| 摘要 |
<p>PURPOSE: To provide a binary system developer which contains no charge control agent so as to provide sufficient chargeability, prevent toner from scattering at the time of copying, provide sufficient transfer efficiency and a copy image having required density stably for many hours, cause no filming, provide sufficient fixing property of transferred image, and prevent offsetting at the time of thermal fixing. CONSTITUTION: It is a binary system developer which contains toner and carrier. The toner contains toner particles. The toner particle contains resin for fixing, magnetic powders, and parting agent. The resin for fixing is composed of a component which contains resin having an anion polar group. The magnetic powders are contained in the toner particle at a predetermined ratio. The parting agent contains a predetermined molecular weight of polypropylene, and polypropylene is contained in the toner particle at a predetermined ratio. A particle of carrier has a core particle composed of a predetermined magnetic material and a covering layer which covers the core particle. The covering layer is composed of a resin component which contains thermosetting resin, and its hardening is 85% or higher.</p> |
