CN110892050A

CN110892050A - Method for improving resistance to timing chain wear with multi-component detergent system

Info

Publication number: CN110892050A
Application number: CN201880045399.1A
Authority: CN
Inventors: 克里斯汀·弗莱彻; 保罗·兰塞姆; 纪尧姆·卡朋特
Original assignee: Afton Chemical Corp
Current assignee: Afton Chemical Corp
Priority date: 2017-06-05
Filing date: 2018-02-28
Publication date: 2020-03-17
Anticipated expiration: 2038-02-28
Also published as: US20180346839A1; CN110892050B; EP3635081B1; JP2020522585A; JP7023296B2; CA3066114A1; WO2018226277A1; EP3635081A1

Abstract

A method for reducing timing chain stretch in an engine comprising the step of lubricating the timing chain with a lubricating oil composition comprising a major amount of a base oil; and a minor amount of an additive package comprising at least one overbased calcium phenate detergent having a total base number of at least 150mg KOH/g as measured by the method of ASTM D-2896, at least one calcium sulfonate detergent; and at least one magnesium-containing detergent. The lubricating oil composition has a weight ratio of total calcium from the at least one calcium sulfonate detergent to total calcium and magnesium in the lubricating oil composition of about 0.06 to less than about 0.45.

Description

Method for improving resistance to timing chain wear with multi-component detergent system

Technical Field

The present disclosure relates to methods of reducing timing chain stretch using lubricating compositions, and to lubricating oil compositions and lubricating oil additive compositions for lubricating timing chains.

Background

There may be a metal chain, also known as a timing chain, in an internal combustion engine, which includes bearing pins, rollers, bushings, and inner and outer plates. Due to the considerable loads and friction exerted on these components, timing chains are susceptible to considerable wear, including corrosive wear. To address this problem, lubricants are formulated to reduce wear between moving parts where there is metal-to-metal contact.

Chain elongation or timing chain stretching is a phenomenon that exists in an internal combustion engine having a timing chain that deteriorates due to wear. Chain elongation occurs primarily at the pin, bushing and side plate wear contact interface. Timing chain stretch can cause significant problems in internal combustion engine operation and can have an impact on engine performance, fuel economy, and emissions.

Timing chain stretch may cause deviations from the desired timing of components operably connected to the timing chain. The deviation may be caused, for example, by the chain skipping one or more sprockets during operation, or by exceeding the adjustability of the cam phaser. These deviations can change the relative timing of the valves and the ignition. Intake valve timing affects when air and/or fuel mixture is drawn into the cylinder. Exhaust valve timing affects power output because if the exhaust valve is not opened at the proper time, power may be lost because gas escapes through the exhaust valve. In addition, when the exhaust valve is not timed correctly, unburned hydrocarbon emissions may increase, as unburned fuel gas may escape via the exhaust valve in such situations.

In research on lubricating effect on Wear of a Timing Chain of a Diesel Engine (Investigation of lubricating effect on a Diesel Engine lubricating Chain Wear), Polat, Ozay, M.Sc. University of Istanibul scientific and technological Institute of Science and technology (2008, 1), the effect of different base oils on Wear of a Timing Chain of a Diesel Engine was studied. This paper concludes that the choice of base oil can affect timing chain wear in diesel engines.

Timing chain wear in light-duty diesel engines is due to a number of factors, one of which is the contribution of soot to abrasion. Li, Shoutian et al, "Wear in Cummins M-11/EGR test engines (Wear in Cummins M-11/EGR)," Society of Automotive Engineers (Inc.) (2001), paper No. 2002-01-1672. This article mentions that in engines with Exhaust Gas Recirculation (EGR) systems, soot causes erosion of the liners, crosshead and top ring surfaces. The article also mentions that soot induced wear in non-EGR diesel engines is mainly concentrated on roll pin wear in GM 6.2L engines and crosshead wear in Cummins M-11 engines.

Timing chain stretching in gasoline engines is typically caused by roller pin wear. As a result, prior art methods for addressing timing chain stretching typically focus on the use and selection of antiwear agents. In TGDi engines, soot is a byproduct of gasoline engine combustion, and thus timing chain stretching can occur in the engine due to soot generation and resulting wear (specifically roll pin wear).

In some cases, dispersants and dispersant viscosity index improvers have been used to address the wear problem. For example, U.S. patent No. 7,572,200B 2 discloses a chain drive system that employs a lubricant designed to coat sliding parts of the system (including chains and sprockets) with a thin hard carbon coating film having a hydrogen content of 10 atomic% or less to reduce the amount of friction and wear on the chain drive system.

U.S. Pat. No. 8,771,119B 2 discloses a lubricating composition for chains comprising 80 to 95 mass% of a lubricant that is liquid at room temperature and 5 to 20 mass% of a wax that is solid at room temperature. It is stated that the addition of wax provides better abrasion resistance and provides elongation resistance and longer life to the chain.

U.S. patent No. 7,053,026B 2 discloses a method for lubricating a conveyor chain system. Conveyor chains may be exposed to high temperatures and often require polyol ester based lubricants. This patent focuses on reducing chain wear and minimizing deposits on the chain surfaces by using a mixture of mineral oil, poly (isobutylene) and polyol esters.

The aforementioned references do not provide a suitable solution for minimizing timing chain stretch in an internal combustion engine. For example, it has been found that the protection provided by the use of the dispersants proposed for this purpose is not sufficient to prevent timing chain stretching. Accordingly, the present disclosure provides a method of employing a calcium detergent and detergent combination to provide a greater reduction in timing chain stretch than that provided by conventional combinations of antiwear agents and/or dispersants.

Disclosure of Invention

In a first aspect, disclosed is a method for reducing timing chain stretch of a timing chain in an engine, comprising the step of lubricating the timing chain with a lubricating oil composition comprising:

a major amount of a base oil; and

a minor amount of an additive package comprising:

a) at least one overbased calcium phenate detergent having a total base number of at least 150mg KOH/g as measured by the method of ASTM D-2896;

b) at least one calcium sulfonate detergent; and

c) at least one magnesium-containing detergent.

The lubricating oil composition has a weight ratio of total calcium from the at least one calcium sulfonate detergent to total calcium and magnesium in the lubricating oil composition of about 0.06 to less than about 0.45.

In the foregoing embodiments, the at least one magnesium-containing detergent may be overbased, having a total base number of at least 225mgKOH/g, or at least about 300mg KOH/g or from about 350 to about 500mg KOH/g, all as measured by the method of ASTM D-2896.

In each of the foregoing embodiments, the at least one magnesium-containing detergent may be selected from the group consisting of overbased magnesium phenates, overbased sulfur-containing magnesium phenates, overbased magnesium sulfonates, overbased magnesium calixarates, overbased magnesium salicylates, overbased magnesium carboxylates, overbased magnesium phosphites, overbased magnesium monosulfosulfates and/or dithiophosphates, overbased magnesium alkylphenates, overbased sulfur-coupled alkyl phenol magnesium compounds, overbased methylene bridged magnesium phenates, and combinations thereof.

In each of the foregoing embodiments, the at least one calcium phenate detergent may be overbased with a total base number of at least 150mg KOH/g or at least about 225mg KOH/g, at least 225mg KOH/g to about 400mg KOH/g, at least about 225mg KOH/g to about 350mg KOH/g, or about 230 to about 350mg KOH/g, all as measured by the method of ASTM D-2896.

In each of the foregoing embodiments, the at least one calcium sulfonate detergent may be overbased with a total base number of at least 225mg KOH/g, or from about 225 to about 500mg KOH/g, or from about 290 to about 500mg KOH/g, or from about 250mg KOH/g to about 400mg KOH/g, or from about 300mg KOH/g to about 400mg KOH/g, as measured by the method of ASTM D-2896.

In each of the foregoing embodiments, the weight ratio of total calcium from the at least one calcium sulfonate detergent of the lubricating oil composition to total calcium and magnesium in the lubricating oil composition may be from about 0.06 to about 0.4 or from about 0.06 to about 0.35.

In each of the foregoing embodiments, the additive package may further comprise one or more additives selected from the group consisting of: antioxidants, friction modifiers, pour point depressants, and viscosity index improvers.

In each of the foregoing embodiments, the antioxidant may be an oil soluble molybdenum complex, or an organo-molybdenum complex of an organo-amide, or a sulfur-free organo-molybdenum complex of an organo-amide.

In each of the foregoing embodiments, the base oil may have an SAE J300 viscosity grade of 5W-X or 0W-X, and the lubricating oil composition may include one or more antioxidants selected from the group consisting of aromatic amines, alkylated diphenylamines, phenyl- α -naphthylamine, alkylated phenyl- α -naphthylamine, and alkylated arylamines, nonyldiphenylamines, dinonyldiphenylamines, octyldiphenylamines, and dioctyldiphenylamines.

In each of the foregoing embodiments, the lubricating oil composition may contain from about 50ppm to about 1650ppm, or from about 80ppm to about 1250ppm, or from about 100ppm to about 900ppm, by total weight of the lubricating oil composition, of calcium provided by the at least one calcium sulfonate detergent.

In each of the foregoing embodiments, the lubricating oil composition may contain from about 100ppm to about 2000ppm, or from about 250ppm to about 1800ppm, or from about 600ppm to about 1500ppm, by total weight of the lubricating oil composition, of calcium provided by the at least one calcium phenate detergent.

In each of the foregoing embodiments, the lubricating oil composition may contain from about 400ppm to about 2200ppm, or from about 500ppm to about 1700ppm, or from about 600ppm to about 1400ppm, or less than 1400ppm, of calcium provided by all overbased calcium-containing detergents, based on the total weight of the lubricating oil composition.

In each of the foregoing embodiments, the total amount of calcium in the lubricating oil composition may be from about 1000ppm to less than about 3090ppm, or from about 1200ppm to about 2000ppm, or from about 1300ppm to about 1600 ppm.

