A kind of anti-ultraviolet textile material and preparation method thereof

Abstract

The present invention belongs to the field of textile materials, and specifically relates to an anti-ultraviolet textile material and a preparation method thereof. The method comprises: (1) preparing a resin substrate from a polymer, a copolymer and an organic anhydride; (2) preparing and modifying a nano inorganic salt, an organic titanium, an alcohol compound and a ketone compound to prepare modified nano particles; (3) preparing carbon sources from acyclic carboxylic acids and amino acids by pyrolysis and preparing carbonized polymer particles with a polymer elastomer; (4) preparing a precursor from the resin substrate, the modified nano particles and the carbonized polymer particles; (5) preparing a melt spinning, cooling and stretching the precursor as a raw material to prepare an anti-ultraviolet textile material. The present invention improves the wet air permeability retention rate of the textile and prolongs the service life of the textile in extreme environments by optimizing the ultraviolet protection performance of the fiber material and structure.

Description

Technical Field

[0001] The invention belongs to the field of textile materials, and in particular relates to an anti-ultraviolet textile material and a preparation method thereof. Background Art

[0002] In the field of outdoor sportswear, medical protective textiles and special military equipment, anti-UV fiber materials have long faced two major technical difficulties: First, the lack of durability in protection. Traditional UV shielding agents, such as TiO2 / PEG coatings, have a UPF value decay of more than 40% after 20 washes due to physical attachment on the surface, which causes the functional particles to fall off. Second, it is difficult to strike a balance between comfort and protection. Although a high content of inorganic nanoparticles of >5wt% can increase the UPF to 50+ and improve the protective effect, it causes the fiber breaking strength to decrease by 18-22%, and the air permeability of the fabric to decrease by about 37%, resulting in a significant decrease in its physical properties and air permeability, and a significant decrease in comfort.

[0003] In the face of the above dilemma, there are currently three main solutions. First, co-spinning is used to blend ZnO nanoparticles with polyester melt, but when the particle size is greater than 30nm, the fiber haze is greater than 85%, which will lead to the loss of the transparent texture demand of textiles and the decrease in comfort and breathability; second, the in-situ mineralization method, constructing metal organic frameworks such as ZIF-8 in cellulose fibers, although it improves washability, but the thermal stability of MOFs is less than 280℃, which is incompatible with the melt spinning process, and the product yield and yield rate are difficult to improve. The cost of industrialization is extremely high, and it is currently limited to experimental research; third, biomimetic method, Rubik's Cube Biology constructs multi-layer reflection, refraction, and interference films to reduce ultraviolet penetration, but the multi-layer film interference structure cannot maintain continuity in the fiber axis, and the actual UPF is far from reaching the theoretical value. The highest value currently recorded is only 32% of the theoretical value.

[0004] In this regard, our R&D personnel have pioneered ideas for modifying and optimizing textile materials from other angles. They can achieve anti-UV effects through the intrinsic mechanisms of directional UV band shielding and dynamic energy dissipation, so that the material itself has good stability. At the same time, they can significantly optimize the anti-UV effect of textile material fabric products, and achieve better anti-UV performance in a lighter and thinner state. They can also greatly maintain the breathability of the fabric while achieving anti-UV, greatly improving comfort. Summary of the invention

[0005] The technical solution of the present invention aims to solve the problem that traditional anti-ultraviolet fibers have poor air permeability in hot and humid environments and cannot meet the needs of hot and sweaty environments, and provides an anti-ultraviolet textile material and a preparation method thereof.

[0006] The main purposes of the present invention are: 1. Improving the wet air permeability retention rate of textiles through material modification.

[0007] 2. Enhance UV protection of textiles.

[0008] 3. Maintain the comfort and durability of textiles.

[0009] To achieve the above objectives, the present invention adopts the following technical solutions.

[0010] A method for preparing an anti-ultraviolet textile material comprises: (1) uniformly mixing a polymer, a copolymer and an organic acid anhydride in proportion, melt blending and granulating to prepare a resin substrate.

[0011] (2) The nano inorganic salt, organic titanium, alcohol compound and ketone compound are mixed evenly in proportion to prepare nano particles, and then immersed in a modification liquid to prepare modified nano particles.

[0012] (3) The acyclic carboxylic acid and the amino acid are mixed uniformly in proportion, and pyrolyzed to prepare a carbon source. The carbon source and the polymer elastomer are mixed uniformly in proportion to prepare carbonized polymer particles.

[0013] (4) The resin substrate, modified nanoparticles and carbonized polymer particles are mixed evenly in proportion, and the particles are melted to prepare a precursor.

