| 摘要 |
PURPOSE:To obtain in good yield a magnetic fluid improved in saturation mag netization by sonicating fine ferrite particles to cause the particles to adsorb an N-polyalkylenepolyamine-substituted alkenylsuccinimide. CONSTITUTION:A solution of an N-polyalkylenepolyamine-substituted alkenylsuccinimide in an organic solvent insoluble or hardly soluble in water is added to an aqueous suspension of fine ferrite particles with agitation to form an emulsion. This emulsion is sonicated to cause the particles to adsorb the alkenylsuccinimide. Water and the organic solvent are then distilled off, and the residual ferrite particles adsorbing the N-polyalkylenepolyamine-substituted alkenylsuccinimide are dispersed in a base oil having a vapor pressure as low as 1.0mmHg or less at 25 deg.C to give the objective magnetic fluid. |
