Low-temperature anti-drag coating for improving equipment system efficiency as well as preparation method and application of low-temperature anti-drag coating

Abstract

The invention discloses a low-temperature anti-drag coating for improving equipment system efficiency and a preparation method and application of the low-temperature anti-drag coating, and belongs to the technical field of machinery and lubrication. The preparation method comprises the following steps: spraying a low-temperature anti-drag coating on the surface of a base material modified by dopamine hydrochloride, and curing to obtain the low-temperature anti-drag coating, the preparation process of the low-temperature anti-drag coating comprises the following steps: in an organic solvent, carrying out modification treatment on nanoparticles by utilizing a silane coupling agent, then sequentially adding a fluorocarbon surfactant, isocyanate, fluorinated acrylate and a photoinitiator, and uniformly stirring to obtain the low-temperature anti-drag coating. The coating prepared by the method disclosed by the invention has a remarkable drag reduction effect in a gearbox oil stirring lubrication transmission part, the stability of the coating is effectively improved, the coating is suitable for a long-time working environment, and the oil stirring resistance moment can be continuously reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of machinery and lubrication technology, and particularly relates to a low-temperature drag-reducing coating for improving the efficiency of a system of equipment, and a preparation method and application thereof. BACKGROUND

[0002] Oil stirring power loss is an important part of power loss of a transmission system, and is particularly significant in a low-temperature environment. In a low-temperature environment, the viscosity of lubricating oil increases, resulting in an increase in the oil stirring resistance torque, and thus an increase in the oil stirring power loss. In addition, the low temperature also reduces the starting performance of a vehicle, and the increase in the resistance torque makes it more difficult for the vehicle to start.

[0003] Super-oleophobic coating is a surface treatment technology characterized by an oil contact angle of more than 150° on a solid surface, thereby significantly reducing the wettability of the oil on the surface. The formation of such a coating requires two aspects: first, the coating material itself has a low surface energy, and second, the surface has a micro-rough structure. The surface friction between the solid and the liquid and the Newtonian internal friction of the oil liquid are key components of the oil stirring resistance torque. The super-oleophobic coating replaces the liquid / solid interface with a liquid / gas / solid interface by forming an air film on the surface, thereby reducing the contact area between the solid surface and the oil liquid and reducing the friction resistance torque between the solid and the liquid. In addition, the Newtonian internal friction is affected by the wetting area, the viscosity of the oil liquid, and the velocity gradient, and the surface structure of the super-oleophobic coating can induce boundary layer slip, thereby reducing the velocity gradient and reducing the Newtonian internal friction.

[0004] Therefore, the application of the super-oleophobic coating to the oil stirring lubrication transmission components can effectively reduce the oil stirring resistance torque, thereby reducing the power loss of the transmission system and improving the cold starting performance of the vehicle.

[0005] However, the stability of the coating is a common problem in the practical application of the super-oleophobic coating. In particular, in components such as gearboxes, the coating is often immersed in lubricating oil for a long time, which can cause the nanoparticles in the coating and the fluorocarbon surfactant loaded thereon to gradually fall off, thereby causing the coating to fail and lose its original drag-reducing effect. Therefore, it is particularly important to enhance the stability of the coating. SUMMARY

[0006] In view of the above technical problems, the present application provides a low-temperature drag-reducing coating for improving the efficiency of equipment systems, as well as a preparation method and application thereof. The specific steps are as follows: first, the nanoparticles are modified with a silane coupling agent, then fluorocarbon surfactant and isocyanate are introduced, and then fluorinated acrylate and a photoinitiator are added to obtain a low-temperature drag-reducing coating; then, the substrate is modified with hydrochloric acid dopamine to enhance the adhesion between the substrate and the coating; finally, the low-temperature drag-reducing coating is uniformly sprayed onto the surface of the modified substrate and is subjected to ultraviolet curing to form a stable low-temperature drag-reducing coating. The coating prepared by the present application has a significant drag-reducing effect in the gear box oil stirring lubrication transmission components, and the stability of the coating is effectively improved, which is suitable for long-term working environment and can continuously reduce the oil stirring drag torque.

[0007] To achieve the above object, the present application provides the following technical solutions:

[0008] One of the technical solutions of the present application is:

[0009] A preparation method of a low-temperature drag-reducing coating for improving the efficiency of equipment systems, comprising the following steps:

[0010] The low-temperature drag-reducing coating is obtained by coating the low-temperature drag-reducing coating on the surface of the substrate modified by hydrochloric acid dopamine and then curing.

