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:
Apr. 05, 2016
Filed:
Dec. 15, 2014
Canon Kabushiki Kaisha, Tokyo, JP;
Takashi Matsui, Mishima, JP;
Michihisa Magome, Mishima, JP;
Kozue Uratani, Mishima, JP;
Atsuhiko Ohmori, Suntou-gun, JP;
CANON KABUSHIKI KAISHA, Tokyo, JP;
Abstract
It is intended to provide magnetic toner that produces a stable image density in long-term use and can prevent ghosting under conditions of low-temperature and low-humidity. The present invention provides magnetic toner including magnetic toner particles each containing a binder resin, a magnetic material and a releasing agent, and silica fine particles, wherein the silica fine particles include silica fine particles A and B, the silica fine particles A have a number-average particle size of 5-20 nm as primary particles, the silica fine particles B are produced by a sol-gel method, and have a number-average particle size of 40-200 nm as primary particles, an abundance ratio of secondary particles of the silica fine particles B is 5-40% by number, and a coverage ratio X1 of the surface of the magnetic toner particles with the silica fine particles determined by ESCA is 40.0-75.0% by area.