Preparation method of high-performance oil-based synthetic coolant and product thereof

Abstract

This invention provides a method and product for preparing a high-performance oil-based synthetic coolant, comprising: pretreatment, mixing polyalphaolefin, ester base oil, and synthetic ester in a mass ratio of 4:3:3 to obtain a composite base oil; pre-stirring and dispersion, including adding the pretreated composite base oil to a reaction vessel and stirring while simultaneously introducing an inert gas for protection; stepwise addition and reaction of additives, including sequentially adding a composite lubricating additive, a rust-inhibiting and anti-corrosion composite agent, an antioxidant, an antifoaming agent, and an antimicrobial agent; constant-temperature aging to obtain a mixture; purification and refining, under the protection of an inert gas, sequentially passing the aged mixture through a filter membrane for two-stage filtration; and final product testing, with the coolant passing performance testing being the high-performance oil-based synthetic coolant. This method is mild, simple to operate, and low in energy consumption, possessing environmentally friendly characteristics of low volatility and low pollution, meeting the stringent operating conditions of modern manufacturing.

Description

Technical Field

[0001] This invention belongs to the field of coolant preparation technology, specifically relating to a method and product for preparing a high-performance oil-based synthetic coolant. Background Technology

[0002] Oil-based synthetic coolants, with their excellent lubricity, high-temperature resistance, flame retardancy, and good chemical stability, are widely used in demanding conditions such as high-speed cutting and heavy-duty grinding in machining, automotive manufacturing, and aerospace industries. As modern manufacturing moves towards higher precision, higher efficiency, and environmental friendliness, higher demands are placed on the comprehensive performance of oil-based synthetic coolants. They not only need excellent cooling and lubrication synergy, but also superior antioxidant and anti-aging properties, rust and corrosion prevention, defoaming properties, and environmentally friendly characteristics such as low volatility and low pollution.

[0003] Existing methods for preparing oil-based synthetic coolants have several shortcomings: First, some preparation processes use a single base oil component, making it difficult to balance the cooling and lubrication performance of the coolant. Under high-speed cutting conditions, this can easily lead to problems such as insufficient heat dissipation or lubrication failure, affecting machining accuracy and tool life. Second, the additives (such as rust inhibitors and antioxidants) added during the preparation process have poor compatibility with the base oil, and long-term use can easily cause stratification and precipitation, reducing the stability and service life of the coolant. Third, some preparation processes require prolonged high-temperature stirring, resulting in high energy consumption and a tendency for thermal decomposition of the base oil and additives, producing harmful volatiles that do not meet environmental protection requirements. In addition, oil-based synthetic coolants prepared by existing methods have weak resistance to microbial contamination, and are prone to bacterial and mold growth under humid conditions, leading to coolant deterioration and foul odor, which harms the environment and the health of operators. Summary of the Invention

[0004] This invention provides a method and product for preparing a high-performance oil-based synthetic coolant. The method is mild, easy to operate, and has low energy consumption. It can produce an oil-based synthetic coolant with excellent cooling and lubrication properties, anti-oxidation and anti-aging properties, rust and corrosion prevention, defoaming and anti-microbial contamination capabilities. It also has environmentally friendly characteristics of low volatility and low pollution, meeting the stringent working conditions of modern manufacturing.

[0005] According to a first aspect of the present invention, one or more embodiments of this application provide a method for preparing a high-performance oil-based synthetic coolant, comprising the following steps: Step 1: Pretreatment, which includes mixing polyα-olefin, ester base oil, and synthetic ester in a mass ratio of 4:3:3 to obtain a composite base oil; placing the composite base oil in a vacuum drying oven and drying it for 1.5-2.5 hours at a temperature of 70-90℃ and a vacuum degree of -0.07-0.09MPa. Step 2: Pre-stirring and dispersion, including adding the pretreated composite base oil to the reactor, heating to 50-60℃, stirring at a rate of 200-300 r / min for 10-15 min, and simultaneously introducing inert gas for protection; Step 3: Addition and reaction of additives in stages, including adding composite lubricating additive, rust and corrosion inhibitor composite agent and antioxidant in sequence, controlling the stirring rate at 400-500 r / min, raising the temperature to 80-90℃, and stirring at a constant temperature for 2-3 hours; then cooling to 60-70℃, adding defoamer and antimicrobial agent, and continuing to stir for 1-1.5 hours. Step 4: Constant temperature maturation, including maintaining a stirring rate of 150-200 r / min, naturally cooling to below 45℃, and maturing at a constant temperature for 1.5-2.5 h to obtain the mixture; Step 5: Purification and refining. Under the protection of inert gas, the matured mixture is filtered in two stages, passing through a 3μm precision filter membrane and a 0.1μm nano filter membrane. Step six, finished product testing: the filtered coolant is subjected to performance testing. Coolant that passes the performance test is a high-performance oil-based synthetic coolant.

