Water-based wheel-rail friction modifier and method of making

Abstract

The application discloses a water-based wheel-rail friction modifier and a preparation method thereof, and raw materials include bentonite, talcum powder, molybdenum disulfide, modified zirconium phosphate, copper-based nanomaterial, silicon dioxide, magnetic iron oxide, sodium silicate, metal passivator, water-based epoxy resin, acrylic emulsion, water-based polyurethane, polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer, ethylene glycol, modified wheat straw powder, sodium dodecyl sulfate, antioxidant, AMP-95, defoaming agent and deionized water. After the above ingredients are weighed, they are sequentially stirred and mixed, and then are ground and homogenized to obtain a finished product. The application solves the problems of the existing water-based tread modifier, such as large friction coefficient fluctuation, easy failure at high temperature and metal corrosion of the water-based system.

Description

Technical Field

[0001] This invention belongs to the field of lubricant technology, specifically relating to a water-based wheel-rail friction modifier and its preparation method. Background Technology

[0002] The wheel-rail system is the core load-bearing and transmission component of railway transportation, and its friction and wear characteristics directly determine the safety, economy, and service life of railway operations. With the development of railways towards high speed and heavy load, the contact stress and impact load on the wheel-rail interface have significantly increased, especially on small-radius curves. This makes it prone to damage such as rail corrugation, polygonal wheel wear, and rolling contact fatigue cracks, accompanied by severe wheel-rail whistling noise. This not only greatly increases the cost of wheel-rail replacement and maintenance but also seriously threatens traffic safety.

[0003] To mitigate wheel-rail damage, the industry commonly employs flange-railside lubrication technology, which reduces wear by lowering the adhesion coefficient between the wheel flange and the rail side. This technology is relatively mature. However, controlling the interface between the wheel tread and the rail top presents specific technical requirements: an excessively low adhesion coefficient can cause wheel slippage and spinning, resulting in insufficient traction or excessively long braking distances; an excessively high adhesion coefficient will exacerbate wear and fatigue damage. Therefore, tread friction modifiers must precisely control the adhesion coefficient within a safe range, but existing technologies struggle to simultaneously meet the comprehensive requirements of "precise control, high load-bearing capacity, and long-term stability."

[0004] Water-based lubricants are becoming a development trend due to their good cooling performance, environmental friendliness, and low cost. However, pure water-based systems have inherent defects such as low viscosity, poor film-forming properties, and easy corrosion of metals. Existing water-based tread modifiers mostly improve performance by adding a single friction-reducing component, which generally suffers from problems such as large fluctuations in the coefficient of friction, easy failure at high temperatures, and easy detachment of the lubricating film. Some products excessively add low-friction coefficient components in pursuit of friction reduction effects, posing a driving safety hazard. Moreover, most products have not solved the metal corrosion problem of water-based systems, which can easily cause wheel and rail corrosion with long-term use. Summary of the Invention

[0005] The purpose of this invention is to provide a water-based wheel-rail friction modifier, which solves the problems of large fluctuations in the friction coefficient, easy failure at high temperatures, and metal corrosion in existing water-based tread modifiers.

[0006] The first technical solution adopted in this invention is a water-based wheel-rail friction modifier, prepared from the following raw materials in parts by weight: 8-12 parts bentonite, 3-10 parts talc, 10-16 parts molybdenum disulfide, 3-15 parts modified zirconium phosphate, 1-3 parts copper-based nanomaterials, 2-3 parts silica, 1-2 parts magnetic iron oxide, 2-3 parts sodium silicate, 1-2 parts metal passivator, 30-80 parts waterborne epoxy resin, 20-35 parts acrylic emulsion, 15-20 parts waterborne polyurethane, 1-2 parts polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer, 15-20 parts ethylene glycol, 8-15 parts modified wheat straw powder, 1-2 parts sodium dodecyl sulfate, 0.5-1 part antioxidant, 1-2 parts AMP-95, 1-3 parts defoamer, and 50-100 parts deionized water.

[0007] The first technical solution of the present invention is further characterized in that, The antioxidant is composed of one or two of 2,6-di-tert-butyl-p-cresol or gallic acid esters in any proportion; The metal passivating agent is composed of one or two of thiadiazole dimers or benzotriazole in any ratio.

[0008] Copper-based nanomaterials include one or two of the following: nano-copper, nano-cuprous oxide, nano-cuprous oxide-copper, and nano-copper oxide, in any ratio.

