A high-refractive-index, large-size glass microbead for road marking and a spheroidization molding preparation method thereof

Abstract

The present invention relates to glass microbeads, and in particular to a high-refractive-index, large-particle-size glass microbead for road marking and a spheroidization and molding preparation method thereof. The glass microbeads comprise, by weight, 30 to 40 parts of titanium dioxide, 30 to 40 parts of silicon dioxide, 10 to 15 parts of barium nitrate, 10 to 15 parts of zirconium nitrate, 5 to 7 parts of zinc oxide, 3 to 5 parts of boric acid, 3 to 5 parts of calcium fluoride, 5 to 110 parts of Nb2O5, and 5 to 15 parts of La2O3-ZrO2 compound. In the present invention, calcination at 900°C for 12 hours helps to improve the thermal stability and mechanical strength of the glass microbeads, enabling them to be used for a long time in harsh outdoor environments without being easily damaged. At a high temperature of 1300°C and a spray velocity of 75 m / s, the precise intersection of two nozzles in the combustion chamber ensures precise control of the melting and molding processes of the glass microbeads, thereby obtaining high-quality, high-refractive-index glass microbeads. The addition of Nb2O5 and La2O3‑ZrO2 complexes not only improves the refractive index of the glass microspheres but also maintains a high yield.

Description

Technical Field

[0001] The invention relates to glass microbeads, in particular to high-refractive-index and large-diameter glass microbeads for road markings and a spheroidization molding preparation method thereof. Background Art

[0002] Glass beads are classified according to their refractive index and are generally divided into three main grades. The first is low-refractive-index glass beads with a refractive index below 1.7. These beads are generally not the first choice in optical applications because they have weak refractive power. The second is quasi-high-refractive-index glass beads with a refractive index between 1.7 and 1.9. Their refractive power is improved compared to the former, but may still not be sufficient to meet the requirements in some high-end applications. Finally, there are high-refractive-index glass beads with a refractive index above 1.9. These beads have become a hot topic of research and application due to their excellent optical properties, especially in the manufacture of retroreflective materials, where they exhibit unparalleled retroreflective capabilities.

[0003] High-refractive-index glass microbeads play a vital role in the production of retroreflective materials, a specialized composite film that combines the principles of optical refraction and reflection to achieve highly efficient light reflection. In countries with more mature glass industry technology, this material has been extensively researched, developed, and applied. It is not only used in traffic signs and signal markings, but also enables these signs to be clearly identified under vehicle headlights at distances of 500 to 700 meters. This material's reflective properties are particularly pronounced at night or in inclement weather conditions, with a reflective intensity nearly 100 times that of traditional painted markings, giving it significant potential for improving road safety.

[0004] At night, the maximum visibility of traditional painted signs under headlights is typically only 50 to 100 meters, which is far from sufficient at high speeds. At speeds exceeding 100 km / h, driver reaction time is significantly shortened. Inadequate traffic sign visibility can easily prevent drivers from identifying the signs in time, leading to traffic accidents. Retroreflective materials made from high-refractive-index glass microbeads significantly improve sign visibility, providing drivers with ample reaction time even at high speeds, thereby effectively reducing the occurrence of traffic accidents.

[0005] With the continuous advancement of technology and the expansion of its application areas, the use of high-refractive-index glass microspheres is no longer limited to road traffic. They are also widely used in other applications requiring high visibility and safety, such as mining, firefighting, emergency rescue, sanitation, municipal administration, and construction. The reflective properties of this material enable it to provide effective indication and warning without the need for an external power source. This not only improves safety but also reduces energy consumption, meeting modern society's requirements for energy conservation and environmental protection. Therefore, high-refractive-index glass microspheres and the retroreflective materials made from them have broad prospects and important application value in future development. Summary of the Invention

[0006] The present invention aims to provide a high-refractive-index, large-diameter glass microsphere for road marking and a spheroidization and molding preparation method thereof.

[0007] The present invention is achieved through the following technical solutions:

[0008] A high-refractive-index, large-particle glass microbead for road marking comprises, by weight, 30-40 parts of titanium dioxide, 30-40 parts of silicon dioxide, 10-15 parts of barium nitrate, 10-15 parts of zirconium nitrate, 5-7 parts of zinc oxide, 3-5 parts of boric acid, 3-5 parts of calcium fluoride, 5-110 parts of Nb2O5, and 5-15 parts of La2O3-ZrO2 compound.

