Permanent magnet and method of producing the same

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EP 0 289 680 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	06.06.1990 Bulletin 1990/23

(43)	Date of publication A2:
	09.11.1988 Bulletin 1988/45

(21)	Application number: 87308666.4

(22)	Date of filing: 30.09.1987

(51)	International Patent Classification (IPC)⁴: H01F 1/053, H01F 41/02

(84)	Designated Contracting States:
	AT CH DE FR GB IT LI NL

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Priority:

30.04.1987 JP 104623/87

(71)	Applicant: SEIKO EPSON CORPORATION
	Shinjuku-ku Tokyo-to (JP)

(72)	Inventors:
	Akioka, Koji Suwa-shi Nagano-ken (JP) Kobayashi, Osamu Suwa-shi Nagano-ken (JP) Shimoda, Tatsuya Suwa-shi Nagano-ken (JP)

(74)	Representative: Sturt, Clifford Mark et al
	J. MILLER & CO. 34 Bedford Row, Holborn London WC1R 4JH London WC1R 4JH (GB)

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References cited: :

(54)	Permanent magnet and method of producing the same

(57) A permanent magnet made from an alloy comprising at least one rare earth element, iron and boron characterised in that the average grain diameter of the crystals of the alloy is not more than 150 µm, the carbon content and the oxygen content of the alloy being not more than 400 ppm and not more than 1000 ppm respectively.

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