Anti-condensation graphene anti-corrosion coatings, their preparation methods and applications

Abstract

This invention relates to the field of corrosion protection, specifically to a condensation-resistant graphene anti-corrosion coating, its preparation method, and its application. The coating comprises component A and component B: by weight, component A includes 5-50 parts of tetrafunctional epoxy resin, 30-65 parts of filler, 3-25 parts of dispersant, and 5-50 parts of solvent; by weight, component B includes 0.5-5 parts of phenol-modified graphene, 20-60 parts of curing agent, and 20-80 parts of solvent; the mass ratio of component A to component B is 2-10:1; the phenol-modified graphene includes graphene oxide and phenolic substances formed on the graphene oxide. The condensation-resistant graphene anti-corrosion coating of this invention can be applied in high humidity environments, exhibits good brushing performance under high humidity conditions, and has a simple application process; the formed coating has advantages such as high density, high cross-linking density, good chemical corrosion resistance under condensation conditions, and high adhesion.

Description

Technical Field

[0001] This invention relates to the field of corrosion protection, specifically to a graphene anti-corrosion coating resistant to condensation, its preparation method, and its application. Background Technology

[0002] The unique geographical location of coastal oil storage facilities and pipelines makes their outer surfaces highly susceptible to condensation. Long-term immersion of the pipeline coating in condensation, along with dissolved acids, alkalis, and organic matter, weakens the coating's adhesion, ultimately leading to aging and failure. This compromises the safe operation of metal structures and pipeline equipment. Currently, there are three main methods for preventing condensation: controlling relative humidity, controlling absolute humidity, and applying a surface coating. Among these, applying a coating offers advantages such as simplicity and versatility compared to the other two methods. This involves applying an anti-condensation coating to surfaces prone to condensation. Commonly used coatings include those with some moisture absorption capacity and hydrophobic surfaces. Moisture-absorbing coatings primarily work by applying moisture-absorbing and releasing materials to the surface of objects prone to condensation, thus delaying condensation. However, their moisture absorption capacity is limited and they cannot be used repeatedly. Hydrophobic surface coatings, which increase the contact angle between the material surface and water, allow water droplets to detach from the coating surface under gravity, thereby preventing condensation. Current hydrophobic surface coatings mainly use fluorocarbon resins as the primary resin, and in practical applications, their hydrophobic angle generally only reaches around 90°, resulting in poor anti-condensation effects. Therefore, it is essential to develop a coating with better anti-condensation performance.

[0003] To address the aforementioned issues, dehumidification and anti-condensation measures for equipment and pipelines are crucial. Existing anti-condensation corrosion technologies primarily focus on increasing the contact angle of water on the coating surface to create a superhydrophobic surface that prevents condensation adsorption and deposition, thereby enhancing the anti-condensation corrosion capability of pipeline metal. CN118085691A discloses an anti-condensation coating and coating method that involves fluorinating epoxy resin and introducing hydrophobic nanoparticles. The fluorinated epoxy resin binds the hydrophobic nanoparticles, increasing the contact angle of the coating to over 160°, thus improving the hydrophobic effect. However, the resin coating uses a two-layer approach of primer and topcoat, resulting in a complex construction process. Furthermore, if the topcoat fails, the entire anti-condensation effect of the coating will be lost. Summary of the Invention

[0004] To overcome the technical problem of poor anti-condensation effect of existing anti-corrosion coatings, this invention provides a condensation-resistant graphene anti-corrosion coating, its preparation method, and its application. The coating formed by the condensation-resistant graphene anti-corrosion coating of this invention has advantages such as strong density, high cross-linking density, high adhesion, and large water contact angle.

[0005] To achieve the above objectives, a first aspect of the present invention provides a graphene-based anti-condensation coating, comprising component A and component B: By weight, component A comprises: 5-50 parts of tetrafunctional epoxy resin, 30-65 parts of filler, 3-25 parts of dispersant, and 5-50 parts of solvent; By weight, component B includes: 0.5-5 parts of phenol-modified graphene, 20-60 parts of curing agent, and 20-80 parts of solvent; The mass ratio of component A to component B is 2-10:1; the phenol-modified graphene includes graphene oxide and phenolic substances formed on the graphene oxide.

[0006] In the phenol-modified graphene of the present invention, phenolic substances are formed on graphene oxide through interactions (van der Waals forces, electrostatic interactions, and hydrogen bonding), for example, adsorbed on graphene oxide through interactions (van der Waals forces, electrostatic interactions, and hydrogen bonding).

