Lubricating oil composition

Abstract

To provide a lubricant composition having improved nitrile elastomer seal compatibility by including a sulfur-containing antioxidant and an alkene.SOLUTION: Disclosed herein is a lubricant composition, wherein the composition contains, or is produced by mixing (A) a large amount of oil having lubrication viscosity; (B) one or more kinds of an oil-soluble or oil-dispersible sulfur-containing antioxidant as an additive of effective small amount to impart 0.01 mass% or more sulfur to the lubricant composition; and (C) one or more kinds of oil-soluble or oil-dispersible alkene containing 10 or more carbon atoms as an additive of effective small amount.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to lubricating oil compositions for automobile engines (automotive lubricating oil compositions), particularly crankcase lubricating oil compositions. More specifically, but not exclusively, the present invention relates to crankcase lubricating oil compositions (crankcase lubricants) for use in gasoline (spark ignition) and diesel (compression ignition) internal combustion engines. In particular, the present invention relates to lubricating oil compositions containing a sulfur-containing additive component, such as a sulfur-containing antioxidant additive component, which typically provide improved performance when used to lubricate automobile engines. Nitrile Elastomer Seal The present invention relates to lubricating oil compositions that exhibit improved nitrile elastomer seal compatibilization performance. Similarly, the present invention relates, but is not exclusive to, lubricating oil compositions containing a sulfur-containing additive component, e.g., a sulfur-containing antioxidant component, that exhibit improved copper and / or lead corrosion performance when used to lubricate an automobile engine. Furthermore, the present invention also relates to the use of an alkene(s) as an additive component in a lubricating oil composition containing a sulfur-containing additive component, particularly a sulfur-containing antioxidant component, to reduce incompatibility with the sulfur-containing additive component with nitrile elastomer seal(s) and / or reduce copper and / or lead corrosion associated with the sulfur-containing additive component when the lubricating oil composition is used to lubricate an engine, such that such improvements in nitrile seal compatibilization performance and / or copper and / or lead corrosion performance are generally achievable while substantially maintaining the antioxidant performance of the lubricating oil (i.e., without substantially affecting the effectiveness of the sulfur-containing antioxidant additive component). [Background technology]

[0002] Lubricating oil compositions for automotive engines (e.g., crankcase lubricants) contain additives to enhance the performance characteristics of the lubricant, as typically required by consumers and engine manufacturers prior to warranting use of a particular lubricant in these engines. However, concurrent with the desire to enhance the performance characteristics of the lubricant, there is a continuing effort to reduce the sulfated ash, phosphorus, and sulfur content of the lubricant, both due to environmental considerations and to ensure compatibility with pollution control devices (e.g., catalytic converters and particulate traps). There are many types of additives for lubricating oil compositions used to enhance engine performance. While a particular additive may exhibit benefits in one aspect of engine performance, the same additive may also exhibit detrimental effects in another aspect. Sulfur-containing compounds have been considered as alternative and complementary additive components in lubricating oils, particularly for their antioxidant performance properties; however, these sulfur-containing compounds have been used with limited and varying degrees of success, primarily due to the sulfur content of such compounds and the introduction of sulfur into the lubricating oil, which is associated with copper and / or lead corrosion (especially copper corrosion), and poor compatibility with nitrile elastomer seals present in modern internal combustion engines and transmissions. Prior to certifying lubricants for use in their engines, engine manufacturers (often referred to as "OEMs") must ensure that the lubricating oil: Nitrile Elastomer Seal The materials must pass a number of performance tests, including tests for compatibility with lead and copper, and lead corrosion tests. Summary of the Invention [Problem to be solved by the invention]

[0003] Accordingly, the present invention is directed to providing a lubricating oil composition (particularly a lubricating oil composition for an automotive internal combustion engine) containing a sulfur-containing additive component, preferably a sulfur-containing antioxidant additive component, which composition, in use, preferably does not significantly impair the antioxidant performance associated with the sulfur-containing additive: Nitrile Elastomer SealSimilarly, the present invention also aims to provide lubricating oil compositions containing sulfur-containing additive compounds, preferably sulfur-containing antioxidant additives, wherein the lubricating oil compositions exhibit improved copper corrosion and / or lead corrosion performance property(ies), particularly copper corrosion performance properties, preferably without significantly impairing the antioxidant performance associated with the sulfur-containing additive. [Means for solving the problem]

[0004] According to a first aspect, the present invention provides a lubricating oil composition comprising: (A) Oil with a large amount of lubricating viscosity; (B) one or more oil-soluble or oil-dispersible sulfur-containing antioxidants as additives in a minor amount effective to provide the lubricating oil composition with at least 0.01 wt. % sulfur; and (C) one or more oil-soluble or oil-dispersible alkenes containing 10 or more carbon atoms as an effective minor additive; or is produced by mixing these. Preferably, the lubricating oil compositions of the present invention are crankcase lubricating oils for internal combustion engines. Suitably, the lubricating oil compositions of the present invention are suitable for lubricating gasoline (spark ignition) and diesel (compression ignition) internal combustion engines.

[0005] Unexpectedly, one or more oil-soluble or oil-dispersible alkenes (C), as defined herein, containing 10 or more carbon atoms (preferably 12 or more carbon atoms), are present in modern internal combustion engines in lubricating oil compositions containing a large amount of an oil of lubricating viscosity and one or more oil-soluble or oil-dispersible sulfur-containing antioxidants (B), as defined herein, as additives in effective minor amounts. Nitrile Elastomer SealIt has been found that one or more oil-soluble or oil-dispersible alkenes (C) containing 10 or more carbon atoms (preferably 12 or more carbon atoms), as defined herein, can be used as additives in effective small amounts to improve the compatibility of the lubricating oil composition with the sulfur-containing antioxidant additive (B). Moreover, the improvement in compatibility of nitrile elastomer seals can typically be achieved while substantially maintaining the antioxidant performance characteristics of the lubricating oil composition and / or the sulfur-containing antioxidant additive (B) (i.e., without substantially impairing the effectiveness of the sulfur-containing antioxidant additive). Thus, when one or more oil-soluble or oil-dispersible alkenes (C) containing 10 or more carbon atoms (preferably 12 or more carbon atoms), as defined herein, are used as additives in effective small amounts in a lubricating composition, and the lubricating oil composition is used to lubricate an engine, particularly an internal combustion engine, the improvement in compatibility of nitrile elastomer seals can be achieved while substantially maintaining the antioxidant performance characteristics of the lubricating oil composition and / or the sulfur-containing antioxidant additive (B) (i.e., without substantially impairing the effectiveness of the sulfur-containing antioxidant additive). Nitrile Elastomer Seal It has been found that it is possible to prevent or inhibit incompatibility between the sulfur-containing antioxidant additive (B) and the sulfur-containing antioxidant additive (B), while still substantially maintaining the antioxidant performance associated with the sulfur-containing antioxidant additive (B).

[0006] In addition, it has been found that one or more oil-soluble or oil-dispersible alkenes (C) containing 10 or more carbon atoms (preferably 12 or more carbon atoms), as defined herein, can be used as additives in effective minor amounts in lubricating oil compositions containing a major amount of an oil of lubricating viscosity and one or more oil-soluble or oil-dispersible sulfur-containing antioxidants (B), as defined herein, as additives in effective minor amounts, to reduce and / or inhibit copper and / or lead, particularly copper, corrosion associated with such lubricating oil compositions. Furthermore, such improvements in rust inhibitor performance can typically be achieved while substantially maintaining the antioxidant performance characteristics of the lubricating oil composition and / or the sulfur-containing antioxidant additive (B) (i.e., without substantially impairing the effectiveness of the sulfur-containing antioxidant additive). Accordingly, it has been found that one or more oil-soluble or oil-dispersible alkenes (C) having 10 or more carbon atoms, preferably 12 or more carbon atoms, as defined herein, can be used as additives in lubricating compositions in effective minor amounts to prevent and / or inhibit corrosion of copper and / or lead, particularly copper, associated with sulfur-containing antioxidant additive (B), as defined herein, when the lubricating oil composition is used to lubricate an engine, particularly an internal combustion engine, while still substantially maintaining the antioxidant performance of the sulfur-containing antioxidant additive (B).

[0007] According to a second aspect, the present invention provides a method of lubricating a spark-ignition or compression-ignition internal combustion engine, the method comprising the step of lubricating the engine with a lubricating oil composition as defined in accordance with the first aspect of the present invention, preferably the spark-ignition or compression-ignition internal combustion engine being an automotive internal combustion engine.

[0008] According to a third aspect, the present invention provides a lubricating oil composition containing a major amount of oil of lubricating viscosity and one or more oil-soluble or oil-dispersible sulfur-containing antioxidants (B) as defined herein as an effective minor amount additive, for use in a spark-ignition or compression-ignition internal combustion engine as an effective minor amount additive to prevent the formation of nitrile elastomer seals present in the engine and the lubricating oil composition. Compatibility The present invention provides the use of one or more oil-soluble or oil-dispersible alkenes (C) as defined herein containing 10 or more carbon atoms (preferably 12 or more carbon atoms) to improve engine performance (e.g., during operation of the engine).

[0009] According to a fourth aspect, the present invention provides a lubricating oil composition containing a major amount of an oil of lubricating viscosity and, as an additive in an effective minor amount, one or more oil-soluble or oil-dispersible sulfur-containing antioxidants (B) as defined herein, in the lubrication of a spark-ignition or compression-ignition internal combustion engine, the lubricating oil composition comprising, as an additive in an effective minor amount, one or more oil-soluble or oil-dispersible sulfur-containing antioxidants (B) as defined herein, the sulfur-containing antioxidant additives (B) being present in said internal combustion engine, and a non-sulfur-containing antioxidant associated with a nitrile elastomer seal present in said internal combustion engine. Compatibility The present invention provides the use of one or more oil-soluble or oil-dispersible alkenes (C) having 10 or more carbon atoms (preferably 12 or more carbon atoms) to prevent and / or inhibit degradation (e.g., during operation of the engine).

[0010] According to a fifth aspect, the present invention provides the use of one or more oil-soluble or oil-dispersible alkenes (C) having 10 or more carbon atoms (preferably 12 or more carbon atoms), as defined herein, as an additive in an effective minor amount in a lubricating oil composition comprising a major amount of oil of lubricating viscosity and one or more oil-soluble or oil-dispersible sulfur-containing antioxidants (B) as defined herein, for reducing and / or inhibiting copper corrosion in the lubricating treatment of a spark-ignition or compression-ignition internal combustion engine (e.g., during operation of the engine).

[0011] According to a sixth aspect, the present invention provides the use of one or more oil-soluble or oil-dispersible alkenes (C) containing 10 or more carbon atoms (preferably 12 or more carbon atoms), as defined herein, as an additive in an effective minor amount in a lubricating oil composition comprising a major amount of oil of lubricating viscosity and one or more oil-soluble or oil-dispersible sulfur-containing antioxidants (B) as defined herein, for reducing and / or inhibiting copper corrosion associated with the sulfur-containing antioxidant additive (B) in the lubrication of a spark-ignition or compression-ignition internal combustion engine (e.g., during operation of the engine).

[0012] According to a seventh aspect, the present invention provides the use of one or more oil-soluble or oil-dispersible alkenes (C) containing 10 or more carbon atoms (preferably 12 or more carbon atoms), as defined herein, as an additive in an effective minor amount in a lubricating oil composition containing a major amount of oil of lubricating viscosity and one or more oil-soluble or oil-dispersible sulfur-containing antioxidants (B), as defined herein, for reducing and / or inhibiting lead corrosion in the lubricating treatment of a spark-ignition or compression-ignition internal combustion engine (e.g., during operation of the engine).

[0013] According to an eighth aspect, the present invention provides the use of one or more oil-soluble or oil-dispersible alkenes (C) having 10 or more carbon atoms (preferably 12 or more carbon atoms), as defined herein, as an additive in an effective minor amount in a lubricating oil composition containing a major amount of oil of lubricating viscosity and one or more oil-soluble or oil-dispersible sulfur-containing antioxidants (B) as defined herein, to reduce and / or inhibit lead corrosion (e.g., during operation of the engine) associated with the sulfur-containing antioxidant additive (B) in the lubrication of a spark-ignition or compression-ignition internal combustion engine.

[0014] Suitably, the use of the one or more oil-soluble or oil-dispersible alkenes (C) having 10 or more carbon atoms (preferably 12 or more carbon atoms), as defined herein, in the lubricating oil compositions of the first aspect of the present invention and defined in the second to eighth aspects of the present invention typically does not significantly affect the antioxidant performance properties of the sulfur-containing antioxidant (B) (i.e., the antioxidant performance associated with the sulfur-containing antioxidant is substantially maintained). Thus, in each of the independent uses according to the third to eighth aspects of the present invention, in the method according to the second aspect of the present invention, and in the lubricating oil composition according to the first aspect of the present invention, the antioxidant performance of the one or more oil-soluble or oil-dispersible sulfur-containing antioxidants (B) and / or the antioxidant performance of the lubricating oil composition is typically substantially maintained (i.e., substantially unaffected) despite the inclusion of the one or more oil-soluble or oil-dispersible alkenes (C) having 10 or more carbon atoms (preferably 12 or more carbon atoms), as defined herein, as an additive component in the lubricating oil composition.

