Bimetal composite soap and preparation method and application thereof, lubricating grease composition and preparation method and application thereof

Abstract

The invention relates to the technical field of lubrication, in particular to bimetallic composite soap and a preparation method and application thereof, and a lubricating grease composition and a preparation method and application thereof. Bimetals of the bimetal composite soap provided by the invention comprise lithium and barium, and negative ions comprise long-chain fatty acid radicals and short-chain acid radicals; the carbon number of the long-chain fatty acid radical is 12-20; the short-chain acid radicals comprise borate radicals and / or short-chain dibasic acid radicals, and the carbon number of the short-chain dibasic acid radicals is smaller than or equal to 10. The bimetallic composite soap is added as a thickening agent, so that the base oil can be firmly locked in a three-dimensional grid of the bimetallic composite soap, the mechanical stability and the bearing capacity of the lubricating grease are remarkably improved, and the lubricating grease can cope with high-speed shearing heavy load working conditions; the lubricating grease composition has excellent mechanical stability, extreme pressure antiwear property and high-speed stability.

Description

Technical Field

[0001] This invention relates to the field of lubrication technology, specifically to a bimetallic composite soap and its preparation method and application, and a lubricating grease composition and its preparation method and application. Background Technology

[0002] With the rapid development of modern industrial technology, the application of high-speed, heavy-duty equipment (such as gearboxes of large wind turbine generators, bearings of high-speed railways, bearings and gears of mining and metallurgical equipment, transmission systems of large engineering machinery, and bearings of heavy rolling mills) is becoming increasingly widespread and the operating conditions are becoming increasingly harsh. This type of equipment typically operates at extremely high speeds (DN values ​​can reach over one million), high loads, wide temperature ranges (especially high temperatures above 200℃), and environments that may be accompanied by vibration, moisture, or pollution. These extreme operating conditions require lubricating greases to possess excellent high-speed stability and anti-loss properties, superior extreme pressure anti-wear performance, excellent high-temperature performance and oxidation stability, good mechanical stability, long service life, and high reliability.

[0003] However, existing high-speed heavy-duty greases still generally suffer from poor mechanical stability and low load-bearing capacity during use.

[0004] Related technologies disclose a high-temperature, high-speed flexible gyroscope motor bearing grease, wherein the thickener is sodium fatty acid soap and / or sodium oleate. Related technologies also disclose a grease composition, wherein the thickener is lithium 12-hydroxystearate soap and C18-C23 long-chain dicarboxylic acid lithium soap. However, the thickeners of the above-mentioned greases are monometallic soaps (sodium or lithium soaps). Under shearing, the soap fibers are prone to breakage and structural collapse, resulting in large changes in cone penetration and poor mechanical stability. This causes the grease to easily thin under high-speed shearing, easily ejected from the lubrication points, causing lubrication failure and making it difficult to meet the requirements of heavy-load conditions.

[0005] The related technology discloses a high-speed, heavy-duty grease composition, in which a commercially available complex lithium soap is used as a thickener. Although the mechanical stability of this high-speed, heavy-duty grease composition is improved by using a complex lithium soap as a thickener, its extreme pressure performance is poor, and its lubrication performance under heavy-duty conditions remains limited.

[0006] Therefore, there is an urgent need to develop high-speed, heavy-duty greases that combine mechanical stability and extreme pressure performance. Summary of the Invention

[0007] Therefore, the present invention aims to provide a bimetallic composite soap, its preparation method and application, and a lubricating grease composition, its preparation method and application. The bimetallic composite soap provided by the present invention, when added as a thickener to a lubricating grease composition, can significantly improve the mechanical stability and extreme pressure anti-wear properties of the lubricating grease composition.

[0008] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a bimetallic composite soap, wherein the bimetallic compound soap comprises lithium and barium, and the negative ion of the bimetallic composite soap comprises a long-chain fatty acid ion and a short-chain acid ion; the long-chain fatty acid ion has 12 to 20 carbon atoms; the short-chain acid ion comprises borate and / or a short-chain dicarboxylic acid ion, wherein the short-chain dicarboxylic acid ion has ≤10 carbon atoms.

[0009] Preferably, the long-chain fatty acid anion includes at least one selected from 12-hydroxystearate, stearate, oleate, and ricinoleate. The short-chain dicarboxylic acid anions include at least one of sebacic acid, azelaic acid, terephthalic acid, and tartrate.

[0010] Preferably, it includes the following steps: Long-chain fatty acids are heated and melted, and lithium hydroxide aqueous solution is added dropwise to carry out the first saponification reaction and then dehydrated. Barium hydroxide is added to carry out the second saponification reaction, and short-chain acids are added to carry out the third saponification reaction. After heating, the fourth saponification reaction is carried out, and then cooled to obtain bimetallic composite soap.

[0011] Preferably, the molar ratio of the long-chain fatty acid to the short-chain acid is 5~10:1; The molar ratio of lithium hydroxide to barium hydroxide is 5~10:1; The ratio of the total molar amount of lithium hydroxide and barium hydroxide to the total molar amount of long-chain fatty acids and short-chain acids is 1.02~1.1:1; The temperatures for the dehydration, first saponification reaction, second saponification reaction, and third saponification reaction are independently 120~140℃; The temperature for the fourth saponification reaction is 140~160℃; The cooling rate is 5~15℃ / min.

[0012] The present invention also provides the application of the bimetallic composite soap described in the above technical solution or the bimetallic composite soap prepared by the above technical solution in a lubricating grease composition.

[0013] The present invention also provides a grease composition comprising the following components in parts by weight: 60-80 parts base oil, 10-20 parts thickener, and 7.5-34 parts composite additive; The thickener includes the bimetallic composite soap described in the above technical solution or the bimetallic composite soap prepared by the preparation method described in the above technical solution; The composite additive includes two-dimensional layered nanomaterials, friction-reducing and wear-resistant agents, and antioxidants; the friction-reducing and wear-resistant agents contain at least three elements selected from sulfur, phosphorus, nitrogen, and zinc.

[0014] Preferably, the base oil is a mixture of hydrocarbon oils of different viscosities; the viscosity of the base oil at 100°C is 15~45 mm. 2 / s.

[0015] Preferably, the composite additive comprises 1-6 parts of two-dimensional layered nanomaterials, 5-20 parts of friction-reducing and wear-resistant agent, and 1-4 parts of antioxidant; The two-dimensional layered nanomaterial includes at least two of graphene, black phosphorus, MXenes, MoS2, and hexagonal boron nitride; the overall thickness of the two-dimensional layered nanomaterial is 1~5 nm; The friction-reducing and wear-resistant agent includes at least three of the following: aminothioester, dialkyl dithiophosphate derivative, zinc dialkyl dithiophosphate, and phosphate amine. The antioxidant includes at least one of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, tri-(2,4-di-tert-butylphenyl) phosphite, and lauryl thiodipropionate.

[0016] Preferably, the composite additive further includes 0.5 to 4 parts of rust inhibitor; The rust inhibitor includes calcium petroleum sulfonate and / or calcium dinonylnaphthalene sulfonate.

