Title:
MAGNETOPLUMBITE-TYPE HEXAGONAL FERRITE MAGNETIC POWDER AND METHOD FOR PRODUCING SAME
Document Type and Number:
WIPO Patent Application WO/2021/161913
Kind Code:
A1
Abstract:
Provided are: a magnetoplumbite-type hexagonal ferrite magnetic powder which can be used suitably as a material for a radio wave absorber having an excellent ability to absorb radio waves in a frequency band from 60 to 85 GHz; and a method for producing the magnetoplumbite-type hexagonal ferrite magnetic powder. A magnetoplumbite-type hexagonal ferrite magnetic powder represented by a compositional formula: A(1+x)Fe(12-y)AlyO(19+x) (wherein A represents at least one element selected from Sr, Ba, Ca and Pb; x = -0.1 to 0.1; y = 1.0 to 2.3) is produced by: mixing powders that are raw materials for the magnetoplumbite-type hexagonal ferrite magnetic powder; granulating and molding the powder to produce a molded article (preferably having a pellet-like form) and firing the molded article (preferably at 1150 to 1400°C) to produce a fired material; pulverizing the fired material (preferably roughly pulverizing the fired material by impact grinding with a hammer mill or the like and then wet-pulverizing the roughly pulverized product); and then subjecting the resultant powder to an annealing treatment (preferably at 800 to 1100°C).
Inventors:
YAMAJI HIDENORI (JP)
GOTOH MASAHIRO (JP)
GOTOH MASAHIRO (JP)
Application Number:
PCT/JP2021/004298
Publication Date:
August 19, 2021
Filing Date:
February 05, 2021
Export Citation:
Assignee:
DOWA ELECTRONICS MATERIALS CO (JP)
International Classes:
H01F1/11; C01G49/00; H05K9/00
Domestic Patent References:
| WO2016052483A1 | 2016-04-07 |
Foreign References:
| JP2009099969A | 2009-05-07 | |||
| JP2007250823A | 2007-09-27 | |||
| JP2016072635A | 2016-05-09 | |||
| JPH05170450A | 1993-07-09 | |||
| JP2012128904A | 2012-07-05 | |||
| JPH1092620A | 1998-04-10 | |||
| JP2020184599A | 2020-11-12 |
Attorney, Agent or Firm:
OKAWA Koichi (JP)
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