阅读说明：本技术 用于防止或减少直喷火花点火式发动机中的低速早燃的组合物和方法 (Compositions and methods for preventing or reducing low speed pre-ignition in direct injection spark-ignition engines ) 是由 I·G·埃利奥特 R·E·切派克 J·R·米勒 T·L·古纳万 A·G·玛丽亚 于 2020-02-05 设计创作，主要内容包括：本发明公开了一种发动机润滑油组合物,所述发动机润滑油组合物包含作为主要组分的润滑油基础油料,和至少一种金属或准金属氢原子供体化合物。本发明还公开了一种用于防止或减少直喷、增压、火花点火式内燃机中的低速早燃的方法,以及发动机润滑油组合物中的至少一种金属或准金属氢原子供体化合物用于防止或减少直喷、增压、火花点火式内燃机中的低速早燃的用途。(An engine lubricating oil composition comprising as essential components a lubricating oil base stock, and at least one metal or metalloid hydrogen atom donor compound. Also disclosed is a method for preventing or reducing low speed pre-ignition in a direct injection, supercharged, spark-ignited internal combustion engine, and the use of at least one metal or metalloid hydrogen atom donor compound in an engine lubricating oil composition for preventing or reducing low speed pre-ignition in a direct injection, supercharged, spark-ignited internal combustion engine.)

1. A lubricating oil composition comprising a metal or metalloid hydrogen atom donor compound selected from the group consisting of silicon hydride, germanium hydride and tin hydride.

2. The lubricating oil of claim 1, wherein the metal or metalloid hydrogen atom donor compound has the formula:

wherein R is₁、R₂And R₃Each independently selected from a hydrogen atom, a C6-C14 aryl group, a saturated OR unsaturated C1-C30 alkyl group, a C3-C10 cycloalkyl group, - (OR)₄)、-NR₅R₆、-O(＝O)R₇Or a chlorine atom, such that R₁、R₂And R₃Not more than one of which is a hydrogen atom; r₄Is C₆-C₁₄An aryl group, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, R₅Is an aryl group of H, C6-C14, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, R₆Is an aryl group of H, C6-C14, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, R₇Is a C6-C14 aryl radical, saturatedAnd or an unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group; and M is a silicon atom, a germanium atom or a tin atom.

3. The lubricating oil of claim 2, wherein the metal or metalloid hydrogen atom donor compound has the formula:

wherein R is₂And R₃Each independently selected from a C6-C14 aryl group, alkyl group OR C3-C10 cycloalkyl group, - (OR)₄)、-NR₅R₆、-O(＝O)R₇Or a chlorine atom, R₄Is a C6-C14 aryl group, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, R₅Is an aryl group of H, C6-C14, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, R₆Is an aryl group of H, C6-C14, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, R₇Is a C6-C14 aryl group, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group; and M is a silicon atom, a germanium atom or a tin atom.

4. The lubricating oil of claim 2, wherein the metal or metalloid hydrogen atom donor compound has the formula:

wherein R is₁、R₂And R₃Each independently selected from a hydrogen atom, a C6-C14 aryl group, a saturated OR unsaturated C1-C30 alkyl group, a C3-C10 cycloalkyl group, - (OR)₄)、-NR₅R₆、-O(＝O)R₇Or a chlorine atom, such that R₁、R₂And R₃Not more than one of which is a hydrogen atom; r₄Is a C6-C14 aryl group, saturated or unsaturated C1-C30 alkyl group, or C3-C10 cycloalkyl group, R₅Is an aryl group of H, C6-C14, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, R₆Is an aryl group of H, C6-C14, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, and R₇Is a C6-C14 aryl group, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group.

5. The lubricating oil of claim 4, wherein the metal or metalloid hydrogen atom donor compound has the formula:

wherein R is₂And R₃Each independently selected from a hydrogen atom, a C6-C14 aryl group, a saturated OR unsaturated C1-C30 alkyl group, a C3-C10 cycloalkyl group, - (OR)₄)、-NR₅R₆、-O(＝O)R₇Or a chlorine atom, R₄Is a C6-C14 aryl group, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, R₅Is an aryl group of H, C6-C14, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, R₆Is an aryl group of H, C6-C14, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, and R₇Is a C6-C14 aryl group, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group.

6. The lubricating oil composition of claim 2, wherein the metal or metalloid hydrogen atom donor compound has the formula:

wherein R is₁、R₂And R₃Each independently selected from a hydrogen atom, a C6-C14 aryl group, a saturated or unsaturated C1-C30 alkyl groupC3-C10 cycloalkyl radical, - (OR)₄)、-NR₅R₆、-O(＝O)R₇Or a chlorine atom, such that R₁、R₂And R₃Not more than one of which is a hydrogen atom; r₄Is a C6-C14 aryl group, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, R₅Is an aryl group of H, C6-C14, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, R₆Is an aryl group of H, C6-C14, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, and R₇Is a C6-C14 aryl group, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group.

7. The lubricating oil composition of claim 2, wherein the metal or metalloid hydrogen atom donor compound has the formula:

wherein R is₁、R₂And R₃Each independently selected from a hydrogen atom, a C6-C14 aryl group, a saturated OR unsaturated C1-C30 alkyl group, a C3-C10 cycloalkyl group, - (OR)₄)、-NR₅R₆、-O(＝O)R₇Or a chlorine atom, such that R₁、R₂And R₃Not more than one of which is a hydrogen atom; r₄Is a C6-C14 aryl group, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, R₅Is an aryl group of H, C6-C14, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, R₆Is an aryl group of H, C6-C14, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, and R₇Is a C6-C14 aryl group, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group.

8. The lubricating oil composition of claim 1, wherein the metal or metalloid hydrogen atom donor compound has the formula:

wherein R is₈Is a C6-C14 aryl group, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group; and n is 0 or an integer from 1 to 400.

9. The lubricating oil composition of claim 1, wherein the metal or metalloid hydrogen atom donor compound has the formula:

wherein n is 0 or an integer from 1 to 400.

10. The lubricating oil composition of claim 1, wherein the metal or metalloid hydrogen atom donor compound has the formula:

wherein R is₉Is a C6-C14 aryl group, a saturated or unsaturated C1-C30 alkyl group; and m is an integer of 1 to 20.

11. The lubricating oil composition of claim 1, wherein the composition further comprises a detergent selected from the group consisting of calcium detergents, magnesium detergents, sodium detergents, lithium detergents, and potassium detergents.

12. The lubricating oil composition of claim 11, wherein the detergent is a carboxylate, salicylate, phenate, or sulfonate detergent.

13. The lubricating oil composition of claim 1, wherein the composition further comprises a molybdenum-containing compound.

14. The lubricating oil composition of claim 1, wherein the composition further comprises at least one other additive selected from the group consisting of ashless dispersants, ashless antioxidants, phosphorus-containing anti-wear additives, friction modifiers, and polymeric viscosity modifiers.

15. A method for preventing or reducing low speed pre-ignition in a direct injection, supercharged, spark-ignited internal combustion engine, said method comprising the step of lubricating the engine crankcase with a lubricating oil composition comprising, based on the total weight of said lubricating oil composition, from about 25ppm to about 3000ppm of a metal from at least one metal or metalloid hydrogen atom donor compound selected from the group consisting of silicon hydride, germanium hydride and tin hydride.

