Lubricants containing thiadiazole derivatives

Abstract

To provide additives for drive lines with low sulfur content and low phosphite content and lubricants thereof.SOLUTION: The lubricant compositions contain base oils, wherein principal parts of the base oils are selected from API group I, II, III, IV, V, and blends thereof, and, based on the total weight of the lubricant compositions, a total of 0.001-0.536 wt.% of specified monohydrocarbyl-substituted dimercaptothiadiazole derivative and less than 0.1 wt.% of phosphites are contained. The lubricant compositions used for lubrication of drive lines, transmissions including manual or automatic transmissions, gears, automatic gears, or shafts, and enhancement of and FZG testing performances is disclosed herein. Moreover, a method for preparation of the lubricant compositions is disclosed herein.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This disclosure relates to novel additive compositions and lubricant compositions, including lubricant compositions for use in drivelines, transmissions, gears, or axles. Furthermore, this disclosure describes the use of additive compositions and lubricant compositions to enhance FZG test performance. [Background technology]

[0002] Different applications of lubricants require different properties and performance characteristics, often leading to subtle adjustments in their composition. The fact that some components can chemically interact with each other and impair the performance of the lubricant exacerbates the difficulties, creating further challenges such as setting unprecedentedly strict maximum levels of environmental and legal requirements, such as sulfur, phosphorus, and other performance standards.

[0003] Therefore, on the one hand, it is generally desirable to reduce the levels of sulfur and phosphorus, especially phosphates, in lubricants exposed to high pressure and heavy loads. On the other hand, wear resistance and extreme pressure performance are often related to the presence of sulfur and phosphate additives.

[0004] Lubricating compositions for driveline applications, particularly in automotive drivelines such as transmissions (manual and automatic), clutches, gearboxes, axles, or differentials, must provide wear resistance, extreme pressure resistance, and load-bearing capacity. Among wear resistance properties, scuff resistance is particularly desirable. Scuffing can be measured and objectively assessed using the CEC L-84-02 industrial standard test to evaluate gear scuffing. This test measures the scuff resistance properties of oils in reduction gears, hypoid gears, and automatic transmission gears. The test uses a 10mm wide FZG A10 type pinion and a 20mm wide wheel. The motor is rotated at a wheel rotation speed of 2880 rpm and a circumferential speed of 16.6 m / s for a total operating time of 7 minutes and 30 seconds at an initial lubricating oil temperature of 90°C. Reported results include failures in the load stage. Typically, better results are obtained for lubricants that report failures in higher load stages.

[0005] Dimercaptothiadiazole (DMTD, formula (I) with R=H) is a known additive in lubricating compositions that provides wear resistance. However, DMTD has the disadvantage of low solubility in lubricating oils and requires pre-mixing with a dispersant before being added to the additive package or lubricating composition. Furthermore, DMTD tends to detach from the solution.

[0006] Another class of known additives with superior oil solubility are 2,5-bis(hydrocarbyldithio)-1,3,4-thiadiazole and 2-hydrocarbyldithio-5-mercapto-1,3,4-thiadiazole. These additives suffer from instability, high reactivity, and interactions with other components, leading to performance degradation. Therefore, automatic transmission fluids (ATFs) that rely on these additives may experience performance degradation in many areas.

[0007] Various classes of thiadiazole-derived compounds, including the above-mentioned 2,5-bis(hydrocarbyldithio)-1,3,4-thiadiazole and 2-hydrocarbyldithio-5-mercapto-1,3,4-thiadiazole, have been proposed for use as components of composite transmission fluids under US2016 / 0168505A1. However, phosphate is required as an essential component, and the total sulfur level is not disclosed.

[0008] This disclosure provides a driveline lubricant additive or driveline lubricant having a low sulfur content and a low phosphate content. This disclosure also provides enhanced wear resistance, specifically gear scuffing resistance to driveline lubrication compositions with a low total sulfur content and little to no phosphate content. [Overview of the project]

[0009] This disclosure is, a) The main component of the base oil of the lubricating viscosity, wherein the base oil is selected from API groups I, II, III, IV, V, or mixtures thereof. b) Based on the entire lubricating composition, a total of 0.001 to 0.536% by weight of one or more monohydrocarbyl-substituted dimercaptothiadiazole derivatives according to the following formula (I), or tautomers or salts thereof,

[0010] [ka]

[0011] In the formula, R is methyl or C2-C4 alkyl. The total lubricating composition contains one or more monohydrocarbyl-substituted dimercaptothiadiazole derivatives, or tautomers or salts thereof, having a sulfur content of up to 2,500 ppm (by weight), c) The present invention relates to a lubricating composition comprising less than 0.1% by weight of phosphate.

[0012] The use of monohydrocarbyl-substituted dimercaptothiadiazole of formula (I) as disclosed herein results in a more stable lubrication composition and allows for a reduction in total sulfur with equivalent or improved gear scuffing resistance.

[0013] In particular, the scuffing resistance of gears is remarkably improved compared to conventional agents such as dimercaptodiazole (formula (I) with R=H) or 2,5-bis(hydrocarbyl dithio)-1,3,4-thiadiazole and 2-hydrocarbyl dithio-5-mercapto-1,3,4-thiadiazole. Furthermore, using mixtures of 2,5-bis(hydrocarbyl dithio)-1,3,4-thiadiazole and 2-hydrocarbyl dithio-5-mercapto-1,3,4-thiadiazole of formula (I) and monohydrocarbyl-substituted dimercaptothiadiazole according to this disclosure, it is possible to further lower the sulfur restriction and reduce the overall load with optimal wear resistance, including gear scuffing resistance, and there is a remarkable synergistic effect.

[0014] Those skilled in the art will understand that the monohydrocarbyl-substituted dimercaptothiadiazole derivatives of formula (I) according to this disclosure may exist in tautomeristic equilibrium and salt forms when exposed to other additives in a lubricant composition.

[0015] In this disclosure, whenever a monohydrocarbyl-substituted dimercaptothiadiazole derivative is referred to, it means the derivative of formula (I), and the tautomeral form and the salt form are treated as synonyms herein. Thus, for example, 5-hydrocarbyl-1,3,4-thiadiazole-2-thiol, 2-hydrocarbyl-1,3,4-thiadiazole-5-thiol, 2-hydrocarbyl-5-mercapto-1,3,4-thiadiazole, or 5-(hydrocarbylthio)-3,4-thiadiazole-2(3H)-thiol all refer to the same compound.

[0016] In one embodiment, the lubricating composition according to the Disclosure contains less than 0.05% by weight of phosphate, or less than 0.01% by weight of phosphate, or less than 0.001% by weight of phosphate. In another embodiment, the composition is essentially phosphate-free.

[0017] In one embodiment, the lubricating composition according to the Disclosure has a sulfur content of 2,500 ppm (by weight), 2,000 ppm (by weight), or 1,800 ppm (by weight), with a maximum of less than 1,500. In another embodiment, the sulfur content is less than 1,500 ppm (by weight) or a maximum of 1,200. In yet another embodiment, the sulfur content is less than 1,200 ppm (by weight), with a maximum of 1,000 ppm or less than 1,000 ppm (by weight).

[0018] In one embodiment, the lubricating composition contains less than 2,500 ppm (by weight) of sulfur and less than 0.1% by weight of phosphate, or 2,000 ppm (by weight) of sulfur and less than 0.01% by weight of phosphate, or less than 2,000 ppm (by weight) of sulfur and less than 0.001% by weight of phosphate, or less than 1,800 ppm (by weight) of sulfur and less than 0.01% by weight of phosphate, or less than 1,800 ppm (by weight) of sulfur and less than 0.001% by weight of phosphate. The product may contain a combination of low sulfur and low phosphate, such as a phosphate of a certain amount, or less than 1,500 ppm (by weight) of sulfur and less than 0.01% by weight of phosphate, or less than 1,500 ppm (by weight) of sulfur and less than 0.001% by weight of phosphate, or less than 1,000 ppm (by weight) of sulfur and less than 0.01% by weight of phosphate, or less than 1,000 ppm (by weight) of sulfur and less than 0.001% by weight of phosphate.

