A biodegradable rail rim lubricating composition and its preparation method

Abstract

This invention relates to the field of lubricant technology and discloses a biodegradable rail wheel rim lubricating composition and its preparation method, comprising 60-88 parts by weight of epoxidized soybean oil base oil, 3-6 parts by weight of organosilicon tetrafluoroborate friction reducer, 3-8 parts by weight of stearic acid, 0.5-5 parts by weight of calcium hydroxide, 1-3.5 parts by weight of aluminum isopropoxide, 1-6 parts by weight of calcium citrate, 1-3 parts by weight of rust inhibitor, and 5-8 parts by weight of thickener. The addition of a temperature-resistant organosilicon tetrafluoroborate friction reducer ensures that the lubricating composition exhibits a low coefficient of friction at different temperatures, which is beneficial for reducing friction and demonstrating excellent friction-reducing and lubricating performance. It has good practical applications in the friction-reducing and lubrication of train track wheel rims.

Description

Technical Field

[0001] This invention relates to the field of lubricant technology, specifically to a biodegradable rail wheel rim lubricating composition and its preparation method. Background Technology

[0002] In my country's high-speed trains, the wheel flanges come into contact with the inner side of the rails, resulting in constant friction. Especially at curves, due to centrifugal force, the wheels are pressed against the rails, causing severe friction and wear on the inner side of the rails against the wheel flanges, thus shortening the service life of both the rails and wheels. Flange lubrication refers to adding lubrication measures at the contact point between the locomotive wheel flange and the rail. This effectively reduces friction on the contact surface, thereby significantly reducing wear on the locomotive wheel flange and rail. Using flange lubricant to lubricate the rails and wheels is the most effective way to reduce friction between the flanges and rails, reduce locomotive power loss, improve wheel-rail interaction, and reduce wheel-rail wear. Currently, the most common method used on Chinese railway locomotives is to install spraying devices and nozzles. These devices allow the train to spray grease onto the inner side of the flanges at a pre-set frequency during operation, ensuring the grease adheres fully to the flanges, reducing friction between rails, and transforming steel-to-steel friction into oil-to-oil friction, thus reducing frictional losses during train operation.

[0003] Lubricants serve various functions, including lubrication, friction reduction, filling gaps, sealing, and rust prevention. They are widely used in railway wheel flanges, automobile engines, transmissions, and precision machine tools. Common lubricants use mineral oils as base oils, which have drawbacks such as difficulty in biodegradation and significant pollution. In recent years, the development of biodegradable lubricants has become a research trend.

[0004] Using vegetable oil-based synthetic esters as base oils for lubricants can compensate for certain performance deficiencies of mineral oil-based lubricants. Furthermore, vegetable oil-based synthetic esters offer advantages such as good biodegradability, simple preparation methods, and good lubrication performance. Examples include castor oil, pentaerythritol oleate, and trimethylolpropane tristearate. Epoxidized soybean oil is inexpensive, readily available, biodegradable, and environmentally friendly, making it widely used in lubricants. Patent CN109536260B discloses an environmentally friendly grease with high lubrication performance and its preparation method. Using epoxidized soybean oil and chlorinated paraffin as base oils, it is compounded with 12-hydroxystearic acid, lithium hydroxide powder, composite heat stabilizers, carboxymethyl cellulose, etc., resulting in an environmentally friendly grease with high lubrication performance and biodegradability. However, this grease does not exhibit a low coefficient of friction or good friction-reducing lubrication properties. Summary of the Invention

[0005] The technical problem to be solved is to provide a lubricating composition for rail wheel rims with good lubrication performance and excellent friction reduction properties, and its preparation method.

[0006] Technical solution: A biodegradable rail wheel rim lubricating composition comprising 60-86 parts by weight of epoxidized soybean oil base oil, 3-6 parts by weight of organosilicon tetrafluoroborate friction reducer, 3-8 parts by weight of stearic acid, 0.5-5 parts by weight of calcium hydroxide, 1-3.5 parts by weight of aluminum isopropoxide, 1-6 parts by weight of calcium citrate, 1-3 parts by weight of rust inhibitor, and 5-8 parts by weight of thickener;

[0007] The preparation methods of epoxidized soybean oil base oil include:

[0008] Step A: Add epoxidized soybean oil and adipic acid to the reaction vessel, heat to 170-180℃, stir and react for 5-10 minutes, stir and cool to room temperature to obtain adipic acid modified epoxidized soybean oil.

