The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 28, 2010
Filed:
Mar. 16, 2007
Masayuki Ishii, Numazu, JP;
Tsuneyasu Nagatomo, Numazu, JP;
Masayuki Ishii, Numazu, JP;
Tsuneyasu Nagatomo, Numazu, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
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.