A quartz glass fiber cloth and a preparation method thereof

Abstract

This invention belongs to the field of glass fiber and composite material preparation technology, and provides a quartz glass fiber cloth and its preparation method. High-purity quartz sand is melted at high temperature to form quartz glass liquid, which is then drawn into continuous quartz fiber bundles through a platinum-rhodium alloy spinneret. The fiber bundles are then acid-washed and pre-baked at low temperature to improve fiber purity and stability. The fiber bundles are coated with sol and doping solution through a dual-channel spinning coating process, followed by drying and sintering to form quartz glass fibers. The fibers are then wound, spun, twisted, and braided to obtain a fiber cloth preform, which is finally sintered at high temperature in an inert atmosphere to form a quartz glass fiber cloth with excellent properties.

Description

Technical Field

[0001] This invention belongs to the field of glass fiber and composite material preparation technology, and relates to a quartz glass fiber cloth and its preparation method. Background Technology

[0002] With the rapid development of electronic technology, the demand for miniaturization, lightweighting, and high performance of electronic components is constantly increasing. In applications, quartz glass fiber cloth has become an indispensable key material due to its excellent high-temperature stability, low dielectric loss, high strength, and good electrical insulation properties. However, as application fields continue to demand higher material performance, especially in terms of ultra-thinness, high strength, and high purity, traditional production processes have revealed many technical bottlenecks in the preparation of electronic-grade quartz glass fiber cloth, failing to fully meet the stringent requirements of the industry.

[0003] Currently, traditional processes for preparing quartz glass fiber cloth often face a series of problems. For example, during fiber drawing, uneven melt flow or inaccurate control of drawing parameters can easily lead to uneven fiber diameter distribution, thus affecting the overall uniformity of the fibers. Furthermore, during the weaving and forming of the fiber cloth, poor fiber dispersion and insufficient thickness control make it difficult to achieve an extremely thin and uniform fabric surface. More importantly, traditional fiber treatment processes have limited effectiveness in improving fiber strength and stability, resulting in fiber cloth that is prone to breakage or performance degradation in practical applications, making it difficult for the material to meet the mechanical performance and reliability requirements of high-end electronic devices. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a quartz glass fiber cloth and its preparation method. Using high-purity quartz sand as raw material, uniform quartz fiber bundles are produced through high-temperature melting, filtration, and drawing using a platinum-rhodium alloy spinneret. Acid washing and low-temperature pre-calcination are then performed to improve purity and thermal stability. In the spinning and coating stage, a dual-channel solution / sol process is employed to achieve uniformity and stability of the fiber surface coating. Subsequently, a precise, staged sintering process eliminates fiber stress and improves mechanical properties, resulting in a uniform fiber cloth preform. This preform is then sintered in a high-temperature inert atmosphere to meet the needs of actual production.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a method for preparing quartz glass fiber cloth, the method comprising:

[0007] S1. High-purity quartz sand is put into an electric arc furnace, melted, filtered and stirred to obtain quartz glass liquid, and then the quartz glass liquid is drawn into continuous quartz fiber bundles. The continuous quartz fiber bundles are then subjected to acid washing and low-temperature pre-calcination in sequence to obtain quartz glass fiber bundles.

[0008] S2, the quartz glass fiber bundle is spun and coated, the coated quartz glass fiber bundle is sintered to obtain quartz glass fiber, and the fiber fabric is obtained by winding the original filament, sorting the filament, twisting the yarn and weaving.

[0009] S3, under an argon atmosphere, the fiber cloth blank is sintered at high temperature and then cooled to room temperature in the furnace to obtain quartz glass fiber cloth.

[0010] Specifically, it includes:

[0011] S1. High-purity quartz sand is put into an electric arc furnace, the temperature is adjusted to the first temperature to melt, and after filtration and stirring, quartz glass liquid is obtained. The quartz glass liquid is then drawn into continuous quartz fiber bundles. The continuous quartz fiber bundles are then subjected to acid washing and low-temperature pre-calcination in sequence to obtain quartz glass fiber bundles.

[0012] S2, place the quartz glass fiber bundle in front of the nozzle for spinning and coating, and after the coated quartz glass fiber bundle is fully dried, place it in a tube furnace for sintering to obtain quartz glass fiber. After the original fiber is wound, sorted, twisted and woven, the fiber fabric is obtained.

