| 摘要 |
<p>PURPOSE: To provide a binary system developer which does not contain any of a charge control agent, which has a sufficient chargeability, which does not scatter toner during copying, which has sufficient transfer efficiency, with which a copied image having a required density can stably be obtained for a long time, with which a copied image having a required density can stably be obtained for a long time, and which gives a transferred image sufficient fixing ability. CONSTITUTION: A binary system developer is composed of carrier and toner containing toner particles which in turn contain fixing resin, magnetic powder, and polyethylene. The fixing resin is a composition containing resin having an anionic polar group, having a predetermined acid value, and the magnetic powder is contained at a predetermined rate. The polyethylene has a predetermined molecular weight, and is contained at a predetermined ration in the toner particles. Each of the carrier particles is composed of a core particle and a cover layer with which the core particle is covered, the core particle being formed at the surface thereof recesses and made of a magnetic material, and the cover layer being made of a composition containing thermosetting resin and thermoplastic material and filled at least in the recesses in the core particle, and covering the surface of the core particle at a predetermined ratio.</p> |
