Copper wire drawing liquid and preparation method thereof

Abstract

The invention discloses a copper wire drawing liquid and a preparation method thereof, and relates to the technical field of metal drawing liquids. Fatty alcohol-polyoxyethylene ether and triglyceride polyoxyethylene ether are compounded according to a ratio of 1: 1, and a nano-scale microemulsion is formed through instantaneous negative interfacial tension, so that the problems of layering and turbidity of a traditional product are thoroughly solved. And moreover, the coating has the characteristics of hard water resistance, acid and alkali resistance and low foam, and is biodegradable. The molecular weight of the natural sodium sulfonate surfactant is optimized to balance emulsibility and anti-rust property, three layers of chemical adsorption films are formed on the metal surface, and efficient rust prevention of the copper wire is achieved; a high-viscosity block polyether surfactant is adopted, a block structure is endowed with super-strong seepage force, a continuous lubricating film is separated out on a hot surface due to the inverse solubility characteristic, and friction is remarkably reduced; the tall oil and the mineral oil are mixed to provide a low viscosity index characteristic to adapt to high-speed drawing; triethanolamine is matched with a benzotriazole antirust agent to synergistically enhance surface adsorption of the copper wire, and an alkaline environment inhibits microorganisms and passivates and prevents rust; the isothiazolinone bactericide is added at low temperature, so that the coating is alkali-resistant, chlorine-free, environment-friendly and long-acting in

Description

Technical Field

[0001] This invention relates to the technical field of metal drawing fluids, specifically to a copper wire drawing fluid and its preparation method. Background Technology

[0002] Traditional copper and aluminum drawing fluids used in machining processes are mostly composed of high-melting-point substances such as sodium and potassium metal soaps of higher fatty acids, waxes, and curing oils, or contain extreme pressure additives such as fluorine-based additives. The large-scale use of these processing fluids has brought various drawbacks to the environment and energy. For example, most of the energy consumed in metal drawing is consumed in the friction between the die and the drawn material, causing the interface temperature to rise and making the lubricating film prone to rupture or even sintering.

[0003] Traditional water-based and semi-synthetic drawing fluids rely on surfactants to stabilize the emulsion system. However, conventional surfactants are insufficient to form nanoscale microemulsions, leading to stratification and turbidity during long-term storage. They also exhibit weak resistance to hard water and significant foaming issues, interfering with continuous production. Additives such as rust inhibitors and extreme pressure agents may form insoluble substances due to salting out or reaction with metal ions, affecting stability. Microbial contamination can disrupt the emulsion system and cause turbidity. Changes in temperature and light can cause emulsion demulsification or component crystallization. Unstable overall product pH affects surfactant ionization, and loss of volatile components or chemical reactions can disrupt the system balance. Excessively high pH values ​​are irritating to humans and corrode metal parts; while excessively low pH values ​​may trigger microbial problems.

[0004] Currently, the main problems with wire drawing fluids include poor emulsion stability, corrosion of metal wires, high energy consumption, difficulty in cleaning, and poor antibacterial properties. These problems limit the quality of wire drawing and drawing, and there is an urgent need to improve the formulation and process to achieve higher efficiency and environmental friendliness. Summary of the Invention

[0005] The purpose of this invention is to provide a copper wire drawing fluid and its preparation method to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a copper wire drawing fluid, comprising at least the following mass percentages: 50%-70% tall oil and mineral oil mixture; 2%-5% triethanolamine; 2%-5% tall oil fatty acids; 10%-18% compound emulsifier; 5%-10% natural sodium sulfonate surfactant; 2%-5% high viscosity block polyether surfactant; 1%-2% benzotriazole rust inhibitor; 5%-10% water; 2%-5% solubilizer; and 0%-1% isothiazolinone bactericide.

[0007] Preferably, the compound emulsifier is prepared by compounding fatty alcohol polyoxyethylene ether and triglyceride polyoxyethylene ether in a 1:1 ratio.

[0008] Preferably, in the mixture of tall oil and mineral oil, mineral oil accounts for more than 50%.

