| 摘要 |
PURPOSE:To provide a magnetic fluid greatly lowered in viscosity, by dispersing fine ferrite particles having a surfactant adsorbed thereon in a low-vapor- pressure base oil using a phosphoric ester dispersant. CONSTITUTION:In a magnetic fluid prepd. by dispersing fine ferrite particles having a surfactant adsorbed thereon in a low-vapor-pressure phosphoric triester base oil using as a dispersant a phosphoric ester having a mono- or di- oxyalkylene substituent, an alkali metal salt or ammonium salt of an unsatd. fatty acid having a double bond in a molecular terminal thereof or a satd. fatty acid having an aryl group in a molecular terminal thereof is used as the surfactant adsorbed on the fine ferrite particles. |
