Preparation of magnetorheological fluid useful in clutches, or vibration control units, involves dispersing magnetic particles coated with hydrophilic surfactant in a mobile phase of water in oil emulsion

摘要

A process for preparing a magnetorheological fluid comprises: (1) stirring water and oil dissolved in emulsifier to give a mobile phase of water in oil emulsion (I); (2) reacting magnetic particles with a hydrophilic surfactant in a vacuum oven at 20-80 [deg]C for 10-30 minutes, washing, and drying to give magnetic particles coated with the surfactant (II); and (3) dispersing (II) in (I) in an amount 5-50 vol.%. An independent claim is also included for a magnetorheological fluid prepared by this process.