[0019] In one embodiment of the present disclosure, a monohydrocarbyl-substituted dimercaptothiadiazole derivative(s) according to formula (I) is present in a total of 0.001 to 0.4% by weight, or 0.001 to 0.40% by weight, or 0.005 to 0.400% by weight, or 0.01 to 0.3%, or 0.05 to 0.2% by weight, based on the total lubricating composition.

[0020] As described above, the monohydrocarbyl-substituted dimercaptothiadiazole derivative(s) used in the present disclosure are monoalkyldimercaptothiadiazole derivative(s). In one embodiment, the alkyl group may be methyl, or ethyl, propyl or butyl, or any combination of C1-C4 alkyls. In another embodiment, the alkyl group is methyl.

[0021] Advantageously, the monohydrocarbyl-substituted dimercaptothiadiazole derivative(s) provide 200-1,500 or 400-1,000 ppm of sulfur to the lubricating composition.

[0022] In one embodiment, the lubricating composition of the present disclosure contains a dispersant. In one embodiment, the lubricating composition contains 0.001-10 wt% of the dispersant based on the total lubricating composition. In another embodiment, the dispersant is present in an amount of 0.01-8 wt%. In another embodiment, the dispersant is 0.1-5 wt% in the lubricating composition based on the total weight of the lubricating composition.

[0023] In the present invention, the dispersant can be selected from the group consisting of its ashless dispersant, boronated ashless dispersant, ash-containing dispersant, and dispersant viscosity index improver, and mixtures thereof. In one embodiment, the dispersant is an ashless dispersant selected from the group consisting of succinimide dispersant, polyisobutylene dispersant, and ethylene-propylene copolymer, and mixtures thereof. In another embodiment, the dispersant is a succinimide dispersant.

[0024] As described above, a synergistic effect on gear scuffing resistance is observed when 0.001 to 0.20 wt% of one or more monohydrocarbyl-substituted dimercaptothiadiazole derivatives are combined with 0.01 to 0.40 wt% of mono and / or bishydrocarbylthio-substituted dimercaptothiadiazoles of formula II / IIa. Alternatively, the lubricating composition may include a combination of 0.01 to 0.15 wt% of one or more monohydrocarbyl-substituted dimercaptothiadiazole derivatives and 0.05 to 0.20 wt% of mono and / or bishydrocarbylthio-substituted dimercaptothiadiazoles.

[0025] [ka]

[0026] In the formula, R is independently C5-C 15 It is alkyl.

[0027] The lubricating compositions according to this disclosure may further comprise one or more additives selected from the group consisting of extreme pressure agents, anti-wear agents, friction modifiers, metal deactivators, cleaning agents, viscosity index improvers, antioxidants, corrosion inhibitors, anti-foaming agents, demulsifiers, pour point depressants, seal swelling agents, and mixtures thereof.

[0028] In aspects of this disclosure, the lubricating composition is used to lubricate drivelines, transmissions including manual or automatic transmissions, gears, automatic gears, or axles.

[0029] In another aspect of the disclosure, the lubricating composition is used to enhance FZG test performance.

[0030] Further aspects of the present disclosure relate to the use or method of lubrication comprising, based on the entire lubricating composition, one or more monohydrocarbyl-substituted dimercaptothiadiazole derivatives (or more) of the following formula (I), or tautomers or salts thereof, in a total amount of 0.001 to 0.536% by weight:

[0031] [ka]

[0032] In the formula, R is a methyl or C2-C4 alkyl in the lubricating composition comprising the main portion of the base oil of the lubricating viscosity, the base oil being selected from API groups I, II, III, IV, V, or mixtures thereof, and the entire lubricating composition having a sulfur content of up to 2,500 ppm (by weight) to enhance the gear scuffing resistance of the lubricating composition. It should be understood that this aspect intends all the options and limitations described in relation to the lubricating compositions of the present disclosure, individually or in combination. For example, the present disclosure also relates to the use in any amount of one or more monohydrocarbyl-substituted dimercaptothiadiazole derivatives or tautomers or salts thereof according to formula (I) in the lubricating compositions of the present disclosure to enhance the gear scuffing resistance of the lubricating compositions.

[0033] Further aspects of the present disclosure are methods for preparing a lubricant comprising blending a base oil of lubricating viscosity, wherein the base oil is selected from API groups I, II, III, IV, V, or mixtures thereof, having one or more monohydrocarbyl-substituted dimercaptothiadiazole derivatives or tautomers thereof according to formula (I).

[0034] [ka]

[0035] In the formula, R is methyl or C2-C4 alkyl, and the lubricant has a maximum sulfur content of 2,500 ppm (by weight) and contains less than 0.1% by weight of phosphate, and the lubricating composition comprises the main part of the base oil and, based on the entire lubricating composition, a total of 0.001 to 0.536% by weight of one or more monohydrocarbyl-substituted dimercaptothiadiazole derivatives according to formula (I), or a tautomer thereof.

[0036] The method may involve dissolving the compound according to formula (I) in the base oil in the presence of a dispersant. The viscosity can be adjusted by adding an oil with a final lubricating viscosity. [Modes for carrying out the invention]

[0037] A transmission lubricant is described as providing improved FZG wear resistance properties. The lubricant is particularly suitable for automatic transmissions, such as dual-clutch transmissions with wet clutch friction discs, but is not limited to them. Such results were obtained not by increasing the levels of sulfur and phosphorus, but by discovering compounds that deliver sulfur more effectively to the metal surface. It was not previously expected that such compounds would have such a dramatic effect on the wear properties of FZG within a transmission lubricant. In one embodiment, the lubricant comprises a large amount of base oil or lubricant(s) and a select amount of a thiadiazole derivative of formula I, as described above in the abstract.

[0038] As used herein, the terms “oil composition,” “lubricating composition,” “lubricating oil composition,” “lubricating oil,” “lubricant composition,” “fully formulated lubricant composition,” and “lubricant” are considered synonymous and fully interchangeable terms referring to a finished lubricating product comprising a large amount of base oil or lubricating oil, plus small amounts of selected dispersants and detergents as described herein. The lubricant may also contain optional additives, as further described below.

[0039] As used herein, the terms “hydrocarbyl substituent” or “hydrocarbyl group” are used in their common sense as is well known to those skilled in the art. Specifically, it refers to a group having carbon atoms directly bonded to the rest of the molecule and having primarily hydrocarbon properties. Examples of hydrocarbyl groups include (a) hydrocarbon substituents, i.e., aliphatic (e.g., alkyl or alkenyl), alicyclic (e.g., cycloalkyl, cycloalkenyl) substituents, aromatic, aliphatic and alicyclic substituted aromatic substituents, and cyclic substituents where the ring is completed via another part of the molecule (e.g., two substituents together form an alicyclic part); (b) substituted hydrocarbon substituents, i.e., substituents containing non-hydrocarbon groups that do not primarily alter the hydrocarbon substituent in the context of this disclosure (e.g., halo (especially chloro and fluoro), hydroxy, alkoxy, mercapto, alkylmercapto, nitro, nitroso, amino, alkylamino, and sulfoxy); and (c) heterosubstituted substituents, i.e., substituents that, in the context of this disclosure, have primarily hydrocarbon properties but contain non-carbon groups in a ring or chain otherwise composed of carbon atoms. Heteroatoms include sulfur, oxygen, and nitrogen, and may also include substituents such as pyridyl, furyl, thienyl, and imidazolyl. Generally, there are two or fewer non-hydrocarbon substituents for every 10 carbon atoms in the hydrocarbyl group, for example, one or fewer, and typically, there are no non-hydrocarbon substituents on the hydrocarbyl group.