In each of the foregoing embodiments, the lubricating oil composition may contain from about 50ppm to about 1650ppm, or from about 80ppm to about 1250ppm, or from about 250ppm to about 1100ppm, by weight of the total lubricating oil composition, of magnesium provided by the at least one magnesium-containing detergent.

In each of the foregoing embodiments, the lubricating oil composition may contain a total of from about 500ppm to less than 3100ppm, or from about 800ppm to about 3000ppm, or from about 1500ppm to about 2700ppm of magnesium and calcium, based on the total weight of the lubricating oil composition.

In each of the foregoing embodiments, the base oil may be at least one selected from the group consisting of: group II base oils, group III base oils, group IV base oils, and group V base oils. In each of the foregoing embodiments, the lubricating oil composition may include greater than 50 wt.% of a group II base oil, a group III base oil, or a combination thereof, or greater than 80 wt.% or greater than 90 wt.% of a group II base oil, a group III base oil, or a combination thereof.

In each of the foregoing embodiments, the lubricating oil composition may further comprise a metal dialkyldithiophosphate or zinc dialkyldithiophosphate.

In each of the foregoing embodiments, the lubricating oil composition may include no more than 10 wt.% of a group IV base oil, a group V base oil, or a combination thereof.

In each of the foregoing embodiments, the lubricating oil composition may include less than 5 wt.% of group V base oil.

In each of the foregoing embodiments, the overbased calcium-containing detergent may optionally not comprise an overbased calcium salicylate detergent.

In each of the foregoing embodiments, the lubricating oil composition may not contain any group IV base oil.

In each of the foregoing embodiments, the lubricating oil composition may not contain any group V base oil.

In each of the foregoing embodiments, the engine may be a spark ignition engine.

In each of the foregoing embodiments, the engine may be a spark ignition passenger car gasoline engine.

In each of the foregoing embodiments, each of the lubricating oil compositions may be capable of reducing timing chain stretch in an engine to 0.1% or less, or 0.1% to 0.01%, as measured by a ford chain Wear Test (FordChain Wear Test) for 216 hours.

Additional features and advantages of the disclosure may be set forth in part in the description which follows, and/or may be learned by practice of the disclosure. The features and advantages of the disclosure may be further realized and obtained by means of the elements and combinations particularly pointed out in the appended claims.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed.

Detailed Description

The following definitions of terms are provided to clarify the meaning of certain terms as used herein.

The terms "oil composition", "lubricating oil", "lubricant composition", "lubricating composition", "fully formulated lubricant composition", "lubricant", "crankcase oil", "crankcase lubricant", "engine oil", "engine lubricant", "motor oil" and "motor lubricant" are considered to be fully interchangeable synonymous terms, all referring to the finished lubricating product comprising a major amount of base oil plus a minor amount of additive composition.

As used herein, the terms "additive package", "additive concentrate", "additive composition", "oil additive package", "oil additive concentrate", "crankcase additive package", "crankcase additive concentrate", "motor oil additive package", "motor oil concentrate" are considered to be synonymous terms that are fully interchangeable, all referring to the portion of the lubricating composition that does not contain a major amount of a base oil stock mixture. The additive package may or may not comprise a viscosity index improver or pour point depressant.

As used herein, the term "hydrocarbyl substituent" or "hydrocarbyl group" is used in its ordinary sense as is well known to those skilled in the art. Specifically, it refers to a group having a carbon atom directly attached to the rest of the molecule and having predominantly hydrocarbon character. Examples of hydrocarbyl groups include:

(a) hydrocarbon substituents, that is, aliphatic substituents (e.g., alkyl or alkenyl), alicyclic (e.g., cycloalkyl, cycloalkenyl) substituents, and aromatic substituents substituted with aromatic, aliphatic, and alicyclic groups, as well as cyclic substituents wherein the ring is completed through another portion of the molecule (e.g., two substituents together form an alicyclic moiety);

(b) substituted hydrocarbon substituents, that is, substituents containing non-hydrocarbon groups which do not alter the predominantly hydrocarbon substituent in the context of this disclosure (e.g., halo (especially chloro and fluoro), hydroxy, alkoxy, mercapto, alkylmercapto, nitro, nitroso, amino, alkylamino, and sulfoxy); and

(c) hetero substituents, that is, substituents that, while having predominantly hydrocarbon character in the context of this disclosure, contain atoms other than carbon in a ring or chain otherwise composed of carbon atoms. Heteroatoms can include sulfur, oxygen, and nitrogen, and encompass substituents as pyridyl, furyl, thienyl and imidazolyl. In general, no more than two, e.g., no more than one, non-hydrocarbon substituent will be present for every ten carbon atoms in the hydrocarbyl group; typically, no non-hydrocarbon substituents will be present in the hydrocarbyl group.

As used herein, unless otherwise expressly specified, the term "weight percent" means the percentage of the stated component by weight of the entire composition.

The terms "soluble", "oil-soluble" or "dispersible" as used herein may, but do not necessarily, indicate that the compound or additive is soluble, miscible or capable of being suspended in all proportions in the oil. However, the foregoing terms actually mean that they are, for example, soluble, suspendable, dissolvable or stably dispersible in oil to an extent sufficient to perform their intended function in the environment in which the oil is employed. Furthermore, the additional incorporation of other additives may also allow for the incorporation of higher levels of particular additives, if desired.

The term "TBN" as used herein is used to denote the total base number in mg KOH/g of the composition as measured by the method of ASTM D2896.

The term "alkyl" as used herein refers to a straight, branched, cyclic, and/or substituted saturated chain moiety of from about 1 to about 100 carbon atoms.

The term "alkenyl" as used herein refers to a straight, branched, cyclic and/or substituted unsaturated chain moiety of about 3 to about 10 carbon atoms.

The term "aryl" as employed herein refers to monocyclic and polycyclic aromatic compounds which may contain alkyl, alkenyl, alkaryl, amino, hydroxyl, alkoxy, and halo substituents, and/or heteroatoms including, but not limited to, nitrogen, oxygen, and sulfur.

Unless otherwise indicated, all percentages are weight percentages, all ppm values are parts per million by weight (ppmw) and all molecular weights are number average molecular weights.

It must be noted that, as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Furthermore, the terms "a" (or "an"), "one or more" and "at least one" are used interchangeably herein. The terms "comprising," "including," "having," and "consisting of" are also used interchangeably.

It is to be understood that each component, compound, substituent or parameter disclosed herein is to be understood as being disclosed for use alone or in combination with one or more of each other component, compound, substituent or parameter disclosed herein.

It is also to be understood that each amount/value or range of amounts/values for each component, compound, substituent or parameter disclosed herein is to be construed as also disclosed in combination with each amount/value or range of amounts/values disclosed for any other component, compound, substituent or parameter disclosed herein, and any combination of amounts/values or ranges of amounts/values for two or more components, compounds, substituents or parameters disclosed herein is therefore also disclosed in combination with each other for the purposes described herein.

It will also be understood that each lower limit of each range disclosed herein can be understood as being disclosed in combination with each upper limit of each range disclosed herein for the same component, compound, substituent or parameter. Accordingly, the disclosure of two ranges should be construed as a disclosure of four ranges by combining each lower limit of each range with each upper limit of each range. Disclosure of three ranges should be construed as disclosure of nine ranges by combining each lower limit of each range with each upper limit of each range, and the like. Additionally, the particular amounts/values of a component, compound, substituent or parameter disclosed in the specification or examples are to be interpreted as disclosing either a lower limit or an upper limit of the range, and thus may be combined with any other lower limit or upper limit or particular amount/value of the range for the same component, compound, substituent or parameter disclosed elsewhere in this application to form a range for that component, compound, substituent or parameter.

The lubricants, combinations of components, or individual components of the present description may be suitable for lubricating timing chains in various types of internal combustion engines. The internal combustion engine may be a gasoline fueled engine, a mixed gasoline/biofuel fueled engine, an alcohol fueled engine, or a mixed gasoline/alcohol fueled engine. The gasoline engine may be a spark ignition engine. Internal combustion engines may also be used in combination with electric or battery power sources. An engine so configured is commonly referred to as a hybrid engine. The internal combustion engine may be a 2-stroke, 4-stroke or rotary engine. Suitable internal combustion engines include marine engines, aviation piston engines, and motorcycle, automobile, locomotive and truck engines.

Internal combustion engines may contain components of one or more of aluminum alloys, lead, tin, copper, cast iron, magnesium, ceramics, stainless steel, composites, and/or mixtures thereof. The composition may be coated with, for example, a diamond-like carbon coating, a lubricious coating, a phosphorous-containing coating, a molybdenum-containing coating, a graphite coating, a nanoparticle-containing coating, and/or mixtures thereof. The aluminum alloy may comprise aluminum silicate, aluminum oxide, or other ceramic material. In one embodiment, the aluminum alloy is an aluminum silicate surface. As used herein, the term "aluminum alloy" is intended to be synonymous with "aluminum composite" and describes a component or surface that includes aluminum and another component that intermix or react at the microscopic or near-microscopic level, regardless of their specific structure. This would include any conventional alloy having a metal other than aluminum and having a composite or alloy-like structure of non-metallic elements or compounds (e.g., having a ceramic-like material).

The lubricant compositions of the present disclosure may be suitable for use in any engine regardless of the sulfur, phosphorus, or sulfated ash (ASTM D-874) content. The lubricating oil may have a sulfur content of about 1 wt.% or less, or about 0.8 wt.% or less, or about 0.5 wt.% or less, or about 0.3 wt.% or less. In one embodiment, the sulfur content may range from about 0.001 wt% to about 0.5 wt%, or from about 0.01 wt% to about 0.3 wt%. The phosphorus content may be about 0.5 wt% or less, or about 0.1 wt% or less, or about 0.094 wt% or less, or about 0.001 wt% to about 0.5 wt%, or about 0.01 wt% to about 0.1 wt%.

