Multi-component composite epoxy coating with high toughness and aging resistance and preparation method thereof

Abstract

The invention relates to the technical field of coating protection, in particular to a multi-component composite epoxy coating with high toughness and aging resistance and a preparation method of the multi-component composite epoxy coating, and discloses the multi-component composite epoxy coating with high toughness and aging resistance. Comprising polyurethane coupled bisphenol A type epoxy molecules, fluorinated phenyl isocyanate graft modified epoxy molecules and a curing agent in a mass ratio of (10-20): (4-8): (2-6). The polyurethane modified epoxy resin is adopted, so that the flexibility of the composite coating can be improved. When the epoxy resin is grafted to the epoxy resin, the weather resistance of the coating can be remarkably improved, and the epoxy composite coating can still keep stability and functionality in a low-temperature, complex and changeable environment in the ocean.

Description

Technical Field

[0001] This invention relates to the field of coating protection technology, and in particular to a multi-component composite epoxy coating with high toughness and anti-aging properties and its preparation method. Background Technology

[0002] Epoxy resin is a polymer compound containing two or more epoxy groups. It reacts with a curing agent to form a thermosetting three-dimensional network structure. Cured epoxy resin exhibits excellent mechanical, thermal, adhesive, and electrical properties, and its dimensions are not easily altered under mechanical force, heat, or other external conditions. Due to its superior comprehensive properties, epoxy resin is widely used in many important materials, such as adhesives, electronic product packaging, coatings, semiconductor potting compounds, machinery, military, and aerospace. However, due to the internal stress, defects, and corrosive media penetration generated after the rigid molecular chains of epoxy resin cure, it is prone to cracking under heavy loads and heat treatment. Furthermore, it suffers from poor weather resistance and adhesion, and is susceptible to aging failure, leading to a decline in the protective performance of coatings. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides the following technical solution:

[0004] A multi-component composite epoxy coating with high toughness and anti-aging properties, comprising:

[0005] The polyurethane-coupled bisphenol A type epoxy molecule, fluorinated phenyl isocyanate grafted modified epoxy molecule, and curing agent are in a mass ratio of (10-20):(4-8):(2-6).

[0006] As an improvement to the above technical solution, the preparation method of the polyurethane-coupled bisphenol A type epoxy molecule includes the following steps:

[0007] Polyethylene glycol and toluene diisocyanate in a molar ratio of 1:(2.5-3) were dissolved in a solvent and heated to 75-80°C under the condition of a catalyst for 4 hours. Vacuum was turned on in the last hour, and after the reaction was completed, isocyanate-terminated polyurethane prepolymer was obtained.

[0008] An epoxy resin and a polyurethane prepolymer with a molar ratio of (1.8–2.2):1 were heated and reacted under nitrogen protection. The heating temperature was 75–80°C and the mixture was kept at that temperature for 4 hours to generate polyurethane-coupled bisphenol A type epoxy molecules.

[0009] As an improvement to the above technical solution, the solvent is at least one of N-methylpyrrolidone, tetrahydrofuran, butanone, and N,N-dimethylformamide; the catalyst is at least one of dibutyltin dilaurate and stannous octoate; and the epoxy resin is at least one of E20, E44, and E51.

[0010] As an improvement to the above technical solution, the molecular structure of the polyurethane-coupled bisphenol A type epoxy is shown below:

[0011]

[0012] Wherein, R1 is polyurethane prepolymer, R2 is epoxy resin, and n is degree of polymerization.

[0013] As an improvement to the above technical solution, the preparation method of the fluorinated phenyl isocyanate grafted modified epoxy molecule includes the following steps:

[0014] Epoxy resin and fluorinated phenyl isocyanate in a molar ratio of 1:(0.8~1.2) were dissolved in a solvent, stirred and heated under a catalyst, with nitrogen gas constantly introduced during the heating process. The heating temperature was 40℃-50℃ and the duration was 12h.

[0015] After the reaction is completed by stirring and heating, the product is purified to generate fluorinated phenyl isocyanate-grafted modified epoxy molecules.

