A semi-synthetic cutting fluid based on self-healing materials, its preparation method and application

Abstract

This application relates to the field of metal cutting fluid technology, specifically a semi-synthetic cutting fluid based on self-healing materials, its preparation method, and its application. The process includes: mixing molybdenum and / or tungsten intercalated magnesium-aluminum LDH, alkanolamine borate ester, dimer acid imidazoline derivative, and water; adjusting the pH and reacting and dispersing to obtain a self-healing functional dispersion; mixing water, monoethanolamine, mixed alkanolamines, amino alcohols, dodecanoic acid, tricarboxylic acid rust inhibitor, and boric acid to obtain an alkaline rust-inhibiting aqueous phase; preparing an oily lubricating emulsion phase; adding the aqueous phase to the oil phase in stages under stirring to form a water-in-oil transition system; adding the self-healing functional dispersion; then adding water at a controlled rate to reverse the phase; and finally adding bactericidal and defoaming components after cooling. Through the combination of raw materials and preparation steps, the resulting cutting fluid can form a dynamically compensating protective film at the machining interface, possessing cooling, lubrication, rust prevention, cleaning, low foaming, hard water resistance, and biological stability properties.

Description

Technical Field

[0001] This application relates to the field of metal cutting fluid technology, specifically to a semi-synthetic cutting fluid based on self-healing materials, its preparation method, and its application. Background Technology

[0002] During metal cutting, a high-temperature, high-pressure, and high-shear friction interface is formed between the tool and the workpiece. Cutting fluid plays a crucial role in this process, providing cooling, lubrication, cleaning, rust prevention, and inhibiting microbial growth. From a technological development perspective, metalworking fluids have evolved through stages: mineral oil-based cutting oils, emulsified oils, semi-synthetic cutting fluids, and fully synthetic cutting fluids. Mineral oil-based cutting oils offer good lubrication but lack sufficient cooling and cleaning properties, and have high oil mist and environmental impact. Emulsified oils improve cooling capacity, but their large emulsion particle size limits their stability and antibacterial properties. Fully synthetic cutting fluids offer strong cooling and cleaning capabilities, but their boundary lubrication performance typically relies on large amounts of water-soluble lubricants and extreme-pressure additives. Semi-synthetic cutting fluids combine the lubricity of emulsified products with the cooling and cleaning properties of synthetic products, making them a widely used type of water-based metalworking fluid in modern machining.

[0003] However, with the development of high-speed machining centers, CNC composite machine tools, and centralized fluid supply systems, higher requirements have been placed on the overall performance of semi-synthetic cutting fluids. Existing semi-synthetic cutting fluids are usually formulated with alkanolamines, diacids or tricarboxylic acids as rust inhibitors, petroleum sulfonates, tall oil derivatives, chlorinated paraffins, base oils, emulsifiers, bactericides, and defoamers, which can meet the needs of general steel material processing. However, under high-speed, high-pressure, and high-precision machining conditions, existing products still have shortcomings: First, the lubricating film mainly relies on the adsorption of polar molecules or the reaction of extreme pressure components to form a continuous compensation capability after being damaged under continuous cutting and shearing. Second, conventional rust inhibitors, lubricants, and extreme pressure agents are mostly in a free state, making it difficult to continuously accumulate at the tool-workpiece interface, resulting in insufficient continuity and stability of the interface protective film. Third, when inorganic nano-anti-wear materials are directly added, problems such as agglomeration, sedimentation, hard water flocculation, nozzle clogging, and poor compatibility with emulsion systems are prone to occur. Fourth, if only simple mixing is used during the preparation of semi-synthetic cutting fluids, the uneven distribution of oil phase, water phase, and functional components can easily lead to a decrease in the storage stability of the original solution and the circulation stability of the diluted solution.

[0004] For example, the invention patent application with publication number CN104087400A discloses an environmentally friendly, high-lubricity semi-synthetic metal cutting fluid, whose components include base oil, anionic surfactant, nonionic surfactant, rust inhibitor, coupling agent, extreme pressure agent, wetting agent, defoamer, bactericide and water. This cutting fluid improves lubrication performance by compounding extreme pressure agent and super wetting agent. However, its lubrication film mainly relies on the physical adsorption of polar molecules on the metal surface or the chemical reaction of extreme pressure components. Under the high shear conditions of continuous high-speed cutting, once the lubrication film is damaged, the system lacks the ability to actively repair and continuously compensate, making it difficult to maintain a continuous and stable protective film at the tool-workpiece interface. In addition, the invention patent application with publication number CN103555392A discloses a microemulsion metal cutting fluid containing ionic liquid, which improves lubrication and extreme pressure performance by adding nano-scale extreme pressure additives to the base oil. However, when inorganic nano anti-wear materials are directly introduced, due to the large specific surface area and high surface energy of nanoparticles, they are prone to agglomeration and sedimentation in the cutting fluid system, which leads to nozzle clogging. Furthermore, the compatibility between nanomaterials and the emulsion system is poor, affecting the stability of the working fluid in circulation.

[0005] Therefore, there is a need to provide a new semi-synthetic cutting fluid and its preparation method, which can form a protective film with dynamic compensation function at the metal processing interface, and at the same time have excellent cooling, lubrication, rust prevention, cleaning, low foaming, hard water resistance and storage stability. Summary of the Invention

[0006] This application aims to overcome at least one of the deficiencies of the prior art by providing a semi-synthetic cutting fluid based on self-healing materials, its preparation method, and its application. By combining raw materials and preparation steps, a self-healing functional dispersion composed of molybdenum and / or tungsten-intercalated magnesium aluminum LDH, alkanolamine borate ester, and dimer acid imidazoline derivative is constructed. The dispersion is then stably introduced into the semi-synthetic cutting fluid using a phase separation preparation and controlled phase inversion compounding process. This results in a product that combines cooling, lubrication, cleaning, rust prevention, low foaming, hard water resistance, and storage stability.

[0007] In a first aspect, embodiments of this application provide a method for preparing a semi-synthetic cutting fluid based on a self-healing material, achieved through the following technical solution: A method for preparing a semi-synthetic cutting fluid based on self-healing materials includes the following steps: S1. Molybdenum and / or tungsten intercalated magnesium aluminum LDH, amino borate ester, dimer acid imidazoline derivative and water are mixed, the pH is adjusted to 7.8-9.2, and the mixture is stirred at 60-90℃ for 1-3 hours. Then, it is dispersed by wet grinding or high-speed shearing to obtain a self-healing functional dispersion with a solid content of 20-45% and a D50 particle size of 80-300nm. S2. Water, monoethanolamine, mixed alkanolamines, amino alcohols, dodecanoic acid, tricarboxylic acid rust inhibitors, and boric acid are mixed and stirred at 55-85°C until clear to obtain an alkaline rust-inhibiting aqueous phase; the mixed alkanolamines are a mixture including at least two of monoethanolamine, diethanolamine, and triethanolamine, and contain at least triethanolamine; the amino alcohols are selected from at least one of monoisopropanolamine, diethylene glycolamine, and 2-amino-2-methyl-1-propanol; S3. Mix base oil, chlorinated paraffin, tall oil derivative, sodium petroleum sulfonate, coupling agent, fatty alcohol polyoxyethylene ether emulsifier, sorbitan oleate, triethylene glycol butyl ether and anti-hard water agent, and stir evenly at 45-75°C to obtain an oily lubricating emulsion phase. S4. Under the conditions of temperature 45-65℃ and stirring speed 800-2500r / min, the alkaline rust-inhibiting aqueous phase obtained in step S2 is added to the oily lubricating emulsion phase obtained in step S3 in 2-5 portions to form an oil-in-water transition system; then the self-healing functional dispersion obtained in step S1 is added, and shearing is continued for 10-40min; then water is added at a rate of 0.5-3 parts by weight / min to cause the system to reverse, and a semi-synthetic cutting fluid premix is ​​obtained. S5. Cool the semi-synthetic cutting fluid premix to 25-45°C, add bactericidal and defoaming components, stir evenly, and filter to obtain the semi-synthetic cutting fluid based on self-healing materials.

[0008] The method for preparing a semi-synthetic cutting fluid based on self-healing materials according to the embodiments of this application has at least the following beneficial effects: This application selects three core components—molybdenum and / or tungsten intercalated magnesium-aluminum layered bimetallic hydroxide, alkanolamine borate, and dimer acid imidazoline derivative—to jointly construct a self-healing functional dispersion. This dispersion has a simple composition and high functional integration. The two-dimensional layered structure of the molybdenum and / or tungsten intercalated magnesium-aluminum layered bimetallic hydroxide can play a physical filling and bearing role in micro-scratches and film damage areas at the friction interface. Molybdate and tungstate ions can enhance the passivation and rust prevention capabilities of the steel surface. Alkanolamine borate enhances the interfacial compatibility between the inorganic layers and the semi-synthetic system, and participates in the formation of a boron-containing protective film under frictional heat and pressure. The dimer acid imidazoline derivative utilizes its polar groups to form a stable adsorbed lubricating film on the metal surface. These three components form a synergistic effect through physical filling, surface adsorption, chemical passivation, and tribochemical reactions, constructing a protective film system with dynamic compensation and self-healing functions at the cutting interface. This effectively overcomes the shortcomings of traditional cutting fluids, where the lubricating film is easily damaged and difficult to regenerate under continuous high-shear conditions.

