A corrosion-resistant coating composition and its preparation method

Abstract

This application belongs to the field of anti-corrosion coating technology, specifically providing an anti-corrosion coating composition and its preparation method, comprising the following components in parts by weight: 80-120 parts epoxy resin, 15-20 parts curing agent, 3-5 parts nano-alumina, 3.5-5 parts modified zirconium phosphate, 5-7.5 parts phenylboronic acid derivative, 5-10 parts end-capped diol, 2-5 parts dispersant, 1-3 parts defoamer, and 0.5-1 part lubricant; wherein the phenylboronic acid derivative is prepared by reacting 2-trifluoromethylphenylboronyl chloride with 4,4'-diaminodiphenylmethane. The anti-corrosion coating prepared by this application has the advantages of good crack resistance, weather resistance, and corrosion resistance.

Description

Technical Field

[0001] This application belongs to the field of anti-corrosion coating technology, and in particular relates to an anti-corrosion coating composition and its preparation method. Background Technology

[0002] Metal corrosion occurs between metallic materials and the external environment, directly damaging the structure and properties of the metal. This is especially true in the power industry, where carbon steel, aluminum alloys, and copper alloys are used extensively in all stages of power generation, transmission, transformation, and distribution, resulting in a range of different types of metal corrosion that significantly impact the safety of power operations.

[0003] Among various anti-corrosion methods, anti-corrosion coatings offer advantages such as simple operation, flexible use, excellent results, aesthetic appeal, and low rework costs. Therefore, applying anti-corrosion coatings to metal surfaces has become one of the most common methods for protecting the base metal from corrosion. Epoxy resins, in particular, are widely used in coating protection due to their excellent corrosion resistance, chemical and thermal stability. However, epoxy resins have some shortcomings, such as high brittleness, curing defects, and low UV resistance. With the development of the power industry towards ultra-high voltage, large capacity, cross-regional operation, and diverse environments, the comprehensive performance of traditional epoxy coatings can no longer meet the requirements, necessitating further overcoming of technical bottlenecks.

[0004] Technicians have optimized epoxy resin coating systems through filler modification, polymer modification, and nanomaterial modification. For example, zinc powder is added to improve corrosion resistance, polyamides and polypyrroles are used to improve the impact resistance of the coating, or nanofillers are introduced to improve the density and corrosion resistance of the coating. However, these modification methods still face problems such as poor interfacial compatibility of the coating system, high intrinsic brittleness, and weather resistance degradation. Therefore, improving the overall performance of epoxy anti-corrosion coatings is the key to their further development. Summary of the Invention

[0005] To address the aforementioned issues and further improve the overall performance of epoxy anti-corrosion coatings, this application provides an anti-corrosion coating composition and its preparation method.

[0006] This application first provides an anti-corrosion coating composition comprising the following components in parts by weight: 80-120 parts epoxy resin, 15-20 parts curing agent, 3-5 parts nano-alumina, 3.5-5 parts modified zirconium phosphate, 5-7.5 parts phenylboronic acid derivative, 5-10 parts end-capped diol, 2-5 parts dispersant, 1-3 parts defoamer, and 0.5-1 part lubricant; wherein the phenylboronic acid derivative is prepared by reacting 2-trifluoromethylphenylboronic acid chloride with 4,4'-diaminodiphenylmethane.

[0007] Furthermore, the phenylboronic acid derivative is prepared by the following steps:

[0008] 1) 2-Trifluoromethylphenylboronic acid was reacted with thionyl chloride under reflux to prepare 2-trifluoromethylphenylboronic acid chloride;

[0009] 2) Dissolve 2-trifluoromethylphenylboronyl chloride in THF, and then slowly add a THF solution containing 4,4'-diaminodiphenylmethane and triethylamine. The product is obtained after the reaction.

[0010] Furthermore, in step 1), the molar ratio of 2-trifluoromethylphenylboronic acid to thionyl chloride is 1:(4-5.5).

[0011] Furthermore, in step 2), the molar ratio of 2-trifluoromethylphenylboronyl chloride to 4,4'-diaminodiphenylmethane is 1:(0.5-0.75).

[0012] Furthermore, the capped diol is prepared by reacting triethyl orthoformate with 1,2-cyclohexanediol.

