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Title:
IRON-BASED OXIDE MAGNETIC POWDER AND METHOD FOR PRODUCING SAME
Document Type and Number:
WIPO Patent Application WO/2021/065935
Kind Code:
A1
Abstract:
[Problem] To provide an iron-based oxide magnetic powder which contains a sufficiently reduced amount of fine particles and coarse particles, has a particle shape close to a true sphere, and is suitable for magnetic recording media applications. [Solution] A raw material solution containing trivalent iron ions, or trivalent iron ions and metal element ions partially replacing Fe-sites, and an alkaline aqueous solution for neutralizing the raw material solution are added to a reaction system to adjust the pH of the reaction system to 1.0-3.0, a hydroxycarboxylic acid is added to the obtained reaction solution and the pH of the reaction system is neutralized to 7.0-10.0, and the obtained precipitate of a substituted metal element-containing iron oxyhydroxide is coated with a silicon oxide and then heated, thereby obtaining an iron-based oxide magnetic powder which contains sufficiently reduced amounts of fine particles and coarse particles, has a particle shape close to a true sphere, and is composed of ε iron oxide particles in which Fe-sites are partially replaced with other metal elements.

Inventors:
MIYAMOTO Yasuto (4-14-1, Sotokanda, Chiyoda-k, Tokyo 21, JP)
YAMAGA Kazuhiro (4-14-1, Sotokanda, Chiyoda-k, Tokyo 21, JP)
MINEYAMA Yuki (4-14-1, Sotokanda, Chiyoda-k, Tokyo 21, JP)
Application Number:
JP2020/036983
Publication Date:
April 08, 2021
Filing Date:
September 29, 2020
Export Citation:
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Assignee:
DOWA ELECTRONICS MATERIALS CO., LTD. (Sotokanda Chiyoda-k, Tokyo 21, JP)
International Classes:
C01G51/00; G11B5/706; G11B5/714; G11B5/84; C01G49/00; H01F1/11
Attorney, Agent or Firm:
KOMATSU Takashi (2-2-12 Nihonbashibakuro-cho, Chuo-k, Tokyo 02, JP)
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