Detergent and dispersant systems for improving steel piston cleanliness in heavy duty lubricants

Abstract

The present disclosure relates to crankcase lubricating oil compositions, particularly heavy crankcase lubricating oil compositions, for which high piston cleanliness of steel pistons is achieved using a detergent system of sulfonate soap and a dispersant system of one or more polyisobutylene succinimide dispersants according to the OM471 piston cleanliness test.

Description

Technical Field

[0001] The present disclosure relates to lubricating compositions, and in particular heavy duty lubricating compositions that exhibit improved piston cleanliness when used with steel pistons and with selected detergent and dispersant systems. Background Art

[0002] Automobile manufacturers continue to promote improved efficiency, fluid life and fuel economy, and therefore, the demand for engines, lubricants and their parts continues to increase. These requirements also mean that engine oil performance must be developed to meet the higher demand of such modern engines and their corresponding performance standards related to their unique purposes and applications. Due to this strict requirement for engine oil, lubricant manufacturers usually customize lubricants and additives thereof to meet certain performance requirements of industrial and / or manufacturer applications. Usually, each application requires specific performance standards so that the lubricant designed for an application cannot meet all performance specifications of different applications.

[0003] For example, the selection of detergents and dispersants in engine oil formulations is often based on a number of factors, including, but not limited to, piston cleanliness, acid neutralization, TBN retention, oxidation, low speed pre-ignition, wear, friction performance, fuel economy, supply and / or cost factors, to name just a few relevant considerations. However, it has been previously accepted that piston cleanliness in diesel engines often requires the use of detergent sources other than sulfonates; thus, diesel engine piston cleanliness often requires a combination of, for example, phenate and sulfonate detergents. These combinations often result in formulation disadvantages by limiting the selection of complementary ingredients in the formulation and / or often result in formulation compromises that can affect overall performance.

[0004] Previous heavy-duty engines (i.e., engines configured for vehicles with a gross vehicle weight of about 6,000 pounds or more) typically used aluminum pistons, and previous phenate and sulfonate detergent systems were effective in maintaining piston cleanliness with such engine configurations. Previously, piston cleanliness for certain applications was evaluated using aluminum pistons according to the OM501LA (CEC L-101-08) test. Recently, some heavy-duty engines (engines configured for vehicles with a gross vehicle weight of about 6,000 pounds or more) have been converted to use steel pistons, which allow increased pressure and temperature in the cylinder to help achieve improved fuel economy performance by generally having less friction, high torque management and / or long durability. However, with the transition to upgraded engines and steel pistons, the industry has also developed a more stringent piston cleanliness test, designated as the OM471 piston cleanliness test of CEC L-118-21. This test uses an engine with a steel piston and is configured to deliver more power and more torque than the engine used in the OM501LA test. This new piston cleanliness test designed for steel pistons is not only more severe than the OM501LA test in terms of pressure and temperature, but the test duration is also twice as long (about 600 hours instead of about 300 hours) and / or at higher maximum power and torque levels. Compared to the OM501LA test, which produced an engine power output of about 358 kW, the OM471 test produced a significantly increased engine power output of about 391 kW.

[0005] Therefore, heavy-duty engine lubricants must now demonstrate acceptable performance when subjected to the more severe operating conditions of the new OM471 piston cleanliness test of CEC L-118-21. However, in many cases, changing the components within the lubricant composition to meet the newer performance characteristics tends to adversely affect one or more other performance characteristics, thus making it challenging for lubricant manufacturers to meet the newer industry performance requirements while also maintaining traditional fluid performance. Summary of the invention

[0006] In one method or embodiment, the present disclosure relates to a method for lubricating a diesel engine, particularly a heavy-duty diesel engine, having a steel piston. The present invention is particularly suitable for lubricating engines having steel pistons, and is particularly suitable for lubricating heavy-duty diesel engines having steel pistons. In one aspect, the method includes lubricating a diesel engine, particularly a steel piston of a heavy-duty diesel engine, with a lubricating oil composition. In another aspect, the lubricating oil composition comprises (i) a detergent system consisting of one or more alkaline earth metal sulfonate detergents, the detergent system delivering up to about 1% by weight of sulfonate soap (preferably about 0.3% by weight to about 1% by weight of sulfonate soap) to the lubricating oil composition, and (ii) a dispersant system including one or more polyisobutylene succinimide dispersants, the dispersant system delivering at least about 5% by weight of one or more dispersants to the lubricating oil composition; and wherein the one or more polyisobutylene succinimide dispersants are derived from a highly reactive polyisobutylene having a number average molecular weight of about 1,200 to about 2,500 and delivering greater than 650 ppm of nitrogen to the lubricating oil composition. In some embodiments, a diesel engine, particularly a heavy-duty diesel engine, is operated under the conditions set forth in the OM471 piston cleanliness test of CEC L-118-21, which in some embodiments lasts for up to about 600 hours (or up to about 400 hours or about 400 hours to about 600 hours) and / or an engine power output of up to about 391 kW. In some embodiments, the lubricating oil composition further comprises an antioxidant system of one or more ashless antioxidants (preferably alkylated diphenylamines and hindered phenols) and a molybdenum-containing antioxidant, wherein the molybdenum-containing antioxidant comprises an oil-soluble molybdenum compound selected from the group of molybdenum dithiocarbamates, molybdenum dialkyl dithiophosphates, sulfur-free organic molybdenum complexes of organic amides, or mixtures thereof, and wherein the one or more ashless antioxidants are selected from hindered phenols, aromatic amines, alkylated diphenylamines, phenyl-α-naphthylamines, alkylated phenyl-α-naphthylamines, hindered non-aromatic amine sulfurized olefins, or mixtures thereof, and in one embodiment, the lubricating composition comprises at least about 2 wt%, at least about 2.2 wt%, or at least about 2.5 wt% of the antioxidant system. In one approach, the antioxidant system may include at least 1.0 wt% of diphenylamine, at least 1.0 wt% of hindered phenols, and less than 0.2 wt% of molybdenum-containing compounds in the lubricating composition.

[0007] In yet further methods or embodiments, the method of lubricating a diesel engine, particularly a heavy-duty diesel engine, having a steel piston of the preceding paragraph may include any combination of optional features, steps or embodiments. These optional features, steps or embodiments may include one or more of the following: wherein the diesel engine, particularly the heavy-duty diesel engine, is configured to power a vehicle having a gross vehicle weight rating of about 6,000 pounds or more; and / or wherein the detergent system is composed of one or more overbased calcium sulfonate detergents and one or more underbased calcium sulfonate detergents, wherein the overbased detergent has a total base number (TBN) of at least about 200 mg KOH / g and the underbased detergent has a total base number (TBN) of about 175 mg KOH / g or less, and the total base number (TBN) is measured by ASTM D2896; and / or wherein the detergent system comprises a weight ratio of one or more overbased sulfonate detergents to one or more underbased sulfonate detergents of from about 3:1 to about 8:1 (in other embodiments, from about 3:1 to about 6:1, from about 3:1 to about 5:1, or from about 3:1 to about 4:1); and / or wherein the detergent system comprises a weight ratio of overbased sulfonate soap to underbased sulfonate soap of from about 2:1 to about 4:1 (in other embodiments, from about 2.1:1 to about 3.5:1, from about 2.2:1 to about 3:1, or from about 2.3:1 to about 2.8:1); and / or wherein the detergent system comprises providing at least about 5 mg of KOH / g and one or more overbased sulfonate detergents in an effective amount and one or more underbased sulfonate detergents in an effective amount to provide about 25 wt. % to about 40 wt. % detergent soap; and / or wherein the detergent system consists essentially of calcium sulfonate detergents; and / or wherein the detergent system is essentially free of magnesium sulfonate detergents, essentially free of phenate detergents, or combinations thereof; and / or wherein the lubricating oil composition comprises from about 50 ppm to about 200 ppm of molybdenum provided by an oil-soluble molybdenum compound selected from the group of molybdenum dithiocarbamates, molybdenum dialkyl dithiophosphates, sulfur-free organo-molybdenum complexes of organic amides, or mixtures thereof; and / or wherein the lubricating oil composition The composition further comprises from about 0.5 weight percent to about 5 weight percent of one or more ashless antioxidants selected from hindered phenols, aromatic amines, alkylated diphenylamines, phenyl-α-naphthylamines, alkylated phenyl-α-naphthylamines, hindered non-aromatic amine sulfurized olefins, or mixtures thereof; and / or wherein the lubricating oil composition comprises up to about 1200 ppm of phosphorus from one or more metal dihydrocarbyl dithiophosphate compounds having a hydrocarbyl group derived from a mixture of a linear or branched primary alcohol and a linear or branched secondary alcohol; and / or wherein the heavy duty crankcase lubricating composition has a negligible amount of magnesium, such as about 20 ppm or less or about 10 ppm or less of magnesium.

[0008] In other methods or embodiments, the disclosure herein provides a crankcase lubricating oil composition, particularly a heavy-duty crankcase lubricating oil composition, suitable for use in diesel engines having a gross vehicle weight of about 6,000 pounds or more and having an engine with steel pistons. In aspects of this embodiment, the crankcase lubricating oil composition, particularly a heavy-duty crankcase lubricating oil composition, comprises one or more base oils of lubricating viscosity; a detergent system consisting of one or more alkaline earth metal sulfonate detergents, the detergent system delivering up to about 1 wt % of sulfonate soap (preferably about 0.3 wt % to about 1 wt % of sulfonate soap) to the lubricating oil composition; a dispersant system comprising one or more polyisobutylene succinimide dispersants, the dispersant system delivering at least about 5 wt % of the one or more dispersants to the lubricating oil composition; and wherein the one or more polyisobutylene succinimide dispersants are derived from a highly reactive polyisobutylene having a number average molecular weight of about 1,200 to about 2,500 and delivering greater than 650 ppm of nitrogen to the lubricating oil composition. In some embodiments, the diesel engine, particularly a heavy-duty diesel engine, is operated under the conditions set forth in the OM471 piston cleanliness test of CEC L-118-21 for, in some embodiments, up to about 600 hours (or up to about 400 hours or about 400 hours to about 600 hours) and / or an engine power output of up to about 391 kW. In some embodiments, the lubricating oil composition achieves at least 90% of the rated cleanliness of a steel piston as measured by the OM471 piston cleanliness test (CEC L-118-21) (a higher rated percentage is a cleaner piston). In other embodiments, the crankcase lubricating oil composition, in particular the heavy duty crankcase lubricating oil composition, further comprises an antioxidant system of one or more ashless antioxidants, preferably alkylated diphenylamines and hindered phenols, and a molybdenum-containing antioxidant, wherein the molybdenum-containing antioxidant comprises an oil-soluble molybdenum compound selected from the group of molybdenum dithiocarbamates, molybdenum dialkyl dithiophosphates, sulfur-free organic molybdenum complexes of organic amides, or mixtures thereof, and wherein the one or more ashless antioxidants are selected from the group of hindered phenols, aromatic amines, alkylated diphenylamines, phenyl-α-naphthylamines, alkylated phenyl-α-naphthylamines, hindered non-aromatic amine sulfurized olefins, or mixtures thereof, and in one embodiment, the lubricating composition comprises at least about 2 wt%, at least about 2.2 wt%, or at least about 2.5 wt% of the antioxidant system. In one approach, the antioxidant system may include at least 1.0 wt% of diphenylamine, at least 1.0 wt% of hindered phenols, and less than 0.2 wt% of molybdenum-containing compounds in the lubricating composition.

[0009] In other methods or embodiments, the crankcase lubricating oil, particularly the heavy duty crankcase lubricating oil, described in the previous paragraph may include any combination of optional features or embodiments. These optional features or embodiments may include one or more of the following: wherein the detergent system consists of one or more overbased calcium sulfonate detergents and one or more underbased calcium sulfonate detergents, wherein the overbased detergent has a total base number (TBN) of at least about 200 mg KOH / g and the underbased detergent has a total base number (TBN) of about 175 mg KOH / g. KOH / g or less, and the total base number (TBN) is determined by ASTM D2896; and / or wherein the detergent system comprises a weight ratio of one or more high-based sulfonate detergents to one or more low-based sulfonate detergents of about 3:1 to about 8:1 (in other embodiments, about 3:1 to about 6:1, about 3:1 to about 5:1, or about 3:1 to about 4:1); and / or wherein the detergent system comprises a weight ratio of high-based sulfonate soap to low-based sulfonate soap of about 2:1 to about 4:1 (in other embodiments, about 2.1:1 to about 3.5:1, about 2.2:1 to about 3:1, or about 2.3:1 to about 2.8:1); and / or wherein the detergent system comprises providing at least about 5 mg of the detergent system with a KOH / g and one or more overbased sulfonate detergents in an effective amount and one or more underbased sulfonate detergents in an effective amount to provide about 25 wt. % to about 40 wt. % detergent soap; and / or wherein the detergent system consists essentially of calcium sulfonate detergents; and / or wherein the detergent system is essentially free of magnesium sulfonate detergents, essentially free of phenate detergents, or combinations thereof; and / or wherein the lubricating oil composition comprises from about 50 ppm to about 200 ppm of molybdenum provided by an oil-soluble molybdenum compound selected from the group of molybdenum dithiocarbamates, molybdenum dialkyl dithiophosphates, sulfur-free organo-molybdenum complexes of organic amides, or mixtures thereof; and / or wherein the lubricating oil composition The composition further comprises from about 0.5 weight percent to about 5 weight percent of one or more ashless antioxidants selected from hindered phenols, aromatic amines, alkylated diphenylamines, phenyl-α-naphthylamines, alkylated phenyl-α-naphthylamines, hindered non-aromatic amine sulfurized olefins, or mixtures thereof; and / or wherein the lubricating oil composition comprises up to about 1200 ppm of phosphorus from one or more metal dihydrocarbyl dithiophosphate compounds having a hydrocarbyl group derived from a mixture of a linear or branched primary alcohol and a linear or branched secondary alcohol; and / or wherein the heavy duty crankcase lubricating oil composition comprises a negligible amount of magnesium, such as about 20 ppm or less or about 10 ppm or less of magnesium.

[0010] In yet further methods or embodiments, the disclosure herein provides for use of any embodiment of the lubricating oil composition of the present overview, particularly the heavy-duty lubricating oil composition, to achieve improved steel piston cleanliness according to the OM471 Piston Cleanliness Test (CEC L-118-21), and in other embodiments at least about 90% of the rated cleanliness of a steel piston as measured by the OM471 Piston Cleanliness Test (CEC L-118-21). DETAILED DESCRIPTION

[0011] The present disclosure is particularly related to a heavy-duty crankcase lubricating oil composition and a method for lubricating a heavy-duty diesel engine with a steel piston, which effectively achieves qualified piston cleanliness according to the new OM471 piston cleanliness test of CEC L-118-21 that meets the ACEA E8 specification. In a method or embodiment, the heavy-duty lubricating oil composition of this article is suitable for achieving qualified piston cleanliness on a steel piston according to the OM471 test. Such heavy-duty diesel engines and lubricants herein are configured to power vehicles with a gross vehicle weight rating of about 6,000 pounds or more. Such engines typically have an engine capacity of 10 liters or more, a steel piston, a maximum power of up to about 600 horsepower, a maximum torque of up to about 1,900 ft-lb, and / or an exhaust gas recirculation system. The present invention is particularly suitable for lubricating engines with steel pistons, and more specifically for lubricating heavy-duty diesel engines with steel pistons.