[0040] base oil or lubricating oil As used herein, the terms “base oil” or “lubricating oil” generally refer to oils classified by the American Petroleum Institute (API) category groups, Groups I through V, as well as animal oils, vegetable oils (e.g., castor oil and lard), petroleum, mineral oils, synthetic oils, and oils derived from coal or shale. The API classifies these different base stock types as follows:

[0041] [Table A]

[0042] Groups I, II, and III are mineral oil processing raw materials. Hydrogenated base stocks and catalytically dewaxed base stocks generally fall into Group II and Group III categories due to their low sulfur and aromatic compound content. Group IV base oils contain true synthetic molecular species produced by the polymerization of olefinic unsaturated hydrocarbons and are substantially free of sulfur and aromatic compounds. Many Group V base oils are also true synthetic products and may include diesters, polyol esters, polyalkylene glycols, alkylated aromatics, polyphosphate esters, polyvinyl ethers, and / or polyphenyl ethers, but can also be naturally occurring oils such as vegetable oils. Although Group III base oils are derived from mineral oils, it should be noted that the harsh processing these fluids undergo makes their physical properties very similar to some true synthetics such as PAOs. Therefore, oils derived from Group III base oils are sometimes referred to as synthetic fluids in the industry.

[0043] The base oils used in the disclosed lubricating oil compositions may be mineral oils, animal oils, vegetable oils, synthetic oils, or mixtures thereof. Suitable oils may be derived from hydrocracking, hydrogenation, hydrofinishing, unrefined, refined, and re-refined oils, as well as mixtures thereof.

[0044] Unrefined oils are derived from natural oils, mineral oils, or synthetic sources that undergo little to no further refining. Refined oils are similar to unrefined oils, except that they are processed through one or more refining steps that may result in improvements to one or more properties. Examples of preferred refining techniques include solvent extraction, secondary distillation, acid or base extraction, filtration, and osmosis. Oils refined to edible quality may or may not be useful. Edible oils are also called white oils. In some embodiments, lubricant compositions do not contain edible oils or white oils.

[0045] Refined oils are also known as recycled oils or reprocessed oils. These oils are obtained in the same way as refined oils using the same or similar processing methods. Often, these oils are further processed by techniques that target the removal of spent additives and oil degradation products.

[0046] Mineral oils may include oils obtained by drilling, or oils obtained from plants and animals, or any mixture thereof. For example, such oils may include, but are not limited to, castor oil, lard, olive oil, peanut oil, corn oil, soybean oil, and linseed oil, as well as mineral lubricants such as liquid petroleum, paraffinic, naphthenic, or paraffin-naphthenic solvent-treated or acid-treated mineral lubricants. If necessary, such oils may be partially or completely hydrogenated. Oils derived from coal or shale may also be useful.

[0047] Useful synthetic lubricants include hydrocarbon oils such as polymerized, oligomerized, or copolymerized olefins (e.g., polybutylene, polypropylene, propylene isobutylene copolymer); trimers or oligomers of poly(1-hexene), poly(1-octene), 1-decene, e.g., poly(1-decene), materials often referred to as α-olefins, and mixtures thereof; alkylbenzenes (e.g., dodecylbenzene, tetradecylbenzene, dinonylbenzene, di-(2-ethylhexyl)-benzene); polyphenyls (e.g., biphenyl, terphenyl, alkylated polyphenyls); diphenylalkanes, alkylated diphenylalkanes, alkylated diphenyl ethers, and alkylated sulfurized diphenyls, as well as their derivatives, analogs, homologs, or mixtures thereof. Polyalphaolefins are typically hydrogenated substances.

[0048] Other synthetic lubricants include polyol esters, diesters, liquid esters of phosphorus-containing acids (e.g., tricresyl phosphate, trioctyl phosphate, and diethyl esters of decanephosphonic acid), or polymeric tetrahydrofurans. Synthetic oils may be produced by the Fischer-Tropsch reaction and are typically hydrogenated isomerized Fischer-Tropsch hydrocarbons or waxes. In one embodiment, the oil can be prepared by the Fischer-Tropsch gas liquefaction synthesis procedure, as well as by other gas liquefaction oils.

[0049] The amount of lubricating viscosity oil present may be the remainder after subtracting the total amount of performance additives, including viscosity index improvers and / or pour point depressants and / or other top-treat additives, from 100% by weight. For example, the amount of lubricating viscosity oil that may be present in the finished fluid may be a majority of about 50% by weight, about 60% by weight, about 70% by weight, about 80% by weight, about 85% by weight, or about 90% by weight.

[0050] The lubricant may contain other optional additives as required for the specific application, provided that the optional components do not affect the fundamental characteristics of the dispersants and cleaning agents described above. Several common optional additives are described herein.

[0051] Optional additive components In addition to the base oils and thiadizol derivatives of formula I described herein, the automatic transmission lubrication compositions herein may also include other additives that perform one or more functions required of the lubricating fluid. Furthermore, one or more of the above-mentioned additives may be multifunctional and may provide functions other than those described herein, or functions other than those described herein.

[0052] For example, the compositions of this specification may contain at least one component selected from the group consisting of friction modifiers, air elimination additives, antioxidants, corrosion inhibitors, anti-foaming agents, seal swelling agents, viscosity index improvers, rust inhibitors, extreme pressure additives, and combinations thereof. Other performance additives, in addition to those specified above, may also include one or more of metal deactivators, ashless TBN boosters, deemulsifiers, emulsifiers, pour point depressants, and mixtures thereof. Typically, a complete lubricating oil will contain one or more of these performance additives. Some examples of common optional additive components are listed below.

[0053] Dispersant Lubricant compositions may contain one or more selective dispersants or mixtures thereof. Dispersants are often known as ashless dispersants because they do not contain ash-forming metals before being mixed into the lubricant composition and typically do not produce any ash when added to the lubricant. Ashless dispersants are characterized by polar groups bonded to hydrocarbon chains with relatively high molecular weights. Typical ashless dispersants include N-substituted long-chain alkenylsuccinimides. N-substituted long-chain alkenylsuccinimides contain polyisobutylene (PIB) substituents, where the number-average molecular weight of the polyisobutylene substituents ranges from about 800 to about 2500 when measured by gel permeation chromatography (GPC) using polystyrene (number-average molecular weight 180 to about 18,000 as a calibration standard). PIB substituents used in dispersants also have a viscosity of about 2100 to about 2700 cSt at 100°C when measured using ASTM D445. Succinimide dispersants and their preparations are disclosed, for example, in U.S. Patent No. 7,897,696 and U.S. Patent No. 4,234,435, which are incorporated herein by reference. Succinimide dispersants are typically imides formed from polyamines, typically poly(ethyleneamines). The dispersant may comprise two succinimide moieties linked by a polyamine. The polyamine may be tetraethylenepentaamine (TEPA), triethylenetetraamine (TETA), pentaethylenehexaamine (PEHA), other high-nitrogen ethylenediamine species, and / or mixtures thereof. The polyamine may be a mixture of linear, branched, and cyclic amines. PIB substituents may be linked to each succinimide moiety.

[0054] In some embodiments, the lubricant composition comprises at least one polyisobutylene succinimide dispersant derived from polyisobutylene having a number average molecular weight in the range of about 350 to about 5000, or about 500 to about 3000, as measured by the GPC method described above. The polyisobutylene succinimide may be used alone or in combination with other dispersants.

[0055] In some embodiments, polyisobutylene (PIB), if present, may have a terminal double bond content of more than 50 mol%, more than 60 mol%, more than 70 mol%, more than 80 mol%, or more than 90 mol%. Such PIBs are also referred to as highly reactive PIBs ("HR-PIBs"). HR-PIBs having a number-average molecular weight in the range of about 800 to about 5000 are suitable for use in embodiments of this disclosure. Conventional non-highly reactive PIBs typically have a terminal double bond content of less than 50 mol%, less than 40 mol%, less than 30 mol%, less than 20 mol%, or less than 10 mol%.

