Graphene long-acting anticorrosive coating and preparation method thereof

Abstract

The invention discloses a graphene long-acting anticorrosive coating and a preparation method thereof. The preparation method comprises the following steps: S1, preparing a silane modified silicon dioxide microsphere solution; s2, under the protection of nitrogen, heating the modified silicon dioxide microsphere solution to 80 DEG C, and performing ultrasonic dispersion for 20 minutes; dropwise adding a graphene ethanol solution, stirring for 2-4 hours at a constant temperature, carrying out centrifugal treatment after the reaction is finished, and washing for 2-4 times by using absolute ethyl alcohol; s3, performing vacuum drying on a product obtained in the step S2, adding a metal reducing substance under the protection of inert gas, and roasting in a high-temperature kiln at 600 DEG C for 2-4 hours to obtain graphene modified nano-microspheres; and S4, adding a film-forming material, an auxiliary agent, a filler and the graphene modified nano-microspheres into a solvent, mixing and grinding to obtain the graphene long-acting anticorrosive coating. The prepared graphene long-acting anticorrosive paint primer is not agglomerated, and the long-acting anticorrosive performance of a coating can be remarkably improved.

Description

Technical Field

[0001] This invention relates to a long-lasting anti-corrosion coating, and more particularly to a novel graphene-based long-lasting anti-corrosion coating. Background Technology

[0002] With the advancement of science and technology and the development of industry, metal corrosion has become a common challenge in many fields. To address this problem, the research and application of anti-corrosion coating materials have become crucial. Currently, while traditional anti-corrosion coating materials can protect metal substrates from corrosion to a certain extent, their corrosion resistance gradually declines during long-term service, requiring frequent maintenance and replacement. This not only increases economic costs but may also affect engineering safety. Therefore, researching new anti-corrosion coatings to improve their corrosion resistance and durability is of great significance for promoting technological progress in related fields.

[0003] Currently, the main anti-corrosion coatings involve adding materials that inhibit metal corrosion (primarily zinc) to the primer to suppress the corrosion rate and protect the materials within the coating from corrosive substances. To improve anti-corrosion performance, the primer usually needs to be modified or high-efficiency anti-corrosion additives need to be added. Currently, adding graphene has become a research hotspot for improving anti-corrosion effects. However, graphene is prone to agglomeration in primers or has storage stability defects. Later, researchers added composite graphene materials to primers through chemical grafting. Although this temporarily solved the agglomeration problem, two main issues remain: first, the grafting of graphene with micro / nano particles of uneven size results in a large size difference in the composite graphene material, which can still agglomerate when added to the primer; second, the organic solvents in the primer can cause the grafting of micro / nano particles onto the graphene to break down over time, leading to graphene agglomeration and affecting performance. Summary of the Invention

[0004] The first objective of this invention is to address the problems described in the background art regarding existing graphene long-lasting anti-corrosion coatings, such as the grafting of graphene with micro-nano particles of uneven particle size, resulting in inconsistent particle sizes of the graphene material, and the problem that organic solvents in the primer cause the grafting of graphene to break off over time. The invention aims to provide a graphene long-lasting anti-corrosion coating that solves these problems.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A graphene-based long-lasting anti-corrosion coating includes the following steps: S1. Soak monodisperse micro-nano microspheres in anhydrous ethanol and stir for 0.5-1.5 h, then perform ultrasonic dispersion treatment for 1-3 h. Add silane coupling agent dropwise to the above solution, and continue stirring and ultrasonic dispersion treatment during the dropwise addition process. After the silane coupling agent is added, continue ultrasonic dispersion treatment for 1 h to obtain silane-modified silica microsphere solution. S2. Under nitrogen protection, the modified silica microsphere solution was heated to 80°C and ultrasonically dispersed for 20 minutes; then graphene ethanol solution was added dropwise, and the mixture was stirred at a constant temperature for 2-4 hours. After the reaction was completed, the mixture was centrifuged and washed 2-4 times with anhydrous ethanol. S3. After vacuum drying of the product obtained in step S2, a metal reducing agent is added under inert gas protection, and the product is calcined in a high-temperature kiln at 600°C for 2-4 hours to obtain graphene-modified nanospheres. S4. The film-forming material, additives, fillers and graphene-modified nanospheres are added to the solvent, mixed and ground to obtain a long-lasting graphene anti-corrosion coating.