[0014] (5) The precursor is used as a raw material for melt spinning, cooling and drawing to prepare UV-resistant textile materials.

[0015] Preferably, the polymer in step (1) is polycaprolactam; the copolymer in step (1) is polyether block amide; the organic anhydride in step (1) is maleic anhydride; and the polymer, copolymer and organic anhydride in step (1) are uniformly mixed in a mass ratio of (85-92):(8-15):0.5.

[0016] Preferably, the melt blending in step (1) is performed by melt stirring for 3 to 5 min at an ambient temperature of 240 to 250 °C; and the granulation in step (1) is performed by using a twin-screw extruder with a temperature of 240 to 250 °C, a screw speed of 280 to 320 rpm, and a feed rate of 14 to 18 kg / h.

[0017] Preferably, the nano inorganic salt in step (2) is nano zinc oxide; the organic titanium in step (2) is tetrabutyl titanate; the alcohol compound in step (2) is ethanol; the ketone compound in step (2) is acetylacetone; and the nano inorganic salt, organic titanium, alcohol compound and ketone compound in step (2) are uniformly mixed in a mass ratio of (4.8-5.2):(3-3.5):(48-52):1.

[0018] Preferably, the specific steps of preparing the nanoparticles in step (2) are: firstly, ultrasonicating the mixture for 30 to 40 minutes, secondly, aging it in an environment with a temperature of 45 to 55°C for 20 to 28 hours, and finally, calcining it in an environment with a temperature of 430 to 470°C for 1 to 3 hours.

[0019] Preferably, the modified liquid in step (2) is composed of γ-aminopropyltriethoxysilane, ethanol and distilled water, wherein γ-aminopropyltriethoxysilane accounts for 3-5%VOL, distilled water accounts for 25-30%VOL, and the balance is ethanol; and the immersion in step (2) is carried out by keeping warm in an environment with a temperature of 38-42°C for 1.75-2.25 h.

[0020] Preferably, the acyclic carboxylic acid in step (3) is citric acid; the amino acid in step (3) is L-cysteine; the acyclic carboxylic acid and the amino acid in step (3) are mixed uniformly in a mass ratio of (5-5.5):1; the pyrolysis in step (3) is carried out by heat preservation for 1.5-2.5 h in an environment with a pressure of 2-3 KPa and a temperature of 180-220 °C; the polymer elastomer in step (3) is polyethylene glycol; the carbon source and the polymer elastomer in step (3) are mixed uniformly in a mass ratio of 1:(40-60); the carbonized polymer in step (3) is reacted in an environment with a temperature of 35-45 °C and a pH of 5-7 for 10-14 h.

[0021] Preferably, in the precursor of step (4), the mass proportion of modified nanoparticles is 18-22 wt%, the mass proportion of carbonized polymer particles is 4-6 wt%, and the balance is resin substrate; the molten plasmid in step (4) is a twin-screw extruder with a temperature of 220-235 °C, a screw speed of 240-260 rpm, and a vacuum degree of -0.08 MPa.

[0022] Preferably, the melt spinning in step (5) uses a three-leaf spinneret with an aspect ratio of 3:1, and the single filament diameter is 18 to 22 μm; the cooling in step (5) is cooling to room temperature under environmental conditions of a wind speed of 0.5 to 1 m / s, a temperature of 15 to 20°C, and a humidity of 65%; the stretching in step (5) is a multi-stage stretching, wherein the first stage stretching is to stretch the fiber to 3 to 4 times the original length at a temperature of 80 to 90°C; and the second stage stretching is to stretch the fiber to 1 to 1.5 times the length of the first stage stretching at a temperature of 100 to 120°C.

[0023] A UV resistant textile material.

[0024] The core of the solution of the present invention is to optimize the raw materials so that the textile has a pore-maintaining effect, so that the textile has a breathable mechanism that is less affected by humidity.

