270 W/(m·K), primary particles of the silica fine particles have a number-average particle diameter (D1) in the range of 5 to 20 nm, the coverage X1 of the magnetic toner surface by the silica fine particles ranges from 40% to 75% by area, as determined using an X-ray photoelectron spectrometer (ESCA), and the diffusion index represented by the following formula 1 satisfies the following formula 2:
Diffusion index=X1/X2  (1)Diffusion index≧−0.0042×X1+0.62  (2) wherein X2 denotes the theoretical coverage of the magnetic toner surface by the silica fine particles.