Anticorrosive epoxy paint and preparation method thereof

Abstract

The invention discloses anti-corrosion epoxy paint and a preparation method thereof, and belongs to the technical field of paint. The anti-corrosion epoxy paint is prepared from the following raw material components in parts by weight: 100 parts by mass of branched epoxy resin, 10 to 20 parts by mass of a curing agent, 0.4 to 0.8 part by mass of composite polyaniline, 4 to 6 parts by mass of a de-foaming agent, 5 parts by mass of a flatting agent, 10 to 15 parts by mass of a solvent and 0.15 to 0.25 part by mass of a photoinitiator, the branched epoxy resin is obtained by mixing and reacting 1 part by mass of trihydroxymethyl triglycidyl ether, 0.1-0.3 part by mass of 4, 4 '-dihydroxyazobenzene and 1.5-2.5 parts by mass of polyvinyl alcohol; the curing agent comprises alpha-cyclodextrin and itaconic acid; the composite aniline is obtained by reacting hyperbranched polysiloxane and polyaniline, wherein the hyperbranched polysiloxane is prepared from 3-glycidyl ether oxypropyl trimethoxy silane and 3-mercaptopropyl trimethoxy silane.

Description

Technical Field

[0001] The invention relates to an anticorrosive epoxy paint and a preparation method thereof. Background Art

[0002] With the development of industrial technology, the demand for high-performance anti-corrosion coatings in the field of materials science is growing. Epoxy resin has become one of the preferred materials in many application fields due to its excellent physical and chemical properties and relatively low cost, including but not limited to aerospace coatings, electronic packaging, advanced composite materials, and adhesives. However, epoxy resin has large internal stress after curing, which not only limits its mechanical properties, such as tensile strength and bending strength, but also easily leads to problems such as brittle fracture or cracking of the material during use. In addition, traditional epoxy paints perform poorly in terms of corrosion resistance and waterproofness. These defects seriously restrict the application scope and development potential of epoxy resins.

[0003] In order to overcome the above challenges, researchers began to explore ways to improve the overall performance of epoxy resins by modifying them. As an environmentally friendly anti-corrosion inhibitor, polyaniline forms a protective film on the metal surface by virtue of its unique "activation-passivation" mechanism, which can significantly improve the material's corrosion resistance. This mechanism is based on the reversible redox reaction between polyaniline and the metal surface, which accelerates the formation of a passivation film on the metal surface, thereby effectively preventing the occurrence of the corrosion process. Introducing polyaniline into the epoxy resin system can theoretically greatly enhance the anti-corrosion effect of the coating.

[0004] However, in actual operation, it is found that there are obvious compatibility issues between aniline monomer and epoxy resin matrix. Directly mixing the two often leads to uneven dispersion and even serious phase separation, which not only affects the appearance quality of the final product, but more importantly, weakens the overall performance of the material and fails to achieve the expected modification effect.

[0005] Therefore, the present invention provides an anticorrosive epoxy paint and a preparation method thereof to solve the above problems. Summary of the invention

[0006] The purpose of the present invention is to provide an anticorrosive epoxy paint and a preparation method thereof to solve the technical problems mentioned in the above background technology.

[0007] The technical solution for achieving the purpose of the present invention is:

[0008] The invention discloses an anticorrosive epoxy paint, wherein the raw material components include, by weight: 100 parts by weight of branched epoxy resin, 10 to 20 parts by weight of curing agent, 0.4 to 0.8 parts by weight of composite polyaniline, 4 to 6 parts by weight of defoaming agent, 5 parts by weight of leveling agent, 10 to 15 parts by weight of solvent and 0.15 to 0.25 parts by weight of photoinitiator.

[0009] Furthermore, the branched epoxy resin is obtained by mixing 1 part by mass of trimethylol triglycidyl ether, 0.1 to 0.3 parts by mass of 4,4'-dihydroxyazobenzene, and 1.5 to 2.5 parts by mass of polyvinyl alcohol.

