Kao Corporation

Kouhei Katayama

Nobumichi Kamiyoshi

Masahito Yamazaki

Yasuki Ohtawa

Hiroyuki Kawaji

Yasuhiro Hidaka

Koji Kameyama

A toner for electrophotography comprising a charge control agent comprising a specified iron-azo complex or a specified metal compound of a benzilic acid derivative, a colorant, and a resin binder comprising a polyester, the polyester being a polyester obtained by polycondensing an alcohol component containing a propylene oxide adduct of bisphenol A and a carboxylic acid component, wherein the propylene oxide adduct of bisphenol A has an average mole of propylene oxide added of from 2.4 to 4.0, and wherein an adduct with 2 mol of propylene oxide is contained in an amount of 60% by mol or less, and an adduct with 4 mol of propylene oxide is contained in an amount of 10% by mol or more, of the propylene oxide adduct of bisphenol A, and wherein the propylene oxide adduct of bisphenol A has a content ratio of primary hydroxyl groups of 10% by mol or less of the entire hydroxyl groups. The toner for electrophotography of the present invention is suitably used in developing latent images and the like formed in electrophotography, electrostatic recording method, electrostatic printing method or the like.

Toner for electrophotography

A toner for electrostatic image development, containing a resin binder containing a polyester having monomer units wherein at least one monomer is selected from the group consisting of fumaric acid and maleic acid, including mixtures thereof; a colorant; and a charge control agent containing a negatively chargeable charge control agent and a positively chargeable charge control agent, wherein the unreacted monomers of fumaric acid, maleic acid or both fumaric acid and maleic acid are contained in the toner in an amount of 0.20% by weight or less. The toner for electrostatic image development of the present invention may be used for the development of a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method or the like.

Toner for electrostatic image development

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Wakayama, Japan

Kouhei Katayama