Flat-paticle iron powder, method for making the same and powder magnetic core using the same

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(11)

EP 0 997 915 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	21.06.2000 Bulletin 2000/25

(43)	Date of publication A2:
	03.05.2000 Bulletin 2000/18

(21)	Application number: 99119376.4

(22)	Date of filing: 29.09.1999

(51)	International Patent Classification (IPC)⁷: H01F 1/20, H01F 1/24, H01F 3/08, H01F 41/02

(84)	Designated Contracting States:
	AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
	Designated Extension States:
	AL LT LV MK RO SI

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Priority:

30.10.1998 JP 27787898

(71)	Applicants:
	Kawasaki Steel Corporation Kobe-shi, Hyogo 651-0075 (JP) VICTOR COMPANY OF JAPAN, LIMITED Yokohama-shi, Kanagawa 221-8528 (JP)

(72)	Inventors:
	Ozaki, Yukiko, c/o Tech. Res. Laboratories Chiba 260-0835 (JP) Ogura, Kuniaki, c/o Tokyo Head Office Chiyoda-ku, Tokyo 100-0011 (JP) Yashiro, Tsutomu Mito-shi, Ibaraki 310-0836 (JP) Murai, Tsuneo Iwai-shi, Ibaraki 306-0632 (JP) Hishiki, Hideo Iwai-shi, Ibaraki 306-0632 (JP)

(74)	Representative: Grünecker, Kinkeldey, Stockmair & Schwanhäusser Anwaltssozietät
	Maximilianstrasse 58 80538 München 80538 München (DE)

(54)	Flat-paticle iron powder, method for making the same and powder magnetic core using the same

(57) A flat-particle iron powder, composed of reduced iron powder obtained by reducing iron oxide, has an average aspect ratio of at least 5 and an average ferrite grain size of 2 to 20 µm, is preferably used for a powder magnetic core, has high permeability over a higher frequency region, and is covered with a compound having an amine-quinone-repeating unit to further improve its magnetic characteristics.

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