[0011] The preparation process of the low-temperature drag-reducing coating is as follows:

[0012] In an organic solvent, the nanoparticles are modified with a silane coupling agent, and then fluorocarbon surfactant, isocyanate, fluorinated acrylate and a photoinitiator are sequentially added thereto, and the mixture is stirred uniformly to obtain the low-temperature drag-reducing coating.

[0013] Beneficial effects: The present application modifies the nanoparticles with a silane coupling agent, combines isocyanate and fluorinated acrylate as a crosslinking agent, and introduces hydrochloric acid dopamine to enhance the adhesion between the coating and the substrate, thereby greatly improving the stability of the coating. These modification measures effectively overcome the stability problem of traditional super-oleophobic coatings, so that the coating can maintain good super-oleophobic properties under the condition of long-term immersion in oil, ensure its continuous and effective reduction of oil stirring drag torque, and improve the overall working efficiency and performance of the system.

[0014] Optionally, the preparation method specifically comprises the following steps:

[0015] (1) Dissolve the nanoparticles and the silane coupling agent in an organic solvent, and perform ultrasonic dispersion and magnetic stirring to complete the modification of the nanoparticles, thereby obtaining a mixed solution;

[0016] (2) adding fluorocarbon surfactant and isocyanate into the mixed solution of step (1), continuing ultrasonic dispersion and magnetic stirring to obtain solution A;

[0017] (3) dissolving fluorinated acrylate into organic solvent and stirring uniformly to obtain solution B, mixing solution B and solution A uniformly, adding photoinitiator and stirring uniformly to obtain low-temperature drag-reducing coating;

[0018] (4) immersing substrate into aqueous solution of dopamine hydrochloride, taking out and storing at room temperature overnight to obtain modified substrate;

[0019] (5) coating low-temperature drag-reducing coating onto surface of modified substrate, and curing to form superoleophobic coating, thereby finally obtaining low-temperature drag-reducing coating.

[0020] Optionally, in step (1), the nanoparticles include at least one of copper oxide, zinc oxide, silicon dioxide and titanium dioxide.

[0021] Optionally, in step (1), the silane coupling agent includes at least one of 3-aminopropyl triethoxysilane, N-(2-aminoethyl)-3-aminopropyl-dimethoxysilane and 3-aminopropyl trimethoxysilane.

[0022] Optionally, in step (1), the mass ratio of organic solvent to nanoparticles is (20-40):1.

[0023] The mass ratio of organic solvent to silane coupling agent is (2-10):1.

[0024] Further, in steps (1) and (3), the organic solvent is acetone.

[0025] Further, in steps (1) and (2), the ultrasonic dispersion time is 1-5 hours, and the magnetic stirring time is 20-50 hours.

[0026] Optionally, in step (1), the mass ratio of organic solvent to fluorocarbon surfactant in step (2) is (1.5-2.5):1.

[0027] In step (1), the mass ratio of organic solvent to isocyanate in step (2) is (500-2000):1.

[0028] Optionally, in step (3), the mass concentration of fluorinated acrylate in solution B is controlled at 10%-50%.

[0029] The mass ratio of solution B to solution A is 1:(1-5).

[0030] The photoinitiator accounts for 1wt%-3wt% of the low-temperature drag-reducing coating.

[0031] Optionally, the concentration of the dopamine hydrochloride aqueous solution is 0.5-10 mg / mL; the pH of the solution is 4.5-8.5.

[0032] Optionally, the soaking time in the soaking process in step (4) is 1-10 hours.

[0033] Optionally, in step (5), the number of coatings is 2-10 times;

[0034] The UV intensity during the curing process is 100-300mW / cm 2 , curing time is 10-50s.

[0035] The second technical solution of the present invention:

[0036] A low-temperature drag-reducing coating for improving the efficiency of equipment systems is prepared by the above-mentioned preparation method.

[0037] The third technical solution of the present invention:

[0038] The above-mentioned low-temperature drag-reducing coating for improving the efficiency of equipment systems is used in oil-lubricated transmission components.

[0039] Compared with the prior art, the present invention has the following advantages and technical effects:

[0040] The present invention modifies the nanoparticles, introduces isocyanate and fluorinated acrylate as cross-linking agents, and utilizes dopamine to enhance the bonding strength between the coating and the substrate, thereby significantly improving the stability of the coating.