In one embodiment, the phosphorus content of the lubricant compositions of the present disclosure may be from about 100ppm to about 1000ppm, or from about 325ppm to about 950 ppm. The total sulfated ash content may be about 2 wt.% or less, or about 1.5 wt.% or less, or about 1.2 wt.% or less. In one embodiment, the sulfated ash content may be from about 0.05 wt.% to about 1.5 wt.%, or from about 0.1 wt.% or from about 0.2 wt.% to about 1.15 wt.%. In another embodiment, the sulfur content may be about 0.4 wt.% or less, the phosphorus content may be about 0.08 wt.% or less, and the sulfated ash is about 1.2 wt.% or less. In yet another embodiment, the sulfur content may be about 0.3 wt.% or less, the phosphorus content is about 0.05 wt.% or less, and the sulfated ash may be about 1.15 wt.% or less.

In one embodiment, the timing chain lubricating composition is also suitable for use as an engine oil, for example, for lubrication of the crankcase of an engine. In other embodiments, the lubricating composition may have (i) a sulfur content of about 0.5 wt% or less, (ii) a phosphorus content of about 0.1 wt% or less, and (iii) a sulfated ash content of about 1.5 wt% or less.

In some embodiments, the lubricating composition is not suitable for use in a 2-stroke or 4-stroke marine diesel internal combustion engine for one or more reasons including, but not limited to, high sulfur content of the fuel used to power the marine engine, and high TBN required for marine-compatible engine oils (e.g., greater than about 40TBN in marine-compatible engine oils).

In some embodiments, the lubricating composition is suitable for use in engines powered by low sulfur fuels (e.g., fuels containing about 1 to about 5% sulfur). Highway vehicle fuels contain about 15ppm sulfur (or about 0.0015% sulfur).

The lubricants of the present specification may be suitable for meeting one or more industry specification requirements, such as ILSAC GF-3, GF-4, GF-5, GF-6, PC-11, CI-4, CJ-4, ACEAA1/B1, A2/B2, A3/B3, A5/B5, C1, C2, C3, C4, E4/E6/E7/E9, Euro 5/6, Jaso DL-1, Low SAPS, Mid SAPS, or original equipment manufacturer specifications, such as Dexos^TM1、Dexos^TM2、MB-Approval 229.51/229.31、VW 502.00、503.00/503.01、504.00、505.00、506.00/506.01、507.00、BMW Longlife-04、Porsche C30、Peugeot

Automobiles B712290, Ford WSS-M2C153-H, WSS-M2C930-A, WSS-M2C945-A, WSS-M2C913A, WSS-M2C913-B, WSS-M2C913-C, GM 6094-M, Chrysler MS-6395, or any past or future PCMO or HDD specification not mentioned herein. In some embodiments of Passenger Car Motor Oil (PCMO) applications, the amount of phosphorus in the finished fluid is 1000ppm or less or 900ppm or less or 800ppm or less.

Other hardware may not be suitable for use with the disclosed lubricant. "functional fluid" is a term that encompasses a variety of fluids, including but not limited to tractor hydraulic fluid; a power transmission fluid comprising: automatic transmission fluids, infinitely variable transmission fluids, and manual transmission fluids; a hydraulic fluid comprising a tractor hydraulic fluid; some gear oil; a power steering fluid; fluids for wind turbines, compressors; some industrial fluids; and a fluid associated with the driveline component. It should be noted that within each category of these fluids (e.g., automatic transmission fluids), there are many different types of fluids because of the various transmissions having different designs, which result in the need for fluids having significantly different functional characteristics. This is in contrast to the term "lubricating fluid" which is not used to generate or transmit power.

When the functional fluid is an automatic transmission fluid, the automatic transmission fluid must have sufficient friction for the clutch plates to transmit power. However, as the fluid heats up during operation, the coefficient of friction of the fluid tends to decrease due to temperature effects. It is important that the tractor hydraulic fluid or automatic transmission fluid maintain its high coefficient of friction at high temperatures, otherwise the brake system or automatic transmission may fail. This is not a function of the lubricating oil of the present invention.

Tractor fluids, and for example Super Tractor Universal Oil (STUO) or Universal Tractor Transmission Oil (UTTO), can combine the performance of engine Oil with the performance of the Transmission, differential, final drive planetary gears, wet brakes, and hydraulics. While many of the additives used to formulate a UTTO or STUO fluid are functionally similar, they can have deleterious effects if not properly combined. For example, some anti-wear and extreme pressure additives may be extremely corrosive to copper components in hydraulic pumps. Detergents and dispersants used for gasoline or diesel engine performance can be detrimental to wet brake performance. Friction modifiers dedicated to eliminating wet brake noise may not have the thermal stability required for oil performance. Each of these fluids, whether functional, tractor or lubricating, is designed to meet specific and stringent manufacturer requirements.

In one embodiment, the present disclosure provides a method for reducing timing chain stretch of a timing chain in an engine, comprising the step of lubricating the timing chain with a lubricating oil composition comprising:

a major amount of a base oil; and

a minor amount of an additive package comprising:

b) at least one calcium sulfonate detergent; and

c) at least one magnesium-containing detergent.

Embodiments of the present disclosure may provide improvements in the following features: timing chain stretch or elongation, sludge and/or soot dispersancy and friction reduction, as well as air entrainment, alcohol fuel compatibility, oxidation resistance, anti-wear properties, biofuel compatibility, foam reduction characteristics, fuel combustion efficiency, deposit reduction, pre-ignition prevention, rust protection, and water resistance.

Lubricating oils suitable for use in the methods of the present disclosure may be formulated by adding additives (as described in detail below) to an appropriate base oil formulation. The additives may be combined with the base oil in one or more additive packages (or concentrates), or may be combined with the base oil alone. Fully formulated lubricating oils may exhibit improved performance characteristics based on the additives added and their respective proportions. The details of the lubricating oil composition used in the method of the present invention are set forth below.

Base oil

The base oil used in the lubricating oil compositions herein may be selected from any of the base oils in groups I-V as specified in the American Petroleum Institute (API) base oil interchangeability guidelines. The five base oil groups were as follows:

group of base oils

Groups 1, II and III are mineral oil process feedstocks. Group 1V base oils contain true synthetic molecular species (true synthetic molecular species) which are produced by the polymerization of ethylenically unsaturated hydrocarbons. Many group V base oils are also true synthetic products and may contain diesters, polyol esters, polyalkylene glycols, alkylated aromatics, polyphosphate esters, polyvinyl ethers and/or polyphenyl ethers, and the like, but may also be naturally occurring oils, such as vegetable oils. It should be noted that although group III base oils are derived from mineral oils, the rigorous processing experienced by these fluids makes their physical properties very similar to some real composites, such as PAOs. Thus, in the industry, oils derived from group III base oils may be referred to as synthetic fluids.

The base oil used in the lubricating oil composition may be a mineral oil, an animal oil, a vegetable oil, a synthetic oil, or a mixture thereof. Suitable oils may be derived from hydrocracking, hydrogenation, hydrofinishing, unrefined, refined, and rerefined oils, and mixtures thereof.

Unrefined oils are those derived from a natural, mineral, or synthetic source with little or no further purification treatment. Refined oils are similar to unrefined oils except that they have been treated in one or more purification steps, which may result in an improvement in one or more properties. Examples of suitable purification techniques are solvent extraction, secondary distillation, acid or base extraction, filtration, percolation, etc. Oils refined to edible quality may or may not be suitable. Edible oils may also be referred to as white oils. In some embodiments, the lubricant composition is free of edible oil or white oil.

Rerefined oils are also known as reclaimed or reprocessed oils. These oils are obtained similarly to refined oils, using the same or similar processes. Typically these oils are additionally processed by techniques directed to the removal of spent additives and oil breakdown products.

The mineral oil may comprise oil obtained by drilling or from plants and animals or any mixture thereof. For example, the oils may include, but are not limited to, castor oil, lard oil, olive oil, peanut oil, corn oil, soybean oil, and linseed oil, as well as mineral lubricating oils such as liquid petroleum oils and solvent-treated or acid-treated mineral lubricating oils of the paraffinic, naphthenic, or mixed paraffinic-naphthenic types. The oil may be partially or fully hydrogenated if desired. Oils derived from coal or shale may also be suitable.

Suitable synthetic lubricating oils may comprise hydrocarbon oils such as polymerized, oligomerized, or interpolymerized olefins (e.g., polybutylenes, polypropylenes, propylene isobutylene copolymers), poly (1-hexenes), poly (1-octenes), trimers or oligomers of 1-decenes, such as poly (1-decene), commonly referred to as α -olefin, and mixtures thereof, alkyl-benzenes (e.g., dodecylbenzenes, tetradecylbenzenes, dinonylbenzenes, di (2-ethylhexyl) -benzenes), polyphenyls (e.g., biphenyls, terphenyls, alkylated polyphenyls), diphenylalkanes, alkylated diphenylethers, and alkylated diphenylsulfides, as well as derivatives, analogs, and homologs thereof, or mixtures thereof. the poly α olefins are typically hydrogenated materials.

Other synthetic lubricating oils contain polyol esters, diesters, liquid esters of phosphorus-containing acids (e.g., tricresyl phosphate, trioctyl phosphate, and diethyl ester of decane phosphionic acid), or polymeric tetrahydrofurans. Synthetic oils may be produced by Fischer-Tropsch reactions (Fischer-Tropsch reactions) and may typically be hydroisomerized Fischer-Tropsch hydrocarbons or waxes. In one embodiment, the oil may be prepared by a fischer-tropsch gas-to-oil synthesis procedure as well as other gas-to-oil oils.