[0056] HR-PIB having a number-average molecular weight in the range of approximately 900 to approximately 3000, as measured by the GPC method described above, may be preferred. Such HR-PIBs are commercially available or can be synthesized by polymerization of isobutene in the presence of a non-chlorinating catalyst such as boron trifluoride, as described in U.S. Patents 4,152,499 and 5,739,355. When used in the aforementioned thermal ene reaction, HR-PIBs may result in a higher conversion rate and less precipitate formation in the reaction due to their increased reactivity.

[0057] In embodiments, the lubricant composition comprises at least one dispersant derived from polyisobutylene succinic anhydride. In one embodiment, the dispersant may be derived from polyalphaolefin (PAO) succinic anhydride. In one embodiment, the dispersant may be derived from an olefin maleic anhydride copolymer. For example, the dispersant may be described as polyPIBSA. In one embodiment, the dispersant may be derived from an anhydride grafted onto an ethylene-propylene copolymer.

[0058] One suitable type of dispersant may be a Mannich base. Mannich bases are materials formed by the condensation of alkyl-substituted phenols, polyalkylene polyamines, and aldehydes (such as formaldehyde) with higher molecular weights. Mannich bases are described in detail by U.S. Patent No. 3,634,515.

[0059] Suitable types of dispersants may be high molecular weight esters or semi-ester amides.

[0060] Dispersants can also be post-treated by conventional methods involving reaction with any of the various agents. These agents include boron, urea, thiourea, dimercaptothiadiazole, carbon disulfide, aldehydes, ketones, carboxylic acids, hydrocarbon-substituted succinic anhydride, maleic anhydride, nitriles, epoxides, carbonates, cyclic carbonates, hindered phenol esters, and phosphorus compounds. Several preferred post-treatment methods and post-treatment products are described in U.S. Patents 7,645,726, 7,214,649, and 8,048,831.

[0061] Suitable boron compounds useful for forming the dispersants of this specification include any boron compound or mixture of boron compounds that can introduce a boron-containing species into the ashless dispersant. Any organic or inorganic boron compound capable of undergoing such a reaction can be used. Thus, HBF4 boric acid (e.g., alkyl-B(OH)2, or aryl-B(OH)2), such as boron oxide, boron oxide hydrate, boron trifluoride, boron tribromide, boron trichloride, boric acid (i.e., H3BO3), tetraboric acid (i.e., H2B5O7), metaboric acid (i.e., HBO2), ammonium salts of such boric acid, and esters of such boric acid can be used. The use of complexes of boron trihalides with ethers, organic acids, inorganic acids, or hydrocarbons is a convenient means of introducing boron reactants into the reaction mixture. Such complexes are known and are exemplified by boron trifluoride-diethyl ether, boron trifluoride-phenol, boron trifluoride-phosphate, boron trichloride-chloroacetic acid, boron tribromide-dioxane, and boron trifluoride-methyl ethyl ether.

[0062] Suitable phosphorus compounds for forming the dispersants of this specification include phosphorus compounds or mixtures of phosphorus compounds that can introduce phosphorus-containing species into the ashless dispersant. Therefore, any organic or inorganic phosphorus compound capable of undergoing such a reaction can be used. Accordingly, such inorganic phosphorus compounds can be used as inorganic phosphoric acid and inorganic phosphorus oxides, including its hydrate. Typical organophosphorus compounds include complete and partial esters of phosphoric acid, such as mono-, di-, and triesters of phosphoric acid, thiophosphate, dithiophosphate, trithiophosphate, and tetrathiophosphate; mono-, di-, and triesters of phosphorous acid, thiophosphate, dithiophosphate, and trithiophosphate; trihydrocarbylphosphine oxides, trihydrocarbylphosphine sulfides, mono- and dihydrocarbyl phosphonates (RPO(OR´)(OR´´), where R and R´ are hydrocarbyl, and R´´ is a hydrogen atom or a hydrocarbyl group); and their mono-, di-, and trithio analogs; mono- and dihydrocarbyl phosphonites (RP(OR´)(OR´´), where R and R´ are hydrocarbyl, and R´´ is a hydrogen atom or a hydrocarbyl group); and their mono- and dithio analogs. Therefore, such compounds include, for example, phosphorous acid (H3PO3, sometimes represented as H2(HPO3), and sometimes called ortho-phosphorous acid or phosphonic acid), phosphoric acid (H3PO4, sometimes called ortho-phosphoric acid), subphosphoric acid (H4P2O6), metaphosphoric acid (HPO3), pyrophosphoric acid (H4P2O7), subphosphorous acid (H3PO2, sometimes called phosphinic acid), pyrosulfite (H4P2O5, sometimes called pyrophosphonic acid), phosphinic acid (H3PO), and tripolyphosphate (H5P3O 10 ), tetrapolyphosphate (H5P4O 13 It can be used as phosphorus trioxide, phosphorus tetraoxide, phosphorus pentoxide, etc. Phosphorotetrathioic acid (H3PS4), phosphoromonothioic acid (H3PO3S), phosphorodioic acid (H3PO2S2), phosphorotrithioic acid (H3POS3), phosphorus sesquisulfide, phosphorus heptasulfide, and phosphorus pentasulfide (P2S5, P4S10 Partial or whole sulfur analogs such as (sometimes referred to as) can also be used to form dispersants for the present disclosure. Inorganic phosphorus halogens such as PCl3, PBr3, POCl3, and PSCl3 can also be used.

[0063] Similarly, such organophosphorus compounds include mono-, di-, and triesters of phosphoric acid (e.g., trihydrocarbyl phosphate, dihydrocarbyl monoacid, monohydrocarbyl phosphate, and mixtures thereof), mono-, di-, and triesters of phosphorous acid (e.g., trihydrocarbyl phosphite, dihydrocarbyl hydrogen phosphite, hydrocarbyl diacid, and mixtures thereof), esters of phosphonic acids (both "primary," RP(O)(OR)2 and "secondary," R2P(O)(OR)), esters of phosphinic acids, phosphonyl halides ( For example, these can be used as RP(O)Cl2 and R2P(O)Cl), halophosphates (e.g., (RO)PCl2 and (RO)2PCl), halophosphates (e.g., ROP(O)Cl2 and (RO)2P(O)Cl), tertiary pyrophosphates (e.g., (RO)2P(O)-OP(O)(OR)2), and all or partial sulfur analogs of any of the aforementioned organophosphorus compounds, with each hydrocarbyl group containing up to about 100 carbon atoms, or up to about 50 carbon atoms, or up to about 24 carbon atoms, or up to about 12 carbon atoms. Halide halophosphines (e.g., tetrahalogenated hydrocarbyl phosphorus, trihalogenated dihydrocarbyl phosphorus, and dihalogenated trihydrocarbyl phosphorus) and halophosphines (monohalophosphines and dihalophosphines) are also available.

[0064] The lubricants of this specification may include a mixture of one or more of the above boronating and phosphorylated dispersants in combination with non-boronating and non-phosphorylating dispersants.

[0065] In one embodiment, the lubricating oil composition may contain at least one boro-dispersant, where the dispersant is a reaction product of an olefin copolymer, or a reaction product of an olefin copolymer having succinic anhydride and at least one polyamine. The ratio of PIBSA to polyamine may be 1:1 to 10:1, or 1:1 to 5:1, or 4:3 to 3:1, or 4:3 to 2:1. Particularly useful dispersants are the polyisobutenyl group of PIBSA having a number-average molecular weight (Mn) in the range of about 500 to 5000 when measured by the GPC method described above, and the general formula H2N(CH2) m -[NH(CH2) m ] n- It contains a (B) polyamine having NH2, where m is in the range of 2 to 4 and n is in the range of 1 to 2.

