High temperature resistant single component epoxy resin coating and preparation method thereof

Abstract

The application belongs to the technical field of composite materials, and discloses a high-temperature-resistant single-component epoxy resin coating and a preparation method thereof, wherein the preparation method comprises the following steps: mixing, stirring and heating a phenolic resin, an epoxy compound and a catalyst to obtain a resin monomer; mixing the resin monomer with an organic silicon epoxy copolymer to obtain an epoxy resin prepolymer, detecting the viscosity of the epoxy resin prepolymer, adjusting the viscosity of the epoxy resin prepolymer until the viscosity of the epoxy resin prepolymer reaches a preset viscosity; adding a functional component into the epoxy resin prepolymer to obtain a resin slurry, and then adding a latent curing agent to obtain the single-component epoxy resin coating. Thus, the fluorine content and the thickness of the resin coating can be reduced, and the heat resistance of the resin coating can be improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of composite materials, in particular to a high-temperature-resistant single-component epoxy resin coating and a preparation method thereof. BACKGROUND

[0002] With the advancement of industrialization, various equipment and components are increasingly used in high-temperature environments, and therefore higher requirements are put forward for the high-temperature resistance of coatings. Although traditional epoxy resin coatings have excellent adhesion and corrosion resistance, they are prone to softening, deformation, aging and other phenomena in high-temperature environments, and cannot meet the demand for long-term stable use under high-temperature conditions. Therefore, developing an epoxy resin coating with excellent high-temperature resistance has become a technical problem to be solved.

[0003] In order to improve the heat resistance of the epoxy resin, a higher fluorine content epoxy resin can be used in combination with silica to improve the performance of the fluorine-containing epoxy resin. However, due to the excessive fluorine content in the resin, potential harm to the environment and human body can be caused, and the addition of silica can also affect the overall transparency or processability of the resin, and even increase the brittleness of the material. Alternatively, thick epoxy resin coatings can be used to enhance the cross-linking structure of the resin and relieve the thermal expansion stress of the resin, thereby improving its heat resistance. However, thick epoxy resin coatings are prone to problems such as "skin formation" on the surface of the resin and incomplete curing inside the resin. SUMMARY

[0004] The technical problem to be solved by the application is to provide a high-temperature-resistant single-component epoxy resin coating and a preparation method thereof, which aims to solve the problem of how to reduce the fluorine content and the thickness of the coating while still improving the heat resistance of the resin coating.

[0005] To solve the above problems, the application provides a preparation method of a single-component epoxy resin coating, which comprises the following steps:

[0006] S1, mixing, stirring and heating a phenolic resin with an epoxy compound and a catalyst to obtain a resin monomer;

[0007] S2, mixing the resin monomer with a silicone epoxy copolymer to obtain an epoxy resin prepolymer, detecting the viscosity of the epoxy resin prepolymer, and adjusting the viscosity of the epoxy resin prepolymer until the viscosity of the epoxy resin prepolymer reaches a preset viscosity;

[0008] S3, adding a functional ingredient to the epoxy resin prepolymer to obtain a resin slurry, and then adding a latent curing agent to obtain a single-component epoxy resin coating.

[0009] In some embodiments, the phenolic resin in step S1 includes at least one of phenol-formaldehyde resin, bisphenol A resin, bisphenol F resin; the epoxy compound includes at least one of epichlorohydrin, epoxy ethylene, epoxy propylene; the catalyst includes at least one of triethylamine, sodium hydroxide, benzoic acid.

[0010] In some embodiments, the organic silicon epoxy copolymer in step S2 includes at least one of polydimethylsiloxane elastomer and / or polyether modified polysiloxane.

[0011] In some embodiments, the functional ingredient in step S3 is at least one of a toughening agent, a leveling agent; the toughening agent includes at least one of carboxyl-terminated butyronitrile-acrylonitrile liquid rubber, polyetherimide, the leveling agent includes polyether modified polydimethylsiloxane and / or polyacrylate, and the latent curing agent includes at least one of 2-phenyl-4-methyl imidazole benzoate, microencapsulated dicyandiamide curing agent, and polyester amine curing agent.

