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

Abstract

The application belongs to the field of functional textile materials, and provides a cool and ultraviolet-resistant nylon fabric and a preparation method thereof.The application adopts a design scheme in which boron nitride / titanium dioxide composite fillers are combined with a surface modification technology of beta-hydroxy ether type ultraviolet absorption silane coupling agents, uniform loading of hexagonal boron nitride on the surface of anatase titanium dioxide is realized through an in-situ heat treatment process, a heat conduction and ultraviolet shielding function composite structure is constructed, and a complete process flow of master batch preparation, melt spinning, weaving and post-finishing is matched, excellent performances that the ultraviolet protection factor UPF of the fabric is not less than 40, the UPF retention rate after 20 household washing cycles is not less than 80%, and the contact instantaneous cool feeling qmax is not less than 0.20 W / cm² are realized, and the technical problems that current nylon fabrics are insufficient in ultraviolet resistance and cool feeling are solved, so the application has wide industrial application value.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of functional textile materials, and provides a cool and anti-ultraviolet nylon fabric and a preparation method thereof. BACKGROUND

[0002] With the improvement of people's living standards and the enhancement of health awareness, outdoor activities, leisure tourism and other activities are increasingly popular, and the functional demand for textiles is also continuously upgraded. In the hot summer environment, traditional textiles often fail to meet the dual requirements of human comfort and health protection, which makes textiles with cool and anti-ultraviolet functions an urgent market demand. The cool function requires the fabric to have excellent thermal conductivity, which can quickly conduct and dissipate human heat, providing a continuous cool feeling for the wearer, thereby effectively improving the thermal comfort in high-temperature environments. The anti-ultraviolet function requires the fabric to effectively block ultraviolet radiation and protect human skin from ultraviolet damage, especially in the case of long-term exposure outdoors. In addition, these functional fabrics also need to have good durability to ensure that they can maintain stable functional effects during multiple washes and long-term use. Meeting these performance requirements not only can significantly improve the added value and market competitiveness of textiles, but also can provide consumers with a more comfortable and safe wearing experience, promoting the development of the functional textile industry towards high-end and intelligent direction. Therefore, it is of great practical significance and broad application prospect to develop textile materials with both cool and anti-ultraviolet functions.

[0003] Currently, the research on functional nylon fabrics mainly focuses on the realization of single function, but there are still many technical challenges in the synergistic integration of cool and anti-ultraviolet dual functions. For example, the Chinese patent with publication number CN215283804U discloses a high-temperature-resistant and anti-ultraviolet environmentally friendly nylon fiber fabric, but it has the shortcomings of single anti-ultraviolet function and lack of cool performance. Traditional functional modification methods often use finishing processes or single filler modification, which is difficult to build a stable multifunctional composite structure inside the fiber, resulting in limited functional effect and poor durability. In the existing composite filler preparation technology, there is a lack of effective interface bonding between different functional components, which easily leads to phase separation, affecting the uniform dispersion of the filler in the matrix and the function exertion. At the same time, the compatibility problem between functional fillers and nylon matrix has always been a key factor restricting the development of functional fibers, and poor interface bonding will lead to filler aggregation and uneven dispersion, thereby affecting the mechanical properties and processing performance of the fiber. In addition, the existing technology often has the problem of mutual restriction between functions when realizing multifunctional integration, which makes it difficult to ensure one function while not affecting the exertion of other functions. For example, the Chinese patent with publication number CN114990716B discloses a cool fiber and a preparation method thereof, but it has the shortcomings of insufficient functional durability and complex preparation process. These technical bottlenecks seriously restrict the industrialization development of high-performance multifunctional nylon fabrics. SUMMARY

[0004] The purpose of the present application is to provide a cool and anti-ultraviolet nylon fabric and a preparation process, which solves the problems of insufficient anti-ultraviolet and coolness of the current nylon fabric.

[0005] In order to achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0006] A cool and anti-ultraviolet nylon fabric, the fabric is obtained by weaving nylon 6 filaments and post-finishing; the fiber matrix of the nylon 6 filaments is dispersed with surface-modified boron nitride / titanium dioxide composite fillers; the composite fillers include anatase titanium dioxide nanoparticles and hexagonal boron nitride loaded on the surface thereof; the composite fillers have a β-hydroxy ether type ultraviolet absorbing silane coupling agent modified layer on the surface; the addition amount of the composite fillers in the nylon 6 is 0.8%-3.0% by mass fraction.

[0007] Further, the β-hydroxy ether type ultraviolet absorbing silane coupling agent contains the following raw materials by weight fraction: 2-(2'-hydroxy-5'-methylphenyl) benzotriazole 1 part, 3-glycidyl ether oxypropyl trimethoxysilane 1.1-1.3 parts, tetrabutylammonium bromide 0.05-0.1 parts, anhydrous potassium carbonate 1.2-1.5 parts.

[0008] Further, the average particle size of the anatase titanium dioxide nanoparticles is 60nm-100nm; the hexagonal boron nitride is generated in situ by heat treatment of a precursor containing boric acid and urea under nitrogen protection and is loaded on the surface of the titanium dioxide, the molar ratio of boric acid to urea is 1:1.8-1:2.5; the composite filler is surface-modified by the β-hydroxy ether type ultraviolet absorbing silane coupling agent.

[0009] Further, the mass ratio of hexagonal boron nitride to anatase titanium dioxide in the composite filler is 1:3-1:6.

[0010] Further, the ultraviolet protection factor UPF of the fabric is not less than 40 and the UPF retention rate after 20 household washing cycles is not less than 80%; the contact instantaneous coolness qmax of the fabric is not less than 0.20W / cm².

[0011] The application adopts the design of boron nitride / titanium dioxide composite filler, which is mainly used to enhance the cool feeling and anti-ultraviolet performance of nylon fabric. The technical scheme realizes the organic combination of heat conduction and ultraviolet protection function by constructing the composite structure of hexagonal boron nitride and anatase titanium dioxide. Hexagonal boron nitride has excellent heat conduction performance, which can quickly conduct and dissipate human heat, providing a lasting cool feeling effect for the fabric. As a carrier, anatase titanium dioxide nanoparticles not only play its inherent ultraviolet shielding role, but also form a stable composite structure with boron nitride through in-situ loading process, enhancing the dispersibility and stability of the filler. The introduction of β-hydroxy ether type ultraviolet absorbing silane coupling layer further strengthens the anti-ultraviolet function, and at the same time, the interfacial compatibility of the composite filler and the nylon 6 matrix is significantly improved through organic surface treatment, ensuring the uniform dispersion of the filler in the fiber. The synergistic effect between the components in the composite filler makes the fabric maintain good mechanical properties while realizing the dual improvement of cool feeling and anti-ultraviolet performance. By accurately controlling the mass ratio of hexagonal boron nitride and anatase titanium dioxide and the addition amount of the composite filler, the balance between functionality and processing performance is ensured, providing an effective technical path for the development of high-performance functional textiles.

[0012] In the cool anti-ultraviolet nylon fabric system, the β-hydroxy ether type ultraviolet absorbing silane coupling agent mainly undertakes the functions of interface modification and ultraviolet protection, while the boron nitride / titanium dioxide composite filler focuses on the heat dissipation and ultraviolet shielding performance improvement. The β-hydroxy ether type ultraviolet absorbing silane coupling agent realizes ultraviolet light absorption conversion through its hydroxybenzotriazole group, and the silane group forms a chemical bond with the nylon matrix to improve the interfacial compatibility; the boron nitride sheet structure provides excellent phonon conduction path to enhance the heat conduction performance, and the anatase titanium dioxide nanoparticles block ultraviolet radiation through scattering and absorption mechanisms. In terms of improving the cool feeling performance, the high thermal conductivity and anisotropic structure of boron nitride build a continuous heat transfer network, and the β-hydroxy ether type silane coupling agent reduces the interfacial thermal resistance through interface optimization. The improvement of ultraviolet protection performance depends on the photocatalytic absorption characteristics of titanium dioxide and the molecular energy level transition absorption of benzotriazole group. The synergistic effect of the two components is reflected in that the silane coupling agent modification significantly improves the dispersion uniformity of the composite filler in the matrix, forming a more effective heat conduction and ultraviolet shielding network; at the same time, the flexibility of the coupling agent molecular chain helps to maintain the orientation of boron nitride sheets, maximizing its heat conduction anisotropy advantage. This multi-level synergistic mechanism realizes the simultaneous optimization of cool feeling and anti-ultraviolet performance, but the understanding of the influence of interface molecular chain conformation on heat conduction path still needs further research.

