Oleophobic coating, oleophobic coating layer and use thereof

Abstract

This invention specifically relates to an oleophobic coating, an oleophobic coating layer, and their applications. The oleophobic coating comprises component A and component B; component A is formed by dispersing fillers in a matrix, the fillers including a composite filler composed of titanium dioxide particles and copper hydroxide particles; the matrix includes a binder and a solvent; the mass ratio of filler to binder is (2-5):10; the volume percentage of binder in the matrix is ​​20-40%; component B is a curing agent. This coating exhibits good oleophobic properties, is suitable for the high water-content atmosphere of oil well produced fluids, and is easy to mass-produce and industrialize.

Description

Technical Field

[0001] This invention relates to the field of oil and gas field surface engineering technology, specifically to an oleophobic coating, an oleophobic coating layer and its application. Background Technology

[0002] In recent years, significant progress has been made in the unheated oil gathering of high water-cut oil wells. Over 100,000 oil wells have adopted single-pipe unheated gathering. The critical wall adhesion temperature has been widely accepted as a replacement for the pour point as the temperature boundary condition for gathering and transporting high water-cut, waxy crude oil. The gathering and transport temperature has decreased from 3-5°C above the traditional pour point to 5-10°C below, greatly reducing the energy consumption of the gathering and transport system. However, the large presence of oil clumps at low temperatures worsens the fluidity of the produced medium, and the increased adhesion of these clumps to gathering and transport pipelines and equipment components negatively impacts the dehydration process after the produced fluid enters the station. Preheating the produced fluid before it enters the station can alleviate this problem, but this method is complex and requires a large amount of energy to heat the aqueous phase. These issues hinder the widespread and in-depth promotion of low-temperature gathering and transport. Oleophobic coatings are a type of superwetting material. By using functional oleophobic coatings to coat the substrate, the adhesion of oil clumps to production facilities can be reduced, and the resistance of produced fluid collection and transportation can be reduced. This is expected to solve the above problems and ensure the smooth operation of cryogenic collection, transportation and treatment. Moreover, oleophobic functional coatings have become a highly regarded approach because they do not require additional energy input, do not require complex equipment, and are easy to maintain.

[0003] Currently, the anti-oil adhesion properties of oleophobic coatings have been preliminarily explored, and the superwetting surfaces intended for oleophobic use are mostly oleophobic surfaces in air environments. According to Young's model theory, the surface energy of a solid must be less than or equal to 1 / 4 of the surface tension of the liquid to achieve intrinsic hydrophobicity. However, most organic liquids have very low surface tensions (mostly ranging from 20 to 40 mN / m), making suitable coating materials even scarcer. Among various materials, fluorinated polymers have the lowest surface tension, as low as around 20 mN / m. Therefore, fluorides are currently often used as low-surface-energy coatings for modification. However, commercially available fluorinated polymers, such as polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), and perfluoropropylene (PFNP), are expensive, significantly limiting the widespread adoption of oleophobic coatings. Furthermore, fluorinated substances gradually decompose within the coating or are lost under external forces. For example, the shear friction generated during the pressurized shear flow of produced media on the coating surface causes the loss of surface fluorinated substances, weakening the oleophobic effect. In addition, the biotoxicity and environmental pollution associated with fluorinated substances also hinder their widespread application. Therefore, the oleophobic coatings currently used in the air environment still have problems such as insufficient adhesion to the substrate, poor wear resistance of the coating itself, low mechanical / chemical stability, and short service life.

[0004] Oil well produced fluid gathering and processing involves typical multiphase flow processes. If oleophobic coatings are used to coat the gathering pipelines and in-station processing equipment, the complex and variable service environment of the coatings presents a significant challenge to the development of adaptable oleophobic coatings. Furthermore, the uncertainties in the physicochemical properties of crude oil itself, such as viscosity, pour point, chemical composition, and pH value, further complicate coating performance and lifespan. More seriously, most major oilfields have now entered a high water-cut stage, and the flow and physical properties of the produced fluids have changed significantly. Existing fluorinated modified oleophobic coatings for air environments are no longer suitable for high water-cut conditions. Therefore, developing hydrophilically modified oleophobic coatings for high water-cut conditions to meet the oleophobic requirements of produced fluids under these conditions is an urgent technical problem to be solved. Summary of the Invention

[0005] This invention provides an oleophobic coating that has good oleophobic effect, is suitable for the high water content atmosphere of oil well produced fluid, has low preparation cost, and is easy to mass-produce and industrialize.

