| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method for realizing a improved carrier for electrophotography which resists destruction such as wear, peeling, crack, and rarely suffers from a spent phenomenon, so it excels in long-term durability and electrostatic stability. SOLUTION: The present invention provides a coating agent for the carrier which is characteristically composed of spherical hydrophobic fine silica particles having primary particles having an average particle diameter of from 0.01 to 5.μm and an organic resin. Those fine silica particles fulfill the following conditions (i) and (ii). (i) When an organic compound which is liquid at room temperature and has a dielectric constant of from 1 to 40 F/m and fine silica particles are mixed in a weight ratio of 5:1 and shaken, the fine silica particles disperse uniformly in the organic compound. (ii) The quantity of primary particles remaining as primary particles when methanol is evaporated under heating by means of an evaporator from a dispersion prepared by dispersing the fine silica particles in methanol and thereafter the particles are held at 100 deg.C for 2 hours, represents at least 20% of the quantity of primary particles originally present.</p> |