[0015] Suitably, each of the lubricating oil compositions defined in the third to eighth aspects of the present invention may each independently comprise one or more sulfur-containing antioxidants (B) as defined herein in an amount to provide the lubricating oil composition with at least 0.01 wt. % sulfur. Preferably, the one or more oil-soluble or oil-dispersible sulfur-containing antioxidants are one or more sulfurized (C4-C 25 ) olefins; one or more sulfur-containing phenolic antioxidants; one or more sulfurized aliphatic (C7-C 29 ) hydrocarbyl fatty acid esters; one or more sulfur-containing molybdenum compounds; and combinations thereof. Highly preferred one or more sulfur-containing antioxidants are one or more sulfurized aliphatic (C7-C 29 ) hydrocarbyl fatty acid esters; one or more sulfur-containing molybdenum compounds; and combinations thereof. Particularly preferred are one or more sulfurized aliphatic (C7-C 29 ) hydrocarbyl fatty acid esters.

[0016] Preferably, the lubricating oil composition(s) according to the first aspect of the present invention and as defined in the second to eighth aspects of the present invention each independently comprise the one or more sulfur-containing antioxidants (B) in an amount sufficient to provide the lubricating oil composition with at least 0.01 mass %, more preferably at least 0.02 mass %, even more preferably at least 0.03 mass %, and even more preferably at least 0.04 mass % sulfur, based on the total mass of the lubricating oil composition. Preferably, the lubricating oil composition(s) according to the first aspect of the present invention and as defined in the second to eighth aspects of the present invention each independently comprise the one or more sulfur-containing antioxidants (B) in an amount sufficient to provide the lubricating oil composition with at most 0.5 mass %, more preferably at most 0.4 mass %, even more preferably at most 0.3 mass %, even more preferably at most 0.2 mass %, and even more preferably at most 0.15 mass % sulfur, based on the total mass of the lubricating oil composition. Suitably, the lubricating oil composition(s) according to the first aspect of the present invention and as defined in the second to eighth aspects of the present invention may each independently comprise the one or more sulfur-containing antioxidants (B) in an amount to provide the lubricating oil composition with from 0.02 to 0.2 mass %, preferably from 0.02 to 0.15 mass %, more preferably from 0.02 to 0.1 mass %, and even more preferably from 0.04 to 0.1 mass % sulfur, based on the total mass of the lubricating oil composition.

[0017] Preferably, the lubricating oil composition(s) according to the first aspect of the present invention and as defined in the second to eighth aspects of the present invention may each independently comprise the one or more oil-soluble or oil-dispersible alkenes (C) having 10 or more carbon atoms (preferably 12 or more carbon atoms) in an amount of 0.01 mass % or more, more preferably 0.03 mass % or more, even more preferably 0.05 mass % or more, still more preferably 0.07 mass % or more, even more preferably 0.10 mass % or more, even more preferably 0.15 mass % or more, and even more preferably 0.20 mass % or more, based on the total mass of the lubricating oil composition. Preferably, the lubricating oil composition(s) according to the first aspect of the present invention and as defined in the second to eighth aspects of the present invention may each independently comprise the one or more oil-soluble or oil-dispersible alkenes (C) having 10 or more carbon atoms (preferably 12 or more carbon atoms) in an amount of 7.5 mass % or less, more preferably 5.0 mass % or less, more preferably 4.0 mass % or less, even more preferably 3.0 mass % or less, even more preferably 2.0 mass % or less, and even more preferably 1.5 mass % or less, based on the total mass of the lubricating oil composition. Suitably, the lubricating oil composition(s) according to the first aspect of the present invention and as defined in the second to eighth aspects of the present invention may each independently comprise the one or more oil-soluble or oil-dispersible alkenes (C) having 10 or more carbon atoms (preferably 12 or more carbon atoms) in an amount of 0.05 to 3.0 mass %, preferably 0.1 to 2.0 mass %, more preferably 0.2 to 1.5 mass %, based on the total mass of the lubricating oil composition.

[0018] The lubricating oil compositions according to the first aspect of the present invention and as defined in the second, third, fourth, fifth, sixth, seventh, and eighth aspects of the present invention can each independently further comprise one or more oil-soluble or oil-dispersible non-sulfur-containing ashless antioxidants (D) as additives in an effective minor amount. Preferably, the one or more non-sulfur-containing ashless antioxidants comprise an aminic antioxidant, such as an aromatic aminic antioxidant, a phenolic antioxidant, such as a hindered phenol ester, or a combination thereof. When present, the one or more non-sulfur-containing ashless antioxidants (D) preferably comprise an aromatic aminic antioxidant. Preferably, when present, the one or more non-sulfur-containing ashless antioxidants (D), or the total amount of such antioxidants, is present in an amount of 0.1 to 5.0 mass %, preferably 0.25 to 3.0 mass %, based on the total mass of the lubricating oil composition.

[0019] Preferably, the lubricating oil composition(s) as defined in the first aspect of the present invention and the second, third, fourth, fifth, sixth, seventh and eighth aspects of the present invention may each independently further comprise one or more dihydrocarbyl dithiophosphate metal salts (E) (e.g., ZDDP(s)) as an additive component in an effective minor amount. Suitably, when present, the one or more dihydrocarbyl dithiophosphate metal salts (e.g., ZDDP(s)) are added to the lubricating oil composition(s) in an amount sufficient to provide not more than 1,200 ppm, preferably not more than 1,000 ppm, more preferably not more than 900 ppm, and most preferably not more than 850 ppm phosphorus, based on the total weight of the lubricating oil composition and as measured in accordance with ASTM D5185. Suitably, when present, the one or more dihydrocarbyl dithiophosphate metal salts (e.g., ZDDP(s)) are added to the lubricating oil composition(s) in an amount sufficient to provide at least 100 ppm, preferably at least 350 ppm, and more preferably at least 500 ppm phosphorous, based on the total mass of the lubricating oil composition and as measured in accordance with ASTM D 5185. It will be understood that while dihydrocarbyl dithiophosphate metal salt(s) (E) can exhibit antioxidant activity, such compounds are not considered to be sulfur-containing antioxidant(s) (B) within the context of the present invention.

[0020] Preferably, the lubricating oil composition(s) according to the first aspect of the present invention and as defined in the second, third, fourth, fifth, sixth, seventh and eighth aspects of the present invention may each independently further comprise one or more ashless dispersants (F). Preferably, the one or more ashless dispersants comprise one or more nitrogen-containing ashless dispersants, more preferably one or more polyalkenyl succinimide dispersants, most preferably one or more polyisobutenyl succinimide dispersants. Suitably, when present, the one or more ashless dispersants are present in an amount of 0.1 to 20 mass %, preferably 1 to 15 mass %, more preferably 2 to 10 mass %, based on the total mass of the lubricating oil composition. Suitably, when present, the one or more nitrogen-containing ashless dispersants contribute up to 0.20, preferably up to 0.15, more preferably up to 0.10, mass % nitrogen to the lubricating oil composition(s), based on the total mass of the composition and as measured in accordance with ASTM method D 5291. Suitably, when present, the one or more nitrogen-containing ashless dispersants contribute 0.01, preferably 0.02, more preferably 0.03, mass % or more nitrogen to the lubricating oil composition(s), based on the total mass of the composition and as measured in accordance with ASTM method D 5291. The one or more ashless dispersants may comprise one or more borated ashless dispersants, which, when present, provide the lubricating oil composition(s) with at least 10 ppm, such as at least 30 ppm, for example at least 50 ppm, or even at least 70 ppm, of boron, based on the total mass of the lubricating oil composition. When present, the borated ashless dispersant(s) suitably provide the lubricating oil composition with no more than 1,000 ppm, preferably no more than 750 ppm, more preferably no more than 500 ppm, of boron, based on the total mass of the lubricating oil composition.

[0021] Preferably, the lubricating oil compositions according to the first aspect of the present invention and as defined in the second, third, fourth, fifth, sixth, seventh and eighth aspects of the present invention may each independently further comprise one or more auxiliary additives other than additive components (B) and (C) and, if present, optional additive components (D) to (F) selected from metal detergents, rust inhibitors, antioxidants, pour point depressants, dispersants, antiwear agents, friction modifiers, demulsifiers, antifoam agents and viscosity modifiers in small effective amounts (e.g., 0.1 to 30 mass %). Suitably, the lubricating oil compositions according to the first aspect of the present invention and as defined in the second, third, fourth, fifth, sixth, seventh and eighth aspects of the present invention each independently have a sulfated ash content of not more than 1.2 mass %, preferably not more than 1.1 mass %, more preferably not more than 1.0 mass % (ASTM D874), based on the total mass of the composition.

[0022] Preferably, the lubricating oil compositions according to the first aspect of the present invention and as defined in the second, third, fourth, fifth, sixth, seventh and eighth aspects of the present invention each independently contain low levels of phosphorus. Suitably, the lubricating oil composition(s) each independently contain phosphorus in an amount of 0.12 mass % or less, preferably 0.11 mass % or less, more preferably 0.10 mass % or less, even more preferably 0.09 mass % or less, even more preferably 0.08 mass % or less, and most preferably 0.07 mass % or less, based on the total mass of the composition (ASTM D5185). Suitably, the lubricating oil composition(s) each independently contain phosphorus in an amount of 0.01 mass % or more, preferably 0.02 mass % or more, more preferably 0.03 mass % or more, and even more preferably 0.05 mass % or more, based on the total mass of the composition (ASTM D5185).

[0023] Typically, the lubricating oil composition(s) may contain low levels of sulfur. Preferably, the lubricating oil compositions according to the first aspect of the present invention and as defined in the second, third, fourth, fifth, sixth, seventh and eighth aspects of the present invention each independently contain sulfur in an amount of up to 0.6, more preferably up to 0.5, even more preferably up to 0.4, even more preferably up to 0.3, and even more preferably up to 0.2 mass % sulfur (ASTM D2622), based on the total mass of the composition. Typically, the lubricating oil compositions according to the first aspect of the invention and as defined in the second, third, fourth, fifth, sixth, seventh and eighth aspects of the invention each independently contain up to 0.30, more preferably up to 0.20, most preferably up to 0.15, mass % nitrogen, based on the total mass of the composition and as measured in accordance with ASTM method D5291.

[0024] Suitably, the lubricating oil compositions according to the first aspect of the present invention and as defined in the second, third, fourth, fifth, sixth, seventh and eighth aspects of the present invention each independently have a total base number (TBN) as measured in accordance with ASTM D2896 of 4 to 15 mg KOH / g, preferably 5 to 12 mg KOH / g. According to one preferred embodiment, the lubricating oil compositions according to the first aspect of the present invention and as defined in the second to eighth aspects of the present invention comprise: (A) A large quantity of oil of lubricating viscosity; (B) sulfurized C4-C lubricating oils as a minor amount of additive effective to provide the lubricating oil composition with at least 0.01 wt. % sulfur. 25 Olefins, sulfurized aliphatic (C7-C 29 ) one or more oil-soluble or oil-dispersible sulfur-containing antioxidants selected from hydrocarbyl fatty acid ester(s), ashless sulfurized phenolic antioxidant(s), sulfur-containing organo-molybdenum compound(s), and combinations thereof; and (C) one or more oil-soluble or oil-dispersible C as an additive in an effective small amount of at least 0.01 wt. % based on the total weight of the lubricating oil composition. 10 ~C20 , preferably C 12 ~C 20 , preferably C 12 ~C 18 , more preferably C 14 ~C 18 Alkenes of or is produced by mixing these.

[0025] Preferably, the one or more oil-soluble or oil-dispersible sulfur-containing antioxidants (B) are one or more sulfurized aliphatic (C-C) sulfur-containing antioxidants, as defined herein. 29 ) hydrocarbyl fatty acid esters, one or more di- or tri-nuclear molybdenum dithiocarbamates and combinations thereof, in particular one or more sulfurized aliphatic (C7-C 29 ) hydrocarbyl fatty acid esters. Preferably, the one or more oil-soluble or oil-dispersible C 10 -C 20 Alkenes are one or more linear, acyclic C 10 -C 20 , more preferably one or more linear acyclic C 12 -C 20 and even more preferably one or more linear acyclic C 12 -C 18 and even more preferably one or more linear acyclic C 14 ~C 18 Alkenes, especially alk-1-ene(s). Highly preferred are one or more oil-soluble or oil-dispersible C 10 -C 20 Alkenes include dec-1-ene, dodec-1-ene, tetradec-1-ene, hexadece-1-ene, octadec-1-ene, and combinations thereof, particularly dodec-1-ene, tetradec-1-ene, hexadece-1-ene, octadec-1-ene, and combinations thereof, more particularly tetradec-1-ene.

[0026] In this specification, the following terms and expressions, if and when used, have the meanings given below: "Active ingredients" or "ai" refers to additive materials that are not diluents or solvents. The term "comprising" or any cognate term specifies the presence of a stated feature, step, or integer or component, but does not preclude the presence or addition of one or more other features, steps, integers, components, or groups thereof. The expressions "consists of" or "consists essentially of" or cognate terms can be included within the scope of "comprises" or any cognate term. The expression "consisting essentially of" allows for the inclusion of substances that do not significantly affect the properties of the composition to which they are applied. The expression "consisting of" or cognate terms only means the presence of the stated feature, step, integer, component, or group to which the expression refers.

[0027] "Hydrocarbyl" means a monovalent chemical group (i.e., a monovalent radical) of a compound that contains hydrogen and carbon atoms, and that is bonded directly to the remainder of the compound through a carbon atom. The group may contain one or more atoms other than carbon and hydrogen, provided that these atoms do not affect the essential hydrocarbyl character of the group. Those skilled in the art will recognize suitable groups (e.g., halo, especially chloro and fluoro, amino, alkoxyl, mercapto, alkylmercapto, nitro, nitroso, sulfoxy, etc.). Preferably, the hydrocarbyl group consists essentially of hydrogen and carbon atoms, unless otherwise specified. More preferably, the hydrocarbyl group consists of hydrogen and carbon atoms, unless otherwise specified. Preferably, the hydrocarbyl group is C1-C 30 Hydrocarbyl groups, more preferably aliphatic hydrocarbyl groups, such as C-C 30 An aliphatic hydrocarbyl group. The term "hydrocarbyl" includes "alkyl," "alkenyl," and "aryl," as defined herein.