The amount of oil of lubricating viscosity present may be the remainder after subtracting the sum of the amounts of performance additives comprising viscosity index improver and/or pour point depressant and/or other pre-treatment additives (top treat additive) from 100 wt.%. For example, the oil of lubricating viscosity that may be present in the finished fluid may be present in 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.%.

In certain embodiments, the particular choice of base oil may provide beneficial results in terms of reducing chain stretch or elongation. For example, in some embodiments, it may be desirable to select a base oil having a viscosity grade of 0W-X or 5W-X. In certain embodiments, advantages may be achieved by selecting a base oil having an SAE viscosity grade of 0W-20, or 5W-40.

Cleaning agent

The lubricant composition of the present disclosure for use in a method of reducing timing chain stretching contains at least one overbased calcium phenate detergent having a total base number of at least 150mg KOH/g as measured by the method of ASTM D-2896; at least one calcium sulfonate detergent; and at least one magnesium-containing detergent.

Overbased calcium phenates typically are formed by overbased calcium alkyl or alkenyl substituents on the aromatic ring, which are substituted with one or more alkyl or alkenyl groups (typically 1 to 2) that render the finished product soluble or at least stably dispersible in oil, the alkyl or alkenyl substituents on the aromatic ring typically contain at least about 6 carbon atoms and may contain up to 500 or more carbon atoms preferred substituents are derived from α -olefins, such as by wax cleavage or chain growth of ethylene on an aluminum alkyl (e.g., triethylaluminum), or from olefin oligomers, such as olefin dimers, trimers, tetramers and/or pentamers.

Overbased sulfurized calcium phenates may be formed from substituted phenols as described above by reacting the substituted phenol with sulfur monochloride, sulfur dichloride, or elemental sulfur. The molar ratio of phenol to sulfur compounds is generally in the range of about 1: 0.5 to about 1: 1.5 or higher. Reaction temperatures in the range of about 60 to about 200 c are generally employed. Generally, the molar ratio of phenolic to sulfur groups in the sulfurized phenate is in the range of about 2: 1 to about 1: 2.

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

The at least one calcium sulfonate detergent may be derived from suitable aliphatic, cycloaliphatic, aromatic or heterocyclic sulfonic acids and/or salts thereof. In general, the acid may beBy the formula R (SO)₃H)_nAnd (R')_xT(SO₃H)_yWherein R is an aliphatic or aliphatically substituted cycloaliphatic radical free of acetylenic unsaturation and having up to about 60 carbon atoms; n is at least one and is generally in the range of 1 to 3; r' is an aliphatic group free of acetylenic unsaturation (typically alkyl or alkenyl) and having from about 4 to about 60 carbon atoms; t is a cyclic nucleus which can be derived from aromatic hydrocarbons such as benzene, toluene, xylene, naphthalene, anthracene, biphenyl, etc., or from heterocyclic compounds such as pyridine, indole, isoindole, etc. Typically T is an aromatic hydrocarbon nucleus such as benzene or naphthalene; and x and y have an average value of about 1 to 4, most typically about 1, per molecule. Examples of such acids are petroleum sulfonic acid, paraffin sulfonic acid, wax-substituted cyclohexyl sulfonic acid, hexadecyl cyclopentyl sulfonic acid, wax-substituted aromatic sulfonic acid, mahogany sulfonic acid (mahogany sulfonic acid), tetraisobutylene sulfonic acid, tetrapentene sulfonic acid, and the like. Most preferably, the overbased calcium salt is formed from an alkaryl sulphonic acid, such as an alkyl benzene sulphonic acid. The one or more alkyl groups present on the aromatic ring typically each contain from about 8 to about 40 carbon atoms. Suitable overbased calcium sulfonate detergents comprising a total base number of at least about 225mg KOH per gram of overbased composition are commercially available from a variety of suppliers. One such material is

611 additive (Ethyl Petroleum Additives, Inc.) with a nominal TBN of about 300mg KOH per gram of composition.

In each of the foregoing embodiments, the calcium sulfonate detergent is overbased, and has a total base number of at least 225mg KOH/g, or from about 225 to about 500mg KOH/g, or from about 290 to about 500mg KOH/g, or from about 250mg KOH/g to about 400mg KOH/g, or from about 300mg KOH/g to about 400mg KOH/g, as measured by the method of ASTM D-2896.

The additive package and lubricant composition of the present disclosure comprise at least one magnesium-containing detergent. Suitable magnesium-containing detergents include overbased magnesium-containing detergents such as overbased magnesium phenates, overbased sulfur-containing magnesium phenates, overbased magnesium sulfonates, overbased calixarenates, overbased magnesium salicylates, overbased magnesium carboxylates, overbased magnesium phosphites, overbased magnesium monothiophosphates and/or dithiophosphates, overbased magnesium alkylphenates, overbased sulfur-coupled alkyl magnesium phenates or overbased methylene-bridged magnesium phenates.

Preferred overbased magnesium salts are overbased magnesium alkylbenzene sulfonate detergent compositions having a total base number of at least about 300mg KOH/g, or a total base number in the range of from about 350 to about 500mg KOH/g. The lubricating oil composition may contain from about 50ppm to about 1650ppm, or from about 80ppm to about 1250ppm, or from about 250ppm to about 1100ppm magnesium provided by at least one magnesium-containing detergent, based on the total weight of the lubricating oil composition.

The lubricating oil composition may contain from about 50ppm to about 1650ppm, or from about 80ppm to about 1250ppm, or from about 100ppm to about 900ppm, by weight of the total weight of the lubricating oil composition, of calcium provided by the at least one calcium sulfonate detergent. The lubricating oil composition may contain from about 100ppm to about 2000ppm, or from about 250ppm to about 1800ppm, or from about 600ppm to about 1500ppm, by weight of the total lubricating oil composition, of calcium provided by the at least one calcium phenate detergent. The lubricating oil composition may contain from about 400ppm to about 2200ppm, or from about 500ppm to about 1700ppm, or from about 800ppm to about 1600ppm, or less than 1550ppm, by total weight of the lubricating oil composition, of calcium provided by all overbased calcium-containing detergents. Further, in some embodiments, the total amount of calcium in the lubricating oil composition from all sources may be from about 1000ppm to less than about 3090ppm, or from about 1200ppm to about 2000ppm, or from about 1300ppm to about 1600 ppm. In some embodiments, the overbased calcium detergent comprises from about 0.9 wt.% to about 10 wt.%, or from about 1 wt.% to about 5 wt.%, or from about 1 wt.% to about 2 wt.% of the lubricating oil composition.

The lubricating oil composition has a weight ratio of total calcium from the at least one calcium sulfonate detergent to total calcium and magnesium in the lubricating oil composition of from about 0.06 to less than about 0.45, or from about 0.06 to about 0.4, or from about 0.06 to about 0.35.

The detergent component may also optionally comprise one or more other overbased calcium salts of at least one acidic organic compound. These comprise overbased calixarenic acid calcium, overbased salicylic acid calcium, overbased calcium carboxylates, overbased calcium phosphites, overbased mono-and/or di-calcium phosphates, overbased calcium alkylphenates, overbased sulfur-coupled calcium alkylphenates compounds, and overbased methylene-bridged calcium phenates.

The term "overbased" refers to metal salts, such as sulfonic, carboxylic and phenolic metal salts, in which the amount of metal present is in excess of stoichiometric. The salt may have a conversion level of over 100% (i.e., it may include more than 100% of the theoretical amount of metal required to convert the acid to its "normal", "neutral" salt). The expression "metal ratio" is often abbreviated MR and is used to denote the ratio of the total stoichiometric amount of metal in the overbased salt to the stoichiometric amount of metal in the neutral salt, according to known chemical reactivity and stoichiometry. The metal ratio is one in normal or neutral salts and MR is greater than one in overbased salts. Salts with MR greater than one are commonly referred to as overbased, superbased or superbased salts and may be salts of organic sulfuric acids, carboxylic acids or phenols.

The actual stoichiometric excess of metal in the overbased salt may vary significantly, for example, from about 0.1 equivalents to about 50 or more equivalents depending on the materials used, the reactions used, and the process conditions used. In general, overbased calcium salts useful in lubricating oil compositions contain from about 1.1 to about 40 or more equivalents of calcium, more preferably from about 1.5 to about 30, and most preferably from about 2 to about 25 equivalents of calcium per equivalent of overbased material. Similarly, overbased magnesium salts useful in lubricating oil compositions contain from about 1.1 to about 40 or more equivalents of magnesium per equivalent of overbased material, more preferably from about 1.5 to about 30, and most preferably from about 2 to about 25 equivalents of magnesium.

Suitable overbased carboxylic acids that may be used in the lubricating oil compositions include overbased aliphatic carboxylic acids, overbased cycloaliphatic carboxylic acids, overbased aromatic carboxylic acids, and overbased heterocyclic carboxylic acids. The acid may be a mono-or polycarboxylic acid and it is essential that the acid has sufficient chain length to be soluble or at least stably dispersible in the lubricating oil. Thus, the acids generally contain from about 8 to about 50, and preferably from about 12 to about 30 carbon atoms, although certain acids (such as alkyl or alkenyl substituted succinic acids) may have an average value of up to 500 or more carbon atoms per molecule. The acid is generally free of acetylenically unsaturated groups. Examples include linolenic acid, capric acid, linoleic acid, oleic acid, stearic acid, lauric acid, ricinoleic acid, undecanoic acid, palmitoleic acid, 2-ethylhexanoic acid, myristic acid, isostearic acid, behenic acid, pelargonic acid, propylene tetramer-substituted succinic acid, isobutylene trimer-substituted succinic acid, octylcyclopentanecarboxylic acid, stearoyl-octahydroindenecarboxylic acid, tall oil acid, rosin acid, polybutenyl succinic acid derived from polybutene having a GPC number average molecular weight in the range of 200 to 1500, acids formed by oxidation of waxes, and the like.