[0012] In the methods or embodiments herein, the crankcase lubricating oil compositions of the present disclosure suitable for such engines and vehicles, especially heavy-duty crankcase lubricating oil compositions, preferably include at least (i) a detergent system including, consisting of, or consisting essentially of one or more alkaline earth metal sulfonate detergents, the detergent system delivering up to about 1% by weight of sulfonate soap to the lubricating oil composition; (ii) a dispersant system including one or more polyisobutylene succinimide dispersants, the dispersant system delivering at least about 5% by weight of one or more dispersants to the lubricating oil composition. In other methods or embodiments, the lubricating oil composition herein may also include one or more optional ashless antioxidants, one or more optional oil-soluble molybdenum compounds, and one or more optional metal dihydrocarbyl dithiophosphate compounds, in an amount effective to help piston cleanliness in the harsh environment of the OM471 piston cleanliness test and when combined with the above-mentioned detergent and dispersant system. In some embodiments, the lubricating oil composition also includes an antioxidant system of one or more ashless antioxidants (preferably alkylated diphenylamines and hindered phenols) and a molybdenum-containing antioxidant. The molybdenum-containing antioxidant may include an oil-soluble molybdenum compound selected from the group of molybdenum dithiocarbamates, molybdenum dialkyl dithiophosphates, sulfur-free organic molybdenum complexes of organic amides, or mixtures thereof. One or more ashless antioxidants may be selected from hindered phenols, aromatic amines, alkylated diphenylamines, phenyl-α-naphthylamines, alkylated phenyl-α-naphthylamines, hindered non-aromatic amine sulfurized olefins, or mixtures thereof. In one embodiment, the lubricating composition comprises at least about 2 wt%, at least about 2.2 wt%, or at least about 2.5 wt% of the antioxidant system, and in some embodiments comprises about 5 wt% or less, about 4 wt% or less, or about 3 wt% or less of the antioxidant system. In one method, the antioxidant system may include at least 1.0 wt% of diphenylamine, at least 1.0 wt% of hindered phenols, and less than 0.2 wt% of the molybdenum-containing compound in the lubricating composition.

[0013] In some methods, the one or more polyisobutylene succinimide dispersants of the dispersant system may be derived from a highly reactive polyisobutylene having a number average molecular weight of about 1,200 to about 2,500 and include at least one borated polyisobutylene succinimide dispersant derived from a polyisobutylene having a number average molecular weight of about 1,000 to about 1,500 and delivering about 100 ppm to about 200 ppm of boron to the lubricating oil composition.

[0014] In other methods or embodiments, the unique detergent system herein provides a TBN from a sulfonate detergent of about 3 mg KOH / g to about 15 mg KOH / g, about 5 mg KOH / g to about 15 mg KOH / g, or about 8 mg KOH / g to about 15 mg KOH / g, and comprises, consists of, or alternatively consists essentially of a calcium sulfonate detergent in an amount that provides the detergent system with a TBN and soap content as discussed herein. In other words, the detergent system herein is primarily a sulfonate detergent, and most preferably is only a sulfonate detergent, with little or no phenates or other detergent types previously required to pass previous heavy-duty diesel engine piston cleanliness tests when aluminum pistons were used (and most preferably no phenates or other detergent additives). Even without detergent soap types other than sulfonates (such as phenate soaps), the lubricants herein surprisingly pass the more stringent OM471 piston cleanliness test, even when steel pistons are used. The detergent systems herein are substantially free of non-sulfonate soaps (such as phenate soaps), which means about 25% or less of phenate soap, about 20% or less, about 15% or less, about 10% or less, about 5% or less, about 2.5% or less, about 1% or less, or no functional amount of phenate soap.

[0015] As discussed more below, the detergent system herein may include a unique blend of a high-based sulfonate detergent and a neutral to low-based sulfonate detergent configured to provide the TBN level and the soap content described. In some methods or embodiments, the detergent system includes a weight ratio of one or more high-based sulfonate detergents to one or more low-based sulfonate detergents of about 3:1 to about 8:1 (in other embodiments, about 3:1 to about 6:1, about 3:1 to about 5:1, or about 3:1 to about 4:1). In an alternative method, the detergent system includes an embodiment in which the weight ratio of high-based sulfonate soap to low-based sulfonate soap is about 2:1 to about 4:1 (in other embodiments, about 2.1:1 to about 3.5:1, about 2.2:1 to about 3:1, or about 2.3:1 to about 2.8:1). Preferably, the detergent system includes an effective amount of one or more overbased sulfonate detergents to provide a minimum TBN of at least about 5 mg KOH / g to the detergent system, and an effective amount of one or more underbased sulfonate detergents to provide from about 25 wt % to about 40 wt % detergent soap in the detergent system.

[0016] Detergent system

[0017] The lubricating compositions herein comprise a detergent system that achieves piston cleanliness according to the stringent OM471 piston cleanliness test for steel pistons, with little or no use of non-sulfonate soaps (such as phenate soaps), preferably no use of phenate soaps. In some approaches, steel piston cleanliness is achieved with a detergent system comprising, consisting of, or consisting essentially of one or more alkaline earth metal sulfonate detergents that deliver up to about 1 wt % soap and preferably up to 1 wt % sulfonate soap to the lubricant, the sulfonate soap having the minimum TBN level provided by the sulfonate detergent, which may be a blend of neutral, low-based, or high-based sulfonate detergents. The preferred TBN level provided by the sulfonate detergent is at least about 3 mg KOH / g, at least about 4 mg KOH / g, at least about 5 mg KOH / g, at least about 3 mg KOH / g to about 15 mg KOH / g, at least about 5 mg KOH / g to about 9 mg KOH / g, about 12 mg KOH / g or less, about 10 mg KOH / g or less, or about 7 mg KOH / g or less. In embodiments, the detergent system herein typically includes one or more alkali metal or alkaline earth metal salts of sulfonates and a small amount, only a residual level, or preferably no other functional detergent additives, such as phenates, calixarene salts, salixarates, salicylates, carboxylic acids, their sulfurized derivatives, or combinations thereof, as long as the minimum amount of sulfonate soap, TBN level, soap content relationship described herein and / or low levels of other detergents are met. Thus, in embodiments, the detergent system herein includes no more than about 0.5 wt%, no more than about 0.2 wt%, or no more than about 0.1 wt% of non-sulfonate detergent.

[0018] Suitable detergents and methods of making them are described in more detail in a number of patent publications, including US 7,732,390 and references cited therein, which are incorporated herein by reference. The lubricant compositions herein may contain from about 0.1 wt % to about 5 wt % of individual and / or total detergent additives, and in other approaches, from about 0.15 wt % to about 3 wt %, and in other approaches, from about 0.5 wt % to 2.6 wt % of individual and / or total detergent additives, as long as the detergent additives meet the sulfonate amounts and other relationships described herein.

[0019] As described above and in some methods, the detergent system provides a selected amount of sulfonate soap and TBN level and an amount of detergent metal. For example, the detergent system herein can provide a total detergent metal amount of greater than about 1200 ppm of metal, or in other methods, about 1200 ppm to about 3500 ppm of total metal, about 1400 ppm to about 3000 ppm of total metal, or about 2000 to about 2500 ppm of total metal. In the method, the detergent metal is calcium, magnesium and / or sodium. In other methods, the detergent metal is calcium and / or magnesium, and in further methods, the detergent metal is preferably only calcium.

[0020] Generally, suitable detergents in the system may include linear or branched alkali or alkaline earth metal salts, such as calcium, sodium or magnesium salts, of petroleum sulfonic acids and long chain mono- or di-alkyl aryl sulfonic acids, wherein the aryl groups are benzyl, tolyl and xylyl, and / or various phenates or phenate derivatives. Examples of suitable detergents (subject to the desired amount of sulfonate soap as described above) include low / neutral and high base forms of the following detergents: calcium phenates, sulfur-containing calcium phenates, calcium sulfonates, calcium calixarates, calcium salixarates, calcium salicylates, calcium carboxylates, calcium phosphates, calcium mono- and / or di-thiophosphates, calcium alkylphenates, sulfur-coupled alkylphenate calcium compounds, methylene-bridged calcium phenates, magnesium phenates, sulfur-containing magnesium phenates, magnesium sulfonates, magnesium calixarates, magnesium salixarates, magnesium salicylates, magnesium carboxylates, magnesium phosphates, magnesium mono- and / or di-thiophosphates, magnesium alkylphenates, sulfur-coupled alkylphenate magnesium compounds, methylene-bridged magnesium phenates, sodium phenates, sulfur-containing sodium phenates, sodium sulfonates, sodium calixarates, sodium salixarates, salixarates), sodium salicylates, sodium carboxylates, sodium phosphates, sodium monothiophosphates and / or sodium dithiophosphates, sodium alkylphenols, sulfur-coupled sodium alkylphenol compounds, or methylene-bridged sodium phenols.

[0021] The detergent additive herein preferably comprises a blend of (i) a neutral to low base detergent in an amount effective to provide minimum soap content and (ii) an overbased detergent in an amount effective to meet a minimum detergent TBN value.

[0022] It should be understood that overbased detergent additives are well known in the art and may be alkali metal or alkaline earth metal overbased detergent additives. Such detergent additives may be prepared by reacting a metal oxide or metal hydroxide with a substrate and carbon dioxide gas. The substrate is typically an acid, such as an aliphatic substituted sulfonic acid, an aliphatic substituted carboxylic acid, or an aliphatic substituted phenol.

[0023] The term "overbased" refers to metal salts, such as metal salts of sulfonic acids, carboxylic acids, salicylic acids and / or phenols, in which the amount of metal present exceeds the stoichiometric amount. Such salts may have a conversion level exceeding 100% (i.e., they may contain 100% of the theoretical amount of metal required to convert the acid into its "normal", "neutral" salt). The expression "metal ratio" is usually abbreviated as MR, which is used to represent the ratio of the total chemical equivalents of the metal in the overbased salt to the chemical equivalents of the metal in the neutral salt, based on known chemical reactivity and stoichiometry. In normal or neutral salts, MR is one, and in overbased salts MR is greater than one. They are often referred to as overbased, superbased or superbasic salts, and may be salts of organic sulfuric acid, carboxylic acid, or phenol.

[0024] As used herein, the term "TBN" is used to represent the total base number in mg KOH / g as measured by the ASTM D2896 method. The detergent can be neutral or overbased. For example, a low-base or neutral detergent can have a total base number (TBN) of up to about 175 mg KOH / g. In another example, the total base number (TBN) of the overbased detergent of the lubricating oil composition can be about 200 mg KOH / g or greater, or about 250 mg KOH / g or greater, or about 350 mg KOH / g or greater, or about 375 mg KOH / g or greater, or about 400 mg KOH / g or greater. The overbased detergent may have a metal to substrate ratio of 1.1:1 or less, or 2:1 or less, or 4:1 or less, or 5:1 or less, or 7:1 or less, or 10:1 or less, or 12:1 or less, or 15:1 or less, or 20:1 or less.

[0025] Examples of suitable overbased detergents (so long as the sulfonate soap and other TBN relationships described herein are met) include, but are not limited to, overbased calcium phenates, overbased sulfur-containing calcium phenates, overbased calcium sulfonates, overbased calcium calixarates, overbased calcium salicylates, overbased calcium carboxylates, overbased calcium phosphates, overbased calcium monothiophosphates and / or dithiophosphates, overbased calcium alkylphenates, overbased sulfur-coupled alkylphenate calcium compounds, overbased methylene-bridged calcium phenates, overbased magnesium phenates, overbased sulfur-containing magnesium phenates, overbased magnesium sulfonates, overbased magnesium calixarates, overbased magnesium salicylates, overbased magnesium carboxylates, overbased magnesium phosphates, overbased magnesium monothiophosphates and / or dithiophosphates, overbased magnesium alkylphenates, overbased sulfur-coupled alkylphenate magnesium compounds, or overbased methylene-bridged magnesium phenates.

[0026] Low base or neutral detergents typically have a TBN of at most 175 mg KOH / g, at most 150 mg KOH / g, at most 100 mg KOH / g, or at most 50 mg KOH / g. Low base / neutral detergents may include calcium-containing detergents. Examples of suitable low base / neutral detergents (as long as the sulfonate soaps and other TBN relationships described herein are met) include, but are not limited to, calcium sulfonates, calcium phenates, calcium salicylates, magnesium sulfonates, magnesium phenates, and / or magnesium salicylates.

[0027] In some embodiments, the detergent used in the lubricants herein includes at least an overbased calcium sulfonate having a total base number of 200 to 400 and in other methods from about 250 to about 350. The above TBN values ​​reflect the values ​​of the finished detergent component that has been diluted in the base oil. In some methods, the detergent system includes a blend of neutral to low basicity and overbased sulfonate detergents, and the lubricants herein may include about 0.1 wt % to about 1.0 wt % of neutral to low basicity sulfonate detergent and about 0.5 wt % to about 3.0 wt % of overbased sulfonate detergent (or in other methods, about 1.0 wt % to about 2.5 wt % of overbased sulfonate detergent). In other methods, the detergent system herein may have a ratio of overbased sulfonate detergent to low basicity sulfonate detergent of about 3:1 to about 8:1. As noted above, the amount of overbased sulfonate detergent is effective to provide a minimum TBN level for the detergent, and the amount of underbased or neutral sulfonate detergent is effective to provide a minimum soap level.

[0028] In other embodiments, the TBN of the detergents herein may reflect the neat or undiluted form of the detergent components. For example, the fluids herein may include as a neat additive an overbased calcium sulfonate having a TBN of about 500 to about 650 and in other approaches about 550 to about 610. The fluids herein may also include as a neat additive a neutral to low-based calcium sulfonate having a TBN of up to 75, up to 70, or from about 40 to about 75, or from about 40 to about 70.

[0029] More specifically, the detergent systems herein include neutral, low-based and / or overbased detergents (preferably neutral to overbased calcium sulfonates) to achieve a detergent TBN of at least about 3 mg KOH / g, at least about 4 mg KOH / g, at least about 5 mg KOH / g, at least about 3 mg KOH / g, or to about 15 mg KOH / g or less, about 5 mg KOH / g or less, or about 9 mg KOH / g or less as measured by ASTM D2896. Preferably, the detergent systems herein include an effective amount of one or more overbased sulfonate detergents to provide the detergent system with a total TBN of at least about 5 mg KOH / g to about 8 mg KOH / g.

[0030] The detergent systems herein have a high level of sulfonate soap content relative to the total soap content, and in particular, the detergent systems have at least about 75% sulfonate soap, and in other approaches, at least about 80% sulfonate soap, at least about 85% sulfonate soap, at least about 90% sulfonate soap, at least about 95% sulfonate soap, at least about 98% sulfonate soap, at least about 99% sulfonate soap, or about 100% sulfonate soap (or any range therebetween). In other approaches, the soap amount of the detergent is balanced with the selected detergent TBN level to achieve steel piston cleanliness, with little or no phenate detergent used. In some approaches, the detergent system of the lubricant herein, particularly a heavy duty lubricant, is substantially free of magnesium sulfonate detergent, substantially free of phenate detergent, or a combination thereof. As used herein, substantially free means about 1 wt % or less, 0.5 wt % or less, about 0.25 wt % or less, about 0.1 wt % or less, or none.

[0031] In other approaches, the detergent systems herein have a selected weight ratio of sulfonate soap to phenate soap in the detergent system of about 75:25 or greater, about 80:20 or greater, about 85:15 or greater, about 90:10 or greater, even about 95:5, about 99:1 or greater (wherein in the context of this ratio, greater means more sulfonate soap relative to phenate soap). Preferably, the detergent systems herein contain only residual levels, if any, of phenate soap, salicylate soap, calixarene soap, or soaps other than sulfonates. Preferably, the detergent system includes an effective amount of one or more low-base sulfonate detergents to provide from about 30 wt % to about 50 wt % detergent soap.

[0032] Soap content generally refers to the amount of neutral organic acid salts, reflecting the cleaning power or detergency and dirt suspension ability of the detergent. The soap content of a lubricant can be determined by ASTM D3712. A more detailed description of "soap content" is known to those skilled in the art and is explained in the standard textbook entitled "Chemistry and Technology of Lubricants" (3rd edition, edited by RM Mortier and ST Orszulik, copyright 2010, pages 219 to 220, under the subheading 7.2.5. Detergent Classification), which reference is incorporated herein by reference.

