| 摘要 |
<p>PURPOSE:To stabilize the electrostatic chargeability to a toner by subjecting the surface of the carrier having polyolefinic resin coating layers formed by polymn. an olefinic monomer on the surfaces of carrier core particles to a surface treatment with specific particulates. CONSTITUTION:The surfaces of the carriers having the polyolefinic resin coating layers are subjected to the surface treatment with the particulates having the average grain size of <=1/10 the average grain size of the carrier. Particles having at least >=20mum are used as the carrier core particles and at least the particles of 100mum size are used. The surfaces of the carriers are coated with the polyolefinic resin at >=70%, preferably >=90% and more preferably >=95%. The packing rate of the carrier core material is set at >=90wt.%, more preferably >=95wt.%. The sp. gr. of the carrier is so set as to indicate the values within a 3.5 to 7.5., preferably 4.0 to 6.0, more preferably 4.0 to 5.5 range.</p> |
