| 摘要 |
PROBLEM TO BE SOLVED: To provide a toner external additive comprising silica powder less liable to aggregate, and a method for manufacturing the same. SOLUTION: The toner external additive comprises the silica powder having a volume average diameter of 0.02-1μm surface-treated with an alkylsilane coupling agent and a fluidity index of the toner external additive measured by the following method is≥70%. There are also provided the method for manufacturing the toner external additive and a treatment method applicable to the method for manufacturing the toner external additive. (Fluidity index): 10 g of styrene resin having an average diameter of 5μm and 0.1 g of the sample are put in a mixer and mixed at 480 rpm for 10 s at room temperature, 2 g of the resulting mixed powder is put in a three-stage sieve of 150μm, 75μm and 45μm and classified by applying vibration of 0.25 mm amplitude for 3 min, and a fluidity index is calculated from the amounts of respective plus sieve residual powders according to expression: 100-50A-30B-10C wherein A is the amount of 150μm plus sieve residual powder; B is the amount of 75μm plus sieve residual powder; and C is the amount of 45μm plus sieve residual powder. COPYRIGHT: (C)2006,JPO&NCIPI |