[0013] S3, under an argon atmosphere, the fiber cloth blank is placed in a tube furnace for high-temperature sintering, and then cooled to room temperature with the furnace to obtain quartz glass fiber cloth.

[0014] In the raw material processing stage, high-purity quartz sand is fed into an electric arc furnace for high-temperature melting. After melting, the molten quartz glass is drawn into continuous quartz fiber bundles. The drawn quartz fiber bundles need to undergo acid washing and low-temperature pre-calcination. The acid washing process uses dilute hydrochloric acid solution to remove metal ions and other acid-soluble impurities adsorbed on the fiber surface. These impurities are dissolved and removed through a chemical reaction. Immediately after acid washing, the fibers are rinsed with water to effectively prevent acid residue from corroding or damaging the fiber structure. Subsequently, a low-temperature pre-calcination treatment is performed. The mechanism is that by slowly raising the temperature and holding it for an appropriate time, adsorbed water and organic residues that may exist inside the fiber are removed, and the microstructure of the fiber is stabilized through heat treatment. Low-temperature pre-calcination can release residual stress in the fiber while avoiding crystal phase precipitation or fiber structural defects that may be caused by high-temperature treatment.

[0015] The spinning and coating stage is a crucial step in enhancing the functionality of quartz glass fibers. A dual-channel solution / sol coating technology is employed, where the dual-channel nozzle features a dual-flow-channel structure within a single nozzle. Liquid exits simultaneously from channels A and B. Under controlled voltage, nozzle distance, and A / B flow rates, a uniform and continuous composite coating layer is obtained. The main sol provides a basic protective layer for the fibers, while the doping solution imparts unique functional properties. The main sol is prepared through a hydrolytic condensation reaction, where tetraethoxysilane undergoes hydrolysis under acidic conditions to generate silanol groups, which then form a silicon-oxygen network structure through condensation. Polyvinylpyrrolidone (PVP) is added as a stabilizer to adjust the sol viscosity, thereby controlling the thickness and uniformity of the coating layer. Simultaneously, a nonionic surfactant further reduces the surface tension of the sol, ensuring the wettability and uniformity of the fiber surface during the coating process. Alumina and boron oxide incorporated into the doping solution enhance the heat resistance and mechanical strength of the coating layer through synergistic effects with the silicon-oxygen network. These dopants also strengthen the structural stability of the fiber surface by forming chemical bonds with the silicon-oxygen network. After fiber coating, the fiber undergoes staged sintering for heat treatment. During sintering, the organic components of the coating layer gradually decompose, while the silicon-oxygen network further crosslinks and densifies. The low-temperature sintering stage primarily removes solvents and organic residues from the coating layer, while the medium-to-high-temperature stage promotes the glass transition of the coating layer, enabling it to form a strong bond with the fiber surface. This gradual heating strategy effectively avoids cracks caused by thermal stress while ensuring the mechanical properties and thermal stability of the fiber.

[0016] In the post-woven fiber fabric processing, high-temperature sintering is a crucial step in improving the fiber fabric's performance. In an inert atmosphere, through gradual heating and appropriate holding time, the microstructure within the fiber fabric is further optimized. Sintering at low temperatures helps eliminate residual stress and micropores in the fiber fabric, while the high-temperature stage promotes densification and controlled crystallization between fibers. Silica undergoes a certain degree of rearrangement at high temperatures, forming a more stable three-dimensional network structure, thereby significantly improving the strength and heat resistance of the fiber fabric. The inert atmosphere effectively prevents oxidation reactions at high temperatures, ensuring the high purity and chemical stability of the fiber fabric.

