| abstract |
Disclosed is a treated silica in which silica is positively charged or low negatively charged while maintaining the inherent fluidity imparting characteristics of silica, and the variation in charge amount is reduced in a low-temperature, low-humidity, high-temperature, high-humidity environment. . SOLUTION: Hydrophobized silica hydrophobized so that surface silanol groups per unit surface area is 0.1 to 1.2 / nm 2 is treated with a silane coupling agent in a dry process to modify hydrophobized silica. And The obtained modified hydrophobized silica is useful as an external additive for toner, and provides a high-performance electrophotographic toner composition. The modified hydrophobized silica can be obtained by subjecting silica to surface treatment without generating aggregates. [Selection figure] None |