Process for the preparation of aqueous dispersions of magnetizable polymer particles with a desired size narrow distribution, and aqueous dispersions thereof, and uses thereof
US5242964A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 29, 1991 |
| Grant date | Sep 7, 1993 |
| Priority date | — |
| Expiry date | Jul 29, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2995
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A process for the preparation of aqueous dispersions of magnetizable polymer particles with a narrow distribution from aqueous dispersions with a wide distribution. The amount of water in the aqueous dispersion with a wide distribution is adjusted so that the proportion by weight of magnetizable polymer particles is between about 1 and 40% of said dispersion. The surfactant concentration of the dispersion after the water adjustment is increased until two phases are obtained: a so-called liquid phase and a so-called solid phase. After separation of these two phases is accomplished, these steps are repeated as desired. An aqueous dispersion with a narrow size distribution is recovered.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.