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:
Jan. 04, 2011
Filed:
Mar. 06, 2009
Yasunori Tabira, Saitama, JP;
Koji Aga, Kashiwa, JP;
Tomoyuki Suwa, Nagareyama, JP;
Mitsui Mining & Smelting Co., Ltd., Tokyo, JP;
Powdertech Co., Ltd., Chiba, JP;
Abstract
A carrier core material for an electrophotographic developer containing Li ferrite, maghemite, and FeO, wherein a part thereof is substituted with Mn, a Li content is 1 to 2.5% by weight, a Mn content is 2 to 7.5% by weight, and a silicon content is 25 to 10,000 ppm, a compression breaking strength is 130 MPa or more, an SF-1 is 125 to 145, respective cumulative strengths of respective spinel crystal structure faces in X-ray diffraction satisfy a certain equation, a vacuum resistivity Racross a 2 mm gap when a measurement voltage of 500 V is applied is 1×10to 5×10Ω, and a vacuum resistivity Racross a 6.5 mm gap when a measurement voltage of 1,000 V is applied is 5×10to 1×10Ω.