| 摘要 |
<p>PURPOSE: To provide a developer which contain specific toner and specific carrier so as to have a satisfactory charge ability without a charge control agent, which scatters little toner and which gives an excellent image quality. CONSTITUTION: A binary system developer is composed of carrier and toner containing toner particles which in turn contain fixing resin and magnetic powder dispersed in the resin. The fixing resin is a composition containing resin having. a monomeric material and a polymeric material which contain therein anionic polar groups, respectively, the acid value of the monomeric material is lower than that of the polymeric material. The magnetic powder is contained by 0.1 to 5 weight parts with respect to 100 weight parts of the fixing resin. The carrier particles contain thermoplastic resin and high resistance magnetic powder dispersed in the resin, having a volumetric reference mean particle size of 50 to 150-μm. The thermoplastic resin is a composition containing having a cationic polar group. The high resistance magnetic powder has a specific resistance of higher than 1×10<5>Ωcm, and is contained by 60 to 90 weight parts in the carrier particles.</p> |