[0017] As a preferred technical solution of the present invention, in S1, the first temperature is 1800-1850℃, for example, it can be 1800℃, 1805℃, 1810℃, 1815℃, 1820℃, 1825℃, 1830℃, 1835℃, 1840℃, 1845℃ or 1850℃, but it is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0018] In some alternative instances, the diameter of the continuous quartz fiber bundle is 5-20 μm, for example, it can be 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm or 20 μm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0019] In some optional examples, the pickling acid is a 5-10 wt.% hydrochloric acid solution, for example, 5.0 wt.%, 5.5 wt.%, 6.0 wt.%, 6.5 wt.%, 7.0 wt.%, 7.5 wt.%, 8.0 wt.%, 8.5 wt.%, 9.0 wt.%, 9.5 wt.%, or 10.0 wt.%, with a residence time of 30-40 s, for example, 30 s, 31 s, 32 s, 33 s, 34 s, 35 s, 36 s, 37 s, 38 s, 39 s, or 40 s. After pickling, the solution is sprayed with water and dried with hot air, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0020] In some optional examples, the low-temperature pre-calcination temperature is 300-320℃, for example, it can be 300℃, 302℃, 304℃, 306℃, 308℃, 310℃, 312℃, 314℃, 316℃, 318℃ or 320℃, the heating rate is 2℃ / min, the holding time is 1h, and the temperature is naturally cooled to room temperature after calcination, but it is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0021] As a preferred technical solution of the present invention, in S2, the spinning coating is a dual-channel solution / sol, the distance between the quartz glass fiber bundle and the nozzle is 15-20cm, for example, it can be 15.0cm, 15.5cm, 16.0cm, 16.5cm, 17.0cm, 17.5cm, 18.0cm, 18.5cm, 19.0cm, 19.5cm or 20.0cm, the voltage is 15-20kV, for example, it can be 15.0kV, 15.5kV, 16.0kV, 16.5kV, 17.0kV, 17.5kV, 18.0kV, 18.5kV, 19.0kV, 19.5kV or 20.0kV, the fiber bundle moving speed is 0.1m / min, but it is not limited to the listed values, other unlisted values ​​within this range are also applicable;

[0022] Channel A is the main sol. The preparation method of the main sol includes: mixing tetraethoxysilane with anhydrous ethanol, adjusting the pH to 2.8-3.0 with 1M HCl solution, adding PVP K30 and a nonionic surfactant, stirring evenly, and allowing it to stand to obtain the main sol. The flow rate of the main sol is 0.8 mL / h. The mass ratio of tetraethoxysilane, anhydrous ethanol, PVP K30, and nonionic surfactant is (50-55):100:(7-8):0.3, for example, it can be (50.0, 50.5, 51.0, 51.5, 52.0, 52.5, 53.0, 53.5, 54.0, 54.5, or 55.0):100:(7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9). (or 8.0): 0.3, but not limited to the listed values; other unlisted values ​​within this range also apply.

[0023] Channel B is the doped solution. The preparation method of the doped solution includes: dispersing aluminum nitrate nonahydrate in an ethanol-water solution, sequentially adding boron oxide and tetraethoxysilane and ultrasonically dispersing, adjusting the pH to 2.8-3.0 using 1 M HCl solution to obtain the doped solution. The flow rate of the doped solution is 0.3 mL / h. The mass ratio of aluminum nitrate nonahydrate, boron oxide, and tetraethoxysilane is (54-60):(15-20):10, for example, it can be (54.0, 54.6, 55.2, 55.8, 56.4, 57.0, 57.6, 58.2, 58.8, 59.4 or 60.0):(15.0, 15.5, 16.0, 16.5, 17.0, 17.5, 18.0, 18.5, 19.0, 19.5). (or 20.0): 10, but not limited to the listed values; other unlisted values ​​within this range also apply.

[0024] In some alternative examples, the sintering is performed by heating to 300°C at a rate of 2°C / min, holding for 1 hour, then heating to 500°C at a rate of 2°C / min, holding for 1 hour, and then heating to 900°C at a rate of 4°C / min, holding for 2 hours.

[0025] In some optional examples, the warp and weft density of the fabric fabric ranges from 30*30 threads / cm. 2 -40*40 pieces / cm 2 .

