Toner, developer, and process for producing the same

摘要

An electrophotographic toner is prepared by melt-kneading a constituent mixture containing a quaternary ammonium salt at a temperature of (M-7) to (M+7) DEG C, where M is the melting point of the quaternary ammonium salt, removing the mixture from the kneading device through a discharge port at a temperature below that at which its melt viscosity is not more than 10,000 Pa.s, rolling the melt-kneaded mixture to a thickness of 1.2 to 3.0 mm, and cooling the mixture. Such a toner retains its charge during copying irrespective of the working atmosphere and conditions of use, thereby maintaining a good image density.