High refractive index large particle size glass microbeads for road marking and method of making

Abstract

The present application relates to the technical field of glass microsphere preparation, and particularly relates to high-refractive large-diameter glass microspheres for road marking and a preparation method thereof, the preparation method comprising the following steps: mixing raw materials such as quartz sand and bismuth carbonate with a nano-domain inducing modifier and performing wet ball milling to obtain mixed fine powder; sequentially performing high-temperature melting, temperature control and phase separation treatment and temperature rising and homogenization treatment on the mixed fine powder to obtain a glass melt, and performing drop shrinkage and ball formation through a porous bushing and performing step cooling and solidification to obtain large-diameter glass microsphere primary products; stirring and reacting the large-diameter glass microsphere primary products with a modified nano-hybrid surface treatment agent under heating, and performing vacuum drying and cooling to obtain high-refractive large-diameter glass microspheres. Through the synergistic effect of the nano-domain inducing modifier and the modified nano-hybrid surface treatment agent, the prepared glass microspheres have internal optical uniformity, high mechanical strength, excellent hydrophobicity and interfacial bonding force on the surface, and the long-term effective reflective life and weather resistance of the road marking are significantly improved.

Description

Technical Field

[0001] This invention relates to the field of glass microsphere preparation technology, specifically to high-refractive-index, large-diameter glass microspheres for road marking and their preparation method. Background Technology

[0002] Road marking reflective glass microspheres need to possess high refractive index and large particle size to ensure visibility at night and in inclement weather. Currently, existing technologies construct high-refractive-index glass systems by introducing heavy metal oxides such as bismuth, titanium, and barium. While these systems improve optical performance, they have certain limitations: high levels of heavy metal oxides can easily lead to abnormal melt viscosity, and component volatilization at high temperatures can cause refractive index fluctuations; furthermore, large-diameter microspheres experience uneven stress release during cooling and solidification, making them prone to internal microcracks. In addition, conventional glass surfaces are rich in silanol groups, exhibiting strong hydrophilicity and readily adsorbing water films in humid environments, leading to decreased interfacial adhesion between the glass and road marking paint, and long-term degradation of weather resistance.

[0003] Therefore, the technical problem that urgently needs to be solved in this field is: how to obtain high-refractive-index large-particle-size glass microspheres with uniform internal structure and no microcracks, and effectively improve the surface hydrophobic properties and interfacial bonding force, thereby improving the long-term effective reflective life of the microspheres under complex road conditions. Summary of the Invention

[0004] The purpose of this invention is to provide high-refractive-index, large-diameter glass microspheres for road markings and a method for their preparation, in order to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A method for preparing high-refractive-index, large-diameter glass microspheres for road marking includes the following steps: S1. Weigh out 68-75 parts of quartz sand, 5-8 parts of boric acid, 5-8 parts of zinc oxide, 3-5 parts of aluminum oxide, 8-12 parts of bismuth carbonate, 1-2 parts of clarifying agent and 2-4 parts of nanodomain inducing modifier by mass. After mixing evenly, add deionized water and grinding media for wet ball milling. After drying, obtain a mixed fine powder. S2. The mixed fine powder is placed in a crucible and subjected to high-temperature melting, temperature-controlled phase separation and heating homogenization in sequence to obtain glass melt. Then, it is dripped through a porous perforator, shrinks into spheres and cools and solidifies to obtain large-diameter glass microspheres as a preliminary product. S3. Place the initial product of large-diameter glass microspheres in a high-speed mixing device and heat it to 80-120℃ and keep it at that temperature for 5-20 minutes. Add the modified nano-hybrid surface treatment agent while keeping it at that temperature, and stir the reaction at a speed of 800-1500 r / min for 1-3 hours. The resulting product is then vacuum dried and cooled to room temperature to obtain high-refractive-index large-diameter glass microspheres.

[0006] Preferably, the preparation of the nanodomain-inducing modifier includes the following steps: S11. Weigh 10-15 parts aluminum phosphate and 5-10 parts sodium fluoride by mass, dissolve them in 20-30 parts deionized water, and stir the mixture at 60-80℃ for 2-4 hours to obtain the reaction solution. S12. The reaction solution is heated and evaporated to concentrate, then vacuum dried at 60-90℃, and then ground to obtain the nanodomain-inducing modifier.