[0010] Furthermore, the curing agent is α-cyclodextrin and itaconic acid.

[0011] Furthermore, the composite polyaniline is obtained by mixing and reacting hyperbranched polysiloxane and polyaniline.

[0012] Furthermore, the hyperbranched polysiloxane is prepared by a mixed reaction of 3-glycidyloxypropyltrimethoxysilane and 3-mercaptopropyltrimethoxysilane.

[0013] A method for preparing an anticorrosive epoxy paint comprises the following preparation steps: adding 100 parts by mass of a branched epoxy resin, 10 to 20 parts by mass of a curing agent, 0.4 to 0.8 parts by mass of a composite polyaniline, 4 to 6 parts by mass of a defoaming agent, 5 parts by mass of a leveling agent, and 10 to 15 parts by mass of a solvent into a reaction kettle, stirring at 1000 to 2000 rpm for 18 to 22 minutes at 48 to 52° C., adding 1.5 to 2.5 parts by mass of a photoinitiator, and continuing to stir and disperse for 1 to 3 hours to obtain an anticorrosive epoxy paint.

[0014] Furthermore, the preparation steps of the branched epoxy resin are as follows: under nitrogen protection, 0.1 to 0.3 parts by mass of 4,4'-dihydroxyazobenzene, 1.5 to 2.5 parts by mass of polyvinyl alcohol, 1 part by mass of trimethylol triglycidyl ether, and 0.0008 to 0.0012 parts by mass of catalyst tetrabutylammonium bromide are placed in a reaction kettle, heated to 78 to 82°C, refluxed for 3.5 to 4.5 hours, cooled to room temperature after the reaction, and then tetrahydrofuran 4 to 6 times its mass is added and stirred until dissolved, then deionized water of an equal volume of tetrahydrofuran is added, and the organic phase is separated and the catalyst and small molecular products in the reaction process are removed, and the above separation operation is repeated three times for purification, and then dried in a vacuum oven at 80°C for 23 to 25 hours to obtain a branched epoxy resin.

[0015] Furthermore, the mass ratio of α-cyclodextrin to itaconic acid in the curing agent is 2 to 4:1.

[0016] Furthermore, the preparation method of the composite polyaniline is as follows: 1 part by mass of polyaniline is added to a reaction kettle, followed by adding 200 parts by mass of dimethyl sulfoxide, and adding 0.15 to 0.25 parts by mass of hyperbranched polysiloxane at a rate of 1 to 3 drops / s under magnetic stirring and N2 protection, reacting at 24 to 26°C for 48 hours, and after the reaction is completed, adding excess methanol for repeated washing and suction filtration, and vacuum drying at 50°C for 23 to 25 hours to obtain the composite polyaniline.

[0017] Furthermore, the preparation method of the hyperbranched polysiloxane is as follows: 13 to 14 parts by mass of 3-glycidyloxypropyltrimethoxysilane, 9 to 11 parts by mass of 3-mercaptopropyltrimethoxysilane, and 15 to 17 parts by mass of ethanol are added to a reaction kettle, and the temperature is raised to 58 to 62° C. under magnetic stirring and N2 protection for reflux condensation, 2 to 2.4 parts by mass of deionized water are added dropwise at a rate of 1 to 3 drops / s, and sodium hydroxide is added to adjust the pH to 9 to 10, and the mixture is stirred at this temperature for 3.5 to 4.5 hours, and then tartaric acid is added for neutralization, followed by filtering and distillation under reduced pressure to obtain a hyperbranched polysiloxane.

[0018] Furthermore, the anticorrosive epoxy paint is used as follows: a frame-type scraper is used to evenly apply the paint on the surface of a low-carbon steel plate, and then the paint is applied at 100 mW / cm 2 , 405nm laser irradiation for 18 to 22 minutes, followed by drying at 29 to 31°C for 2 hours to evaporate the surface solvent, then heating to 78 to 82°C and continuing to cure for 7 to 9 hours.