[0009] Step B: Add toluene, adipic acid-modified epoxidized soybean oil, trimethylolpropane, and p-toluenesulfonic acid to a reaction vessel equipped with a water separator and a reflux condenser. After reaction in a nitrogen atmosphere, distill under reduced pressure and dry to obtain epoxidized soybean oil ester base oil.

[0010] Preferably, in step A, the mass of adipic acid is 8-14% of the mass of epoxidized soybean oil.

[0011] Preferably, in step B, the mass of trimethylolpropane and p-toluenesulfonic acid are 5-8% and 0.8-1.2% of the mass of adipic acid-modified epoxidized soybean oil, respectively.

[0012] Preferably, the reaction temperature in step B is 155-170℃ and the reaction time is 3-5 hours.

[0013] Preferably, the preparation method of the organosilicon tetrafluoroborate friction reducer includes:

[0014] Step (1): Add acetonitrile, 1,3-bis(3-chloropropyl)-1,1,3,3-tetramethyldisiloxane, and N-methylimidazolium to a reaction vessel equipped with a reflux condenser. Place the vessel in a microwave reactor and react for 8-12 minutes at a power of 500-600W. Cool, distill under reduced pressure, wash the product with petroleum ether, and then recrystallize with ethanol to obtain the organosilicon quaternary ammonium salt. The reaction formula is:

[0015]

[0016] Step (2): Add acetonitrile, organosilicon quaternary ammonium salt, water, and sodium tetrafluoroborate to the reaction vessel, heat to 60-70℃, react for 3-5 hours, remove acetonitrile by vacuum distillation, extract the residual solution with dichloromethane, distill the organic phase under vacuum, wash with acetone, and dry to obtain organosilicon tetrafluoroborate friction reducer. The reaction formula is:

[0017]

[0018] Preferably, in step (1), the mass of N-methylimidazolium is 57-65% of the mass of 1,3-bis(3-chloropropyl)-1,1,3,3-tetramethyldisiloxane.

[0019] Preferably, the mass of sodium tetrafluoroborate is 49-56% of the mass of the organosilicon quaternary ammonium salt.

[0020] Preferred method for preparing biodegradable track wheel rim lubricating composition includes: adding epoxidized soybean oil base oil to a reaction vessel, heating to 115-125℃ and adding aluminum isopropoxide; after the aluminum isopropoxide melts, adding stearic acid and stirring for 30-40 minutes (at this point, stearic acid and aluminum isopropoxide react to generate aluminum isopropoxide-based compounds; in conventional aluminum-based grease production, after their reaction is complete, a certain amount of water must be added to continue the reaction; adding water is dangerous during production, firstly because it is prone to overflow, and secondly because the reaction after adding water will rapidly generate a large amount of isopropanol gas, which is flammable and explosive); cooling to 100-110℃ and adding calcium hydroxide, stirring for 30-40 minutes (at this point, excess stearic acid and calcium hydroxide react to slowly generate water and stearic acid). Calcium citrate, water, and the S1 process product aluminum isopropoxide (which slowly releases isopropanol gas) are reacted. The temperature is raised to 150-155℃, calcium citrate is added and stirred for 30-40 minutes, then epoxidized soybean oil base oil is added, and the temperature is raised to 160-165℃ and held for 20-30 minutes to ensure that the aluminum isopropoxide stearate soap, calcium stearate, and calcium citrate form hydrogen bonds and are organically combined. The material is transferred from the reactor to the blending reactor for cooling, then epoxidized soybean oil base oil is added, and the mixture is circulated and sheared for 60-90 minutes. Finally, organosilicon tetrafluoroborate friction reducer, rust inhibitor, and thickener are added, and the mixture is homogenized under medium and high pressure at 110℃ under 30 MPa pressure, degassed, filtered, and packaged to obtain a biodegradable track wheel rim lubricating composition.

[0021] Technical effect: This invention utilizes a carboxyl group of adipic acid to react with the epoxy group of epoxidized soybean oil to obtain adipic acid-modified epoxidized soybean oil. The introduced carboxyl group then undergoes an esterification reaction with trimethylolpropane to obtain a biodegradable vegetable oil-based epoxidized soybean oil ester, which serves as the base oil for lubricating compositions.

