Lubricant composition

Abstract

The present invention relates to a lubricant composition comprising 5 to 99% by weight of a non-halogenated ionic liquid or a mixture of non-halogenated ionic liquids, 0 to 15% by weight of one or more non-halogenated additives for lubricants, and the remainder of a non-halogenated ion thickener, of which at least 1% by weight of a non-halogenated ion thickener. The present invention also relates to a lubricant formulation based solely on the lubricant composition, and to a method for protective surface treatment of components configured to be exposed to wear.

Description

[Technical Field]

[0001] The present invention relates to lubricant compositions based on ionic liquids. More specifically, the present invention relates to lubricant compositions for use in an ambient temperature range of -100°C to at least 200°C, which function as lubricants on components to reduce friction and wear, extend the operating life of components, and protect components equipped with this lubricant from corrosion. [Background technology]

[0002] The development of novel lubricant compositions is related to meeting new and higher demands for performance characteristics, such as reducing friction and wear over a wide operating temperature range at high loads and high speeds, imparting electrical (ionic) conductivity, and preventing corrosion of mechanical components. The use of ionic liquids (ILs) in lubrication technology has been widely studied in recent years.

[0003] The use of ILs raises some environmental, health, and technical performance concerns for a sustainable society. In particular, most known ionic liquid compositions no longer meet the aforementioned requirements for lubricants due to the presence of halogens. Since IL lubricant compositions have traditionally contained halides (F, Cl, Br, I), IL lubricants are undesirable due to the corrosiveness of such compounds on steel surfaces, toxicity to humans, and the ozone-depleting activity of halogen-containing compounds and their decomposition products.

[0004] Ionic liquids are defined as substances containing cations and anions with a melting point below 100°C. Many ionic liquids have low melting points or glass transition temperatures, allowing them to exist as liquids at room temperature and even down to -70°C, preferably -100°C; these will hereafter be referred to as room-temperature ionic liquids (RTILs). RTILs are attracting particular interest, especially in the field of tribology, for use in high-vacuum measuring instruments and space development equipment, because they can be implemented as neat liquids, such as base oils or additives in lubricants. An important class of lubricants is grease. For example, over 90% of rolling bearings are lubricated with grease [Lugt, PM, 2012, Grease lubrication in rolling bearings. John Wiley & Sons]. Grease consists of a base oil and a thickener [ASTM D217-21a]. Functional additives are usually added to grease to enhance wear and friction reduction properties, oxidation stability, and corrosion resistance. When added to grease, RTILs can impart electrical (ionic) conductivity as an additional property, eliminating electrostatic potential and minimizing the risk of discharge between moving components of electromechanical systems. Certain RTILs for lubrication applications contain tribologically effective elements such as phosphorus, boron, and sulfur, which are known to form friction-reducing and / or wear-preventing protective tribofilms on steel surfaces. RTILs may also contain different organic functional groups, such as alkyl-aromatic, aryl-phosphate, or alkyl-phosphate molecular moieties, which are efficient radical trappers that provide further beneficial antioxidant and corrosion-preventive properties to RTIL-based lubricant compositions. Alkyl-phosphate compounds are also known as efficient flame retardants.

[0005] Ionic liquids have very low vapor pressure, are non-flammable, and are often thermally stable at temperatures above 200°C, or even 300-350°C, and can lubricate metallic and non-metallic surfaces at high temperatures. RTILs containing halogens can decompose to produce substances such as hydrofluoric acid (HF) and POF3, which are hazardous to humans at ppm levels in the air and can even be lethal.

[0006] U.S. Patent No. 8455407B2 discloses a lubricating grease composition based on a halogen-containing ionic liquid. Specifically, the ionic liquid used includes a fluorine-containing RTIL-based lubricant.

[0007] A major problem with many conventional RTIL lubricants is that they can cause corrosion, either by themselves or through their decomposition products. Despite this problem, prior art for ionic lubricating greases has persisted in using halide-containing formulations, likely due to reliance on widely studied and commercially available halide-containing ionic species, as well as the difficulty in developing formulations that achieve the desired physical properties and tribological performance with lesser-known, halogen-free ionic species.

[0008] It would be advantageous to realize a composition that overcomes, or at least mitigates, at least one or more of the drawbacks of the prior art. [Overview of the Initiative]

[0009] The object of the present invention is to provide a lubricant composition that provides corrosion prevention properties and better lubrication than most conventional lubricants.

[0010] This objective is achieved by a lubricant composition comprising the following, according to a first aspect of the present invention: -5 to 99% by weight of non-halogenated ionic liquids or mixtures of non-halogenated ionic liquids. -0 to 15% by weight of one or more conventional non-halogenated additives for lubricants, and - A remainder of a non-halogenated ionic enhancer, with at least 1% by weight of the non-halogenated ionic enhancer.

[0011] By avoiding halogen in the lubricant composition, many problems of conventional ILs, such as corrosivity and adverse effects on other environments, are solved. The present invention is based on the idea that the general adverse effects of conventional ILs are due to the presence of halogen in such ionic liquids. Non-halogenated ionic liquids are themselves conventionally known, but their use is limited, and it has not been known to produce a lubricant containing only non-halogenated components.

[0012] The non-halogenated ionic liquid or mixture of non-halogenated ionic liquids according to the present invention has a general formula C , n , 2n+1 , n , 2n+1 ,

[0013] , 2n+1 , H 2n+1 (where the value of 1 ≤ n ≤ 80) a cation selected from the group consisting of tetraalkylphosphonium, tetraalkylammonium, dialkylpyrrolidinium, dialkylpiperidinium, dialkylimidazolium, trialkylimidazolium having a substituent of an alkyl group, and 2,2'-methylenebis(4,6-di-tert-butylphenyl) phosphate, (mandelate)(oxalate) borate, bis(benzylate) borate, bis(2-ethyl-hexyl) phosphate, bis(mandelate) borate, bis(oxalate) borate, bis(salicylate) borate, bis(malonate) borate, bis(succinate) borate, bis(glutarate) borate, bis(adipate) borate, dodecyl sulfate, (2-ethyl-hexyl) sulfate, bis(R1,R2-glycolate) borate (where R1 = H, -C6H5, -C n H 2n+1 (1 ≤ n ≤ 80), and R1 = H, -C6H5, -C n H 2n+1 (1 ≤ n ≤ 80)) and may contain an ionic liquid having an anion selected from the group consisting of.