[0028] "Hydrocarbon" means compounds containing hydrogen and carbon atoms and otherwise defined above as the term "hydrocarbyl." "Alkyl" is C1-C 30 It refers to an alkyl group, preferably a C1-C6 alkyl group, which is directly bonded to the remainder of the compound via a single carbon atom.Unless otherwise specified, the alkyl group can be linear (i.e., unbranched) or branched, and can be cyclic, acyclic, or partially cyclic / acyclic, provided there are a sufficient number of carbon atoms.Preferably, the alkyl group comprises a linear or branched acyclic alkyl group.Representative examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neo-pentyl, hexyl, heptyl, octyl, dimethylhexyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, icosyl, and triacontyl.

[0029] "Alkenyl" means a C-C alkyl group containing at least one carbon-carbon double bond and attached to the remainder of the compound through a single carbon atom, otherwise defined as "alkyl." 30 , preferably C2-C 12 means a group represented by the formula: "Alkylene" is synonymous with "alkanediyl" and refers to a C-C alkylene group derived from an alkane by removing hydrogen atoms from two different carbon atoms. 20 , preferably C2-C 10and more preferably refers to a C2-C6 divalent saturated acyclic aliphatic hydrocarbon radical, which may be linear or branched. Representative examples of alkylene include ethylene (ethanediyl), propylene (propanediyl), butylene (butanediyl), isobutylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, 1-methylethylene, 1-ethylethylene, 1-ethyl-2-methylethylene, 1,1-dimethylethylene, and 1-ethylpropylene. "Poly(alkylene)" is synonymous with "poly(alkene)" and refers to a polymer containing the appropriate alkenediyl repeating groups. Such a polymer may be formed by polymerization of the appropriate alkene (e.g., polyisobutylene may be formed by polymerizing isobutene). "Aryl" refers to a C-C alkyl group optionally substituted with one or more alkyl, halo, hydroxyl, alkoxy, and amino groups. 18 , preferably C6-C 10 It means an aromatic group, which is attached directly to the remainder of the compound through a single carbon atom. Preferred aryl groups include phenyl and naphthyl groups and their substituted derivatives, especially phenyl and its alkyl-substituted derivatives.

[0030] The term "alkene" as used herein refers to a hydrocarbon compound containing at least one carbon-carbon double bond, which, when a sufficient number of carbon atoms are present, may be linear or branched, cyclic, acyclic, or partially cyclic / acyclic. Preferred alkenes include acyclic alkenes, more preferably linear acyclic alkenes. The term alkene includes all geometric and structural isomers. Highly preferred alkene compounds include compounds in which at least one carbon-carbon double bond represents its only functional group. Representative examples of alkenes containing 10 or more carbon atoms as used herein include, but are not limited to, decene, undecene, dodecene, tridecene, tetradecene, pentadecene, hexadecene, heptadecene, octadecene, nonadecene, icosene, heneicosene, and docosene.

[0031] "Monocarboxylic acid" means a hydrocarbyl monocarboxylic acid containing a single carboxylic acid functional group. "Aliphatic hydrocarbyl fatty acids" are aliphatic C7-C 29 , preferably C9-C 27 , most preferably C 11 -C 23 This refers to monocarboxylic acids with a hydrocarbyl chain. Such compounds are referred to herein as aliphatic (C7-C 29 ), more preferably (C9-C 27 ), most preferably (C 11 -C 23 ) can be referred to as hydrocarbyl monocarboxylic acid(s) or hydrocarbyl fatty acid(s) (wherein C x -C y indicates the total number of carbon atoms in the aliphatic hydrocarbyl chain of the fatty acid, and the fatty acid itself, due to the presence of its carboxyl carbon atom, has a total of C x+1 -C y+1(contains at least one carbon atom). Preferably, the aliphatic hydrocarbyl fatty acid contains an even number of carbon atoms, including its carboxyl carbon atom. The aliphatic hydrocarbyl chain of the fatty acid may be saturated or unsaturated (i.e., contains at least one carbon-carbon double bond); preferably, the aliphatic hydrocarbyl chain is unsaturated and contains at least one carbon-carbon double bond; such fatty acids may be obtained from natural sources (e.g., derived from animal or vegetable oils) and / or may be obtained by reduction of the corresponding saturated fatty acid. It will be understood that a proportion of the aliphatic hydrocarbyl chain(s) of the corresponding aliphatic hydrocarbyl fatty acid ester(s) will be unsaturated (i.e., contain at least one carbon-carbon double bond) to allow reaction with sulfur to form the corresponding sulfurized aliphatic hydrocarbyl fatty acid ester(s).

[0032] "Aliphatic hydrocarbyl fatty acid ester" refers to an ester obtained by converting the monocarboxylic acid functionality of the corresponding fatty acid hydrocarbyl fatty acid to an ester group. Suitably, the monocarboxylic acid functionality of the aliphatic hydrocarbyl fatty acid is converted into a hydrocarbyl ester, preferably a C-C 30 The fatty acid functional group of the aliphatic hydrocarbyl fatty acid may be converted to an aliphatic hydrocarbyl ester, such as an alkyl ester, preferably a C1-C6 alkyl ester, especially a methyl ester. Alternatively, or additionally, the monocarboxylic acid functional group of the aliphatic hydrocarbyl fatty acid may be in the form of a natural glycerol ester. Thus, the term "aliphatic hydrocarbyl fatty acid ester" refers to aliphatic hydrocarbyl fatty acid glycerol ester(s) and aliphatic hydrocarbyl fatty acid C1-C6 alkyl esters. 30 It includes aliphatic hydrocarbyl ester(s) (e.g., aliphatic hydrocarbyl fatty acid alkyl ester(s), more preferably aliphatic hydrocarbyl fatty acid C1-C6 alkyl ester(s), especially aliphatic hydrocarbyl fatty acid methyl ester(s)). Suitably, the term "aliphatic hydrocarbyl fatty acid ester" includes aliphatic (C7-C 29 ) hydrocarbyl, more preferably aliphatic (C9-C 27) hydrocarbyl, most preferably aliphatic (C 11 -C 23 ) Hydrocarbyl fatty acid glycerol ester(s) and aliphatic (C7-C 29 ) hydrocarbyl, more preferably aliphatic (C9-C 27 ) hydrocarbyl, most preferably aliphatic (C 11 -C 23 ) Hydrocarbyl fatty acids C1-C 30 aliphatic hydrocarbyl ester(s) wherein a proportion of the aliphatic hydrocarbyl chain(s) of the fatty acid ester(s) are unsaturated and contain at least one carbon-carbon double bond to enable sulfurization of the aliphatic hydrocarbyl fatty acid ester(s). "Sulfurized aliphatic hydrocarbyl fatty acid ester" means a compound obtained by sulfurizing an aliphatic hydrocarbyl fatty acid ester, as defined herein. Suitably, the sulfurized aliphatic hydrocarbyl fatty acid ester(s) is ashless. "Halo" or "halogen" includes fluoro, chloro, bromo and iodo.

[0033] As used herein, the terms "oil-soluble" or "oil-dispersible" or cognate terms do not necessarily mean that the compound or additive is soluble, dissolvable, miscible, or capable of being suspended in the oil in all proportions. However, these terms do mean that the compound or additive is soluble or stably dispersible in the oil to an extent sufficient to exert its intended effect in the environment in which the oil is used. Moreover, the additional incorporation of other additives may allow for even higher levels of incorporation of a particular additive, if desired. "Ashless" in the context of an additive means that the additive is metal-free. "Ash-containing" in reference to an additive means that the additive contains a metal. Nitrile Seal CompatibilityThe resistance is measured using the Mercedes Benz Seals Test in accordance with VDA 675 301. Copper and lead corrosion performance is measured using the High Temperature Corrosion Bench Test (HTCBT) in accordance with ASTM D6594-06. Antioxidant performance is measured using a modified Sequence IIIG Engine Test (ASTM D7320-07) as described herein. "Major amount" means, with respect to a stated ingredient of a composition and expressed with respect to the total weight of the composition, more than 50% by weight of the composition, calculated as the active ingredient of that ingredient. "Minor amount" means less than 50% by weight of a composition, expressed with respect to a stated additive and with respect to the total weight of the composition, calculated as the active ingredient of the additive.

[0034] An "effective minor amount" in reference to an additive means a small amount of such an additive in the compositions of the present invention such that the additive is effective to provide a desired technical effect. "ppm" means parts per million by mass, based on the total mass of the lubricating oil composition. The "metal content" of the lubricating oil composition or additive component, such as the molybdenum content of the lubricating oil composition or its total metal content (i.e., the sum of all individual metal contents), is measured by ASTM D5185.

[0035] Mn is the number average molecular weight and can be measured for polymer entities by gel permeation chromatography. Mw is the weight average molecular weight and can be measured for the bulk polymer by gel permeation chromatography. "TBN" in reference to the additive components of the present invention or in reference to the lubricating oil compositions means Total Base Number (mg KOH / g) as measured by ASTM D2896. "K.V. 40 " means kinematic viscosity at 40°C as measured by ASTM D445. "K.V. 100 " means kinematic viscosity at 100°C as measured by ASTM D445. "Phosphorus content" is measured by ASTM D5185. "Sulfur Content" is measured by ASTM D2622; and "Sulfated ash content" is measured by ASTM D874.

[0036] All percentages reported are by weight on an active ingredient basis, ie, not taking into account carrier or diluent oil, unless otherwise stated. Likewise, it will be understood that the various ingredients employed, both essential and optional and customary, may react under conditions of formulation, storage or use, and that the present invention likewise provides the products thereof obtainable or obtainable as a result of any such reactions. It is further understood that any upper and lower limits of the amounts, ranges, and ratios described herein may be independently combined. Thus, any upper and lower limits of the amounts, ranges, and ratios described herein in connection with a particular technical feature of the present invention may be independently combined with any upper and lower limits of the amounts, ranges, and ratios described herein in connection with one or more other particular technical features of the present invention. Furthermore, any particular technical feature of the present invention, and all preferred variations thereof, may be independently combined with any other particular technical feature(s) and all preferred variations thereof. Likewise, it will be understood that preferred features of each aspect of the invention are to be considered preferred features of every other aspect of the invention. DETAILED DESCRIPTION OF THE INVENTION

[0037] Where appropriate, the above features of the invention relating to each and every aspect of the invention are described in further detail below. Oil of lubricating viscosity (A) Oils of lubricating viscosity (often called "base stocks" or "base oils") are the primary liquid components of lubricating oils into which additives and possibly other oils are blended, for example, to produce the final lubricating oil (or lubricating composition). Base oils are useful for producing concentrates therefrom as well as for producing lubricating oil compositions, and can be selected from natural (vegetable, animal, or mineral) and synthetic lubricating oils and mixtures thereof. The above base stocks are defined in the American Petroleum Institute (API) publication: "Engine Oil Licensing and Certification System," Industry Services Department, 14th Edition, December 1996, Supplement 1, December 1998. Typically, the base stocks have a viscosity of preferably 3-12 mm at 100°C. 2 / s (cSt), preferably 4-10mm 2 / s, most preferably 4.5-8mm 2 / s.

[0038] The definitions of base stocks and base oils in this invention are the same as those found in the American Petroleum Institute (API) publication, "Engine Oil Licensing and Certification System," Industry Services Department, 14th Edition, December 1996, Supplement 1, December 1998. The publication classifies base stocks as follows: a) Group I base stocks contain less than 90% saturates and / or more than 0.03% sulfur and have a viscosity index greater than or equal to 80 and less than 120 when using the test methods specified in Table E-1 below. b) Group II base stocks contain more than or equal to 90 percent saturates and less than or equal to 0.03 percent sulfur and have a viscosity index greater than or equal to 80 and less than 120 when using the test methods specified in Table E-1 below. c) Group III base stocks contain not less than 90 percent saturates and not more than 0.03 percent sulfur and have a viscosity index greater than or equal to 120 when using the test methods specified in Table E-1 below. d) Group IV base stocks are polyalphaolefins (PAOs). e) Group V base stocks include all other base stocks not included in Group I, II, III, or IV.

[0039] [Table 1]

[0040] Other oils of lubricating viscosity that may be included in the lubricating oil composition are detailed below: Natural oils include animal and vegetable oils (e.g., castor oil and lard oil), liquid petroleum oils, and hydrorefined and solvent-treated mineral lubricating oils of the paraffinic, naphthenic, and mixed paraffinic-naphthenic types. Oils of lubricating viscosity derived from coal or shale are also useful base oils. Synthetic lubricating oils include hydrocarbon oils such as polymerized and copolymerized olefins (e.g., polybutylene, polypropylene, propylene-isobutylene copolymers, chlorinated polybutylene, poly(1-hexene), poly(1-octene), poly(1-decene)); alkylbenzenes (e.g., dodecylbenzene, tetradecylbenzene, dinonylbenzene, di(2-ethylhexyl)benzene); polyphenols (e.g., biphenyl, terphenyl, alkylated polyphenols); and alkylated diphenyl ethers and alkylated diphenyl sulfides and their derivatives, analogs, and homologs.

[0041] Another suitable class of synthetic lubricating oils comprises the esters of dicarboxylic acids (e.g., phthalic acid, succinic acid, alkyl and alkenyl succinic acids, maleic acid, azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid dimer, malonic acid, alkyl malonic acids, alkenyl malonic acids) with various alcohols (e.g., butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, ethylene glycol, diethylene glycol monoether, propylene glycol). Specific examples of these esters include dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, didecyl phthalate, dieicosyl sebacate, the 2-ethylhexyl diester of linoleic acid dimer, and the complex ester formed by reacting one mole of sebacic acid with two moles of tetraethylene glycol and two moles of 2-ethylhexanoic acid.

