A functional coating for long-lasting reflective road markings and its preparation method

Abstract

This invention relates to the field of long-lasting reflective road marking coating technology, and discloses a functional coating for long-lasting reflective road marking and its preparation method. The coating, by weight, comprises the following raw materials: 40-60 parts polyacrylic acid resin emulsion, 1-3 parts defoamer, 3-5 parts modified nano-silicon carbide, 1-3 parts modified glass microspheres, 4-10 parts filler, 1-3 parts curing agent, 2-5 parts dispersant, and 30-35 parts deionized water. The nano-silicon carbide is modified with maleic anhydride and then grafted with polyphenylene ether. The polyphenylene ether improves the interfacial compatibility between the nano-silicon carbide and the matrix, promotes uniform dispersion of the nano-silicon carbide, and inhibits agglomeration, significantly improving the coating's wear resistance and impact resistance. The benzophenone structure is grafted onto the glass microspheres using a silane coupling agent, achieving a high-density directional distribution of ultraviolet-absorbing groups. This maintains the coating's transparency, while the surface graft layer inhibits photo-oxidation chain reactions, significantly improving the coating's anti-aging ability.

Description

Technical Field

[0001] This invention relates to the field of coating technology, specifically to a functional coating for long-lasting reflective road markings and its preparation method. Background Technology

[0002] With the rapid development of transportation infrastructure, road markings, as a core element of traffic safety, are facing increasing demands for durability and functionality. Traditional reflective road marking paints mostly rely on glass microspheres for optical reflection, but their reflective performance is easily degraded due to mechanical wear and aging over long-term use, affecting nighttime driving safety. In existing technologies, the insufficient wear resistance and aging resistance of coatings are particularly prominent issues, urgently requiring the development of functional coatings that combine long-lasting reflectivity with high durability.

[0003] Currently, the abrasion resistance of commercially available road marking paints mainly depends on the mechanical strength of the resin base and the reinforcing effect of fillers. For example, although acrylic resin-based paints possess a certain degree of toughness, long-term exposure to vehicle pressure and gravel friction can easily lead to scratches or peeling, resulting in a decrease in surface roughness and the shedding of reflective particles. Studies have shown that optimizing the filler dosage can improve coating hardness, but excessive addition may cause interfacial stress concentration, which in turn accelerates wear. In addition, traditional film-forming aids have limited effects on improving abrasion resistance and may reduce coating adhesion. In existing technologies, orthogonal experiments have shown that the amount of luminescent powder significantly affects abrasion resistance, but its compatibility with the resin matrix remains unresolved, resulting in a non-linear change in abrasion values ​​over time, making it difficult to meet long-term performance requirements.

[0004] The anti-aging properties of road marking paint are mainly affected by ultraviolet radiation, humidity, heat, and chemical corrosion. Conventional reflective road marking paints typically improve their UV resistance by adding UV absorbers. While this partially mitigates photodegradation, small-molecule UV absorbers are prone to leaching, resulting in insufficient UV resistance. Therefore, this invention provides a functional road marking paint for long-lasting reflectivity and its preparation method, addressing the problems of existing technologies. Summary of the Invention

[0005] In order to solve the problems mentioned in the background art, the purpose of this invention is to provide a functional coating for long-lasting reflective road markings and a method for preparing the same.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A functional coating for long-lasting reflective road markings, comprising, by weight, the following raw materials: 40-60 parts of polyacrylic acid resin emulsion, 1-3 parts of defoamer, 3-5 parts of modified nano-silicon carbide, 1-3 parts of modified glass microspheres, 4-10 parts of filler, 1-3 parts of curing agent, 2-5 parts of dispersant, and 30-35 parts of deionized water.

[0008] Furthermore, the defoamer is tributyl phosphate or fatty alcohol polyoxyethylene ether.

[0009] Furthermore, the filler is any one of quartz powder, heavy calcium carbonate, and magnesium hydroxide.

[0010] Furthermore, the dispersant is sodium polyacrylate or ammonium polyacrylate.

[0011] Furthermore, the preparation method of the modified nano-silicon carbide includes the following steps:

[0012] Step A1: Soak nano-silicon carbide powder in concentrated sulfuric acid, stir at 80-100℃ for 3-5 hours, centrifuge and wash until neutral to obtain nano-silicon carbide intermediate, and vacuum dry for later use.