[0013] According to a specific embodiment of the present invention, the ionic non-halogenated enhancer can be an ionic substance made from the following: (i) A lithium thickening agent of n-(hydroxy)stearic acid (n-HSA) in which the position of the -OH group is carbon with n = 2, 3, ... 18, preferably n = 12. (ii) A calcium thickening agent of n-HSA in which the position of the -OH group is carbon with n = 2, 3, ... 18, preferably n = 12. (iii) An aluminum thickening agent of n-HSA in which the position of the -OH group is carbon with n = 2, 3, ... 18, preferably n = 12. (iv) A barium thickening agent of n-HSA in which the position of the -OH group is carbon with n = 2, 3, ... 18, preferably n = 12. (v) A thickening agent based on the above (i) to (iv) and containing lithium, calcium, aluminum, and barium complexes with adipic acid as an additive. (vi) A thickening agent based on the above (i) to (iv) and containing lithium, calcium, aluminum, and barium complexes with sebacic acid as an additive. (vii) Ion polyurea (viii) Calcium sulfonate or calcium sulfonate complex (ix) Lithium calcium sarcosyl complex, and as another option (x) The aluminosilicate component of bentonite or montmorillonite or attapulgite mineral

[0014] In an embodiment of the present invention, the non-halogenated ionic thickening agent is composed of, or contains, an anionic aluminosilicate component (mineral nanosheet) of bentonite or montmorillonite or attapulgite mineral with cations of tetraalkylphosphonium, tetraalkylammonium, dialkylpyrrolidinium, dialkylpiperidinium, di-(or tri-)alkylimidazolium having a substituent of an alkyl group of general formula C n H 2n+1 (1 ≤ n ≤ 80).

[0015] Conventional non-halogenated additives for lubricants that may be used include, but are not limited to, organic or inorganic solid lubricants selected from corrosion inhibitors, antioxidants, wear inhibitors, extreme pressure additives, friction reducers, protective agents against metal effects, UV stabilizers, graphite compounds, metal oxides, boron compounds, molybdenum compounds, and phosphates.

[0016] However, the lubricant composition does not need to contain additives.

[0017] This invention relates to a non-halogenated ionic liquid lubricant composition (nHILLC).

[0018] In embodiments of the present invention, the composition comprises a mixture of non-halogenated ionic liquids constituting 15 to 99% by weight of the lubricant composition, wherein the mixture of non-halogenated ionic liquids consists only of ions (cations and anions) and has a glass transition temperature and melting point in the range of -70°C, preferably -100°C to +200°C.

[0019] In embodiments of the present invention, the composition of the non-halogenated ionic liquid or a mixture of non-halogenated ionic liquids constitutes at least 60% by weight of the lubricant composition, or in some embodiments, it may be more advantageous to have 70%, 80%, or 90% by weight.

[0020] In embodiments of the present invention, the lubricant composition comprises a fluid ionic phase and an ionic thickener, both consisting solely of ions, and neither containing halogen-containing (i.e., F, Cl, Br, I) compounds in their structure. That is, neither the ionic liquid component, the ionic additive, nor the ionic thickener contains halogen atoms to a measurable impurity level of 0.2% by weight, or 2000 mg / kg, i.e., parts per million (ppm), preferably 100 to 1000 mg / kg (parts per million, 0.01 to 0.1% by weight). Halogen-containing compounds are excluded due to their environmental hazards and the formation of corrosive species at tribological contacts.

[0021] In embodiments of the present invention, the lubricant composition comprises, excluding additives, a mixture of one or more of the following non-halogenated ionic liquids and an ionic thickener: -70-95% by weight of trihexyl(tetradecyl)phosphonium bis(mandelate)borate and 5-30% by weight of Li-12HSA thickener; - A mixture of 70-95% by weight (90% by weight of trihexyl(tetradecyl)phosphonium bis(mandelate)borate and 10% by weight of trihexyl(tetradecyl)phosphonium bis(oxalate)borate) and 5-30% by weight of Li-12HSA thickener; - A mixture of 70-95% by weight (50% by weight of trihexyl(tetradecyl)phosphonium bis(mandelate)borate and 50% by weight of trihexyl(tetradecyl)phosphonium bis(oxalate)borate) and 5-30% by weight of Li-12HSA thickener; -70-95% by weight of trihexyl(tetradecyl)phosphonium bis(salilate)borate and 5-30% by weight of Li-12HSA thickener; -70-95% by weight of trihexyl(tetradecyl)phosphonium(mandelate)(oxalate) borate and 5-30% by weight of Li-12HSA thickener; -70-95% by weight of triethyl(octyl)phosphonium bis(mandelate)borate and 5-30% by weight of Li-12HSA thickener; -70-95% by weight of trioctyl(hexadecyl)phosphonium 2,2'-methylenebis(4,6-di-tert-butylphenyl) phosphate and 5-30% by weight of Li-12HSA thickener; -70-95% by weight of trihexyl(tetradecyl)phosphonium 2,2'-methylenebis(4,6-di-tert-butylphenyl) phosphate and 5-30% by weight of Li-12HSA thickener; -70-95% by weight of trihexyl(tetradecyl)phosphonium bis(benzylate)borate and 5-30% by weight of Li-12HSA thickener; -70-95% by weight of trihexyl(tetradecyl)phosphonium bis(2-ethylhexyl) phosphate and 5-30% by weight of Li-12HSA thickener; -70-95% by weight of trihexyl(tetradecyl)phosphonium bis(oxalate)borate and 5-30% by weight of Li-12HSA thickener; -70-95% by weight of trihexyl(tetradecyl)phosphonium bis(mandelate)borate and 5-30% by weight of Ca-12HSA thickener; A composite thickener consisting of -60 to 94% by weight of trihexyl(tetradecyl)phosphonium bis(mandelate)borate, 5 to 30% by weight of Li-12HSA, and 1 to 10% by weight of azelaic acid lithium complex, prepared by a one-step method; A composite thickener consisting of -60 to 94% by weight of trihexyl(tetradecyl)phosphonium bis(mandelate)borate, 5 to 30% by weight of Li-12HSA, and 1 to 10% by weight of azelaic acid lithium complex, prepared by a two-step method; A composite thickener consisting of -60 to 94% by weight of trihexyl(tetradecyl)phosphonium bis(mandelate)borate, 5 to 30% by weight of Li-12HSA, and 1 to 10% by weight of a lithium sebacate complex, prepared by a one-step method; A composite thickener consisting of -60 to 94% by weight of trihexyl(tetradecyl)phosphonium bis(mandelate)borate, 5 to 30% by weight of Li-12HSA, and 1 to 10% by weight of sebacate lithium complex, prepared by a two-step method; A complex thickener consisting of -60 to 94% by weight of trihexyl(tetradecyl)phosphonium bis(oxalate)borate, 5 to 30% by weight of Ca-12HSA, and 1 to 10% by weight of azelaic acid calcium complex, prepared by a one-step method; A complex thickener consisting of -60 to 94% by weight of trihexyl(tetradecyl)phosphonium bis(oxalate)borate, 5 to 30% by weight of Ca-12HSA, and 1 to 10% by weight of sebaciate calcium complex, prepared by a one-step method. Specific example compositions are shown in the description of specific embodiments.

