Magnetic carrier and two-component developer
First Claim
1. A magnetic carrier comprising carrier particles, wherein:
- a BET specific surface area (BET
1) of the magnetic carrier is from 0.02 m2/g to 0.20 m2/g as measured by a BET method, each carrier particle comprises a carrier core and a coat material for coating the carrier core,the carrier core comprises at least a binder resin and magnetic particles dispersed in the binder resin,the coat material has a coat resin,a ratio (A) of a fluorine element abundance ratio (Fatom) to a carbon element abundance ratio (Catom), Fatom/Catom, at a surface of the carrier particle is from 0.10 to 0.85, anda ratio ((A)/(B)) of a ratio (A) of a fluorine element abundance ratio (Fatom) to a carbon element abundance ratio (Catom), Fatom/Catom, at a surface of the carrier particle to a ratio (B) of a fluorine element abundance ratio (Fcalc) to a carbon element abundance ratio (Ccalc) that is theoretically calculable from molecular structure of the coat resin, Fcalc/Ccalc is from 1.01 to 3.00.
1 Assignment
0 Petitions
Accused Products
Abstract
A magnetic carrier composed of carrier particles is provided in which each carrier particle has a carrier core including magnetic fine particles and a binder resin with the carrier core surface being coated with a coat material containing a coat resin. In the magnetic carrier, Fatom/Catom and (Fatom/Catom)/(Fcalc/Ccalc) are respectively in specific ranges, wherein Fatom and Catom represent respectively a fluorine element abundance ratio and a carbon element abundance ratio at the magnetic carrier particle surface, and Fcalc and Ccalc represent respectively a fluorine element abundance ratio and a carbon element abundance ratio which are calculable from the molecular structure of the coat resin.
In addition, a two-component developer is provoded including the magnetic carrier and a toner having a specific contact angle against water.
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Citations
21 Claims
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1. A magnetic carrier comprising carrier particles, wherein:
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a BET specific surface area (BET
1) of the magnetic carrier is from 0.02 m2/g to 0.20 m2/g as measured by a BET method, each carrier particle comprises a carrier core and a coat material for coating the carrier core,the carrier core comprises at least a binder resin and magnetic particles dispersed in the binder resin, the coat material has a coat resin, a ratio (A) of a fluorine element abundance ratio (Fatom) to a carbon element abundance ratio (Catom), Fatom/Catom, at a surface of the carrier particle is from 0.10 to 0.85, and a ratio ((A)/(B)) of a ratio (A) of a fluorine element abundance ratio (Fatom) to a carbon element abundance ratio (Catom), Fatom/Catom, at a surface of the carrier particle to a ratio (B) of a fluorine element abundance ratio (Fcalc) to a carbon element abundance ratio (Ccalc) that is theoretically calculable from molecular structure of the coat resin, Fcalc/Ccalc is from 1.01 to 3.00. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21)
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20. A two-component developer comprising a toner and a magnetic carrier, wherein:
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said toner has toner particles containing at least a binder resin, a release agent and a colorant, and the transmittance of light having a wavelength of 600 nm through a dispersion prepared by dispersing said toner in an aqueous 45% by volume methanol solution is from 10% to 70%; and said magnetic carrier has a BET specific surface area (BET
1) from 0.02 m2/g to 0.20 m2/g as measured by a BET method, and comprises carrier particles, wherein;each carrier particle comprises a carrier core and a coat material for coating the carrier core, the carrier core comprises at least a binder resin and magnetic particles dispersed in the binder resin, the coat material has a coat resin, a ratio (A) of a fluorine element abundance ratio (Fatom) to a carbon element abundance ratio (Catom), Fatom/Catom, at a surface of said carrier particle is from 0.10 to 0.85, and a ratio ((A)/(B)) of a ratio (A) of fluorine element abundance ratio (Fatom) to a carbon element abundance ratio (Catom), Fatom/Catom, at a surface of said carrier particle to a ratio (B) of a fluorine element abundance ratio (Fcalc) to a carbon element abundance ratio (Ccalc) that is theoretically calculable from molecular structure of the coat resin, Fcalc/Ccalc is from 1.01 to 3.00.
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Specification