[0009] In the preparation of the self-healing functional dispersion, this application controls the pH of the system within a weakly alkaline range of 7.8 to 9.2. This pH range ensures the stability of the lamellar structure of the magnesium-aluminum layered bimetallic hydroxide and the effective exfoliation and dispersion of the lamellar layers, while also preventing excessive salinization of the dimer acid imidazoline derivative under strong alkaline conditions. This allows it to maintain appropriate free carboxyl groups and oily lubrication characteristics. The resulting dispersion has a moderate solid content and possesses both excellent storage stability and directional deposition capability at the friction interface, laying the foundation for subsequent phase-inversion composites.

[0010] This application employs a phase-separation preparation combined with a controlled phase-reversal compounding process. First, an alkaline rust-inhibiting aqueous phase is added in stages to an oily lubricating emulsion phase to construct a uniform water-in-oil transition system. Then, a self-healing functional dispersion is introduced for high-speed shear dispersion. Finally, the phase reversal of the system is triggered by controlling the water addition rate. This process path ensures that the self-healing functional components are effectively embedded in the oil-water interface layer and the interior of the dispersed phase, resulting in a semi-transparent system with a narrow particle size distribution and high thermodynamic stability in the final product. By limiting key parameters such as emulsification temperature, shear speed, and water addition rate, the process improves the phase separation and uneven distribution of functional components during the phase reversal process, enhances the long-term storage stability of the semi-synthetic cutting fluid stock solution and the hard water adaptability of the diluent, and enables it to exhibit good anti-settling, anti-soaping, and anti-floating oil capabilities in centralized fluid supply circulation systems, while taking into account comprehensive application performance such as cooling, lubrication, rust prevention, cleaning, and low foaming.

[0011] According to some embodiments of this application, in step S1, the raw materials of the self-healing functional dispersion, by weight, include: 10-35 parts of molybdenum and / or tungsten intercalated magnesium aluminum LDH, 20-55 parts of alcoholic amine borate ester, 10-35 parts of dimer acid imidazoline derivative, and 20-60 parts of water.

[0012] This formulation enables the formation of a stable composite structure between the two-dimensional sheet carrier, the boron-based lubricating modifier, and the imidazoline adsorbent lubricating component. When the amount of molybdenum and / or tungsten intercalated magnesium-aluminum LDH is 10-35 parts, it can provide sufficient filling of bearing sites without excessive agglomeration. When the amount of alcoholamine borate is 20-55 parts, it can fully coat the sheet surface, enhance the interfacial compatibility between inorganic particles and organic systems, and continuously release boron-containing protective components under friction conditions. When the amount of dimer acid imidazoline derivative is 10-35 parts, it can impart appropriate oily adsorption characteristics to the dispersion, ensuring its rapid spread and film formation at the metal interface. The amount of water is controlled at 20-60 parts to make the solid content of the dispersion 20-45%. The resulting dispersion has both storage stability and the ability to maintain directional deposition and self-healing film formation at the friction interface when diluted for use.

[0013] According to some embodiments of this application, in step S2, the raw materials of the alkaline rust-preventing aqueous phase, by weight, include: 5-12 parts of monoethanolamine, 4-12 parts of mixed alcoholamines, 0.5-3 parts of amino alcohol, 0.3-2 parts of dodecanoic acid, 0.2-1.5 parts of tricarboxylic acid rust inhibitor, 0.5-2.5 parts of boric acid, and 70-89 parts of water.

[0014] This formulation uses monoethanolamine and a mixed alkaline amine containing triethanolamine as the main alkaline agents, combined with amino alcohols, dodecanoic acid, tricarboxylic acid rust inhibitors, and boric acid to form a pH-stable buffer system with sufficient alkali reserves. This system can effectively neutralize acidic substances in the processing environment and extend the service life of the working fluid. The composite alkaline amine salt formed in situ by the mixed alkaline amines and the diacarboxylic and tricarboxylic acids generates a dense passivation film on the metal surface, significantly improving the rust prevention performance of cast iron and carbon steel. The amino alcohol enhances the uniformity of rust inhibitor adsorption on iron filings and workpiece surfaces. Boric acid participates in the formation of a boron-based corrosion inhibitor layer and imparts a certain degree of hard water resistance to the aqueous phase. The overall formulation is free of nitrites and phenols, has moderate alkalinity, and helps the phase inversion process to proceed smoothly when combined with the subsequent oil phase, which is beneficial to the stability of the emulsion system.

[0015] According to some embodiments of this application, in step S3, the raw materials of the oily lubricating emulsion phase, by weight, include: 35-65 parts base oil, 5-20 parts chlorinated paraffin, 5-18 parts tall oil derivative, 3-12 parts sodium petroleum sulfonate, 2-10 parts coupling agent, 2-10 parts fatty alcohol polyoxyethylene ether emulsifier, 1-6 parts sorbitan oleate, 1-6 parts triethylene glycol butyl ether, and 0.2-3 parts anti-hard water agent.

[0016] In this oily lubricating emulsion formulation, base oil and chlorinated paraffin are combined to form the main lubricating carrier. Chlorinated paraffin releases active chlorine elements at high-shear interfaces to form an extreme-pressure reaction film, which synergistically enhances boundary lubrication with the physical oil film of the base oil. Tall oil derivatives and sodium petroleum sulfonate have both emulsifying and rust-preventing functions, which can reduce interfacial tension and form a dense chemically adsorbed rust-preventing layer on the metal surface. Sorbitan oleate and fatty alcohol polyoxyethylene ether emulsifiers are combined to form a composite HLB value regulating system, which, together with a coupling agent, promotes the improvement of oil-water interfacial film strength. Triethylene glycol butyl ether is used as a coupling solvent to improve the system's low-temperature fluidity and dilution dispersibility. The anti-hard water agent inhibits the precipitation of fatty acid soaps by chelating calcium and magnesium ions, avoiding oil floating and soap precipitation in the working fluid. The proportions of the above components make it easy for the oily lubricating emulsion to form a semi-synthetic system with uniform particle size and stability during the subsequent phase inversion process.

[0017] According to some embodiments of this application, in step S4, the ratio of the alkaline rust-preventing aqueous phase, the oily lubricating emulsion phase, the self-healing functional dispersion, and water by weight is 20-40:35-65:2-6:5-30, for example, the ratio of the alkaline rust-preventing aqueous phase, the oily lubricating emulsion phase, the self-healing functional dispersion, and water is 30:50:4:20.

[0018] This ratio ensures that the oil and water phases form a uniform water-in-oil transition system in the early stages of emulsification, allowing the alkaline rust-preventing aqueous phase to be fully encapsulated by the oil phase during phase addition. After the self-healing functional dispersion is added, it is concentrated in the oil-water interface layer and within the dispersed phase, preventing the functional components from being free in the continuous phase and causing uneven distribution. At the same time, this water volume, combined with a controlled water addition rate of 0.5–3 parts by weight per minute, can provide suitable shear viscosity and phase transformation driving force at the phase inversion critical point, promoting a smooth phase transition from water-in-oil to oil-in-water. The resulting premixed liquid has a controllable and concentrated particle size, improving the stratification, demulsification, and decreased storage stability caused by incomplete phase inversion.

[0019] According to some embodiments of this application, in step S5, the bactericidal component is 0.5 to 4 parts and the defoaming component is 0.05 to 0.5 parts by weight.

[0020] This dosage range is introduced at a lower temperature of 25–45°C after the system reverses, which avoids the destruction of the activity of the bactericidal and defoaming components by high temperatures, and ensures that they are uniformly dispersed in the formed stable microemulsion system. The amount of bactericidal component is sufficient to inhibit the growth of bacteria and fungi, prevent the working fluid from becoming smelly and deteriorating during recycling, and will not cause additional burden to operators and the environment due to excessive dosage. The amount of defoaming component can effectively control the foaming tendency of the system during high-speed spraying and centralized fluid supply, avoiding insufficient lubrication and overflow problems caused by foam. At the same time, this low addition amount has a slight impact on the transparency of the cutting fluid and does not affect the appearance of the original fluid. The two work together to ensure the biological stability and low-foaming operation performance of the product in long-term centralized fluid supply systems.

[0021] According to some embodiments of this application, the molybdenum and / or tungsten intercalated magnesium aluminum LDH in step S1 is prepared by ion exchange reaction of magnesium aluminum LDH with sodium molybdate and / or sodium tungstate at 60-90°C.