[0013] The application also discloses a preparation method of the cool anti-ultraviolet nylon fabric, which comprises the following steps:

[0014] S1. Masterbatch preparation: The nylon 6 chips are vacuum dried at 80-100°C for 4-6h to reduce the moisture content to less than 0.02%; according to the weight ratio, 8-15 parts of the surface-modified boron nitride / titanium dioxide composite filler, 0.5-2 parts of antioxidant 1010, 0.3-1 part of ultraviolet absorber UV-531 and 0.2-0.8 parts of calcium stearate are added to 100 parts of dried nylon 6 chips, and then the mixture is melt blended and extruded in a twin-screw extruder at a screw temperature of 220-240°C and a screw speed of 80-120 rpm. After water cooling, the pellets are obtained by cutting to obtain a functional masterbatch;

[0015] S2. Spinning raw material preparation: 80-92 parts of nylon 6 chips are mixed with 8-20 parts of functional masterbatch, and vacuum dried to reduce the moisture content to less than 0.02%;

[0016] S3. Melt spinning and drawing: The spinning raw material is melt plasticized at a screw temperature of 230-250°C and a metering pump temperature of 240-260°C, and then extruded through a spinneret with 24-72 holes and a hole diameter of 0.20-0.35 mm at a spinning temperature of 250-270°C after precision filtration. The extruded filaments are cooled and solidified by side blowing. The primary drawing is carried out at a winding speed of 600-1200 m / min and a winding tension of 0.15-0.25 cN / dtex, and the drawing ratio is 3.5-4.8. Then the filaments are drawn for the second time at 80-120°C, and the draw ratio is 1.3-1.8.

[0017] S4. Weaving and finishing: The obtained filaments are woven into fabric gray cloth, and then pre-shrunk, refined, set, and soft finished to obtain the cool and ultraviolet-resistant nylon fabric.

[0018] Further, the preparation method of the surface-modified boron nitride / titanium dioxide composite filler comprises the following steps:

[0019] A1. According to the weight parts, 100 parts of boron nitride / titanium dioxide composite filler are dispersed in 300-500 parts of anhydrous toluene or anhydrous xylene, and ultrasonic dispersion is carried out for 10-20 min;

[0020] A2. A stock solution of β-hydroxy ether type ultraviolet absorbing silane coupling agent with a mass fraction of 20%-30% in toluene or xylene is prepared;

[0021] A3. Under nitrogen protection, 5-15 parts of the stock solution of step A2 are added dropwise to the dispersion liquid of step A1, the temperature of the reaction system is controlled at 80-120°C, and the reaction is carried out for 2-6h;

[0022] A4. After reaction, filtration separation is carried out, the product is washed with anhydrous ethanol for 2-3 times, and vacuum dried at 60-80°C for 4-8h to obtain the surface-modified boron nitride / titanium dioxide composite filler.

[0023] Further, the preparation method of the boron nitride / titanium dioxide composite filler comprises the following steps:

[0024] The preparation method of the boron nitride / titanium dioxide composite filler comprises the following steps:

[0025] B1. Disperse 100 parts of anatase titanium dioxide nanoparticles in 300-500 parts of anhydrous ethanol by weight parts, and ultrasonically disperse for 20-40 minutes;

[0026] B2. Add 15-25 parts of boric acid and 40-60 parts of urea as precursors to the dispersion of step B1. and mechanically stir until completely dissolved;

[0027] B3. Remove the solvent at 60-80°C using a rotary evaporator to obtain a dry precursor mixture;

[0028] B4. Place the mixture of step B3 in a tube furnace, heat to 550-650°C at a heating rate of 3-8°C / min under nitrogen protection, and heat treat for 4-8h to achieve in-situ generation of hexagonal boron nitride and load on the surface of titanium dioxide;

[0029] B5. Naturally cool to room temperature, grind and pass through a 180-250 mesh sieve to obtain a boron nitride / titanium dioxide composite filler.

[0030] Further, the preparation method of the β-hydroxy ether type ultraviolet absorbing silane coupling agent uses 2-(2'-hydroxy-5'-methylphenyl) benzotriazole 1 part, 3-glycidyl ether oxypropyl trimethoxysilane 1.1-1.3 parts, tetrabutylammonium bromide 0.05-0.1 parts, anhydrous potassium carbonate 1.2-1.5 parts as raw materials, under nitrogen protection, 2-(2'-hydroxy-5'-methylphenyl) benzotriazole, tetrabutylammonium bromide and anhydrous potassium carbonate are sequentially added to a reaction bottle containing 5-10 parts of anhydrous acetonitrile dried by molecular sieves, stirred and dissolved, then heated to 65-80°C, then 3-glycidyl ether oxypropyl trimethoxysilane is added dropwise in 3-4 batches, each batch dropwise time is 10-15 minutes, each batch dropwise interval time is 20-30 minutes, after dropwise addition is completed, continue to react for 6-8 hours; after the reaction is completed, cool to room temperature, filter to remove inorganic salts, the filtrate is distilled under reduced pressure to remove the solvent to obtain a crude product, the crude product is purified by silica gel column chromatography, using a mixture of n-hexane and ethyl acetate with a volume ratio of 3:1 to 5:1 as the eluent for gradient elution to obtain the β-hydroxy ether type ultraviolet absorbing silane coupling agent, the HPLC purity of the obtained product is not less than 95%.

[0031] Further, in the S4 step: the warp density is 180-220 / 10cm, the weft density is 160-200 / 10cm; the pre-shrinking temperature is 95-100 DEG C, the time is 10-15 min; the scouring temperature is 60-80 DEG C, the time is 15-20 min, and a non-ionic surfactant is used; the setting temperature is 160-180 DEG C, and the speed is 15-25 m / min; the softening finishing temperature is 40-60 DEG C, and an amino silicon oil softener is used.

[0032] The preparation method of the boron nitride / titanium dioxide composite filler combined with surface modification technology is mainly used for enhancing the cool feeling and anti-ultraviolet comprehensive performance of nylon fabric. The technical scheme realizes uniform loading of hexagonal boron nitride on the surface of anatase titanium dioxide through an in-situ heat treatment process, and constructs a composite structure with heat conduction and ultraviolet shielding functions. Boric acid and urea are used as precursors to react under high-temperature nitrogen protection, and the generated hexagonal boron nitride and the titanium dioxide carrier form a stable interface combination, which not only maintains the excellent heat conduction performance of boron nitride, but also fully plays the ultraviolet absorption characteristics of titanium dioxide. The surface modification treatment of the beta-hydroxy ether type ultraviolet absorption silane coupling agent further enhances the anti-ultraviolet effect, and at the same time, the organic surface significantly improves the compatibility of the composite filler and the nylon 6 matrix. The synergistic cooperation of the antioxidants 1010, the ultraviolet absorber UV-531 and calcium stearate in the master batch preparation process ensures the stable dispersion of the filler in the melting process. The accurate control of the melt spinning and drawing process parameters ensures the uniform distribution of the functional components in the fiber, and the finishing process further optimizes the comprehensive performance of the fabric. The synergistic effect between the components makes the fabric obtain excellent contact instant cool feeling while realizing persistent and stable ultraviolet protection effect, and provides a complete technical solution for the industrial production of high-performance functional textiles.

[0033] The present application has the following beneficial effects:

[0034] 1. Synergistic integration of cool feeling and anti-ultraviolet dual functions: through the design of boron nitride / titanium dioxide composite filler, the excellent heat conduction performance of hexagonal boron nitride and the ultraviolet shielding function of anatase titanium dioxide are organically combined, so that the fabric has persistent cool feeling and high-efficiency anti-ultraviolet performance, the ultraviolet protection coefficient UPF is not less than 40, and the contact instant cool feeling qmax is not less than 0.20 W / cm².

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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

[0040] Figure 1 This is a morphological diagram of the composite filler prepared in Example 1 of the present invention.

[0041] Figure 2 The image shows the XRD phase analysis of the composite packing prepared in Example 1 of this invention.

[0042] Figure 3 The infrared Fourier spectrum of the β-hydroxy ether type ultraviolet-absorbing silane coupling agent prepared in Example 1 of this invention.

[0043] 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.

[0044] 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.

[0045] Figure 6The influence of the amount of the reserve liquid on the performance in the process of surface modification of the boron nitride / titanium dioxide composite filler.

[0046] Figure 7 The influence of the heat treatment temperature on the performance in the process of synthesizing the composite filler.

[0047] Figure 8 The comparison of the UPF value and the UPF retention rate of the examples and the comparative examples of the present application.

[0048] Figure 9 The comparison of the thermal performance of the examples and the comparative examples of the present application.

[0049] Figure 10 The comparison of the breaking strength of the examples and the comparative examples of the present application.

[0050] Figure 11 The comparison of the breaking elongation of the examples and the comparative examples of the present application.

[0051] Figure 12 The comparison of the T5% and the moisture permeability of the examples and the comparative examples of the present application.

[0052] Figure 13 The comparison chart of the contact cool feeling coefficient and the T(UVA) transmittance of the examples and the comparative examples of the present application. DETAILED DESCRIPTION

[0053] In order to make the purpose, the technical scheme and the advantages of the examples of the present application more clear, the technical scheme in the examples of the present application will be described clearly and completely below in combination with the drawings in the examples of the present application.