[0026] In a preferred embodiment of the present invention, in step S3, the high-temperature sintering involves raising the temperature to 1200-1250°C at a rate of 3°C / min, for example, 1200°C, 1205°C, 1210°C, 1215°C, 1220°C, 1225°C, 1230°C, 1235°C, 1240°C, 1245°C, or 1250°C, and holding the temperature for 30-40 minutes, for example, 30 minutes, 31 minutes, 32 minutes, 33 minutes, 34 minutes, 35 minutes, 36 minutes, 37 minutes, 38 minutes, 39 minutes, or 40 minutes, and then raising the temperature to 1450-1500°C at a rate of 3°C / min, for example, 1450°C, 1455°C, 1460°C, 1465°C, 1470°C, 1475°C, 1480°C, 1485°C, 1490°C, or 1495°C. Alternatively, the temperature can be 1500℃, and the holding time can be 30-60 minutes, for example, 30 minutes, 33 minutes, 36 minutes, 39 minutes, 42 minutes, 45 minutes, 48 ​​minutes, 51 minutes, 54 minutes, 57 minutes, or 60 minutes, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0027] In a second aspect, the present invention provides a quartz glass fiber cloth prepared by the preparation method described in the first aspect.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) By melting high-purity quartz sand and using the precise drawing process of platinum-rhodium alloy spinneret, the high purity and diameter uniformity of quartz glass fiber are ensured. Acid washing and low-temperature pre-baking further optimize the chemical purity and thermal stability of the fiber, and improve the mechanical properties of the fiber and its electrical insulation performance suitable for high-frequency scenarios; (2) By adopting dual-channel solution / sol coating technology and combining it with staged sintering treatment, the fiber surface functionalization and coating layer densification are achieved. The introduction of doping solution enhances the high temperature resistance and mechanical strength of the fiber. The gradual heating strategy effectively balances densification and stress release, ensuring the improvement of fiber cloth strength, thickness uniformity and electrical performance. Attached Figure Description

[0029] Figure 1 This is a physical image of the quartz glass fiber cloth provided in Embodiment 1 of the present invention. Detailed Implementation

[0030] The technical solutions of the present invention will be described in detail below with reference to specific embodiments and accompanying drawings. The embodiments described herein are specific implementations of the present invention, used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary, and should not be construed as limiting the implementation methods or the scope of protection of the present invention. In addition to the embodiments described herein, those skilled in the art can employ other obvious technical solutions based on the content disclosed in the claims and specification of this application. These technical solutions include those that make any obvious substitutions and modifications to the embodiments described herein.

[0031] The chemical reagents used in the embodiments and comparative examples of this invention are all commercially available products and have not undergone any further purification treatment.

[0032] Example 1

[0033] This embodiment provides a quartz glass fiber cloth and its preparation method, the preparation method specifically including the following steps:

[0034] S1. High-purity quartz sand is added to an electric arc furnace and the temperature is adjusted to 1800℃ to melt. After filtration and stirring, quartz glass liquid is obtained. The quartz glass liquid is then drawn into continuous quartz fiber bundles with a diameter of 5μm. The continuous quartz fiber bundles are then subjected to acid washing and low-temperature pre-calcination in sequence. The acid washing solution is a 5wt.% hydrochloric acid solution with a residence time of 30s. After acid washing, water is sprayed and hot air is used for drying. The low-temperature pre-calcination temperature is 300℃, the heating rate is 2℃ / min, and the holding time is 1h. After calcination, the temperature is naturally cooled to room temperature to obtain quartz glass fiber bundles.

[0035] S2, a quartz glass fiber bundle is placed in front of the nozzle for spinning and coating. The spinning and coating is a dual-channel solution / sol. The distance between the quartz glass fiber bundle and the nozzle is 15cm, the voltage is 15kV, and the fiber bundle moving speed is 0.1m / min. Channel A is the main sol, which is prepared by mixing tetraethoxysilane with anhydrous ethanol, adjusting the pH to 2.8 with 1M HCl solution, adding PVP K30 and a nonionic surfactant, stirring evenly, and allowing it to stand to obtain the main sol. The flow rate of the main sol is 0.8mL / h. The mass ratio of tetraethoxysilane, anhydrous ethanol, PVP K30, and nonionic surfactant is 50:100:7:0.3. Channel B is the doping solution, which is prepared by dispersing aluminum nitrate nonahydrate in an ethanol aqueous solution, adding boron oxide and tetraethoxysilane sequentially and ultrasonically dispersing, and using 1M HCl solution. The pH was adjusted to 2.8 with HCl solution to obtain a doped solution. The flow rate of the doped solution was 0.3 mL / h. The mass ratio of aluminum nitrate nonahydrate, boron oxide, and tetraethoxysilane was 54:15:10. After the coated quartz glass fiber bundles were thoroughly dried, they were placed in a tube furnace for sintering. The sintering process involved heating to 300°C at 2°C / min, holding for 1 hour, then heating to 500°C at 2°C / min, holding for 1 hour, and then heating to 900°C at 4°C / min, holding for 2 hours to obtain quartz glass fibers. These fibers were then wound, arranged, twisted, and woven to obtain a fiber fabric. The warp and weft density of the fiber fabric ranged from 30*30 threads / cm. 2 ;