[0033] Dispersant system

[0034] The lubricating oil compositions herein, particularly heavy duty crankcase lubricating oil compositions, also include a dispersant system including one or more polyisobutylene succinimide dispersants that deliver at least about 5% by weight of the one or more dispersants to the lubricating oil composition (in other approaches, about 5% to about 15%, about 6% to about 12%, or about 6% to about 10% by weight of the one or more dispersants). Preferably, the one or more polyisobutylene succinimide dispersants are derived from a highly reactive polyisobutylene having a number average molecular weight of about 1,200 to about 2,500, and in some embodiments, may also include at least one borated polyisobutylene succinimide dispersant derived from a highly reactive polyisobutylene having a number average molecular weight of about 1,000 to about 1,500 and delivering about 100 ppm to about 200 ppm of boron to the lubricating oil composition. In some embodiments, the dispersant delivers greater than 650 ppm nitrogen to the lubricating oil composition, and preferably from about 650 ppm to about 1,500 ppm nitrogen. In some methods or embodiments, the dispersant may be diluted with from about 25 wt % to about 50 wt % of a suitable process oil.

[0035] Dispersants are often referred to as ashless dispersants because they do not contain metals that form ash before being mixed into the lubricating composition, and when added to the lubricant, they do not usually provide any ash. Ashless dispersants are characterized in that polar groups are connected to relatively high molecular weight hydrocarbon chains. Typical ashless dispersants include N-substituted long-chain alkenyl succinimides. Examples of nitrogen-substituted long-chain alkenyl succinimides include polyisobutylene succinimides, wherein as measured by GPC, the number average molecular weight of the polyisobutylene substituent is in the range of about 350 to about 5,000, or to about 3,000, or to about 2,000, or to about 1,500. Succinimide dispersants and their preparation are disclosed in, for example, US 7,897,696 and US 4,234,435, which are incorporated herein by reference. The alkenyl substituent can be prepared by polymerizable monomers containing about 2 to about 1 6, or about 2 to about 8, or about 2 to about 6 carbon atoms. Succinimide dispersants are typically imides formed from polyamines, usually poly(ethylene amines).

[0036] In the method, the preferred amine for dispersant can be selected from polyamines and hydroxylamines. The example of usable polyamines includes but is not limited to diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA) and higher homologues, such as pentaethylamine hexamine (PEHA) etc. In some methods, usable so-called heavy polyamines, which are mixtures of polyalkylene-polyamines containing a small amount of low-level polyamine oligomers such as TEPA and PEHA (pentaethylenehexamine) but mainly having 6 or more nitrogen atoms, 2 or more primary amines and oligomers more widely branched than conventional polyamine mixtures per molecule. Heavy polyamines preferably include polyamine oligomers containing 7 or more nitrogens per molecule and having 2 or more primary amines per molecule.

[0037] In some embodiments, when polyisobutylene (PIB) is included, it is a preferred reactant for forming a dispersant and may have a terminal double bond content of greater than 50 mol%, greater than 60 mol%, greater than 70 mol%, greater than 80 mol%, or greater than 90 mol%. Such PIBs are also referred to as highly reactive PIBs ("HR-PIBs"). HR-PIBs having a number average molecular weight in the range of about 800 to about 5000 as determined by GPC are suitable for embodiments of the present disclosure. Conventional PIBs typically have a terminal double bond content of less than 50 vol%, less than 40 vol%, less than 30 vol%, less than 20 vol%, or less than 10 vol%.

[0038] As measured by GPC, HR-PIB with a number average molecular weight in the range of about 900 to about 3,000 may be suitable. Such HR-PIB is commercially available, or can be synthesized by polymerization of isobutylene in the presence of a non-chlorinated catalyst, such as boron trifluoride, as described in US 4,1 52,499 and US5,739,355. When used in the aforementioned hot olefin reaction, HR-PIB can improve the conversion rate in the reaction and reduce the amount of sediment formation due to enhanced reactivity. Suitable methods are described in U.S. Patent No. 7,897,696. In one embodiment, the present disclosure also includes at least one dispersant derived from polyisobutylene succinic anhydride ("PIBSA"). PIBSA can have a succinic acid moiety between about 1.0 and about 2.0 on average per polymer.

[0039] In one embodiment, the dispersant may be derived from polyalphaolefin (PAO) succinic anhydride. In one embodiment, the dispersant may be derived from olefin maleic anhydride copolymer. In another embodiment, the dispersant may be described as polyPIBSA. In an embodiment, the dispersant may be derived from an anhydride grafted to an ethylene-propylene copolymer.

[0040] Suitable classes of nitrogen-containing dispersants can be derived from olefin copolymers (OCPs), more specifically ethylene-propylene dispersants, which can be grafted with maleic anhydride. A more complete list of nitrogen-containing compounds that can react with functionalized OCPs is described in U.S. Pat. Nos. 7,485,603; 7,786,057; 7,253,231; 6,107,257; and 5,075,383; and / or is commercially available.

[0041] A class of suitable dispersants can also be Mannich bases. Mannich bases are substances formed by the condensation of higher molecular weight alkyl-substituted phenols, polyalkylene polyamines and aldehydes (such as formaldehyde). Mannich bases are described in more detail in U.S. Pat. No. 3,634,515. A class of suitable dispersants can also be high molecular weight esters or half ester amides.

[0042] In some methods, the dispersant in the lubricant herein may be optionally post-treated by conventional methods by reacting with any of a variety of reagents. Among these reagents are boron, urea, thiourea, dimercaptothiadiazole, carbon disulfide, aldehydes, ketones, carboxylic acids, hydrocarbon-substituted succinic anhydrides, maleic anhydride, nitriles, epoxides, carbonates, cyclic carbonates, hindered phenolic esters, and phosphorus compounds. (See, for example, US 7,645,726; US 7,214,649; US 8,048,831; and US 5,241,003, which are incorporated herein by reference in their entirety.)

[0043] The boron compound used as the post-treatment agent may be selected from boron oxides, boron halides, boric acids, and boric acid esters in an amount to provide from about 0.1 atomic proportion of boron per mole of nitrogen composition to about 20 atomic proportion of boron per atomic proportion of nitrogen used. The dispersant post-treated with boron may contain from about 0.05 wt % to about 2.0 wt %, or in other approaches, from about 0.5 wt % to about 1.0 wt % boron, based on the total weight of the borated dispersant.

[0044] In other methods, carboxylic acids can be used as post-treatment agents and can be saturated or unsaturated mono-, di- or poly-carboxylic acids. Examples of carboxylic acids include, but are not limited to, maleic acid, fumaric acid, succinic acid and naphthalene dicarboxylic acid (e.g., 1,8-naphthalene dicarboxylic acid). Anhydrides can be used as post-treatment agents and can be selected from the group consisting of monounsaturated anhydrides (e.g., maleic anhydride), alkyl or alkylene substituted cyclic anhydrides (e.g., succinic anhydride or glutamic anhydride) and aromatic carboxylic anhydrides (including naphthalene dicarboxylic anhydride, e.g., 1,8-naphthalene dicarboxylic anhydride).

[0045] In one embodiment, the method for post-processing a dispersant comprises first forming a succinimide product as described above, and then further reacting the succinimide product with a post-processing agent such as a boron compound such as boric acid. In some cases, the dispersant herein can be post-processed with more than one post-processing agent. For example, the dispersant can be post-processed with a boron compound such as boric acid and anhydride such as maleic anhydride. In some cases, the dispersant can be post-processed with anhydrides such as maleic anhydride and / or 1,8-naphthalene dicarboxylic anhydride.

[0046] In addition to the above-mentioned post-treatment, the dispersant can be post-treated with a variety of post-treatments designed to improve or impart different properties. Such post-treatments include those summarized in columns 27 to 29 of U.S. Patent No. 5,241,003, which are incorporated herein by reference. Such treatments include treatments with: inorganic phosphorous acid or anhydrous (e.g., U.S. Patent Nos. 3,403,102 and 4,648,980); organic phosphorus compounds (e.g., U.S. Patent No. 3,502,677); phosphorus pentasulfide; boron compounds as described above (e.g., U.S. Patent Nos. 3,178,663 and 4,652,387); carboxylic acids, polycarboxylic acids, anhydrides and / or acid halides (e.g., U.S. Patent Nos. 3,708,522 and 4,948,3 86); epoxides, polyepoxides or thioepoxides (e.g., U.S. Pat. Nos. 3,859,318 and 5,026,495); aldehydes or ketones (e.g., U.S. Pat. No. 3,458,530); carbon disulfide (e.g., U.S. Pat. No. 3,256,185); glycidol (e.g., U.S. Pat. No. 4,617,137); urea, thiourea or guanidine (e.g., U.S. Pat. Nos. 3,312,619; 3,865,813; and GB 1,065,595); organic sulfonic acids (e.g., U.S. Pat. No. 3,189,544 and GB 2,140,811); alkenyl cyanides (e.g., U.S. Pat. Nos. 3,278,550 and 3,366,569); diketenes (e.g., U.S. Pat. No. 3,546,243); diisocyanates (e.g., U.S. Pat. No. 3,573,205); alkane sultones (e.g., U.S. Pat. No. 3,749,695); 1,3-dicarbonyl compounds (e.g., U.S. Pat. No. 4,579,675); sulfates of alkoxylated alcohols or phenols (e.g., U.S. Pat. No. 3,954,639); ); cyclic lactones (e.g., U.S. Pat. Nos. 4,617,138; 4,645,515; 4,668,246; 4,963,275; and 4,971,711); cyclic carbonates or thiocarbonates, linear monocarbonates or polycarbonates, or chloroformates (e.g., U.S. Pat. Nos. 4,612,132; 4,647,390; 4,648,886; 4,670,170); nitrogen-containing carboxylic acids (e.g., U.S. Pat. No. 4,971,598 and British Patent No. GB 2,140,811); hydroxy protected chlorodicarbonyloxy compounds (e.g., U.S. Pat. No. 4,614,522); lactams, thiolactams, thiolactones or dithiolactones (e.g., U.S. Pat. Nos. 4,614,603 and 4,666,460); cyclic carbonates or thiocarbonates, linear monocarbonates or polycarbonates, or chloroformates (e.g., U.S. Pat. Nos. 4,612,132; 4,647,390; 4,646,860; and 4,670,170);Nitrogen-containing carboxylic acids (e.g., U.S. Pat. No. 4,9711,598 and British Patent GB 2,440,811); hydroxy-protected chlorodicarbonyloxy compounds (e.g., U.S. Pat. No. 4,614,522); lactams, thiolactams, thiolactones or dithiolactones (e.g., U.S. Pat. Nos. 4,614,603 and 4,666,460); cyclic carbamates, cyclic thiocarbamates or cyclic dithiocarbamates (e.g., U.S. Pat. Nos. 4,663,062 and 4,666,459); hydroxy aliphatic carboxylic acids (e.g., U.S. Pat. Nos. 4,482,464; 4,521,318; 4,713,189); oxidants ( For example, U.S. Pat. No. 4,379,064); combinations of phosphorus pentasulfide and polyalkylene polyamines (for example, U.S. Pat. No. 3,185,647); combinations of carboxylic acids or aldehydes or ketones and sulfur or sulfur chloride (for example, U.S. Pat. Nos. 3,390,086; 3,470,098); combinations of hydrazine and carbon disulfide (for example, U.S. Pat. No. 3,519,564); combinations of aldehydes and phenols (for example, U.S. Pat. Nos. 3,649,229; 5,030,249; 5,039,307); combinations of aldehydes and O-diesters of dithiophosphoric acids (for example, U.S. Pat. No. 3,865,644); ,740); a combination of a hydroxyaliphatic carboxylic acid and boric acid (e.g., U.S. Pat. No. 4,554,086); a combination of a hydroxyaliphatic carboxylic acid, then formaldehyde and phenol (e.g., U.S. Pat. No. 4,636,322); a combination of a hydroxyaliphatic carboxylic acid and then an aliphatic dicarboxylic acid (e.g., U.S. Pat. No. 4,663,064); a combination of formaldehyde and phenol and then glycolic acid (e.g., U.S. Pat. No. 4,699,724); a combination of a hydroxyaliphatic carboxylic acid or oxalic acid and then a diisocyanate (e.g., U.S. Pat. No. 4,713,191); an inorganic acid or anhydride of phosphorus or a portion thereof or all sulfur analogs with a boron compound (e.g., U.S. Pat. No. 4,857,214); organic diacids, then unsaturated fatty acids, then nitrosoaromatic amines, optionally followed by boron compounds, and then ethanolating agents (e.g., U.S. Pat. No. 4,973,412); aldehydes and triazoles (e.g., U.S. Pat. No. 4,963,278); aldehydes and triazoles, then boron compounds (e.g., U.S. Pat. No. 4,981,492); cyclic lactones and boron compounds (e.g., U.S. Pat. Nos. 4,963,275 and 4,971,711). The above-mentioned patents are incorporated herein in their entirety. ;

[0047] In other methods, the total amount of dispersant in the dispersant system may be present in an amount of up to about 15% by weight of the lubricating composition, and wherein one or more dispersants are post-treated to provide at least about 40 ppm of boron and up to 300 ppm of boron (preferably about 100 ppm to about 200 ppm of boron) to the lubricating composition. In other methods, the total amount of dispersant may be used in the lubricating composition in an amount of about 5% to about 15% by weight, or about 6% to about 10% by weight, about 7.0% to about 10% by weight, or about 7.0% to about 8% by weight based on the final weight of the lubricating oil composition. As described above, in some methods, the dispersant may be diluted with about 25% to about 50% by weight of the process oil. The dispersant may provide at least about 400 ppm of nitrogen and up to about 1,500 ppm of nitrogen, preferably about 650 ppm to about 1500 ppm of nitrogen, and more preferably about 800 ppm to about 1200 ppm of nitrogen.

[0048] Suitable dispersants may have a TBN of about 10 mg KOH / g to about 60 mg KOH / g dispersant on an oil-free basis, which is comparable to about 5 TBN to about 30 TBN if measured on a dispersant sample containing about 50% diluent oil. TBN is measured by the method of ASTM D2896.

[0049] Oil soluble molybdenum compounds

[0050] The crankcase lubricant of the present disclosure, in particular the heavy duty crankcase lubricant, may optionally include one or more oil-soluble molybdenum-containing compounds. The oil-soluble molybdenum compound may have the functional properties of an antiwear agent, an antioxidant, a friction modifier, or a mixture thereof. The oil-soluble molybdenum compound may be any one of a molybdenum dithiocarbamate, a molybdenum dialkyl dithiophosphate, a molybdenum sulfide, a molybdenum disulfide, a molybdenum dithiophosphinate, an amine salt of a molybdenum compound, a molybdenum xanthate, a molybdenum thioxanthate, a molybdenum sulfide, a molybdenum carboxylate, a molybdenum alkoxide, a trinuclear organic molybdenum compound, and / or a mixture thereof. The molybdenum-containing compound may be a sulfur-containing or sulfur-free compound. The molybdenum disulfide may be in the form of a stable dispersion.

[0051] In one embodiment, the oil-soluble platinum compound can be selected from the group of platinum dithiocarbamates, molybdenum dialkyl dithiophosphates, sulfur-free organic platinum complexes of organic amides, and mixtures thereof. In one embodiment, the oil-soluble platinum compound can be platinum dithiocarbamates. Exemplary sulfur-free organic platinum complexes of organic amides are disclosed in US 5,137,647.

