Magnet powder-resin compound particles, method for producing such compound particles and resin-bonded rare earth magnets formed therefrom
USRE40524E1 · kind E1 · reissue
Assignee
Inventors
Key dates
| Filing date | Jul 20, 2004 |
| Grant date | Sep 30, 2008 |
| Priority date | — |
| Expiry date | Jul 20, 2024 |
Classification
- Technology area (CPC —)General
Abstract
The magnet powder-resin compound particles substantially composed of rare earth magnet powder and a binder resin are in such a round shape that a ratio of the longitudinal size a to the transverse size b (a/b) is more than 1.00 and 3 or less, and that an average particle size defined by (a/b)/2 is 50-300 μm. They are produced by charging a mixture of rare earth magnet powder and a binder resin into an extruder equipped with nozzle orifices each having a diameter of 300 μm or less; extruding the mixture while blending under pressure though the nozzle orifices to form substantially cylindrical, fine pellets; and rounding the pellets by rotation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.