A solvent-free epoxy anticorrosive coating and a preparation method thereof

Abstract

The present application relates to the technical field of building coating, in particular to a solvent-free epoxy anticorrosive coating and a preparation method thereof.The present application introduces epoxy sites by silanizing glass flake with KH560, then covalently grafts the flake with mercapto-fluorosilicon monomer through mercapto-epoxy addition, regenerates epoxy active end groups through secondary crosslinking, and obtains fluorosilicon modified active glass flake filler;compounds hydrogenated bisphenol A type epoxy resin and functional filler, and matches 1,3-cyclohexane diamine curing agent to obtain the target coating.The modified flake can construct a complete three-dimensional crosslinking network with the resin, and eliminate the filler-resin interface pores;the fluorosilicon segment cooperatively endows the coating with hydrophobic self-cleaning and low water absorption characteristics, the silicon segment releases the curing internal stress to improve the film brittleness, and simultaneously solves the traditional flake agglomeration and sedimentation defects.The present coating has no VOC release, excellent wear resistance, salt mist resistance, water resistance and anti-aging performance, and is suitable for heavy-duty anticorrosion working conditions such as chemical storage tanks, marine steel structures and buried pipelines.

Description

Technical Field

[0001] This invention relates to the field of architectural coatings technology, specifically to a solvent-free epoxy anti-corrosion coating and its preparation method. Background Technology

[0002] Epoxy anti-corrosion coatings are widely used in heavy-duty anti-corrosion fields such as steel structures, chemical storage tanks, municipal facilities, and pipeline engineering due to their excellent adhesion, high mechanical strength, and superior resistance to chemical media. Compared with traditional solvent-based epoxy coatings, solvent-free epoxy anti-corrosion coatings release no volatile organic solvents throughout the entire process, possessing advantages such as low VOC, environmental friendliness, dense curing, and large film thickness in a single application, making them the mainstream development direction for heavy-duty anti-corrosion coatings. Glass flakes, with their unique two-dimensional lamellar structure, are widely used as the core functional filler in solvent-free epoxy coatings. Their two-dimensional structure can be stacked in parallel within the coating film to form a labyrinthine shielding structure, which can effectively extend the penetration path of water vapor, oxygen, and acid and alkali corrosive media, significantly improving the coating's resistance to salt spray, water, and media penetration, and greatly extending the service life of the substrate's anti-corrosion properties.

[0003] However, existing conventional glass flake modified solvent-free epoxy coatings have many technical defects that limit their long-term anti-corrosion performance and engineering application effects. The original glass flake surface only has an inert inorganic interface, resulting in poor compatibility with the organic epoxy resin matrix. In the coating system, it is prone to agglomeration, sedimentation, and uneven dispersion. After curing, the filler-resin interface has numerous micropores and defects, allowing corrosive media to easily penetrate along these defects, causing blistering, delamination, and failure of the coating. Furthermore, conventional glass flakes are physically inert fillers, relying solely on physical stacking to achieve a shielding effect, and cannot chemically cross-link with the epoxy resin matrix. This results in weak interfacial bonding, low overall cross-linking density of the coating, and insufficient resistance to cracking, peeling, and aging. Thirdly, traditional solvent-free epoxy coatings have high brittleness and poor stain resistance after curing. When exposed to acids, alkalis, oils, and humid media for extended periods, the surface is prone to scale buildup and penetrating corrosion, leading to poor long-term protective stability. Therefore, it is necessary to overcome these defects to improve the performance of solvent-free epoxy coatings. Summary of the Invention

[0004] The purpose of this invention is to provide a solvent-free epoxy anti-corrosion coating and its preparation method, so as to solve the problem of poor filler dispersion performance in solvent-free epoxy coatings.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] In a first aspect, the present invention provides a method for preparing a solvent-free epoxy anticorrosive coating, comprising the following steps:

[0007] S1. After cleaning and drying the glass flakes, add anhydrous isopropanol, mix well, add KH560, heat to react, centrifuge, wash and dry with anhydrous isopropanol to obtain epoxy-grafted glass flakes.

[0008] S2. 2,3,5,6-Tetrafluoro-4-mercaptobenzoic acid and bis(4-aminophenoxy)dimethylsilane were added to anhydrous toluene under a nitrogen atmosphere, p-toluenesulfonic acid was added, the reaction was heated, and excess solvent was removed by vacuum rotary evaporation to obtain a mercapto-terminated fluorosilicone monomer.