[0009] The second technical solution adopted in this invention is a method for preparing a water-based wheel-rail friction modifier. Using the above-mentioned raw material ratio, two-thirds of the deionized water is added to the reaction vessel, followed by bentonite and talc powder, and the mixture is stirred at 400-500 r / min for 5-10 min. Then, ethylene glycol, sodium dodecyl sulfate, a triblock copolymer, and an antioxidant are added, and the mixture is stirred at the same speed for 5-8 min. Next, molybdenum disulfide, modified zirconium phosphate, modified wheat straw powder, silicon dioxide, magnetic iron oxide, sodium silicate, and a metal passivator are added, and the mixture is stirred at the same speed for 15-20 min. A resin mixture containing copper-based nanomaterials is added, and the mixture is stirred at 300-400 r / min for 8-10 min. AMP-95 and an antifoaming agent are added, and the mixture is stirred for 5-6 min. Finally, the remaining one-third of the deionized water is added, and the mixture is stirred for 10-16 min, followed by grinding in a mill for 5-10 min to obtain the product.

[0010] The second technical solution of the present invention is further characterized in that, The modified zirconium phosphate is prepared by taking water, ferric chloride, calcium chloride and zirconium phosphate in a mass ratio of (5-7):(1-2):(1-2):(6-9). After dissolving ferric chloride and calcium chloride in water, zirconium phosphate is added to obtain a viscous system. The system is then dried and calcined at 250-300℃ for 50-60 min. The temperature is then raised to 500-550℃ and calcined for 100-120 min before annealing to obtain the modified zirconium phosphate.

[0011] The modified wheat straw powder is prepared by taking water, calcium hydroxide and wheat straw powder in a mass ratio of (14-16):1:(8-12). After dissolving the calcium hydroxide in water, the wheat straw powder is added to obtain a viscous system, which is then dried and calcined at 100-120℃ for 50-60 minutes to obtain the modified wheat straw powder.

[0012] The preparation method of the resin mixture containing copper-based nanomaterials is as follows: add waterborne epoxy resin, acrylic emulsion and waterborne polyurethane to copper-based nanomaterials, and stir at a speed of 300-400 r / min for 3 min-5 min.

[0013] The preparation method of copper nanomaterials is as follows: copper acetate is dissolved in ethylene glycol to obtain a copper acetate ethylene glycol solution, and then reduced with hydrazine hydrate to obtain a copper nanomaterial suspension. The mass ratio of copper acetate, ethylene glycol and hydrazine hydrate is (1-2):(15-20):(0.2-0.3). The preparation method of nano-cuprous oxide is as follows: copper acetate is dissolved in ethylene glycol to obtain a copper acetate ethylene glycol solution, and then reduced with 0.1 mol / L ascorbic acid solution to obtain a nano-cuprous oxide suspension. The mass ratio of copper acetate, ethylene glycol and ascorbic acid solution is (1-2):(15-20):(0.6-1.2). In the preparation of cuprous oxide-copper compounds, hydrazine hydrate at a mass ratio of 0.1-0.3 can be added to a nano-cuprous oxide suspension to obtain cuprous oxide-copper compounds; The preparation method of nano copper oxide is as follows: copper acetate is dissolved in ethylene glycol to obtain copper acetate ethylene glycol solution, sodium hydroxide is added and heated to 60-80℃ and stirred for 25-30 min to obtain nano copper oxide suspension. The mass ratio of copper acetate, ethylene glycol and sodium hydroxide is (1-2):(15-20):(0.4-1).

[0014] The beneficial effects of this invention are: (1) This invention adopts the reverse design concept of "high friction substrate + gradient friction reduction control": First, a high-adhesion base film layer is constructed through a ternary composite film-forming system of waterborne epoxy resin, acrylic emulsion, and waterborne polyurethane to provide stable basic friction performance; then, through the compatibility of solid friction-reducing agents such as molybdenum disulfide, the friction coefficient is precisely reduced to a moderate range for driving safety. At the same time, copper-based nanomaterials with gradient hardness are introduced. Soft nano-copper is easy to flow plastically to form a continuous transfer film, repair micro-damage in situ and quickly dissipate frictional heat, while hard copper compounds improve heavy-load wear resistance; the viscosity of the system is controlled by modified wheat straw powder and inorganic thickener, and after high-temperature carbonization, it is combined with nanomaterials to stabilize the friction coefficient, while consolidating the film layer structure and avoiding sudden changes in performance after rolling. This solves the pain point of existing products having large fluctuations in friction coefficient and difficulty in balancing safety and friction reduction.