[0006] This invention provides an oleophobic coating with good oleophobic effect.

[0007] The present invention also provides an oil and gas equipment for high water content and low temperature gathering and transportation processing conditions. This equipment can effectively reduce the adhesion of oil clumps to the equipment and reduce the resistance of produced fluid gathering and transportation.

[0008] The present invention achieves the above-mentioned technical objectives through the following technical solutions:

[0009] An oleophobic coating, characterized in that it comprises component A and component B;

[0010] Component A is formed by dispersing fillers in a matrix, including composite fillers composed of titanium dioxide particles and copper hydroxide particles; the matrix includes binders and solvents; the mass ratio of fillers to binders is (2-5):10; the volume percentage of binders in the matrix is ​​20-40%.

[0011] Component B is the curing agent.

[0012] In the oleophobic coatings described above, some or all of the copper hydroxide particles in the composite filler are located on the outer surface of the titanium dioxide particles.

[0013] The oleophobic coating described above uses a composite filler obtained by reacting divalent copper salt in a solution containing titanium dioxide particles under alkaline conditions.

[0014] Furthermore, the solution also contains hexamethylenetetramine.

[0015] Furthermore, the molar ratio of hexamethylenetetramine to divalent copper ions is (0.8–0.9):1.

[0016] The oleophobic coating described above requires an alkaline pH between 9 and 12, a reaction temperature of 70-90℃, and a stirring speed of 300-430 rpm during the reaction.

[0017] The oleophobic coating described above has a titanium dioxide particle size of 90-110 nm, a molar ratio of titanium dioxide particles to divalent copper ions in the solution of (3-10):1, and a reaction time of 18-22 min.

[0018] The oleophobic coating described above uses a combination of acrylic resin and polyurethane as the binder.

[0019] The solvent for the oleophobic coating described above is one or a combination of water, ethyl acetate, chloroform, and n-hexane.

[0020] The oleophobic coating described above uses a curing agent that is one or a combination of isocyanate, dimethylethylenediimide, and cyclohexanediamine.

[0021] The oleophobic coating described above uses acrylic resin and polyurethane as binders in a volume ratio of (54-70):(40-60) and isocyanate as a curing agent.

[0022] The present invention also provides an oleophobic coating, which is formed by applying the above-mentioned oleophobic coating onto a substrate, wherein component A and component B are compounded in a ratio of 5:(2-3).

[0023] The present invention also provides an oil and gas equipment for high water content and low temperature gathering and transportation processing, wherein at least the side in contact with crude oil has the above-mentioned oleophobic coating.

[0024] This invention utilizes a copper hydroxide-titanium dioxide composite filler, which forms a rough structure through particles and the gaps between particles. This rough structure enhances the binding with water, forming a water film at the contact surface, improving the hydrophilicity and oleophobicity of the coating. Furthermore, the water film has strong resistance to disturbance, making the coating more suitable for collection and drainage processing conditions.

[0025] The oleophobic coating provided by this invention is formed by coating with the above-mentioned paint, and has a good oleophobic effect.

[0026] The present invention provides an oil and gas equipment for high water content and low temperature gathering and transportation conditions. This equipment can effectively reduce the adhesion of oil clumps to production facilities and reduce the resistance of produced fluid gathering and transportation. Attached Figure Description

[0027] Figure 1 This is a SEM image of the titanium dioxide particles prepared in Example 1;

[0028] Figure 2 This is an example of the oil droplet contact angle test results for a substrate coated with the coating in Example 1;

[0029] Figure 3 This is an example of the droplet roll-off angle test results for a substrate coated with the coating in Example 1;

[0030] Figure 4 Example of oil droplet contact angle test results for a substrate coated with the fluoride-containing coating in Comparative Example 1;

[0031] Figure 5 A system for simulating the adhesion of oleophobic properties in a stirred tank. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0033] This invention provides an oleophobic coating comprising component A and component B:

[0034] Component A is formed by dispersing fillers in a matrix, including composite fillers composed of titanium dioxide particles and copper hydroxide particles; the matrix includes binders and solvents; the mass ratio of fillers to binders is (2-5):10; the volume percentage of binders in the matrix is ​​20-40%;

[0035] Component B is the curing agent.

