Semi-synthetic cutting fluid composition, metal working fluid and preparation method of metal working fluid

Abstract

The invention relates to the field of cutting fluid, and particularly discloses a semi-synthetic cutting fluid composition, a metal working fluid and a preparation method of the metal working fluid, and the semi-synthetic cutting fluid composition comprises mineral oil, a nonionic emulsifier, a functional additive, a pH buffering agent, a bacteriostatic agent and the balance of water. The functional additive comprises one or more of a corrosion and rust inhibitor, an oiliness agent, a lubricating extreme pressure agent and a defoaming agent; the pH buffer agent is prepared from one or more of monoethanolamine, diethanolamine, triethanolamine, triisopropanolamine, monoisopropanolamine, 2-amino-2-methyl-1-propanol, dicyclohexylamine and ethanolamine, and the pH buffer agent is prepared from one or more of the following raw materials: sodium dodecyl benzene sulfonate, sodium dodecyl benzene sulfonate, sodium dodecyl benzene sulfonate, sodium dodecyl benzene sulfonate, sodium dodecyl benzene sulfonate and sodium dodecyl benzene sulfonate; the bacteriostatic agent comprises one or more of an isothiazolinone derivative, phenoxyethanol and polyquaternium. The metal working fluid comprises the semi-synthetic cutting fluid composition, the biological stability of the field working fluid can be effectively controlled in the aluminum alloy machining process in a manner of compounding organic alkali and a specific bacteriostatic agent, the growth of bacteria or fungi can be inhibited, and the service life of the working fluid can be prolonged.

Description

Technical Field

[0001] This application relates to the field of cutting fluids, specifically to a semi-synthetic cutting fluid composition, a metalworking fluid, and a method for preparing the same. Background Technology

[0002] Aluminum alloys are lightweight, have high thermal conductivity, are easy to anodize, and are easy to process, making them widely used in the electronics industry. The processing of aluminum alloys for electronic products places higher demands on the performance of metalworking fluids. Due to varying production conditions, the lifespan of traditional metalworking fluids differs. If metalworking fluids are not maintained in a timely manner, unpleasant odors and foul smells can develop at the processing site, seriously affecting the health of workers and the production environment.

[0003] Therefore, it is necessary to develop a metalworking fluid that facilitates efficient processing and has a long service life. Summary of the Invention

[0004] In view of this, this application provides a semi-synthetic cutting fluid composition, a metalworking fluid, and a method for preparing the same to solve at least one of the above-mentioned technical problems.

[0005] To achieve the above objectives, in a first aspect, this application provides a semi-synthetic cutting fluid composition comprising: mineral oil, a nonionic emulsifier, functional additives, a pH buffer, and an antibacterial agent, with the balance being water. The functional additives include one or more of corrosion inhibitors, rust inhibitors, oiliness agents, extreme pressure lubricants, and defoamers. The pH buffer includes one or more of monoethanolamine, diethanolamine, triethanolamine, triisopropanolamine, monoisopropanolamine, 2-amino-2-methyl-1-propanol, dicyclohexylamine, and ethanolamine. The antibacterial agent includes one or more of isothiazolinone derivatives, phenoxyethanol, and polyquaternium salts.

[0006] Based on the first aspect, in some possible implementations, the pH buffer content is 8% to 15% by mass, based on the semi-synthetic cutting fluid composition.

[0007] Based on the first aspect, in some possible implementations, based on a semi-synthetic cutting fluid composition, the mass percentage of the antibacterial agent is 1% to 5%.

[0008] Based on the first aspect, in some possible implementations, based on a semi-synthetic cutting fluid composition, the mass percentage of a nonionic emulsifier is 5% to 15%, and the nonionic emulsifier includes one or more of alkoxylated fatty alcohols and isomeric alcohol polyoxyethylene ethers.

[0009] Based on the first aspect, in some possible implementations, based on a semi-synthetic cutting fluid composition, the mineral oil comprises 25% to 35% by mass, and the mineral oil includes mineral oil.