[0007] Preferably, the preparation of the modified nano-hybrid surface treatment agent includes the following steps: S21. By mass, add 30-50 parts of nano silica sol and 0.5-2 parts of titanate coupling agent to 40-60 parts of anhydrous ethanol, stir and mix to obtain nano silica dispersion. S22. Add 15-25 parts of hydroxyl-terminated polydimethylsiloxane and 10-20 parts of modified fluorinated epoxy silane to the nano silica dispersion, and stir and react at 50-80℃ for 2-6 hours to obtain the modified nano-hybrid surface treatment agent.

[0008] Preferably, the preparation of modified fluorinated epoxy silanes includes the following steps: S111. Mix heptadecafluorodecylglycidylpropyltrimethoxysilane and γ-aminopropyltriethoxysilane at a mass ratio of (2-4):1 to obtain a mixed silane. S112. Add the mixed silane to a reaction medium consisting of an acidic aqueous solution with a pH of 3-4 and anhydrous ethanol, and perform a hydrolysis-condensation reaction at 40-50℃ for 4-6 hours. Remove the solvent by rotary evaporation to obtain the modified fluorinated epoxy silane.

[0009] Preferably, in step S1, the clarifying agent is one or more of antimony trioxide, sodium sulfate, sodium chloride, sodium fluoride, and cerium oxide; The wet ball milling process conditions are as follows: at least one selected from alumina balls and zirconia balls is used as the grinding medium, the rotation speed is 200-500 r / min, and the ball milling time is 4-12 h; In step S1, the total mass of each raw material and the mass ratio of grinding media to deionized water are 1:(1-3):(0.5-1.5). The drying process is vacuum drying, with a drying temperature of 80-120℃ and a drying time of 6-12 hours.

[0010] Preferably, in step S2, the high-temperature melting temperature is 1460-1560℃ and the time is 4-6 hours; The temperature for the temperature-controlled phase separation process is 700-800℃, and the time is 2-3 hours. The temperature for the heating and homogenization process is 1280-1350℃, and the time is 1-2 hours.

[0011] The perforated plate has a pore size of 1.5-2.0 mm and a drop height of molten droplets of 10-20 m. The cooling and solidification process employs a stepped cooling method, first maintaining the temperature at 800-900℃ for 10-20 minutes for slow cooling, and then allowing it to cool naturally to room temperature.

[0012] Preferably, in step S3, the amount of the modified nano-hybrid surface treatment agent added is 2%-5% of the initial mass of the large-diameter glass microspheres; The vacuum drying temperature is 75-85℃, and the drying time is 6-8 hours.

[0013] Preferably, the particle size of the nano-silica sol is 20-30 nm, and the solid content is 28%-32%. The titanate coupling agent is one or more of isopropyl tris(dioctyl pyrophosphoryloxy) titanate, tetraisopropyl di(dioctyl phosphite) titanate, or tetraisopropyl titanate.

[0014] Preferably, the acidic aqueous solution is an acetic acid aqueous solution with a concentration of 0.1-1 wt%, and the added mass is 2-4 times the total mass of the two silanes; The mass of anhydrous ethanol added is 1-2 times the total mass of heptadecafluorodecylglycidylpropyltrimethoxysilane and γ-aminopropyltriethoxysilane.

[0015] High-refractive-index, large-diameter glass microspheres for road markings were prepared using the method described above.