16. Use of at least one metal or metalloid hydrogen atom donor compound selected from the group consisting of silicon hydride, germanium hydride and tin hydride in an engine lubricating oil composition to prevent or reduce low speed pre-ignition in a direct injection, supercharged, spark-ignited internal combustion engine.

17. The use according to claim 16, wherein said at least one metal or metalloid hydrogen atom donor compound is present at from about 25ppm to about 3000ppm of metal from said metal hydride, based on the total weight of the lubricating oil composition.

18. Use according to claim 16, wherein the engine is a small supercharged engine in the range of 0.5 to 3.6 litres.

Technical Field

The present disclosure relates to lubricant compositions comprising at least one metal hydride compound. The present disclosure also relates to lubricant compositions comprising at least one metal or metalloid hydrogen atom donor compound for use in direct injection, supercharged, spark-ignited internal combustion engines. The present disclosure also relates to a method for preventing or reducing low speed pre-ignition in an engine lubricated with a formulated oil. The formulated oil has a composition comprising at least one oil-soluble or oil-dispersible metal or metalloid hydrogen atom donor compound.

Background

In recent years, engine manufacturers have developed smaller (compact) engines that provide higher power densities and superior performance while reducing friction and pumping losses. This is accomplished by increasing boost pressure using a turbocharger or supercharger, and by decelerating the engine using a higher transmission gear ratio allowed by higher torque production at lower engine speeds. However, it has been found that higher torque at lower engine speeds can lead to random pre-ignition in the engine at low speeds, a phenomenon known as low speed pre-ignition or LSPI, leading to extremely high cylinder peak pressures, which can lead to catastrophic engine failure. The possibility of LSPI prevents engine manufacturers from fully optimizing engine torque at lower engine speeds in such smaller, high output engines.

One of the leading theories surrounding the cause of low speed pre-ignition (LSPI) is due, at least in part, to auto-ignition of engine oil droplets entering the engine combustion chamber at high pressure from piston crevices during the period when the engine is operating at low speed and the compression stroke time is longest (Amann et al SAE 2012-01-1140).

While some engine knock and pre-ignition problems can and are being addressed by using new engine technologies such as electronic control and knock sensors and by optimizing engine operating conditions, there remains a need for lubricating oil compositions that can reduce or prevent LSPI problems and also improve or maintain other properties such as wear and oxidation protection.

The present inventors have discovered a solution to the LSPI problem by using metal hydride compounds.

Disclosure of Invention

An engine lubricating oil composition for a small supercharged engine, the engine lubricating oil composition comprising a lubricating oil base stock as a major component, one or more of silicon hydride, germanium hydride and tin hydride as minor components; wherein the small engine ranges from 0.5 liters to 3.6 liters.

Also disclosed is a method for preventing or reducing low speed pre-ignition in a direct injection, supercharged, spark-ignited internal combustion engine, which method comprises the step of lubricating the engine crankcase with a lubricating oil composition comprising, based on the total weight of the lubricating oil composition, from about 25ppm to about 3000ppm of a metal or metalloid from a metal or metalloid hydrogen atom donor from one or more of silicon hydride, germanium hydride and tin hydride.

The invention further discloses the use of one or more of silicon hydride, germanium hydride and tin hydride in an engine lubricating oil composition to prevent or reduce low speed pre-ignition in a direct injection, supercharged, spark-ignited internal combustion engine.

Detailed Description

The term "boost" is used throughout the specification. Supercharging refers to operating the engine at a higher intake pressure than a naturally aspirated engine. The boost condition may be achieved by using a turbocharger (driven by exhaust gas) or a supercharger (driven by the engine). "supercharging" allows engine manufacturers to use smaller engines that provide higher power densities to provide superior performance while reducing friction and pumping losses.

The expression oil-soluble or oil-dispersible is used throughout the specification and claims. Oil-soluble or oil-dispersible means that the amount required to provide the desired level of activity or performance can be incorporated by dissolving, dispersing or suspending in an oil of lubricating viscosity. Typically, this means that at least about 0.001 wt.% of the material can be incorporated into the lubricating oil composition. For further discussion of the terms oil-soluble and oil-dispersible, particularly "stable dispersibility", see U.S. patent 4,320,019, which is expressly incorporated herein by reference for relevant teachings in this regard.

As used herein, the term "sulfated ash" refers to the non-combustible residue produced by detergents and metal additives in lubricating oils. Sulfated ash can be determined using ASTM test D874.

As used herein, the term "total base number" or "TBN" refers to the amount of base equivalent to milligrams of KOH in a gram of sample. Thus, higher TBN values reflect more alkaline products and, therefore, higher alkalinity. TBN was determined using ASTM D2896 testing.

All percentages are by weight unless otherwise indicated.

Typically, the sulfur level in the lubricating oil compositions of the present invention is less than or equal to about 0.7 wt.%, e.g., a sulfur level of from about 0.01 wt.% to about 0.70 wt.%, from 0.01 wt.% to 0.6 wt.%, from 0.01 wt.% to 0.5 wt.%, from 0.01 wt.% to 0.4 wt.%, from 0.01 wt.% to 0.3 wt.%, from 0.01 wt.% to 0.2 wt.%, from 0.01 wt.% to 0.10 wt.%, based on the total weight of the lubricating oil composition. In one embodiment, the sulfur level in the lubricating oil composition of the present invention is less than or equal to about 0.60 wt.%, less than or equal to about 0.50 wt.%, less than or equal to about 0.40 wt.%, less than or equal to about 0.30 wt.%, less than or equal to about 0.20 wt.%, less than or equal to about 0.10 wt.%, based on the total weight of the lubricating oil composition.

In one embodiment, the phosphorus level in the lubricating oil composition of the present invention is less than or equal to about 0.12 wt.%, for example, the phosphorus level is from about 0.01 wt.% to about 0.12 wt.%, based on the total weight of the lubricating oil composition. In one embodiment, the phosphorus level in the lubricating oil composition of the present invention is less than or equal to about 0.11 wt.%, for example, the phosphorus level is from about 0.01 wt.% to about 0.11 wt.%, based on the total weight of the lubricating oil composition. In one embodiment, the phosphorus level in the lubricating oil composition of the present invention is less than or equal to about 0.10 wt.%, for example, the phosphorus level is from about 0.01 wt.% to about 0.10 wt.%, based on the total weight of the lubricating oil composition. In one embodiment, the phosphorus level in the lubricating oil composition of the present invention is less than or equal to about 0.09 wt.%, for example, the phosphorus level is from about 0.01 wt.% to about 0.09 wt.%, based on the total weight of the lubricating oil composition. In one embodiment, the phosphorus level in the lubricating oil composition of the present invention is less than or equal to about 0.08 wt.%, for example, the phosphorus level is from about 0.01 wt.% to about 0.08 wt.%, based on the total weight of the lubricating oil composition. In one embodiment, the phosphorus level in the lubricating oil composition of the present invention is less than or equal to about 0.07 wt.%, for example, the phosphorus level is from about 0.01 wt.% to about 0.07 wt.%, based on the total weight of the lubricating oil composition. In one embodiment, the phosphorus level in the lubricating oil composition of the present invention is less than or equal to about 0.05 wt.%, for example, the phosphorus level is from about 0.01 wt.% to about 0.05 wt.%, based on the total weight of the lubricating oil composition.