[0006] According to the above-described technical solution of the present invention, the following improvements can also be made: Preferably, in step three, the mass percentage of each additive in the composite base oil is as follows: composite lubricating additive 5%-10%, rust and corrosion inhibitor 3%-6%, antioxidant 1%-2.5%, defoamer 0.2%-0.6%, and antimicrobial agent 0.1%-0.3%.

[0007] Preferably, the number-average molecular weight of the polyα-olefin in step one is 800-1500, the ester base oil is pentaerythritol ester or trimethylolpropane ester, and the synthetic ester is diisooctyl adipate or diisooctyl sebacate.

[0008] Preferably, the composite lubricant additive in step three is composed of sulfurized isobutylene, phosphate ester amine salt and organic molybdenum compound in a mass ratio of 3:2:1, wherein the organic molybdenum compound is dialkyl dithiophosphate molybdenum or dialkyl dithiocarbamate molybdenum.

[0009] Preferably, the rust-preventive and corrosion-resistant composite agent in step three is a compound of petroleum sulfonate, benzotriazole and organic amine salt in a mass ratio of 4:2:1.

[0010] Preferably, the antioxidant in step three is an aminophenol composite antioxidant prepared by compounding diphenylamine and 2,6-di-tert-butyl-p-cresol in a mass ratio of 2:1.

[0011] Preferably, the defoamer is a polymethacrylate defoamer.

[0012] Preferably, the antimicrobial agent is an isothiazolinone derivative or a formaldehyde-releasing compound.

[0013] Preferably, the inert gas used in steps two and five is nitrogen or argon.

[0014] According to another aspect of the present invention, a high-performance oil-based synthetic coolant is provided, which is prepared by the preparation method of the high-performance oil-based synthetic coolant described in any one of the above claims.

[0015] The beneficial effects of this invention are as follows: This invention provides a method for preparing a high-performance oil-based synthetic coolant and a product thereof. Compared with the prior art, the method for preparing a high-performance oil-based synthetic coolant of this invention has the following beneficial effects: (1) Mild process and low energy consumption: The reaction temperature of the preparation process of this invention is controlled at 50-90℃, without the need for high temperature and high pressure conditions, and the stirring rate and reaction time of each step are reasonably matched, which greatly reduces energy consumption and equipment requirements; at the same time, vacuum drying pretreatment and inert gas protection measures effectively avoid the oxidation and decomposition of base oil and additives, improve product purity and preparation efficiency, and are easy to industrialize.

[0016] (2) Excellent and balanced cooling and lubrication performance of the product: By reasonably compounding poly-α-olefin, ester base oil and synthetic ester as composite base oil, combined with the synergistic effect of composite lubricating additives, the prepared coolant has both excellent cooling and lubrication performance. It can quickly remove the heat generated during the processing, and at the same time form a stable lubricating protective film on the metal surface, reduce friction and wear between the tool and the workpiece, and improve the processing accuracy and tool life.

[0017] (3) Good component compatibility and strong stability: A composite additive system with excellent compatibility with composite base oil is selected. By adding additives in steps and controlling the reaction temperature, it is ensured that each additive is evenly dispersed and fully integrated with the base oil, which effectively solves the problem of poor compatibility between traditional additives and base oil and easy separation and precipitation. At the same time, the addition of amine phenol composite antioxidant significantly improves the antioxidant and anti-aging properties of the product, ensuring that the coolant can work stably under long-term high temperature conditions and has a service life of more than 12 months.