[0066] In addition to the above, the dispersant is post-treated with an aromatic carboxylic acid, aromatic polycarboxylic acid, or aromatic anhydride so that the total carboxylic acid or anhydride group(s) are directly bonded to the aromatic ring. Such carboxyl-containing aromatic compounds may be selected from 1,8-naphthaleneic acid or anhydride and 1,2-naphthalenedicarboxylic acid or anhydride, 2,3-naphthalenedicarboxylic acid or anhydride, naphthalene-1,4-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, phthalic anhydride, pyromellitic anhydride, 1,2,4-benzenetricarboxylic acid anhydride, diphenic acid or anhydride, 2,3-pyridinedicarboxylic acid or anhydride, 3,4-pyridinedicarboxylic acid or anhydride, 1,4,5,8-naphthalenetetracarboxylic acid or anhydride, perylene-3,4,9,10-tetracarboxylic acid anhydride, pyrenedicarboxylic acid or anhydride, etc. The mole ratio of this post-treated component reacted per mole of polyamine may be in the range of about 0.1:1 to about 2:1. The typical molar ratio of this post-treatment component to the polyamine in the reaction mixture may be in the range of about 0.2:1 to about 2:1. Another possible molar ratio of this post-treatment component to the polyamine may be in the range of 0.25:1 to about 1.5:1. This post-treatment component may be reacted with other components at a temperature in the range of about 140°C to about 180°C.

[0067] Alternatively, or in addition to the post-treatment described above, the dispersant may be post-treated with a non-aromatic dicarboxylic acid or an anhydride. The non-aromatic dicarboxylic acid or its anhydride may have a number average molecular weight of less than 500 when measured by the GPC method described above. Suitable carboxylic acids or their anhydrides include, but are not limited to, acetic acid or its anhydride, oxalic acid or its anhydride, malonic acid or its anhydride, succinic acid or its anhydride, alkenyl succinic acid or its anhydride, glutaric acid or its anhydride, adipic acid or its anhydride, pimelic acid or its anhydride, suberic acid or its anhydride, azelaic acid or its anhydride, sebacic acid or its anhydride, maleic acid or its anhydride, fumaric acid or its anhydride, tartaric acid or its anhydride, glycolic acid or its anhydride, 1,2,3,6-tetrahydronaphthalic acid or its anhydride, and the like.

[0068] Non-aromatic carboxylic acids or anhydrides react with polyamines in a molar ratio ranging from about 0.1 to about 2.5 moles per mole of polyamine. Typically, the amount of non-aromatic carboxylic acid or anhydride used is proportional to the number of secondary amino groups in the polyamine. Thus, a dispersant according to embodiments of this disclosure can be provided by reacting about 0.2 to about 2.0 moles of non-aromatic carboxylic acid or anhydride per secondary amino group in component B with other components. Another possible molar ratio of non-aromatic carboxylic acid or anhydride to polyamine may range from 0.25:1 to about 1.5:1 moles per mole of polyamine. Non-aromatic carboxylic acids or anhydrides can react with other components at temperatures ranging from about 140°C to about 180°C.

[0069] The weight percentage of active substances in alkenyl or alkyl succinic anhydride can be measured using chromatographic techniques. This method is described in columns 5 and 6 of U.S. Patent No. 5,334,321. The conversion rate of polyolefins is calculated from the percentage of active substances using the formulas in columns 5 and 6 of U.S. Patent No. 5,334,321.

[0070] A suitable TBN boro dispersant may have a composition of approximately 10 to 65 mg KOH / gram when oil-free, which is equivalent to a TBN composition of approximately 5 to 30 mg KOH / gram when measured on a dispersant sample containing approximately 50% diluted oil.

[0071] Typically, the above dispersants are supplied in the lubricant at a concentration of approximately 4.5 to 25 weight percent, approximately 4.5 to 12 weight percent by other methods, and approximately 4.5 to 7.7 weight percent by yet another method.

[0072] Extreme pressure agent The lubricating oil compositions of this specification may also optionally contain one or more extreme pressure agents. Oil-soluble extreme pressure (EP) agents include sulfur and chlorosulfur-containing EP agents, chlorinated hydrocarbon EP agents, and phosphorus EP agents. Examples of such EP agents include chlorinated waxes; organic sulfides and polysulfides such as dibenzyl disulfide, bis(chlorobenzyl) disulfide, dibutyl tetrasulfide, methyl sulfide esters of oleic acid, alkylphenol sulfides, dipentene sulfides, terpenes sulfides, and Diels-Alder sulfide adducts; phosphorus sulfide hydrocarbons such as reaction products of phosphorus sulfide with turpentine or methyl oleate; phosphorus esters such as dihydrocarbyl phosphate and trihydrocarbyl phosphate, e.g., dibutyl phosphate, diheptyl phosphate, dicyclohexyl phosphate, pentylphenyl phosphate; dipentylphenyl phosphate, tridecyl phosphate, distearyl phosphate, and polypropylene-substituted phenyl phosphates; metal thiocarbamates such as zinc dioctyl dithiocarbamate and barium heptylphenol dioate; amine salts of alkyl and dialkyl phosphates, e.g., amine salts of reaction products of dialkyldithiophosphate and propylene oxide; and mixtures thereof.

[0073] The extreme pressure additive may be present in an amount of, for example, 0 to 3.0% by weight or 0.1 to 2.0% by weight, based on the total weight of the lubricating oil composition.

[0074] Friction modifier The lubricating oil compositions of this specification may also optionally contain one or more friction modifiers. Suitable friction modifiers may include, but are not limited to, metal-containing and metal-free friction modifiers, and may include imidazolines, amides, amines, succinimides, alkoxylated amines, alkoxylated etheramines, amine oxides, amidoamines, nitriles, betaines, quaternary amines, imines, amine salts, aminoguanidines, alkanolamides, phosphonic acids, metal-containing compounds, glycerol esters, sulfurized aliphatic compounds and olefins, sunflower oil and other naturally occurring vegetable or animal oils, dicarboxylic acid esters, esters or partial esters of polyols with one or more aliphatic or aromatic carboxylic acids, and the like.

[0075] Suitable friction modifiers may contain hydrocarbyl groups selected from linear, branched, or aromatic hydrocarbyl groups, or mixtures thereof, and may be saturated or unsaturated. The hydrocarbyl group may consist of carbon and a heteroatom such as hydrogen or sulfur or oxygen. The hydrocarbyl group may be in the range of 12 to 25 carbon atoms. In some embodiments, the friction modifier may be a long-chain fatty acid ester. In other embodiments, the long-chain fatty acid ester may be a monoester, diester, or (tri)glyceride. The friction modifier may be a long-chain fatty amide, a long-chain fatty ester, a long-chain fatty epoxide derivative, or a long-chain imidazoline.

[0076] Other suitable friction modifiers may include organic, ashless (metal-free), and nitrogen-free organic friction modifiers. Such friction modifiers may include esters formed by reacting carboxylic acids and anhydrides with alkanols, and generally contain polar end groups (e.g., carboxyl or hydroxyl) covalently bonded to a lipophilic hydrocarbon chain. An example of an organic ashless nitrogen-free friction modifier is commonly known as glycerol monooleate (GMO), which may contain mono-, di-, and tri-esters of oleic acid. Other suitable friction modifiers are described in U.S. Patent No. 6,723,685.

[0077] Amine-based friction modifiers may include amines or polyamines. Such compounds may have hydrocarbyl groups that are either saturated or unsaturated linear chains, or mixtures thereof, and may contain 12 to 25 carbon atoms. Further examples of suitable friction modifiers include alkoxylated amines and alkoxylated etheramines. Such compounds may have hydrocarbyl groups that are either saturated, unsaturated, or mixtures thereof linear chains. These may contain about 12 to about 25 carbon atoms. Examples include ethoxylated amines and ethoxylated etheramines.