[0019] By adopting the above technical solution, the present invention has the following beneficial effects:

[0020] The anticorrosive epoxy paint of the present invention comprises, by weight, raw material components: 100 parts by weight of branched epoxy resin, 10-20 parts by weight of curing agent, 0.4-0.8 parts by weight of composite polyaniline, 4-6 parts by weight of defoaming agent, 5 parts by weight of leveling agent, 10-15 parts by weight of solvent, and 0.15-0.25 parts by weight of photoinitiator; wherein the branched epoxy resin is obtained by a mixed reaction of 1 part by weight of trimethylol triglycidyl ether, 0.1-0.3 parts by weight of 4,4'-dihydroxyazobenzene, and 1.5-2.5 parts by weight of polyvinyl alcohol; the curing agent adopts alpha-cyclodextrin and itaconic acid; the composite polyaniline is obtained by a mixed reaction of hyperbranched polysiloxane and polyaniline; and the hyperbranched polysiloxane is obtained by a mixed reaction of 3-glycidyloxypropyltrimethoxysilane and 3-mercaptopropyltrimethoxysilane.

[0021] Firstly, trimethylol triglycidyl ether, 4,4'-dihydroxyazobenzene and polyvinyl alcohol are mixed, and 4,4'-dihydroxyazobenzene, polyvinyl alcohol and trimethylol triglycidyl ether are subjected to a ring-opening reaction through proton transfer polymerization to form a branched epoxy resin. Compared with the linear epoxy resin, the branched epoxy resin and the curing agent can form a three-dimensional cross-linked network to enhance the mechanical properties of the anti-corrosion epoxy paint; at the same time, the introduction of the rigid benzene ring of 4,4'-dihydroxyazobenzene enhances the tensile properties of the branched epoxy resin.

[0022] Secondly, a hyperbranched polysiloxane prepared by 3-glycidyloxypropyltrimethoxysilane and 3-mercaptopropyltrimethoxysilane is reacted with polyaniline to obtain composite aniline; the introduction of hyperbranched polysiloxane into the composite aniline can obtain aniline with a branched structure, the mutual repulsion between the composite aniline molecules leads to a decrease in the crystallization ability, and a large amount of amorphous structure makes it easier for solvent molecules to diffuse into the composite aniline molecules, accelerating the dissolution, thereby improving the compatibility between the composite aniline and the resin base material; at the same time, the hyperbranched polysiloxane effectively improves the thermal stability of the polyaniline.

[0023] Polyaniline is an excellent green corrosion inhibitor. Compared with conventional corrosion inhibitors, it has no environmental side effects and exhibits "activation-passivation" behavior on metal materials, that is, it accelerates the formation of a passivation film on the metal surface through a reversible redox reaction, thereby effectively inhibiting the occurrence of corrosion reactions. The introduction of polyaniline into branched epoxy resin can effectively improve the anti-corrosion performance of branched epoxy resin. When the raw material components are mixed and cured, the branched epoxy resin and the curing agent penetrate into the cavity of the branched aniline to cure and cross-link, forming an interpenetrating network structure with the branched composite polyaniline, which preliminarily improves the composite polyaniline and the branched structure. In order to solve the compatibility problem of epoxy resin, a photoinitiator is introduced. Under the action of light, the thiol group on the composite polyaniline reacts and cross-links with the olefin bonds on the cured branched epoxy resin, further improving the compatibility between the branched structure aniline and the resin base material, thereby enhancing the mechanical properties and anti-corrosion properties of the anti-corrosion epoxy paint. At the same time, after being stimulated by light and heat, cis-azobenzene will be converted into trans-azobenzene and combined with cyclodextrin, which will cause the polymer chain of the branched epoxy resin of the coating to shrink, forming a micro-nano structure on the coating surface, which will also make the composite aniline more exposed on the coating surface, thereby increasing the waterproof performance of the anti-corrosion epoxy paint. DETAILED DESCRIPTION

[0024] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with specific implementation methods.

