| abstract |
PURPOSE:To obtain an electroviscous fluid capable of revealing a high electroviscous effect in both low and high temperature regions and improved in long-term stability by combining a fine organic conductive polymer powder having a specified electron spin density with an electrical insulating oil. CONSTITUTION:This electroviscous fluid is formed from a fine organic conductive polymer powder having an electron spin density of at least 10<17>/g and an electrical insulating oil. As the conductive polymer, those obtained by oxidative polymerization followed by dedoping are used. Examples of the conductive polymer include a polyaniline and its derivative, a polypyrrole, and a polythiophene, among which a polyaniline or its derivative is preferably used. Dedoping can be effected by electrochemical reduction, chemical reduction with a catalyst such as hydrazine, alkali treatment, etc.; however, alkali treatment is desirable since the conductivity of the conductive polymer can be reduced most effectively by adjusting the pH. |