[0036] S3, under an argon atmosphere, the fiber cloth blank is placed in a tube furnace for high-temperature sintering. The high-temperature sintering is carried out by heating to 1200°C at a heating rate of 3°C / min and holding for 30 min, then heating to 1450°C at a heating rate of 3°C / min and holding for 30 min, and then cooling to room temperature with the furnace to obtain quartz glass fiber cloth.

[0037] Figure 1 This is a physical image of the quartz glass fiber cloth provided in this embodiment.

[0038] Example 2

[0039] This embodiment provides a quartz glass fiber cloth and its preparation method, the preparation method specifically including the following steps:

[0040] S1. High-purity quartz sand is added to an electric arc furnace and the temperature is adjusted to 1850℃ to melt. After filtration and stirring, quartz glass liquid is obtained. The quartz glass liquid is then drawn into continuous quartz fiber bundles with a diameter of 10μm. The continuous quartz fiber bundles are then subjected to acid washing and low-temperature pre-calcination in sequence. The acid washing solution is an 8wt.% hydrochloric acid solution with a residence time of 33s. After acid washing, water is sprayed and hot air is used for drying. The low-temperature pre-calcination temperature is 310℃, the heating rate is 2℃ / min, and the holding time is 1h. After calcination, the temperature is naturally cooled to room temperature to obtain quartz glass fiber bundles.

[0041] S2, a quartz glass fiber bundle is placed in front of the nozzle for spinning and coating. The spinning and coating is a dual-channel solution / sol. The distance between the quartz glass fiber bundle and the nozzle is 20 cm, the voltage is 20 kV, and the fiber bundle moving speed is 0.1 m / min. Channel A is the main sol, which is prepared by mixing tetraethoxysilane with anhydrous ethanol, adjusting the pH to 3.0 with 1 M HCl solution, adding PVP K30 and a nonionic surfactant, stirring evenly, and allowing it to stand to obtain the main sol. The flow rate of the main sol is 0.8 mL / h. The mass ratio of tetraethoxysilane, anhydrous ethanol, PVP K30, and nonionic surfactant is 52:100:7.3:0.3. Channel B is the doping solution, which is prepared by dispersing aluminum nitrate nonahydrate in an ethanol aqueous solution, adding boron oxide and tetraethoxysilane sequentially and ultrasonically dispersing, and using 1 M HCl solution. The pH was adjusted to 2.9 with HCl solution to obtain a doped solution. The flow rate of the doped solution was 0.3 mL / h. The mass ratio of aluminum nitrate nonahydrate, boron oxide, and tetraethoxysilane was 58:20:10. After the coated quartz glass fiber bundles were thoroughly dried, they were placed in a tube furnace for sintering. The sintering process involved heating to 300°C at 2°C / min, holding for 1 hour, then heating to 500°C at 2°C / min, holding for 1 hour, and then heating to 900°C at 4°C / min, holding for 2 hours to obtain quartz glass fibers. These fibers were then wound, arranged, twisted, and woven to obtain a fiber fabric. The warp and weft density of the fiber fabric ranged from 40*40 threads / cm. 2 ;

[0042] S3, under an argon atmosphere, the fiber cloth blank is placed in a tube furnace for high-temperature sintering. The high-temperature sintering is carried out by heating to 1220°C at a heating rate of 3°C / min and holding for 33 min, then heating to 1470°C at a heating rate of 3°C / min and holding for 50 min, and then cooling to room temperature with the furnace to obtain quartz glass fiber cloth.

[0043] Example 3

[0044] This embodiment provides a quartz glass fiber cloth and its preparation method, the preparation method specifically including the following steps:

[0045] S1. High-purity quartz sand is added to an electric arc furnace and the temperature is adjusted to 1820℃ to melt. After filtration and stirring, quartz glass liquid is obtained. The quartz glass liquid is then drawn into continuous quartz fiber bundles with a diameter of 20μm. The continuous quartz fiber bundles are then subjected to acid washing and low-temperature pre-calcination in sequence. The acid washing solution is a 6wt.% hydrochloric acid solution with a residence time of 40s. After acid washing, water is sprayed and hot air is used for drying. The low-temperature pre-calcination temperature is 320℃, the heating rate is 2℃ / min, and the holding time is 1h. After calcination, the temperature is naturally cooled to room temperature to obtain quartz glass fiber bundles.

