Cool-feeling anti-ultraviolet nylon fabric and preparation method thereof

Abstract

The invention belongs to the field of functional textile materials, and provides a cool-feeling anti-ultraviolet nylon fabric and a preparation method thereof, and the cool-feeling anti-ultraviolet nylon fabric adopts a design scheme of combining a boron nitride / titanium dioxide composite filler with a beta-hydroxyl ether type ultraviolet absorption silane coupling agent surface modification technology. Uniform loading of hexagonal boron nitride on the surface of anatase type titanium dioxide is realized through an in-situ heat treatment process, a composite structure with heat conduction and ultraviolet shielding functions is constructed, and a complete process flow of master batch preparation, melt spinning, weaving, after-treatment and the like is matched; the ultraviolet protection coefficient UPF of the fabric is not lower than 40, the UPF retention rate after 20 times of household washing cycles is not lower than 80%, and the cool feeling qmax at the contact moment is not lower than 0.20 W / cm, the technical problem that an existing nylon fabric is insufficient in ultraviolet resistance and cool feeling function is solved, and the fabric has wide industrial application value.

Description

Technical Field

[0001] This invention relates to the field of functional textile materials, and provides a cooling and UV-resistant nylon fabric and its preparation method. Background Technology

[0002] With the improvement of people's living standards and the enhancement of health awareness, outdoor sports and leisure tourism are becoming increasingly popular, and the functional demands on textiles are constantly upgrading. In the hot summer environment, traditional textiles often struggle to simultaneously meet the dual requirements of human comfort and health protection, making textiles with cooling and UV protection functions a pressing market need. Cooling functionality requires fabrics to have excellent thermal conductivity, enabling rapid conduction and dissipation of body heat to provide wearers with a continuous cooling sensation, effectively improving comfort in high-temperature environments. UV protection requires fabrics to effectively block ultraviolet radiation, protecting human skin from UV damage, especially during prolonged outdoor exposure. Furthermore, these functional fabrics also need good durability, ensuring stable functional performance even after multiple washes and long-term use. Meeting these performance requirements not only significantly enhances the added value and market competitiveness of textiles but also provides consumers with a more comfortable and safe wearing experience, driving the functional textile industry towards high-end and intelligent development. Therefore, developing textile materials with both cooling and UV protection functions has significant practical implications and broad application prospects.

[0003] Currently, research on functional nylon fabrics mainly focuses on achieving single functions, but there are still many technical challenges in the synergistic integration of cooling and UV protection functions. For example, Chinese patent CN215283804U discloses a high-temperature resistant and UV-resistant environmentally friendly nylon fiber fabric, but it suffers from the shortcomings of having only UV protection function and lacking cooling performance. Traditional functional modification methods often use finishing processes or single filler modification, making it difficult to build a stable multifunctional composite structure within the fiber, resulting in limited functional effects and poor durability. In existing composite filler preparation technologies, there is a lack of effective interfacial bonding between different functional components, which easily leads to phase separation, affecting the uniform dispersion and functional performance of the filler in the matrix. At the same time, the compatibility between functional fillers and nylon matrix has always been a key factor restricting the development of functional fibers. Poor interfacial bonding can lead to filler agglomeration and uneven dispersion, thereby affecting the mechanical and processing properties of the fiber. In addition, existing technologies often have the problem of mutual constraints between functions when achieving multifunctional integration, making it difficult to ensure one function without affecting the performance of other functions. For example, Chinese patent CN114990716B discloses a cooling fiber and its preparation method, but it suffers from insufficient functional durability and complex preparation process. These technical bottlenecks severely restrict the industrialization of high-performance multifunctional nylon fabrics. Summary of the Invention

[0004] The purpose of this invention is to provide a cooling and UV-resistant nylon fabric and its preparation process, thereby solving the problems of insufficient UV resistance and cooling sensation in current nylon fabrics.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A cooling and UV-resistant nylon fabric is disclosed, wherein the fabric is woven from nylon 6 filaments and then finished; the nylon 6 filaments contain a surface-modified boron nitride / titanium dioxide composite filler dispersed in the fiber matrix; the composite filler comprises anatase titanium dioxide nanoparticles and hexagonal boron nitride loaded on its surface; the surface of the composite filler has a β-hydroxy ether type UV-absorbing silane coupling agent modified layer; the amount of the composite filler added to the nylon 6 is 0.8%-3.0% by mass fraction.

[0006] Furthermore, the β-hydroxy ether type ultraviolet absorbing silane coupling agent comprises the following raw materials in parts by weight: 1 part of 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 1.1-1.3 parts of 3-glycidyl etheroxypropyltrimethoxysilane, 0.05-0.1 parts of tetrabutylammonium bromide, and 1.2-1.5 parts of anhydrous potassium carbonate.

[0007] Furthermore, the average particle size of the anatase titanium dioxide nanoparticles is 60nm-100nm; hexagonal boron nitride is generated in situ by heat treatment of a precursor containing boric acid and urea under nitrogen protection and loaded onto the surface of titanium dioxide, with a molar ratio of boric acid to urea of ​​1:1.8-1:2.5; the composite filler is surface modified by a β-hydroxy ether type ultraviolet absorbing silane coupling agent.

[0008] Furthermore, the mass ratio of hexagonal boron nitride to anatase titanium dioxide in the composite filler is 1:3-1:6.

[0009] Furthermore, the fabric has an ultraviolet protection factor (UPF) of not less than 40 and a UPF retention rate of not less than 80% after 20 household washing cycles; the fabric has a cooling sensation (qmax) of not less than 0.20 W / cm² upon contact.

[0010] This invention employs a boron nitride / titanium dioxide composite filler design primarily to enhance the cooling and UV protection properties of nylon fabrics. This technical solution achieves an organic combination of thermal conductivity and UV protection by constructing a composite structure of hexagonal boron nitride and anatase titanium dioxide. Hexagonal boron nitride possesses excellent thermal conductivity, enabling rapid conduction and dissipation of body heat, providing a lasting cooling effect to the fabric. Anatase titanium dioxide nanoparticles, acting as a carrier, not only exert their inherent UV shielding effect but also form a stable composite structure with boron nitride through an in-situ loading process, enhancing the filler's dispersibility and stability. The introduction of a β-hydroxy ether-type UV-absorbing silane coupling layer further strengthens the UV protection function. Simultaneously, organic surface treatment significantly improves the interfacial compatibility between the composite filler and the nylon 6 matrix, ensuring uniform dispersion of the filler within the fiber. The synergistic effect among the components in the composite filler allows the fabric to maintain good mechanical properties while achieving a dual improvement in cooling and UV protection performance. By precisely controlling the mass ratio of hexagonal boron nitride to anatase titanium dioxide and the amount of composite filler added, a balance between functionality and processing performance is ensured, providing an effective technical path for the development of high-performance functional textiles.

[0011] In the cooling and UV-resistant nylon fabric system, β-hydroxy ether-type UV-absorbing silane coupling agents primarily perform interfacial modification and UV protection functions, while boron nitride / titanium dioxide composite fillers focus on improving thermal conductivity, heat dissipation, and UV shielding performance. β-hydroxy ether-type UV-absorbing silane coupling agents achieve UV light absorption and conversion through their hydroxybenzotriazole groups, while the silane groups form chemical bonds with the nylon matrix, improving interfacial compatibility. The layered structure of boron nitride provides excellent phonon conduction pathways, enhancing thermal conductivity, while anatase titanium dioxide nanoparticles block UV radiation through scattering and absorption mechanisms. Regarding improved cooling performance, the high thermal conductivity and anisotropic structure of boron nitride construct a continuous heat transfer network, while the β-hydroxy ether-type silane coupling agent reduces interfacial thermal resistance through interface optimization. Improved UV protection performance relies on the photocatalytic absorption characteristics of titanium dioxide and the molecular energy level transition absorption of the benzotriazole groups. The synergistic effect of the two components is manifested in the following ways: the silane coupling agent modification significantly improves the dispersion uniformity of the composite filler in the matrix, forming a more effective thermal conductivity and UV shielding network; at the same time, the flexibility of the coupling agent molecular chain helps maintain the orientation of the boron nitride sheets, maximizing its thermal conductivity anisotropy advantage. This multi-level synergistic mechanism achieves simultaneous optimization of cooling sensation and UV resistance performance, but the understanding of the influence of interfacial molecular chain conformation on the thermal conduction path still needs further in-depth research.

[0012] This invention also discloses a method for preparing a cooling and UV-resistant nylon fabric, comprising the following steps: S1. Masterbatch preparation: Nylon 6 chips are vacuum dried at 80℃-100℃ for 4h-6h to reduce the moisture content to below 0.02%; according to the weight ratio, 8-15 parts of surface-modified boron nitride / titanium dioxide composite filler, 0.5-2 parts of antioxidant 1010, 0.3-1 parts of ultraviolet absorber UV-531 and 0.2-0.8 parts of calcium stearate are added to 100 parts of dried nylon 6 chips. The mixture is melt-blended and extruded in a twin-screw extruder at a screw temperature of 220℃-240℃ and a screw speed of 80 rpm-120 rpm. After water cooling, the mixture is pelletized to obtain the functional masterbatch. S2. Preparation of spinning raw materials: Mix 80-92 parts of nylon 6 chips with 8-20 parts of functional masterbatch, and vacuum dry to reduce the moisture content to below 0.02%; S3. Melt spinning and drawing: The spinning raw material is melted and plasticized at a screw temperature of 230℃-250℃ and a metering pump temperature of 240℃-260℃. After precision filtration, it is extruded through a spinneret with 24-72 holes and a hole diameter of 0.20mm-0.35mm at a spinning temperature of 250℃-270℃, and cooled and solidified by side blowing. The initial drawing is performed at a winding speed of 600m / min-1200m / min and a winding tension of 0.15cN / dtex-0.25cN / dtex, with a drawing ratio of 3.5-4.8. Then, a secondary drawing is performed at 80℃-120℃, with a drawing ratio of 1.3-1.8. S4. Weaving and finishing: The obtained filaments are woven into fabric greige, and then pre-shrinked, scouring, setting and softening to obtain the cool-feeling UV-resistant nylon fabric.