[0025] In the field of textile materials, although the current anti-ultraviolet fibers have made some contributions in resisting ultraviolet rays, they still have functional defects. When such fibers are wet, water will form a liquid phase blocking layer in the mesoporous and microporous areas through the capillary condensation effect, and the blockage will cause the air permeability to be significantly reduced. According to the principles of fluid mechanics and mass transfer, the reduced air permeability makes the air circulation blocked, and the heat and moisture of the human body cannot be dissipated in time, resulting in a stuffy feeling when wearing, which seriously affects the comfort. In view of the difficulties of the prior art, the present invention proposes an innovative technical solution. The present invention utilizes the conformational memory effect of polyether block polyamide polymer to enable the textile to have a pore maintenance effect. The polymer has a special molecular structure and undergoes reversible conformational changes under different environments. When absorbing water and swelling, the molecular chain specifically stretches and rearranges, expanding the preset microgroove channels on the surface or inside of the fiber. This dynamic pore maintenance mechanism can ensure smooth air circulation even when the fiber is wet, avoid the decrease in air permeability caused by pore blockage, and significantly improve the air permeability and wearing comfort of fiber products. In addition, the present invention introduces carbonized polymer particles to optimize fiber performance. The surface of carbonized polymer particles contains a variety of polar groups, which form hydrogen bonds with water molecules. The formation of hydrogen bonds is selective and directional. The particles specifically capture water molecules and bind them on the surface or inside, reducing the probability of free water accumulation and clogging pores, ensuring smooth pores. The surface of carbonized polymer particles also carries sulfonic acid groups, which are acidic and undergo ion exchange reactions with environmental cations, changing the charge distribution on the fiber surface and reducing the surface free energy. At the same time, the principle of capillary phenomenon shows that the free energy of the fiber surface is reduced, which promotes the diffusion of water along the axial or radial direction of the fiber and accelerates the evaporation of water.

[0026] In the scheme of the present invention, another core point is that through the construction of a multi-stage ultraviolet energy dissipation system, while ensuring that the textile has a strong anti-ultraviolet effect, its mechanical properties are significantly optimized and the service life of the fiber products is extended.

[0027] In the field of textile materials, current anti-ultraviolet fibers have the phenomenon of UV-humidity and heat synergistic degradation. The three environmental factors of ultraviolet radiation, humidity and temperature interact with each other. Especially under high temperature and high humidity conditions, ultraviolet energy stimulates the activity of fiber molecular chains and is easy to react chemically with water vapor. Increased humidity provides reactants, and high temperature accelerates the reaction rate. The three work together to accelerate fiber aging. Aging is manifested as a decrease in physical properties (such as strength and toughness) and chemical properties (such as anti-ultraviolet properties and dyeing properties), shortening the service life of fiber products. This technical solution constructs a ZnO@TiO2 core-shell heterojunction system with directional energy transfer characteristics through molecular engineering design and interface regulation technology, and realizes the topological epitaxial growth of TiO2 on the surface of ZnO nanocrystals through surface coordination chemical reactions. This special band structure induces a significant band bending effect, generates a built-in electric field under ultraviolet light, drives photogenerated electrons to migrate along the ZnO→TiO2 direction, and realizes carrier spatial separation. Compared with the pure ZnO system, the physical barrier effect of the TiO2 shell reduces the contact probability between ZnO and H2O / O2, and constructs a Schottky barrier at the same time. The height of the Schottky barrier induced by the TiO2 shell increases the activation energy that electron migration needs to overcome, inhibits electron-hole recombination, and prolongs the carrier lifetime. In addition, the surface oxygen vacancies act as electron traps to promote the disproportionation reaction of superoxide radicals and inhibit the generation of reactive oxygen. The present invention introduces a carbonized polymer to construct a Z-type heterojunction system. The surface plasmon resonance effect of the carbonized polymer enhances the separation efficiency of photogenerated electron-hole pairs and further promotes the dissipation of ultraviolet energy. Under ultraviolet light irradiation, the ZnO@TiO2 core-shell heterojunction system absorbs ultraviolet photons and excites the generation of electron-hole pairs. Due to the band bending effect, electrons are transferred from the conduction band of ZnO to the conduction band of TiO2, while holes remain in the valence band of ZnO. At the same time, the carbonized polymer particles act as electron acceptors to accept electrons from the conduction band of TiO2 to form a Z-type heterojunction system. This structure not only effectively separates electron-hole pairs, but also reduces the probability of electron-hole recombination, thereby improving the utilization efficiency of ultraviolet energy. In addition, the present invention uses γ-aminopropyltriethoxysilane to perform molecular layer deposition on the fiber surface, and constructs a monolayer amino functionalized interface on the TiO2 surface through a hydrolysis condensation reaction (-Si-O-Ti-), thereby promoting interfacial charge transfer. At the same time, the modification process induces the generation of surface oxygen vacancies, forms new defect energy levels, and broadens the light response range.

[0028] In the scheme of the present invention, the last core point is to achieve the synergistic enhancement of the mechanical properties and functionality of the material by restricting the fiber spinning conditions.