[0046] S2, a quartz glass fiber bundle is placed in front of the nozzle for spinning and coating. The spinning and coating is a dual-channel solution / sol. The distance between the quartz glass fiber bundle and the nozzle is 17 cm, the voltage is 16 kV, and the fiber bundle moving speed is 0.1 m / min. Channel A is the main sol, which is prepared by mixing tetraethoxysilane with anhydrous ethanol, adjusting the pH to 2.9 with 1 M HCl solution, adding PVP K30 and a nonionic surfactant, stirring evenly, and allowing it to stand to obtain the main sol. The flow rate of the main sol is 0.8 mL / h. The mass ratio of tetraethoxysilane, anhydrous ethanol, PVP K30, and nonionic surfactant is 55:100:8:0.3. Channel B is the doping solution, which is prepared by dispersing aluminum nitrate nonahydrate in an ethanol aqueous solution, adding boron oxide and tetraethoxysilane sequentially and ultrasonically dispersing, and using 1 M HCl solution. The pH was adjusted to 3.0 with HCl solution to obtain a doped solution. The flow rate of the doped solution was 0.3 mL / h. The mass ratio of aluminum nitrate nonahydrate, boron oxide, and tetraethoxysilane was 60:17:10. After the coated quartz glass fiber bundles were thoroughly dried, they were placed in a tube furnace for sintering. The sintering process involved heating to 300°C at 2°C / min, holding for 1 hour, then heating to 500°C at 2°C / min, holding for 1 hour, and then heating to 900°C at 4°C / min, holding for 2 hours to obtain quartz glass fibers. These fibers were then wound, arranged, twisted, and woven to obtain a fiber fabric. The warp and weft density of the fiber fabric ranged from 30*30 threads / cm. 2 ;

[0047] S3, under an argon atmosphere, the fiber cloth blank is placed in a tube furnace for high-temperature sintering. The high-temperature sintering is carried out by heating to 1250°C at a heating rate of 3°C / min and holding for 40 min, then heating to 1500°C at a heating rate of 3°C / min and holding for 60 min, and then cooling to room temperature with the furnace to obtain quartz glass fiber cloth.

[0048] Example 4

[0049] This embodiment provides a quartz glass fiber cloth and its preparation method, the preparation method specifically including the following steps:

[0050] S1. High-purity quartz sand is added to an electric arc furnace and the temperature is adjusted to 1840℃ to melt. After filtration and stirring, quartz glass liquid is obtained. The quartz glass liquid is then drawn into continuous quartz fiber bundles with a diameter of 15μm. The continuous quartz fiber bundles are then subjected to acid washing and low-temperature pre-calcination in sequence. The acid washing solution is a 10wt.% hydrochloric acid solution with a residence time of 37s. After acid washing, water is sprayed and hot air is used for drying. The low-temperature pre-calcination temperature is 305℃, the heating rate is 2℃ / min, and the holding time is 1h. After calcination, the temperature is naturally cooled to room temperature to obtain quartz glass fiber bundles.