[0022] By carrying out an ion exchange reaction between magnesium aluminum LDH and sodium molybdate and / or sodium tungstate at 60–90 °C, molybdate or tungstate anions can be inserted into the LDH interlayer, achieving uniform molecular-level loading within the interlayer domain. This intercalation structure can improve the chemical stability of molybdenum and tungstate active components in the system, and improve the prominent problems caused by simple physical mixing, such as the easy precipitation, loss and failure of free molybdate or tungstate in hard water, and the deterioration of the processing fluid. During the cutting friction process, after the layer is subjected to shear and thermal stimulation, the molybdate or tungstate in the interlayer is slowly released and migrates to the tool-workpiece interface, participating in the formation of a passivation film, giving the cutting fluid continuous dynamic rust prevention and anti-wear self-repair function.

[0023] Furthermore, the weight ratio of the magnesium-aluminum LDH to the sodium molybdate and / or sodium tungstate is 100:12 to 25, for example, 100:12, 100:15 to 20, or 100:25. This ratio ensures sufficient interlayer anion exchange reaction, allowing molybdate and / or tungstate ions to effectively insert into the layers and remain stable. If the amount of sodium molybdate or sodium tungstate is below this range, the intercalation amount is insufficient, failing to form a sufficient passivation protective film at the friction interface, resulting in a decrease in self-healing filling and rust prevention compensation capabilities. If the amount is above this range, there are too many free ions, damaging the integrity of the layer structure, and the intercalated product is prone to leakage during subsequent dispersion and compounding, reducing the storage stability and emulsion compatibility of the self-healing functional dispersion. The intercalated product prepared using the above ratio has a moderate interlayer spacing and good lamellar regularity, enabling it to simultaneously exert the physical filling and bearing function of two-dimensional lamellars and the chemical passivation and repair function of intercalated anions in the wear micro-area, thereby achieving a stable and continuous self-healing boundary lubrication effect at the cutting interface.

[0024] According to some embodiments of this application, the alcoholamine borate ester in step S1 is prepared by dehydrating boric acid with at least one of monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diethylene glycolamine, and 2-amino-2-methyl-1-propanol at 80-120°C.

[0025] The alcoholamine borate ester prepared by the dehydration reaction of the aforementioned specific alcoholamine and boric acid at 80–120 °C exhibits good hydrolytic stability and alkali reserve capacity, enabling it to continuously provide an alkaline buffer in the cutting fluid system and suppress the impact of pH fluctuations on the stability of the self-healing functional dispersion. Simultaneously, the molecular structure of this alcoholamine borate ester contains both borate ester groups and polar alcoholamine groups, which can be effectively adsorbed onto the surface of magnesium-aluminum layered bimetallic hydroxide sheets, improving the interfacial compatibility between inorganic particles and the oil and aqueous phases, and reducing the agglomeration and sedimentation of the sheet material. Under cutting friction conditions, the alcoholamine borate ester generates a boron-containing lubricating protective film on the metal surface through tribochemical reaction. This film, along with the passivation effect of molybdate and tungstate ions and the adsorption lubricating film of dimer acid imidazoline derivatives, produces a synergistic effect, jointly enhancing the density and load-bearing capacity of the dynamic compensation protective film at the cutting interface.

[0026] According to some embodiments of this application, the dimer acid imidazoline derivative is prepared by condensing a dimer acid with hydroxyethyl ethylenediamine and / or aminoethyl ethanolamine, followed by partial neutralization with monoethanolamine, triethanolamine or monoisopropanolamine.

[0027] This specific structure allows the molecule to simultaneously contain long-chain alkyl groups, imidazoline heterocycles, amide groups, and hydroxyl groups of dimer acids, endowing it with excellent polar adsorption capacity and oily lubrication properties. The flexible long chains of dimer acids provide a hydrophobic lubrication basis, while the imidazoline rings and active hydrogens introduced by hydroxyethyl ethylenediamine or aminoethyl ethanolamine can be firmly adsorbed onto the metal surface to form a stable boundary lubrication film. By partially neutralizing the product to control the degree of neutralization to 10-45% and the acid value to 20-80 mgKOH / g, and retaining an appropriate amount of free carboxyl groups, it ensures a certain degree of water dispersion compatibility and avoids the lubrication performance degradation caused by complete saponification. Its moderate acid value can also react with the metal surface under frictional heat to generate a metal soap protective film with dynamic compensation function. In synergy with alcoholamine borate esters and molybdenum / tungsten intercalated magnesium aluminum LDH, the cutting interface can actively repair itself after the lubrication film is sheared, improving the boundary lubrication and rust prevention durability of the cutting fluid under harsh working conditions.

[0028] Furthermore, the degree of neutralization of the dimer acid imidazoline derivative is 10-45%, and the acid value is 20-80 mg KOH / g.

[0029] Furthermore, the molar ratio of the dimer acid to the hydroxyethyl ethylenediamine and / or aminoethyl ethanolamine is 1:1 to 1.1. This ratio allows for a slightly excessive condensation reaction between the amine and carboxyl groups, promoting the full formation of the imidazoline ring while controlling the residual carboxyl content. This results in a product with both effective polar adsorption and anchoring capabilities and a suitable acid value. The dimer acid imidazoline derivative obtained in this way can form a dense lubricating film on the metal surface in a self-healing functional dispersion, while avoiding the impact of excessively high acid values ​​on the pH stability and emulsion compatibility of the system. This, in turn, ensures the boundary lubrication performance and long-term storage stability of the semi-synthetic cutting fluid.

[0030] According to some embodiments of this application, the base oil in step S3 is at least one of transformer oil, naphthenic mineral oil, hydrogenated base oil, and low-viscosity white oil. Such base oils have low aromatic content, high saturated hydrocarbon content, and a suitable viscosity range, enabling them to be well miscible with chlorinated paraffin, tall oil derivatives, and emulsifier systems, forming a uniform and stable oily lubricating emulsion phase. In subsequent phase inversion processes, this base oil helps to obtain an emulsion system with fine particle size and narrow distribution, improving the storage stability of the semi-synthetic cutting fluid stock solution and the anti-oil and anti-soaping ability of the diluted solution under hard water conditions, while simultaneously ensuring a balance between the spreadability of the oily lubricating film and its cooling and cleaning performance during processing.

[0031] According to some embodiments of this application, the coupling agent in step S3 is at least one of polyether carboxylates, alcohol ether carboxylates, alkanolamide borate esters, or fatty acid amide coupling agents, such as sodium octylphenol polyoxyethylene ether carboxylate, sodium octyl ether-9 carboxylate, dodecanoic acid diethanolamide borate ester, and oleic acid diethanolamide. These substances possess both polar hydrophilic segments and fatty acid hydrophobic segments in their molecular structure, effectively reducing oil-water interfacial tension and promoting full miscibility and uniform dispersion of the oily lubricating emulsion phase and the alkaline rust-preventing aqueous phase during controlled phase inversion. In particular, alkanolamide borate ester coupling agents, while playing a stabilizing role, can supplement the boron source of the system and synergize with alkanolamide borate esters in the self-healing functional dispersion to enhance the ability to build boundary lubrication films. In the semi-synthetic cutting fluid system, the above-mentioned coupling agents help inhibit the aggregation and precipitation of inorganic nanofunctional components under hard water conditions, avoiding soaping and floating oil phenomena caused by calcium and magnesium ions, thereby improving the long-term storage stability of the product concentrate and the anti-settling and anti-soaping properties of the diluted working fluid in the centralized liquid supply circulation system.

[0032] According to some embodiments of this application, the anti-hard water agent in step S3 is at least one of polycarboxylate, phosphonic acid salt or alcohol ether carboxylate, such as sodium polyacrylate, sodium 2-phosphonobutane-1,2,4-tricarboxylate, or sodium fatty alcohol polyoxyethylene ether carboxylate. This water hardening agent can efficiently chelate and lattice-distort calcium and magnesium ions through active groups such as carboxyl and phosphonic acid groups, inhibiting the combination of anionic components such as fatty acid soaps and petroleum sulfonates with calcium and magnesium ions to form insoluble soap salts under hard water conditions. This prevents the separation of the cutting fluid stock solution and the floating oil and soap precipitation in the diluted solution. At the same time, this type of water hardening agent has good compatibility with nonionic emulsifiers and self-healing dispersions in the system. It will not compete for adsorption at the oil-water interface or destroy the microemulsion structure formed by phase inversion. It avoids the electrolyte disturbance effect commonly introduced by inorganic salt water hardening agents and is not prone to secondary agglomeration of layered bimetallic hydroxide sheets. This ensures that the semi-synthetic cutting fluid maintains uniform particle size, good flowability and filterability during centralized supply and long-term circulation, meeting the requirements of industrial applications in hard water areas for working fluid stability and service life.

