LUBRICATING COMPOSITION AND METHOD OF LUBRICATING AN INTERNAL COMBUSTION ENGINE

Abstract

The disclosed technology relates to lubricants for compression ignition internal combustion engines, particularly those demonstrating at least one of improved seals performance, reduced deposit formation, and excellent durability. The present invention provides a low zinc lubricating composition comprising (a) an oil of lubricating viscosity, (b) a borated dispersant, and (c) a metal-free organo-phosphorus anti-wear additive, wherein the lubricating composition is substantially free of a metal containing sulfur coupled alkyl phenol compound. Further, the low zinc lubricating composition contains zinc in an amount less than 600 ppm by weight of the composition.

Claims

1. A composition for lubricating an internal combustion engine comprising: an oil of lubricating viscosity; and a DMTD derivative comprising the reaction product of 2,5-dimercapto-1,3,4-thiadiazole (DMTD) and an , -unsaturated carbonyl compound.

2. The composition of claim 1, wherein the , -unsaturated carbonyl compound comprises an ester, amide, or imide.

3. The composition of claim 2, wherein the , -unsaturated carbonyl compound is an ester selected from the group consisting of maleates, acrylates, methacrylates, fumarates, crotonates, itaconates, and mixtures thereof.

4. The composition of claim 3, wherein the , -unsaturated ester contains 4 to 24, or 4 to 18, or 4 to 12, or 6 to 8 carbon atoms.

5. The composition of claim 3, wherein the , -unsaturated ester comprises or consists of an alkyl acrylate.

6. The composition of claim 5, wherein the alkyl acrylate comprises or consist of 2-ethyl hexyl acrylate.

7. The composition of claim 3, wherein the , -unsaturated ester comprises or consist of an alkyl methacrylate.

8. The composition of claim 7, wherein the alkyl methacrylate comprises or consists of lauryl methacrylate.

9. The composition of claim 7, wherein the alkyl methacrylate comprises or consists of 2-ethylhexyl methacrylate.

10. The composition of claim 3, wherein the , -unsaturated ester comprises or consists of a dialkyl maleate.

11. The composition of claim 10, wherein the dialkyl maleate comprises or consists of bis-(2-ethylehexyl)maleate.

12. The composition of claim 3, wherein the , -unsaturated ester comprises or consists of a dialkyl itaconate.

13. The composition of claim 12, wherein the dialkyl itaconate comprises or consists of bis(2,4-dimethylpentyl)itaconate.

14. The composition of claim 1, wherein the DMTD derivative is further reacted with a metal oxide, metal hydroxide, or metal alkoxide to form a metal salt.

15. The composition of claim 14, wherein the metal is selected from zinc, titanium, molybdenum, animony, or mixtures thereof.

16. The composition of claim 1, wherein the DMTD derivative is substantially free of or free of zinc.

17. The composition of claim 1, wherein the DMTD derivative is further reacted with an amine to form an amine salt.

18. The composition of claim 17 wherein the amine is selected from the group consisting of methylamine, ethylamine, n-propylamine, n-butylamine, n-hexylamine, n-octylamine, 2-ethylhexylamine, benzylamine, 2-phenylethylamine, cocoamine, oleylamine, tridecylamine, isopropylamine, sec-butylamine, t-butylamine, tert-hexylamine, 1-methyl-1-amino-cyclohexane, tert-octylamine, tert-decylamine, tert-dodecylamine, tert-tetradecylamine, tert-hexadecylamine, tertoctadecylamine, tert-tetracosanylamine, and tertoctacosanylamine, cyclopentylamine, cyclohexylamine, and 1-phenylethylamine; dialkylamines, such as dimethylamine, diethylamine, dipropylamine, diisopropylamine, dibutylamine, dicyclohexylamine, di-(2-ethylhexyl)amine, dihexylamine, ethylbutylamine, N-ethylcyclohexylamine, and N-methylcyclohexylamine; cycloalkylamines, such as piperidine, N-ethylpiperidine, N,N-dimethylpiperazine, morpholine, N-methylmorpholine, N-ethylmorpholine, N-methylpiperidine, pyrrolidine, N-methylpyrrolidine, and N-ethylpyrrolidine; and trialkylamines, such as tetramethylethylenediamine, trimethylamine, triethylamine, tripropylamine, triisopropylamine, tri-butylamine, trihexylamine, N, N-dimethylbenzylamine, dimethylethylamine, dimethylisopropylamine, dimethylbutylamine, and N, N-dimethylcyclohexylamine.

19. The lubricating composition of claim 1, wherein the DMTD derivative is substantially free of or free of alkali metals and/or alkaline earth metals.

20. The composition of claim 1, wherein the DMTD derivative is present in an amount to deliver at least 0.05% to 0.35% by weight or 0.07% to 0.3% by weight or 0.08% to 0.26% by weight sulfur to the lubricating composition.

21. The composition of claim 1, wherein the lubricating composition further comprises one or more metal containing detergents.

22. The composition of claim 21, wherein the metal of the metal containing detergent is selected from magnesium, calcium, sodium, and mixtures thereof.

23. The composition of claim 21, wherein the detergent of the metal containing detergent is selected from sulfonates, phenates, salicylates, salixarates or mixtures thereof.

24. The composition of claim 21, wherein the metal containing detergent comprises a calcium detergent and wherein the calcium detergent is present in an amount sufficient to deliver 500 ppm to 3000 ppm or 1000 ppm to 2500 ppm by weight calcium to the composition.

25. The composition of claim 21, wherein the metal containing detergent comprises a magnesium detergent and wherein the magnesium detergent is present in an amount to deliver up to 500 ppm magnesium to the composition.

26. The composition of claim 1, further comprising a molybdenum compound.

27. The composition of claim 1, wherein the composition comprises phosphorous in amounts of 0.2 wt % or less, or 0.12 wt % or less, or 0.1 wt % or less, or 0.09 wt % or less, or 0.08 wt % or less, or 0.06 wt % or less, 0.05 wt % or less, or 0.03 wt % or less, or even 0.02 wt % or less.

28. The composition of claim 1, wherein the composition is substantially free of or free of phosphorous.

29. The composition of claim 1, further comprising a metal alkylthiophosphate.

30. The composition of claim 29, wherein the metal aklylthiophosphate comprises zinc dialkyldithiophosphate.

31. The composition of claim 30, wherein the zinc dialkyldithiophosphate is present in an amount sufficient to provide from 0.02 to 0.2 wt % zinc to the composition.

32. The composition of claim 1, wherein the composition contains 0.015 wt % or less of zinc.

33. The composition of claim 1, wherein the composition contains zinc in amounts of less than 0.14 wt %, or even less than 0.11 wt %, or even less than 0.09 wt %, or even less than 0.07 wt %, or even less than 0.05 wt %, or even less than 0.03 wt %, or 0.01 wt % to 0.14 wt %.

34. The composition of claim 1, wherein the composition is substantially free of zinc.

35. The composition of claim 1, wherein the composition contains 0.1 to 0.4 wt % sulfurized olefins.

36. The composition of claim 1, wherein the lubricating composition is substantially free of or free of sulfurized olefin additives.

37. The composition of claim 1, wherein the composition has a total sulfated ash content of 2 wt % or less, or 1.6 wt % or less, or 1.1 wt % or less, or 1 wt % or less, or 0.8 wt % or less, or 0.6 wt % or less, or 0.5 wt % or less, or 0.05 wt % to 0.9 wt %, or 0.1 wt % to 0.2 wt % or to 0.45.

38. A method of lubricating an internal combustion engine comprising: operating said engine with a lubricant composition comprising as recited in claim 1.

39. A method of decomposing peroxide in a lubricating composition used to lubricate an internal combustion engine comprising: supplying to said internal combustion engine the lubricating composition as recited in claim 1.

40. (canceled)

Description

DETAILED DESCRIPTION

[0010] Various preferred features and embodiments will be described below by way of non-limiting illustration.

Oil of Lubricating Viscosity

[0011] The lubricating composition comprises an oil of lubricating viscosity. Such oils include natural and synthetic oils, oil derived from hydrocracking, hydrogenation, and hydrofinishing, unrefined, refined, re-refined oils or mixtures thereof. A more detailed description of unrefined, refined and re-refined oils is provided in International Publication WO2008/147704, paragraphs [0054] to [0056](a similar disclosure is provided in US Patent Application 2010/197536, see [0072] to [0073]). A more detailed description of natural and synthetic lubricating oils is described in paragraphs [0058] to [0059] respectively of WO2008/147704 (a similar disclosure is provided in US Patent Application 2010/197536, see [0075] to [0076]). Synthetic oils may also be produced by Fischer-Tropsch reactions and typically may be hydroisomerised Fischer-Tropsch hydrocarbons or waxes. In one embodiment, oils may be prepared by a Fischer-Tropsch gas-to-liquid synthetic procedure as well as other gas-to-liquid oils.

[0012] Oils of lubricating viscosity may also be defined as specified in the April 2008 version of Appendix EAPI Base Oil Interchangeability Guidelines for Passenger Car Motor Oils and Diesel Engine Oils, section 1.3 Sub-heading 1.3. Base Stock Categories. The API Guidelines are also summarized in U.S. Pat. No. 7,285,516 (see column 11, line 64 to column 12, line 10). In one embodiment, the oil of lubricating viscosity may be an API Group II, Group III, or Group IV oil, or mixtures thereof. The five base oil groups are as follows:

TABLE-US-00001 Base Oil Category Sulfur (%) Saturates (%) Viscosity Index Group I >0.03 and/or <90 80 to 120 Group II 0.03 and 90 80 to 120 Group III 0.03 and 90 120 Group IV All polyalphaolefins (PAO) Group V All others not included in Groups I, II, III, or IV

[0013] The amount of the oil of lubricating viscosity present is typically the balance remaining after subtracting from 100 weight % (wt %) the sum of the amount of the compound of the invention and the other performance additives.

