| (19) |
 |
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(11) |
EP 0 421 488 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
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28.08.1991 Bulletin 1991/35 |
| (43) |
Date of publication A2: |
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10.04.1991 Bulletin 1991/15 |
| (22) |
Date of filing: 22.07.1987 |
|
| (51) |
International Patent Classification (IPC)5: H01F 1/053 |
|
| (84) |
Designated Contracting States: |
|
DE FR GB |
| (30) |
Priority: |
23.07.1986 JP 172987/86
07.08.1986 JP 185905/86
14.10.1986 JP 243490/86
06.01.1987 JP 85787/87
|
| (62) |
Application number of the earlier application in accordance with Art. 76 EPC: |
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87110634.0 / 0258609 |
| (71) |
Applicant: HITACHI METALS, LTD. |
|
Chiyoda-ku,
Tokyo 100 (JP) |
|
| (72) |
Inventors: |
|
- Tokunaga, Masaaki
Fukaya-shi,
Saitama (JP)
- Endoh, Minoru
Kumagaya-shi,
Saitama (JP)
- Kogure, Hiroshi
Kumagaya-shi,
Saitama (JP)
|
| (74) |
Representative: Strehl Schübel-Hopf Groening & Partner |
|
Maximilianstrasse 54
80538 München
80538 München (DE) |
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| |
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|
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Remarks: |
|
This application was filed on 07 - 11 - 1990 as a divisional application to the application
mentioned under INID code 60. |
|
| (54) |
Permanent magnet with good thermal stability |
(57) A permanent magnet having good thermal stability, consisting essentially of the composition
represented by the general formula:
R(Fe
1-x-y-z-uCo
xB
yGa
zM
u)
A
wherein R is Nd alone or one or more rare earth elements mainly composed of Nd, Pr
or Ce, part of which may be substituted by Dy, Tb or Ho, M is one or more elements
selected from Nb, W, V, Ta and Mo, 0≦x≦0.7, 0.02≦y≦0.3, 0.001≦z≦0.15, 0.001≦u≦0.1
and 4.0≦A≦7.5.