[0010] Based on the first aspect, in some possible implementations, the water content is 16% to 36% by mass in the semi-synthetic cutting fluid composition.

[0011] Based on the first aspect, in some possible implementations, the corrosion and rust inhibitor accounts for 2.5% to 7.5% by mass of the semi-synthetic cutting fluid composition.

[0012] Based on the first aspect, in some possible implementations, based on a semi-synthetic cutting fluid composition, the oiliness agent accounts for 1% to 5% by mass.

[0013] Based on the first aspect, in some possible implementations, the mass percentage of the extreme pressure lubricant is 10% to 20% based on the semi-synthetic cutting fluid composition.

[0014] Based on the first aspect, in some possible implementations, based on the semi-synthetic cutting fluid composition, the defoamer accounts for 0.05% to 0.3% by mass.

[0015] Based on the first aspect, in some possible implementations, the corrosion inhibitor includes one or more of isodecanoic acid, neodecanoic acid, phosphonates, benzotriazole and its derivatives, p-tert-butylbenzoic acid, N-oleoylsarcosine and dicarboxylic acids.

[0016] Based on the first aspect, in some possible implementations, the oiling agent includes one or more of tall oil fatty acids, vegetable oleic acid, castor oil fatty acids, refined tall oil, and castor oil.

[0017] Based on the first aspect, in some possible implementations, the lubricating extreme pressure agent includes one or more of castor oil oleate, tall oil fatty acid ester, trimethylolpropane oleate, and polyol oleate.

[0018] Based on the first aspect, in some possible implementations, the defoamer includes silicone defoamers.

[0019] Secondly, this application provides a metalworking fluid comprising the aforementioned semi-synthetic cutting fluid composition, wherein the concentration of the semi-synthetic cutting fluid composition in the metalworking fluid is 3% to 15%.

[0020] Thirdly, this application provides a method for preparing the above-mentioned metalworking fluid, comprising: mixing water, a pH buffer, and an antibacterial agent to obtain a first mixture; mixing mineral oil, a nonionic emulsifier, and some functional additives, wherein the functional additives include one or more of corrosion inhibitors, rust inhibitors, oiliness agents, and extreme pressure lubricants to obtain a second mixture; mixing the first mixture and the second mixture, and adding an antifoaming agent to obtain a semi-synthetic cutting fluid composition; and diluting the semi-synthetic cutting fluid composition to obtain the metalworking fluid.

[0021] The semi-synthetic cutting fluid composition of this application is formulated with an organic alkali and a specific antibacterial agent, exhibiting excellent lubrication performance and stability. When used as a metalworking fluid, it meets the strength requirements for machining aluminum alloy electronic products. The organic alkali can be formulated with different functional organic amines, possessing strong buffering capacity, low corrosivity, and strong antibacterial properties. This helps maintain the alkalinity of the resulting metalworking fluid, improves its antibacterial performance and stability, and also enhances the solubility of mineral oil, thus facilitating its removal. The antibacterial agent selected is a non-formaldehyde-releasing antibacterial agent (formaldehyde-releasing antibacterial agents, such as morpholine and triazine derivatives), reducing the formaldehyde release from the metalworking fluid. While ensuring environmental safety, this enhances the antibacterial performance of the resulting metalworking fluid, thereby extending its service life.

[0022] The metalworking fluid of this application, through a compounding of organic alkali and specific antibacterial agents, effectively controls the biostability of the working fluid during aluminum alloy processing. Even after four months of continuous on-site use, the pH remains stable above 8, and the bacterial or fungal content is manageable and controllable, thus extending the service life of the working fluid. Simultaneously, it improves the on-site working environment, reduces the frequency of on-site tank maintenance and fluid changes, shortens wastewater treatment cycles, increases processing efficiency, and lowers production costs. Furthermore, the preparation methods of the semi-synthetic cutting fluid and metalworking fluid of this application are simple, require no heating, and are easy to operate, providing a highly economical and environmentally beneficial solution for aluminum alloy processing. Attached Figure Description

[0023] Figure 1 This is a schematic flowchart of a method for preparing a metalworking fluid according to one embodiment of this application.