[0018] (4) Outstanding rust prevention, corrosion prevention and antimicrobial capabilities: The components of the rust prevention and corrosion prevention composite agent work together to form a dense rust prevention and corrosion prevention protective film on the metal surface, which is suitable for various metal materials such as cast iron, steel and aluminum; the added special antimicrobial agent can effectively inhibit the growth of bacteria, mold and other microorganisms, prevent the coolant from deteriorating and smelling bad, and ensure the safety of the operating environment and the health of the operators.

[0019] (5) Environmental protection and safety: The raw materials selected in this invention are all low-volatility, low-toxicity and environmentally friendly compounds. No harmful by-products are generated during the preparation process. The finished product does not contain toxic heavy metals and volatile harmful substances, which meets the current environmental protection and safety standards. At the same time, the product has a long service life, which reduces the frequency of coolant replacement and waste discharge, further reducing the pollution to the environment.

[0020] (6) Simple and controllable operation: The preparation steps of the present invention are clear, and the process parameters (temperature, stirring rate, reaction time, etc.) are easy to control precisely. It has good repeatability and can stably prepare high-performance oil-based synthetic coolant, which is conducive to large-scale production and has good economic benefits and application prospects. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the preparation process according to an embodiment of the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0023] It should be noted that, unless otherwise defined, the technical or scientific terms used in one or more embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms "first," "second," and similar terms used in one or more embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0024] like Figure 1 As shown, a method for preparing a high-performance oil-based synthetic coolant according to one or more embodiments of this application includes the following steps: Step 1: Pretreatment, including mixing polyalphaolefin, ester base oil, and synthetic ester in a mass ratio of 4:3:3 to obtain a composite base oil; placing the composite base oil in a vacuum drying oven and drying it for 1.5-2.5 hours at a temperature of 70-90℃ and a vacuum degree of -0.07-0.09MPa; the polyalphaolefin has a number average molecular weight of 800-1500, the ester base oil is pentaerythritol ester or trimethylolpropane ester, and the synthetic ester is diisooctyl adipate or diisooctyl sebacate.

[0025] Step 2: Pre-stirring and dispersion, including adding the pretreated composite base oil to the reactor, heating to 50-60℃, stirring at a rate of 200-300 r / min for 10-15 min, and simultaneously introducing an inert gas (nitrogen or argon) for protection. Step 3: Stepwise addition and reaction of additives, including the sequential addition of composite lubricating additive, rust-preventive and anti-corrosion composite agent, and antioxidant, controlling the stirring rate at 400-500 r / min, heating to 80-90℃, and stirring at a constant temperature for 2-3 hours; then cooling to 60-70℃, adding defoamer and antimicrobial agent, and continuing stirring for 1-1.5 hours; the mass percentages of each additive in the composite base oil are as follows: composite lubricating additive 5%-10%, rust-preventive and anti-corrosion composite agent 3%-6%, antioxidant 1%-2.5%, defoamer 0.2%-0.6%, and antimicrobial agent 0.1%-0.3%. The composite lubricating additive is composed of sulfurized isobutylene, phosphate ester amine salt, and organic molybdenum compound in a mass ratio of 3:2:1, wherein the organic molybdenum compound is dialkyl dithiophosphate molybdenum or dialkyl dithiocarbamate molybdenum. The rust-preventive and anti-corrosion composite agent is composed of petroleum sulfonate, benzotriazole, and organic amine salt in a mass ratio of 4:2:1. The antioxidant is an amine-phenol composite antioxidant prepared by compounding diphenylamine and 2,6-di-tert-butyl-p-cresol in a mass ratio of 2:1. The defoamer is a polymethacrylate defoamer. The antimicrobial agent is an isothiazolinone derivative or a formaldehyde-releasing compound.

