PRODUCTION OF TONER FOR DEVELOPING ELECTROSTATIC CHARGE IMAGE

摘要

PURPOSE: To prevent the aggregation of a toner and to efficiently dry specified toner particles without forming granules by suspending the toner particles by mechanical vibration and blowing of gas and drying them while forming a fluidized bed. CONSTITUTION: Toner particles obtd. by a direct polymn. method, having a shape factor SF-1 of 100-140 measured with Luzex and contg. 5-40wt.% low softening point substance are suspended by mechanical vibration and blowing of gas and they are dried while forming a fluidized bed. The low softening point substance has been wrapped with a shell resin and ester wax having one or more >=10C long chain ester parts is preferably contained as the substance. The lower part of a vessel for the suspension and drying is smaller in size than the upper part and the linear velocity of gas at the gas blowing position of the lower part is preferably made >=22 times as high as that at the gas blowing position of the upper part.