[0024] Figure 2 The pH stability test results are for the metalworking fluid provided in Example 2 of this application.

[0025] Figure 3 The test results show the performance of the metalworking fluid provided in Example 2 of this application in inhibiting bacterial growth.

[0026] Figure 4 The test results show the performance of the metalworking fluid provided in Example 2 of this application in inhibiting fungal growth. Detailed Implementation

[0027] The embodiments of this application are described in detail below. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application; it should be noted that, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; where there is no conflict, the implementation methods and features of the implementation methods of this application can be combined with each other; many specific details are set forth in the following description to provide a full understanding of this application, and the described implementation methods are only a part of the implementation methods of this application, and not all of the implementation methods.

[0028] Cutting fluid is an important functional liquid in the metal processing process. According to its chemical composition, it can be divided into two main categories: water-based and oil-based. Among them, water-based cutting fluids include emulsified, semi-synthetic and fully synthetic cutting fluids. Semi-synthetic cutting fluids combine the advantages of emulsified and fully synthetic cutting fluids, which is beneficial for adapting to the processing of aluminum alloys for electronic products.

[0029] To address the adverse consequences of inadequate maintenance of traditional cutting fluids, this problem can be mitigated by extending the service life of the cutting fluid. Since bacteria and fungi do not easily multiply in an alkaline environment, relevant technologies typically add sufficient alkaline agents to maintain the alkalinity of the cutting fluid and preserve its antibacterial properties. However, in aluminum alloy machining, excessively high pH (e.g., pH > 9.5) can lead to pitting or oxidation on the aluminum alloy substrate surface. Therefore, there is an upper limit to the amount of alkaline agent that can be added, resulting in the continued problem of adverse consequences from inadequate maintenance of metalworking fluids. When bacteria or fungi multiply, the antibacterial agents in the metalworking fluid are consumed, and with the pH decreasing, bacteria or fungi multiply rapidly, leading to a cycle that causes the metalworking fluid to deteriorate and develop a foul odor. Therefore, maintaining the stability of the alkalinity and antibacterial properties of the metalworking fluid, while controlling the pH to ≤ 9.5 and maintaining machining efficiency, becomes crucial for extending the service life of the metalworking fluid.

[0030] Based on this, one embodiment of this application provides a semi-synthetic cutting fluid composition comprising: mineral oil, nonionic emulsifier, functional additives, pH buffer, and antibacterial agent, with the balance being water. The functional additives include one or more of corrosion inhibitors, rust inhibitors, oiliness agents, extreme pressure lubricants, and defoamers. The pH buffer includes one or more of monoethanolamine, diethanolamine, triethanolamine, triisopropanolamine, monoisopropanolamine, 2-amino-2-methyl-1-propanol, dicyclohexylamine, and ethanolamine. The antibacterial agent includes one or more of isothiazolinone derivatives, phenoxyethanol, and polyquaternium salts.

[0031] The semi-synthetic cutting fluid composition of this application is formulated with an organic alkali and a specific antibacterial agent, exhibiting excellent lubrication performance and stability. When used as a metalworking fluid, it meets the strength requirements for machining aluminum alloy electronic products. The organic alkali can be formulated with different functional organic amines, possessing strong buffering capacity, low corrosivity, and strong antibacterial properties. This helps maintain the alkalinity of the resulting metalworking fluid, improves its antibacterial performance and stability, and also enhances the solubility of mineral oil, thus facilitating its removal. The antibacterial agent selected is a non-formaldehyde-releasing antibacterial agent (formaldehyde-releasing antibacterial agents, such as morpholine and triazine derivatives), reducing the formaldehyde release from the metalworking fluid. While ensuring environmental safety, this enhances the antibacterial performance of the resulting metalworking fluid, thereby extending its service life.