[0041] In addition, the coating prepared by the present invention is applied to transmission components such as oil stirring lubrication gears, which can effectively reduce the oil stirring resistance torque under low temperature conditions and reduce the power loss of the transmission system. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0043] Figure 1 This is a process flow chart for preparing the low-temperature drag-reducing coating of the present invention;

[0044] Figure 2 This is a contact angle measurement diagram of paraffin oil at room temperature for the low-temperature drag-reducing coating prepared in Example 1;

[0045] Figure 3The low temperature drag reducing coating prepared in Example 1 and the substrate were tested for oil stirring loss resistance torque at -20°C. DETAILED DESCRIPTION

[0046] The following detailed description of various example embodiments of the application is not to be considered limiting of the scope or spirit of the application, but rather as a description of certain aspects, features and embodiments of the application.

[0047] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. Additionally, the use of the term "about" in relation to a value or a range of values is intended to include each and every value falling within the range and each and every value falling within the range as well as the values themselves. The upper and lower limits of each range are included in the range.

[0048] 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. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application, preferred methods and materials are described. All publications mentioned herein are incorporated by reference to disclose and describe the methods and / or materials in connection with which the publications are cited. The citation of any reference is not an admission that it is prior art with respect to the present application.

[0049] Many modifications and variations of this application can be made without departing from its spirit or scope, which will be apparent to those skilled in the art. Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. The specification and examples given are exemplary only. It is to be understood that the application is not limited in scope by the specific embodiments described herein. Rather, the intent is to embrace all changes and modifications that can come within the spirit and scope of the application.

[0050] As used herein, the terms "comprise", "comprising", "include", "including", "have", "having" and the like are open-ended and do not exclude additional elements or steps.

[0051] The embodiments of the application disclose a preparation method of a drag reducing coating with good stability, and the method comprises the following steps.

[0052] The nanoparticles and the silane coupling agent are dissolved in acetone, and ultrasonic dispersion and magnetic stirring are performed to modify the nanoparticles, so that a mixed solution is obtained;

[0053] The fluorocarbon surfactant and the isocyanate are added into the mixed solution, and ultrasonic dispersion and magnetic stirring are continuously performed, so that a solution A to be used is obtained;

[0054] The fluorinated acrylate is dissolved in acetone in a certain proportion and stirred uniformly, then mixed with solution A in a certain proportion, and then the photoinitiator is added and stirred uniformly to obtain the low-temperature drag-reducing coating (wherein the isocyanate and the fluorinated acrylate are introduced as cross-linking agents, which can effectively improve the stability of the coating);

[0055] Dopamine hydrochloride aqueous solution is prepared, and the pH value of the solution is adjusted, and the substrate is soaked in the solution for surface modification (dopamine hydrochloride can increase the adhesion between the substrate and the coating, and plays an important role in improving the stability of the coating);

[0056] The low-temperature drag-reducing coating is uniformly coated on the surface of the modified substrate, and then the coated substrate is placed in a UV curing device for curing, and finally a drag-reducing coating is prepared.

[0057] Unless otherwise specified, "room temperature" in the present application refers to 20-30℃.

[0058] The raw materials used in the present application are all purchased from the market. Among them, the fluorocarbon surfactant is purchased from DuPont Company, the model number is fs-61; 3-aminopropyl triethoxysilane is purchased from Mcmaster-Carr Chemical Technology Co., Ltd., the CAS is 919-30-2; isocyanate is purchased from BASF Company, the model number is HI 100; 2-perfluoroalkyl ethyl acrylate is purchased from Mcmaster-Carr Chemical Technology Co., Ltd., the CAS is 65605-70-1; benzophenone photoinitiator is purchased from Merck Company, the CAS is 106797-53-9; dopamine hydrochloride is purchased from Mcmaster-Carr Chemical Technology Co., Ltd., the model number is 62-31-7.

[0059] The technical solutions of the present application are further illustrated by the following examples.

[0060] Example 1

[0061] As Figure 1 shown, a preparation method of a low-temperature drag-reducing coating for improving the efficiency of an equipment system comprises the following steps:

[0062] (1) First, 0.33g of silicon dioxide nanoparticles (particle size 30nm) and 2g of 3-aminopropyl triethoxysilane (surfactant) are dissolved in 10g of acetone, ultrasonic disperser is used for ultrasonic dispersion for 1 hour, and magnetic stirrer is used for stirring for 48 hours, so as to ensure that the nanoparticles are completely modified and uniformly dispersed in the solution;

[0063] (2) Then, 6 g of fluorocarbon surfactant (purchased from DuPont Company, model fs-61) and 0.01 g of isocyanate (HI 100) were added to the above solution, and ultrasonic dispersion was performed again for 1 hour, followed by magnetic stirring for 24 hours, to ensure that the fluorocarbon surfactant and the isocyanate were fully dissolved and uniformly distributed in the solution, to obtain solution A;