[0026] Step 4: Constant temperature maturation, including maintaining a stirring rate of 150-200 r / min, naturally cooling to below 45℃, and maturing at a constant temperature for 1.5-2.5 h to obtain the mixture; Step 5: Purification and refining. Under the protection of inert gas, the matured mixture is filtered in two stages, passing through a 3μm precision filter membrane and a 0.1μm nano filter membrane. Step Six: Finished Product Inspection. The filtered coolant undergoes performance testing. Coolant that passes the performance test is considered a high-performance oil-based synthetic coolant. Specifically, the performance testing standards are: thermal conductivity ≥0.18 W / (m·K) at 40℃; wear scar diameter ≤0.4 mm in the four-ball test (1500 r / min, 392 N, 60 min); rotating oxygen bomb value (120℃, 100 h) ≥300 min; no rust on cast iron sheets after 48 h; defoaming time ≤10 s; and bacterial content ≤10%. 2 CFU / mL.

[0027] To further illustrate the technical solution of the present invention, the following embodiments are provided for comparison: Example 1 A method for preparing a high-performance oil-based synthetic coolant includes the following steps: (1) Base oil compounding and pretreatment: 40 kg of poly-α-olefin (number average molecular weight 1200), 30 kg of pentaerythritol ester and 30 kg of diisooctyl adipate were mixed to obtain a composite base oil; it was placed in a vacuum drying oven and dried for 2 h at a temperature of 80℃ and a vacuum degree of -0.08MPa. (2) Pre-stirring and dispersion: Add the pretreated composite base oil to the reactor, heat it to 55°C, turn on the stirrer, stir at a rate of 250 r / min for 12 min, and at the same time introduce nitrogen for protection. (3) Stepwise addition and reaction of additives: 7 kg of composite lubricating additive (3.5 kg of sulfurized isobutylene, 2.33 kg of phosphate ester amine salt, 1.17 kg of dialkyl dithiophosphate molybdenum), 4 kg of rust and corrosion inhibitor composite agent (2.29 kg of petroleum sulfonate, 1.14 kg of benzotriazole, 0.57 kg of organic amine salt), and 1.5 kg of amine phenol composite antioxidant (1 kg of diphenylamine and 0.5 kg of 2,6-di-tert-butyl-p-cresol) were added in sequence. The stirring rate was controlled at 450 r / min, the temperature was raised to 85℃, and the reaction was stirred at a constant temperature for 2.5 h. Then the temperature was lowered to 65℃, 0.4 kg of polymethyl methacrylate defoamer and 0.2 kg of isothiazolinone derivative were added, and stirring was continued for 1.2 h. (4) Constant temperature maturation: Turn off the heating device, keep the stirring rate at 180r / min, let it cool naturally to 42℃, and maintain the temperature for 2 hours. (5) Purification and refining: Under nitrogen protection, the matured mixture is filtered sequentially through a 3μm precision filter membrane and a 0.1μm nano filter membrane; (6) Finished product inspection: The test results are as follows: thermal conductivity at 40℃ is 0.20W / (m·K), wear scar diameter in four-ball test is 0.35mm, rotating oxygen bomb value is 350min, cast iron sheet has no rust after 48h, defoaming time is 7s, and bacterial content is 50CFU / mL, which meets the requirements.

