Magnetic toner

US6653035B2 · kind B2 · utility

Assignee

• Canon Kabushiki Kaisha · JP

Inventors

• Keiji Komoto · Numazu, JP
• Tatsuya Nakamura · Shizuoka, JP
• Tatsuhiko Chiba · Kamakura, JP
• Michihisa Magome · Mishima, JP
• Akira Hashimoto · Funabashi, JP
• Takeshi Kaburagi · Nanbu, JP
• Eriko Yanase · Mishima, JP

Key dates

• Filing date: Jul 26, 2002
• Grant date: Nov 25, 2003
• Expiry date: Jul 26, 2022

Classification

• Technology area (CPC G): Physics
• CPC primary: G03G9/08791
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A magnetic toner exhibiting stable performances under various environmental conditions is formed of toner particles each comprising at least a binder resin and iron oxide dispersed therein. Relative to the dry specific gravity (A) of the magnetic toner, the magnetic toner is characterized by a specific gravity distribution of toner particle fractions obtainable through wet sedimentation and including: at most 15 wt. % of a fraction having a specific gravity of above (A)×1.000 and at most (A)×1.025, 0.1-20 wt. % of a fraction having a specific gravity of above (A)×0.975 and at most (A)×1.000, at least 30 wt. % of a fraction having a specific gravity of above (A)×0.950 and at most (A)×0.975, 0.1-20 wt. % of a fraction having a specific gravity of above (A)×0.925 and at most (A)×0.950, and at most 15 wt. % of a fraction having a specific gravity of above (A)×0.900 and at most (A)×0.925.