[0042] Similarly, esters useful as synthetic oils include C5-C 12 These include esters made from monocarboxylic acids and polyols and polyol ethers such as neopentyl glycol, trimethylolpropane, pentaerythritol, dipentaerythritol and tripentaerythritol. Unrefined, refined, and rerefined oils can be used in the compositions of the present invention. Unrefined oils are oils obtained directly from natural or synthetic sources without further purification treatment. For example, shale oil obtained directly from a retort operation, petroleum oil obtained directly by distillation, or ester oil obtained directly from an esterification process, all of which are used without further treatment, would be considered unrefined oils. Refined oils are similar to unrefined oils except that they have been further processed in one or more purification steps to improve one or more properties. Many such purification techniques, such as distillation, solvent extraction, acid or base extraction, filtration, and percolation, are known to those skilled in the art. Rerefined oils are obtained by methods similar to those used to obtain refined oils, but applied to refined oils that have already been used in operations. Such rerefined oils, also known as reclaimed or reprocessed oils, are often additionally processed using techniques to obtain approval for used additives and oil breakdown products.

[0043] Another example of a base oil is a gas-to-liquid ("GTL") base oil, i.e., the base oil may be derived from Fischer-Tropsch synthesized hydrocarbons produced from synthesis gas containing H and CO using a Fischer-Tropsch catalyst. These hydrocarbons typically require further processing to be useful as base oils. For example, they may be hydroisomerized; hydrocracking and hydroisomerized; dewaxed; or hydroisomerized and dewaxed by methods known in the art.

[0044] Although the composition of the base oil will depend on the particular application of the lubricating oil composition, and the oil formulator will select the base oil to achieve the desired performance characteristics at a reasonable cost, the base oil of the lubricating oil composition according to the present invention typically comprises 85 mass % or less of a Group IV base oil, and the base oil may comprise 70 mass % or less of a Group IV base oil, or even 50 mass % or less of a Group IV base oil. The base oil of the lubricating oil composition according to the present invention may comprise 0 mass % of a Group IV base oil. Alternatively, the base oil of the lubricating oil composition according to the present invention may comprise at least 5 mass %, at least 10 mass %, or at least 20 mass % of a Group IV base oil. The base oil of the lubricating oil composition according to the present invention may comprise 0 to 85 mass %, or 5 to 85 mass %, or alternatively 10 to 85 mass % of a Group IV base oil. Preferably, the volatility of the oil or oil blend of lubricating viscosity, as measured by the NOACK test (ASTM D5800), is 20% or less, preferably 16% or less, preferably 12% or less, more preferably 10% or less. Preferably, the oil of lubricating viscosity has a viscosity index (VI) of at least 90, more preferably at least 95, even more preferably at least 110, even more preferably up to 120, even more preferably at least 120, even more preferably at least 125, and most preferably about 130-140. Preferably, the oil of lubricating viscosity contains less than 0.03% sulfur. Preferably, the oil of lubricating viscosity (excluding any diluent oil introduced through the use of an additive concentrate) comprises a Group II base stock, a Group III base stock, or a combination thereof. Most preferably, the oil of lubricating viscosity (excluding any diluent oil introduced through the use of an additive concentrate) consists essentially of a Group III base stock.

[0045] The oil of lubricating viscosity described above is provided in a major amount in combination with minor amounts of additive components (B) and (C), as defined herein, and, if desired, one or more auxiliary additives, such as those described hereinafter, that comprise the lubricating oil composition. This preparation may be accomplished by adding the additive directly to the oil, or by adding the additive in the form of a concentrate thereof and dispersing or dissolving the additive. The additive may be added to the oil by any method known to those skilled in the art, prior to, simultaneously with, or after the addition of other additives. Preferably, the oil of lubricating viscosity is present in an amount greater than 55 mass %, more preferably greater than 60 mass %, even more preferably greater than 65 mass %, based on the total mass of the lubricating oil composition. Preferably, the oil of lubricating viscosity is present in an amount less than 98 mass %, more preferably less than 95 mass %, even more preferably less than 90 mass %, based on the total mass of the lubricating oil composition.

[0046] When a concentrate is used to prepare the lubricating oil composition, the concentrate can be diluted with, for example, 3 to 100 parts by weight, e.g., 5 to 40 parts by weight, of an oil of lubricating viscosity per unit weight of the concentrate. Preferably, the lubricating oil composition is a multigrade oil identified by the viscosity descriptors SAE 20WX, SAE 15WX, SAE 10WX, SAE 5WX, or SAE 0WX, where X represents any one of 20, 30, 40, and 50; characteristics of these various viscosity grades can be found in the SAE J300 classification. In one embodiment of each aspect of the invention, independent of other embodiments, the lubricating oil composition is in the form of SAE 10WX, SAE 5WX, or SAE 0WX, preferably SAE 5WX or SAE 0WX, where X represents any one of 20, 30, 40, and 50. Preferably, X is 20 or 30.

[0047] Sulfur-containing antioxidants (B) The oil-soluble or oil-dispersible sulfur-containing antioxidant additive can be one or more ashless sulfur-containing antioxidant(s), ash-containing sulfur-containing antioxidant(s), or combinations thereof. Preferred ashless sulfur-containing antioxidant(s) include sulfurized olefin(s), sulfur-containing phenol(s), sulfurized aliphatic (C7-C 29 ) hydrocarbyl fatty acid ester(s), and combinations thereof. More preferred ashless sulfur-containing antioxidants include sulfurized olefin(s), sulfurized aliphatic (C7-C 29 ) hydrocarbyl fatty acid ester(s), and combinations thereof. Even more preferred is one or more ashless sulfur-containing antioxidants, such as one or more sulfurized aliphatic (C7-C 29 ) hydrocarbyl fatty acid esters. Preferred ash-containing sulfur-containing antioxidant(s) include sulfur-containing molybdenum compounds, especially sulfur-containing organomolybdenum compounds. Highly preferred one or more sulfur-containing antioxidants are one or more sulfurized aliphatic (C7-C 29 ) hydrocarbyl fatty acid ester(s), sulfur-containing organo-molybdenum compound(s), and combinations thereof. The most preferred sulfur-containing antioxidant(s) are one or more sulfurized aliphatic (C7-C 29 ) hydrocarbyl fatty acid esters.

[0048] Sulfurized olefin(s) The one or more sulfurized olefins can be obtained by sulfurizing the corresponding one or more olefin-containing compounds, as disclosed, for example, in US 2006 / 0205614 A. Suitable sulfur sources that can be used in the sulfurization reaction include elemental sulfur, sulfur monochloride, sulfur dichloride, sodium sulfide, sodium polysulfide, and combinations thereof. Suitable sulfurized olefins are commercially available, particularly those that do not contain nitrogen. Olefin compounds that can be sulfurized vary and contain at least one carbon-carbon non-aromatic double bond. Suitable sulfurizable olefin compound(s) can be of the formula: R1 R 2 C=CR 3 R 4 where R 1 , R 2 , R 3 and R 4 are each independently hydrogen, C1-C 25 Alkyl, CO2R 5 , CO2M, C(R 6 )3, YR 7 , represents X, where R 5 , R 6 and R 7 are each independently hydrogen, C1-C 12 Alkyl, C1-C 12 represents alkenyl, M is a metal cation (e.g., sodium, potassium, or calcium), X is a halogen, and Y is oxygen or sulfur. The preferred sulfurizable olefin compound(s) are C4-C 25 Includes alkene(s) and their carboxylate derivatives, such as butyl cyclohex-1-ene carboxylate and dodecene. Suitable sulfurized olefins can be obtained from Arkema (TPS20, TPS32 and TPS44).

[0049] Sulfurized phenol(s) The preferred one or more sulfur-containing phenols are derived by sulfurizing one or more hindered phenols. Suitable hindered phenols include 2-alkyl-substituted phenol(s), 2,6-dialkyl-substituted phenol(s), and combinations thereof, wherein at least one of the alkyl substituents contains at least 3, preferably at least 4, carbon atoms. Such hindered phenol(s) include 2,6-di-tert-butylphenol, 2-tert-butyl-6-methylphenol, 2-tert-butyl-5-methylphenol, and mixtures thereof. The most preferred one or more sulfurized phenols are derived by sulfurizing one or more 2,6-di-alkylphenols, especially 2,6-di-tert-butylphenol(s). Thus, the one or more sulfurized phenols include 4,4'-thiobis(2,6-di-t-butylphenol), 4,4'-dithiobis(2,6-di-t-butylphenol), 4,4'-thiobis(2-t-butyl-6-methylphenol), 4,4'-dithiobis(2-t-butyl-6-methylphenol), 4,4'-thiobis(2-t-butyl-5-methylphenol), and mixtures thereof, particularly 4,4'-thiobis(2,6-di-t-butylphenol) and 4,4'-dithiobis(2,6-di-t-butylphenol), and mixtures thereof. The sulfurized phenol(s) may be prepared by techniques well known to those skilled in the art, such as those described in U.S. Pat. Nos. 3,250,712 and 4,946,610.

[0050] Sulfurized fatty acid ester(s) The one or more sulfurized fatty acid esters may be one or more sulfurized aliphatic (C7-C 29 ) hydrocarbyl fatty acid esters, which typically contain one or more of the corresponding aliphatic (C-C 29 ) hydrocarbyl fatty acid esters. Suitably, the aliphatic (C7-C 29 To enable sulfurization of the hydrocarbyl fatty acid ester(s), a certain proportion of the fatty acid ester(s) must be aliphatic (C7-C 29) The hydrocarbyl chain(s) are unsaturated and contain at least one carbon-carbon double bond. The fatty acid ester(s) can be derived from any suitable fatty acid(s). Typically, the fatty acid(s) can be obtained from natural sources, for example, by hydrolysis of fatty acid triglycerides obtained from animal or vegetable oils. The fatty acid(s) can then be esterified to form the corresponding fatty acid ester(s), which are then sulfurized by reaction with sulfur. Alternatively, or additionally, the fatty acid triglyceride(s) can be directly sulfurized to form the corresponding sulfurized fatty acid triglyceride(s), or the fatty acid triglyceride(s) can be transesterified to form different fatty acid ester(s), which are then sulfurized by reaction with sulfur. Thus, the one or more sulfurized fatty acid esters are typically derived from fatty acids obtainable from animal or vegetable oils, particularly vegetable oils.

[0051] One or more of the above aliphatic (C7-C 29 Suitable aliphatic hydrocarbyl fatty acid(s) may be derived from and / or obtained from one or more aliphatic (C-C) hydrocarbyl fatty acid esters in their natural esterified form (i.e., their glycerol esters). 29 ), preferably (C9-C 27 ), more preferably (C 11 -C 23 ) hydrocarbyl fatty acids (i.e., aliphatic (C7-C 29 ) hydrocarbyl monocarboxylic acid(s)), wherein C x -C y indicates the total number of carbon atoms in the aliphatic hydrocarbyl chain of the fatty acid, and the fatty acid itself, due to the presence of the carboxyl carbon atom, has a total of C x+1 -C y+1 Preferably, the total number of carbon atoms in the one or more aliphatic hydrocarbyl fatty acids, including the carboxyl carbon atom, is an even number. Suitably, the one or more aliphatic (C-C 29The aliphatic hydrocarbyl chain of the hydrocarbyl fatty acid may be saturated or unsaturated (i.e., contains at least one carbon-carbon double bond), and preferably is one or more aliphatic (C7-C 29 The aliphatic hydrocarbyl chain of the hydrocarbyl fatty acid is unsaturated and contains at least one carbon-carbon double bond. 29 ) Hydrocarbyl fatty acids include one or more of myristoleic acid, palmitoleic acid, sapienic acid, hexadecatrienoic acid, oleic acid, stearidonic acid, elaidic acid, vaccenic acid, linoleic acid, linoelaidic acid, linolenic acid, arachidonic acid, eicosapentaenoic acid, eicosenoic acid, erucic acid, docosahexaenoic acid, docosahexaenoic acid, tetracosapentaenoic acid, and tetracosatetraenoic acid. More preferred are one or more aliphatic (C7-C 29 ) Hydrocarbyl fatty acids include one or more of oleic acid, linoleic acid, and linolenic acid. Oleic acid is particularly preferred.

[0052] One or more of the above aliphatic (C7-C 29 ) hydrocarbyl fatty acid, or reactive derivative(s) thereof, by esterification with one or more alkanols as defined herein to produce one or more corresponding aliphatic (C7-C 29 Suitable alkanols include monohydric (C-C) hydrocarbyl fatty acid esters. 20 ) Alkanol(s), polyhydric (C2-C 20 ) alkanol(s) (e.g., glycerol, neopentyl glycol, trimethylolethane, trimethylolpropane, trimethylolbutane, pentaerythritol, dipentaerythritol, tripentaerythritol, and sorbitol; glycerol is particularly preferred), and combinations thereof. Preferably, the one or more alkanols are monohydric (C1-C 20 )alkanol(s), preferably monohydric (C1-C6)alkanol(s), even more preferably methanol. Therefore, suitable fatty acid ester(s) may comprise one or more aliphatic (C7-C 29 ), preferably (C9-C 27 ), more preferably (C 11 -C 23 ) hydrocarbyl fatty acid esters, which may be one or more of their corresponding aliphatic (C-C) fatty acid esters as defined herein. 29 ) hydrocarbyl fatty acids by reaction with one or more alkanols as defined herein, or in their natural esterified form, i.e., one or more aliphatic (C7-C 29 ) can be obtained in the form of glycerol esters of hydrocarbyl fatty acids. The preferred fatty acid ester(s) are one or more aliphatic (C7-C 29 ), preferably (C9-C 27 ), more preferably (C 11 -C 23 ) C1-C of hydrocarbyl fatty acids 30 More preferably, the fatty acid ester(s) comprise one or more aliphatic (C7-C 29 ), preferably (C9-C 27 ), more preferably (C 11 -C 23 ) hydrocarbyl fatty acid C1-C6 alkyl esters, and even more preferably the fatty acid ester(s) comprise one or more aliphatic (C7-C 29 ), preferably (C9-C 27 ), more preferably (C 11 -C 23 ) methyl esters of hydrocarbyl fatty acids.

