| 摘要 |
<p>PROBLEM TO BE SOLVED: To enhance fluidity, chargeability and durability by incorporating a fine hydrophobic metal oxide powder obtained by processing a fine metal oxide powder specified in specific surface area with a silane having an epoxy group and an organic compound having an amino group and an organopolysiloxane having both terminal reactive groups blocked. SOLUTION: The electrophotographic developer contains a fine hydrophobic metal oxide powder obtained by processing a fine metal oxide powder, such as silica or titania or alumina powder having a specific surface area of 10-400 m<2> /g, with a silane having an epoxy group and the organic compound having an amino group and an organopolysiloxane having both terminal reactive groups blocked. This processing opens the epoxy group and introduces the amino group there and allows the organopolysiloxane having reactive functional groups to react with a ring-opened hydroxyl group and the hydroxyl group of the metal oxide to give the fine metal oxide power high in phydrophobicness and controlled in chargeabilty, and this product is mixed with the electrophotographic toner.</p> |
