| 摘要 |
<p>PURPOSE: To provide a simple structure, a reduced size and high performance for a device and to obtain a magnetic toner not causing untransfer missing and capable of recycling. CONSTITUTION: Starting material 9 is pulverized in a pulverization chamber 7 by ultrahigh-speed collision against a collision plate 8 by means of a jet stream of air generated by introducing compressed air 5 into an ultrasonic nozzle 6 to form fine silicon dioxide particles having <=0.1g/cc still density, <=5.07μm wt. average particle diameter, a wt. distribution in which particles of >=10.0μm account for <=20% and a number distribution in which particles of >=10.0μm account for <=1.0% and the objective magnetic toner is obtd. using the fine silicon dioxide particles.</p> |