[0053] Additionally or alternatively, the fatty acid ester may be in the form of a fatty acid glycerol ester. Suitably, the fatty acid glycerol ester(s) may comprise one or more aliphatic (C7-C 29 ), preferably (C9-C 27 ), more preferably (C 11 -C 23 ) C1-C of hydrocarbyl fatty acids 30Alkyl esters, more preferably glycerol ester(s) of fatty acids. Thus, a proportion of the aliphatic hydrocarbyl chain(s) of the one or more aliphatic hydrocarbyl fatty acid esters described above contain at least one carbon-carbon double bond to enable sulfurization and the formation of the corresponding sulfurized fatty acid ester(s). Suitably, at least about 40% by weight, preferably at least about 50% by weight, and more preferably at least about 55% by weight of the one or more aliphatic hydrocarbyl fatty acid esters contain aliphatic hydrocarbyl chains with at least one carbon-carbon double bond. Suitably, at most about 95% by weight, preferably at most about 90% by weight, and more preferably at most about 85% by weight of the one or more aliphatic hydrocarbyl fatty acid esters contain aliphatic hydrocarbyl chains with at least one carbon-carbon double bond. Alternatively, essentially all of the one or more aliphatic hydrocarbyl fatty acid esters contain aliphatic hydrocarbyl chain(s) with at least one carbon-carbon double bond (i.e., all of the fatty acid ester(s) are derived from unsaturated fatty acid(s)). Suitably, the fatty acid ester(s) can be obtained directly from natural sources, such as plant and / or animal oils. Such fatty acids(s) may already be in the form of fatty acid glycerol esters. The fatty acid glycerol esters can be directly sulfurized to form the corresponding sulfurized fatty acid glycerol esters. Additionally, or alternatively, such fatty acid glycerol ester(s) can be transesterified, as defined herein, to form fatty acid hydrocarbyl ester(s) (e.g., fatty acid methyl ester(s)), which can then be sulfurized to form the corresponding sulfurized fatty acid esters.

[0054] The sulfurized fatty acid ester(s) may be derived from any suitable fatty acid ester(s), but are preferably derived from one or more vegetable oils (e.g., glycerol ester(s) or transesterification product(s)) such as, but not limited to, palm oil, corn oil, grapeseed oil, coconut oil, cottonseed oil, wheat germ oil, soybean oil, safflower oil, olive oil, peanut oil, rapeseed oil, and sunflower oil, or animal oils (e.g., glycerol ester(s) or transesterification product(s)) such as tallow oil or lard oil. Preferably, the sulfurized fatty acid ester(s) are derived from one or more palm oil, rapeseed oil, soybean oil, tallow oil, lard oil, or transesterification products thereof. More preferably, the sulfurized fatty acid ester(s) are derived from a vegetable oil, particularly one or more palm oil, soybean oil, rapeseed oil, or transesterification products thereof. The sulfurized fatty acid ester(s) suitably comprises substantially only sulfurized fatty acid ester(s) and no other sulfurized carboxylic acid ester(s). Therefore, the one or more sulfurized fatty acid esters may be one or more sulfurized aliphatic (C7-C 29 ), preferably (C9-C 27 ), more preferably (C 11 -C 23 ) C1-C of hydrocarbyl fatty acids 30 alkyl esters, especially C1-C6 alkyl ester(s), e.g., methyl ester(s), and / or one or more sulfurized aliphatic (C7-C 29 ), preferably (C9-C 27 ), more preferably (C 11 -C 23 ) C1-C of hydrocarbyl fatty acids 30 Contains glycerol esters. Sulfurized aliphatic (C7-C 29 ), preferably (C9-C 27 ), more preferably (C 11 -C 23 ) C1-C of hydrocarbyl fatty acids 30 Alkyl ester(s), especially C1-C6 alkyl ester(s), such as methyl ester(s), are especially preferred.

[0055] Suitable methods for producing the sulfurized fatty acid ester(s) are well known. For example, one suitable method is described in Lubricant Additives: Chemistry and Applications, edited by Leslie R. Rudnick, Chapter 9 (Sulfur Carriers, T. Rossrucker & A. Fessenbecker), CPC Press, 2003. This method generally involves mixing the starting unsaturated fatty acid ester(s) with elemental sulfur and heating at low or moderate pressure (about 0.1-0.2 MPa (1-2 bar)) to about the melting point of the sulfur. The reaction can be carried out in the presence or absence of a catalyst. The resulting sulfurized fatty acid ester(s) can be post-treated by sparging the ester with nitrogen and / or a mixture of nitrogen and oxygen gas at elevated temperatures. The sulfurized fatty acid ester(s) are preferably derived from natural oils, and therefore typically contain a mixture of different molecular structures, including some unreacted (or unsulfurized) fatty acid ester(s). The sulfurized fatty acid ester(s) typically contain molecules with sulfur bridging groups. Suitably, the sulfurized fatty acid ester(s) contain fatty acid ester molecules linked together exclusively by sulfur bridging groups containing 1 to 8 sulfur atoms. Alternatively or additionally, the sulfurized fatty acid ester(s) may contain molecules with one or more sulfur groups selected from thioether, thiacyclopropane, thiol, dithiirane, thiophene, or thiocarbonyl groups. Preferred sulfurized fatty acid ester(s) for use in the present invention will comprise primarily sulfurized ester molecule(s) having a structure according to Formula 1, shown below. The sulfurized fatty acid ester(s) may contain a minor proportion of compounds having a structure defined by any of Formulas 2-7, shown below. Preferably, these compounds having structures of Formulas 2-7 are present only in impurity quantities.

[0056] [ka]

[0057] The sulfurized fatty acid ester having formula 1 can contain m=1-8, but preferably the greatest proportion of molecules within the sulfurized fatty acid ester contains structures where m=3-5. Suitably, in the above formulas 1 to 7, R 1 and R 3 each independently represents a hydrocarbyl group, preferably an alkyl group, such that the entire backbone, including the methylene groups and sulfur-bonded carbon atoms intervening the carbonyl groups, is 12 to 24 carbon atoms in length; R 2 and R 4 each independently represents H or hydrocarbyl, preferably H or C1-C6 alkyl, especially H or methyl; R 5 represents H or hydrocarbyl, and n=0 to 18, preferably n=0 to 12, more preferably n=0 to 10 or n=0 to 8. Advantageously, the majority of the esters contain molecules with n=7. Suitable sulfurized fatty acid esters are commercially available, and examples of suitable compounds include Dover Chemical's Base 10SE, Additin RC2310 or Additin RC2410 from Rhein Chemie, and Esterol 10S from Arkema.

[0058] The amount of sulfur contributed to the lubricating oil composition by the one or more sulfurized fatty acid ester(s) will depend on the sulfur content of the sulfurized fatty acid ester(s) and the amount of the sulfurized fatty acid ester(s) added to the lubricating oil composition. Suitably, the one or more sulfurized fatty acid esters contribute about 0.01 mass % or more, preferably about 0.02 mass % or more, more preferably 0.03 mass % or more, and even more preferably 0.04 mass % or more of sulfur to the lubricating oil composition, based on the total mass of the lubricating oil composition. Suitably, the one or more sulfurized fatty acid esters contribute about 0.30 mass % or less, preferably 0.25 mass % or less, and more preferably about 0.20 mass % or less of sulfur to the lubricating oil composition, based on the total mass of the lubricating oil composition. Suitably, the one or more sulfurized fatty acid esters contribute 0.02 to 0.30 mass % of sulfur, preferably 0.02 to 0.20 mass % of sulfur, and more preferably 0.02 to 0.10 mass % of sulfur to the lubricating oil composition.

[0059] Suitably, the sulfur content of the sulfurized fatty acid ester(s) is about 5% by weight or more, more preferably about 7% by weight or more, even more preferably about 9% by weight or more, and even more preferably about 10% by weight or more sulfur, based on the weight of the sulfurized fatty acid ester(s). Suitably, the sulfur content of the sulfurized fatty acid ester(s) is about 40% by weight or less, preferably 30% by weight or less, more preferably 25% by weight or less, and preferably 20% by weight or less sulfur, based on the weight of the sulfurized fatty acid ester(s). Any suitable method can be used to measure the sulfur content of the sulfurized fatty acid esters; for example, one suitable method uses a CHNS-932 elemental analyzer available from LECO Corporation, USA. Suitably the sulphurised fatty acid ester(s) are phosphorus free. Suitably the sulphurised fatty acid ester(s) are ashless.

[0060] Molybdenum Compounds Any suitable oil-soluble or oil-dispersible sulfur-containing molybdenum compound(s) having antioxidant properties can be used in the lubricating oil composition; typically, such compounds also exhibit friction modifying properties. Preferably, the oil-soluble or oil-dispersible molybdenum compound(s) is an oil-soluble or oil-dispersible sulfur-containing organo-molybdenum compound. Examples of such sulfur-containing organo-molybdenum compound(s) include molybdenum dithiocarbamate, molybdenum dithiophosphate, molybdenum dithiophosphinate, molybdenum xanthate, molybdenum thioxanthate, molybdenum sulfide, etc., and mixtures thereof. Particularly preferred are molybdenum dithiocarbamate, molybdenum dialkyldithiophosphate, molybdenum alkylxanthate, and molybdenum alkylthioxanthate. An especially preferred sulfur-containing organo-molybdenum compound(s) is molybdenum dithiocarbamate(s), especially molybdenum dialkyldithiocarbamate. The sulfur-containing molybdenum compound(s) may be mononuclear, dinuclear, trinuclear, or tetranuclear. Dinuclear and trinuclear molybdenum compound(s) are preferred, and trinuclear molybdenum compound(s) are particularly preferred. Suitably, preferred sulfur-containing organo-molybdenum compound(s) include dinuclear or trinuclear organo-molybdenum compounds, more preferably dinuclear or trinuclear molybdenum dithiocarbamate(s) (e.g., dialkyldithiocarbamates), especially trinuclear molybdenum dithiocarbamate(s), such as trinuclear molybdenum dialkyldithiocarbamate(s).

[0061] Oil-soluble or oil-dispersible trinuclear molybdenum compounds can be prepared by reacting a molybdenum source, e.g., (NH4)2Mo3S, in a suitable liquid(s) / solvent(s). 13 Other oil-soluble or dispersible trinuclear molybdenum compounds can be prepared by reacting n(H2O) (where n varies between 0 and 2 and includes non-stoichiometric values) with a suitable ligand source, such as tetraalkylthiuram disulfide. Other oil-soluble or dispersible trinuclear molybdenum compounds can be prepared by reacting (NH4)2Mo3S in a suitable solvent(s). 13Molybdenum compounds can be formed during the reaction of a molybdenum source such as tetraalkylthiuram disulfide, dialkyldithiocarbamate, or dialkyldithiophosphate, with a sulfur scavenger such as cyanide ion, sulfite ion, or a substituted phosphine. Alternatively, trinuclear molybdenum-sulfur halide salts, such as [M']2[Mo3S7A6] (where M' is a counterion and A is a halogen such as Cl, Br, or I), can be reacted with a ligand source such as a dialkyldithiocarbamate or dialkyldithiophosphate in a suitable liquid(s) / solvent(s) to form oil-soluble or dispersible trinuclear molybdenum compounds. The suitable liquid / solvent can be, for example, aqueous or organic. Suitably, the sulfur-containing molybdenum compound(s), when present, are present in an amount to provide the lubricating oil composition with at least 5 ppm, for example at least 20 ppm, or at least 40 ppm, preferably at least 60 ppm of molybdenum (ASTM D5185), based on the total mass of the lubricating oil composition. When present, the sulfur-containing molybdenum compound(s) provide the lubricating oil composition with no more than 1,200 ppm, for example no more than 1,000 ppm, or no more than 750 ppm, or no more than 500 ppm, or no more than 200 ppm of molybdenum (ASTM D5185), based on the total mass of the lubricating oil composition. Although the present invention does not require the presence of any sulfur-containing molybdenum compounds, some molybdenum may be beneficial for wear performance. The sulfur-containing molybdenum compound may be present in an amount to provide 2 to 1,200 ppm, suitably 5 to 1,000 ppm, or 5 to 750 ppm, preferably 5 to 500 ppm, and more preferably 5 to 200 ppm, of molybdenum, based on the total weight of the lubricating oil composition.

[0062] Alkene(s)(C) The lubricating oil compositions of the present invention require one or more oil-soluble or oil-dispersible alkenes having 10 or more carbon atoms, preferably 12 or more carbon atoms. Such alkenes can be obtained from fine chemical suppliers such as Sigma-Aldrich. Preferably, the one or more oil-soluble or oil-dispersible alkenes having 10 or more carbon atoms are one or more C 10 -C 22 Alkenes, more preferably one or more C 10 -C 20 Alkenes, more preferably one or more C 10 -C 18 Alkenes, even more preferably one or more C 12 -C 18 Alkenes, especially one or more C 14 -C 18 In a preferred embodiment of the present invention, the lubricating oil composition comprises one or more C alkenes. 14 Contains alkenes. The one or more oil-soluble or oil-dispersible alkenes having 10 or more carbon atoms described above can each independently have an even or odd number of carbon atoms. Preferably, a majority (i.e., greater than 50 mole %) of the one or more oil-soluble or oil-dispersible alkenes having 10 or more carbon atoms described above contain an even number of carbon atoms. Thus, the preferred one or more alkenes having 10 or more carbon atoms include one or more C 10 , C 12 , C 14 , C 16 , C 18 , C 20 , C 22 Alkenes, more preferably one or more C 10 , C 12 , C 14 , C 16 , C 18 , C 20 Alkenes, more preferably one or more C 10 , C 12 , C 14 , C 16 , C 18 Alkenes, more preferably one or more C 12, C 14 , C 16 , C 18 Alkenes, most preferably one or more C 14 , C 16 and C 18 Alkenes, especially one or more C 14 Contains alkenes.