[0013] Furthermore, the modified zirconium phosphate is prepared by the following steps: zirconium phosphate and n-propylamine are added to ethanol and mixed and stirred, and filtered to obtain a precursor; the precursor is dispersed in an ethanol / water mixed solution, and an aqueous solution of ethylenediaminetetramethylenephosphonic acid is slowly added dropwise. After the addition is complete, the mixture is stirred, followed by the addition of a diethylenetriaminepentaacetic acid solution, and stirring is continued. The mixture is then centrifuged and dried to obtain the final product.

[0014] Furthermore, the mass ratio of the precursor material to ethylenediaminetetramethylenephosphonic acid is (3-5):1.

[0015] Furthermore, the molar ratio of ethylenediaminetetramethylenephosphonic acid to diethylenetriaminepentaacetic acid is 1:(0.3-0.8).

[0016] This application also provides a method for preparing an anti-corrosion coating composition, comprising the following steps:

[0017] S1: Mix epoxy resin, nano alumina, modified zirconium phosphate, capped diol, dispersant, and deionized water evenly to obtain a viscous base liquid;

[0018] S2: Add curing agent and phenylboronic acid derivative to the base liquid, stir evenly and allow to mature.

[0019] Furthermore, in step S2, the curing time is 20-35 minutes.

[0020] Compared with the prior art, this application has the following beneficial effects:

[0021] This application introduces a curing agent and phenylboronic acid derivative into the epoxy resin system, enabling the phenylboronic ester bonds to be incorporated into the epoxy crosslinking network, thereby improving the static brittleness of the epoxy system. Furthermore, when microcracks form in the coating, water molecules in the environment react with the end-capped diols to release the diols, which then react with the borate esters, thus achieving slow healing of the microcracks. In addition, to further enhance internal stress deflection and dissipation, modified zirconium phosphate is added. The surface of the zirconium phosphate nanosheets is rich in Lewis acidic zirconium sites, and through coordination bonding between ethylenediaminetetramethylene phosphate and diethylenetriaminepentaacetic acid, the interlayer spacing and arrangement of zirconium phosphate undergo favorable changes. These changes facilitate the barrier against water, oxygen, and other media. Simultaneously, the amino groups form BN coordination with boron atoms in the borate ester groups, further enhancing the toughness and weather resistance of the epoxy resin system. Attached Figure Description

[0022] Figure 1 This is a schematic diagram showing the tensile property test data of the anti-corrosion coating compositions of Examples 1-3 and Control Groups 1-2 of this application. Detailed Implementation

[0023] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0024] Based on extensive experimental research, this application provides an anti-corrosion coating composition comprising the following components in parts by weight: 80-120 parts epoxy resin, 15-20 parts curing agent, 3-5 parts nano-alumina, 3.5-5 parts modified zirconium phosphate, 5-7.5 parts phenylboronic acid derivative, 5-10 parts end-capped diol, 2-5 parts dispersant, 1-3 parts defoamer, and 0.5-1 part lubricant; wherein the phenylboronic acid derivative is prepared by reacting 2-trifluoromethylphenylboronic acid chloride with 4,4'-diaminodiphenylmethane.

[0025] In some specific embodiments, a typical anti-corrosion coating composition comprises the following components in parts by weight: 90 parts epoxy resin, 15 parts curing agent, 4 parts nano-alumina, 3.5 parts modified zirconium phosphate, 6.5 parts phenylboronic acid derivative, 7.5 parts end-capped glycol, 3 parts dispersant, 1.5 parts defoamer, and 0.5 parts lubricant. This approach yields better experimental results.

[0026] Furthermore, the phenylboronic acid derivative is prepared by the following steps:

[0027] 1) 2-Trifluoromethylphenylboronic acid was reacted with thionyl chloride under reflux to prepare 2-trifluoromethylphenylboronic acid chloride;

[0028] 2) Dissolve 2-trifluoromethylphenylboronyl chloride in THF, and then slowly add a THF solution containing 4,4'-diaminodiphenylmethane and triethylamine. The product is obtained after the reaction.

[0029] Furthermore, in step 1), the molar ratio of 2-trifluoromethylphenylboronic acid to thionyl chloride is 1:(4-5.5).

