Dowa Electronics Materials Co., Ltd.

Dowa F-Tec Co., Ltd.

Hiroya Ikeda

Masahiro Kojima

Shuichi Kohayashi

Keisuke Ayabe

Shinichi Suenaga

Satoru Tsuboi

Hideki Katayama

Kazuyuki Nakaue

To provide ferrite magnetic powders for bond magnet capable of surely suppressing residual hexavalent chrome, being an environmental load substance, having no adverse influence on the magnetic characteristics, which is an obstacle in use, and without damaging productivity and at a low cost. The method includes the steps of obtaining sintered powders by sintering raw material powders; wet-pulverizing the sintered powders; wet-cleaning the sintered powders; and annealing the cleaned sintered powders, wherein in the step of the wet-pulverization and in the step of wet-cleaning, generation of the hexavalent chrome, being an environmental load substance, is suppressed by performing the pulverization and cleaning while maintaining pH of a dispersion solvent at 8.5 or less, at the time of pulverization and cleaning.

Ferrite magnetic powder for bond magnet and manufacturing method of the same, and bond magnet

The present invention provides ferrite powders for bonded magnet capable of suppressing increase of SFD, while widening a particle size distribution for obtaining flowability and compressed density, and also capable of suppressing deterioration of orientation and magnetizability, and provides a process for a production magnetoplumbite-type ferrite powders containing an oxide of at least one or more kinds of transition metals selected from a group consisting of Zr, Ti, Zn, Co, Mn, and Ni, having a mean particle size of 0.20 &#x3bc;m or more and less than 5.00 &#x3bc;m, being the ferrite powders for bonded magnet with the ratio of particles having particle size of 1 &#x3bc;m or less being 20 mass % or more in the magnetoplumbite-type ferrite powder size distribution obtained by a laser diffraction type particle size distribution analyzer.

Ferrite powders for bonded magnet, process for the production of the powders, and bonded magnet made by using the same

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Okayama, Japan

Hiroya Ikeda