[0033] According to some embodiments of this application, the bactericidal component in step S5 includes at least one of MBM-type bactericides, BBIT-type bactericides, triazine-type bactericides, and isothiazolinone-type bactericides, such as N,N'-methylenebismorpholine, BBIT20 bactericide, hexahydro-1,3,5-tris(hydroxyethyl)-triazine, and CMIT / MIT complex. The composite bactericidal component can exert a broad-spectrum synergistic antibacterial effect, effectively inhibiting the growth of bacteria, fungi, and yeasts in the cutting fluid circulation system, avoiding pH decrease, putrefaction, and deterioration of rust prevention and lubrication performance caused by microbial metabolites; the combination of components with different bactericidal mechanisms can reduce the risk of microbial tolerance caused by long-term use of a single bactericide, extend the service life of the working fluid, reduce the frequency of replenishment, and ensure the long-term biological stability of the semi-synthetic cutting fluid under centralized supply conditions.

[0034] According to some embodiments of this application, the defoaming component in step S5 is a polyether-modified siloxane defoamer and / or a mineral oil-based defoamer, such as defoamer BD-3037 produced by Hangzhou Baode New Material Technology Co., Ltd., and defoamer S10 produced by Ourunke Bio-Lubricant Co., Ltd. This defoaming component achieves good compatibility with semi-synthetic systems formed by reverse emulsification; the polyether-modified siloxane defoamer, by introducing polyether segments, endows the organosilicon backbone with self-emulsifying and dispersing capabilities, allowing it to spread evenly in the working fluid. It has both rapid elimination and sustained inhibition effects on microbubbles and surface foam, and is less likely to cause pinholes or affect the transparency of the system; the mineral oil-based defoamer has excellent affinity for high-oil-content semi-synthetic systems and has a long-lasting defoaming effect under circulating liquid supply conditions; the two types of defoamers can be used alone or in combination, effectively avoiding problems such as insufficient cooling, lubrication failure, and tank overflow caused by foam accumulation without compromising the stability and processing performance of the emulsion, ensuring long-term low-foaming and stable operation of the product in applications such as high-speed spraying, high-pressure liquid supply, and centralized liquid supply systems.

[0035] Secondly, embodiments of this application provide a semi-synthetic cutting fluid based on a self-healing material prepared using the above-described method for preparing a semi-synthetic cutting fluid based on a self-healing material.

[0036] The semi-synthetic cutting fluid based on self-healing materials according to the embodiments of this application has at least the following beneficial effects: The semi-synthetic cutting fluid prepared using the method described in this application is homogeneous and stable in its concentrate, and the diluted solution has a moderate particle size, exhibiting a semi-transparent microemulsion state. It combines the lubricity of emulsion-type products with the cooling and cleaning properties of fully synthetic products. The product stably incorporates a self-healing functional dispersion at the oil-water interface, composed of molybdenum and / or tungsten intercalated magnesium-aluminum LDH, alkanolamine borate esters, and dimer acid imidazoline derivatives. This dispersion forms a dynamic compensation protective film at the cutting interface, synergistically combining filling, adsorption, passivation, and tribochemical reactions. Under continuous high shear conditions, it continuously reinforces boundary lubrication, effectively reducing tool wear and improving the surface finish. This cutting fluid exhibits good hard water adaptability and is less prone to soap precipitation, floating oil, and sedimentation in centralized fluid supply circulation. It also features a long rust prevention period, rapid defoaming, and strong antibacterial and anti-corrosion capabilities, meeting the comprehensive performance requirements for cooling, lubrication, rust prevention, cleaning, and low foaming in turning, milling, drilling, grinding, and tapping of carbon steel, alloy steel, and cast iron.

[0037] Thirdly, the embodiments of this application provide the application of the above-mentioned semi-synthetic cutting fluid based on self-healing materials in turning, milling, drilling, grinding or tapping of carbon steel, alloy steel, gray cast iron, and ductile cast iron.

[0038] The semi-synthetic cutting fluid of this application can form a dynamic protective film at the tool-workpiece interface with filling, adsorption and passivation functions through a self-healing dispersion, which significantly reduces cutting torque and tool wear and improves the surface finish of the machined parts. For gray cast iron and ductile iron, it can effectively inhibit the adhesion of fine chips and grinding wheel clogging, and maintain excellent cleaning and chip removal capabilities and inter-process rust prevention. Under harsh lubrication conditions such as tapping alloy steel, the protective film can continuously regenerate in the chip breaking and continuous shearing areas, reduce built-up edge and edge chipping tendency, and extend tool life.

[0039] According to some embodiments of this application, the semi-synthetic cutting fluid is diluted with water to a mass concentration of 3-10% before use.

[0040] In this article, the numerical ranges mentioned all include the endpoint values ​​and cover any subranges within that range, such as the ranges obtained by arbitrarily combining the specifically listed numerical values.

[0041] Unless otherwise specified, all parts by weight of raw materials refer to the weight ratio between the raw materials. For example, 10-35 parts of molybdenum and / or tungsten-intercalated magnesium-aluminum LDH indicates the relative amount of molybdenum and / or tungsten-intercalated magnesium-aluminum LDH in the raw materials of the self-healing functional dispersion. Based on 20-55 parts of alkanolamine borate, this can be understood as a weight ratio of molybdenum and / or tungsten-intercalated magnesium-aluminum LDH to alkanolamine borate of 10-35:20-55.

[0042] LDH is short for Layered Double Hydroxide. Attached Figure Description

[0043] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 This is a comparison chart of pH and D50 particle size data of 5% diluted semi-synthetic cutting fluids prepared in Examples 1-4 and Comparative Examples 1-4 of this application; Figure 2 This is a comparison chart of the PB value and wear scar diameter data of the semi-synthetic cutting fluids prepared in Examples 1-4 and Comparative Examples 1-4 of this application. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this application clearer, a further detailed description will be provided below in conjunction with specific embodiments. The embodiments described herein are merely some embodiments of this application and should not be construed as limiting the scope of protection of this application. Unless otherwise specified, the raw materials used in the embodiments are all commercially available, and the equipment and testing methods used are conventional equipment and methods in the art. Unless otherwise specified, "parts" in the embodiments refer to parts by weight.

[0046] The raw materials used in some of the examples are as follows: the tricarboxylic acid rust inhibitor is commercially available CP-50; the tall oil derivative is commercially available DTO-30; the fatty alcohol polyoxyethylene ether emulsifier is a compound of isomeric tridecyl alcohol polyoxyethylene ether 1308 and Tween 80; and the sorbitan oleate is Span-80. The above trade names are only used to indicate the source of optional raw materials and do not constitute a limitation on the scope of protection of this invention.

[0047] Example 1 Preparation of semi-synthetic cutting fluid based on self-healing materials: S1. Preparation of molybdenum-intercalated magnesium-aluminum LDH: 100 parts of magnesium-aluminum LDH were added to 500 parts of deionized water and stirred for 30 min. 18 parts of sodium molybdate were added and stirred for ion exchange at 75℃ for 3 h. After filtration, the mixture was washed with deionized water until the conductivity of the filtrate was less than 1000 μS / cm to obtain wet molybdenum-intercalated magnesium-aluminum LDH. The wet material was dispersed in deionized water to prepare a water-dispersible slurry of molybdenum-intercalated magnesium-aluminum LDH with a solid content of 20%. Preparation of alcoholic amine borate ester: 100 parts boric acid, 220 parts triethanolamine and 60 parts monoethanolamine were added to a reaction vessel and dehydrated under reduced pressure at 100°C for 3 hours to obtain alcoholic amine borate ester; Preparation of dimer acid imidazoline derivative: Dimer acid and hydroxyethyl ethylenediamine were mixed in a molar ratio of 1:1.05 and dehydrated and condensed at 180℃ for 4 hours. After cooling to 90℃, monoethanolamine was added for partial neutralization. The degree of neutralization was controlled at 25% and the acid value was 50 mg KOH / g to obtain dimer acid imidazoline derivative. Take 22 parts of molybdenum intercalated magnesium aluminum LDH aqueous dispersion slurry, add 35 parts of alcohol amine borate ester, 20 parts of dimer acid imidazoline derivative and 40 parts of water according to the dry basis of molybdenum intercalated magnesium aluminum LDH contained therein, and mix them. Adjust the pH to 8.4 with 30% sodium hydroxide solution by mass, stir and react at 75℃ for 2 hours, and then wet grind for 40 minutes to obtain a self-healing functional dispersion with a solid content of 35% and a D50 particle size of 150nm. S2. Mix 80 parts water, 9 parts monoethanolamine, 8 parts mixed alkanolamines, 2 parts amino alcohol, 1 part dodecanoic acid, 0.9 parts tricarboxylic acid rust inhibitor, and 1.5 parts boric acid, and stir at 70°C until clear to obtain an alkaline rust-inhibiting aqueous phase; the mixed alkanolamine is a mixture of diethanolamine and triethanolamine, wherein the weight ratio of diethanolamine to triethanolamine is 30:70, and the amino alcohol is 95% monoisopropanolamine; S3. Mix 50 parts of transformer oil, 12 parts of chlorinated paraffin, 11 parts of tall oil derivative, 8 parts of sodium petroleum sulfonate, 6 parts of dodecanoic acid diethanolamide borate, 6 parts of fatty alcohol polyoxyethylene ether emulsifier, 3 parts of sorbitan oleate, 4 parts of triethylene glycol butyl ether and 2 parts of fatty alcohol polyoxyethylene ether carboxylate, and stir evenly at 60°C to obtain an oily lubricating emulsion phase. S4. At a temperature of 55℃ and a stirring speed of 1500r / min, 30 parts of the alkaline rust-inhibiting aqueous phase obtained in step S2 are added in three equal portions to 50 parts of the oily lubricating emulsion phase obtained in step S3. After the addition is completed, stirring is continued for 20min. Then, 4 parts of the self-healing functional dispersion obtained in step S1 are added and sheared and dispersed for 25min. Then, 20 parts of water are added at a rate of 1 part / min to cause the system to reverse, thus obtaining a semi-synthetic cutting fluid premix. S5. Cool the semi-synthetic cutting fluid premix to 35°C, add 1 part of N,N'-methylenebismorpholine, 1 part of BBIT20 bactericide and 0.3 parts of BD-3037 defoamer produced by Hangzhou Baoerde New Material Technology Co., Ltd., stir for 20 minutes, filter, and obtain a semi-synthetic cutting fluid based on self-healing materials.