[0016] As an improvement to the above technical solution, the fluorinated phenyl isocyanate-grafted modified epoxy molecular structure is shown below:

[0017]

[0018] Wherein, R3 is one of fluoro, trifluoromethoxy, or trifluoromethyl; m is the degree of polymerization.

[0019] As an improvement to the above technical solution, the solvent is at least one of butyl acetate and n-hexane, the catalyst is at least one of dibutyltin dilaurate and stannous octoate, and the epoxy resin is at least one of E20, E44, and E51.

[0020] A method for preparing a multi-component composite epoxy coating with high toughness and anti-aging properties, used to prepare a multi-component composite epoxy coating with high toughness and anti-aging properties as described in any of the foregoing technical solutions, comprising the following steps:

[0021] The polyurethane-coupled bisphenol A type epoxy molecules, fluorinated phenyl isocyanate-grafted modified epoxy molecules, and curing agent are mixed and stirred for 30 minutes at a mass ratio of (10-20):(4-8):(2-6).

[0022] The mixture is applied to the substrate using at least one of the following methods: spraying, dip coating, or brushing. After curing, an epoxy composite coating with high anti-aging properties is obtained.

[0023] As an improvement to the above technical solution, the substrate to be coated is at least one of carbon steel, copper alloy, aluminum alloy, concrete, and polytetrafluoroethylene mold.

[0024] As an improvement to the above technical solution, the curing temperature of the epoxy composite coating is 20-90°C, the curing time is 6-26 hours, and the curing agent is at least one of polyamide PA650 and polyetheramine D230.

[0025] The beneficial effects of this invention are:

[0026] By using polyurethane-modified epoxy resin, the flexibility of the composite coating can be improved. Grafting it onto epoxy resin can significantly enhance the weather resistance of the coating, allowing the epoxy composite coating to maintain stability and functionality in the low-temperature and complex environment of the ocean. Furthermore, polyurethane has high abrasion resistance, and its inherent flexibility can absorb and disperse external stress, reducing crack formation, enhancing the adhesion between the coating and the substrate material, improving the overall anti-aging performance of the coating, and extending its service life. Attached Figure Description

[0027] Figure 1 Nyquist plot of electrochemical impedance spectroscopy test results of high toughness and anti-aging multi-component composite epoxy coating of Example 1 of this application after 105 days of salt spray aging;

[0028] Figure 2 Bode plot of electrochemical impedance spectroscopy test results of the high-toughness and anti-aging multi-component composite epoxy coating of Example 1 of this application after 105 days of salt spray aging;

[0029] Figure 3 The phase angle of the electrochemical impedance spectroscopy test results of the high-toughness and anti-aging multi-component composite epoxy coating of Example 1 of this application after 105 days of salt spray aging;

[0030] Figure 4 Nyquist plot of electrochemical impedance spectroscopy results of the high-toughness and anti-aging multi-component composite epoxy coating prepared in Example 2 of this application after 10 days of cyclic aging under ultraviolet light irradiation and immersion in 5wt.% NaCl;

[0031] Figure 5 Bode plot of electrochemical impedance spectroscopy results of the high-toughness and anti-aging multi-component composite epoxy coating prepared in Example 2 of this application after 10 days of cyclic aging under ultraviolet light irradiation and immersion in 5wt.% NaCl;

[0032] Figure 6The phase angle is the electrochemical impedance spectroscopy result of the high-toughness and anti-aging multi-component composite epoxy coating prepared in Example 2 of this application after 10 days of cyclic aging under ultraviolet light and immersion in 5wt.% NaCl. Detailed Implementation

[0033] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0034] Due to the internal stress, defects, and corrosive media penetration generated after the rigid molecular chains of epoxy resin are cured, epoxy resin is prone to cracking when subjected to large loads and heat treatment. It also has problems such as poor weather resistance and poor adhesion, and is prone to aging failure, which leads to the degradation of coating protective performance.