[0015] (2) This invention constructs a multi-level synergistic protection mechanism: a regular labyrinth barrier structure is formed by calcium and iron-modified layered zirconium phosphate, which prolongs the penetration path of corrosive media and releases active rust-preventing components, achieving a triple rust-preventing effect of physical barrier + chemical passivation + cathodic protection. It also has excellent thermal stability and can maintain its protective performance at high temperatures. On this basis, a thiadiazole dimer-type metal passivating agent is added to form a dense double-tooth coordination passivation film on the wheel and rail surface; combined with components such as sodium silicate and AMP-95, the system is made weakly alkaline, which increases the surface potential of the metal. Multiple mechanisms work together to inhibit the electrochemical corrosion of steel, achieving wear reduction and control without damaging the wheel and rail substrate.

[0016] (3) This invention utilizes the complementary properties of three water-based resins: epoxy resin provides strong adhesion, acrylic emulsion enhances weather resistance and fast drying, and polyurethane strengthens the toughness and wear resistance of the film layer, forming a film-forming substrate that combines mechanical strength and flexibility. Combined with the efficient thermal conductivity of nano-copper, heat from the friction interface is quickly dissipated, preventing localized high temperatures from causing resin softening and carbonization. Furthermore, the use of inorganic fillers such as bentonite and talc enhances the film layer's load-bearing capacity and impact and vibration resistance, making the film layer less prone to cracking and detachment under high contact stress during high-speed, heavy-load conditions. This significantly extends the effective working cycle of the regulator and reduces railway operation and maintenance costs. Detailed Implementation

[0017] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0018] Example 1 This invention relates to a water-based wheel-rail friction modifier, prepared from the following raw materials in parts by weight: 8-12 parts bentonite, 3-10 parts talc, 10-16 parts molybdenum disulfide, 3-15 parts modified zirconium phosphate, 1-3 parts copper-based nanomaterials, 2-3 parts silica, 1-2 parts magnetic iron oxide, 2-3 parts sodium silicate, 1-2 parts metal passivator, 30-80 parts waterborne epoxy resin, 20-35 parts acrylic emulsion, 15-20 parts waterborne polyurethane, 1-2 parts polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer, 15-20 parts ethylene glycol, 8-15 parts modified wheat straw powder, 1-2 parts sodium dodecyl sulfate, 0.5-1 part antioxidant, 1-2 parts AMP-95, 1-3 parts defoamer, and 50-100 parts deionized water.

[0019] This embodiment adopts an overall design concept of "ternary composite film formation + gradient friction reduction control + multiple anti-corrosion protection". Through the synergistic effect of waterborne epoxy resin, acrylic emulsion and waterborne polyurethane, a film-forming substrate with high adhesion and high weather resistance is constructed. With the precise combination of molybdenum disulfide and gradient hardness copper-based nanomaterials, the friction coefficient of the wheel-rail interface can be stably controlled within a safe and moderate range. This effectively reduces wheel-rail wear and noise, and avoids traction and braking failure caused by excessively low friction coefficient. At the same time, it integrates the physical barrier of modified zirconium phosphate, the chemical passivation of metal passivating agents and the cathodic protection of the weak alkaline system to achieve excellent anti-corrosion performance. The all-water-based formula can be naturally evaporated and decomposed after use, with little pollution to the track bed, and has both environmental protection and long-term stability.

[0020] Example 2 Based on Example 1 above, the antioxidant of this invention is composed of one or two of 2,6-di-tert-butyl-p-cresol or gallic acid esters in any ratio; wherein 2,6-di-tert-butyl-p-cresol has high thermal stability and low volatility, and can effectively inhibit the oxidative degradation of organic components under high temperature friction environment, while gallic acid esters have both anti-hydrolysis and metal ion chelating capabilities. The combination of the two can produce a synergistic effect, significantly improving the anti-aging performance and shelf life of the product.