[0032] The metalworking fluid of this application, through a compounding of organic alkali and specific antibacterial agents, effectively controls the biostability of the working fluid during aluminum alloy processing. Even after four months of continuous on-site use, the pH remains stable above 8, and the bacterial or fungal content is manageable and controllable, thus extending the service life of the working fluid. Simultaneously, it improves the on-site working environment, reduces the frequency of on-site tank maintenance and fluid changes, shortens wastewater treatment cycles, increases processing efficiency, and lowers production costs. Furthermore, the preparation methods of the semi-synthetic cutting fluid and metalworking fluid of this application are simple, require no heating, and are easy to operate, providing a highly economical and environmentally beneficial solution for aluminum alloy processing.

[0033] Understandably, corrosion inhibitors and rust inhibitors help improve the corrosion resistance of the resulting metalworking fluid, further reducing the risk of aluminum alloy corrosion in aluminum alloy processing. Oiliness agents and extreme pressure lubricants can improve the lubrication performance of the resulting metalworking fluid, and defoamers can reduce the foaming of semi-synthetic cutting fluid compositions, making them easier to put into processing.

[0034] In some embodiments, the mass percentage of the pH buffer based on the semi-synthetic cutting fluid composition is 8% to 15%. For example, the mass percentage of the pH buffer can be 8%, 8.5%, 9%, 9.5%, 10%, 10.5%, 11%, 11.5%, 12%, 12.5%, 13%, 13.5%, 14%, 14.5%, 15%, or any value within the range of any two of the above values. Controlling the mass percentage of the pH buffer within the above range is beneficial for balancing the upper limit of pH and alkalinity stability of the resulting metalworking fluid. When used for aluminum alloy machining, it helps reduce pitting or oxidation of aluminum alloys caused by excessively high pH, ​​and also helps extend the service life of the resulting metalworking fluid.

[0035] In some embodiments, the antibacterial agent, based on the semi-synthetic cutting fluid composition, comprises 1% to 5% by mass. For example, the mass percentage of the antibacterial agent can be 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, or any value within the range of any two of the above values. Controlling the mass percentage of the antibacterial agent within the above range is beneficial for maximizing the antibacterial properties of the specific antibacterial agent, reducing the use of formaldehyde-releasing antibacterial agents, and, while considering environmental safety, combining it with a specific amount of pH buffer helps improve the antibacterial performance of the resulting metalworking fluid, thereby extending the service life of the working fluid.

[0036] In some embodiments, the nonionic emulsifier, based on the semi-synthetic cutting fluid composition, comprises 5% to 15% by mass. For example, the mass percentage of the nonionic emulsifier can be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, or any value within the range of any two of the above values. In some embodiments, the nonionic emulsifier includes one or more of alkoxylated fatty alcohols and isomeric alcohol polyoxyethylene ethers. Using the above-mentioned nonionic emulsifier facilitates the emulsification of mineral oil in water and forms a stable microemulsion system to create a semi-synthetic cutting fluid, which is beneficial for improving the machining efficiency of the resulting metalworking fluid on aluminum alloys.

[0037] In some embodiments, the mineral oil content in the semi-synthetic cutting fluid composition is 25% to 35% by mass. For example, the mineral oil content can be 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, or any value within the range of any two of the above values. Naphthenic oils, such as naphthenic oil recovery oils, can be used, which helps reduce costs.

[0038] In some embodiments, the water content in the semi-synthetic cutting fluid composition is between 16% and 36% by mass. For example, the water content can be 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, or any value within the range of any two of the above values. Controlling the water content within the above range is beneficial for forming a suitable water-oil balance framework, thereby improving the system stability of the resulting semi-synthetic cutting fluid composition.