[0006] In the above scheme, after adding zinc powder to the graphene long-lasting anti-corrosion coating in step S4 and stirring evenly, a longer-lasting graphene long-lasting anti-corrosion coating is obtained.

[0007] In the above scheme, the micro-nano microspheres are silica microspheres or titanium dioxide microspheres.

[0008] In the above scheme, the silica microspheres or titanium dioxide microspheres are uniform monodisperse silica or titanium dioxide microspheres.

[0009] In the above scheme, the diameter of the monodisperse silica microspheres or titanium dioxide microspheres is 5-40 μm.

[0010] In the above scheme, the silane coupling agent is one or more of KH550, KH560, and KH570.

[0011] In the above scheme, the particle size ratio of the graphene-modified nanospheres to the micro-nanospheres is 10-60:1.

[0012] In the above scheme, the weight ratio of monodisperse micro / nano microspheres in step S1 to graphene in step S2 is 50 to 10:1.

[0013] In the above scheme, the weight percentage of the graphene-modified nanospheres to the graphene long-lasting anti-corrosion coating is 0.01% to 10%.

[0014] The second objective of this invention is to provide a graphene long-lasting anti-corrosion coating prepared using the above-described method for preparing graphene long-lasting anti-corrosion coatings.

[0015] The present invention has positive effects: the preparation method of the graphene long-lasting anti-corrosion coating of the present invention uses monodisperse micro-nano microspheres with uniform particle size. After the silane-modified silica microsphere solution is grafted with graphene, the resulting graphene-modified nano-microspheres have uniform particle size and will not agglomerate in the prepared primer, which can significantly improve the long-lasting anti-corrosion performance of the coating. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the graphene long-lasting anti-corrosion coating of the present invention after it has been sprayed as a primer onto a metal substrate and cured. Detailed Implementation

[0017] The technical solution of the present invention will be clearly and completely described below through embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example

[0018] The preparation method of the graphene long-lasting anti-corrosion coating of the present invention includes the following steps: S1. Soak monodisperse micro / nano microspheres in anhydrous ethanol and stir for 0.5-1.5 hours, for example, 1 hour. Then, perform ultrasonic dispersion treatment for 1-3 hours, for example, 2 hours. Add silane coupling agent dropwise to the above solution while continuously stirring and ultrasonically dispersing during the dropwise addition. After the silane coupling agent is added, continue ultrasonic dispersion treatment for 1 hour to obtain a silane-modified silica microsphere solution. The micro- and nano-sized microspheres are made of silica or titanium dioxide. In the above scheme, the silica microspheres or titanium dioxide microspheres are uniform monodisperse silica or titanium dioxide microspheres.

[0019] In the above scheme, the diameter of the monodisperse silica microspheres or titanium dioxide microspheres is 5-40 μm.

[0020] The silane coupling agent is one or more of KH550, KH560, and KH570.

[0021] S2. Under nitrogen protection, the modified silica microsphere solution was heated to 80°C and ultrasonically dispersed for 20 minutes; then graphene ethanol solution was added dropwise, and the mixture was stirred at a constant temperature for 2-4 hours, for example, for 3 hours. After the reaction was completed, the mixture was centrifuged and washed 2-4 times with anhydrous ethanol. S3. After vacuum drying of the product obtained in step S2, a metal reducing agent is added under inert gas protection, and the product is calcined in a high-temperature kiln at 600°C for 2-4 hours to obtain graphene-modified nanospheres. S4. The film-forming material, additives, fillers and graphene-modified nanospheres are added to the solvent, mixed and ground to obtain a long-lasting graphene anti-corrosion coating.

[0022] The ratio of the microsphere particle size to the micro-nanosphere particle size of the graphene-modified nanospheres is 10-60:1, preferably 15-35:1.

[0023] In the above scheme, the weight ratio of monodisperse micro / nano microspheres in step S1 to graphene in step S2 is 50-10:1, preferably 30-20:1.