[0022] This invention uses an aluminum-based calcium-based composite soap. Instead of the traditional method of adding water to remove isopropanol during the aluminum-based grease reaction, it uses calcium hydroxide and excess stearic acid to react and generate water, which then replaces the isopropanol gas. This also introduces calcium soap, improving the grease's anti-wear properties. Furthermore, the addition of a certain amount of calcium citrate during the reaction, combined with high-temperature compounding, gives the grease a higher dropping point, allowing it to operate at temperatures above 120°C. Additionally, a certain amount of tackifier improves the grease's adhesion, and a certain amount of rust inhibitor further protects the rails from corrosion.

[0023] This invention uses 1,3-bis(3-chloropropyl)-1,1,3,3-tetramethyldisiloxane, N-methylimidazolium, and sodium tetrafluoroborate as reactants. Through quaternization and ion exchange, a novel organosilicon tetrafluoroborate friction reducer is obtained. This is then compounded with epoxidized soybean oil base oil, stearic acid, calcium hydroxide, aluminum isopropoxide, calcium citrate, rust inhibitors, and thickeners to obtain a biodegradable rail wheel flange lubricating composition. This composition exhibits stable grease formation, high cone penetration, and, with the addition of a temperature-resistant organosilicon tetrafluoroborate friction reducer, a smaller wear track diameter and a lower coefficient of friction at different temperatures, thus reducing friction and demonstrating excellent friction-reducing and lubricating performance. It has good practical applications in the friction reduction and lubrication of train track wheel flanges. Detailed Implementation

[0024] The technical solution of the present invention will be illustrated below with examples. The scope of protection sought by the present invention includes, but is not limited to, the following embodiments.

[0025] The rust inhibitor of this invention is BASF I RGACOR NPA, manufactured by Dongguan Heshibi New Materials Co., Ltd. The tackifier is polyisobutylene PB1400, manufactured by Wuxi Bingju Trading Co., Ltd.

[0026] Example 1

[0027] (1) Add 50g of epoxidized soybean oil and 5.2g of adipic acid to the reaction vessel, heat to 170℃, stir and react for 10min, stir and cool to room temperature to obtain adipic acid modified epoxidized soybean oil.

[0028] (2) Add 30 mL of toluene, 50 g of adipic acid-modified epoxidized soybean oil, 3.2 g of trimethylolpropane, and 0.5 g of p-toluenesulfonic acid to a reaction vessel equipped with a water separator and a reflux condenser. Heat to 160 °C under a nitrogen atmosphere and react for 4 h. Distill under reduced pressure and dry to obtain epoxidized soybean oil ester base oil.

[0029] (3) Add 15 mL of acetonitrile, 3 g of 1,3-bis(3-chloropropyl)-1,1,3,3-tetramethyldisiloxane, and 1.72 g of N-methylimidazolium to a reaction vessel equipped with a reflux condenser. Place the vessel in a microwave reactor and react for 10 min at a power of 500 W. Cool the vessel, distill under reduced pressure, wash the product with petroleum ether, and then recrystallize it with ethanol to obtain organosilicon quaternary ammonium salt.

[0030] (4) Add 20 mL of acetonitrile, 4 g of organosilicon quaternary ammonium salt, 10 mL of water and 1.96 g of sodium tetrafluoroborate to the reaction vessel, heat to 65 °C and react for 5 h. Remove acetonitrile by vacuum distillation, extract the residual solution with dichloromethane, distill the organic phase under vacuum, wash with acetone and dry to obtain organosilicon tetrafluoroborate friction reducer.

[0031] (5) Add 24g of epoxidized soybean oil base oil to the reactor, heat to 115℃ and add 2.2g of aluminum isopropoxide. After the aluminum isopropoxide melts, add 4.6g of stearic acid and stir for 40min. Reduce the temperature to 100℃ and add 3.6g of calcium hydroxide and stir for 30min. Increase the temperature to 150℃ and add 1g of calcium citrate and stir for 40min. Add another 24g of epoxidized soybean oil base oil and continue to heat to 165℃ and keep warm for 20min. Transfer the material from the reactor to the blending tank for cooling. Add another 24g of epoxidized soybean oil base oil and circulate shear for 60min. Finally, add 3g of organosilicon tetrafluoroborate friction reducer, 2g of rust inhibitor, and 8g of thickener. Homogenize under high pressure, degas, filter, and package to obtain a biodegradable track wheel rim lubricating composition.