[0052] In one method or embodiment, a suitable molybdenum dithiocarbamate may be represented by the formula:

[0053]

[0054] Where R 5 , R 6 , R 7 and R 8 are independently a hydrogen atom, a C1 to C 20 Alkyl groups, C6 to C 20 A cycloalkyl, aryl, alkylaryl or aralkyl group, or a C3 to C4 alkyl group optionally containing an ester, ether, alcohol or carboxyl group. 20 and X1, X2, Y1 and Y2 are each independently a sulfur or oxygen atom. 5 , R 6 , R 7 and R 8 Examples of suitable groups for each of include 2-ethylhexyl, nonylphenyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, n-hexyl, n-octyl, nonyl, decyl, dodecyl, tridecyl, lauryl, oleyl, linoleyl, cyclohexyl, and phenylmethyl. In other methods, R 5 , R 6 , R 7 and R 8 Each can have C6 to C 18 alkyl group. X1 and X2 may be the same, and Y1 and Y2 may be the same. X1 and X2 may both contain sulfur atoms, and Y1 and Y2 may both contain oxygen atoms. Other examples of molybdenum dithiocarbamates include C6-C 18 Dialkyl or diaryl dithiocarbamates, or alkyl-aryl dithiocarbamates, such as dibutyl-, dipentyl-di-(2-ethylhexyl)-, dilauryl-, dioleyl- and dicyclohexyl-dithiocarbamates.

[0055] Suitable examples of molybdenum compounds that can be used include commercial materials sold under the following trade names: such as RT Vanderbilt Co., Ltd. 822, A. 2000, 807, 855 and 1055, and Sakura-Lube available from Adeka Corporation TM S-165, S-200, S-300, S-310G, S-525, S-600, S-700 and S-710, and mixtures thereof. Suitable platinum components are described in U.S. Pat. Nos. 5,650,381; RE 37,363E1; RE 38,929E1; and RE 40,595E1, the entire contents of which are incorporated herein by reference.

[0056] In one embodiment and if included in the formulation, the oil-soluble platinum compound may be present in a crankcase lubricant, particularly a heavy-duty crankcase lubricant, in an amount to provide up to about 800 ppm of platinum, or about 5 ppm to 800 ppm of platinum. In other embodiments, the oil-soluble platinum compound may be present in an amount to provide about 10 ppm to about 500 ppm of platinum, about 20 ppm to 250 ppm of platinum, about 30 ppm to 175 ppm of platinum, about 40 ppm to 150 ppm of platinum, about 50 ppm to 125 ppm of platinum, or about 60 ppm to 100 ppm of platinum.

[0057] Antioxidants

[0058] The crankcase lubricants herein, particularly heavy duty crankcase lubricants, may also contain one or more antioxidants, and preferably, one or more aminic antioxidants. If used, the antioxidant may be provided in an amount of about 1 wt % to about 5 wt % (in other approaches, about 1.2 wt % to about 4 wt % or about 1.4 wt % to about 3 wt %, or about 2 wt % to about 3 wt %), which, when combined with the dispersant and detergent system herein, can aid in piston cleaning on steel pistons in the harsh environment of the OM471 test.

[0059] Suitable antioxidants may include, for example, phenates, phenate sulfides, sulfurized olefins, phosphosulfurized terpenes, sulfurized esters, aromatic amines, alkylated diphenylamines (e.g., nonyldiphenylamine, dinonyldiphenylamine, octyldiphenylamine, dioctyldiphenylamine), phenyl-α-naphthylamine, alkylated phenyl-α-naphthylamine, hindered non-aromatic amines, phenols, hindered phenols, oil-soluble molybdenum compounds, macromolecular antioxidants, or mixtures thereof. The antioxidant compounds may be used alone or in combination.

[0060] In some methods or embodiments, suitable amine antioxidants may include, but are not limited to, antioxidants selected from aromatic amines, alkylated diphenylamines, phenyl-α-naphthylamines, alkylated phenyl-α-naphthylamines, hindered non-aromatic amines, and the like, or combinations thereof. The total amount of antioxidant in the lubricating composition herein may be present in an amount to deliver up to about 400 ppm of nitrogen, or up to about 300 ppm of nitrogen, or up to about 200 ppm of nitrogen, or about 50 ppm to about 400 ppm of nitrogen, about 60 ppm to about 300 ppm of nitrogen, about 70 ppm to about 200 ppm of nitrogen, or about 80 ppm to about 100 ppm of nitrogen. In other methods, the lubricating composition herein may contain up to about 5 wt% of amine antioxidants, or about 0.1 wt% to about 5 wt% of amine antioxidants, and in other methods, about 0.2 wt% to about 3 wt% or about 0.2 wt% to about 2.0 wt% of amine antioxidants.

[0061] In some methods, the amine antioxidant may be one or more aromatic amine antioxidants, and may include, but are not limited to, diarylamines having the formula:

[0062]

[0063] wherein R' and R" each independently represent a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. If substituted, suitable substituents for the aryl groups of R' and R" include aliphatic hydrocarbon groups such as alkyl groups having 1 to 30 carbon atoms, hydroxyl groups, halogen groups, carboxylic acid or ester groups or nitro groups. The aryl groups may be substituted or unsubstituted phenyl or naphthyl, in particular wherein one or both of these aryl groups are substituted with at least one alkyl group having 4 to 30 carbon atoms, preferably 4 to 18 carbon atoms, most preferably 4 to 9 carbon atoms. In the method, one or both aryl groups are substituted, for example monoalkylated diphenylamine, dialkylated diphenylamine, C9 alkylated diphenylamine or a mixture of monoalkylated diphenylamine and dialkylated diphenylamine.

[0064] Examples of diarylamines that can be used include, but are not limited to, diphenylamine; various alkylated diphenylamines, 3-hydroxydiphenylamine, N-benzene-1,2-phenylenediamine, N-benzene-1,4-phenylenediamine, monobutyldiphenylamine, dibutyldiphenylamine, monooctyldiphenylamine, dioctyldiphenylamine, monononyldiphenylamine, dinonyldiphenylamine, monotetradecyldiphenylamine, tetracosyldiphenylamine, benzene-α-naphthylamine, monooctylbenzene-α-naphthylamine, benzene-β-naphthylamine, monoheptyldiphenylamine, diheptyldiphenylamine, para-oriented styrenated diphenylamines, mixed butyloctyldiphenylamines, and mixed octylstyryldiphenylamines.

[0065] In other methods, suitable antioxidants may include aromatic amine antioxidants. Examples of phenolic antioxidants include N,N'-di-sec-butylphenylenediamine, 4-isopropylaminodiphenylamine, phenyl-α-naphthylamine, phenyl-α-naphthylamine, and cycloalkylated diphenylamine.

[0066] Hindered phenol antioxidants can contain sec-butyl and / or tert-butyl groups as sterically hindered groups. The phenolic group can also be substituted by a hydrocarbyl group and / or a bridging group connected to a second aromatic group. Examples of suitable hindered phenol antioxidants include 2,6-di-tert-butylphenol, 4-methyl-2,6-di-tert-butylphenol, 4-ethyl-2,6-di-tert-butylphenol, 4-propyl-2,6-di-tert-butylphenol or 4-butyl-2,6-di-tert-butylphenol or 4-dodecyl-2,6-di-tert-butylphenol. In one embodiment, the hindered phenol antioxidant can be an ester and can include, for example, Irganox®, which can be purchased from BASF. TML-135 or the addition product derived from 2,6-di-tert-butylphenol and an alkyl acrylate, wherein the alkyl group may contain from about 1 to about 18, or from about 2 to about 12, or from about 2 to about 8, or from about 2 to about 6, or about 4 carbon atoms. Another commercially available hindered phenol antioxidant may be an ester and may include Ethanox 1,6-di-tert-butylphenol, available from Albemarle Corporation. TM 4716.

[0067] Useful antioxidants may include diarylamines and high molecular weight phenols. In one embodiment, the lubricating oil composition may contain a mixture of diarylamines and high molecular weight phenols such that each antioxidant may be present in an amount sufficient to provide up to about 5 weight percent based on the final weight of the lubricating oil composition. In an embodiment, the antioxidant may be a mixture of about 0.3 weight percent to about 1.5 weight percent diarylamine and about 0.4 weight percent to about 2.5 weight percent high molecular weight phenol based on the final weight of the lubricating oil composition.

[0068] The example of suitable olefin that can be sulfurized to form sulfurized olefin comprises propylene, butylene, isobutylene, polyisobutylene, pentene, hexene, heptene, octene, nonene, decene, undecene, dodecene, tridecene, tetradecene, pentadecene, hexadecene, heptadecene, octadecene, nineteendecene, eicosene or their mixture. In one embodiment, hexadecene, heptadecene, octadecene, nineteendecene, eicosene or their mixture, and their dimer, trimer and tetrapolymer are particularly suitable olefins. Alternatively, olefin can be the Diels-Alder adduct of diene (such as 1,3-butadiene) and unsaturated ester (such as butyl acrylate).

[0069] Another class of sulphurized olefins includes sulphurized fatty acids and esters thereof. Fatty acids are usually obtained from vegetable oils or animal oils and usually contain about 4 to about 22 carbon atoms. Examples of suitable fatty acids and esters thereof include triglycerides, oleic acid, linoleic acid, palmitoleic acid or their mixtures. Usually, fatty acids are obtained from lard, pine oil, peanut oil, soybean oil, cottonseed oil, sunflower seed oil or their mixtures. Fatty acids and / or esters can be mixed with olefins (such as alpha-olefins).

[0070] Metal dihydrocarbyl dithiophosphate compounds

[0071] The crankcase lubricants herein, particularly heavy duty crankcase lubricants, may optionally include one or more metal dihydrocarbyl dithiophosphate compounds, such as, but not limited to, zinc dihydrocarbyl dithiophosphate compounds (ZDDP). If used, the one or more metal dihydrocarbyl dithiophosphate compounds may provide at least about 500 ppm of phosphorus to the lubricant, particularly the heavy duty lubricant, in other approaches, about 600 ppm to about 1200 ppm of phosphorus, or about 700 ppm to about 1,000 ppm of phosphorus, or about 700 ppm to about 1,200 ppm of phosphorus. If used herein, the metal dihydrocarbyl dithiophosphate compound preferably includes a hydrocarbyl group derived from a mixture of primary and secondary alcohols.

[0072] Suitable metal dihydrocarbyl dithiophosphate compounds may include 5% to about 10% by weight of metal (such as about 6% to about 9% by weight of metal, such as zinc) and about 8% to about 18% by weight of sulfur (such as about 12% to about 18% by weight of sulfur or about 8% to about 15% by weight of sulfur). Suitable metal dihydrocarbyl dithiophosphate compounds may include dihydrocarbyl dithiophosphate metal salts, wherein the metal may be an alkali metal, an alkaline earth metal, aluminum, lead, tin, molybdenum, manganese, nickel, copper, titanium, zirconium, zinc or a combination thereof. Preferably, the metal is zinc.

[0073] The alkyl groups on the metal dihydrocarbyl dithiophosphate compounds herein may be derived from primary alcohols, secondary alcohols, phenols and / or mixtures thereof, and preferably mixtures of primary and secondary alcohols. For example, all alkyl or hydrocarbyl groups of the metal dihydrocarbyl dithiophosphate compounds herein may be derived from primary alcohols (such as 2-ethylhexanol) and / or mixtures of primary and secondary alcohols (such as, for example, 2-ethylhexanol, isobutyl alcohol and isopropyl alcohol). For example and in one embodiment, about 60 mol % or more of the alkyl groups are derived from primary alcohols of 2-ethylhexanol and / or isobutyl alcohol, and about 40 mol % or less of the alkyl groups are derived from secondary alcohols (such as isopropyl alcohol, methyl isobutyl carbinol, etc., and / or combinations thereof). In optional embodiments, all alkyl groups on the metal dihydrocarbyl dithiophosphate compounds may be derived from primary alcohols, such as 2-ethylhexanol or other substances described below. Preferably, the metal dihydrocarbyl dithiophosphate compound is a ZDDP obtained from 60 to 80 mole % of 2-ethylhexanol and / or isobutyl alcohol and 20 to 40 mole % of isopropyl alcohol, and may contain from about 6 to about 10 weight % phosphorus, from about 7 to about 9 weight % zinc, and from about 15 to about 20 weight % sulfur.

[0074] The metal dihydrocarbyl dithiophosphate compounds herein may be derived from, but are not limited to, alcohols selected from 2-ethylhexanol, methylheptanol, heptanol, octanol, nonanol, decanol, dodecanol, and / or variants thereof. Examples of suitable metal dihydrocarbyl dithiophosphate compounds include, but are not limited to: O,O-di(C 8-14 O,O-zinc dithiophosphate; O,O-bis(2-ethylhexyl)zinc dithiophosphate; O,O-diisooctylzinc dithiophosphate; O,O-bis(dodecylphenyl)zinc dithiophosphate; O,O-diisodecylzinc dithiophosphate; O,O-bis(6-methylheptyl)zinc dithiophosphate; O,O-dioctylzinc dithiophosphate; O,O-dipentylzinc dithiophosphate; O-(2-methylbutyl)-O-(2-methylpropyl)zinc dithiophosphate; and O-(3-methylbutyl)-O-(2-methylpropyl)zinc dithiophosphate, or a combination thereof.

[0075] In methods or embodiments, metal dihydrocarbyl dithiophosphate compounds suitable for use in heavy-duty crankcase lubricants herein may have the structure of Formula I:

[0076]

[0077] Each R in its formula I contains 6 to 18 carbon atoms or 6 to 12 carbon atoms or about 8 to 10 carbon atoms independently, as long as each phosphorus atom has at least 14 total carbons on average, and preferably at least 8 total carbons or 8 to 16 total carbons per phosphorus atom. For example, each R can be independently such as ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, amyl, n-hexyl, isohexyl, n-octyl, decyl, dodecyl, octadecyl, 2-ethylhexyl, phenyl, butylphenyl, cyclohexyl, methylcyclopentyl, propenyl, butenyl. The number of carbon atoms in each R group in the above formula is generally about 3 or larger, about 4 or larger, about 6 or larger, or about 8 or larger. Each R group can average 6 to 10 carbons, and preferably 8 to 10 carbons. Preferably, each R can be a linear or branched C8 or 2-ethylhexyl group, C3 or isopropyl group and / or C4 or isobutyl group. In formula I, A is a metal, such as aluminum, lead, tin, molybdenum, manganese, nickel, copper, titanium, zirconium, zinc or a combination thereof, and preferably, A is zinc. When the metal dialkyl dithiophosphate compound has the structure shown in formula I and A is zinc, the compound can have about 6% by weight to about 9% by weight of phosphorus and about 7% by weight to about 9% by weight of zinc, and the ratio of zinc to phosphorus is about 1.0 to about 1.5. In some methods or embodiments, it should be understood in the art that a more accurate representation of the sulfur-zinc coordination arrangement can be represented by the symmetrical arrangement of the chemical structure with formula II shown below, which is used interchangeably with formula I shown above in this article. It should also be understood that the structures shown in formulas I and II can exist as monomers, dimers, trimers or oligomers (such as tetramers).

[0078]

[0079] Dialkyl dithiophosphate metal salts can be prepared according to known techniques, i.e., first, dialkyl dithiophosphoric acid (DDPA) is formed by reacting one or more alcohols or phenols with P2S5, and then the formed DDPA is neutralized with a metal compound such as zinc oxide. For example, DDPA can be prepared by reacting a mixture of alcohols with P2S5, the mixture of alcohols comprising a suitable amount of primary alcohol (and, if desired, a suitable blend of primary and secondary alcohols). In this case, DDPA comprises an alkyl group derived primarily from a primary alcohol or both a primary alcohol and a secondary alcohol as required to meet the primary alcohol content required in the final product. Alternatively, a variety of DDPAs can be prepared, wherein the alkyl group on one DDPA is completely derived from a secondary alcohol, and the alkyl group on another DDPA is completely derived from a primary alcohol. The DDPAs are then blended together to form a mixture of DDPAs having an alkyl group satisfying the primary alcohol content.