[0009] S3. Epoxy-grafted glass flakes were mixed with anhydrous isopropanol, ultrasonically dispersed, and then protected under a nitrogen atmosphere. A terminal mercapto fluorosilicone monomer was added and mixed evenly. Triethylamine was added, the mixture was heated to react, the precipitate was separated by centrifugation, washed with anhydrous isopropanol, and dried to obtain fluorosilicone modified glass flakes.

[0010] S4. The fluorosilicone modified glass flakes were ultrasonically dispersed again in anhydrous isopropanol under nitrogen atmosphere, 1,4-butanediol diglycidyl ether and triethylamine were added, the mixture was heated to react, centrifuged, and vacuum dried to obtain the modified glass flakes.

[0011] S5. Mix the modified glass flakes with hydrogenated bisphenol A epoxy resin and reactive diluent, stir and disperse evenly, then add dispersant, defoamer and titanium dioxide, mix evenly and obtain the main agent;

[0012] S6. Using 1,3-cyclohexanediamine as a curing agent, the main agent and the curing agent are mixed and stirred evenly to obtain a solvent-free epoxy anti-corrosion coating.

[0013] Furthermore, in S1, the mass ratio of glass flakes, KH560, and deionized water is 100:(3~5):(0.5~1).

[0014] During the heating reaction, the temperature is raised to 75~85℃ and stirred for 4~6 hours.

[0015] Furthermore, in S1, the glass flakes have a particle size of 200-400 mesh.

[0016] Furthermore, in S2, the mass ratio of 2,3,5,6-tetrafluoro-4-mercaptobenzoic acid, bis(4-aminophenoxy)dimethylsilane, and p-toluenesulfonic acid is (1.64~1.66):1:(0.005~0.01).

[0017] During the heating reaction, the temperature is raised to 110~115℃, and the reaction is stirred for 8~12 hours.

[0018] Furthermore, in S3, the mass ratio of epoxy-grafted glass flakes, terminal mercapto-fluorosilicone monomers, and triethylamine is 10:(0.5~1.5):(0.03~0.05).

[0019] During the heating reaction, the temperature is raised to 60~65℃, and the reaction is stirred for 4~6 hours.

[0020] Furthermore, in S4, the mass ratio of fluorosilicone modified glass flakes, 1,4-butanediol diglycidyl ether, and triethylamine is 10:(0.3~0.9):(0.01~0.03).

[0021] During the heating reaction, the temperature is raised to 55~60℃, and the reaction is stirred for 3~4 hours.

[0022] Furthermore, in S5, the mass ratio of modified glass flakes, hydrogenated bisphenol A type epoxy resin, reactive diluent, dispersant, defoamer and titanium dioxide is (25~40): (35~45): (5~10): (0.2~0.5): (0.3~0.5): (10~15).

[0023] Furthermore, in S5, the hydrogenated bisphenol A type epoxy resin is ADEKA RESIN EP-4080E type epoxy resin; the reactive diluent is 1,4-butanediol diglycidyl ether.

[0024] Furthermore, in S6, the mass ratio of the main agent to the curing agent is (75.5~111):(7~11.5).

[0025] Secondly, the present invention also provides a solvent-free epoxy anti-corrosion coating prepared by the above preparation method.

[0026] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0027] To enhance the corrosion resistance and wear resistance of coatings, this invention employs a stepwise thiol-epoxy controlled crosslinking modification process to modify glass flakes, enabling them to covalently integrate with the organic resin matrix. First, KH560 silane is used to stably graft epoxy active functional groups onto the glass flake surface, constructing stable organic reaction sites. Then, relying on the precise ring-opening addition reaction between thiol and epoxy under weakly alkaline catalysis, a self-synthesized end-thiol fluorosilicone monomer is covalently grafted onto the flake surface. Compared to traditional physical coating modification, the grafted layer is more firmly bonded and less prone to detachment. Simultaneously, the process precisely controls the reaction conditions and material ratios, controllably retaining some residual thiol active sites. Through a secondary crosslinking reaction with diglycidyl ether, epoxy active end groups are further grafted onto the filler surface, transforming the inert glass flakes into an active functional filler capable of participating in the curing reaction. This filler can simultaneously construct a three-dimensional covalent crosslinking network with epoxy resin and curing agent, completely eliminating microscopic pores and defects at the filler-resin interface, significantly improving coating density, interfacial adhesion, and peel resistance.