[0007] According to a preferred embodiment of the present invention, in the phenol-modified graphene, the phenolic substances are selected from one or more of phenol, aminophenol, methylphenol and tea polyphenols, preferably one or more of m-aminophenol, p-aminophenol, phenaminophenol, p-cresol, m-cresol, phencresol, tea polyphenols and phenol.

[0008] In this invention, the mass content of phenolic substances in phenol-modified graphene can be selected from a wide range. According to a preferred embodiment of this invention, the mass content of phenolic substances in the phenol-modified graphene is 2wt%-8wt%.

[0009] In this invention, the carbon content in the phenol-modified graphene has a wide range of selectable values. According to a preferred embodiment of this invention, the carbon content in the phenol-modified graphene is 35wt%-60wt%.

[0010] In this invention, the particle size of phenol-modified graphene can be selected over a wide range. According to a preferred embodiment of this invention, the particle size of phenol-modified graphene is 5μm-15μm, for example, 6μm, 8μm, 10μm, 12μm, and 14μm. This invention extends the diffusion path of corrosive agents by introducing phenol-modified graphene, thereby improving the durability of coatings under long-term immersion in liquid and solving the technical problem that traditional liquid coatings are not resistant to chemical corrosion under condensation immersion.

[0011] In this invention, phenolic substances are formed on graphene oxide through van der Waals forces, electrostatic interactions, and hydrogen bonding. There are no particular limitations on the preparation method of the phenol-modified graphene. According to one embodiment of this invention, a method for preparing the phenol-modified graphene is provided, comprising: ultrasonically treating phenolic substances and graphene oxide in the presence of a solvent, followed by washing and drying to obtain phenol-modified graphene.

[0012] According to a preferred embodiment of the present invention, the carboxyl content on the graphene oxide is 3-10%.

[0013] According to a preferred embodiment of the present invention, the graphene oxide content is 0.2-2 wt% of the solvent.

[0014] According to a preferred embodiment of the present invention, the mass ratio of phenolic substances to graphene oxide is 15-30:1.

[0015] According to a preferred embodiment of the present invention, the solvent is selected from one or more of water, ethanol and methanol.

[0016] In this invention, the range of phenolic substances that can be selected is relatively wide. According to a preferred embodiment of this invention, the phenolic substances are selected from one or more of phenol, aminophenol, methylphenol and tea polyphenols, preferably one or more of m-aminophenol, p-aminophenol, phenaminophenol, p-methylphenol, m-methylphenol, phenmethylphenol, tea polyphenols and phenols.

[0017] According to a preferred embodiment of the present invention, the tetrafunctional epoxy resin in component A of the anti-condensation and anti-corrosion coating is 10-40 parts by weight.

[0018] According to a preferred embodiment of the present invention, the filler content in component A of the anti-condensation and anti-corrosion coating is 35-55 parts by weight.

[0019] According to a preferred embodiment of the present invention, the dispersant in component A of the anti-condensation and anti-corrosion coating is 5-20 parts by weight.

[0020] According to a preferred embodiment of the present invention, the phenol-modified graphene in component B of the anti-condensation and anti-corrosion coating is 1-3 parts by weight.

[0021] According to a preferred embodiment of the present invention, the curing agent in component B of the anti-condensation and anti-corrosion coating is 40-55 parts by weight.

[0022] In this invention, the content of components A and B in the anti-condensation and anti-corrosion coating can be selected within a wide range. This is an illustrative example, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the mass ratio of component A to component B is 3-8:1.

[0023] In this invention, the epoxy value of the tetrafunctional epoxy resin can be selected from a wide range. According to a preferred embodiment of this invention, the epoxy value is 0.65-0.95.

[0024] In this invention, the tetrafunctional epoxy resin is selected from tetraglycidylamine type epoxy resin, and according to a preferred embodiment of the invention, it is selected from tetrafunctional epoxy resin having the structural formula shown in formula (1). Equation (1).

[0025] In this invention, in formula (1), R1 is selected from NH, O, and C1-C5 alkylene groups.

[0026] In this invention, the range of types of R2, R3, R4 and R5 in formula (1) is relatively wide. According to a preferred embodiment of this invention, R2, R3, R4 and R5 are each independently selected from H, C1-C6 alkyl groups, and more preferably from H, methyl or ethyl groups.

[0027] In this invention, the alkylene group is a straight-chain alkylene group, and the alkyl group is a straight-chain or branched alkyl group.