[0022] Non-halogenated ionic liquid lubricant compositions exhibit very low volatility, which is one of the main requirements for lubricants in space and ultra-high vacuum applications. In one application body of the present invention, nHILLC can be used as a highly ionic conductive lubricant to extend the life of moving parts in electromechanical elements, generators, and electric vehicles. Based on non-halogenated ionic liquids (ILs), nHILLC exhibits excellent lubrication performance (low friction and low wear) in various lubrication contacts, including fretting steel-to-steel contacts.

[0023] Lubrication technology is crucial for the efficient and long-term operation of machinery. However, despite the unique "functionalizing" properties of ILs in various tribological applications, namely the reduction of friction and wear at tribological contacts, molten salts and / or ionic liquids (RTILs) with melting points below 100°C and room-temperature ionic liquids (ILs) with melting points below 20°C have not been marketed as neat lubricants or / or as additives to lubricants. A specific class of lubricant is grease, which is a composition of liquid lubricant and thickener. The grease market covers a wide range of machinery, from kitchen appliances to vehicles, trains, ships, and airplanes, and even wind turbines.

[0024] nHILLC is particularly necessary in electric vehicles, trains, generators, and other machinery and equipment, where electrostatic discharge and arc discharge between moving parts can shorten the lifespan of the machinery by causing serious damage to frictional surfaces. The markets for all-electric vehicles and wind power plants have grown rapidly over the past 20 years. With the transition from a fossil fuel-based society to a sustainable society powered by "green" energy, this market is likely to grow even further.

[0025] Examples of nHILLC in this invention include the following: (i) A grease made from a complete ionic component comprising neat IL as a base oil and a completely ionic thickener such as a salt of lithium, calcium, aluminum, or barium of anions of non-halogenated organic acids, a complex of lithium, calcium, aluminum, or barium adipic acid and sebaciate, ionic polyurea, calcium sulfonate, calcium sulfonate complex, or lithium calcium sarcosyl complex, or (ii) A composition of IL and an anionic aluminosilicate component of bentonite, montmorillonite, or attapulgite, wherein the hydrophilic / hydrated metal ions (sodium or calcium) are substituted with hydrophobic cations of IL.

[0026] The present invention presents examples of several preparation protocols for nHILLC, which comprises a neat ionic liquid and an ionic thickener that is a salt based on a 12-(hydroxy)stearate anion and a lithium or calcium cation, with or without a dianion of azelate or sebacate, or an anionic aluminosilicate component (mineral nanosheet) of bentonite, montmorillonite, or attapulgite accompanied by a cation of tetraalkylphosphonium, tetraalkylammonium, dialkylpyrrolidinium, dialkylpiperidinium, dialkylimidazolium, or trialkylimidazolium.

[0027] nHILLC is an ionic non-halogenated substance, meaning it consists primarily or entirely of ions, in contrast to commercially available and patented greases, which are mixtures of ionic and molecular components.

[0028] The present invention also includes nHILLC, which has the properties of a grease based on a lithium salt of 12-hydroxystearic acid (12-HSA), with or without a lithium (or calcium) complex with either azelaic acid or sebacic acid, or a lithium salt of n-HSA having a hydroxyl (-OH) group on a carbon at another position in the alkyl chain of n-HSA, n=2, 3, 11, 13, ..., 18, or a calcium salt of 12-HSA (or n-HSA having a hydroxyl (OH) group on a carbon at another position in the alkyl chain of n-HSA, n=2, 3, 11, 13, ..., 18).

[0029] Some of the main features of this invention are as follows: - Ionic liquids or mixtures of ionic liquids completely replace the non-ionic base oils commonly used in commercially available greases. - Non-halogenated ionic liquids are used, and halide ionic liquids are avoided.

[0030] Furthermore, in specific embodiments of the present invention, only ionic additives are considered, which may be any other ionic liquid or ionic salt.

[0031] The preparation protocol of the present invention can yield nHILLC that is non-halogenated and consists solely of ions, i.e., a non-halogenated IL or a mixture of non-halogenated IL as a base oil, a completely ionic non-halogenated thickener, and a completely ionic non-halogenated additive. The final product, nHILLC, is highly hydrophobic, and trace amounts of moisture are removed by thorough drying in a vacuum oven after the saponification reaction. A specific example is shown below.

[0032] In embodiments of the present invention, nHILLC is prepared from a mixture of non-halogenated ionic liquids having different glass transition temperatures and melting points. One non-halogenated ionic liquid preferably has a low glass transition temperature of less than -50°C, and the other non-halogenated ionic liquid preferably has a high melting point of more than +120°C, but even higher, up to +140°C or +160°C.

[0033] Even mixtures of three or more non-halogenated ionic liquids with different glass transition temperatures and melting points can be prepared in various compositions using non-halogenated thickeners so as to adjust the rheological properties and "oil" bleed properties according to the desired application.