[0009] Furthermore, the titanium dioxide is 30 parts, the silicon dioxide is 30 parts, the barium nitrate is 10 parts, the zirconium nitrate is 10 parts, the zinc oxide is 5 parts, the boric acid is 1 part, the calcium fluoride is 3 parts, the Nb2O5 is 5-10 parts, and the La2O3-ZrO2 complex is 5-15 parts.

[0010] Furthermore, the titanium dioxide is 30 parts, the silicon dioxide is 30 parts, the barium nitrate is 10 parts, the zirconium nitrate is 10 parts, the zinc oxide is 5 parts, the boric acid is 1 part, the calcium fluoride is 3 parts, the Nb2O5 is 5 parts, and the La2O3-ZrO2 complex is 5 to 15 parts.

[0011] Furthermore, the titanium dioxide is 30 parts, the silicon dioxide is 30 parts, the barium nitrate is 10 parts, the zirconium nitrate is 10 parts, the zinc oxide is 5 parts, the boric acid is 1 part, the calcium fluoride is 3 parts, the Nb2O5 is 510 parts, and the La2O3-ZrO2 complex is 5 to 15 parts.

[0012] Furthermore, the preparation method of the La2O3-ZrO2 composite is:

[0013] ZrOCl2·8H2O and La(NO3)3·6H2O were dissolved in deionized water, and then 30 mL of anhydrous ethanol was added;

[0014] Ultrasonication for 1 h, then pH adjustment with NH4OH, followed by vigorous stirring for 30 min;

[0015] Transfer to a high-pressure reactor and react at 200°C for 20 h;

[0016] Then the mixture was naturally cooled to room temperature and centrifuged to obtain a precipitate, which was washed with deionized water and then dried at 70 °C for 12 h and then calcined.

[0017] Furthermore, the molar ratio of ZrOCl2·8H2O to La(NO3)3·6H2O is 4.5:1, and the pH is adjusted to 10 with NH4OH. The calcination condition is calcination at 900°C for 12 hours.

[0018] The present invention also provides a spheroidization molding preparation method, characterized by comprising the following steps: uniformly mixing titanium dioxide, silicon dioxide, barium nitrate, zirconium nitrate, zinc oxide, boric acid, calcium fluoride, Nb2O5, and La2O3-ZrO2, then melting them at 1200°C, quenching the molten product with water, drying it, ball milling it, and sieving it to obtain a 50μm precursor. The precursor is divided into two paths, and the precursor in each path is mixed with fuel gas and oxidant under the propulsion of compressed air and injected into the combustion chamber through a nozzle;

[0019] The heating temperature in the combustion chamber is set to 1300°C, and the injection velocity of the nozzle is 75 m / s; the injection trajectories of the two nozzles intersect at one point;

[0020] The two jet paths share an intersection point, allowing the molten glass bead precursor to converge at this point; high-refractive-index glass microbeads are obtained through the screening process. The angle at which the jet trajectories of the two nozzles intersect at this point is 75 degrees.

[0021] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0022] Calcination at 900°C for 12 hours helps improve the thermal stability and mechanical strength of the glass microspheres, enabling them to withstand long-term damage in harsh outdoor environments. At a high temperature of 1300°C and a spray velocity of 75 m / s, the precise intersection of two nozzles within the combustion chamber ensures precise control of the melting and forming processes of the glass microspheres, resulting in high-quality, high-refractive-index glass microspheres. The addition of Nb2O5 and a La2O3-ZrO2 complex not only increases the refractive index of the glass microspheres, but also maintains a high yield. DETAILED DESCRIPTION

[0023] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with examples. The illustrative embodiments of the present invention and their descriptions are only used to explain the present invention and are not intended to limit the present invention.

[0024] The preparation method of the La2O3-ZrO2 complex in the present invention is as follows: 45mmol ZrOCl2·8H2O and 10mmol La(NO3)3·6H2O are weighed and dissolved in 10mL deionized water, and then 30mL anhydrous ethanol is added; ultrasonic treatment is performed for 1h, and then the pH is adjusted to 10 with NH4OH, and then vigorously stirred for 30min, transferred to a high-pressure reactor, and reacted at 200°C for 20h; then naturally cooled to room temperature, and then centrifuged to obtain a precipitate, which is washed with deionized water 5 times, and then dried at 70°C for 12h, and then calcined at 900°C for 12h to obtain the La2O3-ZrO2 complex.

[0025] Example 1

[0026] A high-refractive-index, large-particle glass microbead for road marking comprises, by weight, 30 parts of titanium dioxide, 30 parts of silicon dioxide, 10 parts of barium nitrate, 10 parts of zirconium nitrate, 5 parts of zinc oxide, 3 parts of boric acid, 3 parts of calcium fluoride, 5 parts of Nb2O5, and 5 parts of La2O3-ZrO2 compound.