[0028] Furthermore, this invention, through covalent grafting modification of fluorosilicone hybrid segments, endows epoxy coatings with excellent low surface energy self-cleaning properties and resistance to media corrosion. The terminal mercapto fluorosilicone monomer independently synthesized in this invention combines the rigid corrosion-resistant structure of tetrafluorobenzene with the flexible segments of dimethylsilicon. After being stably grafted onto the surface of glass flakes, it can fully exert the synergistic effect of fluorine and silicon elements. Among them, the highly inert fluorine segments can form a dense hydrophobic and oleophobic interface on the coating surface, effectively blocking the adsorption and penetration of water vapor, oil, and acid and alkali corrosive media, giving the coating excellent self-cleaning and anti-fouling properties, and eliminating the coating failure problem caused by media accumulation and penetration under long-term working conditions. The flexible silicon segments can effectively release the internal stress of the coating curing, make up for the defects of traditional epoxy coatings being brittle and prone to cracking, significantly improve the coating's flexibility and temperature alternation resistance, and comprehensively enhance the coating's overall anti-corrosion performance against salt spray, acids and alkalis, and organic solvents.

[0029] Furthermore, this invention fundamentally optimizes the compatibility between glass flakes and the epoxy system through secondary epoxy regeneration modification, significantly improving the coating's application performance and storage stability. The fluorosilicone-modified glass flakes undergo a secondary thiol-epoxy crosslinking reaction with 1,4-butanediol diglycidyl ether based on residual thiol groups, introducing high-density epoxy functional groups onto the filler surface. This effectively improves the wettability and dispersibility of inorganic flakes in organic resin systems, completely solving the problems of easy agglomeration, sedimentation, and uneven dispersion of traditional glass flakes. Uniform dispersion can be achieved without adding large amounts of volatile co-solvents, making it fully compatible with solvent-free environmentally friendly coating systems.

[0030] This invention utilizes a preferred hydrogenated bisphenol A epoxy resin and a dedicated curing system, further balancing the coating's weather resistance, mechanical properties, and curing density. The selected EP-4080E hydrogenated bisphenol A epoxy resin has a fully saturated molecular chain, lacking the unsaturated benzene ring defects found in ordinary bisphenol A epoxy, resulting in significantly improved resistance to yellowing, hydrolysis, and weathering, making it suitable for complex and harsh conditions such as outdoor use, humidity, and strong corrosion. The accompanying 1,4-butanediol diglycidyl ether reactive diluent effectively reduces the viscosity of the solvent-free system, improving the coating's flowability, and is non-volatile, residue-free, and does not compromise the coating's density. Simultaneously, 1,3-cyclohexanediamine is used as a curing agent, resulting in a mild and uniform curing reaction. It can fully crosslink with the epoxy groups on the modified filler surface and the matrix epoxy, forming a high-density, highly stable three-dimensional crosslinked network, significantly improving the coating's hardness, abrasion resistance, and long-term protective stability. Attached Figure Description

[0031] Figure 1 This is a photograph of the solvent-free epoxy anti-corrosion coating prepared in Example 3 of the present invention after 500 hours of neutral salt spray resistance testing;

[0032] Figure 2 This is a diagram of the reaction equation for step S2 in Embodiment 3 of the present invention. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] The glass flakes used in the embodiments and comparative examples of this invention have a particle size of 200-400 mesh; the dispersant used is WE-D222 type dispersant; and the defoamer used is BYK-1765 type defoamer.

[0035] Example 1

[0036] A method for preparing a solvent-free epoxy anti-corrosion coating includes the following steps:

[0037] S1. After cleaning and drying the glass flakes, add anhydrous isopropanol and deionized water, mix well, add KH560, heat to 75℃, stir and react for 6 hours, centrifuge, wash and dry with anhydrous isopropanol to obtain epoxy-grafted glass flakes.

[0038] The mass ratio of glass flakes, KH560, and deionized water is 100:3:0.5.

[0039] S2. 2,3,5,6-Tetrafluoro-4-mercaptobenzoic acid and bis(4-aminophenoxy)dimethylsilane were added to anhydrous toluene under a nitrogen atmosphere, p-toluenesulfonic acid was added, the mixture was heated to 110°C, stirred and reacted for 12 h, and then the excess solvent was removed by vacuum rotary evaporation to obtain the terminal mercaptofluorosilicone monomer.