[0028] Example 2 A method for preparing a high-performance oil-based synthetic coolant includes the following steps: (1) Base oil compounding and pretreatment: 40 kg of polyα-olefin (number average molecular weight 1000), 30 kg of trimethylolpropane ester and 30 kg of diisooctyl sebacate were mixed to obtain a composite base oil; it was placed in a vacuum drying oven and dried for 1.8 h at a temperature of 75 °C and a vacuum degree of -0.075 MPa. (2) Pre-stirring and dispersion: Add the pretreated composite base oil to the reactor, heat it to 52°C, turn on the stirrer, stir at a rate of 220 r / min for 11 min, and at the same time introduce argon gas for protection; (3) Stepwise addition and reaction of additives: 5 kg of composite lubricating additive (2.5 kg of sulfurized isobutylene, 1.67 kg of phosphate ester amine salt, 0.83 kg of molybdenum dialkyl dithiocarbamate), 3 kg of rust and corrosion inhibitor composite agent (1.71 kg of petroleum sulfonate, 0.86 kg of benzotriazole, 0.43 kg of organic amine salt), and 1 kg of amine phenol composite antioxidant (0.67 kg of diphenylamine and 0.33 kg of 2,6-di-tert-butyl-p-cresol) were added in sequence. The stirring rate was controlled at 400 r / min, the temperature was raised to 82℃, and the reaction was stirred at a constant temperature for 2 h. Then the temperature was lowered to 62℃, 0.2 kg of polymethyl methacrylate defoamer and 0.1 kg of formaldehyde release compound were added, and stirring was continued for 1 h. (4) Constant temperature cooking: Turn off the heating device, keep the stirring rate at 160 r / min, let it cool naturally to 40℃, and cook at a constant temperature for 1.5 h; (5) Purification and refining: Under argon protection, the matured mixture is filtered sequentially through a 3μm precision filter membrane and a 0.1μm nano filter membrane; (6) Finished product inspection: The test results are as follows: thermal conductivity at 40℃ is 0.19W / (m·K), wear scar diameter in four-ball test is 0.38mm, rotating oxygen bomb value is 320min, cast iron sheet has no rust after 48h, defoaming time is 8s, and bacterial content is 80CFU / mL, which meets the requirements.

[0029] Example 3 A method for preparing a high-performance oil-based synthetic coolant includes the following steps: (1) Base oil compounding and pretreatment: 40 kg of poly-α-olefin (number average molecular weight 1400), 30 kg of pentaerythritol ester and 30 kg of diisooctyl sebacate were mixed to obtain a composite base oil; it was placed in a vacuum drying oven and dried for 2.4 h at a temperature of 85℃ and a vacuum degree of -0.085 MPa. (2) Pre-stirring and dispersion: Add the pretreated composite base oil to the reactor, heat to 58°C, turn on the stirrer, stir at a rate of 280 r / min for 14 min, and at the same time introduce nitrogen for protection; (3) Stepwise addition and reaction of additives: 10 kg of composite lubricating additive (5 kg of sulfurized isobutylene, 3.33 kg of phosphate ester amine salt, 1.67 kg of dialkyl dithiophosphate molybdenum), 6 kg of rust and corrosion inhibitor composite agent (3.43 kg of petroleum sulfonate, 1.71 kg of benzotriazole, 0.86 kg of organic amine salt), and 2.5 kg of amine phenol composite antioxidant (1.67 kg of diphenylamine and 0.83 kg of 2,6-di-tert-butyl-p-cresol) were added in sequence. The stirring rate was controlled at 500 r / min, the temperature was raised to 88℃, and the reaction was stirred at a constant temperature for 3 h. Then the temperature was lowered to 68℃, 0.6 kg of polymethyl methacrylate defoamer and 0.3 kg of isothiazolinone derivative were added, and stirring was continued for 1.5 h. (4) Constant temperature cooking: Turn off the heating device, keep the stirring rate at 190 r / min, let it cool naturally to 44℃, and cook at a constant temperature for 2.5 h; (5) Purification and refining: Under nitrogen protection, the matured mixture is filtered sequentially through a 3μm precision filter membrane and a 0.1μm nano filter membrane; (5) Finished product inspection: The test results are as follows: thermal conductivity at 40℃ is 0.21W / (m·K), wear scar diameter in four-ball test is 0.32mm, rotating oxygen bomb value is 380min, cast iron sheet has no rust after 48h, defoaming time is 6s, and bacterial content is 40CFU / mL, which meets the requirements.

[0030] Performance Comparison Test: The performance of the high-performance oil-based synthetic coolant prepared in Examples 1-3 above was compared with that of the oil-based synthetic coolant obtained by existing preparation methods. The test items and results are shown in the table below: As can be seen from the above test results, the high-performance oil-based synthetic coolant prepared in Examples 1-3 of the present invention is significantly superior to the product obtained by the existing preparation method in terms of thermal conductivity, lubrication performance, antioxidant properties, rust prevention, defoaming properties and antimicrobial properties, which fully demonstrates the superiority of the preparation method of the present invention.

