Kyocera Document Solutions Inc.

Masami Tujihiro

Yoshio Ozawa

Toshiki Takemori

Yukinori Nakayama

A carrier for electrostatic latent image developing is composed of carrier core containing a binder resin and magnetic material particles, and a shell layer that covers the carrier core. The binder has an acid value of at least a predetermined value, and contains a resin having a carboxyl group. The shell layer is composed of a resin selected from melamine resin and urea resin.

Carrier and two-component developer

Domains of a charge control resin are formed by dispersing a charge control resin containing a quaternary ammonium salt functional group-containing resin of a copolymer of an addition-polymerizable monomer having a quaternary ammonium salt functional group and a styrene and/or acrylic monomer into a polyester resin as binder resin, and the proportion of the number of domains of the charge control resin with a domain diameter of no less than 0.01 &#x3bc;m to less than 0.3 &#x3bc;m versus the number of domains of the charge control resin with a domain diameter of no less than 0.01 &#x3bc;m, which is measured by a predetermined method, is adjusted to no less than 98% by number.

Positively chargeable toner for electrostatic image development

A developer for electrostatic latent image development including a positively chargeable toner and a fatty acid metal salt is used, in which the fatty acid metal salt is a metal salt selected from the group consisting of zinc, calcium, and magnesium salts of fatty acids of 12 to 20 carbon atoms and has a certain volume average particle diameter and particle size distribution.

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Osaka, Japan

Masami Tujihiro