[0040] The mass ratio of 2,3,5,6-tetrafluoro-4-mercaptobenzoic acid, bis(4-aminophenoxy)dimethylsilane, p-toluenesulfonic acid, and anhydrous toluene is 1.64:1:0.005:15.

[0041] S3. Epoxy-grafted glass flakes were mixed with anhydrous isopropanol, ultrasonically dispersed, and then protected under a nitrogen atmosphere. A terminal mercapto-based fluorosilicone monomer was added and mixed evenly. Triethylamine was added, the temperature was raised to 60°C, and the reaction was stirred for 6 hours. The precipitate was separated by centrifugation, washed with anhydrous isopropanol, and dried to obtain fluorosilicone modified glass flakes.

[0042] The mass ratio of epoxy-grafted glass flakes, mercapto-terminated fluorosilicone monomers, and triethylamine is 10:0.5:0.03.

[0043] S4. Fluorosilicone modified glass flakes were ultrasonically dispersed again in anhydrous isopropanol under nitrogen atmosphere, 1,4-butanediol diglycidyl ether and triethylamine were added, the temperature was raised to 55°C, the reaction was stirred for 4 hours, centrifuged, and vacuum dried to obtain modified glass flakes.

[0044] The mass ratio of fluorosilicone modified glass flakes, 1,4-butanediol diglycidyl ether, and triethylamine is 10:0.3:0.01.

[0045] S5. Mix the modified glass flakes with hydrogenated bisphenol A epoxy resin and reactive diluent, stir and disperse evenly, then add dispersant, defoamer and titanium dioxide, mix evenly and obtain the main agent;

[0046] The mass ratio of modified glass flakes, hydrogenated bisphenol A type epoxy resin, reactive diluent, dispersant, defoamer and titanium dioxide is 25:35:5:0.2:0.3:10;

[0047] S6. Using 1,3-cyclohexanediamine as a curing agent, the main agent and the curing agent are mixed in a mass ratio of 75.5:7 and stirred evenly to obtain a solvent-free epoxy anti-corrosion coating.

[0048] Example 2

[0049] A method for preparing a solvent-free epoxy anti-corrosion coating includes the following steps:

[0050] S1. After cleaning and drying the glass flakes, add anhydrous isopropanol and deionized water, mix well, add KH560, heat to 80℃, stir and react for 5 hours, centrifuge and separate, wash and dry with anhydrous isopropanol to obtain epoxy-grafted glass flakes.

[0051] The mass ratio of glass flakes, KH560, and deionized water is 100:4:0.8.

[0052] S2. 2,3,5,6-Tetrafluoro-4-mercaptobenzoic acid and bis(4-aminophenoxy)dimethylsilane were added to anhydrous toluene under a nitrogen atmosphere, p-toluenesulfonic acid was added, the mixture was heated to 112°C, and the reaction was stirred for 10 h. After removing excess solvent by vacuum rotary evaporation, the terminal mercaptofluorosilicone monomer was obtained.

[0053] The mass ratio of 2,3,5,6-tetrafluoro-4-mercaptobenzoic acid, bis(4-aminophenoxy)dimethylsilane, p-toluenesulfonic acid, and anhydrous toluene is 1.65:1:0.008:15.

[0054] S3. Epoxy-grafted glass flakes were mixed with anhydrous isopropanol, ultrasonically dispersed, and then protected under a nitrogen atmosphere. A terminal mercapto-based fluorosilicone monomer was added and mixed evenly. Triethylamine was added, the temperature was raised to 62°C, and the reaction was stirred for 5 hours. The precipitate was separated by centrifugation, washed with anhydrous isopropanol, and dried to obtain fluorosilicone modified glass flakes.

[0055] The mass ratio of epoxy-grafted glass flakes, mercapto-terminated fluorosilicone monomers, and triethylamine is 10:1:0.04.

[0056] S4. The fluorosilicone modified glass flakes were ultrasonically dispersed again in anhydrous isopropanol under nitrogen atmosphere protection. 1,4-Butanediol diglycidyl ether and triethylamine were added, the mixture was heated to 58°C, stirred and reacted for 3.5 h, centrifuged and vacuum dried to obtain the modified glass flakes.

