A near-zero wear liquid lubricant, its preparation method and application

Abstract

This invention provides a near-zero wear liquid lubricant, its preparation method, and its application, belonging to the field of lubricant technology. The raw materials for preparing the near-zero wear liquid lubricant provided by this invention include base lubricating oil, a CO2 absorbent, and CO2. The CO2 absorbent contains amino and hydroxyl groups, and the mass of the CO2 absorbent is 25-75% of the mass of the base lubricating oil. The CO2 content in the near-zero wear liquid lubricant is 10-15% by mass. The liquid lubricant provided by this invention is a liquid lubricant that can absorb CO2 to achieve near-zero wear, and it exhibits excellent lubrication performance based on CO2 capture and conversion.

Description

Technical Field

[0001] This invention relates to the field of lubricant technology, and in particular to a near-zero wear liquid lubricant, its preparation method, and its application. Background Technology

[0002] With the acceleration of global industrialization, CO2 emissions have continued to grow, causing serious negative impacts on the environment and ecosystems. However, CO2, as an abundant, non-toxic, and renewable carbon resource, is also considered an ideal carbon source for chemical synthesis. How to efficiently capture CO2 and convert it into high-value-added chemicals has become a research hotspot in the field of green chemistry. Existing CO2 capture-conversion technologies generally involve absorbent regeneration, CO2 separation, and the use of catalysts, which greatly increases production costs and limits the large-scale application of existing technologies. Therefore, there is an urgent need to develop new low-cost CO2 capture-conversion technologies and expand the application areas of CO2. The main product of CO2 conversion is carbon materials, which are widely used in tribology for lubrication between contact interfaces and exhibit excellent anti-wear and friction-reducing capabilities. Therefore, CO2 capture-conversion technology has foreseeable application potential in the lubrication field.

[0003] Tribology focuses on friction and wear between contact interfaces, aiming to solve practical problems in engineering applications. Friction and wear, as common phenomena in the operation of moving mechanical parts, accelerate mechanical damage, shorten machine lifespan, and cause enormous energy waste and economic losses. According to incomplete statistics, friction consumes approximately one-third of the world's primary energy, while wear causes about 60% of equipment malfunctions or failures, and mechanical equipment accidents caused by friction and wear account for more than 50%. Friction reduction and wear resistance have always been important topics of concern for researchers in the field of tribology, and are also key to precision machining, intelligent manufacturing, and green environmental development.

[0004] Therefore, developing novel CO2 capture-conversion and utilization technologies and applying them to the field of lubrication is of significant research value. Summary of the Invention

[0005] The purpose of this invention is to provide a near-zero wear liquid lubricant, its preparation method, and its application. The liquid lubricant provided by this invention is a liquid lubricant that can achieve near-zero wear.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a near-zero wear liquid lubricant, the raw materials for which include base lubricating oil, CO2 absorbent and CO2, wherein the CO2 absorbent contains amino and hydroxyl groups, the mass of the CO2 absorbent is 25-75% of the mass of the base lubricating oil, and the mass content of CO2 in the near-zero wear liquid lubricant is 10-15%.

[0007] Preferably, the CO2 absorbent is an alkanolamine, and the alkanolamine has 2 to 5 carbon atoms.

[0008] Preferably, the alcoholamine includes one or more of ethanolamine, propanolamine, butanolamine, and pentanolamine; the ethanolamine is monoethanolamine and / or diethanolamine; the propanolamine is n-propanolamine and / or isopropanolamine; the butanolamine is 4-amino-1-butanol; and the pentanolamine is 5-amino-1-pentanol.

[0009] Preferably, the base lubricating oil is polyethylene glycol, and the number average molecular weight of the polyethylene glycol is 200-600.

[0010] This invention provides a method for preparing the near-zero wear liquid lubricant described in the above technical solution, comprising the following steps: The near-zero wear liquid lubricant is obtained by mixing base lubricating oil, CO2 absorbent and CO2.

[0011] Preferably, the mixing temperature is 20~30℃; the mixing includes: premixing the base lubricating oil with the CO2 absorbent to obtain a premix; introducing CO2 into the premix, or placing the premix in a natural dust-free environment to absorb CO2 autonomously.

[0012] Preferably, the CO2 introduction time is ≤60 min, the CO2 flow rate is 0.8~1.2 L / min, and the placement time is ≤6 days.

