Toner, process cartridge, and electrophotographic image forming apparatus
AssigneeCanon Kabushiki Kaisha
InventorMASASHI UNO
Life of this patent
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Abstract
A toner comprises (1) a toner particle and (2) an external additive. The toner particle (1) comprises a binder resin, a positive-charge control agent, and an ester compound. The binder resin comprises a resin having a vinyl polymer segment, and a polyester segment containing an alkenylsuccinic unit having an alkenyl group with 10 to 22 carbon atoms. The positive-charge control agent is a nigrosine compound. The ester compound is an ester of pentaerythritol or dipentaerythritol and a saturated or unsaturated aliphatic monocarboxylic acid with 10 to 22 carbon atoms. The external additive (2) includes silicone resin particles.
Claims11
A toner comprising:
- a toner particle;
- and
- an external additive, wherein
- (1) the toner particle comprises a binder resin, a positive-charge control agent, and an ester compound,
- the binder resin comprises a resin having a vinyl polymer segment and a polyester segment containing an alkenylsuccinic unit having an alkenyl group with 10 to 22 carbon atoms,
- the positive-charge control agent is a nigrosine compound, and
- the ester compound is an ester of pentaerythritol or dipentaerythritol and a saturated or unsaturated aliphatic monocarboxylic acid with 10 to 22 carbon atoms;
- and
- (2) the external additive comprises silicone resin particles.
A process cartridge capable of being removably mounted in an electrophotographic image forming apparatus, the process cartridge comprising:
- a toner;
- a developing roller that bears the toner;
- and
- a toner regulating member that comes into contact with the developing roller to regulate the toner,
- wherein
- the toner comprises a toner particle and an external additive,
- (1) the toner particle comprises a binder resin, a positive-charge control agent, and an ester compound,
- the binder resin comprises a resin having a vinyl polymer segment and a polyester segment containing an alkenylsuccinic unit having an alkenyl group with 10 to 22 carbon atoms,
- the positive-charge control agent is a nigrosine compound, and
- the ester compound is an ester of pentaerythritol or dipentaerythritol and a saturated or unsaturated aliphatic monocarboxylic acid with 10 to 22 carbon atoms;
- and
- (2) the external additive comprises silicone resin particles.
An electrophotographic image forming apparatus comprising:
- a toner;
- a photosensitive member on which an electrostatic latent image is formed;
- a developing roller that bears the toner and develops the electrostatic latent image into a toner image;
- and
- a toner regulating member that comes into contact with the developing roller to regulate the toner on the developing roller,
- wherein
- the toner comprises a toner particle and an external additive,
- (1) the toner particle comprises a binder resin, a positive-charge control agent, and an ester compound,
- the binder resin comprises a resin having a vinyl polymer segment and a polyester segment containing an alkenylsuccinic unit having an alkenyl group with 10 to 22 carbon atoms,
- the positive-charge control agent is a nigrosine compound, and
- the ester compound is an ester of pentaerythritol or dipentaerythritol and a saturated or unsaturated aliphatic monocarboxylic acid with 10 to 22 carbon atoms;
- and
- (2) the external additive comprises silicone resin particles.
Dependencies are inferred from the claim text.