| 摘要 |
<p>PURPOSE: To secure a developer that is provided with a good chargeability without containing any electrostatic charge control agent utterly, less in toner scattering and excellent in image quality by comprising a toner and a carrier specified each. CONSTITUTION: The developer contains a toner and a carrier. This toner contains toner grains which, in turn, contains fixing resin and magnetic powder dispersed in this resin. The fixing resin is composed of a composition containing a kind of resin with an anionic polar group, and the magnetic powder is contained in the toner grains at a rate from 0.1 to 5 pt.wt to 100 pt.wt in the fixing resin. Carrier grains have a core grain and a covered layer covering this grain. This core grain is made up of a magnetic material to be shown in an equation of MOFe2 O3 , and here M is at least a kind of metal to be selected out of a group consisting of Cu, Zn, Fe, Ba, Ni, Mg, Mn, Al and Co. The covered layer consists of a resin composition comprising thermosetting resin, and hardening degree of this covered layer is higher than 85%.</p> |