[0030] In some specific embodiments, in step 1), the molar ratio of 2-trifluoromethylphenylboronic acid to thionyl chloride can be 1:4, 1:4.1, 1:4.2, 1:4.3, 1:4.4, 1:4.5, 1:4.6, 1:4.7, 1:4.8, 1:4.9, 1:5, 1:5.1, 1:5.2, 1:5.3, 1:5.4, or 1:5.5. Generally, a molar ratio of 1:5 for 2-trifluoromethylphenylboronic acid to thionyl chloride in step 1) yields better technical results.

[0031] Furthermore, in step 2), the molar ratio of 2-trifluoromethylphenylboronyl chloride to 4,4'-diaminodiphenylmethane is 1:(0.5-0.75).

[0032] In some specific embodiments, in step 2), the molar ratio of 2-trifluoromethylphenylboronyl chloride to 4,4'-diaminodiphenylmethane can be 1:(0.5-0.6), 1:(0.6-0.65), or 1:(0.65-0.75). More preferably, in step 2), the molar ratio of 2-trifluoromethylphenylboronyl chloride to 4,4'-diaminodiphenylmethane can be 1:0.5, 1:0.52, 1:0.53, 1:0.55, 1:0.58, 1:0.59, 1:0.6, 1:0.62, 1:0.64, 1:0.65, 1:0.67, 1:0.68, 1:0.69, 1:0.7, 1:0.71, 1:0.72, 1:0.73, 1:0.74, or 1:0.75. Under normal circumstances, the experimental results are better when the molar ratio of 2-trifluoromethylphenylboronyl chloride to 4,4'-diaminodiphenylmethane is 1:0.55, 1:0.56, or 1:0.57 in step 2).

[0033] Furthermore, the capped diol is prepared by reacting triethyl orthoformate with 1,2-cyclohexanediol.

[0034] Furthermore, the modified zirconium phosphate is prepared by the following steps: zirconium phosphate and n-propylamine are added to ethanol and mixed and stirred, and filtered to obtain a precursor; the precursor is dispersed in an ethanol / water mixed solution, and an aqueous solution of ethylenediaminetetramethylenephosphonic acid is slowly added dropwise. After the addition is complete, the mixture is stirred, followed by the addition of a diethylenetriaminepentaacetic acid solution, and stirring is continued. The mixture is then centrifuged and dried to obtain the final product.

[0035] Furthermore, the mass ratio of the precursor material to ethylenediaminetetramethylenephosphonic acid is (3-5):1.

[0036] In some specific embodiments, the mass ratio of the precursor to ethylenediaminetetramethylenephosphonic acid can be 3:1, 3.2:1, 3.5:1, 3.6:1, 3.8:1, 4:1, 4.1:1, 4.3:1, 4.5:1, 4.7:1, 4.8:1, 4.9:1, or 5:1. Generally, a mass ratio of 3.5:1 or 3.6:1 yields better experimental results.

[0037] Furthermore, the molar ratio of ethylenediaminetetramethylenephosphonic acid to diethylenetriaminepentaacetic acid is 1:(0.3-0.8).

[0038] In some specific embodiments, the molar ratio of ethylenediaminetetramethylenephosphonic acid to diethylenetriaminepentaacetic acid can be 1:0.3, 1:0.35, 1:0.4, 1:0.45, 1:0.5, 1:0.55, 1:0.6, 1:0.65, 1:0.7, 1:0.75, or 1:0.8. Generally, a molar ratio of 1:0.6 or 1:0.65 yields better experimental results.

[0039] This application also provides a method for preparing an anti-corrosion coating composition, comprising the following steps:

[0040] S1: Mix epoxy resin, nano alumina, modified zirconium phosphate, capped diol, dispersant, and deionized water evenly to obtain a viscous base liquid;

[0041] S2: Add curing agent and phenylboronic acid derivative to the base liquid, stir evenly and allow to mature.

[0042] Furthermore, in step S2, the curing time is 20-35 minutes.