[0012] In some embodiments, step S1 includes:

[0013] S1.1, after mixing the phenolic resin with the epoxy compound and the catalyst at room temperature, the mixture is loaded into a heated reaction kettle, nitrogen is introduced, heated and stirred for 2-4 hours, cooled to room temperature to obtain a primary product, wherein the mass ratio of the phenolic resin to the epoxy compound is 1.1-1.2:1, the mass of the catalyst is 0.5-1% of the total mass of the reactants, the flow rate of nitrogen is 50-200 mL / min, and the reaction temperature is 100-130°C;

[0014] S1.2, the primary product is washed, stirred and filtered using a solvent to obtain a resin monomer, wherein the solvent includes at least one of methanol, ethanol, and isopropanol, the volume ratio of the solvent to the primary product is 1:3-5, and the stirring time is 30-60 minutes.

[0015] In some embodiments, step S2 includes:

[0016] S2.1, the resin monomer and the organic silicon epoxy copolymer are added to a reaction kettle, nitrogen is introduced, and heated and stirred under vacuum conditions for 2-6 hours to obtain an epoxy resin prepolymer, wherein the mass ratio of the resin monomer to the organic silicon epoxy copolymer is 5.5-6.5:1, the reaction pressure is -0.08 MPa, the reaction temperature is 80-120°C, and the stirring speed is 200-400 rpm;

[0017] S2.2, the viscosity of the epoxy resin prepolymer is detected using a viscometer, and the viscosity of the epoxy resin prepolymer is adjusted until the viscosity of the epoxy resin prepolymer reaches a preset viscosity.

[0018] The viscosity of the epoxy resin prepolymer is adjusted by adding viscosity adjusting components and adjusting reaction conditions, the reaction conditions including stirring time and reaction temperature.

[0019] The step of adjusting the viscosity of the epoxy resin prepolymer until the viscosity of the epoxy resin prepolymer reaches the preset viscosity range includes:

[0020] The step of judging whether the viscosity of the epoxy resin prepolymer reaches the preset viscosity range.

[0021] If yes, step S3 is performed.

[0022] If no, the viscosity adjusting components are added to the epoxy resin prepolymer, and the step of detecting the viscosity of the epoxy resin prepolymer by using a viscometer and judging whether the viscosity of the epoxy resin prepolymer reaches the preset viscosity range is performed.

[0023] If the viscosity of the epoxy resin prepolymer is lower than the preset viscosity range, the coating may be too thin, and the coating is prone to flow after being applied, forming a non-uniform coating and resulting in insufficient coating strength. If the viscosity of the epoxy resin prepolymer is higher than the preset viscosity range, the coating has poor leveling property, and problems such as brush marks and bubbles are generated, affecting the quality of the coating surface and also causing the coating to be non-uniform during the curing process, thereby affecting the hardness, durability and other properties of the coating.

[0024] In some embodiments, the viscosity adjusting components include a thickening agent and a diluent; the thickening agent includes at least one of an acrylate, a urethane and a polyether modified silane, and the diluent includes at least one of ethyl acetate, methyl ethyl ketone and cyclohexane.

[0025] In some embodiments, step S3 includes:

[0026] S3.1, transferring the epoxy resin prepolymer to a shear dispersion machine, heating and adding functional components at the same material temperature under stirring, continuing to stir and react for 20-40 min to obtain a resin slurry, wherein the mass of the functional components is 1-10% of the total mass of the epoxy resin prepolymer, the material temperature is 55-60°C, and the stirring speed is 1000-2000 rpm;

[0027] S3.2, placing the resin slurry into a planetary vacuum defoaming machine, cooling to 40°C, adding a latent curing agent, and stirring by the planet for 8-12 min; then standing at 45°C and -0.09 MPa for 20 min to remove microbubbles, to obtain a one-component epoxy resin coating, wherein the mass of the latent curing agent is 5-10% of the mass of the resin slurry.

[0028] The present application provides a one-component epoxy resin coating prepared by the preparation method of the one-component epoxy resin coating.