[0032] Example 2

[0033] (1) Add 50g of epoxidized soybean oil and 7g of adipic acid to the reaction vessel, heat to 170℃, stir and react for 10min, stir and cool to room temperature to obtain adipic acid modified epoxidized soybean oil.

[0034] (2) Add 30 mL of toluene, 50 g of adipic acid-modified epoxidized soybean oil, 2.5 g of trimethylolpropane, and 0.4 g of p-toluenesulfonic acid to a reaction vessel equipped with a water separator and a reflux condenser. Heat to 155 °C under a nitrogen atmosphere and react for 5 h. Distill under reduced pressure and dry to obtain epoxidized soybean oil ester base oil.

[0035] (3) Add 20 mL of acetonitrile, 3 g of 1,3-bis(3-chloropropyl)-1,1,3,3-tetramethyldisiloxane, and 1 1.95 g of N-methylimidazole to a reaction vessel equipped with a reflux condenser. Place the vessel in a microwave reactor and react for 12 min at a power of 500 W. Cool the vessel, distill under reduced pressure, wash the product with petroleum ether, and then recrystallize it with ethanol to obtain the organosilicon quaternary ammonium salt.

[0036] (4) Add 25 mL of acetonitrile, 4 g of organosilicon quaternary ammonium salt, 15 mL of water and 2.24 g of sodium tetrafluoroborate to the reaction vessel, heat to 60 °C and react for 5 h. Remove acetonitrile by vacuum distillation, extract the residual solution with dichloromethane, distill the organic phase under vacuum, wash with acetone and dry to obtain organosilicon tetrafluoroborate friction reducer.

[0037] (5) Add 20g of epoxidized soybean oil base oil to the reactor, heat to 115℃ and add 3.5g of aluminum isopropoxide. After the aluminum isopropoxide melts, add 3g of stearic acid and stir for 30min. Reduce the temperature to 100℃ and add 0.5g of calcium hydroxide and stir for 30min. Increase the temperature to 155℃ and add 4.6g of calcium citrate and stir for 30min. Add another 20g of epoxidized soybean oil base oil and continue to heat to 160℃ and keep warm for 30min. Transfer the material from the reactor to the blending tank for cooling. Add another 20g of epoxidized soybean oil base oil and circulate and shear for 90min. Finally, add 4g of organosilicon tetrafluoroborate friction reducer, 3g of rust inhibitor, and 7g of thickener. Homogenize under high pressure, degas, filter, and package to obtain a biodegradable track wheel rim lubricating composition.

[0038] Example 3

[0039] (1) Add 50g of epoxidized soybean oil and 4g of adipic acid to the reaction vessel, heat to 180℃, stir for 5min, stir and cool to room temperature to obtain adipic acid modified epoxidized soybean oil.

[0040] (2) Add 30 mL of toluene, 50 g of adipic acid-modified epoxidized soybean oil, 4 g of trimethylolpropane, and 0.6 g of p-toluenesulfonic acid to a reaction vessel equipped with a water separator and a reflux condenser. Heat to 170 °C under a nitrogen atmosphere and react for 3 h. Distill under reduced pressure and dry to obtain epoxidized soybean oil ester base oil.

[0041] (3) Add 15 mL of acetonitrile, 3 g of 1,3-bis(3-chloropropyl)-1,1,3,3-tetramethyldisiloxane and 1.71 g of N-methylimidazolium to a reaction vessel equipped with a reflux condenser. Place the vessel in a microwave reactor and react for 8 min at a power of 600 W. Cool the vessel, distill under reduced pressure, wash the product with petroleum ether, and then recrystallize it with ethanol to obtain organosilicon quaternary ammonium salt.

[0042] (4) Add 25 mL of acetonitrile, 4 g of organosilicon quaternary ammonium salt, 15 mL of water and 2.24 g of sodium tetrafluoroborate to the reaction vessel, heat to 70 °C and react for 3 h. Remove acetonitrile by vacuum distillation, extract the residual solution with dichloromethane, distill the organic phase under vacuum, wash with acetone and dry to obtain organosilicon tetrafluoroborate friction reducer.

