High-solid graphene anticorrosive paint and preparation method thereof

Abstract

The invention relates to a high-solid graphene anticorrosive coating which comprises a component A and a component B. The mass ratio of the component A to the component B is (5-20): 1. The component A comprises the following components in parts by weight: 8-20 parts of modified epoxy resin; 2-10 parts of a solvent; 0.5 to 2 parts of a thixotropic agent; 70 to 85 parts of zinc powder; 0.01 to 0.5 part of a conductive agent; 0.5 to 2 parts of an accelerant; 0.01 to 0.5 part of a defoaming agent; the component B comprises the following components in parts by weight: 40-70 parts of a modified phenolic aldehyde amine curing agent; 10-30 parts of a modified alicyclic amine curing agent; the preparation method comprises the steps of S1, preparation of the component A, S2, preparation of the component B and S3, mixing of the component A and the component B. The zinc powder anticorrosive paint has the advantages that the utilization rate of the zinc powder is increased, the corrosion resistance of a paint film is greatly improved, the solid content is high, VOC emission caused by volatilization of a liquid solvent is reduced, the environmental protection performance is improved, and environmental protection and long-acting corrosion resistance are achieved; and the service life of equipment is greatly prolonged.

Description

Technical Field

[0001] This invention relates to the field of anti-corrosion coatings, and in particular to a high-solids graphene anti-corrosion coating and its preparation method. Background Technology

[0002] Corrosion of marine engineering facilities results in the loss of 10% to 20% of global metal annually, causing substantial economic losses. Therefore, the demand for marine corrosion protective coatings is strong, driving the development of related industries. Marine corrosion protective coatings are used in the corrosion protection of steel structures such as ships, containers, offshore bridges, and dock facilities.

[0003] Currently, the mainstream marine corrosion coating is epoxy zinc-rich primer. However, the following problems have been found during the application of this type of anti-corrosion coating: 1. Only 25% to 35% of the zinc powder in epoxy zinc-rich primer plays a role in cathodic protection. In the initial stage of protection, cathodic protection is the main function. After immersion in corrosive media for more than 168 hours, some zinc powder is oxidized into non-conductive zinc salts, which weakens the interconnection between zinc powders, reduces the cathodic protection effect, and reduces the utilization efficiency of zinc powder. At this time, the coating protection mainly plays a shielding role, which ultimately affects the anti-corrosion performance of the anti-corrosion coating.

[0004] 2. Traditional epoxy zinc-rich primers have low solids content, and the solvents are easily volatile, resulting in high VOC emissions, which cannot meet increasingly stringent environmental protection requirements.

[0005] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention discloses a high-solids graphene anti-corrosion coating and its preparation method.

[0007] A high-solids graphene anti-corrosion coating, comprising component A and component B, wherein the mass ratio of component A to component B is in the range of 5 to 20:1; Component A includes components listed in parts by weight: Modified epoxy resin, 8-20 parts; Solvent, 2-10 parts; Thixotropic agent, 0.5 to 2 parts; Zinc powder, 70-85 parts; Conductive agent, 0.01~0.5 parts; Accelerator, 0.5-2 parts; Defoamer, 0.01~0.5 parts; Component B includes components listed in parts by weight: Modified phenolic amine curing agent, 40-70 parts; Modified cycloaliphatic amine curing agent, 10-30 parts; Solvent, 10-30 parts.

[0008] Furthermore, the modified epoxy resin includes linearly modified bisphenol F epoxy resin.

[0009] Furthermore, the solvent includes propylene glycol methyl ether acetate.

[0010] Furthermore, the thixotropic agent includes modified polyamide wax powder.

[0011] Furthermore, the zinc powder has a particle size range of 1000~1500 mesh.

[0012] Furthermore, the conductive agent includes one or a combination of graphene and single-arm carbon nanotubes.

[0013] Furthermore, the diameter of the single-arm carbon nanotube is 0.01~25μm.

[0014] Furthermore, the accelerator includes a polysiloxane adhesion accelerator, and the defoamer is an organosilicone defoamer.

