Polar grafted polyolefins, methods for their manufacture, and lubricating oil compositions containing them
申请人:——
公开号:US20020042349A1
公开(公告)日:2002-04-11
A grafted polyolefin containing one or more of N-vinylimidazole, 4-vinylpyridine, or other ethylenically-unsaturated nitrogen-containing or oxygen-containing graftable monomers grafted to a polyolefin copolymer is disclosed. The grafted polyolefin preferably has a weight average molecular weight of from about 20,000 to about 500,000, a polydispersity of less than about 10, and an ADT value of at least about 8. The grafted polyolefin can be defined as containing more than about 1.2% by weight of grafted monomer on a polyolefin, or as containing at least about 13 moles of graftable monomers per mole of polyolefin, or as having an asphaltene dispersancy test (ADT) value of at least about 8. Also described is a lubricating oil comprising a lubricant base oil and a grafted polyolefin as described above. Also described is a method of making a dispersant viscosity index improver. N-vinyl-imidazole or other ethylenically unsaturated nitrogen-containing and/or oxygen-containing graftable monomers and a graftable polyolefin are reacted with enough of an initiator to graft the monomer to the polyolefin. The initiator and/or graftable monomer is added to the other ingredients, maintained at the reaction temperature, over a period of time. The reaction temperature is maintained at a level high enough to give acceptable reaction times. The N-vinylimidazole and the initiator each can be added at a uniform, relatively slow rate during the reaction.
本发明公开了一种接枝聚烯烃,它含有接枝到聚烯烃共聚物上的一种或多种 N-乙烯基咪唑、4-乙烯基吡啶或其他乙烯基不饱和含氮或含氧可接枝单体。接枝聚烯烃最好具有约 20,000 至约 500,000 的重量平均分子量、小于约 10 的多分散性和至少约 8 的 ADT 值。还描述了一种润滑油,包括润滑油基础油和上述接枝聚烯烃。还描述了一种制造分散剂粘度指数改进剂的方法。将 N-乙烯基咪唑或其他乙烯基不饱和含氮和/或含氧可接枝单体和可接枝聚烯烃与足够的引发剂反应,以将单体接枝到聚烯烃上。将引发剂和/或可接枝单体添加到其他成分中,并在反应温度下保持一段时间。反应温度要保持在足够高的水平,以提供可接受的反应时间。在反应过程中,N-乙烯基咪唑和引发剂可以以相对缓慢的速度均匀加入。