| 摘要 |
PURPOSE:To prevent the oxidation of ferrite and to stably store the fine particles for a long period by preserving the submicron ferrite fine particles produced by wet coprecipitation or wet oxidation in an alkaline soln. with the pH specified. CONSTITUTION:Submicron ferrite fine particles are produced by wet coprecipitation or wet oxidation. The particles are preserved as such without being washed, and the particles are taken out, as required, washed and used. Since the particles are preserved in an alkaline atmosphere having the potential identical with the zero surface potential of the particle, the potential difference between the surface of the particle and the environment is eliminated, and the ferrous ion in the ferrite is not oxidized to ferric ion during the preservation. The submicron ferrite fine particles are of great use as the material for a ferrite core, the toner carrier of a copying machine, etc. |
