BACKGROUND OF THE DISCLOSURE

Field of the Disclosure

[0001] This disclosure relates generally to lubricant compositions. This disclosure relates more particularly to a low-viscosity, low-wear lubricant compositions suitable for use as automotive lubricants and methods for using them.

Technical Background

[0002] Lubricant compositions are used in many systems for a variety of purposes. For example, lubricant compositions are used to lubricate the moving parts in systems such as gears, motors, engines (e.g., automotive and aircraft engines), turbines, compressors, and manufacturing systems. A lubricant composition is typically circulated through the system passing over or through the components and parts that it lubricates.

[0003] Lubricant compositions generally comprise a base oil of lubricating viscosity together with one or more additives to deliver properties including for example, reduced friction and wear, improved viscosity index, improved dispersancy, detergency, and resistance to oxidation and corrosion. A lubricant base oil may comprise one or more lubricating base stocks.

[0004] Lubricant base stocks used in automotive engine lubricants are generally obtained from petrochemical sources, for example they may be obtained as the higher boiling fractions isolated during the refining of crude oil or as the products of chemical reactions of feedstocks from petrochemical sources. Lubricant base stocks can also be made from Fischer-Tropsch wax.

[0005] Lubricant base stocks may be classified as Group I, II, III, IV and V base stocks according to API standard 1509, "Engine Oil Licensing and Certification System", 17 ^th Edition, Annex E (October 2013 with Errata March 2015), as set out in Table 1. Table 1

[0006] Group I base stocks are typically manufactured by known processes including, for example, solvent extraction and solvent dewaxing, or solvent extraction and catalytic dewaxing. Group II and Group III base stocks are typically manufactured by known processes including, for example, catalytic hydrogenation and/or catalytic hydrocracking, and catalytic hydroisomerisation. Group IV base stocks include for example, hydrogenated oligomers of alpha olefins.

[0007] A combination of properties is desirable in a base stock for conferring to a lubricant composition comprising it. In some instances, for example in passenger car engine oils, it may be desirable for a base stock to confer a low viscosity profile on the lubricant composition, since this leads to improved fuel economy. In particular, it is desirable for base stocks to have a low kinematic viscosity as well as good low-temperature viscosity characteristics, for example a low pour point or low viscosity as measured using a minirotary viscometer (MRV). Critically, low-viscosity compositions tend to be less protective of engine components than higher-viscosity compositions. Low-viscosity oil formulations may suffer from wear issues owing to thin oil films in wear contacts, leading to increased chances of metal-metal contact and hence increased wear rates.

[0008] Accordingly, there is a need in the art for a lubricant composition having a desirable viscosity profile, including good low-temperature viscosity characteristics, but which also exhibits low volatility and an improved degree of lubrication.

SUMMARY OF THE DISCLOSURE

[0009] One aspect of the disclosure provides a lubricant composition with a generally low viscosity and good anti-wear performance. Such lubricant composition includes as a base oil, one or more trimers of C8-C12 linear alpha olefins, present in a total amount of at least 70 wt% of the lubricant composition. [0010] Another aspect of the disclosure provides a mechanical system. The mechanical system includes a lubricant composition of the disclosure as described herein, disposed between opposing surfaces.

[0011] In another aspect, the disclosure provides a method for lubricating a mechanical system of the disclosure as described herein. Such method includes providing the mechanical system of the disclosure as described herein, and moving the opposing surfaces relative to one another.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The accompanying drawings are included to provide a further understanding of the compositions and methods of the disclosure, and are incorporated in and constitute a part of this specification. The drawings are not necessarily to scale, and sizes of various elements may be distorted for clarity. The drawings illustrate one or more embodiment(s) of the disclosure and, together with the description, serve to explain the principles and operation of the disclosure.

[0013] FIG. 1 is a schematic cross-sectional view of method of lubricating a mechanical system according to an embodiment of the disclosure.

DETAILED DESCRIPTION

[0014] The present inventors have noted that low-viscosity lubricants typically suffer from lower wear protection as compared to higher-viscosity lubricants. As lower viscosities correlate with better fuel economy, the present inventors have noted a need in the art to provide lower-viscosity lubricants with improved wear protection.

[0015] The present inventors note that so-called “Fujita” catalysts can be used to prepare poly alpha-olefins that are mainly trimeric in nature, with high control of regioisomeric configuration and in many cases stereoisomeric configuration. For example, in certain embodiments as described below, use of certain Fujita catalysts can generate mainly trimers, with a high proportion of the trimers having the same structure. These substantially trimeric materials can have a generally low viscosity.

[0016] Advantageously, when used in a high proportion as base oil lubricant, such poly alpha-olefin materials can provide improved wear protection. Without intending to be bound by theory, the present inventors surmise that base oils with a high proportion of molecules of similar (or the same) molecular structure can provide molecular coordination (e.g., “freezing”) under the high pressure conditions between opposing surfaces in a lubricated system, providing an apparent higher-viscosity material in these regions. See, e.g., J.P. Ewen et al., “On the effect of confined fluid molecular structure on nonequilibrium phase behavior and friction,” Phys. Chem. Chem. Phys, 19, 17883-94 (2017). Accordingly, such materials can provide a protective oil film in highly-stressed regions of mechanical systems such as engines, leading to reduced wear.

[0017] The combination of low viscosity with the property of being more liable to coordinate or “freeze” under high pressures means that materials based on Fujita-based poly alpha-olefin trimeric materials offer the possibility of generating low-viscosity lubricant formulations with enhanced wear protection derived from the base-oil properties. This can reduce the need for typical remedial wear protection additives. Advantageously, in some embodiments such lubricants can have lower metal, phosphorus and sulfur contents, and thus can be helpful in exhaust gas after-treatment durability.

