Toner for developing electrostatic images containing aromatic hydroxycarboxylic acid and metal compound of the aromatic hydroxycarboxylic acid

摘要

A toner for developing electrostatic images is formed of toner particles comprising (a) a binder resin, (b) a colorant or magnetic material, (c) an aromatic hydroxycarboxylic acid (A), and (d) a metal compound of the aromatic hydroxycarboxylic acid (A). The aromatic hydroxycarboxylic acid (A) and the metal compound of the aromatic hydroxycarboxylic acid (A) are contained in a weight ratio of 1:99 to 10:90. As a result of co-inclusion of a small amount of the aromatic hydroxycarboxylic acid (A) in addition to the metal compound thereof, the resultant toner is provided with a quick chargeability in a low humidity environment and an improved level of triboelectric charge in a high humidity environment, presumably because of the stabilization effect of the small amount of the aromatic hydroxycarboxylic acid (A) on the metal compound thereof.