[0017] The present invention also provides a method for preparing the lubricating grease composition described above, comprising the following steps: Part of the base oil and long-chain fatty acids are heated and melted, and lithium hydroxide aqueous solution is added dropwise to carry out the fifth saponification reaction and then dehydrated. Barium hydroxide is added to carry out the sixth saponification reaction, short-chain acid is added to carry out the seventh saponification reaction, and the temperature is raised to carry out the eighth saponification reaction. After heating, the first mixture is obtained. The first mixture is poured into the remaining base oil and cooled to obtain the second mixture; The second mixture and the composite additive are mixed to obtain a grease composition.

[0018] Preferably, the mass of the base oil portion is 50-80% of the total mass of the base oil; The concentration of the lithium hydroxide aqueous solution is 0.05~0.6 g / mL; the dropping rate of the lithium hydroxide aqueous solution can be 1~2 seconds / drop; The temperatures for the dehydration, fifth saponification reaction, sixth saponification reaction, and seventh saponification reaction are independently 120~140℃; The temperature of the eighth saponification reaction is 140~160℃; The temperature of the first mixture is 210~220℃; The temperature of the second mixture is 80~90℃.

[0019] The present invention also provides the application of the grease composition described in the above technical solution or the grease composition prepared by the preparation method described in the above technical solution in high-speed heavy-duty equipment.

[0020] This invention provides a bimetallic composite soap, wherein the bimetal comprises lithium and barium, and the anion comprises a long-chain fatty acid ion and a short-chain acid ion; the long-chain fatty acid ion has 18 carbon atoms; the short-chain acid ion comprises borate and / or a short-chain dicarboxylic acid ion, wherein the short-chain dicarboxylic acid ion has ≤10 carbon atoms. The bimetallic composite soap provided by this invention has a unique chemical bonding mode and microstructure, wherein the long-chain fatty acid ion provides hydrophobicity and oil solubility, and the short-chain acid ion introduces an additional carboxyl group; the two acid ions can react with two metal ions (Li... + and Ba 2+ Simultaneous bonding and the introduction of carboxyl groups by short-chain acid radicals enhance the polar adsorption force between the metal soap molecules and the base oil, significantly suppressing oil separation. Furthermore, compared to the linear structure of a single metal soap, the two metal ions (Li) in this invention... + and Ba 2+ The bimetallic compound can form a cross-linked co-crystallized fiber three-dimensional network structure with diacid radicals. This cross-linked co-crystallized fiber three-dimensional network structure is more compact, complex, tough, and tightly interwoven. This structure can better disperse shear stress and absorb shear energy. When added to grease as a thickener, it can make the base oil firmly locked in the three-dimensional network of bimetallic composite soap, which significantly improves the mechanical stability and load-bearing capacity of the grease and enables it to cope with high-speed shear and heavy-load conditions.

[0021] By adding the above-mentioned bimetallic composite soap as a thickener, the present invention enables the base oil to be firmly locked in the three-dimensional network of the bimetallic composite soap, which significantly improves the mechanical stability and load-bearing capacity of the grease, enabling it to cope with high-speed shear and heavy-load conditions. The grease composition has excellent mechanical stability, extreme pressure anti-wear properties and high-speed stability.

[0022] The two-dimensional layered nanomaterials used in this invention possess high extreme pressure performance. Under high pressure, relative slippage easily occurs between the layers, forming a lubrication effect similar to a "molecular bearing," significantly reducing the coefficient of friction. Furthermore, the strong covalent bonds endow the two-dimensional layered nanomaterials with high in-plane strength, enabling them to withstand plastic deformation under extreme pressure without cracking, thus greatly improving the extreme pressure performance of the grease. Moreover, the two-dimensional layered nanomaterials exhibit excellent synergistic compounding characteristics with anti-friction and anti-wear agents and antioxidants containing at least three elements from sulfur, phosphorus, nitrogen, and zinc. This synergistic effect significantly improves the extreme pressure performance of the grease, meeting the requirements of high-speed, heavy-load operating conditions.

[0023] Furthermore, this invention employs blended base oils of different viscosities, taking into account both high-speed anti-throwing performance and optimizing synergistic viscosity-temperature performance. Specifically, after blending base oils of different viscosities, in high-temperature local hot spots, the low-viscosity component exhibits dramatically enhanced fluidity, becoming a highly efficient "heat carrier," while the high-viscosity component maintains a relatively high viscosity, serving as a "structural support." The significant viscosity difference between the two components in the same area stimulates a strong micro-convection effect, thereby actively and rapidly carrying and diffusing concentrated heat to the entire lubrication system, preventing heat accumulation. This is a synergistic advantage that single-viscosity base oils do not possess.

[0024] Furthermore, this invention utilizes two-dimensional layered nanomaterials with excellent synergistic properties in combination with friction-reducing and anti-wear agents, antioxidants, and rust inhibitors containing at least three elements selected from sulfur, phosphorus, nitrogen, and zinc. This synergistic effect significantly improves the extreme pressure performance of the grease, meeting the requirements of high-speed, heavy-load conditions (speeds greater than 30,000 r / min and contact stresses greater than 3 GPa). Moreover, this invention significantly improves the corrosion resistance of the grease composition by adding rust inhibitors.

[0025] The present invention, through the combined action of the above-mentioned components, can significantly improve the extreme pressure anti-wear performance and high-speed anti-shake properties of the grease composition under high-speed, heavy-load conditions, thereby extending the service life of equipment. Furthermore, the grease composition provided by the present invention uses inexpensive and readily available raw materials, resulting in low production costs.

[0026] As shown in the test results of the examples, the grease composition provided by the present invention has a steel mesh oil separation rate of 0.11~0.20%, an oxygen pressure drop of 1 kPa, a maximum non-seize load of 1962~2579 N, an anti-wear performance of 0.36~0.61 mm, copper strip corrosion (100℃, 3h) of grades 1a and 1b, and a cone penetration of 219.1~243.8 mm. 5 The secondary shear cone penetration is 236.1~280.4mm, 10 5 The variation of the cone penetration and the cone penetration during each shearing operation is 17~36.6 mm.

[0027] The preparation method provided by this invention is simple in steps, easy to operate, has high production efficiency, low production cost, and is suitable for industrial production. Detailed Implementation

[0028] This invention provides a bimetallic composite soap, wherein the bimetallic compound soap comprises lithium and barium, and the negative ion of the bimetallic composite soap comprises a long-chain fatty acid ion and a short-chain acid ion; the long-chain fatty acid ion has 12 to 20 carbon atoms; the short-chain acid ion comprises borate and / or a short-chain dicarboxylic acid ion, wherein the short-chain dicarboxylic acid ion has ≤10 carbon atoms.

[0029] In this invention, the long-chain fatty acid anion has 12 to 20 carbon atoms, and can be 12 to 15, specifically at least one of 12, 13, 14, 15, 16, 17, 18, 19 and 20; the long-chain fatty acid anion may include at least one of 12-hydroxystearate, stearate, oleate and ricinoleate.

[0030] In this invention, the number of carbon atoms in the short-chain dicarboxylic acid anion is ≤10, and can be 2~10, or 4~10, specifically at least one of 2, 3, 4, 5, 6, 7, 8, 9 and 10; the short-chain dicarboxylic acid anion may include at least one of sebacic acid anion, azelaic acid anion, terephthalic acid anion and tartrate anion.