[0025] The following embodiments are only used to more clearly illustrate the technical solutions of the present invention, and are not intended to limit the protection scope of the present invention.

[0026] Some of the raw material components of the embodiments of the present invention and the comparative examples are as follows:

[0027] The average relative molecular mass of polyvinyl alcohol is about 13,000;

[0028] Polyaniline: average relative molecular mass is about 15000;

[0029] The cyclodextrin used is α-cyclodextrin;

[0030] The solvent used was dimethyl sulfoxide;

[0031] The leveling agent used is BYK-333 from BYK Chemical Company;

[0032] The defoamer is BYK-066N;

[0033] The photoinitiator used was photoinitiator 1173;

[0034] Epoxy resin: Bisphenol A epoxy resin E51, industrial purity, epoxy value is 0.52 mol / 100g.

[0035] (Example 1)

[0036] A method for preparing an anticorrosive epoxy paint comprises the following preparation steps: adding 100 parts by mass of a branched epoxy resin, 10 parts by mass of a curing agent, 0.4 parts by mass of a composite polyaniline, 4 parts by mass of a defoaming agent, 5 parts by mass of a leveling agent, and 10 parts by mass of a solvent into a reaction kettle, stirring at 1000 rpm for 18 minutes at 48°C, adding 1.5 parts by mass of a photoinitiator, and continuing to stir and disperse for 1 hour to obtain an anticorrosive epoxy paint.

[0037] The preparation steps of the branched epoxy resin are as follows: under nitrogen protection, 0.1 parts by mass of 4,4'-dihydroxyazobenzene, 1.5 parts by mass of polyvinyl alcohol, 1 part by mass of trimethylol triglycidyl ether, and 0.0008 parts by mass of catalyst tetrabutylammonium bromide are placed in a reaction kettle, the temperature is raised to 78°C, and the reaction is refluxed for 3.5 hours. After the reaction is completed, the reaction is cooled to room temperature, and then tetrahydrofuran of 4 times the mass is added and stirred until dissolved, and then deionized water of the same volume as the tetrahydrofuran is added, and the organic phase is separated and taken, and the catalyst and small molecular products in the reaction process are removed. The above separation operation is repeated three times for purification, and then dried in a vacuum oven at 80°C for 23 hours to obtain a branched epoxy resin.

[0038] The mass ratio of α-cyclodextrin and itaconic acid in the curing agent is 2:1.

[0039] The preparation method of the composite polyaniline is as follows: 1 part by mass of polyaniline is added into a reaction kettle, followed by adding 200 parts by mass of dimethyl sulfoxide, and adding 0.15 parts by mass of hyperbranched polysiloxane at a rate of 1 drop / s under magnetic stirring and N2 protection, and reacting at 24°C for 48 hours. After the reaction is completed, adding excess methanol, repeatedly washing, filtering, and vacuum drying at 50°C for 23 hours to obtain the composite polyaniline.

[0040] The preparation method of the hyperbranched polysiloxane is as follows: 13 parts by mass of 3-glycidyloxypropyltrimethoxysilane, 9 parts by mass of 3-mercaptopropyltrimethoxysilane, and 15 parts by mass of ethanol are added into a reaction kettle, the temperature is raised to 58° C. under magnetic stirring and N2 protection for reflux condensation, 2 parts by mass of deionized water are added dropwise at a rate of 1 drop / s, sodium hydroxide is added to adjust the pH to 9, the mixture is stirred at the temperature for 3.5 hours, tartaric acid is then added for neutralization, and then filtered and distilled under reduced pressure to obtain the hyperbranched polysiloxane.

