Patent ID: 6903055

Claim:
Lubricating oil composition comprising a polyalkyleneglycol derivative of the formula (I): RX(R a O) x (R b O) y (R c O) z R d (I) wherein: X═O or S, R comprises a C 4 to C 6 heterocyclic moiety derived from tetrahydrofuran, methyltetrahydrofuran, tetrahydrothiophene, methyltetrahydrothiophene, furfuryl or tetrahydrofurfuryl, which is attached to X either directly or via a hydrocarbyl linkage, R a is a C 2 alkylene group, R b is a C 3 alkylene group, R c is a C 4 alkylene group, R d is the same as R, or is H, a C 1 -C 20 alkyl or a C 1 -C 20 acyl, x, y, z are each independently 0 or an integer of 100 or less, and x+y+z=4 to 100.