[0043] Example 1

[0044] The anti-corrosion coating composition of this embodiment includes the following components by weight: 9 kg epoxy resin, 0.15 kg curing agent, 0.4 kg nano alumina, 0.35 kg modified zirconium phosphate, 0.6 kg phenylboronic acid derivative, 0.75 kg end-capped diol, 0.3 kg dispersant, 0.15 kg defoamer, and 0.05 kg smoothing agent.

[0045] The epoxy resin is bisphenol A type epoxy resin, produced by Zhenjiang Danbao Resin Co., Ltd. The curing agent is DETA. The dispersant is BKY-163. The defoamer is BKY-066. The lubricant is 6105, manufactured by Dongguan Hongrui Chemical Co., Ltd.

[0046] The phenylboronic acid derivative in this embodiment was prepared using the following steps:

[0047] 1) Add 20g of 2-trifluoromethylphenylboronic acid to the reaction vessel, then slowly add 62g of thionyl chloride, controlling the dropping rate to keep the reaction temperature below 40℃. After the dropping is complete, add 2g of DMF, slowly raise the temperature to 70℃, and reflux for 6h to obtain 2-trifluoromethylphenylboronic acid chloride.

[0048] 2) Dissolve the above-mentioned 2-trifluoromethylphenylboronyl chloride in anhydrous THF. At a temperature of 0-5°C, slowly add a THF solution containing 10.4 g of 4,4'-diaminodiphenylmethane and 21.2 g of triethylamine dropwise while stirring continuously. After the addition is complete, stir the reaction at room temperature. After the reaction is complete, filter to remove the white precipitate of triethylamine hydrochloride generated in the reaction. Transfer the filtrate to a distillation vessel and distill off most of the THF under reduced pressure. Dissolve the remaining viscous substance in ethyl acetate and wash it successively with 1M HCl aqueous solution, saturated sodium bicarbonate aqueous solution, and deionized water. The resulting organic phase is dried to obtain the final product.

[0049] The modified zirconium phosphate in this embodiment was prepared by the following steps: 500g of zirconium phosphate and 160.6g of n-propylamine were added to ethanol and mixed and stirred. The mixture was then filtered to obtain the precursor. The precursor was dispersed in an ethanol / water mixed solution, and an aqueous solution of ethylenediaminetetramethylenephosphonic acid was slowly added dropwise. After the addition was complete, the mixture was stirred. Then, a solution of diethylenetriaminepentaacetic acid was added, and the mixture was stirred continuously. The mixture was then centrifuged and dried to obtain the final product.

[0050] The end-capped diol in this embodiment was prepared by the following steps: 500g of 1,2-cyclohexanediol, 105g of triethyl orthoformate, and 0.5g of PTSA catalyst were added to a reaction vessel, along with 100g of toluene as a dehydrating agent; the mixture was then heated to 110°C under reflux, and the reaction byproducts were separated using a water separator. The reaction was continued for approximately 8 hours until no water was expelled. After cooling, the mixture was washed with a saturated sodium bicarbonate solution until neutral, and the organic phase was separated and dried over anhydrous magnesium sulfate. Finally, toluene and excess triethyl orthoformate were distilled off under normal pressure, and the mixture was then distilled under reduced pressure at 100°C / -0.098 MPa. The distillate was collected to obtain a colorless and transparent 1,2-cyclohexanediol diacetal liquid product.

[0051] The method for preparing the anti-corrosion coating composition in this embodiment includes the following steps:

[0052] S1: According to the above proportions, epoxy resin, nano alumina, modified zirconium phosphate, capped diol, dispersant, and deionized water are mechanically stirred to ensure that all components are mixed evenly, resulting in a viscous base liquid;

[0053] S2: Add curing agent and phenylboronic acid derivative to base liquid, stir evenly and mature for 25 minutes to obtain.

[0054] Example 2

[0055] The anti-corrosion coating composition of this embodiment includes the following components by weight: 9 kg epoxy resin, 0.15 kg curing agent, 0.4 kg nano alumina, 0.35 kg modified zirconium phosphate, 0.6 kg phenylboronic acid derivative, 0.75 kg end-capped diol, 0.3 kg dispersant, 0.15 kg defoamer, and 0.05 kg smoothing agent.