[0041] (Example 2)

[0042] A method for preparing an anticorrosive epoxy paint comprises the following preparation steps: adding 100 parts by mass of a branched epoxy resin, 15 parts by mass of a curing agent, 0.6 parts by mass of a composite polyaniline, 5 parts by mass of a defoaming agent, 5 parts by mass of a leveling agent, and 13 parts by mass of a solvent into a reaction kettle, stirring at 1500 rpm for 20 minutes at 50°C, adding 2 parts by mass of a photoinitiator, and continuing to stir and disperse for 2 hours to obtain an anticorrosive epoxy paint.

[0043] The preparation steps of the branched epoxy resin are as follows: under nitrogen protection, 0.2 parts by mass of 4,4'-dihydroxyazobenzene, 2 parts by mass of polyvinyl alcohol, 1 part by mass of trimethylol triglycidyl ether, and 0.001 parts by mass of catalyst tetrabutylammonium bromide are placed in a reaction kettle, the temperature is raised to 80°C, refluxed for reaction for 4 hours, cooled to room temperature after the reaction is completed, and then tetrahydrofuran with a mass of 5 times the mass thereof is added and stirred until dissolved, and then deionized water with a volume equal to that of tetrahydrofuran is added, and the organic phase is separated and taken, the catalyst and small molecular products in the reaction process are removed, the above separation operation is repeated three times for purification, and then dried in a vacuum oven at 80°C for 24 hours to obtain a branched epoxy resin.

[0044] The mass ratio of α-cyclodextrin and itaconic acid in the curing agent is 3:1.

[0045] The preparation method of the composite polyaniline is as follows: 1 part by mass of polyaniline is added into a reaction kettle, followed by adding 200 parts by mass of dimethyl sulfoxide, and adding 0.2 parts by mass of hyperbranched polysiloxane at a rate of 2 drops / s under magnetic stirring and N2 protection, and reacting at 25°C for 48 hours. After the reaction is completed, adding excess methanol, repeatedly washing, filtering, and vacuum drying at 50°C for 24 hours to obtain the composite polyaniline.

[0046] The preparation method of the hyperbranched polysiloxane is as follows: 13.5 parts by mass of 3-glycidyloxypropyltrimethoxysilane, 10 parts by mass of 3-mercaptopropyltrimethoxysilane, and 16 parts by mass of ethanol are added into a reaction kettle, the temperature is raised to 60° C. under magnetic stirring and N2 protection for reflux condensation, 2.2 parts by mass of deionized water is added dropwise at a rate of 2 drops / s, and sodium hydroxide is added to adjust the pH to 10, the mixture is kept warm and stirred for 4 hours, tartaric acid is then added for neutralization, and then filtered and distilled under reduced pressure to obtain the hyperbranched polysiloxane.

[0047] (Example 3)

[0048] A method for preparing an anticorrosive epoxy paint comprises the following preparation steps: adding 100 parts by mass of a branched epoxy resin, 20 parts by mass of a curing agent, 0.8 parts by mass of a composite polyaniline, 6 parts by mass of a defoaming agent, 5 parts by mass of a leveling agent, and 15 parts by mass of a solvent into a reaction kettle, stirring at 2000 rpm for 22 minutes at 52° C., adding 2.5 parts by mass of a photoinitiator, and continuing to stir and disperse for 3 hours to obtain an anticorrosive epoxy paint.

[0049] The preparation steps of the branched epoxy resin are as follows: under nitrogen protection, 0.3 parts by mass of 4,4'-dihydroxyazobenzene, 2.5 parts by mass of polyvinyl alcohol, 1 part by mass of trimethylol triglycidyl ether, and 0.0012 parts by mass of catalyst tetrabutylammonium bromide are placed in a reaction kettle, the temperature is raised to 82°C, and the reaction is refluxed for 4.5 hours. After the reaction is completed, the reaction is cooled to room temperature, and then tetrahydrofuran (6 times the mass) is added and stirred until dissolved, and then deionized water of the same volume as the tetrahydrofuran is added, and the organic phase is separated and taken, and the catalyst and small molecular products in the reaction process are removed. The above separation operation is repeated three times for purification, and then dried in a vacuum oven at 80°C for 25 hours to obtain a branched epoxy resin.