[0028] According to a preferred embodiment of the present invention, the tetrafunctional epoxy resin is selected from one or more of N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenyl ether, N,N,N',N'-tetraglycidyl-3,3'-diethyl-4,4'-diaminodiphenylmethane, N,N,N',N'-tetraglycidyl-3,3'-dimethyl-4,4'-diaminodiphenylmethane, and N,N,N',N'-tetraglycidyl-3,3',5,5'-tetramethyl-4,4'-diaminodiphenylmethane.

[0029] According to a preferred embodiment of the present invention, the curing agent is selected from cashew phenol modified curing agents.

[0030] In this invention, the hydrogen equivalent of the cashew phenol modified curing agent can be selected from a wide range, which is illustrative but does not limit the scope of the invention. According to a preferred embodiment of the invention, the hydrogen equivalent is 100-300.

[0031] In this invention, the range of types of cashew phenol modified curing agents is relatively wide. According to a preferred embodiment of this invention, the cashew phenol modified curing agent is selected from cashew phenol modified phenolic amine or cashew phenol modified phenolic amide.

[0032] In this invention, the range of filler types is relatively wide. This is an illustrative example, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the filler is selected from one or more of aluminum tripolyphosphate, bentonite, talc, titanium dioxide, zinc oxide, barium sulfate, carbon black, mica powder, and calcium carbonate.

[0033] In this invention, the filler is selected from filler 1 and filler 2. According to a preferred embodiment of the invention, filler 1 is selected from one or more of aluminum tripolyphosphate, titanium dioxide, mica powder and calcium carbonate; filler 2 is selected from one or more of bentonite, talc, zinc oxide, barium sulfate and carbon black.

[0034] In this invention, the content of filler 1 and filler 2 in the total weight of inorganic filler can be selected within a wide range. According to a preferred embodiment of this invention, filler 1 accounts for 30-65 wt% of the total weight of inorganic filler, and filler 2 accounts for 35-70 wt% of the total weight of inorganic filler.

[0035] In this invention, the range of solvents that can be selected is relatively wide. This is an illustrative example, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the solvent is selected from one or more of toluene, xylene, n-butyl acetate, propylene glycol methyl ether acetate, butanone, methyl isobutyl ketone, propylene glycol methyl ether, diethylene glycol ethyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol butyl ether acetate, and ethyl acetate.

[0036] According to a preferred embodiment of the present invention, the solvent is a mixed solution of toluene, xylene, and n-butyl acetate; more preferably, the volume ratio of toluene, xylene, and n-butyl acetate is 1:1-5:1-10.

[0037] In this invention, a wide range of dispersants can be selected, which is illustrative but does not limit the scope of the invention. According to a preferred embodiment of the invention, the dispersant is selected from one or more of BYK163, BYK310, SY7040, BYK180, SY509 and Efka 4310.

[0038] According to a preferred embodiment of the present invention, the coating is fluorine-free.

[0039] A second aspect of the present invention provides a method for preparing the anti-condensation graphene anti-corrosion coating of the present invention, the method comprising: mixing the components of the coating.

[0040] According to a preferred embodiment of the present invention, the preparation method of the condensation-resistant graphene anti-corrosion coating includes: (1) After mixing filler 1, dispersant and solvent, the mixture is subjected to a first shearing, then tetrafunctional epoxy resin is added and ground, and then filler 2 is added and subjected to a second shearing to obtain component A; (2) After mixing the curing agent, phenol-modified graphene and solvent, the third shear was performed to obtain component B; (3) Mix component A and component B; The mass ratio of component A to component B is 2-10:1.

[0041] In this invention, the first shearing condition is not particularly limited; conventional shearing conditions in the art are sufficient. This is an illustrative example, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the first shearing condition includes: a temperature of 30°C-50°C; a rotation speed of 800 rpm-1500 rpm; and a time that can be determined according to the actual situation, generally 10-60 minutes.

[0042] In this invention, the grinding conditions are not particularly limited; conventional grinding conditions in the art are sufficient. This is an illustrative example, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the grinding conditions include: grinding to a fineness ≤25μm, for example, a sand mill can be used for the grinding. Preferably, the grinding media of the sand mill is 1.5mm-3mm zirconium beads; the rotation speed is 600-3000rpm / min; and the time can be determined according to the actual situation, generally 30-180min.

[0043] In this invention, the second shearing condition is not particularly limited; conventional shearing conditions in the art are sufficient. This is an illustrative example, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the second shearing condition includes: a rotational speed of 600 rpm to 1000 rpm; and a time that can be determined according to the actual situation, generally 30 to 60 minutes.

[0044] In this invention, the third shearing condition is not particularly limited; conventional shearing conditions in the art are sufficient. This is an illustrative example, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the second shearing condition includes: a rotational speed of 800 rpm to 1500 rpm; and a time that can be determined according to the actual situation, generally 10-30 minutes.