[0016] Compared with the prior art, the beneficial effects of the present invention are: The nanodomain-inducing modifier and the modified nano-hybrid surface treatment agent of this invention produce a significant synergistic effect. The nanodomain-inducing modifier promotes the uniform dispersion of raw materials such as bismuth carbonate in the glass melt and increases the density, thereby improving the refractive index and optical uniformity of the initial large-diameter glass microspheres, reducing volatilization and cooling stress, and providing a smooth and strongly bonded surface. The nano-silica and titanate coupling agent in the modified nano-hybrid surface treatment agent fully bond with the surface of the initial large-diameter glass microspheres to strengthen interfacial adhesion. The hydroxyl-terminated polydimethylsiloxane and the modified fluorinated epoxy silane synergistically endow the initial large-diameter glass microspheres with excellent hydrophobicity, and the modified fluorinated epoxy silane enhances the chemical bonding force with road marking paint. Ultimately, this achieves the beneficial effects of improving the retroreflective performance, long-term reflective life, and weather resistance of high-refractive-index large-diameter glass microspheres. Attached Figure Description

[0017] Figure 1This is a process flow diagram for preparing high-refractive-index, large-diameter glass microspheres for road markings according to the present invention. Figure 2 This is a flowchart illustrating the preparation process of the nanodomain-inducing modifier of the present invention. Figure 3 This is a flow chart of the preparation process of the modified nano-hybrid surface treatment agent of the present invention; Figure 4 This is a process flow diagram for preparing the modified fluorinated epoxy silane of this invention. Detailed Implementation

[0018] 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.

[0019] Please see Figures 1-4 The present invention provides a technical solution: In the following examples, antimony trioxide was used as the clarifying agent; isopropyl tris(dioctyl pyrophosphate) titanate was used as the titanate coupling agent; and alumina balls were used as the grinding media.

[0020] Example 1 Preparation of nanodomain-inducing modifier: Weigh 10g of aluminum phosphate and 5g of sodium fluoride, dissolve them in 20g of deionized water, stir and react at 60℃ for 2h to obtain a reaction solution; heat and evaporate the reaction solution to concentrate it, then vacuum dry it at 60℃, and then grind it to obtain the nanodomain-inducing modifier.

[0021] Preparation of modified fluorinated epoxy silane: 10g of heptadecafluorodecylglycidylpropyltrimethoxysilane and 5g of γ-aminopropyltriethoxysilane were mixed (mass ratio of the two was 2:1) to obtain a mixed silane with a total mass of 15g; 15g of mixed silane was added to a reaction medium consisting of 30g of acetic acid aqueous solution (concentration 0.1wt%) with pH 3 and 15g of anhydrous ethanol (mass of acetic acid aqueous solution was twice the total mass of mixed silane, and mass of anhydrous ethanol was once the total mass of mixed silane), and the hydrolysis and condensation reaction was carried out at 40℃ for 4h. The solvent was removed by rotary evaporation to obtain the modified fluorinated epoxy silane.

[0022] Preparation of modified nano-hybrid surface treatment agent: 30g of nano silica sol (particle size 20nm, solid content 28%) and 0.5g of isopropyltris(dioctylpyrophosphoryloxy)titanate were added to 40g of anhydrous ethanol and stirred to obtain a nano silica dispersion; 15g of hydroxyl-terminated polydimethylsiloxane and 10g of modified fluorinated epoxy silane were added to the nano silica dispersion and stirred at 50℃ for 2h to obtain the modified nano-hybrid surface treatment agent.

[0023] The specific steps for preparing high-refractive-index, large-diameter glass microspheres for road marking are as follows: S1: Weigh 68g of quartz sand, 5g of boric acid, 5g of zinc oxide, 3g of aluminum oxide, 8g of bismuth carbonate, 1g of antimony trioxide, and 2g of nanodomain inducing modifier (total mass of raw materials is 92g). After mixing evenly, add 92g of alumina balls and 46g of deionized water for wet ball milling (total mass of raw materials, mass ratio of alumina balls to deionized water is 1:1:0.5, rotation speed is 200r / min, and ball milling time is 4h). Vacuum dry at 80℃ for 6h to obtain mixed fine powder. S2: The mixed fine powder is placed in a crucible and melted at 1460℃ for 4 hours, then subjected to temperature-controlled phase separation treatment at 700℃ for 2 hours, and then subjected to homogenization treatment at 1280℃ for 1 hour to obtain glass melt; then it is dripped through a porous perforator with a pore size of 1.5mm (dropping height 10m), shrinks into spheres, and is cooled in a stepped manner (first held at 800℃ for 10 minutes and then naturally cooled to room temperature) to obtain the initial product of large-diameter glass microspheres.