[0015] A method for preparing a high-solids graphene anti-corrosion coating includes the following steps: Step S1, Preparation of Component A, includes the following steps: The first step is to mix the modified epoxy resin and solvent at a low speed. The second step involves adding the conductive agent, thixotropic agent, and defoamer to the mixture and stirring at medium speed. The third step is to add zinc powder into the mixture, stir it evenly at medium speed, and control the temperature to ≤50℃. The fourth step is to cool the temperature to 25-30℃, add the accelerator, and stir until homogeneous to obtain component A. Step S2, Preparation of Component B: The modified phenolic amine curing agent, modified alicyclic amine curing agent, and solvent were mixed by stirring at medium speed to obtain component B. Step S3: Mix component A and component B according to the mass ratio to obtain the product.

[0016] Furthermore, in the first step of step S1, the stirring speed ranges from 400 to 600 r / min, and the stirring time is 15 min; In the second step of step S1, the stirring speed ranges from 600 to 800 r / min, and the stirring time is 30 min. In the third step of step S1, the stirring speed ranges from 600 to 800 r / min, and the stirring time is 30 min; In step S2, the stirring speed ranges from 600 to 800 r / min, and the stirring time is 20 min.

[0017] The advantages of this invention are: 1. A nano-network structure is constructed in modified epoxy resin using conductive graphene and single-arm carbon nanotubes, which enhances the physical barrier effect of the coating and provides extremely strong anti-corrosion performance. On the other hand, it can improve the utilization rate of zinc powder, greatly improve the anti-corrosion performance of the paint film. The product has a high solid content, which reduces VOC emissions caused by the evaporation of liquid solvents, improves environmental protection performance, achieves environmentally friendly and long-lasting anti-corrosion, and greatly extends the service life of equipment.

[0018] 2. Graphene is a two-dimensional sheet with a single atomic layer thickness, and single-arm carbon nanotubes have a hollow tubular structure. The network structure formed by the interweaving of the two in epoxy resin extends the internal permeation channels. The longer the permeation path, the longer the permeation path of media such as water and oxygen becomes, and the longer it takes for the media to reach the substrate surface. Consequently, the chemical corrosion begins later. During the curing process of epoxy resin, micron-sized micropores are generated due to volume shrinkage. Graphene and single-arm carbon nanotubes can fill the micropores and improve the density of the tissue. The carbon six-membered ring structure of graphene has extremely high molecular density. A single layer of graphene can effectively block the permeation of small molecules and improve the physical barrier effect.

[0019] 3. Both graphene and single-arm carbon nanotubes have high conductivity. The nano-network structure formed by the two creates a continuous conductive path in the resin matrix. Even if the zinc powder does not directly contact the surface of the equipment to be protected, electrons can still be transferred through the conductive path of graphene and carbon nanotubes to achieve cathodic protection. Furthermore, graphene can be adsorbed on the surface of zinc powder, while single-arm carbon nanotubes are interspersed between the zinc powder particles, hindering oxygen contact and preventing the zinc powder from being oxidized to form zinc salts. The combination of conductivity and isolation maximizes the protection of the zinc powder.

[0020] 4. Mix the resin at low speed to reduce air bubbles and lower viscosity. Then increase the speed to mix in the conductive agent and build a network structure to ensure that all components are mixed evenly. Add zinc powder and then control the temperature. Too high a temperature will accelerate the oxidation of zinc powder. Reduce the zinc powder content to allow the accelerator to dissolve evenly in component A without triggering premature curing. Attached Figure Description

[0021] Figure 1 A schematic diagram illustrating the steps of a method for preparing a high-solids graphene anti-corrosion coating. Detailed Implementation

[0022] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0023] Example 1: A high-solids graphene anti-corrosion coating, comprising component A and component B, wherein the mass ratio of component A to component B is 13:1.

[0024] Component A includes components listed in parts by weight: Modified epoxy resin, specifically linear modified bisphenol F epoxy resin (Guodu Chemical YDF-175×90), 10 parts.

[0025] The solvent, specifically propylene glycol methyl ether acetate solvent, is 5.55 parts.

[0026] Thixotropic agent, specifically modified polyamide wax powder (HX-9110 thixotropic agent), 1.2 parts.

[0027] Zinc powder, 1250 mesh, 82 parts; The conductive agent is specifically a single-arm carbon nanotube with a diameter of 0.01~25μm, 0.15 parts.

[0028] The accelerator, specifically a polysiloxane adhesion accelerator (Jiangsu Chenguang A-187), is 1 part.