[0064] (3) 3 g of fluorinated acrylate (2-perfluoroalkylethyl acrylate) was added to 10 g of acetone and stirred until uniform, and then added to solution A, and continued to be stirred, followed by adding 0.6 g of benzophenone photoinitiator to the solution and continuing to stir, to uniformly disperse the photoinitiator, to obtain a low-temperature drag-reducing coating;

[0065] (4) A dopamine hydrochloride solution was prepared, and dopamine hydrochloride was added to deionized water at a concentration of 1 mg / mL and stirred until uniform, and the pH of the solution was adjusted to 4.5; then, the surface of the steel substrate to be treated was sanded to a rough state, and ultrasonic cleaning was performed with deionized water for 15 minutes, to ensure that all dirt and impurities were removed; after the substrate was dried, it was immersed in the dopamine hydrochloride solution for 1 hour to modify the surface of the substrate; then, the modified substrate was taken out and dried in air overnight;

[0066] (5) The low-temperature drag-reducing coating prepared in step (3) was uniformly sprayed onto the surface of the modified substrate of step (4) using a spray gun; after the acetone was completely volatilized, the disc was rotated by 90° and sprayed again, for a total of 5 times, until a uniform and dense coating was formed on the surface. Then it was placed in a UV curing device, with light intensity set to 100 mW / cm 2 , and the curing time was 10 s, to finally obtain a drag-reducing coating.

[0067] Figure 2 The contact angle measurement diagram of the drag-reducing coating prepared in Example 1 in paraffin oil at room temperature; from the diagram, it can be seen that the drag-reducing coating prepared in Example 1 exhibits excellent oleophobicity to paraffin oil at room temperature. Specifically, (1) the left contact angle is 152.0°, and the right contact angle is 151.9°, showing extremely high oleophobicity; (2) the paraffin oil droplet is spherical on the surface of the coating, further proving the high oleophobicity of the coating; (3) the surface of the coating is smooth and uniform, without obvious defects, indicating that the preparation process is good. Therefore, the drag-reducing coating prepared in this example has a significant drag-reducing effect on paraffin oil at room temperature, and has good application prospects.

[0068] Figure 3The drag reduction coating prepared in Example 1 and the substrate were tested for the oil stirring loss resistance torque at -20°C. As can be seen from the graph, the drag reduction coating has a significantly lower oil stirring loss resistance torque than the substrate steel at each rotational speed, showing its excellent drag reduction effect. Although the resistance torque of both materials increases with increasing rotational speed, the growth rate of the drag reduction coating is slower, further proving its superior performance at high speed operating conditions. In addition, the coating still has good drag reduction effect under rapid shearing (450 r / min) of high viscosity oil at low temperature (-30°C), indicating that the coating has not failed, verifying the good stability of the coating. Therefore, the drag reduction coating has significant drag reduction advantage at low temperature environment and is suitable for application scenarios that require reduction of oil stirring loss.

[0069] Example 2

[0070] A preparation method of a low-temperature drag reduction coating for improving the efficiency of equipment systems, which is only different from Example 1 in that,

[0071] (5) The low-temperature drag reduction coating prepared in step (3) is uniformly sprayed on the surface of the substrate modified in step (4) using a spray gun; after the acetone is completely volatilized, the disc is rotated by 90° and sprayed again, a total of 5 times, until a uniform and dense coating is formed on the surface. Then it is placed in a UV curing device, the light intensity is set to 100 mW / cm 2 , the curing time is 30 s, and finally the drag reduction coating is obtained.

[0072] Example 3

[0073] A preparation method of a low-temperature drag reduction coating for improving the efficiency of equipment systems, which comprises the following steps:

[0074] (1)-(2) Same as Example 1;

[0075] (3) 1.5 g of 2-perfluoroalkyl ethyl acrylate is added to 5 g of acetone and stirred until uniform, then it is added to solution A, and continues to be stirred until uniform, then 0.6 g of benzophenone photoinitiator is added and continues to be stirred until the photoinitiator is uniformly dispersed, obtaining a low-temperature drag reduction coating.

[0076] (4) Same as Example 1;

[0077] (5) The low-temperature drag reduction coating prepared in step (3) is uniformly sprayed on the surface of the substrate modified in step (4) using a spray gun; after the acetone is completely volatilized, the disc is rotated by 90° and sprayed again, a total of 5 times, until a uniform and dense coating is formed on the surface. Then it is placed in a UV curing device, the light intensity is set to 100 mW / cm 2 , the curing time is 30 s, and finally the drag reduction coating is obtained.