[0018] Accordingly, one embodiment of the disclosure is a lubricant composition that includes, as a base oil, one or more trimers of C8-C12 linear alpha olefins, present in a total amount of the lubricant composition of at least 50 wt%. For example, in certain embodiments as otherwise described herein, the one or more trimers are present in a total amount of at least 60 wt%, e.g., at least 65 wt%. In certain embodiments as otherwise described herein, the one or more trimers are present in a total amount of at least 60 wt%, e.g., at least 75 wt%. In certain embodiments as otherwise described herein, the one or more trimers are present in a total amount of at least 80 wt%, e.g., at least 85 wt%.

[0019] The present inventors have found that trimers of 1 -decene have especially desirable properties for a lubricant composition, as described below. Accordingly, in certain embodiments as otherwise described herein, the one or more trimers are 1 -decene trimers. Of course, the person of ordinary skill in the art can, based on the present disclosure, provide lubricant compositions based on other alpha olefins. For example, in certain embodiments as otherwise described herein, the one or more trimers are 1 -octene trimers. And in other embodiments as otherwise described herein, the one or more trimers are 1 - dodecene trimers. In certain embodiments, mixtures of trimers (e.g., mixtures of 1 -decene, 1 -octene, and/or 1 -dodecene trimers) can be used. And in certain embodiments, the trimers themselves can be of mixed feeds (e.g., trimers made by trimerizing mixtures of 1 -decene and 1 -octene, or 1 -decene and 1 -dodecene).

[0020] Notably, using Fujita-style catalysts, and particularly using the catalyst systems described herein, alpha olefin oligomerization processes provide not only a high proportion of trimeric product, but also a high proportion of product with the same regioisomeric configuration. For example, in certain embodiments as otherwise described herein, at least 70 wt% (e.g., at least 75 wt%, at least 80 wt%, or at least 85 wt%) of the one or more trimers have the same regioisomeric configuration. For example, in certain such embodiments, the one or more trimers have the structure in which each R _a , Rb and R _c is an alkyl moiety of an alpha olefin feed molecule having the structure R _a -CH=CH ₂ , Rb-CH=CH ₂ , or R _c -CH=CH ₂ .

[0021] In certain embodiments, the catalyst systems described herein can also provide a high degree of diastereoselectivity. For example, in certain embodiments as otherwise described herein, at least 80 wt% of the one or more trimers having the same regioisomeric configuration have the same diastereomeric configuration with respect to at least two stereogenic centers. For example, in certain embodiments, in the predominant diastereomeric configuration the Ra and Rb moieties are configured in a racemo diad:

As used here, two enantiomers with the same relative stereochemistry are considered as having the same diastereomeric configuration.

[0022] As described above, the predominantly trimeric alpha olefin oligomers described herein can be made using so-called “Fujita”-type catalysts. Certain such catalyst systems are generally described in U.S. Patent Application Publication no. 2006/0155083, which is hereby incorporated herein by reference in its entirety. In certain embodiments as otherwise described herein, the catalyst is an (FI)Ti catalyst, i.e., having an Fl moiety coordinated to a titanium atom, which can have other ligands bound thereto. The Fl moiety is N-(5-methyl-3- (1 -adamantyl)-salicylidine-2’-(2”-methoxyphenyl)anilinato. (FI)Ti catalysts can be activated by Lewis acids, e.g., B(C6F ₆ )3 or methyl aluminoxane. (FI)Ti catalysts can advantageously be supported on silica, e.g., silica treated with methylaluminoxane (MAO). Thus, in certain embodiments, the (FI)Ti catalyst has the structure:

In other embodiments, the (FI)Ti catalyst is [(FI)TiMe2][MeB(C6F ₅ )3].

[0023] For example, reaction of a trimethyl titanium complex, (FI)TiMe3 with B(C6F ₅ )3 yields [(FI)TiMe2][MeB(C6F ₅ )3], which when used in oligomerization of alpha olefins displayed high selectivity for trimers (>95%), approximately 85% of which are one regioisomer. Such catalysts are described in A. Sattler et aL, “’’Highly Selective Olefin Trimerization Catalysis by a Borane-Activated Titanium Trimethyl Complex,” Organometallics, 32:6899- 6902 (2013), which is hereby incorporated herein by reference in its entirety.

[0024] Other example catalysts, (FI)Ti(CH ₂ SiMe3)2Me was synthesized and structurally characterized by X-ray diffraction, as described in A. Sattler et aL, “Lewis Acid Promoted Titanium Alkylidene Formation: Off-Cycle Intermediates Relevant to Olefin Trimerization Catalysis,” J. Am. Chem. Soc. 136(30):10790-10800 (2014), which is hereby incorporated herein by reference in its entirety. (FI)Ti(CH ₂ SiMe3)2Me can be activated with B(C6F ₅ )3 to provide the solvent-separated ion pair [(FI)Ti(CH ₂ SiMe3)2][MeB(C6F ₅ )3], which selectively trimerizes alpha olefins.

[0025] Particularly suitable catalysts are described in A. Sattler et aL, “Enhanced Productivity of a Supported Olefin Trimerization Catalyst,” ACS Catalysis, 6:19-22 (2016), which is hereby incorporated herein by reference in its entirety. Here, a heterogeneous supported (FI)Ti trimerization catalyst was made by treating dry silica with methylaluminoxane (MAO), then with ( FQTiCIs- This catalyst was found to exhibit productivity more than ten times higher than analogous homogeneous catalysts. Without intending to be bound by theory, it is believed that immobilization slows the comproportionation to inactive Ti ^IH species to which catalyst decomposition is attributed. This supported (FI)Ti catalyst catalyzes trimerization of alpha olefins with high selectivity. Because s(FI)Ti is preactivated (already in the cationic methylated form) and requires no additional reagent, in certain embodiments solventless catalysis can be possible, e.g., in fixed bed or trickle bed reactors. [0026] A variety of purification methods can be used on the trimerization. For example, in certain embodiments, the trimerization reaction product can be distilled to purify trimeric and other lower molecular weight product away from higher molecular weight by-products.