[0057] The mass ratio of fluorosilicone modified glass flakes, 1,4-butanediol diglycidyl ether, and triethylamine is 10:0.6:0.02.

[0058] S5. Mix the modified glass flakes with hydrogenated bisphenol A epoxy resin and reactive diluent, stir and disperse evenly, then add dispersant, defoamer and titanium dioxide, mix evenly and obtain the main agent;

[0059] The mass ratio of modified glass flakes, hydrogenated bisphenol A type epoxy resin, reactive diluent, dispersant, defoamer and titanium dioxide is 35:40:8:0.4:0.4:12.

[0060] S6. Using 1,3-cyclohexanediamine as a curing agent, the main agent and the curing agent are mixed in a mass ratio of 95.8:9.5 and stirred evenly to obtain a solvent-free epoxy anti-corrosion coating.

[0061] Example 3

[0062] A method for preparing a solvent-free epoxy anti-corrosion coating includes the following steps:

[0063] S1. After cleaning and drying the glass flakes, add anhydrous isopropanol and deionized water, mix well, add KH560, heat to 85℃, stir and react for 4 hours, centrifuge, wash and dry with anhydrous isopropanol to obtain epoxy-grafted glass flakes.

[0064] The mass ratio of glass flakes, KH560, and deionized water is 100:5:1.

[0065] S2. 2,3,5,6-Tetrafluoro-4-mercaptobenzoic acid and bis(4-aminophenoxy)dimethylsilane were added to anhydrous toluene under a nitrogen atmosphere, p-toluenesulfonic acid was added, the mixture was heated to 115°C, stirred and reacted for 8 hours, and then the excess solvent was removed by vacuum rotary evaporation to obtain the terminal mercaptofluorosilicone monomer.

[0066] The mass ratio of 2,3,5,6-tetrafluoro-4-mercaptobenzoic acid, bis(4-aminophenoxy)dimethylsilane, p-toluenesulfonic acid, and anhydrous toluene is 1.66:1:0.01:15.

[0067] S3. Epoxy-grafted glass flakes were mixed with anhydrous isopropanol, ultrasonically dispersed, and then protected under a nitrogen atmosphere. A terminal mercapto-based fluorosilicone monomer was added and mixed evenly. Triethylamine was added, the temperature was raised to 65°C, and the reaction was stirred for 4 hours. The precipitate was separated by centrifugation, washed with anhydrous isopropanol, and dried to obtain fluorosilicone modified glass flakes.

[0068] The mass ratio of epoxy-grafted glass flakes, mercapto-terminated fluorosilicone monomers, and triethylamine is 10:1.5:0.05.

[0069] S4. Fluorosilicone modified glass flakes were ultrasonically dispersed again in anhydrous isopropanol under nitrogen atmosphere, 1,4-butanediol diglycidyl ether and triethylamine were added, the temperature was raised to 60°C, the reaction was stirred for 3 hours, centrifuged and vacuum dried to obtain modified glass flakes.

[0070] The mass ratio of fluorosilicone modified glass flakes, 1,4-butanediol diglycidyl ether, and triethylamine is 10:0.9:0.03.

[0071] S5. Mix the modified glass flakes with hydrogenated bisphenol A epoxy resin and reactive diluent, stir and disperse evenly, then add dispersant, defoamer and titanium dioxide, mix evenly and obtain the main agent;

[0072] The mass ratio of modified glass flakes, hydrogenated bisphenol A epoxy resin, reactive diluent, dispersant, defoamer and titanium dioxide is 40:45:10:0.5:0.5:15.

[0073] S6. Using 1,3-cyclohexanediamine as a curing agent, the main agent and the curing agent are mixed in a mass ratio of 111:11.5 and stirred evenly to obtain a solvent-free epoxy anti-corrosion coating.

[0074] Comparative Example 1

[0075] Compared with Example 3, this comparative example only used glass flakes to prepare the main agent, and the other steps and parameters were the same as in Example 3;

[0076] A method for preparing a solvent-free epoxy anti-corrosion coating includes the following steps:

[0077] Glass flakes are mixed with hydrogenated bisphenol A epoxy resin and reactive diluent. After stirring and dispersing evenly, dispersant, defoamer and titanium dioxide are added and mixed evenly to obtain the main agent.

[0078] The mass ratio of glass flakes, hydrogenated bisphenol A epoxy resin, reactive diluent, dispersant, defoamer and titanium dioxide is 40:45:10:0.5:0.5:15.