[0013] This invention provides the application of the near-zero wear liquid lubricant described in the above technical solution or the near-zero wear liquid lubricant prepared by the preparation method described in the above technical solution in the field of lubrication.

[0014] Preferably, the upper ball material suitable for the near-zero wear liquid lubricant includes silicon nitride, silicon dioxide, bearing steel, polypropylene, or zirconium oxide, and the lower test block material is bearing steel.

[0015] Preferably, the near-zero wear liquid lubricant is suitable for operating conditions with a pressure of 0.66~1.79 GPa and a velocity of 0.0314~0.314 m / s.

[0016] Beneficial effects: The raw materials for preparing the near-zero wear liquid lubricant in this invention include base lubricating oil, CO2 absorbent, and CO2. The CO2 absorbent contains amino and hydroxyl groups. The liquid lubricant provided by this invention has excellent anti-wear properties and can achieve near-zero wear (wear rate <10%). -8 mm 3 ·N -1 ·m -1 ).

[0017] The near-zero wear liquid lubricant of this invention has a simple preparation method, is safe and environmentally friendly, has excellent tribological properties, especially excellent anti-wear properties, and has good prospects for practical industrial application. Attached Figure Description

[0018] Figure 1 Curves showing the coefficient of friction versus time and wear rate for polyethylene glycol 200 (PEG200) base oil and the liquid lubricant in Example 1; Figure 2 The images show the three-dimensional morphology of the wear tracks of PEG200 base oil and the liquid lubricant in Example 1 (reaction time 30 min) after friction testing, and the scanning electron microscope (SEM) morphology of the wear tracks on the lower test plate. Figure 3 Atomic force microscopy (AFM) images and Young's modulus diagrams of PEG200 base oil and the liquid lubricant in Example 1 (reaction time 30 min); Figure 4 Curves showing the coefficient of friction versus time and wear rate for PEG200 base oil and the liquid lubricant in Example 2; Figure 5 Curves showing the coefficient of friction versus time and wear rate for PEG200 base oil and the liquid lubricant in Example 3; Figure 6 The curves showing the coefficient of friction and wear rate over time for PEG200 base oil and the liquid lubricant in Example 4. Detailed Implementation

[0019] This invention provides a near-zero wear liquid lubricant, the raw materials for which include base lubricating oil, CO2 absorbent and CO2, wherein the CO2 absorbent contains amino and hydroxyl groups, the mass of the CO2 absorbent is 25-75% of the mass of the base lubricating oil, and the mass content of CO2 in the near-zero wear liquid lubricant is 10-15%.

[0020] In this invention, unless otherwise specified, all raw materials used are commercially available products well known to those skilled in the art or prepared using methods well known to those skilled in the art.

[0021] The near-zero wear liquid lubricant provided by this invention comprises a base lubricating oil. In one embodiment of this invention, the base lubricating oil is polyethylene glycol (PEG); the number-average molecular weight of the PEG can be 200-600, specifically PEG 200. In this embodiment, using PEG as the base lubricating oil provides a good dissolving medium for the CO2 absorbent and participates in building the network structure, which is beneficial for forming a stable, dense, and high-load-bearing lubricating film during friction, thereby synergistically achieving near-zero wear.

[0022] The near-zero wear liquid lubricant provided by this invention comprises a CO2 absorbent containing amino and hydroxyl groups. In one embodiment, the CO2 absorbent can be an alkanolamine, wherein the alkanolamine has 2-5 carbon atoms, more specifically 2-3. In another embodiment, the alkanolamine can include one or more of ethanolamine, propanolamine, butanolamine, and pentanolamine; the ethanolamine can be monoethanolamine and / or diethanolamine; the propanolamine can be n-propanolamine (i.e., 3-amino-1-propanol) and / or isopropanolamine; the butanolamine can be 4-amino-1-butanol; and the pentanolamine can be 5-amino-1-pentanol. The mass of the CO2 absorbent in this invention is 25-75% of the mass of the base lubricating oil, specifically 25%, 30%, 33%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, or 75%. This invention employs the aforementioned CO2 absorbent containing amino and hydroxyl groups, which can react with CO2 under mild conditions to generate carbamate products. The resulting products can significantly improve the tribological properties of the base lubricating oil. This invention limits the amount of CO2 absorbent within the aforementioned range, effectively absorbing CO2 and ensuring that the concentration of carbamate products in the lubrication system is within the optimal range. This avoids both insufficient concentration leading to an incomplete internal network and insufficient lubrication film carrying capacity, and excessive concentration causing excessive system viscosity and increased frictional resistance. This facilitates the formation of a stable composite film at the friction pair interface, combining hard island support and soft base lubrication, achieving near-zero macroscopic wear.