[0029] The present application has the following advantages:

[0030] The phenolic skeleton in the phenolic resin provides a rigid structure, which enhances the resistance of the resin to high-temperature oxidation and thermal decomposition through the combination of aromatic rings and stable chemical bonds, ensuring that it can still maintain structural integrity at extreme temperatures; the multifunctional epoxy groups can react with the curing agent to form more crosslinking points, thereby generating a more compact three-dimensional network structure, which not only improves the structural stability of the resin but also effectively enhances its resistance to high temperatures, avoiding the problems of thermal expansion and thermal deformation; and the strong bonding energy of the silicon-oxygen bond (Si-O) in the silicone-epoxy copolymer makes the skeleton less prone to breakage or degradation at high temperatures, and the silicon-oxygen skeleton itself has a low thermal expansion coefficient, which can reduce the thermal stress of the resin during temperature changes and avoid deformation or cracking caused by uneven thermal expansion, thereby effectively improving the heat resistance of the one-component epoxy resin coating through the synergistic effect of the phenolic resin and the silicone-epoxy copolymer. DETAILED DESCRIPTION

[0031] In the description of the present application, it should be noted that if the specific conditions are not specified in the examples, the conventional conditions or the conditions recommended by the manufacturer are used. If the reagents or instruments used are not specified by the manufacturer, they are all conventional products that can be purchased on the market.

[0032] The present application provides a preparation method of a one-component epoxy resin coating, which comprises the following steps:

[0033] S1, mixing, stirring and heating the phenolic resin, epoxy compound and catalyst to obtain a resin monomer;

[0034] In step S1, the phenolic resin includes at least one of phenolic resin, bisphenol A resin and bisphenol F resin; the epoxy compound includes at least one of epoxy chloropropane, epoxy ethylene and epoxy propylene; and the catalyst includes at least one of triethylamine, sodium hydroxide and benzoic acid.

[0035] The phenolic skeleton in the phenolic resin provides a rigid structure, which enhances the resistance of the resin to high-temperature oxidation and thermal decomposition through the combination of aromatic rings and stable chemical bonds, ensuring that it can still maintain structural integrity at extreme temperatures; the multifunctional epoxy groups can react with the curing agent to form more crosslinking points, thereby generating a more compact three-dimensional network structure, which not only improves the structural stability of the resin but also effectively enhances its resistance to high temperatures, avoiding the problems of thermal expansion and thermal deformation.

[0036] As a basic catalyst, triethylamine promotes the ring-opening of the epoxy compound by providing a lone pair of electrons of nitrogen to react with the epoxy group in the epoxy compound, thereby enhancing the reactivity with the phenolic resin; as a strong base, sodium hydroxide provides hydroxyl ions (OH- ), by increasing the negative charge of the oxygen atom of the epoxy compound, enhancing its nucleophilicity, further accelerating the reaction of the epoxy compound with the phenolic resin; benzoic acid as an acidic catalyst, by providing a proton (H + ) to make the oxygen atom in the epoxy compound carry a positive charge, enhance its nucleophilicity, and thus promote the reaction with the phenolic resin. Through the action of these catalysts, the reaction can be carried out smoothly at lower temperature and time, improving the efficiency of the reaction and the yield of the product.

[0037] S1.1, the phenolic resin is mixed with the epoxy compound and the catalyst at room temperature, then loaded into a heated reaction kettle, nitrogen is introduced, heated and stirred for 2-4h, cooled to room temperature to obtain the initial product, wherein the mass ratio of phenolic resin to epoxy compound is 1.1-1.2:1, the mass of catalyst is 0.5-1% of the total mass of reactants, the flow rate of nitrogen is 50-200mL / min, and the reaction temperature is 100-130℃.

[0038] Mixing the phenolic resin with the epoxy compound and the catalyst at room temperature and heating and stirring under nitrogen atmosphere for 2-4 hours can prevent the occurrence of oxidation reaction, maintain the reducing property of the reaction environment, and help to promote the chemical reaction of the phenolic resin with the epoxy compound to form the initial product with high mass and purity. The reaction is carried out in a controlled temperature range (100-130℃), which can effectively improve the reaction rate and promote the crosslinking reaction between the epoxy compound and the phenolic resin, thereby enhancing the structural stability and physical properties of the initial product.

[0039] S1.2, the initial product is washed, stirred and filtered using a solvent to obtain a resin monomer, wherein the solvent includes at least one of methanol, ethanol, and isopropanol, the volume ratio of the solvent to the initial product is 1:3-5, and the stirring time is 30-60min.

[0040] Methanol, ethanol and isopropanol are all strong polar solvents that can promote the dissolution and dispersion of impurities. Under the action of stirring, the impurities are fully removed to ensure the purity of the resin monomer; and the volume ratio of the solvent to the initial product is controlled in the range of 1:3-5, which can ensure that there is enough amount of solvent for washing, effectively removing impurities, thereby improving the quality of the resin monomer and avoiding the negative impact of catalyst residues on subsequent reactions or product performance.

