Powdertech Co., Ltd.

Mitsui Minings & Melting Co., Ltd.

Takashi Hikichi

Hiromichi Kobayashi

Yuji Sato

Yoichi Kamikoriyama

Kenji Suzuoka

Kazuya Kinoshita

Takeshi Gondo

Takashi Nakashima

Takao Sugiura

Disclosed are a resin-filled ferrite carrier core material for an electrophotographic developer, including a porous ferrite particle, wherein the composition of the porous ferrite particle is represented by the following formula (1), and part of (MgO) and/or (FeO) in the following formula (1) is replaced with SrO; a ferrite carrier obtained by filling a resin in the voids of the ferrite carrier core material; and an electrophotographic developer using the ferrite carrier: 

Resin-filled ferrite carrier core material for electrophotographic developer, ferrite carrier and electrophotographic developer using the ferrite carrier

A carrier for electrophotographic developer comprises a resin carrier core comprising a binder resin and magnetic powder dispersed in the binder resin, and a coating layer comprising a coating resin on a surface of the core, the binder resin being a silicone resin obtained by curing of a polysiloxane compound (A) having an epoxy group and a polysiloxane compound (B) having a group capable of reacting with the epoxy group, due to a ring-opening addition reaction; the binder resin containing a functional group which is an epoxy group and/or a group capable of reacting with an epoxy group; the coating resin containing a functional group capable of reacting with the functional group of the binder resin; the functional group of the coating resin and the function group of the binder resin forming a chemical bond.

Carrier for electrophotographic developer and two-component electrophotographic developer

Provided are a carrier for electrophotography developers prepared by generating a slight amount of byproducts such as water, alcohol, etc, which carrier is free from release of a magnetic powder, has excellent mechanical strength and durability, and good environmental stability, and further can restrain occurrence of toner spent condition and has favorable fluidity and excellent capability of imparting charging to a toner, a two-component developer comprising the carrier and a method for forming an image using the developer. The carrier for electrophotography developers comprises a magnetic powder dispersed binder resin, the binder resin material comprises (A) a polysiloxane compound having an epoxy group as a functional group and (B) a polysiloxane compound having a group capable of ring-opening addition reaction with the epoxy group of the polysiloxane compound (A), and the binder resin is a silicone resin prepared by curing with ring-opening addition reaction of the epoxy resin. The developer comprises the carrier for electrophotography developers and the toner particle. The method for forming an image comprises developing a static latent image by the developer with an alternating electric field.

Carrier for electrophotography developers, developer prepared by using the carrier and method for forming image

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Nagareyama, Japan

Takashi Hikichi