[0034] A homogeneous mixture of nHILLC is prepared by completely dissolving non-halogenated IL in a solvent (usually DCM or ethyl acetate), and thoroughly mixing this solution with the aid of water bath sonication to ensure homogeneous dissolution of all components in the solution. After homogenization, the mixture is instantaneously frozen with liquid nitrogen and subsequently freeze-dried under vacuum to remove all solvents (DCM or ethyl acetate). The resulting homogeneous mixture of non-halogenated IL is a wax-like nHILLC, the matrix of which is formed by a network of ions derived from a non-halogenated ionic liquid component having a high melting point (preferably above +120 °C), and the channels having voids in this matrix are filled with another non-halogenated ionic liquid component having a low glass transition temperature (preferably below -50 °C).

[0035] One specific example of nHILLC based solely on a mixture of non-halogenated ionic liquids is a mixture of two tetraalkylphosphonium-based ionic liquids (e.g., trihexyl(tetradecyl)phosphonium, [P - and bis(benzylato)borate, [BBB] - having anions with very different chemical functional groups such as etc. (see Figure 1). [BOB] 6,6,6,14 + ), by the cation). [BOB] - has four polar >C=O moieties around the orthoborate BO4 core, while on the other hand [BBB] - has only two polar >C=O moieties and four phenyl chemical groups around the orthoborate BO4 core.

[0036] As a result of these structural differences, [P 6,6,6,14 ​[BOB] is a room-temperature non-halogenated IL (RTIL) with a glass transition temperature of -71°C [MR Shimpi et al., Physical Chemistry Chemical Physics, 23 (2021) 6190], while [P 6,6,6,14 [BBB] is a non-halogenated ionic substance that is solid at room temperature and has a melting point above 80°C. Therefore, [P] prepared using the protocol described above is 6,6,6,14 [BOB] and [P 6,6,6,14 A homogeneous mixture with [BBB] is a completely ionic, non-halogenated waxy substance at around room temperature, and the solid phase is [P 6,6,6,14 [BBB] causes the phenyl group of the adjacent anion and [P 6,6,6,14 ] + Formed through the interaction of cations with alkyl groups, channels and voids are formed in the liquid [P] at a temperature range of approximately -70°C to 80°C. 6,6,6,14 [BOB] (and a certain amount of [P] dissolved in it 6,6,6,14 It is filled with [BBB]). When this material is sheared at the friction contact area, the liquid phase ([P 6,6,6,14 [BOB] and a certain amount of [P 6,6,6,14 [BBB]) bleeds out, promoting the outstanding tribological properties of nHILLC, namely reduced friction and reduced wear. The viscoelastic properties of this non-halogenated ionic liquid mixture can be further adjusted by adding non-halogenated thickeners.

[0037] nHILLC having two, three, or more different compositions of non-halogenated ILs in a homogenized mixture can be prepared for various applications with desired rheological and oil bleed properties.

[0038] According to a second aspect, the present invention relates to a lubricating compound entirely based on the lubricating composition described above.

[0039] The lubricating compound is preferably a semi-solid colloidal lubricating compound having a grease-like consistency ranging from NLGI000 to NLGI6, and containing a mixed phase of liquid and solid or a wax-like semi-solid phase.

[0040] Furthermore, the lubricating compound may contain a liquid phase and a solid phase, and may have a grease-like consistency with an NLGI of 1 to 3, in which case the liquid phase separation according to the standard test method ASTM D6184-22 corresponds to 0.1% to 50% of the total mass of the compound.

[0041] The lubricating compound may contain a liquid phase and a solid phase, and may have a grease-like consistency such that the penetration of the lubricating composition by a cone penetration tester according to the standard test method ASTM D217-21a corresponds to a range of 8.5 to 47.5 millimeters.

[0042] The lubricating compound may contain both a liquid phase and a solid phase, in which case the storage modulus (G') of the lubricant composition is greater than its loss modulus (G'') at a certain shear stress, and the opposite is true as the shear stress increases.

[0043] According to a third aspect, the present invention relates to the use of the above-defined lubricating compound as a lubricating and / or protective surface treatment for a component configured to be exposed to abrasion, wherein the lubricating compound is supplied to the surface of the component. [Brief explanation of the drawing]

[0044] The present invention will be described below with reference to the drawings.

[0045] [Figure 1] Figure 1 shows the metal salt of the bis(oxalate)borate anion, [BOB]- (left), and the lithium salt of the bis(benzilate)borate anion, [BBB]- (right). [Figure 2]Figure 2 shows a polyfunctional nonhalogenated ionic liquid (nHIL) based on the [MBPP]-anion, known as an efficient radical scavenger for terminating polymer elongation reactions. This anion imparts antioxidant and corrosion-resistant properties to nHILC, while the phosphate groups polymerize to form a polyphosphate, creating an abrasion-resistant tribofilm on the friction tracks of steel surfaces. [Figure 3] Figure 3 shows representative examples of the rheological behavior of two types of Li-nGILLC greases. [Modes for carrying out the invention]

[0046] Preparation of Lithium-IL Grease (Li-nHILLC) as nHILLC In all lithium grease preparations described below, 1.5 to 10 g of non-halogenated ionic liquid (nHIL) was used.

[0047] Before synthesizing the grease, 11-20% by weight of 12-hydroxystearic acid (12-HSA) was used in the process, and [Li][12-HSA] and water were obtained by saponification.

[0048] Lithium hydroxide (LiOH) was used in equimolar ratio with 12-HSA.

[0049] Preparation of Lithium-IL Grease as nHILLC 1.12-HSA was mixed with nHIL and heated at a temperature of approximately 75°C (for some nHILs, the temperature was set to approximately 100°C) until the mixture formed a homogeneous, clear liquid. 2. LiOH (solid) was dissolved in a small amount of Milli-Q water (just enough to completely dissolve this base) at 75°C. 3. Next, a LiOH (aqueous) solution was added to the high-temperature mixture of 12-HSA and nHCl under continuous stirring. The saponification reaction occurred spontaneously, and water was discharged from the grease formed during this reaction. 4. Water was removed from the system by heating under vacuum or by heating while stirring.

