CN116194560B - Diesel engine lubricating composition and method of using the same - Google Patents

Abstract

The present disclosure provides a diesel engine lubricating composition and a method for lubricating a diesel engine by supplying the lubricating composition as disclosed herein to the engine. The lubricating composition disclosed herein comprises: between 0.3% and 1.1% by weight total sulfated ash; a kinematic viscosity of less than 8.3 cSt at 100°C; between 0.6% and 2.1% by weight total alkaline earth metal soaps; and a HTHS of less than 2.7 mPa·s as measured according to ASTM D4683. The lubricating composition can be used in diesel engines, particularly heavy-duty diesel engines, to improve one or more of fuel economy and wear protection.

Description

Diesel engine lubricating composition and method of use thereof

Technical Field

The present disclosure provides a diesel engine lubricating composition and a method of lubricating a diesel engine by supplying to the engine a lubricating composition as disclosed herein. The lubricating compositions disclosed herein can be used in diesel engines (including, inter alia, heavy duty diesel engines) to improve one or more of fuel economy and wear protection.

Background

Lubricating oil compositions are used for smooth running of internal combustion engines. Engine oils for internal combustion engines are used, inter alia, (i) to lubricate the various sliding joints between piston rings and cylinder liners, in bearings for crankshafts and connecting rods, and in valve drive mechanisms including cams and valve lifters, (ii) to cool the engine, (iii) to clean and disperse combustion products, and (iv) to prevent corrosion and subsequent rust formation. The stringent requirements for high performance engines in recent years have meant a greater demand for lubricants used in such engines.

There is an increasing interest in improving the fuel efficiency of internal combustion engines. Vehicle manufacturers have improved fuel economy through engine design, and these improvements take advantage of advances in lubricating oils that provide better oxidation stability, wear protection, and reduced friction. Operators of heavy duty diesel vehicles have been reluctant to employ low viscosity grade engine oils to improve fuel economy, and durability (i.e., the ability to keep the vehicle on the road for extended periods of time and mileage) has been and remains a major concern. Thus, the most widely used viscosity grades for highway heavy duty diesel vehicles are SAE 15W-40, 10W-30 and 5W-30. In recent years, there is a continuing push to improve the fuel efficiency of heavy diesel vehicles. Accordingly, there is a need to improve the fuel economy of diesel engines without compromising the durability of the engine or otherwise adversely affecting lubricant performance, including deposit and soot control, and oxidation and corrosion resistance. This is particularly relevant for viscosity grades lower than those of SAE 5W-30, in particular those of 0W-20, 0W-16 and 0W 12.

Accordingly, there is an interest in developing lubricating compositions that can be used in diesel engines that can operate under severe conditions and loads while reducing the effects of soot and soot-related wear and cleanliness, deposits, and better fuel economy.

Disclosure of Invention

The present disclosure relates to a diesel engine lubricating composition for an internal combustion engine (typically a compression ignition engine) to have at least one of reduced soot, improved fuel economy, reduced deposit formation, reduced wear, and improved cleanliness.

The lubricating composition comprises an oil of lubricating viscosity having greater than 50 wt.% (sometimes referred to as "wt.%) of a group III base oil, a group IV base oil, a group V base oil, or a mixture thereof. The composition further comprises a first PIB succinimide dispersant derived from 1800Mn to 2500Mn PIB and a second PIB succinimide dispersant derived from PIB having a Mn less than 1600, provided that at least one of the first PIB succinimide dispersant and the second PIB succinimide dispersant is free of boron, an alkaline earth metal salicylate (such as calcium salicylate) detergent, an alkaline earth metal sulfonate, wherein the alkaline earth metal sulfonate is present to deliver from 0.1 wt.% to 1.2 wt.% alkaline earth metal soap to the composition, a phosphorus antiwear agent present in an amount to deliver from 300ppm to 900ppm phosphorus to the lubricating composition.

The lubricating composition may have a sulfated ash of between 0.3 wt% and 1.1 wt%, a kinematic viscosity at 100 ℃ of less than 8.3cSt, 0.6 wt% to 2.1 wt% total alkaline earth soap, and an HTHS of less than 2.7mpa.s measured according to ASTM D4683.

Detailed Description

The present disclosure provides diesel engine lubricating compositions and methods of using the diesel engine lubricating compositions. The lubricating composition comprises an oil of lubricating viscosity having greater than 50 wt% of a group III base oil, a group IV base oil, a group V base oil, or a mixture thereof, a first PIB succinimide dispersant derived from 1800Mn to 2500Mn PIB, a second PIB succinimide dispersant derived from PIB having Mn less than 1600, wherein at least one of the first and second PIB succinimide dispersants is free of boron, an alkaline earth metal salicylate detergent, an alkaline earth metal sulfonate detergent present in an amount that delivers from 0.1 wt% to 1.2 wt% alkaline earth metal soap to the lubricating composition, and a phosphorus antiwear agent present in an amount that delivers from 300ppm to 900ppm phosphorus to the lubricating composition. The lubricating composition disclosed herein also comprises between 0.3 wt% and 0.9 wt% or between 0.3 wt% and 1.1 wt% total sulfated ash, 0.6 wt% to 2.1 wt% total alkaline earth soap content, and HTHS of less than 2.7mpa.s measured according to ASTM D4683.

Oil of lubricating viscosity

The lubricating composition disclosed herein comprises an oil of lubricating viscosity. Such oils include natural and synthetic oils, oils derived from hydrocracking, hydrogenation, and hydrofinishing, unrefined, refined, re-refined, or mixtures thereof. More detailed descriptions of unrefined, refined, and re-refined oils are provided in paragraphs [0054] to [0056] of international publication WO2008/147704 (similar disclosures are provided in U.S. patent application 2010/197536, see [0072] to [0073 ]). More detailed descriptions of natural and synthetic lubricating oils are described in paragraphs [0058] to [0059] of WO2008/147704, respectively (similar disclosures are provided in U.S. patent application 2010/197536, see [0075] to [0076 ]). The synthetic oil may also be produced by a fischer-tropsch reaction and may typically be hydroisomerised fischer-tropsch hydrocarbons or waxes. In one embodiment, the oil may be prepared by a Fischer-Tropsch gas to liquid synthesis process and other gas to liquid oils.

An oil of lubricating viscosity may also be defined as specified in subheading 1.3 of section 4 of "Appendix E-API Base Oil Interchangeability Guidelines for Passenger Car Motor Oils and Diesel Engine Oils", 2008. "base stock category". API guidelines are also summarized in U.S. Pat. No. 3, 7,285,516 (see column 11, line 64 to column 12, line 10).

Class IV (also known as polyalphaolefins or PAOs) are known in the art and are prepared by oligomerization or polymerization of linear alpha olefins. The base oil PAO is characteristically a water white oil with excellent low temperature viscosity properties (as measured) as well as a high viscosity index. Typical PAOs suitable for use in internal combustion engines include polyalphaolefins having a kinematic viscosity of 3 to 10m ²/s, such as PAO-4 and PAO-6, i.e., about 4m ²/s and 6m ²/s, respectively.

In addition to conventional group III and group IV base oils, some group V base oils, especially group V ester base oils, may be present at low levels. The ester base fluids include esters of monocarboxylic acids and monohydric alcohols, diesters of diols and monocarboxylic acids and diesters of dicarboxylic acids and monohydric alcohols, polyol esters of monocarboxylic acids and polyesters of monohydric alcohols and polycarboxylic acids, and mixtures thereof. Esters can be broadly divided into two categories, synthetic esters and natural esters.

Synthetic esters may include esters of dicarboxylic acids (e.g., phthalic acid, succinic acid, alkyl succinic acids and alkenyl succinic acids, maleic acid, azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid dimer, malonic acid, alkyl malonic acids and alkenyl malonic acids) with any of a variety of monohydric alcohols (e.g., butanol, hexanol, dodecanol, 2-ethylhexanol, ethylene glycol, diethylene glycol monoether, and propylene glycol). Specific examples of these esters include dibutyl adipate, di (2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, didecyl phthalate, biseicosanyl sebacate, 2-ethylhexyl diester of linoleic acid dimer, and complex esters formed by reacting 1 mole of sebacic acid with 2 moles of tetraethylene glycol and 2 moles of 2-ethylhexanoic acid. Other synthetic esters include esters prepared from C5 to C12 monocarboxylic acids and polyols and polyol ethers such as neopentyl glycol, trimethylol propane, pentaerythritol, dipentaerythritol, and tripentaerythritol. The esters may also be monoesters of monocarboxylic acids and monohydric alcohols.

Natural (or bio-derived) esters refer to substances derived from renewable biological resources, organisms or entities, which are different from substances derived from petroleum or equivalent raw materials. Natural lipids include fatty acid triglycerides, hydrolyzed or partially hydrolyzed triglycerides, or transesterified triglycerides, such as fatty acid methyl esters (or referred to as FAMEs). Suitable triglycerides include, but are not limited to, palm oil, soybean oil, sunflower oil, canola oil, olive oil, linseed oil and related substances. Other sources of triglycerides include, but are not limited to, algae, tallow, and zooplankton. Methods for producing biological lubricants from natural triglycerides are described, for example, in U.S. patent publication 2011/0009300 A1.

In one embodiment, the lubricant composition of the present disclosure comprises 0.1 to 10 wt% of an ester base fluid or 0.25 to 5 wt% or 0.1 to 2 wt% of an ester base fluid. In one embodiment, the lubricating composition comprises no greater than 5 wt.% of the ester base fluid, no greater than 2.5 wt.% or no greater than 1 wt.% of the ester base fluid. In one embodiment, the lubricant composition is free or substantially free (i.e., contains less than 0.2 wt.%) of intentionally added ester base fluid.

In one embodiment, the oil of lubricating viscosity may be a base oil comprising an API group I to group IV oil, an ester or synthetic oil, or a mixture thereof. In one embodiment, the oil of lubricating viscosity may be an API group II oil, a group III oil, a group IV oil, an ester or a synthetic oil, or mixtures thereof. In some embodiments, the oil of lubricating viscosity comprises at least 50 wt% or at least 60 wt% or at least 70 wt% or at least 80 wt% or at least 90 wt% or at least 95 wt% or at least 100 wt% of a group III base oil or a group IV base oil or a mixture of a group III base oil and a group IV base oil.

The amount of oil of lubricating viscosity present is typically the balance remaining after subtracting the sum of the amounts of additives and other performance additives of the disclosed compositions from 100 wt.%.

The lubricating composition may be in the form of a concentrate and/or a fully formulated lubricant. If the lubricating compositions described herein (including the additives disclosed herein) are in the form of concentrates that can be combined with additional oil to form, in whole or in part, a finished lubricant, the ratio of these additives to oil of lubricating viscosity and/or to diluent oil includes the range of 1:99 to 99:1 by weight or 80:20 to 10:90 by weight. Typically, the lubricating composition described herein comprises at least 50 wt.% or at least 60 wt.% or at least 70 wt.% or at least 80 wt.% of an oil of lubricating viscosity.