[0031] The present invention also provides a method for preparing the bimetallic composite soap described in the above technical solution, comprising the following steps: heating and melting long-chain fatty acids, adding lithium hydroxide aqueous solution dropwise for a first saponification reaction and then dehydrating, adding barium hydroxide for a second saponification reaction, adding short-chain acids for a third saponification reaction, heating and then carrying out a fourth saponification reaction, heating and then cooling to obtain bimetallic composite soap.

[0032] Unless otherwise specified, the materials and equipment used in this invention are all commercially available products in the field.

[0033] In this invention, the number of carbon atoms in the long-chain fatty acid and the short-chain dicarboxylic acid is the same as the number of carbon atoms in the long-chain fatty acid radical and the short-chain dicarboxylic acid radical, respectively, and will not be repeated here. In this invention, the long-chain fatty acid may include at least one of C12, C13, C14, C15, C16, C17, C18, C19, and C20 fatty acids, specifically at least one of 12-hydroxystearic acid, stearic acid, oleic acid, and ricinoleic acid.

[0034] In this invention, the short-chain acid includes boric acid and / or short-chain dicarboxylic acid; the short-chain dicarboxylic acid may include at least one of C2 dicarboxylic acid, C3 dicarboxylic acid, C4 dicarboxylic acid, C5 dicarboxylic acid, C6 dicarboxylic acid, C7 dicarboxylic acid, C8 dicarboxylic acid, C9 dicarboxylic acid and C10 dicarboxylic acid, specifically at least one of sebacic acid, azelaic acid, terephthalic acid and tartaric acid.

[0035] In this invention, the molar ratio of the long-chain fatty acid to the short-chain acid can be 5 to 10:1, specifically 5:1, 6:1, 7:1, 8:1, 9:1 or 10:1.

[0036] In this invention, the molar ratio of lithium hydroxide to barium hydroxide in the lithium hydroxide aqueous solution can be 5~10:1, specifically 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1. In this invention, the barium hydroxide can be anhydrous barium hydroxide or barium hydroxide containing water of crystallization. In this invention, the lithium hydroxide can be anhydrous lithium hydroxide or lithium hydroxide containing water of crystallization. In this invention, the concentration of the lithium hydroxide aqueous solution can be 0.05~0.6 g / mL, specifically 0.05 g / mL, 0.1 g / mL, 0.2 g / mL, 0.3 g / mL, 0.3 g / mL, 0.4 g / mL, 0.5 g / mL, 0.55 g / mL, or 0.6 g / mL. In this invention, the dropping rate of the lithium hydroxide aqueous solution can be 1~2 seconds / drop. In this invention, the first saponification reaction occurs simultaneously with the dropping of the lithium hydroxide aqueous solution.

[0037] In this invention, the ratio of the total molar amount of lithium hydroxide and barium hydroxide to the total molar amount of long-chain fatty acids and short-chain acids can be 1.02 to 1.1:1, specifically 1.02:1, 1.03:1, 1.04:1, 1.05:1, 1.06:1, 1.07:1, 1.08:1, 1.09:1 or 1.1:1.

[0038] In this invention, the heating and melting temperature can be 120~140℃, specifically 120℃, 125℃, 130℃, 135℃ or 140℃.

[0039] In this invention, the dehydration temperature can be 120~140℃, specifically 120℃, 125℃, 130℃, 135℃ or 140℃; the dehydration time can be 60~120min, specifically 60min, 70min, 80min, 90min, 100min, 110min or 120min.

[0040] In this invention, the temperature of the second saponification reaction can be 120~140℃, specifically 120℃, 125℃, 130℃, 135℃ or 140℃; the time of the second saponification reaction can be 30~60min, specifically 30min, 40min, 50min or 60min.

[0041] In this invention, the temperature of the third saponification reaction can be 120~140℃, specifically 120℃, 125℃, 130℃, 135℃ or 140℃; the time of the third saponification reaction can be 30~60min, specifically 30min, 40min, 50min or 60min.

[0042] In this invention, the temperature of the fourth saponification reaction can be 140~160℃, specifically 140℃, 145℃, 150℃, 155℃ or 160℃; the time of the fourth saponification reaction can be 60~120min, specifically 60min, 70min, 80min, 90min, 100min, 110min or 120min.

[0043] The present invention enables complete saponification by performing a third and a fourth saponification reaction.

[0044] In this invention, the heated temperature can be 210~220℃, specifically 210℃, 212℃, 214℃, 216℃, 218℃, or 220℃; the heating rate can be 5~15℃ / min, specifically 5℃ / min, 8℃ / min, 10℃ / min, 12℃ / min, or 15℃ / min. In this invention, after heating, the entire material system melts into a homogeneous and transparent liquid.

[0045] In this invention, the cooling rate can be 5~15℃ / min, specifically 5℃ / min, 8℃ / min, 10℃ / min, 12℃ / min, or 15℃ / min. This invention rapidly cools the heated material, preventing the coarsening of the bimetallic composite soap fibers.

[0046] In the preparation of bimetallic composites, this invention first forms lithium salts and then barium salts. The core advantage of this process lies in the fact that lithium soap is first used to form a high-temperature resistant, high-strength three-dimensional fibrous framework, serving as a stable foundation for the grease. Subsequently, the barium soap component undergoes a metathesis reaction using lithium soap fibers as a "crystallization template," allowing its molecules to uniformly adhere to and fill the framework, achieving a strong molecular-level composite. This structure enables the barium soap to effectively enhance and densify the original lithium soap network, thereby synergistically improving the grease's dropping point, mechanical stability, and colloidal stability.

[0047] The present invention also provides the application of the bimetallic composite soap described in the above technical solution or the bimetallic composite soap prepared by the above technical solution in a lubricating grease composition.

[0048] Greases made with sodium soap (sodium hydroxide as the alkali) have extremely poor water resistance and a low dropping point. Upon contact with water, they absorb moisture and emulsify, leading to the destruction of the metal soap structure and causing the grease to thin and leak. Greases made with potassium soap (potassium hydroxide as the alkali) have a very soft structure, a very low dropping point, and poor mechanical stability and water resistance. Calcium hydroxide forms short and hard soap fibers, resulting in greases with extremely poor temperature resistance and mechanical stability; their structure is easily destroyed at high temperatures. Magnesium hydroxide has low reactivity and reacts very slowly and incompletely with fatty acids, making it extremely difficult to form an effective soap fiber structure. In this invention, two metal ions (Li... + and Ba 2+ The cross-linked co-crystallized network formed by the α- and β-acids (long-chain fatty acids and short-chain acids) is denser than the linear structure of a single metal soap. The resulting fibrous three-dimensional network structure is more complex, tougher, and more tightly interwoven. This structure can better disperse shear stress and absorb shear energy, and can firmly lock the base oil in the three-dimensional network, significantly improving the mechanical stability of the grease, thereby improving the high-speed stability and service life of the grease composition.

