Magnetic particles
US4873102A · kind A · utility
48Cited by
5References
13Claims
0Family size
Inventors
Key dates
| Filing date | Mar 14, 1988 |
| Grant date | Oct 10, 1989 |
| Priority date | — |
| Expiry date | Mar 14, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2446/10
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Magnetic polymer particles are formed by swelling porous, polymer particles and impregnating the particles with an aqueous solution of precursor magnetic metal salt such as an equimolar mixture of ferrous chloride and ferric chloride. On addition of a basic reagent such as dilute sodium hydroxide, the metal salts are converted to crystals of magnetite which are uniformly contained througout the pores of the polymer particle. The magnetite content can be increased and neutral buoyancy achieved by repetition of the impregnaton and neutralization steps to adjust the magnetite content to a desired level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.