ELECTROSTATIC CHARGE IMAGE DEVELOPING TONER

摘要

PROBLEM TO BE SOLVED: To obtain a toner having a high electrification charges and electrification rate by controlling the proportion of a electrification controlling agent in the toner surface layer to a specified value. SOLUTION: The proportion (wt.%) of the electrification controlling agent in the toner surface layer is >=4.0 times as the proportion (wt.%) of the electrification controlling agent in the whole toner. The surface layer of the toner preferably can be analyzed by XPS (X-ray photoelectron spectroscopy). The weight ratio (wt.%) of the electrification controlling agent in the toner surface layer calculated from the amt. (atm.%) of each element except for hydrogen which constitutes the toner surface layer measured by XPS is preferably >=4.0 times as the weight ratio (wt.%) of the electrification controlling agent in the whole toner. The proportion of the electrification controlling agent present in the toner surface layer is preferably >=22 wt.% (to the weight of the toner surface layer).