[0049] The present invention also provides a grease composition comprising the following components in parts by weight: 60-80 parts base oil, 10-20 parts thickener, and 7.5-34 parts composite additive; The thickener includes a bimetallic composite soap, which is the bimetallic composite soap described in the above technical solution or a bimetallic composite soap prepared by the preparation method described in the above technical solution; The composite additive includes two-dimensional layered nanomaterials, friction-reducing and wear-resistant agents, and antioxidants; the friction-reducing and wear-resistant agents contain at least three elements selected from sulfur, phosphorus, nitrogen, and zinc.

[0050] The lubricating grease composition provided by this invention comprises 60-80 parts by weight of base oil, specifically 60, 65, 70, 75, or 80 parts. In this invention, the viscosity of the base oil at 100°C can be 15-45 mm. 2 / s, which can be specifically 15mm 2 / s, 20mm 2 / s, 25mm 2 / s, 30mm 2 / s, 35mm 2 / s, 40mm 2 / s or 45mm 2 / s. In this invention, the base oil can be a mixture of hydrocarbon oils of different viscosities; the hydrocarbon oil can be PAO. In this invention, the base oil can be a mixture of PAO100, PAO40, and PAO10; the mass ratio of PAO100, PAO40, and PAO10 in the mixture can be 1~3:5~7:1~2, specifically 1:5:1, 1:5:1.5, 1:5:2, 1:5.5:1, 1:5.5:1.5, 1:5.5:2, 1:6:1, 1:6:1.5, 1:6:2, 1:6.5:1, 1:6 .5:1.5, 1:6.5:2, 1:7:1, 1:7:1.5, 1:7:2, 1.5:5:1, 1.5:5:1.5, 1.5:5:2, 1.5:5.5:1, 1.5:5.5:1.5, 1.5:5.5:2, 1.5:6:1, 1.5:6:1.5, 1.5:6:2, 1.5:6.5:1, 1.5:6.5:1.5, 1.5:6.5:2, 1.5:7:1, 1.5:7:1.5, 1.5:7:2, 2:5: 1, 2:5:1.5, 2:5:2, 2:5.5:1, 2:5.5:1.5, 2:5.5:2, 2:6:1, 2:6:1.5, 2:6:2, 2:6.5:1, 2:6.5:1.5, 2:6.5:2, 2:7:1, 2:7:1.5, 2:7:2, 2.5:5:1, 2.5:5:1.5, 2.5:5:2, 2.5:5:1, 2.5:5.5:1.5, 2.5:5.5:2, 2.5:6:1, 2.5:6:1 0.5, 2.5:6:2, 2.5:6.5:1, 2.5:6.5:1.5, 2.5:6.5:2, 2.5:7:1, 2.5:7:1.5, 2.5:7:2, 3:5:1, 3:5:1.5, 3:5:2, 3:5.5:1, 3:5.5:1.5, 3:5.5:2, 3:6:1, 3:6:1.5, 3:6:2, 3:6.5:1, 3:6.5:1.5, 3:6.5:2, 3:7:1, 3:7:1.5 or 3:7:2.

[0051] This invention employs a blend of base oils with varying viscosities, achieving both high-speed anti-slinging performance and optimized synergistic viscosity-temperature properties. Specifically, after blending base oils of different viscosities, in high-temperature local hot spots, the low-viscosity component exhibits dramatically enhanced fluidity, becoming a highly efficient "heat carrier," while the high-viscosity component maintains a relatively high viscosity, providing "structural support." The significant viscosity difference between the two components in the same area stimulates a strong micro-convection effect, thereby actively and rapidly carrying and diffusing concentrated heat throughout the entire lubrication system, preventing heat accumulation—a synergistic advantage not found in single-viscosity base oils. Furthermore, PAO-based oils inherently possess excellent oxidation resistance, further enhancing the high-temperature stability of the grease composition.

[0052] Based on the mass fraction of the base oil, the lubricating grease composition provided by the present invention includes 10-20 parts of thickener, specifically 10, 11, 12, 13, 14, 15, 16, 17, 17.95, 18, 19, 19.5, or 20 parts. In the present invention, the thickener is the bimetallic composite soap described in the above technical solution or the bimetallic composite soap prepared by the preparation method described in the above technical solution.

[0053] The bimetallic composite soap used in this invention is a composite metal soap prepared from two acids (long-chain fatty acids and short-chain acids) and two bases (lithium hydroxide and barium hydroxide). It is a core thickener for high-speed, heavy-duty lubricating greases, and its advantages stem from its unique chemical bonding mode and microstructure. The long-chain fatty acid provides hydrophobicity and oil solubility, while the short-chain acid introduces an additional carboxyl group. The two acids can react with two metal ions (Lithium hydroxide and barium hydroxide). + and Ba 2+ Simultaneous bonding and the introduction of carboxyl groups by short-chain acids enhance the polar adsorption force between the metal soap molecules and the base oil, significantly suppressing oil separation. Furthermore, compared to the linear structure of a single metal soap, the two metal ions (Li) in this invention... + and Ba 2+ The bimetallic composite soap, when combined with diacids, can form a cross-linked co-crystalline fiber three-dimensional network structure. This cross-linked co-crystalline fiber three-dimensional network structure is denser, more complex, tougher, and more tightly interwoven. This structure can better disperse shear stress and absorb shear energy, allowing the base oil to be firmly locked in the three-dimensional network, significantly improving the mechanical stability and load-bearing capacity of the grease, enabling it to cope with high-speed shear and heavy-load conditions. Grease compositions using bimetallic composite soap as a thickener exhibit excellent mechanical stability, extreme pressure anti-wear properties, and high-speed stability.

[0054] Based on the mass fraction of the base oil, the lubricating grease composition provided by the present invention comprises 7.5 to 34 parts of a composite additive, specifically 7.5, 8, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 22, 24, 26, 28, 30, 32, or 34 parts. In the present invention, the composite additive comprises two-dimensional layered nanomaterials, friction-reducing and anti-wear agents, and antioxidants; the composite additive may include 1 to 6 parts of two-dimensional layered nanomaterials, 5 to 20 parts of friction-reducing and anti-wear agents, and 1 to 4 parts of antioxidants; the composite additive may also include 0.5 to 4 parts of rust inhibitors.

[0055] Based on the mass fraction of the base oil, the lubricating grease composition provided by this invention may include 1 to 6 parts of two-dimensional layered nanomaterials, specifically 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.1 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, 5.5 parts, or 6 parts. In this invention, the overall thickness of the two-dimensional layered nanomaterials may be 1 to 5 nm, specifically 1 nm, 1.5 nm, 2 nm, 2.5 nm, 3 nm, 3.5 nm, 4 nm, 4.5 nm, or 5 nm. In this invention, the two-dimensional layered nanomaterials may include graphene, black phosphorus, MXenes, MoS2, and hexagonal boron nitride (…). h At least two of the following: WS2 and h-BN. In this invention, the two-dimensional layered nanomaterial can be a mixture of graphene and MXenes, a mixture of MXenes and MoS2, a mixture of MoS2 and black phosphorus, a mixture of WS2 and h-BN, a mixture of graphene and MoS2, a mixture of graphene and black phosphorus, or a mixture of graphene and... h A mixture of -BN, MXenes, and black phosphorus, wherein the mass ratio of the two two-dimensional layered nanomaterials in the mixture can be 1:0.5 to 2, specifically 1:0.5, 1:1, 1:1.5, or 1:2.