[0063] The one or more oil-soluble or oil-dispersible alkenes having 10 or more carbon atoms may each independently have one or more carbon-carbon double bonds. Preferably, a majority (i.e., greater than 50 mol%) of the one or more alkenes having 10 or more carbon atoms have a single carbon-carbon double bond. Suitably, greater than 60 mol%, more preferably greater than 70 mol%, even more preferably greater than 75 mol%, even more preferably greater than 80 mol%, even more preferably greater than 85 mol%, and even more preferably greater than 90 mol% of the one or more alkenes containing 10 or more carbon atoms as defined herein have a single carbon-carbon double bond. The one or more oil-soluble or oil-dispersible alkenes having 10 or more carbon atoms each independently contain one or more terminal carbon-carbon double bonds, one or more internal carbon-carbon double bonds, or a combination thereof. Preferably, a majority (i.e., greater than 50 mol%) of the one or more alkenes having 10 or more carbon atoms contain only one or more terminal carbon-carbon double bonds (i.e., no internal carbon-carbon double bonds), in particular only a single terminal carbon-carbon double bond. Suitably, more than 60 mol%, preferably more than 70 mol%, even more preferably more than 75 mol%, even more preferably more than 80 mol%, even more preferably more than 85 mol%, and even more preferably more than 90 mol% of the one or more alkenes having 10 or more carbon atoms contain only one or more terminal carbon-carbon double bonds, in particular only a single terminal carbon-carbon double bond. Suitably, the one or more alkenes having 10 or more carbon atoms, as defined herein, contain one or more C 10 -C 22 It comprises an alk-1-ene (ie, an α-olefin is preferred).

[0064] Thus, the preferred one or more oil-soluble or oil-dispersible alkenes having 10 or more carbon atoms are one or more C 10 -C 22 Alk-1-enes, more preferably one or more C 10 -C 20 Alk-1-enes, even more preferably one or more C 10 -C 18 Alk-1-enes, more preferably one or more C 12 -C 18 Alk-1-enes, more preferably one or more C 14 -C 18 It includes alk-1-enes, particularly those alk-1-enes containing an even number of carbon atoms as defined herein. The one or more oil-soluble or oil-dispersible alkenes having 10 or more carbon atoms described above may be linear or branched, and may be cyclic, acyclic, or partially cyclic / acyclic, provided that a sufficient number of carbon atoms are present. Preferably, a major proportion (i.e., greater than 50 mole %) of the one or more alkenes having 10 or more carbon atoms described above is one or more acyclic C alkenes, as defined herein. 10 -C 22 Alkenes, more preferably one or more linear acyclic C 10 -C 20 and even more preferably one or more linear acyclic C 10 -C 18 and even more preferably one or more linear acyclic C 12 -C 18 and even more preferably one or more linear acyclic C 14 -C 18 Suitably, more than 50 mol%, preferably more than 60 mol%, more preferably more than 70 mol%, even more preferably more than 75 mol%, even more preferably more than 80 mol%, even more preferably more than 85 mol%, even more preferably more than 90 mol% of the one or more alkenes having 10 or more carbon atoms as defined herein are acyclic, more preferably acyclic linear C 10 -C 22 Alkene(s) (preferably C12 -C 18 It is an alkene (class). Thus, highly preferred one or more alkenes having 10 or more carbon atoms include one or more C 12 ~C 18 Alkenes, more preferably one or more linear acyclic C 12 -C 18 Alkenes, more preferably one or more linear acyclic C 12 -C 18 Alk-1-enes, even more preferably one or more linear acyclic C 12 , C 14 , C 16 , C 18 Alk-1-enes (i.e., dodec-1-ene, tetradec-1-ene, hexadece-1-ene, octadec-1-ene), more preferably one or more linear acyclic C 14 , C 16 , C 18 Alk-1-enes (i.e., tetradec-1-ene, hexadece-1-ene, octadec-1-ene), in particular one or more linear acyclic C 14 Includes alk-1-enes, especially tetradec-1-ene.

[0065] The one or more oil-soluble or oil-dispersible alkenes having 10 or more carbon atoms, as defined herein, are typically present in an amount of 0.01 mass % or more, more preferably 0.03 mass % or more, even more preferably 0.05 mass % or more, even more preferably 0.07 mass % or more, even more preferably 0.10 mass % or more, even more preferably 0.15 mass % or more, and even more preferably 0.20 mass % or more, based on the total mass of the lubricating oil composition. Preferably, the one or more oil-soluble or oil-dispersible alkenes having 10 or more carbon atoms, as defined herein, are typically present in an amount of 5.0 mass % or less, more preferably 4.0 mass % or less, even more preferably 3.0 mass % or less, even more preferably 2.0 mass % or less, and even more preferably 1.5 mass % or less, based on the total mass of the lubricating oil composition. Thus, the one or more oil-soluble or oil-dispersible alkenes having 10 or more carbon atoms are typically present in an amount of 0.05 to 3.0 mass %, preferably 0.1 to 2.0 mass %, and more preferably 0.2 to 1.5 mass %, based on the total mass of the lubricating oil composition.

[0066] Ashless antioxidant (D) The lubricating oil composition may optionally contain an effective minor amount of one or more oil-soluble or oil-dispersible ashless, non-sulfur-containing antioxidants (D). Suitably, the one or more oil-soluble or oil-dispersible ashless, non-sulfur-containing antioxidants include oil-soluble or oil-dispersible amine-based antioxidants, such as aromatic amine antioxidants (e.g., dialkyl-substituted diphenylamine(s)), phenol-based antioxidants, such as hindered phenol-based antioxidants (e.g., dialkyl-substituted phenol antioxidants), or combinations thereof. Ashless amine-based antioxidant(s), particularly aromatic amine-based antioxidant(s), such as dialkyl-substituted diphenylamine(s), are especially preferred. The most preferred antioxidant(s) are the dialkyl-substituted diphenylamines, such as di-C4-C 20 Alkyl-substituted diphenylamines and / or the above hindered phenols, such as iso-octyl-3,5-di-tert-butyl-4-hydroxycinnamate. Suitably, the one or more ashless, non-sulphur-containing antioxidants may be present in an amount of 0.1 to 10 mass %, preferably 0.25 to 7.5 mass %, more preferably 0.5 to 5 mass %, based on the total mass of the lubricating oil composition. It is preferred, but not required, that the lubricating oil composition include one or more oil-soluble or oil-dispersible ashless, non-sulfur-containing antioxidants (D).

[0067] Dihydrocarbyl dithiophosphate metal salts (E) The lubricating oil composition may optionally contain an effective minor amount of one or more oil-soluble or oil-dispersible dihydrocarbyl dithiophosphate metal salts (E), particularly one or more dihydrocarbyl dithiophosphate zinc salts (ZDDP(s)). The dihydrocarbyl dithiophosphate metal salt(s), where the metal can be an alkali or alkaline earth metal, or aluminum, lead, tin, molybdenum, nickel, copper, or preferably zinc, represents an antiwear compound(s) that reduces friction and excessive wear. The dihydrocarbyl dithiophosphate metal salt(s) can be prepared in accordance with known techniques by first forming a dihydrocarbyl dithiophosphoric acid (DDPA), usually by reacting P2S5 with one or more alcohols or phenols, and then neutralizing the DDPA formed with a metal compound. The preferred one or more zinc dihydrocarbyl dithiophosphates (ZDDP(s)) are oil-soluble salts of dihydrocarbyl dithiophosphates and can be represented by the following formula:

[0068] [ka]

[0069] Here, R and R' may be the same or different hydrocarbyl radicals containing 1 to 18, preferably 2 to 12, carbon atoms, including alkyl, alkenyl, aryl, arylalkyl, alkaryl, and alicyclic radicals. Particularly preferred as R and R' groups are alkyl groups having 2 to 8 carbon atoms. Thus, the radicals may be, for example, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, amyl, n-hexyl, i-hexyl, n-octyl, decyl, dodecyl, octadecyl, 2-ethylhexyl, phenyl, butylphenyl, cyclohexyl, methylcyclopentyl, propenyl, or butenyl. To achieve oil solubility, the total number of carbon atoms in the dithiophosphoric acid (i.e., R and R') will generally be about 5 or greater. The one or more zinc dihydrocarbyl dithiophosphates may therefore include one or more zinc dialkyldithiophosphates. Suitably, when present, the one or more dihydrocarbyl dithiophosphate metal salts (E), in particular one or more dihydrocarbyl dithiophosphate zinc salts (ZDDP(s)), as defined herein, are added to the lubricating oil composition in an amount sufficient to provide the lubricating oil composition with not more than 1,200 ppm (ppm) by mass, preferably not more than 1,000 ppm, more preferably not more than 900 ppm, and most preferably not more than 850 ppm by mass of phosphorus, based on the total mass of the lubricating oil composition and as measured in accordance with ASTM D 5185. The ZDDP is suitably added to the lubricating oil composition in an amount sufficient to provide the lubricating oil composition with at least 100 ppm, preferably at least 350 ppm, and more preferably at least 500 ppm by mass of phosphorus, based on the total mass of the lubricating oil composition and as measured in accordance with ASTM D 5185. Although it is preferred to include additive (E) in the lubricating oil composition, it is not required.

[0070] Ashless Dispersant (F) The lubricating oil composition may optionally contain, in effective minor amounts, one or more oil-soluble or oil-dispersible ashless dispersants. Ashless dispersants are nonmetallic organic materials that do not substantially form ash upon combustion, in contrast to metal-containing and therefore ash-forming materials. They comprise long-chain hydrocarbons with a polar head, the polarity of which is derived from the inclusion of, for example, an O, P, or N atom. The hydrocarbon confers oil solubility and is an oleophilic group, for example, having 40 to 500 carbon atoms. Thus, ashless dispersants can comprise an oil-soluble polymeric hydrocarbon backbone with functional groups capable of bonding with particles to be dispersed. Typically, dispersants contain amine, alcohol, amide, or ester-based polar moieties attached to the polymer backbone, often via a bridging group. For example, ashless dispersants can be selected from oil-soluble salts, esters, aminoesters, amides, imides and oxazolines of long-chain hydrocarbon-substituted mono- and dicarboxylic acids or their anhydrides; thiocarboxylate derivatives of long-chain hydrocarbons; long-chain aliphatic hydrocarbons having polyamines directly bonded thereto; and Mannich condensation products formed by condensing long-chain substituted phenols with formaldehyde and alkylene polyamines, as described, for example, in U.S. Pat. No. 3,442,808.

[0071] The oil-soluble polymeric hydrocarbon backbone is typically an olefin polymer or polyene, particularly a C-C polymer having a large molar amount (i.e., greater than 50 mole %). 18 Polymers containing olefins (e.g., ethylene, propylene, butylene, isobutylene, pentene, octane-1, styrene), and typically C2-C5 olefins. The oil-soluble polymeric hydrocarbon backbone can be a homopolymer or a copolymer of two different α-olefins. A preferred class of olefin polymers includes polybutenes, especially polyisobutene (PIB) or poly-n-butenes, which can be produced, for example, by polymerization of C4 refinery streams. Other classes of olefin polymers include ethylene-α-olefin (EAO) copolymers and α-olefin homo- and copolymers.

[0072] For example, ashless dispersants include derivatives of long-chain hydrocarbon-substituted carboxylic acids, such as high-molecular-weight hydrocarbyl-substituted succinic acids. A notable class of dispersants is hydrocarbyl-substituted succinimides, which are prepared by reacting the high-molecular-weight hydrocarbyl-substituted succinic acids (or their derivatives) with nitrogen-containing compounds, preferably polyalkene polyamines, such as polyethylene polyamines. Particularly preferred are reaction products of polyalkylene polyamines with polyalkene succinic anhydrides, particularly polyisobutenyl succinic anhydrides, such as those described in U.S. Pat. Nos. 3,202,678; 3,154,560; 3,172,892; 3,024,195; 3,024,237; 3,219,666; and 3,216,936; and BE-A-66,875. Preferred dispersants are polyalkene-substituted succinimides, in which the polyalkene group has a number average molecular weight in the range of 900 to 5,000, as measured by gel permeation chromatography (GPC). The polyalkene group contains a majority molar amount (i.e., greater than 50 mole %) of C2 to C6. 18 The polyalkene group may comprise an alkene such as ethene, propene, butene, isobutene, pentene, octane-1, and styrene. Preferably, the alkene is a C2-C5 alkene, more preferably butene or isobutene, which may be produced, for example, by polymerization of a C4 refinery stream. Most preferably, the number average molecular weight of the polyalkene group is in the range of 950 to 2,800. Highly preferred ashless dispersants include one or more polyalkene succinimides, especially one or more polyisobutene succinimides (PIBSA-PAM). Suitably, the number average molecular weight of the polyalkene group (i.e., the polyisobutene group of the polyisobutene succinimide) is in the range of 950 to 2,800. Such dispersant(s) are typically formed by reacting the corresponding polyalkene succinic anhydride (e.g., PIBSA) with a polyamine (PAM). When one or more ashless dispersants are present, the one or more polyalkene succinimides, especially one or more polyisobutylene succinimides, preferably represent the only ashless-containing dispersants in the lubricating oil composition.