The overbased detergent may have a metal to substrate ratio of 1.1: 1, or 2: 1, or 4: 1, or 5: 1, or 7: 1, or 10: 1.

The lubricant compositions of the present disclosure may also optionally comprise one or more neutral or low alkaline detergents or mixtures thereof. Low alkaline cleaners are those having a TBN greater than 0 and up to less than 150mg KOH/g of the composition. The one or more additional neutral or low alkaline detergents may be selected from neutral or low alkaline calcium sulfonate detergents, neutral or low alkaline calcium salicylate detergents, or any combination thereof.

Suitable low alkaline calcium alkyl benzene sulfonate detergent compositions, most preferably low alkaline propylene derived calcium alkaryl sulfonate, are formed by: alkali or alkaline earth metal salts of alkylbenzene sulphonic acid are prepared and the salt is subjected to the action of an acidic material such as carbon dioxide in the presence of a small excess of alkali or alkaline earth metal base such as an oxide, hydroxide or alcoholate as required so that a small amount of overbasing occurs. This controlled overbasing can be performed in substantially the same manner as the overbasing described above using the same materials, except, of course, that the amount of metal base is such that the desired total base number of the resulting composition can be obtained. Suitable low alkali materials of the foregoing type are commercially available.

614 additive (Ethyl Petroleum additives Co.) isGood examples of commercially available calcium alkyl benzene sulfonates. Low base sulfurized calcium alkyl phenates are also suitable components in the compositions of the present disclosure.

The total amount of detergent that may be present in the lubricating oil composition may be from about 1 wt.% to about 15 wt.%, or from about 1 wt.% to about 10 wt.%, or from about 1 wt.% to about 8 wt.%, or from about 1 wt.% to about 4 wt.%, or greater than about 4 wt.% to about 8 wt.%, based on the total weight of the lubricating oil composition.

Antiwear agent

The lubricating oil compositions of the present disclosure may optionally contain one or more metal dialkyldithiophosphate antiwear agents. The metal in the dialkyldithiophosphate may be an alkali metal, an alkaline earth metal, aluminum, lead, tin, molybdenum, manganese, nickel, copper, titanium or zinc. A particularly suitable metal dialkyldithiophosphate may be zinc dialkyldithiophosphate.

Zinc dialkyldithiophosphates (ZDDP) are oil soluble salts of dialkyldithiophosphoric acids and may be represented by the following formula:

wherein R is₅And R₆May be the same or different alkyl and/or cycloalkyl groups containing from 1 to 18 carbon atoms, or from 2 to 12 carbon atoms, or from 2 to 8 carbon atoms. Thus, the alkyl and/or cycloalkyl group may be, for example, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, pentyl, n-hexyl, isohexyl, n-octyl, decyl, dodecyl, octadecyl, 2-ethylhexyl, cyclohexyl, methylcyclopentyl, propenyl, or butenyl.

The metal dialkyldithiophosphates may be prepared according to known techniques by first forming a dialkyldithiophosphoric acid (DDPA), typically by reaction of one or more alcohols, and then neutralizing the formed DDPA with a metal compound. For the preparation of the metal salts, any basic or neutral metal compound may be used, but oxides, hydroxides and carbonates are most commonly employed. The zinc dialkyldithiophosphate of component (i) may be prepared by a process such as the process generally described in U.S. patent No. 7,368,596.

In some embodiments, the at least one metal dialkyl dithiophosphate may be present in the lubricating oil in an amount sufficient to provide from about 100 to about 1200ppm phosphorus, or from about 200 to about 1100ppm phosphorus, or from about 300 to about 1000ppm phosphorus, or from about 400 to about 1000ppm phosphorus, or from about 550 to about 980ppm phosphorus. In some embodiments, the at least one metal dialkyl dithiophosphate may be present in the lubricating oil in an amount from about 0 wt.% to about 6.0 wt.%, or from about 0.1 wt.% to about 4.0 wt.%, based on the total weight of the lubricating oil composition.

In some embodiments, the metal dialkyldithiophosphate can be zinc dialkyldithiophosphate (ZDDP). In some embodiments, the additive package may include two or more metal dialkyldithiophosphates, and one, two, or all are ZDDPs. The zinc dialkyldithiophosphate can deliver from about 600ppm to about 1300ppm, or from about 750ppm to about 1200ppm, or from about 800ppm to about 1100ppm of zinc to the lubricating oil composition.

The lubricating oil compositions of the present disclosure may also optionally contain one or more additional antiwear agents. Examples of suitable additional anti-wear agents include, but are not limited to, metal thiophosphates; a phosphate ester or a salt thereof; a phosphate ester; a phosphite ester; phosphorus-containing carboxylic acid esters, ethers or amides; a sulfurized olefin; a thiocarbamate-containing compound comprising a thiocarbamate, an alkylene-coupled thiocarbamate, and a bis (S-alkyldithiocarbamoyl) disulfide; and mixtures thereof. Phosphorus-containing anti-wear agents are more fully described in european patent 612839. The metal may be an alkali metal, an alkaline earth metal, aluminium, lead, tin, molybdenum, manganese, nickel, copper, titanium or zinc.

Other examples of suitable additional anti-wear agents include: titanium compounds, tartaric acid esters, tartaric imides, oil-soluble amine salts of phosphorus compounds, sulfurized 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 alkyl ester groups in which the total number of carbon atoms on the alkyl group may be at least 8. In one embodiment, the anti-wear agent may comprise a citrate ester.

The additional antiwear agent may be used in an amount of about 0.0 to 1.0 wt.%, or about 0.0 to about 0.8 wt.%, based on the total weight of the lubricating oil composition. The total amount of antiwear agent present in the lubricating oil composition may range from about 0 wt.% to about 7 wt.%, or from about 0.01 wt.% to about 5 wt.%, or from about 0.1 wt.% to about 4.8 wt.%, based on the total weight of the lubricating oil composition.

Dispersing agent

The lubricant composition may optionally further comprise one or more dispersants or mixtures thereof. Dispersants are generally referred to as ashless-type dispersants because they do not contain ash-forming metals prior to mixing in a lubricating oil composition, and they do not generally provide any ash when added to a lubricant. Ashless type dispersants are characterized by a polar group attached to a molecule or relatively high weight hydrocarbon chain. Typical ashless dispersants comprise an N-substituted long chain alkenyl succinimide. Examples of N-substituted long chain alkenyl succinimides include polyisobutylene succinimides having a number average molecular weight of the polyisobutylene substituent from about 350 to about 5000, or from about 500 to about 3000. Succinimide dispersants and their preparation are disclosed, for example, in U.S. patent No. 7,897,696 and U.S. patent No. 4,234,435. Succinimide dispersants are typically imides formed from polyamines, typically poly (ethyleneamines).

In some embodiments, the lubricant composition includes at least one polyisobutylene succinimide dispersant derived from polyisobutylene having a number average molecular weight in the range of about 350 to about 5000, or about 500 to about 3000. The polyisobutylene succinimide may be used alone or in combination with other dispersants.

In some embodiments, when included, the Polyisobutylene (PIB) terminal double bonds may be present in an amount greater than 50 mole%, greater than 60 mole%, greater than 70 mole%, greater than 80 mole%, or greater than 90 mole%. The PIB is also known as a highly reactive PIB ("HR-PIB"). HR-PIB having a number average molecular weight in the range of about 800 to about 5000 is suitable for use in embodiments of the present disclosure. The terminal double bond content of conventional non-highly reactive PIB is typically less than 50 mole%, less than 40 mole%, less than 30 mole%, less than 20 mole%, or less than 10 mole%.

HR-PIB having a number average molecular weight in the range of about 900 to about 3000 may be suitable. The 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 U.S. Pat. No. 4,152,499 and U.S. Pat. No. 5,739,355. When used in the aforementioned thermal ene reactions, HR-PIB can increase conversion in the reaction, as well as reduce the amount of sediment formation, due to the enhanced reactivity.

In one embodiment, the dispersant may be described as a poly pibsa.

One class of suitable dispersants may be Mannich bases (Mannich bases). Mannich bases are materials formed from 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. patent No. 3,634,515.

A suitable class of dispersants may be high molecular weight esters or half ester amides.

The dispersant may also be post-treated by conventional means by reaction with any of a variety of reagents. Among these agents are boron, urea, thiourea, dimercaptothiadiazoles, carbon disulfide, aldehydes, ketones, carboxylic acids, hydrocarbon-substituted succinic anhydrides, maleic anhydride, nitriles, epoxides, carbonates, cyclic carbonates, hindered phenolic esters, and phosphorus compounds. U.S. patent No. 7,645,726; us 7,214,649; and us 8,048,831 describe some suitable post-treatment methods and post-treated products.

In one embodiment, the lubricating oil composition may comprise at least one borated dispersant, wherein the dispersant is the reaction product of an olefin copolymer or the reaction product of an olefin copolymer with succinic anhydride, and at least one polyamine. The ratio of PIBSA to polyamine may be from 1: 1 to 10: 1, preferably from 1: 1 to 5: 1, or from 4: 3 to 3: 1 or from 4: 3 to 2: 1. Particularly useful dispersants contain polyisobutenyl groups of PIBSA having a number average molecular weight (Mn) in the range of about 500 to 5000, as determined by GPC using polystyrene as a calibration reference, and (B) a polyamine having the formula H₂N(CH₂)m-[NH(CH₂)_m]_n-NH₂Wherein m ranges from 2 to 4 and n ranges from 1 to 2.