[0056] In this invention, under localized high temperature and heavy-load friction, the easily sheared two-dimensional layered nanomaterials can disperse sliding stress. Simultaneously, their nanoscale size allows for uniform penetration into the gaps between friction pairs, filling tiny pits on the metal surface, reducing the coefficient of friction, and preventing wear on critical components such as piston rings, bearings, and gears. This invention, through the combined effects of various two-dimensional layered nanomaterials, further significantly improves the extreme pressure performance and load-bearing capacity of the grease composition.

[0057] Based on the mass fraction of the base oil, the lubricating grease composition provided by the present invention may include 5 to 20 parts of a friction-reducing and anti-wear agent, specifically 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 parts. In the present invention, the friction-reducing and anti-wear agent contains at least three elements selected from sulfur, phosphorus, nitrogen, and zinc. In the present invention, the friction-reducing and anti-wear agent may include at least three of the following: aminothioester (T323), dialkyl dithiophosphate derivative (IR353), zinc dialkyl dithiophosphate (ZDDP), and ammonium phosphate (IR349). In this invention, the friction-reducing and anti-wear agent can be a three-component mixture or a four-component mixture. The three-component mixture can be a mixture of T323, IR353, and ZDDP, or a mixture of T323, IR353, and IR349, or a mixture of T323, IR349, and ZDDP. The four-component mixture is a mixture of T323, IR353, IR349, and ZDDP. The mass ratio of the different friction-reducing and anti-wear agents in the three-component mixture can be 1~3:1~ The ratio of 3:1 to 3 can be specifically 1:1:1, 1:1:2, 1:1:3, 2:2:1, 2:2:3, 3:3:1, or 3:3:3; the mass ratio of different friction-reducing and anti-wear agents in the four mixtures can be 1 to 3:1 to 3:1 to 3:1 to 3:1 to 3, specifically 1:1:1:1, 1:1:1:2, 1:1:1:3, 2:2:1:1, 2:2:2:1, 2:2:2:3, 3:3:3:1, or 3:3:3:2.

[0058] Based on the mass fraction of the base oil, the lubricating grease composition provided by the present invention may include 1 to 4 parts of an antioxidant, specifically 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, or 4 parts. In the present invention, the antioxidant may include at least one of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (1076), tri-(2,4-di-tert-butylphenyl) phosphite (168), and lauryl thiodipropionate (DLTP).

[0059] Based on the mass fraction of the base oil, the lubricating grease composition provided by this invention may include 0.5 to 4 parts of rust inhibitor, specifically 0.5 parts, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, or 4 parts. In this invention, the rust inhibitor may include calcium petroleum sulfonate (T106) and / or calcium dinonylnaphthalene sulfonate (T705C). The rust inhibitor used in this invention has excellent acid neutralization ability and good high-temperature detergency. High-speed, heavy-load operating conditions easily generate high temperatures that cause additives to decompose, producing acidic substances such as carboxylic acids. The rust inhibitor neutralizes these acidic substances through a chemical reaction, significantly reducing the acid value of the oil, thereby delaying oil aging and extending the service life of the lubricating grease composition.

[0060] The present invention, through the combined action of the above components, can significantly improve the extreme pressure anti-wear performance and high-speed anti-shake properties of the grease composition under high-speed, heavy-load conditions, thereby extending the service life of equipment. The grease composition for high-speed, heavy-load equipment provided by the present invention has excellent extreme pressure anti-wear performance, anti-shake performance, oxidation stability, and high-speed stability, and can meet the lubrication requirements of equipment under harsh high-speed, heavy-load conditions.

[0061] The present invention also provides a method for preparing the lubricating grease composition described above, comprising the following steps: Part of the base oil and long-chain fatty acids are heated and melted, and lithium hydroxide aqueous solution is added dropwise to carry out the fifth saponification reaction and then dehydrated. Barium hydroxide is added to carry out the sixth saponification reaction, short-chain acid is added to carry out the seventh saponification reaction, and the temperature is raised to carry out the eighth saponification reaction. After heating, the first mixture is obtained. The first mixture is poured into the remaining base oil and cooled to obtain the second mixture; The second mixture and the composite additive are mixed to obtain a grease composition.

[0062] In this invention, a portion of the base oil and long-chain fatty acids are heated and melted. A lithium hydroxide aqueous solution is added dropwise for a fifth saponification reaction, followed by dehydration. Barium hydroxide is added for a sixth saponification reaction, and short-chain acids are added for a seventh saponification reaction. After heating, an eighth saponification reaction is carried out, and the mixture is heated to obtain a first mixture. The first mixture is then poured into the remaining base oil and cooled to obtain a second mixture.

[0063] In this invention, the mass of the base oil is 50-80% of the total mass of the base oil, specifically 50%, 55%, 60%, 65%, 70%, 75% or 80%.

[0064] In this invention, the temperature of the remaining base oil is room temperature. The invention involves rapidly cooling the bimetallic soap-base oil into the remaining base oil, which prevents the coarsening of the bimetallic composite soap fibers. In this invention, the temperature of the second mixture can be 80~90℃, specifically 80℃, 82℃, 84℃, 86℃, 88℃, or 90℃.

[0065] In this invention, the difference between the preparation method of the second mixture and the preparation method of the bimetallic soap lies only in that: the heating and melting involves heating and melting a portion of the base oil and long-chain fatty acids; and the cooling involves pouring the first mixture into the remaining base oil and cooling it.

[0066] After obtaining the second mixture, the present invention mixes the second mixture with a composite additive to obtain a lubricating grease composition. In the present invention, mixing the second mixture with the composite additive specifically involves sequentially adding a friction-reducing and anti-wear agent, an antioxidant, a rust inhibitor, and a two-dimensional layered nanomaterial to the second mixture, followed by sequential stirring and milling. In the present invention, the milling can be performed 2 to 4 times, specifically 3 times; the milling can be performed using a three-roll mill.

[0067] The present invention also provides the application of the grease composition described in the above technical solution or the grease composition prepared by the preparation method described in the above technical solution in high-speed heavy-duty equipment.

[0068] In this invention, the high-speed heavy-duty equipment may include large wind turbine gearboxes, high-speed railway bearings, mining and metallurgical equipment bearings and gears, large engineering machinery transmission systems, or heavy rolling mill bearings.

[0069] In this invention, the grease composition can be applied to the lubrication of at least one of piston rings, bearings, and gears in the high-speed, heavy-duty equipment. The grease composition provided by this invention has good mechanical stability and adhesion, is not easily ejected at high speeds, has a maximum non-seize load value greater than 2000N, and possesses excellent extreme pressure performance. It can provide good lubrication protection for high-speed, heavy-duty equipment and prevent wear on key components such as piston rings, bearings, and gears.

[0070] To further illustrate the present invention, the following detailed description of the lubricating grease composition, its preparation method, and its application, in conjunction with embodiments, is provided but should not be construed as limiting the scope of protection of the present invention.