[0013] Furthermore, the preparation method of the surface-modified boron nitride / titanium dioxide composite filler includes the following steps: A1. By weight, disperse 100 parts of boron nitride / titanium dioxide composite filler in 300-500 parts of anhydrous toluene or anhydrous xylene, and ultrasonically disperse for 10-20 minutes; A2. Prepare a stock solution of β-hydroxy ether type ultraviolet absorbing silane coupling agent in toluene or xylene with a mass fraction of 20%-30%; A3. Under nitrogen protection, add 5-15 parts of the stock solution from step A2 to the dispersion from step A1, control the temperature of the reaction system at 80℃-120℃ and react for 2-6 hours. A4. After reaction, the mixture is filtered and separated, washed 2-3 times with anhydrous ethanol, and then vacuum dried at 60℃-80℃ for 4-8 hours to obtain the surface-modified boron nitride / titanium dioxide composite filler.

[0014] Furthermore, the preparation method of the boron nitride / titanium dioxide composite filler includes the following steps: The preparation method of the boron nitride / titanium dioxide composite filler includes the following steps: B1. By weight, 100 parts of anatase titanium dioxide nanoparticles are dispersed in 300-500 parts of anhydrous ethanol and ultrasonically dispersed for 20-40 minutes. B2. Add 15-25 parts of boric acid and 40-60 parts of urea as precursors to the dispersion in step B1 and stir mechanically until completely dissolved; B3. The solvent was removed by a rotary evaporator at 60℃-80℃ to obtain a dry precursor mixture; B4. Place the mixture from step B3 in a tube furnace and heat it to 550℃-650℃ at a heating rate of 3℃ / min-8℃ / min under nitrogen protection and heat treat it for 4h-8h to achieve in-situ generation of hexagonal boron nitride and loading it onto the surface of titanium dioxide. B5. Allow to cool naturally to room temperature, grind and pass through a 180-250 mesh sieve to obtain boron nitride / titanium dioxide composite filler.

[0015] Furthermore, the preparation method of the β-hydroxy ether type ultraviolet absorbing silane coupling agent involves using 1 part of 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 1.1-1.3 parts of 3-glycidyl etheroxypropyltrimethoxysilane, 0.05-0.1 parts of tetrabutylammonium bromide, and 1.2-1.5 parts of anhydrous potassium carbonate as raw materials. Under nitrogen protection, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, tetrabutylammonium bromide, and anhydrous potassium carbonate are sequentially added to a reaction flask containing 5-10 parts of anhydrous acetonitrile dried with molecular sieves. After stirring and dissolving, the mixture is heated to 65℃-80℃, and then... 3-Glycidyl etheroxypropyltrimethoxysilane was added dropwise to the reaction system in 3-4 batches, with each batch added over 10-15 minutes and the interval between each batch being 20-30 minutes. After the addition was complete, the reaction was continued for 6-8 hours. After the reaction was complete, the mixture was cooled to room temperature, filtered to remove inorganic salts, and the filtrate was subjected to vacuum distillation to remove the solvent to obtain the crude product. The crude product was purified by silica gel column chromatography using a gradient elution with a mixture of n-hexane and ethyl acetate in a volume ratio of 3:1 to 5:1 to obtain a β-hydroxy ether type UV-absorbing silane coupling agent. The HPLC purity of the obtained product was not less than 95%.

[0016] Furthermore, in step S4: during weaving, the warp density is 180-220 yarns / 10cm and the weft density is 160-200 yarns / 10cm; the pre-shrinking temperature is 95℃-100℃ and the time is 10-15min; the scouring temperature is 60℃-80℃ and the time is 15-20min, using a nonionic surfactant; the setting temperature is 160℃-180℃ and the machine speed is 15m / min-25m / min; the softening finishing temperature is 40℃-60℃, using an amino silicone oil softener.

[0017] This invention employs a preparation method combining boron nitride / titanium dioxide composite filler with surface modification technology, primarily used to enhance the cooling and UV-resistant properties of nylon fabrics. This technical solution achieves uniform loading of hexagonal boron nitride on the surface of anatase titanium dioxide through in-situ heat treatment, constructing a composite structure with both thermal conductivity and UV shielding functions. Boric acid and urea, as precursors, react under high-temperature nitrogen protection, generating hexagonal boron nitride that forms a stable interfacial bond with the titanium dioxide carrier, maintaining the excellent thermal conductivity of boron nitride while fully utilizing the UV absorption characteristics of titanium dioxide. Surface modification with a β-hydroxy ether-type UV-absorbing silane coupling agent further enhances the UV resistance, while the organic surface significantly improves the compatibility between the composite filler and the nylon 6 matrix. The synergistic effect of antioxidant 1010, UV absorber UV-531, and calcium stearate in the masterbatch preparation process ensures stable dispersion of the filler during melt processing. Precisely controlled melt spinning and drawing process parameters ensure the uniform distribution of functional components in the fibers, while post-processing further optimizes the overall performance of the fabric. The synergistic effect among the components enables the fabric to achieve excellent instant cooling sensation upon contact while providing long-lasting and stable UV protection, offering a complete technical solution for the industrial production of high-performance functional textiles.

[0018] The present invention has the following beneficial effects: 1. Achieving synergistic integration of cooling sensation and UV protection: Through the design of boron nitride / titanium dioxide composite filler, the excellent thermal conductivity of hexagonal boron nitride and the UV shielding function of anatase titanium dioxide are successfully combined, so that the fabric has both long-lasting cooling sensation and high-efficiency UV protection performance, with a UV protection factor UPF of not less than 40 and an instantaneous cooling sensation qmax of not less than 0.20W / cm².

[0019] 2. Significantly improves functional durability and stability: The composite filler prepared by in-situ heat treatment process has a stable interfacial bond. The surface modification of the β-hydroxy ether type ultraviolet absorbing silane coupling layer further enhances the bonding strength between the functional components and the matrix, ensuring that the UPF retention rate of the fabric is not less than 80% after 20 household washing cycles. The functional durability is significantly better than that of traditional finishing processes.

[0020] 3. Optimize filler dispersibility and compatibility: The surface organic treatment of β-hydroxy ether type ultraviolet absorbing silane coupling agent effectively improves the interfacial compatibility between the composite filler and the nylon 6 matrix, avoids filler agglomeration and phase separation, and ensures uniform dispersion and stable distribution of functional components in the fiber.

[0021] 4. Maintain excellent processing and mechanical properties: Precisely control the amount and proportion of composite fillers, and combine with optimized masterbatch preparation, melt spinning and finishing process parameters to ensure that the fabric maintains good spinning processing performance and mechanical strength while obtaining dual functions, without affecting the conventional textile processing flow.

[0022] 5. Complete process route suitable for industrialization: It provides a complete technical route from composite filler preparation, surface modification, masterbatch preparation to melt spinning and weaving. The process parameters are clear, the operation is simple, and it is easy to scale up production and promote industrial application.

[0023] 6. Significant cost-effectiveness: Using conventional chemical raw materials and mature textile processing equipment, production costs are controllable. At the same time, functional integration reduces finishing processes, improves production efficiency, and has good economic benefits and market competitiveness. Attached Figure Description

[0024] Figure 1 This is a morphological diagram of the composite filler prepared in Example 1 of the present invention.

[0025] Figure 2 The image shows the XRD phase analysis of the composite packing prepared in Example 1 of this invention.

[0026] Figure 3 The infrared Fourier spectrum of the β-hydroxy ether type ultraviolet-absorbing silane coupling agent prepared in Example 1 of this invention.

[0027] Figure 4 The effect of the amount of 3-glycidyl etheroxypropyltrimethoxysilane on the performance of the β-hydroxy ether type ultraviolet absorbing silane coupling agent synthesized in this invention is investigated.

[0028] Figure 5 The effect of reaction temperature on the performance of the β-hydroxy ether type ultraviolet absorbing silane coupling agent synthesized in this invention is investigated.

[0029] Figure 6 This invention relates to the effect of the amount of stock solution added during the surface modification of boron nitride / titanium dioxide composite filler on its performance.

[0030] Figure 7 The effect of heat treatment temperature on the performance of the composite filler synthesized in this invention is explained.

[0031] Figure 8 This is a comparison of UPF values ​​and UPF retention rates in the embodiments and comparative examples of the present invention.

[0032] Figure 9 This is a comparison of the thermal performance of the embodiments and comparative examples of the present invention.

[0033] Figure 10 This is a comparison of the fracture strength of the embodiments and comparative examples of the present invention.

[0034] Figure 11 This is a comparison of the elongation at break of the embodiments and comparative examples of the present invention.

[0035] Figure 12 This is a comparison of T5% and moisture permeability between the embodiments and comparative examples of the present invention.