In some embodiments, the oil of lubricating viscosity may comprise a base oil of kinematic viscosity of 2.4m ²/s to 6.4m ²/s measured at 100 ℃. In some embodiments, the kinematic viscosity is 3.8m ²/s to 5.0m ²/s or 5.2m ²/s to 5.8m ²/s or 6.0m ²/s to 6.5m ²/s. In other embodiments, the base oil has a kinematic viscosity of 4.5m ²/s or 4.3m ²/s or 4.2m ²/s.

Polyisobutene (PIB) succinimide dispersants

The lubricating composition of the present disclosure further comprises a first polyisobutylene succinimide dispersant and a second polyisobutylene succinimide dispersant. The polyisobutylene succinimide dispersant referred to herein refers to both the first and second polyisobutylene succinimide dispersants. The difference is that the first polyisobutylene succinimide dispersant is derived from a polyisobutylene-based moiety having a greater number average molecular weight (Mn) than the PIB of the second polyisobutylene succinimide dispersant.

The first polyisobutylene succinimide and/or the second polyisobutylene succinimide dispersant may each be prepared (or "derivatized" as used herein) from a polyisobutylene ("PIB") succinimide dispersant that is a "conventional" PIB or high vinylidene PIB. The difference between conventional polyolefins and high vinylidene polyolefins can be illustrated by reference to PIB production. In a process for producing conventional PIB, isobutylene is polymerized in the presence of AlCl ₃ to produce a mixture of polymers comprising predominantly tri-substituted olefin (III) end groups and tetra-substituted olefin (IV) end groups, wherein only a very small number (e.g., less than 20%) of the chains contain terminal vinylidene groups (I). In an alternative process, isobutylene is polymerized in the presence of a BF ₃ catalyst to produce a mixture of polymers comprising predominantly (e.g., at least 70%) terminal vinylidene groups, a small amount of tetra-substituted end groups, and other structures. Materials produced in alternative processes (sometimes referred to as "high vinylidene PIB") are also described in U.S. patent 6,165,235, which is incorporated herein by reference in its entirety. In one embodiment, the polyisobutylene-derived dispersant is a conventional polyisobutylene-derived dispersant. In another embodiment, the polyisobutylene-derived dispersant is a high or medium vinylidene succinimide dispersant. The polyisobutylene-derived dispersants used herein are generally known in the art.

The polyisobutene-derived acylating agents may be prepared/obtained/obtainable by reaction of an "ene" or "thermal" reaction (also known as direct alkylation) with maleic anhydride. The "ene" reaction mechanism and general reaction conditions are summarized in MALEIC ANHYDRIDE, pages 147 to 149, by b.c. trivedi and b.c. culbertson, and published by Plenum Press in 1982. The polyisobutylene-derived dispersants prepared by a process comprising an "ene" reaction comprise dispersants having a carbocycle present on less than 50 mole% or 0 mole% to less than 30 mole% or 0 mole% to less than 20 mole% or 0 mole% of the dispersant molecules. The "ene" reaction may have a reaction temperature of 180 ℃ to less than 300 ℃, or 200 ℃ to 250 ℃, or 200 ℃ to 220 ℃.

The polyisobutene-derived acylating agents may also be obtained/obtainable from a chlorine-assisted process, which typically involves a diels-alder reaction, resulting in the formation of a carbocyclic ring linkage. This process is known to those skilled in the art. The chlorine assisted process can produce acylating agents having a carbocycle present on 50 mole% or more or 60 mole% to 100 mole% of the molecule. Both the heat and chlorine assisted processes are described in more detail in U.S. patent 7,615,521, columns 4 to 5 and preparations a and B.

The polyisobutene-derived acylating agent may also be prepared/obtained/obtainable by a free radical process, wherein the acylating agent is reacted with the polyisobutene in the presence of a free radical initiator. Such free radical processes are well known in the art and may be performed in the presence of additional alpha-olefins.

The polyisobutylene-derived acylating agent may be obtained from reacting a polyisobutylene with an acylating agent (i.e., an ethylenically unsaturated carbonyl compound) to form an acylated polyisobutylene, which may be functionalized with an amine or further alcohol to form a suitable dispersant. Suitable acylating agents include maleic anhydride or reactive equivalents thereof (such as acids or esters), i.e., succinic acid and reactive equivalents thereof. In one embodiment, the polyisobutylene may be reacted with maleic anhydride to form an acylated product, wherein the conversion is between 1 and 2. In one embodiment, monosuccinic acid is reacted with the amine such that the desired product comprises a mixture wherein all anhydride present in the acylating agent has been converted to an imide.

The polyisobutylene-derived dispersant may have a carbonyl to nitrogen ratio (CO: N ratio) of 5:1 to 1:10, 2:1 to 1:10, or 2:1 to 1:5, or 2:1 to 1:2. In one embodiment, the dispersant may have a CO to N ratio of 2:1 to 1:10 or 2:1 to 1:5 or 2:1 to 1:2 or 1:1.4 to 1:0.6.

The polyisobutylene succinimide dispersants of the present disclosure may be prepared by reaction of an acylated PIB with a suitable amine compound. Suitable amines include one or more hydrocarbyl amines, amino alcohols, polyether amines, or combinations thereof.

In one embodiment, the hydrocarbyl amine component may comprise at least one aliphatic amine containing at least one amino group capable of condensing with the acyl group to provide a pendant group and at least one additional group comprising at least one nitrogen, oxygen, or sulfur atom. Suitable aliphatic amines include polyethylene polyamines such as tetraethylene pentamine (TEPA), triethylenetetramine (TETA), pentaethylene hexamine (PEHA), and polyamine bottoms, N-Dimethylaminopropylamine (DMAPA), N- (aminopropyl) morpholine, N-diisostearylaminopropylamine, ethanolamine, and combinations thereof.

In one embodiment, the hydrocarbyl amine component may comprise at least one aromatic amine containing at least one amino group capable of condensing with the acyl group to provide a pendant group and at least one additional group comprising at least one nitrogen, oxygen, or sulfur atom, wherein the aromatic amine is selected from the group consisting of (i) nitro-substituted aniline, (ii) amine containing two aromatic moieties linked by a C (O) NR-group, -C (O) O-group, -O-group, n=n-group, or-SO 2-group, wherein R is hydrogen or a hydrocarbyl group, one of the aromatic moieties bearing the condensable amino group, (iii) aminoquinoline, (iv) aminobenzimidazole, (v) N, N-dialkylphenylenediamine, (vi) aminodiphenylamine (also referred to as N, N-phenylenediamine), and (vii) a ring-substituted benzylamine.

In one embodiment, the polyetheramine compound may comprise an amine-terminated polyether compound. The amine-terminated polyether compound may comprise units derived from ethylene oxide, propylene oxide, butylene oxide, or some combination thereof. Suitable polyether compounds include those available from HuntsmanA series of polyetheramines.

In one embodiment, the first polyisobutylene succinimide dispersant may be prepared by the thermal direct alkylation processes described herein. In another embodiment, the second polyisobutylene succinimide dispersant may be prepared by the thermal direct alkylation processes described herein.

The polyisobutylene-derived dispersants as described herein may be further described as having a TBN. In one embodiment, the first polyisobutylene succinimide dispersant has a TBN of 15 to 25. In another embodiment, the first polyisobutylene succinimide dispersant has a TBN of 15 to 20. In one embodiment, the second polyisobutylene succinimide dispersant has a TBN of 20 to 35. In another embodiment, the second polyisobutylene succinimide dispersant has a TBN of 25 to 30. In one embodiment, the second polyisobutylene succinimide dispersant has a TBN of 27 to 28.

In one embodiment, the first polyisobutylene succinimide dispersant is derived from PIB having a number average molecular weight in the range 1720 to 2200. In another embodiment, the first polyisobutylene succinimide dispersant is derived from PIB having a number average molecular weight in the range 1800 to 2100. In one embodiment, the first polyisobutylene succinimide dispersant is derived from PIB having a number average molecular weight in the range 1850 to 2150.

In one embodiment, the second polyisobutylene succinimide dispersant is derived from PIB having a number average molecular weight in the range of 750 to 1600. In another embodiment, the second polyisobutylene succinimide dispersant is derived from PIB having a number average molecular weight in the range of 1000 to 1600. In one embodiment, the second polyisobutylene succinimide dispersant is derived from PIB having a number average molecular weight in the range of 1200 to 1600. In one embodiment, the second polyisobutylene succinimide dispersant is derived from PIB having a number average molecular weight in the range of 800 to 1150. In another embodiment, the second polyisobutylene succinimide dispersant is derived from PIB having a number average molecular weight in the range of 900 to 1100.

In one embodiment, the first polyisobutylene succinimide dispersant may be present in the lubricating composition in an amount of 0.5 wt.% to 10 wt.%. In another embodiment, the first polyisobutylene succinimide dispersant may be present in the lubricating composition in an amount of 0.8 wt.% to 6 wt.%. In one embodiment, the first polyisobutylene succinimide dispersant may be present in the lubricating composition in an amount of 1 wt.% to 5 wt.%. In one embodiment, the first polyisobutylene succinimide dispersant may be present in the lubricating composition in an amount of 1.1 wt.% to 2.2 wt.%.

In one embodiment, the second polyisobutylene succinimide dispersant is present in the lubricating composition in an amount of 1 wt.% to 5 wt.%. In another embodiment, the second polyisobutylene succinimide dispersant is present in the lubricating composition in an amount of 1.5 wt.% to 4.8 wt.%. In another embodiment, the second polyisobutylene succinimide dispersant is present in the lubricating composition in an amount of 1.8 wt.% to 4.6 wt.%. In another embodiment, the second polyisobutylene succinimide dispersant is present in the lubricating composition in an amount of 1.9 wt.% to 3.3 wt.%.

In one embodiment, the first polyisobutylene succinimide dispersant may comprise a mixture of two or more dispersants, wherein each of the two or more dispersants falls within a range including, but not limited to, PIB Mn, TBN, and processing rate of the first polyisobutylene succinimide dispersant as disclosed herein. In another embodiment, the first polyisobutylene succinimide dispersant may comprise a mixture of two dispersants, wherein each of the two dispersants falls within a range including, but not limited to, PIB Mn, TBN, and processing rate of the first polyisobutylene succinimide dispersant as disclosed herein.