[0009] Preferably, the molecular weight of the natural sodium sulfonate surfactant is 420-500, and the polar end of the natural sodium sulfonate surfactant (-SO3) - Na + The positive end is used to adsorb onto the copper surface or the oil-water interface to form a rust-preventive film or reduce interfacial tension; while the negative end (-R) is soluble in the oil phase and stabilizes the emulsion system.

[0010] A method for preparing a copper wire drawing fluid includes at least the following steps: S1, adding tall oil and mineral oil to a mixing tank in proportion, turning on the stirrer, stirring at medium speed to ensure that the two oils are fully mixed and uniform, and controlling the temperature of the mixing tank to be 40-50℃. S2. While stirring, slowly add triethanolamine and tall oil fatty acids to form fatty acid amine salts; S3. Slowly add the pre-mixed fatty alcohol polyoxyethylene ether and triglyceride polyoxyethylene ether into the mixing tank, and continue stirring to ensure that the compounded emulsifier is fully dissolved and dispersed. Then add natural sodium sulfonate surfactant, high viscosity block polyether surfactant and solubilizer to ensure that the high viscosity block polyether surfactant is fully dissolved and dispersed. S4. While stirring, slowly add benzotriazole rust inhibitor and deionized water or softened water; S5. Turn off the heating and start the cooling system to slowly cool the product temperature in the reactor to below 40°C. Add isothiazolinone bactericide slowly while stirring to disperse it evenly, then stop stirring.

[0011] The copper wire drawing fluid and its preparation method proposed in this invention have the following advantages: 1. Breakthrough design of compound emulsifier: A 1:1 compound of fatty alcohol polyoxyethylene ether and triglyceride polyoxyethylene ether (10%-18%) is used to form a nanoscale microemulsion through instantaneous negative interfacial tension, completely solving the problems of layering and turbidity in traditional products, significantly extending shelf life. It also possesses resistance to hard water, acids and alkalis, low foaming properties, and is biodegradable, exhibiting excellent environmental performance.

[0012] 2. Synergistic effect of compound surfactants: The molecular weight of natural sodium sulfonate surfactants (420-500) is optimized to balance emulsification and rust prevention, forming a three-layer chemical adsorption film on the metal surface to achieve efficient rust prevention of copper wires; High-viscosity block polyether surfactants are used, and the block structure gives them super-strong penetrability. Their reverse solubility properties allow them to precipitate a continuous lubricating film on hot surfaces, significantly reducing friction. 3. Optimization of base oil and functional additives: Tall oil mixed with mineral oil provides stable viscosity, and its low viscosity index is suitable for high-speed drawing; triethanolamine, in combination with benzotriazole rust inhibitor, synergistically enhances the adsorption on the copper wire surface; through the synergistic effect of triethanolamine and tall oil fatty acids, the pH value of the product is controlled at 9.1-9.3, which avoids the dual risks of extreme acid and alkali values ​​while maintaining surfactant activity and stabilizing the system composition. That is, too high a pH will enhance alkaline corrosion and cause damage to the human body and metal parts such as aluminum; too low a pH will make it difficult to inhibit bacterial growth due to the near-neutral environment, leading to the deterioration and stratification of the drawing fluid; isothiazolinone bactericide is added at low temperature, which is alkali-resistant, chlorine-free, environmentally friendly, and has a long-lasting antibacterial effect.

[0013] In summary, this invention achieves a green drawing fluid solution with high lubricity, long service life, and easy cleaning through three major innovations: compound emulsifier microemulsion technology, block polyether reverse dissolution lubrication, and natural sodium sulfonate molecular rust prevention. Detailed Implementation

[0014] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0015] This invention provides a technical solution: a copper wire drawing fluid and its preparation method, S1, adding a mixture of tall oil and mineral oil to a stirring vessel at a mass percentage of 50%-70%. Turn on the stirrer and stir at medium speed to ensure the two oils are thoroughly mixed, controlling the temperature of the stirring vessel to 40-50℃; Tall oil contains natural fatty acids and resin acids, which can form a strong lubricating film on the mold and copper wire surface, significantly reducing the risk of direct metal contact, and is particularly suitable for high compression ratio drawing processes.