[0045] A third aspect of the present invention provides a condensation-resistant graphene anti-corrosion coating, wherein the condensation-resistant graphene anti-corrosion coating is obtained by mixing and coating components A and B of the condensation-resistant graphene anti-corrosion coating of the present invention.

[0046] In this invention, the coating method is not particularly limited, and any conventional coating method in the art is acceptable, such as spraying, roller coating, or dip coating.

[0047] The advantages of the present invention are illustrated by spraying in the embodiments of the present invention, but this does not limit the scope of the present invention. According to a preferred embodiment of the present invention, a two-coat spraying process is adopted, with a spraying pressure of 0.2-0.5 MPa and an interval of 1-5 hours between the two sprayings.

[0048] In this invention, the thickness of the anti-condensation graphene anti-corrosion coating can be selected from a wide range, which is illustrative but does not limit the scope of the invention. According to a preferred embodiment of the invention, the thickness is 80μm-300μm.

[0049] In this invention, the adhesion of the anti-condensation graphene anti-corrosion coating has a wide range of selectable values. According to a preferred embodiment of this invention, the adhesion of the coating is ≥8MPa, preferably 10-12 MPa.

[0050] In this invention, the water contact angle of the anti-condensation graphene anti-corrosion coating has a wide range of options. According to a preferred embodiment of this invention, the water contact angle is ≥110°, more preferably ≥120°.

[0051] The fourth aspect of the present invention provides an application of the condensation-resistant graphene anti-corrosion coating or condensation-resistant graphene anti-corrosion coating of the present invention in the condensation-resistant corrosion protection of metals, preferably in the condensation-resistant corrosion protection of coastal steel structure platforms, coastal oil and gas transportation pipelines or coastal oil storage pipelines.

[0052] Through the above technical solution, the condensation-resistant graphene anti-corrosion coating of the present invention can be applied in high humidity environments and has good brushing performance in high humidity conditions, without bubbling, peeling, or sagging; the construction process is simple, and both spraying and brushing are possible; the formed coating has the advantages of strong density, high cross-linking density, good chemical corrosion resistance and high adhesion under condensation conditions, which solves the technical problem of traditional liquid coatings being not resistant to chemical corrosion under condensation immersion, so that the coating exhibits excellent salt spray corrosion resistance, damp heat resistance, no bubbling and no peeling characteristics under long-term liquid immersion.

[0053] Meanwhile, the anti-condensation graphene anti-corrosion coating of the present invention has improved anti-condensation immersion performance. Under the conditions of high density, high cross-linking density and large water contact angle, it ensures good toughness of the coating and does not crack or fall off on irregularly shaped substrates.

[0054] Furthermore, in the anti-condensation graphene anti-corrosion coating of the present invention, phenol-modified graphene is used as a curing agent component and as a macromolecular curing accelerator, which solves the problem of graphene dispersion in the liquid phase and helps to solve the problem of gelation of the curing agent after long-term storage, thereby improving the storage performance of the coating. Attached Figure Description

[0055] Figure 1 This is a water contact angle diagram of the coating formed by the paint prepared in Example 1 of the present invention. Detailed Implementation

[0056] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0057] In the context and embodiments of this invention, the condensation-resistant anti-corrosion coating's resistance to damp heat is tested using the continuous condensation method according to GB / T 13893.2-2019, the salt spray test is conducted according to GB / T1771-2007, the film adhesion test is conducted according to GB / T9286-2021, and the film is cleaned according to GB / T8923.1-2011 before coating.

[0058] In the following embodiments, room temperature refers to 25°C.

[0059] In the following examples, the hydrogen equivalent of cashew nut shell oil modified phenolic amide (LITE-3100) is 150; the hydrogen equivalent of phenolic amine curing agent (TZ-500) is 265. In the following embodiments, the paint film is applied using a two-coat spraying process with a spraying pressure of 0.6 MPa, an interval of 2 hours between the two sprays, and a paint film thickness of 250 μm.

[0060] To illustrate the invention more clearly, the following embodiments are provided, but the scope of the invention is not limited to the embodiments.