In one embodiment, the level of sulfated ash produced by the lubricating oil composition of the present invention is less than or equal to about 1.60 wt.%, as determined by ASTM D874, for example the level of sulfated ash is from about 0.10 wt.% to about 1.60 wt.%, as determined by ASTM D874. In one embodiment, the level of sulfated ash produced by the lubricating oil composition of the present invention is less than or equal to about 1.00 wt.% as determined by ASTM D874, for example the level of sulfated ash is from about 0.10 wt.% to about 1.00 wt.% as determined by ASTM D874. In one embodiment, the level of sulfated ash produced by the lubricating oil composition of the present invention is less than or equal to about 0.80 wt.%, as determined by ASTM D874, for example the level of sulfated ash is from about 0.10 wt.% to about 0.80 wt.%, as determined by ASTM D874. In one embodiment, the level of sulfated ash produced by the lubricating oil composition of the present invention is less than or equal to about 0.60 wt.%, as determined by ASTM D874, for example the level of sulfated ash is from about 0.10 wt.% to about 0.60 wt.%, as determined by ASTM D874.

Suitably, the lubricating oil composition of the present invention may have a Total Base Number (TBN) of from 4 to 15mg KOH/g (e.g. from 5 to 12mg KOH/g, from 6 to 12mg KOH/g or from 8 to 12mg KOH/g).

Low speed pre-ignition is most likely to occur in direct injection, supercharged (turbo-or supercharged) spark-ignition (gasoline) internal combustion engines which in operation generate brake mean effective pressure (break mean effective pressure) levels greater than about 15 bar (peak torque), such as at least about 18 bar, particularly at least about 20 bar, at engine speeds of about 1500 to about 2500 revolutions per minute (rpm), such as at engine speeds of about 1500 to about 2000 rpm. As used herein, Brake Mean Effective Pressure (BMEP) is defined as the work performed during one engine cycle divided by the engine working volume; the engine torque is normalized by the engine displacement. The term "braking" means the actual torque/power available at the engine flywheel as measured on a dynamometer. Therefore, BMEP is a measure of the useful power output of the engine.

In one embodiment of the invention, the engine is operated at a speed between 500rpm and 3000rpm, or 800rpm to 2800rpm, or even 1000rpm to 2600 rpm. Further, the engine may be operated at a brake mean effective pressure of 10 to 30 bar, or 12 to 24 bar.

LSPI events, while relatively uncommon, can be catastrophic in nature. Accordingly, it is desirable to drastically reduce or even eliminate LSPI events during normal or sustained operation of a direct fuel injection engine. In one embodiment, the method of the invention results in the presence of less than 150 LSPI events per million combustion cycles (which may also be expressed as 15 LSPI events per 100,000 combustion cycles) or less than 100 LSPI events per million combustion cycles or less than 70 LSPI events per million combustion cycles or less than 60 LSPI events per million combustion cycles, or less than 50 LSPI events per million combustion cycles, or less than 40 LSPI events per million combustion cycles, less than 30 LSPI events per million combustion cycles, less than 20 LSPI events per million combustion cycles, less than 10 LSPI events per million combustion cycles, or possibly 0 LSPI events per million combustion cycles.

Accordingly, in one aspect, the present disclosure provides a method for preventing or reducing low speed pre-ignition in a direct injection, supercharged, spark-ignited internal combustion engine comprising the step of lubricating the engine crankcase with a lubricating oil composition comprising at least one metal hydride compound. In one embodiment, the amount of metal from the at least one metal hydride in the lubricating oil composition is from about 100ppm to about 3000ppm, from about 200ppm to about 3000ppm, from about 250ppm to about 2500ppm, from about 300ppm to about 2500ppm, from about 350ppm to about 2500ppm, from about 400ppm to about 2500ppm, from about 500ppm to about 2500ppm, from about 600ppm to about 2500ppm, from about 700ppm to about 2000ppm, from about 700ppm to about 1500 ppm. In one embodiment, the amount of metal from the metal or metalloid hydrogen atom donor compound in the lubricating oil composition is no more than about 2000ppm or no more than 1500 ppm.

In one embodiment, the methods of the invention reduce the number of LSPI events by at least 10%, or at least 20%, or at least 30%, or at least 50%, or at least 60%, or at least 70%, or at least 80%, or at least 90%, or at least 95% compared to oil that does not contain at least one metal hydride compound.

In another aspect, the present disclosure provides a method for reducing the severity of low speed pre-ignition events in a direct injection, boosted, spark-ignited internal combustion engine, comprising the step of lubricating the crankcase of the engine with a lubricating oil composition comprising at least one metal hydride compound. The LSPI event is determined by monitoring the peak cylinder pressure (PP) of the fuel charge in the cylinder and the crank angle for 2% mass fraction burn (MFB 02). When both criteria are met, it can be said that an LSPI event has occurred. The threshold for peak cylinder pressure varies from test to test, but is typically 4-5 standard deviations above the average cylinder pressure. Likewise, the MFB02 crank angle threshold is typically 4-5 standard deviations earlier than the average MFB02 crank angle. The LSPI events may be reported as an average event per test, an event per 100,000 combustion cycles, an event per cycle, and/or a combustion cycle per event. In one embodiment, the number of LSPI events for which MFB02 and Peak Pressure (PP) require a pressure greater than 90 bar is less than 15 events, less than 14 events, less than 13 events, less than 12 events, less than 11 events, less than 10 events, less than 9 events, less than 8 events, less than 7 events, less than 6 events, less than 5 events, less than 4 events, less than 3 events, less than 2 events, or less than 1 event per 100,000 combustion cycles. In one embodiment, the number of LSPI events greater than 90 bar is zero events, or in other words, the LSPI events greater than 90 bar are completely suppressed. In one embodiment, the number of LSPI events for which MFB02 and Peak Pressure (PP) require a pressure greater than 100 bar is less than 15 events, less than 14 events, less than 13 events, less than 12 events, less than 11 events, less than 10 events, less than 9 events, less than 8 events, less than 7 events, less than 6 events, less than 5 events, less than 4 events, less than 3 events, less than 2 events, or less than 1 event per 100,000 combustion cycles. In one embodiment, the number of LSPI events greater than 100 bar is zero events, or in other words, greater than 100 bar of LSPI events are completely suppressed. In one embodiment, the number of LSPI events for which MFB02 and Peak Pressure (PP) require a pressure greater than 110 bar is less than 15 events, less than 14 events, less than 13 events, less than 12 events, less than 11 events, less than 10 events, less than 9 events, less than 8 events, less than 7 events, less than 6 events, less than 5 events, less than 4 events, less than 3 events, less than 2 events, or less than 1 event per 100,000 combustion cycles. In one embodiment, the number of LSPI events greater than 110 bar is zero events, or in other words, LSPI events greater than 110 bar are completely suppressed. For example, per 100,000 combustion cycles, the number of LSPI events where MFB02 and Peak Pressure (PP) require a pressure that is greater than 120 bar is less than 15 events, less than 14 events, less than 13 events, less than 12 events, less than 11 events, less than 10 events, less than 9 events, less than 8 events, less than 7 events, less than 6 events, less than 5 events, less than 4 events, less than 3 events, less than 2 events, or less than 1 event. In one embodiment, the number of LSPI events greater than 120 bar is zero events, or in other words, very severe LSPI events (i.e., events greater than 120 bar) are completely suppressed.