[0027] The person of ordinary skill in the art will appreciate that in some embodiments it may be desirable to provide a base oil with a relatively low degree of olefin character. Accordingly, in certain embodiments, one or more of the trimers are saturated. The trimerization reaction with Fujita catalyst provide a material having an olefin, e.g., in which the structure

But in certain desirable embodiments, the reaction product can be hydrogenated or otherwise reacted to provide saturated trimers, e.g., in which the structure

In typical cases, while the relative stereochemistry of R _a and R _b may be fixed by the catalytic reaction (e.g., in a racemo diad as described above), the stereochemistry of R _c is provided by the hydrogenation or other saturation reaction, and may be, e.g., a random mixture of diastereomers at this stereogenic center. In certain desirable embodiments, the one or more trimers are at least 92% saturated, e.g., at least 95% saturated, or at least 97% saturated.

[0028] As noted above, the lubricant compositions include at least 50 wt% of one or more trimers of C8-C12 alpha olefins. While the reactions used to make such lubricant compositions are highly selective for trimers, in any real world system there will always be side products. For example, in certain embodiments, the lubricant compositions as otherwise described herein further include one or more non-trimeric alpha olefin oligomers, for example, dimers, tetramers, pentamers, hexamers, heptamers, octamers and nonamers, e.g., based on the alpha olefin(s) underlying the trimeric compound(s). While the reaction is selective for trimerization, a trimeric reaction product (i.e., having a single olefin) can further react with two molecules of alpha olefin to make pentamer, or with a molecule of reaction product and a molecule of alpha olefin to make heptamer, or can further trimerize to make nonamer. Also present can be unreacted alpha olefin, e.g., the alpha olefin(s) of the trimeric compound(s). In all cases, these can include saturated forms, e.g., in which at least these other alpha olefin-based substances are at least 80% saturated, e.g., at least 85% saturated, or at least 90% saturated.

[0029] The lubricant compositions of the disclosure can also include a variety of other components, such as those conventional in lubricant compositions for industrial and automotive lubricants.

[0030] In certain embodiments as otherwise described herein, the lubricant composition can include one or more additional base oils. Such additional base oil(s) can be used to tune properties of the lubricant composition, e.g., with respect to viscosity, or to help provide a lower-cost lubricant composition. The person of ordinary skill in the art will determine an amount of additional base oil(s) that provides desired properties, e.g., while still providing an overall lubricant composition having desirable wear protection.

[0031] For example, the lubricant composition may further include an oil, e.g., a mineral oil, a synthetic oil, or a silicone oil. For example, in certain embodiments, the oil is a low- viscosity Group I, II, III, IV, or V base oil as defined by the American Petroleum Institute (API Publication 1509). These are shown in Table 1 above. Group II and Group III base oils (such as hydrocracked and hydroprocessed base oils as well as synthetic oils such as hydrocarbon oils, polyalphaolefins, alkyl aromatics, and synthetic esters) and Group IV base oils (such as polyalphaolefins (PAG)) are well-known base oils.

[0032] In certain embodiments, a lubricant composition of the disclosure further comprises a Group II, Group III, Group IV, or Group V base oil. For example, in certain embodiments, the thermal management fluid of the disclosure further comprises a Group II or Group III base oil. In certain other embodiments, a lubricant composition of the disclosure further comprises a Group IV base oil such as other polyalphaolefins.

[0033] The lubricant compositions of disclosure can include any of a variety of additives, including those typically used in industrial and vehicular lubricants. Additives can be present in a variety of amounts, typically up to 30 wt%, e.g., up to 25 wt%, or up to 20 wt%. In certain embodiments, additives are present in the range of 2-30 wt%, e.g., 2-25 wt% or 2-20 wt%.

[0034] For example, in various embodiments as otherwise described herein, a lubricant composition can further include one or more additives selected from dispersants, detergents (including metallic and non-metallic detergents), friction modifiers, viscosity modifiers, dispersant viscosity modifiers, viscosity index improvers, pour point depressants, anti-wear additives, rust inhibitors, corrosion inhibitors, antioxidants (sometimes also called oxidation inhibitors), anti-foams (sometimes also called anti-foaming agents), seal swell agents (sometimes also called seal compatibility agents), extreme pressure additives (including metallic, non-metallic, phosphorus containing, non-phosphorus containing, sulphur containing and non-sulphur containing extreme pressure additives), surfactants, demulsifiers, anti-seizure agents, wax modifiers, lubricity agents, anti-staining agents, chromophoric agents, and metal deactivators.

[0035] In certain embodiments as otherwise described herein, the lubricant composition includes a dispersant additive, e.g., in an amount up to 10 wt%, e.g., 0.5-10 wt%. Dispersants of use in connection with the lubricant compositions described herein include both metallic and non-metallic dispersants. Examples of suitable ashless dispersants include oil soluble salts, esters, amino-esters, amides, imides and oxazolines of long chain hydrocarbon-substituted mono- and polycarboxylic acids or anhydrides thereof; thiocarboxylate derivatives of long chain hydrocarbons; long chain aliphatic hydrocarbons containing polyamine moieties attached directly thereto such as polyisobutylene succinyl anhydride-polyamines (PIBSA-PAM); Mannich condensation products formed by condensing a long chain substituted phenol with formaldehyde and polyalkylene polyamine; Koch reaction products and the like. Particularly preferred dispersants for use in the present invention are long chain aliphatic hydrocarbons containing polyamine moieties attached directly thereto such as polyisobutylene succinyl anhydride-polyamines (PIBSA-PAM). Certain useful dispersants suitably have a molecular weight of less than 20,000 g/mol, preferably less than 15,000 g/mol, such as less than 12,000 g/mol or less than 10,000 g/mol. In preferred embodiments, the dispersants for use in connection with the present invention have a molecular weight of from 500 to 20,000 g/mol, 500 to 15,000 g/mol, 800 to 10,000 g/mol or 1 ,200 to 7,500 g/mol. Molecular weight of the dispersants may readily be determined, for instance, by gel permeation chromatography or light scattering methods.