[0061] Example 1 (1) Take 5 parts of titanium dioxide, 2 parts of aluminum tripolyphosphate, 12 parts of mica powder, 5 parts of BYK163, 3 parts of BYK310, 2 parts of SY509, and 15 parts of solvent (toluene, xylene, and n-butyl acetate mixed solvent, volume ratio 1:2:4), add them to a high-speed shear mixer, adjust the speed to 1200 rpm, shear and disperse for 60 min, control the shear temperature to 40℃, until all solids are evenly dispersed and no stratification occurs. Add 25 parts of epoxy resin with an epoxy value of 0.8 (AG-80, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane epoxy resin), mechanically stir, transfer to a sand mill, speed 2500 rpm, grind for 30 min, grind until the fineness is ≤25μm. Add 5 parts bentonite, 15 parts barium sulfate, 6 parts zinc oxide, and 5 parts solvent (a mixture of toluene, xylene, and n-butyl acetate in a volume ratio of 1:2:4) to the above mixture. Then add these components sequentially to a high-speed shear mixer and shear and disperse them at 1000 rpm for 30 minutes to obtain component A.

[0062] (2) Take 43 parts of cashew shell oil modified phenolic amide (LITE-3100), 2 parts of p-methylphenol modified graphene (carbon content 50wt%, phenol content 6wt%, sheet diameter 12μm), and 55 parts of solvent (a mixed solvent of toluene, xylene and n-butyl acetate, volume ratio 1:1:1). After mixing, shear at 1000rpm for 15min to obtain component B.

[0063] (3) Mix component A obtained in step (1) with component B obtained in step (2) at a mass ratio of 5:1.

[0064] The coating was tested using the aforementioned testing standards: the adhesion of the coating formed by the coating obtained in Example 1 was 12 MPa; the coating was subjected to a damp heat resistance test, and the results showed that after 5000 hours, the coating began to exhibit blistering, cracking, and peeling. After a 3000-hour neutral salt spray test, corrosion at the scribe line of the coating began to spread to both sides. The water contact angle of the coating is as follows. Figure 1 As shown, the water contact angle is 131°.

[0065] Example 2 The method was carried out according to Example 1, except that the number of parts of the tetrafunctional epoxy resin was 43 parts.

[0066] The coating was tested using the aforementioned testing standards, and the results showed that the adhesion of the resulting coating was 12 MPa. The coating underwent a damp heat resistance test, and the results showed that after 4000 hours, blistering, cracking, and peeling began to occur. After 2500 hours of neutral salt spray testing, corrosion at the scribe line of the coating began to spread to both sides. The water contact angle of the coating and... Figure 1 Similarly, the water contact angle is 126°.

[0067] Example 3 The procedure was carried out according to Example 1, except that in step 2, 4 parts of phenol-modified graphene (50wt% carbon content, 6wt% phenol content, 12μm sheet diameter) were added. The coating was tested using the aforementioned testing standards. The results showed that the adhesion of the resulting coating was 10 MPa. The coating underwent a damp heat resistance test, and the results showed that after 4300 hours, blistering, cracking, and peeling began to occur. After 2700 hours of neutral salt spray testing, corrosion at the scribe line of the coating began to spread laterally. The water contact angle of the coating and... Figure 1 Similarly, the water contact angle is 121°.

[0068] Example 4 The procedure was carried out according to Example 1, except that in step 2, phenolic amine curing agent (TZ-500) was used instead of cashew nut shell oil modified phenolic amide as the curing agent.

[0069] The coating was tested using the aforementioned testing standards. The results showed that the adhesion of the resulting coating was 10 MPa. The coating underwent a damp heat resistance test, and the results showed that after 4000 hours, blistering, cracking, and peeling began to occur. After 2650 hours of neutral salt spray testing, corrosion at the scribe line of the coating began to spread laterally. The water contact angle of the coating and... Figure 1 Similarly, the water contact angle is 123°.

[0070] Example 5 The procedure was carried out according to Example 1, except that in step 3, component A and component B were mixed at a mass ratio of 2:1.

[0071] The coating was tested using the aforementioned testing standards. The results showed that the adhesion of the resulting coating was 12 MPa. The coating underwent a damp heat resistance test, and the results showed that after 3800 hours, blistering, cracking, and peeling began to occur. After 2730 hours of neutral salt spray testing, the scratch corrosion of the coating began to spread to both sides. The water contact angle of the coating and... Figure 1 Similarly, the water contact angle is 118°.

