Lubricating oil compositions
AssigneeInfineum International Limited
InventorsChristopher J. Locke, Isabel P. MacDonald
Life of this patent
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Abstract
A heavy duty diesel engine lubricating oil composition having no more than 0.10 wt. % phosphorus comprises an ashless dispersant, a neutral calcium phenate, an overbased calcium or magnesium sulfonate, a metal dihydrocarbyldithiophosphate, and a phenolic or aminic antioxidant.
Claims10
A heavy duty diesel engine lubricating oil composition comprising a major amount of oil of lubricating viscosity to which has been added:
- (a) a lubricating oil borated or non-borated ashless dispersant which has not more than 0.3, for example not more than 0.2, such as not more than 0.1, mass % boron, in a minor amount;
- (b) an oil-soluble neutral calcium phenate detergent in a minor amount;
- (c) an oil-soluble overbased calcium or magnesium sulfonate or mixture thereof present in a minor amount so that not more than 0.1, for example not more than 0.05, such as not more than 0.025, mass % magnesium is present in the composition;
- (d) a metal dihydrocarbyldithiophosphate present in such amount so that the phosphorus content of the composition is from 0.025 to 0.10, such as 0.05 to 0.07 or 0.08, mass %;
- and
- (e) a phenolic or aminic preferably a hindered phenol, antioxidant in a minor amount,
- the composition being free of any neutral metal sulfonate and any other neutral metal detergent, other than the phenate (b).
The composition of any preceding claim wherein there is present 0.2 to 2 mass % of the overbased calcium or magnesium sulfonate or mixture thereof.
The composition of any preceding claim wherein the metal dihydrocarbyldithiophosphate is a zinc dialkyldithiophosphate where the alkyl groups have 2 to 8 carbon atoms.
The composition of any preceding claim wherein there is present 0.1 to 1.5 mass % of antioxidant (e) in the form of a hindered phenol.
A concentrate for blending with an oil of lubricating viscosity to provide a heavy duty diesel engine lubricating oil composition, said concentrate comprising:
- (a) a lubricating oil borated or non-borated ashless dispersant which has not more than 0.3, for example not more than 0.2, such as not more than 0. 1, mass % boron;
- (b) an oil-soluble neutral calcium phenate detergent;
- (c) an oil-soluble overbased calcium or magnesium sulfonate or mixture thereof present in such an amount so that not more than 0.3 mass % magnesium is present in the concentrate;
- (d) a metal dihydrocarbyldithiophosphate present in such amount so that the phosphorus content of the concentrate is up to 0.7 mass %;
- and
- (f) a phenolic or aminic, preferably a hindered phenol, antioxidant,
- the concentrate being free of any neutral metal sulfonate and any other neutral metal detergent, other than the phenate (b).
Dependencies are inferred from the claim text.