[0054] Example 1: A cool-feeling and ultraviolet-resistant nylon fabric, the fabric of the present example is woven from nylon 6 filaments and obtained after finishing; the nylon 6 filaments of the present example have surface-modified boron nitride / titanium dioxide composite fillers dispersed in the fiber matrix; the composite fillers of the present example include anatase titanium dioxide nanoparticles and hexagonal boron nitride loaded on the surface thereof; the composite fillers of the present example have a β-hydroxy ether type ultraviolet absorbing silane coupling agent modified layer on the surface; the addition amount of the composite fillers in the nylon 6 of the present example is 1.8% by mass fraction. The β-hydroxy ether type ultraviolet absorbing silane coupling agent of the present example contains the following raw materials by weight fraction: 2-(2'-hydroxy-5'-methylphenyl) benzotriazole 1 part, 3-glycidyl ether oxypropyl trimethoxysilane 1.2 parts, tetrabutylammonium bromide 0.075 parts, anhydrous potassium carbonate 1.35 parts. The average particle size of the anatase titanium dioxide nanoparticles of the present example is 80 nm; the hexagonal boron nitride is generated in situ by heat treatment of a precursor containing boric acid and urea under nitrogen protection and is loaded on the surface of the titanium dioxide, the molar ratio of boric acid to urea is 1:2.1; the composite filler is surface-modified by the β-hydroxy ether type ultraviolet absorbing silane coupling agent. The mass ratio of hexagonal boron nitride to anatase titanium dioxide in the composite filler of the present example is 1:4.5.

[0055] The preparation method of the cool-feeling and ultraviolet-resistant nylon fabric of the present example includes the following steps: S1. Masterbatch preparation: dry the nylon 6 chips at 90°C under vacuum for 5h to reduce the moisture content to less than 0.02%; according to the weight ratio, add 11.5 parts of surface-modified boron nitride / titanium dioxide composite fillers, 1.25 parts of antioxidant 1010, 0.65 parts of ultraviolet absorber UV-531 and 0.5 parts of calcium stearate to 100 parts of dried nylon 6 chips, melt blend and extrude in a twin-screw extruder at a screw temperature of 230°C and a screw rotation speed of 100 revolutions / minute, cut into particles after water cooling to obtain a functional masterbatch; S2. Spinning raw material preparation: mix 86 parts of nylon 6 chips with 14 parts of functional masterbatch and vacuum dry to reduce the moisture content to less than 0.02%; S3. Melt spinning and drawing: melt plasticize the spinning raw material at a screw temperature of 240°C and a metering pump temperature of 250°C, extrude through a spinneret with 48 holes and a hole diameter of 0.27mm at a spinning temperature of 260°C after precision filtration, and cool and solidify by side blowing; primary drawing is carried out at a winding speed of 900m / min and a winding tension of 0.20cN / dtex, the drawing ratio is 4.1; then secondary stretching is carried out at 100°C, the stretching multiple is 1.5; S4. Weaving and finishing: the obtained filaments are woven into fabric gray cloth, and the cool-feeling and ultraviolet-resistant nylon fabric of the present example is obtained after pre-shrinking, scouring, setting and soft finishing.

[0056] The preparation method of the surface-modified boron nitride / titanium dioxide composite filler of the present embodiment comprises the following steps: A1. Disperse 100 parts of boron nitride / titanium dioxide composite filler in 400 parts of anhydrous toluene by weight, and ultrasonically disperse for 15 min; A2. Prepare a 25% mass fraction of β-hydroxy ether type ultraviolet absorbing silane coupling agent in toluene stock solution; A3. Under nitrogen protection, add 10 parts of the stock solution of step A2 to the dispersion liquid of step A1, control the reaction system temperature to be 100℃ and react for 4h; A4. After reaction, filter and separate, wash twice with anhydrous ethanol and vacuum dry at 70℃ for 6h to obtain the surface-modified boron nitride / titanium dioxide composite filler.

[0057] The preparation method of the boron nitride / titanium dioxide composite filler of the present embodiment comprises the following steps: B1. Disperse 100 parts of anatase titanium dioxide nanoparticles in 400 parts of anhydrous ethanol by weight, and ultrasonically disperse for 30 min; B2. Add boric acid 20 parts and urea 50 parts as precursors to the dispersion liquid of step B1 and mechanically stir until completely dissolved; B3. Use a rotary evaporator to remove the solvent at 70℃ to obtain a dry precursor mixture; B4. Place the mixture of step B3 in a tube furnace, heat to 600℃ at a heating rate of 5℃ / min under nitrogen protection, and heat treat for 6h to achieve in-situ generation of hexagonal boron nitride and load on the surface of titanium dioxide; B5. Naturally cool to room temperature, grind and pass through a 200 mesh sieve to obtain the boron nitride / titanium dioxide composite filler.

[0058] The preparation method of the β-hydroxy ether type ultraviolet absorbing silane coupling agent of the present embodiment, using 2-(2'-hydroxy-5'-methylphenyl) benzotriazole 1 part, 3-glycidyl ether oxypropyl trimethoxysilane 1.2 parts, tetrabutylammonium bromide 0.075 parts, anhydrous potassium carbonate 1.35 parts as raw materials, under nitrogen protection, 2-(2'-hydroxy-5'-methylphenyl) benzotriazole, tetrabutylammonium bromide and anhydrous potassium carbonate were sequentially added to a reaction bottle containing 7.5 parts of anhydrous acetonitrile dried by molecular sieves, stirred and dissolved, then heated to 72℃, and then 3-glycidyl ether oxypropyl trimethoxysilane was added dropwise into the reaction system in 3 batches, each batch dropwise time was 12 minutes, and each batch dropwise interval time was 25 minutes, after dropwise addition was completed, the reaction was continued for 7 hours; after the reaction was completed, it was cooled to room temperature, the inorganic salt was removed by filtration, 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, a mixed solvent of n-hexane and ethyl acetate with a volume ratio of 4:1 was used as the eluent for gradient elution, and the β-hydroxy ether type ultraviolet absorbing silane coupling agent was obtained, the HPLC purity of the obtained product was not less than 95%.

[0059] In the S4 step of this embodiment: the warp density is 200 threads / 10 cm and the weft density is 180 threads / 10 cm during weaving; the pre-shrinking temperature is 97 ℃ and the time is 12 min; the scouring temperature is 70 ℃ and the time is 17 min, a non-ionic surfactant is used; the setting temperature is 170 ℃ and the speed is 20 m / min; the softening finishing temperature is 50 ℃, and an amino silicone oil softener is used. The ultraviolet protection factor UPF of the fabric of this embodiment is not less than 40, and the UPF retention rate after 20 home washing cycles is not less than 80%; the contact instantaneous cool feeling qmax of the fabric of this embodiment is not less than 0.20 W / cm².

[0060] Features of Example 1: In this embodiment, moderate parameters are used, and the addition amount of the composite filler is 1.8%, which ensures a good balance between the anti-ultraviolet performance and the cool feeling effect. The mass ratio of hexagonal boron nitride to titanium dioxide is selected as the median value of 1:4.5, which provides stable thermal conductivity. The process parameters are selected to be moderate, and have good industrial production stability and reproducibility. It is suitable for high-end outdoor sportswear, protective workwear and other application scenarios with high comprehensive performance requirements.

[0061] Example 2: A cool and anti-ultraviolet nylon fabric, the fabric of this embodiment is obtained by weaving and finishing nylon 6 filaments; the fiber matrix of the nylon 6 filaments of this embodiment disperses surface-modified boron nitride / titanium dioxide composite fillers; the composite filler of this embodiment includes anatase titanium dioxide nanoparticles and hexagonal boron nitride loaded on the surface thereof; the composite filler of this embodiment has a β-hydroxy ether type ultraviolet absorbing silane coupling agent modified layer on the surface; the addition amount of the composite filler in the nylon 6 of this embodiment is 2.6% by mass fraction. The β-hydroxy ether type ultraviolet absorbing silane coupling agent of this embodiment contains the following raw materials by weight fraction: 2-(2'-hydroxy-5'-methylphenyl) benzotriazole 1 part, 3-glycidyl ether propyl trimethoxysilane 1.3 parts, tetrabutylammonium bromide 0.1 parts, anhydrous potassium carbonate 1.5 parts. The average particle size of the anatase titanium dioxide nanoparticles of this embodiment is 60 nm; the hexagonal boron nitride is generated in situ by heat treatment of a precursor containing boric acid and urea under nitrogen protection and is loaded on the surface of the titanium dioxide, the molar ratio of boric acid to urea is 1:1.8; the composite filler is surface-modified by the β-hydroxy ether type ultraviolet absorbing silane coupling agent. The mass ratio of hexagonal boron nitride to anatase titanium dioxide in the composite filler of this embodiment is 1:3.

[0062] The preparation method of the cool and ultraviolet resistant nylon fabric of the embodiment comprises the following steps: S1. Masterbatch preparation: dry nylon 6 chips at 100 ℃ under vacuum for 4 h to reduce the moisture content to less than 0.02%; according to the weight ratio, add 15 parts of surface-modified boron nitride / titanium dioxide composite filler, 2 parts of antioxidant 1010, 1 part of ultraviolet absorber UV-531 and 0.8 parts of calcium stearate to 100 parts of dried nylon 6 chips, melt blend and extrude in a twin-screw extruder at a screw temperature of 240 ℃ and a screw rotation speed of 120 r / min, cut into particles after water cooling to obtain a functional masterbatch; S2. Spinning raw material preparation: mix 80 parts of nylon 6 chips with 20 parts of functional masterbatch and vacuum dry to reduce the moisture content to less than 0.02%; S3. Melt spinning and drawing: melt plasticize the spinning raw material at a screw temperature of 250 ℃ and a metering pump temperature of 260 ℃, extrude through a spinneret with 24 holes and a hole diameter of 0.35 mm at a spinning temperature of 270 ℃ after precise filtration, and cool and solidify by side blowing; primary drawing is performed at a winding speed of 600 m / min and a winding tension of 0.25 cN / dtex, and the drawing ratio is 4.8; then secondary stretching is performed at 120 ℃, and the stretching multiple is 1.8; S4. Weaving and finishing: the obtained filaments are woven into fabric gray cloth, and the cool and ultraviolet resistant nylon fabric of the embodiment is obtained after pre-shrinking, scouring, setting and soft finishing.