[0035] To solve the above problems, the following solution is provided:

[0036] Option 1

[0037] A multi-component composite epoxy coating with high toughness and anti-aging properties, comprising:

[0038] The polyurethane-coupled bisphenol A type epoxy molecule, fluorinated phenyl isocyanate grafted modified epoxy molecule, and curing agent are in a mass ratio of (10-20):(4-8):(2-6).

[0039] The preparation method for polyurethane-coupled bisphenol A type epoxy molecules includes the following steps:

[0040] Polyethylene glycol and toluene diisocyanate in a molar ratio of 1:(2.5-3) were dissolved in a solvent and heated to 75-80°C under the condition of a catalyst for 4 hours. Vacuum was turned on in the last hour, and after the reaction was completed, isocyanate-terminated polyurethane prepolymer was obtained.

[0041] An epoxy resin and a polyurethane prepolymer with a molar ratio of (1.8–2.2):1 were heated and reacted under nitrogen protection. The heating temperature was 75–80°C and the mixture was kept at that temperature for 4 hours to generate polyurethane-coupled bisphenol A type epoxy molecules.

[0042] Specifically, the solvent in the above scheme can be at least one of N-methylpyrrolidone, tetrahydrofuran, butanone, and N,N-dimethylformamide; the catalyst can be at least one of dibutyltin dilaurate and stannous octoate; and the epoxy resin can be at least one of E20, E44, and E51.

[0043] The molecular structure of the polyurethane-coupled bisphenol A epoxy prepared by the above method is shown below:

[0044]

[0045] Wherein, R1 is polyurethane prepolymer, R2 is epoxy resin, and n is degree of polymerization.

[0046] The preparation mechanism of the above reaction is as follows:

[0047]

[0048] The grafting process can be summarized into the following two stages: (1) Reaction of isocyanate with diol (HO-R-OH): First, nucleophilic addition occurs: the O atom in the hydroxyl group (-OH) of the diol acts as the nucleophilic center, attacking the partially positively charged C atom in the isocyanate (-NCO) (because N electronegativity > C, C is electron-deficient), forming an unstable tetrahedral intermediate. Then, the intermediate rapidly rearranges to eliminate the unstable structure, and finally forms a urethane bond to generate a polyurethane prepolymer. (2) Second stage: Reaction of the prepolymer containing hydroxyl and epoxy groups with the urethane prepolymer: hydroxyl group continues to react: the unreacted -OH in the prepolymer repeats the first stage "nucleophilic addition → rearrangement" process, and continues to generate urethane bonds with the residual -NCO, extending the molecular chain. Epoxy ring opening (if involved): If the system contains epoxy groups (such as epichlorohydrin-derived structures), the epoxy ring is attacked and opened by nucleophiles (such as -NH-, -O-, etc. in urethane bonds), introducing new linkage sites, further expanding the molecular chain network, or cross-linking to form a more complex structure (depending on reaction conditions and raw material ratios), ultimately obtaining the polyurethane-coupled bisphenol A type epoxy molecule required for the experiment.

[0049] The preparation method of fluorinated phenyl isocyanate-grafted modified epoxy molecules in composite coatings includes the following steps:

[0050] Epoxy resin and fluorinated phenyl isocyanate in a molar ratio of 1:(0.8~1.2) were dissolved in a solvent, stirred and heated under a catalyst, with nitrogen gas constantly introduced during the heating process. The heating temperature was 40℃-50℃ and the duration was 12h.

[0051] After the reaction is completed by stirring and heating, the product is purified to generate fluorinated phenyl isocyanate-grafted modified epoxy molecules.

[0052] The solvent in the above steps can be at least one of butyl acetate and n-hexane, the catalyst can be at least one of dibutyltin dilaurate and stannous octoate, and the epoxy resin can be at least one of E20, E44, and E51.

[0053] The fluorinated phenyl isocyanate-grafted modified epoxy molecular structure obtained by the above steps is shown below:

[0054]

[0055] Wherein, R3 is one of fluoro, trifluoromethoxy, or trifluoromethyl; m is the degree of polymerization.