[0050] Several Li-nHILLCs (with different weight percentages of the thickeners 12-HSA and Li(OH)) were successfully prepared for various nHILs.

[0051] The non-halogenated orthoborate-based anions described below are known to possess friction-reducing and wear-resistant properties [FU Shah et al. Physical Chemistry Chemical Physics, 13 (2011) 12865-12873], and readily approach the positively charged steel surface at the friction contact point during friction.

[0052] The following non-halogenated [MBPP] - Anions are known in polymer chemistry as efficient radical scavengers that terminate polymer chain elongation. Therefore, these anions impart antioxidant and corrosion-preventive properties to nHILLC, where they are used as a main component or in mixtures with other non-halogenated ILs.

[0053] The notations for the cations and anions of non-halogenated IL (nHIL) used in the following example of grease prepared without problems are as follows: · 2,2'-Methylenebis(4,6-di-tert-butylphenyl)phosphate anion: [MBPP] - • (Mandelaat)(Oxalat) Borate Anion: [MOB] - • Bis(benzilate)borate anion: [BBB] - • Bis(2-ethylhexyl)phosphate anion: [BEHP] - • Bis(mandelato)borate anion: [BMB] - • Bis(oxalate)borate anion: [BOB] - • Bis(salicylate)borate anion: [BScB] - • Triethyl(octyl)phosphonium cation: [P 2,2,2,8 ] + • Trihexyl (tetradecyl)phosphonium cation: [P 6,6,6,14 ] + • Trioctyl (hexadecyl)phosphonium cation: [P 8,8,8,16 ] +

[0054] Example of Li-nHILLC grease 1.Li-nHILLC-(P66614-BMB, using Li(OH), 11% by weight 12-HSA, 75℃) 2.Li-nHILLC-(P66614-BMB, using Li(OH), 20% by weight 12-HSA, 75℃) 3.Li-nHILLC-90% P66614-BMB+10% P66614-BOB, using Li(OH), 11% by weight 12-HSA, 75℃) 4.Li-nHILLC-(90% P66614-BMB+10% P66614-BOB, using Li(OH), 15% by weight 12-HSA, 75℃) 5.Li-nHILLC-(50% P66614-BMB+50% P66614-BOB, using Li(OH), 20% by weight 12-HSA, 75℃) 6.Li-nHILLC-(P66614-BScB, using Li(OH), 11% by weight 12-HSA, 75℃) 7.Li-nHILLC-(P66614-MOB, using Li(OH), 20% by weight 12-HSA, 75℃) 8.Li-nHILLC-(P2228-BMB, using Li(OH), 20% by weight 12-HSA, 75℃) 9.Li-nHILLC-(P88816-MBPP, using Li(OH), 11% by weight 12-HSA, 75℃) 10.Li-nHILLC-(P66614-BBB, using Li(OH), 11% by weight 12-HSA, 100℃) 11.Li-nHILLC-(P66614-BEHP, using Li(OH), 20% by weight 12-HSA, 75℃) 12.Li-nHILLC-(P66614-BOB, using Li(OH), 11% by weight 12-HSA, 100℃) 13.Li-nHILLC-(P66614-BOB, using Li(OH), 15% by weight 12-HSA, 100℃) 14.Li-nHILLC-(P66614-BOB, using Li(OH), 20% by weight 12-HSA, 100℃) 15.Li-nHILLC-(P66614-MBPP, using Li(OH), 11% by weight 12-HSA, 100℃) 16.Li-nHILLC-(P66614-MBPP, using Li(OH), 20% by weight 12-HSA, 100℃)

[0055] Preparation of calcium-IL grease (Ca-nHILLC) as nHILLC Calcium-based nHILLC and Ca-nHILLC were prepared using an anhydrous method and by using Ca(OH)2 instead of Li(OH). During the saponification reaction, Ca 2+ (Aqueous) ions and Ca(OH) + Since both (aqueous) ions are formed, 0.75 mol Ca(OH)2 was used instead of 1 mol Li(OH)2. 12-HSA was dissolved in IL at 70°C (for some nHILs, the temperature was around 100°C). Ca(OH)2 was added little by little as a fine powder while vigorously mixing. Finally, a homogeneous but turbid liquid mixture was obtained. After cooling, the mixture formed a homogeneous grease. The sample was dried under reduced pressure at 75°C for 6 hours. During drying, the sample was mechanically stirred several times. The Ca-nHILLC sample prepared in this way 1 In the 1H NMR spectrum, water-derived 1 The 1H NMR signal (4.8 ppm) was never detected above the noise level.

[0056] The following time-stable Ca-nHILLC was prepared without any problems. 17.Ca-nHILLC-(P66614-BMB, using Ca(OH)2, 11% by weight 12-HSA, 100℃) 18.Ca-nHILLC-(P66614-BMB, using Ca(OH)2, 20% by weight 12-HSA, 100℃)

[0057] Preparation of lithium composite-IL grease (LiX-nHILLC) as nHILLC Lithium-based greases containing 12-HSA and azelaic acid (Az) or sebacic acid (Seb) were prepared using two methods: a two-step method and / or a one-step method.

[0058] Two-step method (2): In the first step, a grease was prepared from nHIL and 11% by weight of 12-HSA using equimolar amounts of LiOH (aqueous solution). In the second step, a powder sample of Az acid or Seb acid (approximately 1 / 3 the weight of 12-HSA) was added to the grease and mixed at 80°C. Finally, the Az acid or Seb acid was neutralized with LiOH (aqueous solution) at a molar ratio of 2:1. In the final step, moisture was removed in an oven, similar to the preparation of Li-nHILLC.

[0059] One-step method (1): 11% by weight of 12-HSA and approximately 4% by weight of Az acid or Seb acid were mixed together, and then added to a hot IL until the mixture became clear. Subsequently, the acid was neutralized with the corresponding amount of LiOH (aqueous solution), similar to the two-step method described above. The preparation of the LiX-nHILLC system containing sebacic acid was more difficult than that of the LiX-nHILLC system containing azelaic acid. It took approximately 48 hours to dissolve the sebacic acid granules in the IL.