[0039] In some embodiments, the corrosion and rust inhibitor is present in a mass percentage of 2.5% to 7.5% based on the semi-synthetic cutting fluid composition. For example, the mass percentage of the corrosion and rust inhibitor may be 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, or any value within the range of any two of the above values. In some embodiments, the corrosion and rust inhibitor includes one or more of isodecanoic acid, neodecanoic acid, phosphonates, benzotriazole and its derivatives, p-tert-butylbenzoic acid, N-oleoylsarcosine, and dicarboxylic acids.

[0040] In some embodiments, the oiliness agent, based on the semi-synthetic cutting fluid composition, comprises 1% to 5% by mass. For example, the oiliness agent may comprise 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, or any value within the range of any two of the above values. In some embodiments, the oiliness agent comprises one or more of tall oil fatty acids, vegetable oleic acid, castor oil fatty acids, refined tall oil, and castor oil.

[0041] In some embodiments, the mass percentage of the extreme pressure lubricant based on the semi-synthetic cutting fluid composition is 10% to 20%. For example, the mass percentage of the extreme pressure lubricant may be 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, or any value within the range of any two of the above values. In some embodiments, the extreme pressure lubricant includes one or more of castor oil ester, tall oil fatty acid ester, trimethylolpropane oleate, and polyol oleate.

[0042] In some embodiments, the defoamer, based on the semi-synthetic cutting fluid composition, comprises 0.05% to 0.3% by mass. For example, the defoamer may comprise 0.05%, 0.75%, 0.1%, 0.125%, 0.15%, 0.175%, 0.2%, 0.225%, 0.25%, 0.275%, 0.3%, or any value within the range of any two of the above values. In some embodiments, the defoamer comprises a silicone defoamer.

[0043] The use of the aforementioned corrosion and rust inhibitors, while controlling the alkalinity of the semi-synthetic cutting fluid, synergistically improves the corrosion resistance of the resulting metalworking fluid. The combination of the aforementioned oiliness agent and extreme pressure lubricant synergistically enhances the lubrication performance of the resulting metalworking fluid, making it more suitable for tapping, broaching, deep hole drilling, and threading operations in aluminum alloy machining, while protecting cutting tools and achieving good surface finish. The use of the aforementioned defoamer effectively reduces foam generation in aluminum alloy machining, which is prone to foaming, thus mitigating the risks of poor cooling, fluid loss, and environmental pollution caused by foam overflow.

[0044] One embodiment of this application also provides a metalworking fluid comprising the aforementioned semi-synthetic cutting fluid composition, wherein the concentration of the semi-synthetic cutting fluid composition in the metalworking fluid is 3% to 15%. For example, the concentration of the semi-synthetic cutting fluid composition in the metalworking fluid can be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, or any value within the range of any two of the above values. Controlling the concentration of the semi-synthetic cutting fluid composition in the metalworking fluid within the above range can achieve good cutting performance, improve the efficiency of metalworking, and keep costs under control.

[0045] This application also provides a method for preparing the above-mentioned metalworking fluid according to one embodiment. Please refer to [link to relevant documentation]. Figure 1 ,include: S1: Mix water, pH buffer and antibacterial agent to obtain the first mixture.

[0046] S2: A second mixture is obtained by mixing mineral oil, nonionic emulsifier, and some functional additives, including one or more of corrosion inhibitors, rust inhibitors, oiliness agents, and extreme pressure lubricants.

[0047] S3: Mix the first mixture and the second mixture, add defoamer, and obtain a semi-synthetic cutting fluid composition.

[0048] S4: Dilute the semi-synthetic cutting fluid composition to obtain a metalworking fluid.

[0049] Understandably, the above mixing can be achieved by stirring, with the stirring speed controlled between 400 rpm and 600 rpm, for example, 400 rpm, 420 rpm, 440 rpm, 460 rpm, 480 rpm, 500 rpm, 520 rpm, 540 rpm, 560 rpm, 580 rpm, and 600 rpm. The stirring time can be adjusted according to the actual production volume.