[0036] This invention employs a copper hydroxide-titanium dioxide composite filler. This filler can form a rough structure through particles and the gaps between particles. This rough structure strengthens the binding of hydroxyl groups with water, forming a water film at the contact surface, improving the hydrophilicity and oleophobicity of the coating. Furthermore, the water film has strong resistance to disturbance, making the coating more suitable for collection and dissipation processes. In addition, the filler-to-matrix ratio not only affects the final coating's mechanical strength but also its apparent chemical composition and morphology. When the filler content is too low, the cross-linking between the coating matrix is ​​tighter, resulting in higher mechanical stability, but it is less likely to form a layered rough structure, and the filler is more easily embedded in the matrix, reducing the content of hydrophilic groups on the outermost layer of the coating. When the filler content is too high, it is easier to form a layered structure exposing hydrophilic groups, but the microstructure is more fragile, and the coating's stability is worse. Studies have found that when the mass ratio of composite filler (precipitated particles) to matrix is ​​(2-5):10 and the volume percentage of binder in the matrix is ​​20-40%, the overall performance of the coating is better. When the mass ratio of composite filler (precipitated particles) to matrix is ​​(3-4):10 and the volume percentage of binder in the matrix is ​​25-35%, the performance is even better.

[0037] Furthermore, the hydrophilic and oleophobic effects are even better when some or all of the copper hydroxide particles in the composite filler are located on the outer surface of the titanium dioxide particles. This is because copper hydroxide particles contain hydrophilic hydroxyl groups. Placing the copper hydroxide particles on the outside ensures that the hydrophilic hydroxyl groups are exposed as much as possible, thus enhancing the hydrophilic and oleophobic effect.

[0038] There are no restrictions on the method for achieving copper hydroxide on the surface of titanium dioxide. It can be achieved by generating the two types of particles separately and then coating them, or by using the method in this application, which is to prepare copper hydroxide under alkaline conditions in a solution in which divalent copper salt is present in titanium dioxide particles, thereby ensuring that copper hydroxide grows on the surface of titanium dioxide.

[0039] In some specific embodiments, when preparing the titanium dioxide particles using a solution containing divalent copper salts, hexamethylenetetramine can also be added to the solution. Hexamethylenetetramine has a special spatial configuration and the polarity of quaternary ammonium salts, exhibiting strong dissociation and complexation capabilities. It can react with alkali to form intermediates, which then gradually release hydroxide ions in the solution, providing a mild and continuous alkaline environment. This slowly released hydroxide ions gradually induce the precipitation of copper ions, forming nanoscale copper hydroxide particles. This control mechanism reduces the rapid aggregation and irregular growth of copper hydroxide crystal chains, promoting the formation of uniform and regular particles at the microscale, thereby further optimizing their adhesion and distribution on the titanium dioxide surface and ensuring better oleophobic effects.

[0040] When the molar ratio of hexamethylenetetramine to divalent copper ions (Cu2+) is controlled at (0.8–0.9):1, the resulting filler exhibits superior hydrophilic and oleophobic properties. This is because under this ratio, the release rate of hydroxide ions in the solution is moderate, enabling the formation of a regular copper hydroxide structure and preventing disordered precipitation caused by excessive hydroxide ions. In other words, a reasonable molar ratio can balance the stability of the reaction and regulate the surface characteristics of the generated particles. For example, controlling the surface structure and porosity of the generated particles allows the filler particles to possess suitable specific surface area and surface energy. A regular particle structure enhances the hydrophilicity of its surface while reducing the tendency for oil phase adhesion, thus achieving a superior hydrophilic and oleophobic effect.