[0021] The metal passivating agent is composed of one or two of thiadiazole dimers or benzotriazole in any ratio. The thiadiazole dimer can form a dense bidental coordination passivation film with iron atoms on the rail surface, while providing excellent extreme pressure and anti-wear performance. Benzotriazole has good passivation effect on a variety of metals such as copper and iron, and has excellent stability in alkaline environment. The combination of the two constructs a multi-layer metal protection system, which not only achieves efficient corrosion protection, but also further enhances the anti-wear and extreme pressure performance of the modifier.

[0022] Copper-based nanomaterials include one or two of the following: nano-copper, nano-cuprous oxide, nano-cuprous oxide-copper, and nano-copper oxide, in any ratio. They form a copper-based lubrication system with gradient hardness. Soft nano-copper is soft and has excellent ductility. During friction, it can easily flow plastically to form a continuous and uniform transfer film, which can achieve in-situ repair and self-healing of micro-damage and quickly dissipate frictional heat. Hard copper compounds have higher hardness and better wear resistance, and can provide stable anti-wear support under heavy-load conditions. The two work together to balance the friction reduction effect and driving safety, and avoid drastic fluctuations in the coefficient of friction.

[0023] Example 3 The preparation method of the water-based wheel-rail friction modifier of the present invention adopts the above-mentioned raw material ratio, adding two-thirds of deionized water to the reaction vessel, adding bentonite and talc powder, and stirring at 400-500 r / min for 5-10 min; then adding ethylene glycol, sodium dodecyl sulfate, triblock copolymer and antioxidant, and stirring at the same speed for 5-8 min; adding molybdenum disulfide, modified zirconium phosphate, modified wheat straw powder, silicon dioxide, magnetic iron oxide, sodium silicate and metal passivator, and continuing to stir at the same speed for 15-20 min; adding a resin mixture containing copper-based nanomaterials, and stirring at 300-400 r / min for 8-10 min; adding AMP-95 and defoamer and stirring for 5-6 min; finally adding the remaining one-third of deionized water and stirring for 10-16 min, and then grinding with a grinder for 5-10 min to obtain the product.

[0024] The preparation method of modified zirconium phosphate is as follows: water, ferric chloride, calcium chloride and zirconium phosphate are taken in a mass ratio of (5-7):(1-2):(1-2):(6-9). Ferric chloride and calcium chloride are dissolved in water and then added to zirconium phosphate. After obtaining a viscous system, it is dried and then fired at 250-300℃ for 50-60min to remove bound water and residual organic impurities in the system, so that the zirconium phosphate layered structure is initially unfolded. Then the temperature is raised to 500-550℃ and fired for 100-120min to make calcium and iron ions uniformly embedded in the zirconium phosphate layered structure to form a regular intercalation structure. After annealing, modified zirconium phosphate is obtained, which has the triple rust prevention effect of physical barrier, chemical passivation and cathodic protection. The thermal stability is greatly improved and it can still maintain protective performance in high temperature friction environment.

[0025] The preparation method of modified wheat straw powder is as follows: water, calcium hydroxide and wheat straw powder are taken in a mass ratio of (14-16):1:(8-12). After dissolving the calcium hydroxide in water, the wheat straw powder is added to obtain a viscous system, which is then dried. Then, it is calcined at 100-120℃ for 50-60 minutes to remove easily decomposable impurities such as lignin and hemicellulose in the wheat straw powder. At the same time, the surface hydroxyl groups are activated to improve its compatibility with the aqueous system, thus obtaining modified wheat straw powder. It can not only precisely control the viscosity of the system, but also carbonize under frictional high temperature to form a hard carbon skeleton, which works synergistically with copper-based nanomaterials to stabilize the friction coefficient and prevent the friction coefficient from dropping sharply.

[0026] The preparation method of the resin mixture containing copper-based nanomaterials is as follows: add waterborne epoxy resin, acrylic emulsion and waterborne polyurethane to the copper-based nanomaterials, and stir at a speed of 300-400 r / min for 3 min-5 min; adopt a pre-dispersion process to make the nanomaterials uniformly dispersed in the resin phase first, which can avoid the agglomeration of nanoparticles due to excessive surface energy when they are directly added to the aqueous system, significantly improve the dispersion uniformity of the nanomaterials, and give full play to their in-situ repair and thermal conductivity functions.

[0027] The preparation method of copper nanomaterials is as follows: copper acetate is dissolved in ethylene glycol to obtain a copper acetate ethylene glycol solution, and then reduced with hydrazine hydrate to obtain a copper nanomaterial suspension. The mass ratio of copper acetate, ethylene glycol and hydrazine hydrate is (1-2):(15-20):(0.2-0.3). The reaction conditions of this method are mild, and the obtained copper nanomaterials have uniform particle size and good dispersibility. They can be used directly without subsequent separation and purification, which simplifies the production process.