[0078] Example 4

[0079] A method for preparing a low-temperature drag-reducing coating for improving the efficiency of a system of equipment, comprising the following steps:

[0080] (1) Dissolve 0.33 g of silicon dioxide (particle size 20 nm) and 6 g of (3- aminopropyl) triethoxysilane in 10 g of acetone, and perform ultrasonic dispersion for 1 hour using an ultrasonic disperser, and perform magnetic stirring for 48 hours, to ensure that the nanoparticles and the silane coupling agent are fully reacted and modified;

[0081] (2)-(4) Same as Example 1;

[0082] (5) Use a spray gun to uniformly spray the low-temperature drag-reducing coating prepared in step (3) on the surface of the substrate modified in step (4); after observing the volatilization of acetone, rotate the disc by 90° and spray again, a total of 5 times, until a uniform and dense coating is formed on the surface. Then place it in a UV curing device, set the light intensity to 100 mW / cm 2 , and the curing time to 30 s, to finally obtain a drag-reducing coating.

[0083] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for preparing a low-temperature drag-reducing coating for improving the efficiency of an equipment system, characterized in that: The following steps are involved: Applying a low-temperature drag-reducing coating to the surface of the substrate modified with dopamine hydrochloride, and then curing the substrate to obtain the low-temperature drag-reducing coating; Among them, the preparation process of low-temperature drag reducing coating is: The nanoparticles are modified by using a silane coupling agent in an organic solvent, and then a fluorocarbon surfactant, isocyanate, fluorinated acrylate and a photoinitiator are added thereto in sequence, and the mixture is stirred evenly to obtain the low-temperature drag-reducing coating.

2. The method for preparing a low-temperature drag-reducing coating for improving equipment system efficiency according to claim 1, characterized in that: The preparation method specifically comprises the following steps: (1) dissolving the nanoparticles and the silane coupling agent in a first organic solvent, performing ultrasonic dispersion and magnetic stirring to obtain a mixed solution; (2) adding a fluorocarbon surfactant and an isocyanate to the mixed solution of step (1), and continuing ultrasonic dispersion and magnetic stirring to obtain a solution A; (3) dissolving the fluorinated acrylate in a second organic solvent and stirring uniformly to obtain a solution B, uniformly mixing the solution B with the solution A, and then adding a photoinitiator and continuing to stir uniformly to obtain a low-temperature drag-reducing coating; (4) soaking the substrate in an aqueous solution of dopamine hydrochloride to obtain a modified substrate; (5) applying the low-temperature drag-reducing coating to the surface of the modified substrate and curing the coating to obtain the low-temperature drag-reducing coating.

3. The method for preparing a low-temperature drag-reducing coating for improving equipment system efficiency according to claim 2, characterized in that: In step (1), the nanoparticles include at least one of copper oxide, zinc oxide, silicon dioxide, and titanium dioxide; The silane coupling agent includes at least one of 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyl-dimethoxysilane, and 3-aminopropyltrimethoxysilane.

4. The method for preparing a low-temperature drag-reducing coating for improving equipment system efficiency according to claim 2, characterized in that: In step (1), the mass ratio of the first organic solvent to the nanoparticles is (20-40):1; The mass ratio of the first organic solvent to the silane coupling agent is (2-10):

1.

5. The method for preparing a low-temperature drag-reducing coating for improving equipment system efficiency according to claim 2, characterized in that: The mass ratio of the first organic solvent in step (1) to the fluorocarbon surfactant in step (2) is (1.5-2.5):1; The mass ratio of the first organic solvent in step (1) to the isocyanate in step (2) is (500-2000):

1.

6. The method for preparing a low-temperature drag-reducing coating for improving equipment system efficiency according to claim 2, characterized in that: In step (3), the mass concentration of the fluorinated acrylate in the solution B is 10%-50%; The mass ratio of solution B to solution A is 1:(1-5); The photoinitiator accounts for 1wt%-3wt% of the low-temperature drag-reducing coating.

7. The method for preparing a low-temperature drag-reducing coating for improving equipment system efficiency according to claim 2, characterized in that: The concentration of the dopamine hydrochloride aqueous solution is 0.5-10 mg / mL.

8. The method for preparing a low-temperature drag-reducing coating for improving equipment system efficiency according to claim 2, characterized in that: The soaking time in the soaking process in step (4) is 1-10 hours; In step (5), the number of coatings is 2-10 times; The UV intensity during the curing process is 100-300mW / cm 2 , curing time is 10-50s.

9. A low-temperature drag-reducing coating for improving the efficiency of equipment systems, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the low-temperature drag-reducing coating for improving equipment system efficiency as claimed in claim 9 in oil-stirring lubrication transmission components.

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