[0056] The preparation mechanism of the above reaction is as follows:

[0057]

[0058] The grafting process can be summarized into the following three steps: (1) Nucleophilic attack. Under the action of a catalyst, the hydroxyl group -OH deprotonates to form the alkoxy anion RO. - As a nucleophile, it attacks the positively charged middle carbon in the RN=C=O region of the isocyanate, causing the C=N double bond to break; (2) the intermediate rearranges. Due to the C=N breakage, the middle carbon interacts with the RO on the epoxy backbone. - (3) Protonation. At this time, the N element of the C=N break carries a negative charge and is reprotonated by the H element removed during the nucleophilic attack of the epoxy resin backbone. Theoretically, a single polymer product without additional small molecule products is generated, namely the epoxy molecule grafted with fluorinated phenyl isocyanate.

[0059] Option 2

[0060] To prepare the composite coating described in Example 1, a method for preparing a multi-component composite epoxy coating with high toughness and anti-aging properties is provided, comprising the following steps:

[0061] The polyurethane-coupled bisphenol A type epoxy molecules, fluorinated phenyl isocyanate grafted modified epoxy molecules, and curing agent are mixed and stirred for 30 minutes at a mass ratio of (10-20):(4-8):(2-6).

[0062] The mixture is applied to the substrate using at least one of the following methods: spraying, dip coating, or brushing. After curing, an epoxy composite coating with high anti-aging properties is obtained.

[0063] The substrate coated in the preparation step can be at least one of carbon steel, copper alloy, aluminum alloy, concrete, or polytetrafluoroethylene mold.

[0064] In the preparation steps, the curing temperature of the epoxy composite coating is 20-90℃, the curing time is 6-26 hours, and the curing agent is at least one of polyamide PA650 and polyetheramine D230.

[0065] To further verify the functional properties of the composite epoxy coatings prepared by Scheme 1 and Scheme 2, several examples are provided for verification, as follows:

[0066] Example 1

[0067] (1) The raw materials must be dehydrated before preparing polyurethane. Polyethylene glycol was added to a 500ml four-necked flask, heated to 120℃, and dehydrated under vacuum for 5 hours. Since the synthesized polyurethane prepolymer also contains a certain amount of NCO groups, the epoxy resin used for grafting with it should also undergo the same dehydration treatment as the polyethylene glycol. The main experimental procedures are as follows:

[0068] When the temperature of 26.4 g of polyethylene glycol (M = 400 g / mol) dropped to 70 °C, 30 g of toluene diisocyanate (M = 174.16 g / mol) was dissolved in N-methylpyrrolidone. The mixture was then slowly added dropwise to a four-necked flask, with two drops of dibutyltin dilaurate added as a catalyst. The temperature was raised to 75 °C, and the mixture was stirred and kept at this temperature for 4 hours. Vacuum was then applied during the last hour to obtain -NCO (isocyanate)-terminated polyurethane. 54.02 g of ester prepolymer (M = 972 g / mol) was added to a four-necked flask along with 19.75 g of epoxy resin E44 (M = 455 g / mol), which had also undergone dehydration treatment, and 20 g of polyurethane prepolymer. N2 was introduced for protection to eliminate interference from O2 and water in the air. The temperature was raised to 75 °C and held for 4 h. Finally, 39.75 g of bisphenol A type epoxy molecules (M = 1500 g / mol) grafted onto polyurethane prepolymer were obtained.

[0069] (2) In a beaker, 24g of E44 epoxy resin and 6g of butyl acetate (M = 116.16g / mol) were first mixed to dilute the viscous epoxy resin into a transparent organic solution with suitable flow. Then, the solution was poured into a three-necked flask and 1.12g of trifluoromethoxyphenyl isocyanate (M = 203.12g / mol) was added to the solution. 0.25g of dibutyltin dilaurate was slowly added dropwise as a catalyst. The reaction was stirred for 12h under N2 atmosphere, 400rpm / min and 40℃. After the reaction was completed, the residual catalyst, small molecules and solvent were removed by rotary evaporator to obtain 25.12g of fluorinated phenyl isocyanate grafted modified epoxy molecules (M = 861g / mol).