[0036] In certain embodiments, the dispersant additive for use in connection with the present invention is a nitrogen-containing dispersant. In particularly preferred embodiments, the nitrogen-containing dispersant has a molecular weight of from 500 to 20,000 g/mol, 500 to 15,000 g/mol, 800 to 10,000 g/mol or 1 ,200 to 7,500 g/mol.

[0037] In other embodiments, the dispersant additive for use in connection with the present invention is a non-nitrogen-containing dispersant. The non-nitrogen-containing dispersant may in some embodiments have a molecular weight of from 500 to 20,000 g/mol, 500 to 15,000 g/mol, 800 to 10,000 g/mol or 1 ,200 to 7,500 g/mol.

[0038] In certain embodiments, a lubricant composition as otherwise described herein includes a detergent. Examples of detergents include ashless detergents (that is, non-metal containing detergents) and metal-containing detergents. Suitable non-metallic detergents are described for example in U.S. Pat. No. 7,622,431. Metal-containing detergents comprise at least one metal salt of at least one organic acid, which is called soap or surfactant. Suitable organic acids include for example, sulphonic acids, phenols (suitably sulphurised and including for example, phenols with more than one hydroxyl group, phenols with fused aromatic rings, phenols which have been modified for example, alkylene bridged phenols, and Mannich base-condensed phenols and saligenin-type phenols, produced for example by reaction of phenol and an aldehyde under basic conditions) and sulphurised derivatives thereof, and carboxylic acids including for example, aromatic carboxylic acids (for example hydrocarbyl-substituted salicylic acids and derivatives thereof, for example hydrocarbyl substituted salicylic acids and sulphurised derivatives thereof).

[0039] In certain embodiments, a lubricant composition as otherwise described herein includes a friction modifier. Suitable friction modifiers include for example, ash-producing additives and ashless additives. Examples of suitable friction modifiers include fatty acid derivatives including for example, fatty acid esters, amides, amines, and ethoxylated amines. Examples of suitable ester friction modifiers include esters of glycerol for example, mono-, di-, and tri-oleates, mono-palmitates and mono-myristates. A particularly suitable fatty acid ester friction modifier is glycerol monooleate. Examples of suitable friction modifiers also include molybdenum compounds for example, organo molybdenum compounds, molybdenum dialkyldithiocarbamates, molybdenum dialkylthiophosphates, molybdenum disulphide, tri-molybdenum cluster dialkyldithiocarbamates, non-sulphur molybdenum compounds and the like. Suitable molybdenum-containing compounds are described for example, in EP 1533362 A1 for example in paragraphs [0101 ] to [0117],

[0040] In certain embodiments, a lubricant composition as otherwise described herein includes a dispersant viscosity modifier. Examples of suitable dispersant viscosity modifiers (i.e., distinguished from mere dispersants as having a molecular weight of at least 20000 g/mol) and methods of making them are described in WO 99/21902, WO 2003/099890 and WO 2006/099250.

[0041] In certain embodiments, a lubricant composition as otherwise described herein includes a viscosity index improver. Examples of suitable viscosity modifiers include high molecular weight hydrocarbon polymers (for example polyisobutylene, copolymers of ethylene and propylene and higher alpha-olefins); polyesters (for example polymethacrylates); hydrogenated poly(styrene-co-butadiene or isoprene) polymers and modifications (for example star polymers); and esterified poly(styrene-co-maleic anhydride) polymers. Oil-soluble viscosity modifying polymers generally exhibit number average molecular weights of at least about 15,000 to about 1 ,000,000, such as about 20,000 to about 600,000 as determined by gel permeation chromatography or light scattering methods. [0042] In certain embodiments, a lubricant composition as otherwise described herein includes a pour point depressant. Examples of suitable pour point depressants include C ₈ to C dialkyl fumarate/vinyl acetate copolymers, methacrylates, polyacrylates, polyarylamides, polymethacrylates, polyalkyl methacrylates, vinyl fumarates, styrene esters, condensation products of haloparaffin waxes and aromatic compounds, vinyl carboxylate polymers, terpolymers of dialkyfumarates, vinyl esters of fatty acids and allyl vinyl ethers, wax naphthalene and the like.

[0043] In certain embodiments, a lubricant composition as otherwise described herein includes at least one anti-wear additive. As described below, in certain embodiments the lubricant compositions of the disclosure can include reduced amounts of anti-wear additives, but the person of ordinary skill in the art will appreciate that such additives can in other embodiments be present in conventional amounts.

[0044] Examples of suitable anti-wear additives include non-phosphorus containing additives for example, sulphurised olefins. Examples of suitable anti-wear additives also include phosphorus-containing anti-wear additives. Examples of suitable ashless phosphorus-containing anti-wear additives include trilauryl phosphite and triphenylphosphorothionate and those disclosed in paragraph [0036] of US 2005/0198894. Examples of suitable ash-forming, phosphorus-containing anti-wear additives include dihydrocarbyl dithiophosphate metal salts. Examples of suitable metals of the dihydrocarbyl dithiophosphate metal salts include alkali and alkaline earth metals, aluminium, lead, tin, molybdenum, manganese, nickel, copper and zinc. Particularly suitable dihydrocarbyl dithiophosphate metal salts are zinc dihydrocarbyl dithiophosphates (ZDDP). Molybdenum dithiocarbamate, molybdenum dithiophospage, and trimeric molybdenum additives can also be used.

[0045] In certain embodiments, a lubricant composition as otherwise described herein includes a rust inhibitor. Examples of suitable rust inhibitors include non-ionic polyoxyalkylene polyols and esters thereof, polyoxyalkylene phenols, polyoxyalkylene polyols, anionic alkyl sulphonic acids, zinc dithiophosphates, metal phenolates, basic metal sulphonates, fatty acids and amines.