[0079] Using 1,3-cyclohexanediamine as a curing agent, the main agent and the curing agent are mixed in a mass ratio of 111:11.5 and stirred evenly to obtain a solvent-free epoxy anti-corrosion coating.

[0080] Comparative Example 2

[0081] Compared with Example 3, this comparative example only used epoxy-grafted glass flakes to replace the modified glass flakes in equal amounts, and all other steps and parameters were the same as in Example 3.

[0082] A method for preparing a solvent-free epoxy anti-corrosion coating includes the following steps:

[0083] S1. After cleaning and drying the glass flakes, add anhydrous isopropanol and deionized water, mix well, add KH560, heat to 85℃, stir and react for 4 hours, centrifuge, wash and dry with anhydrous isopropanol to obtain epoxy-grafted glass flakes.

[0084] The mass ratio of glass flakes, KH560, and deionized water is 100:5:1.

[0085] S2. Epoxy-grafted glass flakes are mixed with hydrogenated bisphenol A type epoxy resin and reactive diluent. After stirring and dispersing evenly, dispersant, defoamer and titanium dioxide are added and mixed evenly to obtain the main agent.

[0086] The mass ratio of epoxy-grafted glass flakes, hydrogenated bisphenol A type epoxy resin, reactive diluent, dispersant, defoamer and titanium dioxide is 40:45:10:0.5:0.5:15.

[0087] Using 1,3-cyclohexanediamine as a curing agent, the main agent and the curing agent are mixed in a mass ratio of 111:11.5 and stirred evenly to obtain a solvent-free epoxy anti-corrosion coating.

[0088] Detection method:

[0089] The solvent-free epoxy anti-corrosion coatings prepared in Examples 1-3 and Comparative Examples 1-2 were sprayed onto the surface of carbon steel plates and cured into a film to obtain test samples.

[0090] According to the GB / T 1768-2006 testing standard, the abrasion resistance of the test samples was tested.

[0091] According to the GB / T 1771-2007 testing standard, the test samples were subjected to neutral salt spray resistance testing.

[0092] According to the GB / T 9274-1988 testing standard, the water resistance of the test samples was tested.

[0093] According to the GB / T 14522-2008 testing standard, the aging resistance performance of the test samples was tested.

[0094] The test results are shown in Table 1 below.

[0095] Table 1. Performance test results of solvent-free epoxy anticorrosion coatings prepared in Examples 1-3 and Comparative Examples 1-2 after sample preparation.

[0096]

[0097] As shown in the table above, the wear resistance of the solvent-free epoxy anti-corrosion coatings prepared in Examples 1-3 of this invention ranges from 0.022 to 0.026 g, and the wear amount continues to decrease as the amount of modified flakes added increases.

[0098] Furthermore, the salt spray resistance of Examples 1-3 was greater than 2700h, while Comparative Example 2 showed scratches, blistering, and rust penetration after only 1800h, and Comparative Example 1 showed substrate corrosion after only 1000h. The reason for this is that the original flakes in Comparative Example 1 only relied on physical stacking for shielding, and the gaps at the flake-resin interface became a rapid channel for the corrosive medium. In contrast, Comparative Example 2 only had silane-grafted flakes without a fluorine hydrophobic barrier layer, and water vapor and chloride ions continuously wetted the interface. Although it was better than pure original flakes, its long-term anti-corrosion ability was far inferior to that of the complete fluorosilicone modified system.

[0099] Regarding aging resistance, all samples in Examples 1-3 of this invention exhibited a chalking grade of <1 after 3000 hours of aging, with only slight loss of gloss and no cracking or yellowing. Comparative Example 2 showed a chalking grade of 2, with fine cracks appearing in the paint film. Comparative Example 1 exhibited a chalking grade of 3, with severe loss of gloss, yellowing, and embrittlement of the paint film. The reason for this is that in the examples of this invention, the grafted silicon-oxygen segments on the flake surface can absorb and dissipate ultraviolet light energy, while the fluorine segments resist ozone and rainwater erosion, thus doubly inhibiting the photo-oxidative chain scission of the resin. This makes it less prone to chalking during long-term outdoor use. In contrast, no fluorosilicone monomer components were introduced in the comparative examples, leading to a decrease in aging resistance.