[0014] The lubricating composition may be in the form of a concentrate and/or a fully formulated lubricant. If the lubricating composition of the invention (comprising the additives disclosed herein) is in the form of a concentrate which may be combined with additional oil to form, in whole or in part, a finished lubricant), the ratio of the of these additives to the oil of lubricating viscosity and/or to diluent oil include the ranges of 1:99 to 99:1 by weight, or 80:20 to 10:90 by weight.

[0015] In one embodiment, the base oil has a kinematic viscosity at 100 C. from 2 mm.sup.2/s (centiStokescSt) to 16 mm.sup.2/s, from 3 mm.sup.2/s to 10 mm.sup.2/s, or even from 4 mm.sup.2/s to 8 mm.sup.2/s.

[0016] In one embodiment, the base oil comprises at least 30 wt % of Group II or Group III base oil. In another embodiment, the base oil comprises at least 60 weight % of Group II or Group III base oil, or at least 80 wt % of Group II or Group III base oil. In one embodiment, the lubricant composition comprises less than 20 wt % of Group IV (i.e. polyalphaolefin) base oil. In another embodiment, the base oil comprises less than 10 wt % of Group IV base oil. In one embodiment, the lubricating composition is substantially free of (i.e. contains less than 0.5 wt %) of Group IV base oil.

[0017] Ester base fluids, which are characterized as Group V oils, have high levels of solvency as a result of their polar nature. Addition of low levels (typically less than 10 wt %) of ester to a lubricating composition may significantly increase the resulting solvency of the base oil mixture. Esters may be broadly grouped into two categories: synthetic and natural. An ester base fluid would have a kinematic viscosity at 100 C. suitable for use in an engine oil lubricant, such as between 2 cSt and 30 cSt, or from 3 cSt to 20 cSt, or even from 4 cSt to 12 cSt.

[0018] Synthetic esters may comprise 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 variety of monohydric alcohols (e.g., butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, 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, dieicosyl sebacate, the 2-ethylhexyl diester of linoleic acid dimer, and the complex ester formed by reacting one mole of sebacic acid with two moles of tetraethylene glycol and two moles of 2-ethylhexanoic acid. Other synthetic esters include those made from C5 to C12 monocarboxylic acids and polyols and polyol ethers such as neopentyl glycol, trimethylolpropane, pentaerythritol, dipentaerythritol, and tripentaerythritol. Esters can also be monoesters of mono-carboxylic acids and monohydric alcohols.

[0019] Natural (or bio-derived) esters refer to materials derived from a renewable biological resource, organism, or entity, distinct from materials derived from petroleum or equivalent raw materials. Natural esters include fatty acid triglycerides, hydrolyzed or partially hydrolyzed triglycerides, or transesterified triglyceride esters, such as fatty acid methyl ester (or FAME). Suitable triglycerides include, but are not limited to, palm oil, soybean oil, sunflower oil, rapeseed oil, olive oil, linseed oil, and related materials. Other sources of triglycerides include, but are not limited to, algae, animal tallow, and zooplankton. Methods for producing biolubricants from natural triglycerides is described in, e.g., United States patent application 2011/0009300A1.

[0020] In one embodiment, the lubricating composition comprises at least 2 wt % of an ester base fluid. In one embodiment the lubricating composition of the invention comprises at least 4 wt % of an ester base fluid, or at least 7 wt % of an ester base fluid, or even at least 10 wt % of an ester base fluid.

Dimercaptothiadiazole Derivative Additive

[0021] Dimercaptodithiadiazole, referred to herein as DMTD, can be derivatized by the reaction product resulting from the Michael addition of ,-unsaturated carbonyl compounds and DMTD, that is, a 1,4 addition between DMTD and acarbonyl compound, such as ester, amide, or imide groups capable of 1,4 addition.

[0022] While the reaction products to prepare the derivatives often result in a mixture of products, the products can be provided as pure compounds as well. In general, the DMTD derivatives can be represented in the pure form by formula I:

##STR00001## [0023] where [0024] X is a metal, an amine, or H; [0025] where Y is a group derived from a carboxylate such as an itaconate, maleate, fumarate, or a (meth)acrylate; and [0026] n is 1, 2, 3 or 4.

[0027] Metals can include transition metals such as zinc, titanium, cobalt, zirconium, manganese, or molybdenum, for example, post-transition metals and even some metalloids, such as, for example, aluminum, antimony or boron. Where a salt is desired, it can be obtained by 1,4 addition to the ester monomer followed by reaction with a metal oxide or hydroxide. In some embodiments, the DMTD can be substantially free of or free of antimony.

[0028] In one embodiment, the carbonyl compound is a carboxylate group capable of 1,4 addition. Such carboxylate groups capable of 1,4 addition (i.e., ,-unsaturated carbonyl compounds) can be readily envisaged by those of skill in the art, and include, both mono-carboxylates and di-carboxylates as well as higher carboxylates, e.g., tricarboxylates, tetracarboxylates, etc. In general, the carboxylate may be a C4 to C24 carboxylate, or a C5 to C22 carboxylate, or C6 to C20 carboxylate, or even a C6 to C18 carboxylate. In some circumstances C6 to C12 carboxylate or even C6 to C10 carboxylate and even a C8 to C12 carboxylate are often sufficient. Example carboxylates can include, but not be limited to itaconates, citraconates, maleates, fumarates, mesaconates, as well as (meth)acrylates (where the parentheses ( ) around (meth) indicate the methyl group may or may not be present). In the present invention, the carboxylates are in the form of an ester.

[0029] In another embodiment, the carbonyl compound may be in the form of an amide or imide.

[0030] As used herein, the term group, for example as in a (meth)acrylate group, depending on the context, refers to the structure of the stated group on its own or as the structure in which the group would form after reaction with another compound. For example, a methyl group, or, as a further example, methyl acrylate, could refer to CH.sub.2CHC(O)OCH.sub.3, as in its lone state, or CH.sub.2CH.sub.2C(O)OCH.sub.3, as in its bonded form.

[0031] An example of the DMTD derivative can include the DMTD derivative resulting from the 1,4 addition between DMTD and a methacrylate, for example wherein the substituent Y of the DMTD derivatives of Formula I can be, for example, a methyl methacrylate group, for example, as represented by Formula IL

##STR00002##

[0032] In the foregoing example, the DMTD derivative could also be salted, for example, by reacting Formula II with a half a molar equivalent of a metal oxide or hydroxide, such as a zinc oxide to form a compound represented, for example, by Formula IIa:

##STR00003##

[0033] A further example can include the DMTD derivative resulting from the 1,4 addition between DMTD and an acrylate, wherein the substituent Y of the DMTD derivatives of Formula I can be, for example, a 2-ethylhexyl acrylate group, for example, as represented by Formula III:

##STR00004##

[0034] A salt of the foregoing formula can be prepared by the reaction with a metal hydroxide, such as, for example, a titanium alkoxide to obtain the salt of Formula IIIa below.

##STR00005##

[0035] A still further example can include the DMTD derivative resulting from the 1,4 addition between DMTD and a maleate, wherein the substituent Y of the DMTD derivatives of Formula I can be, for example, a diethylhexyl maleate group, for example, as represented by Formula IV:

##STR00006##

[0036] A salt of the foregoing formula can be prepared by the reaction with a metal oxide, such as, for example, an antimony oxide to obtain the salt of Formula IVa below.

##STR00007##

[0037] Further examples could include DMTD derivatives resulting from the 1,4 addition between DMTD and a dialkyl itaconate, such as dimethyl itaconate, dimethyl citraconate, dimethyl fumarate, and dimethyl mesaconate and the like.

[0038] Other embodiments may include DMTD derivatives resulting from the Michael addition of an ,-unsaturated carbonyl compounds and DMTD, salted with an amine compound. The amines which may be suitable for use as the amine salt include mono-, di-, or tri-substituted amine with secondary and tertiary amines preferred. Specific examples include primary alkylamines, such as methylamine, ethylamine, n-propylamine, n-butylamine, n-hexylamine, n-octylamine, 2-ethylhexylamine, benzylamine, 2-phenylethylamine, cocoamine, oleylamine, and tridecylamine (CAS #86089-17-0); secondary and tertiary alkylamines such as isopropylamine, sec-butylamine, t-butylamine, tert-hexylamine, 1-methyl-1-amino-cyclohexane, tert-octylamine, tert-decylamine, tert-dodecylamine, tert-tetradecylamine, tert-hexadecylamine, tertoctadecylamine, tert-tetracosanylamine, and tertoctacosanylamine, cyclopentylamine, cyclohexylamine, and 1-phenylethylamine; dialkylamines, such as dimethylamine, diethylamine, dipropylamine, diisopropylamine, dibutylamine, dicyclohexylamine, di-(2-ethylhexyl)amine, dihexylamine, ethylbutylamine, N-ethylcyclohexylamine, and N-methylcyclohexylamine; cycloalkylamines, such as piperidine, N-ethylpiperidine, N,N-dimethylpiperazine, morpholine, N-methylmorpholine, N-ethylmorpholine, N-methylpiperidine, pyrrolidine, N-methylpyrrolidine, and N-ethylpyrrolidine; and trialkylamines, such as tetramethylethylenediamine, trimethylamine, triethylamine, tripropylamine, triisopropylamine, tri-butylamine, trihexylamine, N, N-dimethylbenzylamine, dimethylethylamine, dimethylisopropylamine, dimethylbutylamine, and N, N-dimethylcyclohexylamine.

[0039] The DMTD derivatives can be employed in an automotive or industrial lubricant at 0.05 wt. % to 2 wt. %, or from 0.08 wt. % to 1.8 wt. %, or even from 0.1 wt. % to 1.6 wt. % or 0.12 wt. % to 1.4 wt. % or even 0.15 wt. % to 1.2 or even 0.4 to 1 wt. %. In another embodiment, the DMTD derivative is present in an amount to deliver at least 0.05% to 0.35% by weight or 0.07% to 0.3% by weight or 0.08% to 0.26% by weight sulfur to the lubricating composition.

