Anticorrosive epoxy paint and preparation method thereof

Abstract

The invention discloses an anti-corrosion epoxy paint and a preparation method thereof, belonging to the technical field of coatings. The anti-corrosion epoxy paint of the invention comprises, by weight, raw material components: 100 parts by weight of a branched epoxy resin, 10-20 parts by weight of a curing agent, 0.4-0.8 parts by weight of a composite polyaniline, 4-6 parts by weight of a defoamer, 5 parts by weight of a leveling agent, 10-15 parts by weight of a solvent, and 0.15-0.25 parts by weight of a photoinitiator. 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 comprises alpha-cyclodextrin and itaconic acid. The composite aniline is obtained by a reaction of a hyperbranched polysiloxane prepared from 3-glycidyloxypropyltrimethoxysilane and 3-mercaptopropyltrimethoxysilane with the polyaniline.

Description

Technical Field

[0001] The invention relates to an anti-corrosion 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. Due to its excellent physical and chemical properties and relatively low cost, epoxy resin has become one of the preferred materials in many application fields, 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 flexural strength, but also easily leads to problems such as brittle fracture or cracking during use. In addition, traditional epoxy paints perform poorly in terms of corrosion resistance and water resistance. These defects seriously restrict the application scope and development potential of epoxy resin.

[0003] To overcome these challenges, researchers have begun exploring ways to improve the overall performance of epoxy resins by modifying them. Polyaniline, an environmentally friendly corrosion inhibitor, forms a protective film on metal surfaces through its unique "activation-passivation" mechanism, significantly enhancing the material's corrosion resistance. This mechanism is based on a reversible redox reaction between polyaniline and the metal surface, accelerating the formation of a passivation film on the metal surface and effectively preventing the onset of corrosion. Introducing polyaniline into an epoxy resin system could theoretically significantly enhance the coating's corrosion resistance.

[0004] However, in practice, significant compatibility issues have been discovered between aniline monomer and epoxy resin substrates. Directly mixing the two often results in uneven dispersion and even severe phase separation. This not only affects the appearance of the final product but, more importantly, weakens the overall performance of the material, preventing the desired modification effect.

[0005] Therefore, the present invention provides an anti-corrosion 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 anti-corrosion 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 anti-corrosion epoxy paint, wherein the raw material components include, by weight, 100 parts by weight of a branched epoxy resin, 10 to 20 parts by weight of a curing agent, 0.4 to 0.8 parts by weight of a composite polyaniline, 4 to 6 parts by weight of a defoaming agent, 5 parts by weight of a leveling agent, 10 to 15 parts by weight of a solvent, and 0.15 to 0.25 parts by weight of a 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 or itaconic acid.

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

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

[0013] A method for preparing an anti-corrosion epoxy paint comprises the following preparation steps: adding 100 parts by mass of a branched epoxy resin, 10-20 parts by mass of a curing agent, 0.4-0.8 parts by mass of a composite polyaniline, 4-6 parts by mass of a defoamer, 5 parts by mass of a leveling agent, and 10-15 parts by mass of a solvent into a reactor, stirring at 1000-2000 rpm for 18-22 minutes at 48-52°C, adding 1.5-2.5 parts by mass of a photoinitiator, and continuing to stir and disperse for 1-3 hours to obtain an anti-corrosion 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 reactor, heated to 78 to 82°C, refluxed for 3.5 to 4.5 hours, cooled to room temperature after the reaction, and then added with tetrahydrofuran 4 to 6 times its mass and stirred until dissolved, followed by adding deionized water equal to the volume of tetrahydrofuran, standing and separating to obtain an organic phase, removing the catalyst and small molecular products in the reaction process, repeating the above separation operation three times for purification, and then drying 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 reactor, followed by adding 200 parts by mass of dimethyl sulfoxide, and 0.15 to 0.25 parts by mass of hyperbranched polysiloxane is added dropwise at a rate of 1 to 3 drops / s under magnetic stirring and N2 protection, and the reaction is carried out at 24 to 26°C for 48 hours. After the reaction is completed, excess methanol is added for repeated washing and filtration, and vacuum drying is carried out 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-glycidoxypropyltrimethoxysilane, 9 to 11 parts by mass of 3-mercaptopropyltrimethoxysilane, and 15 to 17 parts by mass of ethanol are added to a reactor, the mixture is heated to 58 to 62° C. under magnetic stirring and N2 protection, and reflux condensed, 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, the mixture is kept warm and stirred for 3.5 to 4.5 hours, and tartaric acid is then added for neutralization, followed by filtration and reduced pressure distillation to obtain a hyperbranched polysiloxane.