[0041] S2, the resin monomer is mixed with an organic silicon epoxy copolymer to obtain an epoxy resin prepolymer, the viscosity of the epoxy resin prepolymer is detected, and the viscosity of the epoxy resin prepolymer is adjusted until the viscosity of the epoxy resin prepolymer reaches a preset viscosity.

[0042] The organic silicon epoxy copolymer in step S2 includes polydimethylsiloxane elastomer and / or polyether modified polysiloxane.

[0043] The strong silicon-oxygen bonds (Si-O) in organosilicon epoxy copolymers make the skeleton less prone to breakage or degradation at high temperatures, thus maintaining good structural stability. At the same time, the silicon-oxygen skeleton itself has a low coefficient of thermal expansion, which can reduce the thermal stress of the resin during temperature changes and avoid deformation or cracking caused by uneven thermal expansion.

[0044] Step S2 includes:

[0045] S2.1 Add the resin monomer and the organosilicon epoxy copolymer into a reactor, introduce nitrogen gas, and heat and stir under vacuum for 2-6 hours to obtain an epoxy resin prepolymer. The mass ratio of the resin monomer to the organosilicon epoxy copolymer is 5.5-6.5:1, the nitrogen flow rate is 50-200 mL / min, the reaction pressure is -0.08 MPa, the reaction temperature is 80-120℃, and the stirring speed is 200-400 rpm.

[0046] The nitrogen flow rate is controlled between 50 and 200. Within the mL / min range, oxygen can be effectively eliminated to prevent oxidation reactions, thus ensuring the reaction takes place in an inert atmosphere, improving product purity and reaction efficiency. A negative pressure setting of -0.08 MPa helps remove volatile byproducts, reduces side reactions, and further promotes complete reaction. A reaction temperature between 80 and 120°C ensures a moderate reaction rate, avoiding degradation or incomplete reaction due to excessively high temperatures, thus guaranteeing epoxy resin quality. Simultaneously, a reaction time of 2–6 hours ensures sufficient reaction time, avoiding incomplete reactions due to too short a time or the risk of side reactions due to too long a time. Finally, the mass ratio of resin monomer to organosilicon epoxy copolymer is 5.5–6.5:1. This ratio ensures the integrity of the epoxy resin's main chain structure, while the organosilicon portion provides appropriate flexibility and heat resistance to the prepolymer, thus optimizing the performance of the final product. A stirring speed controlled between 200 and 400 rpm ensures uniform mixing of reactants, improving reaction efficiency, while avoiding excessive bubbles caused by excessive stirring, which could affect reaction quality.

[0047] S2.2 Use a viscometer to test the viscosity of the epoxy resin prepolymer, and adjust the viscosity of the epoxy resin prepolymer until the viscosity of the epoxy resin prepolymer reaches the preset viscosity.

[0048] If the preset viscosity range of the epoxy resin prepolymer is lower than this range, the coating may be too thin and prone to flowing after application, forming an uneven coating and resulting in insufficient coating strength. If it is higher than this viscosity range, the coating will have poor leveling properties, resulting in brush marks, bubbles and other problems, which will affect the quality of the coating surface and also cause uneven curing of the coating, thus affecting the hardness, durability and other properties of the coating.

[0049] Adjusting the viscosity of epoxy resin prepolymer involves increasing viscosity-adjusting components and adjusting reaction conditions, including stirring time and reaction temperature.

[0050] The steps for adjusting the viscosity of the epoxy resin prepolymer until it reaches a preset viscosity range include:

[0051] Determine whether the viscosity of the epoxy resin prepolymer has reached the preset viscosity range;

[0052] If so, proceed to step S3;

[0053] If not, add viscosity-adjusting components to the epoxy resin prepolymer and perform the steps of using a viscometer to detect the viscosity of the epoxy resin prepolymer and determine whether the viscosity of the epoxy resin prepolymer reaches the preset viscosity range.

[0054] The viscosity-adjusting components include thickeners and diluents; the thickeners include at least one of acrylate, urethane, and polyether-modified silane, and the diluents include at least one of ethyl acetate, methyl ethyl ketone, and cyclohexane.