[0040] Likewise, the DMTD derivatives can be employed in an automotive or industrial lubricant sufficient to provide from 100 to 5000 ppm sulfur, or even from 250 to 4000 ppm sulfur or 500 to 3000 ppm sulfur, or even from 750 to 2500 ppm sulfur or 1050 to 2000 ppm sulfur.

Other Additives

[0041] The compositions of the invention may optionally comprise one or more other additional performance additives. These additional performance additives may include, but are not limited to, one or more dispersants, including borated dispersants, anti-wear additives, detergents, metal deactivators, viscosity modifiers, detergents, friction modifiers, antiwear agents, corrosion inhibitors, dispersant viscosity modifiers, extreme pressure agents, antioxidants, foam inhibitors, demulsifiers, pour point depressants, seal swelling agents, and any combination or mixture thereof. Typically, fully-formulated lubricating oil will contain one or more of these performance additives, and often a package of multiple performance additives.

[0042] In one embodiment, the lubricating compositions of the present invention may contain a borated dispersant. The borated dispersant may be a succinimide dispersant, a Mannich dispersant, a polyolefin succinic acid ester, amide, or ester-amide, or mixtures thereof, borated using one or more of a variety of agents selected from the group consisting of the various forms of boric acid (including metaboric acid, HBO.sub.2, orthoboric acid, H.sub.3BO.sub.3, and tetraboric acid, H.sub.2B.sub.4O.sub.7), boric oxide, boron 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 dispersant may be prepared in such a way that they contain 0.1 wt % to 2.5 wt % boron, or 0.1 wt % to 2.0 wt % boron or 0.2 to 1.5 wt % boron or 0.3 to 1.0 wt % boron.

[0043] In one embodiment, the borated dispersant may be a borated succinimide dispersant. The succinimide dispersant may be a derivative of an aliphatic polyamine, or mixtures thereof. The aliphatic polyamine may be aliphatic polyamine such as an ethylenepolyamine, a propylenepolyamine, a butylenepolyamine, or mixtures thereof. In one embodiment, the aliphatic polyamine may be ethylenepolyamine. In one embodiment the aliphatic polyamine may be selected from the group consisting of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, polyamine still bottoms, and mixtures thereof.

[0044] The succinimide dispersant may be a derivative of an aromatic amine, an aromatic polyamine, or mixtures thereof. The aromatic amine may be 4-aminodiphenylamine (ADPA) (also known as N-phenylphenylenediamine), derivatives of ADPA (as described in United States Patent Publications 2011/0306528 and 2010/0298185), a nitroaniline, an aminocarbazole, an amino-indazolinone, an aminopyrimidine, 4-(4-nitrophenylazo)aniline, or combinations thereof. In one embodiment, the dispersant is derivative of an aromatic amine wherein the aromatic amine has at least three non-continuous aromatic rings.

[0045] The succinimide dispersant may be a derivative of a polyether amine or polyether polyamine. Typical polyether amine compounds contain at least one ether unit and will be chain terminated with at least one amine moiety. The polyether polyamines can be based on polymers derived from C.sub.2-C.sub.6 epoxides such as ethylene oxide, propylene oxide, and butylene oxide. Examples of polyether polyamines are sold under the Jeffamine brand and are commercially available from Huntsman Corporation located in Houston, Texas.

[0046] The borated dispersant may be based upon a borated polyisobutylene succinimide dispersant, wherein the polyisobutylene of the borated polyisobutylene succinimide has a number average molecular weight of 350 to 5000, or 550 to 3000 or 750 to 2500 or 350 to 2200, or 350 to 1350, or 350 to 1150 or 350 to 750 or 550 to 2200 or 550 to 1350 or 750 to 2200.

[0047] Suitable polyisobutylenes for use in the borated polyisobutylene succinimide dispersant may include those formed from polyisobutylene or highly reactive polyisobutylene having at least about 50 mol %, such as about 60 mol %, and particularly from about 70 mol % to about 90 mol % or greater than 90 mol %, terminal vinylidene content. Suitable polyisobutenes may include those prepared using BF.sub.3 catalysts. In one embodiment, the borated dispersant is derived from a polyolefin having number average molecular weight of 350 to 3000 Daltons and a vinylidene content of at least 50 mol %, or at least 70 mol %, or at least 90 mol %.

[0048] The dispersant may be prepared/obtained/obtainable from reaction of succinic anhydride by an ene or thermal reaction, by what is referred to as a direct alkylation process. The ene reaction mechanism and general reaction conditions are summarised in Maleic Anhydride, pages, 147-149, Edited by B. C. Trivedi and B. C. Culbertson and Published by Plenum Press in 1982. The dispersant prepared by a process that includes an ene reaction may be a polyisobutylene succinimide having a carbocyclic ring present on less than 50 mole %, or 0 to less than 30 mole %, or 0 to less than 20 mole %, or 0 mole % of the dispersant molecules. The ene reaction may have a reaction temperature of 180 C. to less than 300 C., or 200 C. to 250 C., or 200 C. to 220 C.

[0049] The dispersant may also be obtained/obtainable from a chlorine-assisted process, often involving Diels-Alder chemistry, leading to formation of carbocyclic linkages. The process is known to a person skilled in the art. The chlorine-assisted process may produce a dispersant that is a polyisobutylene succinimide having a carbocyclic ring present on 50 mole % or more, or 60 to 100 mole % of the dispersant molecules. Both the thermal and chlorine-assisted processes are described in greater detail in U.S. Pat. No. 7,615,521, columns 4-5 and preparative examples A and B.

[0050] In one embodiment, the borated dispersant may be a borated polyolefin succinic acid ester, amide, or ester-amide. For instance, a polyolefin succinic acid ester may be a polyisobutylene succinic acid ester of pentaerythritol, or mixtures thereof. A polyolefin succinic acid ester-amide may be a polyisobutylene succinic acid reacted with an alcohol (such as pentaerythritol) and an amine (such as a diamine, typically diethyleneamine).

[0051] The borated dispersant may be used alone or as part of a mixture of borated dispersants. If a mixture of borated dispersants is used, there may be two to five, or two to three or two borated dispersants.

[0052] The boron-containing dispersant may be present in an amount to deliver at least 25 ppm boron, at least 50 ppm boron, or at least 100 ppm boron to the lubricant composition.

[0053] The borated dispersant is typically present at 0.1 wt % to 10 wt %, or 0.5 wt % to 7 wt %, or 0.8 wt % to 4.5 wt %, or 1.0 wt % to 4.5 wt % or 2.0 wt % to 4.0 wt % or 1.5 wt % to 3 wt % of the lubricating oil composition.

[0054] In some embodiments, the lubricating composition may comprise a non-borated dispersant. Non-borated dispersants may comprise any non-borated version of the borated dispersants described above. In one embodiment, the non-borated dispersant may comprise a polyisobutylene succinimide dispersant, wherein the polyisobutylene has a number average molecular weight of 350 to 5000, or 550 to 3000 or 750 to 2500 or 350 to 2200, or 350 to 1350, or 350 to 1150 or 350 to 750 or 550 to 2200 or 550 to 1350 or 750 to 2200.

[0055] In another embodiment, a non-borated ashless dispersant may comprise a polyalphaolefins (PAO) containing dispersant selected from the group consisting of a polyalphaolefin succinimide, a polyalphaolefin succinamide, a polyalphaolefin acid ester, a polyalphaolefin oxazoline, a polyalphaolefin imidazoline, a polyalphaolefin succinamide imidazoline, and combinations thereof.

[0056] Polyalphaolefins (PAO) useful as feedstock in forming the PAO containing dispersants are those derived from oligomerization or polymerization of ethylene, propylene, and -olefins. Suitable -olefins include 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, and 1-octadecene. Feedstocks containing a mixture of two or more of the foregoing monomers as well as other hydrocarbons are typically employed when manufacturing PAOs commercially. The PAO may take the form of dimers, trimers, tetramers, polymers, and the like.

[0057] The PAO may be reacted with maleic anhydride (MA) to form the polyalphaolefin succinic anhydride (PAO-SA) and subsequently the anhydride may reacted with one or more of polyamines, aminoalcohols, and alcohols/polyols to form polyalphaolefin succinimide, polyalphaolefin succinamide, polyalphaolefin succinic acid ester, polyalphaolefin oxazoline, polyalphaolefin imidazoline, polyalphaolefin-succinamide-imidazoline, and mixtures thereof.

[0058] The non-borated, ashless dispersant may be present at 0.1 wt % to 10 wt %, or 0.5 wt % to 7 wt %, or 1 wt % to 5 wt %, or 1.5 wt % to 4 wt % of the lubricating oil composition.

[0059] Either or both of the borated and non-borated 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: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, or 0.9:1 to 1.6:1, or 0.95:1 to 1.5:1, or 1:1 to 1:4.

[0060] In one embodiment, the invention provides a lubricating composition further comprising a detergent. In one embodiment, the detergent may be an alkali or alkaline earth metal sulfonate detergent, an alkali or alkaline earth metal salicylate detergent, an alkali or alkali earth metal salixarate detergent, or an alkali or alkaline earth metal phenate deterrent. The detergent may be an overbased detergent. Overbased detergents, otherwise referred to as overbased or superbased salts, are characterized by a metal content in excess of that which would be necessary for neutralization according to the stoichiometry of the metal and the particular acidic organic compound reacted with the metal. Overbased detergents are known in the art and the lubricating composition of the present invention may contain detergents that are now known or hereafter developed and understood to be useful in the present invention to those skilled in the art.

[0061] In one embodiment, the detergent may comprise an overbased metal-containing sulfonate detergent. Overbased metal-containing sulfonate detergents may include calcium salts, magnesium salts, sodium salts, or mixtures thereof of one or more sulfonates. Other useful metals may include titanium and zirconium. Overbased sulfonates typically have a total base number of 250 to 600, or 300 to 500. In one embodiment, the sulfonate detergent may be predominantly a linear alkylbenzene sulfonate detergent having a metal ratio of at least 8 as is described in paragraphs [0026] to [0037] of US Patent Publication 2005065045 (and granted as U.S. Pat. No. 7,407,919). The linear alkylbenzene sulfonate detergent may be particularly useful for assisting in improving fuel economy. The linear alkyl group may be attached to the benzene ring anywhere along the linear chain of the alkyl group, but often in the 2, 3 or 4 position of the linear chain, and in some instances, predominantly in the 2 position, resulting in the linear alkylbenzene sulfonate detergent.