[0023] The near-zero wear liquid lubricant provided by this invention includes CO2 as a raw material. The mass content of CO2 in the near-zero wear liquid lubricant is 10-15%, specifically 10%, 11%, 12%, 13%, 14%, or 15%. By controlling the CO2 content within the above range, this invention optimizes the polarity and internal network strength of the lubricant, which is beneficial for maintaining elastohydrodynamic lubrication under wide load and wide speed conditions to significantly suppress wear and achieve a near-zero wear level.

[0024] In the near-zero wear liquid lubricant provided by this invention, the CO2 absorbent can rapidly absorb CO2 under mild conditions and react with CO2 to generate carbamate anions and cations. The ion-base lubricant (polyethylene glycol) complex forms a dynamic, spatially extended filamentous network structure in the interface region through hydrogen bonding and electrostatic interaction. The lubricant has uneven hardness and an island-like structure, which can effectively form a robust, high-load-bearing separation layer between friction interfaces, preventing direct contact between interfaces and thus avoiding wear. Therefore, the near-zero wear liquid lubricant provided by this invention has excellent lubrication performance.

[0025] This invention provides a method for preparing the near-zero wear liquid lubricant described in the above technical solution, comprising the following steps: The near-zero wear liquid lubricant is obtained by mixing base lubricating oil, CO2 absorbent and CO2.

[0026] In one embodiment of the present invention, the mixing temperature can be 20~30℃, specifically 25℃. In another embodiment, the mixing may include: premixing the base lubricating oil with a CO2 absorbent to obtain a premix; introducing CO2 into the premix, or placing the premix in a natural dust-free environment to allow it to absorb CO2 from the air. The present invention does not specifically limit the premixing method, as long as the two are mixed evenly. In another embodiment, the CO2 introduction time can be ≤60 min, further 10~60 min, specifically 10 min, 20 min, 30 min, 40 min, 50 min, or 60 min; the CO2 flow rate can be 0.8~1.2 L / min, specifically 1 L / min; the CO2 introduction process is preferably carried out under stirring conditions. The present invention does not specifically limit the stirring speed, as long as the CO2 can fully react with the absorbent. As one embodiment of the present invention, the placement time is ≤6 days, and can be 1 to 6 days, specifically 1 day, 2 days, 3 days, 4 days, 5 days or 6 days.

[0027] This invention provides the application of the near-zero wear liquid lubricant described in the above technical solution or the near-zero wear liquid lubricant prepared by the preparation method described in the above technical solution in the field of lubrication.

[0028] The near-zero wear liquid lubricant of this invention can be used directly without the addition of other reagents. This invention does not impose any special limitations on the application method of the near-zero wear liquid lubricant; it can be applied according to methods well known in the art. As one embodiment of this invention, the suitable upper ball material for the near-zero wear liquid lubricant includes silicon nitride, silicon dioxide, bearing steel, polypropylene, or zirconium oxide, and the lower test block material is bearing steel. Applicable working conditions include: pressure 0.66~1.79 GPa, specifically 1.42 GPa; speed 0.0314~0.314 m / s, further specifically 0.0942~0.251 m / s.

[0029] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0030] Unless otherwise specified, the experimental methods described in the following embodiments are conventional methods; unless otherwise specified, all percentages mentioned in this invention are mass percentages.

[0031] Example 1 40g of monoethanolamine (MEA) and polyethylene glycol 200 (PEG200) base oil were mixed at a mass ratio of 1:3 at room temperature (25℃). Carbon dioxide was introduced under magnetic stirring at a flow rate of 1L / min and the reaction was carried out at a temperature of 25℃ for 10min, 30min, and 60min respectively (a comparative experiment was also set with a reaction time of 0min, i.e., no carbon dioxide was introduced), to obtain a liquid lubricant.

