To reduce the size and cost of a device for which a toner is used, to simplify the device and to ensure high image quality, that is, a high density and low fog by specifying the relation between the specific surface area of a toner compsn. before dry mixing and that after the mixing.
This toner is produced by dry-mixing a toner compsn. with a high-speed agitating mixer so as to simultaneously satisfy the formulae Sp≥0.5×Sb, Tm≤0.5×Tw and V×N≥2,000, wherein Sp is the specific surface area (m2/g) of the toner compsn. after the dry mixing, Sp is the specific surface area (m2/g) of the toner compsn. before the mixing, Tm is the internal temp. (°C) of the mixer during the mixing, Tw is the softening point (°C) of wax, V is the peripheral speed (m/sec) of each blade of the mixer and N is mixing time (sec). This toner ensures superior fixability, developing performance and transfer efficiency and prevents untransfer and filming on a photoreceptor and an intermediate transfer medium.
YUASA YASUHITO
TATEMATSU HIDEKI
MAEDA MASATOSHI