[0071] Example 1 The composition of the grease composition, by weight percentage: The blended base oil comprises 70% PAO100, PAO40, and PAO10 in a mass ratio of 20:60:20. The viscosity of the blended base oil at 100°C is 37.458 mmHg. 2 / s.

[0072] Thickener: 15%, prepared from 12-hydroxystearic acid, lithium hydroxide monohydrate, barium hydroxide octahydrate, and sebacic acid in a mass ratio of 12:1.68:2.58:16.2.

[0073] Two-dimensional layered nanomaterials: 3%, with an overall thickness of 1~5nm, and a mass ratio of graphene to MXenes of 1:1.

[0074] Friction-reducing and wear-resistant agent: 10%, wherein the mass ratio of aminothioester (T323), dialkyl dithiophosphate derivative (IR353) and zinc dialkyl dithiophosphate (ZDDP) is 1:1:3.

[0075] Antioxidant: 1%, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl ester (1076).

[0076] Rust inhibitor: 1%, calcium petroleum sulfonate (T106).

[0077] Preparation of the grease composition: 2 / 3 of the compound base oil and long-chain fatty acid (12-hydroxystearic acid) were mechanically stirred and mixed evenly in a clean container. The mixture was heated to about 100°C to melt the material. The temperature was then raised to 120°C, and a lithium hydroxide monohydrate aqueous solution (concentration of 0.2 g / mL) was added dropwise at a rate of 1-2 seconds / drop. After the addition was complete, the mixture was kept at 120°C for 1 hour to dehydrate. Barium hydroxide octahydrate was added, and the mixture was stirred at 120°C for 30 minutes. Short-chain acid (sebacic acid) was added, and the mixture was stirred at 120°C for 0.5 hours. The temperature was raised to 140°C and stirred for 1 hour. The temperature was then rapidly raised to 210-220°C at a rate of 10°C / min. When the entire material system melted into a homogeneous and transparent liquid, the heat source was removed, and the mixture was poured into the remaining 1 / 3 of the compound base oil and rapidly cooled to 80°C. Then, friction-reducing and anti-wear agents, antioxidants, rust inhibitors, and two-dimensional layered nanomaterials were added sequentially and stirred evenly. The mixture was then milled three times using a three-roll mill to obtain the grease composition. The stirring speed is 80 r / min.

[0078] Example 2 The composition of the grease composition, by weight percentage: Blended base oil: 70%, PAO100, PAO40 and PAO10 in a mass ratio of 20:60:20, viscosity at 100℃: 37.458 mm. 2 / s.

[0079] Thickener: 15%, prepared from 12-hydroxystearic acid, lithium hydroxide monohydrate, barium hydroxide octahydrate, and sebacic acid in a mass ratio of 12:1.68:2.58:16.2.

[0080] Two-dimensional layered nanomaterials: 3%, with an overall thickness of 1~5nm, and a mass ratio of MXenes to MoS2 of 1:1.

[0081] Friction-reducing and wear-resistant agent: 10%, with the mass ratio of aminothioester (T323), dialkyl dithiophosphate derivative (IR353), and zinc dialkyl dithiophosphate (ZDDP) being 1:3:3.

[0082] Antioxidant: 1%, tri-(2,4-di-tert-butylphenyl) phosphite (168).

[0083] Rust inhibitor: 1%, calcium petroleum sulfonate (T106).

[0084] The preparation method of the grease composition is the same as that in Example 1.

[0085] Example 3 The composition of the grease composition, by weight percentage: Blended base oil: 70%, PAO100, PAO40 and PAO10 in a mass ratio of 20:60:20, viscosity at 100℃: 37.458 mm. 2 / s.

[0086] Thickener: 15%, raw materials for preparation are stearic acid, lithium hydroxide monohydrate, barium hydroxide octahydrate, and azelaic acid in a mass ratio of 11.85:1.75:2.68:1.6.

[0087] Two-dimensional layered nanomaterials: 3%, with an overall thickness of 1~5nm, and a mass ratio of MoS2 to black phosphorus of 1:1.

[0088] Friction-reducing and wear-resistant agent: 10% (the mass ratio of aminothioester (T323), dialkyl dithiophosphate derivative (IR353), and zinc dialkyl dithiophosphate (ZDDP) is 3:3:1).

[0089] Antioxidant: 1%, lauryl thiodipropionate (DLTP).

[0090] Rust inhibitor: 1%, calcium petroleum sulfonate (T106).

[0091] The preparation method of the grease composition is the same as that in Example 1.

[0092] Example 4 The composition of the grease composition, by weight percentage: Blended base oil: 70%, PAO100, PAO40 and PAO10 in a mass ratio of 20:70:10, viscosity at 100℃: 42.849 mm. 2 / s.

[0093] Thickener: 15%, raw materials for preparation are stearic acid, lithium hydroxide monohydrate, barium hydroxide octahydrate, and azelaic acid in a mass ratio of 11.85:1.75:2.68:1.6.

[0094] Two-dimensional layered nanomaterials: 3%, with an overall thickness of 1~5nm, and a WS2 to h-BN mass ratio of 1:1.

[0095] Friction-reducing and wear-resistant agent: 10%, with a mass ratio of aminothioester (T323), dialkyl dithiophosphate derivative (IR353), and phosphate amine mixture (IR349) of 3:3:1.

[0096] Antioxidant: 1%, lauryl thiodipropionate (DLTP).

[0097] Rust inhibitor: 1%, calcium petroleum sulfonate (T106).

[0098] The preparation method of the grease composition is the same as that in Example 1.

[0099] Example 5 The composition of the grease composition, by weight percentage: Blended base oil: 70%, PAO100, PAO40 and PAO10 in a mass ratio of 20:70:10, viscosity at 100℃: 42.849 mm. 2 / s.

[0100] Thickener: 15%, prepared from oleic acid, lithium hydroxide monohydrate, barium hydroxide octahydrate, and terephthalic acid in a mass ratio of 12:1.79:2.74:1.41.

[0101] Two-dimensional layered nanomaterials: 3%, with an overall thickness of 1~5nm, and a graphene to MoS2 mass ratio of 1:1.

[0102] Friction-reducing and wear-resistant agent: 10%, with the mass ratio of aminothioester (T323), amine phosphate mixture (IR349), and zinc dialkyl dithiophosphate (ZDDP) being 1:1:3.

[0103] Antioxidant: 1%, lauryl thiodipropionate (DLTP).

[0104] Rust inhibitor: 1%, dinonylnaphthalenesulfonate calcium (T705C).

[0105] The preparation method of the grease composition is the same as that in Example 1.

[0106] Example 6 The composition of the grease composition, by weight percentage: Blended base oil: 80%, with a mass ratio of PAO100, PAO40, and PAO10 of 20:70:10; viscosity at 100℃: 42.849 mmHg. 2 / s.

[0107] Thickener: 10%, prepared from oleic acid, lithium hydroxide monohydrate, barium hydroxide octahydrate, and terephthalic acid in a mass ratio of 8.07:1.2:1.84:0.95.

[0108] Two-dimensional layered nanomaterials: 2%, with an overall thickness of 1~5nm, and a graphene to black phosphorus mass ratio of 1:1.