In some embodiments, the second polyisobutylene succinimide dispersant may comprise a mixture of two or more dispersants, wherein each of the two or more dispersants falls within a range including, but not limited to, PIB Mn, TBN, and processing rate of the second polyisobutylene succinimide dispersant as disclosed herein. In another embodiment, the second polyisobutylene succinimide dispersant comprises 1 wt.% to 5 wt.% of a PIB succinimide dispersant derived from a PIB having a Mn of 900 to 1100 and 1 wt.% to 5 wt.% of a PIB succinimide dispersant derived from a PIB having a Mn of 1200 to 1600.

The lubricating composition of the present disclosure also provides that at least one of the first polyisobutylene succinimide dispersant and the second polyisobutylene succinimide dispersant is free of boron. In one embodiment, the first polyisobutylene succinimide dispersant is free of boron and the second polyisobutylene succinimide dispersant is borated. In another embodiment, the first polyisobutylene succinimide dispersant is borated and the second polyisobutylene succinimide dispersant is free of boron.

In preparing the boron-containing polyisobutylene succinimide dispersant, the first polyisobutylene-derived succinimide dispersant or the second polyisobutylene-derived succinimide dispersant as described herein may be post-treated by conventional methods, including reaction with a boron compound to produce the boron-containing polyisobutylene succinimide dispersant. Suitable boron compounds that may be used to borated polyisobutylene-derived dispersants include one or more of a variety of agents selected from the group consisting of various forms of boric acid (including metaboric acid HBO ₂, orthoboric acid H ₃BO₃, and tetraboric acid H ₂B₄O₇), boric oxide, boric trioxide, and alkyl borates. In one embodiment, the borating agent is boric acid, which may be used alone or in combination with other borating agents. Methods of preparing borated dispersants are known in the art. The borated dispersants may be prepared in such a way that they contain from 0.1 to 2.5 wt% boron or from 0.1 to 2.0 wt% boron or from 0.2 to 1.5 wt% boron or from 0.3 to 1.0 wt% boron.

In some embodiments, the borated first polyisobutylene succinimide dispersant or borated second polyisobutylene succinimide dispersant is present in an amount that delivers at least 25ppm or at least 50ppm or at least 75ppm boron to the lubricating composition. In another embodiment, either of the borated first polyisobutylene succinimide dispersant and the borated second polyisobutylene succinimide dispersant is present in an amount to deliver 25ppm to 400ppm boron to the lubricating composition. In another embodiment, either of the borated first polyisobutylene succinimide dispersant and the borated second polyisobutylene succinimide dispersant are present in an amount that delivers 25ppm to 400ppm or 50ppm to 200ppm or 75ppm to 150ppm or 78ppm to 100ppm boron to the lubricating composition.

Washing agent

The lubricating composition of the present disclosure further comprises an alkaline earth metal salicylate detergent and at least one alkaline earth metal sulfonate detergent as described herein. Metal-containing detergents are known in the art. They generally consist of metal salts of acidic organic substrates, in particular alkali metals and alkaline earth metals. The metal-containing detergents may be neutral (i.e., stoichiometric salts of metal and substrate, also known as neutral soaps or soaps), or overbased.

Metal overbased detergents (also known as overbased detergents, metal-containing overbased detergents, or overbased salts) are characterized by a metal content in excess of that required for neutralization based on the stoichiometry of the metal and the particular acidic organic compound (i.e., substrate) reacted with the metal. The overbased detergent may comprise one or more of sulfonates, salicylates, sulfur-free phenates, sulfur-containing phenates, and mixtures thereof.

The amount of excess metal relative to the substrate is typically expressed in terms of metal ratio. The term "metal ratio" is used in the prior art and herein to define the ratio of the total chemical equivalent of metal in the overbased salt to the chemical equivalent of metal in the salt, which is desirably derived from the reaction between the hydrocarbyl-substituted organic acid, hydrocarbyl-substituted phenol, or mixture thereof, to be overbased, and the alkali metal compound, according to the known chemical reactivity and stoichiometry of the two reactants. Thus, in normal or neutral salts (i.e. soaps), the metal ratio is 1, and in overbased salts, the metal ratio is greater than 1, in particular greater than 1.3. The overbased metal detergent may have a metal ratio of 5 to 30 or a metal ratio of 7 to 22 or a metal ratio of 11 to 18 or a metal ratio of at least 11.

Metal-containing detergents may also include "mixed" detergents formed with mixed surfactant systems that include phenate and/or sulfonate components, e.g., phenate-salicylate, sulfonate-phenate, sulfonate-salicylate, sulfonate-phenate-salicylate, as described, for example, in U.S. Pat. Nos. 6,429,178, 6,429,179, 6,153,565, and 6,281,179. In the case of, for example, mixed sulfonate/salicylate detergents, the mixed detergents will be considered equivalent to the amounts of different salicylate and sulfonate detergents incorporating the same amounts of salicylate and sulfonate soaps, respectively. Overbased phenates and salicylates typically have a total base number of 180 to 450 TBN. The overbased sulfonates typically have a total base number of from 250 to 800 or 300 to 600. Overbased detergents are known in the art.

Alkylphenols are generally used as ingredients in overbased detergents and/or as building blocks for overbased detergents. Alkylphenols may be used to prepare phenate, salicylate alkoxide or salicin detergents, or mixtures thereof. Suitable alkylphenols may include para-substituted hydrocarbyl phenols. The hydrocarbyl group may be a straight or branched chain aliphatic group of 1 to 60 carbon atoms, 8 to 40 carbon atoms, 10 to 24 carbon atoms, 12 to 20 carbon atoms, or 16 to 24 carbon atoms. In one embodiment, the alkylphenol overbased detergent is prepared from alkylphenols or mixtures thereof that are free or substantially free (i.e., contain less than 0.1 wt%) of para-dodecylphenol. In one embodiment, the lubricating composition contains less than 0.3 wt.% alkylphenol, less than 0.1 wt.% alkylphenol, or less than 0.05 wt.% alkylphenol. In one embodiment, the alkylphenol detergent is a salicylate.

Alkaline earth metal salicylates

Salicylate detergents and overbased salicylate detergents may be prepared in at least two different ways. Carbonylation (also known as carboxylation) of para-alkylphenols is described in a number of references, including U.S. patent 8,399,388. The carbonylation may be followed by overbasing to form the overbased salicylate detergents. Suitable para-alkylphenols include those having straight and/or branched hydrocarbon groups of 1 to 60 carbon atoms, 4 to 34 carbon atoms, 14 to 24 carbon atoms, and combinations thereof. Salicylate detergents can also be prepared by alkylation of salicylic acid followed by overbasing, as described in U.S. patent 7,009,072. Salicylate detergents prepared in this manner can be prepared from linear and/or branched alkylating agents (typically 1-olefins) containing from 6 to 50 carbon atoms, from 10 to 30 carbon atoms or from 14 to 24 carbon atoms. In one embodiment, the overbased detergent is a salicylate detergent. In one embodiment, the salicylate detergent is free of unreacted para-alkylphenol (i.e., contains less than 0.1 wt%). In one embodiment, the salicylate detergent is prepared by alkylation of salicylic acid.

In one embodiment, the alkaline earth metal salicylate detergent has a TBN (KOH/g) of 200 to 575 or 200 to 500. In another embodiment, the alkaline earth metal salicylate detergent has a TBN (KOH/g) of from 250 to 350. In one embodiment, the alkaline earth metal salicylate detergent has a metal ratio of from 2 to 7 or from 2 to 4 or from 2.5 to 3.5. In one embodiment, the alkaline earth metal salicylate detergent is present in the lubricating composition in an amount of from 0.1 wt.% to 5 wt.%. In another embodiment, the alkaline earth metal salicylate detergent is present in the lubricating composition in an amount of from 0.2 wt.% to 3 wt.%. In one embodiment, the alkaline earth metal salicylate detergent is present in the lubricating composition in an amount of from 0.5 wt.% to 3 wt.%. In one embodiment, the alkaline earth metal salicylate detergent is present in the lubricating composition in an amount of from 0.8 wt.% to 2.5 wt.%. In one embodiment, the calcium alkaline earth metal detergent is present in the lubricating composition in an amount of from 0.9 wt.% to 2.3 wt.%.

In one embodiment, the alkaline earth metal salicylate detergent may be calcium salicylate, magnesium salicylate, or a combination thereof. In one embodiment, the alkaline earth metal salicylate is calcium salicylate. In one embodiment, the alkaline earth metal salicylate is magnesium salicylate. The calcium salicylate may be present in an amount that delivers 150ppm to 1500ppm calcium to the lubricant composition or 250ppm to 1100ppm calcium to the composition. The magnesium salicylate may be present in an amount to deliver 100ppm to 2000ppm magnesium to the lubricant composition or 250ppm to 1750ppm magnesium or 300ppm to 1550ppm magnesium to the lubricant composition.

Alkaline earth metal sulfonate detergent

The alkaline earth metal sulfonate may be a neutral sulfonate (metal ratio less than 1.3), a low overbasing detergent (metal ratio of 1.5 to 6), or a high overbasing detergent (metal ratio of at least 8), or any combination thereof, such that at least 0.1 wt.% alkaline earth metal soap is present in the lubricant composition.

The alkaline earth metal sulfonate detergent may be a linear alkylbenzene sulfonate detergent as described in paragraphs [0026] to [0037] of U.S. patent publication 2005/065045 (and granted as US 7,407,919). Linear alkylbenzene sulfonate detergents may be particularly useful to help improve fuel economy. The linear alkyl group may be attached to the benzene ring at any position along the linear chain of the alkyl group (but typically at the 2, 3 or 4 position of the linear chain and in some cases predominantly at the 2 position) to give a linear alkylbenzene sulfonate detergent.

In one embodiment, the alkaline earth metal sulfonate detergent of the present disclosure is selected from the group consisting of calcium sulfonate detergents and magnesium sulfonate detergents. In another embodiment, the alkaline earth metal sulfonate detergent is a calcium sulfonate detergent. In one embodiment, the calcium sulfonate detergent has a TBN of less than 250 on an oil-free basis. In another embodiment, the calcium sulfonate detergent has a TBN of less than 200 or less than 150 or less than 80. In one embodiment, the calcium sulfonate detergent has a TBN of 50 to 90. In one embodiment, the calcium sulfonate has a TBN of 120 to 250mg KOH/g and a metal ratio of 1.5 to 5.

In one embodiment, the alkaline earth metal sulfonate detergent is a calcium sulfonate detergent present in the lubricating composition in an amount of from 0.1 wt.% to 2.0 wt.%. In another embodiment, the calcium sulfonate detergent is present in the lubricating composition in an amount of from 0.3 wt.% to 1.5 wt.%.

In one embodiment, the alkaline earth metal sulfonate detergent is a magnesium sulfonate detergent. The magnesium sulfonate may have a TBN (mg KOH/g) of 300 to 800 on an oil-free basis. In some embodiments, the magnesium sulfonate may have a TBN (mg KOH/g) of 400 to 750. In other embodiments, the magnesium sulfonate may have a TBN (mg KOH/g) of 250 to 350. In other embodiments, the magnesium sulfonate may have a TBN (mg KOH/g) of 350 to 375. In one embodiment, the magnesium sulfonate may have a metal ratio of 8 to 30, 10 to 25, or 12 to 18.