[0050] The metalworking fluid preparation method of this application, by controlling the mixing order of the above-mentioned raw materials, helps to reduce the formation of colloidal substances. Colloidal substances may cause some raw materials to agglomerate and precipitate, thus facilitating the formation of a stable semi-synthetic cutting fluid composition. This allows the components in the resulting metalworking fluid to be compounded in reasonable amounts and function effectively. Furthermore, the preparation method of this application is simple and controllable, reducing the production safety risks associated with heating.

[0051] The present application's solution will be explained below with reference to embodiments. Those skilled in the art will understand that the following examples are for illustrative purposes only and should not be construed as limiting the present application. Unless otherwise stated, reagents, software, and instruments involved in the following embodiments that are not specifically mentioned are all conventional commercially available products or open-source materials.

[0052] Examples 1-6, Comparative Example 1: A metalworking fluid, according to the semi-synthetic cutting fluid compositions in Table 1, is prepared by a method comprising: Step 1: Mix water, pH buffer, and antibacterial agent to obtain the first mixture; Step 2: Mix mineral oil, nonionic emulsifier, corrosion and rust inhibitor, oiliness agent and extreme pressure lubricant to obtain a second mixture; Step 3: Mix the first and second mixtures to obtain a homogeneous transparent solution, add an antifoaming agent to obtain a semi-synthetic cutting fluid composition.

[0053] Step 4: Prepare a 10% dilution of the semi-synthetic cutting fluid composition mother liquor to obtain the metalworking fluid.

[0054] In Table 1, pure water was used for all water, naphthenic oil was used for all mineral oil, alkoxylated fatty alcohol was used for all nonionic emulsifiers, neodecanoic acid was used for all corrosion and rust inhibitors, tall oil fatty acid was used for all oiliness agents, trimethylolpropane oleate was used for all extreme pressure lubricants, and silicone defoamers were used for all defoamers.

[0055] According to Table 1, Examples 1-4 mainly used different types or amounts of pH buffers, different amounts of mineral oil, and different amounts of emulsifiers. Example 5 differs from Example 1 in that the mass percentage of pH buffer is 5%, and the mass percentage of antibacterial agent is 0.5%. Example 6 differs from Example 1 in that the mass percentage of pH buffer is 20%, and the mass percentage of antibacterial agent is 6%. The main difference between Comparative Example 1 and the Examples is that a morpholine-based antibacterial agent was used.

[0056] The metalworking fluids of this application conform to the requirements of GB / T 6144-2010.

[0057] This application tested the corrosion resistance and tapping torque of the metalworking fluids from Examples 1-6 and Comparative Example 1. The corrosion resistance test used cast iron, 2-series / 6-series / 7-series aluminum alloys, and copper test blocks, conducted according to GB / T 6144-2010. For cast iron, single-piece rust prevention test results showed Grade A as no rust after five drops; for cast iron stacked-piece rust prevention test results, "qualified" indicated no rust or obvious overlapping marks. For copper, Grade A indicated no rust and a new luster, Grade B indicated slight discoloration, Grade C indicated moderate discoloration, and Grade D indicated severe discoloration. For aluminum alloy, Grade A indicated no rust and a new luster, Grade B indicated slight darkening, Grade C indicated moderate darkening, and Grade D indicated severe darkening. The tapping torque test conditions included using a TTT Testbar-Art. TAL04C 3.4365 MEF2 / Φ3.7 mm 20 mm (7075) test block and a rotation speed of 1200 rpm. The parameters were: rpm, orifice depth 12 mm, and maximum torque 400 Ncm. This application also tested the pH value, defoaming properties, and antibacterial performance of the metalworking fluids of Examples 1-6 and Comparative Example 1. The test results are shown in Table 2.

[0058] This application also tested the pH value and antibacterial stability of the metalworking fluids from the embodiments of this application. Taking Example 2 as an example, the metalworking fluid of Example 2 was used in aluminum alloy processing production. A total of 58 machines were subjected to pH and antibacterial stability analysis over a period of 4 months. The antibacterial performance of the metalworking fluid was characterized by testing bacterial and fungal content using bacterial strips. Please refer to the above test results. Figure 2 , Figure 3 and Figure 4 .