[0062] In one embodiment, the lubricating composition may comprise an alkali or alkaline earth metal salicylate detergent or salixarate detergent or mixture thereof. The metal containing salicylate or salixarate detergent may be an overbased detergent. Useful salicylate and salixarate detergents may include calcium salts, magnesium salts, sodium salts or mixtures thereof. Other useful metals may include titanium and zirconium. An overbased metal salicylate detergent may be present at 0.1 wt % to 15 wt %, or 0.1 wt % to 10 wt %, or 0.2 wt % to 8 wt %, or 0.2 wt % to 3 wt %. An overbased metal salixarate detergent may be present at 0.1 wt % to 15 wt %, or 0.1 wt % to 10 wt %, or 0.2 wt % to 8 wt %, or 0.2 wt % to 3 wt 0.

[0063] In one embodiment, the lubricating composition may contain a metal containing sulfur coupled alkyl phenol compound. Such compounds may be exemplified by alkali and alkaline earth metal containing phenate detergents, such as magnesium phenate detergents, calcium phenate detergents and sodium phenate detergents and further including overbased metal containing phenate detergents, all of which are known in the art. In one embodiment, the lubricating composition comprises less than 0.2 wt. % or 0.1 wt. % or 0.05 wt. % or 0.01 wt. % or 0.005 wt % of a metal containing sulfur coupled alkyl phenol compound.

[0064] In one embodiment, an overbased calcium detergent may be present in an amount to deliver at least 500 ppm calcium by weight and no more than 3000 ppm calcium by weight, or at least 1000 ppm calcium by weight, or at least 2000 ppm calcium by weight, or at least 1200 ppm calcium by weight to 1400 ppm calcium by weight, or no more than 2500 ppm calcium by weight to the lubricating composition. In one embodiment, the overbased magnesium detergent may be present in an amount to deliver no more than 500 ppm by weight of magnesium to the lubricating composition, or no more than 330 ppm by weight, or no more than 125 ppm by weight, or no more than 45 ppm by weight. In one embodiment, the overbased a magnesium detergent may be present in an amount to deliver at least 200 ppm by weight of magnesium, or at least 450 ppm by weight magnesium, or at least 700 ppm by weight magnesium to the lubricating composition. In one embodiment, the formulation is free of or substantially free of magnesium. In one embodiment, both calcium and magnesium containing detergents may be present in the lubricating composition. Calcium and magnesium detergents may be present such that the weight ratio of calcium to magnesium is 10:1 to 1:10, or 8:3 to 4:5, or 1:1 to 1:3. One or more overbased detergents may be present at 0.1 wt % to 15 wt %, or 0.1 wt % to 10 wt %, or 0.2 wt % to 8 wt %, or 0.2 wt % to 3 wt % of the lubricating composition.

[0065] In one embodiment, where the detergent comprises a mixture of calcium and magnesium containing detergents such as those disclosed herein, this detergent may provide 800 to 1300 ppm calcium and 450 to 800 ppm magnesium and in another embodiment 900 to 1200 ppm calcium and 500 to 750 ppm magnesium.

[0066] According to some embodiments, the total amount of soap contributed by the detergent may be from about 0.08 or 1.0 to less than 0.9 or 0.7 or 0.5 or 0.4 or 0.3 or 0.25 wt. % with respect to the lubricating composition. The lubricating composition may be free or substantially free of phenate soap. As used herein the term soap means the surfactant portion of a detergent and does not include a metal base, such as calcium carbonate. The soap term may also be referred to as a detergent substrate. For example, the sulfonate detergents described herein, the soap or substrate may be a neutral salt of an alkylbenzenesulfonic acid.

[0067] Metal-containing detergents may also contribute sulfated ash to a lubricating composition. Sulfated ash may be determined by ASTM D874. In one embodiment, the lubricating composition of the invention comprises a metal-containing detergent in an amount to deliver at least 0.4 wt. % sulfated ash to the total composition. In another embodiment, the metal-containing detergent is present in an amount to deliver at least 0.6 wt. % sulfated ash, or at least 0.75 wt. % sulfated ash, or even at least 0.9 wt. % sulfated ash to the lubricating composition.

[0068] In some embodiments, the lubricating compositions of the present invention may contain an organophosphorous anti-wear agent. The organo-phosphorus anti-wear agent may be a metal free organo-phosphorus anti-wear agent. The organo-phosphorus agent may contain sulfur or may be sulfur-free. Sulfur-free phosphorus-containing antiwear agents may be phosphites, phosphonates, alkylphosphate esters, amine or ammonium phosphate salts, or mixtures thereof.

[0069] Phosphorus esters such as the dihydrocarbon and trihydrocarbon phosphites, e.g., dibutyl phosphite, diheptyl phosphite, dicyclohexyl phosphite, pentylphenyl phosphite; dipentylphenyl phosphite, tridecyl phosphite, distearyl phosphite and polypropylene substituted phenol phosphite; metal thiocarbamates such as zinc dioctyldithiocarbamate and barium heptylphenol diacid; amine salts of alkyl and dialkylphosphoric acids or derivatives including, for example, the amine salt of a reaction product of a dialkyldithiophosphoric acid with propylene oxide and subsequently followed by a further reaction with P2O5; and mixtures thereof (as described in U.S. Pat. No. 3,197,405).

[0070] Amine phosphates may be amine salts of (i) monohydrocarbylphosphoric acid, (ii) dihydrocarbylphosphoric acid, (iii) hydroxy-substituted di-ester of phosphoric acid, or (iv) phosphorylated hydroxy-substituted di- or tri-ester of phosphoric acid. The amine salt of a sulfur-free phosphorus-containing compound may be salts of primary amines, secondary amines, tertiary amines, or mixtures thereof.

[0071] Amine phosphate salts may be derived from mono- or di-hydrocarbyl phosphoric acid (typically alkyl phosphoric acid), or mixtures thereof. The alkyl of the mono- or di-hydrocarbyl phosphoric acid may comprise linear or branched alkyl groups of 3 to 36 carbon atoms. The hydrocarbyl group of the linear or branched hydrocarbylphosphoric acid may contain 4 to 30, or 8 to 20 carbon atoms. Examples of a suitable hydrocarbyl group of the hydrocarbyl phosphoric acid may include isopropyl, n-butyl, sec-butyl, amyl, 4-methyl-2-pentyl (i.e., methylamyl), n-hexyl, n-heptyl, n-octyl, iso-octyl, 2-ethylhexyl, nonyl, 2-propylheptyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, oleyl, or combinations thereof. In one embodiment, the phosphate is a mixture of mono- and di-(2-ethyl)hexylphosphate.

[0072] Examples of suitable primary amines include ethylamine, propylamine, butylamine, 2-ethylhexylamine, octylamine, and dodecylamine, as well as such fatty amines as n-octylamine, n-decylamine, n-dodecylamine, n-tetradecylamine, n-hexadecylamine, n-octadecylamine and oleyamine. Other useful fatty amines include commercially available fatty amines such as Armeen. amines (products available from Akzo Chemicals, Chicago, Ill.), such as Armeen C, Armeen O, Armeen O L, Armeen T, Armeen H T, Armeen S and Armeen S D, wherein the letter designation relates to the fatty group, such as coco, oleyl, tallow, or stearyl groups.

[0073] In one embodiment, the metal-free phosphorus anti-wear agent may be present in the lubricant composition in amount of 0.01 to 5 wt %, or 0.1 to 3.2 wt %, or 0.35 to 1.8 wt %, or 0.5 to 1.5 wt %, or 0.5 to 0.9 wt %. In one embodiment, the metal-free phosphorus anti-wear agent may be present in an amount to provide 0.01 wt % to 0.15 wt % phosphorus, or 0.01 to 0.08 wt % phosphorus, or 0.025 to 0.065 wt % phosphorus to the composition.

[0074] In another embodiment, the lubricating composition of the present invention is free of or substantially free of phosphorous or phosphorous containing agents.

[0075] In one embodiment, the invention provides a lubricating composition which further includes an ashless antiwear agent different from the organo-phosphorus antiwear agent described above. Examples of suitable antiwear agents include hydroxy-carboxylic acid derivatives such as esters, amides, imides or amine or ammonium salt, sulfurized olefins, thiocarbamate-containing compounds, such as thiocarbamate esters, thiocarbamate amides, thiocarbamic ethers, alkylene-coupled thiocarbamates, and bis(S-alkyldithiocarbamyl) disulphides.

[0076] In one embodiment, an ashless antiwear agent may include a compound derived from a hydroxycarboxylic acid. In one embodiment the ashless antiwear agent is derived from at least one of hydroxy-polycarboxylic acid di-ester, a hydroxy-polycarboxylic acid di-amide, a hydroxy-polycarboxylic acid imide, and a hydroxy-polycarboxylic acid ester amide. In one embodiment the ashless antiwear agent is derived from a hydroxy-polycarboxylic acid imide.

[0077] Examples of a suitable a hydroxycarboxylic acid include citric acid, tartaric acid, lactic acid, glycolic acid, hydroxy-propionic acid, hydroxyglutaric acid, or mixtures thereof. In one embodiment ashless antiwear agent is derived from tartaric acid, citric acid, hydroxy-succinic acid, dihydroxy mono-acids, mono-hydroxy diacids, or mixtures thereof. In one embodiment the ashless antiwear agent includes a compound derived from tartaric acid or citric acid. In one embodiment the ashless antiwear agent includes a compound derived from tartaric acid.

[0078] US Patent Application 2005/198894 discloses suitable hydroxycarboxylic acid compounds, and methods of preparing the same.