[0036] Figure 13 This is a comparison chart of the contact cooling coefficient and T(UVA) transmittance for embodiments and comparative examples of the present invention. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0038] Example 1: A cooling and UV-resistant nylon fabric. The fabric of this example is woven from nylon 6 filaments and then finished. The nylon 6 filaments of this example contain a surface-modified boron nitride / titanium dioxide composite filler dispersed in their fiber matrix. The composite filler of this example includes anatase titanium dioxide nanoparticles and hexagonal boron nitride loaded on their surface. The surface of the composite filler of this example has a β-hydroxy ether type UV-absorbing silane coupling agent modified layer. The amount of the composite filler added to nylon 6 in this example is 1.8% by mass. The β-hydroxy ether type UV-absorbing silane coupling agent of this example contains the following raw materials in parts by weight: 1 part 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 1.2 parts 3-glycidyl etheroxypropyltrimethoxysilane, 0.075 parts tetrabutylammonium bromide, and 1.35 parts anhydrous potassium carbonate. In this embodiment, the anatase titanium dioxide nanoparticles have an average particle size of 80 nm. Hexagonal boron nitride is generated in situ by heat treatment of a precursor containing boric acid and urea under nitrogen protection and then loaded onto the surface of titanium dioxide. The molar ratio of boric acid to urea is 1:2.1. The composite filler is surface-modified with a β-hydroxy ether type ultraviolet-absorbing silane coupling agent. In this embodiment, the mass ratio of hexagonal boron nitride to anatase titanium dioxide in the composite filler is 1:4.5.

[0039] The preparation method of the cooling and UV-resistant nylon fabric in this embodiment includes the following steps: S1. Masterbatch preparation: Nylon 6 chips are vacuum dried at 90°C for 5 hours to reduce the moisture content to below 0.02%; according to the weight ratio, 11.5 parts of surface-modified boron nitride / titanium dioxide composite filler, 1.25 parts of antioxidant 1010, 0.65 parts of UV absorber UV-531 and 0.5 parts of calcium stearate are added to 100 parts of dried nylon 6 chips. The mixture is melt-blended and extruded in a twin-screw extruder at a screw temperature of 230°C and a screw speed of 100 rpm. After water cooling, the mixture is pelletized to obtain the functional masterbatch; S2. Spinning raw material preparation: 86 parts of nylon 6 chips are mixed with 14 parts of functional masterbatch. Vacuum drying reduces the moisture content to below 0.02%; S3. Melt spinning and drawing: The spinning raw material is melted and plasticized at a screw temperature of 240℃ and a metering pump temperature of 250℃. After precision filtration, it is extruded through a spinneret with 48 holes and a hole diameter of 0.27mm at a spinning temperature of 260℃, and cooled and solidified by side blowing; the initial drawing is performed at a winding speed of 900m / min and a winding tension of 0.20cN / dtex, with a drawing ratio of 4.1; then a second drawing is performed at 100℃ with a drawing ratio of 1.5; S4. Weaving and finishing: The obtained filaments are woven into fabric, and after pre-shrinking, scouring, setting, and softening finishing, the cool-feeling UV-resistant nylon fabric of this embodiment is obtained.

[0040] The preparation method of the surface-modified boron nitride / titanium dioxide composite filler in this embodiment includes the following steps: A1. Disperse 100 parts by weight of boron nitride / titanium dioxide composite filler in 400 parts by weight of anhydrous toluene and ultrasonically disperse for 15 min; A2. Prepare a stock solution of 25% by weight of β-hydroxy ether type ultraviolet absorbing silane coupling agent in toluene; A3. Under nitrogen protection, add 10 parts by weight of the stock solution in step A2 to the dispersion in step A1, control the reaction system temperature at 100℃ and react for 4 h; A4. After the reaction, filter and separate, wash twice with anhydrous ethanol and vacuum dry at 70℃ for 6 h to obtain the surface-modified boron nitride / titanium dioxide composite filler.

[0041] The preparation method of boron nitride / titanium dioxide composite filler in this embodiment includes the following steps: B1. Disperse 100 parts by weight of anatase titanium dioxide nanoparticles in 400 parts by weight of anhydrous ethanol and ultrasonically disperse for 30 min; B2. Add 20 parts by weight of boric acid and 50 parts by weight of urea to the dispersion in step B1 as precursors and mechanically stir until completely dissolved; B3. Remove the solvent at 70°C using a rotary evaporator to obtain a dry precursor mixture; B4. Place the mixture in step B3 in a tube furnace, heat it to 600°C at a heating rate of 5°C / min under nitrogen protection, and heat treat for 6 h to achieve in-situ generation of hexagonal boron nitride and loading it onto the surface of titanium dioxide; B5. Allow it to cool naturally to room temperature, grind it, and pass it through a 200-mesh sieve to obtain the boron nitride / titanium dioxide composite filler.

[0042] The preparation method of the β-hydroxy ether type ultraviolet absorbing silane coupling agent in this embodiment uses 1 part of 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 1.2 parts of 3-glycidyl etheroxypropyltrimethoxysilane, 0.075 parts of tetrabutylammonium bromide, and 1.35 parts of anhydrous potassium carbonate as raw materials. Under nitrogen protection, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, tetrabutylammonium bromide, and anhydrous potassium carbonate are sequentially added to a reaction flask containing 7.5 parts of anhydrous acetonitrile dried with molecular sieves. After stirring and dissolving, the mixture is heated to 72°C, and then... 3-Glycidyl etheroxypropyltrimethoxysilane was added dropwise to the reaction system in three batches, with each batch added over 12 minutes and an interval of 25 minutes between each batch. After the addition was complete, the reaction continued for 7 hours. After the reaction was complete, the mixture was cooled to room temperature, filtered to remove inorganic salts, and the filtrate was distilled under reduced pressure to remove the solvent, yielding a crude product. The crude product was purified by silica gel column chromatography using a gradient elution with a 4:1 (v / v) mixture of n-hexane and ethyl acetate as the eluent to obtain a β-hydroxy ether type UV-absorbing silane coupling agent. The HPLC purity of the obtained product was not less than 95%.

[0043] In step S4 of this embodiment: the warp density during weaving is 200 yarns / 10cm and the weft density is 180 yarns / 10cm; the pre-shrinking temperature is 97℃ and the time is 12min; the scouring temperature is 70℃ and the time is 17min, using a nonionic surfactant; the setting temperature is 170℃ and the machine speed is 20m / min; the softening finishing temperature is 50℃, using an amino silicone oil-based softener. The fabric of this embodiment has an UV protection factor (UPF) of not less than 40 and a UPF retention rate of not less than 80% after 20 household washing cycles; the instantaneous cooling sensation (qmax) of the fabric in this embodiment is not less than 0.20W / cm².

[0044] Features of Example 1: This example uses moderately high parameter configurations, with a composite filler addition of 1.8%, ensuring a good balance between UV resistance and cooling effect. The median mass ratio of hexagonal boron nitride to titanium dioxide is chosen at 1:4.5, providing stable thermal conductivity. The selected process parameters are moderate, exhibiting good industrial production stability and reproducibility. It is suitable for high-end outdoor sportswear, protective workwear, and other applications requiring high overall performance.

[0045] Example 2: A cooling and UV-resistant nylon fabric. The fabric in this example is woven from nylon 6 filaments and then finished. The nylon 6 filaments in this example contain a surface-modified boron nitride / titanium dioxide composite filler dispersed in their fiber matrix. The composite filler in this example includes anatase titanium dioxide nanoparticles and hexagonal boron nitride loaded on their surface. The surface of the composite filler in this example has a β-hydroxy ether type UV-absorbing silane coupling agent modified layer. The amount of the composite filler added to nylon 6 in this example is 2.6% by mass. The β-hydroxy ether type UV-absorbing silane coupling agent in this example contains the following raw materials in parts by weight: 1 part 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 1.3 parts 3-glycidyl etheroxypropyltrimethoxysilane, 0.1 parts tetrabutylammonium bromide, and 1.5 parts anhydrous potassium carbonate. In this embodiment, the anatase titanium dioxide nanoparticles have an average particle size of 60 nm. Hexagonal boron nitride is generated in situ by heat treatment of a precursor containing boric acid and urea under nitrogen protection and then loaded onto the surface of titanium dioxide. The molar ratio of boric acid to urea is 1:1.8. The composite filler is surface-modified with a β-hydroxy ether type ultraviolet-absorbing silane coupling agent. In this embodiment, the mass ratio of hexagonal boron nitride to anatase titanium dioxide in the composite filler is 1:3.

[0046] The preparation method of the cooling and UV-resistant nylon fabric in this embodiment includes the following steps: S1. Masterbatch preparation: Nylon 6 chips are vacuum dried at 100°C for 4 hours to reduce the moisture content to below 0.02%; according to the weight ratio, 15 parts of surface-modified boron nitride / titanium dioxide composite filler, 2 parts of antioxidant 1010, 1 part of UV absorber UV-531 and 0.8 parts of calcium stearate are added to 100 parts of dried nylon 6 chips, and the mixture is melt-blended and extruded in a twin-screw extruder at a screw temperature of 240°C and a screw speed of 120 rpm. After water cooling, the mixture is pelletized to obtain the functional masterbatch; S2. Spinning raw material preparation: 80 parts of nylon 6 chips are mixed with 20 parts of functional masterbatch, and vacuum-dried... Drying reduces the moisture content to below 0.02%; S3. Melt spinning and drawing: The spinning raw material is melted and plasticized at a screw temperature of 250°C and a metering pump temperature of 260°C. After precision filtration, it is extruded through a spinneret with 24 holes and a diameter of 0.35 mm at a spinning temperature of 270°C, and cooled and solidified by side blowing; the initial drawing is performed at a winding speed of 600 m / min and a winding tension of 0.25 cN / dtex, with a drawing ratio of 4.8; then a second drawing is performed at 120°C, with a drawing ratio of 1.8; S4. Weaving and finishing: The obtained filaments are woven into fabric, and after pre-shrinking, scouring, setting, and softening finishing, the cool-feeling UV-resistant nylon fabric of this embodiment is obtained.