[0080] Base oil or base oil blend:

[0081] The base oil used in the crankcase lubricating oil composition, especially the heavy-duty crankcase lubricating oil composition herein can be an oil of lubricating viscosity and is selected from any of the API Group I to Group V base oils specified by the American Petroleum Institute (API) Base Oil Interchangeability Guide. The heavy-duty crankcase lubricant may have a kV100 (ASTM D445) of about 9 cSt to about 20 cSt. In some cases, even lower viscosities are targeted, and the crankcase lubricant, especially the heavy-duty crankcase lubricant, has a kV100 (ASTM D445) of about 5 cSt to about 9 cSt. The five base oil groups are generally listed in Table 1 below:

[0082] Table 1

[0083]

[0084] Class I, Class II and Class III are mineral oil processing raw materials.Class IV base oil contains real synthetic molecular species, and these synthetic molecular species are prepared by the polymerization of olefinically unsaturated hydrocarbons.Many Class V base oils are also real synthetic products, and can include diesters, polyol esters, polyalkylene glycols, alkylated aromatic compounds, polyphosphates, polyvinyl ethers and / or polyphenylene ethers etc., but can also be naturally occurring oils, such as vegetable oils.It should be noted that although Class III base oil is derived from mineral oil, the strict processing of these fluid experiences causes their physical properties to be very similar to some real synthetic oils, such as PAO.Therefore, the oil derived from Class III base oil can be called synthetic fluid in industry.The II+ class can include high viscosity index Class II.

[0085] The base oil blend used in the disclosed lubricating oil composition can be a mineral oil, an animal oil, a vegetable oil, a synthetic oil, a synthetic oil blend, or a mixture thereof. Suitable oils can be derived from hydrocracked, hydrogenated, hydrorefined, unrefined, refined and re-refined oils and mixtures thereof.

[0086] Unrefined oils are those derived from natural, mineral or synthetic sources with little or no further purification. Refined oils are similar to unrefined oils, except that they have been subjected to one or more purification steps, which may result in improvements in one or more properties. Examples of suitable purification techniques are solvent extraction, secondary distillation, acid or base extraction, filtration, percolation, etc. Refining to edible quality oils may or may not be useful. Edible oils may also be referred to as white oils. In some embodiments, the lubricating oil composition does not contain edible oils or white oils.

[0087] Re-refined oils are also called reclaimed oils or reprocessed oils. Similar to refined oils, these oils are obtained using the same or similar processes. Typically these oils are further processed by techniques directed to the removal of spent additives and oil breakdown products.

[0088] Mineral oil can include the oil obtained by drilling or the oil from plants and animals or any mixture thereof. For example, this type of oil can include but is not limited to castor oil, lard, olive oil, peanut oil, corn oil, soybean oil and linseed oil, and mineral lubricating oils, such as liquid petroleum and solvent-treated or acid-treated paraffin, cycloalkane or mixed paraffin-cycloalkane type mineral lubricating oils. If desired, this type of oil can be partially or completely hydrogenated. The oil derived from coal or shale can also be useful.

[0089] Useful synthetic lubricating oils may include hydrocarbon oils such as polymerized, oligomeric or copolymerized olefins (e.g., polybutene, polypropylene, propylene isobutylene copolymers); poly(1-hexene), poly(1-octene), 1-decene trimers or oligomers, such as poly(1-decene), such materials are generally referred to as alpha-olefins, and mixtures thereof; alkyl-benzenes (e.g., dodecylbenzene, tetradecylbenzene, dinonylbenzene, di-(2-ethylhexyl)-benzene); polyphenyls (e.g., biphenyl, terphenyl, alkylated polyphenyls); diphenylalkanes, alkylated diphenylalkanes, alkylated diphenyl ethers and alkylated diphenyl sulfides and derivatives, analogs and homologs thereof or mixtures thereof. Polyalpha-olefins are typically hydrogenated materials.

[0090] Other synthetic lubricating oils include polyol esters, diesters, liquid esters (e.g., diethyl esters of toluene phosphate, trioctyl phosphate and decanephosphonic acid) or polytetrahydrofurans containing phosphoric acid. Synthetic oils can be produced by Fischer-Tropsch reaction and can generally be Fischer-Tropsch hydrocarbons or waxes of hydroisomerization. In one embodiment, oil can be prepared by Fischer-Tropsch gas-liquid synthesis procedures and other gas-liquid oils.

[0091] The major amount of base oil included in the lubricating composition may be selected from Group I, Group II, Group III, Group IV, Group V, and combinations of two or more of the foregoing, and wherein the major amount of the base oil is different from the base oil resulting from providing an additive component or a viscosity index improver in the composition. In another embodiment, the major amount of base oil included in the lubricating composition may be selected from Group II, Group III, Group IV, Group V, and combinations of two or more of the foregoing, and wherein the major amount of the base oil is different from the base oil resulting from providing an additive component or a viscosity index improver in the composition.

[0092] The oil of lubricating viscosity may be present in an amount that is the remainder remaining after the total amount of performance additives (including viscosity index improvers and / or pour point depressants and / or other top treatment additives) is subtracted from 100 wt %. For example, the oil of lubricating viscosity that may be present in the finished fluid may be a major amount, such as greater than about 50 wt %, greater than about 60 wt %, greater than about 70 wt %, greater than about 80 wt %, greater than about 85 wt %, or greater than about 90 wt %.

[0093] In some methods or embodiments, the base oil system herein includes one or more base oils from Group I to Group V base oils and may have a KV100 of about 2 to about 20 cSt, about 2 to about 10 cSt in other methods, about 2.5 to about 6 cSt, about 2.5 to about 3.5 cSt in still other methods, and about 2.5 to about 4.5 cSt in other methods.

[0094] As used herein, the terms "oil composition," "lubricating composition," "lubricating oil composition," "lubricating oil," "lubricant composition," "fully formulated lubricant composition," "lubricant," and "lubricating and cooling fluid" are considered to be synonymous and fully interchangeable terms that refer to a finished lubricating product comprising a major amount of a base oil component plus minor amounts of detergents and other optional components.

[0095] Optional additives :

[0096] The lubricating oil compositions herein, especially the heavy duty lubricating oil compositions, may also include a number of optional additives in combination with the detergent system and dispersant system discussed above and as required to meet the performance criteria. Those optional additives are described in the following paragraphs.

[0097] Antiwear Agents :The lubricating oil composition of the present invention may also optionally contain additional antiwear agents. Examples of suitable antiwear agents include, but are not limited to, metal thiophosphates; dialkyl dithiophosphate metal salts; phosphates or their salts; phosphate esters; phosphites; phosphorus-containing carboxylates, ethers or amides; sulfurized olefins; compounds containing thiocarbamates, including thiocarbamates, alkylene coupled thiocarbamates and bis(S-alkyl dithiocarbamoyl) disulfides; and mixtures thereof. A suitable antiwear agent may be molybdenum dithiocarbamates. Phosphorus-containing antiwear agents are more fully described in European Patent 612839. The metal in the dialkyl dithiophosphate may be an alkali metal, an alkaline earth metal, aluminum, lead, tin, molybdenum, manganese, nickel, copper, titanium or zinc. A suitable antiwear agent may be zinc dialkyl dithiophosphate.

[0098] Other examples of suitable additional antiwear agents include titanium compounds, tartrates, tartrimides, oil-soluble amine salts of phosphorus compounds, sulphurized olefins, phosphites (such as dibutyl phosphite), phosphonates, thiocarbamate-containing compounds (such as thiocarbamates, thiocarbamate amides, thiocarbamate ethers, alkylene-coupled thiocarbamates, and bis(S-alkyldithiocarbamoyl)disulfides). The tartrate or tartrimide may contain an alkyl ester group, wherein the total number of carbon atoms in the alkyl group may be at least 8. In one embodiment, the antiwear agent may include a citrate ester.

[0099] Additional antiwear agents may be present in a range comprising about 0 wt % to about 15 wt %, or about 0.01 wt % to about 10 wt %, or about 0.05 wt % to about 5 wt %, or about 0.1 wt % to about 3 wt % of the lubricating oil composition.

[0100] Boron compounds :The lubricating oil composition of the present invention may optionally contain one or more boron-containing compounds. Examples of boron-containing compounds include borate esters, borated fatty amines, borated epoxides, borated detergents, dispersed hydrated sodium or potassium borates, and borated dispersants, such as borated succinimide dispersants, as disclosed in U.S. Pat. No. 5,883,057. The boron-containing compound, if present, may be used in an amount sufficient to provide up to about 8% by weight, about 0.01% by weight to about 7% by weight, about 0.05% by weight to about 5% by weight, or about 0.1% by weight to about 3% by weight of the lubricating oil composition.

[0101] Additional detergents: The lubricating oil composition may optionally further comprise one or more neutral, low-basic or high-basic detergents and mixtures thereof. Suitable detergent matrices include benzoates, sulfur-containing benzoates, sulfonates, calixformates, salicylates, salicylates, carboxylic acids, phosphoric acid, monothiophosphoric acid and / or dithiophosphoric acid, alkylphenols, sulfur-coupled alkylphenol compounds or methylene-bridged phenols. Suitable detergents and methods for their preparation are described in more detail in a number of patent publications, including US 7,732,390 and references cited therein.

[0102] The detergent matrix can be salified with alkali metals or alkaline earth metals such as, but not limited to, calcium, magnesium, potassium, sodium, lithium, barium, or mixtures thereof. In some embodiments, the detergent is barium-free. In some embodiments, the detergent may contain trace amounts of other metals, such as magnesium or calcium, such as 50 ppm or less, 40 ppm or less, 30 ppm or less, 20 ppm or less, or 10 ppm or less. Suitable detergents may include alkali metal or alkaline earth metal salts of petroleum sulfonic acids and long chain mono- or dialkyl aryl sulfonic acids, wherein the aryl groups are benzyl, tolyl, and xylyl. Examples of suitable detergents include, but are not limited to, calcium phenate, sulfur-containing calcium phenate, calcium sulfonate, calcium calixarate, calcium salicyclic acid, calcium salicylate, calcium carboxylate, calcium phosphate, calcium monothiophosphate and / or calcium dithiophosphate, calcium alkyl phenate, sulfur-coupled alkyl phenate calcium compounds, methylene-bridged calcium phenate, magnesium phenate, sulfur-containing magnesium phenate, magnesium sulfonate, magnesium calixarate, magnesium salicyclic acid, magnesium salicylate, magnesium carboxylate, magnesium phosphate, magnesium monothiophosphate and / or magnesium dithiophosphate, magnesium alkyl phenate, sulfur-coupled alkyl phenate magnesium compounds, methylene-bridged magnesium phenate, sodium phenate, sulfur-containing sodium phenate, sodium sulfonate, sodium calixarate, sodium salicyclic acid, sodium salicylate, sodium carboxylate, sodium phosphate, sodium monothiophosphate and / or sodium dithiophosphate, sodium alkyl phenate, sulfur-coupled sodium alkyl phenate compounds, or methylene-bridged sodium phenate.

[0103] Overbased detergent additives are well known in the art and may be alkali metal or alkaline earth metal overbased detergent additives. Such detergent additives may be prepared by reacting a metal oxide or metal hydroxide with a substrate and carbon dioxide gas. The substrate is typically an acid, such as an aliphatic substituted sulfonic acid, an aliphatic substituted carboxylic acid, or an aliphatic substituted phenol.

[0104] The total base number (TBN) of the overbased detergent of the lubricating oil composition may be about 200 mg KOH / g or greater, or as other examples, about 250 mg KOH / g or greater, or about 350 mg KOH / g or greater, or about 375 mg KOH / g or greater, or about 400 mg KOH / g or greater. TBN is measured by the method of ASTM D2896.

[0105] Examples of suitable overbased detergents include, but are not limited to, overbased calcium phenates, overbased sulfur-containing calcium phenates, overbased calcium sulfonates, overbased calcium calixarates, overbased calcium salicylates, overbased calcium carboxylates, overbased calcium phosphates, overbased calcium monothiophosphates and / or dithiophosphates, overbased calcium alkylphenates, overbased sulfur-coupled alkylphenate calcium compounds, overbased methylene-bridged calcium phenates, overbased magnesium phenates, overbased sulfur-containing magnesium phenates, overbased magnesium sulfonates, overbased magnesium calixarates, overbased magnesium salicylates, overbased magnesium carboxylates, overbased magnesium phosphates, overbased magnesium monothiophosphates and / or dithiophosphates, overbased magnesium alkylphenates, overbased sulfur-coupled alkylphenate magnesium compounds, or overbased methylene-bridged magnesium phenates.

[0106] The overbased calcium phenate detergent has a total base number of at least about 150 mg KOH / g, at least about 225 mg KOH / g, at least about 225 mg KOH / g to about 400 mg KOH / g, at least about 225 mg KOH / g to about 350 mg KOH / g, or about 230 mg KOH / g to about 350 mg KOH / g, all as measured by the method of ASTM D 2896. When such detergent compositions are formed in an inert diluent (e.g., process oil, typically mineral oil), the total base number reflects the basicity of the overall composition, which includes the diluent and any other materials that may be contained in the detergent composition (e.g., accelerators, etc.).

[0107] The metal to substrate ratio of the overbased detergent may be 1.1:1, or 2:1, or 4:1, or 5:1, or 7:1, or 10:1. In some embodiments, the detergent is effective in reducing or preventing rust in the engine or other automotive parts such as transmissions or gears. The detergent may be present in the lubricating composition at about 0 wt % to about 10 wt %, or about 0.1 wt % to about 8 wt %, or about 1 wt % to about 4 wt %, or greater than about 4 wt % to about 8 wt %.

[0108] Extreme Pressure AgentsThe lubricating oil composition herein may also optionally contain one or more extreme pressure agents. Extreme pressure (EP) agents soluble in oil include sulfur-containing and chlorine-containing sulfur-containing EP agents, chlorinated hydrocarbon EP agents, and phosphorus EP agents. Examples of such EP agents include chlorinated waxes; organic sulfides and polysulfides such as bisdibenzyl disulfide, bis(chlorobenzyl) disulfide, dibutyl tetrasulfide, sulfurized methyl oleate, sulfurized alkylphenols, sulfurized dipentenes, sulfurized terpenes, sulfurized Diels-Alder adducts; phosphosulfurized hydrocarbons such as the reaction product of phosphorus sulfide with turpentine or methyl oleate; phosphites such as dialkyl phosphites and trialkyl phosphites, for example, dibutyl phosphite, diheptyl phosphite, dicyclohexyl phosphite, amylphenyl phosphite; diamylphenyl phosphite, tridecyl phosphite, distearyl phosphite, and polypropylene-substituted phenyl phosphites; metal thiocarbamates such as zinc dioctyldithiocarbamate and barium heptylphenol dioate; amine salts of alkyl and dialkyl phosphoric acids, including, for example, amine salts of the reaction product of dialkyldithiophosphoric acids with propylene oxide; and mixtures thereof.

[0109] Friction modifiers The lubricating oil composition herein may also optionally contain one or more friction modifiers. Suitable friction modifiers may include metal-containing and metal-free friction modifiers and may include, but are not limited to, imidazolines, amides, amines, succinimides, alkoxylated amines, alkoxylated ether amines, amine oxides, amidoamines, nitriles, betaines, quaternary amines, imines, amine salts, aminoguanidines, alkanolamides, phosphonates, metal-containing compounds, glycerides, sulfurized fatty compounds and olefins, sunflower oil, other naturally occurring plant or animal oils, dicarboxylic acid esters, esters or partial esters of polyols, and one or more aliphatic or aromatic carboxylic acids, and the like.

[0110] Suitable friction modifiers may contain a hydrocarbyl group selected from a linear, branched or aromatic hydrocarbyl group or a mixture thereof, and may be saturated or unsaturated. The hydrocarbyl group may be composed of carbon and hydrogen or heteroatoms, such as sulfur or oxygen. The hydrocarbyl group may be in the range of about 12 to about 25 carbon atoms. In some embodiments, the friction modifier may be a long-chain fatty acid ester. In another embodiment, the long-chain fatty acid ester may be a monoester or a diester or a (tri) glyceride. The friction modifier may be a long-chain fatty amide, a long-chain fatty ester, a long-chain fatty epoxide derivative or a long-chain imidazoline.