[0060] The following time-stable LiX-nHILLC was prepared without any problems. 19. LiX-nHILLC-(P66614-BMB-Az(2), using Li(OH), 11 wt% 12-HSA, 4 wt% azelaic acid, two-step reaction, 100℃) 20. LiX-nHILLC-(P66614-BMB-Az(1), using Li(OH), 11 wt% 12-HSA, 4 wt% azelaic acid, one-step reaction, 100℃) 21. LiX-nHILLC-(P66614-BMB-Seb(2), using Li(OH), 11 wt% 12-HSA, 4 wt% sebacic acid, two-step reaction, 100℃) 22. LiX-nHILLC-(P66614-BMB-Seb(1), using Li(OH), 11 wt% 12-HSA, 4 wt% sebacic acid, one-step reaction, 100℃)

[0061] Preparation of calcium complex-IL grease (CaX-nHILLC) as nHILLC Grease was prepared using an anhydrous method from P66614-BOB, 12-HSA (11 wt%), azelaic acid (4 wt%, i.e., about 1 / 3 of 12-HSA), and Ca(OH)2. 12-HSA and azelaic acid were dissolved in P66614-BOB at 100°C. Ca(OH)2 was added gradually as a fine powder while vigorously mixing. The mixture was homogeneous during preparation and after cooling. The sample was dried under reduced pressure at 75°C for 6 hours.

[0062] Grease was prepared using the anhydrous method from P66614-BOB, 12-HSA (11 wt%), sebacic acid (4 wt%, i.e., about 1 / 3 of 12-HSA), and Ca(OH)2. 12-HSA and sebacic acid were dissolved in P66614-BOB at 160°C. Ca(OH)2 was added gradually as a fine powder while vigorously mixing. The mixture was homogeneous during preparation and after cooling. The sample was dried under reduced pressure at 75°C for 6 hours. 23. CaX-nHILLC-(P66614-BOB-Az(1), using Ca(OH)2, 11 wt% 12-HSA, 4 wt% azelaic acid, one-step reaction, 100℃) 24. CaX-nHILLC-(P66614-BOB-Seb(1), using Ca(OH)2, 11 wt% 12-HSA, 4 wt% sebacic acid, one-step reaction, 160℃)

[0063] Rheological testing of Li-nHILLC grease Using a TA Instruments HR-3 rheometer, we evaluated whether the fabricated Li / Ca-nHILLC grease exhibited normal rheological behavior for typical lubricating greases. The evaluation followed a procedure based on the DIN 51810-4 standard. This procedure consisted of two parts. First, a tempering and relaxation process was performed. In this process, a Li / Ca-nHILLC grease sample was applied to a plate at 25°C using a spatula. Subsequently, the upper geometry (cone diameter 20 mm, angle 0.9839°) was lowered to a "trimming" gap (73 μm), and excess grease was carefully removed with a spatula. After this, the cone was lowered to a "geometry gap" (23 μm), and the sample was allowed to stand for 10 minutes. The second step consisted of increasing strain (0.01% to 1000%) and amplitude sweeping using a frequency of 10 rad / s.

[0064] The rheological results for Li / Ca-nHILLC grease showed characteristic viscoelastic behavior typical of lubricating greases with NLGI parameters in the range of 2 to 5, depending on the relative content of the thickener in the lubricating composition.

[0065] Figure 3 shows the results of the storage modulus G’ (elastic part) and loss modulus G’’ (viscous part) for two types of greases tested. At low shear stress or amplitude stress, the elastic behavior of the grease dominates this region (G’ > G’’). This region is characterized by being a plateau and the ratio of G’ to G’’ being constant, and is known as the linear viscoelastic region (LVE). For the greases tested, G’ and G’’ in this region were calculated. As the shear stress increases, G’ begins to decrease and the contribution of the viscous part becomes more dominant. The yield stress is the shear stress at which G’ is 90% of G’ in the LVE. Finally, at high shear stress, the contribution of the viscous (liquid phase) becomes more dominant (G’ < G’’) and the grease begins to flow. According to the DIN 51810-4 standard, the last four points in this region can be used to calculate the equivalent penetration consistency of the metal saponified grease. Table 1 shows the aforementioned calculated properties of the Li / Ca-nHILLC grease. TIFF2026522018000002.tif73170

[0066] Tribology Tests of Li / Ca-nHILLC Grease Tribological screening of the lubrication behavior of non-halogenated ionic liquid lubricant compositions (nHILLC) was performed using a PCS Instruments high-frequency reciprocating rig (HFRR). nHILLC was used to lubricate steel-to-steel ball-on-flat fretting contacts, while simultaneously recording the friction response. The ball specimens conformed to the standard ASTM D6079 test method, except for the disc specimens, which had a higher hardness (800 HV). The tests were conducted at 26°C, 50 Hz, with a stroke of 70 μm and 500,000 fretting cycles at a maximum Hertz pressure of 1.4 GPa. Under these conditions, the occurrence of high-friction events (friction coefficient greater than 0.2) indicates critical lubricant failure, corresponding to metal-to-metal contact and significant adhesive wear. The performance of nHILLC, in terms of mean and standard deviation of the friction coefficient and the number of fretting cycles during high-friction events, is reported in Table 2. The standard deviation of the friction coefficient is an indicator of how stable the friction is, while the number of cycles during high-friction events indicates the severity of lubrication failure. These results show that many of the formulations examined exhibit remarkable and consistent lubrication behavior, even when compared to commercially available products intended for fretting applications. TIFF2026522018000003.tif162170