[0100] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention 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 the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a solvent-free epoxy anti-corrosion coating, characterized in that, Includes the following steps: S1. After cleaning and drying the glass flakes, add anhydrous isopropanol and deionized water, mix well, add KH560, heat to react, centrifuge, wash and dry with anhydrous isopropanol to obtain epoxy-grafted glass flakes. S2. 2,3,5,6-Tetrafluoro-4-mercaptobenzoic acid and bis(4-aminophenoxy)dimethylsilane were added to anhydrous toluene under a nitrogen atmosphere, p-toluenesulfonic acid was added, the reaction was heated, and excess solvent was removed by vacuum rotary evaporation to obtain a mercapto-terminated fluorosilicone monomer. S3. Epoxy-grafted glass flakes were mixed with anhydrous isopropanol, ultrasonically dispersed, and then protected under a nitrogen atmosphere. A terminal mercapto fluorosilicone monomer was added and mixed evenly. Triethylamine was added, the mixture was heated to react, the precipitate was separated by centrifugation, washed with anhydrous isopropanol, and dried to obtain fluorosilicone modified glass flakes. S4. The fluorosilicone modified glass flakes were ultrasonically dispersed again in anhydrous isopropanol under nitrogen atmosphere, 1,4-butanediol diglycidyl ether and triethylamine were added, the mixture was heated to react, centrifuged, and vacuum dried to obtain the modified glass flakes. S5. Mix the modified glass flakes with hydrogenated bisphenol A epoxy resin and reactive diluent, stir and disperse evenly, then add dispersant, defoamer and titanium dioxide, mix evenly and obtain the main agent; S6. Using 1,3-cyclohexanediamine as a curing agent, the main agent and the curing agent are mixed and stirred evenly to obtain a solvent-free epoxy anti-corrosion coating.

2. The method for preparing a solvent-free epoxy anti-corrosion coating according to claim 1, characterized in that: In S1, the mass ratio of glass flakes, KH560, and deionized water is 100:(3~5):(0.5~1). During the heating reaction, the temperature is raised to 75~85℃ and stirred for 4~6 hours.

3. The method for preparing a solvent-free epoxy anti-corrosion coating according to claim 1, characterized in that: In S1, the glass flakes have a particle size of 200-400 mesh.

4. The method for preparing a solvent-free epoxy anti-corrosion coating according to claim 1, characterized in that: In S2, the mass ratio of 2,3,5,6-tetrafluoro-4-mercaptobenzoic acid, bis(4-aminophenoxy)dimethylsilane, and p-toluenesulfonic acid is (1.64~1.66):1:(0.005~0.01). During the heating reaction, the temperature is raised to 110~115℃, and the reaction is stirred for 8~12 hours.

5. The method for preparing a solvent-free epoxy anti-corrosion coating according to claim 1, characterized in that: In S3, the mass ratio of epoxy-grafted glass flakes, mercapto-terminated fluorosilicone monomer, and triethylamine is 10:(0.5~1.5):(0.03~0.05). During the heating reaction, the temperature is raised to 60~65℃, and the reaction is stirred for 4~6 hours.

6. The method for preparing a solvent-free epoxy anti-corrosion coating according to claim 1, characterized in that: In S4, the mass ratio of fluorosilicone modified glass flakes, 1,4-butanediol diglycidyl ether, and triethylamine is 10:(0.3~0.9):(0.01~0.03). During the heating reaction, the temperature is raised to 55~60℃, and the reaction is stirred for 3~4 hours.

7. The method for preparing a solvent-free epoxy anti-corrosion coating according to claim 1, characterized in that: In S5, the mass ratio of modified glass flakes, hydrogenated bisphenol A type epoxy resin, reactive diluent, dispersant, defoamer and titanium dioxide is (25~40): (35~45): (5~10): (0.2~0.5): (0.3~0.5): (10~15).

8. The method for preparing a solvent-free epoxy anti-corrosion coating according to claim 1, characterized in that: In S5, the hydrogenated bisphenol A type epoxy resin is ADEKA RESIN EP-4080E type epoxy resin; the reactive diluent is 1,4-butanediol diglycidyl ether.

9. The method for preparing a solvent-free epoxy anti-corrosion coating according to claim 1, characterized in that: In S6, the mass ratio of the main agent to the curing agent is (75.5~111):(7~11.5).

10. A solvent-free epoxy anti-corrosion coating, characterized in that, It was prepared using the preparation method described in any one of claims 1 to 9.

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