[0013] Step A2: Disperse the nano-silicon carbide intermediate in toluene, then add maleic anhydride and catalyst, and react in an oil bath at 80-100℃ for 4-6 hours. After centrifugation, separate the solid material, wash and dry to obtain the intermediate product.

[0014] Step A3: Disperse the intermediate product in N,N-dimethylformamide, sonicate for 30-50 min, then add 4-dimethylaminopyridine and N,N'-dicyclohexylcarbodiimide, stir at 40-50℃ for 2-4 h, continue to add polyphenylene ether, after the addition is complete, raise the temperature to 120-130℃, stir magnetically for 12-16 h, separate the product, wash and vacuum dry to obtain modified nano-silicon carbide.

[0015] In the above technical solution, nano-silicon carbide is acid-treated to make its surface rich in hydroxyl groups. The hydroxyl groups on the surface of nano-silicon carbide react with the anhydride groups of maleic anhydride to generate nano-silicon carbide containing carboxylic acid on its surface. The hydroxyl groups contained in polyphenylene ether react with the carboxylic acid groups, thereby grafting polyphenylene ether onto the modified nano-silicon carbide through chemical bonds.

[0016] Furthermore, in step A2, the mass ratio of the nano-silicon carbide intermediate to maleic anhydride is 8:1-2.

[0017] Furthermore, in step A2, the catalyst is p-toluenesulfonic acid or methanesulfonic acid.

[0018] Furthermore, the preparation method of the modified glass microspheres includes the following steps:

[0019] Step B1: Immerse the glass microspheres in concentrated sulfuric acid for 2-5 hours, then wash and vacuum dry to obtain the glass microsphere intermediate.

[0020] Step B2: The glass microsphere intermediate was ultrasonically dispersed in toluene, and silane coupling agent KH-560 was added. After ultrasonication for 15-20 min, the mixture was continuously stirred in an oil bath at 60-80℃ for 3-5 h. After the reaction was completed, the mixture was centrifuged, washed, and vacuum dried to obtain the modified glass microsphere intermediate.

[0021] Step B3: The modified glass microsphere intermediate was ultrasonically dispersed in toluene solution, and then the catalyst Amberlyst-15 and 2,4-dihydroxybenzophenone were added to the solution and heated to 60-80℃ for 3 hours. After the reaction was completed, the mixture was filtered, washed, and vacuum dried to obtain the modified glass microspheres.

[0022] In the above technical solution, the glass microspheres are treated with a silane coupling agent to make the surface rich in epoxy groups. 2,4-Dihydroxybenzophenone can react with the epoxy groups on the surface of the glass microspheres under the catalysis of the catalyst, and 2,4-Dihydroxybenzophenone is grafted onto the surface of the glass microspheres through chemical bonds, thereby obtaining modified glass microspheres.

[0023] Furthermore, in step B2, the volume fraction of the ethanol solution is 65-75%.

[0024] A method for preparing a functional coating for long-lasting reflective road markings includes the following steps:

[0025] Step 1: Mix the polyacrylic acid resin emulsion with the modified nano silicon carbide. After mixing, add the filler, modified glass microspheres, dispersant, and deionized water into the mixer. Stir well and then add the defoamer and let it stand to form a premix.

[0026] Step 2: After mixing the premix and curing agent evenly, store at room temperature.

[0027] The beneficial effects of this invention are:

[0028] (1) The present invention prepares nano-silicon carbide with polyphenylene ether on its surface as a functional additive for coatings. The presence of polyphenylene ether enables nano-silicon carbide to form a strong interfacial bond with the film-forming material matrix of the coating, promotes uniform dispersion of nano-silicon carbide, thereby optimizing stress transmission efficiency and significantly improving the wear resistance and impact resistance of the coating.

[0029] (2) This invention prepares glass microspheres containing benzophenone structure to achieve uniform distribution of ultraviolet absorbing groups, which can effectively absorb ultraviolet light. As a rigid carrier, the glass microspheres can enhance the mechanical strength of the coating. After grafting, the core-shell structure is formed, which makes the ultraviolet absorber and the glass microspheres have a synergistic effect. It can maintain the transparency of the coating, delay the yellowing and chalking of the resin, and greatly improve the anti-aging ability of the glass microspheres.

[0030] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 Infrared spectroscopy images of the nano-silicon carbide intermediate and modified nano-silicon carbide in Example 1;

[0033] Figure 2 Infrared test images of the glass microsphere intermediate and modified glass microspheres in Example 1. Detailed Implementation

[0034] 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.