[0063] The preparation method of the surface-modified boron nitride / titanium dioxide composite filler of the embodiment comprises the following steps: A1. Disperse 100 parts of boron nitride / titanium dioxide composite filler in 500 parts of anhydrous xylene according to weight parts, and ultrasonic dispersion for 20 min; A2. Prepare a 30% mass fraction β-hydroxy ether type ultraviolet absorbing silane coupling agent stock solution in xylene; A3. Under nitrogen protection, add 15 parts of the stock solution of step A2 to the dispersion liquid of step A1, control the reaction system temperature to be 120 ℃ and react for 6 h; A4. After reaction, separate by filtration, wash with anhydrous ethanol for 3 times and vacuum dry at 80 ℃ for 8 h to obtain the surface-modified boron nitride / titanium dioxide composite filler.

[0064] The preparation method of the boron nitride / titanium dioxide composite filler of the embodiment comprises the following steps: B1. Disperse 100 parts of anatase titanium dioxide nanoparticles in 500 parts of anhydrous ethanol according to weight parts, and ultrasonic dispersion for 40 min; B2. Add boric acid 25 parts and urea 60 parts as precursors to the dispersion liquid of step B1 and mechanically stir until completely dissolved; B3. Use a rotary evaporator to remove the solvent at 80 ℃ to obtain a dry precursor mixture; B4. Place the mixture of step B3 in a tube furnace, heat to 650 ℃ at a heating rate of 8 ℃ / min under nitrogen protection and heat treat for 8 h to realize in-situ generation of hexagonal boron nitride and loading on the surface of titanium dioxide; B5. Naturally cool to room temperature, grind and pass through a 250 mesh sieve to obtain the boron nitride / titanium dioxide composite filler.

[0065] The preparation method of the beta-hydroxy ether type ultraviolet absorption silane coupling agent of the present embodiment uses 1 part of 2-(2'-hydroxy-5'-methylphenyl) benzotriazole, 1.3 parts of 3-glycidyl ether oxypropyl trimethoxysilane, 0.1 part 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 bottle containing 10 parts of anhydrous acetonitrile dried by molecular sieves. After stirring and dissolving, the temperature is raised to 80°C. Then 3-glycidyl ether oxypropyl trimethoxysilane is added dropwise in 4 batches, with a dropwise addition time of 15 minutes for each batch and an interval of 30 minutes between each batch. After the dropwise addition is completed, the reaction is continued for 8 hours. After the reaction is completed, the temperature is cooled to room temperature, and the inorganic salt is removed by filtration. The filtrate is distilled under reduced pressure to remove the solvent to obtain a crude product. The crude product is purified by silica gel column chromatography, and a mixed solvent of n-hexane and ethyl acetate with a volume ratio of 5:1 is used as the eluent for gradient elution to obtain the beta-hydroxy ether type ultraviolet absorption silane coupling agent. The HPLC purity of the obtained product is not less than 95%.

[0066] In the S4 step of the present embodiment: the warp density is 220 threads / 10 cm, the weft density is 200 threads / 10 cm; the pre-shrinking temperature is 100°C, and the time is 15 min; the scouring temperature is 80°C, and the time is 20 min, a non-ionic surfactant is used; the setting temperature is 180°C, and the speed is 25 m / min; the softening finishing temperature is 60°C, and an amino silicone oil softener is used. The ultraviolet protection factor UPF of the fabric of the present embodiment is not less than 40, and the UPF retention rate after 20 home washing cycles is not less than 80%; the contact instantaneous cool feeling qmax of the fabric of the present embodiment is not less than 0.20 W / cm².

[0067] The features of Example 2: This embodiment uses a high filler addition amount of 2.6% to emphasize the anti-ultraviolet function. A smaller titanium dioxide particle size of 60 nm and a higher proportion of hexagonal boron nitride (1:3) are selected to significantly improve the ultraviolet protection effect. Higher spinning temperature and draft ratio are used to ensure the fiber forming quality under high filler content. It is suitable for professional protective clothing in strong ultraviolet environment, such as desert work clothes, high-altitude outdoor equipment, and other application scenarios with extreme anti-ultraviolet performance requirements.

[0068] Example 3: A cool and ultraviolet resistant nylon fabric, the fabric of the present example is woven from nylon 6 filaments and obtained after finishing; the nylon 6 filaments of the present example have surface-modified boron nitride / titanium dioxide composite fillers dispersed in the fiber matrix; the composite fillers of the present example include anatase titanium dioxide nanoparticles and hexagonal boron nitride loaded on the surface thereof; the composite fillers of the present example have a β-hydroxy ether type ultraviolet absorbing silane coupling agent modified layer on the surface; the addition amount of the composite fillers in the nylon 6 of the present example is 1.2% by mass fraction. The β-hydroxy ether type ultraviolet absorbing silane coupling agent of the present example contains the following raw materials by weight fraction: 2-(2'-hydroxy-5'-methylphenyl) benzotriazole 1 part, 3-glycidyl ether oxypropyl trimethoxysilane 1.1 parts, tetrabutylammonium bromide 0.05 parts, anhydrous potassium carbonate 1.2 parts. The average particle size of the anatase titanium dioxide nanoparticles of the present example is 100 nm; the hexagonal boron nitride is generated in situ by heat treatment of a precursor containing boric acid and urea under nitrogen protection and is loaded on the surface of the titanium dioxide, the molar ratio of boric acid to urea is 1:2.5; the composite filler is surface-modified by the β-hydroxy ether type ultraviolet absorbing silane coupling agent. The mass ratio of hexagonal boron nitride to anatase titanium dioxide in the composite filler of the present example is 1:6.

[0069] The preparation method of the cool and ultraviolet resistant nylon fabric of the present example includes the following steps: S1. Masterbatch preparation: dry the nylon 6 chips at 80°C under vacuum for 6h to reduce the moisture content to less than 0.02%; according to the weight ratio, add 8 parts of surface-modified boron nitride / titanium dioxide composite fillers, 0.5 parts of antioxidant 1010, 0.3 parts of ultraviolet absorber UV-531 and 0.2 parts of calcium stearate to 100 parts of dried nylon 6 chips, melt blend and extrude in a twin-screw extruder at a screw temperature of 220°C and a screw rotation speed of 80 revolutions / minute, cut into particles after water cooling to obtain a functional masterbatch; S2. Spinning raw material preparation: mix 92 parts of nylon 6 chips with 8 parts of functional masterbatch and vacuum dry to reduce the moisture content to less than 0.02%; S3. Melt spinning and drawing: melt plasticize the spinning raw material at a screw temperature of 230°C and a metering pump temperature of 240°C, extrude through a spinneret with 72 holes and a hole diameter of 0.20mm at a spinning temperature of 250°C after precision filtration, and cool and solidify by side blowing; primary drawing is carried out at a winding speed of 1200m / min and a winding tension of 0.15cN / dtex, and the drawing ratio is 3.5; then secondary stretching is carried out at 80°C, and the stretching ratio is 1.3; S4. Weaving and finishing: the obtained filaments are woven into fabric gray cloth, and the cool and ultraviolet resistant nylon fabric of the present example is obtained after pre-shrinking, scouring, setting and soft finishing.

[0070] The preparation method of the surface-modified boron nitride / titanium dioxide composite filler of the embodiment comprises the following steps: A1. dispersing 100 parts of boron nitride / titanium dioxide composite filler in 300 parts of anhydrous toluene by weight, and ultrasonic dispersion for 10 min; A2. preparing a 20% mass fraction of β-hydroxy ether type ultraviolet absorbing silane coupling agent in toluene stock solution; A3. under nitrogen protection, adding 5 parts of the stock solution of step A2 to the dispersion liquid of step A1, controlling the reaction system temperature to be 80℃ and reacting for 2h; A4. after reaction, filtering separation, washing twice with anhydrous ethanol and vacuum drying at 60℃ for 4h to obtain the surface-modified boron nitride / titanium dioxide composite filler.

[0071] The preparation method of the boron nitride / titanium dioxide composite filler of the embodiment comprises the following steps: B1. dispersing 100 parts of anatase titanium dioxide nanoparticles in 300 parts of anhydrous ethanol by weight, and ultrasonic dispersion for 20 min; B2. adding boric acid 15 parts and urea 40 parts as precursors to the dispersion liquid of step B1 and mechanically stirring until completely dissolved; B3. using a rotary evaporator to remove the solvent at 60℃ to obtain a dry precursor mixture; B4. placing the mixture of step B3 in a tube furnace, heating to 550℃ at a heating rate of 3℃ / min under nitrogen protection and heat treating for 4h to realize in-situ generation of hexagonal boron nitride and loading on the surface of titanium dioxide; B5. naturally cooling to room temperature, grinding and passing through a 180 mesh sieve to obtain the boron nitride / titanium dioxide composite filler.