[0041] Further research has found that when the alkaline conditions are controlled at a pH between 9 and 12, the reaction temperature at 70-90℃, and the stirring speed at 300-430 rpm, the particle size of copper hydroxide can be guaranteed to be between 30-40 nm, resulting in better hydrophilic and oleophobic effects of the coating.

[0042] When the particle size of titanium dioxide is 90-110 nm, the molar ratio of titanium dioxide particles to divalent copper ions in the solution is (3-10):1, and the reaction time is 18-22 min, it can better ensure that the copper hydroxide particles are better and more uniformly dispersed on the surface of the titanium dioxide particles, the hydroxyl groups are best exposed, the hydrophilic and oleophobic effects of the coating are better, and the overall quality of the coating is better.

[0043] In some specific embodiments, when preparing the solution by means of divalent copper salt in the presence of titanium dioxide particles, when adding titanium dioxide particles to the divalent copper salt solution, the temperature is first maintained at 25-35℃ and stirred at 300-430 rpm for 20-23 minutes to ensure that the titanium dioxide particles can be uniformly dispersed before the formation of copper hydroxide.

[0044] In this invention, the choice of divalent copper salt is not limited; for example, copper nitrate, copper sulfate, and copper chloride can be selected. In some specific embodiments, copper nitrate is used as the divalent copper salt.

[0045] In some specific embodiments, hexamethylenetetramine is added to the mixed solution in solution form, wherein the concentration of the hexamethylenetetramine solution is 10-31 mmol / L. Adding it in solution form ensures that it can be rapidly and uniformly dispersed in the reaction system.

[0046] In some specific embodiments, titanium dioxide particles are uniformly dispersed in ethanol to form a titanium dioxide dispersion system. This dispersion system is then added to a divalent copper salt solution to obtain a mixed solution containing spherical titanium dioxide particles and divalent copper salt. The addition of titanium dioxide as a solution ensures rapid and uniform dispersion in the reaction system. The mass concentration of the titanium dioxide dispersion system is 1-30%, and the concentration of copper ions in the divalent copper salt solution is 17-25 mmol / L.

[0047] Taking copper nitrate as an example, in some specific embodiments, the preparation of the copper hydroxide-titanium dioxide composite filler can be detailed as follows: Solid copper nitrate is dissolved in water in a beaker to prepare a 17-25 mmol / L copper nitrate solution; solid hexamethylenetetramine is dissolved in water in a beaker to prepare a 10-31 mmol / L hexamethylenetetramine solution; solid sodium hydroxide is dissolved in water in a beaker to prepare a 9-27 mmol / L sodium hydroxide solution. Under controlled temperature and continuous magnetic stirring conditions (stirring speed controlled at 300-430 r / min, temperature maintained at 25-35℃), the prepared titanium dioxide filler dispersion system solution is added to the copper nitrate solution, and stirring is maintained for 20-23 min. Continuing to maintain magnetic stirring, the prepared hexamethylenetetramine solution is added, and magnetic stirring is maintained for 14-15 min. The prepared sodium hydroxide solution is then added to maintain the entire reaction system at pH 9-12, and stirring is maintained at 70-90℃ for 18-22 min. The obtained precipitate was filtered, the sample was collected and fully granulated, washed several times with distilled water and anhydrous alcohol, and dried at room temperature in an atmosphere to obtain copper hydroxide-titanium dioxide composite filler for later use (copper hydroxide particle size is about 30-40 nm, and titanium dioxide particle size is about 90-110 nm).

[0048] It should be noted that titanium dioxide particles can be purchased or prepared at home. In some specific embodiments, titanium dioxide particles are obtained by reacting tetrabutyl titanate with ammonia. Specifically, ammonia is added to a prepared tetrabutyl titanate solution to react and generate titanium dioxide precipitate, which is then filtered to obtain spherical titanium dioxide particles. A more specific method is as follows: 10-15g of liquid tetrabutyl titanate is dissolved in 230-270mL of ethanol to obtain a tetrabutyl titanate solution. Ammonia is added to the prepared tetrabutyl titanate solution to adjust the pH to 8-11, generating titanium dioxide precipitate, which is then filtered to obtain spherical titanium dioxide particles with a particle size of approximately 90-110nm. The generated titanium dioxide is dispersed in 470mL of ethanol and stirred until uniformly dispersed (stirring speed controlled at 450-700r / min, stirring time 17-25min) to form a titanium dioxide filler dispersion system.