[0035] Example 1: A functional coating for long-lasting reflective road markings, comprising the following raw materials by weight: 40 parts polyacrylic acid resin emulsion, 3 parts defoamer tributyl phosphate, 3 parts modified nano silicon carbide, 1 part modified glass microspheres, 4 parts filler heavy calcium carbonate, 1 part curing agent aziridine, 3 parts dispersant sodium polyacrylate, and 35 parts deionized water.

[0036] The preparation method of this coating includes the following steps:

[0037] Step 1: Mix the polyacrylic acid resin emulsion with modified nano silicon carbide. After mixing, add the filler heavy calcium carbonate, modified glass microspheres, dispersant sodium polyacrylate, and deionized water into a mixer. After stirring evenly, add the defoamer tributyl phosphate and let it stand to form a premix.

[0038] Step 2: After mixing the premix with the curing agent aziridine evenly, store at room temperature.

[0039] The modified nano-silicon carbide was prepared using the following method:

[0040] Step A1: Soak 1.2g of nano silicon carbide powder in 20ml of concentrated sulfuric acid, stir at 80℃ for 3h, centrifuge and wash until neutral to obtain nano silicon carbide intermediate, and vacuum dry for later use.

[0041] Step A2: Disperse 1.8g of nano-silicon carbide intermediate in 30ml of toluene, then add 0.2g of maleic anhydride and 0.05g of catalyst p-toluenesulfonic acid. After reacting in an oil bath at 80℃ for 4h, centrifuge to separate the solid material, wash and dry to obtain the intermediate product.

[0042] Step A3: Disperse 1.6g of intermediate product in 30ml of N,N-dimethylformamide, sonicate for 30-50min, then add 0.16g of 4-dimethylaminopyridine and 0.05g of N,N'-dicyclohexylcarbodiimide, stir at 50℃ for 2h, then add 1.2g of polyphenylene ether. After the addition is complete, raise the temperature to 120℃ and stir magnetically for 12h. Separate the product, wash and vacuum dry to obtain modified nano-silicon carbide.

[0043] A comparative diagram of infrared testing of nano-silicon carbide and modified nano-silicon carbide is shown below. Figure 1 As shown in the infrared spectrum of nano-silicon carbide, the characteristic absorption peak of OH in nano-silicon carbide is at 3364 cm⁻¹, and the characteristic absorption peak of Si-C is at 889 cm⁻¹. In the infrared spectrum of modified nano-silicon carbide, the characteristic absorption peak of OH is at 3189-3340 cm⁻¹, the characteristic absorption peak of newly generated C=O is at 1743 cm⁻¹, the special absorption peak of ether bond is at 1116 cm⁻¹, the characteristic absorption peak of Si-OC is at 1094 cm⁻¹, and the characteristic absorption peak of Si-C is at 892 cm⁻¹.

[0044] The modified glass microspheres were prepared using the following method:

[0045] Step B1: Immerse 1.3g of glass microspheres in 20ml of concentrated sulfuric acid for 5 hours, then wash and dry under vacuum at 120℃ for 6 hours to obtain the glass microsphere intermediate.

[0046] Step B2: 1.1g of glass microsphere intermediate was ultrasonically dispersed in 100ml of 75% ethanol solution, 0.3g of silane coupling agent KH-560 was added, and after ultrasonication for 20min, the mixture was continuously stirred in an oil bath at 80℃ for 3h. After the reaction was completed, the mixture was centrifuged, washed, and vacuum dried to obtain the modified glass microsphere intermediate.

[0047] Step B3: 1.4 g of modified glass microsphere intermediate was ultrasonically dispersed in 30 ml of toluene solution. Then, 0.6 g of Amberlyst-15 and 1.3 g of 2,4-dihydroxybenzophenone were added to the solution and heated to 80 °C. The reaction was carried out for 3 h. After the reaction was completed, the mixture was filtered, washed, and vacuum dried to obtain modified glass microspheres.