[0016] Mineral oil, due to its stable viscosity, can form a uniform oil film during the drawing process, effectively reducing friction between the die and the copper wire and preventing surface scratches. It not only improves lubrication and oxidation resistance and reduces evaporation loss, but also withstands higher loads and exhibits good reactivity with other additives.

[0017] Mineral oil accounts for more than 50% of the composition, and this high proportion of mineral oil ensures the continuity and stability of basic lubrication. This blended base oil ensures a reasonable molecular weight distribution, giving the product suitable viscosity, good fluidity, and excellent viscosity-temperature properties.

[0018] This formulation results in a product with a low viscosity index, indicating that the viscosity is sensitive to temperature changes—significantly decreasing at high temperatures and significantly increasing at low temperatures. This helps to accelerate circulation at higher temperatures, thereby improving cooling efficiency. Its high chemical reactivity allows the drawing fluid to form a readily shearable surface film through extreme pressure chemical reactions between the lubricant and the metal surface, resulting in limited and controllable corrosion. This achieves lubrication, reduces friction, improves workpiece surface finish, and extends tool life. Furthermore, the degreasing and cleaning process is relatively simple after using this mixed grease-based drawing fluid.

[0019] S2. While stirring, slowly add 2%-5% by mass of triethanolamine and tall oil fatty acids, and continue stirring for 10-15 minutes. Triethanolamine mainly reacts with the added tall oil fatty acids to form fatty acid amine salts, which play a role in emulsifying and stabilizing the system.

[0020] In this application, triethanolamine provides alkaline support, while tall oil fatty acids regulate alkalinity to prevent it from becoming too high. Together, they control the pH of the overall drawing solution at 9.1-9.3, which inhibits bacterial growth, ensures the stability of the copper material, and avoids the damage of strong alkalinity to the human body and the metal.

[0021] Specifically, from the perspective of microbial growth, the closer the pH value is to neutral, the easier it is for bacteria to multiply. This can lead to the deterioration and stratification of the drawing solution, thus affecting its performance. However, in a slightly alkaline environment of 9.1-9.3, bacterial growth is inhibited, which helps maintain the stability of the drawing solution.

[0022] From the perspective of its effects on the human body and metals, excessively high pH values ​​can irritate the human body and may corrode metal components. For copper materials, controlling the pH value of the drawing solution within the range of 9.1-9.3 avoids the adverse effects of excessively high pH values ​​on the human body and metals (especially aluminum parts that may come into contact with the metal), while also inhibiting the growth of microorganisms through a slightly alkaline environment. Therefore, this pH range balances the stability, safety, and adaptability of the drawing solution to copper materials, ensuring both the performance of the drawing solution and the quality of the copper wire.

[0023] Furthermore, triethanolamine can passivate and protect the copper surface, reducing oxidation and corrosion, making it particularly suitable for short-term storage after copper wire processing. Tall oil fatty acids are powerful oiling agents and extreme pressure agents. Their polar molecules can tightly adhere to the metal surface, and under high pressure and high temperature drawing conditions (especially during high compression ratios or fine wire drawing), they react chemically with the copper surface to form a metallic soap film, providing excellent boundary lubrication and extreme pressure lubrication protection, preventing adhesion and scratches.

[0024] S3. Slowly add the fatty alcohol polyoxyethylene ether and triglyceride polyoxyethylene ether, which have been pre-mixed in a 1:1 ratio, into the stirred tank. Continue stirring to ensure that the compounded emulsifier is fully dissolved and dispersed. Then add 5%-10% by weight of natural sodium sulfonate surfactant, 2%-5% of high viscosity block polyether surfactant, and 2%-5% of solubilizer to ensure that the high viscosity block polyether surfactant is fully dissolved and dispersed.