[0079] Canadian Patent 1 183 125; US Patent Publication numbers 2006/0183647 and US-2006-0079413: U.S. Patent Application No. 60/867,402; and British Patent 2 105743 A. all disclose examples of suitable tartaric acid derivatives. The antiwear agent may in one embodiment include a 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, where the sum of carbon atoms on the alkyl groups is at least 8. The antiwear agent may in one embodiment include a citrate.

[0080] An ashless phosphorus-free antiwear agent may be present at 0.1 to 5 wt %, 0.1 wt % to 3 wt %, or 0.2 to 3 or 0.1 wt % to 1.5 wt %, or 0.5 wt % to 1.1 wt % of the lubricating composition.

[0081] In one embodiment, the invention may also provide a lubricating composition which further includes a metal dialkyldithiophosphate. Typically, the metal dialkyldithiophosphate may be a zinc dialkyldithiophosphate (ZDDP), or mixtures thereof. Zinc dialkyldithiophosphates are known in the art. The zinc dialkyldithiophosphate may be present at 0 wt % to 3 wt %, or 0.1 wt % to 1.5 wt %, or 0.5 wt % to 0.9 wt % of the lubricating composition. In another embodiment, ZDDP is present in amounts such that the total zinc contributed to the lubricant composition does not exceed 0.15 weight percent of the composition, for example, zinc may be presents in amounts of from 0 wt % to 0.15 wt %, or even less than 0.14 wt %, or even less than 0.11 wt %, or even less than 0.09 wt %, or even less than 0.07 wt %, or even less than 0.05 wt %, or even less than 0.03 wt % and in another embodiment 0.01 wt % to 0.14 wt %. In another embodiment, the lubricating composition is substantially free of zinc.

[0082] The zinc dialkyldithiophosphate may be derived from primary alcohols, secondary alcohols, or combinations thereof. Typically, they are derived from primary and secondary alcohols containing 3 to 12 carbon atoms and combinations thereof. In one embodiment the zinc alkyldithiophosphate comprises at least 25 mol % secondary alkyl groups, or at least 40 mol % secondary alkyl groups, or at least 75 mol % secondary alkyl groups, or at least 90 mol % secondary alkyl groups.

[0083] In one embodiment, the lubricating composition of the invention also comprises a dispersant viscosity modifier. The dispersant viscosity modifier may be present at 0.05 wt % to 5 wt %, or 0.05 wt % to 4 wt %, or 0.05 wt % to 2 wt % of the lubricating composition.

[0084] Suitable dispersant viscosity modifiers include functionalized polyolefins, for example, ethylene-propylene copolymers that have been functionalized with an acylating agent such as maleic anhydride and an amine; polymethacrylates functionalized with an amine, or esterified styrene-maleic anhydride copolymers reacted with an amine. More detailed description of dispersant viscosity modifiers are disclosed in International Publication WO2006/015130 or U.S. Pat. Nos. 4,863,623; 6,107,257; 6,107,258; and 6,117,825. In one embodiment, the dispersant viscosity modifier may include those described in U.S. Pat. No. 4,863,623 (see column 2, line 15 to column 3, line 52) or in International Publication WO2006/015130 (see page 2, paragraph [0008] and preparative examples are described at paragraphs [0065] to [0073]).

[0085] Antioxidants provide and/or improve the anti-oxidation performance of organic compositions, including lubricant compositions that contain organic components, by preventing or retarding oxidative and thermal decomposition. Suitable antioxidants may be catalytic or stoichiometric in activity and include any compound capable of inhibiting or decomposing free radicals, including peroxide.

[0086] Ashless antioxidants of the invention may comprise one or more of arylamines, diarylamines, alkylated arylamines, alkylated diaryl amines, phenols, hindered phenols, sulfurized olefins, or mixtures thereof. In one embodiment the lubricating composition includes an antioxidant, or mixtures thereof. The antioxidant may be present at 0.05 wt % to 15 wt %, or 0.1 wt % to 10 wt %, or 0.5 wt % to 5 wt %, or 0.5 wt % to 3 wt %, or 0.3 wt % to 1.5 wt % of the lubricating composition.

[0087] The diarylamine or alkylated diarylamine may be a phenyl--naphthylamine (PANA), an alkylated diphenylamine, or an alkylated phenylnapthylamine, or mixtures thereof. The alkylated diphenylamine may include di-nonylated diphenylamine, nonyl diphenylamine, octyl diphenylamine, di-octylated diphenylamine, di-decylated diphenylamine, decyl diphenylamine and mixtures thereof. In one embodiment, the diphenylamine may include nonyl diphenylamine, dinonyl diphenylamine, octyl diphenylamine, dioctyl diphenylamine, or mixtures thereof. In one embodiment the alkylated diphenylamine may include nonyl diphenylamine, or dinonyl diphenylamine. The alkylated diarylamine may include octyl, di-octyl, nonyl, di-nonyl, decyl or di-decyl phenylnapthylamines.

[0088] The diarylamine antioxidant of the invention may be present on a weight basis of the lubrication composition at 0.1% to 10%, 0.35% to 5%, or even 0.5% to 2%.

[0089] The phenolic antioxidant may be a simple alkyl phenol, a hindered phenol, or coupled phenolic compounds.

[0090] The hindered phenol antioxidant often contains a secondary butyl and/or a tertiary butyl group as a sterically hindering group. The phenol group may be further substituted with a hydrocarbyl group (typically linear or branched alkyl) and/or a bridging group linking to a second aromatic group. Examples of suitable hindered phenol antioxidants include 2,6-di-tert-butylphenol, 4-methyl-2,6-di-tert-butylphenol, 4-ethyl-2,6-di-tert-butylphenol, 4-propyl-2,6-di-tert-butylphenol or 4-butyl-2,6-di-tert-butylphenol, 4-dodecyl-2,6-di-tert-butylphenol, or butyl 3-(3,5-ditert-butyl-4-hydroxyphenyl)propanoate. In one embodiment, the hindered phenol antioxidant may be an ester and may include, e.g., Irganox L-135 from Ciba.

[0091] Coupled phenols often contain two alkylphenols coupled with alkylene groups to form bisphenol compounds. Examples of suitable coupled phenol compounds include 4,4-methylene bis-(2,6-di-tert-butyl phenol), 4-methyl-2,6-di-tert-butylphenol, 2,2-bis-(6-t-butyl-4-heptylphenol); 4,4-bis(2,6-di-t-butyl phenol), 2,2-methylenebis(4-methyl-6-t-butylphenol), and 2,2-methylene bis(4-ethyl-6-t-butylphenol).

[0092] Phenols of the invention also include polyhydric aromatic compounds and their derivatives. Examples of suitable polyhydric aromatic compounds include esters and amides of gallic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 1,4-dihydroxy-2-naphthoic acid, 3,5-dihydroxynaphthoic acid, 3,7-dihydroxy naphthoic acid, and mixtures thereof.

[0093] In one embodiment, the phenolic antioxidant comprises a hindered phenol. In another embodiment the hindered phenol is derived from 2,6-ditertbutyl phenol.

[0094] In one embodiment the lubricating composition of the invention comprises a phenolic antioxidant in a range of 0.01 wt % to 5 wt %, or 0.1 wt % to 4 wt %, or 0.2 wt % to 3 wt %, or 0.5 wt % to 2 wt % of the lubricating composition.

[0095] Sulfurized olefins are well known commercial materials, and those which are substantially nitrogen-free, that is, not containing nitrogen functionality, are readily available. The olefinic compounds which may be sulfurized are diverse in nature. They contain at least one olefinic double bond, which is defined as a non-aromatic double bond; that is, one connecting two aliphatic carbon atoms. These materials generally have sulfide linkages having 1 to 10 sulfur atoms, for instance, 1 to 4, or 1 or 2. In one embodiment, the lubricating composition of the invention comprises a sulfurized olefin in a range 0.2 weight percent to 2.5 weight percent, or 0.5 weight percent to 2.0 weight percent, or 0.7 weight percent to 1.5 weight percent.

[0096] The ashless antioxidants of the invention may be used separately or in combination. In one embodiment of the invention, two or more different antioxidants are used in combination, such that there is at least 0.1 weight percent of each of the at least two antioxidants and wherein the combined amount of the ashless antioxidants is 0.5 to 5 weight percent. In one embodiment, there may be at least 0.25 to 3 weight percent of each ashless antioxidant. In one embodiment, there may be 1.0 to 5.0 weight percent of one or more ashless antioxidants, or 1.4 to 3.0 weight percent of one or more antioxidants.

[0097] In one embodiment, the invention provides a lubricating composition further comprising a molybdenum compound. The molybdenum compound may be selected from the group consisting of molybdenum dialkyldithiophosphates, molybdenum dithiocarbamates, amine salts of molybdenum compounds, and mixtures thereof. The molybdenum compound may provide the lubricating composition with 0 to 1000 ppm, or 5 to 1000 ppm, or 10 to 750 ppm, or 5 ppm to 300 ppm, or 20 ppm to 250 ppm of molybdenum.

[0098] In one embodiment, the invention provides a lubricating composition further comprising a friction modifier. Examples of friction modifiers include long chain fatty acid derivatives of amines, fatty esters, or epoxides; fatty imidazolines such as condensation products of carboxylic acids and polyalkylene-polyamines; amine salts of alkylphosphoric acids; fatty alkyl tartrates; fatty alkyl tartrimides; or fatty alkyl tartramides. The term fatty, as used herein, can mean having a C8-22 linear alkyl group.

[0099] Friction modifiers may also encompass materials such as sulfurized fatty compounds and olefins, molybdenum dialkyldithiophosphates, molybdenum dithiocarbamates, sunflower oil or monoester of a polyol and an aliphatic carboxylic acid.

[0100] In one embodiment, the friction modifier may be selected from the group consisting of long chain fatty acid derivatives of amines, long chain fatty esters, or long chain fatty epoxides; fatty imidazolines; amine salts of alkylphosphoric acids; fatty alkyl tartrates; fatty alkyl tartrimides; and fatty alkyl tartramides. The friction modifier may be present at 0.05 wt % to 6 wt %, or 0.05 wt % to 4 wt %, or 0.1 wt % to 2 wt % of the lubricating composition.

