| 摘要 |
PURPOSE:To provide an electroviscous fluid showing a delayed field-responsing reaction and capable of application, e.g. to a delayed switch for idling. CONSTITUTION:An electroviscous fluid in which electrical insulating particles containing a polyamide resin carrying a metal salt adsorbed thereon are dispersed in an electrical insulating dispersion medium. An electrical insulating oil such as a silicone oil is especially preferable as the dispersion medium and a univalent or divalent copper halide as the metal salt. In an electroviscous fluid in this invention, viscosity increase is not recognized by application of an electric field thereto although the metal salt is dissociated to a cation and an anion and desorbed from the polyamide resin. If the applied electric field is subsequently removed, the viscosity temporarily increases by formation of an electrical bond between the dispersed particles through the cation and the anion of the metal salt, due to competitive adsorption of the cations and the anions of the metal salt between the polyamide resin particles, derived from temporary formation of dipole at amide bond parts of the respective polyamide resins. |