[0055] In one embodiment, when the viscosity of the epoxy resin prepolymer is too low, acrylate is used as a thickener because the unsaturated double bonds in the acrylate molecule can react with the epoxy resin during the crosslinking process to form a three-dimensional network structure. This crosslinking effect not only enhances the adhesion and durability of the resin, but also improves the thickness uniformity and rheological properties of the coating, making the coating easier to control during the coating process and avoiding uneven coating or sagging. When the viscosity of the epoxy resin prepolymer is too high, ethyl acetate is used as a diluent. By interacting with the polar functional groups (such as epoxy groups) in the epoxy resin, it breaks the hydrogen bonds between resin molecules, reduces the viscosity of the resin, and provides a better dispersion medium for the toughening agent. As a result, the cyano or carboxyl groups in the toughening agent can react chemically with the epoxy groups of the epoxy resin to form a crosslinked structure, thereby enhancing the toughness of the resin.

[0056] In one embodiment, the following formula is proposed for calculating an accurate preset viscosity range:

[0057]

[0058] in:

[0059] a0 (mPa·s), a1 (mPa·s / K), a2 (mPa·s / K²), and a3 (mPa·s·K) are temperature coefficients obtained by isothermal scanning tests using a rotational rheometer and then fitting experimental data from different temperature ranges. In this embodiment, T can be 360K, 370K, 380K, or 390K. Calculations show that a0 ranges from -200 to 500, a1 ranges from -5.0 to 0.5, a2 ranges from -0.02 to 0.005, and a3 ranges from 2.0 × 10⁻⁶. 3 ~1.0×10 5 .

[0060] b0 (unit: mPa·s) ^0.5 b1 (unit: mPa·s) -1 b2 (unit: mPa·s) -2 The time coefficient is used to monitor the degree of crosslinking and simultaneously record viscosity changes using a differential scanning calorimeter. In this embodiment, the value of t can be 2h, 3h, 4h, 5h, or 6h (the unit needs to be converted to seconds for calculation). Then, the degree of crosslinking is calculated according to the quantitative formula in the field of thermal analysis. The value range of b0 is 0~0.2, the value range of b1 is 0~0.001, and the value range of b2 is -1×10. -8 ~1×10 -7 ;

[0061] c0 (mPa·s / rad), c1 (mPa·s / rad²), and c2 (mPa·s·rad) are shear coefficients, measured using a cone-plate rheometer from 0.1 to 1000 s⁻¹. -1 Shear rate scanning records shear stress τ and shear rate ω. In this embodiment, ω can take values ​​of 200 rpm, 250 rpm, 300 rpm, 350 rpm, and 400 rpm. Then, through calculation, c0 is found to have a value range of -0.8 to 0.2, and c1 is found to have a value range of -1 × 10⁻⁶. -4 ~5×10 -5 The value range of c2 is 1×10. 4 ~1×10 5 ;

[0062] k1, k2, and k3 are dimensionless weighting coefficients. Their contributions to the reaction temperature, reaction time, and stirring rate were determined using an orthogonal experimental design method. Specifically, k1 ranges from 0.42 to 0.58, k2 from 0.25 to 0.38, and k3 from 0.08 to 0.18 (Σk n =1, that is, k1 + k2 + k3 = 1).

[0063] ε is the correction term (mPa·s). In this case, the resin is an epoxy resin system. The residuals between the model predictions and the measured values ​​are collected and calculated. The value of ε ranges from 7 to 70.

[0064] η1 represents the viscosity component determined by temperature (mPa·s), η2 represents the viscosity component determined by time (mPa·s), and η3 represents the viscosity component determined by shear rate (mPa·s); T is the temperature (in K), t is the reaction time (s), ω is the stirring speed (rpm), and η is the final viscosity (mPa·s).

[0065] In one embodiment, a0 = 50 mPa·s, a1 = -1.2 mPa·s / K, a2 = -0.015 mPa·s / K², a3 = 1.5 × 10⁻⁶ mPa·s / K². 4 mPa·s / K²,‌b0=0.1‌mPa·s ^0.5 b1 = 0.0005 mPa·s -1 b2 = 0.5 × 10 -7 mPa·s -2 , c0=0.05‌mPa·s / rad, c1=3×10 -5 mPa·s / rad², c²=5×10 4 Given mPa·s·rad, k1=0.50, k2=0.32, k3=0.18, ε=35 mPa·s, by adjusting the reaction temperature, reaction time, and stirring speed within the range, the maximum / minimum value of the preset viscosity range can be obtained, thereby determining how to adjust the state of the epoxy resin prepolymer.