[0067] Preparation of nHILLC using anionic aluminosilicate components (mineral nanosheets) of bentonite, montmorillonite, or attapulgite minerals. One of the objectives of the present invention is an nHILLC having the known properties of an ionogel, formed as a result of intercalating a non-halogenated ionic liquid between negatively charged sheets of montmorillonite mineral that function as a thickener and plasticizer for nHILLC. The structure of sodium montmorillonite or calcium montmorillonite is stabilized by metal ions, usually by sodium cations or calcium cations. However, these cations each have a hydration shell of up to about 8-12 or 4-6 water molecules. These ions cause hydrophilicity in Na-montmorillonite and Ca-montmorillonite, which readily absorb water and form a paste with specific rheological properties of the binder. In this invention, the thickener for nHILLC is produced by, in step 1, substituting sodium cations and / or calcium cations with hydrophobic cations (Cat) such as tetraalkylphosphonium, tetraalkylammonium, dialkylpyrrolidinium, dialkylpiperidinium, and di-(or tri-)alkylimidazolium cations in a metathesis reaction between Na / Ca-montmorillonite and the halogen of the above cations, and subsequently washing the Na / Ca halogen from the reaction mixture to obtain a Cat-montmorillonite paste / thickener in the metathesis solvent (usually dichloromethane, DCM). In step 2, a pre-selected non-halogenated ionic liquid is added to the Cat-montmorillonite DCM solution and thoroughly mixed, after which the DCM is evaporated in a rotary evaporator to obtain nHILLC in which the montmorillonite sheet forms the thickener matrix and the non-halogenated ionic liquid is the base oil lubricant.

[0068] The final product, nHILLC, is entirely ionic, as all components of the montmorillonite and ionic liquid consist solely of ions. The main difference of this invention from previously reported techniques, namely IL-based ionogels [AV Agafonov et al., Journal of Molecular Liquid, 315 (2020) 113703], lies in the substitution / washing away of hydrophilic, water-absorbent sodium, calcium (and other types) metal ions from the montmorillonite, which can lead to corrosion on steel surfaces lubricated by previously reported IL-Na / Ca ionogels [AV Agafonov et al., Journal of Molecular Liquid, 315 (2020) 113703]. In this invention, the metal ions are substituted with hydrophobic, non-halogenated cations, which also have compatibility with hydrophobic ions in the non-halogenated ionic liquid, which is added and mixed with the thickener solution during step 2 of the synthesis. Next, this final system is dried in a vacuum oven to remove any remaining trace moisture after the metathesis / washing procedure of the final product, nHILLC. The present invention protects different compositions of non-halogenated Cat-montmorillonite thickeners and non-halogenated ionic liquids or mixtures of several non-halogenated ionic liquids in order to achieve the desired rheological properties, oil bleeding points, high thermal stability, and good electrical conductivity in the final product, nHILLC, in combination with the outstanding tribological properties of nHILLC. The final performance actually depends not only on the friction and wear reduction properties of the non-halogenated IL (or mixtures of non-halogenated IL), but also on the interaction between the ions and the montmorillonite sheets in these nHILLCs.

[0069] The present invention also functions even when nHILLC contains a very small amount of non-halogenated IL or a mixture of non-halogenated IL. Due to interfacial properties, a small amount of tribologically effective components such as non-halogenated IL may be sufficient to achieve the properties required at the interface of a friction track lubricated with nHILLC, namely, reduction of friction and wear, and imparting sufficient electrical conductivity to the nHILLC. These different nHILLCs may be semi-solid colloidal substances such as non-halogenated grease or non-halogenated wax-like semi-solid substances.

[0070] The present invention has been described above with reference to specific embodiments. However, the present invention is not limited to these embodiments. It will be apparent to those skilled in the art that other embodiments are possible within the scope of the following claims.

Claims

1. 5 to 99% by weight of a non-halogenated ionic liquid or a mixture of non-halogenated ionic liquids, 0 to 15% by weight of one or more non-halogenated additives for lubricants, and Of the remaining amount, the non-halogenated ion thickener contains at least 1% by weight of the non-halogenated ion thickener. A lubricant composition comprising the following.

2. The lubricant composition according to claim 1, comprising a mixture of non-halogenated ionic liquids constituting 15 to 99% by weight of the lubricant composition, wherein the mixture of non-halogenated ionic liquids consists only of ions (cations and anions) and has a glass transition temperature and melting point in the range of -70°C, preferably -100°C to +200°C.

3. The non-halogenated ionic liquid or the mixture of the non-halogenated ionic liquids contains an ionic liquid having a cation selected from the group consisting of tetraalkylphosphonium, tetraalkylammonium, dialkylpyrrolidinium, dialkylpiperidinium, dialkylimidazolium, and trialkylimidazolium having a substituent of an alkyl group of the general formula C ｎ H ２ｎ＋１ (where the value of 1 ≦ n ≦ 80), and an anion selected from the group consisting of 2,2'-methylenebis(4,6-di-tert-butylphenyl) phosphate, (mandelato)(oxalato) borate, bis(benzylato) borate, bis(2-ethylhexyl) phosphate, bis(mandelato) borate, bis(oxalato) borate, bis(salicylato) borate, bis(malonato) borate, bis(succinato) borate, bis(glutarato) borate, bis(adipato) borate, dodecyl sulfate, (2-ethylhexyl) sulfate, bis(R １ , R ２ -glycolato) borate (where R １ = H, -C ６ H ５ , -C ｎ H ２ｎ＋１ (1 ≦ n ≦ 80), and R １ = H, -C ６ H ５ , -C ｎ H ２ｎ＋１ (1 ≦ n ≦ 80)), the lubricant composition according to claim 1 or 2.

4. The aforementioned non-halogenated ion thickener is (i) Lithium n-hydroxy-stearic acid (n-HSA) thickener, wherein the position of the -OH group is n=2, 3, ... 18, preferably n=12 carbon. (ii) The position of the (ii)-OH group is on the 2nd, 3rd, ... 18th carbon, preferably the 12th carbon, n-HSA calcium thickener, n-HSA aluminum thickener, in which the position of the (iii)-OH group is on the 2nd, 3rd, ... 18th carbon, preferably n=12th carbon. n-HSA barium thickener, in which the position of the (iv)-OH group is on the carbon at n=2, 3, ... 18, preferably n=12. (v) A thickener based on (i) to (iv) above, containing a lithium, calcium, aluminum, and barium complex with adipic acid as an additive. (vi) A thickener based on (i) to (iv) above, containing a lithium, calcium, aluminum, and barium complex with sebaciate as an additive. (vii) Ionic polyureas, (viiii) Calcium sulfonate or calcium sulfonate complex, and (ix) Lithium calcium sarcosyl complex, A lubricant composition according to any one of claims 1 to 3, selected from the group consisting of the following.