[0018] Furthermore, the anti-corrosion epoxy paint is used as follows: a frame-type scraper is used to evenly apply the paint on the surface of the low-carbon steel plate, and then the paint is applied at 100 mW / cm 2 , 405nm laser irradiation for 18 to 22 minutes, then 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 anti-corrosion epoxy paint of the present invention comprises, by weight, raw material components: 100 parts by weight of a branched epoxy resin, 10-20 parts by weight of a curing agent, 0.4-0.8 parts by weight of a composite polyaniline, 4-6 parts by weight of a defoamer, 5 parts by weight of a leveling agent, 10-15 parts by weight of a solvent, and 0.15-0.25 parts by weight of a photoinitiator. 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 is α-cyclodextrin and itaconic acid; the composite polyaniline is obtained by a mixed reaction of a hyperbranched polysiloxane and polyaniline; and the hyperbranched polysiloxane is obtained by a mixed reaction of 3-glycidyloxypropyltrimethoxysilane and 3-mercaptopropyltrimethoxysilane.

[0021] First, trihydroxymethyl triglycidyl ether, 4,4'-dihydroxyazobenzene, and polyvinyl alcohol are mixed, and 4,4'-dihydroxyazobenzene, polyvinyl alcohol, and trihydroxymethyl triglycidyl ether undergo a ring-opening reaction through proton transfer polymerization to form a branched epoxy resin. Compared with linear epoxy resins, branched epoxy resins and curing agents can form a three-dimensional cross-linked network, thereby enhancing the mechanical properties of 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 reacts with polyaniline to obtain composite aniline. The introduction of hyperbranched polysiloxane into composite aniline can produce aniline with a branched structure. The mutual repulsion between the composite aniline molecules leads to a reduced crystallization ability. The large amount of amorphous structure makes it easier for solvent molecules to diffuse into the composite aniline molecules, accelerating dissolution and 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 polyaniline.

[0023] Polyaniline is an excellent green corrosion inhibitor. Compared with conventional corrosion inhibitors, it has no environmental side effects and exhibits an "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 structure aniline to cure and cross-link, forming an interpenetrating network structure with the branched structure composite polyaniline, which preliminarily improves the corrosion resistance of 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 bond on the cured branched epoxy resin, further improving the compatibility between the branched structure aniline and the resin base, 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 surface of the coating, and making the composite aniline more exposed on the surface of the coating, 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 examples are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0026] Some of the raw material components of the examples and comparative examples of the present invention 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] BYK-333 from BYK Chemicals was used as the leveling agent;

[0032] BYK-066N is used as defoamer;

[0033] The photoinitiator used was photoinitiator 1173;

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

[0035] (Example 1)