In one embodiment, the magnesium sulfonate detergent is present in the lubricating composition in an amount of from 0.05 wt.% to 0.5 wt.%, or from 0.05 wt.% to 0.2 wt.%. In another embodiment, the magnesium sulfonate detergent is present in the lubricating composition in an amount of 0.06 wt.% to 0.1 wt.%, or 0.06 wt.% to 0.2 wt.%.

In one embodiment, the alkaline earth metal sulfonate may be a combination of at least one neutral or low overbased alkaline earth metal sulfonate (i.e., a metal ratio of less than 6) and at least one high overbased alkaline earth metal sulfonate (a metal ratio of at least 8).

Alkaline earth metal detergents as used herein may be sodium, calcium, magnesium salts of sulfonates, or mixtures thereof. In one embodiment, the alkaline earth metal sulfonate detergent is a calcium sulfonate detergent, a magnesium sulfonate detergent, or a mixture thereof. In one embodiment, one or more of the calcium sulfonate detergent and the magnesium sulfonate detergent is overbased. In one embodiment, the alkaline earth metal detergent is a overbased calcium sulfonate detergent. In another embodiment, the alkaline earth metal detergent is a magnesium overbased sulfonate detergent. In yet another embodiment, the alkaline earth metal detergent is a mixture of a calcium overbased sulfonate detergent and a magnesium overbased sulfonate detergent. In one embodiment, the alkaline earth metal sulfonate detergent is a mixture of 0.6 wt.% to 1.5 wt.% of a calcium sulfonate detergent having a TBN (mg KOH/g) of 50 to 200 and 0.04 wt.% to 0.1 wt.% of a magnesium overbased sulfonate detergent having a TBN (mg KOH/g) of 400 to 800.

The detergents of the disclosed lubricating compositions may include alkaline earth metals from the detergents. In one embodiment, the calcium salicylate detergent is present in an amount to deliver 150ppm to 1500ppm or 250ppm to 1100ppm or 300ppm to 800ppm calcium to the lubricating composition. In embodiments wherein the alkaline earth metal detergent comprises a calcium sulfonate detergent, the calcium sulfonate detergent may be present in an amount that delivers 100ppm to 1000ppm, 150ppm to 800ppm, or 250ppm to 650ppm of calcium to the lubricating composition. In embodiments wherein the alkaline earth metal detergent comprises a magnesium sulfonate detergent, the magnesium sulfonate detergent may be present in an amount that delivers 50ppm to 500ppm, 100ppm to 425ppm, or 150ppm to 350ppm magnesium to the lubricating composition. In some embodiments, the alkaline earth metal detergent comprises a calcium sulfonate detergent and the total amount of calcium delivered to the lubricating composition from the calcium salicylate detergent and the calcium sulfonate detergent is 800ppm to 2500ppm, 900ppm to 1800ppm, 950ppm to 1450ppm calcium delivered to the lubricating composition.

Metal-containing detergents provide sulfated ash to lubricating compositions. Sulphated ash may be determined by ASTM D874. In one embodiment, the total sulfated ash delivered to the lubricating composition from the alkaline earth metal salicylate detergent and alkaline earth metal detergent is from 0.25 wt% to 0.95 wt%. In other embodiments, the alkaline earth metal salicylate detergent is present in an amount that delivers from 0.05 wt% to 0.5 wt% or from 0.1 wt% to 0.35 wt% sulfated ash to the lubricating composition. In another embodiment, the alkaline earth metal detergent is present in an amount that delivers 0.05 wt.% to 0.75 wt.% or 0.1 wt.% to 0.6 wt.% sulfated ash to the lubricating composition.

In addition to ash and TBN, overbased detergents provide detergent soaps (also known as neutral detergents) to lubricating compositions. As a metal salt of the substrate, the soap may act as a surfactant in the lubricating composition. In one embodiment, the alkaline earth metal sulfonate detergent is present in an amount that delivers from 0.1 wt% to 1.5 wt% or from 0.15 wt% to 1.2 wt% or from 0.2 wt% to 0.9 wt% sulfonate soap to the lubricant composition. In one embodiment, the alkaline earth metal salicylate detergent is present in an amount to deliver from 0.3 wt% to 1.4 wt% or from 0.35 wt% to 1.2 wt% or from 0.4 wt% to 1.0 wt% salicylate soap to the lubricant composition. In one embodiment, the alkaline earth metal soap may be calcium, magnesium, or any mixture thereof. In one embodiment, the alkaline earth metal sulfonate soap is present in an amount of 0.2 wt% to 0.8 wt% of the lubricant composition and the alkaline earth metal salicylate soap is present in an amount of 0.3 wt% to 1.0 wt% of the lubricant composition. The total amount of all alkaline earth metal detergent soaps may be present in an amount of 0.6 to 2.1 wt% or 0.7 to 1.4 wt% of the lubricant composition.

Antiwear agent

The lubricating composition of the present disclosure also comprises one or more phosphorus-containing antiwear agents.

Phosphorus-containing antiwear agents are well known to those skilled in the art and include metal dialkyl (dithio) phosphates, hydrocarbyl phosphites, hydrocarbyl phosphines, hydrocarbyl phosphonates, alkyl phosphates, amine or ammonium (alkyl) phosphates, and combinations thereof.

In one embodiment, the phosphorus-containing antiwear agent may be a metal dialkyldithiophosphate, which may include zinc dialkyldithiophosphate. Such zinc salts are commonly referred to as zinc dialkyldithiophosphates (ZDDP) or simply Zinc Dithiophosphates (ZDP). They are well known and readily available to those skilled in the art of lubricant formulations. In addition, zinc dialkyldithiophosphates can be described as primary or secondary zinc dialkyldithiophosphates, depending on the structure of the alcohol used in their preparation. In some embodiments, the present compositions may comprise a primary zinc dialkyldithiophosphate. In some embodiments, the composition comprises a secondary zinc dialkyldithiophosphate. In some embodiments, the composition comprises a mixture of primary and secondary zinc dialkyldithiophosphates. In some embodiments, component (b) is a mixture of primary and secondary zinc dialkyldithiophosphates, wherein the ratio (on a weight basis) of primary to secondary zinc dialkyldithiophosphates is at least 1:1 or even at least 1:1.2 or even at least 1:1.5 or 1:2 or 1:10.

Examples of suitable dialkyldithiometal phosphates include metal salts of the formula:

Wherein R ¹ and R ² are independently hydrocarbyl groups containing 3 to 24 carbon atoms or 3 to 12 carbon atoms or 3 to 8 carbon atoms, M is a metal having a valence n, and typically includes zinc, copper, iron, cobalt, antimony, manganese, and combinations thereof. In one embodiment, R ¹ and R ² are secondary aliphatic hydrocarbyl groups containing 3 to 8 carbon atoms, and M is zinc.

In one embodiment, the phosphorus-containing antiwear agent may be a phosphorus-containing compound that does not contain zinc. The zinc-free phosphorus antiwear agent may or may not contain sulfur. Sulfur-free phosphorus-containing antiwear agents include hydrocarbyl phosphites, hydrocarbyl phosphines, hydrocarbyl phosphonates, alkyl phosphates, amine or ammonium phosphates, or mixtures thereof.

In one embodiment, the phosphorus-containing antiwear agent is present in the lubricating composition in an amount that delivers 300ppm to 900ppm phosphorus to the lubricating composition. In one embodiment, the antiwear agent is ZDDP and is present in the composition in an amount that delivers 400ppm to 850ppm or 450ppm to 800ppm or 500ppm to 800ppm or 550ppm to 780ppm or 650ppm to 780ppm phosphorus to the lubricating composition.

In one embodiment, the phosphorus-containing antiwear agent is present in an amount of 0.2 wt% to 2 wt% or 0.3 wt% to 1.3 wt% or 0.5 wt% to 0.95 wt% of the lubricant composition.

Other Performance additives

The lubricating composition may be prepared by blending an oil of lubricating viscosity, a first PIB succinimide dispersant, a second succinimide dispersant, a calcium salicylate detergent, an alkaline earth metal detergent, a phosphorus antiwear agent, and optionally one or more performance additives (described below).

Other performance additives include at least one of metal deactivators, viscosity modifiers, friction modifiers, antiwear agents, corrosion inhibitors, extreme pressure agents, antioxidants, foam inhibitors, demulsifiers, pour point depressants, seal swelling agents, and mixtures thereof. Typically, fully formulated lubricating oils will contain one or more of these performance additives.

The lubricating composition in another embodiment comprises an antioxidant, wherein the antioxidant comprises a phenolic antioxidant, or an aminic antioxidant, or a mixture thereof. Antioxidants include diarylamines, alkylated diarylamines, hindered phenols, or mixtures thereof. When present, each antioxidant is independently present at 0.1 wt% to 3 wt% or 0.5 wt% to 2.75 wt% or 1 wt% to 2.5 wt% of the lubricating composition.

The diarylamine or alkylated diarylamine may be phenyl-alpha-naphthylamine (PANA), alkylated diphenylamine, or alkylated phenyl-naphthylamine, or mixtures thereof. The alkylated diphenylamines may include dinonylated diphenylamine, nonylaniline, octyldiphenylamine, dioctylated diphenylamine, didecylated diphenylamine, decyldiphenylamine, and mixtures thereof. In one embodiment, the diphenylamine may comprise nonyldiphenylamine, dinonyldiphenylamine, octyldiphenylamine, dioctyldiphenylamine, or mixtures thereof. In another embodiment, the alkylated diphenylamine may comprise nonyldiphenylamine or dinonyldiphenylamine. The alkylated diarylamines may include octyl, dioctyl, nonyl, dinonyl, decyl or didecylphenyl naphthylamine.

Hindered phenolic antioxidants typically contain sec-butyl and/or tert-butyl groups as steric hindrance groups. The phenolic group may typically be further substituted with a hydrocarbyl group (typically a straight or branched chain alkyl group) and/or a bridging group attached to the 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 include, for example, irganox ^TM L-135 from Ciba. Suitable hindered phenolic esters include hydrocarbyl esters of 3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid, such as hydrocarbyl esters containing 3 to 18 carbon atoms or 4 to 12 carbon atoms or 6 to 10 carbon atoms. A more detailed description of suitable ester-containing hindered phenol antioxidant chemistries is found in U.S. patent 6,559,105.

In one embodiment, the lubricating composition contains a friction modifier. The friction modifier may be selected from the group consisting of long chain fatty acid derivatives of amines, long chain fatty esters or derivatives of long chain fatty epoxides, fatty imidazolines, amine salts of alkyl phosphates, fatty alkyl tartrates, fatty alkyl tartrimides, fatty glycolates, fatty hydroxyacetamides, and combinations thereof.