It has now been found that the occurrence of LSPI in engines susceptible to LSPI can be reduced by lubricating such engines with a lubricating oil composition comprising a metal hydride compound.

The present disclosure also provides for the methods described herein wherein the engine is fueled with a liquid hydrocarbon fuel, a liquid nonhydrocarbon fuel, or mixtures thereof.

Lubricating oil compositions suitable for use as passenger car motor oils conventionally comprise a major amount of an oil of lubricating viscosity and a minor amount of a performance enhancing additive, including an ash-containing compound. Conveniently, the metal as described herein is incorporated into the lubricating oil compositions used in the practice of the present disclosure by one or more metal or metalloid hydrogen atom donor compounds.

Oil/base oil component of lubricating viscosity

The oil of lubricating viscosity, also referred to as a base oil, used in the lubricating oil compositions of the present disclosure is typically present in a major amount, for example, in an amount of greater than 50 wt.%, preferably greater than about 70 wt.%, more preferably from about 80 wt.% to about 99.5 wt.%, most preferably from about 85 wt.% to about 98 wt.%, based on the total weight of the composition. As used herein, the expression "base oil" should be understood to mean a base stock or blend of base stocks that is a lubricant component produced by a single manufacturer to the same specifications (regardless of feed source or manufacturer's location), that meets the same manufacturer's specifications, and that is identified by a unique formulation, product identification number, or both. The base oil for use herein can be any presently known or later-discovered oil of lubricating viscosity used to formulate lubricating oil compositions for any and all such applications, e.g., engine oils, marine cylinder oils, functional fluids (such as hydraulic oils, gear oils, transmission fluids), and the like. In addition, the base oils for use herein may optionally comprise viscosity index modifiers, such as polymerized alkyl methacrylates; olefin copolymers such as ethylene-propylene copolymers or styrene-diene copolymers; and the like and mixtures thereof.

As one skilled in the art will readily appreciate, the viscosity of the base oil depends on the application. Thus, the viscosity of the base oils used herein is typically from about 2 centistokes to about 2000 centistokes (cSt) at 100 ℃ (C). Typically, the kinematic viscosity range at 100 ℃ of the base oil used as an engine oil is from about 2cSt to about 30cSt, preferably from about 3cSt to about 16cSt, most preferably from about 4cSt to about 12cSt, alone, and will be selected or blended depending on the desired end use and the additives in the finished oil to give the desired grade of engine oil, e.g., SAE viscosity grades of 0W, 0W-4, 0W-8, 0W-12, 0W-16, 0W-20, 0W-26, 0W-30, 0W-40, 0W-50, 0W-60, 5W-20, 5W-30, 5W-40, 5W-50, 5W-60, 10W-20, 10W-30, 10W-40, 10W-50, 15W-20, 15W-30, 15W-40, 30, 40, etc.

Group I base oils typically refer to petroleum-derived lubricating base oils having a saturates content of less than 90 wt% (as determined by ASTM D2007) and/or a total sulfur content of greater than 300ppm (as determined by ASTM D2622, ASTM D4294, ASTM D4297 or ASTM D3120) and a Viscosity Index (VI) of greater than or equal to 80 and less than 120 (as determined by ASTM D2270).

Group II base oils generally refer to petroleum-derived lubricating base oils having a total sulfur content of equal to or less than 300 parts per million (ppm) (as determined by ASTM D2622, ASTM D4294, ASTM D4927, or ASTM D3120), a saturates content of equal to or greater than 90 weight percent (as determined by ASTM D2007), and a Viscosity Index (VI) between 80 and 120 (as determined by ASTM D2270).

Group III base oils generally refer to petroleum-derived lubricating base oils having a sulfur content of less than 300ppm, a saturates content of greater than 90 wt%, and a VI of 120 or more.

Group IV base oils are Polyalphaolefins (PAO).

Group V base oils include all other base oils not included in group I, II, III or IV.

The lubricating oil composition may contain minor amounts of other base oil components. For example, the lubricating oil composition may comprise minor amounts of base oils derived from natural lubricating oils, synthetic lubricating oils, or mixtures thereof. Suitable base oils include base stocks obtained by isomerization of synthetic and slack waxes, as well as hydrocracked base stocks produced by hydrocracking (rather than solvent extracting) the aromatic and polar components of the crude. Suitable natural oils include mineral lubricating oils (such as, for example, liquid petroleum oils, solvent-treated or acid-treated mineral lubricating oils of the paraffinic, naphthenic, or mixed paraffinic-naphthenic types), oils derived from coal or shale, animal oils, vegetable oils (e.g., rapeseed oils, castor oils, and lard oil), and the like.

Suitable synthetic lubricating oils include, but are not limited to: hydrocarbon oils and halo-substituted hydrocarbon oils such as polymerized and interpolymerized olefins, e.g., polybutylenes, polypropylenes, propylene-isobutylene copolymers, chlorinated polybutylenes, poly (1-hexenes), poly (1-octenes), poly (1-decenes), and the like, and mixtures thereof; alkylbenzenes such as dodecylbenzene, tetradecylbenzene, dinonylbenzene, di (2-ethylhexyl) benzene, and the like; polyphenyls such as biphenyls, terphenyls, alkylated polyphenyls, and the like; alkylated diphenyl ethers and alkylated diphenyl sulfides and the derivatives, analogs and homologs thereof and the like.

Other synthetic lubricating oils include, but are not limited to, oils made by polymerizing olefins of less than 5 carbon atoms, such as ethylene, propylene, butylenes, isobutene, pentene, and mixtures thereof. Methods for preparing such polymer oils are well known to those skilled in the art.

Additional synthetic hydrocarbon oils include liquid polymers of alpha-olefins of suitable viscosity. Particularly useful synthetic hydrocarbon oils are C₆To C₁₂Hydrogenated liquid oligomers of alpha olefins, such as, for example, 1-decene trimer.

Another class of synthetic lubricating oils includes, but is not limited to, alkylene oxidesPolymers, i.e. homopolymers, interpolymers and derivatives thereof, wherein the terminal hydroxyl groups have been modified by, for example, esterification or etherification. Examples of such oils are oils prepared by polymerization of ethylene oxide or propylene oxide, alkyl ethers and phenyl ethers of these polyoxyalkylene polymers (e.g., methyl polypropylene glycol ether having an average molecular weight of 1,000, polyethylene glycol diphenyl ether having a molecular weight of 500-1000, polypropylene glycol diethyl ether having a molecular weight of 1,000-1,500, etc.) or monocarboxylic acid esters and polycarboxylic acid esters thereof such as, for example, acetic acid esters, mixed C-s₃-C₈C of fatty acid esters or tetraethylene glycol₁₃A diester of oxo acid.

