磁性トナー

Japanese Patent JP5089612

B2

Provided is a magnetic toner with which images each of which has good developing ability, is free of fogging, has a high degree of blackness even at a halftone site, and is free of density unevenness can be stably formed. The magnetic toner is a magnetic toner having magnetic toner particles each containing at least a binder resin and a magnetic iron oxide particle, in which: when a solution is prepared by dissolving the magnetic iron oxide particles in an acidic aqueous solution and an Fe element amount in a solution in which all the magnetic iron oxide particles are dissolved is defined as a total Fe element amount, a ratio X of the amount of Fe(2+) in a solution in which the magnetic iron oxide particles are dissolved to a state where 10 mass% of the total Fe element amount is present in the solution (solution having an Fe element-dissolving ratio of 10 mass%) to an Fe element amount in the solution having an Fe element-dissolving ratio of 10 mass% is 34 mass% or more and 50 mass% or less; and the dielectric loss tangents of the magnetic toner measured at a temperature of 40°C satisfy the following conditions (a) to (c): (a) a dielectric loss tangent A at a frequency of 10,000 Hz is 1.0 × 10 -6 or more and 1.0 × 10 -1 or less; (b) a dielectric loss tangent B at a frequency of 1,000 Hz is 1.0 × 10 -6 or more and 1.0 × 10 -1 or less; and (c) a ratio (A/B) of the dielectric loss tangent A to the dielectric loss tangent B is 0.10 or more and 10.00 or less.

Daisuke Yoshiha

JP2008555088A

December 05, 2012

January 23, 2008

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Canon Inc

G03G9/083; G03G9/08

JPH04141664A	1992-05-15
JP2005265958A	2005-09-29

Kazunobu Sera
Yoshiyuki Kawaguchi
Mayuko Wakuda
Koichiro Sakai
Takeshi Nakamura
Takeshi Niwa

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