| abstract |
The invention provides a fluid composition for a fluid coupling, which is excellent in viscosity stability and torque stability, and comprises a polyorganosiloxane base oil having a viscosity of 3,000-500,000 mm²/sec at 25°C and at least one 5-membered heterocyclic compound incorporated in a proportion of 0.01-3.0 wt.% based on the total weight of the composition, said 5-membered heterocyclic compound being selected from the group consisting of thiadiazole derivatives and thiazole derivatives, both, having at least one monovalent group represented by the formula -S x -R⁶ in which R⁶ is a saturated or unsaturated monovalent group or atom composed of at least one atom selected from a carbon atom, a hydrogen atom, an oxygen atom, a nitrogen atom and a sulfur atom, and x is a number of 1 or greater. |