[0024] In the above scheme, the weight percentage of the graphene-modified nanospheres to the graphene long-lasting anti-corrosion coating is 0.01% to 10%, preferably 0.1% to 7%. Example

[0025] Two 500ml three-necked flasks were filled with 200ml of anhydrous ethanol solution, and 20g of monodisperse silica microspheres with a particle size of 5μm were added to each flask. The mixture was stirred for 1 hour, followed by ultrasonic dispersion for 2 hours. Then, 1.5g of silane coupling agent KH560 was gradually added dropwise to the solution while stirring and sonicating. After the silane coupling agent addition was complete, ultrasonic dispersion was continued for another 1 hour to obtain a silane-modified silica microsphere solution. The microsphere solution was then heated to 80°C under nitrogen protection and ultrasonically dispersed for 20 minutes. Next, 10g of 10% graphene ethanol solution was added dropwise, and the mixture was stirred at a constant temperature for 3 hours. After the reaction was complete, the mixture was centrifuged and washed three times with anhydrous ethanol. The product was then vacuum dried and calcined in a high-temperature furnace at 600°C for 3 hours under inert gas protection to obtain graphene-modified nanospheres. Take 10g of the obtained graphene-modified nanospheres and gradually add them to 1000g of a pre-coating for corrosion protection, which contains epoxy resin, additives, fillers, etc., to obtain the corrosion protection coating. Example

[0026] Based on Example 1, an appropriate amount of zinc powder is added to the graphene long-lasting anti-corrosion coating obtained in step S4. After stirring evenly, a longer-lasting graphene long-lasting anti-corrosion coating can be obtained. The mass ratio of zinc powder to graphene long-lasting anti-corrosion coating can be 30% to 60%.

[0027] In the above embodiments 1-3, the film-forming component can be any film-forming component known to those skilled in the art, such as epoxy resin, polyester resin, thermosetting acrylic resin, thermoplastic acrylic resin, etc. The preferred film-forming component is epoxy resin. The epoxy resin used in this invention is well known to those skilled in the art, examples of which include bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenolic epoxy resin, alicyclic epoxy resin, etc. More preferably, the epoxy resin used in this invention is selected from bisphenol A type epoxy resin.

[0028] Solvents can be common solvents or mixtures thereof, including but not limited to aromatics such as xylene and toluene; esters such as ethyl acetate, butyl acetate, and isoamyl acetate; alcohols such as butanol, isobutanol, and benzyl alcohol; ethers such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, and propylene glycol diethyl ether; and ketones such as methyl isobutyl ketone, acetophenone, and isophorone. Those skilled in the art can determine the amount of solvent used based on the desired properties of the coating according to this invention, such as coating performance.

[0029] The coatings of this invention may also contain other components known to those skilled in the art, such as silane coupling agents, defoamers, wetting agents, dispersants, emulsifiers, anti-settling agents, stabilizers, anti-skinning agents, leveling agents, drying agents, anti-sagging agents, plasticizers, matting agents, flame retardants, mildew inhibitors, bactericides, and trapping agents. Those skilled in the art can determine the specific types and amounts of these other components according to the desired properties of the coatings, such as bactericidal properties.

[0030] The coating of the present invention prepared as described above can be sealed and stored in a dry environment. Of course, it is preferable to prepare and use the coating of the present invention immediately.

[0031] The coating of the present invention can be applied to the surface of the material to be coated by any suitable method known to those skilled in the art, such as roller coating, spraying, dipping, brushing, scraping, etc.

[0032] like Figure 1 The diagram shown is a schematic representation of the graphene long-lasting anti-corrosion coating of the present invention after curing on a metal substrate. Figure 1 In the diagram, the left side shows the state of the primer after curing, while the right side, from top to bottom, shows the states of the topcoat, intermediate coat, and primer. Figure 1 As can be seen, after the graphene long-lasting anti-corrosion coating of the present invention is cured, the paint film is uniform and the graphene material does not agglomerate.

[0033] Test comparison The graphene long-lasting anti-corrosion coatings prepared in Examples 1-3 were tested, and the results are shown in Table 1.