[0051] S2, a quartz glass fiber bundle is placed in front of the nozzle for spinning and coating. The spinning and coating is a dual-channel solution / sol. The distance between the quartz glass fiber bundle and the nozzle is 19 cm, the voltage is 18 kV, and the fiber bundle moving speed is 0.1 m / min. Channel A is the main sol, which is prepared by mixing tetraethoxysilane with anhydrous ethanol, adjusting the pH to 2.8 with 1 M HCl solution, adding PVP K30 and a nonionic surfactant, stirring evenly, and allowing it to stand to obtain the main sol. The flow rate of the main sol is 0.8 mL / h. The mass ratio of tetraethoxysilane, anhydrous ethanol, PVP K30, and nonionic surfactant is 54:100:7.7:0.3. Channel B is the doping solution, which is prepared by dispersing aluminum nitrate nonahydrate in an ethanol aqueous solution, adding boron oxide and tetraethoxysilane sequentially and ultrasonically dispersing, and using 1 M HCl solution. The pH was adjusted to 2.9 with HCl solution to obtain a doped solution. The flow rate of the doped solution was 0.3 mL / h. The mass ratio of aluminum nitrate nonahydrate, boron oxide, and tetraethoxysilane was 56:19:10. After the coated quartz glass fiber bundles were thoroughly dried, they were placed in a tube furnace for sintering. The sintering process involved heating to 300°C at 2°C / min, holding for 1 hour, then heating to 500°C at 2°C / min, holding for 1 hour, and then heating to 900°C at 4°C / min, holding for 2 hours to obtain quartz glass fibers. These fibers were then wound, arranged, twisted, and woven to obtain a fiber fabric. The warp and weft density of the fiber fabric ranged from 40*40 threads / cm. 2 ;

[0052] S3, under an argon atmosphere, the fiber cloth blank is placed in a tube furnace for high-temperature sintering. The high-temperature sintering is carried out by heating to 1240°C at a heating rate of 3°C / min and holding for 38 min, then heating to 1490°C at a heating rate of 3°C / min and holding for 40 min, and then cooling to room temperature with the furnace to obtain quartz glass fiber cloth.

[0053] Comparative Example 1

[0054] This comparative example provides a quartz glass fiber cloth and its preparation method. The difference between this example and Example 1 is that the main sol is not used in step S2, while the other process parameters and operating conditions are exactly the same as in Example 1.

[0055] Comparative Example 2

[0056] This comparative example provides a quartz glass fiber cloth and its preparation method. The difference between this example and Example 1 is that no doping solution is used in step S2, while the other process parameters and operating conditions are exactly the same as in Example 1.

[0057] Dielectric constant test method: Ten circular samples are cut from a smooth, flawless area of ​​the fabric to be tested. Wearing clean gloves, the ten samples are neatly stacked along the warp and weft directions. The stacked samples are placed in a 120℃ forced-air drying oven and dried at a constant temperature for 2 hours. After drying, the hot samples are immediately transferred to a desiccator using tweezers and cooled to room temperature for testing. Before measurement, the instrument needs to be preheated for 30 minutes to achieve thermal stability, and open-circuit / short-circuit calibration is performed to eliminate parasitic impedance of the test fixture and cables. The test frequency is set to 1 MHz. The pretreated sample is placed between the electrodes, and a constant uniaxial pressure of 0.2 MPa is applied. After the pressure stabilizes, the compressed thickness d and capacitance C of the sample under this pressure are simultaneously collected, ε=(C*d) / (ε0*A), where C is the capacitance value of the sample in farads (F); d is the total thickness of the sample in meters (m); and ε0 is the vacuum dielectric constant, approximately 8.854*10⁻⁶. -12 F / m, where A is the electrode area, in square meters (m²). 2 Each sample was measured three times, and the arithmetic mean was calculated.

[0058] Mechanical property testing method: GB / T7689.5-2013 "Test methods for reinforced woven fabrics - Part 5: Determination of tensile breaking strength and elongation at break of glass fiber".

[0059] Chemical corrosion resistance test method: Electronic grade quartz glass fiber cloth was immersed in 1 mol / L hydrochloric acid, sodium hydroxide solution, and common organic solvent for 24 hours, respectively. The change rate of mechanical properties and mass of the fiber cloth was measured. The test results are shown in Table 1.

[0060] Table 1. Test results of quartz glass fiber cloth in Examples 1-4 and Comparative Examples 1-2

[0061]

[0062] As shown in Table 1, compared to Example 1, Comparative Example 1 exhibits increased dielectric constant, decreased tensile breaking strength, increased mass change rate after chemical immersion, and increased mechanical property change rate after chemical immersion; Comparative Example 2 also shows increased dielectric constant, decreased tensile breaking strength, increased mass change rate after chemical immersion, and increased mechanical property change rate after chemical immersion. The main role of the master sol is to form a silicon-oxygen network through the hydrolysis and condensation reaction of tetraethoxysilane, creating a uniform protective layer on the fiber surface. In Comparative Example 1, no master sol was used, resulting in a lack of a dense silicon-oxygen protective layer on the quartz glass fiber surface, increased surface defects and micropores, and an increased dielectric constant. Simultaneously, the concentrated stress effect of surface defects reduces tensile breaking strength, leading to increased mass change rate and mechanical property change rate after chemical immersion. In Comparative Example 2, no doping solution was used, resulting in a lack of reinforcing components such as alumina and boron oxide, decreased fiber surface chemical stability, increased dielectric constant, decreased tensile breaking strength, increased mass change rate after chemical immersion, and increased mechanical property change rate after chemical immersion.

