To obtain a multifunctional additive which acts as a viscosity modifier and a dispersant for lubricating oils and fuels by incorporating a hydrocarbon polymer having specific pendant groups bonded thereto and a specified mol.wt. into the same.
This additive contains a hydrocarbon polymer which, when it is not a star polymer, has an Mn of 20,000 to about 500,000 and when it is a star polymer, has a GPC peak mol.wt. of up to about 4,000,000 and which has pendant groups Aa and Bb bonded thereto. Here, A is a group of formula I, and B is a group of formula II. In the formulas, R3 is II or hydrocarbyl; R4 is a divalent hydrocarbylene; n is 0 or 1; R9 and R10 are each H, alkoxyhydocarbyl, aminohydrocarbyl, or the like; X is O, S, or NRb; Rb is H, NH2, or the like; Z is a group of formula III; Ra is ethylene or propylene; a is 0 to about 50; and b is 1 to about 30. Pref. examples of the hydrocarbon polymer are a diene polymer, a conjugated diene-vinylarom. compd. copolymer, and a polymer of a 2 to about 28C aliph. olefin.
LANGE RICHARD M
VARGO DANIEL M
ADAMS PAUL E
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