[0048] Comparison of infrared test results between glass microsphere intermediates and modified glass microspheres is shown in the figure below. Figure 2As shown in the infrared spectrum of the glass microsphere intermediate, the peak at 3216 cm⁻¹ is the characteristic absorption peak of OH, and the peak at 1096 cm⁻¹ is the characteristic absorption peak of Si-O-Si. In the infrared spectrum of the modified glass microsphere, the peak at 3312 cm⁻¹ is the characteristic absorption peak of OH, the peak at 1627 cm⁻¹ is the characteristic absorption peak of ketone C=O, the peak between 1450 and 1600 cm⁻¹ is the characteristic absorption peak of the benzene ring skeleton, the peak at 1258 cm⁻¹ is the characteristic absorption peak of CO in the ester, the peak at 1112 cm⁻¹ is the characteristic absorption peak of Si-O-Si, and the peak at 1098 cm⁻¹ is the characteristic absorption peak of COC.

[0049] Example 2: A functional coating for long-lasting reflective road markings, comprising the following raw materials by weight: 50 parts polyacrylic acid resin emulsion, 2 parts defoamer tributyl phosphate, 4 parts modified nano silicon carbide, 2 parts modified glass microspheres, 8 parts filler heavy calcium carbonate, 3 parts curing agent aziridine, 3 parts dispersant sodium polyacrylate, and 35 parts deionized water.

[0050] The coating preparation method includes the following steps:

[0051] Step 1: Mix the polyacrylic acid resin emulsion with modified nano silicon carbide. After mixing, add the filler heavy calcium carbonate, modified glass microspheres, dispersant sodium polyacrylate, and deionized water into a mixer. After stirring evenly, add the defoamer tributyl phosphate and let it stand to form a premix.

[0052] Step 2: After mixing the premix with the curing agent aziridine evenly, store at room temperature.

[0053] The preparation methods for modified nano-silicon carbide and modified glass microspheres are the same as in Example 1.

[0054] Example 3: A functional coating for long-lasting reflective road markings, comprising the following raw materials by weight: 60 parts polyacrylic acid resin emulsion, 3 parts defoamer tributyl phosphate, 5 parts modified nano silicon carbide, 5 parts modified glass microspheres, 10 parts filler heavy calcium carbonate, 3 parts curing agent aziridine, 5 parts dispersant sodium polyacrylate, and 35 parts deionized water.

[0055] The coating preparation method includes the following steps:

[0056] Step 1: Mix the polyacrylic acid resin emulsion with modified nano silicon carbide. After mixing, add the filler heavy calcium carbonate, modified glass microspheres, dispersant sodium polyacrylate, and deionized water into a mixer. After stirring evenly, add the defoamer tributyl phosphate and let it stand to form a premix.

[0057] Step 2: After mixing the premix with the curing agent aziridine evenly, store at room temperature.

[0058] The preparation methods for modified nano-silicon carbide and modified glass microspheres are the same as in Example 1.

[0059] Comparative Example 1:

[0060] A functional coating for long-lasting reflective road markings, by weight, comprises the following raw materials: 60 parts polyacrylic acid resin emulsion, 3 parts defoamer tributyl phosphate, 5 parts nano-silicon carbide, 5 parts modified glass microspheres, 10 parts filler heavy calcium carbonate, 3 parts curing agent aziridine, 5 parts dispersant sodium polyacrylate, and 35 parts deionized water. The preparation method of this coating includes the following steps:

[0061] Step 1: Mix polyacrylic acid resin emulsion with nano silicon carbide. After mixing, add filler heavy calcium carbonate, modified glass microspheres, dispersant sodium polyacrylate, and deionized water into a mixer. After stirring evenly, add defoamer tributyl phosphate and let stand to form a premix.

[0062] Step 2: After mixing the premix with the curing agent aziridine evenly, store at room temperature.

[0063] The preparation method of the modified glass microspheres is the same as that in Example 1.

[0064] Comparative Example 2:

[0065] A functional coating for long-lasting reflective road markings, comprising, by weight, the following raw materials: 60 parts polyacrylic acid resin emulsion, 3 parts defoamer tributyl phosphate, 5 parts modified glass microspheres, 10 parts filler heavy calcium carbonate, 3 parts curing agent aziridine, 5 parts dispersant sodium polyacrylate, and 35 parts deionized water. The preparation method of this coating includes the following steps:

[0066] Step 1: Mix the polyacrylic acid resin emulsion with the filler heavy calcium carbonate. After mixing, add the dispersant sodium polyacrylate, modified glass microspheres, and deionized water into the mixer. Stir well and then add the defoamer tributyl phosphate. Let it stand to form a premix.

[0067] Step 2: After mixing the premix with the curing agent aziridine evenly, store at room temperature.