[0078] Amines and amides can be used on their own or as adducts or reaction products with boron compounds such as boron oxide, boron halides, metaborates, boric acid, or mono-, di-, or tri-alkylborates. Other suitable friction modifiers are described in U.S. Patent No. 6,300,291.

[0079] The friction modifier may optionally be present in a range such as 0% to 6% by weight, 0.01% to 4% by weight, or 0.05% to 2% by weight.

[0080] Cleaning agent The lubricant composition also includes one or more selected detergents or mixtures thereof to provide the lubricant composition with specific amounts of metal and soap content. In one method, the detergent is a metal-containing detergent, such as a neutral to overbasic detergent. Suitable detergent substrates include phenates, sulfur-containing phenates, sulfonates, calixalates, salixalates, salicylates, carboxylic acids, phosphoric acids, mono- and / or dithiophosphates, alkylphenols, sulfur-linked alkylphenol compounds, and methylene crosslinked phenols. Suitable detergents and methods for preparing them are described in more detail in numerous patent publications, including U.S. Patent No. 7,732,390 and the references cited therein. In one method, the detergent is a neutral to overbasic sulfonate, phenate, or carboxylate, containing an alkali metal or alkaline earth metal salt. The detergent may be linear or branched, such as a linear or branched sulfonate. Linear detergents contain linear chains without side chains and typically contain carbon atoms bonded to only one or two other carbon atoms. Branched detergents have one or more side chains bonded to the molecular skeleton and may contain carbon atoms bonded to one, two, three, or four other carbon atoms. In one embodiment, a sulfonate detergent may be a linear alkylbenzene sulfonate detergent. In some embodiments, the linear alkyl (or hydrocarbyl) group may be bonded to the benzene ring anywhere along the linear chain of the alkyl group, but is often at the 2nd, 3rd, or 4th position of the linear chain, and in some examples, is mainly at the 2nd position. In other embodiments, the alkyl (or hydrocarbyl) group may be branched, i.e., formed from propylene or a branched olefin such as 1-butene or isobutene. Sulfonate detergents having mixtures of linear and branched alkyl groups may also be used.

[0081] The detergent substrates, though not limited to these, can be based with alkali metals or alkaline earth metals such as calcium, magnesium, potassium, sodium, lithium, barium, or mixtures thereof. In some embodiments, the detergent does not contain barium. Preferred detergents may include alkali or alkaline earth metal salts of petroleum sulfonic acid and long-chain mono- or di-alkylaryl sulfonic acid, where the aryl group is one of benzyl, tolyl, and xylyl.

[0082] Overbasic detergent additives are well known in the art and may be alkaline or alkaline earth metal overbasic detergent additives. Such detergent additives may be prepared by reacting a metal oxide or metal hydroxide with a substrate and carbon dioxide gas. The substrate is typically an acid, such as an aliphatic-substituted sulfonic acid, aliphatic-substituted carboxylic acid, or aliphatic-substituted phenol. Generally, the term “overbasic” refers to metal salts such as metal salts of sulfonates, carboxylates, and phenates in which the amount of metal present exceeds the stoichiometric amount. Such salts may have a conversion level of over 100% (i.e., they may contain more than 100% of the theoretical amount of metal required to convert an acid to its “positive” salt, “neutral” salt). The expression “metallic ratio,” often abbreviated as MR, is used to indicate the ratio of the total stoichiometric equivalents of metal in an overbasic salt to the stoichiometric equivalents of metal in a neutral salt, based on known chemical reactivity and stoichiometry. In normal or neutral salts, the metal ratio is 1, while in hyperbasic salts, the metal ratio (MR) is greater than 1. Such salts are generally referred to as hyperbasic, highly basic, or ultrabasic salts and may be salts of organic sulfur acids, carboxylic acids, or phenols. Detergents may exhibit a total base number (TBN) of about 27 to about 307, and in other methods, about 200 to about 307.

[0083] In the transmission fluid, the detergent provides less than about 455 ppm of metal to the lubricant composition. Higher levels of metal will fail one or more of the friction durability or wear tests described herein. In other methods, the detergent provides from about 0 to about 281 ppm of metal. In still other methods, the detergent provides from about 0 to about 100 ppm of metal to the lubricant composition.

[0084] The detergent also provides a selected level of soap content to the lubricant composition, and the amount of soap provided is balanced with the level of metal, so that increasing the soap content will not give desirable results if the metal is not within the desired range, as will be described in more detail in the examples herein. By one method, the detergent provides a soap content of from about 0.02 to about 0.15 percent, such as sulfonate soap, phenate soap, and / or carboxylate soap, to the final lubricating composition. In other methods, the detergent provides from about 0.02 to about 0.1 percent of soap, and in still other methods, from about 0.02 to about 0.05 percent of soap.

[0085] The soap content generally refers to the amount of neutral organic acid salts and reflects the detergent's ability to purify, or detergency, and its ability to float dirt. The soap content can be determined by the following formula using an exemplary calcium sulfonate detergent represented by (where v, w, x, and y respectively represent the number of sulfonate groups, calcium atoms, carbonate groups, and hydroxyl groups): v Ca w (CO3) x (Oh) y Soap content = Soap content = [(RSO 3 ) 2 Formula weight of Ca × 100 Effective formula weight The effective formula weight is the formula (RSO3) v Ca w (CO3) x (OH) yThis is the sum of the weights of all the atoms constituting it plus the weights of any other lubricant composition. A detailed explanation of how to determine the soap content can be found in the Fuels and Lubricants Handbook, Technology, Properties, Performance, and Testing, George Totten, editor, ASTM International, 2003, the relevant parts of which are incorporated herein by reference.

[0086] The amount of cleaning agent used can range from about 0.08% to about 1% by weight, based on the total weight of the lubricant composition. In some methods, the metal-containing cleaning agent is not borated, so that the boron in the lubricant is provided solely by the dispersant.

[0087] The total amount of detergent that may be present in the lubricating oil composition may be 0% to 2% by weight, or about 0% to about 0.5% by weight, or about 0% to about 0.15% by weight.

[0088] Viscosity index improver The lubricating oil compositions of this specification may also optionally contain one or more viscosity index improvers. Suitable viscosity index improvers include polyolefins, olefin copolymers, ethylene / propylene copolymers, polyisobutene, styrene-isoprene polymers, styrene / maleate copolymers, styrene-butadiene copolymers, styrene-isoprene polymers, alpha-olefin maleic anhydride copolymers, polymethacrylates, polyacrylates, polyalkylstyrenes, hydrated alkenylaryl conjugated diene copolymers, or mixtures thereof. Viscosity index improvers may also include star polymers, and suitable examples are described in U.S. Publication No. 2012 / 0101017A1.

[0089] The lubricating oil compositions herein may also optionally contain one or more dispersant viscosity index improvers in addition to, or in place of, a viscosity index improver. Suitable viscosity index improvers may include functionalized polyolefins, such as ethylene-propylene copolymers functionalized with the reaction product of an acylating agent (e.g., maleic anhydride) and an amine, amine-functionalized polymethacrylates, or esterified maleic anhydride-styrene copolymers reacted with an amine.

[0090] Viscosity index improvers and / or dispersants: The total amount of viscosity index improvers may be 0% to 20% by weight, 0.1% to 15% by weight, 0.25% to 12% by weight, or 0.5% to 10% by weight of the lubricating composition.

[0091] Antioxidant The lubricating oil compositions described herein may also optionally contain one or more antioxidants. Known antioxidant compounds include, for example, phenates, phenate sulfides, sulfurized olefins, phosphosulfur terpenes, sulfurized esters, aromatic amines, alkylated diphenylamines (e.g., nonyldiphenylamine, di-nonyldiphenylamine, octyldiphenylamine, dioctyldiphenylamine), phenyl-alpha-naphthylamines, alkylated phenyl-alpha-naphthylamines, hindered non-aromatic amines, phenols, hindered phenols, oil-soluble molybdenum compounds, polymeric antioxidants, or mixtures thereof. Antioxidant compounds may be used alone or in combination.

