Aminated polymeric additives for fuel and lubricants

Claim 1

In a process for aminating and thereafter decreasing the molecular weight of an olefin copolymer to form an oil-soluble aminated copolymer useful as a sludge dispersing-viscosity index improving, additive for lubricating oil, the improvement which comprises: (a) carrying out said amination without substantial molecular weight degradation of said copolymer by mechanically working a mixture consisting essentially of amine and said copolymer at a temperature of about 130° to 260° C., under an inert gas atmosphere, for about 0.5 to 12 hours to thereby incorporate about 0.01 to 0.5 weight percent nitrogen into said copolymer, wherein said copolymer is a copolymer having a number average molecular weight in the range of about 700 to 250,00 and consists essentially of ethylene in an amount in the range of 2 to 98 wt. %, and one or more C 3 to C 28 alpha-olefins, and wherein said amine is a saturated, aliphatic hydrocarbyl polyamine of 3 to 20 carbon atoms and 2 to 6 nitrogen atoms; and, (b) thereafter, mechanically-oxidatively degrading said copolymer product in the presence of an oxygen-containing gas and at an elevated temperature in the range of about 95° C. to 260° C. for a period of from about 0.25 to 20 hours whereby the number average molecular weight of said copolymer is reduced.