| 摘要 |
<p>PURPOSE: To provide a developer that is provided with a good chargeability with no electrostatic charge control agent, less in toner scattering and excellent in image quality by comprising a toner and a carrier specified each. CONSTITUTION: This developer comprises a toner and a carrier. Toner grains contain a fixing resin and magnetic powder dispersed in this resin plus a mold releasing agent. The fixing resin contains a kind of resin with an anionic polar group. The magnetic powder is contained in the toner grain at the rate of 0.1 to 5 pt.wt to 100 parts by weight of the fixing resin. The mold releasing agent contains polypropylene of more than 7000 of number-average molecular weight, and this polypropylene is contained in the rate of 0.1 to 6 pt.wt to 100 parts by weight of the fixing resin. Carrier grains have a core grain and a covered layer. This core grain is composed of a magnetic material to be expressed by a formula of MOFe2 O3 , wherein M is a metal to be selected out of a group consisting of Cu, Zn, Fe, Ba, Ni, Mg. Mn, Al and Co. In this connection, the covered layer consists of a resin composition containing a resin with a cationic polar group.</p> |