[0092] Useful antioxidants may include diarylamines and high molecular weight phenols. In one embodiment, the lubricating oil composition may contain a mixture of diarylamines and high molecular weight phenols, so that each antioxidant may be present in an amount sufficient to provide up to about 5% by weight, based on the final weight of the lubricating oil composition. In one embodiment, the antioxidant may be a mixture of 0.3 to 2% by weight of diarylamine and 0.4 to 2% by weight of high molecular weight phenol, based on the final weight of the lubricating oil composition.

[0093] One or more antioxidants may be present in the lubricating composition in an amount of 0% to 5% by weight, or 0.01% to 5% by weight, or 0.1% to 3% by weight, or 0.8% to 2% by weight.

[0094] Corrosion inhibitor Automatic transmission lubricants may further contain additional corrosion inhibitors (it should be noted that some of the other mentioned components may also have copper corrosion inhibitory properties). Suitable additional inhibitors of copper corrosion include etheramines, polyethoxylated compounds such as ethoxylated amines and ethoxylated alcohols, imidazolines, monoalkyl and dialkylthiadiazoles.

[0095] Thiazoles, triazoles, and thiadiazoles can also be used as lubricants. Examples include benzotriazole, toltriazole, octyltriazole, decyltriazole, dodecyltriazole, 2-mercaptobenzothiazole, 2,5-dimercapto-1,3,4-thiadiazole, 2-mercapto-5-hydrocarbylthio-1,3,4-thiadiazole, and 2-mercapto-5-hydrocarbyldithio-1,3,4-thiadiazole. In one embodiment, the thiadiazole is 1,3,4-thiadiazole. In another embodiment, the thiadiazole is 2-hydrocarbyldithio-5-mercapto-1,3,4-dithiadiazole. Many thiadiazoles are commercially available.

[0096] If present, corrosion inhibitors may be used in an amount sufficient to provide 0% to 5% by weight, 0.01% to 3% by weight, or 0.1% to 2% by weight, based on the final weight of the lubricating oil composition.

[0097] Antifoaming agent / Defoaming agent Defoaming agents / surfactants may also be included in the fluids of this disclosure. Various agents are known for such applications. In one embodiment, the agent is a copolymer of ethyl acrylate and hexylethyl acrylate, such as PC-1244, available from Solutia. In another embodiment, the agent is a silicone fluid, such as 4% DCF. In yet another embodiment, the agent is a mixture of defoaming agents.

[0098] Rust inhibitor Various known rust inhibitors or additives are known to be used in transmission fluids and are suitable for use in the fluids of this disclosure. Rust inhibitors include alkyl polyoxyalkylene ethers such as Mazawet® 77, C-8 acids such as Neofat® 8, oxyalkylamines such as Tomah PA-14, 3-decyloxypropylamine, and polyoxypropylene-polyoxyethylene block copolymers such as Pluronic® L-81.

[0099] Pour point depressant Suitable pour point depressants may include polymethyl methacrylate or a mixture thereof. The pour point depressant may be present in an amount sufficient to provide 0% to 1% by weight, 0.01% to 0.5% by weight, or 0.02% to 0.4% by weight, based on the total weight of the lubricating composition.

[0100] Sealing Swelling Agent The automatic transmission fluids of this disclosure may further comprise seal swelling agents. Seal swelling agents such as esters, adipic acid esters, sebacate acid esters, azelaic acid esters, phthalate esters, sulfones, alcohols, alkylbenzenes, substituted sulfolanes, aromatic compounds, or mineral oils cause swelling of elastomer materials used as seals in engines and automatic transmissions.

[0101] Alcohol-type seal swelling agents are generally low-volatility linear alkyl alcohols such as decyl alcohol, tridecyl alcohol, and tetradecyl alcohol. Examples of alkylbenzenes useful as seal swelling agents include dodecylbenzene, tetradecylbenzene, dinonylbenzene, and di(2-ethylhexyl)benzene. Substituted sulfolanes (e.g., those described in U.S. Patent No. 4,029,588, incorporated herein by reference) are also useful as seal swelling agents in the compositions according to the present invention. Mineral oils useful as seal swelling agents in this disclosure include low-viscosity mineral oils having a high naphthenic or aromatic content. Aromatic seal swelling agents include the commercially available Exxon Aromatic 200 ND seal swelling agent. Examples of commercially available mineral oil seal swelling agents include Exxon® Necton®-37 (FN 1380) and Exxon® Mineral Seal Oil (FN 3200).

[0102] Generally speaking, a suitable lubricant may contain additive components within the range listed in Table 1.

[0103] [Table 1]

[0104] The additives used in formulating the compositions described herein may be blended with the base oil individually or in various partial combinations. However, it may be preferable to mix all the components simultaneously using an additive concentrate (i.e., the additive plus a diluent such as a hydrocarbon solvent).

[0105] A better understanding of this disclosure and its many advantages can be made possible by the following examples. These examples are illustrative and do not limit them in any way in terms of scope or spirit. Those skilled in the art will readily understand that variations of the components, methods, processes, and apparatus described in these examples can be used. Unless otherwise noted, all percentages, ratios, and parts in this disclosure are by weight. [Examples]

[0106] As shown in Table 2, lubricating compositions were prepared according to Examples 1-5 and Comparative Examples 1-3.

[0107] Synthesis Example A was prepared by mixing 266 g of succinimide dispersant with 5.0 g of DMTD and 46 g of PAO-4, and stirring under nitrogen protection at 110°C for 1 hour, then at 130°C for 1 hour, and then at 140°C for 1 hour to obtain a dark brown oil.

[0108] Synthesis Example B was prepared by mixing 221.3 g of succinimide dispersant with 8.27 g of the compound of formula I or a tautomer thereof, where R is methyl (also known as 5-(methylthio)-3,4-thiadiazole-2(3H)-thion), and the mixture was stirred at 80°C for 1.5 hours under nitrogen protection, followed by 1 hour at 105°C to obtain a light brown oil.

[0109] Synthesis Example C was prepared by mixing 428 g of succinimide dispersant with 20.4 g of the compound of formula I or a tautomer thereof, where R is methyl (also known as 5-(methylthio)-3,4-thiadiazole-2(3H)-thion), and the mixture was stirred under nitrogen protection at 90°C for 30 minutes, then at 100°C for 30 minutes, and then at 105°C for 1 hour to obtain a light brown oil.

[0110] All examples and comparative examples were formulated to have a kinematic viscosity equivalent to that at 100°C (KV100).

[0111] [Table 2]

[0112] A comparison of Examples 1 and 2 with Comparative Example 1 demonstrates that the lubricating compositions of the present disclosure perform better than conventional lubricating compositions containing 2,5-bis-(hydrocarbyldithio)-1,3,4-thiadiazole, despite the lower sulfur levels delivered by the agents of the present invention. In Example 2, a specific synergistic effect is observed in the combination of conventional mixtures of 2,5-bis-(hydrocarbyldithio)-1,3,4-thiadiazole and its monohydrocarbyl derivatives with the agents of the present invention, resulting in the same FZG test performance at lower sulfur levels.

[0113] The comparison between Example 3 and Comparative Example 2 shows that phosphates have an adverse effect on FZG test performance.

[0114] A comparison between Comparative Examples 3 and 4 and Example 4 shows that the agent of the present invention performs better than DMTD, and that the FZG test performance is further enhanced in the absence of detergents, particularly salicylate detergents.

[0115] [Table 3]

[0116] As used herein and in the claims, the indefinite articles "a" and "an" should be understood to mean "at least one" unless explicitly stated otherwise.