[0048] Example 2 Preparation of semi-synthetic cutting fluid based on self-healing materials: S1. Preparation of tungsten-intercalated magnesium-aluminum LDH: 100 parts of magnesium-aluminum LDH were added to 500 parts of deionized water and stirred and dispersed for 30 min. 25 parts of sodium tungstate were added and stirred for ion exchange at 60℃ for 3 h. After filtration, the filtrate was washed with deionized water until the conductivity of the filtrate was less than 1000 μS / cm to obtain wet tungsten-intercalated magnesium-aluminum LDH. The wet filtrate was dispersed in deionized water to prepare a tungsten-intercalated magnesium-aluminum LDH aqueous dispersion slurry with a solid content of 20%. Preparation of alcoholic amine borate ester: 100 parts boric acid, 120 parts triethanolamine, 100 parts diethanolamine and 60 parts monoisopropanolamine were added to a reaction vessel and dehydrated under reduced pressure at 120°C for 3 hours to obtain alcoholic amine borate ester. Preparation of dimer acid imidazoline derivative: Dimer acid and aminoethylethanolamine were mixed in a molar ratio of 1:1 and dehydrated and condensed at 180℃ for 4 hours. After cooling to 90℃, triethanolamine was added for partial neutralization. The degree of neutralization was controlled at 45% and the acid value was 20 mg KOH / g to obtain dimer acid imidazoline derivative. Take 35 parts of tungsten-intercalated magnesium-aluminum LDH aqueous dispersion slurry, add 20 parts of alkanolamine borate ester, 35 parts of dimer acid imidazoline derivative and 20 parts of water according to the dry basis of tungsten-intercalated magnesium-aluminum LDH contained therein, and mix them. Adjust the pH to 9.2 with 30% sodium hydroxide solution by mass, stir and react at 60℃ for 3h, and then disperse by high-speed shear for 40min to obtain a self-healing functional dispersion with a solid content of 20% and a D50 particle size of 300nm. S2. Mix 70 parts water, 12 parts monoethanolamine, 4 parts mixed alkanolamines, 3 parts amino alcohol, 0.3 parts dodecanoic acid, 1.5 parts tricarboxylic acid rust inhibitor, and 0.5 parts boric acid, and stir at 85°C until clear to obtain an alkaline rust-inhibiting aqueous phase; the mixed alkanolamine is a mixture of diethanolamine and triethanolamine, wherein the weight ratio of diethanolamine to triethanolamine is 30:70, and the amino alcohol is 95% monoisopropanolamine; S3. Mix 35 parts of naphthenic mineral oil, 20 parts of chlorinated paraffin, 5 parts of tall oil derivative, 12 parts of sodium petroleum sulfonate, 2 parts of sodium octanol polyether-9 carboxylate, 10 parts of fatty alcohol polyoxyethylene ether emulsifier, 1 part of sorbitan oleate, 6 parts of triethylene glycol butyl ether and 0.2 parts of sodium polyacrylate, and stir evenly at 75°C to obtain an oily lubricating emulsion phase; S4. At a temperature of 45℃ and a stirring speed of 2500r / min, 20 parts of the alkaline rust-inhibiting aqueous phase obtained in step S2 are added in 5 equal portions to 35 parts of the oily lubricating emulsion phase obtained in step S3. After the addition is completed, stirring is continued for 20min. Then, 6 parts of the self-healing functional dispersion obtained in step S1 are added and sheared and dispersed for 10min. Then, 30 parts of water are added at a rate of 3 parts / min to cause the system to reverse, thus obtaining a semi-synthetic cutting fluid premix. S5. Cool the semi-synthetic cutting fluid premix to 25°C, add 2 parts of N,N'-methylenebismorpholine, 2 parts of hexahydro-1,3,5-tris(hydroxyethyl)-triazine and 0.05 parts of S10 defoamer produced by Euronco Bio-Lubricants Co., Ltd., stir for 20 minutes, filter, and obtain a semi-synthetic cutting fluid based on self-healing materials.

[0049] Example 3 Preparation of semi-synthetic cutting fluid based on self-healing materials: S1. Preparation of molybdenum-intercalated magnesium-aluminum LDH: 100 parts of magnesium-aluminum LDH were added to 500 parts of deionized water and stirred for 30 min. 12 parts of sodium molybdate were added and stirred for ion exchange at 90℃ for 3 h. After filtration, the mixture was washed with deionized water until the conductivity of the filtrate was less than 1000 μS / cm to obtain wet molybdenum-intercalated magnesium-aluminum LDH. The wet material was dispersed in deionized water to prepare a water-dispersible slurry of molybdenum-intercalated magnesium-aluminum LDH with a solid content of 20%. Preparation of alcoholic amine borate ester: 100 parts boric acid, 200 parts diethylene glycolamine and 80 parts monoethanolamine were added to a reaction vessel and dehydrated under reduced pressure at 80°C for 3 hours to obtain alcoholic amine borate ester; Preparation of dimer acid imidazoline derivative: Dimer acid and aminoethylethanolamine were mixed in a molar ratio of 1:1.1 and dehydrated and condensed at 180°C for 4 hours. After cooling to 90°C, monoisopropanolamine was added for partial neutralization. The degree of neutralization was controlled at 10% and the acid value was 80 mg KOH / g to obtain dimer acid imidazoline derivative. Take 10 parts of molybdenum intercalated magnesium aluminum LDH aqueous dispersion slurry, add 55 parts of alcohol amine borate ester, 10 parts of dimer acid imidazoline derivative and 60 parts of water according to the dry basis of molybdenum intercalated magnesium aluminum LDH contained therein, and mix them. Adjust the pH to 7.8 with 30% sodium hydroxide solution by mass, stir and react at 90℃ for 1 hour, and then wet grind for 40 minutes to obtain a self-healing functional dispersion with a solid content of 45% and a D50 particle size of 80nm. S2. Mix 89 parts water, 5 parts monoethanolamine, 12 parts mixed alkanolamines, 0.5 parts amino alcohol, 2 parts dodecanoic acid, 0.2 parts tricarboxylic acid rust inhibitor, and 2.5 parts boric acid, and stir at 55°C until clear to obtain an alkaline rust-inhibiting aqueous phase; the mixed alkanolamine is a mixture of diethanolamine and triethanolamine, wherein the weight ratio of diethanolamine to triethanolamine is 30:70, and the amino alcohol is 95% monoisopropanolamine; S3. Mix 65 parts of hydrogenated base oil, 5 parts of chlorinated paraffin, 18 parts of tall oil derivative, 3 parts of sodium petroleum sulfonate, 10 parts of sodium octylphenol polyoxyethylene ether carboxylate, 2 parts of fatty alcohol polyoxyethylene ether emulsifier, 6 parts of sorbitan oleate, 1 part of triethylene glycol butyl ether, and 3 parts of sodium 2-phosphonobutane-1,2,4-tricarboxylate, and stir evenly at 45°C to obtain an oily lubricating emulsion phase; S4. At a temperature of 65℃ and a stirring speed of 800r / min, 40 parts of the alkaline rust-inhibiting aqueous phase obtained in step S2 were added in two equal portions to 65 parts of the oily lubricating emulsion phase obtained in step S3. After the addition was completed, stirring was continued for 20min. Then, 2 parts of the self-healing functional dispersion obtained in step S1 were added and sheared and dispersed for 40min. Then, 5 parts of water were added at a rate of 0.5 parts / min to cause the system to reverse, thus obtaining a semi-synthetic cutting fluid premix. S5. Cool the semi-synthetic cutting fluid premix to 45°C, add 0.3 parts of hexahydro-1,3,5-tris(hydroxyethyl)-triazine, 0.2 parts of CMIT / MIT compound, and 0.5 parts of BD-3037 defoamer produced by Hangzhou Baoerde New Material Technology Co., Ltd., stir for 20 minutes, filter, and obtain a semi-synthetic cutting fluid based on self-healing materials.

