Low ash natural gas engine oil and additive system
AssigneeExxon Research & Engineering Co.
InventorsAlan G. Blahey, James W. Finch
Life of this patent
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Abstract
The present invention is directed to a low ash natural gas engine oil which contains an additive package including a particular combination of detergents and also containing other standard additives such as dispersants, antioxidants, antiwear agents, metal deactivators, antifoamants and pour point depressants and viscosity index improvers. The low ash natural gas engine oil exhibits reduced deposit formation and enhanced resistance to oil oxidation and nitration.
Claims7
A method for enhancing the resistance of a natural gas engine oil to oxidation, nitration, deposits formation comprising adding to a natural gas engine oil base stock having a kinematic viscosity at 100.degree. C. of about 5 to 16 cSt a minor amount sufficient to contribute a sulfated ash content of about 0.1 to 0.6% ash by ASTM D-874 of an additive mixture comprising a mixture of detergents comprising at least one first alkali or alkaline earth metal salt or mixture thereof of low Total Base Number (TBN) of about 250 and less and at least one second alkali or alkaline earth metal salt or mixture thereof which is more neutral than the first low TBN salt.
Dependencies are inferred from the claim text.