[0029] Defoamer, silicone defoamer (Defom6800), 0.1 parts.

[0030] Component B includes components listed in parts by weight: Modified phenolic amine curing agent, specifically NX-2003 phenolic amine curing agent, 60 parts.

[0031] Modified cycloaliphatic amine curing agent, specifically 486 cycloaliphatic amine curing agent, 25 parts.

[0032] The solvent, specifically propylene glycol methyl ether acetate solvent, is 10 parts.

[0033] Its preparation method, such as Figure 1 As shown, it includes the following steps: Step S1, Preparation of Component A, includes the following steps: The first step is to mix the modified epoxy resin and solvent at a low speed, with a stirring speed range of 400~600 r / min and a stirring time of 15 min.

[0034] The second step involves adding the conductive agent, thixotropic agent, and defoamer to the mixture and stirring at a medium speed of 600-800 r / min for 30 minutes.

[0035] The third step is to add zinc powder into the mixture, stir at a medium speed (600-800 r / min) for 30 minutes, and control the temperature to ≤50℃.

[0036] The fourth step is to cool the temperature to 25-30℃, add the accelerator, and stir until homogeneous to obtain component A. Step S2, Preparation of Component B: The modified phenolic amine curing agent, modified alicyclic amine curing agent, and solvent were mixed by stirring at a medium speed (600-800 r / min) for 20 min to obtain component B.

[0037] Step S3: Mix component A and component B according to the mass ratio to obtain the product.

[0038] Example 2: The difference from Example 1 is that: A high-solids graphene anti-corrosion coating, comprising component A and component B, wherein the mass ratio of component A to component B is 7:1.

[0039] Component A includes components listed in parts by weight: Modified epoxy resin, specifically linear modified bisphenol F epoxy resin (Guodu Chemical YDF-175×90), 15 parts.

[0040] The solvent, specifically propylene glycol methyl ether acetate solvent, is 6.5 parts.

[0041] Thixotropic agent, specifically modified polyamide wax powder (HX-9110 thixotropic agent), 0.7 parts.

[0042] Zinc powder, 1000 mesh, 75 parts; The conductive agent, specifically single-arm carbon nanotubes with a diameter of 0.01~25μm, is 0.3 parts.

[0043] The accelerator, specifically a polysiloxane adhesion accelerator (Jiangsu Chenguang A-187), is 0.5 parts.

[0044] Defoamer, silicone defoamer (Defom6800), 0.3 parts.

[0045] Component B includes components listed in parts by weight: Modified phenolic amine curing agent, specifically NX-2003 phenolic amine curing agent, 50 parts.

[0046] Modified cycloaliphatic amine curing agent, specifically 486 cycloaliphatic amine curing agent, 15 parts.

[0047] The solvent, specifically propylene glycol methyl ether acetate solvent, is 20 parts.

[0048] Prepared using the same process parameters.

[0049] Example 3: The difference from Example 1 is that: A high-solids graphene anti-corrosion coating, comprising component A and component B, wherein the mass ratio of component A to component B is 20:1.

[0050] Component A includes components listed in parts by weight: Modified epoxy resin, specifically linear modified bisphenol F epoxy resin (Guodu Chemical YDF-175×90), 20 parts.

[0051] The solvent, specifically propylene glycol methyl ether acetate solvent, is 10 parts.

[0052] Thixotropic agent, specifically modified polyamide wax powder (HX-9110 thixotropic agent), 1.8 parts.

[0053] Zinc powder, 1150 mesh, 85 parts; The conductive agent is specifically a single-arm carbon nanotube with a diameter of 0.01~25μm, 0.5 parts.

[0054] The accelerator, specifically a polysiloxane adhesion accelerator (Jiangsu Chenguang A-187), is 1.5 parts.

[0055] Defoamer, silicone defoamer (Defom6800), 0.5 parts.

[0056] Component B includes components listed in parts by weight: Modified phenolic amine curing agent, specifically NX-2003 phenolic amine curing agent, 60 parts.

[0057] Modified cycloaliphatic amine curing agent, specifically 486 cycloaliphatic amine curing agent, 25 parts.

[0058] The solvent, specifically propylene glycol methyl ether acetate solvent, is 25 parts.

[0059] Prepared using the same process parameters.