[0032] Example 2 Diethanolamine (DEA) and PEG200, with a total mass of 40g, were mixed at a mass ratio of 1:3 at room temperature. Carbon dioxide was introduced under magnetic stirring at a gas flow rate of 1L / min, and the reaction was carried out at a temperature of 25℃ for 10min, 30min, and 60min respectively (a control experiment was also set with a reaction time of 0min, i.e., no carbon dioxide was introduced), to obtain a liquid lubricant.

[0033] Example 3 40g of n-propanolamine (MPA) and PEG200 were mixed at a mass ratio of 1:3 at room temperature. Carbon dioxide was introduced under magnetic stirring at a flow rate of 1L / min and the reaction was carried out at 25℃ for 10min, 30min and 60min respectively (a control experiment was also set with a reaction time of 0min, i.e. no carbon dioxide was introduced) to obtain a liquid lubricant.

[0034] Example 4 40g of monoethanolamine (MEA) and PEG200 were mixed at a mass ratio of 1:3 at room temperature and placed in a natural dust-free environment at 25°C for 6 days. During the placement process, the mixture absorbed carbon dioxide autonomously to obtain a liquid lubricant.

[0035] Test Example 1 The tribological properties of the liquid lubricant prepared in Example 1 were tested using a multifunctional tribometer (UMT) in rotation mode, and compared with PEG200 base oil. Specifically, GCr15 steel balls (diameter = 6 mm, Rockwell hardness HRC = 60 ± 2) and steel discs (24 × 7.9 mm, HRC = 60 ± 2) were used as friction samples (surface roughness less than 20 nm), and tribological tests were conducted under the following conditions: The constant load was 10 N (initial Hertzian contact pressure was 1.42 GPa), the rotation speed was 300 rpm (0.0942 m / s), the test temperature was 25 ℃, and the duration was 1800 s.

[0036] To reduce contamination, the steel disc and steel balls were ultrasonically cleaned with petroleum ether before the friction test. The volume of liquid lubricant used in each friction test was 0.025 mL.

[0037] Figure 1 The curves showing the coefficient of friction versus time and the wear rate for PEG200 base oil and the liquid lubricant (PEG-MEA-CO2) in Example 1 are shown, where a is the curve showing the coefficient of friction versus time, and b is the average coefficient of friction and wear rate. Figure 1 As can be seen from a, the friction coefficients of PEG base oil and liquid lubricant without CO2 introduction fluctuated significantly throughout the test (1800s). However, for the liquid lubricant prepared in Example 1, the friction coefficient remained within the range of 0.070 to 0.075, and the friction coefficient curve was relatively smooth. Figure 2 The images show the three-dimensional morphology of the wear tracks of PEG200 base oil and the liquid lubricant in Example 1 (reaction time 30 min) after friction testing, along with scanning electron microscopy (SEM) images of the wear tracks on the lower test plate. Images a and c show the three-dimensional wear track morphology and SEM image of the PEG base oil, respectively; images b and d show the three-dimensional wear track morphology and SEM image of the liquid lubricant in Example 1, respectively. Figure 1 b and Figure 2 It can be seen that the wear rate of PEG base oil after friction testing is as high as 4.68 × 10⁻⁶. -7 mm 3 ·N -1 ·m -1 The morphology of the wear marks on the lower test plate indicated that the sample surface was severely damaged, and there were obvious furrows at the wear marks. In contrast, the liquid lubricant in Example 1 showed extremely low wear after the friction test. The wear volume and morphology could not be measured using a three-dimensional optical profilometer or scanning electron microscope. The surface of the lower test plate was very smooth, showing almost no wear. These results indicate that, compared with PEG base oil, the liquid lubricant prepared in Example 1 has excellent anti-wear and friction-reducing properties, especially its anti-wear properties, which are almost wear-free.

[0038] Figure 3 Atomic force microscopy (AFM) images and Young's modulus diagrams of PEG200 base oil and the liquid lubricant (reaction time 30 min) in Example 1 are shown. Specifically, a and b are the AFM images and Young's modulus diagrams of the PEG200 base oil, respectively; c and d are the AFM images and Young's modulus diagrams of the liquid lubricant in Example 1, respectively. Figure 3As shown in 'c', the liquid lubricant exhibits a structure composed of filamentous networks of varying lengths. This network originates from the dynamic, spatially extended filamentous network structure formed within the lubricant through electrostatic and hydrogen bonding interactions of the ion-PEG complex. Figure 3 As can be seen from d, the internal hardness of the liquid lubricant is uneven, exhibiting an island-like distribution structure. This structure can effectively form a robust, high-load-bearing separation layer between the friction interfaces, preventing direct contact between the interfaces and thus avoiding wear.