[0028] The preparation method of nano-cuprous oxide is as follows: copper acetate is dissolved in ethylene glycol to obtain copper acetate ethylene glycol solution, and then reduced with 0.1 mol / L ascorbic acid solution to obtain nano-cuprous oxide suspension. The mass ratio of copper acetate, ethylene glycol and ascorbic acid solution is (1-2):(15-20):(0.6-1.2). Ascorbic acid is a green reducing agent, the reaction process is controllable, and the obtained nano-cuprous oxide has high purity and complete crystal form, and has excellent dispersion stability in aqueous system.

[0029] When preparing cuprous oxide-copper compounds, hydrazine hydrate at a mass ratio of 0.1-0.3 can be added to a nano-cuprous oxide suspension to obtain cuprous oxide-copper compounds. By controlling the amount of hydrazine hydrate added, the degree of reduction can be precisely controlled to form composite structures with different proportions, which combine the wear-reducing properties of soft copper and the wear-resistant properties of hard cuprous oxide, and can adapt to the wheel-rail working conditions with different loads.

[0030] The preparation method of nano-copper oxide is as follows: copper acetate is dissolved in ethylene glycol to obtain a copper acetate ethylene glycol solution, sodium hydroxide is added and heated to 60-80℃ and stirred for 25-30 min to obtain a nano-copper oxide suspension. The mass ratio of copper acetate, ethylene glycol and sodium hydroxide is (1-2):(15-20):(0.4-1). By controlling the reaction temperature and the amount of alkali, this method can obtain nano-copper oxide with uniform particle size and good dispersibility. It has excellent high temperature stability and anti-wear extreme pressure performance, and is particularly suitable for heavy-load and high-temperature wheel-rail friction conditions.

[0031] Example 4 The water-based wheel-rail friction modifier of this embodiment comprises the following raw materials in parts by weight: 8 parts bentonite, 3 parts talc, 10 parts molybdenum disulfide, 3 parts modified zirconium phosphate, 2 parts nano copper, 2 parts silica, 1 part magnetic iron oxide, 2 parts sodium silicate, 1 part thiadiazole dimer, 30 parts waterborne epoxy resin, 20 parts acrylic emulsion, 15 parts waterborne polyurethane, 1 part polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer, 15 parts ethylene glycol, 1 part sodium dodecyl sulfate, 8 parts modified wheat straw powder, 0.5 parts 2,6-di-tert-butyl-p-cresol, 1 part AMP-95, 1 part defoamer, and 50 parts water.

[0032] The preparation method of the water-based wheel-rail friction modifier in this embodiment includes the following steps: 1) Add two-thirds of the total volume of deionized water to the reactor, then add bentonite and talc powder and stir to fully impregnate them. The stirring speed is controlled at 400 r / min and the dispersion time is 5 min. 2) Add ethylene glycol, sodium dodecyl sulfate, polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer and 2,6-di-tert-butyl-p-cresol, and disperse them completely. The stirring speed is controlled at 400 r / min and the dispersion time is 5 min. 3) Take 5 parts of water, add 1 part of ferric chloride and 1 part of calcium chloride to completely dissolve them, then add zirconium phosphate to the solution to obtain a viscous system. Dry the system, then calcine it at 250℃ for 50 min, then raise the temperature to 500℃ and calcine it for 100 min, and then anneal it to obtain modified zirconium phosphate; Take 14 parts of water, add 1 part of calcium hydroxide to completely dissolve them, then add wheat straw powder to the solution to obtain a viscous system. Dry the system, then calcine it at 100℃ for 50 min to obtain modified wheat straw powder; 4) Add molybdenum disulfide, modified zirconium phosphate, modified wheat straw powder, silicon dioxide, magnetic iron oxide, sodium silicate, and thiadiazole dimer and stir to disperse evenly. The stirring speed is controlled at 400 r / min and the dispersion time is 15 min. 5) Dissolve 1 part of copper acetate in 15 parts of ethylene glycol to obtain a copper acetate ethylene glycol solution. Then, under stirring, add 0.2 parts of hydrazine hydrate to reduce it to obtain a nano copper suspension. Then, add waterborne epoxy resin, acrylic emulsion, and waterborne polyurethane to it and stir at 300 r / min for 3 min. Then, add the entire system to the above waterborne system and continue stirring. The stirring speed is controlled at 400 r / min and the dispersion time is 8 min. 6) Add AMP-95 and defoamer, control the stirring speed at 300 r / min, and disperse for 5 min; 7) Add the remaining one-third of the deionized water and continue stirring to disperse. The stirring speed should be controlled at 300 r / min, and the dispersion time should be 10 min. 8) Grind the above system for 5 minutes to obtain the product.