[0034] Existing anti-corrosion coatings Example 1 Example 2 Example 3 State in the container After stirring and mixing, there are no lumps and the mixture is homogeneous. After stirring and mixing, there are no lumps and the mixture is homogeneous. After stirring and mixing, there are no lumps and the mixture is homogeneous. After stirring and mixing, there are no lumps and the mixture is homogeneous. Constructability Construction barrier-free Construction barrier-free Construction barrier-free Construction barrier-free Paint film appearance normal normal normal normal Adhesion 6MPa 6.5MPa 7MPa 6.7MPa Impact 50cm / pass 50cm / pass 50cm / pass 50cm / pass neutral salt spray 1450h 2100h 3000h 2700h .

[0035] The test data shows that the graphene-modified nanospheres prepared by the method of this invention do not easily agglomerate, and after long-term storage, the grafting of the graphene-modified nanospheres will not be dissolved by organic solvents or break, thus ensuring the anti-corrosion performance of the coating. Compared with existing anti-corrosion coatings, the graphene-modified ...

[0036] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a graphene long-lasting anti-corrosion coating, characterized in that, Includes the following steps: S1. Soak monodisperse micro-nano microspheres in anhydrous ethanol and stir for 0.5-1.5 h, then perform ultrasonic dispersion treatment for 1-3 h. Add silane coupling agent dropwise to the above solution, and continue stirring and ultrasonic dispersion treatment during the dropwise addition process. After the silane coupling agent is added, continue ultrasonic dispersion treatment for 1 h to obtain silane-modified silica microsphere solution. S2. Under nitrogen protection, the modified silica microsphere solution was heated to 80°C and ultrasonically dispersed for 20 minutes; then graphene ethanol solution was added dropwise, and the mixture was stirred at a constant temperature for 2-4 hours. After the reaction was completed, the mixture was centrifuged and washed 2-4 times with anhydrous ethanol. S3. After vacuum drying of the product obtained in step S2, a metal reducing agent is added under inert gas protection, and the product is calcined in a high-temperature kiln at 600°C for 2-4 hours to obtain graphene-modified nanospheres. S4. The film-forming material, additives, fillers and graphene-modified nanospheres are added to the solvent, mixed and ground to obtain a long-lasting graphene anti-corrosion coating.

2. The method for preparing the graphene long-lasting anti-corrosion coating according to claim 1, characterized in that: After adding zinc powder to the graphene long-lasting anti-corrosion coating in step S4 and stirring evenly, a longer-lasting graphene long-lasting anti-corrosion coating is obtained.

3. The method for preparing the graphene long-lasting anti-corrosion coating according to claim 1, characterized in that: The micro-nano spheres are either silica microspheres or titanium dioxide microspheres.

4. The method for preparing the graphene long-lasting anti-corrosion coating according to claim 1, characterized in that: The silica microspheres or titanium dioxide microspheres are uniform monodisperse silica or titanium dioxide microspheres.

5. The method for preparing the graphene long-lasting anti-corrosion coating according to claim 1, characterized in that: The monodisperse silica microspheres or titanium dioxide microspheres have a diameter of 5-40 μm.

6. The method for preparing the graphene long-lasting anti-corrosion coating according to claim 1, characterized in that: The silane coupling agent is one or more of KH550, KH560, and KH570.

7. The method for preparing the graphene long-lasting anti-corrosion coating according to claim 1, characterized in that: The ratio of the microsphere particle size to the micro-nanosphere particle size of the graphene-modified nanospheres is 10-60:

1.

8. The method for preparing the graphene long-lasting anti-corrosion coating according to claim 1, characterized in that: The weight ratio of the monodisperse micro / nanospheres in step S1 to the graphene in step S2 is 50–10:

1.

9. The method for preparing the graphene long-lasting anti-corrosion coating according to claim 1, characterized in that: The weight percentage of the graphene-modified nanospheres to the graphene long-lasting anti-corrosion coating is 0.01% to 10%.

10. A graphene long-lasting anti-corrosion coating prepared by the method of any one of claims 1-9.

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