| 摘要 |
PURPOSE:To provide a method for producing a magnetic fluid which is obtained by dispersing fine ferrite particles containing an adsorbed surfactant comprising a phosphoric ester having a mono or di-oxyalkylene substituent in a base oil having a low vapor pressure using a surfactant comprising a phosphoric ester having a mono- or dioxyalkylene substituent and which has a greatly reduced viscosity and greatly prolonged life. CONSTITUTION:In this method for producing a magnetic fluid by dispersing fine ferrite particles containing an adsorbed surfactant comprising a phosphoric ester having a mono- or di-oxyalkylene substituent in a base oil of low vapor pressure based on a phosphoric triester using a surfactant comprising a phosphoric ester having a mono or di-oxyalkylene substituent, fine magnetite particles which contain an adsorbed surfactant comprising a phosphoric ester having a mono-or di-oxyalkylene substituent and which are treated and dispersed with a toluene/ethanol mixture and agglomerated with acetone from the centrifugally separated supernatant liquid, are used. |