[0111] Other suitable friction modifiers may include organic, ashless (metal-free), nitrogen-free organic friction modifiers. Such friction modifiers may include esters formed by reacting carboxylic acids and anhydrides with alkanols, and generally contain polar terminal groups (e.g., carboxyl or hydroxyl groups) covalently bonded to oleophilic hydrocarbon chains. An example of an organic ashless, nitrogen-free friction modifier is generally known as glyceryl monooleate (GMO), which may contain monoesters, diesters, and triesters of oleic acid. Other suitable friction modifiers are described in U.S. Pat. No. 6,723,685, which is incorporated herein by reference in its entirety.

[0112] Amine friction modifiers can include amines or polyamines. Such compounds can have straight chain, saturated or unsaturated hydrocarbon groups, or mixtures thereof, and can contain from about 12 to about 25 carbon atoms. Other examples of suitable friction modifiers include alkoxylated amines and alkoxylated ether amines. Such compounds can have straight chain, saturated or unsaturated hydrocarbon groups, or mixtures thereof. They can contain from about 12 to about 25 carbon atoms. Examples include ethoxylated amines and ethoxylated ether amines.

[0113] The amines and amides can be used as such or in the form of adducts or reaction products with boron compounds such as boron oxide, boron halides, metaborates, boric acid or mono-, di- or tri-alkyl borate esters. Other suitable friction modifiers are described in U.S. Pat. No. 6,300,291, which is incorporated herein by reference in its entirety.

[0114] Friction modifiers may optionally be present in a range such as from about 0 wt % to about 10 wt %, or from about 0.01 wt % to about 8 wt %, or from about 0.1 wt % to about 4 wt %.

[0115] Compounds containing transition metals In another embodiment, the oil-soluble compound may be a compound containing a transition metal or a metalloid. The transition metal may include, but is not limited to, titanium, vanadium, copper, zinc, zirconium, molybdenum, tantalum, tungsten, etc. Suitable metalloids include, but are not limited to, boron, silicon, antimony, tellurium, etc.

[0116] In one embodiment, the oil-soluble transition metal-containing compound can function as an antiwear agent, a friction modifier, an antioxidant, a deposit control additive, or more than one of these functions. In one embodiment, the oil-soluble transition metal-containing compound can be an oil-soluble titanium compound, such as titanium (IV) alkoxide. Among the titanium-containing compounds that can be used in the disclosed technology or can be used to prepare the oil-soluble materials of the disclosed technology are various Ti (IV) compounds, such as titanium (IV) oxide; titanium (IV) sulfide; titanium (IV) nitrate; titanium (IV) alkoxide, such as titanium methoxide, titanium ethoxide, titanium propoxide, titanium isopropoxide, titanium butoxide, 2-ethylhexyl titanium; and other titanium compounds or complexes, including but not limited to titanium phenolate; titanium carboxylate, such as 2-ethyl-1-3-adipate titanium (IV) or titanium citrate or titanium oleate; and (triethanolamine) isopropoxide titanium (IV). Other forms of titanium encompassed within the disclosed technology include titanium phosphates, such as titanium dithiophosphates (e.g., titanium dialkyl dithiophosphates), and titanium sulfonates (e.g., titanium alkylbenzene sulfonates), or generally, the reaction products of titanium compounds reacting with various acidic materials to form salts (e.g., oil-soluble salts). Titanium compounds can therefore be derived, in particular, from organic acids, alcohols, and glycols. Ti compounds can also exist in dimerized or oligomeric forms, containing Ti--O--Ti structures. Such titanium materials are commercially available or can be readily prepared by appropriate synthesis techniques readily known to those skilled in the art. They exist at room temperature in solid or liquid form, depending on the specific compound. They can also be provided in the form of solutions in suitable inert solvents.

[0117] In one embodiment, titanium can be supplied as a Ti-modified dispersant, such as a succinimide dispersant. Such materials can be prepared by forming a titanium mixed anhydride between a titanium alkoxide and a hydrocarbyl-substituted succinic anhydride, such as an alkenyl (or alkyl) succinic anhydride. The resulting titanate-succinate intermediate can be used directly, or it can be reacted with any of a number of materials, such as (a) a polyamine-based succinimide / amide dispersant having a free, condensable-NH functional group; (b) components of a polyamine-based succinimide / amide dispersant, i.e., alkenyl (or alkyl) succinic anhydride and a polyamine, (c) a hydroxyl-containing polyester dispersant prepared by reacting a substituted succinic anhydride with a polyol, an amino alcohol, a polyamine, or a mixture thereof. Alternatively, the titanate-succinate intermediate can be reacted with other reagents, such as an alcohol, an amino alcohol, an ether alcohol, a polyether alcohol, or a polyol or a fatty acid, and the product thereof can be used directly to impart Ti to the lubricant, or alternatively, reacted with a succinic acid dispersant as described herein. As an example, 1 part (by mole) of tetraisopropyl titanate can be reacted with about 2 parts (by mole) of polyisobutylene-substituted succinic anhydride at 140° C. to 150° C. for 5 to 6 hours to provide a titanium-modified dispersant or intermediate. The resulting material (30 g) can also be reacted with a succinimide dispersant from polyisobutylene-substituted succinic anhydride and a polyethylene polyamine mixture (127 g + diluent oil) at 150° C. for 1.5 hours to produce a titanium-modified succinimide dispersant.

[0118] Another titanium-containing compound can be a titanium alkoxide with a C6 to C 25 The reaction product of carboxylic acid. The reaction product can be represented by the following formula:

[0119]

[0120] wherein n is an integer selected from 2, 3 and 4, and R is a hydrocarbyl group containing from about 5 to about 24 carbon atoms, or is represented by the formula:

[0121]

[0122] wherein m+n=4 and n is in the range of 1 to 3, R4 is an alkyl moiety having a carbon atom range of 1 to 8, R1 is selected from a hydrocarbon group containing about 6 to 25 carbon atoms, and R2 and R3 are the same or different and are selected from a hydrocarbon group containing about 1 to 6 carbon atoms, or the titanium compound can be represented by the following formula:

[0123]

[0124] wherein x is in the range of 0 to 3, R1 is selected from a hydrocarbon group containing about 6 to 25 carbon atoms, R2 and R3 are the same or different and are selected from a hydrocarbon group containing about 1 to 6 carbon atoms, and R4 is selected from H, or C6 to C25 A group consisting of carboxylic acid moieties.

[0125] Suitable carboxylic acids may include, but are not limited to, caproic acid, caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, oleic acid, erucic acid, linoleic acid, linolenic acid, cyclohexanecarboxylic acid, phenylacetic acid, benzoic acid, neodecanoic acid, and the like.

[0126] In embodiments, the oil soluble titanium compound may be present in the lubricating oil composition in an amount providing 0 ppm to 3000 ppm by weight titanium, or 25 ppm to about 1500 ppm by weight titanium, or about 35 ppm to 500 ppm by weight titanium, or about 50 ppm to about 300 ppm by weight.

[0127] Viscosity Index Improver :The lubricating oil composition of the present invention may also optionally contain one or more viscosity index improvers. Suitable viscosity index improvers may include polyolefins, olefin copolymers, ethylene / propylene copolymers, polyisobutylene, hydrogenated styrene-isoprene polymers, styrene / maleic acid ester copolymers, hydrogenated styrene / butadiene copolymers, hydrogenated isoprene polymers, alpha-olefin maleic anhydride copolymers, polymethacrylates, polyacrylates, polyalkylstyrenes, hydrogenated alkenyl aryl conjugated diene copolymers, or mixtures thereof. Viscosity index improvers may include star polymers, and suitable examples are described in U.S. Publication No. 20120101017A1.

[0128] The lubricating oil compositions herein may optionally contain one or more dispersant viscosity index improvers in addition to or in place of the viscosity index improvers. Suitable viscosity index improvers may include functionalized polyolefins, for example, ethylene-propylene copolymers that have been functionalized with the reaction product of an acylating agent (such as maleic anhydride) and an amine; polymethacrylates functionalized with amines, or esterified maleic anhydride-styrene copolymers reacted with amines.

[0129] Viscosity Index Improvers and / or Dispersants The total amount of viscosity index improvers can be from about 0 wt % to about 20 wt %, from about 0.1 wt % to about 15 wt %, from about 0.1 wt % to about 12 wt %, or from about 0.5 wt % to about 10 wt % of the lubricating oil composition.

[0130] Other optional additives Other additives may be selected to perform one or more functions required of the lubricating fluid. In addition, one or more of the additives mentioned may be multifunctional and provide functions other than those described herein or different from those specified herein.

[0131] Lubricating oil compositions according to the present disclosure may optionally include other performance additives. Other performance additives may be additives other than the specified additives of the present disclosure and / or may include one or more of the following: metal passivators, viscosity index improvers, detergents, ashless TBN promoters, friction modifiers, antiwear agents, corrosion inhibitors, rust inhibitors, dispersants, dispersant viscosity index improvers, extreme pressure agents, antioxidants, foam inhibitors, demulsifiers, emulsifiers, pour point depressants, seal swell agents and mixtures thereof. Typically, a fully formulated lubricating oil will contain one or more of these performance additives.

[0132] Suitable metal deactivators may include derivatives of benzotriazole (typically tolyltriazole), dithiothiadiazole derivatives, 1,2,4-triazole, benzimidazole, 2-alkyldithiobenzimidazole or 2-alkyldithiobenzothiazole; foam inhibitors including copolymers of ethyl acrylate and 2-ethylhexyl acrylate and optionally vinyl acetate; demulsifiers including trialkyl phosphates, polyethylene glycol, polyethylene oxide, polypropylene oxide and (ethylene oxide-propylene oxide) polymers; pour point depressants including esters of maleic anhydride-styrene, polymethacrylates, polyacrylates or polyacrylamides.

[0133] Suitable foam suppressors include silicon-based compounds such as siloxanes.

[0134] Suitable pour point depressants may include polymethyl methacrylate or mixtures thereof. The pour point depressant may be present in an amount sufficient to provide from about 0 wt % to about 1 wt %, from about 0.01 wt % to about 0.5 wt %, or from about 0.02 wt % to about 0.04 wt % based on the final weight of the lubricating oil composition.

[0135] Suitable rust inhibitors can be single compounds or compound mixtures with properties that inhibit corrosion of ferrous metal surfaces. Non-limiting examples of useful rust inhibitors herein include: oil-soluble high molecular weight organic acids, such as 2-ethylhexanoic acid, lauric acid, myristic acid, palmitic acid, oleic acid, linoleic acid, linolenic acid, behenic acid, and cerotic acid; and oil-soluble polycarboxylic acids including dimer acids and trimer acids, such as those produced by pine oil fatty acids, oleic acid, and linoleic acid. Other suitable corrosion inhibitors include long-chain α, ω-dicarboxylic acids with a molecular weight ranging from about 600 to about 3000, and alkenyl succinic acids in which the alkenyl group contains about 10 or more carbon atoms, such as tetrapropylene succinic acid, tetradecene succinic acid, and hexadecene succinic acid. Another type of acidic corrosion inhibitor available is a half ester of alkenyl succinic acid and an alcohol (such as polyethylene glycol) having about 8 to about 24 carbon atoms in the alkenyl group. The corresponding half amides of such alkenyl succinic acids are also useful. Useful rust inhibitors are high molecular weight organic acids.

[0136] Rust inhibitors, if present, may be used in amounts sufficient to provide from about 0 wt % to about 5 wt %, from about 0.01 wt % to about 3 wt %, from about 0.1 wt % to about 2 wt %, based on the final weight of the lubricating oil composition.

[0137] Generally speaking, suitable lubricants including the detergent metals herein may include additive components within the ranges listed in the following table.

[0138] Table 2: Suitable lubricating compositions

[0139]

[0140] The percentages of each component above represent the weight percentage of each component based on the weight of the final lubricating oil composition. The remainder of the lubricating oil composition consists of one or more base oils. The additives used to formulate the compositions described herein can be blended into the base oil individually or in various sub-combinations. However, it may be appropriate to blend all components simultaneously using an additive concentrate (i.e., additives plus diluents, such as hydrocarbon solvents). A fully formulated lubricant typically contains an additive package, referred to herein as a dispersant / inhibitor package or DI package, which will supply the desired features in the formulation.

[0141] definition

[0142] For purposes of this disclosure, chemical elements are identified according to the Periodic Table of the Elements, CAS version, Handbook of Chemistry and Physics, 75th edition. In addition, general principles of organic chemistry are described in Organic Chemistry, Thomas Sorrell, University Science Books, Sausolito: 1999 and March's Advanced Organic Chemistry, 5th edition, eds. Smith, MB and March, J., John Wiley & Sons, New York: 2001, the entire contents of which are incorporated herein by reference.

[0143] As described herein, compounds may be optionally substituted with one or more substituents, such as described generally above, or as exemplified by particular classes, subclasses, and species of the present disclosure.

[0144] Unless it is obvious from the context, the term "major amount" should be understood to mean an amount greater than or equal to 50% by weight, such as from about 80% by weight to about 98% by weight, relative to the total weight of the composition. In addition, as used herein, the term "minor amount" should be understood to mean an amount less than 50% by weight relative to the total weight of the composition.

[0145] As used herein, the term "hydrocarbyl group" or "hydrocarbyl" is used in its ordinary sense as is known to those skilled in the art. Specifically, it refers to a group having carbon atoms directly attached to the remainder of the molecule and having predominantly hydrocarbon character. Examples of hydrocarbyl groups include: (1) hydrocarbon substituents, i.e., aliphatic (e.g., alkyl or alkenyl), alicyclic (e.g., cycloalkyl, cycloalkenyl) substituents, and aromatic, aliphatic, and alicyclic substituted aromatic substituents, as well as cyclic substituents in which the ring is completed by another part of the molecule (e.g., two substituents together form an alicyclic group); (2) substituted hydrocarbon substituents, i.e., substituents containing non-hydrocarbyl groups which, in the context described herein, do not alter the predominant hydrocarbon substituent (e.g., halogens (especially chlorine and fluorine), hydroxyl, alkoxy, mercapto, alkylmercapto, nitro, nitroso, amino, alkylamino, and sulfoxyl); (3) heterosubstituents, i.e., substituents which, in the context of this specification, although predominantly hydrocarbon in character, contain atoms other than carbon in a ring or chain that is otherwise composed of carbon atoms. Heteroatoms include sulfur, oxygen, nitrogen, and encompass substituents such as pyridyl, furanyl, thienyl, and imidazolyl. Generally, for every ten carbon atoms in the hydrocarbyl group, there are no more than two, or as another example, no more than one, non-hydrocarbon substituent group; in some embodiments, there are no non-hydrocarbon substituent groups in the hydrocarbyl group.

[0146] As used herein, the term "aliphatic" includes the terms alkyl, alkenyl, alkynyl, each of which is optionally substituted as described below.

