Patent ID: 7348120
Filing Date: 2008-03-25
Classification: G03G

Abstract:
1. A toner for electrostatic image development, obtainable by a process comprising the steps of: (I) melt-kneading a raw material mixture comprising a resin binder, a releasing agent, and a colorant; cooling the melt-kneaded mixture; and pulverizing the cooled mixture; and (II) further pulverizing a pulverized product obtained in the step (I) in the presence of an external additive comprising at least two kinds of inorganic oxides subjected to hydrophobic treatment, having different average particle sizes from each other; and classifying the pulverized product, wherein the inorganic oxides subjected to hydrophobic treatment in the step (II) have an average particle size of 20 nm or less, and a difference in average particle size of 3 to 10 nm.