Long life medium and high ash oils with enhanced nitration resistance
AssigneeExxonMobil Research and Engineering Company
InventorsStanley James Cartwright, James Walter Finch
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Abstract
A long life lubricating oil as evidenced by a reduction in viscosity increase, oxidation and nitration, comprises a major amount of a base oil of lubricating viscosity and a minor amount of a mixture of high TBN, medium TBN and low/neutral TBN detergents wherein metal salicylate detergent is at least one of the medium or low/neutral TBN detergents.
Claims28
A long life lubricant comprising a major amount of an oil of lubricating viscosity and a minor amount of additives comprising a mixture of detergents comprising a first metal salt or group of metal salts selected from the group consisting of one or more metal salicylate(s), metal sulfonate(s), metal phenate(s), and mixtures thereof having a high Total Base Number (TBN) of greater than about 150 or higher used in an amount in combination with the other metal salts or groups of metal salts sufficient to achieve a lubricating oil of at least 0.65 wt % sulfated ash content, a second metal salt or group of metal salts selected from the group consisting of one or more metal salicylate(s) metal sulfonate(s), metal phenate(s) and mixture thereof having a medium TBN of greater than about 50 to 150, and a third metal salt or group of metal salts selected from the group consisting of one or more metal sulfonate(s), metal salicylate(s) and mixtures thereof having a low/neutral TBN of about 10 to 50, the total amount of medium plus low/neutral TBN detergents being about 0.7 vol % or higher (based on active ingredient), the total amount of high TBN detergents being about 0.3 vol % or higher (based on active ingredient) and the volume ratio (based on active ingredient) of high TBN detergent to medium plus low/neutral TBN detergent is in the range of about 0.15 to 3.5, wherein at least one of the medium or low/neutral TBN detergent(s) is metal salicylate.
A method for enhancing the life of a lubricating oil composition as evidenced by a reduction in viscosity increase, oxidation and nitration by adding to the oil a minor amount of additives comprising a mixture of detergents comprising a first metal salt or group of metal salts selected from the group consisting of one or more metal salicylate(s), metal sulfonate(s), metal phenate(s), and mixtures thereof having a high Total Base Number (TBN) of greater than about 150 or higher used in an amount in combination with the other metal salts or groups of metal salts sufficient to achieve a lubricating oil of at least 0.65 wt % sulfated ash content, a second metal salt or group of metal salts selected from the group consisting of one or more metal salicylate(s), metal sulfonate(s), metal phenate(s), and mixture thereof having a medium TBN of greater than about 50 to 150, and a third metal salt or group of metal salts selected from the group consisting of one or more metal sulfonate(s), metal salicylate(s) and mixtures thereof having a low/neutral TBN of about 10 to 50, the total amount of medium plus low/neutral TBN detergents being about 0.7 vol % or higher (based on active ingredient), the total amount of high TBN detergents being about 0.3 vol % or higher (based on active ingredient) and the volume ratio (based on active ingredient) of high TBN detergent to medium plus low/neutral TBN detergent is in the range of about 0.15 to 3.5, wherein at least one of the medium or low/neutral TBN detergent(s) is metal salicylate.
Dependencies are inferred from the claim text.