[0073] Suitably, when present, the one or more ashless dispersants are present in an amount of 0.1 to 20 mass %, preferably 1 to 15 mass %, more preferably 2 to 10 mass %, based on the total mass of the lubricating oil composition. Suitably, when present, the one or more nitrogen-containing ashless dispersants contribute up to 0.20 mass %, preferably up to 0.15 mass %, more preferably up to 0.10 mass %, of nitrogen to the lubricating oil composition(s), based on the total mass of the composition and as measured in accordance with ASTM method D5291. Suitably, when present, the one or more nitrogen-containing ashless dispersants contribute 0.01 mass % or more, preferably 0.02 mass % or more, more preferably 0.03 mass % or more of nitrogen to the lubricating oil composition(s), based on the total mass of the composition and as measured in accordance with ASTM method D5291. The above ashless dispersants can be post-treated with boron to form the corresponding borated dispersants in a manner known in the art, for example as described in U.S. Pat. Nos. 3,087,936, 3,254,025, and 5,430,105. Boronation can be achieved, for example, by treating an acyl nitrogen-containing dispersant with a boron compound selected from boron oxide, boron halides, boric acid, and esters of boric acid in an amount sufficient to provide from about 0.1 to about 20 atomic proportions of boron for each mole of ashless dispersant. When a borated dispersant is present in the lubricating oil composition, the amount of boron contributed by the borated dispersant to the lubricating oil composition is suitably at least 10 ppm, such as at least 30 ppm, for example at least 50 ppm or even at least 65 ppm, of boron based on the total mass of the lubricating oil composition.When present, the borated dispersant suitably contributes no more than 1,000 ppm, preferably no more than 750 ppm, more preferably no more than 500 ppm of boron to the lubricating oil composition, based on the total mass of the lubricating oil composition. Although it is preferred to include additive (E) in the lubricating oil composition, it is not essential.

[0074] engine The lubricating oil compositions of the present invention may be used to lubricate mechanical engine components, particularly in internal combustion engines, such as spark-ignition or compression-ignition internal combustion engines, especially spark-ignition or compression-ignition two-stroke or four-stroke reciprocating engines, by adding the compositions thereto. The engines may be conventional gasoline or diesel engines designed to be powered by gasoline or petroleum diesel, respectively, or the engines may be specially modified to be powered by alcohol-based fuels or biodiesel fuels.

[0075] auxiliary additives In addition to additives (B) and (C), and optional additives (D), (E), and (F), if present, other auxiliary additives that may be included in the lubricating oil composition include one or more oil-soluble or oil-dispersible auxiliary additives selected from metal-containing detergents, rust inhibitors, pour point depressants, antiwear agents, friction modifiers, antifoam agents, viscosity modifiers, and demulsifiers. Suitably, such auxiliary additive(s) (i.e., the total amount of all such auxiliary additives) is present in an amount of 0.1 to 30 mass % active ingredient, based on the total mass of the lubricating oil composition. Typical effective amounts of co-additives different from additive components (B) and (C), including optional components (D), (E), and (F) above, which may also be present, are listed below; all values ​​listed are stated as active ingredient in mass % in the fully formulated lubricating oil.

[0076] [Table 2] (1): Viscosity modifiers are used only in multigrade oils.

[0077] The final lubricating oil composition, which is typically made by blending the or each additive in the base oil, may contain from 5 to 25 mass %, preferably from 5 to 18 mass %, typically from 7 to 15 mass %, of the auxiliary additive, with the remainder being oil of lubricating viscosity. The above co-additives are discussed in more detail below: As is known in the art, some additives can provide multiple benefits, for example, a single additive can act as a dispersant and as an antioxidant. Anti-wear agentreduce friction and excessive wear and are usually based on compounds containing sulfur or phosphorus or both, for example, they allow the deposition of polysulfide films on the relevant surfaces. Of note are the dihydrocarbyl dithiophosphate metal salts (E) described herein, where the metal can be an alkali or alkaline earth metal, or aluminum, lead, tin, molybdenum, manganese, nickel, copper, or preferably zinc. Examples of ashless antiwear agents include 1,2,3-triazoles, benzotriazoles, sulfurized fatty acid esters, and dithiocarbamate derivatives. There can be Metal cleaning agent These include oil-soluble neutral and overbased salicylates, sulfonates, phenates, sulfurized phenates, thiophosphonates, and naphthenates, as well as other oil-soluble carboxylates, of metals, particularly alkali or alkaline earth metals, such as sodium, potassium, lithium, calcium, and magnesium. The most commonly used metals are calcium and magnesium (both of which can be present in detergents used in lubricating oils), and mixtures of calcium and / or magnesium with sodium. Combinations of detergents, whether overbased or neutral, or both, can also be used.

[0078] Ashless friction modifierThe friction modifiers that can be present in the lubricating oil compositions of the present invention are generally known and include esters formed by the reaction of carboxylic acids and anhydrides with alkanols, and amine-based friction modifiers. Other useful friction modifiers generally contain a polar end group (e.g., carboxyl or hydroxyl) covalently bonded to an oleophilic hydrocarbon chain. Esters of carboxylic acids and anhydrides with alkanols are described in U.S. Pat. No. 4,702,850. Examples of other conventional organic friction modifiers are described by M. Belzer in "Journal of Tribology," (1992), Vol. 114, pp. 675-682, and by M. Belzer and S. Jahanmir in "Lubrication Science," (1988), Vol. 1, pp. 3-26. Preferred organic ashless nitrogen-free friction modifiers are ester or ester-based, and a particularly preferred organic ashless nitrogen-free friction modifier is glycerol monooleate (GMO). Similarly, ashless aminic or amine-based friction modifiers may also be used and include oil-soluble alkoxylated mono- and diamines, which improve boundary layer lubrication properties. Typically, the total amount of additional organic ashless friction modifiers in lubricating oils according to the present invention does not exceed 5 mass %, and preferably does not exceed 2 mass %, and more preferably does not exceed 0.5 mass %, based on the total mass of the lubricating oil composition.

[0079] Viscosity modifierThe VM functions to impart high- and low-temperature operability to the lubricating oil. The VM used can have that sole function or can be multifunctional. Multifunctional viscosity modifiers that also function as dispersants are also known. Suitable viscosity modifiers are polyisobutylene, copolymers of ethylene with propylene and higher α-olefins, polymethacrylates, polyalkyl methacrylates, methacrylate copolymers, copolymers of unsaturated dicarboxylic acids and vinyl compounds, copolymers of styrene and acrylic esters, and partially hydrogenated copolymers of styrene / isoprene, styrene / butadiene, and isoprene / butadiene, as well as partially hydrogenated homopolymers of butadiene and isoprene, and isoprene / divinylbenzene. Corrosion inhibitors can be used, which is selected from the group consisting of nonionic polyoxyalkylene polyols and esters thereof, polyoxyalkylene phenols, and anionic alkyl sulfonic acids. Copper and lead-bearing rust inhibitors Although additives such as thiosulfenamides can be used, they are generally not required for the formulations of the present invention. Typically, such compounds are thiadiazole polysulfides containing 5 to 50 carbon atoms, their derivatives, and polymers thereof. Typical are 1,3,4-thiadiazole derivatives, such as those described in U.S. Patent Nos. 2,719,125; 2,719,126; and 3,087,932. Other similar materials are described in U.S. Patent Nos. 3,821,236; 3,904,537; 4,097,387; 4,107,059; 4,136,043; 4,188,299; and 4,193,882. Other additives include thio- and polythiosulfenamides of thiadiazoles, such as those described in British Patent Specification No. 1,560,830. Similarly, benzothiazole derivatives also fall within this class of additives. When these compounds are included in the lubricating oil composition, they are preferably present in an amount not exceeding 0.2 mass % active ingredient.

[0080] Demulsifier ingredientcan be used in small amounts. A preferred demulsifier component is described in EP 330522. It is obtained by reacting an alkene oxide with an adduct obtained by reacting a bis-epoxide with a polyhydric alcohol. The demulsifier should be used at a level not exceeding 0.1% by weight active ingredient. Treat rates of 0.001 to 0.05% by weight active ingredient are convenient. Pour Point Depressants are also known as lube oil flow improvers, which lower the minimum temperature at which the fluid will flow or can be poured. Such additives are well known. Typical of those additives that improve the low temperature fluidity of the fluid are C8-C 18 Dialkyl fumarate / vinyl acetate copolymer, polyalkyl methacrylate, etc. Foam Control can be provided by many compounds including polysiloxane type antifoaming agents, such as silicone oil or polydimethylsiloxane. The individual additives can be incorporated into the base stock in any convenient manner. Thus, each of the components can be added directly to the base stock or base oil blend by dispersing or dissolving it in the base stock or base oil blend at the desired concentration level. Such blending can occur at ambient or elevated temperatures.

[0081] Preferably, all of the additives other than the viscosity modifier and the pour point depressant are blended into a concentrate or additive package, which is described herein as an additive package that is then blended into a base stock to produce a finished lubricant. The concentrate will typically be formulated to contain the additive(s) in an amount appropriate to provide the desired concentration in the final formulation when the concentrate is combined with a predetermined amount of base lubricant. Preferably, the concentrate is prepared according to the method described in U.S. Pat. No. 4,938,880, which describes the preparation of a premix of ashless dispersant and metal detergent, which is preblended at a temperature of at least about 100° C. The premix is ​​then cooled to at least 85° C. and the additional ingredients are added. The final lubricating oil formulation may use 2 to 20 mass %, preferably 4 to 18 mass %, and most preferably 5 to 17 mass % of the concentrate or additive package, with the remainder being base stock. [Example]

[0082] The present invention is illustrated in the following examples, which are not intended to limit the scope of the claims. Nitrile Elastomer Seal Compatibility test (VDA 675 301) Compatibility with nitrile elastomer seals is measured using the Mercedes Benz Seals Test in accordance with VDA 675 301. This performance is measured against the GF-5 requirements of a limit of -35% maximum elongation at break (EAB); and a limit of -20% maximum change in tensile strength (TS). Higher values ​​for EAB and / or TS indicate improved nitrile elastomer seal performance.

[0083] High-Temperature Corrosion Bench Test (ASTM D6594-06) Corrosion control is measured using the High Temperature Corrosion Bench Test (HTCBT) in accordance with ASTM D6594-06. This test method simulates corrosion of non-ferrous metals, such as copper and lead, found in cam followers and bearings in lubricating oil, where the corrosion process under investigation is induced by the lubricant chemistry rather than lubricant breakdown or contamination. The copper and lead concentrations in the lubricating oil composition after testing and in a reference sample of the lubricating oil composition (i.e., a fresh sample of the lubricating oil composition before testing) are then measured according to ASTM D5185. The difference between the concentration of each metal contaminant in the tested lubricating oil composition and those concentrations in the reference sample lubricating oil composition provides a value for the change in the various metal concentrations before and after the test. Industry standard limits to meet the requirements of API CJ-4 are a maximum of 20 ppm for copper and a maximum of 120 ppm for lead.

[0084] Sequence IIIG Engine Test (ASTM D7320-07) The viscosity increase of a lubricating oil composition is measured using the Sequence IIIG Engine Test in accordance with the method of ASTM D7320-07. This test is modified by running the engine in question for the time required for the viscosity (KV40) of the lubricating oil composition(s) to increase by 50% as measured by ASTM D445. A longer time required for the KV40 to increase by 50% indicates improved oxidation stability for the lubricating oil composition.

[0085] Examples 1 to 10: Sulfurized fatty acid esters The lubricating oil compositions of Examples 1 to 10, as well as Reference Lubricant 1 (Ref 1) and Comparative Lubricants A, B, and C, detailed in Table 1, were tested. Nitrile Elastomer SealThe lubricating oil compositions were subjected to the Nitrile Elastomer Seal Compatibility Test (VDA 675 301) and, where indicated, the High Temperature Corrosion Bench Test (ASTM D6594-06). In addition to the additive components detailed in Table 1, the lubricating oil compositions of Examples 1-10, Comparative Lubricants A, B, and C, and Reference Lubricant 1 each contained the same amounts of the following components: dispersant; ZDDP; overbased sulfonate detergent; organo-molybdenum trimer (providing 50 ppm molybdenum); aromatic amine antioxidant; and viscosity modifier. In the above examples, sulfurized rapeseed oil methyl ester (SRME) was obtained by sulfurizing rapeseed oil methyl ester (sulfur content of about 17%) as previously described, and dec-1-ene (C 10 α-olefin), dodec-1-ene (C 12 α-olefin), tetrapropylene (C 12 Branched olefin), tetradec-1-ene (C 14 α-olefin), hexadec-1-ene (C 16 α-olefin), octadec-1-ene (C 18 The α-olefins can be obtained from Sigma Aldrich. Polyisobutylene (PIB) has an Mn of about 950 and is available from Infineum UK Ltd. The amount of each additive in each lubricating oil composition is expressed in mass % active ingredient basis, based on the total mass of the lubricating oil composition.

