PARTICLE CONTAINING MAGNETICALLY REACTIVE SUBSTANCE AND PREPARATION THEREOF

摘要

PURPOSE: To prepare particles containing a magnetically responsive laminate material having a very narrow particle size distribution and a dispersant without any classification steps by adding a base to the mixture obtained by mixing the magnetically responsive material with the dispersant. CONSTITUTION: The mixture is formed by mixing the magnetically responsive material such as magnetite with the dispersant such as dextran. The formed mixture is suspended in a gel phase of gelatin, etc., which is then brought in contact with the base such as sodium hydroxide for an appropriate time under appropriate conditions to form magnetically responsive material-dispersant particles. These particles comprise the magnetically responsive material and the dispersant and >=90% of the particles have about 2-10 nm particle size.