[0059] Table 1. Composition of the semi-synthetic cutting fluid compositions of Examples 1-6 and Comparative Example 1 of this application .

[0060] Table 2. Performance test results of the metalworking fluids of Examples 1-6 and Comparative Example 1 of this application .

[0061] The semi-synthetic cutting fluid compositions of Examples 1-6 of this application are formulated with organic alkali and specific antibacterial agents, exhibiting excellent lubrication performance and stability. When used as metalworking fluids, they can meet the strength requirements of aluminum alloy electronic product processing. The organic alkali can be formulated with different functional organic amines, possessing strong buffering capacity, low corrosivity, and strong antibacterial properties. This helps maintain the alkalinity of the resulting metalworking fluid, improves its antibacterial performance and stability, and also enhances the solubility of mineral oil, thus facilitating its removal. The antibacterial agent selected is a non-formaldehyde-releasing antibacterial agent (formaldehyde-releasing antibacterial agents, such as morpholine and triazine derivatives), reducing the formaldehyde release from the metalworking fluid. While ensuring environmental safety, this enhances the antibacterial performance of the resulting metalworking fluid, thereby extending its service life.

[0062] The metalworking fluids described in Examples 1-6 of this application, through a compounding of organic alkali and specific antibacterial agents, effectively control the biostability of the working fluid during aluminum alloy processing. Even after four months of continuous on-site use, the pH remains stable above 8, and the bacterial or fungal content is manageable and controllable, thus extending the service life of the working fluid. Simultaneously, it improves the on-site working environment, reduces the frequency of on-site tank maintenance and fluid changes, shortens wastewater treatment cycles, increases processing efficiency, and lowers production costs. Furthermore, the preparation methods for the semi-synthetic cutting fluid and metalworking fluid of this application are simple, require no heating, and are easy to operate, providing a highly economical and environmentally beneficial solution for aluminum alloy processing.

[0063] For example, see Embodiment 2. Figure 2 During the four-month testing period, the metalworking fluid of this application was able to maintain a suitable alkalinity.

[0064] Please refer to the following: Figure 3 and Figure 4 During the four-month testing period, the metalworking fluid of this application effectively inhibited the growth of bacteria or fungi. Therefore, the content of bacteria or fungi in the test samples was basically manageable and controllable, effectively extending the service life of the metalworking fluid and making it easier to maintain the metalworking fluid in a timely manner, thus improving the adverse consequences caused by the deterioration of the metalworking fluid.

[0065] Compared with Examples 5-6, Examples 1-4 further control the mass ratio and dosage of pH buffer and antibacterial agent within a preset range, which is beneficial to balancing the upper limit of pH and alkalinity stability of the obtained metal processing fluid. When used for aluminum alloy processing, it is beneficial to reduce pitting corrosion or oxidation of aluminum alloy caused by excessively high pH. At the same time, combined with the antibacterial properties of specific antibacterial agents, the use of formaldehyde-releasing antibacterial agents can be reduced.

[0066] Compared to Examples 1-3, the formaldehyde-releasing antibacterial agent (morpholine-based) used in Comparative Example 1, combined with other components to form a semi-synthetic cutting fluid composition, resulted in a metalworking fluid with inferior antibacterial properties compared to the examples in this application. This demonstrates that the present application uses an organic base combined with a specific antibacterial agent, resulting in better antibacterial performance and improved pH and antibacterial stability, thereby extending the service life of the working fluid. Furthermore, the morpholine-based antibacterial agent in Comparative Example 1 releases formaldehyde, impacting the production and processing environment.

[0067] The above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the above preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of this application should not depart from the spirit and scope of the technical solutions of this application.

