| 摘要 |
PURPOSE:To obtain an excellent electrostatically charging characteristic, aging degradation resistance and moisture resistance by using a phtalocyanine series blue organic pigment whose surface is covered with a negatively electrostatically charged hydrophobic silica as a coloring agent. CONSTITUTION:The surface of the phtalocyanine series blue organic pigment is covered with the negatively electrostatically charged hydrophobic silica. By covering the surface of the pigment with the negatively electrostatically charged hydrophobic silica, a positive charge for which the pigment itself has, is neutralized or the pigment is electrostatically charged at a negative side. Then the polarity of the toner is coincided with that of the pigment and the occurrence of the opposite electrostatically charged toner is prevented. Also since the silica has a hydrophobic property, the improved moisture resistance is provided in a high humidity condition. Thus the negatively electrostatically charged toner with the improved electrostatically charging characteristic, aging degradation resistance and moisture resistance is obtained. |