[0043] (5) Add 28g of epoxidized soybean oil base oil to the reactor, heat to 120℃ and add 1g of aluminum isopropoxide. After the aluminum isopropoxide melts, add 8g of stearic acid and stir for 40min. Reduce the temperature to 100℃ and add 5g of calcium hydroxide and stir for 40min. Increase the temperature to 150℃, add 6g of calcium citrate and stir for 30min. Add 28g of epoxidized soybean oil base oil and continue to heat to 160℃ and keep warm for 30min. Transfer the material from the reactor to the blending tank for cooling. Add 28g of epoxidized soybean oil base oil and circulate shear for 60min. Finally, add 5g of organosilicon tetrafluoroborate friction reducer, 1g of rust inhibitor, and 5g of thickener. Homogenize under high pressure, degas, filter, and package to obtain a biodegradable track wheel rim lubricating composition.

[0044] Example 4

[0045] (1) Prepare epoxidized soybean oil base oil according to the method of Example 1.

[0046] (2) Prepare organosilicon tetrafluoroborate friction reducer according to the method of Example 1.

[0047] (3) Add 26g of epoxidized soybean oil base oil to the reactor, heat to 125℃ and add 1.6g of aluminum isopropoxide. After the aluminum isopropoxide melts, add 6.2g of stearic acid and stir for 30min. Reduce the temperature to 100℃ and add 4.4g of calcium hydroxide and stir for 40min. Increase the temperature to 155℃ and add 2.6g of calcium citrate and stir for 30min. Add another 26g of epoxidized soybean oil base oil and continue to heat to 160℃ and keep warm for 30min. Transfer the material from the reactor to the blending tank for cooling. Add another 26g of epoxidized soybean oil base oil and circulate shear for 60min. Finally, add 6g of organosilicon tetrafluoroborate friction reducer, 2.2g of rust inhibitor, and 6.8g of thickener. Homogenize under high pressure, degas, filter, and package to obtain a biodegradable track wheel rim lubricating composition.

[0048] Comparative Example 1

[0049] (1) Prepare organosilicon tetrafluoroborate friction reducer according to the method of Example 1.

[0050] (2) Add 24g of epoxidized soybean oil to the reactor, heat to 115℃ and add 2.2g of aluminum isopropoxide. After the aluminum isopropoxide melts, add 4.6g of stearic acid and stir for 40min. Reduce the temperature to 100℃ and add 3.6g of calcium hydroxide and stir for 30min. Increase the temperature to 150℃ and add 1g of calcium citrate and stir for 40min. Add 24g of epoxidized soybean oil and continue to heat to 165℃ and keep warm for 20min. Transfer the material from the reactor to the mixing tank for cooling. Add 24g of epoxidized soybean oil and circulate and shear for 60min. Finally, add 3g of organosilicon tetrafluoroborate friction reducer, 2g of rust inhibitor, and 8g of thickener. Homogenize under high pressure, degas, filter, and package to obtain a biodegradable track wheel rim lubricating composition.

[0051] Comparative Example 2

[0052] (1) Prepare adipic acid modified epoxidized soybean oil according to the method of Example 1.

[0053] (2) Prepare organosilicon tetrafluoroborate friction reducer according to the method of Example 1.

[0054] (3) Add 24g of adipic acid-modified epoxidized soybean oil to the reactor, heat to 115℃ and add 2.2g of aluminum isopropoxide. After the aluminum isopropoxide melts, add 4.6g of stearic acid and stir for 40min. Reduce the temperature to 100℃ and add 3.6g of calcium hydroxide and stir for 30min. Increase the temperature to 150℃ and add 1g of calcium citrate and stir for 40min. Add 24g of adipic acid-modified epoxidized soybean oil and continue to heat to 165℃ and keep warm for 20min. Transfer the material from the reactor to the blending vessel for cooling. Add 24g of adipic acid-modified epoxidized soybean oil and circulate and shear for 60min. Finally, add 3g of organosilicon tetrafluoroborate friction reducer, 2g of rust inhibitor, and 8g of thickener. Homogenize under high pressure, degas, filter, and package to obtain a biodegradable track wheel rim lubricating composition.

[0055] Comparative Example 3

[0056] (1) Prepare epoxidized soybean oil base oil according to the method of Example 1.