In addition to boration, the dispersant may be post-treated with an aromatic carboxylic acid, an aromatic polycarboxylic acid, or an aromatic anhydride, wherein all carboxylic acid or anhydride groups are directly attached to the aromatic ring. The aromatic compound containing a carboxyl group may be selected from 1, 8-naphthalenedicarboxylic acid or anhydride and 1, 2-naphthalenedicarboxylic acid or anhydride, 2, 3-naphthalenedicarboxylic acid or anhydride, naphthalene-1, 4-dicarboxylic acid, naphthalene-2, 6-dicarboxylic acid, phthalic anhydride, pyromellitic anhydride, 1, 2, 4-benzenetricarboxylic anhydride, diphenic acid or anhydride, 2, 3-pyridinedicarboxylic acid or anhydride, 3, 4-pyridinedicarboxylic acid or anhydride, 1, 4,5, 8-naphthalenetetracarboxylic acid or anhydride, flower-3, 4, 9, 10-tetracarboxylic anhydride, pyrenedicarboxylic acid or anhydride, and the like. The moles of such post-treatment components per mole of polyamine reaction may range from about 0.1: 1 to about 2: 1. Typical molar ratios of such post-treatment components to polyamine in the reaction mixture may range from about 0.2: 1 to about 2: 1. Another molar ratio of such post-treatment component to polyamine that can be used can be in the range of 0.25: 1 to about 1.5: 1. Such post-treatment components may be reacted with other components at a temperature of about 140 ℃ to about 180 ℃.

Alternatively, or in addition to the post-treatment described in the preceding paragraph, the borated dispersant may be post-treated with a non-aromatic dicarboxylic acid or anhydride. The number average molecular weight of the non-aromatic dicarboxylic acid or anhydride may be less than 500. Suitable carboxylic acids or anhydrides thereof can include, but are not limited to, acetic acid or anhydride, oxalic acid and anhydride, malonic acid and anhydride, succinic acid and anhydride, alkenyl succinic acid and anhydride, glutaric acid and anhydride, adipic acid and anhydride, pimelic acid and anhydride, suberic acid and anhydride, azelaic acid and anhydride, sebacic acid and anhydride, maleic acid and anhydride, fumaric acid and anhydride, tartaric acid and anhydride, glycolic acid and anhydride, 1, 2,3, 6-tetrahydronaphthalene dicarboxylic acid and anhydride, and the like.

The non-aromatic carboxylic acid or anhydride is reacted with the polyamine in a molar ratio in the range of about 0.1 to about 2.5 moles per mole of polyamine. Typically, the amount of non-aromatic carboxylic acid or anhydride used will be relative to the number of secondary amino groups in the polyamine. Thus, from about 0.2 to about 2.0 moles of non-aromatic carboxylic acid or anhydride per secondary amino group in component B can be reacted with the other components to provide a dispersant according to embodiments of the present disclosure. Another mole ratio of non-aromatic carboxylic acid or anhydride to polyamine that can be used can be from 0.25: 1 to about 1.5: 1 moles per mole of polyamine. The non-aromatic carboxylic acid or anhydride may be reacted with the other components at a temperature of about 140 c to about 180 c.

The post-treatment step may be carried out after the reaction of the olefin copolymer with succinic anhydride, and at least one polyamine is complete. In certain embodiments, the borated dispersant is post-treated with maleic anhydride and/or naphthalic anhydride, and in these embodiments, the lubricating oil composition may have a molybdenum content of at least 80ppm, or at least 100ppm, or at least 150 ppm.

The% activity of alkenyl or alkyl succinic anhydrides can be determined using chromatographic techniques. Such a method is described in columns 5 and 6 of U.S. patent No. 5,334,321. The percent conversion of the polyolefin was calculated from the activity% using the equations in columns 5 and 6 of U.S. patent No. 5,334,321.

In one embodiment, the borated dispersant may be derived from poly α olefin (PAO) succinic anhydride.

In one embodiment, the borated dispersant may be derived from an olefin maleic anhydride copolymer. As an example, the borated dispersant may be described as poly PIBSA.

In one embodiment, the borated dispersant may be derived from an anhydride grafted to an ethylene-propylene copolymer.

One suitable class of dispersants for use as borated dispersants may be borated Mannich bases. Mannich bases are materials formed from 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. patent No. 3,634,515.

A suitable class of borated dispersants may also comprise high molecular weight ester or half ester amides.

The TBN of suitable borated dispersants may range from about 10 to about 65mg KOH/gram of composition on an oil-free basis, which if measured on a dispersant sample containing about 50% diluent oil, corresponds to a TBN of from about 5 to about 30mg KOH/gram of composition.

Dispersants, if present, may be used in amounts sufficient to provide up to about 20 wt.%, based on the total weight of the lubricating oil composition. The amount of dispersant that may be used may be from about 0.1 wt.% to about 15 wt.%, or from about 0.1 wt.% to about 10 wt.%, or from about 0.5 wt.% to about 10 wt.%, or from about 1 wt.% to about 8 wt.%, or from about 7 wt.% to about 12 wt.%, based on the total weight of the lubricating oil composition. In one embodiment, the lubricating oil composition utilizes a mixed dispersant system.

Component containing molybdenum

The lubricating oil compositions of the present disclosure may optionally contain one or more 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 comprise molybdenum dithiocarbamate, molybdenum dialkyldithiophosphate, molybdenum dithiophosphinate, amine salts of molybdenum compounds, molybdenum xanthate, molybdenum thioxanthate, molybdenum sulfide, molybdenum carboxylate, molybdenum alkoxide, trinuclear organo-molybdenum compounds, and/or mixtures thereof. The molybdenum sulfide comprises molybdenum disulfide. The molybdenum disulfide may be in the form of a stable dispersion. In one embodiment, the oil soluble molybdenum compound may be selected from molybdenum dithiocarbamates, molybdenum dialkyldithiophosphates, amine salts of molybdenum compounds, and mixtures thereof. In one embodiment, the oil soluble molybdenum compound may be molybdenum dithiocarbamate.

Suitable examples of molybdenum compounds that can be used include the commercial materials sold under the following trademarks: molyvan 822 from van der bilt co., Ltd^TM、Molyvan^TMA、Molyvan 2000^TMAnd Molyvan 855^TMAnd Sakura-Lube available from Adeka Corporation^TMS-165, S-200, S-300, S-310G, S-525, S-600, S-700, and S-710, and mixtures thereof. Suitable molybdenum components are described in US 5,650,381; US RE 37,363E 1; US RE 38,929E 1; and US RE 40,595E 1.

Additionally, the molybdenum compound may be an acidic molybdenum compound. Comprising molybdic acid, ammonium molybdate, sodium molybdate, potassium molybdate and other alkali metal molybdates and other molybdenum salts, e.g. sodium hydrogen molybdate, MoOCl₄、MoO₂Br₂、Mo₂O₃Cl₆Molybdenum trioxide or similar acidic molybdenum compounds. Alternatively, the composition may be provided with molybdenum by a molybdenum/sulfur complex of a basic nitrogen compound, as described, for example, in U.S. patent No. 4,263,152; nos. 4,285,822; U.S. Pat. No. 4,283,295; 4,272,387 No; no. 4,265,773; nos. 4,261,843; nos. 4,259,195 and 4,259,194; and in WO 94/06897.

Another suitable class of organo-molybdenum compounds are trinuclear molybdenum compounds, e.g., of the formula Mo₃S_kL_nQ_zWherein S represents sulfur, L represents an independently selected ligand having an organic group in a sufficient number of carbon atoms to render the compound soluble or dispersible in oil, n is 1 to 4, k varies from 4 to 7, Q is selected from the group of neutral electron donating compounds such as water, amines, alcohols, phosphines, and ethers, and z ranges from 0 to 5 and comprises non-stoichiometric values, and mixtures thereof. At least 21 total carbon atoms may be present in all ligand organo groups, such as at least 25, at least 30, or at least 35 carbon atoms. Additional suitable molybdenum compounds are described in U.S. patent No. 6,723,685.

The oil soluble molybdenum compound may be present in an amount sufficient to provide from about 80ppm to about 2000ppm, from about 150ppm to about 800ppm, from about 100ppm to about 600ppm, from about 150ppm to about 550ppm molybdenum to the lubricating oil composition. In another embodiment, the molybdenum compound may be present in an amount sufficient to provide from about 100ppm to about 1000ppm, or from about 150ppm to about 600ppm, molybdenum to the lubricating oil composition. In another embodiment, the lubricating oil composition may have less than about 200ppm molybdenum, or less than about 5ppm, or from about 10ppm to about 150ppm molybdenum.

In certain embodiments of the present disclosure, the lubricating oil composition may contain at least 40ppm molybdenum when the base oil has a viscosity grade of 0W-20, a boron content of at least 100ppm, and a sulfur content of no greater than 2100.

Antioxidant agent

Antioxidant compounds are known and include, for example, phenates, phenol 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, macroantioxidants, or mixtures thereof.

The hindered phenol antioxidant may contain a secondary butyl group and/or a tertiary butyl group as a steric hindering group. The phenolic group may be further substituted with a hydrocarbyl group and/or a bridging group attached 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 may be an ester and may comprise, for example, Irganox, available from BASF^TML-135, or derived from the addition product of 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 can be an ester, and can includeContaining Ethanox available from Albemarle Corporation^TM4716。

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 wt.%, based on the final weight of the lubricating oil composition. In one embodiment, the antioxidant can be a mixture of about 0.3 to about 1.5 wt.% diarylamines and about 0.4 to about 2.5 wt.% high molecular weight phenols, based on the final weight of the lubricating oil composition.

Examples of suitable olefins that may be sulfurized to form sulfurized olefins include propylene, butene, isobutylene, polyisobutylene, pentene, hexene, heptene, octene, nonene, decene, undecene, dodecene, tridecene, tetradecene, pentadecene, hexadecene, heptadecene, octadecene, nonadecene, eicosene, or mixtures thereof. In one embodiment, hexadecene, heptadecene, octadecene, nonadecene, eicosene, or mixtures thereof, as well as dimers, trimers, and tetramers thereof, are particularly suitable olefins. Alternatively, the olefin may be a Diels-Alder adduct of a diene (e.g., 1, 3-butadiene) with an unsaturated ester (e.g., butyl acrylate).