[0072] The preparation method of the β-hydroxy ether type ultraviolet absorbing silane coupling agent of the embodiment, using 2-(2'-hydroxy-5'-methylphenyl) benzotriazole 1 part, 3-glycidyl ether oxypropyl trimethoxysilane 1.1 part, tetrabutylammonium bromide 0.05 part, anhydrous potassium carbonate 1.2 parts as raw materials, under nitrogen protection, 2-(2'-hydroxy-5'-methylphenyl) benzotriazole, tetrabutylammonium bromide and anhydrous potassium carbonate were sequentially added to a reaction bottle containing 5 parts of anhydrous acetonitrile dried by molecular sieves, stirred and dissolved, then heated to 65℃, and then 3-glycidyl ether oxypropyl trimethoxysilane was added dropwise into the reaction system in 3 batches, each batch dropwise adding time was 10 minutes, and each batch dropwise adding interval time was 20 minutes, after dropwise adding was completed, the reaction was continued for 6 hours; after the reaction was completed, it was cooled to room temperature, the inorganic salt was removed by filtration, and the filtrate was distilled under reduced pressure to remove the solvent to obtain a crude product, the crude product was purified by silica gel column chromatography, a mixed solvent of n-hexane and ethyl acetate with a volume ratio of 3:1 was used as an eluent for gradient elution, and the β-hydroxy ether type ultraviolet absorbing silane coupling agent was obtained, the HPLC purity of the obtained product was not less than 95%.

[0073] In the S4 step of this embodiment: the warp density is 180 threads / 10 cm and the weft density is 160 threads / 10 cm during weaving; the pre-shrinking temperature is 95°C and the time is 10 min; the scouring temperature is 60°C and the time is 15 min, a non-ionic surfactant is used; the setting temperature is 160°C and the speed is 15 m / min; the softening finishing temperature is 40°C, and an amino silicone oil softener is used. The ultraviolet protection factor UPF of the fabric of this embodiment is not less than 40, and the UPF retention rate after 20 home washing cycles is not less than 80%; the contact instantaneous cool feeling qmax of the fabric of this embodiment is not less than 0.20 W / cm².

[0074] Features of Example 3: This embodiment preferentially enhances the cool feeling performance, uses a lower filler addition amount of 0.8% and a highest mass ratio of hexagonal boron nitride to titanium dioxide of 1:6, maximizes the heat conduction effect of boron nitride. A larger titanium dioxide particle size of 100 nm and a high winding speed of 1200 m / min are selected, which is beneficial to the improvement of fiber softness and air permeability. It is suitable for summer sportswear, close-fitting underwear, yoga clothes and other application scenarios with higher requirements for cool feeling comfort.

[0075] Example 4: A cool feeling anti-ultraviolet nylon fabric, the fabric of this embodiment is obtained by weaving and finishing nylon 6 filaments; the fiber matrix of the nylon 6 filaments of this embodiment disperses surface-modified boron nitride / titanium dioxide composite fillers; the composite fillers of this embodiment include anatase titanium dioxide nanoparticles and hexagonal boron nitride loaded on the surface thereof; the composite fillers of this embodiment have a β-hydroxy ether type ultraviolet absorbing silane coupling agent modified layer on the surface; the addition amount of the composite fillers in the nylon 6 of this embodiment is 3.0% by mass fraction. The β-hydroxy ether type ultraviolet absorbing silane coupling agent of this embodiment comprises the following raw materials by weight fraction: 2-(2'-hydroxy-5'-methylphenyl)benzotriazole 1 part, 3-glycidyl ether propyl trimethoxysilane 1.25 parts, tetrabutylammonium bromide 0.08 parts, anhydrous potassium carbonate 1.4 parts. The average particle size of the anatase titanium dioxide nanoparticles of this embodiment is 75 nm; the hexagonal boron nitride is generated in situ by heat treatment of a precursor containing boric acid and urea under nitrogen protection and is loaded on the surface of the titanium dioxide, the molar ratio of boric acid to urea is 1:2.2; the composite fillers are surface-modified by the β-hydroxy ether type ultraviolet absorbing silane coupling agent. The mass ratio of hexagonal boron nitride to anatase titanium dioxide in the composite fillers of this embodiment is 1:3.8.

[0076] The preparation method of the cool and anti-ultraviolet nylon fabric of the embodiment comprises the following steps: S1. Master batch preparation: dry nylon 6 chips at 95°C under vacuum for 4.5h to reduce the moisture content to less than 0.02%; according to the weight ratio, add 12 parts of surface-modified boron nitride / titanium dioxide composite filler, 1.5 parts of antioxidant 1010, 0.8 parts of ultraviolet absorber UV-531 and 0.6 parts of calcium stearate to 100 parts of dried nylon 6 chips, melt blend and extrude in a twin-screw extruder at a screw temperature of 235°C and a screw rotation speed of 110 revolutions / minute, cut into particles after water cooling to obtain a functional master batch; S2. Spinning raw material preparation: mix 75 parts of nylon 6 chips with 25 parts of functional master batch and vacuum dry to reduce the moisture content to less than 0.02%; S3. Melt spinning and drawing: melt plasticize the spinning raw material at a screw temperature of 245°C and a metering pump temperature of 255°C, extrude through a spinneret with 36 holes and a hole diameter of 0.30mm at a spinning temperature of 265°C after precision filtration, and cool and solidify by side blowing; primary drawing is performed at a winding speed of 800m / min and a winding tension of 0.22cN / dtex, and the drawing ratio is 4.2; then secondary stretching is performed at 105°C, and the stretching multiple is 1.6; S4. Weaving and finishing: the obtained filaments are woven into fabric gray cloth, and the cool and anti-ultraviolet nylon fabric of the embodiment is obtained after pre-shrinking, scouring, setting and soft finishing.

[0077] The preparation method of the surface-modified boron nitride / titanium dioxide composite filler of the embodiment comprises the following steps: A1. Disperse 100 parts of boron nitride / titanium dioxide composite filler in 450 parts of anhydrous xylene according to weight parts, and ultrasonic dispersion for 18min; A2. Prepare a 28% mass fraction β-hydroxy ether type ultraviolet absorbing silane coupling agent stock solution in xylene; A3. Under nitrogen protection, add 12 parts of the stock solution of step A2 to the dispersion liquid of step A1, control the reaction system temperature to be 110°C and react for 5h; A4. After reaction, filter and separate, wash with anhydrous ethanol for 3 times and vacuum dry at 75°C for 7h to obtain the surface-modified boron nitride / titanium dioxide composite filler.

[0078] The preparation method of the boron nitride / titanium dioxide composite filler of the embodiment comprises the following steps: B1. Disperse 100 parts of anatase titanium dioxide nanoparticles in 450 parts of anhydrous ethanol according to weight parts, and ultrasonic dispersion for 35min; B2. Add boric acid 22 parts and urea 55 parts as precursors to the dispersion liquid of step B1 and mechanically stir until completely dissolved; B3. Use a rotary evaporator to remove the solvent at 75°C to obtain a dry precursor mixture; B4. Place the mixture of step B3 in a tube furnace, heat to 620°C at a heating rate of 6°C / min under nitrogen protection and heat treat for 7h to realize in-situ generation of hexagonal boron nitride and loading on the surface of titanium dioxide; B5. Naturally cool to room temperature, grind and pass through a 220 mesh sieve to obtain the boron nitride / titanium dioxide composite filler.

[0079] The preparation method of the beta-hydroxy ether type ultraviolet absorption silane coupling agent of the present embodiment uses 1 part of 2-(2'-hydroxy-5'-methylphenyl) benzotriazole, 1.25 parts of 3-glycidyl ether oxypropyl trimethoxysilane, 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 bottle containing 8 parts of anhydrous acetonitrile dried by molecular sieves, stirred and dissolved, then heated to 75°C, and then 3-glycidyl ether oxypropyl trimethoxysilane is added dropwise into the reaction system in 4 batches, with a dropwise adding time of 13 minutes for each batch and an interval time of 28 minutes between each batch. After the dropwise addition is completed, the reaction is continued for 7.5 hours. After the reaction is completed, it is cooled to room temperature, the inorganic salt is removed by filtration, and the filtrate is distilled under reduced pressure to remove the solvent to obtain a crude product. The crude product is purified by silica gel column chromatography, and a mixed solvent of n-hexane and ethyl acetate with a volume ratio of 4.5:1 is used as an eluent for gradient elution to obtain the beta-hydroxy ether type ultraviolet absorption silane coupling agent. The HPLC purity of the obtained product is not less than 95%.

[0080] In the S4 step of the present embodiment: the warp density is 210 yarns / 10 cm, the weft density is 190 yarns / 10 cm; the pre-shrinking temperature is 98°C, and the time is 13 min; the scouring temperature is 75°C, and the time is 18 min, using a non-ionic surfactant; the setting temperature is 175°C, and the speed is 22 m / min; the soft finishing temperature is 55°C, using an amino silicone oil softener. The fabric of the present embodiment has an ultraviolet protection factor UPF of not less than 40, and the UPF retention rate after 20 home washing cycles is not less than 80%; the fabric of the present embodiment has a contact instantaneous cool feeling qmax of not less than 0.20 W / cm².