[0086] Examples 2, 4, and 6 each contain the same amount of each alkene on an active ingredient molar mass basis (i.e., the molar amount of each alkene in each of these Examples is the same), and these Examples are directly comparable. Similarly, Examples 7-10 and Comparative Example C each contain the same amount of each alkene on an active ingredient molar mass basis (i.e., the molar amount of each alkene in each of these Examples is the same), and these Examples are directly comparable. In Comparative Example A and Examples 1-6, the SRME contributes 400 ppm sulfur to the lubricating oil composition, while in Comparative Examples B and C and Examples 7-10, the SRME contributes 800 ppm sulfur to the lubricating oil composition. From the results of the above seal test and HTCBT in Table 1, the addition of sulfur-containing antioxidant (SRME) to standard lubricant 1 has an effect on the nitrile seal Compatibility It is clear that the additive reduces corrosion resistance and increases both copper and lead corrosion (compare Standard Lubricant 1 with Comparative Lubricants A and B). The seal test data above demonstrate that the addition of alkenes, particularly alkenes with 10 or more carbon atoms, to lubricating oils containing sulfur-containing antioxidants (SRMEs) typically has a significant effect on the performance of nitrile seals, as evidenced by the results regarding changes in tensile strength (TS) and elongation at break (EAB). Compatibility (Compare Examples 1, 2, 5, and 6 with Comparative Lubricant A, and Examples 7-10 with Comparative Lubricant B.) The C10 alk-1-enes are also useful in nitrile seals. Compatibility (Compare Examples 5 and 6 with Comparative Lubricant A), but at equal molar treat rates, it is clear that the C14 alk-1-ene gives better results (compare TS and EAB results for Example 2 with those for Example 6). Furthermore, at equal molar treat rates with respect to each alkene, the C12-C18 alk-1-ene significantly and essentially outperforms the nitrile seal with comparable propensity. Compatibility(Compare TS and EAB results for Examples 7-10 with Comparative Example B), and such improvement(s) are significantly greater than the use of polyisobutylene (PIB; see Comparative Example C).

[0087] The above HTCBT data demonstrate that the addition of alkenes containing 10 or more carbon atoms, particularly alkenes containing at least 14 carbon atoms, to lubricating oils containing sulfur-containing antioxidants (SRMEs) typically improves copper corrosion performance (compare Examples 1 and 2 with Comparative Lubricant A). Moreover, the addition of alkenes, particularly alkenes containing at least 10 carbon atoms, to lubricating oils containing sulfur-containing antioxidants (SRMEs) typically improves lead corrosion performance (compare Examples 1-6 with Comparative Lubricant A).

[0088] [Table 3]

[0089] Examples 11 to 13: Sulfurized fatty acid esters The lubricating oil compositions of Examples 17-19, as well as Reference Lubricant 2 (Ref 2) and Comparative Lubricant D, as detailed in Table 2, each contained a nitrile elastomer seal. Compatibility The lubricating oil compositions were subjected to a performance test (VDA 675 301) and a high-temperature corrosion bench test (ASTM D6594-06). In addition to the additive components detailed in Table 2, the lubricating oil compositions of Examples 11-13, Comparative Lubricant D, and Reference Lubricant 2 each contained the same amounts of the following identical components: dispersant; ZDDP; overbased sulfonate / phenate detergent; organo-molybdenum trimer (50 ppm molybdenum); aromatic amine antioxidant; and viscosity modifier. In these examples, the sulfur-containing antioxidant is a sulfurized fatty acid ester (Base 10 SE, available from Dover Chemicals), and the alkene is tetradec-1-ene (a C14 α-olefin) available from Sigma-Aldrich. The amount of each additive in each lubricating oil composition is expressed in mass % active ingredient, based on the total mass of the lubricating oil composition. In Comparative Example D and Examples 11-13, the sulfurized fatty acid ester (Base 10 SE) contributes 800 ppm of sulfur to each lubricating oil composition.

[0090] [Table 4] *TS represents the change in tensile stress; **EAB represents the elongation at break.

[0091] The results in Table 2 show that the addition of sulfur-containing antioxidant (Base 10SE) to standard lubricant 2 significantly improved the nitrile seal Compatibility It is clear that this deteriorates the corrosion resistance and enhances both copper and lead corrosion (compare standard lubricant 2 with comparative lubricant D). The above seal test data demonstrate that the addition of the above C14 α-olefin (tetradec-1-ene) to a lubricating oil containing a sulfur-containing antioxidant (Base 10SE) significantly affects the performance of nitrile seals, as evidenced by the results regarding changes in tensile strength (TS) and elongation at break (EAB). Compatibility (Compare Examples 11-13 with Comparative Lubricant D.) Furthermore, this nitrile seal Compatibility The improvement in performance is further improved by increasing the amount of alkene in the lubricating oil (compare Examples 11-13). The above HTCBT data demonstrate that the addition of alkenes, particularly alkenes having at least 14 carbon atoms, to lubricating oils containing sulfur-containing antioxidants (Base 10 SE) typically improves copper and / or lead corrosion performance (compare Examples 11-13 with Comparative Lubricant D).

[0092] Examples 14 to 18: Molybdenum-based antioxidants Each of Reference Lubricant 3 (Ref 3), Comparative Lubricant E, and Lubricants 14-18, as detailed in Table 3, contained a nitrile elastomer seal. Compatibility The lubricating oil compositions were subjected to a performance test (VDA 675 301). In addition to the additive components detailed in Table 3, the lubricating oil compositions of Examples 14-18, Comparative Lubricant E, and Reference Lubricant 3 each contained the same amounts of the following identical components: dispersant, ZDDP, overbased sulfonate / phenate detergent, aromatic amine antioxidant, and viscosity modifier. Trinuclear molybdenum dithiocarbamate (MoT), available from Infineum UK Ltd., was used in Comparative Lubricant E and Lubricants 14-18 in an amount to provide the lubricants with 200 ppm molybdenum and 360 ppm sulfur, and the molybdenum trimer provided 90 ppm molybdenum relative to Standard Lubricant 3. Tetradec-1-ene was used as the alkene.

[0093] [Table 5] *TS represents the change in tensile stress; **EAB represents the elongation at break.

[0094] The seal test data in Table 3 show that the addition of sulfur-containing molybdenum compounds to standard lubricant 3 significantly improved the non-stick properties of the seals with nitrile elastomer seals. Compatibility It is clear that the lubricant containing such sulfur-containing molybdenum compounds significantly enhances the sealability of nitrile elastomer seals (compare Comparative Lubricant E with Standard Lubricant 3). Compatibility The toxicity is mitigated by including tetradec-1-ene in the lubricating oil composition (compare Lubricants 14-18 and Comparative Lubricant E).

[0095] Example 19: Sequence IIIG Engine Test Each of Reference Lubricant 4 (Ref 4), Comparative Lubricant F, and Lubricant 19, as detailed in Table 4 below, was subjected to the above Sequence IIIG engine test and the time required for the KV40 viscosity to increase by 50% was measured (ASTM D445). In addition to the additive components detailed in Table 4, Reference Lubricant 4, Comparative Lubricant F, and Lubricant 19 each contained the same amounts of the following components: dispersant, ZDDP, overbased sulfonate detergent, aromatic amine antioxidant, and viscosity modifier. SRME (sulfurized rapeseed oil methyl ester (17% sulfur content)) was used as the sulfur-containing antioxidant and in an amount to provide 800 ppm sulfur to the lubricating oil, and tetradec-1-ene was used as the alkene.

[0096] [Table 6]

[0097] The data in Table 4 demonstrate that the addition of a sulfur-containing antioxidant to the standard lubricant 4 increases the time required for the lubricant's viscosity (KV40) to increase by 50%, thereby demonstrating that the presence of the sulfur-containing antioxidant improves the lubricant's oxidation stability (compare Lubricant F with Standard Lubricant 4). The lubricant's oxidation stability is further improved with the addition of the combination of the sulfur-containing antioxidant and tetradec-1-ene, as evidenced by the longer time to a 50% KV40 increase (compare Lubricant 19 with Lubricant F and also with Standard Lubricant 4).

Claims

1. 1. A lubricating oil composition comprising: (A) an oil of lubricating viscosity present in an amount greater than 50 weight percent, based on the total weight of the lubricating oil composition; (B) one or more oil-soluble or oil-dispersible sulfur-containing antioxidants as additives present in an amount to provide the lubricating oil composition with 0.01 to 0.3 wt. % sulfur, based on the total weight of the lubricating oil composition, and 7 -C 29 ) one or more oil-soluble or oil-dispersible sulfur-containing antioxidants selected from hydrocarbyl fatty acid esters, one or more sulfur-containing molybdenum compounds, and combinations thereof; (C) one or more oil-soluble or oil-dispersible linear, acyclic C as an additive in an amount of 0.05 to 3.0 mass % based on the total mass of the lubricating oil composition. 12 -C 18 Alke-1-enes; and (E) one or more dihydrocarbyl dithiophosphate zinc salts as an additive in an amount to provide the lubricating oil composition with at least 100 ppm by weight, and not more than 1,200 ppm by weight, of phosphorus (ASTM D5185), based on the total weight of the lubricating oil composition. The lubricating oil composition comprising:

2. The one or more oil-soluble or oil-dispersible sulfur-containing antioxidants (B) are one or more sulfurized aliphatic (C 7 -C 29 2. The composition of claim 1, wherein the carboxylic acid is selected from the group consisting of: carboxylic acid esters;

3. The one or more sulfur-containing antioxidants (B) are one or more sulfurized aliphatic antioxidants (C 7 -C 29 ) Hydrocarbyl fatty acids (C 1 -C 20 ) alkyl esters; one or more sulfurized aliphatic (C 7 -C 29 3. The composition of claim 1 or 2, wherein the glycerol esters are selected from the group consisting of: ) hydrocarbyl fatty acid glycerol esters; and combinations thereof.

4. The one or more sulfur-containing antioxidants (B) are one or more sulfurized aliphatic antioxidants (C 7 -C 29 4. The composition of claim 3, wherein the methyl ester is a hydrocarbyl fatty acid methyl ester.

5. The one or more oil-soluble or oil-dispersible sulfurized aliphatic acid (C 7 -C 29 5. The composition of claim 2, wherein the hydrocarbyl fatty acid ester is derived from a vegetable oil and / or a transesterification product of a vegetable oil.

6. The one or more oil-soluble or oil-dispersible sulfurized aliphatic acid (C 7 -C 29 6. The composition of claim 5, wherein the hydrocarbyl fatty acid ester is derived from palm oil, corn oil, grapeseed oil, coconut oil, cottonseed oil, wheat germ oil, soybean oil, safflower oil, olive oil, peanut oil, rapeseed oil, sunflower oil, or transesterification products thereof, and combinations thereof, by sulfurization.

7. The one or more sulfurized aliphatic compounds (C 7 -C 29 ) hydrocarbyl fatty acid ester is one or more sulfurized aliphatic (C 7 -C 29 ) A composition according to any one of claims 2 to 6, having a sulfur content of 5 to 30% by weight, based on the weight of the hydrocarbyl fatty acid ester.

8. 2. The composition of claim 1, wherein the one or more sulfur-containing molybdenum compounds are one or more sulfur-containing organo-molybdenum compounds.

9. 9. The composition of any one of claims 1 to 8, wherein the sulfur-containing antioxidant is present in an amount to provide the lubricating oil composition with 0.02 to 0.2 wt. % sulfur, based on the total weight of the lubricating oil composition.

10. The one or more oil-soluble or oil-dispersible linear acyclic C 12 -C 18 10. The composition of any one of claims 1 to 9, wherein the alk-1-ene (C) comprises dodec-1-ene, tetradec-1-ene, hexadec-1-ene, octadec-1-ene, or a combination thereof.

11. The one or more oil-soluble or oil-dispersible linear acyclic C 12 -C 18 The composition of claim 10, wherein the alk-1-ene (C) comprises tetradec-1-ene.

12. The one or more oil-soluble or oil-dispersible linear acyclic C 12 -C 18 12. The composition of any one of claims 1 to 11, wherein the alk-1-ene (C) is present in an amount of 0.1 mass % or more and 2.0 mass % or less, based on the total mass of the lubricating oil composition.

13. The composition of any one of claims 1 to 12, wherein the lubricating oil composition further comprises one or more auxiliary additives other than additive components (B) and (C) selected from ashless dispersants, metal detergents, rust inhibitors, antioxidants, pour point depressants, antiwear agents, friction modifiers, demulsifiers, antifoam agents, and viscosity modifiers, in an amount of 0.1 to 30 mass %, based on the total mass of the lubricating oil composition.

14. A method of lubricating a spark ignition or compression ignition internal combustion engine, said method comprising the step of lubricating said engine with a lubricating oil composition according to any one of claims 1 to 13.

15. 14. A lubricating oil composition comprising an oil of lubricating viscosity with a large amount of oil and one or more oil-soluble or oil-dispersible sulfur-containing antioxidants (B) as defined in any one of claims 1 to 13, present as an additive in an amount to provide the lubricating oil composition with 0.01 to 0.3 mass % sulfur, based on the total mass of the lubricating oil composition, wherein the one or more oil-soluble or oil-dispersible linear, acyclic C nitriles as defined in any one of claims 1 to 13, as an additive in an amount of 0.05 to 3.0 mass %, based on the total mass of the lubricating oil composition, for improving compatibility of the lubricating oil composition with nitrile elastomer seals present in the internal combustion engine in the lubrication of a spark ignition or compression ignition internal combustion engine. 12 -C 18 Use of alk-1-enes (C).

16. 14. A lubricating oil composition comprising a large amount of oil of lubricating viscosity and one or more oil-soluble or oil-dispersible sulfur-containing antioxidants (B) as defined in any one of claims 1 to 13, present as an additive in an amount to provide the lubricating oil composition with 0.01 to 0.3 mass % sulfur, based on the total mass of the lubricating oil composition, comprising one or more oil-soluble or oil-dispersible linear, acyclic C nitrile elastomeric (C nitrile elastomeric) compounds as defined in any one of claims 1 to 13, as an additive in an amount of 0.05 to 3.0 mass %, based on the total mass of the lubricating oil composition, for preventing and / or inhibiting incompatibilities associated with the sulfur-containing antioxidant (B) and nitrile elastomer seals present in the internal combustion engine in the lubrication of a spark-ignition or compression-ignition internal combustion engine. 12 -C 18 Use of alk-1-enes (C).

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