5. The aforementioned non-halogenated ion thickener is of general formula C ｎ H ２ｎ＋１ A lubricant composition according to any one of claims 1 to 3, comprising an anionic aluminosilicate component (mineral nanosheet) of a bentonite, montmorillonite, or attapulgite mineral accompanied by a cation of a tetraalkylphosphonium, tetraalkylammonium, dialkylpyrrolidinium, dialkylpiperidinium, or di-(or tri-)alkylimidazolium having alkyl group substituents (1 ≤ n ≤ 80).

6. The lubricant composition according to any one of claims 1 to 5, wherein the one or more non-halogenated additives are selected from the group consisting of organic or inorganic solid lubricants selected from corrosion inhibitors, antioxidants, wear inhibitors, extreme pressure additives, friction reducers, protective agents against the effects of metals, UV stabilizers, graphite compounds, metal oxides, boron compounds, molybdenum compounds, and phosphates.

7. The lubricant composition according to any one of claims 1 to 6, wherein the non-halogenated ionic liquid or a mixture of the non-halogenated ionic liquids constitutes at least 70% by weight of the lubricant composition.

8. The lubricant composition is a mixture of one or more of the following non-halogenated ionic liquids and the ion thickener, excluding additives: - 70-95% by weight of trihexyl(tetradecyl)phosphonium bis(mandelate)borate and 5-30% by weight of Li-12HSA thickener; - A mixture of 70-95% by weight (90% by weight of trihexyl(tetradecyl)phosphonium bis(mandelate)borate and 10% by weight of trihexyl(tetradecyl)phosphonium bis(oxalate)borate) and 5-30% by weight of Li-12HSA thickener; - A mixture of 70-95% by weight (50% by weight of trihexyl(tetradecyl)phosphonium bis(mandelate)borate and 50% by weight of trihexyl(tetradecyl)phosphonium bis(oxalate)borate) and 5-30% by weight of Li-12HSA thickener; - 70-95% by weight of trihexyl(tetradecyl)phosphonium bis(salilate)borate and 5-30% by weight of Li-12HSA thickener; - 70-95% by weight of trihexyl(tetradecyl)phosphonium(mandelate)(oxalate) borate and 5-30% by weight of Li-12HSA thickener; - 70-95% by weight of triethyl(octyl)phosphonium bis(mandelate)borate and 5-30% by weight of Li-12HSA thickener; - 70-95% by weight of trioctyl(hexadecyl)phosphonium 2,2'-methylenebis(4,6-di-tert-butylphenyl) phosphate and 5-30% by weight of Li-12HSA thickener; - 70–95% by weight of trihexyl(tetradecyl)phosphonium 2,2'-methylenebis(4,6-di-tert-butylphenyl) phosphate and 5–30% by weight of Li-12HSA thickener; - 70-95% by weight of trihexyl(tetradecyl)phosphonium bis(benzilate)borate and 5-30% by weight of Li-12HSA thickener; - 70-95% by weight of trihexyl(tetradecyl)phosphonium bis(2-ethyl-hexyl) phosphate and 5-30% by weight of Li-12HSA thickener; - 70-95% by weight of trihexyl(tetradecyl)phosphonium bis(oxalate)borate and 5-30% by weight of Li-12HSA thickener; - 70-95% by weight of trihexyl(tetradecyl)phosphonium bis(mandelate)borate and 5-30% by weight of Ca-12HSA thickener; - A composite thickener consisting of 60-94% by weight of trihexyl(tetradecyl)phosphonium bis(mandelate)borate, 5-30% by weight of Li-12HSA, and 1-10% by weight of azelaic acid lithium complex, prepared by a one-step method; - A composite thickener consisting of 60-94% by weight of trihexyl(tetradecyl)phosphonium bis(mandelate)borate, 5-30% by weight of Li-12HSA, and 1-10% by weight of azelaic acid lithium complex, prepared by a two-step process; - A composite thickener consisting of 60-94% by weight of trihexyl(tetradecyl)phosphonium bis(mandelate)borate, 5-30% by weight of Li-12HSA, and 1-10% by weight of a lithium sebacate complex, prepared by a one-step method; - A composite thickener consisting of 60-94% by weight of trihexyl(tetradecyl)phosphonium bis(mandelate)borate, 5-30% by weight of Li-12HSA, and 1-10% by weight of a lithium sebacate complex, prepared by a two-step process; - A complex thickener consisting of 60-94% by weight of trihexyl(tetradecyl)phosphonium bis(oxalate)borate, 5-30% by weight of Ca-12HSA, and 1-10% by weight of azelaic acid calcium complex, prepared by a one-step method; - A complex thickener composed of 60-94% by weight of trihexyl(tetradecyl)phosphonium bis(oxalate)borate, 5-30% by weight of Ca-12HSA, and 1-10% by weight of sebaciate calcium complex, prepared by a one-step method. A lubricant composition according to any one of claims 1 to 7, comprising:

9. A lubricating compound that is based solely on the lubricant composition described in any one of claims 1 to 8, has a grease-like consistency ranging from NLGI000 to NLGI6, and is a semi-solid colloidal lubricating compound containing a mixed phase of liquid and solid or a wax-like semi-solid phase.

10. The lubricating compound according to claim 9, comprising a liquid phase and a solid phase, having a grease-like consistency with an NLGI of 1 to 3, wherein the weight of the separated liquid phase according to ASTM D6184-22 corresponds to 0.1% to 50% of the total mass of the compound.

11. The lubricating compound according to claim 9 or 10, comprising a liquid phase and a solid phase, having a grease-like consistency such that the penetration of the lubricating composition by a cone penetration tester in accordance with ASTM D217-21a corresponds to a range of 8.5 to 47.5 millimeters.

12. A lubricating compound according to any one of claims 9 to 11, comprising a liquid phase and a solid phase, wherein the storage modulus (G') of the lubricant composition is greater than its loss modulus (G'') at a certain shear stress, and the opposite is true as the shear stress increases.

13. Use of a lubricating compound according to any one of claims 9 to 12 as a lubricating and / or protective surface treatment for a component configured to be exposed to abrasion, wherein the lubricating compound is supplied to the surface of the component.

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