Compositions for hydraulic, lubricating and coupling

A composition for use in a viscous coupling, comprising an organopolysiloxane having a viscosity of 1,000 to 300,000 cSt at 25.degree. C. and of the formula:

• ##STR12## wherein each R represents a hydrocarbon group containing 1 to 18 carbon atoms, which may be halogenated, and n is an integer of 1 to 3,000:
• and, as an anti-wear agent, at least one compound of formulas (I) to (IV) alone or together with a storage stabilizer:
• ##STR13## wherein each of R.sub.1 to R.sub.4 is hydrogen or a monovalent hydrocarbon group containing 1 to 20 carbon atoms;
• each of R.sub.5 to R.sub.7 is a divalent hydrocarbon group containing 1 to 6 carbon atoms;
• each of X.sub.1 to X.sub.4 is oxygen or sulfur;
• Y is either a direct bond or oxygen or sulfur;
• and n is an integer of 0 to 2, provided that both X.sub.2 and X.sub.3 are sulfur when n is 0;
• ##STR14## wherein R.sub.1 to R.sub.7, X.sub.1 to X.sub.4, Y and n are as defined in formula (I):
• ##STR15## wherein each of R.sub.1 to R.sub.4 is hydrogen or a monovalent hydrocarbon group containing 1 to 20 carbon atoms;
• each of R.sub.5 and R.sub.6 is a divalent hydrocarbon group containing 1 to 6 carbon atoms;
• each of X.sub.1 to X.sub.4 is oxygen or sulfur;
• and Y is either a direct bond or oxygen or sulfur;
• and n is an integer of 0 to 2, ##STR16## wherein each of R.sub.1 and R.sub.2 is hydrogen or a monovalent hydrocarbon group containing 1 to 20 carbon atoms;
• R.sub.8 is a hydrocarbon group containing 1 to 20 carbon atoms and containing at least one ester bond;
• each of X.sub.1 and X.sub.2 is oxygen or sulfur;
• and Y is either a direct bond or oxygen or sulfur.