[0147] As used herein, an "alkyl" group refers to a saturated aliphatic hydrocarbon group containing 1-12 (e.g., 1-8, 1-6, or 1-4) carbon atoms. The alkyl group can be straight chain or branched. Examples of alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, isobutyl, n-pentyl, n-heptyl, or 2-ethylhexyl. The alkyl group may be substituted (i.e., optionally substituted) with one or more substituents such as halo, phosphate, cycloaliphatic [e.g., cycloalkyl or cycloalkenyl], heterocycloaliphatic [e.g., heterocycloalkyl or heterocycloalkenyl], aryl, heteroaryl, alkoxy, aroyl, heteroaroyl, acyl [e.g., (aliphatic)carbonyl, (cycloaliphatic)carbonyl, or (heterocycloaliphatic)carbonyl], nitro, cyano, acylamino [e.g., (cycloalkylalkyl)carbonylamino, arylcarbonylamino, aralkylcarbonylamino, (heterocycloalkyl)carbonylamino, (heterocycloalkylalkyl)carbonylamino] The invention can be substituted with any of the following: alkyl, heteroarylcarbonylamino, heteroaralkylcarbonylamino, alkylaminocarbonyl, cycloalkylaminocarbonyl, heterocycloalkylaminocarbonyl, arylaminocarbonyl or heteroarylaminocarbonyl], amino [e.g., aliphatic amino, cycloaliphatic amino or heterocycloaliphatic amino], sulfonyl [e.g., aliphatic -SO2-], sulfinyl, sulfhydryl, sulfoxy, urea, thiourea, sulfamoyl, sulfonamide, pendant oxy, carboxyl, carbamoyl, cycloaliphatic oxy, heterocycloaliphatic oxy, aryloxy, heteroaryloxy, aralkyloxy, heteroaralkyloxy, alkoxycarbonyl, alkylcarbonyloxy or hydroxy. Without limitation, some examples of substituted alkyl groups include carboxyalkyl (such as HOOC-alkyl, alkoxycarbonylalkyl, and alkylcarbonyloxyalkyl), cyanoalkyl, hydroxyalkyl, alkoxyalkyl, acylalkyl, aralkyl, (alkoxyaryl)alkyl, (sulfonylamino)alkyl (such as (alkyl-SO2-amino)alkyl), aminoalkyl, amidoalkyl, (cycloaliphatic)alkyl, or haloalkyl.

[0148] As used herein, an "alkenyl" group refers to an aliphatic carbon group containing 2 to 8 (e.g., 2 to 12, 2 to 6, or 2 to 4) carbon atoms and at least one double bond. Like alkyl groups, alkenyl groups can be straight or branched. Examples of alkenyl groups include, but are not limited to, allyl, isopropenyl, 2-butenyl, and 2-hexenyl. The alkenyl group may be optionally substituted with one or more substituents such as halo, phosphate, cycloaliphatic [e.g., cycloalkyl or cycloalkenyl], heterocycloaliphatic [e.g., heterocycloalkyl or heterocycloalkenyl], aryl, heteroaryl, alkoxy, aroyl, heteroaroyl, acyl [e.g., (aliphatic)carbonyl, (cycloaliphatic)carbonyl, or (heterocycloaliphatic)carbonyl], nitro, cyano, amide [e.g., (cycloalkylalkyl)carbonylamino, arylcarbonylamino, aralkylcarbonylamino, (heterocycloalkyl)carbonylamino, (heterocycloalkylalkyl)carbonylamino, heteroarylcarbonylamino, heteroaralkylcarbonylamino,

[0013] The invention further comprises a cycloalkylamino, cycloalkylaminocarbonyl, heterocycloalkylaminocarbonyl, arylaminocarbonyl or heteroarylaminocarbonyl group, an amino group [e.g., an aliphatic amino, a cycloaliphatic amino, a heterocycloaliphatic amino or an aliphatic sulfonylamino group], a sulfonyl group [e.g., an alkyl-SO2-, a cycloaliphatic-SO2- or an aryl-SO2-], a sulfinyl group, a sulfhydryl group, a sulfoxy group, a urea, a thiourea, a sulfamoyl group, a sulfonamide group, a pendant oxy group, a carboxyl group, a carbamoyl group, a cycloaliphatic oxy group, a heterocycloaliphatic oxy group, an aryloxy group, a heteroaryloxy group, an aralkyloxy group, a heteroaralkyloxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group or a hydroxyl group. Without limitation, some examples of substituted alkenyl groups include cyanoalkenyl, alkoxyalkenyl, acylalkenyl, hydroxyalkenyl, arylalkenyl, (alkoxyaryl)alkenyl, (sulfonylamino)alkenyl (such as (alkyl-SO2-amino)alkenyl), aminoalkenyl, amidoalkenyl, (cycloaliphatic)alkenyl, or haloalkenyl.

[0149] As used herein, an "alkynyl" group refers to an aliphatic carbon group containing 2 to 8 (e.g., 2 to 12, 2 to 6, or 2 to 4) carbon atoms and having at least one triple bond. The alkynyl group may be straight or branched. Examples of alkynyl groups include, but are not limited to, propargyl and butynyl. The alkynyl group may be optionally substituted with one or more substituents such as aroyl, heteroaroyl, alkoxy, cycloalkyloxy, heterocycloalkoxy, aryloxy, heteroaryloxy, aralkoxy, nitro, carboxyl, cyano, halide, hydroxyl, sulfonic acid, mercapto, sulfenyl [e.g., aliphatic sulfenyl or cycloaliphatic sulfenyl], sulfinyl [e.g., aliphatic sulfinyl or cycloaliphatic sulfinyl], sulfonyl [e.g., aliphatic-SO2-, aliphatic amino-SO2-, or cycloaliphatic-SO2-], acylamino [e.g., aminocarbonyl, alkylaminocarbonyl, alkylcarbonylamino, cycloalkylaminocarbonyl, heterocycloalkylaminocarbonyl, , cycloalkylcarbonylamino, arylaminocarbonyl, arylcarbonylamino, aralkylcarbonylamino, (heterocycloalkyl)carbonylamino, (cycloalkylalkyl)carbonylamino, heteroaralkylcarbonylamino, heteroarylcarbonylamino or heteroarylaminocarbonyl], urea, thiourea, sulfamoyl, sulfonamide, alkoxycarbonyl, alkylcarbonyloxy, cycloaliphatic, heterocycloaliphatic, aryl, heteroaryl, acyl [e.g., (cycloaliphatic)carbonyl or (heterocycloaliphatic)carbonyl], amino [e.g., aliphaticamino], sulfoxy, pendant, carboxyl, carbamoyl, (cycloaliphatic)oxy, (heterocycloaliphatic)oxy or (heteroaryl)alkoxy.

[0150] As used herein, an "amino" group refers to -NRXRY, wherein each of Rx and Ry is independently hydrogen, alkyl, cycloalkyl, (cycloalkyl)alkyl, aryl, aralkyl, heterocycloalkyl, (heterocycloalkyl)alkyl, heteroaryl, carboxyl, sulfenyl, sulfonyl, (alkyl)carbonyl, (cycloalkyl)carbonyl, ((cycloalkyl)alkyl)carbonyl, arylcarbonyl, (aralkyl)carbonyl, (heterocycloalkyl)carbonyl, ((heterocycloalkyl)alkyl)carbonyl, (heteroaryl)carbonyl or (heteroaralkyl)carbonyl, each of which is defined herein and is optionally substituted. Examples of amino groups include alkylamino, dialkylamino or arylamino. When the term "amino" is not a terminal group (e.g., alkylcarbonylamino), it is represented by -NRX-. Rx has the same meaning as defined above.

[0151] As used herein, a "cycloalkyl" group refers to a saturated carbocyclic monocyclic or bicyclic (fused or bridged) ring of 3-10 (e.g., 5-10) carbon atoms. Examples of cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, adamantyl, norbornyl, cycloheptyl, octahydro-indenyl, decahydronaphthyl, bicyclo[3.2.1]octyl, bicyclo[2.2.2]octyl, bicyclo[3.3.1]nonyl, bicyclo[3.3.2.]decyl, bicyclo[2.2.2]octyl, adamantyl, or ((aminocarbonyl)cycloalkyl)cycloalkyl.

[0152] As used herein, a "heterocycloalkyl" group refers to a 3-10 membered mono- or bicyclic (fused or bridged) (e.g., a 5- to 10-membered mono- or bicyclic) saturated ring structure in which one or more ring atoms is a heteroatom (e.g., N, O, S, or a combination thereof). Examples of heterocycloalkyl groups include piperidinyl, piperazinyl, tetrahydropyranyl, tetrahydrofuranyl, 1,4-dioxolanyl, 1,4-dithianyl, 1,3-dioxolanyl, oxazolidinyl, isoxazolidinyl, morpholinyl, thiomorpholinyl, octahydrobenzofuranyl, octahydrochromenyl, octahydrothiochromenyl, octahydroindolyl, octahydropyridinyl, decahydroquinolinyl, octahydrobenzo[b]thienyl, 2-oxa-bicyclo[2.2.2]octyl, 1-aza-bicyclo[2.2.2]octyl, 3-aza-bicyclo[3.2.1]octyl and 2,6-dioxa-tricyclo[3.3.1.0]nonyl. Monocyclic heterocycloalkyl groups may be fused with a phenyl moiety to form a structure such as tetrahydroisoquinoline, which would be classified as a heteroaryl.

[0153] As used herein, a "heteroaryl" group refers to a monocyclic, bicyclic, or tricyclic ring system having 4 to 15 ring atoms, wherein one or more of the ring atoms is a heteroatom (e.g., N, O, S, or a combination thereof), and wherein the monocyclic ring system is aromatic, or at least one of the bicyclic or tricyclic ring systems is aromatic. Heteroaryl groups include benzo-fused ring systems having 2 to 3 rings. For example, benzo-fused groups include benzo fused to one or two 4 to 8-membered heterocyclic aliphatic moieties (e.g., indolizyl, indolyl, isoindolyl, 3H-indolyl, dihydroindole, benzo[b]furanyl, benzo[b]thienyl, quinolyl, or isoquinolyl). Some examples of heteroaryl groups are pyridinyl, 1H-indazolyl, furanyl, pyrrolyl, thienyl, thiazolyl, oxazolyl, imidazolyl, tetrazolyl, benzofuranyl, isoquinolyl, benzothiazolyl, xanthene, thioxanthene, phenothiazine, indoline, benzo[1,3]dioxole, benzo[b]furanyl, benzo[b]thienyl, indazolyl, benzimidazolyl, benzothiazolyl, furanyl, cinnolyl, quinolyl, quinazolinyl, cinnolyl, phthalazyl, quinazolinyl, quinoxalinyl, isoquinolyl, 4H-quinolizyl, benzo-1,2,5-thiadiazolyl, or 1,8-naphthyridyl.

[0154] Without limitation, monocyclic heteroaryl groups include furanyl, thienyl, 2H-pyrrolyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, pyrazolyl, isoxazolyl, isothiazolyl, 1,3,4-thiadiazolyl, 2H-pyranyl, 4-H-pyranyl, pyridinyl, pyridazinyl, pyrimidinyl, pyrazolyl, pyrazinyl or 1,3,5-triazinyl. Monocyclic heteroaryl groups are numbered according to standard chemical nomenclature.

[0155] Without limitation, bicyclic heteroaryl groups include indolizinyl, indolyl, isoindolyl, 3H-indolyl, dihydroindole, benzo[b]furanyl, benzo[b]thienyl, quinolyl, isoquinolyl, indolizinyl, isoindolyl, indolyl, benzo[b]furanyl, benzo[b]thienyl, indazolyl, benzimidazolyl, benzothiazolyl, purinyl, 4H-quinolizinyl, quinolyl, isoquinolyl, cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, 1,8-naphthyridinyl or pteridyl. Bicyclic heteroaryl groups are numbered according to standard chemical nomenclature.

[0156] As used herein, the term "treat rate" refers to the weight percentage of a component in a lubricating composition.

[0157] Both the weight average molecular weight (Mw) and the number average molecular weight (Mn) can be measured using a gel permeation chromatography (GPC) instrument available from Waters or a similar instrument, and the data are processed using Waters Empower software or a similar software using commercially available polystyrene standards (Mn of 180 to about 18,000 as a calibration reference). See, e.g., WW Yau, JJ Kirkland and DD Bly, "Modern Size Exclusion Liquid Chromatography", John Wiley and Sons, New York, 1979, which is also incorporated herein by reference.

[0158] Example

[0159] The present disclosure and its many advantages can be better understood by the following examples. The following examples are illustrative and do not limit their scope or spirit. It will be readily appreciated by those skilled in the art that variations of the parts, methods, steps and equipment described in these examples can be used. Unless otherwise indicated or apparent from the context of the following examples and the entire disclosure, all percentages, ratios and parts mentioned in the present disclosure are by weight.

[0160] Comparative and inventive heavy duty crankcase lubricating oil compositions were evaluated for piston cleanliness on steel pistons according to the OM471 Piston Cleanliness Test of CEC L-118-21. The lubricating compositions evaluated for this example contained sulfonate and / or phenate detergents to provide the fluid relationships of Table 3 below. Aside from the changes in the detergent system, Inventive 1 and Comparative 1 contained otherwise identical additive packages (with identical treat rates), and thus had identical dispersant systems, anti-wear systems, antioxidant systems, defoamers, pour point depressants, viscosity improvers, and had a balance of API Group III base oils to achieve a target KV100 of 11.4 cSt to about 11.7 cSt as measured according to ASTM D445. The antioxidant systems of Inventive 1 and Comparative 1 contained at least 1.0 wt% diphenylamine, at least 1.0 wt% hindered phenols, and less than 0.2 wt% molybdenum-containing compounds. In addition to the changes in the detergent system, Comparative Example 2 also contained a reduced dispersant treat rate in its dispersant system, a reduced antioxidant treat rate in its antioxidant system, and an increased zinc dithiophosphate treat rate in its antiwear system. It is also noted that each fluid contained slight variations in the process oil due to differences in the amounts of additives provided. The soap content was calculated as explained in the textbook entitled "Lubricant Chemistry and Technology" (3rd edition, edited by R.M. Mortier and S.T. Orszulik, copyright 2010, pages 219 to 220 under the subheading 7.2.5. Detergent Classification).

[0161] Table 3: Heavy-duty lubricant composition

[0162]

[0163] *The TBN of each sulfonate and phenate detergent was measured by ASTM D2896, and the TBN contribution from the sulfonate was calculated based on the treat rate in the lubricating oil composition.

[0164] The detergent system and dispersant system of the heavy-duty crankcase lubricant of Table 3 above include the following components:

[0165] • Detergent A is an overbased calcium phenate having a TBN of about 250 and about 9.3 wt % calcium.

[0166] • Detergent B is an overbased calcium sulfonate having a TBN of about 307 and about 11.9 wt % calcium.

[0167] • Detergent C is a low base calcium sulfonate having a TBN of about 28 and about 2.6 wt % calcium.

[0168] • The dispersant system contains a combination of polyisobutylene succinimide dispersants derived from highly reactive polyisobutylene, each having a number average molecular weight between 1000 and 2500.

[0169] Each dispersant has 1.0 wt % to 1.7 wt % nitrogen.

[0170] The antioxidant system contains a mixture of alkylated diphenylamine, hindered phenol antioxidant and molybdenum-containing compound.

[0171] • The antiwear system includes one or more zinc dithiophosphates that deliver phosphorus to the fluid.

[0172] The heavy-duty lubricants of Table 3 were evaluated for piston cleanliness according to the OM471 Piston Cleanliness Test (CEC L-118-21) using steel pistons. The results are provided in Table 4 below. Although Comparative Example 1 was previously acceptable in the previous piston cleanliness test of OM501LA (CEC L-101-08) when using aluminum pistons, Comparative Example 1 did not achieve high piston cleanliness when tested using the new OM471 test on steel pistons. Unexpectedly, Invention 1, containing only sulfonate soap, achieved high piston cleanliness on steel pistons under the newer, more stringent OM471 test. It is further expected that Invention 1 will achieve high piston cleanliness in a modified form of the OM471 test using a shorter test duration.

[0173] Table 4: OM471 steel piston cleanliness (CEC L-118-21)

[0174]

[0175] *Comparative Example 1 and Comparative Example 2 fluids were unable to complete the entire test and are scored for reported results only after 400 hours.

[0176] It should be noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless expressly and affirmatively limited to one referent. Thus, for example, reference to "an antioxidant" includes two or more different antioxidants. The term "comprising" and its grammatical variations as used herein are intended to be non-limiting, such that recitation of items in a list does not exclude other similar items that can be substituted or added to the listed items.

[0177] For purposes of this specification and the appended claims, unless otherwise indicated, all numbers and other numerical values ​​used in the specification and claims indicating quantities, percentages or ratios should be understood to be modified in all cases by the term "about". Therefore, unless otherwise indicated, the numerical parameters set forth in the following specification and the appended claims are approximate values ​​that may vary depending on the desired properties attempted to be obtained by the present disclosure. At a minimum, and without attempting to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be interpreted in light of the number of reported significant figures and by applying ordinary rounding techniques.