Claims

1. A semi-synthetic cutting fluid composition characterized in that, The semi-synthetic cutting fluid composition comprises: mineral oil, non-ionic emulsifier, functional additive, pH buffer and bacteriostatic agent, the balance being water, the functional additive comprising one or more of corrosion and rust inhibitor, oiliness agent, lubricating extreme pressure agent and defoaming agent; wherein, the pH buffer comprises one or more of monoethanolamine, diethanolamine, triethanolamine, triisopropanolamine, mono-isopropanolamine, 2-amino-2-methyl-1-propanol, dicyclohexylamine and ethanolamine; the bacteriostatic agent comprises one or more of isothiazolinone derivative, phenoxyethanol and polyquaternary ammonium salt.

2. The semi-synthetic cutting fluid composition of claim 1, wherein, Based on the semi-synthetic cutting fluid composition, the mass percentage of the pH buffer is 8% to 15%.

3. The semi-synthetic cutting fluid composition of claim 1, wherein, Based on the semi-synthetic cutting fluid composition, the mass percentage of the bacteriostatic agent is 1% to 5%.

4. The semi-synthetic cutting fluid composition of claim 1, wherein, Based on the semi-synthetic cutting fluid composition, the mass percentage of the non-ionic emulsifier is 5% to 15%, the non-ionic emulsifier comprising one or more of alkoxylated fatty alcohol and isomeric alcohol polyoxyethylene ether.

5. The semi-synthetic cutting fluid composition of claim 1, wherein, Based on the semi-synthetic cutting fluid composition, the mass percentage of the mineral oil is 25% to 35%, the mineral oil comprising naphthenic oil.

6. The semi-synthetic cutting fluid composition of claim 1, wherein, Based on the semi-synthetic cutting fluid composition, the mass percentage of the water is 16% to 36%.

7. The semi-synthetic cutting fluid composition of claim 1, wherein, The semi-synthetic cutting fluid composition further satisfies at least one of the following conditions: (1) based on the semi-synthetic cutting fluid composition, the mass percentage of the corrosion and rust inhibitor is 2.5% to 7.5%; (2) based on the semi-synthetic cutting fluid composition, the mass percentage of the oiliness agent is 1% to 5%; (3) based on the semi-synthetic cutting fluid composition, the mass percentage of the lubricating extreme pressure agent is 10% to 20%; (4) based on the semi-synthetic cutting fluid composition, the mass percentage of the defoaming agent is 0.05% to 0.3%.

8. The semi-synthetic cutting fluid composition of claim 7, wherein, The semi-synthetic cutting fluid composition further satisfies at least one of the following conditions: (1) the corrosion and rust inhibitor comprises one or more of isomeric decanoic acid, neodecanoic acid, phosphonate, benzotriazole and its derivatives, p-tert-butyl benzoic acid, N-oleoyl sarcosine and dicarboxylic acid; (2) the oiliness agent comprises one or more of tall oil fatty acid, vegetable oil acid, castor oil fatty acid, refined tall oil and castor oil; (3) the lubricating extreme pressure agent comprises one or more of ricinoleate, tall oil fatty acid ester, trimethylolpropane oleate and polyol oleate; (4) the defoaming agent comprises silicone defoaming agent.

9. A metal working fluid characterized by, The metal working fluid comprises the semi-synthetic cutting fluid composition according to any one of claims 1-8, the concentration of the semi-synthetic cutting fluid composition in the metal working fluid being 3% to 15%.

10. A method of preparing a metal working fluid as claimed in claim 9, characterized in that, comprises: mixing the water, the pH buffer and the bacteriostatic agent to obtain a first mixed solution; mixing the mineral oil, the non-ionic emulsifier and part of the functional additive, part of the functional additive comprising one or more of the corrosion and rust inhibitor, the oiliness agent and the lubricating extreme pressure agent to obtain a second mixed solution; mixing the first mixed solution and the second mixed solution and adding the defoaming agent to obtain the semi-synthetic cutting fluid composition; diluting the semi-synthetic cutting fluid composition to obtain the metal working fluid.

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