Polymer lubricating oil additives bearing nitrogen groups and their use as additives for lubricating oils

Abstract

Novel lubricating oil polymer additives are obtained by the following: (1) by preparing, by anionic polymerization, a living diene polymer of an Mn of between about 20,000 and 300,000; (2) by functionalizing the said polymer by means of a non-polymerizable nitrogen compound having at least two <C--N=C> groups, such as the polypyridines, pyrimidine and its derivatives, pyrazine and its derivatives, 2,4,6-tri-(2-pyridyl)-1,3,5-triazine, dipyridyl sulfide, etc.; and (3) by hydrogenating the said functionalized polymer. A variant method of preparaing the said polymers comprises metalating the living polymer before functionalization; in accordance with this variant, the hydrogenation operation may take place before metalation or after functionalization. The said polymers can be used as additives which improve the viscosity index and the dispersing power of the lubricating oils. The amount of additive added is between about 0.1 and 10 percent by weight.

Dependencies are inferred from the claim text.