[0024] S3. Place the initial product of large-diameter glass microspheres (mass of 50g) in a high-speed mixer and heat it to 80℃ and keep it at that temperature for 5min. Add 1g of modified nano-hybrid surface treatment agent while keeping it at that temperature, and stir the mixture at 800r / min for 1h. The resulting product is then vacuum dried at 75℃ for 6h and cooled to room temperature to obtain high-refractive-index large-diameter glass microspheres. The average particle size of the glass microspheres was measured to be 0.8mm.

[0025] Example 2 The specific steps for preparing high-refractive-index, large-diameter glass microspheres for road marking are as follows: Preparation of nanodomain-inducing modifier: Weigh 15g of aluminum phosphate and 10g of sodium fluoride, dissolve them in 30g of deionized water, stir and react at 80℃ for 4h to obtain a reaction solution; heat and evaporate the reaction solution to concentrate it, then vacuum dry it at 90℃, and then grind it to obtain the nanodomain-inducing modifier.

[0026] Preparation of modified fluorinated epoxy silane: 20g of heptadecafluorodecylglycidylpropyltrimethoxysilane and 5g of γ-aminopropyltriethoxysilane were mixed (mass ratio of the two was 4:1) to obtain a total mass of 25g of mixed silane; 25g of mixed silane was added to a reaction medium consisting of 100g of acetic acid aqueous solution (concentration 1wt%) with pH 4 and 50g of anhydrous ethanol (mass of acetic acid aqueous solution was 4 times the total mass of mixed silane, and mass of anhydrous ethanol was 2 times the total mass of mixed silane), and the hydrolysis and condensation reaction was carried out at 50℃ for 6h. The solvent was removed by rotary evaporation to obtain the modified fluorinated epoxy silane.

[0027] Preparation of modified nano-hybrid surface treatment agent: 50g of nano silica sol (particle size 30nm, solid content 32%) and 2g of isopropyltris(dioctylpyrophosphoryloxy)titanate were added to 60g of anhydrous ethanol and stirred to obtain a nano silica dispersion; 25g of hydroxyl-terminated polydimethylsiloxane and 20g of modified fluorinated epoxy silane were added to the nano silica dispersion and stirred at 80℃ for 6h to obtain the modified nano-hybrid surface treatment agent.

[0028] S1: Weigh 75g of quartz sand, 8g of boric acid, 8g of zinc oxide, 5g of aluminum oxide, 12g of bismuth carbonate, 2g of antimony trioxide, and 4g of nanodomain inducing modifier (total mass of raw materials is 114g). After mixing evenly, add 342g of alumina balls and 171g of deionized water for wet ball milling (total mass of raw materials, mass ratio of alumina balls to deionized water is 1:3:1.5, rotation speed is 500r / min, and ball milling time is 12h). Vacuum dry at 120℃ for 12h to obtain mixed fine powder. S2: The mixed fine powder is placed in a crucible and melted at 1560℃ for 6 hours, then subjected to temperature-controlled phase separation treatment at 800℃ for 3 hours, and then subjected to homogenization treatment at 1350℃ for 2 hours to obtain glass melt; then it is dripped through a porous perforator with a pore size of 2.0 mm (dropping height 20 m), shrinks into spheres, and is cooled in a stepped manner (first held at 900℃ for 20 minutes and then naturally cooled to room temperature) to obtain the initial product of large-diameter glass microspheres.

[0029] S3: 50g of large-diameter glass microspheres were placed in a high-speed mixer and heated to 120°C for 20min. 2.5g of modified nano-hybrid surface treatment agent was added while the mixture was kept at this temperature. The mixture was stirred at 1500r / min for 3h. The resulting product was vacuum dried at 85°C for 8h and then cooled to room temperature to obtain high-refractive-index large-diameter glass microspheres. The average particle size of the glass microspheres was measured to be 1.45mm.