As used herein, the term "fatty alkyl" or "fat" in connection with friction modifiers refers to a carbon chain having from 10 to 24 carbon atoms, typically a linear carbon chain, which may be saturated or unsaturated.

Examples of suitable friction modifiers include long chain fatty acid derivatives of amines, fatty acid esters or fatty epoxides, fatty imidazolines such as condensation products of carboxylic acids and polyalkylene polyamines, amine salts of alkylphosphoric acids, fatty alkyl tartrates, fatty alkyltartrates, fatty phosphonates, fatty phosphites, borated phospholipids, borated fatty epoxides, glycerides, borated glycerides, fatty amines, alkoxylated fatty amines, borated alkoxylated fatty amines, hydroxy and polyhydroxy fatty amines including tertiary hydroxy fatty amines, hydroxyalkylamides, metal salts of fatty acids, metal salts of alkylsalicylates, fatsOxazolines, fatty ethoxylated alcohols, condensation products of carboxylic acids and polyalkylene polyamines, or reaction products from fatty carboxylic acids with guanidine, aminoguanidine, urea or thiourea, and salts thereof.

Friction modifiers may also include materials such as sulfurized aliphatic compounds and olefins, molybdenum compounds such as molybdenum dialkyldithiophosphates, molybdenum dithiocarbamates, amine-salted molybdic acid compounds, and molybdenum post-treated succinimide dispersants. Molybdenum dithiocarbamates may be mononuclear, dinuclear, or even trinuclear complexes. Suitable molybdenum compounds may exist as Mo (IV) complexes or Mo (V) complexes or Mo (VI) complexes, or combinations thereof, and include commercial materials such as Sakura-tube 525 from Adeka Co.Ltd and Vanderbilt CHEMICALS LLC from Vanderbilt855。

In another embodiment, the friction modifier may be a long chain fatty acid ester. In another embodiment, the long chain fatty acid ester may be a monoester, and in another embodiment, the long chain fatty acid ester may be a triglyceride. Suitable triglycerides include vegetable oils such as soybean oil or sunflower oil.

The ashless friction modifier may be present in the lubricating composition in an amount of from 0.01 wt.% to 2.5 wt.%, or from 0.1 wt.% to 0.5 wt.%, or from 0.3 wt.% to 2.0 wt.%, or from 0.5 wt.% to 0.9 wt.%.

The lubricating composition optionally also comprises at least one antiwear agent other than the phosphorus-containing antiwear agents described above. Examples of suitable antiwear agents include titanium compounds, tartrates, tartrimides, thiocarbamate-containing compounds such as thiocarbamates, thiocarbamate amides, thiocarbamate ethers, alkylene-coupled thiocarbamates and bis (S-alkyl dithiocarbamoyl) dithios. In one embodiment, the antiwear agent may comprise tartrate or tartrimide, as disclosed in International publication WO 2006/044411 or Canadian patent CA 1 183 125. The tartrate or tartrimide may contain alkyl-ester groups wherein the sum of carbon atoms on the alkyl groups is at least 8. In one embodiment, the antiwear agent may comprise a citrate salt, as disclosed in U.S. patent application 20050198894.

Another class of additives includes oil-soluble titanium compounds, as disclosed in US 7,727,943 and US 2006/0014651. The oil-soluble titanium compound may be used as an antiwear agent, friction modifier, antioxidant, deposit control additive, or more than one of these functions. In one embodiment, the oil-soluble titanium compound is a titanium (IV) alkoxide. The titanium alkoxide is formed from a monohydric alcohol, a polyhydric alcohol, or a mixture thereof. The monoalkoxides may have from 2 to 16 carbon atoms or from 3 to 10 carbon atoms. In one embodiment, the titanium alkoxide is titanium (IV) isopropoxide. In one embodiment, the titanium alkoxide is titanium (IV) 2-ethylhexanoate. In one embodiment, the titanium compound comprises an alkoxide of an ortho-1, 2-diol or polyol. In one embodiment, the 1, 2-o-diol comprises a fatty acid monoester of glycerol, typically the fatty acid is oleic acid.

In one embodiment, the oil-soluble titanium compound is a titanium carboxylate. In another embodiment, the titanium (IV) carboxylate is titanium neodecanoate.

Extreme Pressure (EP) agents that are soluble in oil include sulfur-and sulfur-containing EP agents, dimercaptothiadiazole or CS ₂ derivatives of dispersants (typically succinimide dispersants), chlorinated hydrocarbon EP agents, and phosphorous EP agent derivatives. Examples of such EP agents include chlorinated waxes, sulfurized olefins (such as sulfurized isobutylene), hydrocarbyl-substituted 2, 5-dimercapto-1, 3, 4-thiadiazoles or oligomers thereof, organic sulfides and polysulfides (such as dibenzyldisulfide, bis- (chlorobenzyl) disulfide, dibutyl tetrasulfide), sulfurized methyl oleate, sulfurized alkylphenols, sulfurized dipentene, sulfurized terpenes and sulfurized diels-alder adducts, phosphorus sulfurized hydrocarbons such as the reaction product of phosphorus sulfide with turpentine or methyl oleate, phosphites such as dienes and triocarbon phosphites, for example dibutyl phosphite, diheptyl phosphite, dicyclohexyl phosphite, pentylphenyl phosphite, dipentylphenyl phosphite, tridecyl phosphite, distearyl phosphite and polypropylene-substituted phenol phosphite, amine salts or derivatives of metal thiocarbamates such as zinc dioctyl dithiocarbamate and barium heptyl phenol diacrylate, alkyl and dialkyl phosphoric acid including, for example, the product of dialkyl dithiophosphoric acid with propylene oxide and subsequent further reaction with P ₂O₅, and mixtures thereof (as in US 197, 3, 197).

Foam inhibitors that may be used in the present compositions include polysiloxanes, copolymers of ethyl acrylate and 2-ethylhexyl acrylate, and optionally vinyl acetate, and demulsifiers including fluorinated polysiloxanes, trialkyl phosphates, polyethylene glycols, polyethylene oxides, polypropylene oxides, and (ethylene oxide-propylene oxide) polymers.

Polymeric viscosity index improvers, also known as Viscosity Modifiers (VM) or Dispersant Viscosity Modifiers (DVM), may be used in the compositions disclosed herein. Dispersant viscosity modifiers can generally be understood as functionalized (i.e., derivatized) forms of polymers similar to polymeric viscosity modifiers. The polymeric viscosity modifier may be an olefin (co) polymer, a poly (meth) acrylate (PMA), or a mixture thereof. In one embodiment, the polymeric viscosity modifier is an olefin (co) polymer or a dispersant viscosity modifier derived therefrom.

The olefin polymer may be derived from isobutylene or isoprene. In one embodiment, the olefin polymer is prepared from ethylene and a high carbon olefin in the range of C3-C10 alpha-mono-olefins, for example, the olefin polymer may be prepared from ethylene and propylene.

Useful olefin polymers, particularly ethylene-alpha-olefin copolymers, have a number average molecular weight of 4500 to 500000 (e.g., 5000 to 100,000 or 7500 to 60000 or 8000 to 45000).

The formation of functionalized ethylene-alpha-olefin copolymers is well known in the art, for example, those described in U.S. Pat. No. 7,790,661, column 2, line 48 to column 10, line 38. Additional details of similarly functionalized ethylene-alpha-olefin copolymers are found in International publication WO2006/015130 or U.S. Pat. Nos. 4,863,623, 6,107,257, 6,107,258, 6,117,825 and U.S. Pat. No. 7,790,661. In one embodiment, the functionalized ethylene- α -olefin copolymer may include those described in U.S. Pat. No. 4,863,623 (see column 2, line 15 to column 3, line 52) or International publication No. WO2006/015130 (see page 2, paragraph [0008] and preparation examples as described in paragraphs [0065] to [0073 ].

In one embodiment, the lubricating composition comprises a Dispersant Viscosity Modifier (DVM). The DVM may include an olefin polymer that has been modified by the addition of a polar moiety.

The olefin polymer is functionalized by modifying the polymer by the addition of polar moieties. In one useful embodiment, the functionalized copolymer is the reaction product of an olefin polymer grafted with an acylating agent. In one embodiment, the acylating agent may be an ethylenically unsaturated acylating agent. Useful acylating agents are typically alpha beta-unsaturated compounds having at least one olefinic bond (prior to reaction) and at least one (e.g., two) carboxylic acid (or anhydride thereof) group or polar groups convertible by oxidation or hydrolysis to the carboxylic groups. The acylating agent is grafted onto the olefin polymer to give two carboxylic acid functionalities. Examples of useful acylating agents include maleic anhydride, chloromaleic anhydride, itaconic anhydride or reactive equivalents thereof, e.g., the corresponding dicarboxylic acids such as maleic acid, fumaric acid, cinnamic acid, (meth) acrylic acid, esters of these compounds and acid chlorides of these compounds.

In one embodiment, the functionalized ethylene-alpha-olefin copolymer comprises an olefin copolymer grafted with acyl groups, the copolymer being further functionalized with hydrocarbyl amine, hydrocarbyl alcohol groups, amino or hydroxyl terminated polyether compounds, and mixtures thereof.

In one embodiment, the hydrocarbyl amine may be selected from aromatic amines, aliphatic amines, and mixtures thereof. In one embodiment, the hydrocarbyl amine component may comprise at least one aromatic amine containing at least one amino group capable of condensing with the acyl group to provide a pendant group and at least one additional group comprising at least one nitrogen, oxygen, or sulfur atom, wherein the aromatic amine is selected from the group consisting of (i) nitro-substituted aniline, (ii) amine containing two aromatic moieties linked by a C (O) NR-group, -C (O) O-group, -O-group, n=n-group, or-SO 2-group, wherein R is hydrogen or a hydrocarbyl group, one of the aromatic moieties bearing the condensable amino group, (iii) aminoquinoline, (iv) aminobenzimidazole, (v) N, N-dialkylphenylenediamine, (vi) aminodiphenylamine (also known as N-phenylphenylenediamine), (vii) ring-substituted benzylamine, and (viii) methylene-bound dimer of aminodiphenylamine.

In one embodiment, the lubricating composition may comprise a poly (meth) acrylate polymer viscosity modifier. As used herein, the term "(meth) acrylate" and its cognate are meant to refer to either methacrylate or acrylate, as will be readily understood.

In one embodiment, the poly (meth) acrylate polymer is prepared from a monomer mixture comprising (meth) acrylate monomers having alkyl groups of different lengths. The (meth) acrylate monomer may contain an alkyl group that is a straight or branched chain group. The alkyl group may contain 1 to 24 carbon atoms, for example, 1 to 20 carbon atoms.