[0056] The epoxy resin is bisphenol A type epoxy resin, produced by Zhenjiang Danbao Resin Co., Ltd. The curing agent is DETA. The dispersant is BKY-163. The defoamer is BKY-066. The lubricant is 6105, manufactured by Dongguan Hongrui Chemical Co., Ltd. The terminal glycol is ethylene oxide-terminated butanediol.

[0057] The phenylboronic acid derivative in this embodiment was prepared using the following steps:

[0058] 1) Add 20g of 2-trifluoromethylphenylboronic acid to the reaction vessel, then slowly add 62g of thionyl chloride, controlling the dropping rate to keep the reaction temperature below 40℃. After the dropping is complete, add 2g of DMF, slowly raise the temperature to 70℃, and reflux for 6h to obtain 2-trifluoromethylphenylboronic acid chloride.

[0059] 2) Dissolve the above-mentioned 2-trifluoromethylphenylboronyl chloride in anhydrous THF. At a temperature of 0-5°C, slowly add a THF solution containing 10.4 g of 4,4'-diaminodiphenylmethane and 21.2 g of triethylamine dropwise while stirring continuously. After the addition is complete, stir the reaction at room temperature. After the reaction is complete, filter to remove the white precipitate of triethylamine hydrochloride generated in the reaction. Transfer the filtrate to a distillation vessel and distill off most of the THF under reduced pressure. Dissolve the remaining viscous substance in ethyl acetate and wash it successively with 1M HCl aqueous solution, saturated sodium bicarbonate aqueous solution, and deionized water. The resulting organic phase is dried to obtain the final product.

[0060] The modified zirconium phosphate in this embodiment was prepared by the following steps: 500g of zirconium phosphate and 160.6g of n-propylamine were added to ethanol and mixed and stirred. The mixture was then filtered to obtain the precursor. The precursor was dispersed in an ethanol / water mixed solution, and an aqueous solution of ethylenediaminetetramethylenephosphonic acid was slowly added dropwise. After the addition was complete, the mixture was stirred. Then, a solution of diethylenetriaminepentaacetic acid was added, and the mixture was stirred continuously. The mixture was then centrifuged and dried to obtain the final product.

[0061] The method for preparing the anti-corrosion coating composition in this embodiment includes the following steps:

[0062] S1: According to the above proportions, epoxy resin, nano alumina, modified zirconium phosphate, capped diol, dispersant, and deionized water are mechanically stirred to ensure that all components are mixed evenly, resulting in a viscous base liquid;

[0063] S2: Add curing agent and phenylboronic acid derivative to base liquid, stir evenly and mature for 25 minutes to obtain.

[0064] Example 3

[0065] The anti-corrosion coating composition of this embodiment includes the following components by weight: 9 kg epoxy resin, 0.15 kg curing agent, 0.4 kg nano alumina, 0.35 kg modified zirconium phosphate, 0.6 kg phenylboronic acid derivative, 0.75 kg end-capped diol, 0.3 kg dispersant, 0.15 kg defoamer, and 0.05 kg smoothing agent.

[0066] The epoxy resin is bisphenol A type epoxy resin, produced by Zhenjiang Danbao Resin Co., Ltd. The curing agent is DETA. The dispersant is BKY-163. The defoamer is BKY-066. The lubricant is 6105, manufactured by Dongguan Hongrui Chemical Co., Ltd.

[0067] The phenylboronic acid derivative in this embodiment was prepared using the following steps:

[0068] 1) Add 20g of 2-trifluoromethylphenylboronic acid to the reaction vessel, then slowly add 62g of thionyl chloride, controlling the dropping rate to keep the reaction temperature below 40℃. After the dropping is complete, add 2g of DMF, slowly raise the temperature to 70℃, and reflux for 6h to obtain 2-trifluoromethylphenylboronic acid chloride.

[0069] 2) Dissolve the above-mentioned 2-trifluoromethylphenylboronyl chloride in anhydrous THF. At a temperature of 0-5°C, slowly add a THF solution containing 10.4 g of 4,4'-diaminodiphenylmethane and 21.2 g of triethylamine dropwise while stirring continuously. After the addition is complete, stir the reaction at room temperature. After the reaction is complete, filter to remove the white precipitate of triethylamine hydrochloride generated in the reaction. Transfer the filtrate to a distillation vessel and distill off most of the THF under reduced pressure. Dissolve the remaining viscous substance in ethyl acetate and wash it successively with 1M HCl aqueous solution, saturated sodium bicarbonate aqueous solution, and deionized water. The resulting organic phase is dried to obtain the final product.