[0033] According to the test results, the product of this embodiment has a gray and uniform paste appearance, a solid content of 31.5%, a pH value of 8.1, and a flash point of ≥70℃; 45# steel sheets do not rust after being soaked at 50℃ for 24 hours; the initial friction coefficient is 0.26, and the friction coefficient is 0.28 after 12 months, which is suitable for wheel-rail friction control of light-load branch railways.

[0034] Example 5 The water-based wheel-rail friction modifier of this embodiment comprises the following raw materials in parts by weight: 10 parts bentonite, 6.5 parts talc, 13 parts molybdenum disulfide, 9 parts modified zirconium phosphate, 2.5 parts nano cuprous oxide, 2.5 parts silica, 1.5 parts magnetic iron oxide, 2.5 parts sodium silicate, 1.5 parts thiadiazole dimer, 55 parts waterborne epoxy resin, 27.5 parts acrylic emulsion, 17.5 parts waterborne polyurethane, 1.5 parts polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer, 17.5 parts ethylene glycol, 1.5 parts sodium dodecyl sulfate, 11.5 parts modified wheat straw powder, 0.75 parts 2,6-di-tert-butyl-p-cresol, 1.5 parts AMP-95, 2 parts defoamer, and 75 parts water.

[0035] The preparation method of the water-based wheel-rail friction modifier in this embodiment includes the following steps: 1) Add two-thirds of the total volume of deionized water to the reactor, then add bentonite and talc powder and stir to fully impregnate them. The stirring speed is controlled at 450 r / min and the dispersion time is 7.5 min. 2) Add ethylene glycol, sodium dodecyl sulfate, polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer and 2,6-di-tert-butyl-p-cresol, and disperse them completely. The stirring speed is controlled at 450 r / min and the dispersion time is 6.5 min. 3) Take 6 parts of water, add 1.5 parts of ferric chloride and 1.5 parts of calcium chloride to completely dissolve them, then add zirconium phosphate to the solution to obtain a viscous system. Dry the system, then calcine it at 275℃ for 55 minutes, then raise the temperature to 525℃ and calcine it for 110 minutes, and then anneal it to obtain modified zirconium phosphate; Take 15 parts of water, add 1 part of calcium hydroxide to completely dissolve them, then add wheat straw powder to the solution to obtain a viscous system. Dry the system, then calcine it at 110℃ for 55 minutes to obtain modified wheat straw powder; 4) Add molybdenum disulfide, modified zirconium phosphate, modified wheat straw powder, silicon dioxide, magnetic iron oxide, sodium silicate, and thiadiazole dimer and stir to disperse evenly. The stirring speed is controlled at 450 r / min and the dispersion time is 17.5 min. 5) Dissolve 1.5 parts of copper acetate in 17.5 parts of ethylene glycol to obtain a copper acetate ethylene glycol solution. Then, under stirring, add 0.9 parts of 0.1 mol / L ascorbic acid solution to reduce it to obtain a nano cuprous oxide suspension. Then, add waterborne epoxy resin, acrylic emulsion, and waterborne polyurethane to it and stir at 350 r / min for 4 min. Then, add the entire system to the above waterborne system and continue stirring at a stirring speed of 350 r / min for a dispersion time of 9 min. 6) Add AMP-95 and defoamer, control the stirring speed at 350 r / min, and disperse for 5.5 min; 7) Add the remaining one-third of the deionized water and continue stirring to disperse. The stirring speed should be controlled at 350 r / min, and the dispersion time should be 13 min. 8) Grind the above system for 7.5 min to obtain the product.

[0036] Testing revealed that the product in this embodiment has a uniform gray paste appearance, a solid content of 35%, a pH value of 8.6, and a flash point ≥70℃; 45# steel sheets showed no rust after immersion at 50℃ for 24 hours; the initial coefficient of friction was 0.27, and the coefficient of friction after 12 months was 0.25, making it suitable for wheel-rail friction control on lightly loaded branch lines.

