The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 25, 2008
Filed:
Apr. 11, 2005
Akihiro Eida, Wakayama, JP;
Jun Shimizu, Wakayama, JP;
Akihiro Eida, Wakayama, JP;
Jun Shimizu, Wakayama, JP;
Kao Corporation, Tokyo, JP;
Abstract
The present invention relates to a toner for electrostatic image development, obtainable by a process including the steps of (I) melt-kneading a raw material mixture containing 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 containing 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; and a process for preparing the toner. The toner of the present invention can be suitably used, for instance, for the development of a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method or the like.