[0070] The modified zirconium phosphate in this embodiment was prepared by the following steps: 500g of zirconium phosphate was dispersed in 5L of ethanol solution, 1kg of KH550 was added, stirring was continued, centrifugation was performed, and the mixture was dried to obtain the final product.

[0071] The end-capped diol in this embodiment was prepared by the following steps: 500g of 1,2-cyclohexanediol, 105g of triethyl orthoformate, and 0.5g of PTSA catalyst were added to a reaction vessel, along with 100g of toluene as a dehydrating agent; the mixture was then heated to 110°C under reflux, and the reaction byproducts were separated using a water separator. The reaction was continued for approximately 8 hours until no water was expelled. After cooling, the mixture was washed with a saturated sodium bicarbonate solution until neutral, and the organic phase was separated and dried over anhydrous magnesium sulfate. Finally, toluene and excess triethyl orthoformate were distilled off under normal pressure, and the mixture was then distilled under reduced pressure at 100°C / -0.098 MPa. The distillate was collected to obtain a colorless and transparent 1,2-cyclohexanediol diacetal liquid product.

[0072] The method for preparing the anti-corrosion coating composition in this embodiment includes the following steps:

[0073] S1: According to the above proportions, epoxy resin, nano alumina, modified zirconium phosphate, capped diol, dispersant, and deionized water are mechanically stirred to ensure that all components are mixed evenly, resulting in a viscous base liquid;

[0074] S2: Add curing agent and phenylboronic acid derivative to base liquid, stir evenly and mature for 25 minutes to obtain.

[0075] Control group 1

[0076] The anti-corrosion coating composition of this control group includes the following components by weight: 9 kg epoxy resin, 0.15 kg curing agent, 0.4 kg nano alumina, 0.35 kg zirconium phosphate, 0.3 kg dispersant, 0.15 kg defoamer, and 0.05 kg smoothing agent.

[0077] The epoxy resin is bisphenol A type epoxy resin, produced by Zhenjiang Danbao Resin Co., Ltd. The curing agent is DETA. The dispersant is BKY-163. The defoamer is BKY-066. The lubricant is 6105, manufactured by Dongguan Hongrui Chemical Co., Ltd.

[0078] The preparation method of the anti-corrosion coating composition in this control group includes the following steps:

[0079] S1: According to the above proportions, mechanically stir the epoxy resin, nano alumina, zirconium phosphate, dispersant and deionized water to mix the components evenly and obtain a viscous base liquid.

[0080] S2: Add curing agent to base liquid, stir evenly and mature for 25 minutes to obtain.

[0081] Control group 2

[0082] The anti-corrosion coating composition of this control group includes the following components by weight: 9 kg epoxy resin, 0.15 kg curing agent, 0.4 kg nano alumina, 0.35 kg zirconium phosphate, 0.6 kg 2-trifluoromethylphenylboronic acid, 0.75 kg 1,2-cyclohexanediol, 0.3 kg dispersant, 0.15 kg defoamer, and 0.05 kg smoothing agent.

[0083] The epoxy resin is bisphenol A type epoxy resin E44, produced by Zhenjiang Danbao Resin Co., Ltd. The curing agent is DETA. The dispersant is BKY-163. The defoamer is BKY-066. The lubricant is 6105, manufactured by Dongguan Hongrui Chemical Co., Ltd.

[0084] The preparation method of the anti-corrosion coating composition in this control group includes the following steps:

[0085] S1: According to the above ratio, epoxy resin, nano alumina, zirconium phosphate, 1,2-cyclohexanediol, dispersant and deionized water are mechanically stirred to make the components evenly mixed to obtain a viscous base liquid.

[0086] S2: Add curing agent and 2-trifluoromethylphenylboronic acid to the base liquid, stir evenly and mature for 25 minutes to obtain the product.

