| abstract |
A graft polymer and lubricating oil compositions thereof, said polymer functioning as a multipurpose lube oil additive having viscosity index improving properties, pour depressing properties and detergent-dispersant properties, said graft polymer comprising an oil soluble substantially linear hydrocarbon terpolymer backbone having grafted thereon polymethacrylate polymers, said terpolymer backbone composed of ethylene, terminally unsaturated straight chain alkene of 3 to 12 carbons and terminally unsaturated non conjugated diolefin of 5 to 8 carbons, said polymethacrylate graft being composed of monomer member(s) selected from the group consisting of (1). N,Ndialkylaminoalkyl methacrylate, (2). a mixture of C10-C15 alkyl methacrylate and C16-C20 alkyl methacrylate and (3). a mixture of 1 and 2. |