[0081] Features of Example 4: The present embodiment uses the highest filler addition amount of 3.0% to achieve the maximum of both ultraviolet resistance and cool feeling. A medium particle size of 75 nm and a mass ratio of hexagonal boron nitride to titanium dioxide of 1:3.8 are selected to ensure functionality while considering fiber processing performance. Relatively mild spinning parameters are used to address the processing challenges brought by high filler content. It is suitable for professional protective equipment in extreme environments, such as polar exploration suits, high radiation area workwear, and other special application scenarios with extreme performance requirements.

[0082] Comparative Example 1: Basically the same as Example 1, except that the addition amount of the composite filler in nylon 6 in step S1 is 0.5% by mass, not 1.8%.

[0083] Comparative Example 2: Basically the same as Example 1, except that the heat treatment temperature in step B4 is 450°C, not 600°C, and other heat treatment conditions remain unchanged.

[0084] Comparative Example 3: Essentially 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.

[0085] Comparative Example 4: Essentially the same as Example 1, except that the average particle size of the anatase titanium dioxide nanoparticles is 150 nm, instead of 80 nm, which are prepared by a sol-gel method and calcined at 500°C for 4 hours.

[0086] Comparative Example 5: Essentially 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.

[0087] Comparative Example 6: Essentially the same as Example 1, except that the spinning temperature in step S3 is 220°C, instead of 260°C.

[0088] Comparative Example 7: Essentially the same as Example 1, except that the temperature of the reaction system in step A3 is 50°C, instead of 100°C, and the reaction time is extended to 8 hours.

[0089] Comparative Example 8: Essentially the same as Example 1, except that the amount of 3-glycidyloxypropyltrimethoxysilane in the β-hydroxy ether type ultraviolet absorbing silane coupling agent is 0.8 parts, instead of 1.2 parts.

[0090] Comparative Example 9: Essentially the same as Example 1, except that the draw ratio in step S3 is 2.8, instead of 4.1.

[0091] Comparative Example 10: Essentially 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 remains unchanged at 600°C.

[0092] Comparative Example 11: Essentially the same as Example 1, except that no ultrasonic dispersion treatment is performed in step A1, and direct mechanical stirring is used for 30 minutes for dispersion.

[0093] Comparative Example 12: Essentially the same as Example 1, except that the secondary stretching temperature in step S3 is 60°C, instead of 100°C.

[0094] Comparative Example 13: Essentially the same as Example 1, except that the surface of the composite filler is not modified with the β-hydroxy ether type ultraviolet absorbing silane coupling agent, and the unmodified boron nitride / titanium dioxide composite filler is used directly.

[0095] Comparative Example 14: Essentially the same as Example 1, except that the winding speed in step S3 is 400 m / min, instead of 900 m / min.

[0096] Comparative Example 15: Essentially the same as Example 1, except that the hexagonal boron nitride was a commercial powder that was mixed with anatase titanium dioxide nanoparticles by ball milling for 6 hours to produce the composite filler, rather than being produced in situ by heat treatment of boric acid and urea precursors.

[0097] Performance test:

[0098] Ultraviolet protection performance test: The test object is a cool ultraviolet-resistant nylon fabric product. The purpose of the test is to evaluate the fabric's ability to protect against ultraviolet rays and the ultraviolet protection factor UPF value. Test principle: Based on ultraviolet transmittance determination, the UPF value is calculated by measuring the blocking effect of the fabric on UVA (315-400 nm) and UVB (280-315 nm) band ultraviolet rays. Experimental method: Use an ultraviolet spectrophotometer, place the fabric sample in an integrating sphere, and measure the transmittance every 5 nm in the wavelength range of 280-400 nm. The sample needs to be rotated in multiple directions to test at least 5 points and include the warp and weft directions. Calculate the average UVA transmittance, average UVB transmittance, and UPF value. Standard basis: GB / T 18830-2009 "Evaluation of the Anti-Ultraviolet Performance of Textiles", respectively according to the respective standards for calculation and grading. Key parameters: Standard atmospheric conditions temperature 20±2℃, relative humidity 65±4%, humidity adjustment ≥24h, sample size not less than 10cm×10cm, test points not less than 5 including warp and weft directions. Data processing: Calculate the UPF value according to GB / T 18830-2024 and AS / NZS4399:2017 respectively, record the UVA transmittance and the lower limit of confidence of UPF, report the UPF retention rate before and after washing, and require UPF≥40 and UVA transmittance <5%.

[0099] Instant cooling performance test: test object is finished product of cooling anti-UV nylon fabric. Test purpose: evaluate the instant cooling intensity of the fabric when it contacts with human skin. Test principle: evaluate the instant cooling effect quantitatively by measuring the maximum heat flow peak value qmax of the fabric when it contacts with the standard hot plate. Experimental method: use the cooling tester, lay the fabric sample on the test table, the standard hot plate (simulating human skin temperature 35℃) contacts the surface of the fabric under the contact pressure of 0.1N±10% specified in GB / T 35263, record the heat flow change curve at the moment of contact and extract the maximum heat flow peak value, test each sample at least 5 times. Standard basis: GB / T 35263-2017 "determination and evaluation of instant cooling performance of textiles". Key parameters: standard atmospheric conditions temperature 20±2℃, relative humidity 65±4%, humidity adjustment≥24h, hot plate temperature 35±0.1℃, contact pressure 0.1N±10%, data acquisition frequency 100Hz, test duration 10s. Data processing: extract the maximum heat flow peak value qmax within 5 seconds after contact, unit: W / cm², report the mean value±standard deviation, simultaneously compare the ordinary nylon reference cloth to calculate the difference value Δqmax, require qmax≥0.20W / cm² to have cooling effect.

[0100] Tensile strength and elongation test: test object is finished product of cooling anti-UV nylon fabric. Test purpose: evaluate the mechanical strength performance and ductility of the fabric. Test principle: apply tensile load to the fabric under standard conditions until it breaks, measure the breaking strength and breaking elongation. Experimental method: prepare the fabric sample into standard test sample (width 50mm, gauge length 100mm), prepare 5 test samples in warp and weft directions respectively, use the universal material testing machine to test strictly according to the pre-tension and tensile speed specified in GB / T 3923.1, record the force-displacement curve and extract the breaking strength and breaking elongation. Standard basis: GB / T 3923.1-2013 "textile fabric tensile properties part 1: determination of breaking strength and breaking elongation (strip method)". Key parameters: standard atmospheric conditions temperature 20±2℃, relative humidity 65±4%, humidity adjustment≥24h, clamping distance 100mm, tensile speed 100±10mm / min, set the pre-tension according to the standard. Data processing: calculate the breaking strength (N), breaking elongation (%) and strength variation coefficient in warp and weft directions, report the strength per unit area or specific strength, report the mean value±standard deviation in warp and weft directions respectively.

[0101] Washing color fastness and UPF retention test: test object is cool feel anti-ultraviolet nylon fabric finished product. Test purpose: evaluate the color stability and ultraviolet protection performance retention rate of the fabric after domestic washing. Test principle: simulate the domestic washing conditions to carry out multiple washing cycles, and measure the color change and UPF value change of the fabric before and after washing. Experimental method: according to ISO 6330 domestic washing procedure combined with ISO 105-C06 standard, 0, 5, 10, 20 washing cycles are carried out, the color change and UPF value of the fabric are measured at each node, the specified drying procedure (line drying or flat drying) is adopted, and the color fastness grade and UPF retention rate are calculated. Standard basis: ISO6330:2012 Textiles - Domestic washing and drying procedures for textile testing, key parameters: washing temperature 40±2℃, select appropriate washing program according to ISO 6330, standard detergent, according to the specified drying procedure. Data processing: use gray sample card to evaluate the color change grade (1-5 grade), calculate the UPF retention rate=(washed UPF / initial UPF)×100%, record the mass loss and hand feeling change, require color change grade≥4 grade, UPF retention rate≥80%.

[0102] Thermal stability and thermal decomposition temperature test: test object is nylon 6 fiber sample containing composite filler. Test purpose: evaluate the influence of composite filler on the thermal stability of nylon 6 matrix and the temperature range of the material. Test principle: measure the change of sample mass with temperature under programmed temperature conditions, analyze the thermal decomposition process and characteristic temperature. Experimental method: take 5-10 mg of fiber sample, heat from room temperature to 600℃ at a heating rate of 10℃ / min and 5℃ / min under nitrogen and air atmosphere respectively, record the thermogravimetric curve and differential thermogravimetric curve, extract the initial decomposition temperature, maximum decomposition rate temperature and residual carbon rate, and compare and analyze the difference of oxidation stability. Standard basis: GB / T 6425-2008 Thermal gravimetric analysis method for determining the thermal stability of polymers. Key parameters: sample mass 5-10 mg, heating rate 10℃ / min and 5℃ / min, nitrogen and air flow 50 mL / min, temperature range 30-600℃, balance precision ±0.1 μg. Data processing: determine 5% mass loss temperature T5%, maximum decomposition rate temperature Tmaxand 600℃ residual carbon rate, analyze DTG peak decomposition stage, report the influence of filler residue on residual carbon rate.