[0049] In addition, to ensure that the filler is evenly distributed in the matrix, a long-term ultrasonic treatment method can be used, such as using an ultrasonic power of 200-500W and an ultrasonic duration of 20-40 minutes.

[0050] There are no strict restrictions on the choice of binder. Commonly used binders in coatings can be used, such as one or more combinations of acrylic resin, polyurethane, epoxy resin, carbon-based resin, phenolic resin, alkyd resin, and polyester resin. Furthermore, the coating performance is better when the binder is a combination of acrylic resin and polyurethane. For example, acrylic resin and polyurethane can be blended, ensuring a volume ratio of (54-70):(40-60) as the binder.

[0051] The solvent in the matrix can be any conventional solvent in the art, such as water, or organic solvents such as ethyl acetate, chloroform, or n-hexane. For example, in some specific embodiments, the matrix can be prepared by dissolving 54-70 mL of acrylic resin liquid in 137-160 mL of ethyl acetate and dissolving 40-60 mL of polyurethane liquid in 90-110 mL of ethyl acetate to prepare matrix solutions. The prepared acrylic resin and polyurethane solutions are mixed and stirred thoroughly (stirring speed of 600-700 r / min is recommended) to obtain a mixed matrix solution.

[0052] The curing agent can also be any conventional curing agent in the field, such as a combination of one or more of isocyanates, dimethylethylenediimide, and cyclohexanediamine. Specifically, when using epoxy resin or acrylic resin as the binder, amine or anhydride curing agents can be selected to enhance chemical properties; when using a combination of polyurethane or acrylic resin, isocyanate curing agents are preferred, as they can affect the surface energy and microstructure of the coating, thereby improving oleophobic properties and adhesion.

[0053] The present invention also provides an oleophobic coating, which is formed by applying the above-mentioned oleophobic coating onto a substrate, wherein component A and component B are compounded in a ratio of 5:(2-3).

[0054] This invention also provides an oil and gas equipment for high water content and low temperature gathering and transportation operations, wherein at least the side in contact with crude oil has the aforementioned oleophobic coating. This equipment can effectively reduce the adhesion of oil clumps to the equipment and reduce the resistance to produced fluid gathering and transportation.

[0055] The present invention will now be described in detail with reference to specific embodiments.

[0056] Example 1

[0057] Packing material preparation: Dissolve 12g of tetrabutyl titanate liquid in 250mL of ethanol to obtain a tetrabutyl titanate liquid solution. Add ammonia to the prepared tetrabutyl titanate solution to adjust the pH to 9-10. Filter to obtain titanium dioxide packing particles (particle size measured to be approximately 95nm, as shown in the scanning electron microscope results). Figure 1 (As shown). The titanium dioxide-ethanol dispersion system was dispersed in 470 mL of ethanol by stirring at 470 r / min for 20 min.

[0058] Add 340 mL of 19 mmol / L copper nitrate solution to the titanium dioxide-ethanol dispersion system (controlling the molar ratio of titanium dioxide to divalent copper ions in the solution to 5:1), stir at 320 r / min for 22 min, then add 280 mL of 20 mmol / L hexamethylenetetramine solution and maintain magnetic stirring for 15 min. Add 10 mmol / L sodium hydroxide solution, and maintain the entire reaction system at pH = 11, temperature 75℃, and stirring speed 320-330 rpm for 18 min. Filter, wash, and dry the resulting precipitate to obtain copper hydroxide-titanium dioxide composite filler (copper hydroxide particle size approximately 37 nm).

[0059] Matrix preparation: Dissolve 60 mL of chlorinated acrylic resin liquid (brand name: CMPP-3108) in 140 mL of ethyl acetate, and dissolve 50 mL of polyurethane liquid (purchased from Shenzhen Yoshida Company, brand name F0401) in 100 mL of ethyl acetate. Mix the two solutions and stir at 650 r / min to obtain a mixed matrix solution.