[0117] As used herein and in the claims, the phrase “and / or” should be understood to mean “either or both” of the elements thus combined, i.e., elements that exist sometimes associatively and otherwise separately. Multiple elements enumerated by “and / or” should be interpreted similarly, i.e., “one or more” of the elements thus combined. Other elements other than those specifically identified by the “and / or” clause may exist, whether or not they relate to the specifically identified elements. Thus, as a non-restrictive example, a reference to “A and / or B” when used with unrestrictive language such as “including” may, in one embodiment, refer to A only (including elements other than B), in another embodiment, refer to B only (including elements other than A), and in yet another embodiment, refer to both A and B (including other elements).

[0118] Where used herein and in the claims, “or” should be understood to have the same meaning as “and / or” as defined above. For example, when separating items in a list, “or” or “and / or” shall be interpreted as inclusive, that is, including not only multiple elements or lists of elements, but also, optionally, at least one additional item not on the list, but two or more. Where used in the claims, only contrastingly clear terms such as “only one of,” “exactly one of,” or “consisting of” refer to including exactly one element from multiple or enumerated elements. Generally, where used herein, the term “or” shall be interpreted as indicating no choice (i.e., “one or the other, but not both”) only when preceded by an exclusive term such as “either,” “one of,” “only one of,” or “exactly one of.” Where used in the claims, “essentially consisting of” shall have its usual meaning where it is used in the field of patent law.

[0119] As used herein and in the claims, the phrase “at least one” relating to a list of one or more elements should be understood to mean at least one element selected from any one or more elements in the list of elements, but not necessarily all of the elements specifically enumerated in the list of elements and at least one of each of those elements, nor exclude any combination of elements in the list of elements. This definition also allows for the optional presence of elements other than those specifically identified in the list of elements to which the phrase “at least one” refers, whether or not they are related to those specifically identified elements. Therefore, as a non-limiting example, “at least one of A and B” (or equivalently, “at least one of A or B” or equivalently, “at least one of A and / or B”) may mean, in one embodiment, at least one optionally comprising two or more A's and not B's (and optionally comprising elements other than B's); in another embodiment, at least one optionally comprising two or more B's and not A's (and optionally comprising elements other than A's); and in yet another embodiment, at least one optionally comprising two or more A's and at least one optionally comprising two or more B's (and optionally comprising other elements).

[0120] Where the term "approximately" is used herein in relation to a number, it should be understood that yet another embodiment of the invention includes that number which is not altered by the presence of the term "approximately." Unless otherwise understood in the context of this disclosure, all numbers herein are altered by the term "approximately."

[0121] Conversely, unless explicitly stated otherwise, in any method claimed herein that includes two or more steps or actions, the order of the steps or actions of the method is not necessarily limited to the order in which the steps or actions of the method are listed, unless indicated by the context of the method.

[0122] In the claims and the above specification, all transitional phrases and similar terms such as “equipment,” “includes,” “carries,” “possesses,” “contains,” “accompanys,” “holds,” and “consist of” should be understood as unrestrictive, meaning they include but are not limiting. Only the transitional phrases “consisting of” and “consisting essentially of” are considered limiting or partially limiting transitional phrases, respectively, as set forth in the U.S. Patent and Trademark Office Patent Examination Procedure, Amendment 7.2015, Section 2111.03.

[0123] While several embodiments of the present invention have been described and illustrated herein, those skilled in the art will readily conceive of various other means and / or structures for performing the function and / or obtaining the results and / or one or more advantages described herein, and each of the variations and / or modifications will be considered within the scope of the present invention. More generally, those skilled in the art will understand that all parameters, dimensions, materials and configurations described herein are illustrative, and that actual parameters, dimensions, materials and / or configurations will depend on the specific application, or that the teachings of the present invention will be used in the application. Those skilled in the art will recognize many equivalents to specific embodiments of the compositions and methods described herein, or can verify them using only routine experiments. Therefore, it should be understood that the embodiments described herein are presented only as examples, and within the scope of the appended claims and their equivalents, this disclosure can be implemented in ways other than those specifically described and claimed. This disclosure covers each individual feature, system, article, material, kit and / or method described herein. Furthermore, any combination of two or more such features, systems, articles, materials, kits, and / or methods is included within the scope of this disclosure, provided that they are not inconsistent with each other.

Claims

1. A lubricating composition, The main part of the lubricating viscosity base oil, wherein the base oil is selected from the group consisting of API groups I, II, III, IV, V and mixtures thereof, Based on the entire lubricating composition, a total of 0.08 to 0.16% by weight of a monohydrocarbyl-substituted dimercaptothiadiazole derivative according to the following formula (I), or a tautomer or salt thereof, 【Chemistry 1】 In the formula, R is methyl, and is a monohydrocarbyl-substituted dimercaptothiadiazole derivative, or a tautomer or salt thereof. A dispersant is included, The lubricating composition further contains less than 0.1% by weight of phosphate or does not contain phosphate. The lubricating composition has a total sulfur content of 480 to 940 ppm (by weight).

2. The lubricating composition according to claim 1, wherein the monohydrocarbyl-substituted dimercaptothiadiazole derivative according to formula (I) is present in a total amount of 0.08 to 0.15% by weight based on the entire lubricating composition.

3. The lubricating composition according to claim 1, further comprising one or more additives selected from the group consisting of extreme pressure agents, anti-wear agents, friction modifiers, metal deactivators, cleaning agents, viscosity index improvers, antioxidants, corrosion inhibitors, anti-foaming agents, demulsifiers, pour point depressants, seal swelling agents, and mixtures thereof.

4. The lubricating composition according to claim 1, comprising less than 0.05% by weight of phosphate.

5. The lubricating composition according to claim 1, wherein the dispersant is present in the lubricating composition in an amount of 0.001 to 10% by weight based on the total lubricating composition, or the dispersant is selected from the group consisting of ashless dispersants, boronated ashless dispersants, ash-containing dispersants, and dispersant viscosity index improvers, and combinations thereof.

6. The lubricating composition according to claim 1, wherein the lubricating composition does not contain phosphate.

7. A method for lubricating a driveline, a transmission including a manual or automatic transmission, gears, automatic gears, or axle, comprising lubricating the driveline, the transmission, the gears, automatic gears, or axle with a lubricating composition, wherein the lubricating composition is The main part of the lubricating viscosity base oil, wherein the base oil is selected from the group consisting of API groups I, II, III, IV, V and mixtures thereof, Based on the entire lubricating composition, a total of 0.08 to 0.16% by weight of a monohydrocarbyl-substituted dimercaptothiadiazole derivative according to the following formula (I), or a tautomer or salt thereof, 【Chemistry 2】 In the formula, R is methyl, and is a monohydrocarbyl-substituted dimercaptothiadiazole derivative, or a tautomer or salt thereof. A dispersant is included, The lubricating composition further contains less than 0.1% by weight of phosphate or does not contain phosphate. A method wherein the lubricating composition has a total sulfur content of 480 to 940 ppm (by weight).

8. The method according to claim 7, wherein the lubricating composition is for enhancing FZG test performance, or the lubricating composition is for enhancing the gear scuffing resistance of the lubricating composition.

9. The method according to claim 8, wherein the enhanced FZG test performance includes an enhanced FLS score.

10. A method for preparing a lubricating composition, comprising blending a base oil of lubricating viscosity with a monohydrocarbyl-substituted dimercaptothiadiazole derivative according to formula (I) or a tautomer thereof, 【Transformation 3】 In the formula, R is methyl, The base oil is selected from the group consisting of API groups I, II, III, IV, V and mixtures thereof, and the lubricating composition has a total sulfur content of 480 to 940 ppm (by weight) and contains or does not contain 0.1% by weight of phosphate. A method for preparing a lubricating composition comprising 0.08 to 0.16% by weight of the monohydrocarbyl-substituted dimercaptothiadiazole derivative.

11. The method according to claim 10, wherein the monohydrocarbyl-substituted dimercaptothiadiazole derivative according to formula (I) is present in a total amount of 0.08 to 0.15% by weight based on the entire lubricating composition.

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