[0039] comprehensive Figure 2 and Figure 3 The results show that the lubrication system formed after introducing carbon dioxide possesses a large and mechanically strong network structure. Under the same pressure conditions, this robust network structure can effectively and uniformly distribute contact pressure, preventing stress concentration on a few micro-protrusions, thereby inhibiting abrasive and adhesive wear. Therefore, under the same macroscopic load, the stress distribution at each contact point is more uniform, and the material's load-bearing efficiency is higher. The formation of this dynamic network self-assembly structure endows the liquid lubricant with excellent tribological properties.

[0040] Test Example 2 The tribological properties of the liquid lubricant prepared in Example 2 were tested using a multifunctional tribometer (UMT) in rotation mode, and compared with PEG200 base oil. Specifically, GCr15 steel balls (diameter = 6 mm, HRC = 60 ± 2) and steel discs (24 × 7.9 mm, HRC = 60 ± 2) were used as friction samples (surface roughness less than 20 nm), and tribological tests were conducted under the following conditions: The constant load was 10 N (initial Hertzian contact pressure was 1.42 GPa), the rotation speed was 300 rpm (0.0942 m / s), the test temperature was 25 ℃, and the duration was 1800 s.

[0041] To reduce contamination, the steel disc and steel balls were ultrasonically cleaned with petroleum ether before the friction test. The volume of liquid lubricant used in each friction test was 0.025 mL.

[0042] Figure 4 The curves showing the coefficient of friction versus time and the wear rate of the PEG200 base oil and the liquid lubricant (PEG-DEA-CO2) in Example 2 are shown, where a is the curve of the coefficient of friction versus time, and b is the average coefficient of friction and wear rate. The results show that, compared with the PEG200 base oil, the coefficient of friction of the liquid lubricant prepared in Example 2 decreased from 0.116 to 0.079, a decrease of approximately 32%, and the wear rate after introducing carbon dioxide was ≤10. -8 mm 3 ·N -1 ·m-1 The carbon dioxide introduction time is ≥60 min, which achieves an almost imperceptible, wear-free state. These results indicate that the liquid lubricant prepared in Example 2 also exhibits superior anti-wear and friction-reducing capabilities compared to PEG200 base oil.

[0043] Test Example 3 The tribological properties of the liquid lubricant prepared in Example 3 were tested using a multifunctional tribometer (UMT) in rotation mode, and compared with PEG200 base oil. Specifically, GCr15 steel balls (diameter = 6 mm, HRC = 60 ± 2) and steel discs (24 × 7.9 mm, HRC = 60 ± 2) were used as friction samples (surface roughness less than 20 nm), and tribological tests were conducted under the following conditions: The constant load was 10 N (initial Hertzian contact pressure was 1.42 GPa), the rotation speed was 300 rpm (0.0942 m / s), the test temperature was 25 ℃, and the duration was 1800 s.

[0044] To reduce contamination, the steel disc and steel balls were ultrasonically cleaned with petroleum ether before the friction test. The volume of liquid lubricant used in each friction test was 0.025 mL.

[0045] Figure 5 The curves showing the coefficient of friction versus time and the wear rate of the PEG200 base oil and the liquid lubricant (PEG-MPA-CO2) in Example 3 are shown, where a is the curve of the coefficient of friction versus time, and b is the average coefficient of friction and wear rate. The results show that, compared with the PEG200 base oil, the coefficient of friction of the liquid lubricant prepared in Example 3 decreased from 0.116 to 0.077, a decrease of approximately 34%, and the wear rate after introducing carbon dioxide was ≤10. -8 mm 3 ·N -1 ·m -1 The near-wear-free state can be achieved by introducing carbon dioxide for ≥60 minutes. These results demonstrate that the liquid lubricant prepared in Example 3 also exhibits superior anti-wear and friction-reducing capabilities compared to PEG base oil.

[0046] Test Example 4 The tribological properties of the liquid lubricant prepared in Example 4 were tested using a Universal Multi-Functional Tribometer (UMT) in rotation mode, and compared with PEG200 base oil. Specifically, GCr15 steel balls (diameter = 6 mm, HRC = 60 ± 2) and steel discs (24 × 7.9 mm, HRC = 60 ± 2) were used as friction samples (surface roughness less than 20 nm), and tribological tests were conducted under the following conditions: The constant load was 10 N (initial Hertzian contact pressure was 1.42 GPa), the rotation speed was 800 rpm (0.251 m / s), the test temperature was 25 ℃, and the duration was 1800 s.