[0068] The preparation method of the modified glass microspheres is the same as that in Example 1.

[0069] Comparative Example 3:

[0070] A functional coating for long-lasting reflective road markings, comprising the following raw materials by weight: 60 parts polyacrylic acid resin emulsion, 3 parts defoamer tributyl phosphate, 5 parts modified nano silicon carbide, 5 parts glass microspheres, 10 parts filler heavy calcium carbonate, 3 parts curing agent aziridine, 5 parts dispersant sodium polyacrylate, and 35 parts deionized water.

[0071] The coating preparation method includes the following steps:

[0072] Step 1: Mix the polyacrylic acid resin emulsion with the modified nano silicon carbide. After mixing, add the filler heavy calcium carbonate, glass microspheres, dispersant sodium polyacrylate, and deionized water into the mixer. Stir well and then add the defoamer tributyl phosphate and let it stand to form a premix.

[0073] Step 2: After mixing the premix with the curing agent aziridine evenly, store at room temperature.

[0074] The preparation method of modified nano-silicon carbide is the same as that in Example 1.

[0075] Comparative Example 4:

[0076] A functional coating for long-lasting reflective road markings, comprising, by weight, the following raw materials: 60 parts polyacrylic acid resin emulsion, 3 parts defoamer tributyl phosphate, 5 parts modified nano-silicon carbide, 10 parts filler heavy calcium carbonate, 3 parts curing agent aziridine, 5 parts dispersant sodium polyacrylate, and 35 parts deionized water. The preparation method of this coating includes the following steps:

[0077] Step 1: Mix the polyacrylic acid resin emulsion with the modified nano silicon carbide. After mixing, add the filler heavy calcium carbonate, the dispersant sodium polyacrylate, and deionized water into the mixer. Stir well and then add the defoamer tributyl phosphate. Let it stand to form a premix.

[0078] Step 2: After mixing the premix with the curing agent aziridine, store at room temperature.

[0079] The preparation method of modified nano-silicon carbide is the same as that in Example 1.

[0080] Comparative Example 5:

[0081] A functional coating for long-lasting reflective road markings, comprising the following raw materials by weight: 60 parts polyacrylic acid resin emulsion, 3 parts defoamer tributyl phosphate, 10 parts filler heavy calcium carbonate, 3 parts curing agent aziridine, 5 parts dispersant sodium polyacrylate, and 35 parts deionized water.

[0082] The coating preparation method includes the following steps:

[0083] Step 1: Mix the polyacrylic acid resin emulsion with the filler heavy calcium carbonate. After mixing, add the dispersant sodium polyacrylate and deionized water into the mixer. Stir well and then add the defoamer tributyl phosphate. Let it stand to form a premix.

[0084] Step 2: After mixing the premix with the curing agent aziridine, store at room temperature.

[0085] Performance testing:

[0086] According to the industry standard JT / T280-2004 for road marking paints, the long-lasting reflective road marking functional paints prepared in Examples 1-3 and Comparative Examples 1-5 of this invention were tested for abrasion resistance, paint appearance, and sample aging. The prepared long-lasting reflective road marking functional paints were continuously irradiated in a 1000W high-pressure mercury lamp ultraviolet aging chamber, and the time when phenomena such as bubbles, cracks, and peeling appeared in the coating were recorded to evaluate the anti-ultraviolet aging performance of the paints. The test results are shown in the table below:

[0087]

[0088] As can be seen from the table above, the coatings prepared in Examples 1-3 showed the least weight loss in the abrasion resistance test, good abrasion resistance, and no blistering, cracking, or peeling occurred within 1000 hours. They also exhibited excellent UV resistance and good anti-aging properties.

[0089] Comparative Example 1 added ordinary nano-silicon carbide and modified glass microspheres to the coating. The weight reduction was average after wear resistance test, and the wear resistance was average. However, no blistering, cracking, or peeling occurred within 1000 hours. It had excellent UV resistance and good anti-aging properties.

[0090] Comparative Example 2 only added modified glass microspheres during the coating preparation process. After wear resistance test, the weight loss was significant and the wear resistance was poor. No blistering, cracking, or peeling occurred within 1000 hours. It also showed excellent UV resistance and good anti-aging properties.

[0091] Comparative Example 3 showed that the addition of modified silicon carbide and ordinary glass microspheres during the preparation of the coating resulted in blistering, cracking, and peeling after 723 hours. It also showed poor UV resistance and poor aging resistance. However, the wear resistance test showed that the weight reduction was small and the wear resistance was good.