[0047] The preparation method of the surface-modified boron nitride / titanium dioxide composite filler in this embodiment includes the following steps: A1. Disperse 100 parts by weight of boron nitride / titanium dioxide composite filler in 500 parts by weight of anhydrous xylene and ultrasonically disperse for 20 min; A2. Prepare a stock solution of 30% by weight of β-hydroxy ether type ultraviolet absorbing silane coupling agent in xylene; A3. Under nitrogen protection, add 15 parts by weight of the stock solution in step A2 to the dispersion in step A1, control the reaction system temperature at 120℃ and react for 6 h; A4. After the reaction, filter and separate, wash three times with anhydrous ethanol and vacuum dry at 80℃ for 8 h to obtain the surface-modified boron nitride / titanium dioxide composite filler.

[0048] The preparation method of boron nitride / titanium dioxide composite filler in this embodiment includes the following steps: B1. Disperse 100 parts by weight of anatase titanium dioxide nanoparticles in 500 parts by weight of anhydrous ethanol and ultrasonically disperse for 40 min; B2. Add 25 parts by weight of boric acid and 60 parts by weight of urea to the dispersion in step B1 as precursors and mechanically stir until completely dissolved; B3. Remove the solvent using a rotary evaporator at 80°C to obtain a dry precursor mixture; B4. Place the mixture from step B3 in a tube furnace, heat it to 650°C at a heating rate of 8°C / min under nitrogen protection, and heat treat for 8 h to achieve in-situ generation of hexagonal boron nitride and loading it onto the surface of titanium dioxide; B5. Allow it to cool naturally to room temperature, grind it, and pass it through a 250-mesh sieve to obtain the boron nitride / titanium dioxide composite filler.

[0049] The preparation method of the β-hydroxy ether type ultraviolet absorbing silane coupling agent in this embodiment uses 1 part of 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 1.3 parts of 3-glycidyl etheroxypropyltrimethoxysilane, 0.1 parts of tetrabutylammonium bromide, and 1.5 parts of anhydrous potassium carbonate as raw materials. Under nitrogen protection, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, tetrabutylammonium bromide, and anhydrous potassium carbonate are sequentially added to a reaction flask containing 10 parts of anhydrous acetonitrile dried with molecular sieves. After stirring and dissolving, the mixture is heated to 80°C, and then 3- Glycidyl etheroxypropyltrimethoxysilane was added dropwise to the reaction system in four batches, with each batch added over 15 minutes and the interval between each batch being 30 minutes. After the addition was complete, the reaction continued for 8 hours. After the reaction was complete, the mixture was cooled to room temperature, filtered to remove inorganic salts, and the filtrate was subjected to vacuum distillation to remove the solvent, yielding a crude product. The crude product was purified by silica gel column chromatography using a gradient elution with a 5:1 (v / v) mixture of n-hexane and ethyl acetate as the eluent to obtain a β-hydroxy ether type UV-absorbing silane coupling agent. The HPLC purity of the obtained product was not less than 95%.

[0050] In step S4 of this embodiment: the warp density during weaving is 220 yarns / 10cm and the weft density is 200 yarns / 10cm; the pre-shrinking temperature is 100℃ and the time is 15min; the scouring temperature is 80℃ and the time is 20min, using a nonionic surfactant; the setting temperature is 180℃ and the machine speed is 25m / min; the softening finishing temperature is 60℃, using an amino silicone oil softener. The fabric of this embodiment has an ultraviolet protection factor (UPF) of not less than 40 and a UPF retention rate of not less than 80% after 20 household washing cycles; the instantaneous cooling sensation (qmax) of the fabric of this embodiment is not less than 0.20W / cm².

[0051] Example 2 Features: This example uses a high filler content of 2.6% to significantly enhance UV protection. The selection of smaller titanium dioxide particle size (60nm) and a higher hexagonal boron nitride ratio (1:3) significantly improves UV protection. Higher spinning temperature and draw ratio ensure fiber forming quality despite the high filler content. Suitable for professional protective clothing in strong UV environments, such as desert workwear and high-altitude outdoor gear, where extreme UV protection is required.

[0052] Example 3: A cooling and UV-resistant nylon fabric. The fabric in this example is woven from nylon 6 filaments and then finished. The nylon 6 filaments in this example contain a surface-modified boron nitride / titanium dioxide composite filler dispersed in their fiber matrix. The composite filler in this example includes anatase titanium dioxide nanoparticles and hexagonal boron nitride loaded on their surface. The surface of the composite filler in this example has a β-hydroxy ether type UV-absorbing silane coupling agent modified layer. The amount of the composite filler added to nylon 6 in this example is 1.2% by mass. The β-hydroxy ether type UV-absorbing silane coupling agent in this example contains the following raw materials in parts by weight: 1 part 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 1.1 parts 3-glycidyl etheroxypropyltrimethoxysilane, 0.05 parts tetrabutylammonium bromide, and 1.2 parts anhydrous potassium carbonate. In this embodiment, the anatase titanium dioxide nanoparticles have an average particle size of 100 nm. Hexagonal boron nitride is generated in situ by heat treatment of a precursor containing boric acid and urea under nitrogen protection and then loaded onto the surface of titanium dioxide. The molar ratio of boric acid to urea is 1:2.5. The composite filler is surface-modified with a β-hydroxy ether type ultraviolet-absorbing silane coupling agent. In this embodiment, the mass ratio of hexagonal boron nitride to anatase titanium dioxide in the composite filler is 1:6.

[0053] The preparation method of the cooling and UV-resistant nylon fabric in this embodiment includes the following steps: S1. Masterbatch preparation: Nylon 6 chips are vacuum dried at 80°C for 6 hours to reduce the moisture content to below 0.02%; according to the weight ratio, 8 parts of surface-modified boron nitride / titanium dioxide composite filler, 0.5 parts of antioxidant 1010, 0.3 parts of UV absorber UV-531 and 0.2 parts of calcium stearate are added to 100 parts of dried nylon 6 chips, and the mixture is melt-blended and extruded in a twin-screw extruder at a screw temperature of 220°C and a screw speed of 80 rpm. After water cooling, the mixture is pelletized to obtain the functional masterbatch; S2. Spinning raw material preparation: 92 parts of nylon 6 chips are mixed with 8 parts of functional masterbatch, and vacuum-dried... Drying reduces the moisture content to below 0.02%; S3. Melt spinning and drawing: The spinning raw material is melted and plasticized at a screw temperature of 230°C and a metering pump temperature of 240°C. After precision filtration, it is extruded through a spinneret with 72 holes and a hole diameter of 0.20 mm at a spinning temperature of 250°C, and cooled and solidified by side blowing; the initial drawing is performed at a winding speed of 1200 m / min and a winding tension of 0.15 cN / dtex, with a drawing ratio of 3.5; then a second drawing is performed at 80°C with a drawing ratio of 1.3; S4. Weaving and finishing: The obtained filaments are woven into fabric, and after pre-shrinking, scouring, setting, and softening finishing, the cool-feeling UV-resistant nylon fabric of this embodiment is obtained.

[0054] The preparation method of the surface-modified boron nitride / titanium dioxide composite filler in this embodiment includes the following steps: A1. Disperse 100 parts by weight of boron nitride / titanium dioxide composite filler in 300 parts by weight of anhydrous toluene and ultrasonically disperse for 10 min; A2. Prepare a stock solution of 20% by weight of β-hydroxy ether type ultraviolet absorbing silane coupling agent in toluene; A3. Under nitrogen protection, add 5 parts by weight of the stock solution from step A2 to the dispersion from step A1, control the reaction system temperature at 80℃ and react for 2 h; A4. After the reaction, filter and separate, wash twice with anhydrous ethanol and vacuum dry at 60℃ for 4 h to obtain the surface-modified boron nitride / titanium dioxide composite filler.

[0055] The preparation method of boron nitride / titanium dioxide composite filler in this embodiment includes the following steps: B1. Disperse 100 parts by weight of anatase titanium dioxide nanoparticles in 300 parts by weight of anhydrous ethanol and ultrasonically disperse for 20 min; B2. Add 15 parts by weight of boric acid and 40 parts by weight of urea to the dispersion in step B1 as precursors and mechanically stir until completely dissolved; B3. Remove the solvent using a rotary evaporator at 60°C to obtain a dry precursor mixture; B4. Place the mixture from step B3 in a tube furnace, heat it to 550°C at a heating rate of 3°C / min under nitrogen protection, and heat treat it for 4 h to achieve in-situ generation of hexagonal boron nitride and loading it onto the surface of titanium dioxide; B5. Allow it to cool naturally to room temperature, grind it, and pass it through an 180-mesh sieve to obtain the boron nitride / titanium dioxide composite filler.

[0056] The preparation method of the β-hydroxy ether type ultraviolet absorbing silane coupling agent in this embodiment uses 1 part of 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 1.1 parts of 3-glycidyl etheroxypropyltrimethoxysilane, 0.05 parts of tetrabutylammonium bromide, and 1.2 parts of anhydrous potassium carbonate as raw materials. Under nitrogen protection, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, tetrabutylammonium bromide, and anhydrous potassium carbonate are sequentially added to a reaction flask containing 5 parts of anhydrous acetonitrile dried with molecular sieves. After stirring and dissolving, the mixture is heated to 65°C, and then 3- Glycidyl etheroxypropyltrimethoxysilane was added dropwise to the reaction system in three batches, with each batch added over 10 minutes and the interval between each batch being 20 minutes. After the addition was complete, the reaction continued for 6 hours. After the reaction was complete, the mixture was cooled to room temperature, filtered to remove inorganic salts, and the filtrate was subjected to vacuum distillation to remove the solvent, yielding a crude product. The crude product was purified by silica gel column chromatography using a gradient elution with a 3:1 (v / v) mixture of n-hexane and ethyl acetate as the eluent to obtain a β-hydroxy ether type UV-absorbing silane coupling agent. The HPLC purity of the obtained product was not less than 95%.

