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:
Oct. 01, 2013
Filed:
Mar. 30, 2010
Ryo Iwai, Hiroshima-ken, JP;
Mamoru Kamigaki, Hiroshima-ken, JP;
Nobuya Shimo, Hiroshima-ken, JP;
Naoki Uchida, Hiroshima-ken, JP;
Ryo Iwai, Hiroshima-ken, JP;
Mamoru Kamigaki, Hiroshima-ken, JP;
Nobuya Shimo, Hiroshima-ken, JP;
Naoki Uchida, Hiroshima-ken, JP;
Toda Kogyo Corporation, Otake-shi, Hiroshima-ken, JP;
Abstract
The present invention relates to black magnetic iron oxide particles comprising magnetite as a main component, wherein when the black magnetic iron oxide particles are molded into a tablet shape, an electric resistance value of the tablet in an alternating current electric field is controlled to produce an impedance of not less than 2×10Ωcm as measured in a characteristic frequency range thereof. The black magnetic iron oxide particles according to the present invention can provide a toner capable of exhibiting a good charging performance and a uniform charging property under the high-temperature and high-humidity conditions, so that when developing an electrostatic latent image therewith, it is possible to obtain toner images having a high resolution or definition, and further the use of heavy metal elements in the black magnetic iron oxide particles can be minimized.