[0092] Comparative Example 4 only added modified silicon carbide during the coating preparation process. The coating showed blistering after 410 hours, indicating poor UV resistance and aging resistance. However, the coating still contained modified nano-silicon carbide, so its wear resistance was good.

[0093] Comparative Example 5 did not add either nano-silicon carbide or glass microspheres during the preparation of the coating, so it had the worst wear resistance, the worst UV resistance, and the worst aging resistance.

[0094] The above description is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined in the claims, they should all fall within the protection scope of the present invention.

Claims

1. A functional coating for long-lasting reflective road markings, characterized in that, By weight, it includes the following raw materials: 40-60 parts of polyacrylic acid resin emulsion, 1-3 parts of defoamer, 3-5 parts of modified nano silicon carbide, 1-3 parts of modified glass microspheres, 4-10 parts of filler, 1-3 parts of curing agent, 2-5 parts of dispersant, and 30-35 parts of deionized water. The method for preparing the modified nano-silicon carbide includes the following steps: Step A1: Soak nano-silicon carbide powder in concentrated sulfuric acid, stir at 80-100℃ for 3-5 hours, centrifuge and wash until neutral to obtain nano-silicon carbide intermediate, and vacuum dry for later use. Step A2: Disperse the nano-silicon carbide intermediate in toluene, then add maleic anhydride and catalyst, react in an oil bath at 80-100℃ for 4-6 hours, centrifuge to separate the solid material, wash and dry to obtain the intermediate product; Step A3: Disperse the intermediate product in N,N-dimethylformamide, sonicate for 30-50 min, then add 4-dimethylaminopyridine and N,N'-dicyclohexylcarbodiimide, stir at 40-50℃ for 2-4 h, continue to add polyphenylene ether, after the addition is complete, raise the temperature to 120-130℃, stir magnetically for 12-16 h, separate the product, wash and vacuum dry to obtain modified nano-silicon carbide; The method for preparing the modified glass microspheres includes the following steps: Step B1: Immerse the glass microspheres in concentrated sulfuric acid for 2-5 hours, then wash and vacuum dry to obtain the glass microsphere intermediate. Step B2: The glass microsphere intermediate was ultrasonically dispersed in an ethanol solution, and silane coupling agent KH-560 was added. After ultrasonication for 15-20 min, the mixture was continuously stirred in an oil bath at 60-80℃ for 3-5 h. After the reaction was completed, the mixture was centrifuged, washed, and vacuum dried to obtain the modified glass microsphere intermediate. Step B3: The modified glass microsphere intermediate is ultrasonically dispersed in toluene solution, and then the catalyst Amberlyst-15 and 2,4-dihydroxybenzophenone are added to the solution and heated to 60-80℃. The reaction is carried out for 3-5 hours. After the reaction is completed, the mixture is filtered, washed, and vacuum dried to obtain the modified glass microspheres.

2. The functional coating for long-lasting reflective road markings according to claim 1, characterized in that, The defoamer is tributyl phosphate or fatty alcohol polyoxyethylene ether.

3. The functional coating for long-lasting reflective road markings according to claim 1, characterized in that, The filler is any one of quartz powder, heavy calcium carbonate, and magnesium hydroxide.

4. The functional coating for long-lasting reflective road markings according to claim 1, characterized in that, The dispersant is sodium polyacrylate or ammonium polyacrylate.

5. A functional coating for long-lasting reflective road markings according to claim 1, characterized in that, In step A2, the mass ratio of the nano-silicon carbide intermediate to maleic anhydride is 8:1-2.

6. The functional coating for long-lasting reflective road markings according to claim 1, characterized in that, In step A2, the catalyst is p-toluenesulfonic acid or methanesulfonic acid.

7. The functional coating for long-lasting reflective road markings according to claim 1, characterized in that, In step B2, the volume fraction of the ethanol solution is 65-75%.

8. The preparation method of a long-lasting reflective road marking functional coating as described in claim 1, characterized in that, Includes the following steps: Step 1: Mix the polyacrylic acid resin emulsion with the modified nano silicon carbide. After mixing, add the filler, modified glass microspheres, dispersant, and deionized water into the mixer. Stir well and then add the defoamer and let it stand to form a premix. Step 2: After mixing the premix and curing agent evenly, store at room temperature.

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