[0060] Example 4: The difference from Example 1 is that: Conductive agent, specifically graphene, 0.15 parts.

[0061] The remaining components are the same, and the same process parameters are used for preparation.

[0062] Example 5: The difference from Example 1 is that: The conductive agent is specifically graphene, 0.05 parts, and single-arm carbon nanotubes with a diameter of 0.01~25μm, 0.10 parts, for a total of 0.15 parts.

[0063] The remaining components are the same, and the same process parameters are used for preparation.

[0064] Comparative Example 1: The performance test results of conventional epoxy zinc-rich primers from domestic and foreign paint companies are shown in Table 1 below. Table 1 The samples randomly selected from the products prepared in Examples 1 to 5 were subjected to comprehensive performance testing. The test results are shown in Table 2.

[0065] Table 2 in conclusion: The samples tested in Examples 1-5 exhibited excellent comprehensive mechanical properties, high VOC content, and high non-volatile matter content, without causing excessive VOC emission pollution. No paint film failure was observed in humid and hot environments, salt spray environments, and 3% NaCl immersion environments, proving that the use of conductive graphene and single-arm carbon nanotubes to construct a nano-network structure in the modified epoxy resin is effective in enhancing corrosion resistance.

[0066] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A high-solids graphene anti-corrosion coating, characterized in that, It includes component A and component B, wherein the mass ratio of component A to component B ranges from 5 to 20:1; Component A includes components listed in parts by weight: Modified epoxy resin, 8-20 parts; Solvent, 2-10 parts; Thixotropic agent, 0.5 to 2 parts; Zinc powder, 70-85 parts; Conductive agent, 0.01~0.5 parts; Accelerator, 0.5-2 parts; Defoamer, 0.01~0.5 parts; Component B includes components listed in parts by weight: Modified phenolic amine curing agent, 40-70 parts; Modified cycloaliphatic amine curing agent, 10-30 parts; Solvent, 10-30 parts.

2. The high-solids graphene anti-corrosion coating according to claim 1, characterized in that: The modified epoxy resin includes linearly modified bisphenol F epoxy resin.

3. The high-solids graphene anti-corrosion coating according to claim 1, characterized in that: The solvent includes propylene glycol methyl ether acetate.

4. The high-solids graphene anti-corrosion coating according to claim 1, characterized in that: The thixotropic agent includes modified polyamide wax powder.

5. The high-solids graphene anti-corrosion coating according to claim 1, characterized in that: The zinc powder has a particle size range of 1000~1500 mesh.

6. The high-solids graphene anti-corrosion coating according to claim 1, characterized in that: The conductive agent includes one or a combination of graphene and single-arm carbon nanotubes.

7. The high-solids graphene anti-corrosion coating according to claim 6, characterized in that: The diameter of the single-arm carbon nanotubes ranges from 0.01 to 25 μm.

8. The high-solids graphene anti-corrosion coating according to claim 1, characterized in that: The accelerator includes a polysiloxane adhesion promoter, and the defoamer is an organosilicone defoamer.

9. A method for preparing a high-solids graphene anti-corrosion coating according to any one of claims 1 to 8, comprising the following steps: Step S1, Preparation of Component A, includes the following steps: The first step is to mix the modified epoxy resin and solvent at a low speed. The second step involves adding the conductive agent, thixotropic agent, and defoamer to the mixture and stirring at medium speed. The third step is to add zinc powder into the mixture, stir it evenly at medium speed, and control the temperature to ≤50℃. The fourth step is to cool the temperature to 25-30℃, add the accelerator, and stir until homogeneous to obtain component A. Step S2, Preparation of Component B: The modified phenolic amine curing agent, modified alicyclic amine curing agent, and solvent were mixed by stirring at medium speed to obtain component B. Step S3: Mix component A and component B according to the mass ratio to obtain the product.

10. The method for preparing the high-solids graphene anti-corrosion coating according to claim 9, characterized in that: In the first step of step S1, the stirring speed ranges from 400 to 600 r / min, and the stirring time is 15 min. In the second step of step S1, the stirring speed ranges from 600 to 800 r / min, and the stirring time is 30 min. In the third step of step S1, the stirring speed ranges from 600 to 800 r / min, and the stirring time is 30 min; In step S2, the stirring speed ranges from 600 to 800 r / min, and the stirring time is 20 min.

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