[0057] In step S4 of this embodiment: the warp density during weaving is 180 yarns / 10cm and the weft density is 160 yarns / 10cm; the pre-shrinking temperature is 95℃ and the time is 10min; the scouring temperature is 60℃ and the time is 15min, using a nonionic surfactant; the setting temperature is 160℃ and the machine speed is 15m / min; the softening finishing temperature is 40℃, using an amino silicone oil-based softener. The fabric of this embodiment has an UV protection factor (UPF) of not less than 40 and a UPF retention rate of not less than 80% after 20 household washing cycles; the instantaneous cooling sensation (qmax) of the fabric in this embodiment is not less than 0.20W / cm².

[0058] Example 3 Features: This example prioritizes enhancing cooling performance by employing a relatively low filler content of 0.8% and the highest hexagonal boron nitride to titanium dioxide mass ratio of 1:6 to maximize the thermal conductivity of boron nitride. The selection of a relatively large titanium dioxide particle size of 100nm and a high winding speed of 1200m / min contributes to improved fiber softness and breathability. It is suitable for applications requiring high cooling comfort, such as summer sportswear, underwear, and yoga wear.

[0059] Example 4: A cooling and UV-resistant nylon fabric. The fabric in this example is woven from nylon 6 filaments and then finished. The nylon 6 filaments in this example contain a surface-modified boron nitride / titanium dioxide composite filler dispersed in their fiber matrix. The composite filler in this example includes anatase titanium dioxide nanoparticles and hexagonal boron nitride loaded on their surface. The surface of the composite filler in this example has a β-hydroxy ether type UV-absorbing silane coupling agent modified layer. The amount of the composite filler added to nylon 6 in this example is 3.0% by mass fraction. The β-hydroxy ether type UV-absorbing silane coupling agent in this example contains the following raw materials in parts by weight: 1 part 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 1.25 parts 3-glycidyl etheroxypropyltrimethoxysilane, 0.08 parts tetrabutylammonium bromide, and 1.4 parts anhydrous potassium carbonate. In this embodiment, the anatase titanium dioxide nanoparticles have an average particle size of 75 nm. Hexagonal boron nitride is generated in situ by heat treatment of a precursor containing boric acid and urea under nitrogen protection and then loaded onto the surface of titanium dioxide. The molar ratio of boric acid to urea is 1:2.2. The composite filler is surface-modified with a β-hydroxy ether type ultraviolet-absorbing silane coupling agent. In this embodiment, the mass ratio of hexagonal boron nitride to anatase titanium dioxide in the composite filler is 1:3.8.

[0060] The preparation method of the cooling and UV-resistant nylon fabric in this embodiment includes the following steps: S1. Masterbatch preparation: Nylon 6 chips are vacuum dried at 95°C for 4.5 hours to reduce the moisture content to below 0.02%; according to the weight ratio, 12 parts of surface-modified boron nitride / titanium dioxide composite filler, 1.5 parts of antioxidant 1010, 0.8 parts of UV absorber UV-531 and 0.6 parts of calcium stearate are added to 100 parts of dried nylon 6 chips. The mixture is melt-blended and extruded in a twin-screw extruder at a screw temperature of 235°C and a screw speed of 110 rpm. After water cooling, the mixture is pelletized to obtain the functional masterbatch; S2. Spinning raw material preparation: 75 parts of nylon 6 chips are mixed with 25 parts of functional masterbatch. Vacuum drying reduces the moisture content to below 0.02%; S3. Melt spinning and drawing: The spinning raw material is melted and plasticized at a screw temperature of 245°C and a metering pump temperature of 255°C. After precision filtration, it is extruded through a spinneret with 36 holes and a diameter of 0.30 mm at a spinning temperature of 265°C, and cooled and solidified by side blowing; the initial drawing is performed at a winding speed of 800 m / min and a winding tension of 0.22 cN / dtex, with a drawing ratio of 4.2; then a second drawing is performed at 105°C, with a drawing ratio of 1.6; S4. Weaving and finishing: The obtained filaments are woven into fabric, and after pre-shrinking, scouring, setting, and softening finishing, the cool-feeling UV-resistant nylon fabric of this embodiment is obtained.

[0061] The preparation method of the surface-modified boron nitride / titanium dioxide composite filler in this embodiment includes the following steps: A1. Disperse 100 parts by weight of boron nitride / titanium dioxide composite filler in 450 parts by weight of anhydrous xylene and ultrasonically disperse for 18 min; A2. Prepare a stock solution of 28% by weight of β-hydroxy ether type ultraviolet absorbing silane coupling agent in xylene; A3. Under nitrogen protection, add 12 parts by weight of the stock solution from step A2 to the dispersion from step A1, control the reaction system temperature at 110℃ and react for 5 h; A4. After the reaction, filter and separate, wash three times with anhydrous ethanol and vacuum dry at 75℃ for 7 h to obtain the surface-modified boron nitride / titanium dioxide composite filler.

[0062] The preparation method of boron nitride / titanium dioxide composite filler in this embodiment includes the following steps: B1. Disperse 100 parts by weight of anatase titanium dioxide nanoparticles in 450 parts by weight of anhydrous ethanol and ultrasonically disperse for 35 min; B2. Add 22 parts by weight of boric acid and 55 parts by weight of urea to the dispersion in step B1 as precursors and mechanically stir until completely dissolved; B3. Remove the solvent using a rotary evaporator at 75°C to obtain a dry precursor mixture; B4. Place the mixture from step B3 in a tube furnace, heat it to 620°C at a heating rate of 6°C / min under nitrogen protection, and heat treat it for 7 h to achieve in-situ generation of hexagonal boron nitride and loading it onto the surface of titanium dioxide; B5. Allow it to cool naturally to room temperature, grind it, and pass it through a 220-mesh sieve to obtain the boron nitride / titanium dioxide composite filler.

[0063] The preparation method of the β-hydroxy ether type ultraviolet absorbing silane coupling agent in this embodiment uses 1 part of 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 1.25 parts of 3-glycidyl etheroxypropyltrimethoxysilane, 0.08 parts of tetrabutylammonium bromide, and 1.4 parts of anhydrous potassium carbonate as raw materials. Under nitrogen protection, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, tetrabutylammonium bromide, and anhydrous potassium carbonate are sequentially added to a reaction flask containing 8 parts of anhydrous acetonitrile dried with molecular sieves. After stirring and dissolving, the temperature is raised to 75°C, and then 3-glycidyl etheroxypropyltrimethoxysilane is added. Glyceryl etheroxypropyltrimethoxysilane was added dropwise to the reaction system in four batches, with each batch added over 13 minutes and an interval of 28 minutes between each batch. After the addition was complete, the reaction continued for 7.5 hours. After the reaction was complete, the mixture was cooled to room temperature, filtered to remove inorganic salts, and the filtrate was subjected to vacuum distillation to remove the solvent, yielding a crude product. The crude product was purified by silica gel column chromatography using a gradient elution with a mixture of n-hexane and ethyl acetate in a volume ratio of 4.5:1, to obtain a β-hydroxy ether type UV-absorbing silane coupling agent. The HPLC purity of the obtained product was not less than 95%.

[0064] In step S4 of this embodiment: the warp density during weaving is 210 yarns / 10cm and the weft density is 190 yarns / 10cm; the pre-shrinking temperature is 98℃ and the time is 13min; the scouring temperature is 75℃ and the time is 18min, using a nonionic surfactant; the setting temperature is 175℃ and the machine speed is 22m / min; the softening finishing temperature is 55℃, using an amino silicone oil-based softener. The fabric of this embodiment has an UV protection factor (UPF) of not less than 40 and a UPF retention rate of not less than 80% after 20 household washing cycles; the instantaneous cooling sensation (qmax) of the fabric in this embodiment is not less than 0.20W / cm².

[0065] Example 4 Features: This example employs an extreme configuration with a maximum filler content of 3.0%, aiming to maximize both UV resistance and cooling properties. A medium particle size of 75nm and a 1:3.8 hexagonal boron nitride to titanium dioxide mass ratio are selected to ensure functionality while also considering fiber processing performance. Relatively mild spinning parameters are used to address the processing challenges posed by the high filler content. It is suitable for specialized protective equipment in extreme environments, such as polar research suits and high-radiation area workwear, and other special applications requiring extreme performance.

[0066] Comparative Example 1: It is basically the same as Example 1, except that the amount of composite filler added to nylon 6 in step S1 is 0.5% by mass fraction instead of 1.8%.

[0067] Comparative Example 2: It is basically the same as Example 1, except that the heat treatment temperature in step B4 is 450°C instead of 600°C, while other heat treatment conditions remain unchanged.

[0068] Comparative Example 3: It is basically the same as Example 1, except that the mass ratio of hexagonal boron nitride to anatase titanium dioxide in the composite filler is 1:8 instead of 1:4.5.

[0069] Comparative Example 4: It is basically the same as Example 1, except that the average particle size of the anatase titanium dioxide nanoparticles is 150 nm instead of 80 nm. The titanium dioxide nanoparticles are prepared by the sol-gel method and calcined at 500 °C for 4 hours.

[0070] Comparative Example 5: It is basically the same as Example 1, except that the molar ratio of boric acid to urea in step B2 is 1:1.2 instead of 1:2.1.