[0060] Component A: The filler and matrix are controlled with a filler particle to binder mass ratio of 3:10. The ultrasonic power is controlled at 300W and the ultrasonic dispersion is carried out for 22 minutes. The filler is uniformly dispersed in the coating to form Component A.

[0061] Component B: Phenyl-toluene diisocyanate (brand name: TDI 80).

[0062] Coating application: Component A and Component B are physically blended in a mass ratio of 5:2 and then sprayed onto the surface of the steel plate.

[0063] Example 2

[0064] Packing material preparation: Dissolve 13g of tetrabutyl titanate liquid in 250mL of ethanol to obtain a tetrabutyl titanate liquid solution. Add ammonia to the prepared tetrabutyl titanate solution to adjust the pH to 10-11, and filter to obtain titanium dioxide packing particles (particle size measured to be approximately 95nm). Stir at 470r / min for 20min to disperse the particles in 500mL of ethanol to obtain a titanium dioxide-ethanol dispersion system.

[0065] Add 390 mL of 22 mmol / L copper nitrate solution (controlling the molar ratio of titanium dioxide to divalent copper ions in the solution to 6:1) to the titanium dioxide-ethanol dispersion system, and stir at 320 r / min for 22 min. Then, add 420 mL of 18 mmol / L hexamethylenetetramine solution and maintain magnetic stirring for 15 min. Add 21 mmol / L sodium hydroxide solution, and maintain the entire reaction system at pH = 11, temperature 80℃, and stirring speed 400-410 rpm for 20 min. Filter, wash, and dry the resulting precipitate to obtain copper hydroxide-titanium dioxide composite filler (copper hydroxide particle size approximately 33 nm).

[0066] Matrix preparation: Dissolve 55 mL of chlorinated acrylic resin liquid (brand name: CMPP-3108) in 155 mL of water, and dissolve 40 mL of polyurethane liquid (purchased from Shenzhen Yoshida Company, brand name F0401) in 94 mL of water. Mix the two solutions and stir at a stirring speed of 630 r / min to obtain a mixed matrix solution.

[0067] Component A: The filler and matrix are controlled with a filler particle to binder mass ratio of 2:5. The ultrasonic power is controlled at 300W and the ultrasonic dispersion is carried out for 23 minutes. The filler is uniformly dispersed in the coating to form Component A.

[0068] Component B: Phenyl-toluene diisocyanate (brand name: TDI 80).

[0069] Coating application: Component A and Component B are physically blended in a mass ratio of 5:3 and then sprayed onto the surface of the steel plate.

[0070] Example 3

[0071] The difference between this embodiment and Embodiment 1 is that the matrix uses only chlorinated acrylic resin liquid (brand name: CMPP-3108), that is, polyurethane is replaced with acrylic resin.

[0072] Example 4

[0073] The difference between this embodiment and Embodiment 1 is that, in the matrix preparation, epoxy resin (purchased from Dow Chemical Company, model: DER331) is used instead of acrylic resin, that is, the matrix is ​​a combination of epoxy resin and polyurethane.

[0074] Example 5

[0075] The difference between this embodiment and Example 1 is that component B is dimethylethylenediimide.

[0076] Example 6

[0077] The difference between this embodiment and Embodiment 1 is that the titanium dioxide particles are commercially available products with a particle size of 95-100 nm, purchased from Alfa Aesar.

[0078] Example 7

[0079] The difference between this embodiment and Embodiment 1 is that the titanium dioxide particles were purchased with a particle size of 60-65 nm (purchased from Alfa Aesar).

[0080] Comparative Example 1

[0081] A coating is formed by dissolving commercially available fluorinated polyhexafluoropropylene (French Arcoma polyvinylidene fluoride hexafluoropropylene copolymer, molecular weight 300,000) in NMP (N-methylpyrrolidone).