[0050] The mass ratio of α-cyclodextrin to itaconic acid in the curing agent is 4:1.

[0051] The preparation method of the composite polyaniline is as follows: 1 part by mass of polyaniline is added into a reaction kettle, followed by adding 200 parts by mass of dimethyl sulfoxide, and adding 0.25 parts by mass of hyperbranched polysiloxane at a rate of 3 drops / s under magnetic stirring and N2 protection, and reacting at 26°C for 48 hours. After the reaction is completed, adding excess methanol, repeatedly washing, filtering, and vacuum drying at 50°C for 25 hours to obtain the composite polyaniline.

[0052] The preparation method of the hyperbranched polysiloxane is as follows: 14 parts by mass of 3-glycidyloxypropyltrimethoxysilane, 11 parts by mass of 3-mercaptopropyltrimethoxysilane, and 17 parts by mass of ethanol are added into a reaction kettle, the temperature is raised to 62° C. under magnetic stirring and N2 protection for reflux condensation, 2.4 parts by mass of deionized water is added dropwise at a rate of 3 drops / s, and sodium hydroxide is added to adjust the pH to 10, the mixture is kept warm and stirred for 4.5 hours, tartaric acid is then added for neutralization, and then filtered and distilled under reduced pressure to obtain the hyperbranched polysiloxane.

[0053] (Comparative Example 1)

[0054] The difference between Comparative Example 1 and Example 2 is that the raw material components of the anti-corrosion epoxy paint include: bisphenol A type epoxy resin, curing agent, composite polyaniline, defoaming agent, leveling agent, solvent, and photoinitiator; the remaining steps and ingredients are the same as those in Example 2.

[0055] (Comparative Example 2)

[0056] The difference between Comparative Example 2 and Example 2 is that the raw material components of the anti-corrosion epoxy paint include: branched epoxy resin, curing agent, polyaniline, defoaming agent, leveling agent, solvent, and photoinitiator; the remaining steps and ingredients are the same as those in Example 2.

[0057] (Comparative Example 3)

[0058] The difference between Comparative Example 3 and Example 2 is that the raw material components of the anti-corrosion epoxy paint include: branched epoxy resin, curing agent, composite polyaniline, defoaming agent, leveling agent, and solvent; the remaining steps and ingredients are the same as those of Example 2.

[0059] (Comparative Example 4)

[0060] The difference between Comparative Example 4 and Example 2 is that only α-cyclodextrin is used as the curing agent, and the remaining steps and components are the same as those of Example 2.

[0061] (Comparative Example 5)

[0062] The difference between Comparative Example 5 and Example 2 is that only itaconic acid is used as the curing agent, and the remaining steps and components are the same as those of Example 2.

[0063] (Comparative Example 6)

[0064] The difference between Comparative Example 6 and Example 2 is that the branched epoxy resin is prepared by reacting trimethylol triglycidyl ether and polyvinyl alcohol only, and the remaining steps and components are the same as those of Example 2.

[0065] (Comparative Example 7)

[0066] The difference between Comparative Example 7 and Example 2 is that the hyperbranched polysiloxane is prepared only by polycondensation of 3-glycidyloxypropyltrimethoxysilane, and the remaining steps and components are the same as those of Example 2.

[0067] Effect example:

[0068] Tensile properties: The tensile properties of the anticorrosive epoxy paints prepared in the examples and comparative examples were tested using Shimadzu's electronic universal tensile testing machine AGS-X10KN in accordance with GB / T7762.

[0069] Bending strength: The bending performance of HPB-CN cured product was tested using the HZ-1003B tensile testing machine produced by Lixian Instrument Technology Co., Ltd. The anti-corrosion epoxy paint was poured into rectangular strips with a length of 80±2mm, a width of 15±0.2mm, and a thickness of 4±0.2mm according to the national standard GB / T1043-2008; it was fixed on the testing machine and subjected to a bending test at a speed of 2mm / min.