Suitable fatty acids and esters thereof include triglycerides, oleic acid, linoleic acid, palmitoleic acid, or mixtures thereof.

The one or more antioxidants may be present from about 0 wt% to about 5 wt%, or from about 0.01 wt% to about 5 wt%, or from about 0.1 wt% to about 3 wt%, or from about 0.8 wt% to about 2 wt% of the lubricating composition.

Extreme pressure agent

The lubricating oil compositions herein may also optionally contain one or more extreme pressure agents. Extreme Pressure (EP) agents that are soluble in oil include sulfur-and sulfur-containing EP agents, chlorinated hydrocarbon EP agents, and phosphorus EP agents. Examples of the EP agent include: chlorinated wax; organic sulfides and polysulfides, such as benzhydryl disulfide, bis (chlorophenylmethyl) disulfide, dibutyl tetrasulfide, sulfurized methyl ester of oleic acid, sulfurized alkylphenols, sulfurized dipentene, sulfurized terpenes, and sulfurized diels-alder adducts; phosphosulfurized hydrocarbons, such as the reaction product of phosphorus sulfide with turpentine or methyl oleate; phosphorus esters, such as dihydrocarbyl and trihydrocarbyl phosphites, for example dibutyl, diheptyl, dicyclohexyl, pentylphenyl phosphite; dipentylphenyl phosphite, tridecyl phosphite, distearyl phosphite and polypropylene-substituted phenyl phosphite; metal thiocarbamates such as zinc dioctyldithiocarbamate and barium heptylphenol dicarboxylate; amine salts of alkyl and dialkylphosphoric acids, including, for example, amine salts of the reaction product of a dialkyldithiophosphoric acid with a propane oxide; and mixtures thereof.

The extreme pressure agent may be present in an amount of, for example, about 0 to 6.0 wt.%, or about 0.1 to 4.0 wt.%, based on the total weight of the lubricating oil composition.

Friction adjusting agent

The lubricating oil compositions herein may also optionally contain one or more friction modifiers. Suitable friction modifiers may include metal-containing as well as 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 vegetable or animal oils, dicarboxylic acid esters, esters or partial esters of polyols and one or more aliphatic or aromatic carboxylic acids, and the like.

Suitable friction modifiers may contain hydrocarbyl groups selected from straight chain, branched chain or aromatic hydrocarbyl groups or mixtures 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 range from 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 mono-or di-ester 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.

Other suitable friction modifiers may include organic, ashless (metal-free), nitrogen-free organic friction modifiers. The friction modifier may comprise an ester formed by reacting a carboxylic acid and anhydride with an alkanol, and typically comprises a polar terminal group (e.g., carboxyl or hydroxyl) covalently bonded to an oleophilic hydrocarbon chain. An example of an organic ashless, nitrogen-free friction modifier is generally known as Glycerol Monooleate (GMO), which may contain mono-, di-and tri-esters of oleic acid. Other suitable friction modifiers are described in U.S. patent No. 6,723,685.

The amine-based friction modifier may comprise an amine or polyamine. The compounds may have linear, saturated or unsaturated hydrocarbon groups, or mixtures thereof, and may contain from about 12 to about 25 carbon atoms. Other examples of suitable friction modifiers include alkoxylated amines and alkoxylated ether amines. The compounds may have linear, saturated or unsaturated hydrocarbon groups, or mixtures thereof. Which may contain from about 12 to about 25 carbon atoms. Examples include ethoxylated amines and ethoxylated ether amines.

The amines and amides can be used as such or in the form of adducts or reaction products with boron compounds, such as boron oxides, boron halides, metaborates, boric acid or monoalkyl borates, dialkyl borates or trialkyl borates. Other suitable friction modifiers are described in U.S. Pat. No. 6,300,291.

The friction modifier may optionally be present in a range of from about 0 wt% to about 5 wt%, or from about 0.01 wt% to about 4 wt%, or from about 0.05 wt% to about 2 wt%.

Boron-containing compounds

The lubricating oil compositions herein may optionally contain one or more boron-containing compounds in addition to the borated dispersants described above.

Examples of boron-containing compounds include borate esters, borated fatty amines, borated epoxides, and borated detergents.

The additional boron-containing compound, if present, may be used in an amount sufficient to provide up to about 8 wt.%, from about 0.001 wt.% to about 7 wt.%, from about 0.01 wt.% to about 5 wt.%, or from about 0.1 wt.% to about 3 wt.% of the lubricating composition. In each of the foregoing embodiments, the lubricating oil compositions herein may contain less than 200ppm boron, or 180ppm or less, or 150ppm or less boron.

Titanium-containing compound

Another optional additive that may be used in the lubricating oil compositions of the present invention is an oil soluble titanium compound. The oil soluble titanium compound may serve 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 titanium compound may be a titanium (IV) alkoxide. The titanium alkoxide can be formed from a monohydric alcohol, a polyhydric alcohol, or a mixture thereof. The monoalkanol salt may have 2 to 16, or 3 to 10 carbon atoms. In one embodiment, the titanium alkoxide may be titanium (IV) isopropoxide. In one embodiment, the titanium alkoxide may be titanium (IV) 2-ethylhexanoate. In one embodiment, the titanium compound may be an alkoxide of a1, 2-diol or polyol. In one embodiment, the 1, 2-diol comprises a fatty acid monoglyceride, such as oleic acid. In one embodiment, the oil soluble titanium compound may be a titanium carboxylate. In one embodiment, the titanium (IV) carboxylate may be titanium neodecanoate.

In one embodiment, the oil soluble titanium compound may be present in the lubricating composition in an amount capable of providing zero to about 1500ppm by weight titanium, or about 10ppm to 500ppm by weight titanium, or about 25ppm to about 150ppm titanium.

Viscosity index improver

Suitable viscosity index improvers can include polyolefins, olefin copolymers, ethylene/propylene copolymers, polyisobutylene, hydrogenated styrene-isoprene polymers, styrene/maleate copolymers, hydrogenated styrene/butadiene copolymers, hydrogenated isoprene polymers, α -olefin maleic anhydride copolymers, polymethacrylates, polyacrylates, polyalkylstyrenes, hydrogenated alkenyl aryl conjugated diene copolymers, or mixtures thereof.

The lubricating oil compositions herein may also 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 (e.g., maleic anhydride) and an amine; with amine functionalized polymethacrylates, or esterified maleic anhydride-styrene copolymers reacted with amines.

The total amount of viscosity index improver and/or dispersant viscosity index improver may be from about 0 wt% to about 20 wt%, from about 0.1 wt% to about 15 wt%, from about 0.25 wt% to about 12 wt%, or from about 0.5 wt% to about 10 wt% of the lubricating composition.

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 in addition to or different from those specified herein.

The lubricating composition according to the present disclosure may optionally include other performance additives. In addition to the specified additives of the present disclosure, other performance additives may be and/or may include one or more of the following: metal deactivators, ashless TBN accelerators, corrosion inhibitors, rust inhibitors, dispersant viscosity index improvers, 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.

Suitable metal deactivators may comprise, benzotriazole derivatives (typically tolyltriazole), dimercaptothiadiazole derivatives, 1, 2, 4-triazole, benzimidazole, 2-alkyldithiobenzimidazole or 2-alkyldithiobenzothiazole; a foam inhibitor comprising a copolymer of ethyl acrylate and 2-ethylhexyl acrylate and optionally vinyl acetate; a demulsifier comprising a trialkyl phosphate, polyethylene glycol, polyethylene oxide, polypropylene oxide, and a (ethylene oxide-propylene oxide) polymer; a pour point depressant comprising an ester of maleic anhydride-styrene, polymethacrylate, polyacrylate, or polyacrylamide.

Suitable foam inhibitors include silicon-based compounds, such as silicones.

Suitable pour point depressants may comprise polymethyl methacrylate or mixtures thereof. The pour point depressant may be present in an amount sufficient to provide from about 0 wt.% to about 5 wt.%, from about 0.01 wt.% to about 1.5 wt.%, or from about 0.02 wt.% to about 0.04 wt.%, based on the final weight of the lubricating oil composition.

Other suitable corrosion inhibitors include long chain α, omega-dicarboxylic acids having a molecular weight in the range of about 600 to about 3000, and alkenyl succinic acids in which the alkenyl group contains about 10 or more carbon atoms, such as tetrapropenyl succinic acid, tetradecenyl succinic acid, and hexadecenyl succinic acid.

The rust inhibitor, if present, may be used in an amount 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.

In general, suitable lubricants may comprise additive components in the ranges listed in table 1.

TABLE 1

The above percentages for each component represent the weight percent of each component based on the weight of the final lubricating oil composition. The remainder of the lubricating oil composition is comprised 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 suitable to blend all of the components simultaneously using an additive concentrate (i.e., additive plus diluent, such as a hydrocarbon solvent).

In certain embodiments of the present disclosure, the method of using the lubricating oil composition is capable of reducing timing chain stretch to 0.2% or less, or 0.1% or less, or 0.09% or less, as measured by a ford chain wear test over a period of 216 hours. Further, in certain embodiments of the invention, the engine is a spark-ignition engine, or more particularly a spark-ignition passenger car gasoline engine.

The invention also encompasses the use of the above lubricating oil composition to reduce timing chain stretch or elongation of a timing chain of an engine, such as a spark-ignited engine or a spark-ignited passenger car engine.

Examples of the invention

The following examples are illustrative of the methods and compositions of the present disclosure and are not limiting. Other suitable modifications and adaptations of the various conditions and parameters normally encountered in the art and which are obvious to those skilled in the art are within the scope of this disclosure.