[0036] A method for preparing an anti-corrosion 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 defoamer, 5 parts by mass of a leveling agent, and 10 parts by mass of a solvent into a reactor, stirring at 48° C. and 1000 rpm for 18 minutes, adding 1.5 parts by mass of a photoinitiator, and continuing to stir and disperse for 1 hour to obtain an anti-corrosion 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 reactor, 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 (4 times the mass of the tetrahydrofuran) is added and stirred until dissolved. Then, deionized water with 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. 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 the 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 to a reaction kettle, followed by adding 200 parts by mass of dimethyl sulfoxide, and adding 0.15 parts by mass of hyperbranched polysiloxane dropwise 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, excess methanol is added for repeated washing, filtration, 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-glycidoxypropyltrimethoxysilane, 9 parts by mass of 3-mercaptopropyltrimethoxysilane, and 15 parts by mass of ethanol are added to a reaction kettle, the temperature is raised to 58° C. under magnetic stirring and N2 protection, and reflux condensation is performed, 2 parts by mass of deionized water is added dropwise at a rate of 1 drop / s, and sodium hydroxide is added to adjust the pH to 9. The mixture is kept warm and stirred for 3.5 hours, and tartaric acid is then added for neutralization. The mixture is then filtered and distilled under reduced pressure to obtain the hyperbranched polysiloxane.

[0041] (Example 2)

[0042] A method for preparing an anti-corrosion 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 composite polyaniline, 5 parts by mass of a defoamer, 5 parts by mass of a leveling agent, and 13 parts by mass of a solvent into a reactor, stirring at 1500 rpm at 50° C. for 20 minutes, adding 2 parts by mass of a photoinitiator, and continuing to stir and disperse for 2 hours to obtain an anti-corrosion 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 reactor, the temperature is raised to 80°C, and the reaction is refluxed for 4 hours. After the reaction is completed, the reaction is cooled to room temperature, and then tetrahydrofuran (5 times the mass of the tetrahydrofuran) is added and stirred until dissolved. Then, deionized water with 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. 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 the 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 to a reaction kettle, followed by adding 200 parts by mass of dimethyl sulfoxide, and adding 0.2 parts by mass of hyperbranched polysiloxane dropwise 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, excess methanol is added for repeated washing, filtration, 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-glycidoxypropyltrimethoxysilane, 10 parts by mass of 3-mercaptopropyltrimethoxysilane, and 16 parts by mass of ethanol are added to a reaction kettle, the temperature is raised to 60° C. under magnetic stirring and N2 protection, and reflux condensation is performed, 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, and tartaric acid is then added for neutralization. The mixture is then filtered and distilled under reduced pressure to obtain the hyperbranched polysiloxane.

[0047] (Example 3)

[0048] A method for preparing an anti-corrosion 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 defoamer, 5 parts by mass of a leveling agent, and 15 parts by mass of a solvent into a reactor, stirring at 2000 rpm at 52° C. for 22 minutes, adding 2.5 parts by mass of a photoinitiator, and continuing to stir and disperse for 3 hours to obtain an anti-corrosion 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 reactor, 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 of the tetrahydrofuran) is added and stirred until dissolved. Then, deionized water with 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. 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 the branched epoxy resin.

[0050] The mass ratio of α-cyclodextrin and 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 to a reaction kettle, followed by adding 200 parts by mass of dimethyl sulfoxide, and 0.25 parts by mass of hyperbranched polysiloxane is added dropwise at a rate of 3 drops / s under magnetic stirring and N2 protection, and the mixture is reacted at 26°C for 48 hours. After the reaction is completed, excess methanol is added for repeated washing, filtration, 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-glycidoxypropyltrimethoxysilane, 11 parts by mass of 3-mercaptopropyltrimethoxysilane, and 17 parts by mass of ethanol are added to a reaction kettle, the temperature is raised to 62° C. under magnetic stirring and N2 protection, and reflux condensation is performed, 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, and tartaric acid is then added for neutralization. The mixture is 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 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 in 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 ingredients are the same as those in 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 in Example 2.

[0063] (Comparative Example 6)

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

[0067] Effect example:

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

[0069] Bending Strength: The bending properties of HPB-CN cured products were tested using an HZ-1003B tensile testing machine manufactured by Lixian Instrument Technology Co., Ltd. The anti-corrosion epoxy paint was cast into rectangular strips 80 ± 2 mm long, 15 ± 0.2 mm wide, and 4 ± 0.2 mm thick in accordance with the national standard GB / T1043-2008. These strips were fixed to the testing machine and subjected to bending tests at a speed of 2 mm / min.