[0050] Example 4 Preparation of semi-synthetic cutting fluid based on self-healing materials: S1. Preparation of tungsten-intercalated magnesium-aluminum LDH: 100 parts of magnesium-aluminum LDH were added to 500 parts of deionized water and stirred and dispersed for 30 min. 20 parts of sodium tungstate were added and stirred for ion exchange at 70℃ for 3 h. After filtration, the filtrate was washed with deionized water until the conductivity of the filtrate was less than 1000 μS / cm to obtain wet tungsten-intercalated magnesium-aluminum LDH. The wet filtrate was dispersed in deionized water to prepare a tungsten-intercalated magnesium-aluminum LDH aqueous dispersion slurry with a solid content of 20%. Preparation of alcoholic amine borate ester: 100 parts of boric acid, 220 parts of triethanolamine and 60 parts of 2-amino-2-methyl-1-propanol were added to a reaction vessel and dehydrated under reduced pressure at 110℃ for 3 h to obtain alcoholic amine borate ester; Preparation of dimer acid imidazoline derivative: Dimer acid and hydroxyethyl ethylenediamine were mixed in a molar ratio of 1:1.04 and dehydrated and condensed at 180℃ for 4 hours. After cooling to 90℃, monoisopropanolamine was added for partial neutralization, and the degree of neutralization was controlled at 20%. The acid value was 60 mg KOH / g to obtain dimer acid imidazoline derivative. Take 20 parts of tungsten-intercalated magnesium-aluminum LDH aqueous dispersion slurry, add 30 parts of alkanolamine borate ester, 15 parts of dimer acid imidazoline derivative and 40 parts of water according to the dry basis of tungsten-intercalated magnesium-aluminum LDH contained therein, and mix them. Adjust the pH to 8.3 with 30% sodium hydroxide solution by mass, stir and react at 80℃ for 2 hours, and then disperse by high-speed shear for 40 minutes to obtain a self-healing functional dispersion with a solid content of 35% and a D50 particle size of 200nm. S2. Mix 75 parts water, 8 parts monoethanolamine, 6 parts mixed alkanolamines, 2 parts amino alcohol, 1.5 parts dodecanoic acid, 1 part tricarboxylic acid rust inhibitor, and 2 parts boric acid, and stir at 70°C until clear to obtain an alkaline rust-inhibiting aqueous phase; the mixed alkanolamines are a mixture of diethanolamine and triethanolamine, wherein the weight ratio of diethanolamine to triethanolamine is 30:70, and the amino alcohol is 95% monoisopropanolamine; S3. Mix 55 parts of low viscosity white oil, 15 parts of chlorinated paraffin, 15 parts of tall oil derivative, 7 parts of sodium petroleum sulfonate, 6 parts of oleic acid diethanolamide, 8 parts of fatty alcohol polyoxyethylene ether emulsifier, 3 parts of sorbitan oleate, 4 parts of triethylene glycol butyl ether and 2 parts of fatty alcohol polyoxyethylene ether carboxylate, and stir evenly at 55°C to obtain an oily lubricating emulsion phase. S4. At a temperature of 50℃ and a stirring speed of 1300r / min, 30 parts of the alkaline rust-inhibiting aqueous phase obtained in step S2 were added in four equal portions to 55 parts of the oily lubricating emulsion phase obtained in step S3. After the addition was completed, stirring was continued for 20min. Then, 3 parts of the self-healing functional dispersion obtained in step S1 were added and sheared and dispersed for 20min. Then, 10 parts of water were added at a rate of 1.5 parts / min to cause the system to reverse, thus obtaining a semi-synthetic cutting fluid premix. S5. Cool the semi-synthetic cutting fluid premix to 40°C, add 2 parts of BBIT20 bactericide, 1 part of hexahydro-1,3,5-tris(hydroxyethyl)-triazine and 0.2 parts of S10 defoamer produced by Euronco Bio-Lubricants Co., Ltd., stir for 20 minutes, filter, and obtain a semi-synthetic cutting fluid based on self-healing materials.

[0051] Comparative Example 1 (different from Example 1 in that no self-healing dispersion was added) Preparation of semi-synthetic cutting fluid: S1. Mix 80 parts water, 9 parts monoethanolamine, 8 parts mixed alkanolamines, 2 parts amino alcohol, 1 part dodecanoic acid, 0.9 parts tricarboxylic acid rust inhibitor, and 1.5 parts boric acid, and stir at 70°C until clear to obtain an alkaline rust-inhibiting aqueous phase; the mixed alkanolamines are a mixture of diethanolamine and triethanolamine, wherein the weight ratio of diethanolamine to triethanolamine is 30:70, and the amino alcohol is 95% monoisopropanolamine; S2. Mix 50 parts of transformer oil, 12 parts of chlorinated paraffin, 11 parts of tall oil derivative, 8 parts of sodium petroleum sulfonate, 6 parts of dodecanoic acid diethanolamide borate, 6 parts of fatty alcohol polyoxyethylene ether emulsifier, 3 parts of sorbitan oleate, 4 parts of triethylene glycol butyl ether and 2 parts of fatty alcohol polyoxyethylene ether carboxylate, and stir evenly at 60°C to obtain an oily lubricating emulsion phase. S3. Under the conditions of 55℃ and 1500r / min, 30 parts of the alkaline rust-inhibiting aqueous phase obtained in step S1 are added in three equal portions to 50 parts of the oily lubricating emulsion phase obtained in step S2. After the addition is completed, stirring is continued for 20min. Then, 20 parts of water are added at a rate of 1 part / min to cause the system to reverse and obtain a semi-synthetic cutting fluid premix. S4. Cool the semi-synthetic cutting fluid premix to 35°C, add 1 part of N,N'-methylenebismorpholine, 1 part of BBIT20 bactericide and 0.3 parts of BD-3037 defoamer produced by Hangzhou Baoerde New Material Technology Co., Ltd., stir for 20 minutes, filter, and obtain the semi-synthetic cutting fluid.

[0052] Comparative Example 2 (different from Example 1 in that a magnesium-aluminum LDH slurry is used instead of the self-healing dispersion) Preparation of semi-synthetic cutting fluid based on self-healing materials: S1. Mix 80 parts water, 9 parts monoethanolamine, 8 parts mixed alkanolamines, 2 parts amino alcohol, 1 part dodecanoic acid, 0.9 parts tricarboxylic acid rust inhibitor, and 1.5 parts boric acid, and stir at 70°C until clear to obtain an alkaline rust-inhibiting aqueous phase; the mixed alkanolamines are a mixture of diethanolamine and triethanolamine, wherein the weight ratio of diethanolamine to triethanolamine is 30:70, and the amino alcohol is 95% monoisopropanolamine; S2. Mix 50 parts of transformer oil, 12 parts of chlorinated paraffin, 11 parts of tall oil derivative, 8 parts of sodium petroleum sulfonate, 6 parts of dodecanoic acid diethanolamide borate, 6 parts of fatty alcohol polyoxyethylene ether emulsifier, 3 parts of sorbitan oleate, 4 parts of triethylene glycol butyl ether and 2 parts of fatty alcohol polyoxyethylene ether carboxylate, and stir evenly at 60°C to obtain an oily lubricating emulsion phase. S3. At a temperature of 55℃ and a stirring speed of 1500r / min, 30 parts of the alkaline rust-inhibiting aqueous phase obtained in step S1 are added in three equal portions to 50 parts of the oily lubricating emulsion phase obtained in step S2. After the addition is completed, stirring is continued for 20min. Then, 4 parts of magnesium-aluminum LDH slurry are added and sheared and dispersed for 25min. Then, 20 parts of water are added at a rate of 1 part / min to cause the system to reverse, thus obtaining a semi-synthetic cutting fluid premix. S4. Cool the semi-synthetic cutting fluid premix to 35°C, add 1 part of N,N'-methylenebismorpholine, 1 part of BBIT20 bactericide and 0.3 parts of BD-3037 defoamer produced by Hangzhou Baoerde New Material Technology Co., Ltd., stir for 20 minutes, filter, and obtain a semi-synthetic cutting fluid based on self-healing materials.