[0066] S3. Add functional components to epoxy resin prepolymer to obtain resin slurry, then add latent curing agent to obtain single-component epoxy resin coating.

[0067] Plasticizers improve the flexibility and processability of resins by lowering their glass transition temperature (Tg), resulting in coatings with better impact and flexural resistance after curing. They also improve resin flowability, facilitating uniform coating distribution during application. Leveling agents help improve the surface smoothness of the coating, preventing bubbles, scratches, or unevenness during application and ensuring the coating's appearance quality. Latent curing agents activate the epoxy resin under appropriate temperature and conditions, promoting the curing reaction. Due to their low reactivity, latent curing agents do not cure prematurely at room temperature, allowing for a longer working time during storage and use. Once heated or under specific conditions, the curing agent initiates the cross-linking reaction of the epoxy resin, ultimately forming a hard and durable film. By incorporating plasticizers, leveling agents, and latent curing agents, epoxy resin coatings can achieve excellent processing performance, coating quality, and long-term stable storage, meeting the needs of various coating applications.

[0068] The functional component in step S3 is at least one of a toughening agent and a leveling agent; the toughening agent includes at least one of carboxyl-terminated butadiene-acrylonitrile liquid rubber and polyetherimide; the leveling agent includes polyether-modified polydimethylsiloxane and / or polyacrylate; the latent curing agent includes at least one of 2-phenyl-4-methylimidazolium benzoate, microencapsulated dicyandiamine curing agent, and polyesteramine curing agent.

[0069] Step S3 includes:

[0070] S3.1 Transfer the epoxy resin prepolymer to a shear disperser, heat it and add the functional component with the same material temperature while stirring, continue stirring and reacting for 20~40 minutes to obtain a resin slurry, wherein the mass of the functional component is 1~10% of the total mass of the epoxy resin prepolymer, the material temperature is 55~60℃, and the stirring speed is 1000~2000rpm.

[0071] During the preparation of resin slurry, a material temperature of 55-60℃ can promote the effective reaction between epoxy groups and functional components, while avoiding side reactions caused by high temperature; high-speed shearing and stirring at 1000-2000rpm ensures uniform dispersion of functional components and strengthens interfacial bonding; the addition ratio of 1-10% of functional components achieves both modification effect and maintains system stability; and a reaction time of 20-40min ensures full bonding. These conditions work together to form a resin slurry with uniform structure and stable performance.

[0072] S3.2 Place the resin slurry into a planetary vacuum degassing machine, cool it to 40°C, add the latent curing agent, and stir planetarily for 8~12 minutes; then let it stand at 45°C and -0.09MPa for 20 minutes to remove microbubbles, and obtain a single-component epoxy resin coating, wherein the mass of the latent curing agent is 5~10% of the mass of the resin slurry.

[0073] Vacuum degassing removes microbubbles, improving the mechanical properties of epoxy resin coatings and preventing stress concentration points from forming after bubble curing, which can lead to a decrease in strength. It also ensures the appearance quality of epoxy resin coatings and prevents surface defects such as pinholes and fisheyes from appearing on the coating.

[0074] The above embodiments are preferred embodiments of this application, but the implementation of this application is not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of this application shall be considered equivalent substitutions and shall be included within the protection scope of this application.

Claims

1. A method for preparing a one-component epoxy resin coating, characterized in that, The preparation method includes the following steps: S1. Phenolic resin is mixed with epoxy compound and catalyst, stirred and heated to obtain resin monomer; S2. Mix the resin monomer with the organosilicon epoxy copolymer to obtain the epoxy resin prepolymer, detect the viscosity of the epoxy resin prepolymer, and adjust the viscosity of the epoxy resin prepolymer until the viscosity of the epoxy resin prepolymer reaches the preset viscosity. S3. Add functional components to epoxy resin prepolymer to obtain resin slurry, then add latent curing agent to obtain single-component epoxy resin coating. Step S1 includes: S1.