[0063] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preparing quartz glass fiber cloth, characterized in that, The preparation method includes: S1. High-purity quartz sand is put into an electric arc furnace, melted, filtered and stirred to obtain quartz glass liquid, and then the quartz glass liquid is drawn into continuous quartz fiber bundles. The continuous quartz fiber bundles are then subjected to acid washing and low-temperature pre-calcination in sequence to obtain quartz glass fiber bundles. S2, the quartz glass fiber bundle is spun and coated, the coated quartz glass fiber bundle is sintered to obtain quartz glass fiber, and the fiber fabric is obtained by winding the original filament, sorting the filament, twisting the yarn and weaving. S3, under an argon atmosphere, the fiber cloth blank is sintered at high temperature and then cooled to room temperature in the furnace to obtain quartz glass fiber cloth; The spinning coating is a dual-channel solution / sol, with channel A as the main sol. The preparation method of the main sol includes: mixing tetraethoxysilane with anhydrous ethanol, adjusting the pH to 2.8-3.0 with 1 M HCl solution, adding PVP K30 and a nonionic surfactant, stirring evenly and allowing it to stand to obtain the main sol. The flow rate of the main sol is 0.8 mL / h. The mass ratio of tetraethoxysilane, anhydrous ethanol, PVP K30 and nonionic surfactant is (50-55):100:(7-8):0.

3. The spinning coating is a dual-channel solution / sol, where channel B is the doping solution. The preparation method of the doping solution includes: dispersing aluminum nitrate nonahydrate in an ethanol aqueous solution, adding boron oxide and tetraethoxysilane sequentially and dispersing by ultrasonication, adjusting the pH to 2.8-3.0 with 1 M HCl solution to obtain the doping solution, the flow rate of the doping solution is 0.3 mL / h, and the mass ratio of aluminum nitrate nonahydrate, boron oxide and tetraethoxysilane is (54-60):(15-20):

10.

2. The method for preparing a quartz glass fiber cloth according to claim 1, characterized in that, In S1: The diameter of the continuous quartz fiber bundle is 5-20 μm.

3. The method for preparing a quartz glass fiber cloth according to claim 1, characterized in that, In S1: The pickling acid solution is a 5-10 wt.% hydrochloric acid solution, the residence time is 30-40 seconds, and after pickling, water is sprayed and hot air is dried. The low-temperature pre-calcination temperature is 300-320℃, the heating rate is 2℃ / min, the holding time is 1h, and the temperature is naturally cooled to room temperature after calcination.

4. The method for preparing a quartz glass fiber cloth according to claim 1, characterized in that, In S2: The spinning coating is a dual-channel solution / sol, the distance between the quartz glass fiber bundle and the nozzle is 15-20cm, the voltage is 15-20kV, and the fiber bundle moving speed is 0.1m / min.

5. The method for preparing a quartz glass fiber cloth according to claim 1, characterized in that, In S2: The sintering process involves heating to 300°C at a rate of 2°C / min, holding for 1 hour, then heating to 500°C at a rate of 2°C / min, holding for 1 hour, and then heating to 900°C at a rate of 4°C / min, holding for 2 hours.

6. The method for preparing a quartz glass fiber cloth according to claim 1, characterized in that, In S2: The warp and weft density of the fiber fabric is in the range of 30*30 threads / cm. 2 -40*40 pieces / cm 2 .

7. The method for preparing a quartz glass fiber cloth according to claim 1, characterized in that, In S3: The high-temperature sintering process involves heating the temperature to 1200-1250℃ at a rate of 3℃ / min, holding it at that temperature for 30-40 minutes, and then heating it to 1450-1500℃ at a rate of 3℃ / min, holding it at that temperature for 30-60 minutes.

8. A quartz glass fiber cloth is obtained by the preparation method according to any one of claims 1-7.

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