[0025] Fatty alcohol polyoxyethylene ethers impart emulsifying stability, while triglyceride polyoxyethylene ethers enhance permeability. The synergistic effect of these two components effectively solves the industry problem of easy stratification in traditional drawing fluids, exhibiting excellent hard water resistance, low foaming properties, and non-ionization in water, demonstrating good resistance to interference from acids, alkalis, and inorganic salts. Its broad compatibility makes it highly compatible with anionic and other ionic surfactants, providing great design flexibility for compound formulations. Simultaneously, this system possesses good biodegradability, aligning with green environmental protection trends.

[0026] This compound emulsifier, with a mass percentage of 10%-18%, significantly reduces the oil / water interfacial tension, even generating instantaneous negative interfacial tension. Therefore, the system will spontaneously expand the interface until the interfacial tension returns to zero or a small positive value, forming a microemulsion. This effectively solves the technical problem of traditional copper wire drawing solutions easily becoming stratified and turbid during long-term storage, improving product shelf life and quality. It achieves synergistic effects between molecules, significantly enhancing the overall performance of the emulsifier, particularly emulsification stability and dispersion uniformity.

[0027] Sodium sulfonate surfactants are derived from natural substances, exhibiting higher environmental compatibility and suitability for environmentally friendly product systems. Adding them to copper wire drawing fluids fully utilizes the hydrophobicity of the hydrocarbon chain portion and the hydrophilicity of the sulfonic acid groups in their molecular structure, enabling sodium sulfonate to form a stable emulsion system at the oil-water interface. Low molecular weight (420-500) sodium sulfonate improves the product's emulsifying performance, allowing for uniform emulsification and dispersion in water; the smaller the molecular weight, the stronger the emulsifying ability. Conversely, higher molecular weights provide better rust prevention. This product selects sodium sulfonate with an appropriate molecular weight, combining both emulsifying and rust-preventing properties. Its molecular structure consists of polar groups (-SO3). - Na +The non-polar groups (-R) possess oleophilic and hydrophobic properties. When sodium sulfonate is added to the formulation system and coated onto the metal surface, molecular thermal motion occurs at the oil-metal interface. The polar groups tend to adhere to the metal surface, while the non-polar groups, due to their similar structure to the base oil, tend to dissolve into the oil. This results in directional adsorption at the oil-metal interface. Chemical adsorption is the primary method, supplemented by physical adsorption, forming a three-layer protective film on the metal surface. This film blocks the corrosion of oxygen, moisture, and chemicals, slowing down the corrosion rate. It exhibits considerable resistance to saltwater immersion and provides excellent rust prevention for both ferrous and non-ferrous metals.

[0028] The high-viscosity block polyether surfactant used in this invention exhibits significant reverse solubility, effectively enhancing lubrication performance in copper wire drawing fluid. This polyether is uniformly dispersed in water at room temperature, forming a stable emulsion system. When the copper wire passes over a hot surface during the forming process, the temperature of the liquid rises rapidly, exceeding the cloud point of the polyether. This causes numerous fine polyether droplets to form within the emulsion, uniformly dispersing on the metal surface and wetting the metal substrate. These droplets form a continuous and well-lubricated oil film at the forming point, effectively reducing friction and improving lubrication.

[0029] The arrangement of EO and PO in polyether surfactants affects the properties of random polyethers. This change reaches its limit, transforming from random to block polyethers, resulting in a qualitative change in performance. For example, in terms of penetration, EO end-capping is detrimental to penetration in random polyethers, while PO end-capping improves it. However, when it becomes a block polyether, even with all EO at the end, its penetration is far superior to all random polyethers (including PO-end-capped random polyethers). Due to these characteristics of block polyethers, the drawing fluid possesses multiple functions, including excellent penetration, emulsification, lubrication, and defoaming. Compared to traditional polyether materials, the lubrication performance of this system is improved by at least 20%, significantly enhancing the smoothness and efficiency of copper wire drawing.

[0030] Furthermore, this high-viscosity block polyether exhibits excellent low-foaming properties, generating very little foam during production. This effectively avoids the impact of foam on calendering, traction, and molding processes, ensuring production stability and product quality. Its reverse solubility, combined with excellent lubrication and friction-reducing effects, provides an innovative high-performance lubrication solution for copper wire drawing fluids, helping to extend equipment life, improve production efficiency, and meet the environmental requirements for high-performance lubricants. The addition of a solubilizer further enhances the compatibility between the components in the system, ensuring the uniformity and stability of the entire system and preventing stratification and precipitation.

