| 摘要 |
PROBLEM TO BE SOLVED: To provide an electroviscous fluid which changes its viscosity in a broad level range in accordance with applied voltage and shows reversible viscosity change characteristics to exhibit the required electroviscous effect, and a method for the preparation of the same. SOLUTION: A desired electroviscous fluid contains 5-50 wt.% titanium oxide particles having an average particle diameter of 0.03-0.20μm and a weight decrease up to 950 deg.C by thermogravimetry of 1-7 wt.%. Preferred titanium dioxide are the ones obtained by hydrothermal treatment of titania sol at 110-170 deg.C or by coating at least one type of oxides or water-containing oxides of silicon, aluminum or titanium in an amount of 1-20 wt.% as SiO2, Al2O3 or TiO2. The electroviscous fluid is prepared by forming titania sol from meta titanic acid, neutralizing, filtering and washing the resulting titania sol and then, rendering it an aqueous slurry of 50-200 g/L water, adjusting the pH to 7-9, subjecting the resulting slurry to hydrothermal treatment at a temperature of 110-170 deg.C and then, filtering, washing and drying the product and subsequently, cracking the resulting product to obtain titanium oxide particles, and dispersing the titanium oxide particles thus obtained into an electrical insulating solvent.
|