[0046] In certain embodiments, a lubricant composition as otherwise described herein includes a corrosion inhibitor. Examples of suitable corrosion inhibitors include phosphosulphurised hydrocarbons and the products obtained by the reaction of phosphosulphurised hydrocarbon with an alkaline earth metal oxide or hydroxide, non-ionic polyoxyalkylene polyols and esters thereof, polyoxyalkylene phenols, thiadiazoles, triazoles and anionic alkyl sulphonic acids. Examples of suitable epoxidised ester corrosion inhibitors are described in US 2006/0090393.

[0047] In certain embodiments, a lubricant composition as otherwise described herein includes an antioxidant. Examples of suitable antioxidants include alkylated diphenylamines, N-alkylated phenylenediamines, phenyl-a-naphthylamine, alkylated phenyl-a- naphthylamines, dimethylquinolines, trimethyldihydroquinolines and oligomeric compositions derived therefrom, hindered phenolics (including ashless (metal-free) phenolic compounds and neutral and basic metal salts of certain phenolic compounds), aromatic amines (including alkylated and non-alkylated aromatic amines), sulphurised alkyl phenols and alkali and alkaline earth metal salts thereof, alkylated hydroquinones, hydroxylated thiodiphenyl ethers, alkylidenebisphenols, thiopropionates, metallic dithiocarbamates, 1 ,3,4- dimercaptothiadiazole and derivatives, oil soluble copper compounds (for example, copper dihydrocarbyl thio- or thio-phosphate, copper salts of a synthetic or natural carboxylic acids, for example a C8 to C18 fatty acid, an unsaturated acid or a branched carboxylic acid, for example basic, neutral or acidic Cu(l) and/or Cu(ll) salts derived from alkenyl succinic acids or anhydrides), alkaline earth metal salts of alkylphenolthioesters, suitably containing C5 to C12 alkyl side chains, calcium nonylphenol sulphide, barium t-octylphenyl sulphide, dioctylphenylamine, phosphosulphised or sulphurised hydrocarbons, oil soluble phenates, oil soluble sulphurised phenates, calcium dodecylphenol sulphide, phosphosulphurised hydrocarbons, sulphurised hydrocarbons, phosphorus esters, low sulphur peroxide decomposers and the like.

[0048] In certain embodiments, a lubricant composition as otherwise described herein includes an antifoam agent. Examples of suitable anti-foam agents include silicones, organic polymers, siloxanes (including poly siloxanes and (poly) dimethyl siloxanes, phenyl methyl siloxanes), acrylates and the like.

[0049] In certain embodiments, a lubricant composition as otherwise described herein includes a seal swell agent. Examples of suitable seal swell agents include long chain organic acids, organic phosphates, aromatic esters, aromatic hydrocarbons, esters (for example butylbenzyl phthalate) and polybutenyl succinic anhydride.

[0050] Examples of amounts of various additives for use in certain embodiments of the disclosure are described in Table 2 below. Of course, these amounts can vary, especially in the case of lubricant compositions having reduced amounts of antiwear additives. Table 2.

[0051] Without intending to be bound by theory, the present inventors believe that the use of a high proportion of trimers (e.g., with a high proportion of a single regioisomeric configuration) can allow for molecules to associate with one another (in a psuedocrystallizing or “freezing”) manner) under higher pressure to provide for a higher effective lubricant viscosity in interfaces between components. Accordingly, this can in some embodiments allow for the use of relatively less antiwear additives than in conventional low-viscosity lubricants.

[0052] Accordingly, in certain embodiments, a lubricant composition as otherwise described herein has no more than 400 ppmw phosphorus from phosphorus-containing antiwear and/or anti-friction additives (such as dihydrocarbyl dithiophosphates like ZDDP and dialkylthiophosphates like molybdenum dialkylthiophosphates), for example, no more than 350 ppmw, no more than 300 ppmw or no more than 250 ppmw phosphorus from phosphorus-containing anti-wear and/or anti-friction additives (such as dihydrocarbyl dithiophosphates like ZDDP and dialkylthiophosphates like molybdenum dialkylthiophosphates). In certain embodiments, a lubricant composition has in the range of 10-400 ppmw phosphorus from anti-wear and/or anti-friction additives, e.g., 50-400 ppmw, or 100-400 ppmw, or 200-400 ppmw, or 10-300 ppmw, or 50-300 ppmw, or 100-300 ppmw, or 200-300 ppmw, or 10-250 ppmw, or 50-250 ppmw, or 100-250 ppmw, or 200-250 ppmw.

[0053] In certain embodiments, a lubricant composition as otherwise described herein includes no more than 400 ppmw molybdenum from molybdenum-containing anti-wear and/or anti-friction additives. In certain embodiments, a lubricant composition as otherwise described herein has no more than 300 ppmw, e.g., no more than 200 ppmw molybdenum- containing anti-wear and/or anti-friction additives. For example, in certain embodiments as otherwise described herein, a lubricant composition has in the range of 10-400 ppmw molybdenum, e.g., 50-400 ppmw, or 100-400 ppmw, or 10-300 ppmw, or 50-300 ppmw, or 100-300 ppmw, or 10-200 ppmw, or 50-200 ppmw from molybdenum-containing anti-wear and/or anti-friction additives.

[0054] The use of lower amounts of these additives allows the oils to have a lower tendency to poison catalytic after-treatment systems and to provide relatively lower metallic and sulfurous emissions. The person of ordinary skill in the art can use an amount of additive that provides acceptable wear resistance while in many cases reducing the total amount of additives necessary as compared to conventional lubricants.

[0055] The lubricant compositions of the disclosure can be provided with a set of properties desirable for use in a variety of applications. For example, a low viscosity is desirable for a lubricant composition, especially for use in a vehicular lubricant in order to improve fuel efficiency. In certain embodiments, a lubricant composition as otherwise described herein has a kinematic viscosity at 40 °C of no more than 40 cSt, e.g., no more than 35 cSt, no more than 30 cSt, no more than 25 cSt, no more than 20 cSt, or no more than 17 cSt, as measured in accordance with ASTM D7279. In certain embodiments, the kinematic viscosity at 40 °C is in the range of 10 to 40 cSt, e.g., in the range of 10 to 35 cSt, or 10 to 30 cSt, or 10 to 25 cSt, or 10 to 20 cSt, or 10 to 17 cSt. In certain embodiments, a lubricant composition s as otherwise described herein has a kinematic viscosity at 40 °C in the range of 15 to 40 cSt, e.g., in the range of 15 to 35 cSt, or 15 to 30 cSt, or 15 to 25 cSt, or 15 to 20 cSt .

[0056] The lubricant compositions may have a Noack volatility of less than about 25%, such as less than about 15%, or less than about 10% by weight. Noack volatility may be measured according to CEC-L-40-A-93 (“Evaporation Loss of Lubricating Oils”).

[0057] The lubricant compositions described herein can be useful in lubrication of many different types of mechanical systems. Thus, one aspect of the disclosure provides a mechanical system including the lubricant composition as disclosed herein, disposed between opposing surfaces. The disclosure also provides methods for lubricating a mechanical system as described herein. Such methods include providing the mechanical system, and moving the opposing surfaces relative to one another, i.e., with a lubricant composition as described herein disposed between them.

[0058] An embodiment of the system and method of the disclosure is illustrated with reference to FIG. 1 , in which a portion of a mechanical system 100 is shown in a schematic cross-sectional view. The mechanical system 100 includes a lubricant composition 110 that is disposed in an interface 140 between opposing surfaces 120 and 130. While the opposing surfaces are illustrated herein as relatively similar in size and shape, this is merely a schematic representation. It will be apparent to those skilled in the art that the opposing surfaces can be different in size, shape, material from which they are made, etc., depending on the particular mechanical system of which they are a part.

[0059] In certain embodiments, a lubricant composition of the disclosure may be used to lubricate a solid surface, including for example metallic surfaces and non-metallic surfaces. In certain embodiments, both of the opposed surfaces are metallic. Suitable metallic surfaces include surfaces of ferrous based materials, for example cast iron and steels; surfaces of aluminum-based solids, for example aluminum-silicon alloys; surfaces of metal matrix compositions; surfaces of copper and copper alloys; surfaces of lead and lead alloys; surfaces of zinc and zinc alloys; and surfaces of chromium-plated materials. Suitable non- metallic surfaces include surfaces of ceramic materials; surfaces of polymer materials; surfaces of carbon-based materials; and surfaces of glass. Other surfaces which may be lubricated include surfaces of coated materials for example surfaces of hybrid materials for example metallic materials coated with non-metallic materials and non-metallic materials coated with metallic materials; surfaces of diamond-like carbon coated materials and SUMEBore materials for example as described in Sultzer technical review 4/2009 pages 11 - 13.

[0060] The lubricant compositions can be especially useful when opposing surfaces are close enough to rub against one another. Accordingly, in certain embodiments as otherwise described herein, the opposing surfaces are within 250 microns of one another, e.g., within 100 microns of one another, or within 50 microns of one another.

[0061] During the operation of the system, the opposing surfaces 120 and 130 are moved relative to one another, while the lubricant composition 110 disposed in the interface between the opposing surfaces, thereby lubricating the interface.

[0062] In certain embodiments, the mechanical system is part of an engine, motor, turbine, or transmission. Suitable surfaces include those in power transmission systems, for example, bearings, drive lines and gear boxes for example for vehicles including for example passenger vehicles and heavy duty vehicles; and those in internal combustion engines, for example the crankcases of internal combustion engines. Suitable surfaces also include those in turbine bearings for example in water turbine bearings.

[0063] The engine may be a spark-ignition, internal combustion engine, or a compressionignition, internal combustion engine. The internal combustion engine may be a sparkignition internal combustion engine used in automotive applications. The internal combustion engine may also be a two-stroke compression-ignition or a four-stroke compression ignition engine. Suitable internal combustion engines include, for example, engines used in automotive or aviation applications, engines used in marine applications and engines used in land-based power generation plants. The lubricant compositions are particularly suited to use in an automotive internal combustion engine. In certain embodiments, a mechanical system of the disclosure is part of an aviation internal combustion engine. The two-stroke compression-ignition engine may be used in marine applications, e.g., power boats.

[0064] The lubricating compositions described herein may also be used as or in the preparation of metalworking fluids. Accordingly, another aspect of the disclosure is a metalworking fluid including a lubricating composition as described herein. The lubricating composition described herein can be provided, e.g., as a micellar suspension in an aqueous medium, e.g., together with one or more surfactants. A metalworking fluid as described herein can be used for example in a method of working a metal, e.g., in destructive metalworking (i.e., applications in which material is substantially removed from the workpiece, such as in the form of chips or other particles, such as milling or grinding) and in deformation metalworking (i.e., applications in which material is not substantially removed from the workpiece, such as rolling). The methods can include working a surface of a metal with a tool (e.g., a cutting tool, a grinding tool, a roller) while the surface and the tool are in contact with a metalworking fluid as described herein.

[0065] In certain embodiments, a lubricant composition of the disclosure may be used to lubricate a surface at any typical temperature which might be encountered in a lubricating environment, for example at a temperature such as may be encountered in an internal combustion engine, for example a temperature in the range of ambient to 250 °C, e.g. 50 to 220 °C, or 50 to 200 °C, or 90 to 200 °C, or 90 to 120 °C. Typically ambient temperature may be 20 °C, but may be less than 20°C, for example 0°C, -5°C, -10°C, etc.

