| US 7,371,494 B2 | ||
| Magnetic toner and method of manufacturing magnetic toner | ||
| Tatsuhiko Chiba, Kamakura (Japan); Michihisa Magome, Shizuoka-ken (Japan); Eriko Yanase, Mishima (Japan); and Takeshi Kaburagi, Numazu (Japan) | ||
| Assigned to Canon Kabushiki Kaisha, Tokyo (Japan) | ||
| Filed on Sep. 13, 2004, as Appl. No. 10/938,590. | ||
| Claims priority of application No. 2003-321825 (JP), filed on Sep. 12, 2003. | ||
| Prior Publication US 2005/0089785 A1, Apr. 28, 2005 | ||
| Int. Cl. G03G 9/083 (2006.01) | ||
| U.S. Cl. 430—106.2 [430/108.4; 430/137.17] | 24 Claims |
| 1. A magnetic toner comprising toner particles each containing at least a binder resin, a polar compound and a magnetic iron
oxide fine particle, wherein:
I) a ratio (B/A) of an iron element content (B) to a carbon element content (A) present on the surface of the toner particle,
measured by X-ray photoelectron spectroscopy, is less than 0.0010;
II) when a projected area diameter of toner particles obtained through cross-section observation of the toner particles using
a transmission electron microscope (TEM) is denoted by C and a minimum value for a distance between a magnetic iron oxide
fine particle and the toner particle surface is denoted by D, toner particles each satisfying a relationship of D/C≤0.02 are
present in an amount of 50% by number or more;
III) in the cross-section observation of the toner particles, toner particles, which satisfy a structure where 70% by number
or more of the magnetic iron oxide fine particles in the respective toner particles are present up to a depth of 0.2 times
as far as the projected area diameter C from the toner particle surface, are present in an amount of 40 to 95% by number;
and
IV) wherein the polar compound contains a maleic anhydride copolymer represented by following general formula (1) or a ring-opened
compound of the maleic anhydride copolymer
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