[0071] Comparative Example 6: It is basically the same as Example 1, except that the spinning temperature in step S3 is 220°C instead of 260°C.

[0072] Comparative Example 7: It is basically the same as Example 1, except that the reaction system temperature in step A3 is 50°C instead of 100°C, and the reaction time is extended to 8 hours.

[0073] Comparative Example 8: It is basically the same as Example 1, except that the amount of 3-glycidoxypropyltrimethoxysilane in the β-hydroxy ether type UV-absorbing silane coupling agent is 0.8 parts instead of 1.2 parts.

[0074] Comparative Example 9: Basically the same as Example 1, except that the draw ratio in step S3 is 2.8 instead of 4.1.

[0075] Comparative Example 10: It is basically the same as Example 1, except that the heat treatment time in step B4 is 2 hours instead of 6 hours, and the heat treatment temperature is kept constant at 600°C.

[0076] Comparative Example 11: It is basically the same as Example 1, except that ultrasonic dispersion was not performed in step A1, and mechanical stirring was used directly for dispersion for 30 minutes.

[0077] Comparative Example 12: It is basically the same as Example 1, except that the secondary stretching temperature in step S3 is 60°C instead of 100°C.

[0078] Comparative Example 13: Basically the same as Example 1, except that the surface of the composite filler is not modified with β-hydroxy ether type ultraviolet absorbing silane coupling agent, and the unmodified boron nitride / titanium dioxide composite filler is used directly.

[0079] Comparative Example 14: Basically the same as Example 1, except that the winding speed in step S3 is 400m / min instead of 900m / min.

[0080] Comparative Example 15: It is basically the same as Example 1, except that hexagonal boron nitride is prepared by mixing commercial hexagonal boron nitride powder with anatase titanium dioxide nanoparticles by ball milling for 6 hours to prepare a composite filler, instead of preparing it by in-situ generation through heat treatment of boric acid and urea precursor.

[0081] Performance testing: UV Protection Performance Test: The test subject is a finished product of a cool-feeling, UV-resistant nylon fabric. Test Objective: To evaluate the fabric's ability to protect against ultraviolet (UV) radiation and its UV Protection Factor (UPF) value. Test Principle: Based on UV transmittance measurement, the UPF value is calculated by measuring the fabric's blocking effect on UVA (315-400nm) and UVB (280-315nm) wavelengths. Experimental Method: Using a UV spectrophotometer, the fabric sample is placed inside an integrating sphere. Transmittance is measured at 5nm intervals within the 280-400nm wavelength range. The sample must be rotated in multiple directions for testing at least 5 points, including both warp and weft directions. The average UVA transmittance, average UVB transmittance, and UPF value are calculated. Standard Basis: GB / T 18830-2009 "Evaluation of Ultraviolet Protection Performance of Textiles," with calculations and ratings based on their respective standards. Key parameters: Standard atmospheric conditions: temperature 20±2℃, relative humidity 65±4%, conditioning for ≥24h, sample size not less than 10cm×10cm, and at least 5 test points including latitude and longitude directions. Data processing: Calculate UPF values ​​according to GB / T 18830-2024 and AS / NZS4399:2017 respectively, record UVA transmittance and UPF confidence limit, and report UPF retention rate before and after washing. UPF ≥ 40 and UVA transmittance < 5% are required.

[0082] Instantaneous Cooling Performance Test: The test subject is a finished product of a cooling and UV-resistant nylon fabric. Test Objective: To evaluate the intensity of the cooling sensation upon contact between the fabric and human skin. Test Principle: The instantaneous cooling effect is quantitatively evaluated by measuring the peak value of the maximum heat flux (qmax) at the instant the fabric contacts a standard hot plate. Experimental Method: Using a cooling tester, the fabric sample is laid flat on the test platform. A standard hot plate (simulating human skin temperature 35℃) is lowered to contact the fabric surface at a contact pressure of 0.1N±10% as specified in GB / T 35263. The heat flux change curve at the instant of contact is recorded, and the peak value of the maximum heat flux is extracted. Each sample is tested at least 5 times. Standard Basis: GB / T 35263-2017 "Test and Evaluation of Instantaneous Cooling Performance of Textiles". Key Parameters: Standard atmospheric conditions: temperature 20±2℃, relative humidity 65±4%, conditioning ≥24h, hot plate temperature 35±0.1℃, contact pressure 0.1N±10%, data acquisition frequency 100Hz, test duration 10s. Data processing: Extract the peak heat flow qmax within 5 seconds after contact, in W / cm², and report the mean ± standard deviation. Simultaneously compare with the ordinary nylon reference fabric to calculate the difference Δqmax. A qmax ≥ 0.20 W / cm² is required to have a cooling effect.

[0083] Tensile Strength and Elongation Test: The test object is a finished cool-feeling UV-resistant nylon fabric. Test Objective: To evaluate the mechanical strength and extensibility of the fabric. Test Principle: Under standard conditions, a tensile load is applied to the fabric until it breaks, and the breaking strength and elongation at break are measured. Experimental Method: The fabric sample is prepared into standard specimens (50mm width, 100mm gauge length). Five specimens are prepared in both the warp and weft directions. The test is conducted using a universal testing machine strictly according to the pretension and tensile rate specified in GB / T 3923.1. The force-displacement curve is recorded, and the breaking strength and elongation at break are extracted. Standard Basis: GB / T 3923.1-2013 "Textiles - Tensile Properties of Fabrics - Part 1: Determination of Breaking Strength and Elongation at Break (Strip Method)". Key Parameters: Standard atmospheric conditions: temperature 20±2℃, relative humidity 65±4%, conditioning ≥24h, clamping distance 100mm, tensile speed 100±10mm / min, pretension set according to standard. Data processing: Calculate the breaking strength (N), elongation at break (%), and coefficient of variation of strength in the latitude and longitude directions. Report the strength / unit area or specific strength. Report the mean ± standard deviation for the latitude and longitude directions respectively.

[0084] Colorfastness to Wash and UPF Retention Test: The test subject is a finished cool-feeling UV-resistant nylon fabric. Test Objective: To evaluate the color stability and UV protection retention rate of the fabric after household washing. Test Principle: Multiple washing cycles are performed under simulated household washing conditions, and the degree of color change and UPF value change of the fabric before and after washing are measured. Experimental Method: 0, 5, 10, and 20 washing cycles are performed according to the ISO 6330 household washing procedure combined with the ISO 105-C06 standard. The color change and UPF value of the fabric are measured at each stage. The specified drying procedure (line-dry or flat-dry) is used, and the colorfastness grade and UPF retention rate are calculated. Standard Basis: ISO 6330:2012 "Textiles - Domestic washing and drying procedures for textile testing", key parameters: washing temperature 40±2℃, appropriate washing procedure selected according to ISO 6330, standard detergent, and specified drying procedure. Data processing: The gray scale is used to assess the color change level (levels 1-5). The UPF retention rate is calculated as (UPF after washing / initial UPF) × 100%. The quality loss and changes in feel are recorded. The color change level is required to be ≥ 4 and the UPF retention rate is required to be ≥ 80%.

[0085] Thermal stability and thermal decomposition temperature test: The test object is nylon 6 fiber samples containing composite fillers. Test objective: To evaluate the influence of composite fillers on the thermal stability of the nylon 6 matrix and the material's operating temperature range. Test principle: Under programmed temperature control, the change in sample mass with temperature is measured to analyze the thermal decomposition process and characteristic temperature. Experimental method: 5-10 mg of fiber sample is taken and heated from room temperature to 600 °C under nitrogen and air atmospheres at heating rates of 10 °C / min and 5 °C / min, respectively. Thermogravimetric curves and differential thermogravimetric curves are recorded. The initial decomposition temperature, maximum decomposition rate temperature, and char residue are extracted, and the differences in oxidative stability are compared and analyzed. Standard basis: GB / T 6425-2008 "Thermogravimetric Analysis of Thermoplastic Plastics - Determination of Thermal Stability of Polymers". Key parameters: Sample mass 5-10 mg, heating rate 10 °C / min and 5 °C / min, nitrogen and air flow rate 50 mL / min, temperature range 30-600 °C, balance accuracy ±0.1 μg. Data processing: Determine the 5% mass loss temperature T5%, the maximum decomposition rate temperature Tmax, and the char rate at 600℃; analyze the decomposition stage of the DTG peak; and report the impact of packing residue on the char rate.

[0086] Thermal Conductivity Performance Test: The test subject is a finished product of a cooling and UV-resistant nylon fabric. Test Objective: To determine the thermal resistance and thermal conductivity characteristics of the fabric and evaluate the contribution of its thermal conductivity to the cooling effect. Test Principle: The thermal resistance of the fabric is measured using the steady-state heat flow method, or the thermal diffusivity is measured using the laser flash method to calculate the thermal conductivity. Experimental Method: The thermal resistance Rct and moisture permeability Ret of the fabric are measured using ISO 11092 standard, or the thermal diffusivity α of the sheet is measured using the laser flash method (ASTM E1461). The thermal conductivity k = αρCp is calculated by combining the density ρ and specific heat Cp, and compared with ordinary nylon fabric. Key Parameters: The test environment temperature is 35±1℃ (simulating the human body), the relative humidity is 40±3%, the wind speed is 1±0.05m / s, and the sample area is at least 0.025m². Data Processing: Calculate the thermal resistance Rct (m²·K / W) or the thermal conductivity k (W / m·K), calculate the relative improvement percentage compared with ordinary nylon, explain the limitations of the method, and report the difference with ordinary nylon.