[0087] Performance testing

[0088] 1. The anti-corrosion coating compositions of Examples 1-3 and Control Groups 1-2 were poured into a mold and cured at room temperature for 48 hours to obtain the test material. Tensile tests were performed at room temperature according to GB / T 2567-2008 using a WH-300D testing machine at a test speed of 2 mm / min. The test results are as follows: Figure 1 As shown.

[0089] 2. The anti-corrosion coating compositions of Examples 1-3 and Control Groups 1-2 were coated onto the surface of the base metal (the base metal was a standard tinplate sheet with dimensions of 120mm×25mm×0.88mm, the surface of which was polished smooth and cleaned with deionized water and anhydrous ethanol) using a coater. The samples were dried and cured in a vacuum drying oven to obtain samples. The coating thickness of each sample was maintained at about 100μm. Then, the polarization corrosion performance of each sample was tested using an electrochemical workstation. The uncoated tinplate sheet was used as the blank group. The test results are shown in Table 1.

[0090]

[0091] analyze Figure 1 As can be seen from Table 1, the anti-corrosion coating composition of this application has excellent anti-corrosion performance. The modified zirconium phosphate can effectively block the intrusion of corrosive media into the coating and the base metal, and delay the movement and migration of corrosive media. In addition, the coating also has good toughness and crack resistance, effectively improving the intrinsic brittleness of the coating, compensating for the curing defects of the coating, and exhibiting good weather resistance and mechanical properties.

[0092] Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this invention.

Claims

1. A corrosion protective coating composition characterized in that: The product comprises the following components in parts by weight: 80-120 parts epoxy resin, 15-20 parts curing agent, 3-5 parts nano-alumina, 3.5-5 parts modified zirconium phosphate, 5-7.5 parts phenylboronic acid derivative, 5-10 parts end-capped diol, 2-5 parts dispersant, 1-3 parts defoamer, and 0.5-1 part smoothing agent; the phenylboronic acid derivative is prepared by the following steps: 1) 2-Trifluoromethylphenylboronic acid was reacted with thionyl chloride under reflux to prepare 2-trifluoromethylphenylboronic acid chloride; 2) Dissolve 2-trifluoromethylphenylboronyl chloride in THF, and then slowly add a THF solution containing 4,4'-diaminodiphenylmethane and triethylamine. The product is obtained after the reaction.

2. The anticorrosive coating composition according to claim 1, characterized in that: In step 1), the molar ratio of 2-trifluoromethylphenylboronic acid to thionyl chloride is 1:(4-5.5).

3. The anti-corrosion coating composition according to claim 1, characterized in that: In step 2), the molar ratio of 2-trifluoromethylphenylboronyl chloride to 4,4'-diaminodiphenylmethane is 1:(0.5-0.75).

4. The anti-corrosion coating composition according to claim 1, characterized in that: The terminated diol is prepared by reacting triethyl orthoformate with 1,2-cyclohexanediol.

5. The anti-corrosion coating composition according to claim 1, characterized in that: The modified zirconium phosphate is prepared by the following steps: zirconium phosphate and n-propylamine are added to ethanol and mixed and stirred, and filtered to obtain a precursor; the precursor is dispersed in an ethanol / water mixed solution, and an aqueous solution of ethylenediaminetetramethylenephosphonic acid is slowly added dropwise. After the addition is complete, the mixture is stirred, followed by the addition of a diethylenetriaminepentaacetic acid solution, and stirring is continued. The mixture is then centrifuged and dried to obtain the final product.

6. The anti-corrosion coating composition according to claim 5, characterized in that: The mass ratio of the precursor material to ethylenediaminetetramethylenephosphonic acid is (3-5):

1.

7. The anti-corrosion coating composition according to claim 5, characterized in that: The molar ratio of ethylenediaminetetramethylenephosphonic acid to diethylenetriaminepentaacetic acid is 1:(0.3-0.8).

8. A method for preparing the anti-corrosion coating composition as described in claim 1, characterized in that: Includes the following steps: S1: Mix epoxy resin, nano alumina, modified zirconium phosphate, capped diol, dispersant, and deionized water evenly to obtain a viscous base liquid; S2: Add curing agent and phenylboronic acid derivative to the base liquid, stir evenly and allow to mature.

9. The method for preparing the anti-corrosion coating composition according to claim 8, characterized in that: In step S2, the curing time is 20-35 minutes.

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