In one embodiment, the poly (meth) acrylate polymer comprises dispersant monomers including those that are copolymerizable with the (meth) acrylate monomers and contain one or more heteroatoms in addition to the carbonyl groups of the (meth) acrylate. The dispersant monomer may contain nitrogen-containing groups, oxygen-containing groups, or mixtures thereof.

The dispersant monomer may be present in an amount up to 5 mole% of the monomer composition of the (meth) acrylate polymer. In one embodiment, the poly (meth) acrylate is present in an amount of 0 to 5 mole%, 0.5 to 4 mole%, or 0.8 to 3 mole% of the polymer composition. In one embodiment, the poly (meth) acrylate is free or substantially free of dispersant monomers.

In one embodiment, the poly (meth) acrylate polymer (P) is a block or tapered block copolymer comprising at least one polymer block (Bi) that is insoluble or substantially insoluble in the base oil and a second polymer block (B2) that is soluble or substantially soluble in the base oil.

In one embodiment, the poly (meth) acrylate polymer may have a structure selected from linear, branched, hyperbranched, crosslinked, star-shaped (also referred to as "radial"), or a combination thereof. Star or radial refers to multi-arm polymers. Such polymers include (meth) acrylate-containing polymers comprising 3 or more arms or branches, which in some embodiments contain at least about 20 or at least 50 or 100 or 200 or 350 or 500 or 1,000 carbon atoms. The arms are typically attached to a multivalent organic moiety that acts as a "core" or "coupling agent. The multi-arm polymer may be referred to as a radial or star polymer or even a "comb" polymer or a polymer that otherwise has multiple arms or branches as described herein.

The linear poly (meth) acrylate, random, block, or in other forms, can have a weight average molecular weight (Mw) of 1,000 daltons to 400,000 daltons, 1,000 daltons to 150,000 daltons, or 15,000 daltons to 100,000 daltons. In one embodiment, the poly (meth) acrylate may be a linear block copolymer having a Mw of 5000 daltons to 40000 daltons or 10,000 daltons to 30000 daltons. Radial, crosslinked or star copolymers may be derived from linear random or diblock copolymers having molecular weights as described above. The star polymer may have a weight average molecular weight of 10,000 daltons to 1,500,000 daltons, 40,000 daltons to 1,000,000 daltons, 300,000 to 850,000 daltons.

Another class of polymeric viscosity modifiers are styrene-diene (SD) copolymers, such as Styrene Isoprene (SI) and Styrene Butadiene (SBR). The styrene-diene copolymer may be linear or radial (star-shaped) and typically contains one or more different blocks of styrene linked to one or more different blocks of hydrogenated diene.

The lubricating composition may comprise from 0.05 wt% to 2 wt% or from 0.08 wt% to 1.2 wt% or from 0.1 wt% to 0.8 wt% of one or more polymeric viscosity modifiers and/or dispersant viscosity modifiers.

Pour point depressants that may be used in the compositions disclosed herein include polyalphaolefins, esters of maleic anhydride-styrene copolymers, poly (meth) acrylates, polyacrylates, or polyacrylamides.

Demulsifiers include trialkyl phosphates, and various polymers and copolymers of ethylene glycol, ethylene oxide, propylene oxide, or mixtures thereof.

The metal deactivator includes a benzotriazole (typically tolyltriazole), a1, 2, 4-triazole, a benzimidazole, a 2-alkyldithiobenzimidazole, or a derivative of 2-alkyldithiobenzothiazole. Metal deactivators may also be described as resists.

Seal swelling agents include butadiene sulfone derivatives Exxon Necton-37 ^TM (FN 1380) and Exxon MINERAL SEAL Oil ^TM (FN 3200).

The lubricating composition may also comprise one or more dispersants other than the first PIB succinimide dispersant and the second PIB succinimide dispersant of the compositions disclosed herein. Such dispersants include dispersants other than succinimide dispersants of the composition, mannich dispersants, polyolefin succinic acid esters, amides or ester-amides, or mixtures thereof.

The additional dispersant may be a PIB succinimide similar to the dispersant of the composition, derived from a polyisobutylene having a number average molecular weight of 800 daltons to 2,600 daltons. Additional dispersants may be present to provide a promotion of soot handling or as a source of ashless TBN. The soot dispersants may be functionalized with aromatic (poly) amines. Dispersants used as TBN accelerators typically have a high TBN, such as greater than 80mg KOH/g, greater than 95mg KOH/g, or even greater than 110mg KOH/g.

The additional dispersant may be present in an amount of 0.05 wt% to 2 wt%, or 0.1 wt% to 1.1 wt%, or 0.2 wt% to 0.8 wt% of the lubricant composition.

Industrial application

The lubricating composition disclosed herein is suitable for use in a diesel engine. Diesel engines are classified by their Gross Vehicle Weight Rating (GVWR). GVWR includes the maximum rated weight of the vehicle and cargo, including passengers. GVWR applies to trucks or trailers, but not to a combination of both, which is a separate rating called the total combined weight rating (GCWR). GVWR for each type of diesel engine is set forth in the following table:

Light vehicles are classified as those belonging to the classes 1 to 3. Class 2A vehicles are commonly referred to as "light" vehicles, and class 2B vehicles are commonly referred to as "light heavy" vehicles.

Medium-sized vehicles refer to those belonging to the classes 4 to 6. Heavy vehicles are those classified into class 7 and class 8.

There is a significant difference between the vehicle classes as they relate to operating conditions. The difference in size means that the higher class of vehicles have engines that will experience significantly different operating conditions such as load, oil temperature, duty cycle, and engine speed. Heavy duty diesel engines are designed to maximize torque for traction payloads with maximum fuel economy, while passenger vehicles (lower class vehicles) are designed to perform personnel commute and accelerate with maximum fuel economy. The design goals of engine traction and commute result in different hardware designs and stresses applied to lubricants designed to protect and lubricate the engine. Another obvious design difference is the number of Revolutions Per Minute (RPM) at which each engine operates for traction and commute. Heavy duty diesel engines (such as typical 12-13 liter truck engines) typically do not exceed 2200rpm, whereas passenger car engines can reach 4500rpm.

In one embodiment, the internal combustion engine is a heavy duty diesel compression ignition (or spark assisted compression ignition) internal combustion engine.

The sulfur content of the lubricating composition may be 1 wt.% or less or 0.8 wt.% or less or 0.5 wt.% or less or 0.3 wt.% or less. In one embodiment, the sulfur content may be in the range of 0.001 wt% to 0.5 wt% or 0.01 wt% to 0.3 wt%. The phosphorus content may be 0.2 wt% or less or 0.12 wt% or less or 0.1 wt% or less or 0.085 wt% or less or 0.08 wt% or less or even 0.06 wt% or less, 0.055 wt% or less or 0.05 wt% or less. In one embodiment, the phosphorus content may be 0.04 wt% to 0.12 wt%. In one embodiment, the phosphorus content may be 100ppm to 1000ppm or 200ppm to 600ppm. The total sulphated ash content may be 0.3 wt% to 1.2 wt% or 0.5 wt% to 1.1 wt% of the lubricating composition.

In one embodiment, the sulfated ash content may be 0.2 wt% to 1.2 wt% of the lubricating composition. The lubricating composition disclosed herein can have a sulfated ash content of 0.2 wt% to 1.2 wt% or 0.3wt% to 1.1 wt% or 0.4 wt% to 0.8 wt%.

As used herein, TBN value (total base number) is measured by the method described in ASTM D4739 (buffer).

The lubricating composition may be characterized as having a Total Base Number (TBN) content of at least 3mg KOH/g, or at least 4mg KOH/g, or at least 5mg KOH/g.

The lubricating composition may be characterized as having a Total Base Number (TBN) content of 5mg KOH/g to 10mg KOH/g or 5mg KOH/g to 8.5mg KOH/g.

The lubricating composition disclosed herein has a kinematic viscosity of 2.5cSt to 8.3cSt or 3.5cSt to 6.5cSt (mm ²/s) at 100 ℃ and a kinematic viscosity of 15cSt to 30cSt (mm ²/s) at 40 ℃ as measured by ASTM D-445. In another embodiment, the lubricating composition has a kinematic viscosity at 100 ℃ of from 2.5cSt to 6.5cSt or from 3cSt to 5.5cSt (mm ²/s) and a kinematic viscosity at 40 ℃ of from 15cSt to 25cSt (mm ²/s).

The lubricating composition disclosed herein has a high temperature high shear viscosity (HTHS) of less than 2.6mPa-s or less than 2.5mPa-s or less than 2.3mPa-s or less than 2.1mPa-s at 150 ℃ as measured by ASTM D4683. In another embodiment, the HTHS of the lubricating composition is from 1.4 mPas to 2.5 mPas or from 1.6 mPas to 2.1 mPas or from 1.8 mPas to 2.1 mPas or from 1.9 mPas to 2.0 mPas.

The lubricating composition may have an SAE viscosity grade of 0W-Y, where Y may be 12, 16 or 20. In one embodiment, the lubricating composition has an SAE viscosity grade of 0W-12.

The internal combustion engine disclosed herein may have a steel surface on the cylinder bore, cylinder block, or piston ring.

The internal combustion engine may have a surface of steel or an aluminum alloy or an aluminum composite.

In general, compression ignition internal combustion engines have a maximum load mass in excess of 3,500 kg.

The present disclosure also relates to a method of lubricating a diesel engine by supplying to the diesel engine any of the lubricating compositions disclosed herein. In one embodiment, the method comprises lubricating said diesel engine by supplying to the engine a lubricating composition having an oil of lubricating viscosity having greater than 50 wt.% of a group III base oil, a group IV base oil, or a mixture thereof, a first PIB succinimide dispersant derived from 1800Mn to 2500Mn PIB, a second PIB succinimide dispersant derived from PIB having Mn less than 1600, wherein at least one of the first and second PIB succinimide dispersants is free of boron, a calcium salicylate detergent, an alkaline earth sulfonate detergent present in an amount that delivers between 0.3 wt.% and 2.1 wt.% alkaline earth soap to the lubricating composition, and a phosphorus antiwear agent present in an amount that delivers between 300ppm and 900ppm phosphorus to the lubricating composition, wherein the lubricating composition further comprises between 0.3 wt.% and 0.9 wt.% sulfated ash and less than ASTM HS.4683, measured according to ASTM D.469.

Another embodiment provides for the use of any of the lubricating compositions disclosed herein for improving at least one of wear protection and fuel economy of a compression ignition internal combustion engine, typically a heavy duty diesel internal combustion engine.

In various embodiments, the lubricating compositions disclosed herein can have the compositions set forth in the following table:

The following examples provide illustrations of the compositions. These examples are not exhaustive and are not intended to limit the scope of the invention.