[0070] (3) Mix 20g of bisphenol A type epoxy molecules grafted onto polyurethane prepolymer and 16g of fluorinated phenyl isocyanate grafted modified epoxy molecules for 30 minutes, then add 4g of polyamide PA650 to obtain a composite coating. Apply the composite coating to the surface of Q235 carbon steel using a spraying method. The average thickness of the coating on the carbon steel surface is about 100 micrometers, and then place it in an environment of 25°C for 20 hours to cure.

[0071] To further verify the performance of the solution in Example 1, an anti-aging test was conducted on the composite coating prepared in Example 1. The performance was evaluated according to the GB / T 10125-2021 standard, as follows:

[0072] Q235 carbon steel electrodes coated with a composite coating and those coated with E44 epoxy resin were placed in a salt spray chamber for accelerated aging tests under neutral salt spray conditions. The sodium chloride concentration was 5%, the spray pressure was maintained at 110 kPa, the spray chamber temperature was 35℃, and the average deposition rate was 2.0 mL / h. During the test, the sample test surface was positioned at a 15° angle to the vertical direction, and the spraying time was 70 days. After the salt spray test, both types of carbon steel electrodes were removed. The prepared coated electrode was used as the working electrode (WE), the platinum electrode as the counter electrode (CE), and the saturated calomel electrode as the reference electrode (RE). The data testing frequency range was 10. 5 ~10 -1 Hz. Electrochemical impedance spectroscopy was performed in a 5% sodium chloride solution, and the impedance modulus as a function of frequency is shown in the following results. Figures 1 to 3 As shown. Figures 1 to 3 Electrochemical impedance spectroscopy test results of the high-toughness and anti-aging multi-component composite epoxy coating prepared in Example 1 of this application after 105 days of salt spray aging;

[0073] Based on the test data of the multi-component composite epoxy coating, it can be found that the impedance Rc value was around 10 during the initial test. 10 Approximately Ω·cm², after being corroded by the corrosive medium, the impedance continuously decreases, the impedance semicircle becomes increasingly pronounced, and the value of impedance Rc is around 10. 9 The impedance remains around Ω·cm², exhibiting strong corrosion and aging resistance. Around 28 days, the impedance Rc test value showed a rebound, and in subsequent tests, up to 105 days, the impedance of the multi-component composite epoxy coating remained consistently around 10 Ω·cm². 10 With a concentration of Ω·cm², it provides long-lasting corrosion and anti-aging capabilities, demonstrating excellent anti-aging performance.

[0074] Example 2

[0075] (1) Polyethylene glycol was added to a 500 ml four-necked flask and heated to 125 °C. The mixture was then dehydrated under vacuum for 5 h. Afterward, when the temperature of 53.2 g of polyethylene glycol (M = 400 g / mol) dropped to 70 °C, 43.54 g of toluene diisocyanate (TDI) (M = 174.16 g / mol) was dissolved in tetrahydrofuran. The mixture was then slowly added dropwise to the four-necked flask, with three drops of stannous octoate added as a catalyst. The temperature was raised to 80 °C, and the mixture was stirred and kept at this temperature for 4 h. Vacuum was opened in the last h to obtain -NCO (isocyanate)-terminated polyethylene glycol. 89.04 g of urethane prepolymer (M = 972 g / mol) was added to a four-necked flask along with 87.77 g of epoxy resin E44 (M = 455 g / mol), which had also undergone dehydration treatment, and 20 g of polyurethane prepolymer. N2 was introduced for protection to eliminate interference from O2 and water in the air. The temperature was raised to 80 °C and maintained for 4 hours. Finally, 176.81 g of bisphenol A type epoxy molecules (M = 1500 g / mol) grafted onto the polyurethane prepolymer were obtained.

