Hydrolytically stable viscosity index improvers

摘要

An acrylic acid ester polymer having improved characteristics and oleaginous compositions containing the acrylic acid ester polymer. The acrylic acid ester polymer includes a copolymer derived from a first acrylic acid ester monomer having from about 1 to about 4 carbon atoms, a second acrylic acid ester monomer having from about 12 to about 14 carbon atoms, and a third acrylic acid ester monomer having from about 16 to about 20 carbon atoms. The copolymer has a weight average molecular weight ranging from about 20,000 to about 100,000 daltons and contains no more than about 1 weight percent unreacted monomer.