Magnetic powder and production process thereof
US4668283A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 20, 1985 |
| Grant date | May 26, 1987 |
| Priority date | — |
| Expiry date | Jun 20, 2005 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2991
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Magnetic powder protected from subsequent oxidation and deterioration can be obtained by effecting contact of starting magnetic powder, which is formed of an intermetallic compound containing a rare-earth metal and an iron-group metal as principal components thereof, with a phosphorus compound containing at least one active proton having a pKa of 4 or smaller and exposure of the starting magnetic powder to an oxygen-containing atmosphere in an arbitrary order or simultaneously. Production of a plastic magnet with the magnetic powder of this invention allows to avoid danger and deterioration in magnetic characteristics of the resulting product due to oxidation of the magnetic powder even if exposed to elevated temperatures during its production or use.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.