摘要 |
PURPOSE:To scarcely generate the breakdown of a toner grain by allowing the toner to contain polyester obtained by bringing a specific simple substance composite to polycondensation reaction, as a binding resin. CONSTITUTION:A toner is allowed to contain polyester obtained by bringing a simple substance composite containing trivalent or more of polyvalent monomers of benzene tricarboxylic acid, etc., aromatic dicarboxylic acid and aliphatic dialcohol to polycondensation reaction, as a binding resin. In such a way, the breakdown of a toner grain is scarcely generated and an electrostatic developer which can display a stable and positive triboelectrification property extending over a long period of time is obtained. |