FERRITE CARRIER CORE MATERIAL FOR ELECTROPHOTOGRAPHIC DEVELOPERS, FERRITE CARRIER, AND MANUFACTURING PROCESSES FOR BOTH, AND ELECTROPHOTOGRAPHIC DEVELOPERS USING THE FERRITE CARRIER

Title:

FERRITE CARRIER CORE MATERIAL FOR ELECTROPHOTOGRAPHIC DEVELOPERS, FERRITE CARRIER, AND MANUFACTURING PROCESSES FOR BOTH, AND ELECTROPHOTOGRAPHIC DEVELOPERS USING THE FERRITE CARRIER

Document Type and Number:

WIPO Patent Application WO/2012/105078

Kind Code:

A1

Abstract:

The purpose of the present invention is to provide: a ferrite carrier core material for electrophotographic developers which have excellent electrification properties and which are less susceptible to carrier scattering caused by the fracture and/or chipping of core material and thus exhibit a long service life; a ferrite carrier; processes for producing both; and electrophotographic developers using the ferrite carrier. In order to achieve the purpose, employed are a ferrite carrier core material for electrophotographic developers and a ferrite carrier therefor, said core material having the characteristics: (1) the ferrite has a composition which contains 0.5 to 2.5wt% of Sr and in which the quantity of present Sr-Fe oxides satisfies a specific conditional expression; (2) the shape factor SF-2 has a specific frequency distribution; (3) the BET specific surface area is 0.15 to 0.30m2/g; (4) the median particle diameter (D50) is 20 to 35μm; and (5) the magnetization is 50 to 65Am2/kg. Also employed are manufacturing processes for both, and so on.

Inventors:

SUWA TOMOYUKI (JP)
IWATA TORU (JP)
AGA KOJI (JP)

Application Number:

PCT/JP2011/069435

Publication Date:

August 09, 2012

Filing Date:

August 29, 2011

Export Citation:

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Assignee:

POWDERTECH CO LTD (JP)
SUWA TOMOYUKI (JP)
IWATA TORU (JP)
AGA KOJI (JP)

International Classes:

G03G9/107; G03G9/113

Foreign References:

JP2010243798A	2010-10-28
JP2010055014A	2010-03-11
JP2010181524A	2010-08-19
JP2010039368A	2010-02-18
JP2010181525A	2010-08-19
JPH0822150A	1996-01-23
JP2004004648A	2004-01-08
JP2010039368A	2010-02-18
JP2008096977A	2008-04-24
JP2007271662A	2007-10-18
JP2006267345A	2006-10-05

Other References: