Thermally stable, low coefficient of traction lubricant

Abstract

The disclosed technology relates to lubricants for transmission systems and industrial gears containing a combination of viscosity modifiers and optionally esters; and methods of lubricating transmission systems and industrial gears with such lubricants.

Description

Background Technology

[0001] The disclosed technology relates to lubricants for transmission systems and industrial gears, the lubricants containing a combination of viscosity modifiers and optional esters, and methods for lubricating transmission systems and industrial gears with such lubricants.

[0002] Market demand is driving the development of lubricating fluids towards lower viscosity to minimize energy loss during mechanical operation. Achieving the performance required for transmission systems and industrial lubricants at lower viscosities is becoming increasingly challenging. For example, removing viscosity modifiers to obtain lower viscosity fluids can compromise thermal stability and traction performance. New solutions are needed to address these issues. Summary of the Invention

[0003] Therefore, the disclosed technology addresses the problem of providing improved efficiency performance with clean operation, minimized viscosity increase, and reduced traction and friction by combining two types of viscosity modifiers with optional esters.

[0004] Therefore, one aspect of the technology disclosed herein relates to a lubricant composition containing a) a hydrocarbon lubricating base oil and b) a viscosity modifier composition.

[0005] The viscosity modifier composition itself will contain: i) at least one olefin polymer having a number average molecular weight (“Mn”) of about 1,000 to about 10,000 (measured by gel permeation chromatography (“GPC”) using a polystyrene standard), and ii) at least one grafted olefin polymer having a Mn of about 1,000 to about 10,000 (measured by GPC using a polystyrene standard), comprising a carboxylic acid functional group or a reactive equivalent thereof grafted onto the polymer backbone, wherein the carboxylic acid functional group or the reactive equivalent thereof further reacts with an amine.

[0006] The lubricant composition may additionally contain a carboxylic acid ester. The carboxylic acid ester may be, for example, a monocarboxylic acid ester, a dicarboxylic acid diester, or a combination thereof.

[0007] The technology also provides a method for lubricating a transmission system or industrial gear with the composition as described, and for operating the transmission system or industrial gear. Detailed Implementation

[0008] The preferred features and implementation schemes will now be described in a non-restrictive manner.

[0009] Hydrocarbon lubricating base oils

[0010] One component of the disclosed technology is a hydrocarbon lubricating base oil. Such oils include natural oils and synthetic oils; oils derived from hydrogen cracking, hydrogenation, and hydrogen refining; unrefined oils, refined oils, and re-refined oils; and mixtures thereof.

[0011] Unrefined oils are oils typically obtained directly from natural or synthetic sources without (or with minimal) further purification. Refined oils are similar to unrefined oils, except that they have undergone further processing in one or more purification steps to improve one or more properties. Purification techniques are known in the art and include solvent extraction, double distillation, acid or alkali extraction, filtration, percolation, etc. Re-refined oils, also known as regenerated or reprocessed oils, are obtained through processes similar to those used to obtain refined oils and typically involve additional processing using techniques aimed at removing ineffective additives and oil decomposition products.

[0012] Natural oils that can be used to make the lubricants of this invention include mineral lubricating oils (such as liquid petroleum and solvent-treated or acid-treated alkane-, cycloalkane-, or mixed alkane-cycloalkane-type mineral lubricating oils) and oils derived from coal or shale or mixtures thereof.

[0013] Suitable synthetic hydrocarbon lubricants include Group IV oils or polyalphaolefins (PAOs). Group IV oils include hydrocarbon oils such as polymeric and interpolymerized olefins (e.g., polybutene, polypropylene, propylene-isobutylene polymers); poly(1-hexene), poly(1-octene), poly(1-decene), and mixtures thereof.

[0014] Oils with lubricating viscosity can also be defined as specified in the American Petroleum Institute (API) Base Oil Interchangeability Guidelines (2011). Suitable base oil groups include Group II, Group II+, Group III, Group III+, and Group IV oils. Group II and Group III oils have a sulfur content ≤0.03% by weight and a saturation ≥90% by weight. Group II oils have a viscosity index of 80 to less than 120, while Group III oils have a viscosity index ≥120. Group II+ base oils refer to API Group II base oils with a viscosity index greater than or equal to 110 and less than 120, as described in the following literature: SAE Publication “Design Practice: Passenger Car Automatic Transmissions”, 4th Edition, AE-29, 2012, pp. 12-9; and U.S. Patent No. 8,216,448, column 1, line 57. Group III+ base oils are characterized by significantly lower cycloalkanes and higher isoalkanes compared to their corresponding Group III base oils, resulting in a 4 to 10 unit increase in VI in III+ oils compared to III oils. Group III+ base oils include isomerized waxes, such as gas-liquid (“GTL”) oils, which include oils produced via the Fischer-Tropsch reaction, as well as other GTL oils. Group IV oils include all polyalphaolefins (PAOs).

[0015] The hydrocarbon lubricating base oil can be API Group IV oil or a mixture thereof, i.e., polyalphaolefins. Polyalphaolefins can be prepared by metallocene catalytic methods or by non-metallocene methods.

[0016] Hydrocarbon lubricating base oils may contain API Group II oils or mixtures thereof. Hydrocarbon lubricating base oils may contain API Group II+ oils or mixtures thereof. Hydrocarbon lubricating base oils may also be Group III oils or mixtures thereof. Hydrocarbon lubricating base oils may contain API Group III+ oils or mixtures thereof. Hydrocarbon lubricating base oils may also be Group IV oils or mixtures thereof. Hydrocarbon lubricating base oils may contain a mixture of at least two of API Group II, Group II+, API Group III, Group III+, and API Group IV oils.

[0017] As measured by ASTM D445, the kinematic viscosity of hydrocarbon lubricating base oils or base oils at 100°C will generally be 2 cSt to 10 cSt, or in some embodiments 2.25 cSt to 9 cSt, 2.5 cSt to 6 cSt, 7 cSt, or 8 cSt. A kinematic viscosity of approximately 3.5 cSt to 6 cSt or 6 cSt to 8 cSt at 100°C is also suitable.

[0018] The amount of hydrocarbon lubricating base oil present is typically the balance remaining after subtracting the sum of the amounts of performance additives in the composition from 100% by weight. Exemplary amounts may include 50% to 99% by weight, or 60% to 98% by weight, or 70% to 95% by weight, or 80% to 94% by weight, or 85% to 93% by weight.

[0019] Viscosity modifier composition

[0020] The technology also includes viscosity modifier compositions combining i) an olefin polymer and ii) a grafted olefin polymer. As used herein, the term "a" in "a" viscosity modifier or "a" olefin polymer is not limited to only one of the elements, but is used to mean "at least one," which includes one or more of the elements, as well as two or more, three or more, etc.

[0021] i) Olefin polymers

[0022] Olefin polymers can be prepared from ethylene and propylene, or they can be prepared from ethylene and C3-C4 polymers. 10 Preparation of higher olefins within the α-monoolefin range. In some embodiments, the olefin polymer may be prepared from isobutylene or isoprene.

[0023] More complex polymer substrates, commonly referred to as interpolymers, can be prepared using a third component. The third component typically used to prepare interpolymer substrates can be a polyene monomer selected from conjugated or non-conjugated dienes and trienes. The non-conjugated diene component can be a diene component having about 5 to about 14 carbon atoms. The diene monomer is characterized by the presence of vinyl groups in its structure and can include cyclic and bicyclic compounds. Representative dienes include 1,4-hexadiene, 1,4-cyclohexadiene, dicyclopentadiene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 1,5-heptadiene, and 1,6-octadiene. Mixtures of more than one diene can be used to prepare interpolymers.

[0024] Triene components may also exist, which will have at least two non-conjugated double bonds and up to about 30 carbon atoms. Typical trienes include 1-isopropylidene-3a,4,7,7a-tetrahydroindene, 1-isopropylidene-dicyclopentadiene, and 2-(2-methylene-4-methyl-3-pentenyl)-[2.2.1]bicyclo-5-heptene.

[0025] Suitable main-chain polymers for olefin polymers include ethylene-propylene polymers, ethylene-propylene-α-olefin terpolymers, ethylene-α-olefin polymers, ethylene-propylene polymers containing non-conjugated dienes, and isobutylene / conjugated diene polymers.

[0026] Ethylene-propylene or higher α-monoolefin polymers may consist of 15 mol% to 80 mol% ethylene and 20 mol% to 85 mol% propylene or higher monoolefins. In some embodiments, the molar ratio is 30 mol% to 80 mol% ethylene and 20 mol% to 70 mol% at least one C3 to C4 olefin. 10 α-monoolefins, such as 40 mol% to 80 mol% ethylene and 20 mol% to 60 mol% propylene. In another embodiment, the ethylene-propylene or higher α-monoolefin polymer may consist of 15 mol% to 80 mol% propylene and 20 mol% to 85 mol% ethylene or higher monoolefins, and in some embodiments, the molar ratio is 30 mol% to 80 mol% propylene and 20 mol% to 70 mol% at least one C3 to C4 olefin. 10 α-monoolefins, such as 45 mol% to 75 mol% propylene and 25 mol% to 55 mol% ethylene, or 50 mol% to 75 mol% propylene and 25 mol% to 50 mol% ethylene. Terpolymer variants of the aforementioned polymers may contain up to 15 mol% of non-conjugated diene or triene.

[0027] In these embodiments, the polymer substrate (such as an ethylene polymer or a terpolymer) can be substantially linear and oil-soluble, and in one embodiment is a liquid. Furthermore, in some embodiments, the polymer can be in forms other than substantially linear; that is, it can be a branched polymer or a star-shaped polymer. The polymer can also be a random polymer or a block polymer, including diblocks and more advanced blocks, including graded blocks and various other structures. These types of polymer structures are known in the art, and their preparation is within the capabilities of those skilled in the art.

[0028] The term polymer is generally used to refer to polymers, copolymers, terpolymers, or interpolymers that include ethylene and / or higher α-monoolefins. These substances may contain small amounts of other olefin monomers, as long as their fundamental properties are not significantly altered.

[0029] The olefin polymers disclosed in the technology may have a number average molecular weight (by gel permeation chromatography, polystyrene standard) that is typically from about 1,000 to about 10,000, or from about 1,250 to about 9,500, or from about 1,500 to about 9,000, or from about 1,750 to about 8,500, or from about 2,000 to about 8,000, or from about 2,500 to about 7,000 or 7,500, or even from about 3,000 to about 6,500, or from about 4,000 to about 6,000. In some cases, the number average molecular weight may be from about 1,000 to 5,000, or from about 1,500 or 2,000 to about 4,000.

[0030] ii) Grafted olefin polymers

[0031] Another component is a graft copolymer, which is the product of the condensation reaction of an olefin polymer to which a carboxylic acid (or equivalent) functional group is grafted, and the grafted olefin reacts with a monoamine or polyamine that may have a single primary amino group. If the olefin polymer is an ethylene / propylene copolymer, then the polyamine is not poly(ethyleneamine).

[0032] The polymer substrate will be an olefin polymer, such as those described above. The olefin polymer substrate used in the derived graft copolymer will contain grafted carboxylic acid functional groups or reactive equivalents of carboxylic acid functional groups (e.g., acid anhydrides or esters). The reactive carboxylic acid functional groups will typically exist as side groups attached via, for example, a grafting process.

[0033] Alkene-bonded unsaturated carboxylic acids are typically grafted onto the polymer backbone. These substances attached to the polymer usually contain at least one alkene bond (before the reaction) and at least one carboxylic acid (or its anhydride) group, or a polar group that can be converted into said carboxyl group by oxidation or hydrolysis. Maleic anhydride or its derivatives are suitable. Grafting it onto olefin polymers (e.g., ethylene copolymers or terpolymers) yields two carboxylic acid functional groups. Examples of additional unsaturated carboxylic acids include maleic anhydride, itaconic anhydride, or corresponding dicarboxylic acids such as maleic acid, fumaric acid, and their esters, as well as cinnamic acid and its esters.

[0034] Alkenyl unsaturated carboxylic acids can be grafted onto polymers (such as ethylene / propylene copolymers). Radical-induced grafting of alkenyl unsaturated carboxylic acids can also be carried out in solvents (such as hexane or mineral oil). This can be done at high temperatures ranging from 100°C to 250°C, for example 120°C to 190°C, or 150°C to 180°C, for example above 160°C.

[0035] Suitable free radical initiators include peroxides, hydroperoxides, and azo compounds, typically those with boiling points greater than about 100°C and which thermally decompose within the grafting temperature range to provide free radicals. Representative examples of these free radical initiators include azobisisobutyronitrile (AIBN) and 2,5-dimethyl-hex-3-yne-2,5-bis-tert-butylperoxide. The amount of initiator can be from 0.005% to 1% by weight of the reaction mixture solution. Grafting can be carried out under an inert atmosphere, such as under nitrogen cover. The resulting polymer intermediate is characterized by the presence of carboxylic acid acylation functional groups within its structure.

[0036] In an alternative embodiment, an unsaturated carboxylic acid (such as maleic anhydride) may first be condensed with a monoamine or polyamine that typically has a single primary amino group (as described below), and the condensation product itself is subsequently grafted onto the polymer backbone in a similar manner to that described above.

[0037] The amount of reactive carboxylic acids on the polymer chain, and especially the amount of grafted carboxylic acids on the chain, is typically 0.5% to 8% by weight, or 1% to 7% by weight, or 1.5% to 6% by weight, or in some embodiments 2% to 5% by weight, based on the weight of the polymer backbone. In some embodiments, the amount of reactive carboxylic acids on the polymer chain, and especially the amount of grafted carboxylic acids on the chain, can be about 1% to about 2% by weight, or in other embodiments about 2% to 3% by weight, or about 3% to 4% by weight, or 4% to 5% by weight. These figures represent the amount of carboxylic acid-containing species, particularly referring to maleic anhydride as the grafting material. As will be apparent to those skilled in the art, this amount can be adjusted to account for carboxylic acid-containing species having higher or lower molecular weights or higher or lower amounts of acid functional groups per molecule. Grafting can be to a certain extent an acid-functionalized polymer that provides a total acid value (TAN, according to ASTM D664) of 5 mg KOH / g to 100 mg KOH / g, 10 mg KOH / g to 80 mg KOH / g, or 15 mg KOH / g to 75 mg KOH / g, or 20 mg KOH / g to 70 mg KOH / g, or about 20 mg KOH / g to about 60 mg KOH / g or 65 mg KOH / g.

[0038] Acid-containing polymers react with monoamines or polyamines, typically having a single primary amino group. If the olefin polymer is an ethylene / propylene copolymer, then the polyamine is not poly(ethyleneamine). The reaction may consist of a condensation to form an imide, amide, or semiamide, or amide ester (assuming a portion of the alcohol also reacts), or an amine salt. The primary amino group will typically condense to form an amide, or, in the case of maleic anhydride, an imide. It should be noted that in some embodiments, the amine will have a single primary amino group, that is, it will not have two or more primary amino groups (except for a negligible amount of additional primary amino groups that may be present throughout the amine composition, e.g., less than 5%, 2%, 1%, or 0.5%, or 0.01% to 0.1%, especially 1% or less, such as 0.01% to 1% of the amino groups being primary amino groups). This characteristic minimizes the amount of crosslinking that would otherwise be possible. Poly(ethyleneamine) can generally and in an oversimplified manner be described as H2N-(C2H4-NH-). n -C2H4-NH2, where n can be, for example, 2 to 6. These typically have an average of about 2 primary amines, and therefore are generally undesirable for use in the functionalization of ethylene / propylene copolymers, thereby minimizing or avoiding any undesirable crosslinking. In those embodiments where the polyamine is not poly(ethyleneamine), the amine component used to prepare the condensation product will be free of or substantially free of poly(ethyleneamine), such as less than 5% by weight, or less than 1% by weight, or 0.01% by weight to 0.1% by weight of the amine component being poly(ethyleneamine).

[0039] Suitable primary amines may include aromatic amines, such as amines in which the carbon atom of the aromatic ring structure is directly attached to the amino nitrogen. Amines may be monoamines or polyamines. The aromatic ring will typically be a mononuclear aromatic ring (i.e., a ring derived from benzene), but may include fused aromatic rings, such as those derived from naphthalene. Examples of aromatic amines include aniline, N-alkylanilines (such as N-methylaniline) and N-butylaniline, di-(p-methylphenyl)amine, naphthylamine, 4-aminodiphenylamine, N,N-dimethylphenyldiamine, 4-(4-nitrophenylazo)aniline (Disperse Orange 3), sulfadiazine, 4-phenoxyaniline, 3-nitroaniline, 4-aminoacetaniline, phenyl 4-amino-2-hydroxybenzoate (phenyl aminosalicylate), N-(4-amino-5-methoxy-2-methyl-phenyl)-benzamide (Glass Violet B), N-(4-amino-2,5-dimethoxy-phenyl)-benzamide (Glass Blue RR), N-(4-amino-2,5-diethoxy-phenyl)-benzamide (Glass Blue BB), N-(4-amino-phenyl)-benzamide, and 4-phenylazoaniline. Other examples include p-ethoxyaniline, p-dodecylaniline, cyclohexyl-substituted naphthylamine, and thiophene-substituted aniline. Other suitable aromatic amines include amino-substituted aromatic compounds and amines in which the amine nitrogen is part of the aromatic ring, such as 3-aminoquinoline, 5-aminoquinoline, and 8-aminoquinoline. Also included are aromatic amines such as 2-aminobenzimidazole, which contain a secondary amino group directly attached to the aromatic ring and a primary amino group attached to the imidazole ring. Other amines include N-(4-anilinophenyl)-3-aminobutyramide (i.e., φ-NH-φ-NH-COCH2CH(CH3)NH2). Additional aromatic amines include aminocarbazole, aminoindole, aminopyrrole, aminoinzolone, aminopteridine, mercaptotriazole, aminophenithiazine, aminopyridine, aminopyrazine, aminopyrimidine, pyridine, pyrazine, pyrimidine, aminothiadiazole, aminothiothiadiazole, and aminobenzotriazole. Other suitable amines include 3-amino-N-(4-anilinophenyl)-N-isopropylbutyramide and N-(4-anilinophenyl-3-{(3-aminopropyl)-(cocoyl)amino}butyramide. Other usable aromatic amines include various aromatic amine dye intermediates containing multiple aromatic rings linked by, for example, amide structures. Examples include substances with the general formula φ-CONH-φ-NH2, wherein the phenyl group may be substituted. Suitable aromatic amines include those in which the amine nitrogen is a substituent on an aromatic carboxylic acid compound, i.e., the nitrogen is not sp. within the aromatic ring. 2 Hybridization.

[0040] Amines can also be non-aromatic, or in other words, amines in which the amino nitrogen is not directly attached to a carbon atom of an aromatic ring, or amines in which the amine nitrogen is not part of an aromatic ring, or amines in which the amine nitrogen is not a substituent on an aromatic carboxylic acid compound. In some cases, such non-aromatic amines may be considered aliphatic or cycloaliphatic. Such amines can be straight-chain, branched, or functionalized with certain functional groups. Non-aromatic amines can include monoamines having, for example, 1 to 8 carbon atoms, such as methylamine, ethylamine, and propylamine, as well as various higher amines. Diamines or polyamines may also be used, and will generally have only a single primary amino group. Examples include dimethylaminopropylamine, diethylaminopropylamine, dibutylaminopropylamine, dimethylaminoethylamine, diethylaminoethylamine, dibutylaminoethylamine, 1-(2-amino-ethyl)piperidine, 1-(2-aminoethyl)pyrrolidone, N,N-dimethylethylamine; 3-(dimethylamino)-1-propylamine; O-(2-aminopropyl)-O′-(2-methoxyethyl)polypropylene glycol; N,N-dimethyldipropylenetriamine, aminoethylmorpholine, 3-morpholinopropylamine; aminoethyl ethylidene urea, and aminopropylmorpholine.

[0041] In some embodiments, non-aromatic amines may be used alone or in combination with each other or in combination with aromatic amines. In some embodiments, the amount of aromatic amines may be trace compared to the amount of non-aromatic amines, or in some cases, the composition may be substantially free of or contain no aromatic amines.

[0042] In some embodiments, the grafted olefin polymer may have a nitrogen content of 0.05 wt% to 3 wt%, or 0.1 wt% to 2.5 wt%, or 0.15 wt% to 2 wt%, or 0.2 wt% to 1.75 wt%, or 0.25 wt% to 1.6 wt%, calculated using ASTM D5291.

[0043] Amount of olefin polymers and grafted olefin polymers

[0044] Olefin polymers and grafted olefin polymers can be added to the lubricant composition in amounts to achieve the desired viscosity grade.

[0045] Typically, the amount of olefin polymer may be from 0.1% to 20% by weight, or from 1% to 19% by weight, or from 2.5% to 18% by weight, or from 5% to 17% by weight, or from 10% to 16% by weight of the lubricant composition, or from 10% to 20% by weight, or from 11% to 19% by weight, or from 12% to 18% by weight, or from 13% to 17% by weight, or from 14% to 16% by weight of the lubricant composition.

[0046] Typically, the amount of grafted olefin polymer can be from 0.1% to 10% by weight, or from 0.2% to 9% by weight, or from 0.3% to 8% by weight, or from 0.4% to 7% by weight, or from 0.5% to 6% by weight of the lubricant composition.

[0047] In one embodiment, the lubricant composition may contain 10% to 20% olefin polymer and 0.1% to 10% grafted olefin polymer. In one embodiment, the lubricant composition may contain 11% to 19% olefin polymer and 0.2% to 9% grafted olefin polymer. In one embodiment, the lubricant composition may contain 12% to 18% olefin polymer and 0.3% to 8% grafted olefin polymer. In one embodiment, the lubricant composition may contain 13% to 17% olefin polymer and 0.4% to 7% grafted olefin polymer. In one embodiment, the lubricant composition may contain 14% to 16% olefin polymer and 0.5% to 6% grafted olefin polymer.

[0048] In any case, the olefin polymer and the grafted olefin polymer in the composition may be in a ratio of about 90 / 10 wt% to about 40 / 60 wt%. In some embodiments, the olefin polymer and the grafted olefin polymer in the composition may be in a ratio of about 85 / 15 wt% to about 45 / 55 wt%. In some embodiments, the olefin polymer and the grafted olefin polymer in the composition may be in a ratio of about 80 / 20 wt% to about 50 / 50 wt%.

[0049] Ester-based oils

[0050] The lubricant composition may optionally contain at least one carboxylic acid ester, in the form of a monocarboxylic acid ester or a mixture thereof, a dicarboxylic acid diester or a mixture thereof, or a combination of a monocarboxylic acid ester or a mixture thereof with a dicarboxylic acid diester or a mixture thereof.

[0051] Carboxylic acid monoesters are molecules having the formula RC(O)OR', where RC(O)O- represents the carboxylic acid moiety and R' represents the hydrocarbon group.

[0052] The R group of the carboxylic acid moiety RC(O)O- in a carboxylic acid monoester can be C2 to C3. 18 Straight-chain or branched hydrocarbon groups. In some embodiments, the R group of the carboxylic acid moiety of the carboxylic acid monoester can be C4 to C5. 15 , or C6 to C 12 A straight-chain or branched hydrocarbon group. In some embodiments, the hydrocarbon group may contain heteroatoms, but in many cases, the hydrocarbon group will be an alkyl group. Therefore, in some embodiments, the R group of the carboxylic acid moiety of the carboxylic acid monoester can be C2 to C3. 18C4 to C 15 Or C6 to C 12 Or even C8 to C 12 Straight-chain or branched alkyl groups.

[0053] The RC(O)O- moiety can be derived from carboxylic acids, including but not limited to lauric acid, tallow acid, oleic acid, and palmitic acid. Therefore, carboxylic acid monoesters can be, for example, lauric acid monoester, tallow acid monoester, oleic acid monoester, palmitic acid monoester, and combinations thereof.

[0054] The hydrocarbon group R' of a carboxylic acid monoester can be C6 to C6. 12 Straight-chain or branched alkyl moiety. Contemplated alkyl moiety includes, but is not limited to, for example, hexyl moiety, ethylhexyl moiety, methylpentyl moiety, ethylpentyl moiety, dimethylhexyl moiety, ethylmethylhexyl moiety, etc.

[0055] In one embodiment, the carboxylic acid monoester can be, for example, 2-ethylhexyl resinate, 2-ethylhexyl oleate, 2-ethylhexyl laurate, 2-ethylhexyl palmitate, and combinations thereof.

[0056] The carboxylic acid monoester may be present in the lubricant composition at about 1% or 1.5% to about 15% by weight, or about 2% to about 12.5% ​​by weight, or about 10% to about 15% by weight, or even about 3% to about 10% by weight or about 4% to 8% by weight.

[0057] Dicarboxylic acid diesters are molecules having the formula R'O(O)CRC(O)OR', where -O(O)CRC(O)O- represents the dicarboxylic acid moiety and each R' represents a hydrocarbon group.

[0058] The R group of the dicarboxylic acid moiety -O(O)CRC(O)O- in the dicarboxylic acid diester can be C3 to C4. 12 Or C6 to C 12 A straight-chain or branched hydrocarbon group. In some embodiments, the hydrocarbon group may contain heteroatoms, but in many cases, the hydrocarbon group will be an alkyl group. Therefore, in some embodiments, the R group of the carboxylic acid moiety of the carboxylic acid monoester may be C3 to C4. 12 Or C6 to C 12 Straight-chain or branched alkyl groups.

[0059] The dicarboxylic acids derived from its -O(O)CRC(O)O- portion include, but are not limited to, glutaric acid, adipic acid, azelaic acid, sebacic acid, etc. Therefore, dicarboxylic acid diesters can be, for example, glutaric acid diesters, adipic acid diesters, azelaic acid diesters, sebacic acid diesters, and combinations thereof.

[0060] The hydrocarbon group R' of the dicarboxylic acid diester can be C6 to C6. 12Straight-chain or branched alkyl moiety. Contemplated alkyl moiety includes, but is not limited to, for example, hexyl moiety, ethylhexyl moiety, methylpentyl moiety, ethylpentyl moiety, dimethylhexyl moiety, ethylmethylhexyl moiety, etc.

[0061] In one embodiment, the dicarboxylic acid diester may be, for example, di-2-ethylhexyl azelate, diisotridecyl adipic acid, diisooctyl adipic acid, and combinations thereof.

[0062] Dicarboxylic acid diesters may be present in the lubricant composition at about 1% or 1.5% to about 15% by weight, or about 2% to about 12.5% ​​by weight, or about 10% to about 15% by weight, or even about 3% to about 10% by weight or about 4% to 8% by weight.

[0063] The total amount of monocarboxylic acid esters and dicarboxylic acid esters may be from 2% or 3% to about 30% by weight, or from about 4% to about 25% by weight, or from about 20% to about 30% by weight, or even from about 6% to about 20% by weight, or from about 8% to 16% by weight, or from about 10% to 14% by weight.

[0064] The ratio of monocarboxylic acid ester to dicarboxylic acid diester can be 90 wt%:10 wt% to 10 wt%:90 wt%, or 80 wt%:20 wt% to 20 wt%:80 wt%, or even 75 wt%:25 wt% to 25 wt%:75 wt%. In embodiments, the ratio of monocarboxylic acid ester to dicarboxylic acid diester can be 60 wt%:40 wt% to 40 wt%:60 wt%, or even 55 wt%:45 wt% to 45 wt%:55 wt%, or in some cases even 50 wt%:50 wt%.

[0065] Other additives

[0066] Lubricant compositions can be used in transmission system applications or industrial gear applications. As transmission system lubricants, lubricant compositions may contain other additives commonly used in transmission system applications, including, for example, detergents, dispersants, extreme pressure agents, friction modifiers, anti-wear agents, corrosion inhibitors, viscosity modifiers, antioxidants, oil-soluble titanium compounds, metallic alkyl thiophosphates, organic sulfides, including polysulfides such as sulfide olefins, thiadiazoles and thiadiazole adducts, and post-treatment dispersants.

[0067] The organic sulfide may be present in the range of 0 wt% to 6 wt%, 4 wt% to 6 wt%, 0.5 wt% to 3 wt%, 3 wt% to 5 wt%, 0 wt% to 1 wt%, or 0.1 wt% to 0.5 wt% of the lubricating composition.

[0068] Organic sulfur compounds may alternatively be polysulfides. In one embodiment, at least about 50% by weight of the polysulfide molecules are a mixture of trisulfides or tetrasulfides. In other embodiments, at least about 55% by weight, or at least about 60% by weight of the polysulfide molecules, are a mixture of trisulfides or tetrasulfides. Polysulfides include sulfurized organic polysulfides derived from oils, fatty acids or esters, olefins, or polyolefins.

[0069] Oils that can be vulcanized include natural or synthetic oils, such as mineral oils, lard, carboxylic acid esters derived from aliphatic alcohols and fatty acids or aliphatic carboxylic acids (e.g., myristate oleate and oleyl oleate), and synthetic unsaturated esters or glycerides.

[0070] Fatty acids include those containing 8 to 30, or 12 to 24 carbon atoms. Examples of fatty acids include oleic acid, linoleic acid, linolenic acid, and tall oil. Sulfated fatty acid esters are prepared from a mixture of unsaturated fatty acid esters, such as those obtained from animal fats and vegetable oils (including tall oil, flaxseed oil, soybean oil, rapeseed oil, and fish oil).

[0071] Polysulfides can also be derived from olefins, which are derived from a wide range of alkenes (typically having one or more double bonds). In one embodiment, the olefin contains 3 to 30 carbon atoms. In other embodiments, the olefin contains 3 to 16 or 3 to 9 carbon atoms. In one embodiment, the sulfurized olefin includes olefins derived from propylene, isobutylene, pentene, or mixtures thereof. In one embodiment, the polysulfide includes a polyolefin derived from a polymerized olefin such as the above-described olefins using known techniques. In one embodiment, the polysulfide includes dibutyltetrasulfide, methyl sulfide of oleic acid, sulfurized alkylphenol, sulfurized dipentene, sulfurized dicyclopentadiene, sulfurized terpenes, and sulfurized Diels-Alder adducts; phosphorus sulfurized hydrocarbons.

[0072] Examples of thiadiazoles include 2,5-dimercapto-1,3,4-thiadiazole or oligomers thereof, alkyl-substituted 2,5-dimercapto-1,3,4-thiadiazoles, alkyl-sulfur-substituted 2,5-dimercapto-1,3,4-thiadiazoles or oligomers thereof. Oligomers of alkyl-substituted 2,5-dimercapto-1,3,4-thiadiazoles typically form oligomers of two or more of the thiadiazole units by forming sulfur-sulfur bonds between the 2,5-dimercapto-1,3,4-thiadiazole units. Further examples of thiadiazole compounds can be found in WO 2008,094759, paragraphs 0088 to 0090.

[0073] In one embodiment, the lubricant composition may have a total sulfur level from all additives (i.e., excluding base oils) of about 0.5 wt% or 0.6 wt% to about 3 wt%, or about 0.5 wt% or 0.6 wt% to about 2.5 wt%, or about 0.5 wt% or 0.6 wt% to about 2 wt%. In another embodiment, the lubricant composition may have a total sulfur level from all additives (i.e., excluding base oils) of about 0.2 wt% to about 0.75 wt%, or about 0.25 wt% to about 0.5 wt%.

[0074] In one embodiment, the lubricant composition may be substantially free of or free of sulfurized olefins.

[0075] The presence of non-metallic phosphorus compounds distinguishes lubricant compositions for automotive gears, axles, and bearings from other lubricant compositions, such as those for engine oils. The lubricant compositions described herein will contain only these types of non-metallic phosphorus compounds. These compounds may include, for example, phosphine salts, sulfur-containing phosphine salts, phosphites, phosphonates, sulfur-containing phosphites, sulfur-containing phosphonates, and non-metallic dithiophosphates. These compounds, alone or in combination, may contribute to a total phosphorus level of about 0.03 wt% to about 0.5 wt%, or 0.03 wt% to about 0.35 wt%, or even about 0.05 wt% to about 0.3 wt%, or about 0.08 wt% to about 0.2 wt%, or about 0.13 wt% to about 0.2 wt%, or about 0.1 wt% to about 0.25 wt%.

[0076] Phosphoamine salts can be one or more of the following amine salts: phosphate esters, dialkyl dithiophosphate esters, phosphites, phosphonates, and mixtures thereof. The amine salts of phosphate esters can contain any of a variety of chemical structures. In particular, when the phosphate ester compound contains one or more sulfur atoms, i.e., when the phosphorus-containing acid is a thiophosphate ester, including monothiophosphate or dithiophosphate esters, a variety of structures are possible. Phosphate esters can be prepared by reacting a phosphorus compound (such as phosphorus pentoxide) with an alcohol. Suitable alcohols include alcohols containing up to 30, 24, or 12 carbon atoms, including primary or secondary alcohols, such as isopropanol, butanol, pentanol, sec-pentanol, 2-ethylhexanol, hexanol, cyclohexanol, octanol, decanol, and oleyl alcohol, as well as any of a variety of commercial alcohol mixtures having, for example, 8 to 10, 12 to 18, or 18 to 28 carbon atoms. Polyols, such as diols, can also be used. Amines suitable for use as amine salts include primary amines, secondary amines, tertiary amines, and mixtures thereof, including amines having at least one hydrocarbon group, or in some embodiments, amines having, for example, two or three hydrocarbon groups having 2 to 30, 8 to 26, 10 to 20, or 13 to 19 carbon atoms.

[0077] In one embodiment, the phosphatamine salt may comprise, for example, a substantially sulfur-free alkyl phosphate amine salt having at least 30 mol% phosphorus atoms in an alkyl pyrophosphate structure (sometimes referred to as a POP structure), which is the opposite of an orthophosphate (or monomeric phosphate) structure, as shown, for example, by the following formula: R 1 O(O2)POP(O2)OR 1 ·(R 2 3)NH + Or its variants, wherein each R 1 Independently, it is an alkyl group having 3 to 12 carbon atoms, and each R 2 Independently a hydrogen or hydrocarbon group, or an ester-containing group, or an ether-containing group, provided that at least one R 2 The group is a hydrocarbon group, an ester group, or an ether group (i.e., not NH3).

[0078] Other phosphate salts can be amine salts of phosphate hydrocarbon esters, which are prepared by the reaction of phosphorus pentoxide with an alcohol (having 4 to 18 carbon atoms), and then reacted with a primary amine (e.g., 2-ethylhexylamine), a secondary amine (e.g., dimethylamine) or a tertiary amine (e.g., dimethyloleylamine) to form amine salts of phosphate hydrocarbon esters.

[0079] In one embodiment, sulfur-containing amine phosphates can be prepared by reacting an alkyl thiophosphate with an epoxide or a polyol (such as glycerol). The reaction product can be used alone or further reacted with phosphoric acid, anhydride, or a lower ester. The epoxide is typically an aliphatic epoxide or styrene oxide. Examples of useful epoxides include ethylene oxide, propylene oxide, butane oxide, octane oxide, dodecane oxide, styrene oxide, etc. Ethylene oxide and propylene oxide are preferred. The diol can be an aliphatic diol having 2 to about 12, or 2 to about 6, or 2 or 3 carbon atoms. Diols include ethylene glycol, propylene glycol, etc. Alkyl thiophosphates, diols, epoxides, inorganic phosphorus reagents, and methods for reacting them are described in U.S. Patents 3,197,405 and 3,544,465, the disclosures of which are incorporated herein by reference.

[0080] In some embodiments, the nonmetallic phosphorus-containing compound may be a phosphite or a phosphonate. Suitable phosphites or phosphonates include those having at least one hydrocarbon group containing 3 or 4 or more, or 8 or more, or 12 or more carbon atoms. Phosphites may be monoalkyl-substituted, dialkyl-substituted, or trialkyl-substituted phosphites. Phosphonates may be monoalkyl-substituted, dialkyl-substituted, or trialkyl-substituted phosphonates.

[0081] In one embodiment, the phosphite is sulfur-free, i.e., the phosphite is not a thiophosphite.

[0082] Phosphite or phosphonate can be represented by the following formula:

[0083]

[0084] At least one R group may be a hydrocarbon group containing at least three carbon atoms, and the other R groups may be hydrogen. In one embodiment, two of the R groups are hydrocarbon groups, and the third is hydrogen. In one embodiment, each R group is a hydrocarbon group, i.e., the phosphite is a trialkyl-substituted phosphite. The hydrocarbon group may be alkyl, cycloalkyl, aryl, acyclic hydrocarbon, or a mixture thereof.

[0085] In this art, phosphonates (i.e., formula XI, R = hydrocarbon group) may also be referred to as phosphites. When one of the R groups in formula XII is an H group, the compound is generally considered a phosphite, but such compounds can often exist between tautomers of formulas XI and XII, and therefore may also be referred to as phosphonates or phosphites. For ease of reference, the term phosphite as used herein will be considered to include both phosphites and phosphonates.

[0086] The R hydrocarbon group can be straight-chain or branched, typically straight-chain, and can be saturated or unsaturated, typically saturated.

[0087] In one embodiment, the other phosphorus-containing compound may be C 3-8 Hydroxyl phosphites or mixtures thereof, wherein each R can independently be hydrogen or a hydrocarbon group having 3 to 8, or 4 to 6, carbon atoms, typically 4 carbon atoms. Typically, C 3-8 Hydrocarbon-based phosphites include dibutyl phosphite.

[0088] In one embodiment, the phosphorus-containing compound may be C 12-22 Hydroxyl phosphites or mixtures thereof, wherein each R can independently be hydrogen or a hydrocarbon group having 12 to 24, or 14 to 20, carbon atoms, typically 16 to 18 carbon atoms. Typically, C 12-22 Hydroxyphosphites include C 16-18 Hydroxyl phosphite. R 3 R 4 and R 5 Examples of alkyl groups include octyl, 2-ethylhexyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecanyl, octadecyl, octadecenyl, nonadecanyl, eicosyl, or mixtures thereof.

[0089] In some embodiments, other phosphorus-containing compounds may include C 3-8 Hydroxyl phosphites and C 12 To C 24Both hydrocarbon-based phosphites.

[0090] In one embodiment, the phosphite comprises (a) a monomeric phosphate or its ester and (b) a reaction product of at least two alkylene glycols, wherein the at least two alkylene glycols are: a first alkylene glycol (i) having two hydroxyl groups in a 1,4, 1,5, or 1,6 relationship, and a second alkylene glycol (ii) being an alkyl-substituted 1,3-propanediol.

[0091] Sulfur-containing phosphites may include, for example, those of the formula [R] 1 O(OR 2 (S)PSC2H4(C)(O)OR 4 O] n P(OR 5 ) 2-n (O)H represents the substance, where R 1 and R 2 Each is independently a hydrocarbon group having 3 to 12 carbon atoms or 6 to 8 carbon atoms, or wherein R 1 and R 2 Together with adjacent O and P atoms, it forms a ring containing 2 to 6 carbon atoms; R 4 It is an alkylene group having 2 to 6 carbon atoms or 2 to 4 carbon atoms; R 5 It is hydrogen or a hydrocarbon group having 1 to about 12 carbon atoms; and n is 1 or 2.

[0092] In one embodiment, another phosphorus-containing compound may be a phosphoramide. Phosphoramides can be prepared by reacting dithiophosphoric acid with an unsaturated amide. Examples of unsaturated amides include acrylamide, N,N'-methylenebisacrylamide, methacrylamide, crotonamide, etc. The reaction product of phosphoric acid and the unsaturated amide can be further reacted with a linking or coupling compound such as formaldehyde or paraformaldehyde. Phosphoramides are known in the art and disclosed in U.S. Patents 4,670,169, 4,770,807, and 4,876,374, the disclosures of these patents concerning phosphoramides and their preparation thereof are incorporated herein by reference.

[0093] The phosphorus-containing compound can also be a dithiophosphate ester, which can be formed by reacting dithiophosphate, represented by (RO)2PSSH, with an unsaturated compound. In one embodiment, the unsaturated compound is an unsaturated carboxylic acid or ester. Examples of unsaturated carboxylic acids or anhydrides include acrylic acid or esters, methacrylic acid or esters, itaconic acid or esters, fumaric acid or esters, and maleic acid, anhydrides or esters.

[0094] For example, other substances may be present in the lubricant composition in their usual amounts, including, for example, viscosity modifiers, dispersants, pour point additives, extreme pressure agents, defoamers, copper corrosion inhibitors (such as dimercaptothiadiazole compounds), iron corrosion inhibitors, friction modifiers, dyes, fragrances, optional detergents and antioxidants, and, for example, color stabilizers.

[0095] The final lubricant composition may have a 3mm thickness at 100°C according to ASTM D445. 2 / s to 28mm 2 / s, or 3.5mm 2 / s to 26mm 2 / s, or even 3mm 2 / s or 4mm 2 / s to 24mm 2 / s, or 4.5mm 2 / s to 22mm 2 The kinematic viscosity is 3.8 mm / s. In one embodiment, the final lubricant composition may have a kinematic viscosity of 3.8 mm / s at 100°C according to ASTM D445. 2 / s to 5.0mm 2 / s, or 5.0mm 2 / s to 6.5mm 2 / s, or 6.6mm 2 / s to 8.5mm 2 / s, or 8.5mm 2 / s to 11.0mm 2 The kinematic viscosity is 5.5 mm² / s. In some embodiments, the lubricant composition may have a kinematic viscosity of 5.5 mm² / s according to ASTM D445 at 100°C. 2 / s to 7mm 2 / s, or 5mm 2 / s to 6.5mm 2 / s, or 5mm 2 / s to 6mm 2 The kinematic viscosity is 3.8 μL / s. The final lubricant composition may have a kinematic viscosity of 3.8 μL / s according to ASTM D445 at 100°C. 2 / s to 6.5mm 2 / s, or 6.5mm 2 / s to 11.0mm 2 / s, or even 11.0mm 2 / s to 13.5mm 2 / s, or 13.5mm 2 / s to 18.5mm 2 / s, or even 18.5mm 2 / s to 28mm 2The kinematic viscosity is / s. In some embodiments, the final lubricant composition may have a kinematic viscosity that meets the SAE viscosity grades shown in the table below:

[0096]

[0097] As a lubricant for industrial gears, the lubricant composition may contain other additives commonly used in industrial gear applications, including, for example, foam inhibitors, demulsifiers, pour point depressants, antioxidants, dispersants, metal passivators (such as copper passivators), anti-wear agents, extreme pressure agents, viscosity modifiers, or mixtures thereof. The additives may each be present in the range of up to 5 wt%, 4 wt%, 3 wt%, 2 wt%, or even 1.5 wt%, from 50 ppm, 75 ppm, 100 ppm, or even 150 ppm, or from 75 ppm to 0.5 wt%, from 100 ppm to 0.4 wt%, or from 150 ppm to 0.3 wt%, where the wt% values ​​are relative to the total lubricant composition. In other embodiments, other industrial additives as part of the total additive package may be present in the total lubricant composition from 1 wt% to 20 wt% or from 1 wt% to 10 wt%. However, it should be noted that some additives (including viscosity-modifying polymers) that can be alternatively considered as part of the base fluid may be present in higher amounts (including up to 30%, 40%, or even 50% by weight) when considered to be separate from the base fluid. Additives may be used alone or as mixtures thereof.

[0098] In some embodiments, the industrial lubricant additive package or the resulting industrial lubricant composition comprises a demulsifier, a corrosion inhibitor, a friction modifier, or a combination of two or more thereof. In some embodiments, the corrosion inhibitor comprises toluenetriazole. In other embodiments, the industrial additive package or the resulting industrial lubricant composition comprises one or more sulfurized olefins or polysulfides; one or more phosphoamine salts; one or more thiophosphates, one or more thiadiazoles, toluenetriazoles, polyethers and / or alkenylamines; one or more ester polymers; one or more carboxylic acid esters; one or more succinimide dispersants, or any combination thereof.

[0099] The disclosed technology provides a method for lubricating a transmission system device such as automotive gears, axles, or transmissions, the method comprising: supplying thereto a lubricant composition as described herein, namely a lubricant composition having (a) a hydrocarbon lubricating base oil and (b) a viscosity modifier combination, and optionally (c) a carboxylic acid ester, the viscosity modifier composition comprising a combination of i) an olefin polymer and ii) a graft olefin copolymer; and operating the transmission system device. In one embodiment, the lubricant composition disclosed herein can be used to improve the traction coefficient of lubricated gears at temperatures below 100°C.

[0100] Automotive gears may include gears in a vehicle's transmission (e.g., a manual or automatic transmission), in an axle or differential, or in other drivetrain power transmission devices. Automotive gears may also include bearings. Lubricating gears may include hypoid gears, such as those in rear-drive axles. Axles may be from conventional petroleum-powered vehicles, electric vehicles, or hybrid vehicles. Electric drive axles may combine an electric motor, power electronics, and a transmission into a single unit, directly powering the vehicle's axle.

[0101] The disclosed technology also provides a method for lubricating industrial gears, the method comprising: supplying thereto a lubricant composition as described herein, namely a lubricant composition having (a) a hydrocarbon lubricating base oil and (b) a viscosity modifier composition, and optionally (c) a carboxylic acid ester, the viscosity modifier composition comprising a combination of i) an olefin polymer and ii) a graft olefin copolymer; and operating a transmission system device. In one embodiment, the lubricant composition disclosed herein can be used to improve the traction coefficient of lubricated gears at temperatures below 100°C.

[0102] Unless otherwise stated, the amounts of each chemical component mentioned do not include any solvents or diluents that are commonly found in commercial substances, i.e., based on active chemicals. However, unless otherwise stated, each chemical or composition mentioned herein should be interpreted as a commercial-grade substance that may contain isomers, byproducts, derivatives, and other such substances generally understood to be present in commercial-grade forms.

[0103] As used herein, the terms "hydrocarbon substituent" or "hydrocarbon group" are used in their common sense, as is well known to those skilled in the art. Specifically, it refers to a group having a carbon atom directly bonded to the rest of the molecule and exhibiting predominantly hydrocarbon characteristics. Examples of hydrocarbon groups include:

[0104] • Hydrocarbon substituents, namely aliphatic (e.g., alkyl or alkenyl), alicyclic (e.g., cycloalkyl, cycloalkenyl) substituents and aromatic substituents substituted with aromatic, aliphatic and alicyclic groups, as well as cyclic substituents, wherein the ring is completed by another part of the molecule (e.g., two substituents together form a ring).

[0105] • Substituted hydrocarbon substituents, i.e. substituents containing non-hydrocarbon groups, which, in the context of this invention, do not alter the primary hydrocarbon properties of the substituent (e.g., halogens (especially chlorine and fluorine), hydroxyl groups, alkoxy groups, mercapto groups, alkyl mercapto groups, nitro groups, nitroso groups, and thiooxy groups);

[0106] • Heterosubstituents, in the context of this invention, are substituents that, while possessing the characteristics of a predominantly hydrocarbon group, contain atoms other than carbon in a ring or chain originally composed of carbon atoms, and include substituents such as pyridyl, furanyl, thiophene, and imidazolyl. Heteroatoms include sulfur, oxygen, and nitrogen. Typically, for every ten carbon atoms in a hydrocarbon group, there will be no more than two or no more than one non-hydrocarbon substituent; alternatively, non-hydrocarbon substituents may be absent from the hydrocarbon group.

[0107] It is known that some of the substances described above can interact in the final formulation, such that the composition of the final formulation may differ from those initially added. For example, metal ions (e.g., metal ions in detergents) can migrate to other acidic or anionic sites of other molecules. The resulting products, including those formed when the compositions of the present invention are used for their intended purpose, may not be easily described. However, all such conditioning and reaction products are included within the scope of the present invention. The present invention includes compositions prepared by mixing the above-described components.

[0108] As used herein, the term "about" means that the value of a given quantity is within ±20% of the stated value. In other embodiments, the value is within ±15% of the stated value. In other embodiments, the value is within ±10% of the stated value. In other embodiments, the value is within ±5% of the stated value. In other embodiments, the value is within ±2.5% of the stated value. In other embodiments, the value is within ±1% of the stated value.

[0109] The invention described herein can be used with fully formulated gear oils or industrial gear oils, and can be better understood with reference to the following examples.

[0110] Example

[0111] Copolymer A is an olefin copolymer of ethylene and propylene (43:57) with an Mn of 4900 as measured by gel permeation chromatography (“GPC”) using a polystyrene standard.

[0112] Functionalized copolymer B was prepared by reacting olefin copolymer A with 2% by weight methacrylic acid in the presence of a peroxide initiator. The grafted olefin from this reaction was then further reacted with n-aminopropylmorpholine. The product was diluted with PAO-4 synthetic oil to 80% active material.

[0113] A series of fully blended automotive gear oils were prepared according to the formulations in Table 1 below.

[0114] Table 1: Group III Formulations

[0115]

[0116] Oxidation tests were performed on these fully formulated lubricants using the CEC L-48 DKA oxidation method. In this test, the fluid sample was heated to 160°C in a glass tube and purged with air at a rate of 5 L / h for 192 hours. At the end of the test, the kinematic viscosity of the fluid was measured at both 40°C and 100°C, and the tube was rated for deposits. A visual rating of 1, 2, or 3 indicates the cleanliness of the tube containing the fluid. The lower the value, the cleaner the tube. The results in Table 2 below show that viscosity control is good when only unfunctionalized olefin copolymer A is present; however, the cleanliness rating is higher than expected. Cleanliness is improved without significantly affecting viscosity properties by producing a mixture of functionalized and unfunctionalized copolymers containing only 20% by weight of functionalized olefin copolymer. If 100% of the viscosity modifier is functionalized olefin copolymer B, the cleanliness ratio is good, but the viscosity increases significantly by the end of the test.

[0117] Table 2: Group III Formulations

[0118] DKA performance Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Copolymer A / Copolymer B 100 / 0 80 / 20 50 / 50 20 / 80 0 / 100 KV100, % change 38 53 71 116 162 KV40, % change 47 63 88 156 236 Appearance 2 1 1 1 1

[0119] Considering that the viscosity modifier mixture (sample 2) containing 80 wt% copolymer A and 20 wt% copolymer B exhibited both good cleanliness and good viscosity control after oxidation, another mixture containing 70 wt% and 90 wt% copolymer A respectively mixed with 30 wt% and 10 wt% copolymer B was prepared.

[0120] Table 3: Group III Formulations

[0121]

[0122] Samples 6 to 8 were also evaluated using the CEC L-48DKA oxidation method. The results shown in Table 4 indicate that 10% by weight of copolymer B is insufficient to improve the cleanliness grade from a2 to a1.

[0123] Table 4: Group III Formulations

[0124] Sample 6 Sample 7 Sample 8 Copolymer A / Copolymer B 70 / 30 80 / 20 90 / 10 KV100% change 56 47 44 KV40% change 68 55 51 Appearance 1 1 2

[0125] Promising results were given in the DKA oxidation test, and the viscosity modifier 80 / 20 mixture was tested with three different additive packages in the extended 200-hour test of L-60-1 (ASTM D5704).

[0126] Table 5: Group IV formulations

[0127] Sample 9 Sample 10 Sample 11 Add 1% by weight to the package 10 - - Add 2% by weight to the package - 12.5 - Add 3% by weight to the package - - 10 Boron ppm 221 91 231 phosphorus ppm 1334 1341 1623 sulfur ppm 21211 20800 18830 Zinc ppm 336 copolymer A 13.2 13.2 13.2 copolymer B 3.3 3.3 3.3 Oil with lubricating viscosity The sum is 100 The sum is 100 The sum is 100

[0128] Table 6 shows the varnish and sludge grades for each fluid in the extended 200-hour L-60-1 test, all of which are acceptable in industry.

[0129] Table 6 .

[0130] L-60-1 (200 hours) L-60-1 (Minimum pass requirement of 50 hours) Sample 9 Sample 10 Sample 11 Varnish (Advantages) 7.5 9.7 9.2 10 Sludge 9.4 9.6 9.7 9.8

[0131] While cleanliness is an important performance attribute, fluid efficiency is another key performance parameter. One way to study fluid efficiency is to measure the fluid's drag coefficient. Drag is the internal resistance of a fluid and plays a dominant role in both mixed lubrication and boundary lubrication states. The copolymers described herein were then evaluated using a standard miniature drag unit (MTM) under a frictional force of 1.0 GPa. Each fluid was operated at six temperatures with a slip-to-roll ratio from 0.025 to 50. Samples 12 through 15 all contained the same additive package and were used as... Sample 2042 was commercially available from Lubrizol Corporation. Sample 12 contained only copolymer A, sample 13 contained only copolymer B, sample 14 contained an 80 / 20 mixture of copolymer A and copolymer B without pour point inhibitors, and sample 15 contained an 80 / 20 mixture of copolymer A and copolymer B and a pour point inhibitor. Selected traction coefficient data for these fluids are available in Table 7.

[0132] Table 7: Group III Formulations

[0133]

[0134] The traction coefficient data indicate that copolymers A and B have similar properties when used alone. However, when used in combination, the traction coefficient decreases, indicating a synergistic effect when the copolymers are used in combination.

[0135] Further improvement in the traction coefficient was observed by adding the mixture of esters to samples 12 through 15. Samples 16 through 18 all contained a 50:50 mixture of monoester and diester. Sample 16 contained only copolymer A, sample 17 contained only copolymer B, and sample 18 contained an 80 / 20 mixture of copolymer A and copolymer B.

[0136] Table 8: Group III Formulations

[0137]

[0138]

[0139] The traction coefficients of samples 16 to 18 containing the ester mixture were all lower than those of samples 12 to 15 without the ester mixture. Similarly, a synergistic improvement in the traction coefficient of the 80 / 20 copolymer mixture was observed compared to either copolymer alone.

[0140] Each of the foregoing references is incorporated herein by reference, including any prior application claiming priority thereto, whether or not specifically listed above. Any reference to any reference is not an admission that the reference conforms to the prior art or constitutes general knowledge of a person skilled in the art in any jurisdiction. Unless expressly indicated in the examples or otherwise elsewhere, all numerical quantities of material amounts, reaction conditions, molecular weights, carbon number, etc., specified in this specification should be understood to be modified by the word “about.” It should be understood that the upper and lower limits of the quantities, ranges, and proportions described herein can be combined independently. Similarly, the ranges and quantities of each element of the invention can be used in conjunction with the ranges or quantities of any other element.

[0141] As used herein, the transitional term “comprising,” synonymous with “comprising,” “containing,” or “characterized in,” is inclusive or open-ended and does not exclude additional, unlisted elements or method steps. However, in every use of “comprising” herein, it is intended that the term also cover the phrases “consistently composed of” and “composed of” as alternative embodiments, wherein “composed of” excludes any elements or steps not specified, and “consistently composed of” allows the inclusion of additional, undescribed elements or steps that do not materially affect the essential or essential and novel characteristics of the composition or method under consideration.

[0142] While certain representative embodiments and details have been shown to illustrate the purpose of this invention, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the scope of the invention. In this respect, the scope of the invention is defined only by the following claims.

[0143] A lubricant composition comprising: a) a hydrocarbon lubricating base oil, b) a viscosity modifier composition comprising, by weight, 90 / 10 to 40 / 60% of a polymer bi) / bii): bi) at least one olefin copolymer having a number-average molecular weight (“Mn”) of about 1,000 to about 10,000 as measured by gel permeation chromatography (“GPC”) using a polystyrene standard, and bii) at least one grafted olefin copolymer having a Mn of about 1,000 to about 10,000 as measured by GPC using a polystyrene standard, comprising a carboxylic acid functional group or its reactive equivalent grafted onto the polymer backbone, wherein the carboxylic acid functional group or its reactive equivalent is further substituted with an amine.

[0144] According to any of the preceding sentences, the lubricant composition wherein the weight ratio of bi) / bii) is 85 / 15 to 45 / 55 by weight.

[0145] According to any of the preceding sentences, the lubricant composition wherein the weight ratio of bi) / bii) is 80 / 20 to 50 / 50 by weight.

[0146] According to any of the preceding sentences, the lubricant composition wherein the olefin polymer of i) comprises an ethylene / propylene copolymer.

[0147] According to any of the preceding sentences, the lubricant composition wherein the olefin polymer of i) comprises ethylene-C3-C 10 α-Monoolefin copolymer.

[0148] According to any of the preceding sentences, the lubricant composition wherein the olefin polymer of i) comprises an ethylene-C3-C8α-monoolefin copolymer.

[0149] According to any of the preceding sentences, the lubricant composition wherein the olefin polymer of i) comprises an ethylene-C3-C6α-monoolefin copolymer.

[0150] According to any of the preceding sentences, the lubricant composition wherein the olefin polymer of i) comprises an isobutylene polymer.

[0151] According to any of the preceding sentences, the lubricant composition wherein the olefin polymer of i) comprises an isoprene polymer.

[0152] According to any of the preceding sentences, the lubricant composition wherein the olefin polymer of i) comprises an ethylene-propylene-α-olefin terpolymer.

[0153] According to any of the preceding sentences, the lubricant composition wherein the olefin polymer of i) comprises an ethylene-propylene polymer, said ethylene-propylene polymer further comprising a non-conjugated diene of 5 to 14 carbon atoms.

[0154] According to any of the preceding sentences, the lubricant composition wherein the olefin polymer of i) comprises an isobutylene / conjugated diene polymer having 5 to 14 carbon atoms.

[0155] According to any of the preceding sentences, the lubricant composition wherein the olefin polymer of i) comprises 15 mol% to 80 mol% ethylene and 20 mol% to 85 mol% propylene or a higher monoolefin.

[0156] According to any of the preceding sentences, the lubricant composition wherein i) the olefin polymer comprises 30 mol% to 80 mol% ethylene and 20 mol% to 70 mol% of at least one C3 to C4 alloy. 10 α-monoolefin.

[0157] According to any of the preceding sentences, the lubricant composition wherein the olefin polymer of i) comprises 40 mol% to 80 mol% ethylene and 20 mol% to 60 mol% propylene.

[0158] According to any of the preceding sentences, the lubricant composition wherein i) the olefin polymer comprises 15 mol% to 80 mol% propylene and 20 mol% to 85 mol% ethylene or a higher monoolefin.

[0159] According to any of the preceding sentences, the lubricant composition wherein i) the olefin polymer comprises 30 mol% to 80 mol% propylene and 20 mol% to 70 mol% of at least one C3 to C4 alloy. 10 α-monoolefin.

[0160] The lubricant composition according to any of the preceding sentences, wherein the olefin polymer of i) comprises 45 mol% to 75 mol% propylene and 25 mol% to 55 mol% ethylene.

[0161] According to any of the preceding sentences, the lubricant composition wherein the olefin polymer of i) comprises 15 mol% of a non-conjugated diene or triene.

[0162] The lubricant composition according to any of the preceding sentences, wherein the olefin polymer of i) has an Mn of about 1250 to about 9500.

[0163] The lubricant composition according to any of the preceding sentences, wherein the olefin polymer of i) has an Mn of about 1500 to about 9000.

[0164] The lubricant composition according to any of the preceding sentences, wherein the olefin polymer of i) has an Mn of about 1750 to about 8500.

[0165] The lubricant composition according to any of the preceding sentences, wherein the olefin polymer of i) has an Mn of about 2000 to about 8000.

[0166] The lubricant composition according to any of the preceding sentences, wherein the olefin polymer of i) has an Mn of about 2500 to about 7000.

[0167] The lubricant composition according to any of the preceding sentences, wherein the olefin polymer of i) has an Mn of about 2500 to about 7500.

[0168] The lubricant composition according to any of the preceding sentences, wherein the olefin polymer of i) has an Mn of about 3000 to about 6500.

[0169] The lubricant composition according to any of the preceding sentences, wherein the olefin polymer of i) has an Mn of about 4000 to about 6000.

[0170] According to any of the preceding sentences, the lubricant composition wherein the olefin polymer of i) has an Mn of about 1,000 to 5,000.

[0171] The lubricant composition according to any of the preceding sentences, wherein the olefin polymer of i) has an Mn of about 1500 to about 4000.

[0172] The lubricant composition according to any of the preceding sentences, wherein the olefin polymer of i) has an Mn of about 2000 to about 4000.

[0173] According to any of the preceding sentences, the lubricant composition comprises 0.1% to 20% by weight of i) an olefin polymer.

[0174] According to any of the preceding sentences, the lubricant composition comprises 1% to 19% by weight of i) an olefin polymer.

[0175] According to any of the preceding sentences, the lubricant composition comprises 2.5% to 18% by weight of i) an olefin polymer.

[0176] According to any of the preceding sentences, the lubricant composition comprises 5% to 17% by weight of i) an olefin polymer.

[0177] According to any of the preceding sentences, the lubricant composition comprises 10% to 16% by weight of i) an olefin polymer.

[0178] According to any of the preceding sentences, the lubricant composition comprises 10% to 20% by weight of i) an olefin polymer.

[0179] According to any of the preceding sentences, the lubricant composition comprises 11% to 19% by weight of i) an olefin polymer.

[0180] According to any of the preceding sentences, the lubricant composition comprises 12% to 18% by weight of i) an olefin polymer.

[0181] According to any of the preceding sentences, the lubricant composition comprises 13% to 17% by weight of i) an olefin polymer.

[0182] According to any of the preceding sentences, the lubricant composition comprises 14% to 16% by weight of i) an olefin polymer.

[0183] According to any of the preceding sentences, the lubricant composition comprises 0.1% to 10% by weight of i) an olefin polymer.

[0184] According to any of the preceding sentences, the lubricant composition comprises 0.2% to 9% by weight of i) an olefin polymer.

[0185] According to any of the preceding sentences, the lubricant composition comprises 0.3% to 8% by weight of i) an olefin polymer.

[0186] According to any of the preceding sentences, the lubricant composition comprises 0.4% to 7% by weight of i) an olefin polymer.

[0187] According to any of the preceding sentences, the lubricant composition comprises 0.5% to 6% by weight of i) an olefin polymer.

[0188] According to any of the preceding sentences, the lubricant composition comprises 0.2% to 9% by weight of i) a grafted olefin polymer.

[0189] According to any of the preceding sentences, the lubricant composition comprises 0.3% to 8% by weight of i) a grafted olefin polymer.

[0190] According to any of the preceding sentences, the lubricant composition comprises 0.4% to 7% by weight of i) a grafted olefin polymer.

[0191] According to any of the preceding sentences, the lubricant composition comprises 0.5% to 6% by weight of i) a grafted olefin polymer.

[0192] The lubricant composition according to any of the preceding sentences, wherein the grafted olefin polymer comprises the olefin polymer according to any of the preceding sentences.

[0193] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer comprises a maleic acid graft.

[0194] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer comprises maleic anhydride grafts.

[0195] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer comprises maleate.

[0196] The lubricant composition according to any of the preceding sentences, wherein the grafted olefin polymer comprises itaconic acid graft.

[0197] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer comprises itaconic anhydride graft.

[0198] The lubricant composition according to any of the preceding sentences, wherein the grafted olefin polymer comprises itaconic acid ester.

[0199] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer comprises a cinnamic acid graft.

[0200] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer comprises a cinnamic anhydride graft.

[0201] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer comprises cinnamic acid ester.

[0202] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer comprises a fumaric acid graft.

[0203] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer comprises a fumaric anhydride graft.

[0204] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer comprises fumarate.

[0205] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer comprises a hydrated glyoxylic acid graft.

[0206] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer comprises a hydrated glyoxylic anhydride graft.

[0207] The lubricant composition according to any of the preceding sentences, wherein the grafted olefin polymer comprises glyoxylate.

[0208] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer comprises 0.5% to 8% by weight of a carboxylic acid graft based on the weight of the polymer backbone.

[0209] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer comprises a carboxylic acid graft of 1% to 7% by weight based on the polymer backbone.

[0210] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer comprises 1.5% to 6% by weight of a carboxylic acid graft based on the weight of the polymer backbone.

[0211] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer comprises 2% to 5% by weight of a carboxylic acid graft based on the weight of the polymer backbone.

[0212] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer comprises 1% to 2% by weight of a carboxylic acid graft based on the weight of the polymer backbone.

[0213] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer comprises 2% to 3% by weight of a carboxylic acid graft based on the weight of the polymer backbone.

[0214] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer comprises 3% to 4% by weight of a carboxylic acid graft based on the weight of the polymer backbone.

[0215] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer comprises 4% to 5% by weight of a carboxylic acid graft based on the weight of the polymer backbone.

[0216] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is grafted to a total acid value (“TAN”) of 5 mg KOH / g to 100 mg KOH / g according to ASTM D664.

[0217] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is grafted to a total acid value (“TAN”) of 10 mg KOH / g to 80 mg KOH / g according to ASTM D664.

[0218] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is grafted to a total acid value (“TAN”) of 15 mg KOH / g to 75 mg KOH / g according to ASTM D664.

[0219] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is grafted to a total acid value (“TAN”) of 20 mg KOH / g to 70 mg KOH / g according to ASTM D664.

[0220] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is grafted to a total acid value (“TAN”) of 25 mg KOH / g to 65 mg KOH / g according to ASTM D664.

[0221] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is grafted to a total acid value (“TAN”) of about 25 mg KOH / g to about 60 mg KOH / g according to ASTM D664.

[0222] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is substantially free of poly(ethylene amine).

[0223] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer reacts with a primary amine.

[0224] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer reacts with aniline.

[0225] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with N-alkylaniline.

[0226] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with di-(p-methylphenyl)amine.

[0227] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer reacts with naphthylamine.

[0228] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with 4-aminodiphenylamine.

[0229] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with N,N-dimethylphenylenediamine.

[0230] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with 4-(4-nitrophenyl-azo)aniline.

[0231] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with sulfamethazine.

[0232] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with 4-phenoxyaniline.

[0233] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with 3-nitro-aniline.

[0234] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with 4-aminoacetanilide.

[0235] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with phenyl 4-amino-2-hydroxybenzoate (phenylaminosalicylate).

[0236] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with N-(4-amino-5-methoxy-2-methyl-phenyl)-benzamide.

[0237] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with N-(4-amino-2,5-dimethoxy-phenyl)-benzamide.

[0238] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with N-(4-amino-2,5-diethoxy-phenyl)-benzamide.

[0239] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with N-(4-amino-phenyl)-benzamide.

[0240] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with 4-phenylazoaniline.

[0241] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with p-ethoxyaniline.

[0242] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with p-dodecylaniline.

[0243] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer reacts with cyclohexyl-substituted naphthylamine.

[0244] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer reacts with thiophene-substituted aniline.

[0245] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with 3-aminoquinoline.

[0246] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with 5-aminoquinoline.

[0247] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with 8-aminoquinoline.

[0248] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with 2-aminobenzimidazole.

[0249] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with N-(4-anilinophenyl)-3-aminobutyramide.

[0250] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with aminocarbazole.

[0251] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer reacts with aminoindole.

[0252] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer reacts with aminopyrrole.

[0253] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with aminoindazolinone.

[0254] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer reacts with aminopyridine.

[0255] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with mercaptotriazole.

[0256] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with aminophenothiazide.

[0257] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with aminopyridine.

[0258] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with aminopyrazine.

[0259] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer reacts with aminopyrimidine.

[0260] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer reacts with pyridine.

[0261] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with pyrazine.

[0262] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer reacts with pyrimidine.

[0263] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with aminothiadiazole.

[0264] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with aminothiothiadiazole.

[0265] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with aminobenzotriazole.

[0266] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with 3-amino-N-(4-anilinephenyl)-N-isopropylbutyramide.

[0267] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with N-(4-anilinophenyl)-3-{(3-aminopropyl)-(cocoyl)amino}butyramide.

[0268] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer reacts with a substance having the general formula φ-CONH-φ-NH2, wherein the phenyl group may be substituted.

[0269] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer reacts with methylamine.

[0270] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer reacts with ethylamine.

[0271] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer reacts with propylamine.

[0272] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with dimethylaminopropylamine.

[0273] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with dimethylaminopropylamine.

[0274] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with dibutylaminopropylamine.

[0275] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with dimethylaminoethylamine.

[0276] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with diethylaminoethylamine.

[0277] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with dibutylaminoethylamine.

[0278] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with 1-(2-amino-ethyl)piperidine.

[0279] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with 1-(2-aminoethyl)-pyrrolidone.

[0280] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with N,N-dimethylethylamine.

[0281] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with 3-(dimethylamino)-1-propylamine.

[0282] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with O-(2-aminopropyl)-O'-(2-methoxyethyl)polypropylene glycol.

[0283] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with N,N-dimethyldipropylenetriamine.

[0284] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with aminoethylmorpholine.

[0285] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with 3-morpholinopropylamine.

[0286] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with aminoethyl ethylidene urea.

[0287] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer is reacted with aminopropylmorpholine.

[0288] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer has a nitrogen content of 0.05% to 3% by weight calculated using ASTM D5291.

[0289] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer has a nitrogen content of 0.1% to 2.5% by weight calculated using ASTM D5291.

[0290] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer has a nitrogen content of 0.15% to 2% by weight calculated using ASTM D5291.

[0291] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer has a nitrogen content of 0.2% to 1.75% by weight calculated using ASTM D5291.

[0292] According to any of the preceding sentences, the lubricant composition wherein the grafted olefin polymer has a nitrogen content of 0.25% to 1.6% by weight calculated using ASTM D5291.

[0293] According to any of the preceding sentences, the lubricant composition comprises 0.1% to 10% by weight of a grafted olefin polymer.

[0294] According to any of the preceding sentences, the lubricant composition comprises 0.2% to 9% by weight of a grafted olefin polymer.

[0295] According to any of the preceding sentences, the lubricant composition comprises 0.3% to 8% by weight of a grafted olefin polymer.

[0296] According to any of the preceding sentences, the lubricant composition comprises 0.4% to 7% by weight of a grafted olefin polymer.

[0297] According to any of the preceding sentences, the lubricant composition comprises 0.5% to 6% by weight of a grafted olefin polymer.

[0298] According to any of the preceding sentences, the lubricant composition comprises c) a carboxylic acid ester.

[0299] The lubricant composition according to any of the preceding sentences, wherein the carboxylic acid ester includes a monocarboxylic acid ester.

[0300] According to any of the preceding sentences, the lubricant composition wherein the carboxylic acid monoester comprises C8 to C96. 18 Straight-chain or branched carboxylic acids.

[0301] According to any of the preceding sentences, the lubricant composition wherein the carboxylic acid monoester comprises C6 to C6. 12 Straight-chain or branched alkoxy groups.

[0302] According to any of the preceding sentences, the lubricant composition wherein the carboxylic acid monoester comprises C4 to C5. 14 Straight-chain or branched alkoxy groups.

[0303] According to any of the preceding sentences, the lubricant composition wherein the carboxylic acid monoester comprises C8 to C96. 14 Straight-chain or branched alkoxy groups.

[0304] According to any of the preceding sentences, the lubricant composition wherein the carboxylic acid monoester comprises C 10 To C 14 Straight-chain or branched alkoxy groups.

[0305] According to any of the preceding sentences, the lubricant composition wherein the carboxylic acid monoester comprises C 11 To C 13 Straight-chain or branched alkoxy groups.

[0306] The lubricant composition according to any of the preceding sentences, wherein the carboxylic acid monoester includes monolaurate, monotallowate, monooleate, monopalmitate, and combinations thereof.

[0307] According to any of the preceding sentences, the lubricant composition wherein the carboxylic acid monoester comprises a 2-ethylhexylalkoxy group.

[0308] The lubricant composition according to any of the preceding sentences, wherein the carboxylic acid monoester includes 2-ethylhexyl resinate.

[0309] The lubricant composition according to any of the preceding sentences, wherein the carboxylic acid monoester includes 2-ethylhexyl oleate.

[0310] The lubricant composition according to any of the preceding sentences, wherein the carboxylic acid monoester includes 2-ethylhexyl laurate.

[0311] The lubricant composition according to any of the preceding sentences, wherein the carboxylic acid monoester includes 2-ethylhexyl palmitate.

[0312] According to any of the preceding sentences, the lubricant composition wherein the monoester is present in about 1.5% by weight to about 15% by weight.

[0313] The lubricant composition according to any of the preceding sentences, wherein the monoester is present in about 2% by weight to about 12.5% ​​by weight.

[0314] According to any of the preceding sentences, the lubricant composition wherein the monoester is present in about 3% to about 10% by weight.

[0315] According to any of the preceding sentences, the lubricant composition wherein the monoester is present in about 4% to about 8% by weight.

[0316] According to any of the preceding sentences, the lubricant composition wherein the monoester is present in about 10% to about 15% by weight.

[0317] The lubricant composition according to any of the preceding sentences, wherein the carboxylic acid ester includes a dicarboxylic acid diester.

[0318] According to any of the preceding sentences, the lubricant composition wherein the dicarboxylic acid diester comprises C3 to C4. 12 Straight-chain or branched dicarboxylic acids.

[0319] According to any of the preceding sentences, the lubricant composition wherein the dicarboxylic acid diester comprises C4 to C6. 11 Straight-chain or branched dicarboxylic acids.

[0320] According to any of the preceding sentences, the lubricant composition wherein the dicarboxylic acid diester comprises C5 to C6. 10 Straight-chain or branched dicarboxylic acids.

[0321] According to any of the preceding sentences, the lubricant composition wherein the dicarboxylic acid diester comprises a C6 to C9 straight-chain or branched dicarboxylic acid.

[0322] According to any of the preceding sentences, the lubricant composition, wherein the dicarboxylic acid diester includes adipate diester, azelaic acid diester, and combinations thereof.

[0323] The lubricant composition according to any one of the preceding claims, wherein the dicarboxylic acid diester includes di-2-ethylhexyl azelate.

[0324] According to any of the preceding sentences, the lubricant composition wherein the dicarboxylic acid diester includes diisotridecyl adipate.

[0325] According to any of the preceding sentences, the lubricant composition wherein the dicarboxylic acid diester includes diisooctyl adipate.

[0326] According to any of the preceding sentences, the lubricant composition wherein the dicarboxylic acid diester comprises di-C 6-10 - Azelaic acid ester.

[0327] According to any of the preceding sentences, the lubricant composition wherein the dicarboxylic acid diester comprises di-C 6-10 -Adipic acid ester.

[0328] The lubricant composition according to any of the preceding sentences, wherein the dicarboxylic acid diester includes di-C8-azelate.

[0329] The lubricant composition according to any of the preceding sentences, wherein the dicarboxylic acid diester includes di-C8 adipate.

[0330] According to any of the preceding sentences, the lubricant composition wherein the diester is present in about 1% to about 15% by weight.

[0331] According to any of the preceding sentences, the lubricant composition wherein the diester is present in about 1.5% by weight to about 15% by weight.

[0332] According to any of the preceding sentences, the diester is present in about 2% to about 12.5% ​​by weight in the lubricant composition.

[0333] According to any of the preceding sentences, the lubricant composition wherein the diester is present in about 3% to about 10% by weight.

[0334] According to any of the preceding sentences, the lubricant composition wherein the diester is present in about 4% to about 8% by weight.

[0335] According to any of the preceding sentences, the lubricant composition wherein the diester is present in about 10% to about 15% by weight.

[0336] According to any of the preceding sentences, the total amount of the monocarboxylic acid ester and the dicarboxylic acid ester is from about 2% to about 30% by weight.

[0337] According to any of the preceding sentences, the total amount of the monocarboxylic acid ester and the dicarboxylic acid ester is from about 3% to about 30% by weight.

[0338] According to any of the preceding sentences, the total amount of the monocarboxylic acid ester and the dicarboxylic acid ester is from about 4% to about 25% by weight.

[0339] According to any of the preceding sentences, the total amount of the monocarboxylic acid ester and the dicarboxylic acid ester is about 20% to about 30% by weight.

[0340] According to any of the preceding sentences, the total amount of the monocarboxylic acid ester and the dicarboxylic acid ester is from about 6% to about 20% by weight.

[0341] According to any of the preceding sentences, the total amount of the monocarboxylic acid ester and the dicarboxylic acid ester is from about 8% to about 16% by weight.

[0342] According to any of the preceding sentences, the total amount of the monocarboxylic acid ester and the dicarboxylic acid ester is from about 10% to about 14% by weight.

[0343] According to any of the preceding sentences, the ratio of the monocarboxylic acid ester to the dicarboxylic acid ester is from 90 wt%:10 wt% to 10 wt%:90 wt%.

[0344] According to any of the preceding sentences, the ratio of the monocarboxylic acid ester to the dicarboxylic acid ester is from 80 wt%:20 wt% to 20 wt%:80 wt%.

[0345] According to any of the preceding sentences, the ratio of the monocarboxylic acid ester to the dicarboxylic acid ester is from 75 wt%:25 wt% to 25 wt%:75 wt%.

[0346] According to any of the preceding sentences, the ratio of the monocarboxylic acid ester to the dicarboxylic acid ester is from 60 wt%:40 wt% to 40 wt%:60 wt%.

[0347] According to any of the preceding sentences, the ratio of the monocarboxylic acid ester to the dicarboxylic acid ester is from 55 wt%:45 wt% to 45 wt%:55 wt%.

[0348] According to any of the preceding sentences, the lubricant composition wherein the ratio of the monocarboxylic acid ester to the dicarboxylic acid ester is 50% by weight: 50% by weight.

[0349] According to any of the preceding sentences, the lubricant composition wherein the hydrocarbon lubricant base oil comprises American Petroleum Institute (“API”) Group IV polyalphaolefin.

[0350] According to any of the preceding sentences, the lubricant composition wherein the hydrocarbon lubricating base oil comprises American Petroleum Institute (“API”) Group III oil mineral oils.

[0351] According to any of the preceding sentences, the lubricant composition wherein the hydrocarbon lubricating base oil comprises American Petroleum Institute (“API”) Group II oil mineral oils.

[0352] According to any of the preceding sentences, the lubricant composition contains a total sulfur level of about 0.5% to about 3% by weight from all additives (i.e., excluding base oil).

[0353] According to any of the preceding sentences, the lubricant composition contains a total sulfur level of about 0.6% to about 3% by weight from all additives (i.e., excluding base oil).

[0354] According to any of the preceding sentences, the lubricant composition contains a total sulfur level of about 0.5% to about 2.5% by weight from all additives (i.e., excluding base oil).

[0355] According to any of the preceding sentences, the lubricant composition contains a total sulfur level of about 0.6% to about 2.5% by weight from all additives (i.e., excluding base oil).

[0356] According to any of the preceding sentences, the lubricant composition contains a total sulfur level of about 0.5% to about 2% by weight from all additives (i.e., excluding base oil).

[0357] According to any of the preceding sentences, the lubricant composition contains a total sulfur level of about 0.6% to about 2% by weight from all additives (i.e., excluding base oil).

[0358] According to any of the preceding sentences, the lubricant composition contains a total sulfur level of about 0.2% by weight to about 0.75% by weight from all additives (i.e., excluding base oil).