[0082] Performance testing:

[0083] The coatings obtained in the examples and comparative examples were sprayed onto the surface of a steel plate (coating thickness 150±50 μm). A substrate without coating was used as a control. The macroscopic oil contact angle of the coating to the solidified oil in an aqueous environment was measured using a contact angle meter. The overall water content of the test system was 80%, representing a high water content state, and the oil's pour point was 26°C. The adhesion force between the liquid and the surface was measured using a high-precision microelectromechanical balance system, and the bonding strength between the coating and the substrate was determined using the cross-cut adhesion test. Figure 5 The self-made stirred tank shown simulates oil droplet adhesion under shear conditions (rotation speed 300 r / min, temperature 21℃). The temperature is below the oil's pour point, and the results are as follows. Figure 2-4 As shown in Table 1, the data is as follows.

[0084] Table 1

[0085]

[0086]

[0087] The results above show that the coating prepared using the coating described in this invention exhibits excellent hydrophilic and oleophobic properties in an aqueous environment, and demonstrates high bonding strength with the substrate. Specifically, the oil contact angle in an aqueous environment can reach over 140°, the roll-off angle can reach below 14°, the adhesion force can reach below 30 mN, and the bonding strength with the substrate can withstand over 440 peel cycles.

[0088] When the particle size of titanium dioxide is further controlled to be 90-110nm and the particle size of copper hydroxide is between 30-40nm, the coating prepared by the coating can achieve an oil contact angle of more than 150° in an aqueous environment (meeting the standard of superoleophobicity), a roll-off angle of less than 13°, an adhesion force of less than 25mN, and a bonding strength with the substrate and a peel cycle count of more than 450 times.

[0089] When acrylic resin and polyurethane are further selected as binders and isocyanate is selected as curing agents, the resulting coating can achieve an oil contact angle of over 160° in an aqueous environment (meeting the superoleophobic standard), a roll-off angle of less than 8.5°, an adhesion force of less than 20mN, and a bonding strength with the substrate with a peel cycle of over 460 cycles.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An oleophobic coating, characterized in that, Includes component A and component B; Component A is formed by dispersing fillers in a matrix, including composite fillers composed of titanium dioxide particles and copper hydroxide particles; the matrix includes binders and solvents; the mass ratio of fillers to binders is (2-5):10; the volume percentage of binders in the matrix is ​​20-40%; Component B is the curing agent.

2. The oleophobic coating according to claim 1, characterized in that, In the composite filler, some or all of the copper hydroxide particles are located on the outer surface of the titanium dioxide particles.

3. The oleophobic coating according to claim 1 or 2, characterized in that, The composite filler is obtained by reacting divalent copper salt in a solution containing titanium dioxide particles under alkaline conditions.

4. The oleophobic coating according to claim 3, characterized in that, The solution also contains hexamethylenetetramine; and / or The molar ratio of hexamethylenetetramine to divalent copper ions is (0.8-0.9):

1.

5. The oleophobic coating according to claim 4, characterized in that, The alkaline conditions are a pH between 9 and 12, a reaction temperature of 70-90℃, and a stirring speed of 300-430 rpm during the reaction.

6. The oleophobic coating according to claim 5, characterized in that, The titanium dioxide particles have a diameter of 90-110 nm, the molar ratio of titanium dioxide to divalent copper ions in the solution is (3-10):1, and the reaction time is 18-22 min.

7. The oleophobic coating according to claim 1 or 2, characterized in that, The adhesive is a combination of acrylic resin and polyurethane; and / or The solvent is one or more of water, ethyl acetate, chloroform, and n-hexane; and / or The curing agent is one or a combination of isocyanate, dimethylethylenediimide, and cyclohexanediamine.

8. The oleophobic coating according to claim 7, characterized in that, The adhesive is acrylic resin and polyurethane in a volume ratio of (54-70):(40-60), and the curing agent is isocyanate.

9. An oleophobic coating, characterized in that, The oleophobic coating is formed by applying the oleophobic coating according to any one of claims 1-8 onto a substrate, wherein component A and component B are compounded in a ratio of 5:(2-3).

10. An oil and gas gathering and transportation system for high water content and low temperature processing conditions, characterized in that, At least the side that comes into contact with crude oil has the oleophobic coating as described in claim 9.

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