[0087] Moisture permeability test: The test subject is a finished product of a cool-feeling, UV-resistant nylon fabric. Test objective: To evaluate the water vapor permeability of the fabric and ensure wearing comfort. Test principle: The amount of water vapor permeating a unit area of ​​fabric per unit time is measured under standard temperature and humidity gradient conditions. Experimental method: Using ASTM E96 / E96M Procedure BW, the fabric sample is sealed in a moisture permeability cup with a desiccant inside. It is placed in a constant temperature and humidity environment of 23℃ / 50%RH, and the water vapor permeability is measured at regular intervals under specified wind speed conditions. The moisture permeability rate is calculated. Key parameters: Test temperature 23±1℃, relative humidity 50±2%, conditioning ≥24h, test area 50cm², weighing interval as specified in the standard, wind speed as set in the standard. Data processing: The moisture permeability rate WVT is calculated as WVT = Δm / (A×t), in g / (m²·24h). The mean ± standard deviation is reported. Air permeability (GB / T 5453) is also measured as a supplement to comfort assessment.

[0088] The systematic analysis of the effects of various process parameters during composite filler preparation and fiber forming on the final UV protection and cooling properties, as shown in Tables 1 and 2, indicates that the filler addition amount is the primary factor determining the functional effect. When the addition amount increases from 0.5% in Comparative Example 1 to 1.2-3.0% in the Example series, the effective concentration of functional filler in the composite fiber gradually increases, the UV scattering and absorption capacity is significantly enhanced, the heat conduction path density increases, and the UPF value and cooling effect show a clear concentration-dependent increasing trend. However, excessively high addition amounts may also lead to a decrease in the stability of the spinning process and fiber properties. A moderate sacrifice in mechanical properties; during the process of increasing the heat treatment temperature from 450℃ in Comparative Example 2 to 550-650℃ in the Example Standard, the in-situ crystallization degree of hexagonal boron nitride was significantly improved. Under low temperature conditions, the insufficient reaction of boric acid and urea precursors led to an excessively high proportion of amorphous structure, while the appropriate high temperature promoted the complete formation and highly ordered arrangement of the h-BN layered lattice, directly improving the thermal conductivity and UV shielding efficiency of the composite filler; when the BN / TiO2 mass ratio was optimized from 1:8 in Comparative Example 3 to 1:6-1:4 in the Example Series, the thermally conductive phase and the UV-protective phase... The synergistic balance was improved. An excessively low BN ratio limited the construction of the heat conduction network and affected the cooling performance, while a reasonable ratio achieved the best match between UV protection and thermal conductivity. The TiO2 particle size was reduced from 150 nm in Comparative Example 4 to the 60-100 nm range in the Example series. This increased the specific surface area of ​​the nanoparticles and improved light scattering efficiency. Smaller particle sizes exhibited stronger Mie scattering effects in the UV band, but excessively small particle sizes may also bring the risk of agglomeration and challenges to dispersion stability. The boric acid / urea precursor molar ratio was adjusted from 1:1.2 in Comparative Example 5 to the Example series. When the standard ratio is 1:2.5, the optimization of the stoichiometric relationship ensures the completeness of the hexagonal boron nitride formation reaction, avoiding the negative impact of unreacted precursor residues and byproduct formation on the final performance. Each deviation from the optimal range in processing parameters such as spinning temperature, surface modification temperature, draw ratio, heat treatment time, ultrasonic dispersion, secondary stretching temperature, and winding speed will affect the microstructural characteristics of the composite filler in the polymer matrix, including dispersion uniformity, interfacial bonding strength, fiber molecular chain orientation, and crystalline structure integrity, leading to a systematic decline in macroscopic functional properties. When all key parameters are synergistically optimized, such as the 3.0% maximum addition amount in Example 4 combined with a medium particle size of 75 nm and complete surface modification treatment, the composite fiber achieves an ultimate UV protection effect of UPF 50+ and excellent instant cooling performance. However, significant deviations from any single parameter, such as the lack of surface modification treatment in Comparative Example 13, lead to a sharp deterioration in interfacial compatibility and a severe deficiency in wash fastness, fully verifying the crucial importance of multi-parameter synergistic optimization strategies for achieving high-performance functional textile materials.

[0089] Table 1 Core Function Performance Data Table

[0090] Table 2 Mechanical Performance and Wearability Data

[0091] Combination Figure 1 morphological observation Figure 2 XRD phase analysis and Figure 3 The FTIR infrared characterization fully demonstrates the rationality, reliability, and effectiveness of this scheme: First, Figure 1 The composite filler particles are uniformly dispersed, with dense interfacial bonding, regular morphology, and no obvious agglomeration. This indicates that the selected solvent system, stirring, and dropping rhythm can stably control the particle size and surface structure, ensuring the reproducible preparation of the composite filler at the microscopic level. Secondly, Figure 2 Each characteristic diffraction peak corresponds one-to-one with the standard card of the target crystal phase. The peak positions are matched and the full width at half maximum (FWHM) is moderate. No impurity phases were observed or only negligible weak impurity peaks were observed, indicating that no destructive side reactions were introduced during the reaction process. The material has complete crystallization and high phase purity, providing a structural basis for subsequent performance stability. Finally, Figure 3 In the FTIR spectrum, the characteristic peak of epoxy (approximately 912 cm⁻¹) was significantly weakened or even disappeared, while the stretching vibration of Si–O–C bonds (approximately 1055–1065 cm⁻¹) was significantly enhanced. Simultaneously, the broad O–H peak appearing and strengthening at 3200–3500 cm⁻¹ and the aromatic ring skeleton peaks (approximately 1600 and 1500 cm⁻¹) remained stable, collectively indicating that the β-hydroxy ether bond had been successfully formed and the benzotriazole UV absorption unit was fully preserved. Furthermore, the Si–O–Si region (approximately 1115–1130 cm⁻¹)... The silane coupling agent (cm⁻¹) exhibited only weak shoulders or controlled enhancement, without significant condensation side reactions or decomposition characteristics. This comprehensively demonstrates that the batch-drop addition, temperature control, and alkali-promoted reaction pathway accurately achieved the directional transformation from raw materials to the target silane coupling agent. Thus, the uniformity and density at the morphological level, the single phase at the crystallographic level, and the confirmation of characteristic bonds at the molecular structure level corroborate each other, proving that the preparation scheme of this invention has clear operability and process controllability within the process window. The structure of the obtained product is verifiable, the purity meets the requirements, and it satisfies the stability and reliability of repeated processing required for application.

[0092] Figures 4 to 7The comprehensive experimental results fully demonstrate the scientific nature of the key process parameters of the present invention and the necessity of synergistic optimization. The optimization experiment of 3-glycidyl etheroxypropyltrimethoxysilane dosage shows that, under fixed conditions, as the silane dosage increases from 0.9 parts to 1.4 parts, the UPF and qmax exhibit a typical parabolic trend of first increasing and then decreasing. When the dosage is insufficient, the reactant molar ratio imbalance leads to incomplete coupling reaction, resulting in a UPF of only 31.2-45.2 and a qmax of only 0.158-0.208 W / cm². Conversely, when the dosage is excessive, the excess silane triggers side reactions and a decrease in product purity, leading to performance degradation to a UPF of 42.1-46.3 and a qmax of 0.201-0.218 W / cm². The key... The optimal point was found to be 1.2 parts silane, where the UPF peaked at 52.1 and the qmax peaked at 0.238 W / cm². Optimization experiments with reaction temperature revealed the decisive influence of temperature on the coupling reaction efficiency. Under the condition of 1.2 parts silane and other fixed process parameters, a clear temperature-dependent performance change pattern was observed as the temperature increased from 60℃ to 85℃. When the temperature was too low, insufficient activation energy led to incomplete coupling, resulting in a UPF of only 35.8-47.3 and a qmax of only 0.192-0.228 W / cm². When the temperature was too high, the high temperature promoted irreversible side reactions and product decomposition, causing a rapid decline in performance to a UPF of 43.5-46.8 and a qmax of only 0.203-0.216 W / cm². The optimal reaction temperature for qmax was 72℃, at which UPF and qmax reached peak values ​​of 52.1 and 0.238 W / cm², respectively. A systematic study of the stock solution addition amount confirmed the quantitative relationship between the degree of surface modification and performance. Under optimized conditions, increasing the stock solution amount from 3 parts to 18 parts resulted in a typical saturation curve. Insufficient addition led to an inefficient range of 28.9-43.1 W / cm² and 0.148-0.195 W / cm² due to the low density of the coupling agent, while excessive addition resulted in an overly thick coating layer that hindered the function of the composite filler, causing performance degradation to UPF of 42.3-45.7 and qmax of 0.194-0.209 W / cm². The key breakthrough occurred at the 10-part mark, where both UPF and qmax reached their highest values ​​of 52.1 and 0.238 W / cm², respectively. Heat treatment temperature experiments clarified the optimal conditions for in-situ formation of h-BN from a materials crystallography perspective. Under standardized process conditions, increasing the heat treatment temperature from 500℃ to 700℃ demonstrated the complete crystallization process of hexagonal boron nitride. Insufficient temperature resulted in insufficient reaction driving force, leading to incomplete h-BN crystallization and an excessively high proportion of amorphous structures, resulting in UPF and qmax reaching only 32.4-45.8 and 0.162-0.209 W / cm², respectively. Excessive temperature caused lattice defects and structural damage, causing a rapid decline in performance to a UPF of 42.8-46.2 and a qmax of 0.198-0.238 W / cm².The optimal heat treatment temperature was precisely determined to be 600℃, with a qmax of 213 W / cm². The peak UPF and qmax reached 52.1 W / cm² and 0.238 W / cm², respectively, which precisely corresponds to the optimal crystallization temperature of hexagonal boron nitride. All four key process parameters found their true performance optimum, consistently achieving peak performance of 52.1 W / cm² UPF and 0.238 W / cm² under optimal conditions. This fully verifies the scientific rationality of the parameter settings and the technological advancement of the multi-parameter synergistic optimization strategy.

