| 摘要 |
<p>PURPOSE: To provide a binary system developer which does not contain any of a charge control agent, with which the toner has a sufficient chargeability, which does not cause a spent, which does not scatter toner, which scarcely causes coagulation of magnetic carrier particles and adhesion of the carrier particles to the surface of a photosensitive medium, and with which a copied image having a required density can stably be obtained for a long time. CONSTITUTION: Toner particles contain fixing resin and magnetic powder with a predetermined ratio. The fixing resin is a composition containing resin composed of a monomeric material and a polymeric material, which respectively have an anionic polar group. The content ratio of the anionic polar group in the monomeric material, is less than that in the polymeric material. Further, the SP value of the monomeric material is less than that of the polymeric material. The carrier particles contain thermoplastic resin and high resistance magnetic powder, the thermoplastic resin containing resin having a cationic polar group.</p> |