Examples

A series of 0W-12 engine lubricants in group III base oils of lubricating viscosity were prepared containing the above additives along with conventional additives including polymeric viscosity modifiers, corrosion inhibitors, pour point depressants, and other performance additives as follows (table 1). Elements are included to demonstrate the relative equivalent of the composition.

TABLE 1 lubricating compositions ¹

1. All treatment rates presented are free of oil unless otherwise indicated

2. Polyisobutene succinimide dispersants (TBN 54mg KOH/g) prepared from 2300Mn low vinylidene PIB via the chlorodiels-Alder process

3. Borated analogues of the above dispersants (1 wt% boron)

PIB succinimide aromatic amine soot dispersants

5. Polyisobutene succinimide dispersants prepared from high vinylidene 2000Mn PIB via thermal olefine alkylation (TBN 26mg KOH/g)

6. Polyisobutene succinimide dispersant prepared from 980Mn PIB (TBN 25mg KOH/g)

7. Polyisobutene succinimide dispersants prepared from high vinylidene 1550Mn PIB via thermal olefine alkylation (TBN 17mg KOH/g)

8. Overbased calcium alkylbenzenesulfonate (TBN 520mg KOH/g;48% substrate)

9. Overbased calcium alkylsalicylate detergent (TBN 300mg KOH/g; metal ratio 2.8)

10. Low TBN calcium alkyl benzene sulfonate detergent (TBN 170mg KOH/g;84% substrate; metal ratio 2.7)

11. A combination of a diarylamine, a hindered phenol, and a sulfurized olefin.

12. Combination of low Mn (10 kDa) and high Mn (60 kDa) substituted ethylene-propylene copolymers functionalized with aromatic amines

13. Oil-based tartaric acid imide (44 wt.%), a premix of a borating agent, basic nitrogen and a compatibilizer (0.46 wt.% boron; TBN 17mg KOH/g)

14. Sulfur-bridged molybdenum (V) dimer, dithiocarbamate complex (commercially available as Sakurolube from Adeka)

15. Other additives include pour point depressants, foam inhibitors, and low levels of corrosion inhibitors and compatibilizers.

The lubricating examples of table 1 were evaluated for their ability to improve fuel economy and prevent/reduce wear. The results are summarized along with other chemical and physical properties related to performance (table 2). Fuel economy improvement was measured according to Volvo D13TC fuel economy test. In this test, improvement was measured relative to a pre-selected reference oil, and in these data, example 8 (EX 8) was selected as the reference oil.

Abrasion resistance (also referred to as durability) was measured on a High Frequency Reciprocating Rig (HFRR) available from PCS Instruments. The HFRR conditions used for evaluation were 500g load, 75 minutes duration, 1000 micrometer stroke, 20 Hz frequency and temperature at 105 ℃. The wear and contact potential were then measured.

TABLE 2

The results obtained demonstrate that the lubricant composition is capable of providing improved fuel economy while maintaining or even enhancing wear control.

The lubricant compositions described herein also provide cleanliness, deposit control, and oxidation control in suitable bench tests. The deposit performance may be measured according to the thermal oxidation engine oil simulation test (TEOST 33) as set forth in ASTM D6335. The results of the TEOST 33 test show milligrams deposited after the engine oil is run at elevated temperature. Lower TEOST 33 results indicate improved resistance to deposit formation. Deposition control of the lubricating composition can be tested in a Panel maker heated to 325 ℃, with a sump temperature of 105 ℃ and a splash/bake cycle of 120s/45s. The air flow rate was 350ml/min, with a spindle speed of 1000rpm, and the test was continued for 4 hours. The oil was sprayed onto the aluminum plate and then optically assessed by a computer. The performance ranges from 0% (black panel) to 100% (clean panel).

The disclosed lubricating composition may be tested for fuel economy and may be improved according to any of the M111 fuel economy test (CEC L-54-96), daimler OM501LA fuel economy test, NEDC MB fuel economy test, and ILSAC sequence VI engine test. Friction performance may also be evaluated in any of several High Frequency Reciprocating Rig (HFRR) bench tests, such as ASTM D6079.

Unless otherwise indicated herein, references to the treatment rates or amounts of components present in the lubricating compositions disclosed herein are based on oil free, i.e., the amount of active.

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. In particular, it refers to a group having a carbon atom directly attached to the rest of the molecule and having predominantly hydrocarbon character, the hydrogen character comprising one or more double bonds. Examples of hydrocarbyl groups include hydrocarbon substituents, i.e., aliphatic (e.g., alkyl or alkenyl), cycloaliphatic (e.g., cycloalkyl, cycloalkenyl) substituents, and aromatic, aliphatic, and cycloaliphatic substituted aromatic substituents, as well as cyclic substituents, wherein the ring is completed through another portion of the molecule (e.g., the two substituents together form a ring), substituted hydrocarbon substituents, i.e., substituents containing non-hydrocarbon groups that, in the context of the present invention, do not alter the predominantly hydrocarbon nature of the substituent (e.g., halogen (especially chlorine and fluorine), hydroxy, alkoxy, mercapto, alkylmercapto, nitro, nitroso, and sulfoxy), hetero substituents, i.e., substituents that, in the context of the present invention, although having predominantly hydrocarbon character, are substituents that contain atoms other than carbon in the ring or chain that are composed, including substituents such as pyridyl, furyl, thienyl, imidazolyl, and the like. Heteroatoms include sulfur, oxygen, and nitrogen. Typically, no more than two or no more than one non-hydrocarbon substituent will be present for every ten carbon atoms in the hydrocarbyl group, alternatively, no non-hydrocarbon substituent may be present in the hydrocarbyl group.

The present disclosure is not to be limited to the specific embodiments described herein, which are intended as illustrations of various aspects. It will be apparent to those skilled in the art that many modifications and variations can be made without departing from the spirit and scope of the application. Functionally equivalent methods and components within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing description. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is to be understood that this disclosure is not limited to particular methods, reagents, compounds, or compositions, which may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.

As used in this document, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Nothing in this disclosure should be construed as an admission that the embodiments described in this disclosure are not entitled to antedate such disclosure by virtue of prior invention. As used herein, the term "comprising" means "including, but not limited to.

While the various compositions, methods, and devices are described in terms of "comprising" various components or steps (interpreted as meaning "including, but not limited to"), the compositions, methods, and devices may also "consist essentially of" or "consist of" the various components and steps, and such terms should be interpreted as defining a substantially closed group of members.

With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. For clarity, various singular/plural permutations may be explicitly set forth herein.

It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims), are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including, but not limited to," the term "having" should be interpreted as "having at least," the term "including" should be interpreted as "including, but not limited to," etc.). Those skilled in the art will further understand that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a") and indefinite articles such as "a" or "an" are intended to mean "at least one" or "one or more"). In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, means at least two recitations, or two or more recitations). Further, in those instances where a convention analogous to "at least one of A, B and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B and C" would include but not be limited to systems that have a alone, B alone, C alone, a and B together, a and C together, B and C together, and/or A, B and C together, etc.). In those instances where a convention analogous to "at least one of A, B or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B or C" would include but not be limited to systems that have a alone, B alone, C alone, a and B together, a and C together, B and C together, and/or A, B and C together, etc.). Those skilled in the art will further appreciate that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "a or B" will be understood to include the possibilities of "a" or "B" or "a and B".

Further, where features or aspects of the present disclosure may be described in terms of markush groups, those skilled in the art will recognize that the present disclosure is also thereby described in terms of any individual member or subgroup of members of the markush group.

As will be understood by those of skill in the art, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof for any and all purposes, such as in terms of providing a written description. Any listed range can be readily considered as sufficiently descriptive and so that the same range can be broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As non-limiting examples, each of the ranges discussed herein can be readily broken down into a lower third, a middle third, an upper third, and the like. As will also be understood by those skilled in the art, all language (such as "up to", "at least", etc.) includes the stated numbers and refers to ranges that can be subsequently broken down into sub-ranges as described above. Finally, as will be understood by those skilled in the art, a range includes each individual member. Thus, for example, a group having 1 wt% to 3 wt% refers to a group having 1 wt%, 2 wt%, or 3 wt%. Similarly, a group having 1 wt% to 5 wt% refers to a group having 1 wt%, 2 wt%, 3 wt%, 4 wt%, or 5 wt%, etc., including all points therebetween.

Furthermore, when a stated range for processing rates is provided, it is contemplated that the range should include processing rates for individual components and/or mixtures of components. Thus, for example, a range of 1 wt% to 3 wt% contemplates that a given component may be present in a range of 1 wt% to 3 wt% or a mixture of similar components may be present in a range of 1 wt% to 3 wt%.

As used herein, the term "about" means that a given amount of value is within ±20% of the specified value. In other embodiments, the value is within ±15% of the specified value. In other embodiments, the value is within ±10% of the specified value. In other embodiments, the value is within ±5% of the specified value. In other embodiments, the value is within ±2.5% of the specified value. In other embodiments, the value is within ±1% of the specified value.

As used herein, unless otherwise indicated, "wt%" shall refer to weight percent based on the total weight of the composition on an oil-free basis.

As described below, the number average molecular weight of the dispersant viscosity modifier and viscosity modifier has been determined using known methods, such as GPC analysis using polystyrene standards. Methods for determining the molecular weight of polymers are well known. For example, these methods are described (i) P.J.Flory, "PRINCIPLES OF POLYMER CHEMISTRY", cornell University Press 91953), chapter VII, pages 266 to 315, or (ii) Macromolecules, an Introduction to Polymer Science ", by F.A.Bovey and F.H.Winslow, ACADEMIC PRESS (1979), pages 296 to 312.

While the invention has been explained in relation to its preferred embodiments, it is to be understood that various modifications thereof will become apparent to those skilled in the art upon reading the specification. It is, therefore, to be understood that the invention disclosed herein is intended to cover such modifications as fall within the scope of the appended claims.

Claims (72)

1. A lubricating composition for a diesel engine, the diesel engine lubricating composition comprises:

An oil of lubricating viscosity having greater than 50 weight percent of a group III base oil, a group IV base oil, a group V base oil, or a mixture thereof;

a first Polyisobutylene (PIB) succinimide dispersant derived from PIB having a number average molecular weight of 1800 to 2100 and present in the lubricating composition in an amount of 0.8 wt.% to 6 wt.%;

A second Polyisobutylene (PIB) succinimide dispersant derived from PIB having a Mn less than or equal to 1600, wherein at least one of the first PIB succinimide dispersant and the second PIB succinimide dispersant is free of boron;

Alkaline earth metal salicylate detergents;

An alkaline earth metal sulfonate detergent present in an amount to deliver from 0.1 wt.% to 1.2 wt.% of alkaline earth metal soap to the lubricating composition, and

A phosphorus antiwear agent present in an amount to deliver 300ppm to 900ppm phosphorus to the lubricating composition,

The lubricating composition has a total sulfated ash of between 0.3 wt% and 0.9 wt% as determined according to ASTM D874, a kinematic viscosity of less than 8.3cSt at 100 ℃ as measured according to ASTM D-445, a total alkaline earth soap of 0.6 wt% to 2.1 wt% and an HTHS of less than 2.7mpa.s as measured according to ASTM D4683.

