| abstract |
(57) [Summary] (Modified) [Structure] A composition obtained by adding an antiwear agent of the formula (I) to an organopolysiloxane. (In the formula, R 1 to R 4 are hydrogen, a monovalent hydrocarbon group having 1 to 20 carbon atoms, R 5 to R 7 are divalent hydrocarbon groups having 1 to 6 carbon atoms, X 1 to X 4 and Y is an oxygen atom or a sulfur atom and may be the same or different, but R 1 to R 4 may be directly bonded to the phosphorus atom without interposing Y, and n represents an integer of 0 to 2. However, when n is 0, both X 2 and X 3 represent a sulfur atom.) [Effect] This is excellent in heat resistance, hardly changes in viscosity, excellent in durability, and useful in operation and lubrication. -It is a composition for fluid coupling. |