[0053] Comparative Example 3 (different from Example 1 in that a magnesium-aluminum LDH aqueous dispersion slurry is used instead of a molybdenum intercalated magnesium-aluminum LDH aqueous dispersion slurry) Preparation of semi-synthetic cutting fluid based on self-healing materials: S1. Add 100 parts of magnesium aluminum LDH to 500 parts of deionized water, stir and disperse for 30 minutes to prepare a magnesium aluminum LDH water dispersion slurry with a solid content of 20%; Preparation of alcoholic amine borate ester: 100 parts boric acid, 220 parts triethanolamine and 60 parts monoethanolamine were added to a reaction vessel and dehydrated under reduced pressure at 100°C for 3 hours to obtain alcoholic amine borate ester; Preparation of dimer acid imidazoline derivative: Dimer acid and hydroxyethyl ethylenediamine were mixed in a molar ratio of 1:1.05 and dehydrated and condensed at 180℃ for 4 hours. After cooling to 90℃, monoethanolamine was added for partial neutralization. The degree of neutralization was controlled at 25% and the acid value was 50 mg KOH / g to obtain dimer acid imidazoline derivative. Take 22 parts of magnesium aluminum LDH aqueous dispersion slurry, add 35 parts of alcohol amine borate ester, 20 parts of dimer acid imidazoline derivative and 40 parts of water according to the dry basis of magnesium aluminum LDH contained therein, mix, adjust the pH to 8.4 with 30% sodium hydroxide solution, stir and react at 75℃ for 2h, and then wet grind for 40min to obtain a self-healing functional dispersion with a solid content of 35% and a D50 particle size of 150nm; S2. Mix 80 parts water, 9 parts monoethanolamine, 8 parts mixed alkanolamines, 2 parts amino alcohol, 1 part dodecanoic acid, 0.9 parts tricarboxylic acid rust inhibitor, and 1.5 parts boric acid, and stir at 70°C until clear to obtain an alkaline rust-inhibiting aqueous phase; the mixed alkanolamine is a mixture of diethanolamine and triethanolamine, wherein the weight ratio of diethanolamine to triethanolamine is 30:70, and the amino alcohol is 95% monoisopropanolamine; S3. Mix 50 parts of transformer oil, 12 parts of chlorinated paraffin, 11 parts of tall oil derivative, 8 parts of sodium petroleum sulfonate, 6 parts of dodecanoic acid diethanolamide borate, 6 parts of fatty alcohol polyoxyethylene ether emulsifier, 3 parts of sorbitan oleate, 4 parts of triethylene glycol butyl ether and 2 parts of fatty alcohol polyoxyethylene ether carboxylate, and stir evenly at 60°C to obtain an oily lubricating emulsion phase. S4. At a temperature of 55℃ and a stirring speed of 1500r / min, 30 parts of the alkaline rust-inhibiting aqueous phase obtained in step S2 are added in three equal portions to 50 parts of the oily lubricating emulsion phase obtained in step S3. After the addition is completed, stirring is continued for 20min. Then, 4 parts of the self-healing functional dispersion obtained in step S1 are added and sheared and dispersed for 25min. Then, 20 parts of water are added at a rate of 1 part / min to cause the system to reverse, thus obtaining a semi-synthetic cutting fluid premix. S5. Cool the semi-synthetic cutting fluid premix to 35°C, add 1 part of N,N'-methylenebismorpholine, 1 part of BBIT20 bactericide and 0.3 parts of BD-3037 defoamer produced by Hangzhou Baoerde New Material Technology Co., Ltd., stir for 20 minutes, filter, and obtain a semi-synthetic cutting fluid based on self-healing materials.

[0054] Comparative Example 4 (The difference from Example 1 is that in S4, the alkaline rust-inhibiting aqueous phase is added directly all at once, and the water is poured in directly without controlling the addition speed) Preparation of semi-synthetic cutting fluid based on self-healing materials: S1. Preparation of molybdenum-intercalated magnesium-aluminum LDH: 100 parts of magnesium-aluminum LDH were added to 500 parts of deionized water and stirred for 30 min. 18 parts of sodium molybdate were added and stirred for ion exchange at 75℃ for 3 h. After filtration, the mixture was washed with deionized water until the conductivity of the filtrate was less than 1000 μS / cm to obtain wet molybdenum-intercalated magnesium-aluminum LDH. The wet material was dispersed in deionized water to prepare a water-dispersible slurry of molybdenum-intercalated magnesium-aluminum LDH with a solid content of 20%. Preparation of alcoholic amine borate ester: 100 parts boric acid, 220 parts triethanolamine and 60 parts monoethanolamine were added to a reaction vessel and dehydrated under reduced pressure at 100°C for 3 hours to obtain alcoholic amine borate ester; Preparation of dimer acid imidazoline derivative: Dimer acid and hydroxyethyl ethylenediamine were mixed in a molar ratio of 1:1.05 and dehydrated and condensed at 180℃ for 4 hours. After cooling to 90℃, monoethanolamine was added for partial neutralization. The degree of neutralization was controlled at 25% and the acid value was 50 mg KOH / g to obtain dimer acid imidazoline derivative. Take 22 parts of molybdenum intercalated magnesium aluminum LDH aqueous dispersion slurry, add 35 parts of alcohol amine borate ester, 20 parts of dimer acid imidazoline derivative and 40 parts of water according to the dry basis of molybdenum intercalated magnesium aluminum LDH contained therein, and mix them. Adjust the pH to 8.4 with 30% sodium hydroxide solution by mass, stir and react at 75℃ for 2 hours, and then wet grind for 40 minutes to obtain a self-healing functional dispersion with a solid content of 35% and a D50 particle size of 150nm. S2. Mix 80 parts water, 9 parts monoethanolamine, 8 parts mixed alkanolamines, 2 parts amino alcohol, 1 part dodecanoic acid, 0.9 parts tricarboxylic acid rust inhibitor, and 1.5 parts boric acid, and stir at 70°C until clear to obtain an alkaline rust-inhibiting aqueous phase; the mixed alkanolamine is a mixture of diethanolamine and triethanolamine, wherein the weight ratio of diethanolamine to triethanolamine is 30:70, and the amino alcohol is 95% monoisopropanolamine; S3. Mix 50 parts of transformer oil, 12 parts of chlorinated paraffin, 11 parts of tall oil derivative, 8 parts of sodium petroleum sulfonate, 6 parts of dodecanoic acid diethanolamide borate, 6 parts of fatty alcohol polyoxyethylene ether emulsifier, 3 parts of sorbitan oleate, 4 parts of triethylene glycol butyl ether and 2 parts of fatty alcohol polyoxyethylene ether carboxylate, and stir evenly at 60°C to obtain an oily lubricating emulsion phase. S4. At a temperature of 55℃ and a stirring speed of 1500r / min, 30 parts of the alkaline rust-inhibiting aqueous phase obtained in step S2 are directly added to 50 parts of the oily lubricating emulsion phase obtained in step S3. After the addition is completed, stirring is continued for 20min. Then, 4 parts of the self-healing functional dispersion obtained in step S1 are added and sheared and dispersed for 25min. Then, 20 parts of water are directly poured in to cause the system to reverse, and a semi-synthetic cutting fluid premix is ​​obtained. S5. Cool the semi-synthetic cutting fluid premix to 35°C, add 1 part of N,N'-methylenebismorpholine, 1 part of BBIT20 bactericide and 0.3 parts of BD-3037 defoamer produced by Hangzhou Baoerde New Material Technology Co., Ltd., stir for 20 minutes, filter, and obtain a semi-synthetic cutting fluid based on self-healing materials.

[0055] Experimental Example The semi-synthetic cutting fluids obtained in Examples 1-4 and Comparative Examples 1-4 were diluted with deionized water at a mass concentration of 5% and their performance was tested. The test method is as follows: The appearance of the undiluted fluid was evaluated visually. pH value was determined according to GB / T 6368. Stability, defoaming properties, gray cast iron corrosion tests, and rust prevention tests were conducted according to GB / T 6144 "Synthetic Cutting Fluids," with the single-piece rust prevention test for gray cast iron at 35±2℃ for 24h, and the full immersion corrosion test at 55±2℃ for 24h. The maximum non-jamming load PB of the four-ball mill was determined according to GB / T 3142. Wear scar diameter was determined according to SH / T 0189, with test conditions of 392N, 75℃, 1200r / min, and 60min. Particle size was determined using a laser particle size analyzer. Machining evaluation was conducted using a CK45 steel turning test, with a cutting fluid concentration of 5%, carbide cutting tools, a cutting speed of 180m / min, a feed rate of 0.18mm / r, and a depth of cut of 1.0mm. The surface roughness Ra of the workpiece is evaluated according to the parameters specified in GB / T 1031 and measured using a roughness tester; the tool flank wear VB is measured under the same cutting time.

[0056] The test data is shown in Table 1 below: Table 1. Performance Test Data of Semi-synthetic Cutting Fluid Reference Figures 1-2 As can be seen from Table 1, the semi-synthetic cutting fluids prepared in Examples 1 to 4 of this application all exhibit good performance in terms of rust prevention, low foaming, hard water stability, particle size stability, and anti-wear properties.