[0076] (2) 35g of E44 epoxy resin and 8.75g of butyl acetate (M=116.16g / mol) were first mixed in a beaker to dilute the viscous epoxy resin into a transparent organic solution with suitable flowability. Then, the solution was poured into a three-necked flask and 29.62g of p-fluorophenyl isocyanate was added to the solution. 0.64g of dibutyltin dilaurate was slowly added dropwise as a catalyst. The reaction was stirred for 12h under N2 atmosphere, 400rpm / min and 50℃. After the reaction was completed, a rotary evaporator was used with the rotary evaporation temperature set to 90℃ and the vacuum degree ≤5mmHg to ensure that the residual catalyst, small molecules and solvent were removed to obtain 64.62g of fluorinated phenyl isocyanate grafted modified epoxy molecules (M=840g / mol).

[0077] (3) Mix 50g of bisphenol A type epoxy molecules grafted onto polyurethane prepolymer and 40g of fluorinated phenyl isocyanate grafted modified epoxy molecules for 30 minutes, then add 10g of polyetheramine D230 to obtain a composite coating. Apply the composite coating to the surface of C30 concrete and the polytetrafluoroethylene mold using a spraying method. The average thickness of the coating on the concrete surface is about 100 micrometers, and the thickness in the mold is 2mm. Then, place it in a 30°C environment for curing for 16 hours.

[0078] To further evaluate the mechanical tensile properties of the composite coating prepared in Example 2, the epoxy solid cured in a polytetrafluoroethylene mold was cut and subjected to mechanical tensile testing. The sample specifications conformed to the 1BA type specimen size in GB / T 1040.1-2018, with a width b = 4.05 mm, a thickness d = 2.05 mm, and an initial gauge length of 25.05 mm. The tensile rate was set to 5 mm / min during the test. The test results are shown in the table below:

[0079] Table 1 Tensile test parameters for each coating

[0080]

[0081] As shown in Table 1, the multi-component composite epoxy coating exhibits stronger tensile strength than the blank EP coating in its initial state, and its elongation at break also increases to some extent. The modified multi-component composite epoxy coating, compared to the blank epoxy coating, shows a 51.88% increase in tensile strength. Although the tensile strength of the coating decreased after 14 days of salt spray aging, and the elongation at break increased, the tensile strength of the modified coating remained stronger than that of the blank EP coating. The multi-component composite epoxy resin possesses superior mechanical properties and maintains a longer service life.

[0082] To further test the anti-aging properties of the composite coating prepared in Example 2, tests were conducted and evaluated according to the requirements of GB / T14522-2008, as follows:

[0083] Exposure cycle type 6 was selected, consisting of 8 hours of drying (60℃), 0.25 hours of water spraying, and 3.75 hours of condensation (50℃). The fluorescent ultraviolet lamp type was UVA-340, and the irradiance was set to 1.55±0.02W / m². 2 The wavelength was controlled at 340 nm. After a 24-hour exposure cycle, the coated electrode was immersed in a 5 wt.% NaCl solution for 24 hours, and electrochemical impedance spectroscopy (EIS) was performed in a 5% sodium chloride solution. The prepared coated electrode was used as the working electrode (WE), a platinum electrode as the counter electrode (CE), and a saturated calomel electrode as the reference electrode (RE). The data measurement frequency range was 10 nm. 5 ~10 -1 Hz. Impedance modulus as a function of frequency test results are as follows: Figures 4 to 6 As shown. Figures 4 to 6 The electrochemical impedance spectroscopy results are shown for the high-toughness, anti-aging multi-component composite epoxy coating prepared in Example 2 of this application, after 10 days of cyclic aging under ultraviolet light and immersion in 5wt.% NaCl.

[0084] Combination Figures 4 to 6 The test data shows that the impedance value Rc of the composite epoxy coating synthesized in Example 2 remained at 10 after 10 days of aging. 11 Ω·cm 2 The levels remained around 100°C, with no significant downward trend, confirming its excellent anti-aging properties.

[0085] The above embodiments are merely illustrative of the technical solutions of the present invention and are not intended to limit it. Anyone skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A multi-component composite epoxy coating with high toughness and anti-aging properties, characterized in that, include: The polyurethane-coupled bisphenol A type epoxy molecule, fluorinated phenyl isocyanate grafted modified epoxy molecule, and curing agent are in a mass ratio of (10-20):(4-8):(2-6).