[0359] According to any of the preceding sentences, the lubricant composition contains a total sulfur level of about 0.25% by weight to about 0.5% by weight from all additives (i.e., excluding base oil).

[0360] According to any of the preceding sentences, the lubricant composition contains about 0.03% by weight to about 0.5% by weight of total phosphorus.

[0361] According to any of the preceding sentences, the lubricant composition contains about 0.03% by weight to about 0.35% by weight of total phosphorus.

[0362] According to any of the preceding sentences, the lubricant composition contains about 0.05% by weight to about 0.3% by weight of total phosphorus.

[0363] According to any of the preceding sentences, the lubricant composition contains about 0.08% by weight to about 0.2% by weight of total phosphorus.

[0364] According to any of the preceding sentences, the lubricant composition contains about 0.13% by weight to about 0.2% by weight of total phosphorus.

[0365] According to any of the preceding sentences, the lubricant composition contains a total phosphorus level of about 0.1% to about 0.25% by weight.

[0366] According to any of the preceding sentences, the lubricant composition has a 3mm thickness at 100°C as per ASTM D445. 2 / s to 28mm 2 kinematic viscosity / s.

[0367] According to any of the preceding sentences, the lubricant composition has a thickness of 3.5 mm at 100°C according to ASTM D445. 2 / s to 26mm 2 kinematic viscosity / s.

[0368] According to any of the preceding sentences, the lubricant composition has a 4mm thickness at 100°C as per ASTM D445. 2 / s to 24mm 2 kinematic viscosity / s.

[0369] According to any of the preceding sentences, the lubricant composition has a thickness of 4.5 mm at 100°C according to ASTM D445. 2 / s to 22mm 2 kinematic viscosity / s.

[0370] According to any of the preceding sentences, the lubricant composition has a thickness of 3.8 mm at 100°C according to ASTM D445. 2 / s to 5.0mm 2 kinematic viscosity / s.

[0371] According to any of the preceding sentences, the lubricant composition has a thickness of 5.0 mm at 100°C according to ASTM D445. 2 / s to 6.5mm 2 kinematic viscosity / s.

[0372] According to any of the preceding sentences, the lubricant composition has a thickness of 6.6 mm at 100°C according to ASTM D445. 2 / s to 8.5mm 2 kinematic viscosity / s.

[0373] According to any of the preceding sentences, the lubricant composition has a thickness of 8.5 mm at 100°C according to ASTM D445. 2 / s to 11.0mm 2 kinematic viscosity / s.

[0374] According to any of the preceding sentences, the lubricant composition has a thickness of 5.5 mm at 100°C according to ASTM D445. 2 / s to 7mm 2 kinematic viscosity / s.

[0375] The lubricant composition according to any of the preceding sentences has a 5mm thickness at 100°C according to ASTM D445. 2 / s to 6.5mm 2 kinematic viscosity / s.

[0376] The lubricant composition according to any of the preceding sentences has a 5mm thickness at 100°C according to ASTM D445.2 / s to 6mm 2 kinematic viscosity / s.

[0377] According to any of the preceding sentences, the lubricant composition has a thickness of 3.8 mm at 100°C according to ASTM D445. 2 / s to 6.5mm 2 kinematic viscosity / s.

[0378] According to any of the preceding sentences, the lubricant composition has a thickness of 6.5 mm at 100°C according to ASTM D445. 2 / s to 11.0mm 2 kinematic viscosity / s.

[0379] According to any of the preceding sentences, the lubricant composition has a thickness of 11.0 mm at 100°C as per ASTM D445. 2 / s to 13.5mm 2 kinematic viscosity / s.

[0380] According to any of the preceding sentences, the lubricant composition has a thickness of 13.5 mm at 100°C according to ASTM D445. 2 / s to 18.5mm 2 kinematic viscosity / s.

[0381] The lubricant composition according to any of the preceding sentences has a thickness of 18.5 mm at 100°C according to ASTM D445. 2 / s to 28mm 2 kinematic viscosity / s.

[0382] A method for increasing the traction coefficient of a lubricated gear, the method comprising supplying the gear with a lubricant composition according to any of the preceding sentences.

[0383] According to the method described in any of the preceding sentences, the lubricant composition is provided at a temperature below 100°C.

[0384] A method for lubricating a gear, the method being carried out by supplying the gear with a lubricant composition according to any one of paragraphs

[0115] to

[0353] .

[0385] According to the method described in any of the preceding sentences, the gear includes a bearing.

[0386] According to the method described in paragraph

[0365] or

[0357] , the gear includes a hypoid gear.

[0387] The method according to any of paragraphs

[0365] to

[0358] , wherein the gear includes an industrial gear.

[0388] Monoesters are used in lubricant compositions for gears to improve the traction coefficient.

[0389] According to the use described in the preceding sentence, the use is carried out at a temperature below 100°C.

[0390] Combinations of olefin polymers, grafted olefin polymers, monoesters, and diesters are used in lubricant compositions for gears to improve thermal stability and traction coefficient.

Claims

1. A lubricant composition comprising: a) Hydrocarbon-based lubricating oils. b) A viscosity modifier composition comprising, in a proportion of less than 90 / 10 to greater than or equal to 40 / 60% by weight of polymer i) / ii): i) at least one olefin copolymer having a number-average molecular weight ("Mn") of 1,000 to 10,000 as measured by gel permeation chromatography ("GPC") with a polystyrene standard, wherein the olefin copolymer includes an ethylene / propylene copolymer. ii) at least one grafted olefin copolymer having an Mn of 1,000 to 10,000 as measured by GPC using the polystyrene standard, the grafted olefin copolymer comprising a carboxylic acid functional group or its reactive equivalent grafted onto the polymer backbone, wherein the carboxylic acid functional group or its reactive equivalent is further substituted with an amine, wherein the polymer backbone comprises an ethylene / propylene copolymer.

2. The lubricant composition according to claim 1, wherein the copolymer of b)i) comprises 15 mol% to 80 mol% ethylene and 20 mol% to 85 mol% propylene or a higher monoolefin.

3. The lubricant composition according to claim 1, wherein the copolymer of b)i) comprises 30 mol% to 80 mol% ethylene and 20 mol% to 70 mol% of at least one C3 to C4 group. 10 α-monoolefin.

4. The lubricant composition according to claim 1, wherein the copolymer of b)i) comprises 40 mol% to 80 mol% ethylene and 20 mol% to 60 mol% propylene.

5. The lubricant composition according to claim 1, wherein the copolymer of b)i) comprises 15 mol% to 80 mol% propylene and 20 mol% to 85 mol% ethylene or a higher monoolefin.

6. The lubricant composition according to any one of claims 1-5, wherein the grafted olefin copolymer of b)ii) comprises an ethylene / propylene copolymer backbone having grafted succinic anhydride functional groups.

7. The lubricant composition of claim 6, wherein the succinic anhydride functional group is replaced by a primary amine.

8. The lubricant composition according to claim 6, wherein the succinic anhydride functional group is replaced by an aliphatic amine, a heterocyclic amine, an aromatic amine, or a mixture thereof.

9. The lubricant composition according to any one of claims 1-5 and 7-8, wherein the grafted olefin polymer is reacted with aminopropylmorpholine.

10. The lubricant composition of claim 6, wherein the grafted olefin polymer is reacted with aminopropylmorpholine.

11. The lubricant composition according to any one of claims 1-5 and 7-8, wherein the grafted olefin polymer is reacted with dimethylaminopropylamine.

12. The lubricant composition of claim 10, wherein the grafted olefin polymer is reacted with dimethylaminopropylamine.

13. The lubricant composition according to any one of claims 1-5 and 7-8, wherein the lubricant composition comprises c) a carboxylic acid ester.

14. The lubricant composition according to claim 12, wherein the lubricant composition comprises c) a carboxylic acid ester.

15. The lubricant composition according to claim 13, wherein the carboxylic acid ester comprises c)i) a monocarboxylic acid ester, c)ii) a dicarboxylic acid diester and c)iii) a mixture thereof.

16. The lubricant composition of claim 15, wherein the lubricant composition comprises 1% to 15% by weight of a monocarboxylic acid ester.

17. The lubricant composition according to claim 15, wherein the carboxylic acid monoester of c)i) comprises C8 to C96. 18 Straight-chain or branched carboxylic acids.

18. The lubricant composition according to claim 15, wherein the carboxylic acid monoester of c)i) comprises C4 to C5. 14 Straight-chain or branched carboxylic acids.

19. The lubricant composition according to claim 15, wherein the carboxylic acid monoester of c)i) comprises C8 to C96. 14 Straight-chain or branched carboxylic acids.

20. The lubricant composition according to claim 15, wherein the carboxylic acid monoester of c)i) comprises C 10 To C 14 Straight-chain or branched carboxylic acids.

21. The lubricant composition according to claim 15, wherein the carboxylic acid monoester of c)i) comprises C 11 To C 13 Straight-chain or branched carboxylic acids.

22. The lubricant composition of claim 15, wherein the carboxylic acid monoester comprises C6 or C8 to C6. 12 Straight-chain or branched alkoxy groups.

23. The lubricant composition of claim 15, wherein the carboxylic acid monoester comprises laurate monoester, tallow monoester, oleate monoester, palmitate monoester, and combinations thereof.

24. The lubricant composition of claim 15, wherein the carboxylic acid monoester comprises a 2-ethylhexylalkoxy group.

25. The lubricant composition of claim 15, wherein the carboxylic acid monoester comprises at least one of the following: 2-ethylhexyl resinate, 2-ethylhexyl oleate, 2-ethylhexyl laurate, 2-ethylhexyl palmitate, and combinations thereof.

26. The lubricant composition of claim 15, wherein the lubricant composition comprises 1% to 15% by weight of a dicarboxylic acid diester.

27. The lubricant composition of claim 15, wherein the dicarboxylic acid diester comprises C3 to C4. 12 Straight-chain or branched dicarboxylic acids.

28. The lubricant composition of claim 15, wherein the dicarboxylic acid diester comprises C4 to C6. 11 Straight-chain or branched dicarboxylic acids.

29. The lubricant composition of claim 15, wherein the dicarboxylic acid diester comprises C5 to C6. 10 Straight-chain or branched dicarboxylic acids.

30. The lubricant composition of claim 15, wherein the dicarboxylic acid diester comprises C6 to C9 straight-chain or branched dicarboxylic acids.

31. The lubricant of claim 15, wherein the dicarboxylic acid diester comprises adipate diester, azelaic acid diester, and combinations thereof.

32. The lubricant composition of claim 15, wherein the dicarboxylic acid diester comprises at least one of the following: di-2-ethylhexyl azelate, diisotridecyl adipate, diisooctyl adipate, and combinations thereof.

33. The lubricant composition of claim 15, wherein the dicarboxylic acid diester comprises at least one of the following: azelaic acid di-C 6-10 Ester, adipic acid di-C 6-10 Esters and their combinations.

34. The lubricant composition of claim 15, wherein the dicarboxylic acid diester comprises at least one of the following: di-C8 azelaic acid ester, di-C8 adipic acid ester, and combinations thereof.

35. A method for lubricating a transmission system, the method being carried out by supplying the transmission system with a lubricant composition according to any one of claims 1 to 34.

36. A method for lubricating a gear, the method being carried out by supplying the gear with a lubricant composition according to any one of claims 1 to 34.

37. The method of claim 36, wherein the gear comprises a bearing.

38. The method of claim 36, wherein the gear comprises a hypoid gear.

39. The method of claim 36, wherein the gear comprises an industrial gear.

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