PURPOSE: To obtain an electroviscous fluid with improved stability to an extract of rubber, resin or the like by dispersing particles with prescribed water and oxygen contents in an insulating oily medium in the presence of a compound with hydrophilic groups.
CONSTITUTION: A non-aqueous electroviscous fluid containing 0.01 to 10wt.% compound with hydrophilic groups, which is obtained by dispersing organic or inorganic powder having a water content and an oxygen atom content of less than 1wt.% and less than 10wt.%, respectively, in an insulating oily medium. The compound with hydrophilic groups means a compound in which part or the whole of its molecule consists of hydrophilic functional groups. The compound is required to have an HLB value (representing the properties of a surfactant) of not less than 0.03. Examples of the group constituting a hydrophilic group include an ether bond, a carbonyl group, a hydroxy group, an amino group and a sulfone group.
OSAKI TOSHIYUKI
TANAKA MITSUYA
ISHINO YUICHI
SAITO TASUKU