[0030] Example 3 The specific steps for preparing high-refractive-index, large-diameter glass microspheres for road marking are as follows: Preparation of nanodomain-inducing modifier: Weigh 12.5g of aluminum phosphate and 7.5g of sodium fluoride, dissolve them in 25g of deionized water, stir and react at 70℃ for 3h to obtain a reaction solution; heat and evaporate the reaction solution to concentrate it, then vacuum dry it at 75℃, and then grind it to obtain the nanodomain-inducing modifier.

[0031] Preparation of modified fluorinated epoxy silane: 15g of heptadecafluorodecylglycidylpropyltrimethoxysilane and 5g of γ-aminopropyltriethoxysilane were mixed (mass ratio of the two was 3:1) to obtain a total mass of 20g of mixed silane; 20g of mixed silane was added to a reaction medium consisting of 60g of acetic acid aqueous solution (concentration 0.5wt%) with pH 3.5 and 30g of anhydrous ethanol (mass of acetic acid aqueous solution was 3 times the total mass of mixed silane, and mass of anhydrous ethanol was 1.5 times the total mass of mixed silane), and the hydrolysis and condensation reaction was carried out at 45℃ for 5h. The solvent was removed by rotary evaporation to obtain the modified fluorinated epoxy silane.

[0032] Preparation of modified nano-hybrid surface treatment agent: 40g of nano silica sol (particle size 25nm, solid content 30%) and 1.25g of isopropyltris(dioctylpyrophosphoryloxy)titanate were added to 50g of anhydrous ethanol and stirred to obtain a nano silica dispersion; 20g of hydroxyl-terminated polydimethylsiloxane and 15g of modified fluorinated epoxy silane were added to the nano silica dispersion and stirred at 65℃ for 4h to obtain the modified nano-hybrid surface treatment agent.

[0033] S1: Weigh 71g of quartz sand, 6.5g of boric acid, 6.5g of zinc oxide, 4g of alumina, 10g of bismuth carbonate, 1.5g of antimony trioxide, and 3g of nanodomain inducing modifier (total mass of raw materials is 102.5g). After mixing evenly, add 205g of alumina balls and 102.5g of deionized water for wet ball milling (total mass of raw materials, mass ratio of alumina balls to deionized water is 1:2:1, rotation speed is 350r / min, and ball milling time is 8h). Vacuum dry at 100℃ for 9h to obtain mixed fine powder. S2: The mixed fine powder is placed in a crucible and melted at 1510℃ for 5 hours, then subjected to temperature-controlled phase separation at 750℃ for 2.5 hours, and then subjected to homogenization treatment at 1315℃ for 1.5 hours to obtain glass melt; then it is dripped through a porous perforator with a pore size of 1.75mm (dropping height 15m), shrinks into spheres, and is cooled in a stepped manner (first held at 850℃ for 15 minutes and then naturally cooled to room temperature) to obtain the initial product of large-diameter glass microspheres.

[0034] S3: The initial product of large-diameter glass microspheres (mass of 50g) was placed in a high-speed mixer and heated to 100℃ and kept at that temperature for 12min. Under the condition of keeping at that temperature, 1.75g ​​of the above-mentioned modified nano-hybrid surface treatment agent was added, and the mixture was stirred and reacted at a speed of 1150r / min for 2h. The resulting product was vacuum dried at 80℃ for 7h and cooled to room temperature to obtain high-refractive-index large-diameter glass microspheres. The average particle size of the glass microspheres was measured to be 1.10mm.

[0035] Comparative Example 1 The difference from Example 3 is that no nanodomain inducing modifier is added in step S1, while the remaining raw material ratios, process parameters and operating steps are consistent with those of Example 3.

[0036] Comparative Example 2 The difference from Example 3 is that no modified nano-hybrid surface treatment agent is added in step S3, while the remaining raw material ratios, process parameters and operating steps are consistent with those of Example 3.

[0037] Comparative Example 3 The difference from Example 3 is that no nanodomain inducing modifier and modified nano-hybrid surface treatment agent are added, while the remaining raw material ratios, process parameters and operating steps are consistent with Example 3.