[0070] Anti-corrosion performance: The anti-corrosion epoxy paints prepared in the examples and comparative examples were evenly coated on the surface of the mild steel plate using a frame-type scraper with a gap width of 120 μm. 2 , irradiated with 405nm laser for 18-22min, then dried at 29-31℃ for 2h to evaporate the surface solvent, then heated to 78-82℃ and continued 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 a JC2000DM contact angle meter produced by Shanghai Zhongchen Digital Technology Equipment Co., Ltd., using 2 μL of deionized water each time.

[0072] Table 1 below shows the performance test results of the anti-corrosion epoxy paints prepared in 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] Comparing Example 1 with Example 2, Comparative Example 1 uses bisphenol A epoxy resin to prepare anti-corrosion epoxy paint, which cannot form an epoxy resin with a branched structure, and cannot form a micro-nano structure after subsequent photothermal stimulation, and has poor tensile performance, bending performance, and waterproof properties.

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

[0078] Comparative Example 3 is 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 reaction between the thiol group and the olefin bond, and has poor tensile and bending properties.

[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, resulting in poor tensile and bending properties.

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

[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 are only specific embodiments of the present invention and are 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 scope of protection 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 a branched epoxy resin, 10-20 parts by weight of a curing agent, 0.4-0.8 parts by weight of a composite polyaniline, 4-6 parts by weight of a defoaming agent, 5 parts by weight of a leveling agent, 10-15 parts by weight of a solvent, and 0.15-0.25 parts by weight of a photoinitiator. 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 is α-cyclodextrin and itaconic acid. The composite polyaniline is obtained by a mixed reaction of a hyperbranched polysiloxane and polyaniline. The hyperbranched polysiloxane is obtained by a mixed reaction of 3-glycidyloxypropyltrimethoxysilane and 3-mercaptopropyltrimethoxysilane.

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

3. The method for preparing the anticorrosive epoxy paint according to claim 2, wherein The preparation steps of the branched epoxy resin are as follows: under nitrogen protection, 0.1-0.3 parts by mass of 4,4'-dihydroxyazobenzene, 1.5-2.5 parts by mass of polyvinyl alcohol, 1 part by mass of trimethylol triglycidyl ether, and 0.0008-0.0012 parts by mass of catalyst tetrabutylammonium bromide are placed in a reactor, 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 4-6 times the mass of tetrahydrofuran is added and stirred until dissolved. Then, deionized water with 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. The above separation operation is repeated three times for purification, and then the branched epoxy resin is dried in a vacuum oven at 80°C for 23-25 ​​hours to obtain the branched epoxy resin.

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

1.

5. The method for preparing the anticorrosive epoxy paint according to claim 2, wherein: 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 dropwise at a rate of 1 to 3 drops per second under magnetic stirring and N2 protection, and reacting at 24 to 26°C for 48 hours. After the reaction is completed, excessive methanol is added for repeated washing, filtration, and vacuum drying at 50°C for 23 to 25 hours to obtain the composite polyaniline.

6. The method for preparing the anticorrosive epoxy paint according to claim 5, wherein: The preparation method of the hyperbranched polysiloxane is as follows: 13-14 parts by mass of 3-glycidoxypropyltrimethoxysilane, 9-11 parts by mass of 3-mercaptopropyltrimethoxysilane, and 15-17 parts by mass of ethanol are added to a reaction kettle, the temperature is raised to 58-62° C. under magnetic stirring and N2 protection, and reflux condensation is performed, 2-2.4 parts by mass of deionized water is added dropwise at a rate of 1-3 drops / s, and sodium hydroxide is added to adjust the pH to 9-10, the mixture is kept warm and stirred for 3.5-4.5 hours, and tartaric acid is then added for neutralization, followed by filtration and reduced pressure distillation to obtain the hyperbranched polysiloxane.

Images