Another class of synthetic lubricating oils includes, but is not limited to: esters of dicarboxylic acids (e.g., phthalic acid, succinic acid, alkyl succinic acids, alkenyl succinic acids, maleic acid, azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid dimer, malonic acid, alkylmalonic acids, alkenyl malonic acids, etc.) with a variety of alcohols (e.g., butanol, hexanol, dodecanol, 2-ethylhexanol, ethylene glycol, diethylene glycol monoether, propylene glycol, etc.). Specific examples of such esters include dibutyl adipate, di (2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, didecyl phthalate, dieicosyl sebacate, the 2-ethylhexyl diester of linoleic acid dimer, the complex ester formed by reacting one mole of sebacic acid with two moles of tetraethylene glycol and two moles of 2-ethylhexanoic acid, and the like.

Esters useful as synthetic oils also include, but are not limited to, esters made from carboxylic acids having from about 5 to about 12 carbon atoms with alcohols (e.g., methanol, ethanol, etc.), polyols, and polyol ethers such as neopentyl glycol, trimethylolpropane, pentaerythritol, dipentaerythritol, tripentaerythritol, and the like.

Silicon-based oils such as, for example, polyalkyl-, polyaryl-, polyalkoxy-, or polyaryloxy-siloxane oils and silicate oils, constitute another useful class of synthetic lubricating oils. Specific examples of such oils include, but are not limited to, tetraethyl silicate, tetraisopropyl silicate, tetra- (2-ethylhexyl) silicate, tetra- (4-methyl-hexyl) silicate, tetra- (p-tert-butylphenyl) silicate, hexyl- (4-methyl-2-pentoxy) disiloxane, poly (methyl) siloxanes, poly (methylphenyl) siloxanes, and the like. Still other useful synthetic lubricating oils include, but are not limited to, liquid esters of phosphorus-containing acids (e.g., tricresyl phosphate, trioctyl phosphate, diethyl ester of decane phosphionic acid, etc.), polymeric tetrahydrofurans and the like.

The lubricating oil may be derived from unrefined, refined and rerefined oils, or be a mixture of two or more of any of these of the natural, synthetic or hereinbefore disclosed types. Unrefined oils are those obtained directly from a natural or synthetic source (e.g., coal, shale, or tar sands bitumen) without further purification or treatment. Examples of unrefined oils include, but are not limited to, a shale oil obtained directly from retorting operations, a petroleum oil obtained directly from distillation, or an ester oil obtained directly from an esterification process, each of which is then used without further treatment. Refined oils are similar to unrefined oils except they have been further treated in one or more purification steps to improve one or more characteristics. Such purification techniques are known to those skilled in the art and include, for example, solvent extraction, secondary distillation, acid or base extraction, filtration, percolation, hydrotreating, dewaxing, and the like. Rerefined oils are obtained by treating used oils in processes similar to those used to obtain refined oils. Such rerefined oils are also known as reclaimed or reprocessed oils and are typically additionally processed by techniques directed to the removal of spent additives and oil breakdown products.

Lubricating oil base stocks derived from the hydroisomerization of wax may also be used, either alone or in combination with the natural and/or synthetic base stocks described above. Such wax isomerate oils are produced by the hydroisomerization of natural or synthetic waxes or mixtures thereof over a hydroisomerization catalyst.

Natural waxes are typically slack waxes recovered by solvent dewaxing of mineral oils; synthetic waxes are typically waxes produced by the fischer-tropsch process.

Other useful fluids of lubricating viscosity include unconventional or unconventional base stocks that have been processed (preferably catalyzed) or synthesized to provide high performance lubricating properties.

A metal or metalloid hydrogen atom donor compound. The lubricating oil compositions herein may comprise one or more metal or metalloid hydrogen atom donor compounds selected from the group consisting of silicon hydride, germanium hydride and tin hydride.

In one aspect, the one or more metal or metalloid hydrogen atom donor compounds have the formula:

wherein R is₁、R₂And R₃Each independently selected from a hydrogen atom, a C6-C14 aryl group, a saturated OR unsaturated C1-C30 alkyl group, a C3-C10 cycloalkyl group, - (OR)₄)、-NR₅R₆、-O(＝O)R₇Or a chlorine atom, such that R₁、R₂And R₃Not more than one of which is a hydrogen atom; r₄Is C₆-C₁₄An aryl group, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, R₅Is an aryl group of H, C6-C14, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, R₆Is an aryl group of H, C6-C14, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, R₇Is a C6-C14 aryl group, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group; and M is a silicon atom, a germanium atom or a tin atom.

In one embodiment, the one or more metal or metalloid hydrogen atom donor compounds have the formula:

wherein R is₂And R₃Each independently selected from a C6-C14 aryl group, alkyl group OR C3-C10 cycloalkyl group, - (OR)₄)、-NR₅R₆、-O(＝O)R₇Or a chlorine atom, R₄Is a C6-C14 aryl group, a saturated or unsaturated C1-C30 alkyl groupA group, or a C3-C10 cycloalkyl group, R₅Is an aryl group of H, C6-C14, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, R₆Is an aryl group of H, C6-C14, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, R₇Is a C6-C14 aryl group, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group; and M is a silicon atom, a germanium atom or a tin atom.

In one embodiment, the one or more metal or metalloid hydrogen atom donor compounds have the formula:

wherein R is₁、R₂And R₃Each independently selected from a hydrogen atom, a C6-C14 aryl group, a saturated OR unsaturated C1-C30 alkyl group, a C3-C10 cycloalkyl group, - (OR)₄)、-NR₅R₆、-O(＝O)R₇Or a chlorine atom, such that R₁、R₂And R₃Not more than one of which is a hydrogen atom; r₄Is a C6-C14 aryl group, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, R₅Is an aryl group of H, C6-C14, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, R₆Is an aryl group of H, C6-C14, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, R₇Is a C6-C14 aryl group, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group.

In one embodiment, the one or more metal or metalloid hydrogen atom donor compounds have the formula:

wherein R is₂And R₃Each independently selected from a hydrogen atom, a C6-C14 aryl group, a saturated OR unsaturated C1-C30 alkyl group, a C3-C10 cycloalkyl group, - (OR)₄)、-NR₅R₆、-O(＝O)R₇Or a chlorine atom, R₄Is a C6-C14 aryl group, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, R₅Is an aryl group of H, C6-C14, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, R₆Is an aryl group of H, C6-C14, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, and R₇Is a C6-C14 aryl group, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group.

In one embodiment, the one or more metal or metalloid hydrogen atom donor compounds have the formula:

wherein R is₁、R₂And R₃Each independently selected from a hydrogen atom, a C6-C14 aryl group, a saturated OR unsaturated C1-C30 alkyl group, a C3-C10 cycloalkyl group, - (OR)₄)、-NR₅R₆、-O(＝O)R₇Or a chlorine atom, such that R₁、R₂And R₃Not more than one of which is a hydrogen atom; r₄Is a C6-C14 aryl group, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, R₅Is an aryl group of H, C6-C14, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, R₆Is an aryl group of H, C6-C14, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, R₇Is a C6-C14 aryl group, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group.