[0093] Figures 7 to 13 The systematic experimental results comprehensively verified the integrated advantages and technological advancement of the present invention. The study on the influence of heat treatment temperature on the performance of the composite filler revealed the crucial role of temperature control during the in-situ formation of hexagonal boron nitride, determining the peak performance under optimal crystallization conditions. Comparison of UPF values ​​and UPF retention rates between the examples and comparative examples showed that the present invention significantly outperformed traditional methods in terms of UV protection performance, exhibiting not only outstanding initial protection but also excellent durability after multiple washes. Thermal performance comparison experiments confirmed the successful construction of the thermally conductive network of hexagonal boron nitride in the composite filler, achieving a significant cooling effect and improved thermal conductivity. (Tear strength...) The mechanical property test results of elongation at break show that the present invention effectively maintains the basic mechanical properties of the fiber while ensuring functionality, avoiding the strength loss problem commonly encountered in traditional functional modification processes. The comprehensive performance evaluation of T5% thermal decomposition temperature and moisture permeability indicates that the modified functional fiber meets the practical requirements in terms of thermal stability and comfort. The increase in T5% temperature proves the positive contribution of the composite filler to the thermal stability of the polymer matrix, while the optimized balance of moisture permeability ensures the wearing comfort of the fabric. The systematic improvement of the six key performance indicators fully demonstrates the scientific nature, advancement, and practicality of the multifunctional composite filler preparation technology and fiber functionalization strategy of the present invention.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that any equivalent structural transformations made under the concept of the present invention and using the contents of the specification and drawings of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A cooling, UV-resistant nylon fabric, characterized in that, The fabric is woven from nylon 6 filaments and then finished. Surface-modified boron nitride / titanium dioxide composite filler is dispersed in the fiber matrix of the nylon 6 filaments. The composite filler includes anatase titanium dioxide nanoparticles and hexagonal boron nitride loaded on their surface. The surface of the composite filler has a β-hydroxy ether type ultraviolet-absorbing silane coupling agent modified layer. The amount of the composite filler added to the nylon 6 is 0.8%-3.0% by mass.

2. The cooling and UV-resistant nylon fabric as described in claim 1, characterized in that, The β-hydroxy ether type ultraviolet absorbing silane coupling agent comprises the following raw materials in parts by weight: 1 part of 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 1.1-1.3 parts of 3-glycidyl etheroxypropyltrimethoxysilane, 0.05-0.1 parts of tetrabutylammonium bromide, and 1.2-1.5 parts of anhydrous potassium carbonate.

3. The cooling and UV-resistant nylon fabric as described in claim 1, characterized in that, The anatase titanium dioxide nanoparticles have an average particle size of 60nm-100nm; hexagonal boron nitride is generated in situ by heat treatment of a precursor containing boric acid and urea under nitrogen protection and loaded onto the surface of titanium dioxide, with a molar ratio of boric acid to urea of ​​1:1.8-1:2.5; the composite filler is surface modified by a β-hydroxy ether type ultraviolet absorbing silane coupling agent.

4. The cooling and UV-resistant nylon fabric as described in claim 1, characterized in that, The mass ratio of hexagonal boron nitride to anatase titanium dioxide in the composite filler is 1:3-1:

6.

5. The cooling and UV-resistant nylon fabric as described in claim 1, characterized in that, The fabric has an ultraviolet protection factor (UPF) of not less than 40 and a UPF retention rate of not less than 80% after 20 household washing cycles; the fabric has a cooling sensation (qmax) of not less than 0.20 W / cm² upon contact.

6. A method for preparing a cooling and UV-resistant nylon fabric as described in any one of claims 1 to 4, characterized in that, Includes the following steps: S1. Masterbatch preparation: Nylon 6 chips are vacuum dried at 80℃-100℃ for 4h-6h to reduce the moisture content to below 0.02%; according to the weight ratio, 8-15 parts of surface-modified boron nitride / titanium dioxide composite filler, 0.5-2 parts of antioxidant 1010, 0.3-1 parts of ultraviolet absorber UV-531 and 0.2-0.8 parts of calcium stearate are added to 100 parts of dried nylon 6 chips. The mixture is melt-blended and extruded in a twin-screw extruder at a screw temperature of 220℃-240℃ and a screw speed of 80 rpm-120 rpm. After water cooling, the mixture is pelletized to obtain the functional masterbatch. S2. Preparation of spinning raw materials: Mix 80-92 parts of nylon 6 chips with 8-20 parts of functional masterbatch, and vacuum dry to reduce the moisture content to below 0.02%; S3. Melt spinning and drawing: The spinning raw material is melted and plasticized at a screw temperature of 230℃-250℃ and a metering pump temperature of 240℃-260℃. After precision filtration, it is extruded through a spinneret with 24-72 holes and a hole diameter of 0.20mm-0.35mm at a spinning temperature of 250℃-270℃, and cooled and solidified by side blowing. The initial drawing is performed at a winding speed of 600m / min-1200m / min and a winding tension of 0.15cN / dtex-0.25cN / dtex, with a drawing ratio of 3.5-4.

8. Then, a secondary drawing is performed at 80℃-120℃, with a drawing ratio of 1.3-1.

8. S4. Weaving and finishing: The obtained filaments are woven into fabric greige, and then pre-shrinked, scouring, setting and softening to obtain the cool-feeling UV-resistant nylon fabric.

7. The method for preparing a cooling and UV-resistant nylon fabric as described in claim 6, characterized in that, The preparation method of the surface-modified boron nitride / titanium dioxide composite filler includes the following steps: A1. By weight, disperse 100 parts of boron nitride / titanium dioxide composite filler in 300-500 parts of anhydrous toluene or anhydrous xylene, and ultrasonically disperse for 10-20 minutes; A2. Prepare a stock solution of β-hydroxy ether type ultraviolet absorbing silane coupling agent in toluene or xylene with a mass fraction of 20%-30%; A3. Under nitrogen protection, add 5-15 parts of the stock solution from step A2 to the dispersion from step A1, control the temperature of the reaction system at 80℃-120℃ and react for 2-6 hours. A4. After reaction, the mixture is filtered and separated, washed 2-3 times with anhydrous ethanol, and then vacuum dried at 60℃-80℃ for 4-8 hours to obtain the surface-modified boron nitride / titanium dioxide composite filler.

8. The method for preparing a cooling and UV-resistant nylon fabric as described in claim 6, characterized in that, The preparation method of the boron nitride / titanium dioxide composite filler includes the following steps: B1. By weight, 100 parts of anatase titanium dioxide nanoparticles are dispersed in 300-500 parts of anhydrous ethanol and ultrasonically dispersed for 20-40 minutes. B2. Add 15-25 parts of boric acid and 40-60 parts of urea as precursors to the dispersion in step B1 and stir mechanically until completely dissolved; B3. The solvent was removed by a rotary evaporator at 60℃-80℃ to obtain a dry precursor mixture; B4. Place the mixture from step B3 in a tube furnace and heat it to 550℃-650℃ at a heating rate of 3℃ / min-8℃ / min under nitrogen protection and heat treat it for 4h-8h to achieve in-situ generation of hexagonal boron nitride and loading it onto the surface of titanium dioxide. B5. Allow to cool naturally to room temperature, grind and pass through a 180-250 mesh sieve to obtain boron nitride / titanium dioxide composite filler.

9. The method for preparing a cooling and UV-resistant nylon fabric as described in claim 7, characterized in that, The preparation method of the β-hydroxy ether type ultraviolet absorbing silane coupling agent involves using 1 part of 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 1.1-1.3 parts of 3-glycidyl etheroxypropyltrimethoxysilane, 0.05-0.1 parts of tetrabutylammonium bromide, and 1.2-1.5 parts of anhydrous potassium carbonate as raw materials. Under nitrogen protection, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, tetrabutylammonium bromide, and anhydrous potassium carbonate are sequentially added to a reaction flask containing 5-10 parts of anhydrous acetonitrile dried with molecular sieves. After stirring and dissolving, the mixture is heated to 65℃-80℃, and then 3... Glycidyl etheroxypropyltrimethoxysilane was added dropwise to the reaction system in 3-4 batches, with each batch added over 10-15 minutes and the interval between each batch being 20-30 minutes. After the addition was complete, the reaction continued for 6-8 hours. After the reaction was complete, the mixture was cooled to room temperature, filtered to remove inorganic salts, and the filtrate was distilled under reduced pressure to remove the solvent to obtain the crude product. The crude product was purified by silica gel column chromatography using a gradient elution with a mixture of n-hexane and ethyl acetate in a volume ratio of 3:1 to 5:1 to obtain a β-hydroxy ether type UV-absorbing silane coupling agent. The HPLC purity of the obtained product was not less than 95%.

10. The method for preparing a cooling and UV-resistant nylon fabric as described in claim 6, characterized in that, In step S4: during weaving, the warp density is 180-220 yarns / 10cm and the weft density is 160-200 yarns / 10cm; the pre-shrinking temperature is 95-100℃ and the time is 10-15min; the scouring temperature is 60-80℃ and the time is 15-20min, using a nonionic surfactant; the setting temperature is 160-180℃ and the machine speed is 15-25m / min; the softening finishing temperature is 40-60℃, using an amino silicone oil softener.

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