[0072] Example 6 (1) Take 7 parts titanium dioxide, 5 parts aluminum tripolyphosphate, 8 parts mica powder, 6 parts Efka4310, 2 parts BYK180, 2 parts SY509, and 5 parts solvent (toluene, xylene, and n-butyl acetate mixed solvent, volume ratio 1:1:3), and add them sequentially to a high-speed shear mixer. Adjust the speed to 800 rpm and shear disperse for 60 min, controlling the shear temperature at 50℃, until all solids are evenly dispersed and no stratification occurs. Add 40 parts epoxy resin (MY721, N,N,N',N'-tetraglycidyl-3,3'-dimethyl-4,4'-diaminodiphenylmethane) with an epoxy value of 0.7, mechanically stir, and then transfer it to a sand mill. Grind at 2500 rpm for 120 min until the fineness is ≤25 μm. Add 5 parts bentonite, 8 parts barium sulfate, 7 parts zinc oxide, and 5 parts solvent (a mixture of toluene, xylene, and n-butyl acetate in a volume ratio of 1:1:3) to the above mixture. Then add these components sequentially to a high-speed shear mixer and shear and disperse them at 800 rpm for 30 minutes to obtain component A.

[0073] (2) Take 50 parts of cashew shell oil modified phenolic amide (LITE-3100), 1 part of p-aminophenol modified graphene (carbon content 60wt%, phenol content 2wt%, sheet diameter 12μm), and 49 parts of solvent (a mixed solvent of toluene, xylene and n-butyl acetate, volume ratio 1:1:3). After mixing, shear at 800rpm for 30min to obtain component B.

[0074] (3) Mix component A obtained in step (1) with component B obtained in step (2) at a mass ratio of 3:1.

[0075] The coating was tested using the aforementioned testing standards. The results showed that the adhesion of the resulting coating was 10 MPa. The coating underwent a damp heat resistance test, and the results showed that after 4500 hours, blistering, cracking, and peeling began to occur. After 2800 hours of neutral salt spray testing, corrosion at the scribe line of the coating began to spread laterally. The water contact angle of the coating and... Figure 1 Similarly, the water contact angle is 126°.

[0076] Example 7 (1) Take 7 parts titanium dioxide, 3 parts aluminum tripolyphosphate, 5 parts mica powder, 8 parts Efka4310, 3 parts BYK180, 4 parts SY509, and 25 parts solvent (toluene, xylene, and n-butyl acetate mixed solvent, volume ratio 1:3:5), and add them sequentially to a high-speed shear mixer. Adjust the speed to 1200 rpm and shear disperse for 60 min, controlling the shear temperature at 40℃, until all solids are evenly dispersed and no stratification occurs. Add 15 parts epoxy resin (AG-80H, N,N,N',N'-tetraglycidyl-3,3',5,5'-tetramethyl-4,4'-diaminodiphenylmethane) with an epoxy value of 0.9, mechanically stir, and then transfer it to a sand mill. Grind at 2000 rpm for 60 min until the fineness is ≤25 μm. Add 8 parts bentonite, 12% barium sulfate, 5 parts zinc oxide, and 5 parts solvent (a mixture of toluene, xylene, and n-butyl acetate in a volume ratio of 1:2:1) to the above mixture and then add them to a high-speed shear mixer. Shear and disperse the mixture at 1000 rpm for 30 minutes to obtain component A.

[0077] (2) Take 40 parts of cashew shell oil modified phenolic amide (LITE-3100), 3 parts of tea polyphenol modified graphene (carbon content 40wt%, phenol content 8wt%, sheet diameter 12μm), and 57 parts of solvent (mixed solvent of toluene, xylene and n-butyl acetate, volume ratio 1:3:5). After mixing, shear at 1000rpm for 15min to obtain component B.

[0078] (3) Mix component A obtained in step (1) with component B obtained in step (2) at a mass ratio of 7:1.

[0079] The coating was tested using the aforementioned testing standards. The results showed that the adhesion of the resulting coating was 10 MPa. The coating underwent a damp heat resistance test, and the results showed that after 4300 hours, blistering, cracking, and peeling began to occur. After 2770 hours of neutral salt spray testing, corrosion at the scribe line of the coating began to spread laterally. The water contact angle of the coating and... Figure 1 Similarly, the water contact angle is 125°.

[0080] Comparative Example 1 The implementation method is the same as in Example 1, except that an equal number of bisphenol A type epoxy resins (E-51) are used to replace epoxy resin (AG-80), and the other conditions are the same as in Example 1.

[0081] The coating was tested using the aforementioned testing standards. The test results showed that the adhesion of the resulting coating was 8 MPa. The coating underwent a damp heat resistance test, and the results showed that blistering, cracking, and peeling occurred after 1000 hours. After 1800 hours of neutral salt spray testing, corrosion at the scribe line of the coating began to spread laterally. The water contact angle of the coating and... Figure 1 Similarly, the water contact angle is 78°.