[0101] In one embodiment, the friction modifier may be a long chain fatty acid ester. In another embodiment the long chain fatty acid ester may be a mono-ester or a diester or a mixture thereof, and in another embodiment the long chain fatty acid ester may be a triglyceride.

[0102] Other performance additives such as corrosion inhibitors include those described in paragraphs 5 to 8 of US Application U.S. Ser. No. 05/038,319, published as WO2006/047486, octyl octanamide, condensation products of dodecenyl succinic acid or anhydride and a fatty acid such as oleic acid with a polyamine. In one embodiment, the corrosion inhibitors include the Synalox (a registered trademark of The Dow Chemical Company) corrosion inhibitor. The Synalox corrosion inhibitor may be a homopolymer or copolymer of propylene oxide. The Synalox corrosion inhibitor is described in more detail in a product brochure with Form No. 118-01453-0702 AMS, published by The Dow Chemical Company. The product brochure is entitled SYNALOX Lubricants, High-Performance Polyglycols for Demanding Applications.

[0103] The lubricating composition may further include metal deactivators, including derivatives of benzotriazoles (typically tolyltriazole), dimercaptothiadiazole derivatives, 1,2,4-triazoles, benzimidazoles, 2-alkyldithiobenzimidazoles, or 2-alkyldithiobenzothiazoles; foam inhibitors, including copolymers of ethyl acrylate and 2-ethylhexylacrylate and copolymers of ethyl acrylate and 2-ethylhexylacrylate and vinyl acetate; demulsifiers including trialkyl phosphates, polyethylene glycols, polyethylene oxides, polypropylene oxides and (ethylene oxide-propylene oxide) polymers; and pour point depressants, including esters of maleic anhydride-styrene, polymethacrylates, polyacrylates or polyacrylamides.

[0104] Pour point depressants that may be useful in the compositions of the invention further include polyalphaolefins, esters of maleic anhydride-styrene, poly(meth)acrylates, polyacrylates or polyacrylamides.

[0105] In different embodiments, the lubricating composition may have a composition as described in the following table:

TABLE-US-00002 Embodiments (wt %) Additive A B C Borated Dispersant 0.05 to 12 0.75 to 8 0.5 to 6 Organo-phosphorus Antiwear Agent 0 to 15 0 to 10 00 to 5 Phosphorus-free Anti-Wear Agent 0 to 1 0.01 to 0.5 0.03 to 0.3 Overbased Detergent 0 to 15 0.1 to 10 0.2 to 8 Antioxidant 0 to 15 0.1 to 10 0.5 to 5 Dispersant Viscosity Modifier 0 to 5 0 to 4 0.05 to 2 Other Detergent 0 to 15 0.1 to 10 0.2 to 8 Other Dispersant 0 to 10 0.1 to 5 1.0 to 4 Friction Modifier 0 to 6 0.05 to 4 0.1 to 2 Viscosity Modifier 0 to 10 0.5 to 8 1 to 6 Any Other Performance Additive 0 to 10 0 to 8 0 to 6 Oil of Lubricating Viscosity Balance to Balance to Balance to 100% 100% 100%

[0106] The present invention provides a surprising ability to provide antioxidant benefits, including deposit control. The composition of the present invention maintains the oil in good operating condition (e.g. pumpability, cleanliness etc.), which provides benefits in terms of engine wear and longevity. This is accomplished while maintaining fuel economy performance, low sulfated ash levels, and other limitations, required by increasingly stringent government regulations.

INDUSTRIAL APPLICATION

[0107] As described above, the invention provides for a method of lubricating an internal combustion engine comprising supplying to the internal combustion engine a lubricating composition as disclosed herein. Generally, the lubricant is added to the lubricating system of the internal combustion engine, which then delivers the lubricating composition to the critical parts of the engine, during its operation, that require lubrication

[0108] The lubricating compositions described above may be utilized in an internal combustion engine. The engine components may have a surface of steel or aluminum (typically a surface of steel), and may also be coated for example with a diamond-like carbon (DLC) coating.

[0109] An aluminum surface may be comprised of an aluminum alloy that may be a eutectic or hyper-eutectic aluminum alloy (such as those derived from aluminum silicates, aluminum oxides, or other ceramic materials). The aluminum surface may be present on a cylinder bore, cylinder block, or piston ring having an aluminum alloy, or aluminum composite.

[0110] The internal combustion engine may be fitted with an emission control system or a turbocharger. Examples of the emission control system include diesel particulate filters (DPF), or systems employing selective catalytic reduction (SCR).

[0111] The internal combustion engine of the present invention is distinct from a gas turbine. In an internal combustion engine, individual combustion events translate from a linear reciprocating force into a rotational torque through the rod and crankshaft. In contrast, in a gas turbine (which may also be referred to as a jet engine) a continuous combustion process generates a rotational torque continuously without translation, and can also develop thrust at the exhaust outlet. These differences in operation conditions of a gas turbine and internal combustion engine result in different operating environments and stresses.

[0112] The lubricant composition for an internal combustion engine may be suitable for any engine lubricant irrespective of the sulfur, phosphorus or sulfated ash (ASTM D-874) content. The sulfur content of the engine oil lubricant may be 1 wt % or less, or 0.8 wt % or less, or 0.5 wt % or less, or 0.3 wt % or less, Or 0.25% or less. In one embodiment, the sulfur content may be in the range of 0.05 wt % to 0.5 wt %, or 0.1 wt % to 0.3 wt or even 0.15 to 0.25 wt %. The phosphorus content may be 0 to 0.2 wt %, or even 0.2 wt % or less, or 0.12 wt % or less, or 0.1 wt % or less, or 0.09 wt % or less, or 0.08 wt % or less, or even 0.06 wt % or less, 0.05 wt % or less, or 0.03 wt % or less, or even 0.02 wt % or less or substantially free of added phosphorus. In one embodiment the phosphorus content may be 0 ppm to 1000 ppm, or 100 to 900 ppm, or 200 ppm to 600 ppm. In another embodiment, the phosphorous content is less than 10 ppm by weight or even less than 5 ppm by weight. The total sulfated ash content may be 2 wt % or less, or 1.6 wt % or less, or 1.1 wt % or less, or 1 wt % or less, or 0.8 wt % or less, or 0.6 wt % or less, or 0.5 wt % or less. In one embodiment, the sulfated ash content may be 0.05 wt % to 0.9 wt %, or 0.1 wt % to 0.2 wt % or to 0.45 wt %.

[0113] In one embodiment, the lubricating composition may be an engine oil, wherein the lubricating composition may be characterized as having at least one of (i) a sulfur content of 0.5 wt % or less, (ii) a phosphorus content of 0.1 wt % or less, (iii) a sulfated ash content of 1.5 wt % or less, or combinations thereof.

[0114] As set forth herein, the present invention provides a composition for lubricating an internal combustion engine which comprises an oil of lubricating viscosity and a DMTD derivative comprising the reaction product of 2,5-dimercapto-1,3,4-thiadiazole (DMTD) and an , -unsaturated carbonyl compound, wherein the , -unsaturated carbonyl compound comprises an ester, amide, or imide containing 4 to 24, or 4 to 18, or 4 to 12, or 6 to 8 carbon atoms. In the composition of this paragraph, the DMTD derivative is further reacted with a metal oxide, metal hydroxide, or metal alkoxide to form a metal salt, wherein the metal is selected from zinc, titanium, molybdenum, animony, or mixtures thereof or the DMTD derivative is further reacted with an amine to form an amine salt. In the composition of this paragraph, the DMTD derivative is present in an amount to deliver at least 0.05% to 0.35% by weight or 0.07% to 0.3% by weight or 0.08% to 0.26% by weight sulfur to the lubricating composition. In addition, in the composition of this paragraph further comprises one or more metal containing detergents, wherein the metal containing detergent is selected from magnesium, calcium, sodium and mixtures thereof and wherein the detergent is selected from sulfonates, phenates, salicylates, salixarates or mixtures thereof. The composition of this paragraph contains a calcium detergent in an amount sufficient to deliver 500 ppm to 3000 ppm or 1000 ppm to 2500 ppm by weight calcium to the composition. The composition of this paragraph may be substantially free of or free of phosphorous. The composition of this paragraph may be free of or substantially free of zinc or may contain up to 0.15 wt % zinc. The present invention provides a method of lubricating an internal combustion engine comprising operating said engine with a lubricant composition comprising as described in this paragraph. The present invention provides a method of decomposing peroxide in a lubricating composition used to lubricate an internal combustion engine comprising supplying to said internal combustion engine the lubricating composition as described in this paragraph. In addition, the present invention includes the use of the lubricating composition as described in this paragraph for oxidation and deposit control in an internal combustion engine

[0115] The present invention also provides a composition for lubricating an internal combustion engine which comprises an oil of lubricating viscosity and a DMTD derivative comprising the reaction product of 2,5-dimercapto-1,3,4-thiadiazole (DMTD) and an , -unsaturated carbonyl compound, wherein the , -unsaturated carbonyl compound is an ester selected from the group consisting of maleates, acrylates, methacrylates, fumarates, crotonates, itaconates, and mixtures thereof, wherein the ester contains 4 to 24, or 4 to 18, or 4 to 12, or 6 to 8 carbon atoms. In the composition of this paragraph, the DMTD derivative is further reacted with a metal oxide, metal hydroxide, or metal alkoxide to form a metal salt, wherein the metal is selected from zinc, titanium, molybdenum, animony, or mixtures thereof or the DMTD derivative is further reacted with an amine to form an amine salt. In the composition of this paragraph, the DMTD derivative is present in an amount to deliver at least 0.05% to 0.35% by weight or 0.07% to 0.3% by weight or 0.08% to 0.26% by weight sulfur to the lubricating composition. In addition, in the composition of this paragraph further comprises one or more metal containing detergents, wherein the metal containing detergent is selected from magnesium, calcium, sodium and mixtures thereof and wherein the detergent is selected from sulfonates, phenates, salicylates, salixarates or mixtures thereof. The composition of this paragraph contains a calcium detergent in an amount sufficient to deliver 500 ppm to 3000 ppm or 1000 ppm to 2500 ppm by weight calcium to the composition. The composition of this paragraph may be substantially free of or free of phosphorous. The composition of this paragraph may be free of or substantially free of zinc or may contain up to 0.15 wt % zinc. The present invention provides a method of lubricating an internal combustion engine comprising operating said engine with a lubricant composition comprising as described in this paragraph. The present invention provides a method of decomposing peroxide in a lubricating composition used to lubricate an internal combustion engine comprising supplying to said internal combustion engine the lubricating composition as described in this paragraph. In addition, the present invention includes the use of the lubricating composition as described in this paragraph for oxidation and deposit control in an internal combustion engine

