Abstract: A method of producing a toner having a process of mixing colored particles and outer-additives by using a mixer with an agitating blade whose shaft portion is sealed with a gas having a flow rate of from 0.4 m3/hr to 3 m3/hr and which rotates at such a high speed as a peripheral speed at a tip of said agitating blade in a range of from 20 m/sec to 50 m/sec. When the colored particles and outer-additives are mixed with each other, there is no generation of aggregates thereby and the toner can be obtained at a high yield. Therefore the toner which hardly generates a white streak and fog, even after a long period of continuous operation of development of electrophotographs is performed, can be obtained.

Abstract: A toner can be produced by dispersing a colorant in a dispersion medium essentially composed of a polymerizable monomer by using a media-type dispersing device at a tip speed of a stirring body of 3 to 20 m/s with a residence time being 0.03 to 0.5 hour to obtain a monomer composition A; dispersing or dissolving a charge control agent in a dispersion medium to obtain a monomer composition B; dispersing or dissolving a parting agent in a dispersion medium to obtain a monomer composition C; mixing or dispersing the monomer composition A, the monomer composition B and the monomer composition C in a dispersion medium to obtain a polymerizable composition D; and homogenizing the composition D in an aqueous dispersion medium containing a dispersion stabilizer to generate droplets; polymerizing the droplets to obtain colored polymer particles; and attaching an outer-additive on the colored polymer particles.

Abstract: A method of producing a toner having a process of mixing colored particles and outer-additives by using a mixer with an agitating blade whose shaft portion is sealed with a gas having a flow rate of from 0.4 m3/hr to 3 m3/hr and which rotates at such a high speed as a peripheral speed at a tip of said agitating blade in a range of from 20 m/sec to 50 m/sec. When the colored particles and outer-additives are mixed with each other, there is no generation of aggregates thereby and the toner can be obtained at a high yield. Therefore the toner which hardly generates a white streak and fog, even after a long period of continuous operation of development of electrophotographs is performed, can be obtained.

Abstract: An object of the present invention is to provide an electrophotographic developer having a good fluidity, an excellent shelf stability, and a lesser reduction in image quality under various conditions.An electrophotographic one component nonmagnetic developer includes toner particles obtained by polymerizing a polymerizable monomer component, such as styrene, methacrylate, acrylate and the like, and outer-additives, such as silicon dioxide particles, on the toner particles. The developer has pH of 4 to 7 measured by a decoction method, and .sigma.2 of not more than 20 .mu.S/cm and .sigma.2-.sigma.1 of 0 to 10 .mu.S/cm, in which .sigma.1 is an electric conductivity of water, .sigma.2 is an electric conductivity measured by a decoction method.

Abstract: An object of the present invention is to provide an electrophotographic developer having a good fluidity, an excellent shelf stability, and a lesser reduction in image quality under various conditions.An electrophotographic one component nonmagnetic developer includes toner particles obtained by polymerizing a polymerizable monomer component, such as styrene, methacrylate, acrylate and the like, and outer-additives, such as silicon dioxide particles, on the toner particles. The developer has pH of 4 to 7 measured by a decoction method, and .sigma.2 of not more than 20 .mu.S/cm and .sigma.2 - .sigma.1 of 0 to 10 .mu.S/cm, in which .sigma.1 is an electric conductivity of water, .sigma.2 is an electric conductivity measured by a decoction method.