[0082] Comparative Example 2 The implementation method is the same as in Example 1, except that an equal amount of carbon black is used to replace the p-methylphenol-modified graphene, and the other conditions are the same as in Example 1.

[0083] The coating was tested using the aforementioned testing standards. The results showed that the adhesion of the resulting coating was 10 MPa. The coating underwent a damp heat resistance test, and the results showed that blistering, cracking, and peeling began to occur after 800 hours. After a 1500-hour neutral salt spray test, corrosion began to spread laterally at the etched areas of the coating. The water contact angle of the coating and... Figure 1 Similarly, the water contact angle is 90°.

[0084] Comparative Example 3 The implementation method is the same as in Example 1, except that phenol-modified graphene is not added, while the other conditions are the same as in Example 1.

[0085] The coating was tested using the aforementioned testing standards. The results showed that the adhesion of the resulting coating was 6 MPa. The coating underwent a damp heat resistance test, and the results showed that blistering, cracking, and peeling began to occur after 500 hours. After 800 hours of neutral salt spray testing, corrosion began to spread laterally at the etched areas of the coating. The water contact angle of the coating and... Figure 1 Similarly, the water contact angle is 80°.

[0086] Comparative Example 4 (1) Take 5 parts of titanium dioxide, 2 parts of aluminum tripolyphosphate, 12 parts of mica powder, 5 parts of BYK163, 3 parts of BYK310, 2 parts of SY509, and 15 parts of solvent (toluene, xylene, and n-butyl acetate mixed solvent, volume ratio 1:2:4), add them to a high-speed shear mixer, adjust the speed to 1200 rpm, shear and disperse for 60 min, control the shear temperature to 40℃, until all solids are evenly dispersed and no stratification occurs. Add 25 parts of epoxy resin with an epoxy value of 0.8 (AG-80, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane epoxy resin), mechanically stir, transfer to a sand mill, speed 2500 rpm, grind for 30 min, grind until the fineness is ≤25μm. Add 5 parts bentonite, 15 parts barium sulfate, 6 parts zinc oxide, and 5 parts solvent (a mixture of toluene, xylene, and n-butyl acetate in a volume ratio of 1:2:4) to the above mixture. Then add these components sequentially to a high-speed shear mixer and shear and disperse them at 1000 rpm for 30 minutes to obtain component A.

[0087] (2) Take 43 parts of cashew shell oil modified phenolic amide (LITE-3100), 0.15 parts of p-methylphenol, 2 parts of graphene oxide, and 54.85 parts of solvent (a mixed solvent of toluene, xylene and n-butyl acetate in a volume ratio of 1:1:1). After mixing, shear at 1000 rpm for 15 min to obtain component B.

[0088] (3) Mix component A obtained in step (1) with component B obtained in step (2) at a mass ratio of 5:1.

[0089] The coating was tested using the aforementioned testing standards: the test results showed that the adhesion of the coating formed by the obtained coating was 5 MPa; the coating was subjected to a damp heat resistance test, and the results showed that blistering, cracking, and peeling began to occur after 1000 hours. After a 600-hour neutral salt spray test, corrosion at the scribe line of the coating began to spread to both sides. The water contact angle of the coating and Figure 1 Similarly, the water contact angle is 95°.

[0090] This is because graphene oxide is difficult to disperse in the curing agent. When it is added to component B and mixed with component A for coating, it leads to coating defects and causes a significant reduction in test performance.

[0091] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A condensation-resistant graphene anticorrosive coating, characterized by, The coating consists of component A and component B: By weight, component A comprises: 5-50 parts of tetrafunctional epoxy resin, 30-65 parts of filler, 3-25 parts of dispersant, and 5-50 parts of solvent; By weight, component B includes: 0.5-5 parts of phenol-modified graphene, 20-60 parts of curing agent, and 20-80 parts of solvent; The mass ratio of component A to component B is 2-10:1; the phenol-modified graphene includes graphene oxide and phenolic substances formed on the graphene oxide.

2. The anti-corrosion coating according to claim 1, wherein, By weight, component A contains 10-40 parts of tetrafunctional epoxy resin; and / or The filler content is 35-55 parts; and / or The dispersant is 5-20 parts; and / or By weight, component B contains 1-3 parts of phenol-modified graphene; and / or The curing agent is 40-55 parts; and / or The mass ratio of component A to component B is 3-8:

1.