[0057] (2) Add 24g of epoxidized soybean oil base oil to the reactor, heat to 115℃ and add 2.2g of aluminum isopropoxide. After the aluminum isopropoxide melts, add 4.6g of stearic acid and stir for 40min. Reduce the temperature to 100℃ and add 3.6g of calcium hydroxide and stir for 30min. Increase the temperature to 150℃ and add 1g of calcium citrate and stir for 40min. Add another 24g of epoxidized soybean oil base oil and continue to heat to 165℃ and keep warm for 20min. Transfer the material from the reactor to the blending tank for cooling. Add another 24g of epoxidized soybean oil base oil and circulate and shear for 60min. Finally, add 2g of rust inhibitor and 8g of thickener, homogenize under high pressure, degas, filter, and package to obtain a biodegradable track wheel rim lubricating composition.

[0058] Comparative Example 4

[0059] (1) Add 15 mL of acetonitrile, 3 g of 1,6-dichlorohexane, and 3.18 g of N-methylimidazole to a reaction vessel equipped with a reflux condenser. Place the vessel in a microwave reactor and react for 10 min at a power of 500 W. Cool, distill under reduced pressure, wash the product with petroleum ether, and dry to obtain a quaternary ammonium salt. The structural formula is:

[0060]

[0061] (2) Add 20 mL of acetonitrile, 4 g of quaternary ammonium salt, 10 mL of water, and 2.78 g of sodium tetrafluoroborate to a reaction vessel. Heat to 65 °C and react for 5 h. Remove acetonitrile by vacuum distillation, dry to remove water, wash with petroleum ether, and dry to obtain a tetrafluoroborate friction reducer. The structural formula is:

[0062] (3) Add 24g of epoxidized soybean oil base oil to the reactor, heat to 115℃ and add 2.2g of aluminum isopropoxide. After the aluminum isopropoxide melts, add 4.6g of stearic acid and stir for 40min. Reduce the temperature to 100℃ and add 3.6g of calcium hydroxide and stir for 30min. Increase the temperature to 150℃ and add 1g of calcium citrate and stir for 40min. Add 24g of epoxidized soybean oil base oil and continue to heat to 165℃ and keep warm for 20min. Transfer the material from the reactor to the blending tank for cooling. Add 24g of epoxidized soybean oil base oil and circulate shear for 60min. Finally, add 3g of tetrafluoroborate friction reducer, 2g of rust inhibitor, and 8g of thickener. Homogenize under high pressure, degas, filter, and package to obtain a biodegradable track wheel rim lubricating composition.

[0063] Observe the grease-forming stability of the biodegradable track wheel rim lubricant composition.

[0064] The penetration of the lubricating composition was tested according to the method of GB / T 269-2023.

[0065] The degradation rate of the lubricating composition was tested according to the method of GB / T 21856-2008.

[0066] The corrosion resistance of the lubricating composition was tested according to the method of GB / T 5018-2008.

[0067] The performance test results are shown in Table 1.

[0068] Table 1: Performance Tests

[0069]

[0070] The anti-wear properties and wear track diameter of the lubricating composition were tested using a four-ball friction testing machine according to SHT 0204-1992, at a test temperature of 75℃. When testing the coefficient of friction of the lubricating composition, the load was 196N, the rotation speed was 1000 r / min, and the test temperature was 75-100℃. The performance test results are shown in Table 2.

[0071] Table 2: Performance Testing

[0072]

[0073] As shown in Tables 1 and 2, in Examples 1-4, the esterification product of adipic acid-modified epoxidized soybean oil and trimethylolpropane, epoxidized soybean oil trimethylolpropane ester, was used as the base oil of the lubricating composition, and organosilicon tetrafluoroborate was used as the friction reducer. The resulting biodegradable track wheel rim lubricating composition has the characteristics of stable grease formation and large cone penetration. In addition, the addition of temperature-resistant organosilicon tetrafluoroborate friction reducer resulted in a smaller wear track diameter and a smaller coefficient of friction at different temperatures, demonstrating excellent friction-reducing and lubrication performance.

[0074] Comparative Examples 1 and 2 used epoxidized soybean oil and adipic acid-modified epoxidized soybean oil as the base oils for their lubricating compositions. The resulting grease formation was unstable, and the penetration was small, while the wear track diameter and friction coefficient were large.

[0075] Comparative Example 3, which did not contain silicone tetrafluoroborate friction reducer, had larger wear track diameter and friction coefficient, resulting in poor friction reduction and lubrication performance.

[0076] The tetrafluoroborate friction reducer added in Comparative Example 4 does not contain an organosilicon structure, has poor temperature resistance, and poor friction reduction and lubrication performance. This results in a larger coefficient of friction and wear track diameter in the lubrication composition compared to the examples, leading to poor friction reduction and lubrication performance.