A series of tests were performed to determine the effect of calcium sulfonate detergents, calcium phenate detergents and magnesium-containing detergents on chain elongation. The operation of the timing chain was simulated by the ford chain wear test described in more detail below.

Each of the lubricating oil compositions contains a major amount of a base oil and basic conventional Dispersant Inhibitor (DI) packages, wherein the basic DI packages provide from about 8 to about 12 weight percent of the lubricating oil composition. The basic DI contains conventional amounts of dispersants, antiwear additives, antioxidants, friction modifiers, pour point depressants, and viscosity index improvers as set forth in Table 2. The major amount of base oil is present in the lubricating oil composition in an amount of about 74 wt.% to about 87 wt.%. The varied components are specified in the following tables and discussion of the examples. Unless otherwise specified, all values listed are stated as weight percentages of the components based on the total weight of the lubricating oil composition (i.e., the amounts of the components reflect the active ingredient plus diluent oil, if present).

TABLE 2

Composition of DI packets	By weight%
		Antioxidant agent	0.5 to 2.5
Antiwear agents comprising any metal dihydrocarbyl dithiophosphate	0.0 to 5.0
		Cleaning agent	0.0
Dispersing agent	2.0 to 6.0
		Friction adjusting agent	0.05 to 1.25
Pour point depressant	0.05 to 0.5
		Viscosity index improver	0.25 to 9.0

Detergent was different in the following experiments, therefore the detergent amount was set to zero for the purpose of the base formulation.

Comparative example A

To demonstrate the significance of wear on chain extension of the timing chain, a control lubricating oil composition was used. The composition has a viscosity grade of 5W-40 and contains greater than about 70 wt% base oil and an additive package without intentionally added magnesium detergent. Details of the detergent components used in the composition of comparative example a are shown in table 3 below.

Example 1

The lubricating oil composition of example 1 had a viscosity grade of 5W-40 and contained greater than about 70 wt.% base oil and an additive package containing magnesium detergent in an amount to supply about 910ppm Mg to the finished fluid. Details of the detergent components employed in the composition of example 1 are shown in table 3 below.

Example 2

The lubricating oil composition of example 2 had a viscosity grade of 5W-40 and contained greater than about 70 wt.% base oil and an additive package containing a magnesium detergent. Details of the detergent components in the composition of example 2 are shown in table 3 below.

Example 3

The lubricating oil composition of example 3 had a viscosity grade of 5W-20 and contained greater than about 80 wt.% base oil and an additive package containing a magnesium detergent. Details of the detergent components contained in the composition of example 3 are shown in table 3 below.

Example 4

The lubricating oil composition of example 4 has a viscosity grade of 0W-20 and contains greater than about 80 wt.% base oil and an additive package containing a magnesium sulfonate detergent. Details of the detergent components of the composition of example 4 are shown in table 3 below.

TABLE 3

a: a timing chain stretch of 0.1% or less is an acceptable ratio

Ford chain wear test

The lubricating oils of comparative example a and examples 1-4 as set forth above were tested in the ford chain wear test using a test duration of 216 hours, and then the timing chain was tested for timing chain stretch.

The ford chain wear test is a method of evaluating timing chain stretch in an engine. The ford chain wear test used a 2012 ford 2.0 liter EcoBoost TGDi four cylinder test engine. The procedure followed to generate the data presented above (the CW astm drift R18 procedure) requires that the engine be operated at low to medium speed and load at low and normal operating temperatures in a two-stage test. The test cycle consisted of an 8 hour break-in period followed by 216 hours cycling of the test conditions. The timing chain is measured after the break-in period and this measurement is used as a baseline measurement for the timing chain stretch calculation at the end of the test. At the end of the test, the timing chain is measured again.

Stage 1 of the test was run at low speed, low load and low temperature with a rich combustion cycle. Stage 2 was run at moderate speed, moderate load and moderate temperature using stoichiometric conditions. Between phase 1 and phase 2, the temperature, speed and load are ramped at a specified rate.

The timing chain stretch results are presented in table 3 above.

The results obtained using the lubricating oil compositions of comparative example a and examples 1-4 show that the lubricating method of the present invention provides improved resistance to timing chain stretching as compared to the lubricating method of comparative example a. Comparative example a and examples 1-4 demonstrate that the lubrication method employing a lubricating oil composition including a magnesium-containing detergent greatly improves resistance to timing chain stretching when compared to a lubricating oil composition that does not include a magnesium-containing detergent. Further, the examples emphasize that the weight ratio of total calcium from the calcium sulfonate detergent to total calcium and magnesium in the lubricating oil of the composition providing reduced timing chain stretching is from about 0.06 to about 0.33.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the embodiments disclosed herein. As used throughout the specification and claims, "a" and/or "an" may mean one or more than one. Unless otherwise indicated, all numbers expressing quantities of ingredients, properties, such as molecular weight, percentages, ratios, reaction conditions, and so forth, used in the specification and claims are to be understood as being modified in all instances by the term "about", whether or not the term "about" is present. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the specification and claims are approximations that may vary depending upon the desired properties sought to be obtained by the present disclosure. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the disclosure are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

The foregoing embodiments are susceptible to considerable variation in practice. Accordingly, the embodiments are not intended to be limited to the specific exemplifications set forth hereinabove. Rather, the foregoing embodiments are within the spirit and scope of the appended claims, including the equivalents thereof available as a matter of law.

Applicants do not intend to dedicate any disclosed embodiments to the public, and to the extent any disclosed modifications or alterations may not literally fall within the scope of the claims, they are considered to be part hereof under the doctrine of equivalents.

All patents and publications cited herein are fully incorporated by reference in their entirety.

The claims (modification according to treaty clause 19)

1. A method for reducing timing chain stretch of a timing chain in an engine comprising the step of lubricating the timing chain with a lubricating oil composition comprising:

a major amount of a base oil; and

a minor amount of an additive package comprising:

a) at least one overbased calcium phenate detergent having a total base number of at least 150mgKOH/g as measured by the method of ASTM D-2896;

b) at least one calcium sulfonate detergent; and

c) at least one magnesium-containing detergent;

wherein the lubricating oil composition has a weight ratio of total calcium from the at least one calcium sulfonate detergent to total calcium and magnesium in the lubricating oil composition of from 0.06 to 0.35.

2. The method of claim 1, wherein the at least one magnesium-containing detergent is overbased, having a total base number of at least 225mg KOH/g as measured by the method of ASTM D-2896.

3. The method of claim 1, wherein the at least one magnesium-containing detergent is selected from the group consisting of overbased magnesium phenates, overbased sulfur-containing magnesium phenates, overbased magnesium sulfonates, overbased magnesium calixarates, overbased magnesium salicylates, overbased magnesium phosphites, overbased magnesium mono-and/or dithiophosphates, overbased magnesium alkylphenates, overbased sulfur-coupled alkyl phenate compounds, overbased methylene-bridged magnesium phenates, and combinations thereof.

4. The method of claim 1, wherein the at least one calcium sulfonate detergent is overbased, having a total base number of at least 225mg KOH/g as measured by the method of ASTM D-2896.

5. The method of claim 1, wherein the weight ratio of total calcium from the at least one calcium sulfonate detergent of the lubricating oil composition to total calcium and magnesium in the lubricating oil composition is from about 0.06 to about 0.4.

6. The method of claim 1, wherein the additive package further comprises one or more additives selected from the group consisting of: antioxidants, friction modifiers, pour point depressants, and viscosity index improvers.

7. The method of claim 6, wherein the antioxidant is an oil soluble molybdenum complex.

8. The method of claim 1, wherein the base oil has a viscosity grade of 5W-X or 0W-X, and the lubricating oil composition comprises one or more antioxidants selected from the group consisting of aromatic amines, alkylated diphenylamines, phenyl- α -naphthylamine, and alkylated phenyl- α -naphthylamine.

9. The method of claim 1, wherein the lubricating oil composition contains from about 50ppm to about 1650ppm of calcium provided by the at least one calcium sulfonate detergent, based on the total weight of the lubricating oil composition.

10. The method of claim 1, wherein the lubricating oil composition contains from about 100ppm to about 2000ppm of calcium provided by the at least one calcium phenate detergent, based on the total weight of the lubricating oil composition.

11. The method of claim 1, wherein the lubricating oil composition contains from about 400ppm to about 2200ppm of calcium provided by all overbased calcium-containing detergents, based on the total weight of the lubricating oil composition.

12. The method of claim 1, wherein the total amount of calcium in the lubricating oil composition is from about 1000ppm to less than about 3090 ppm.

13. The method of claim 1, wherein the lubricating oil composition contains from about 50ppm to about 1650ppm magnesium provided by the at least one magnesium-containing detergent, based on the total weight of the lubricating oil composition.

14. The method of claim 1, wherein the lubricating oil composition contains from about 500ppm to less than 3100ppm total magnesium and calcium, based on the total weight of the lubricating oil composition.

15. The method of claim 1, wherein the lubricating oil composition further comprises a metal dialkyldithiophosphate.

16. The method of claim 1, wherein the engine is a spark-ignition engine.

17. The method of claim 1, wherein the engine is a spark-ignited passenger car gasoline engine.

18. The method of claim 1, wherein the lubricating oil composition is capable of reducing the timing chain stretch in an engine to 0.1% or less as measured by the ford chain Wear Test (FordChain Wear Test) over a period of 216 hours.

Claims

a major amount of a base oil; and

a minor amount of an additive package comprising:

b) at least one calcium sulfonate detergent; and

c) at least one magnesium-containing detergent;

wherein the lubricating oil composition has a weight ratio of total calcium from the at least one calcium sulfonate detergent to total calcium and magnesium in the lubricating oil composition of from 0.06 to 0.45.

16. The method of claim 1, wherein the engine is a spark-ignition engine.