Toner for developing electrostatic image, method for producing the same, developer, image forming apparatus, process cartridge, and image forming method
AssigneeRicoh Company, Ltd.
InventorHideki Sugiura
Life of this patent
Estimating the term…
Abstract
A toner is disclosed, for developing electrostatic images by means of image forming apparatuses, that comprises toner particles, and an external additive, wherein the toner particles comprise a binder resin and a colorant, the external additive is introduced onto the surface of the toner particles, the external additive liberates from the surface of the toner particles in a rate of 7% to 50% under the condition that the toner is dispersed within a surfactant-containing electrolyte at 20 W output power and 20 kHz frequency for one minute by means of an ultrasonic homogenizer.
Claims45
A toner for developing an electrostatic image comprising:
- toner particles, and
- an external additive,
- wherein the toner particles comprise a binder resin and a colorant, the external additive is located on the surface of the toner particles, and
- when the toner is dispersed in a surfactant-containing electrolyte at 20 W output power and 20 kHz frequency for one minute by means of an ultrasonic homogenizer, 7% to 50% of the external additive is liberated from the surface of the toner particles.
A two-component developer for developing an electrostatic image formed on a photoconductor, comprising:
- a toner for developing an electrostatic image, and
- a magnetic carrier,
- wherein the toner contains toner particles that comprise a binder resin and a colorant, and an external additive that is located on the surface of the toner particles, and
- when the toner is dispersed in a surfactant-containing electrolyte at 20 W output power and 20 kHz frequency for one minute by means of an ultrasonic homogenizer, 7% to 50% of the external additive is liberated from the surface of the toner particles.
A monocomponent developer for developing an electrostatic image formed on a photoconductor, comprising:
- a toner for developing an electrostatic image,
- wherein the toner contains toner particles that comprise a binder resin and a colorant, and an external additive that is located on the surface of the toner particles, and
- when the toner is dispersed in a surfactant-containing electrolyte at 20 W output power and 20 kHz frequency for one minute by means of an ultrasonic homogenizer, 7% to 50% of the external additive is liberated from the surface of the toner particles.
An image forming apparatus, comprising:
- a photoconductor, a charging unit configured to charge the photoconductor uniformly, an exposing unit configured to expose the charged photoconductor depending on image data to form an electrostatic latent image, a developing unit configured to develop the electrostatic latent image by means of a developer to form a toner image, a transferring unit configured to transfer the toner image onto a transfer material, and a cleaning unit configured to clean the surface of the photoconductor, a developer comprising a toner,
- wherein the toner contains toner particles that comprise a binder resin and a colorant, and an external additive that is located on the surface of the toner particles, and
- when the toner is dispersed in a surfactant-containing electrolyte at 20 W output power and 20 kHz frequency for one minute by means of an ultrasonic homogenizer, 7% to 50% of the external additive is liberated from the surface of the toner particles.
A process cartridge comprising:
- a photoconductor, a developing unit configured to develop an electrostatic latent image by means of a developer to form a toner image, and a developer comprising a toner,
- wherein the process cartridge is detachably attached to an mage forming apparatus to form a unitary construction,
- the toner contains toner particles that comprise a binder resin and a colorant, and an external additive that is located on the surface of the toner particles, and
- when the toner is dispersed in a surfactant-containing electrolyte at 20 W output power and 20 kHz frequency for one minute by means of an ultrasonic homogenizer, 7% to 50% of the external additive is liberated from the surface of the toner particles.
An image forming method comprising:
- charging a photoconductor, exposing the charged photoconductor to form an electrostatic latent image, developing an electrostatic latent image by means of a developer comprising a toner to form a toner image, and transferring the toner image onto a transferring material,
- wherein the toner contains toner particles that comprise a binder resin and a colorant, and an external additive that is located on the surface of the toner particles, and
- when the toner is dispersed in a surfactant-containing electrolyte at 20 W output power and 20 kHz frequency for one minute by means of an ultrasonic homogenizer, 7% to 50% of the external additive is liberated from the surface of the toner particles.
Dependencies are inferred from the claim text.