[0178] It should be understood that each component, compound, substituent or parameter disclosed herein should be interpreted as disclosed for use alone or in combination with one or more of each of the other components, compounds, substituents or parameters disclosed herein.

[0179] It should be further understood that each range disclosed herein should be interpreted as a disclosure of each specific value within the disclosed range with the same number of significant figures. Thus, for example, a range of 1 to 4 should be interpreted as an explicit disclosure of the values ​​1, 2, 3, and 4, as well as any range of such values.

[0180] It should be further understood that each lower limit of each scope disclosed herein should be interpreted as being disclosed in combination with each upper limit of each scope disclosed herein for the same component, compound, substituent or parameter and each specific value in each scope. Therefore, the disclosure should be interpreted as being disclosed by combining each lower limit of each scope with each upper limit of each scope or with each specific value in each scope, or by combining each upper limit of each scope with each specific value in each scope. That is, it should also be further understood that any scope between the endpoint values ​​in a wide range is also discussed herein. Therefore, the scope of 1 to 4 also means the scope of 1 to 3, 1 to 2, 2 to 4, 2 to 3, etc.

[0181] In addition, a specific amount / value of a component, compound, substituent or parameter disclosed in this specification or the examples should be interpreted as a disclosure of a lower or upper limit of a range, and therefore can be combined with any other lower or upper limit or specific amount / value of a range for the same component, compound, substituent or parameter disclosed elsewhere in this disclosure to form a range for that component, compound, substituent or parameter.

[0182] Although specific embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are not currently foreseen or may not currently be foreseen may occur to applicants or other persons skilled in the art. Therefore, the appended claims as filed and as they may be amended are intended to cover all such alternatives, modifications, variations, improvements, and substantial equivalents.

[0183] The present invention also relates to the following numbered embodiments:

[0184] 1. A method of lubricating a heavy-duty diesel engine having a steel piston, the method comprising:

[0185] lubricating the steel piston of the heavy-duty diesel engine with a lubricating oil composition;

[0186] wherein the lubricating oil composition comprises (i) a detergent system consisting of one or more alkaline earth metal sulfonate detergents, the detergent system delivering from 0.3 wt % to about 1 wt % of sulfonate soap to the lubricating oil composition, and (ii) a dispersant system including one or more polyisobutylene succinimide dispersants, the dispersant system delivering at least about 5 wt % of the one or more dispersants to the lubricating oil composition; and

[0187] wherein the one or more polyisobutylene succinimide dispersants are derived from a highly reactive polyisobutylene having a number average molecular weight of about 1,200 to about 2,500 and delivering greater than 650 ppm of nitrogen to the lubricating oil composition.

[0188] 2. A method of lubricating a heavy-duty diesel engine having a steel piston according to embodiment 1, wherein the heavy-duty diesel engine is operated under the conditions set forth in the OM471 Piston Cleanliness Test of CEC L-118-21.

[0189] 3. The method of lubricating a heavy-duty diesel engine having a steel piston according to embodiment 1, wherein the heavy-duty diesel engine is configured to power a vehicle having a gross vehicle weight rating of about 6,000 pounds or more.

[0190] 4. A method for lubricating a heavy-duty diesel engine having a steel piston according to embodiment 1, wherein the detergent system consists of one or more overbased calcium sulfonate detergents and one or more underbased calcium sulfonate detergents, wherein the overbased detergent has a total base number (TBN) of at least about 300 mg KOH / g and the underbased detergent has a total base number (TBN) of about 175 mg KOH / g or less, and the total base number (TBN) is determined by ASTM D2896.

[0191] 5. The method of lubricating a heavy-duty diesel engine having a steel piston according to embodiment 4, wherein the lubricating composition comprises from about 0.3 wt % to about 0.7 wt % of the sulfonate soap.

[0192] 6. A method for lubricating a heavy-duty diesel engine having a steel piston according to embodiment 4, wherein the detergent system comprises an effective amount of the one or more overbased sulfonate detergents to provide at least about 5 mgKOH / g to the detergent system and an effective amount of the one or more low-based sulfonate detergents to provide about 25 wt. % to about 40 wt. % detergent soap.

[0193] 7. The method of lubricating a heavy duty diesel engine having a steel piston according to embodiment 1, wherein the detergent system consists essentially of calcium sulfonate detergent.

[0194] 8. The method of lubricating a heavy-duty diesel engine having a steel piston according to embodiment 1, wherein the detergent system is substantially free of magnesium sulfonate detergents, substantially free of phenate detergents, or a combination thereof.

[0195] 9. A method for lubricating a heavy-duty diesel engine having a steel piston according to embodiment 1, wherein the lubricating oil composition comprises from about 50 ppm to about 200 ppm of molybdenum provided by an oil-soluble molybdenum compound selected from the group consisting of molybdenum dithiocarbamates, molybdenum dialkyl dithiophosphates, sulfur-free organic molybdenum complexes of organic amides, or mixtures thereof.

[0196] 10. The method of lubricating a heavy-duty diesel engine having a steel piston according to claim 1, wherein the lubricating oil composition further comprises from about 0.5 wt. % to about 5 wt. % of one or more ashless antioxidants selected from hindered phenols, aromatic amines, alkylated diphenylamines, phenyl-α-naphthylamines, alkylated phenyl-α-naphthylamines, hindered non-aromatic amine sulfurized olefins, or mixtures thereof.

[0197] 11. A method for lubricating a heavy-duty diesel engine having a steel piston according to embodiment 1, wherein the lubricating oil composition comprises up to about 1200 ppm of phosphorus from one or more metal dihydrocarbyl dithiophosphate compounds having a hydrocarbyl group derived from a mixture of a linear or branched primary alcohol and a linear or branched secondary alcohol.

[0198] 12. A heavy duty crankcase lubricant composition suitable for use in a diesel engine having a gross vehicle weight of about 6,000 pounds or more, the heavy duty crankcase lubricant composition being suitable for use in a diesel engine having a gross vehicle weight of about 6,000 pounds or more

[0199] The crankcase lubricating oil composition comprises:

[0200] one or more base oils of lubricating viscosity;

[0201] a detergent system comprised of one or more alkaline earth metal sulfonate detergents, the detergent system delivering up to about 1 weight percent sulfonate soap to the lubricating oil composition;

[0202] a dispersant system comprising one or more polyisobutylene succinimide dispersants, the dispersant system delivering at least about 5 weight percent of the one or more dispersants to the lubricating composition; and

[0203] wherein the one or more polyisobutylene succinimide dispersants are derived from a highly reactive polyisobutylene having a number average molecular weight of about 1,200 to about 2,500 and delivering greater than 650 ppm of nitrogen to the lubricating oil composition.

[0204] 13. The heavy crankcase lubricating oil composition according to embodiment 12, wherein the lubricating

[0205] The oil composition achieves the following as passing the OM471 piston cleanliness test (CEC L-118-21)

[0206] Measured cleanliness rating of at least approximately 90% for steel pistons.

[0207] 14. A heavy duty crankcase lubricating oil composition according to embodiment 12, wherein the detergent system consists of one or more overbased calcium sulfonate detergents and one or more underbased calcium sulfonate detergents, wherein the overbased detergent has at least about 200 mg

[0208] The total base number (TBN) of KOH / g and the low base detergent has a total base number (TBN) of about 175 mg KOH / g or less, and the total base number (TBN) is measured by ASTM

[0209] Determined by D2896.

[0210] 15. The heavy duty crankcase lubricating oil composition of embodiment 13, wherein the detergent system comprises an effective amount of the one or more overbased sulfonate detergents to provide at least about 5 mg KOH / g to the detergent system and about 25 wt % to about 40 wt % of the one or more overbased sulfonate detergents to provide about 5 mg KOH / g to the detergent system.

[0211] The one or more low base sulfonate detergents are present in an effective amount of % of the detergent soap.

[0212] 16. The heavy duty crankcase lubricating oil composition of embodiment 12, wherein the detergent system consists essentially of calcium sulfonate detergent.

[0213] 17. The heavy duty crankcase lubricating oil composition of embodiment 12, wherein the detergent system is substantially free of magnesium sulfonate detergents, substantially free of phenate detergents, or a combination thereof.

[0214] 18. The heavy-duty crankcase lubricating oil composition according to embodiment 12, wherein the lubricating

[0215] The oil composition comprises from about 50 ppm to about 200 ppm of molybdenum provided by an oil-soluble molybdenum compound selected from the group consisting of molybdenum dithiocarbamates, molybdenum dialkyl dithiophosphates, sulfur-free organo-molybdenum complexes of organic amides, or mixtures thereof.

[0216] 19. The heavy-duty crankcase lubricating oil composition according to embodiment 12, wherein the lubricating

[0217] The oil composition also contains from about 0.5 wt. % to about 5 wt. % of one or more ashless antioxidants selected from hindered phenols, aromatic amines, alkylated diphenylamines, phenyl-α-naphthylamines, alkylated phenyl-α-naphthylamines, hindered non-aromatic amine sulfurized olefins, or mixtures thereof.

[0218] 20. A heavy duty crankcase lubricating oil composition according to embodiment 1, wherein the lubricating oil composition comprises up to about 1200 ppm of phosphorus from one or more metal dihydrocarbyl dithiophosphate compounds having a hydrocarbyl group derived from a mixture of a linear or branched primary alcohol and a linear or branched secondary alcohol.

Claims

1. A method of lubricating a heavy-duty diesel engine having a steel piston, the method comprising: lubricating the steel piston of the heavy-duty diesel engine with a lubricating oil composition; wherein the lubricating oil composition comprises (i) a detergent system consisting of one or more alkaline earth metal sulfonate detergents, the detergent system delivering from 0.3 wt % to about 1 wt % of sulfonate soap to the lubricating oil composition, and (ii) a dispersant system including one or more polyisobutylene succinimide dispersants, the dispersant system delivering at least about 5 wt % of the one or more dispersants to the lubricating oil composition; and wherein the one or more polyisobutylene succinimide dispersants are derived from a highly reactive polyisobutylene having a number average molecular weight of about 1,200 to about 2,500 and delivering greater than 650 ppm of nitrogen to the lubricating oil composition.

2. A method for lubricating a heavy-duty diesel engine having a steel piston according to claim 1, wherein the heavy-duty diesel engine is operated under the conditions set forth in the OM471 piston cleanliness test of CEC L-118-21; and / or wherein the heavy-duty diesel engine is configured to power a vehicle having a gross vehicle weight rating of approximately 6,000 pounds or more.

3. The method of lubricating a heavy duty diesel engine having a steel piston according to claim 1, wherein the detergent system consists of one or more overbased calcium sulfonate detergents and one or more underbased calcium sulfonate detergents, wherein the overbased detergent has a total base number (TBN) of at least about 300 mg KOH / g and the underbased detergent has a total base number (TBN) of about 175 mg KOH / g or less, and the total base number (TBN) is determined by ASTM D2896.

4. The method of lubricating a heavy duty diesel engine having a steel piston according to claim 3, wherein the lubricating composition comprises from about 0.3 wt. % to about 0.7 wt. % of the sulfonate soap.

5. The method of lubricating a heavy duty diesel engine having a steel piston according to claim 3, wherein the detergent system comprises an effective amount of the one or more overbased sulfonate detergents to provide at least about 5 mg KOH / g to the detergent system and an effective amount of the one or more underbased sulfonate detergents to provide from about 25 wt % to about 40 wt % detergent soap.

6. The method of lubricating a heavy-duty diesel engine having a steel piston according to claim 1, wherein the detergent system consists essentially of a calcium sulfonate detergent; and / or wherein the detergent system is substantially free of a magnesium sulfonate detergent, substantially free of a phenate detergent, or a combination thereof.

7. The method of lubricating a heavy-duty diesel engine having a steel piston according to claim 1, wherein the lubricating oil composition comprises from about 50 ppm to about 200 ppm of molybdenum provided by an oil-soluble molybdenum compound selected from the group of molybdenum dithiocarbamates, molybdenum dialkyl dithiophosphates, sulfur-free organo-molybdenum complexes of organic amides, or mixtures thereof.

8. The method of lubricating a heavy-duty diesel engine having a steel piston according to claim 1, wherein the lubricating oil composition further comprises from about 0.5 wt. % to about 5 wt. % of one or more ashless antioxidants selected from hindered phenols, aromatic amines, alkylated diphenylamines, phenyl-α-naphthylamines, alkylated phenyl-α-naphthylamines, hindered non-aromatic amine sulfurized olefins, or mixtures thereof.

9. The method of lubricating a heavy-duty diesel engine having steel pistons according to claim 1, wherein the lubricating oil composition comprises up to about 1200 ppm phosphorus from one or more metal dihydrocarbyl dithiophosphate compounds having a hydrocarbyl group derived from a mixture of a linear or branched primary alcohol and a linear or branched secondary alcohol.

10. A heavy-duty crankcase lubricant composition suitable for use in a diesel engine having a gross vehicle weight of about 6,000 pounds or more, the heavy-duty crankcase lubricant composition comprising: one or more base oils of lubricating viscosity; a detergent system consisting of one or more alkaline earth metal sulfonate detergents, the detergent system delivering up to about 1 weight percent sulfonate soap to the lubricating oil composition; a dispersant system comprising one or more polyisobutylene succinimide dispersants, the dispersant system delivering at least about 5 weight percent of the one or more dispersants to the lubricating composition; and wherein the one or more polyisobutylene succinimide dispersants are derived from a highly reactive polyisobutylene having a number average molecular weight of about 1,200 to about 2,500 and delivering greater than 650 ppm of nitrogen to the lubricating oil composition.

11. The heavy duty crankcase lubricating oil composition of claim 10, wherein the lubricating oil composition achieves a steel piston rated cleanliness of at least about 90% as measured by the OM471 Piston Cleanliness Test (CEC L-118-21).

12. The heavy duty crankcase lubricating oil composition of claim 10, wherein the detergent system consists of one or more overbased calcium sulfonate detergents and one or more underbased calcium sulfonate detergents, wherein the overbased detergent has a total base number (TBN) of at least about 200 mg KOH / g and the underbased detergent has a total base number (TBN) of about 175 mg KOH / g or less, and the total base number (TBN) is determined by ASTM D2896.

13. The heavy duty crankcase lubricating oil composition of claim 10, wherein the detergent system comprises an effective amount of the one or more overbased sulfonate detergents to provide at least about 5 mgKOH / g to the detergent system and an effective amount of the one or more underbased sulfonate detergents to provide about 25 wt % to about 40 wt % of the detergent soap; and / or wherein the detergent system consists essentially of calcium sulfonate detergents; and / or wherein the detergent system is substantially free of magnesium sulfonate detergents, substantially free of phenate detergents, or combinations thereof.

14. The heavy duty crankcase lubricating oil composition of claim 10, wherein the lubricating oil composition comprises from about 50 ppm to about 200 ppm of molybdenum provided by an oil soluble molybdenum compound selected from the group consisting of molybdenum dithiocarbamates, molybdenum dialkyl dithiophosphates, sulfur-free organo-molybdenum complexes of organic amides, or mixtures thereof.

15. The heavy duty crankcase lubricating oil composition of claim 10, wherein the lubricating oil composition further comprises from about 0.5 wt. % to about 5 wt. % of one or more ashless antioxidants selected from hindered phenols, aromatic amines, alkylated diphenylamines, phenyl-α-naphthylamines, alkylated phenyl-α-naphthylamines, hindered non-aromatic amine sulfurized olefins, or mixtures thereof; and / or wherein the lubricating oil composition comprises up to about 1200 ppm of phosphorus from one or more metal dihydrocarbyl dithiophosphate compounds having a hydrocarbyl group derived from a mixture of a linear or branched primary alcohol and a linear or branched secondary alcohol.

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