EXAMPLE

[0066] Certain aspects of the disclosure are now explained further via the following nonlimiting examples. Preparation of the (FI)Ti catalyst of the disclosure

[0067] The (FI)Ti catalyst of the disclosure may be prepared as disclosed in A. Sattler et al., “Enhanced Productivity of a Supported Olefin Trimerization Catalyst,” ACS CataL 6:19- 22 (2016), incorporated by reference herein. In short, a suspension of dry MS3030 silica (2 g) in toluene (30 mL) is treated with methylaluminoxane (MAO) (30% in toluene, 3.5 mL). The mixture is stirred at room temperature for 2 hours, and then treated with a solution of (FI)TiCls (33 mg, 0.055 mmol) in toluene (15 mL). The mixture is then stirred at room temperature for 1 hour, after which the volatile components are removed in vacuo at 30 °C, giving a dry yellow powder (3.046 g, 0.0179 mmol Ti/g of silica; Al :Ti ratio is 300:1 ).

Catalytic Trimerization of o-Olefin

[0068] In a typical experiment, s(FI)Ti (50 - 200 mg, 0.9 - 3.6 pmol) is added to a 20 mL glass vial with a magnetic stir bar and was treated with an a-olefin (e.g., 5 - 10 mL of 1 - octene or 1 -decene). The vial is capped, and the suspension is stirred for 1 - 2 days. Adamantane (ca. 25 mg) is then added as an internal integration standard, and the mixture is treated with acetone (ca. 5 mL) and methanol (ca. 5 mL) to help precipitate any poly-1 - olefin. The solids are allowed to settle, and an aliquot of the supernatant is filtered through a plug of silica gel and analyzed by GC. The polymer/silica solids are isolated by filtration, dried at 70 °C, and then dried in vacuo, and weighed to obtain yields.

[0069] A C30 trimer-containing oligomerization product prepared from 1 -decene according to the above-provided procedure and purified by distillation to cut off high-molecular weight material was analyzed by gas chromatography. GC confirmed that only trace amounts of dimers and tetramers were present. The physical properties of this C30 trimer-containing product were evaluated and are provided in Table 3.

Table 3. [0070] Other aspects of the disclosure are described with respect to the following enumerated embodiments, which may be combined in any fashion and in any number that is not technically or logically inconsistent.

[0071] Embodiment 1 is directed to a lubricant composition comprising as a base oil, one or more trimers of C ₈ -Ci ₂ linear alpha olefins, present in a total amount of at least 50 wt% of the lubricant composition.

[0072] Embodiment 2 is directed to a lubricant composition according to embodiment 1 , wherein the one or more trimers are present in a total amount of at least 60 wt% of the lubricant composition, e.g., at least 65 wt%.

[0073] Embodiment 3 is directed to a lubricant composition according to embodiment 1 , wherein the one or more trimers are present in a total amount of at least 70 wt% of the lubricant composition, e.g., at least 75 wt%.

[0074] Embodiment 4 is directed to the lubricant composition according to any of embodiments 1 -3, wherein the one or more trimers are 1 -decene trimers.

[0075] Embodiment 5 is directed to the lubricant composition according to any of embodiments 1 -3, wherein the one or more trimers are 1 -octene trimers.

[0076] Embodiment 6 is directed to the lubricant composition according to any of embodiments 1 -3, wherein the one or more trimers are 1 -dodecene trimers.

[0077] Embodiment 7 is directed to the lubricant composition according to any of embodiments 1 -6, wherein at least 70% of the one or more trimers have the same regioisomeric configuration.

[0078] Embodiment 8 is directed to the lubricant composition according to any of embodiments 1 -6, wherein at least 75 wt% (e.g., at least 80 wt%, or at least 85 wt%) of the one or more trimers have the same regioisomeric configuration.

[0079] Embodiment 9 is directed to the lubricant composition according to embodiment 6 or embodiment 7, wherein the regioisomeric configuration is in which each R _a , Rb and R _c is an alkyl moiety of an alpha olefin feed molecule having the structure R _a -CH=CH ₂ , Rb-CH=CH ₂ , or R _c -CH=CH ₂ . [0080] Embodiment 10 is directed to the lubricant composition according to any of embodiments 7-9, wherein at least 80 wt% of the one or more trimers having the same regiochemistry have the same diastereomeric configuration with respect to at least two stereogenic centers.

[0081] Embodiment 11 is directed to the lubricant composition according to embodiment 9, wherein in the diastereomeric configuration the R _a and R _b moieties are configured in a racemo diad.

[0082] Embodiment 12 is directed to the lubricant composition according to any of embodiments 1-11 , wherein the one or more trimers are made by a process comprising contacting an alpha olefin with an (FI)Ti catalyst.

[0083] Embodiment 13 is directed to the lubricant composition according to embodiment 12, wherein the (FI)Ti catalyst has the structure

[0084] Embodiment 14 is directed to the lubricant composition according to any of embodiments 1-13, wherein one or more of the trimers are saturated.

[0085] Embodiment 15 is directed to the lubricant composition according to any of embodiments 1-13, wherein the one or more trimers are at least 80% saturated, e.g., at least 85% saturated, or at least 90% saturated.

[0086] Embodiment 16 is directed to the lubricant composition according to any of embodiments 1 -15, further comprising one or more non-trimeric alpha olefin oligomers and/or alpha olefin.

[0087] Embodiment 17 is directed to the lubricant composition according to any of embodiments 1-17, further comprising one or more additional base oils.

[0088] Embodiment 18 is directed to the lubricant composition according to any of embodiments 1-17, further comprising one or more additives selected from dispersants, detergents (including metallic and non-metallic detergents), friction modifiers, viscosity modifiers, dispersant viscosity modifiers, viscosity index improvers, pour point depressants, anti-wear additives, rust inhibitors, corrosion inhibitors, antioxidants (sometimes also called oxidation inhibitors), anti-foams (sometimes also called anti-foaming agents), seal swell agents (sometimes also called seal compatibility agents), extreme pressure additives (including metallic, non-metallic, phosphorus containing, non-phosphorus containing, sulphur containing and non-sulphur containing extreme pressure additives), surfactants, demulsifiers, anti-seizure agents, wax modifiers, lubricity agents, anti-staining agents, chromophoric agents, and metal deactivators.