[0027] A spheroidization method for preparing high-refractive-index, large-particle glass microspheres for road markings involves uniformly mixing titanium dioxide, silicon dioxide, barium nitrate, zirconium nitrate, zinc oxide, boric acid, calcium fluoride, Nb2O5, and La2O3-ZrO2. The mixture is then melted at 1200°C. The molten product is water-quenched, dried, ball-milled, and sieved to obtain a 50μm precursor. The precursor is then divided into two paths. The precursor in each path is propelled by compressed air and mixed with fuel gas and an oxidant before being injected through a nozzle into a combustion chamber. The heating temperature in the combustion chamber is set at 1300°C, and the nozzle injection velocity is 75 m / s. During this process, the injection trajectories of the two nozzles intersect at a point, forming a 75° angle. The two injection paths share a common intersection point, where the molten glass bead precursor converges. Finally, a screening process yields high-refractive-index glass microspheres.

[0028] Example 2

[0029] A high-refractive-index, large-particle glass microbead for road marking comprises, by weight, 30 parts of titanium dioxide, 30 parts of silicon dioxide, 10 parts of barium nitrate, 10 parts of zirconium nitrate, 5 parts of zinc oxide, 3 parts of boric acid, 3 parts of calcium fluoride, 5 parts of Nb2O5, and 10 parts of La2O3-ZrO2 compound.

[0030] A spheroidization method for preparing high-refractive-index, large-particle glass microspheres for road markings involves uniformly mixing titanium dioxide, silicon dioxide, barium nitrate, zirconium nitrate, zinc oxide, boric acid, calcium fluoride, Nb2O5, and La2O3-ZrO2. The mixture is then melted at 1200°C. The molten product is water-quenched, dried, ball-milled, and sieved to obtain a 50μm precursor. The precursor is then divided into two paths. The precursor in each path is propelled by compressed air and mixed with fuel gas and an oxidant before being injected through a nozzle into a combustion chamber. The heating temperature in the combustion chamber is set at 1300°C, and the nozzle injection velocity is 75 m / s. During this process, the injection trajectories of the two nozzles intersect at a point, forming a 75° angle. The two injection paths share a common intersection point, where the molten glass bead precursor converges. Finally, a screening process yields high-refractive-index glass microspheres.

[0031] Example 3

[0032] A high-refractive-index, large-particle glass microbead for road marking comprises, by weight, 30 parts of titanium dioxide, 30 parts of silicon dioxide, 10 parts of barium nitrate, 10 parts of zirconium nitrate, 5 parts of zinc oxide, 3 parts of boric acid, 3 parts of calcium fluoride, 5 parts of Nb2O5, and 15 parts of a La2O3-ZrO2 complex.

[0033] A spheroidization method for preparing high-refractive-index, large-particle glass microspheres for road markings involves uniformly mixing titanium dioxide, silicon dioxide, barium nitrate, zirconium nitrate, zinc oxide, boric acid, calcium fluoride, Nb2O5, and La2O3-ZrO2. The mixture is then melted at 1200°C. The molten product is water-quenched, dried, ball-milled, and sieved to obtain a 50μm precursor. The precursor is then divided into two paths. The precursor in each path is propelled by compressed air and mixed with fuel gas and an oxidant before being injected through a nozzle into a combustion chamber. The heating temperature in the combustion chamber is set at 1300°C, and the nozzle injection velocity is 75 m / s. During this process, the injection trajectories of the two nozzles intersect at a point, forming a 75° angle. The two injection paths share a common intersection point, where the molten glass bead precursor converges. Finally, a screening process yields high-refractive-index glass microspheres.

[0034] Example 4

[0035] A high-refractive-index, large-particle glass microbead for road marking comprises, by weight, 30 parts of titanium dioxide, 30 parts of silicon dioxide, 10 parts of barium nitrate, 10 parts of zirconium nitrate, 5 parts of zinc oxide, 3 parts of boric acid, 3 parts of calcium fluoride, 10 parts of Nb2O5, and 5 parts of a La2O3-ZrO2 complex.