2. The multi-component composite epoxy coating with high toughness and anti-aging properties according to claim 1, characterized in that: The method for preparing the polyurethane-coupled bisphenol A type epoxy molecule includes the following steps: Polyethylene glycol and toluene diisocyanate in a molar ratio of 1:(2.5-3) were dissolved in a solvent and heated to 75-80°C under the condition of a catalyst for 4 hours. Vacuum was turned on in the last hour, and after the reaction was completed, isocyanate-terminated polyurethane prepolymer was obtained. An epoxy resin and a polyurethane prepolymer with a molar ratio of (1.8–2.2):1 were heated and reacted under nitrogen protection. The heating temperature was 75–80°C and the mixture was kept at that temperature for 4 hours to generate polyurethane-coupled bisphenol A type epoxy molecules.

3. The multi-component composite epoxy coating with high toughness and anti-aging properties according to claim 2, characterized in that: The solvent is at least one of N-methylpyrrolidone, tetrahydrofuran, butanone, and N,N-dimethylformamide; the catalyst is at least one of dibutyltin dilaurate and stannous octoate; and the epoxy resin is at least one of E20, E44, and E51.

4. The multi-component composite epoxy coating with high toughness and anti-aging properties according to claim 2, characterized in that: The molecular structure of the polyurethane-coupled bisphenol A type epoxy is shown below: Wherein, R1 is polyurethane prepolymer, R2 is epoxy resin, and n is degree of polymerization.

5. A multi-component composite epoxy coating with high toughness and anti-aging properties according to claim 1, characterized in that: The preparation method of the fluorinated phenyl isocyanate grafted modified epoxy molecule includes the following steps: Epoxy resin and fluorinated phenyl isocyanate in a molar ratio of 1:(0.8~1.2) were dissolved in a solvent, stirred and heated under a catalyst, with nitrogen gas constantly introduced during the heating process. The heating temperature was 40℃-50℃ and the duration was 12h. After the reaction is completed by stirring and heating, the product is purified to generate fluorinated phenyl isocyanate-grafted modified epoxy molecules.

6. A multi-component composite epoxy coating with high toughness and anti-aging properties according to claim 5, characterized in that: The structural formula of the fluorinated phenyl isocyanate-grafted modified epoxy molecule is shown below: Wherein, R3 is one of fluoro, trifluoromethoxy, or trifluoromethyl; m is the degree of polymerization.

7. A multi-component composite epoxy coating with high toughness and anti-aging properties according to claim 5, characterized in that: The solvent is at least one of butyl acetate and n-hexane, the catalyst is at least one of dibutyltin dilaurate and stannous octoate, and the epoxy resin is at least one of E20, E44, and E51.

8. A method for preparing a multi-component composite epoxy coating with high toughness and anti-aging properties, used to prepare the multi-component composite epoxy coating with high toughness and anti-aging properties as described in any one of claims 1-7, characterized in that, The steps include: The polyurethane-coupled bisphenol A type epoxy molecules, fluorinated phenyl isocyanate grafted modified epoxy molecules, and curing agent are mixed and stirred for 30 minutes at a mass ratio of (10-20):(4-8):(2-6). The mixture is applied to the substrate using at least one of the following methods: spraying, dip coating, or brushing. After curing, an epoxy composite coating with high anti-aging properties is obtained.

9. The method for preparing a multi-component composite epoxy coating with high toughness and anti-aging properties according to claim 8, characterized in that: The substrate to which the coating is applied is at least one of carbon steel, copper alloy, aluminum alloy, concrete, and polytetrafluoroethylene mold.

10. The method for preparing a multi-component composite epoxy coating with high toughness and anti-aging properties according to claim 8, characterized in that: The curing temperature of the epoxy composite coating is 20-90°C, the curing time is 6-26 hours, and the curing agent is at least one of polyamide PA650 and polyetheramine D230.

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