2. The composition of claim 1, wherein the first PIB succinimide dispersant has a TBN of 15 to 25 measured according to ASTM D4739.

3. The composition of claim 1, wherein the first PIB succinimide dispersant has a TBN of 15 to 20 measured according to ASTM D4739.

4. A composition according to any one of claims 1 to 3, wherein the first PIB succinimide dispersant is present in the lubricating composition in an amount of 1 wt.% to 5 wt.%.

5. A composition according to any one of claims 1 to 3, wherein the first PIB succinimide dispersant is present in the lubricating composition in an amount of 1.5 wt.% to 5 wt.%.

6. A composition according to any one of claims 1 to 3, wherein the first PIB succinimide dispersant is prepared by a thermal direct alkylation process.

7. A composition according to any one of claims 1 to 3, wherein the first PIB succinimide dispersant comprises a mixture of two dispersants.

8. A composition according to any one of claims 1 to 3, wherein the second PIB succinimide dispersant is derived from PIB having a number average molecular weight of 750 to 1600.

9. A composition according to any one of claims 1 to 3, wherein the second PIB succinimide dispersant is derived from PIB having a number average molecular weight of 1000 to 1600.

10. A composition according to any one of claims 1 to 3, wherein the second PIB succinimide dispersant is derived from PIB having a number average molecular weight of 1200 to 1600.

11. The composition of claim 8, wherein the second PIB succinimide dispersant is derived from PIB having a number average molecular weight of 800 to 1150.

12. The composition of claim 8, wherein the second PIB succinimide dispersant is derived from PIB having a number average molecular weight of 900 to 1100.

13. A composition according to any one of claims 1 to 3, wherein the second PIB succinimide dispersant is prepared by a thermal direct alkylation process.

14. A composition according to any one of claims 1 to 3, wherein the second PIB succinimide dispersant is present in the lubricating composition in an amount of 1 wt.% to 5 wt.%.

15. A composition according to any one of claims 1 to 3, wherein the second PIB succinimide dispersant is present in the lubricating composition in an amount of 1.5 wt.% to 4.8 wt.%.

16. A composition according to any one of claims 1 to 3, wherein the second PIB succinimide dispersant is present in the lubricating composition in an amount of 1.8 wt.% to 4.6 wt.%.

17. A composition according to any one of claims 1 to 3, wherein the second PIB succinimide dispersant is present in the lubricating composition in an amount of 1.9 wt.% to 4.6 wt.%.

18. A composition according to any one of claims 1 to 3, wherein the second PIB succinimide dispersant comprises 1 wt% to 5 wt% of a PIB succinimide dispersant derived from PIB having a Mn of 900 to 1100 and 1 wt% to 5 wt% of a PIB succinimide dispersant derived from PIB having a Mn of 1200 to 1600.

19. A composition according to any one of claims 1 to 3, wherein the second PIB succinimide dispersant has a TBN of 20 to 35 measured according to ASTM D4739.

20. A composition according to any one of claims 1 to 3, wherein the second PIB succinimide dispersant has a TBN of 25 to 30 measured according to ASTM D4739.

21. A composition according to any one of claims 1 to 3, wherein the second PIB succinimide dispersant has a TBN of 27 to 28 measured according to ASTM D4739.

22. A composition according to any one of claims 1to 3, wherein the first PIB succinimide dispersant is borated.

23. The composition of claim 22, wherein the second PIB succinimide dispersant is borated.

24. The composition of claim 23, wherein the first and second PIB succinimide dispersants are present in an amount that independently delivers 25ppm to 400ppm boron by weight to the lubricating composition.

25. The composition of claim 23, wherein the first and second PIB succinimide dispersants are present in an amount that independently delivers 50ppm to 200ppm boron by weight to the lubricating composition.

26. A composition according to any one of claims 1 to 3, wherein the alkaline earth metal salicylate detergent has a TBN of 200 to 575 measured according to ASTM D4739.

27. A composition according to any one of claims 1 to 3, wherein the alkaline earth metal salicylate detergent has a TBN of 200 to 500 measured according to ASTM D4739.

28. A composition according to any one of claims 1 to 3, wherein the alkaline earth metal salicylate is a calcium salicylate detergent having a TBN of 250 to 350 measured according to ASTM D4739.

29. A composition according to any one of claims 1 to 3 wherein the alkaline earth metal salicylate detergent has a metal ratio of from 2 to 7.

30. A composition according to any one of claims 1 to 3 wherein the alkaline earth metal salicylate detergent has a metal ratio of from 2 to 4.

31. A composition according to any one of claims 1 to 3 wherein the alkaline earth metal salicylate detergent has a metal ratio of from 2.5 to 3.5.

32. A composition according to any one of claims 1 to 3, wherein the alkaline earth metal sulfonate detergent is selected from calcium sulfonate detergents and magnesium sulfonate detergents.

33. A composition according to any one of claims 1 to 3 wherein the alkaline earth metal sulfonate detergent is a calcium sulfonate detergent.

34. The composition of claim 33, wherein the calcium sulfonate detergent has a TBN of less than 200 measured according to astm d 4739.

35. The composition of claim 33, wherein the calcium sulfonate detergent has a TBN of less than 150 measured according to astm d 4739.

36. The composition of claim 33, wherein the calcium sulfonate detergent has a TBN of less than 100 measured according to astm d 4739.

37. The composition of claim 33, wherein the calcium sulfonate detergent has a TBN of less than 80 measured according to astm d 4739.

38. The composition of claim 33, wherein the calcium sulfonate detergent has a TBN of 50 to 90 measured according to astm d 4739.

39. The composition of claim 33, wherein the calcium sulfonate detergent is present in the lubricant composition in an amount of 0.5 wt.% to 2.0 wt.%.

40. The composition of claim 33, wherein the calcium sulfonate detergent is present in the lubricant composition in an amount of 0.6 wt.% to 1.5 wt.%.

41. The composition of claim 38, wherein the calcium sulfonate detergent is present in the lubricant composition in an amount of 0.5 wt.% to 2.0 wt.%.

42. The composition of claim 38, wherein the calcium sulfonate detergent is present in the lubricant composition in an amount of 0.6 wt.% to 1.5 wt.%.

43. A composition according to any one of claims 1 to 3 wherein the alkaline earth metal sulfonate detergent is a magnesium overbased sulfonate detergent.

44. The composition according to claim 43, wherein said overbased magnesium sulfonate detergent has a TBN of 200 to 500 measured according to ASTM D4739.

45. The composition according to claim 43, wherein said overbased magnesium sulfonate detergent has a TBN of 250 to 400 measured according to ASTM D4739.

46. The composition according to claim 43, wherein said overbased magnesium sulfonate detergent has a TBN of 250 to 350 measured according to ASTM D4739.

47. The composition according to claim 43, wherein said overbased magnesium sulfonate detergent has a TBN of 350 to 375 measured according to ASTM D4739.

48. The composition according to claim 43, wherein said overbased magnesium sulfonate detergent is present in said lubricating composition in an amount of 0.05 wt.% to 0.2 wt.%.

49. The composition according to claim 43, wherein said overbased magnesium sulfonate detergent is present in said lubricating composition in an amount of 0.06 wt.% to 0.1 wt.%.

50. The composition of any of claims 1-3, wherein the alkaline earth metal sulfonate comprises a mixture of 0.6 wt.% to 1.5 wt.% of a calcium sulfonate detergent having a TBN of 50 to 100 measured according to ASTM D4739 and 0.05 wt.% to 0.1 wt.% of a magnesium overbased sulfonate detergent having a TBN of 250 to 350 measured according to ASTM D4739.

51. A composition according to any one of claims 1 to 3, wherein the total alkaline earth metal soap of the lubricating composition is from 0.6 wt% to 1.5 wt%.

52. A composition according to any one of claims 1 to 3, wherein the total alkaline earth metal soap of the lubricating composition is from 0.7 wt% to 1.4 wt%.

53. The composition of any of claims 1 to 3, wherein the phosphorus antiwear agent is zinc dialkyldithiophosphate in an amount to deliver 400ppm to 850ppm to the lubricating composition.

54. The composition of any of claims 1 to 3, wherein the phosphorus antiwear agent is zinc dialkyldithiophosphate in an amount to deliver 450ppm to 800ppm to the lubricating composition.

55. The composition of any of claims 1 to 3, wherein the phosphorus antiwear agent is zinc dialkyldithiophosphate in an amount to deliver 500ppm to 800ppm to the lubricating composition.

56. The composition of any of claims 1 to 3, wherein the phosphorus antiwear agent is zinc dialkyldithiophosphate in an amount to deliver 550ppm to 780ppm to the lubricating composition.

57. The composition of any of claims 1 to 3, wherein the phosphorus antiwear agent is zinc dialkyldithiophosphate in an amount to deliver 650ppm to 780ppm to the lubricating composition.

58. A composition according to any one of claims 1 to 3, wherein the total sulfated ash is between 0.4% and 0.8% by weight.

59. A composition according to any one of claims 1 to 3, wherein the HTHS is less than 2.5.

60. A composition according to any one of claims 1 to 3, wherein the HTHS is less than 2.3.

61. A composition according to any one of claims 1 to 3, wherein the HTHS is less than 2.1.

62. A composition according to any one of claims 1 to 3, wherein the HTHS is from 1.4 to 2.5.

63. A composition according to any one of claims 1 to 3, wherein the HTHS is from 1.6 to 2.1.

64. A composition according to any one of claims 1 to 3, wherein the HTHS is from 1.8 to 2.1.

65. A composition according to any one of claims 1 to 3, wherein the HTHS is from 1.9 to 2.0.

66. A composition according to any one of claims 1 to 3, further comprising an ashless friction modifier.

67. A composition according to any one of claims 1 to 3, further comprising a dispersant other than the first PIB succinimide dispersant and the second PIB succinimide dispersant.

68. A composition according to any one of claims 1to 3, further comprising one or more additional additives selected from antioxidants, foam inhibitors and resists.

69. A composition according to any one of claims 1 to 3, wherein the kinematic viscosity is from 2.5cSt to 8.3cSt at 100 ℃.

70. A composition according to any one of claims 1 to 3, wherein the kinematic viscosity is from 3.5cSt to 6.5cSt at 100 ℃.

71. A method of lubricating a diesel engine comprising supplying to the engine the lubricant composition of any preceding claim.

72. Use of the lubricating composition of any one of claims 1 to 69 for improving one or more of fuel economy in a diesel engine and wear protection in a diesel engine.