[0070] Anti-corrosion performance: The anti-corrosion epoxy paint prepared in the examples and comparative examples was uniformly applied to the surface of the mild steel plate using a frame-type scraper with a gap width of 120 μm, and then 2 , 405nm laser irradiation for 18-22min, then drying at 29-31℃ for 2h to evaporate the surface solvent, then heating to 78-82℃, and continuing to cure for 7-9h to obtain an anti-corrosion epoxy coating. The salt spray resistance of the anti-corrosion epoxy coating was tested according to GB / T1771.

[0071] Waterproofness: The contact angle of the anti-corrosion epoxy coating was measured using the JC2000DM contact angle meter produced by Shanghai Zhongchen Digital Technology Equipment Co., Ltd. The test conditions were 2 μL of deionized water each time.

[0072] Table 1 below shows the performance test results of the anticorrosive epoxy paints prepared in the examples and comparative examples:

[0073] Table 1

[0074]

[0075] It can be seen from Table 1 above that the anti-corrosion epoxy paints prepared in Examples 1 to 3 have good tensile properties, bending properties, anti-corrosion properties and waterproof properties.

[0076] Comparison Example 1 is compared with Example 2. Comparison Example 1 uses bisphenol A epoxy resin to prepare anti-corrosion epoxy paint, which cannot form an epoxy resin with a branched structure. After subsequent photothermal stimulation, it cannot form a micro-nano structure, and the tensile performance, bending performance, and waterproof performance are poor.

[0077] Compared with Example 2, Comparative Example 2 uses polyaniline to prepare anti-corrosion epoxy paint, which cannot form an interconducting network structure, has poor compatibility, poor tensile and bending properties, and the lack of hyperbranched polysiloxane leads to poor overall waterproofness.

[0078] Compared with Example 2, the anti-corrosion epoxy paint of Comparative Example 3 does not add a photoinitiator, and cannot form a cross-linked network of the mercapto group and the olefin bond reaction, and the tensile performance and bending performance are poor.

[0079] Compared with Example 2, in Comparative Example 4, the curing agent does not use itaconic acid, and a cross-linked network of the mercapto group and the olefin bond cannot be formed, and the tensile property and bending property are poor.

[0080] Compared with Example 2, Comparative Example 5 does not use α-cyclodextrin as the curing agent, and cannot form a micro-nano structure, resulting in poor water resistance.

[0081] Comparative Example 6 Compared with Example 2, the branched epoxy resin in Comparative Example 6 does not add 4,4'-dihydroxyazobenzene, and cannot form a micro-nano structure, and has poor waterproofness and poor tensile properties.

[0082] Comparative Example 7 is compared with Example 2. In Comparative Example 7, the hyperbranched polysiloxane is not added with 3-mercaptopropyltrimethoxysilane, and a cross-linked network of mercapto groups and olefin bonds cannot be formed, and the tensile properties and bending properties are poor.

[0083] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An anticorrosive epoxy paint, characterized in that: The raw material components include, by weight: 100 parts by weight of branched epoxy resin, 10 to 20 parts by weight of curing agent, 0.4 to 0.8 parts by weight of composite polyaniline, 4 to 6 parts by weight of defoaming agent, 5 parts by weight of leveling agent, 10 to 15 parts by weight of solvent, and 0.15 to 0.25 parts by weight of photoinitiator.

2. The anticorrosive epoxy paint according to claim 1, characterized in that: The branched epoxy resin is obtained by mixing 1 part by mass of trimethylol triglycidyl ether, 0.1 to 0.3 parts by mass of 4,4'-dihydroxyazobenzene and 1.5 to 2.5 parts by mass of polyvinyl alcohol.

3. The anticorrosive epoxy paint according to claim 1, characterized in that: The curing agent is α-cyclodextrin and itaconic acid.