[0031] S4. While stirring, slowly add 1%-2% of a benzotriazole rust inhibitor and 5%-10% of deionized water or softened water. The triethanolamine-based benzotriazole rust inhibitor improves the corrosion resistance to copper. Benzotriazole itself may not dissolve evenly in the drawing fluid or adhere to the copper wire surface easily. Triethanolamine helps benzotriazole dissolve better in the drawing fluid, making the entire rust inhibitor system more stable and evenly dispersed in the liquid. The combination of the two allows the drawing fluid to be more firmly and evenly adsorbed onto the copper wire surface.

[0032] Slowly adding water and continuous stirring are key to forming a stable emulsion (or microemulsion) and avoiding "demulsification." During this stage, the oil phase is gradually encapsulated by water or forms stable emulsion particles.

[0033] In copper wire drawing fluids, water, as a core component, not only provides cooling, lubrication, and cleaning, but also plays a crucial role in solving compatibility issues. Firstly, the water-based system effectively dissolves polar benzotriazole rust inhibitors and isothiazolinone bactericides through solubilization, preventing precipitation and failure, while simultaneously promoting the compatibility of fatty acids with the oil phase, forming a stable emulsion structure. Through the synergistic effect of compound emulsifiers, the oil-water interfacial tension is reduced, forming a uniformly sized nanoscale microemulsion, enhancing the system's temperature resistance and long-term stability. Indirectly improving functionality, the solubilizer ensures the efficient adsorption of active lubricants, such as tall oil fatty acids and high-viscosity block polyether surfactants, at the friction interface, guaranteeing extreme pressure lubrication performance and reducing friction fluctuations and the risk of wire breakage. Regarding cleaning performance, the solubilizer helps surfactants encapsulate and suspend copper powder and oxide impurities, preventing precipitation even after long-term storage, and promoting the removal of residual oil films during subsequent water rinsing, ensuring the cleanliness of the copper wire. The addition of triethanolamine to adjust the pH to 9.47 enhances rust prevention and corrosion resistance, while preventing localized enrichment and extending the fluid change cycle. Overall, the addition of water greatly improves the compatibility and stability of the emulsion system, ensuring the simultaneous improvement of lubrication, cooling, cleaning and environmental performance in high-speed drawing processes, and providing reliable technical support for copper wire production.

[0034] S5. Turn off the heating and start the cooling system to slowly cool the product temperature in the reactor to below 40°C, preferably around 30°C. Add 0%-1% isothiazolinone bactericide slowly while stirring until it is evenly dispersed, then stop stirring. Isothiazolinone bactericides are heat-sensitive, and high temperatures may cause them to decompose and become ineffective. After filtering the drawing liquid in the stirred tank to remove impurities, fill it into clean and dry packaging containers to complete the preparation.

[0035] Isothiazolinone bactericides have unique advantages in this copper wire drawing solution: they are highly effective, have a broad spectrum of antibacterial activity, are environmentally friendly and low in toxicity, and have strong pH adaptability. Compared with traditional phenolic or quaternary ammonium salt bactericides, they maintain stable activity in alkaline environments, do not precipitate with anionic surfactants (such as sodium sulfonate), and can inhibit microorganisms for a long time at low concentrations, avoiding drug resistance. Their low-foaming properties work synergistically with the block polyether in the formulation, without affecting the stability of the emulsion system, and meet the environmental protection requirements of being chlorine-free and phenol-free, thus solving the pain points of traditional bactericides such as high toxicity, easy failure, or conflict with components.

