| 摘要 |
PURPOSE:To lower the bulk density of a carrier, to increase a saturated magnetization and to increase the electric resistance by forming complex particles from a specific high magnetic fine particles and a phenol resin and covering the particle surface with a specified polymer. CONSTITUTION:This magnetic carrier has 10-1000mum of a number mean particle size, and <=2.0 g/cm<2> of a bulk density. The surface of the complex particle (A) with a content of 80-99 wt.% of fine particles of high magnetic material, is covered with an acrylonitrile type polymer. The particle A is composed of the fine particles of high magnetic material and a cured phenol resin and this particle A is preferred to produce by reacting a phenol group with an aldehyde group in the presence of that fine particles, a suspension stabilizer and a basic catalyst. Also in a water type medium an acrylonitrile monomer if polymerized and the particle A is preferred to be covered with it. |