In one embodiment, the one or more metal or metalloid hydrogen atom donor compounds have the formula:

wherein R is₁、R₂And R₃Each independently selected fromA hydrogen atom, a C6-C14 aryl group, a saturated OR unsaturated C1-C30 alkyl group, a C3-C10 cycloalkyl group, - (OR)₄)、-NR₅R₆、-O(＝O)R₇Or a chlorine atom, such that R₁、R₂And R₃Not more than one of which is a hydrogen atom; r₄Is a C6-C14 aryl group, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, R₅Is an aryl group of H, C6-C14, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, R₆Is an aryl group of H, C6-C14, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group, R₇Is a C6-C14 aryl group, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group.

In one embodiment, the one or more metal or metalloid hydrogen atom donor compounds have the formula:

wherein R is₈Is a C6-C14 aryl group, a saturated or unsaturated C1-C30 alkyl group, or a C3-C10 cycloalkyl group; and n is 0 or an integer from 1 to 400.

In one embodiment, the one or more metal or metalloid hydrogen atom donor compounds have the formula:

wherein n is 0 or an integer from 1 to 400.

In one embodiment, the one or more metal or metalloid hydrogen atom donor compounds have the formula:

wherein R is₉Is a C6-C14 aryl group, a saturated or unsaturated C1-C30 alkyl group; and m is 1 to 20An integer number.

In one embodiment, the metal or metalloid hydrogen atom donor compound is a compound in which the hydride is directly bonded to the metal atom. In one embodiment, the metal hydride is not a silazane.

Generally, the amount of metal or metalloid hydrogen atom donor compound can be from about 0.001 wt.% to about 25 wt.%, from about 0.05 wt.% to about 20 wt.%, or from about 0.1 wt.% to about 15 wt.%, or from about 0.1 wt.% to about 5 wt.%, or from about 0.1 wt.% to about 4.0 wt.%, based on the total weight of the lubricating oil composition.

In one aspect, the present disclosure provides an engine lubricating oil composition for a direct injection, supercharged, spark-ignited internal combustion engine, comprising at least one metal hydride compound. In one embodiment, the amount of metal from the at least one metal or metalloid hydrogen atom donor compound is from about 25ppm to about 3000ppm, from about 100ppm to about 3000ppm, from about 200ppm to about 3000ppm, or from about 250ppm to about 2500ppm, from about 300ppm to about 2500ppm, from about 350ppm to about 2500ppm, from about 400ppm to about 2500ppm, from about 500ppm to about 2500ppm, from about 600ppm to about 2500ppm, from about 700ppm to about 2000ppm, from about 700ppm to about 1500 ppm. In one embodiment, the amount of metal from the metal or metalloid hydrogen atom donor compound is no more than about 2000ppm or no more than about 1500 ppm. The metal in each of these embodiments is selected from silicon, germanium, tin, or combinations thereof.

In one embodiment, the metal or metalloid hydrogen atom donor compound may be combined with conventional lubricating oil detergent additives comprising magnesium and/or calcium. In one embodiment, the calcium detergent in the lubricating oil composition may be added in an amount sufficient to provide the lubricating oil composition with from 0ppm to about 2400ppm calcium metal, from 0ppm to about 2200ppm calcium metal, from 100ppm to about 2000ppm calcium metal, from 200ppm to about 1800ppm calcium metal, or from about 100ppm to about 1800ppm, or from about 200ppm to about 1500ppm, or from about 300ppm to about 1400ppm, or from about 400ppm to about 1400ppm calcium metal. In one embodiment, the magnesium detergent in the lubricating oil composition may be added in an amount sufficient to provide the lubricating oil composition with from about 100ppm to about 1000ppm magnesium metal, or from about 100ppm to about 600ppm, or from about 100ppm to about 500ppm, or from about 200ppm to about 500ppm magnesium metal.

In one embodiment, the metal or metalloid hydrogen atom donor compound may be combined with a conventional lubricating oil detergent additive comprising lithium. In one embodiment, the lithium detergent in the lubricating oil composition may be added in an amount sufficient to provide the lubricating oil composition with from 0ppm to about 2400ppm lithium metal, from 0ppm to about 2200ppm lithium metal, from 100ppm to about 2000ppm lithium metal, from 200ppm to about 1800ppm lithium metal, or from about 100ppm to about 1800ppm, or from about 200ppm to about 1500ppm, or from about 300ppm to about 1400ppm, or from about 400ppm to about 1400ppm lithium metal.

In one embodiment, the metal or metalloid hydrogen atom donor compound may be combined with a conventional lubricating oil detergent additive comprising sodium. In one embodiment, the sodium detergent in the lubricating oil composition may be added in an amount sufficient to provide the lubricating oil composition with 0ppm to about 2400ppm of sodium metal, 0ppm to about 2200ppm of sodium metal, 100ppm to about 2000ppm of sodium metal, 200ppm to about 1800ppm of sodium metal, or about 100ppm to about 1800ppm, or about 200ppm to about 1500ppm, or about 300ppm to about 1400ppm, or about 400ppm to about 1400ppm of sodium metal.

In one embodiment, the metal or metalloid hydrogen atom donor compound may be combined with a conventional lubricating oil detergent additive comprising potassium. In one embodiment, the potassium detergent in the lubricating oil composition may be added in an amount sufficient to provide the lubricating oil composition with from 0ppm to about 2400ppm of potassium metal, from 0ppm to about 2200ppm of potassium metal, from 100ppm to about 2000ppm of potassium metal, from 200ppm to about 1800ppm of potassium metal, or from about 100ppm to about 1800ppm, or from about 200ppm to about 1500ppm, or from about 300ppm to about 1400ppm, or from about 400ppm to about 1400ppm of potassium metal.

In one embodiment, the present disclosure provides an engine lubricating oil composition comprising as a major component a lubricating oil base stock; and as a minor component at least one metal hydride compound; and wherein the engine exhibits a reduction in low speed pre-ignition of greater than 50% based on a normalized low speed pre-ignition (LSPI) count per 100,000 engine cycles, engine operation between 500 revolutions per minute and 3,000 revolutions per minute, and Brake Mean Effective Pressure (BMEP) between 10 bar and 30 bar, as compared to low speed pre-ignition performance achieved in an engine using a lubricating oil that does not contain at least one metal hydride compound.

In one aspect, the present disclosure provides an engine lubricating oil composition for a small supercharged engine, the engine lubricating oil composition comprising as a major component a lubricating oil basestock; and as a minor component at least one metal hydride compound; wherein the small engine ranges from about 0.5 liters to about 3.6 liters, from about 0.5 liters to about 3.0 liters, from about 0.8 liters to about 3.0 liters, from about 0.5 liters to about 2.0 liters, or from about 1.0 liters to about 2.0 liters. The engine may have two, three, four, five or six cylinders.

In one aspect, the present disclosure provides the use of at least one metal or metalloid hydrogen atom donor compound to prevent or reduce low speed pre-ignition in a direct injection, supercharged, spark-ignited internal combustion engine.

Lubricating oil additive

In addition to the metal or metalloid hydrogen atom donor compounds described herein, the lubricating oil compositions may also comprise additional lubricating oil additives.