[0036] After preparation, the following quality tests are performed: In terms of appearance, qualified products should exhibit a clear brownish-yellow color, with higher clarity than commercially available ordinary drawing fluids; viscosity testing requires the product to reach 200 mm² / s, which is more in line with process standards compared to the control group's 300 mm² / s; stability testing requires the product to remain clear and stable without turbidity under both high-temperature (50℃) and low-temperature (4℃) environments; solubility in 5% deionized water should reach a good level, and the prepared working solution should be semi-transparent; the pH value should be controlled at approximately 9.1-9.3, which both inhibits… This solution inhibits bacterial growth, ensures the stability of copper materials, and avoids the damage to humans and metals caused by strong alkalinity. The conductivity remains at 317 µS / cm, significantly lower than the control group. The initial foam volume of the 5% deionized water working solution is 30 ml, defoaming to 0 ml within 12 seconds, superior to the control group's 50 ml foam volume and 25-second defoaming time. Regarding static stability, the working solution should maintain a good appearance after standing overnight at room temperature, with no precipitation. The maximum non-seize PB value needs to reach 45 kg, higher than the 36 kg of commercially available ordinary drawing solutions, ensuring excellent extreme pressure performance. Transfer the prepared copper wire drawing solution concentrate to a clean, dry, and sealed storage tank. Store in a cool, well-ventilated place, avoiding direct sunlight and extreme temperatures.

[0037] project Experimental group (this product) Control group (commercially available ordinary drawing solution) Appearance Clear, brownish-yellow Poor clarity, brownish-yellow Viscosity 200 mm² / s 300 mm² / s Stability (high temperature 50℃, low temperature 4℃) All are clear and stable All turbid 5% deionized water solubility good good 5% deionized water working solution translucent translucent pH 5% deionized water 9.1-9.3 9.05 5% deionized water 317µS / cm 659µS / cm 5% deionized water working solution 30ml, 12s, 0ml 50ml, 25s, 1ml Appearance of the working solution (after standing overnight at room temperature) good There was sediment the next day. Maximum non-stick bite value (PB value) 45kg 36kg Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A copper wire drawing fluid, characterized in that: It consists of at least the following mass percentages: A mixture of 50%-70% tall oil and mineral oil; 2%-5% triethanolamine; 2%-5% tall oil fatty acids; 10%-18% compound emulsifier; 5%-10% natural sodium sulfonate surfactant; 2%-5% high viscosity block polyether surfactant; 1%-2% benzotriazole rust inhibitor; 5%-10% water; 2%-5% solubilizer; 0%-1% isothiazolinone bactericide.

2. The copper wire drawing fluid according to claim 1, characterized in that: The compound emulsifier is prepared by compounding fatty alcohol polyoxyethylene ether and triglyceride polyoxyethylene ether in a 1:1 ratio.

3. The copper wire drawing fluid according to claim 1, characterized in that: In the mixture of tall oil and mineral oil, mineral oil accounts for more than 50%.

4. The copper wire drawing fluid according to claim 1, characterized in that: The natural sodium sulfonate surfactant has a molecular weight of 420-500, and the polar end of the natural sodium sulfonate surfactant (-SO3) - Na + The positive end is used to adsorb onto the copper surface or the oil-water interface to form a rust-preventive film or reduce interfacial tension; while the negative end (-R) is soluble in the oil phase and stabilizes the emulsion system.

5. The method for preparing a copper wire drawing fluid according to claim 1, characterized in that: At least including: S1. Add tall oil and mineral oil to the mixing tank according to the ratio, turn on the stirrer and stir at medium speed to make the two oils fully mixed and control the temperature of the mixing tank at 40-50℃. S2. While stirring, slowly add triethanolamine and tall oil fatty acids to form fatty acid amine salts; S3. Slowly add the pre-mixed fatty alcohol polyoxyethylene ether and triglyceride polyoxyethylene ether into the mixing tank, and continue stirring to ensure that the compounded emulsifier is fully dissolved and dispersed. Then add natural sodium sulfonate surfactant, high viscosity block polyether surfactant and solubilizer to ensure that the high viscosity block polyether surfactant is fully dissolved and dispersed. S4. While stirring, slowly add benzotriazole rust inhibitor and deionized water or softened water; S5. Turn off the heating and start the cooling system to slowly cool the product temperature in the reactor to below 40°C. Add isothiazolinone bactericide slowly while stirring to disperse it evenly, then stop stirring.