[0103] Thermal Conductivity Test: Test object is finished cool- feeling anti-UV nylon fabric. Test purpose: Measure the thermal resistance and thermal conductivity of the fabric, and evaluate the contribution of thermal conductivity to the cool- feeling effect. Test principle: Measure the thermal resistance of the fabric based on the steady-state heat flow method, or use the laser flash method to measure the thermal diffusivity to calculate the thermal conductivity. Experimental method: Measure the thermal resistance Rct and moisture permeability resistance Ret of the fabric according to ISO 11092 standard, or use the laser flash method (ASTM E1461) to measure the thermal diffusivity a of the sheet, combined with the density p and specific heat Cp to calculate the thermal conductivity k = apCp, and compare with ordinary nylon fabric. Key parameters: Test environment temperature 35±1℃ (simulating human body), relative humidity 40±3%, wind speed 1±0.05m / s, sample area at least 0.025m². Data processing: Calculate the thermal resistance Rct (m²·K / W) or thermal conductivity k (W / m·K), calculate the relative percentage increase compared with ordinary nylon, and explain the limitations of the method, report the difference from ordinary nylon.

[0104] Moisture Permeability Test: Test object is finished cool- feeling anti-UV nylon fabric. Test purpose: Evaluate the water vapor transmission performance of the fabric to ensure wearing comfort. Test principle: Measure the amount of water vapor per unit area of fabric per unit time under standard temperature and humidity gradient conditions. Experimental method: According to ASTM E96 / E96M Procedure BW, seal the fabric sample on the moisture permeable cup, place desiccant in the cup, and place it in a 23℃ / 50%RH constant temperature and humidity environment, weigh and measure the water vapor transmission amount at specified wind speed conditions, and calculate the moisture permeability. Key parameters: Test temperature 23±1℃, relative humidity 50±2%, humidity adjustment ≥24h, test area 50cm², weighing interval according to standard, wind speed according to standard. Data processing: Calculate the moisture permeability WVT = Am / (At), unit g / (m²·24h), report mean ± standard deviation, and measure the air permeability (GB / T 5453) at the same time as a comfort supplement.

[0105] The systematic influence of each process parameter in the composite filler preparation and fiber forming process on the final UV protection and cooling performance is analyzed from Table 1 and Table 2. The results show 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 fillers in the composite fiber gradually increases, the UV scattering and absorption capacity significantly enhances, and the heat conduction path density increases. The UPF value and cooling effect show a clear concentration-dependent increasing trend. However, excessive addition amount may cause a decrease in spinning process stability and a moderate sacrifice of fiber 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 is significantly improved. Insufficient reaction of boric acid and urea precursors at low temperatures leads to a high proportion of amorphous structure, while suitable high temperature promotes the complete formation and highly ordered arrangement of h-BN layered lattice, directly improving the thermal conductivity and UV shielding efficiency of the composite filler. When the BN / TiO2 mass ratio is optimized from 1:8 in Comparative Example 3 to 1:6-1:4 in the example series, the synergistic balance of the heat conduction phase and the UV protection phase is improved. A low BN ratio limits the construction of the heat conduction network, affecting the cooling performance, while a reasonable ratio configuration achieves the best match of UV protection and heat conduction functions. When the TiO2 particle size is reduced from 150nm in Comparative Example 4 to 60-100nm in the example series, the specific surface area of the nanoparticles increases and the light scattering efficiency improves. Smaller particle sizes exhibit stronger Mie scattering effects in the ultraviolet band, but excessively small particle sizes may also pose agglomeration risks and challenges to dispersion stability. When the molar ratio of boric acid / urea precursors is adjusted from 1:1.2 in Comparative Example 5 to 1:2.5 in the example standard, the optimization of the stoichiometric relationship ensures the completeness of the hexagonal boron nitride generation reaction, avoiding the negative effects of unreacted precursor residues and byproduct generation on the final performance. Deviation of each processing parameter such as spinning temperature, surface modification temperature, draw ratio, heat treatment time, ultrasonic dispersion, secondary stretching temperature, and winding speed from the optimal range will affect the dispersion uniformity, interfacial bonding strength, fiber molecular chain orientation, and crystalline structure integrity of the composite filler in the polymer matrix, leading to a systematic decline in macroscopic functional performance. When all key parameters are optimally configured, such as the 3.0% limit addition amount in Example 4 combined with 75nm medium particle size and complete surface modification treatment, the composite fiber achieves an extreme UV protection effect of UPF 50+ and excellent instant cooling performance. Any significant deviation of a single parameter, such as the lack of surface modification treatment in Comparative Example 13, will lead to a dramatic deterioration of interfacial compatibility and a severe lack of wash fastness, fully verifying the key importance of multi-parameter synergistic optimization strategy for achieving high-performance functional textile materials.

[0106] Table 1 Core functional performance data table

[0107]

[0108] Table 2 Mechanical properties and wearability data

[0109]

[0110] Combining Figure 1 the morphology observation, Figure 2 XRD phase analysis and Figure 3 FTIR infrared characterization, the rationality, reliability and effectiveness of the scheme can be fully proved: first, Figure 1 the composite filler particles are uniformly dispersed, the interface is dense, the morphology is regular and there is no obvious agglomeration, which shows that the selected solvent system, stirring and dropwise adding rhythm can stably control the particle size and surface structure, and ensure the repeatable preparation of the composite filler from the micro level; second, Figure 2 the characteristic diffraction peaks in the standard card of the target crystal phase are one-to-one corresponding, the peak position is matched and the half width is moderate, and there is no impurity phase or only negligible weak impurity peaks, which shows that no destructive side reaction is introduced in the reaction process, the material crystallization is complete and the phase purity is high, which provides a structural basis for the subsequent performance stability; finally, Figure 3 in the FTIR spectrum, the epoxy characteristic peak (about 912 cm⁻¹) is significantly weakened or even disappeared, the Si–O–C bond stretching vibration (about 1055-1065 cm⁻¹) is obviously enhanced, and the O–H wide peak (about 3200-3500 cm⁻¹) and the aromatic ring skeleton peak (about 1600, 1500 cm⁻¹) are stable, which together indicates that the β-hydroxy ether bond has been successfully formed and the benzotriazole ultraviolet absorption unit is completely retained; and the Si–O–Si region (about 1115-1130 cm⁻¹) only shows weak shoulder or controlled enhancement, without significant condensation side reaction or decomposition characteristics, which comprehensively shows that the dropwise batch, temperature control and alkali-promoted reaction path accurately realizes the directional conversion from the raw material to the target silane coupling agent; thus, the uniform and dense morphology, the single phase from the crystallographic level and the characteristic bond from the molecular structure level confirm the triple evidences to each other, which proves that the preparation scheme of the present application has clear operability and process controllability within the process window, the structure of the obtained product can be verified, the purity can meet the requirements, and the stable performance and reliable repeatability required for application are met.

[0111] Figures 4 to 7The comprehensive experimental results fully prove the scientificity of the key process parameters of the technical scheme and the necessity of synergistic optimization, the 3-glycidyloxypropyltrimethoxysilane dosage optimization experiment shows that under the fixed basic conditions, the UPF value and qmax present a typical parabolic trend of first increasing and then decreasing when the silane dosage increases from 0.9 parts to 1.4 parts, when the dosage is insufficient, the molar ratio imbalance of reactants leads to incomplete coupling reaction, so that the UPF is only 31.2-45.2 and the qmax is only 0.158-0.208 W / cm², and when the dosage is excessive, the excessive silane causes side reactions and the purity of the product decreases, so that the performance decays to 42.1-46.3 UPF and 0.201-0.218 W / cm² qmax, the key finding is that the optimal point is at 1.2 parts, the UPF reaches the peak value of 52.1 and the qmax reaches the peak value of 0.238 W / cm²; the reaction temperature optimization experiment reveals that the temperature has a decisive influence on the coupling reaction efficiency, under the conditions of silane dosage of 1.2 parts and other process parameters fixed, the temperature increases from 60 DEG C to 85 DEG C, and the temperature-dependent performance change rule is exhibited, when the temperature is too low, the insufficient reaction activation energy leads to incomplete coupling reaction, which is characterized by UPF of only 35.8-47.3 and qmax of only 0.192-0.228 W / cm², and when the temperature is too high, high temperature promotes irreversible side reactions and product decomposition, leading to rapid performance decay to 43.5-46.8 UPF and 0.203-0.216 W / cm² qmax, the optimal reaction temperature appears at 72 DEG C, the UPF and qmax reach the peak values of 52.1 and 0.238 W / cm² respectively; the systematic study of the reserve liquid addition amount confirms the quantitative relationship between the surface modification degree and the performance, under the optimized conditions, when the reserve liquid dosage increases from 3 parts to 18 parts, a typical saturation curve characteristic is presented, when the addition amount is insufficient, the coupling agent coverage density is too low to form an effective modified layer, so that the UPF and qmax remain in the low-efficiency interval of 28.9-43.1 and 0.148-0.195 W / cm², and when the addition amount is excessive, the thick coating layer hinders the function of the composite filler, leading to performance degradation to 42.3-45.7 UPF and 0.194-0.209 W / cm² qmax, the key breakthrough point appears at 10 parts, the UPF and qmax reach the highest values of 52.1 and 0.238 W / cm² respectively; the heat treatment temperature experiment explains the optimal conditions of in-situ generation of h-BN from the perspective of material crystallography, under the standard process conditions, the heat treatment temperature increases from 500 DEG C to 700 DEG C, and the complete process of hexagonal boron nitride crystallization is exhibited, when the temperature is insufficient, the insufficient reaction driving force leads to incomplete h-BN crystallization, so that the proportion of amorphous structure is too high, and the UPF and qmax only reach 32.4-45.8 and 0.162-0.209 W / cm² respectively, and when the temperature is too high, the high temperature causes lattice defects and structure damage, so that the performance rapidly decays to 42.8-46.2 UPF and 0.198-0.213W / cm2 of qmax, the optimal heat treatment temperature is accurately positioned at 600℃, UPF and qmax reach the peak values of 52.1 and 0.238W / cm2 respectively, which correspond to the optimal crystallization temperature of hexagonal boron nitride, the four key process parameters all find the real performance optimum point and under the optimal condition combination, the peak performance of UPF 52.1 and qmax 0.238W / cm2 is achieved, which fully verifies the scientific rationality of the technical scheme parameter setting and the technical advancement of the multi-parameter synergistic optimization strategy.