4. The anticorrosive epoxy paint according to claim 1, characterized in that: The composite polyaniline is obtained by mixing and reacting hyperbranched polysiloxane and polyaniline.

5. The anticorrosive epoxy paint according to claim 1, characterized in that: The hyperbranched polysiloxane is prepared by mixed reaction of 3-glycidyloxypropyltrimethoxysilane and 3-mercaptopropyltrimethoxysilane.

6. A method for preparing an anticorrosive epoxy paint, characterized in that: The invention comprises the following preparation steps: adding 100 parts by weight of branched epoxy resin, 10 to 20 parts by weight of curing agent, 0.4 to 0.8 parts by weight of composite polyaniline, 4 to 6 parts by weight of defoaming agent, 5 parts by weight of leveling agent and 10 to 15 parts by weight of solvent into a reaction kettle, stirring at 1000 to 2000 rpm for 18 to 22 minutes at 48 to 52° C., adding 1.5 to 2.5 parts by weight of photoinitiator, and continuing stirring and dispersing for 1 to 3 hours to obtain an anticorrosive epoxy paint.

7. The method for preparing the anticorrosive epoxy paint according to claim 6, characterized in that: The preparation steps of the branched epoxy resin are as follows: under nitrogen protection, 0.1-0.3 parts by weight of 4,4'-dihydroxyazobenzene, 1.5-2.5 parts by weight of polyvinyl alcohol, 1 part by weight of trimethylol triglycidyl ether, and 0.0008-0.0012 parts by weight of catalyst tetrabutylammonium bromide are placed in a reaction kettle, the temperature is raised to 78-82° C., and the reaction is refluxed for 3.5-4.5 hours. After the reaction is completed, the reaction is cooled to room temperature, and then tetrahydrofuran in an amount of 4-6 times the weight of the tetrahydrofuran is added and stirred until dissolved, and then deionized water of an equal volume of tetrahydrofuran is added, and the organic phase is separated and taken, the catalyst and small molecular products in the reaction process are removed, and the above separation operation is repeated three times for purification, and then the branched epoxy resin is obtained by drying in a vacuum oven at 80° C. for 23-25 ​​hours.

8. The method for preparing the anticorrosive epoxy paint according to claim 6, characterized in that: The mass ratio of α-cyclodextrin to itaconic acid in the curing agent is 2-4:

1.

9. The method for preparing the anticorrosive epoxy paint according to claim 6, characterized in that: The preparation method of the composite polyaniline is as follows: 1 part by mass of polyaniline is added into a reaction kettle, followed by adding 200 parts by mass of dimethyl sulfoxide, and adding 0.15 to 0.25 parts by mass of hyperbranched polysiloxane at a rate of 1 to 3 drops / s under magnetic stirring and N2 protection, and reacting at 24 to 26° C. for 48 hours. After the reaction is completed, adding excess methanol, repeatedly washing, filtering, and vacuum drying at 50° C. for 23 to 25 hours to obtain the composite polyaniline.

10. The method for preparing the anticorrosive epoxy paint according to claim 6, characterized in that: The preparation method of the hyperbranched polysiloxane is as follows: 13 to 14 parts by weight of 3-glycidyloxypropyltrimethoxysilane, 9 to 11 parts by weight of 3-mercaptopropyltrimethoxysilane, and 15 to 17 parts by weight of ethanol are added into a reaction kettle, the temperature is raised to 58 to 62° C. under magnetic stirring and N2 protection for reflux condensation, 2 to 2.4 parts by weight of deionized water are added dropwise at a rate of 1 to 3 drops / s, and sodium hydroxide is added to adjust the pH to 9 to 10, the reaction is stirred at this temperature for 3.5 to 4.5 hours, tartaric acid is then added for neutralization, and then the reaction is filtered and distilled under reduced pressure to obtain the hyperbranched polysiloxane.

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