[0089] Embodiment 19 is directed to the lubricant composition according to embodiment 17, wherein the one or more additives is present in an amount up to 30 wt%, e.g., in the range of 2-30 wt%.

[0090] Embodiment 20 is directed to the lubricant composition according to any of embodiments 1-19, comprising no more than 400 ppmw phosphorus from phosphorus- containing anti-wear and/or anti-friction additives.

[0091] Embodiment 21 is directed to the lubricant composition according to any of embodiments 1-19, comprising no more than 300 ppmw phosphorus (e.g., no more than 200 ppmw phosphorus) from phosphorus-containing anti-wear and/or anti-friction additives.

[0092] Embodiment 22 is directed to the lubricant composition according to any of embodiments 1-21 , comprising no more than 400 ppmw molybdenum from molybdenum- containing anti-wear and/or anti-friction additives.

[0093] Embodiment 23 is directed to the lubricant composition according to any of embodiments 1-21 , comprising no more than 300 ppmw molybdenum (e.g., no more than 200 ppmw molybdenum) from molybdenum-containing anti-wear and/or anti-friction additives.

[0094] Embodiment 24 is directed to the lubricant composition according to any of embodiments 1 -23, having a KV40 no more than 30 cSt, e.g., no more than 25 cSt.

[0095] Embodiment 25 is directed to the lubricant composition according to any of embodiments 1 -23, having a KV40 of no more than 20 cSt, e.g., no more than 17 cSt.

[0096] Embodiment 26 is directed to a mechanical system comprising the lubricant composition according to any of embodiments 1 -25, disposed between opposing surfaces.

[0097] Embodiment 27 is directed to a method for lubricating a mechanical system comprising providing the mechanical system of embodiment 25, and moving the opposing surfaces relative to one another. [0098] Embodiment 28 is directed to the mechanical system or method according to embodiment 26 or embodiment 27, wherein the mechanical surfaces form an interface with one another, with the lubricant composition disposed in the interface.

[0099] Embodiment 29 is directed to the mechanical system or method according to any of embodiments 26-28, wherein one or both of the opposed surfaces are metallic.

[0100] Embodiment 30 is directed to the mechanical system or method according to any of embodiments 26-29, wherein the opposed surfaces are within 250 microns of one another, e.g., within 100 microns or 50 microns of one another.

[0101] Embodiment 31 is directed to the mechanical system or method according to any of embodiments 26-30, wherein the mechanical system is in the form of a bearing, a gearbox, or a drivetrain.

[0102] Embodiment 32 is directed to the mechanical system or method according to any of embodiments 26-31 , wherein the mechanical system is part of an internal combustion engine.

[0103] Embodiment 33 is directed to the mechanical system or method according to any of embodiments 26-32, wherein the mechanical system is a part of a vehicle, e.g., an automobile or truck.

[0104] Embodiment 34 is directed to a metalworking fluid comprising a micellar suspension of a lubricating composition according to any of embodiments 1 -25 in an aqueous fluid, the micellar suspension including one or more surfactants.

[0105] Embodiment 35 is directed to a method of working a metal, the method comprising of a fluid composition method of working a metal, the method comprising working a surface of a metal with a tool (e.g., a cutting tool, a grinding tool, a roller) while the surface and the tool are in contact with a metalworking fluid according to embodiment 34.

[0106] The particulars shown herein are by way of example and for purposes of illustrative discussion of certain embodiments of the present disclosure only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of various embodiments of the disclosure. In this regard, no attempt is made to show structural details of the materials and methods in more detail than is necessary for the fundamental understanding thereof, the description taken with the drawings and/or examples making apparent to those skilled in the art how the several forms of the materials and methods described herein may be embodied in practice. Thus, before the disclosed materials and methods are described, it is to be understood that the aspects described herein are not limited to specific embodiments, apparatus, or configurations, and as such can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and, unless specifically defined herein, is not intended to be limiting.

[0107] The terms “a,” “an,” “the” and similar referents used in the context of describing the materials and methods of the disclosure (especially in the context of the following embodiments and claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context.

[0108] All methods described herein can be performed in any suitable order of steps unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the materials and methods otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the materials and methods described herein.

[0109] As will be understood by one of ordinary skill in the art, each embodiment disclosed herein can comprise, consist essentially of or consist of its particular stated element, step, ingredient or component. As used herein, the transition terms “comprise” and “includes” means includes, but is not limited to, and allows for the inclusion of unspecified elements, steps, ingredients, or components, even in major amounts. The transitional phrase “consisting of” excludes any element, step, ingredient or component not specified. The transition phrase “consisting essentially of” limits the scope of the embodiment to the specified elements, steps, ingredients or components and to those that do not materially affect the embodiment.

[0110] All percentages, ratios and proportions herein are by weight, unless otherwise specified.

[0111] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the disclosure are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

[0112] Groupings of alternative elements or embodiments of the disclosure are not to be construed as limitations. Each group member may be referred to and claimed individually or in any combination with other members of the group or other elements found herein. It is anticipated that one or more members of a group may be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.

[0113] Some embodiments of various aspects of the disclosure are described herein, including the best mode known to the inventors for carrying out the methods described herein. Of course, variations on these described embodiments will become apparent to those of ordinary skill in the art upon reading the foregoing description. The skilled artisan will employ such variations as appropriate, and as such the methods of the disclosure can be practiced otherwise than specifically described herein. Accordingly, the scope of the disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.

[0114] It will be apparent to those skilled in the art that various modifications and variations can be made to the materials and methods described here without departing from the scope of the disclosure. Thus, it is intended that the present disclosure cover such modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.