Zeon Corporation

Hidetoshi Azuma

Kazuhiro Sato

Makoto Watanabe

Kazunori Shigemori

Nobuyasu Ota

Hiroshi Yamamoto

Hirosi Yamamoto

Yoshihiro Makuta

Ryuji Ota

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 m /hr to 3 m /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.

Method for producing toner by mixing colored particles and outer-additive by mixer with stirrer of high speed rotation

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.

Method for producing toner

Growing community of inventors

Tokyo, Japan

Hidetoshi Azuma