[0047] To reduce contamination, the steel disc and steel balls were ultrasonically cleaned with petroleum ether before the friction test. The volume of liquid lubricant used in each friction test was 0.025 mL.

[0048] Figure 6 The curves showing the coefficient of friction versus time and the wear rate for PEG200 base oil and the liquid lubricant in Example 4 are shown, where a represents the coefficient of friction versus time, and b represents the average coefficient of friction and wear rate. The results show that, compared to PEG200 base oil, the coefficient of friction of the liquid lubricant prepared in Example 4 decreased from 0.080 to 0.054, a decrease of approximately 33%. After absorbing carbon dioxide in the natural environment for 6 days, it also achieved a near-zero wear state, with a wear rate of 1.6 × 10⁻⁶. -9 mm 3 ·N -1 ·m -1 The above results indicate that natural absorption of carbon dioxide can also achieve near-zero wear.

[0049] As can be seen from the above embodiments, the liquid lubricant provided by the present invention forms a dynamic, spatially extended filamentous network structure in the interface region due to the electrostatic interaction and hydrogen bonding interaction of the ion-based lubricating oil (PEG200) complex. The internal hardness of the lubricant is uneven, and it has an island-like structure, which can effectively form a robust high-load-bearing separation layer between the friction interfaces, preventing direct contact between the interfaces and thus avoiding wear. The raw materials used are all commercially available basic chemical raw materials, which have the advantages of easy availability, low cost, simple preparation process, and only need to be mixed in proportion. It has good economic efficiency and scalability, and shows significant practical value in industrial applications.

[0050] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A near-zero wear liquid lubricant, the raw materials for preparation include a base lubricating oil, a CO2 absorbent and CO2, wherein the CO2 absorbent contains amino and hydroxyl groups, the mass of the CO2 absorbent is 25-75% of the mass of the base lubricating oil, and the mass content of CO2 in the near-zero wear liquid lubricant is 10-15%.

2. The near zero wear liquid lubricant of claim 1, wherein, The CO2 absorbent is an alkanolamine, and the alkanolamine has 2 to 5 carbon atoms.

3. The near zero wear liquid lubricant of claim 2, wherein, The alkanolamine includes one or more of ethanolamine, propanolamine, butanolamine, and pentanolamine; the ethanolamine is monoethanolamine and / or diethanolamine; the propanolamine is n-propanolamine and / or isopropanolamine; the butanolamine is 4-amino-1-butanol; and the pentanolamine is 5-amino-1-pentanol.

4. The near zero wear liquid lubricant according to any one of claims 1 to 3, characterized in that, The base lubricating oil is polyethylene glycol, and the number average molecular weight of the polyethylene glycol is 200-600.

5. A method for preparing the near-zero wear liquid lubricant according to any one of claims 1 to 4, comprising the following steps: The near-zero wear liquid lubricant is obtained by mixing base lubricating oil, CO2 absorbent and CO2.

6. The production method according to claim 5, wherein The mixing temperature is 20~30℃; the mixing includes: premixing the base lubricating oil with the CO2 absorbent to obtain a premix; introducing CO2 into the premix, or placing the premix in a natural dust-free environment to absorb CO2 autonomously.

7. The production method according to claim 6, wherein The CO2 introduction time is ≤60 min, and the CO2 flow rate is 0.8~1.2 L / min; the placement time is ≤6 days.

8. The application of the near-zero wear liquid lubricant according to any one of claims 1 to 4 or the near-zero wear liquid lubricant prepared by the preparation method according to any one of claims 5 to 7 in the field of lubrication.

9. Use according to claim 8, characterized in that, The near-zero wear liquid lubricant is suitable for upper ball materials including silicon nitride, silicon dioxide, bearing steel, polypropylene, or zirconium oxide, and the lower test block material is bearing steel.

10. Use according to claim 8 or 9, characterized in that, The near-zero wear liquid lubricant is suitable for operating conditions with a pressure of 0.66~1.79 GPa and a velocity of 0.0314~0.314 m / s.

Images