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US 7,803,508 B2Granted
Toner as well as developer and image forming method using the same
AssigneeRicoh Company, Ltd.
InventorsMasayuki Ishii, Tsuneyasu Nagatomo
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AssigneeRicoh Company, Ltd.
InventorsMasayuki Ishii, Tsuneyasu Nagatomo
Estimating the term…
A toner which combines excellent cleaning ability, image quality and durability, as well as a developer and an image forming method using the toner are provided. A toner comprising a toner base particle which comprises at least a binding resin and a colorant, and an external additive, wherein an external additive is a non-spherical amorphous silica particle and a major axis of the silica particle is 40 nm to 180 nm. An aspect wherein the non-spherical amorphous silica particle has a true specific gravity of 1.8 to 2.3 and the silica particle is hydrophobilized and a hydrophobilization degree is 40 or more, and an aspect wherein the non-spherical amorphous silica particle is produced by a dry system and a mass reduction rate is 5% by mass or less when the silica particle is heated from 30° C. up to 250° C. are preferable.
A toner comprising a toner base particle which comprises at least a binding resin and a colorant, and an external additive,
A two-component developer composed of a toner and a carrier, wherein the toner comprises a toner base particle which comprises at least a binding resin and a colorant, and an external additive,
An image forming method comprising a latent electrostatic image forming step of forming a latent electrostatic image on a latent electrostatic image bearing member, a developing step of developing said latent electrostatic image using a toner to form a visible image, a transferring step of transferring said visible image on a recording medium and a fixing step of fixing a transfer image transferred onto the recording medium, wherein the toner comprises a toner base particle which comprises at least a binding resin and a colorant, and an external additive,
Dependencies are inferred from the claim text.