Patents Assigned to Exxon Chemical Limited
  • Patent number: 5789355
    Abstract: This invention relates to low volatility 5W20, 5W30, 10W40, 10W50, 15W40 or 15W50 multigrade oils for crankcase lubrication of gasoline and diesel engines, the oils comprising:a) basestock having an average basestock neutral number of not less than 105 for a 5W multigrade, not less than 145 for a 10W multigrade and not less than 200 for a 15W multigrade,b) a detergent inhibitor package including an ashless dispersant comprising an oil soluble polymeric hydrocarbon backbone having functional groups in which the hydrocarbon backbone is derived from an ethylene alpha-olefin (EAO) copolymer or alpha-olefin homo- or copolymer having an M.sub.n of from 500 to 7000, and preferably having >30% of terminal vinylidene unsaturation, andc) a viscosity modifier.These multigrade crankcase oils provide better volatility with reduced use or even without the need for expensive light neutral basestocks or non-conventional lubricant basestocks, while at the same time providing adequate control of sludge and varnish.
    Type: Grant
    Filed: December 20, 1996
    Date of Patent: August 4, 1998
    Assignee: Exxon Chemical Limited
    Inventors: David Robert Adams, Paul Brice