The lubricating oil compositions of the present disclosure may also contain other conventional additives that may impart or improve any desired characteristics of the lubricating oil composition in which they are dispersed or dissolved. Any additive known to one of ordinary skill in the art may be used in the lubricating oil compositions disclosed herein. Some suitable additives have been described in the following documents: mortier et al, "Chemistry and Technology of Lubricants", 2 nd edition, London, Springer, (1996); and Leslie R.Rudnick, "scientific Additives: Chemistry and Applications," New York, Marcel Dekker (2003), both of which are incorporated herein by reference. For example, the lubricating oil composition may be blended with antioxidants, anti-wear agents, metal detergents, rust inhibitors, dehazing agents, demulsifying agents, metal deactivating agents, friction modifiers, pour point depressants, antifoaming agents, co-solvents, anti-corrosion agents, ashless dispersants, multi-functional agents, dyes, extreme pressure agents, and the like, and mixtures thereof. Various additives are known and commercially available. These additives or their analogous compounds can be used to prepare the lubricating oil compositions of the present disclosure by conventional mixing procedures.

The lubricating oil compositions of the present invention may comprise one or more detergents. Metal-containing or ash-forming detergents are useful as both detergents to reduce or remove deposits and as acid neutralizers or rust inhibitors, thereby reducing wear and corrosion and extending engine life. The cleanser typically includes a polar head and a long hydrophobic tail. The polar head comprises a metal salt of an acidic organic compound. These salts may contain a substantially stoichiometric amount of the metal, in which case they are generally described as normal or neutral salts. Large amounts of metal base can be incorporated by reacting an excess of metal compound (e.g., oxide or hydroxide) with an acidic gas (e.g., carbon dioxide).

Detergents which may be used include oil-soluble neutral and overbased sulfonates, phenates, sulfurized phenates, thiophosphonates, salicylates, and naphthenates of metals, particularly alkali or alkaline earth metals, such as barium, sodium, potassium, lithium, calcium, and magnesium, and other oil-soluble carboxylates. The most commonly used metals are calcium and magnesium (which may all be present in detergents used in lubricants) and mixtures of calcium and/or magnesium with sodium.

The lubricating oil compositions of the present invention may contain one or more antiwear agents capable of reducing friction and excessive wear. Any antiwear agent known to those of ordinary skill in the art may be used in the lubricating oil composition. Non-limiting examples of suitable antiwear agents include zinc dithiophosphates, metal (e.g., Pb, Sb, Mo, etc.) salts of dithiophosphoric acids, metal (e.g., Zn, Pb, Sb, Mo, etc.) salts of dithiocarbamic acids, metal (e.g., Zn, Pb, Sb, etc.) salts of fatty acids, boron compounds, phosphate esters, phosphite esters, amine salts of phosphate esters or thiophosphate esters, reaction products of dicyclopentadiene and thiophosphoric acids, and combinations thereof. The amount of antiwear agent may vary from about 0.01 wt.% to about 5 wt.%, from about 0.05 wt.% to about 3 wt.%, or from about 0.1 wt.% to about 1 wt.%, based on the total weight of the lubricating oil composition.

In certain embodiments, the antiwear agent is or comprises a dihydrocarbyl dithiophosphate metal salt, such as a zinc dialkyl dithiophosphate compound. The metal of the dihydrocarbyl dithiophosphate metal salt may be an alkali or alkaline earth metal, or aluminum, lead, tin, molybdenum, manganese, nickel or copper. In some embodiments, the metal is zinc. In other embodiments, the alkyl group of the dihydrocarbyl dithiophosphate metal salt has from about 3 to about 22 carbon atoms, from about 3 to about 18 carbon atoms, from about 3 to about 12 carbon atoms, or from about 3 to about 8 carbon atoms. In further embodiments, the alkyl group is linear or branched.

The amount of dihydrocarbyl dithiophosphate metal salt that includes a zinc salt of a dialkyl dithiophosphate in the lubricating oil compositions disclosed herein is measured by its phosphorus content. In some embodiments, the lubricating oil compositions disclosed herein have a phosphorus content of from about 0.01 wt.% to about 0.14 wt.%, based on the total weight of the lubricating oil composition.

The lubricating oil compositions of the present invention may contain one or more friction modifiers capable of reducing friction between moving parts. Any friction modifier known to those of ordinary skill in the art may be used in the lubricating oil composition. Non-limiting examples of suitable friction modifiers include fatty carboxylic acids; derivatives of fatty carboxylic acids (e.g., alcohols, esters, borates, amides, metal salts, etc.); mono-, di-or tri-alkyl substituted phosphoric or phosphonic acids; derivatives (e.g., esters, amides, metal salts, etc.) of mono-, di-, or tri-alkyl substituted phosphoric or phosphonic acids; mono-, di-or tri-alkyl substituted amines; mono-or di-alkyl substituted amides and combinations thereof. In some embodiments, examples of friction modifiers include, but are not limited to, alkoxylated fatty amines; borated fatty epoxides; fatty phosphites, fatty epoxides, fatty amines, borated alkoxylated fatty amines, fatty acid metal salts, fatty acid amides, glycerol esters, borated glycerol esters; and fatty imidazolines, as disclosed in U.S. Pat. No. 6,372,696, which is incorporated herein by referenceThe contents of which are incorporated herein by reference; from C₄To C₇₅Or C₆To C₂₄Or C₆To C₂₀A friction modifier obtained from the reaction product of a fatty acid ester and a nitrogen-containing compound selected from the group consisting of ammonia, alkanolamines, and the like, and mixtures thereof. The amount of friction modifier may vary from about 0.01 to about 10 wt.%, from about 0.05 to about 5 wt.%, or from about 0.1 to about 3 wt.%, based on the total weight of the lubricating oil composition.

The lubricating oil compositions of the present disclosure may comprise a molybdenum-containing friction modifier. The molybdenum-containing friction modifier can be any of the known molybdenum-containing friction modifiers or known molybdenum-containing friction modifier compositions.

Preferred molybdenum-containing friction modifiers are, for example, oxymolybdenum dithiocarbamate sulfide, oxymolybdenum dithiophosphate sulfide, amine-molybdenum complex compounds, oxymolybdenum diethylate, and oxymolybdenum monoglyceride. Most preferred are molybdenum dithiocarbamate friction modifiers.

The lubricating oil compositions of the present invention typically comprise a molybdenum-containing friction modifier in an amount of from 0.01 wt.% to 0.15 wt.%, based on the molybdenum content.

The lubricating oil composition of the present invention preferably comprises the organic oxidation inhibitor in an amount of 0.01 wt.% to 5 wt.%, preferably 0.1 wt.% to 3 wt.%. The oxidation inhibitor may be a hindered phenol oxidation inhibitor or a diarylamine oxidation inhibitor. Diarylamine oxidation inhibitors are advantageous in providing a base number derived from a nitrogen atom. The hindered phenol oxidation inhibitor is advantageous in that no NOx gas is generated.