[0036] A spheroidization method for preparing high-refractive-index, large-particle glass microspheres for road markings involves uniformly mixing titanium dioxide, silicon dioxide, barium nitrate, zirconium nitrate, zinc oxide, boric acid, calcium fluoride, Nb2O5, and La2O3-ZrO2. The mixture is then melted at 1200°C. The molten product is water-quenched, dried, ball-milled, and sieved to obtain a 50μm precursor. The precursor is then divided into two paths. The precursor in each path is propelled by compressed air and mixed with fuel gas and an oxidant before being injected through a nozzle into a combustion chamber. The heating temperature in the combustion chamber is set at 1300°C, and the nozzle injection velocity is 75 m / s. During this process, the injection trajectories of the two nozzles intersect at a point, forming a 75° angle. The two injection paths share a common intersection point, where the molten glass bead precursor converges. Finally, a screening process yields high-refractive-index glass microspheres.

[0037] Example 5

[0038] A high-refractive-index, large-particle glass microbead for road marking comprises, by weight, 30 parts of titanium dioxide, 30 parts of silicon dioxide, 10 parts of barium nitrate, 10 parts of zirconium nitrate, 5 parts of zinc oxide, 3 parts of boric acid, 3 parts of calcium fluoride, 10 parts of Nb2O5, and 10 parts of a La2O3-ZrO2 complex.

[0039] A spheroidization method for preparing high-refractive-index, large-particle glass microspheres for road markings involves uniformly mixing titanium dioxide, silicon dioxide, barium nitrate, zirconium nitrate, zinc oxide, boric acid, calcium fluoride, Nb2O5, and La2O3-ZrO2. The mixture is then melted at 1200°C. The molten product is water-quenched, dried, ball-milled, and sieved to obtain a 50μm precursor. The precursor is then divided into two paths. The precursor in each path is propelled by compressed air and mixed with fuel gas and an oxidant before being injected through a nozzle into a combustion chamber. The heating temperature in the combustion chamber is set at 1300°C, and the nozzle injection velocity is 75 m / s. During this process, the injection trajectories of the two nozzles intersect at a point, forming a 75° angle. The two injection paths share a common intersection point, where the molten glass bead precursor converges. Finally, a screening process yields high-refractive-index glass microspheres.

[0040] Example 6

[0041] A high-refractive-index, large-particle glass microbead for road marking comprises, by weight, 30 parts of titanium dioxide, 30 parts of silicon dioxide, 10 parts of barium nitrate, 10 parts of zirconium nitrate, 5 parts of zinc oxide, 3 parts of boric acid, 3 parts of calcium fluoride, 10 parts of Nb2O5, and 15 parts of a La2O3-ZrO2 complex.

[0042] A spheroidization method for preparing high-refractive-index, large-particle glass microspheres for road markings involves uniformly mixing titanium dioxide, silicon dioxide, barium nitrate, zirconium nitrate, zinc oxide, boric acid, calcium fluoride, Nb2O5, and La2O3-ZrO2. The mixture is then melted at 1200°C. The molten product is water-quenched, dried, ball-milled, and sieved to obtain a 50μm precursor. The precursor is then divided into two paths. The precursor in each path is propelled by compressed air and mixed with fuel gas and an oxidant before being injected through a nozzle into a combustion chamber. The heating temperature in the combustion chamber is set at 1300°C, and the nozzle injection velocity is 75 m / s. During this process, the injection trajectories of the two nozzles intersect at a point, forming a 75° angle. The two injection paths share a common intersection point, where the molten glass bead precursor converges. Finally, a screening process yields high-refractive-index glass microspheres.

[0043] Comparative Example 1

[0044] A high-refractive-index, large-particle glass microbead for road marking comprises, by weight, 30 parts of titanium dioxide, 30 parts of silicon dioxide, 10 parts of barium nitrate, 10 parts of zirconium nitrate, 5 parts of zinc oxide, 3 parts of boric acid, 3 parts of calcium fluoride, and 5 parts of Nb2O5.

[0045] A spheroidization method for preparing high-refractive-index, large-particle glass microspheres for road markings involves uniformly mixing titanium dioxide, silicon dioxide, barium nitrate, zirconium nitrate, zinc oxide, boric acid, calcium fluoride, and Nb2O5. The mixture is then melted at 1200°C. The molten product is water-quenched, dried, ball-milled, and sieved to obtain a 50μm precursor. The precursor is then divided into two paths. The precursor in each path is propelled by compressed air and mixed with fuel gas and an oxidant before being injected through a nozzle into a combustion chamber. The heating temperature in the combustion chamber is set at 1300°C, and the nozzle injection velocity is 75 m / s. During this process, the injection trajectories of the two nozzles intersect at a point, forming a 75° angle. The two injection paths share a common intersection point, where the molten glass bead precursor converges. Finally, a screening process yields high-refractive-index glass microspheres.