[0038] I. Performance Testing Standards 1. Refractive index: The refractive index of the glass microspheres was determined using an Abbe refractometer in accordance with GB / T 24722-2009 standard; 2. Hydrophobicity (Contact Angle): According to the test specifications in GB / T 24368-2009 "Detection of Hydrophobic Contaminants on Glass Surface - Method for Measurement of Contact Angle", glass microspheres are pressed into flat sheets, and the static contact angle of deionized water droplets on the surface is measured using an optical contact angle meter (using the seated drop method). 3. Interfacial adhesion strength: Glass microspheres are evenly spread on the surface of standard hot-melt road marking paint to prepare a test plate. After complete curing, the adhesion strength (unit: MPa) between the glass microspheres and the road marking paint interface is determined using a pull-out adhesion tester (such as a pull-out tester) according to GB / T 5210-2006 "Paints and Varnishes - Pull-out Adhesion Test". 4. Weather resistance (reflectance retention rate after aging): After a 1000-hour accelerated aging test with a xenon lamp according to GB / T 16422.2, the retroreflection coefficient was measured using a retroreflection meter, and the reflectance retention rate after aging was calculated.

[0039] II. Performance Test Result Comparison Table Table 1: Performance Test Results III. Test Result Analysis The comparison shows: When the nanodomain-inducing modifier was absent (Comparative Example 1), the refractive index plummeted to 1.65, the interfacial adhesion strength decreased to 2.5 MPa, and the reflectivity retention rate after 1000 h of aging dropped to 78.3%. This indicates that the nanodomain-inducing modifier can reduce the volatilization of high-temperature components to achieve an increase in refractive index and provide a smooth and strongly bonded surface state to ensure interfacial adhesion and long-term reflectivity lifetime. When the modified nano-hybrid surface treatment agent was absent (Comparative Example 2), the contact angle plummeted to 45° and the interfacial adhesion strength decreased to 1.2 MPa. a. The reflectivity retention rate decreased to 62.1% after aging, indicating that the modified nano-hybrid surface treatment agent can fully combine with the surface of the large-diameter glass microspheres to enhance interfacial adhesion, give it excellent hydrophobicity and enhance its chemical bonding with the marking paint. When the two-component modified system (Comparative Example 3) is missing, the refractive index decreases to 1.63, the contact angle decreases to 40°, and the interfacial adhesion strength decreases to 0.9 MPa, verifying that the lack of synergistic improvement of internal optical performance and surface hydrophobicity will lead to accelerated deterioration of optical refractive performance and weather resistance.

[0040] Through a series of analyses in the table, it can be found that the synergistic modification process of the two can simultaneously improve the refractive index, contact angle, interfacial adhesion strength and long-term reflectivity retention rate, and has significant engineering application value in the fields of high-grade highway markings, traffic safety facilities in severe weather and long-lasting reflective materials.