[0037] Example 6 The water-based wheel-rail friction modifier comprises the following raw materials in parts by weight: 12 parts bentonite, 10 parts talc, 16 parts molybdenum disulfide, 15 parts modified zirconium phosphate, 3 parts nano cuprous oxide-copper, 3 parts silica, 2 parts magnetic iron oxide, 3 parts sodium silicate, 2 parts thiadiazole dimer, 80 parts waterborne epoxy resin, 35 parts acrylic emulsion, 20 parts waterborne polyurethane, 2 parts polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer, 20 parts ethylene glycol, 2 parts sodium dodecyl sulfate, 15 parts modified wheat straw powder, 1 part 2,6-di-tert-butyl-p-cresol, 2 parts AMP-95, 3 parts defoamer, and 100 parts water.

[0038] The preparation method of water-based wheel-rail friction modifier includes the following steps: 1) Add two-thirds of the total volume of deionized water to the reactor, then add bentonite and talc powder and stir to fully impregnate them. The stirring speed is controlled at 500 r / min and the dispersion time is 10 min. 2) Add ethylene glycol, sodium dodecyl sulfate, polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer and 2,6-di-tert-butyl-p-cresol, and disperse them completely. The stirring speed is controlled at 500 r / min and the dispersion time is 8 min. 3) Take 7 parts of water, add 2 parts of ferric chloride and 2 parts of calcium chloride to completely dissolve them, then add zirconium phosphate to the solution to obtain a viscous system. Dry the system, then calcine it at 300℃ for 60 minutes, then raise the temperature to 550℃ and calcine it for 120 minutes, and then anneal it to obtain modified zirconium phosphate; Take 16 parts of water, add 1 part of calcium hydroxide to completely dissolve them, then add wheat straw powder to the solution to obtain a viscous system. Dry the system, then calcine it at 120℃ for 60 minutes to obtain modified wheat straw powder; 4) Add molybdenum disulfide, modified zirconium phosphate, modified wheat straw powder, silicon dioxide, magnetic iron oxide, sodium silicate, and thiadiazole dimer and stir to disperse evenly. The stirring speed is controlled at 500 r / min and the dispersion time is 20 min. 5) Dissolve 2 parts of copper acetate in 20 parts of ethylene glycol to obtain a copper acetate ethylene glycol solution. Then, under stirring, add 1.2 parts of 0.1 mol / L ascorbic acid solution to reduce it to obtain a nano cuprous oxide suspension. Then, add 0.3 parts of hydrazine hydrate to continue the reduction to obtain a nano cuprous oxide-copper composite suspension. Then, add waterborne epoxy resin, acrylic emulsion, and waterborne polyurethane to it and stir at 400 r / min for 5 min. Then, add the entire system to the above waterborne system and continue stirring at a stirring speed of 400 r / min for a dispersion time of 10 min. 6) Add AMP-95 and defoamer, control the stirring speed at 400 r / min, and disperse for 6 min; 7) Add the remaining one-third of the deionized water and continue stirring to disperse. The stirring speed should be controlled at 400 r / min, and the dispersion time should be 16 min. 8) Grind the above system for 10 minutes to obtain the product.

[0039] Testing revealed that the product in this embodiment has a uniform gray-black paste appearance, a solid content of 38.6%, a pH value of 8.8, and a flash point ≥70℃; 45# steel sheets showed no rust after immersion at 50℃ for 24 hours; the initial coefficient of friction was 0.28, and the coefficient of friction after 12 months was 0.26, making it suitable for wheel-rail friction control on lightly loaded branch lines.

[0040] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0041] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A water-based wheel-rail friction modifier, characterized in that, It is prepared from the following raw materials in parts by weight: 8-12 parts bentonite, 3-10 parts talc, 10-16 parts molybdenum disulfide, 3-15 parts modified zirconium phosphate, 1-3 parts copper-based nanomaterials, 2-3 parts silica, 1-2 parts magnetic iron oxide, 2-3 parts sodium silicate, 1-2 parts metal passivator, 30-80 parts waterborne epoxy resin, 20-35 parts acrylic emulsion, 15-20 parts waterborne polyurethane, 1-2 parts polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer, 15-20 parts ethylene glycol, 8-15 parts modified wheat straw powder, 1-2 parts sodium dodecyl sulfate, 0.5-1 part antioxidant, 1-2 parts AMP-95, 1-3 parts defoamer, and 50-100 parts deionized water.