3. The anti-corrosion coating according to claim 1 or 2, wherein, In the phenol-modified graphene, the phenolic substances are selected from one or more of phenol, aminophenol, methylphenol, and tea polyphenols, preferably one or more of m-aminophenol, p-aminophenol, anthranilin, p-methylphenol, m-methylphenol, anthranilin, tea polyphenols, and phenol; and / or In the phenol-modified graphene, the phenolic content is 2wt%-8wt%; and / or The phenol-modified graphene contains 35wt%-60wt% carbon; and / or The phenol-modified graphene has a sheet diameter of 5μm-15μm.

4. The anticorrosive coating according to any one of claims 1 to 3, wherein In component A, The epoxy value of the tetrafunctional epoxy resin is 0.65-0.95; and / or The tetrafunctional epoxy resin is selected from tetraglycidylamine type epoxy resins. Preferably, the tetrafunctional epoxy resin has the structural formula shown in formula (1). Equation (1), In formula (1), R1 is selected from NH, O, C1-C5 alkylene groups; and / or R2, R3, R4, and R5 are each independently selected from H and C1-C6 alkyl groups, preferably H, methyl, or ethyl; More preferably, the tetrafunctional epoxy resin is selected from one or more of N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenyl ether, N,N,N',N'-tetraglycidyl-3,3'-diethyl-4,4'-diaminodiphenylmethane, N,N,N',N'-tetraglycidyl-3,3'-dimethyl-4,4'-diaminodiphenylmethane, and N,N,N',N'-tetraglycidyl-3,3',5,5'-tetramethyl-4,4'-diaminodiphenylmethane.

5. The anti-corrosion coating according to any one of claims 1-4, wherein, The curing agent is selected from cashew nut phenol modified curing agents, and more preferably the cashew nut phenol modified curing agent has a hydrogen equivalent of 100-300; Preferably, the cashew phenol modified curing agent is selected from cashew phenol modified phenolic amine and / or cashew phenol modified phenolic amide.

6. The anti-corrosion coating according to any one of claims 1-5, wherein, The filler is selected from one or more of the following: aluminum tripolyphosphate, bentonite, talc, titanium dioxide, zinc oxide, barium sulfate, carbon black, mica powder, and calcium carbonate; and / or The preferred packing material is selected from packing material 1 and packing material 2, wherein, Filler 1 is selected from one or more of aluminum tripolyphosphate, titanium dioxide, mica powder and calcium carbonate; Filler 2 is selected from one or more of bentonite, talc, zinc oxide, barium sulfate, and carbon black; Preferably, packing 1 accounts for 30-65 wt% of the total weight of the packing, and packing 2 accounts for 35-70 wt% of the total weight of the packing.

7. The anti-corrosion coating according to any one of claims 1-6, wherein, The solvent is selected from one or more of toluene, xylene, n-butyl acetate, propylene glycol methyl ether acetate, butanone, methyl isobutyl ketone, propylene glycol methyl ether, diethylene glycol ethyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol butyl ether acetate and ethyl acetate; Preferably, it is a mixed solution of toluene, xylene, and n-butyl acetate; more preferably, the volume ratio of toluene, xylene, and n-butyl acetate is 1:1-5:1-10; and / or The dispersant is selected from one or more of BYK163, BYK310, SY7040, BYK180, SY509, and Efka 4310; and / or The coating does not contain fluorine.

8. The method for preparing the condensation-resistant graphene anti-corrosion coating according to any one of claims 1-7, characterized in that, The method includes: mixing the components of the coating; Preferably, the preparation method includes: (1) After mixing filler 1, dispersant and solvent, the mixture is subjected to a first shearing, then tetrafunctional epoxy resin is added and ground, and then filler 2 is added and subjected to a second shearing to obtain component A; (2) After mixing the curing agent, phenol-modified graphene and solvent, the third shear was performed to obtain component B; (3) Mix component A and component B; The mass ratio of component A to component B is 2-10:

1.

9. A graphene anti-corrosion coating resistant to condensation, characterized in that, The anti-condensation graphene anti-corrosion coating is obtained by mixing and coating components A and B of the anti-condensation graphene anti-corrosion coating according to any one of claims 1-6. Preferably, the thickness of the condensation-resistant graphene anti-corrosion coating is 80μm-300μm; and / or The adhesion of the anti-condensation graphene anti-corrosion coating is ≥8MPa, preferably 10-12MPa; and / or The water contact angle of the condensation-resistant graphene anti-corrosion coating is ≥110°, preferably ≥120°.

10. The application of the anti-condensation graphene anti-corrosion coating according to any one of claims 1-6 or the anti-condensation graphene anti-corrosion coating according to claim 9 in anti-condensation corrosion protection of metals, preferably in anti-condensation corrosion protection of coastal steel structure platforms, coastal oil and gas pipelines or coastal oil storage pipelines.

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