Invention Grant
- Patent Title: Magnetic toner
- Patent Title (中): 磁性调色剂
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Application No.: US14892575Application Date: 2014-07-30
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Publication No.: US09588450B2Publication Date: 2017-03-07
- Inventor: Shohei Tsuda , Koji Nishikawa , Katsuhisa Yamazaki , Yojiro Hotta , Kazuo Terauchi , Motohide Shiozawa , Takeshi Naka , Takuya Mizuguchi , Takayuki Itakura
- Applicant: CANON KABUSHIKI KAISHA
- Applicant Address: JP Tokyo
- Assignee: CANON KABUSHIKI KAISHA
- Current Assignee: CANON KABUSHIKI KAISHA
- Current Assignee Address: JP Tokyo
- Agency: Fitzpatrick, Cella, Harper & Scinto
- Priority: JP2013-158911 20130731
- International Application: PCT/JP2014/070659 WO 20140730
- International Announcement: WO2015/016384 WO 20150205
- Main IPC: G03G9/08
- IPC: G03G9/08 ; G03G9/083 ; G03G9/087 ; G03G9/097

Abstract:
Provided is a magnetic toner in which enhancement of initial transfer efficiency and transfer efficiency that is stable during a long-term use are achieved by simultaneously suppressing the friction force between the toner and a drum and the cohesion between toners, and further the degradation in chargeability and fluidity caused by the deterioration of the toner. The magnetic toner includes: a magnetic toner particle; a first external additive; and a second external additive. The first external additive includes an organic-inorganic composite fine particle, a plurality of convexes derived from an inorganic fine particle being present on a surface of the organic-inorganic composite fine particle, and has a number-average particle diameter of 50 nm or more and 500 nm or less. The second external additive includes a silica fine particle and has a number-average particle diameter of 5 nm or more and 30 nm or less. A shear load calculated from a rotation torque is 0.50 kPa or more and 2.00 kPa or less when a disc-shaped disc is pressed against a surface of a magnetic toner powder layer, the magnetic toner powder layer being produced by applying a vertical load of 9.0 kPa to the magnetic toner, under a vertical load of 5.0 kPa, and the disc which is being pressed is rotated, and an absolute value |ζ(T)−ζ(A1)| of a difference between a zeta potential ζ(T) of the magnetic toner particle dispersed in water and a zeta potential ζ(A1) of the first external additive dispersed in water is 50 mV or less.
Public/Granted literature
- US20160091809A1 MAGNETIC TONER Public/Granted day:2016-03-31
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