| 摘要 |
<p>PURPOSE: To provide a binary system developer which does not contain any charge control agent, which contains toner having a sufficient chargeability, which does not scatter the toner during copying, and with which a copied image having a required density is stably obtained for a long time. CONSTITUTION: Toner particles contain fixing resin, and magnetic powder dispersed in the resin, the fixing resin being a composition including one kind of styrene-acrylic group polymer, having an anionic polar group, a component having an alkyl group with a carbon number of more than 12 in the side chain, and grafted wax component. The styrene-acrylic group polymer satisfies the following conditions: (a) a peak molecular weight of 4,000 to 30,000, (b) a mean molecular weight of 70,000 to 200,000, and (c) an acid value of 4 to 20. Each of particles of the carrier a core particle and a cover layer with which the core particle is covered, the cover layer being made of a resin composition which contain thermosetting resin.</p> |