[0057] In Comparative Example 1, the self-healing functional dispersion was not added, and all other steps were the same as in Example 1. The semi-synthetic cutting fluid prepared in Comparative Example 1 had a lower PB value, a larger wear scar diameter, and significantly worse workpiece surface roughness Ra and tool flank wear VB. This indicates that the self-healing functional dispersion introduced in this application can significantly improve the extreme pressure anti-wear performance and machining lubrication ability of the cutting fluid, and help reduce tool wear and improve workpiece surface machining quality, thus demonstrating its technical effect of forming a dynamic compensation protective film at the cutting interface.

[0058] In the preparation method of Comparative Example 2, magnesium aluminum LDH slurry was used instead of the self-healing functional dispersion, and the rest was the same as in Example 1. The semi-synthetic cutting fluid prepared in Comparative Example 2 showed poor dilution stability, rust prevention and defoaming properties, indicating that it is difficult to form a stable synergy with the system by adding magnesium aluminum LDH slurry alone, and it cannot take into account dispersion stability, rust prevention and low foaming performance. However, the self-healing functional dispersion of this application can significantly improve the system compatibility and use stability.

[0059] The preparation method of Comparative Example 3 used magnesium-aluminum LDH aqueous dispersion slurry instead of molybdenum intercalated magnesium-aluminum LDH aqueous dispersion slurry, and the rest was the same as in Example 1. The semi-synthetic cutting fluid prepared in Comparative Example 3 showed a deterioration in anti-wear and machining performance, indicating that molybdenum intercalated magnesium-aluminum LDH can more effectively improve the load-bearing and anti-wear performance and machining lubrication effect of the system compared with unintercalated magnesium-aluminum LDH, which is beneficial to reduce tool wear and improve the surface quality of the machined surface.

[0060] In the preparation method of Comparative Example 4, the alkaline rust-inhibiting aqueous phase was added directly in one step, and the water was added directly without controlling the addition rate. All other steps were the same as in Example 1. The semi-synthetic cutting fluid system prepared in Comparative Example 4 had larger particle size and poorer storage stability. This indicates that the addition of the alkaline rust-inhibiting aqueous phase in stages and the controlled water addition during the phase reversal process play an important role in forming an emulsion system with smaller particle size and uniform distribution. The controlled feeding method is conducive to the stable distribution of the self-healing functional dispersion at the oil-water interface, promotes the smooth phase reversal of the system, and thus improves the storage stability, hard water adaptability and overall performance of the product.

[0061] Therefore, the semi-synthetic cutting fluid based on self-healing materials provided in this application can achieve good cooling, lubrication, rust prevention and stable use in the cutting of steel and cast iron materials, and has good prospects for industrial application.

[0062] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions or alterations can be made to these embodiments without departing from the principles and spirit of this application, and the technical solutions resulting from such changes, modifications, substitutions or alterations will all fall within the protection scope of this application.

Claims

1. A method for preparing a semi-synthetic cutting fluid based on self-healing materials, characterized in that, Includes the following steps: S1. Molybdenum and / or tungsten intercalated magnesium aluminum LDH, amino borate ester, dimer acid imidazoline derivative and water are mixed, the pH is adjusted to 7.8-9.2, and the mixture is stirred at 60-90℃ for 1-3 hours. Then, it is dispersed by wet grinding or high-speed shearing to obtain a self-healing functional dispersion with a solid content of 20-45% and a D50 particle size of 80-300nm. S2. Water, monoethanolamine, mixed alkanolamines, amino alcohols, dodecanoic acid, tricarboxylic acid rust inhibitors, and boric acid are mixed and stirred at 55-85°C until clear to obtain an alkaline rust-inhibiting aqueous phase; the mixed alkanolamines are a mixture including at least two of monoethanolamine, diethanolamine, and triethanolamine, and contain at least triethanolamine; the amino alcohols are selected from at least one of monoisopropanolamine, diethylene glycolamine, and 2-amino-2-methyl-1-propanol; S3. Mix base oil, chlorinated paraffin, tall oil derivative, sodium petroleum sulfonate, coupling agent, fatty alcohol polyoxyethylene ether emulsifier, sorbitan oleate, triethylene glycol butyl ether and anti-hard water agent, and stir evenly at 45-75°C to obtain an oily lubricating emulsion phase. S4. Under the conditions of temperature 45-65℃ and stirring speed 800-2500r / min, the alkaline rust-inhibiting aqueous phase obtained in step S2 is added to the oily lubricating emulsion phase obtained in step S3 in 2-5 portions to form an oil-in-water transition system; then the self-healing functional dispersion obtained in step S1 is added, and shearing is continued for 10-40min; then water is added at a rate of 0.5-3 parts by weight / min to cause the system to reverse, and a semi-synthetic cutting fluid premix is ​​obtained. S5. Cool the semi-synthetic cutting fluid premix to 25-45°C, add bactericidal and defoaming components, stir evenly, and filter to obtain the semi-synthetic cutting fluid based on self-healing materials.

2. The method for preparing a semi-synthetic cutting fluid based on self-healing materials according to claim 1, characterized in that, In step S1, the raw materials of the self-healing functional dispersion, by weight, include: 10-35 parts of molybdenum and / or tungsten intercalated magnesium aluminum LDH, 20-55 parts of alcoholic amine borate ester, 10-35 parts of dimer acid imidazoline derivative, and 20-60 parts of water. And / or, in step S2, the raw materials of the alkaline rust-preventing aqueous phase, by weight, include: 5-12 parts monoethanolamine, 4-12 parts mixed alcoholamines, 0.5-3 parts amino alcohol, 0.3-2 parts dodecanoic acid, 0.2-1.5 parts tricarboxylic acid rust inhibitor, 0.5-2.5 parts boric acid, and 70-89 parts water; And / or, in step S3, the raw materials of the oily lubricating emulsion phase, by weight, include: 35-65 parts base oil, 5-20 parts chlorinated paraffin, 5-18 parts tall oil derivative, 3-12 parts sodium petroleum sulfonate, 2-10 parts coupling agent, 2-10 parts fatty alcohol polyoxyethylene ether emulsifier, 1-6 parts sorbitan oleate, 1-6 parts triethylene glycol butyl ether, and 0.2-3 parts anti-hard water agent.

3. The method for preparing a semi-synthetic cutting fluid based on a self-healing material according to claim 1, characterized in that, In step S4, the ratio of the alkaline anti-rust aqueous phase, the oily lubricating emulsion phase, the self-healing functional dispersion, and water by weight is 20-40:35-65:2-6:5-30.

4. The method for preparing a semi-synthetic cutting fluid based on a self-healing material according to claim 1, characterized in that, The molybdenum and / or tungsten intercalated magnesium aluminum LDH mentioned in step S1 is prepared by ion exchange reaction of magnesium aluminum LDH with sodium molybdate and / or sodium tungstate at 60-90°C.

5. The method for preparing a semi-synthetic cutting fluid based on a self-healing material according to claim 4, characterized in that, The weight ratio of the magnesium aluminum LDH to the sodium molybdate and / or sodium tungstate is 100:12-25.

6. The method for preparing a semi-synthetic cutting fluid based on a self-healing material according to claim 1, characterized in that, The alcoholic amine borate ester described in step S1 is prepared by dehydrating boric acid with at least one of monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diethylene glycolamine, and 2-amino-2-methyl-1-propanol at 80–120 °C.

7. The method for preparing a semi-synthetic cutting fluid based on a self-healing material according to claim 1, characterized in that, The dimer acid imidazoline derivative is prepared by condensing a dimer acid with hydroxyethyl ethylenediamine and / or aminoethyl ethanolamine, followed by partial neutralization with monoethanolamine, triethanolamine or monoisopropanolamine. The degree of neutralization of the dimer acid imidazoline derivative is 10-45%, and the acid value is 20-80 mg KOH / g.

8. The method for preparing a semi-synthetic cutting fluid based on a self-healing material according to claim 1, characterized in that, The base oil mentioned in step S3 is at least one of transformer oil, naphthenic mineral oil, hydrogenated base oil, and low viscosity white oil; And / or, the coupling agent in step S3 is at least one of polyether carboxylates, alcohol ether carboxylates, alkanolamide borate esters, or fatty acid amide coupling agents; And / or, the anti-hard water agent in step S3 is at least one of polycarboxylate, phosphonate, or alcohol ether carboxylate; And / or, the bactericidal component in step S5 includes at least one of MBM-type bactericides, BBIT-type bactericides, triazine-type bactericides, and isothiazolinone-type bactericides; And / or, the defoaming component in step S5 is a polyether-modified siloxane defoamer and / or a mineral oil-based defoamer.

9. A semi-synthetic cutting fluid based on a self-healing material prepared by the preparation method of a semi-synthetic cutting fluid based on a self-healing material as described in any one of claims 1 to 8.

10. The application of a semi-synthetic cutting fluid based on self-healing materials as described in claim 9 in turning, milling, drilling, grinding or tapping of carbon steel, alloy steel, gray cast iron, and ductile cast iron.

Images