| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent the fluidity and durability of a developer from being deteriorated and to prevent the image quality from being deteriorated. <P>SOLUTION: A developer comprises toner base particles composed of at least a binder resin and an external additive adhered on the surface of the toner base particles. As the external additive, hydrophobic silica fine particles, colloidal silic fine particles having an average particle diameter larger than that of hydrophobic silica fine particles and melamine resin fine particles are used. Since hydrophobic silica fine particles, colloidal silic fine particles having an average particle diameter larger than that of hydrophobic silica fine particles and melamine resin fine particles are used as the external additive, the colloidal silica fine particles act as a buffer material against the load applied on the developer in an image forming unit and the load prevent the hydrophobic silica fine particles from being buried in the toner base particles, thereby enabling preventing the fluidity and durability of the developer from being deteriorated and improving the image quality. <P>COPYRIGHT: (C)2013,JPO&INPIT |