[0031] In another embodiment, a high-performance oil-based synthetic coolant is provided, which is prepared by any of the above-described methods for preparing high-performance oil-based synthetic coolants.

[0032] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0033] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for preparing a high-performance oil-based synthetic coolant, characterized in that, Includes the following steps: Step 1: Pretreatment, which includes mixing polyα-olefin, ester base oil, and synthetic ester in a mass ratio of 4:3:3 to obtain a composite base oil; placing the composite base oil in a vacuum drying oven and drying it for 1.5-2.5 hours at a temperature of 70-90℃ and a vacuum degree of -0.07-0.09MPa. Step 2: Pre-stirring and dispersion, including adding the pretreated composite base oil to the reactor, heating to 50-60℃, stirring at a rate of 200-300 r / min for 10-15 min, and simultaneously introducing inert gas for protection; Step 3: Addition and reaction of additives in stages, including adding composite lubricating additive, rust and corrosion inhibitor composite agent and antioxidant in sequence, controlling the stirring rate at 400-500 r / min, raising the temperature to 80-90℃, and stirring at a constant temperature for 2-3 hours; then cooling to 60-70℃, adding defoamer and antimicrobial agent, and continuing to stir for 1-1.5 hours. Step 4: Constant temperature maturation, including maintaining a stirring rate of 150-200 r / min, naturally cooling to below 45℃, and maturing at a constant temperature for 1.5-2.5 h to obtain the mixture; Step 5: Purification and refining. Under the protection of inert gas, the matured mixture is filtered in two stages, passing through a 3μm precision filter membrane and a 0.1μm nano filter membrane. Step six, finished product testing: the filtered coolant is subjected to performance testing. Coolant that passes the performance test is a high-performance oil-based synthetic coolant.

2. The method for preparing the high-performance oil-based synthetic coolant according to claim 1, characterized in that, In step three, the mass percentages of each additive in the composite base oil are as follows: composite lubricating additive 5%-10%, rust and corrosion inhibitor 3%-6%, antioxidant 1%-2.5%, defoamer 0.2%-0.6%, and antimicrobial agent 0.1%-0.3%.

3. The method for preparing the high-performance oil-based synthetic coolant according to claim 1, characterized in that, The poly-α-olefin mentioned in step one has a number average molecular weight of 800-1500, the ester base oil is pentaerythritol ester or trimethylolpropane ester, and the synthetic ester is diisooctyl adipate or diisooctyl sebacate.

4. The method for preparing the high-performance oil-based synthetic coolant according to claim 1, characterized in that, The composite lubricant additive mentioned in step three is composed of sulfurized isobutylene, phosphate ester amine salt and organic molybdenum compound in a mass ratio of 3:2:1, wherein the organic molybdenum compound is dialkyl dithiophosphate molybdenum or dialkyl dithiocarbamate molybdenum.

5. The method for preparing the high-performance oil-based synthetic coolant according to claim 1, characterized in that, The rust-preventive and corrosion-resistant composite agent described in step three is a compound of petroleum sulfonate, benzotriazole and organic amine salt in a mass ratio of 4:2:

1.

6. The method for preparing the high-performance oil-based synthetic coolant according to claim 1, characterized in that, The antioxidant mentioned in step three is an aminophenol composite antioxidant prepared by compounding diphenylamine and 2,6-di-tert-butyl-p-cresol in a mass ratio of 2:

1.

7. The method for preparing the high-performance oil-based synthetic coolant according to claim 1, characterized in that, The defoamer is a polymethyl methacrylate defoamer.

8. The method for preparing the high-performance oil-based synthetic coolant according to claim 1, characterized in that, The antimicrobial agent is an isothiazolinone derivative or a formaldehyde-releasing compound.

9. The method for preparing the high-performance oil-based synthetic coolant according to claim 1, characterized in that, The inert gas used in steps two and five is nitrogen or argon.

10. A high-performance oil-based synthetic coolant, characterized in that, It is prepared by the method of any one of claims 1-9 for preparing high-performance oil-based synthetic coolant.

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