| 摘要 |
PURPOSE:To obtain an electroviscous fluid improved in the Winslow effect by dispersing silica particles obtained by substituting water adsorbed on the surfaces of wet silica particles with a specific organic compound in an electrical insulating liquid. CONSTITUTION:An electroviscous fluid is prepared by dispersing in an electrical insulating liquid 0.1-50wt.% silica particles obtained by substituting water adsorbed on the surfaces of wet silica particles with an organic compound containing in each molecule at least one nitrile, hydroxyl or acid group. As the wet silica particles, use may be made of those with an average particle size of 10-500mum and a pH of a 4wt.% suspension of 6.5 or less. Examples of the organic compound include acetonitrile, benzonitrile, methanol, ethanol, acetic acid and propionic acid. As the electrical insulating liquid, silicone oil is desirable. In particular, diorganopolysiloxane containing a fluoroalkyl group is desirable since it can help the Winslow effect to be manifested more successfully and can prevent sedimentation of the particles due to a difference in specific gravity. |