1. Phenolic resin, epoxy compound, and catalyst are mixed at room temperature and then placed into a heated reaction vessel. Nitrogen gas is introduced, and the mixture is heated and stirred for 2-4 hours. After cooling to room temperature, the initial product is obtained. The mass ratio of phenolic resin to epoxy compound is 1.1-1.2:1, the mass of catalyst is 0.5-1% of the total reactant mass, the flow rate of nitrogen gas is 50-200 mL / min, and the reaction temperature is 100-130℃. S1.2 The initial product is washed, stirred and filtered using a solvent to obtain resin monomers. The solvent includes at least one of methanol, ethanol and isopropanol. The volume ratio of the solvent to the initial product is 1:3~5, and the stirring time is 30~60 min. Step S2 includes: S2.1 Add the resin monomer and the organosilicon epoxy copolymer to the reactor, introduce nitrogen gas, and heat and stir under vacuum for 2-6 hours to obtain the epoxy resin prepolymer. The mass ratio of the resin monomer to the organosilicon epoxy copolymer is 5.5-6.5:1, the reaction pressure is -0.08MPa, the reaction temperature is 80-120℃, and the stirring speed is 200-400rpm. S2.2 Use a viscometer to test the viscosity of the epoxy resin prepolymer, and adjust the viscosity of the epoxy resin prepolymer until the viscosity of the epoxy resin prepolymer reaches the preset viscosity. Step S3 includes: S3.1 Transfer the epoxy resin prepolymer to a shear disperser, heat it and add the functional component with the same material temperature while stirring, continue stirring and reacting for 20~40 minutes to obtain a resin slurry, wherein the mass of the functional component is 1~10% of the total mass of the epoxy resin prepolymer, the material temperature is 55~60℃, and the stirring speed is 1000~2000rpm. S3.2 Place the resin slurry into a planetary vacuum degassing machine, cool it to 40°C, add the latent curing agent, and stir planetarily for 8~12 minutes; then let it stand at 45°C and -0.09MPa for 20 minutes to remove microbubbles, and obtain a single-component epoxy resin coating, wherein the mass of the latent curing agent is 5~10% of the mass of the resin slurry.

2. The method for preparing a single-component epoxy resin coating according to claim 1, characterized in that, The phenolic resin in step S1 includes at least one of phenolic resin, bisphenol A resin, and bisphenol F resin; the epoxy compound includes at least one of epichlorohydrin, ethylene oxide, and propylene oxide; and the catalyst includes at least one of triethylamine, sodium hydroxide, and benzoic acid.

3. The method for preparing a single-component epoxy resin coating according to claim 1, characterized in that, The organosilicon epoxy copolymer in step S2 includes polydimethylsiloxane elastomer and / or polyether-modified polysiloxane.

4. The method for preparing a single-component epoxy resin coating according to claim 1, characterized in that, The functional component in step S3 is at least one of a toughening agent and a leveling agent; the toughening agent includes at least one of carboxyl-terminated butadiene-acrylonitrile liquid rubber and polyetherimide; the leveling agent includes polyether-modified polydimethylsiloxane and / or polyacrylate; and the latent curing agent includes at least one of 2-phenyl-4-methylimidazolium benzoate, microencapsulated dicyandiamine curing agent, and polyesteramine curing agent.

5. The method for preparing a single-component epoxy resin coating according to claim 1, characterized in that, Adjusting the viscosity of epoxy resin prepolymers includes increasing viscosity-adjusting components and adjusting reaction conditions, including stirring time and reaction temperature. The steps for adjusting the viscosity of the epoxy resin prepolymer until it reaches the preset viscosity range include: Determine whether the viscosity of the epoxy resin prepolymer has reached the preset viscosity range; If so, proceed to step S3; If not, add viscosity-adjusting components to the epoxy resin prepolymer and perform the steps of using a viscometer to detect the viscosity of the epoxy resin prepolymer and determine whether the viscosity of the epoxy resin prepolymer reaches the preset viscosity range.

6. The method for preparing a single-component epoxy resin coating according to claim 5, characterized in that, The viscosity-adjusting components include thickeners and diluents; the thickeners include at least one of acrylates, urethane, and polyether-modified silanes, and the diluents include at least one of ethyl acetate, methyl ethyl ketone, and cyclohexane.

7. A one-component epoxy resin coating, characterized in that, It is prepared by the method of any one of claims 1-6 for preparing a single-component epoxy resin coating.

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