[0116] The present invention also provides a composition for lubricating an internal combustion engine which comprises an oil of lubricating viscosity and a DMTD derivative comprising the reaction product of 2,5-dimercapto-1,3,4-thiadiazole (DMTD) and an , -unsaturated carbonyl compound, wherein the , -unsaturated carbonyl compound comprises or consists of an alkyl acrylate, such as 2-ethyl hexyl acrylate or a alkyl methacrylate, such as lauryl methacrylate, or 2-ethylhexyl methacrylate. In the composition of this paragraph, the DMTD derivative is further reacted with a metal oxide, metal hydroxide, or metal alkoxide to form a metal salt, wherein the metal is selected from zinc, titanium, molybdenum, animony, or mixtures thereof or the DMTD derivative is further reacted with an amine to form an amine salt. In the composition of this paragraph, the DMTD derivative is present in an amount to deliver at least 0.05% to 0.35% by weight or 0.07% to 0.3% by weight or 0.08% to 0.26% by weight sulfur to the lubricating composition. In addition, in the composition of this paragraph further comprises one or more metal containing detergents, wherein the metal containing detergent is selected from magnesium, calcium, sodium and mixtures thereof and wherein the detergent is selected from sulfonates, phenates, salicylates, salixarates or mixtures thereof. The composition of this paragraph contains a calcium detergent in an amount sufficient to deliver 500 ppm to 3000 ppm or 1000 ppm to 2500 ppm by weight calcium to the composition. The composition of this paragraph may be substantially free of or free of phosphorous. The composition of this paragraph may be free of or substantially free of zinc or may contain up to 0.15 wt % zinc. The present invention provides a method of lubricating an internal combustion engine comprising operating said engine with a lubricant composition comprising as described in this paragraph. The present invention provides a method of decomposing peroxide in a lubricating composition used to lubricate an internal combustion engine comprising supplying to said internal combustion engine the lubricating composition as described in this paragraph. In addition, the present invention includes the use of the lubricating composition as described in this paragraph for oxidation and deposit control in an internal combustion engine

[0117] The present invention also provides a composition for lubricating an internal combustion engine which comprises an oil of lubricating viscosity and a DMTD derivative comprising the reaction product of 2,5-dimercapto-1,3,4-thiadiazole (DMTD) and an , -unsaturated carbonyl compound, wherein the , -unsaturated carbonyl compound comprises or consists of a dialkyl maleate such as bis-(2-ethylhexyl) maleate. In the composition of this paragraph, the DMTD derivative is further reacted with a metal oxide, metal hydroxide, or metal alkoxide to form a metal salt, wherein the metal is selected from zinc, titanium, molybdenum, animony, or mixtures thereof or the DMTD derivative is further reacted with an amine to form an amine salt. In the composition of this paragraph, the DMTD derivative is present in an amount to deliver at least 0.05% to 0.35% by weight or 0.07% to 0.3% by weight or 0.08% to 0.26% by weight sulfur to the lubricating composition. In addition, in the composition of this paragraph further comprises one or more metal containing detergents, wherein the metal containing detergent is selected from magnesium, calcium, sodium and mixtures thereof and wherein the detergent is selected from sulfonates, phenates, salicylates, salixarates or mixtures thereof. The composition of this paragraph contains a calcium detergent in an amount sufficient to deliver 500 ppm to 3000 ppm or 1000 ppm to 2500 ppm by weight calcium to the composition. The composition of this paragraph may be substantially free of or free of phosphorous. The composition of this paragraph may be free of or substantially free of zinc or may contain up to 0.15 wt % zinc. The present invention provides a method of lubricating an internal combustion engine comprising operating said engine with a lubricant composition comprising as described in this paragraph. The present invention provides a method of decomposing peroxide in a lubricating composition used to lubricate an internal combustion engine comprising supplying to said internal combustion engine the lubricating composition as described in this paragraph. In addition, the present invention includes the use of the lubricating composition as described in this paragraph for oxidation and deposit control in an internal combustion engine

[0118] The present invention also provides a composition for lubricating an internal combustion engine which comprises an oil of lubricating viscosity and a DMTD derivative comprising the reaction product of 2,5-dimercapto-1,3,4-thiadiazole (DMTD) and an , -unsaturated carbonyl compound, wherein the , -unsaturated carbonyl compound comprises or consists of a dialkyl itaconate such as bis(2,4-dimethylpentyl)itaconate. In the composition of this paragraph, the DMTD derivative is further reacted with a metal oxide, metal hydroxide, or metal alkoxide to form a metal salt, wherein the metal is selected from zinc, titanium, molybdenum, animony, or mixtures thereof or the DMTD derivative is further reacted with an amine to form an amine salt. In the composition of this paragraph, the DMTD derivative is present in an amount to deliver at least 0.05% to 0.35% by weight or 0.07% to 0.3% by weight or 0.08% to 0.26% by weight sulfur to the lubricating composition. In addition, in the composition of this paragraph further comprises one or more metal containing detergents, wherein the metal containing detergent is selected from magnesium, calcium, sodium and mixtures thereof and wherein the detergent is selected from sulfonates, phenates, salicylates, salixarates or mixtures thereof. The composition of this paragraph contains a calcium detergent in an amount sufficient to deliver 500 ppm to 3000 ppm or 1000 ppm to 2500 ppm by weight calcium to the composition. The composition of this paragraph may be substantially free of or free of phosphorous. The composition of this paragraph may be free of or substantially free of zinc or may contain up to 0.15 wt % zinc. The present invention provides a method of lubricating an internal combustion engine comprising operating said engine with a lubricant composition comprising as described in this paragraph. The present invention provides a method of decomposing peroxide in a lubricating composition used to lubricate an internal combustion engine comprising supplying to said internal combustion engine the lubricating composition as described in this paragraph. In addition, the present invention includes the use of the lubricating composition as described in this paragraph for oxidation and deposit control in an internal combustion engine

EXAMPLES

[0119] The invention will be further illustrated by the following examples, which set forth particularly advantageous embodiments. While the examples are provided to illustrate the invention, they are not intended to limit it.

[0120] Examples 1-5 are formed by reaction of DMTD and an ,-unsaturated carbonyl compound and are of Formula V below:

##STR00008##

In general, DMTD and solvent (ethyl acetate or toluene) were added to the reaction vessel. The unsaturated carbonyl compound was added to the reaction flask and the mixture was heated at elevated temperature (reaction temperatures ranged from 40 C. to 120 C.) for 2.5 to 30 hours. The solvent was removed in vacuo. For Examples 1-5, X=H, and, n=1.

TABLE-US-00003 TABLE 1 Adducts formed by the Michael addition of DMTD with the unsaturated carbonyl compounds listed below. Unsaturated carbonyl compound R.sub.1 R.sub.2 R.sub.3 Example 1 Bis-(2-ethylhexyl)maleate COOR.sub.3 H 2-EHL.sup.1 Example 2 2-ethylhexyl acrylate H H 2-EHL Example 3 2-ethylhexyl methacrylate H CH.sub.3 2-EHL Example 4 Bis(2,4-dimethylpentyl)itaconate H CH.sub.2COOR.sub.3 DMP.sup.2 Example 5 Lauryl methacrylate H CH.sub.3 .sup.12-EHL = 2-ethylhexyl .sup.2DMP = dimethylpentyl

[0121] Examples 6-7 are salts formed by further reacting Example 1 with a metal source. Examples 8-11 are salts formed by further reacting Example 2 with a metal source or an amine. Salting reactions were generally conducted by adding either Example 1 or Example 2 to the reaction flask and then adding the salting agent listed in the table below. Reactants were heated at reaction temperatures between 40 and 150 C for 1 to 6 hours. In some cases, the reactant mixture was placed under vacuum to remove volatile side products.

TABLE-US-00004 TABLE 2 Salted adducts Unsaturated carbonyl compound R.sub.1 R.sub.2 R.sub.3 Salting agent Example 6 Bis-(2-ethylhexyl)maleate COOR.sub.3 H 2-EHL ZnO Example 7 Bis-(2-ethylhexyl)maleate COOR.sub.3 H 2-EHL Ti(iOPr).sub.4 Example 8 2-ethylhexyl acrylate H H 2-EHL TMEDA.sup.3 Example 9 2-ethylhexyl acrylate H H 2-EHL TTZL.sup.4 Example 10 2-ethylhexyl acrylate H H 2-EHL Ti(iOPr).sub.4 Example 11 2-ethylhexyl acrylate H H 2-EHL Sb.sub.2O.sub.3 .sup.3TMEDA = tetra methyl ethylene diamine .sup.4TTZL = tolyltriazole

[0122] The Examples from Table 1 above were blended into a fully formulated fluid according to the recipes listed in Table 3.