[0112] Figures 7 to 13 The systematic experimental results fully verify the comprehensive advantages and technical advancement of the technical scheme of the present application, the influence of heat treatment temperature on the performance of the composite filler reveals the key role of temperature control in the in-situ generation process of hexagonal boron nitride, and determines the performance peak under the optimal crystallization condition; the UPF values and UPF retention rates of the examples and comparative examples show that the technical scheme of the present application is significantly superior to the traditional method in terms of ultraviolet protection performance, not only the initial protection effect is outstanding, but also excellent durability can be maintained after multiple washing; the thermal performance comparison experiment proves that the thermal network of hexagonal boron nitride in the composite filler is successfully constructed, realizing the significant cooling effect and the improvement of thermal conductivity performance; the mechanical property test results of breaking strength and elongation at break show that the present application effectively maintains the basic mechanical properties of the fiber while ensuring the functionality, avoiding the common strength loss problem in the traditional functional modification process; the comprehensive performance evaluation of T5% thermal decomposition temperature and moisture permeability shows that the modified functional fiber meets the practical requirements in terms of thermal stability and comfort, the improvement of T5% temperature proves the positive contribution of the composite filler to the thermal stability of the polymer matrix, and the optimized balance of moisture permeability ensures the wearing comfort of the fabric, the systematic improvement of the six key performance indicators fully proves the scientificity, advancement and practicality of the multifunctional composite filler preparation technology and fiber functionalization strategy of the present application.

[0113] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application and not to limit it, although the present application has been described in detail with reference to the above examples, those skilled in the art should understand that any equivalent structural transformation made under the concept of the present application and using the contents of the present application specification and drawings should be covered within the protection scope of the claims of the present application.

Claims

1. A cool-feeling, ultraviolet resistant nylon fabric, characterized by, The fabric is woven by nylon 6 filaments and obtained after finishing; the fiber matrix of the nylon 6 filaments is dispersed with surface-modified boron nitride / titanium dioxide composite filler; the composite filler comprises anatase titanium dioxide nanoparticles and hexagonal boron nitride loaded on the surface thereof; the composite filler has a β-hydroxy ether type ultraviolet absorption silane coupling agent modified layer on the surface thereof; the addition amount of the composite filler in the nylon 6 is 0.8%-3.0% by mass fraction; The β-hydroxy ether type ultraviolet absorption silane coupling agent comprises the following raw materials by weight fraction: 2-(2'-hydroxy-5'-methylphenyl) benzotriazole 1 part, 3-glycidyl ether oxypropyl trimethoxysilane 1.1-1.3 parts, tetrabutylammonium bromide 0.05-0.1 parts, anhydrous potassium carbonate 1.2-1.5 parts; The average particle size of the anatase titanium dioxide nanoparticles is 60 nm-100 nm; the hexagonal boron nitride is generated in situ by heat treatment of a precursor containing boric acid and urea under nitrogen protection and is loaded on the surface of the titanium dioxide, the molar ratio of boric acid to urea is 1:1.8-1:2.5; the composite filler is surface-modified by the β-hydroxy ether type ultraviolet absorption silane coupling agent; The mass ratio of hexagonal boron nitride to anatase titanium dioxide in the composite filler is 1:3-1:

6.

2. The cooling and UV-resistant nylon fabric as described in claim 1, characterized in that, The ultraviolet protection factor UPF of the fabric is not less than 40 and the UPF retention rate after 20 household washing cycles is not less than 80%; the contact instantaneous cool feeling qmax of the fabric is not less than 0.20 W / cm².

3. The process for preparing the cool and UV resistant nylon fabric according to claim 1, characterized in that, The method comprises the following steps: S1. Master batch preparation: dry nylon 6 chips at 80-100°C under vacuum for 4-6h to reduce the moisture content to less than 0.02%; according to the weight ratio, add 8-15 parts of surface-modified boron nitride / titanium dioxide composite filler, 0.5-2 parts of antioxidant 1010, 0.3-1 part of ultraviolet absorber UV-531 and 0.2-0.8 parts of calcium stearate to 100 parts of dried nylon 6 chips, melt blend and extrude in a twin-screw extruder at a screw temperature of 220-240°C and a screw rotation speed of 80-120 rpm, cut into granules after water cooling to obtain a functional master batch; S2. Spinning raw material preparation: mix 80-92 parts of nylon 6 chips with 8-20 parts of functional master batch and vacuum dry to reduce the moisture content to less than 0.02%; S3. Melt spinning and drawing: melt plasticize the spinning raw material at a screw temperature of 230-250°C and a metering pump temperature of 240-260°C, extrude through a spinneret with a hole number of 24-72 and a hole diameter of 0.20-0.35 mm at a spinning temperature of 250-270°C after precision filtration, and cool and solidify by side blowing; primary drawing is performed at a winding speed of 600-1200 m / min and a winding tension of 0.15-0.25 cN / dtex, and the drawing ratio is 3.5-4.8; then secondary stretching is performed at 80-120°C, and the stretching ratio is 1.3-1.8; S4. Weaving and finishing: the obtained filaments are woven into fabric gray cloth, and the fabric gray cloth is pre-shrunk, refined, shaped, and soft finished to obtain the cool and ultraviolet resistant nylon fabric.

4. The method for preparing a cooling and UV-resistant nylon fabric as described in claim 3, characterized in that, The preparation method of the surface-modified boron nitride / titanium dioxide composite filler comprises the following steps: A1. Disperse 100 parts of boron nitride / titanium dioxide composite filler in 300-500 parts of anhydrous toluene or anhydrous xylene by weight, and ultrasonically disperse for 10-20 min; A2. Prepare a stock solution of a β-hydroxy ether type ultraviolet absorbing silane coupling agent with a mass fraction of 20%-30% in toluene or xylene; A3. Under nitrogen protection, add 5-15 parts of the stock solution of step A2 to the dispersion liquid of step A1 dropwise, control the reaction system temperature to be 80-120℃, and react for 2-6 h; A4. After reaction, separate by filtration, wash 2-3 times with anhydrous ethanol, and vacuum dry at 60-80℃ for 4-8 h to obtain the surface-modified boron nitride / titanium dioxide composite filler.

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

6. The method for preparing a cooling and UV-resistant nylon fabric as described in claim 4, characterized in that, The preparation method of the beta-hydroxy ether type ultraviolet absorption silane coupling agent takes 2-(2'-hydroxy-5'-methylphenyl) benzotriazole 1 part, 3-glycidyl ether oxypropyl trimethoxysilane 1.1-1.3 parts, tetrabutylammonium bromide 0.05-0.1 parts, anhydrous potassium carbonate 1.2-1.5 parts as raw materials, under the protection of nitrogen, 2-(2'-hydroxy-5'-methylphenyl) benzotriazole, tetrabutylammonium bromide and anhydrous potassium carbonate are sequentially added into a reaction bottle containing 5-10 parts of anhydrous acetonitrile dried by molecular sieves, after stirring and dissolving, the temperature is increased to 65-80 DEG C, then 3-glycidyl ether oxypropyl trimethoxysilane is added dropwise into the reaction system in 3-4 batches, the dropwise adding time of each batch is 10-15 minutes, the interval time of each batch is 20-30 minutes, after the dropwise adding is completed, the reaction is continued for 6-8 hours, after the reaction is completed, the temperature is cooled to room temperature, the inorganic salt is removed by filtration, the filtrate is distilled under reduced pressure to remove the solvent to obtain a crude product, the crude product is purified by silica gel column chromatography, a mixed solvent of n-hexane and ethyl acetate with a volume ratio of 3:1 to 5:1 is used as an eluent to perform gradient elution, and the beta-hydroxy ether type ultraviolet absorption silane coupling agent is obtained, the HPLC purity of the obtained product is not less than 95%.

7. The method for preparing a cooling and UV-resistant nylon fabric as described in claim 3, characterized in that, In the S4 step, the warp density is 180-220 per 10 cm, the weft density is 160-200 per 10 cm; the pre-shrinking temperature is 95-100 DEG C, the time is 10-15 min; the scouring temperature is 60-80 DEG C, the time is 15-20 min, a non-ionic surfactant is used; the setting temperature is 160-180 DEG C, and the speed is 15-25 m / min; the soft finishing temperature is 40-60 DEG C, and an amino silicone oil softener is used.

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