[0109] Friction-reducing and wear-resistant agent: 6%, with the mass ratio of aminothioester (T323), phosphate amine mixture (IR349), and zinc dialkyl dithiophosphate (ZDDP) being 1:1:3.

[0110] Antioxidant: 1%, lauryl thiodipropionate (DLTP).

[0111] Rust inhibitor: 1%, dinonylnaphthalenesulfonate calcium (T705C).

[0112] The preparation method of the grease composition is the same as that in Example 1.

[0113] Example 7 The composition of the grease composition, by weight percentage: Blended base oil: 80%, with a mass ratio of PAO100, PAO40, and PAO10 of 20:70:10; viscosity at 100℃: 42.849 mmHg. 2 / s.

[0114] Thickener: 10%, raw materials for preparation are ricinoleic acid, lithium hydroxide monohydrate, barium hydroxide octahydrate, and boric acid in a mass ratio of 9.33:1.31:1.01:0.19.

[0115] Two-dimensional layered nanomaterials: 2%, with an overall thickness of 1-5 nm, including graphene and h The BN mass ratio is 1:1.

[0116] Friction-reducing and wear-resistant agent: 6%, with the mass ratio of aminothioester (T323), dialkyl dithiophosphate derivative (IR353), and zinc dialkyl dithiophosphate (ZDDP) being 1:1:3.

[0117] Antioxidant: 1%, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl ester (1076).

[0118] Rust inhibitor: 1%, dinonylnaphthalenesulfonate calcium (T705C).

[0119] The preparation method of the grease composition is the same as that in Example 1.

[0120] Example 8 The composition of the grease composition, by weight percentage: Blended base oil: 80%, with a mass ratio of PAO100, PAO40, and PAO10 of 20:70:10; viscosity at 100℃: 42.849 mmHg. 2 / s.

[0121] Thickener: 10%, raw materials for preparation are ricinoleic acid, lithium hydroxide monohydrate, barium hydroxide octahydrate, and boric acid in a mass ratio of 8.96:1.26:0.97:0.45.

[0122] Two-dimensional layered nanomaterials: 4%, with an overall thickness of 1~5nm, and a mass ratio of MXenes to black phosphorus of 1:1.

[0123] Friction-reducing and wear-resistant agent: 4%, with the mass ratio of aminothioester (T323), dialkyl dithiophosphate derivative (IR353), and zinc dialkyl dithiophosphate (ZDDP) being 1:1:3.

[0124] Antioxidant: 1%, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl ester (1076).

[0125] Rust inhibitor: 1%, dinonylnaphthalenesulfonate calcium (T705C).

[0126] The preparation method of the grease composition is the same as that in Example 1.

[0127] Example 9 The only difference from Example 1 is that graphene is used as a two-dimensional layered nanomaterial.

[0128] Example 10 The only difference from Example 1 is that zinc dialkyl dithiophosphate (ZDDP) is used as the friction-reducing and wear-resistant agent.

[0129] Example 11 The only difference from Example 1 is that no rust inhibitor is added.

[0130] Example 12 The only difference from Example 1 is that the base oil is only PAO10.

[0131] Comparative Example 1 The only difference from Example 1 is that the raw materials for preparing the thickener are only the saponification of 12-hydroxystearic acid and lithium hydroxide monohydrate.

[0132] Comparative Example 2 The only difference from Example 1 is that no antioxidant is added.

[0133] Comparative Example 3 The only difference from Example 1 is that lithium hydroxide monohydrate is replaced with sodium hydroxide.

[0134] Comparative Example 4 The only difference from Example 1 is that lithium hydroxide monohydrate is replaced with potassium hydroxide.

[0135] Comparative Example 5 The only difference from Example 1 is that barium hydroxide octahydrate is replaced with magnesium hydroxide. Magnesium hydroxide cannot be soaped and therefore cannot be used to make grease.

[0136] Comparative Example 6 The only difference from Example 1 is that barium hydroxide octahydrate is replaced with calcium hydroxide.

[0137] Comparative Example 7 The only difference from Example 1 is that no two-dimensional layered nanomaterials, friction-reducing and anti-wear agents, antioxidants and rust inhibitors are added, and the resulting grease is used as a blank grease.

[0138] Test Example 1 The performance of the grease compositions prepared in each embodiment and comparative example, as well as the blank grease, was tested, and the results are shown in Table 1.

[0139] Table 1. Performance test results of the greases and blank greases prepared in the examples and comparative examples.

[0140] Note: Grade description: 1a copper sheet is light orange in color, almost the same as newly polished copper sheet, and is judged to be rust-free; 1b copper sheet is dark orange in color and is judged to be slightly corroded.

[0141] Anti-slip performance test: Apply each grease evenly to a clean steel sheet, apply to 3 sheets, for a total of 6 sides; any displacement or loss of grease on the test sheet is considered slippage; if the grease does not slip off any of the 6 sides, it is considered qualified.

[0142] The grease composition prepared with potassium hydroxide showed severe shear thinning after 100,000 shear cycles, making it impossible to measure the cone penetration after shearing. Magnesium hydroxide could not be soaped and therefore could not be used to prepare grease, so its performance was not tested.

[0143] As shown in Table 1, the grease composition provided by this invention exhibits a lower oil separation rate at high temperatures, effectively suppressing the precipitation of base oil under high-speed, heavy-load conditions and ensuring continuous lubrication. The high oil separation rates of dipotassium-based and calcium-based soaps indicate poor colloidal stability, making them unsuitable as high-speed, heavy-load greases. The grease prepared from the single-lithium soap in Comparative Example 1 has a relatively high oil separation rate due to its limited ability to form a three-dimensional structure to coat the base oil. Table 1 shows the oxidation stability results. Compared to the grease without antioxidants, the pressure drop of the grease composition with added antioxidants decreased from 3 kPa to 1 kPa within a specified time, a very small decrease, demonstrating excellent oxidation resistance. This indicates that the grease composition can effectively slow down oxidation caused by frictional heating under high-speed, heavy-load conditions. In contrast, the oxidation stability of Comparative Example 2, which did not contain antioxidants, deteriorated rapidly. As shown in Table 1, the maximum non-seize load and anti-wear performance results indicate that, compared to the blank grease, the PB value of the grease composition in this invention, after incorporating two-dimensional layered nanomaterials and anti-friction agents, was significantly improved. Compared to the blank grease, the PB value of Example 1 was significantly higher. BThe increase exceeded approximately 1638 N, and the wear scar diameter decreased by more than half, indicating that the added two-dimensional layered nanomaterials and anti-wear additives were effective, exhibiting excellent load-bearing capacity under high loads and meeting the requirements for high loads. However, Example 9, which used only graphene as the two-dimensional layered nanomaterial, and Example 10, which used only zinc dialkyl dithiophosphate (ZDDP) as the friction-reducing and anti-wear agent, showed a decrease in maximum non-seizure load and anti-wear performance compared to the examples due to the limited variety of added two-dimensional layered nanomaterials and friction-reducing and anti-wear agents. From the copper sheet corrosion results in Table 1, the grease composition of Example 11 without rust inhibitor showed slight corrosion, while the other examples of grease compositions with rust inhibitor showed almost no corrosion marks, demonstrating excellent corrosion resistance. This indicates that the grease composition provided by the present invention has excellent protective performance and can better protect high-speed, heavy-load components.