TABLE-US-00005 TABLE 3 Fully formulated fluids containing the inventive components Fluid 1 Fluid 2 Fluid 3 Fluid 4 Fluid 5 Fluid 6 Fluid 7 Succinimde dispersant 2.92 2.92 2.92 2.92 2.92 2.92 2.92 Borated succinimide 2.85 2.85 2.85 2.85 2.85 2.85 2.85 dispersant Alkoxylated phenol 2 2 2 2 2 2 2 Ca salicylate 1.12 1.12 1.12 1.12 1.12 1.12 1.12 Mg sulfonate 0.29 0.29 0.29 0.29 0.29 0.29 0.29 detergent Si based antifoam 0.01 0.01 0.01 0.01 0.01 0.01 0.01 Phenolic antioxidant 1.5 1.5 1.5 1.5 1.5 1.5 Aminic antioxidant 0.8 Zinc 0.8 dialkyldithiophosphate Sulfurized olefin 0.5 Example 1 1.22 Example 2 0.83 Example 3 0.86 Example 4 1.11 Example 5 1.05 S, % (ASTM D4951) 0.0117 0.246 0.249 0.233 0.244 0.278 0.267 Zn, ppm 0 874

[0123] The Examples from Table 2 were blended into fully formulated fluids according to the recipes in Table 4.

TABLE-US-00006 TABLE 4 Fully formulated fluids containing the inventive components. Fluid Fluid Fluid Fluid Fluid Fluid 8 9 10 11 12 13 Succinimde dispersant 2.92 2.92 2.92 2.92 2.92 2.92 Borated succinimide 2.85 2.85 2.85 2.85 2.85 2.85 dispersant Alkoxylated phenol 2 2 2 2 2 2 Ca salicylate 1.12 1.12 1.12 1.12 1.12 1.12 Mg sulfonate detergent 0.29 0.29 0.29 0.29 0.29 0.29 Si based antifoam 0.01 0.01 0.01 0.01 0.01 0.01 Phenolic antioxidant 1.5 1.5 1.5 1.5 1.5 1.5 Example 6 1.29 Example 7 1.24 Example 8 1.02 Example 9 1.11 Example 10 0.89 Example 11 0.81 S % (ASTM D4951) 0.246 0.251 0.251 0.251 0.258 0.235

[0124] Each of the fully formulated fluids listed in Tables 3 and 4 was evaluated in a Hydroperoxide Decomposer (HPD) Test according to the following procedure. In this test, 50 g of each fully formulated fluid is added to a 3 neck 100 ml flask equipped with a magnetic stirrer. The samples are heated to 140 C., and 0.5 ml tert-butyl hydroperoxide solution is added and a stopwatch is started. After 2 min. 55 sec, a 2 ml sample of the reaction mixture is removed and stored in a vial. After 3 min, another 0.5 ml of tert-butyl hydroperoxide solution is added to the 100 ml flask. After 5 min, 55 sec, a second 2 ml sample is removed and stored in a vial. After 6 min., another 0.5 ml of tert-butyl hydroperoxide solution is added. After 9 minutes, 14 minutes and 19 minutes additional 2 ml samples are removed and stored in vials. Each sample collected is then tested by iodometric titration to determine the hydroperoxide number of each (ie the remaining amount of peroxide present in each sample).

[0125] For each sample collected, 5 ml of titration solvent (3:2 acetic acid: chloroform) is added. The vials are capped and swirled to stir the contents. Saturated potassium iodide solution (0.4 ml) is added into each vial. The vials are capped and swirled again. The vials are then stored in the dark, leaving them overnight (min. of 16 hours) to allow iodine to liberate from solution. The next day 5 ml deionized water is added to each sample vial. The vials are capped and swirled to mix. Starch indicator solution (3-4 drops) is added to the sample vial immediately before titrating. A dark blue-purple color develops. Each sample is titrated with 0.1 M sodium thiosulfate solution until a sharp color change occurs. Ensure the color change is permanent by swirling for a few moments. If the blue-purple color reappears, continue to titrate. Record the titer volume in ml. The hydrogen peroxide number (HPN) can be calculated by the following equation:

HPN=Volume of titer (ml)molarity of titrant1000 Weight of sample (g)

[0126] Lower values for HIPN indicate that the formulation was an effective hydroperoxide decomposer, while higher HPN values are indicative of formulations with less effective hydroperoxide decomposers. The results are summarized in Tables 5 and 6.

TABLE-US-00007 TABLE 5 HPN results for fluids 1-7. Fluid Fluid Fluid Fluid Fluid Fluid Fluid 1* 2* 3 4 5 6 7 0.5 ml 111 11 15 17 34 16 58 peroxide (3 min) 1.0 ml 199 83 61 73 146 133 122 peroxide (6 min) 1.5 ml 115 168 141 146 205 180 185 peroxide (9 min) Hold 1 265 149 113 133 184 161 166 (14 min) Hold 2 245 140 103 122 165 147 157 (19 min) Average HPN 227 110 87 98 140 119 137 *Numbers reported are the average of five separate analyses

TABLE-US-00008 TABLE 6 HPN results for fluids 8-13. Fluid 8 Fluid 9 Fluid 10 Fluid 11 Fluid 12 Fluid 13 0.5 ml peroxide 16 21 10 11 19 28 (3 min) 1.0 ml peroxide 72 177 63 76 71 116 (6 min) 1.5 ml peroxide 156 228 151 151 123 210 (9 min) Hold 1 142 216 135 134 92 199 (14 min) Hold 2 114 180 114 128 72 179 (19 min) Average HPN 100 164 95 100 75 146

[0127] It is known that some of the materials described above may interact in the final formulation, so that the components of the final formulation may be different from those that are initially added. The products formed thereby, including the products formed upon employing lubricant composition of the present invention in its intended use, may not be susceptible of easy description. Nevertheless, all such modifications and reaction products are included within the scope of the present invention; the present invention encompasses lubricant composition prepared by admixing the components described above.

[0128] Each of the documents referred to above is incorporated herein by reference, as is the priority document and all related applications, if any, which this application claims the benefit of. Except in the Examples, or where otherwise explicitly indicated, all numerical quantities in this description specifying amounts of materials, reaction conditions, molecular weights, number of carbon atoms, and the like, are to be understood as modified by the word about. Unless otherwise indicated, each chemical or composition referred to herein should be interpreted as being a commercial grade material which may contain the isomers, by-products, derivatives, and other such materials which are normally understood to be present in the commercial grade. However, the amount of each chemical component is presented exclusive of any solvent or diluent oil, which may be customarily present in the commercial material, unless otherwise indicated. It is to be understood that the upper and lower amount, range, and ratio limits set forth herein may be independently combined. Similarly, the ranges and amounts for each element of the invention may be used together with ranges or amounts for any of the other elements.

[0129] As used herein, the term hydrocarbyl refers to a group having a carbon atom directly attached to the remainder of the molecule, where the group includes at least carbon and hydrogen atoms. If the hydrocarbyl group comprises more than one carbon atom, then those carbons need not necessarily be linked to each other. For example, at least two of the carbons may be linked via a suitable element or group. In various embodiments, the term hydrocarbyl refers to a group having a carbon atom directly attached to the remainder of the molecule, where the group consists of carbon, hydrogen, optionally one or more heteroatoms provided the heteroatoms do not alter the predominantly hydrocarbon nature of the substituent. The heteroatom may link at least two of the carbons in the hydrocarbyl group, and optionally no more than two non-hydrocarbon substituents. Suitable heteroatoms will be apparent to those skilled in the art and include, for instance, sulphur, nitrogen, oxygen, phosphorus and silicon. Where the hydrocarbyl contains heteroatoms, optionally, no more than two heteroatoms will be present for every ten carbon atoms in the hydrocarbyl group. Suitable non-hydrocarbon substituents will also be apparent to those skilled in the art and include, for instance, halo, hydroxy, alkoxy, mercapto, alkylmercapto, nitro, nitroso, and sulphoxy.

[0130] Examples of hydrocarbyls within the context of the present technology therefore include: [0131] (i) hydrocarbon groups selected from aliphatic (e.g. alkyl or alkenyl), alicyclic (e.g. cycloalkyl, cycloalkenyl, cycloalkadienyl), and aromatic groups; [0132] (ii) substituted hydrocarbon groups, selected from hydrocarbon groups defined in (i) substituted with no more than two non-hydrocarbon substituents and/or one or more hydrocarbon substituents, the non-hydrocarbon substituents being selected from the group consisting of halo, hydroxy, alkoxy, mercapto, alkylmercapto, nitro, nitroso, and sulphoxy; [0133] (iii) hetero-containing hydrocarbon groups, selected from hydrocarbon groups defined in (i) containing one or more heteroatom in the ring or chain, provided that the group has no more than two heteroatoms present for every ten carbon atoms in the group, the heteroatoms being selected from sulphur, nitrogen, oxygen, phosphorus and silicon. The hetero-containing hydrocarbon groups may be substituted with no more than two non-hydrocarbon substituents and/or one or more hydrocarbon substituents.

[0134] In some embodiments, the term hydrocarbyl refers to a group having a carbon atoms directly attached to the remainder of the molecule, where the group consists of carbon and hydrogen atoms

[0135] As used herein, the transitional term comprising, which is synonymous with including, containing, or characterized by, is inclusive or open-ended and does not exclude additional, un-recited elements or method steps. However, in each recitation of comprising herein, it is intended that the term also encompass, as alternative embodiments, the phrases consisting essentially of and consisting of, where consisting of excludes any element or step not specified and consisting essentially of permits the inclusion of additional un-recited elements or steps that do not materially affect the essential or basic and novel characteristics of the composition or method under consideration. The expression consisting of or consisting essentially of, when applied to an element of a claim, is intended to restrict all species of the type represented by that element, notwithstanding the presence of comprising elsewhere in the claim. As used herein, substantially free means that the amount of the material in question is less than an amount that will affect the relevant performance of the fluid in a measurable way. Substantially free may also mean that the material in question is not intentionally added to the composition but does not exclude the presence of such material as contaminants. Substantially free may also mean that the material in question may be present in amounts lower than the detection limit of standard test methods now known to those skilled in the art or hereafter developed. In some embodiments, substantially free may mean less than 10 ppm by weight or even less than 5 ppm by weight.

[0136] 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. Therefore, it is to be understood that the invention disclosed herein is intended to cover such modifications as fall within the scope of the appended claims.