Examples of the hindered phenol oxidation inhibitor include 2, 6-di-t-butyl-p-cresol, 4 '-methylenebis (2, 6-di-t-butylphenol), 4' -methylenebis (6-t-butyl-o-cresol), 4 '-isopropylidenebis (2, 6-di-t-butylphenol), 4' -bis (2, 6-di-t-butylphenol), 2 '-methylenebis (4-methyl-6-t-butylphenol), 4' -thiobis (2-methyl-6-t-butylphenol), 2-thiodiethylene-bis [3- (3, 5-di-t-butyl-4-hydroxyphenyl) propionate]Octyl 3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, octadecyl 3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate and 3- (3, 54)Octyl-butyl-4-hydroxy-3-methylphenyl) propionate and commercial products such as, but not limited to, Irganox(BASF)、Naugalube(Chemtura) and Ethanox(SI Group)。

Examples of diarylamine oxidation inhibitors include alkyldiphenylamines having a mixture of alkyl groups of 3 to 9 carbon atoms, p-dioctyldiphenylamines, phenyl-naphthylamines, alkylated-naphthylamines, and alkylated phenyl-naphthylamines. The diarylamine oxidation inhibitor can have 1 to 3 alkyl groups.

Each of the hindered phenol oxidation inhibitor and the diarylamine oxidation inhibitor may be used alone or in combination. If desired, other oil-soluble oxidation inhibitors may be used in combination with the above-described oxidation inhibitors.

The lubricating oil compositions of the present invention may also comprise an oxymolybdenum complex of succinimide, particularly a sulfur-containing oxymolybdenum complex of succinimide. When the sulfur-oxygen-containing molybdenum complex of succinimide is used in combination with the above-mentioned phenolic or amine-based oxidation inhibitor, enhanced oxidation inhibition can be provided.

In the preparation of lubricating oil formulations, it is common practice to incorporate additives in the form of a 10% to 80% by weight active ingredient concentrate in a hydrocarbon oil (e.g., mineral lubricating oil or other suitable solvent).

Typically, these concentrates may be diluted with from 3 to 100 parts by weight, such as from 5 to 40 parts by weight, of lubricating oil per part by weight additive package when forming a finished lubricant (e.g., crankcase oil). The purpose of the concentrate is, of course, to make handling of the various materials less difficult and awkward and to facilitate dissolution or dispersion in the final mixture.

Process for preparing lubricating oil compositions

The lubricating oil compositions disclosed herein can be prepared by any method known to those of ordinary skill in the art for preparing lubricating oils. In some embodiments, the base oil may be blended or mixed with the metal or metalloid hydrogen atom donor compounds described herein. Optionally, one or more further additives may be added in addition to the metal or metalloid hydrogen atom donor compound. The metal or metalloid hydrogen atom donor compound and optional additives may be added to the base oil separately or simultaneously. In some embodiments, the metal or metalloid hydrogen atom donor compound and optional additives are added separately in one or more additions to the base oil, and the additions may be in any order. In other embodiments, the metal or metalloid hydrogen atom donor compound and the additive are added to the base oil simultaneously, optionally in the form of an additive concentrate. In some embodiments, the dissolution of the metal or metalloid hydrogen atom donor compound or any solid additive in the base oil may be aided by heating the mixture to a temperature of from about 25 ℃ to about 200 ℃, from about 50 ℃ to about 150 ℃, or from about 75 ℃ to about 125 ℃.

Any mixing or dispersing apparatus known to those of ordinary skill in the art may be used to blend, mix, or dissolve the ingredients. Blending, mixing, or dissolving may be performed with a blender, stirrer, disperser, mixer (e.g., planetary mixer and double planetary mixer), homogenizer (e.g., Gaulin homogenizer and Rannie homogenizer), mill (e.g., colloid mill, ball mill, and sand mill), or any other mixing or dispersing device known in the art.

Use of lubricating oil compositions

The lubricating oil compositions disclosed herein may be suitable for use as engine oil (i.e., engine oil or crankcase oil) in spark-ignited internal combustion engines, particularly direct-injection supercharged engines that are susceptible to low-speed pre-ignition.

The following examples are presented to illustrate embodiments of the invention, but are not intended to limit the invention to the specific embodiments set forth. Unless stated to the contrary, all parts and percentages are by weight. All numerical values are approximate. When numerical ranges are given, it should be understood that embodiments outside the stated ranges may still fall within the scope of the invention. The specific details described in each embodiment should not be construed as essential features of the invention.

Examples

The following examples are intended for illustrative purposes only and are not intended to limit the scope of the present invention in any way.

Test compounds were blended in lubricating oils and their ability to reduce LSPI events was determined using the test method described below.

The low speed pre-ignition event was measured in a Ford 2.0L Ecoboost engine. The engine is a turbocharged Gasoline Direct Injection (GDI) engine. The ford Ecoboost engine was run in four iterations of approximately 4 hours. The engine was operated at 1750rpm and 1.7MPa Brake Mean Effective Pressure (BMEP) with an oil sump temperature of 95 ℃. The engine was run for 175,000 combustion cycles per phase and LSPI events were calculated.

The LSPI event is determined by monitoring the peak cylinder pressure (PP) of the fuel charge in the cylinder and the crank angle for 2% mass fraction burn (MFB 02). When both criteria are met, it can be said that an LSPI event has occurred. The threshold for peak cylinder pressure varies from test to test, but is typically 4-5 standard deviations above the average cylinder pressure. Likewise, the MFB02 threshold is typically 4-5 standard deviations earlier than the average MFB02 (in crank degrees). The LSPI events may be reported as an average event per test, an event per 100,000 combustion cycles, an event per cycle, and/or a combustion cycle per event. The results of this test are shown below.

Additives associated with test lubricants that reduce LSPI frequency are considered LSPI frequency mitigating additives when compared to the corresponding baseline lubricant. The test results are listed in table 1.

Baseline formulation

The baseline formulation comprised a group 2 base oil, a mixture of primary and secondary zinc dialkyldithiophosphates in an amount to provide 737ppm to 814ppm phosphorus to the lubricating oil composition, a mixture of polyisobutenyl succinimide dispersants (borated and ethylene carbonate post-treatment), a molybdenum succinimide complex, an alkylated diphenylamine antioxidant, a borated friction modifier, a foam inhibitor, a pour point depressant and an olefin copolymer viscosity index improver.

The lubricating oil composition is blended into a 5W-30 viscosity grade oil.

Metal or metalloid hydrogen atom donor compounds A

(triphenylsilane)

Triphenylsilanes are available from MilliporeOrAre commercially available.

Metal or metalloid hydrogen atom donor compounds B

(Tributylgermane)

Tributylgermane is available from MilliporeAre commercially available.

Example 1

Lubricating oil compositions were prepared by adding 458ppm of silicon from triphenylsilane and 2164ppm of calcium from the combination of overbased calcium sulfonate and phenate detergent to the baseline formulation.

Comparative example 1

Lubricating oil compositions were prepared by adding 2255ppm of calcium from the combination of overbased calcium sulfonate and phenate detergent to the baseline formulation.

Example 2

Lubricating oil compositions were prepared by adding 1483ppm germanium from tributylgermane and 2204ppm calcium from a combination of overbased calcium sulfonate and phenate detergent to the baseline formulation.

TABLE 1 LSPI test results in the Ford LSPI test

Calculate all LSPI cycles that meet both MFB02 and peak pressure requirements.

The data shows that applicants' inventive examples containing the metal or metalloid hydrogen atom donor compounds of the present disclosure provide significantly better LSPI performance in both number of events and number of severe LSPI events compared to comparative examples that do not contain a metal or metalloid hydrogen atom donor in ford engines. The severity is reduced by reducing the number of high pressure events (i.e. over 120 bar) that may damage the engine.