2. The water-based wheel-rail friction modifier according to claim 1, characterized in that, The antioxidant is one or two of 2,6-di-tert-butyl-p-cresol or gallic acid esters in any ratio; The metal passivating agent is one or two of thiadiazole dimers or benzotriazole, in any ratio.

3. The water-based wheel-rail friction modifier according to claim 1, characterized in that, The copper-based nanomaterials include one or two of the following in any proportion: nano-copper, nano-cuprous oxide, nano-cuprous oxide-copper, and nano-copper oxide.

4. A method for preparing a water-based wheel-rail friction modifier, using the raw material ratio described in claim 1, involves adding two-thirds deionized water to a reaction vessel, adding bentonite and talc, and stirring at 400-500 r / min for 5-10 min; then adding ethylene glycol, sodium dodecyl sulfate, triblock copolymer, and antioxidant, and stirring at the same speed for 5-8 min; adding molybdenum disulfide, modified zirconium phosphate, modified wheat straw powder, silicon dioxide, magnetic iron oxide, sodium silicate, and metal passivator, and continuing to stir at the same speed for 15-20 min; adding a resin mixture containing copper-based nanomaterials, and stirring at 300-400 r / min for 8-10 min; adding AMP-95 and defoamer and stirring for 5-6 min; finally adding the remaining one-third deionized water and stirring for 10-16 min, followed by grinding in a grinder for 5-10 min to obtain the product.

5. The preparation method of the water-based wheel-rail friction modifier according to claim 4, characterized in that, The modified zirconium phosphate is prepared by taking water, ferric chloride, calcium chloride and zirconium phosphate in a mass ratio of (5-7):(1-2):(1-2):(6-9). After dissolving ferric chloride and calcium chloride in water, zirconium phosphate is added to obtain a viscous system. The system is then dried and calcined at 250-300℃ for 50-60 min. The temperature is then raised to 500-550℃ and calcined for 100-120 min before annealing to obtain the modified zirconium phosphate.

6. The preparation method of the water-based wheel-rail friction modifier according to claim 4, characterized in that, The modified wheat straw powder is prepared by taking water, calcium hydroxide and wheat straw powder in a mass ratio of (14-16):1:(8-12). After dissolving the calcium hydroxide in water, the wheat straw powder is added to obtain a viscous system, which is then dried and calcined at 100-120℃ for 50-60 minutes to obtain the modified wheat straw powder.

7. The preparation method of the water-based wheel-rail friction modifier according to claim 4, characterized in that, The method for preparing the resin mixture containing copper-based nanomaterials is as follows: add aqueous epoxy resin, acrylic emulsion and aqueous polyurethane to the copper-based nanomaterials, and stir at a speed of 300-400 r / min for 3 min-5 min.

8. The preparation method of the water-based wheel-rail friction modifier according to claim 7, characterized in that, The method for preparing the copper nanomaterials is as follows: copper acetate is dissolved in ethylene glycol to obtain a copper acetate ethylene glycol solution, and then reduced with hydrazine hydrate to obtain a copper nanomaterial suspension. The mass ratio of copper acetate, ethylene glycol and hydrazine hydrate is (1-2):(15-20):(0.2-0.3). The preparation method of nano-cuprous oxide is as follows: copper acetate is dissolved in ethylene glycol to obtain a copper acetate ethylene glycol solution, and then reduced with 0.1 mol / L ascorbic acid solution to obtain a nano-cuprous oxide suspension. The mass ratio of copper acetate, ethylene glycol and ascorbic acid solution is (1-2):(15-20):(0.6-1.2). In the preparation of cuprous oxide-copper compounds, hydrazine hydrate at a mass ratio of 0.1-0.3 can be added to a nano-cuprous oxide suspension to obtain cuprous oxide-copper compounds; The preparation method of nano copper oxide is as follows: copper acetate is dissolved in ethylene glycol to obtain copper acetate ethylene glycol solution, sodium hydroxide is added and heated to 60-80℃ and stirred for 25-30 min to obtain nano copper oxide suspension. The mass ratio of copper acetate, ethylene glycol and sodium hydroxide is (1-2):(15-20):(0.4-1).