[0077] The above embodiments are merely best examples and are not intended to limit the implementation of the present invention. In addition to the above embodiments, the present invention may have other embodiments. All technical solutions formed by equivalent substitution or equivalent transformation fall within the protection scope claimed by the present invention.

Claims

1. A biodegradable rail rim lubricating composition, characterized in that, The biodegradable track wheel rim lubricating composition comprises 60-86 parts by weight of epoxidized soybean oil base oil, 3-6 parts by weight of organosilicon tetrafluoroborate friction reducer, 3-8 parts by weight of stearic acid, 0.5-5 parts by weight of calcium hydroxide, 1-3.5 parts by weight of aluminum isopropoxide, 1-6 parts by weight of calcium citrate, 1-3 parts by weight of rust inhibitor, and 5-8 parts by weight of tackifier polyisobutylene PB1400. The preparation method of the epoxidized soybean oil base oil includes: Step A: Add epoxidized soybean oil and adipic acid to a reaction vessel, heat to 170-180℃, stir and react for 5-10 minutes, stir and cool to room temperature to obtain adipic acid-modified epoxidized soybean oil; wherein the mass of adipic acid is 8-14% of the mass of epoxidized soybean oil; Step B: Toluene, adipic acid-modified epoxidized soybean oil, trimethylolpropane, and p-toluenesulfonic acid are added to a reaction vessel equipped with a water separator and a reflux condenser. The reaction is carried out under a nitrogen atmosphere at 155-170℃ for 3-5 hours. After the reaction, the mixture is distilled under reduced pressure and dried to obtain epoxidized soybean oil ester base oil. The mass percentages of trimethylolpropane and p-toluenesulfonic acid are 5-8% and 0.8-1.2% of the mass of the adipic acid-modified epoxidized soybean oil, respectively. The structural formula of the organosilicon tetrafluoroborate friction reducer is: 。 2. The biodegradable track rim lubricating composition according to claim 1, characterized in that, The preparation method of the organosilicon tetrafluoroborate friction reducer includes: Step (1): Add acetonitrile, 1,3-bis(3-chloropropyl)-1,1,3,3-tetramethyldisiloxane, and N-methylimidazolium to a reaction vessel equipped with a reflux condenser. Place the vessel in a microwave reactor for reaction, distill under reduced pressure, wash, and recrystallize to obtain organosilicon quaternary ammonium salt. Step (2): Add acetonitrile, organosilicon quaternary ammonium salt, water, and sodium tetrafluoroborate to the reaction vessel, heat to 60-70℃, react for 3-5 hours, distill under reduced pressure, extract, wash, and dry to obtain organosilicon tetrafluoroborate friction reducer.

3. The biodegradable track rim lubricating composition according to claim 2, characterized in that, In step (1), the mass of N-methylimidazolium is 57-65% of the mass of 1,3-bis(3-chloropropyl)-1,1,3,3-tetramethyldisiloxane.

4. The biodegradable track rim lubrication composition according to claim 2, characterized in that, In step (1), the power of the microwave reactor during the reaction is 500-600W, and the reaction time is 8-12min.

5. The biodegradable track rim lubricating composition according to claim 2, characterized in that, In step (2), the mass of sodium tetrafluoroborate is 49-56% of the mass of organosilicon quaternary ammonium salt.

6. A method for preparing a biodegradable rail rim lubricating composition as described in any one of claims 1-5, characterized in that, The preparation method includes: adding epoxidized soybean oil base oil into a reaction vessel, heating to 115-125℃ and adding aluminum isopropoxide; after the aluminum isopropoxide melts, adding stearic acid and stirring for 30-40 minutes; lowering the temperature to 100-110℃ and adding calcium hydroxide, stirring for 30-40 minutes; raising the temperature to 150-155℃ and adding calcium citrate, stirring for 30-40 minutes, then adding more epoxidized soybean oil base oil, continuing to raise the temperature to 160-165℃ and holding for 20-30 minutes; transferring the material from the reaction vessel to a blending vessel for cooling, then adding more epoxidized soybean oil base oil, and circulating shearing for 60-90 minutes; finally adding organosilicon tetrafluoroborate friction reducer, rust inhibitor, and thickener, high-pressure homogenization, degassing, filtration, and packaging to obtain a biodegradable track wheel rim lubricating composition.

Images