[0041] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing high-refractive-index, large-diameter glass microspheres for road markings, characterized in that, Includes the following steps: S1. Weigh out 68-75 parts of quartz sand, 5-8 parts of boric acid, 5-8 parts of zinc oxide, 3-5 parts of aluminum oxide, 8-12 parts of bismuth carbonate, 1-2 parts of clarifying agent and 2-4 parts of nanodomain inducing modifier by mass. After mixing evenly, add deionized water and grinding media for wet ball milling. After drying, obtain a mixed fine powder. S2. The mixed fine powder is placed in a crucible and subjected to high-temperature melting, temperature-controlled phase separation and heating homogenization in sequence to obtain glass melt. Then, it is dripped through a porous perforator, shrinks into spheres and cools and solidifies to obtain large-diameter glass microspheres as a preliminary product. S3. Place the initial product of large-diameter glass microspheres in a high-speed mixing device and heat it to 80-120℃ and keep it at that temperature for 5-20 minutes. Add the modified nano-hybrid surface treatment agent while keeping it at that temperature, and stir the reaction at a speed of 800-1500 r / min for 1-3 hours. The resulting product is then vacuum dried and cooled to room temperature to obtain high-refractive-index large-diameter glass microspheres. The preparation of the nanodomain-inducing modifier includes the following steps: S11. Weigh 10-15 parts aluminum phosphate and 5-10 parts sodium fluoride by mass, dissolve them in 20-30 parts deionized water, and stir the mixture at 60-80℃ for 2-4 hours to obtain the reaction solution. S12. The reaction solution is heated and evaporated to concentrate, then vacuum dried at 60-90℃, and then ground to obtain a nanodomain-inducing modifier. The preparation of the modified nano-hybrid surface treatment agent includes the following steps: S21. By mass, add 30-50 parts of nano silica sol and 0.5-2 parts of titanate coupling agent to 40-60 parts of anhydrous ethanol, stir and mix to obtain nano silica dispersion. S22. Add 15-25 parts of hydroxyl-terminated polydimethylsiloxane and 10-20 parts of modified fluorinated epoxy silane to the nano silica dispersion, and stir and react at 50-80℃ for 2-6 hours to obtain the modified nano hybrid surface treatment agent. The high-temperature melting temperature is 1460-1560℃, and the time is 4-6 hours; The temperature for the temperature-controlled phase separation process is 700-800℃, and the time is 2-3 hours. The temperature for the heating and homogenization treatment is 1280-1350℃, and the time is 1-2 hours; The perforated plate has a pore size of 1.5-2.0 mm and a drop height of molten droplets of 10-20 m. The cooling and solidification process employs a stepped cooling method, first maintaining the temperature at 800-900℃ for 10-20 minutes for slow cooling, and then allowing it to cool naturally to room temperature.

2. The method for preparing high-refractive-index, large-diameter glass microspheres for road markings according to claim 1, characterized in that, The preparation of the modified fluorinated epoxy silane includes the following steps: S111. Mix heptadecafluorodecylglycidylpropyltrimethoxysilane and γ-aminopropyltriethoxysilane at a mass ratio of (2-4):1 to obtain a mixed silane. S112. Add the mixed silane to a reaction medium consisting of an acidic aqueous solution with a pH of 3-4 and anhydrous ethanol, and perform a hydrolysis-condensation reaction at 40-50℃ for 4-6 hours. Remove the solvent by rotary evaporation to obtain the modified fluorinated epoxy silane.

3. The method for preparing high-refractive-index, large-diameter glass microspheres for road markings according to claim 1, characterized in that, In step S1, the clarifying agent is one or more of antimony trioxide, sodium sulfate, sodium chloride, sodium fluoride, and cerium oxide; The process conditions for wet ball milling are as follows: at least one selected from alumina balls and zirconia balls is used as the grinding medium, the rotation speed is 200-500 r / min, and the ball milling time is 4-12 h. In step S1, the total mass of each raw material and the mass ratio of grinding media to deionized water are 1:(1-3):(0.5-1.5). The drying process is vacuum drying, with a drying temperature of 80-120℃ and a drying time of 6-12 hours.

4. The method for preparing high-refractive-index, large-diameter glass microspheres for road markings according to claim 1, characterized in that, In step S3, the amount of the modified nano-hybrid surface treatment agent added is 2%-5% of the initial mass of the large-diameter glass microspheres; The vacuum drying temperature is 75-85℃, and the drying time is 6-8 hours.

5. The method for preparing high-refractive-index, large-diameter glass microspheres for road markings according to claim 1, characterized in that, The nano-silica sol has a particle size of 20-30 nm and a solid content of 28%-32%. The titanate coupling agent is one or more of isopropyl tris(dioctyl pyrophosphoryloxy) titanate, tetraisopropyl di(dioctyl phosphite) titanate, or tetraisopropyl titanate.

6. The method for preparing high-refractive-index, large-diameter glass microspheres for road markings according to claim 2, characterized in that, The acidic aqueous solution is an acetic acid aqueous solution with a concentration of 0.1-1 wt%, and the added mass is 2-4 times the total mass of the two silanes; The mass of anhydrous ethanol added is 1-2 times the total mass of heptadecafluorodecylglycidylpropyltrimethoxysilane and γ-aminopropyltriethoxysilane.

7. High-refractive-index, large-diameter glass microspheres for road markings, characterized in that, It is prepared by the preparation method according to any one of claims 1-6.

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