Magnetic particles
US5217804A · kind A · utility
53Cited by
10References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 6, 1990 |
| Grant date | Jun 8, 1993 |
| Priority date | — |
| Expiry date | Nov 6, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31971
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Magnetic particles are cobalt surface treated gamma iron oxide (Fe.sub.2 O.sub.3) having a specific area of at least 30 m.sup.2 /g and a powder coercivity greater than about 450 Oe, the particles being coated with from about 10 to about 50% by weight of a material having a refractive index less than about the refractive index of a binder for the particles.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.