[0046] Comparative Example 2

[0047] A high-refractive-index, large-particle glass microbead for road marking comprises, by weight, 30 parts of titanium dioxide, 30 parts of silicon dioxide, 10 parts of barium nitrate, 10 parts of zirconium nitrate, 5 parts of zinc oxide, 3 parts of boric acid, 3 parts of calcium fluoride, 5 parts of Nb2O5, 2.5 parts of La2O3, and 2.5 parts of ZrO2.

[0048] A spheroidization method for preparing high-refractive-index, large-particle glass microspheres for road markings involves uniformly mixing titanium dioxide, silicon dioxide, barium nitrate, zirconium nitrate, zinc oxide, boric acid, calcium fluoride, Nb2O5, La2O3, and ZrO2. The mixture is then melted at 1200°C. The molten product is water-quenched, dried, ball-milled, and sieved to obtain a 50μm precursor. The precursor is then divided into two paths. The precursor in each path is propelled by compressed air and mixed with fuel gas and an oxidant before being injected through a nozzle into a combustion chamber. The heating temperature in the combustion chamber is set at 1300°C, and the nozzle injection velocity is 75 m / s. During this process, the injection trajectories of the two nozzles intersect at a point, forming a 75° angle. The two injection paths share a common intersection point, where the molten glass bead precursor converges. Finally, a screening process produces high-refractive-index glass microspheres.

[0049] Test Example 1

[0050] The refractive index of Examples 1-6 and Comparative Examples 1-2 was measured by oil immersion method, and the yield of the products with a size of 600-850 μm was calculated. The yield is the mass percentage of the products obtained by screening to the total products. See Table 1 for details.

[0051] Table 1 Test results

[0052] Refractive index Yield rate (%) Example 1 2.02 91.4 Example 2 2.02 91.3 Example 3 2.04 92.7 Example 4 2.07 91.5 Example 5 2.07 90.6 Example 6 2.08 92.1 Comparative Example 1 2.01 60.7 Comparative Example 2 2.01 67.2

[0053] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A high refractive index large particle size glass microbead for road marking, characterized in that: In parts by weight, the ingredients include: 30 to 40 parts titanium dioxide, 30 to 40 parts silicon dioxide, 10 to 15 parts barium nitrate, 10 to 15 parts zirconium nitrate, 5 to 7 parts zinc oxide, 3 to 5 parts boric acid, 3 to 5 parts calcium fluoride, 5 to 15 parts Nb2O55 to 10 parts La2O3-ZrO2 complex; The preparation method of the La2O3-ZrO2 composite is as follows: ZrOCl2·8H2O and La(NO3)3·6H2O are dissolved in deionized water, and then 30 mL of anhydrous ethanol is added; ultrasonication is performed for 1 hour, and then the pH is adjusted with NH4OH, and then vigorously stirred for 30 minutes; the mixture is transferred to a high-pressure reactor and reacted at 200°C for 20 hours; then naturally cooled to room temperature, and then centrifuged to obtain a precipitate, which is washed with deionized water, dried at 70°C for 12 hours, and then calcined.

2. The high refractive index large particle size glass microspheres for road marking according to claim 1, characterized in that: The molar ratio of ZrOCl2·8H2O and La(NO3)3·6H2O is 4.5:

1.

3. The high refractive index large particle size glass microspheres for road marking according to claim 2, characterized in that: The pH was adjusted to 10 with NH4OH.

4. The high refractive index large particle size glass microspheres for road marking according to claim 3, characterized in that: The calcination condition is calcination at 900°C for 12h.

5. The method for preparing high-refractive-index, large-diameter glass microspheres for road marking by spheroidization molding according to claim 1, characterized in that: The process comprises the following steps: uniformly mixing titanium dioxide, silicon dioxide, barium nitrate, zirconium nitrate, zinc oxide, boric acid, calcium fluoride, Nb2O5 and La2O3-ZrO2, then melting the mixture at 1200°C, quenching the melted product with water, drying it, ball milling it, and sieving it to obtain a 50-μm precursor; dividing the precursor into two paths, and mixing the precursor in each path with a fuel gas and an oxidant under the propulsion of compressed air, and injecting the mixture into a combustion chamber through a nozzle; The heating temperature in the combustion chamber is set to 1300°C, and the nozzle injection velocity is 75 m / s; the injection trajectories of the two nozzles intersect at one point; The two jet paths share an intersection point, causing the molten glass bead precursor to converge at this point; high refractive index glass microbeads are obtained through the screening process.

6. The spheroidization molding preparation method according to claim 5, characterized in that: The spray trajectories of the two nozzles intersect at an angle of 75° at one point.