[0144] As shown in Table 1, the cone penetration and shear cone penetration results indicate that after 100,000 shear cycles, the cone penetration changes of the grease compositions in the examples are all within 36.6, demonstrating that the grease compositions provided by this invention have excellent mechanical stability and can meet the requirements of stable lubrication under high-speed and heavy-load conditions. In contrast, the grease compositions of Comparative Example 3 (using sodium-based soap), Comparative Example 4 (using potassium-based soap), and Comparative Example 6 (using calcium-based soap as thickeners) exhibit significant cone penetration changes, indicating poor mechanical stability and unsuitability as high-speed, heavy-load greases.

[0145] The anti-slip properties of the grease were tested using the standard method of NB / SH / T0387-2014. Grease was coated onto a copper sheet, which was then vertically suspended in an oven. After a specific temperature (60±0.5℃) and a specific time (1h), the grease was tested for slippage. The results in Table 1 show that the blank grease formulated with different viscosities of PAO, Examples 1-11, Comparative Examples 1-2, and Comparative Example 6 all passed the tests. However, Example 12 and Comparative Examples 3-4 showed slippage. This indicates that the formulation of different viscosities of PAO significantly improves the anti-slip properties of the grease, ensuring that it is not flung out during high-speed operation. It also demonstrates that grease compositions using sodium-based and potassium-based soaps as thickeners have poor anti-slip properties and are unsuitable as high-speed, heavy-duty greases. However, Example 12, with PAO10 as the base oil, Comparative Example 1, with lithium as the thickener, Comparative Example 3, with sodium as the thickener, and Comparative Example 4, with potassium as the thickener, exhibit poor anti-slip properties due to their single base oil or single soap structure. In summary, the grease composition for high-speed, heavy-duty equipment provided by this invention possesses excellent extreme pressure anti-wear properties, excellent anti-slip properties, oxidation stability, and overall stability, meeting the lubrication requirements of equipment under harsh high-speed, heavy-duty operating conditions.

[0146] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A bimetallic composite soap, wherein the bimetal comprises lithium and barium, and the anion comprises a long-chain fatty acid radical and a short-chain acid radical; the long-chain fatty acid radical has 12 to 20 carbon atoms; the short-chain acid radical comprises borate and / or a short-chain dicarboxylic acid radical, wherein the short-chain dicarboxylic acid radical has ≤10 carbon atoms.

2. The bimetallic composite soap according to claim 1, characterized in that, The long-chain fatty acid anions include at least one of 12-hydroxystearate, stearate, oleate, and ricinoleate. The short-chain dicarboxylic acid anions include at least one of sebacic acid, azelaic acid, terephthalic acid, and tartrate.

3. The method for preparing the bimetallic composite soap according to claim 1 or 2, characterized in that, Includes the following steps: Long-chain fatty acids are heated and melted, and lithium hydroxide aqueous solution is added dropwise to carry out the first saponification reaction and then dehydrated. Barium hydroxide is added to carry out the second saponification reaction, and short-chain acids are added to carry out the third saponification reaction. After heating, the fourth saponification reaction is carried out, and then cooled to obtain bimetallic composite soap.

4. The preparation method according to claim 3, characterized in that, The molar ratio of the long-chain fatty acid to the short-chain acid is 5~10:1; The molar ratio of lithium hydroxide to barium hydroxide is 5~10:1; The ratio of the total molar amount of lithium hydroxide and barium hydroxide to the total molar amount of long-chain fatty acids and short-chain acids is 1.02~1.1:1; The temperatures for the dehydration, first saponification reaction, second saponification reaction, and third saponification reaction are independently 120~140℃; The temperature for the fourth saponification reaction is 140~160℃; The cooling rate is 5~15℃ / min.

5. The use of the bimetallic composite soap according to claim 1 or 2 or the bimetallic composite soap prepared by the preparation method according to claim 3 or 4 in a lubricating grease composition.

6. A lubricating grease composition, characterized in that, It includes the following components in parts by weight: 60-80 parts base oil, 10-20 parts thickener, and 7.5-34 parts compound additives; The thickener includes the bimetallic composite soap according to claim 1 or 2 or the bimetallic composite soap prepared by the preparation method according to claim 3 or 4; The composite additive includes two-dimensional layered nanomaterials, friction-reducing and wear-resistant agents, and antioxidants; the friction-reducing and wear-resistant agents contain at least three elements selected from sulfur, phosphorus, nitrogen, and zinc.

7. The lubricating grease composition according to claim 6, characterized in that, The base oil is a mixture of hydrocarbon oils of different viscosities; the viscosity of the base oil at 100°C is 15~45 mm. 2 / s.

8. The grease composition according to claim 6, characterized in that, The composite additive includes 1-6 parts of two-dimensional layered nanomaterials, 5-20 parts of friction-reducing and wear-resistant agent, and 1-4 parts of antioxidant; The two-dimensional layered nanomaterial includes at least two of graphene, black phosphorus, MXenes, MoS2, and hexagonal boron nitride; the overall thickness of the two-dimensional layered nanomaterial is 1~5 nm; The friction-reducing and wear-resistant agent includes at least three of the following: aminothioester, dialkyl dithiophosphate derivative, zinc dialkyl dithiophosphate, and phosphate amine. The antioxidant includes at least one of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, tri-(2,4-di-tert-butylphenyl) phosphite, and lauryl thiodipropionate.

9. The grease composition according to claim 6 or 8, characterized in that, The composite additive also includes 0.5 to 4 parts of rust inhibitor; The rust inhibitor includes calcium petroleum sulfonate and / or calcium dinonylnaphthalene sulfonate.

10. A method for preparing the lubricating grease composition according to any one of claims 6 to 9, characterized in that, Includes the following steps: Part of the base oil and long-chain fatty acids are heated and melted, and lithium hydroxide aqueous solution is added dropwise to carry out the fifth saponification reaction and then dehydrated. Barium hydroxide is added to carry out the sixth saponification reaction, short-chain acid is added to carry out the seventh saponification reaction, and the temperature is raised to carry out the eighth saponification reaction. After heating, the first mixture is obtained. The first mixture is poured into the remaining base oil and cooled to obtain the second mixture; The second mixture and the composite additive are mixed to obtain a grease composition.

11. The preparation method according to claim 10, characterized in that, The mass of the base oil in question is 50-80% of the total mass of the base oil. The concentration of the lithium hydroxide aqueous solution is 0.05~0.6 g / mL; the dropping rate of the lithium hydroxide aqueous solution can be 1~2 seconds / drop; The temperatures for the dehydration, fifth saponification reaction, sixth saponification reaction, and seventh saponification reaction are independently 120~140℃; The temperature of the eighth saponification reaction is 140~160℃; The temperature of the first mixture is 210~220℃; The temperature of the second mixture is 80~90℃.

12. The application of the grease composition according to any one of claims 6 to 9 or the grease composition prepared by the preparation method according to claim 10 or 11 in high-speed heavy-duty equipment.

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