[0029] In the prior art, adding functional additives to fibers often leads to problems such as deterioration of spinning processability and loss of fiber strength. Functional additives may produce complex interactions with fiber polymer molecules, including strong hydrogen bonding, electrostatic interactions, or steric hindrance effects. These interactions will interfere with the orderly arrangement and relative sliding of polymer molecular chains, resulting in significant changes in the melt viscosity of the material, which no longer meets the rheological properties required by the spinning process. This abnormal fluctuation in viscosity will cause melt rupture, uneven filaments, and increased breakage during the spinning process, seriously interfering with the continuity and stability of spinning. The introduction of functional additives may affect the strength of the fiber in many ways. On the one hand, the dispersion of additives inside the fiber is difficult to achieve an ideal uniform state, and it is easy to form local agglomerations or concentration gradients. These uneven areas become stress concentration points inside the fiber. Under the action of external forces, stress will preferentially concentrate in these weak parts, thereby initiating the initiation and expansion of cracks and reducing the overall strength of the fiber. On the other hand, the interfacial bonding between the functional additive and the fiber polymer may be insufficient. When subjected to external forces, debonding may easily occur at the interface, making it impossible for the fiber to effectively transmit and disperse stress, further weakening the fiber's load-bearing capacity. In addition, the chemical properties of the additive may be incompatible with the fiber polymer. During long-term use, it may trigger a chemical reaction, destroy the fiber's molecular chain structure, and cause the fiber strength to gradually decrease over time.

[0030] In the present invention, in order to improve the fiber structure and its performance, a three-leaf structure is constructed by adopting a special-shaped cross-section design to enhance the comprehensive performance of the fiber. The bending stiffness of the fiber is a key indicator to measure its ability to resist bending deformation, and has a decisive influence on the morphological retention and mechanical performance of the fiber in practical applications. The introduction of the three-leaf structure significantly increases the moment of inertia of the fiber by changing the cross-sectional geometry of the fiber, and the increase in the moment of inertia directly leads to an effective improvement in the bending stiffness of the fiber. In the fiber system involved in the present invention, although the addition of polyether block polyamide gives the fiber functional characteristics, it inevitably leads to a loss in the fiber modulus. The improvement in bending stiffness brought about by the three-leaf structure appropriately compensates for the modulus loss caused by the addition of polyether block polyamide, ensuring that the fiber can maintain a good balance of mechanical properties while having new functions.

[0031] In the present invention, a chemical reaction occurs between the amino group of the carbonized polymer and the carboxyl group at the end of the polyamide. The amino group has a strong nucleophilicity and can undergo a nucleophilic addition-elimination reaction with the carboxyl group at the end of the polyamide to eventually form a graft copolymer. The formation of the graft copolymer means that a tighter and more stable chemical bond connection is established between the carbonized polymer and the polyamide. Compared with simple physical mixing, this chemical bond connection greatly improves the interfacial bonding force between the two. The enhancement of the interfacial bonding force has many positive effects on the improvement of the overall performance of the fiber. It helps to achieve more effective stress transfer between different components, so that the fibers can work together as a whole when subjected to stress, avoiding performance degradation caused by interface debonding. This enhanced interfacial bonding force can improve the tensile strength, toughness and other mechanical performance indicators of the fiber, and may also have a positive indirect effect on the thermal stability, chemical corrosion resistance and other properties of the fiber, thereby comprehensively improving the comprehensive performance of the fiber.

[0032] In addition, the present invention adopts multi-stage drawing-induced crystallization technology in the fiber forming process. The crystal morphology and structure have an impact on the physical and chemical properties of the fiber. Different crystal forms have different molecular arrangements and lattice parameters, which leads to significant differences in density, hardness, tensile strength, thermal stability and other aspects of the fiber. In the multi-stage drawing-induced crystallization process, the molecular chains of the first-stage drawing fibers are gradually arranged in an orderly manner, inducing the formation of α crystals. The α crystal usually has a relatively regular molecular arrangement structure, and its formation helps to preliminarily construct the crystal skeleton of the fiber, laying the foundation for subsequent crystal transformation and performance optimization. Subsequently, the second-stage drawing further plays a role on this basis, promoting the transformation of the β crystal, and having better flexibility and plasticity.

[0033] The advantages of the present invention are: by optimizing the ultraviolet protection performance of the fiber material and structure, the wet air permeability retention rate of the textile is improved, and the service life of the textile in extreme environments is extended. DETAILED DESCRIPTION

[0034] The present invention is further described in detail below in conjunction with specific embodiments. Those of ordinary skill in the art will be able to implement the present invention based on these descriptions. In addition, the embodiments of the present invention involved in the following description are generally only embodiments of a part of the present invention, rather than all embodiments. Therefore, based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work should fall within the scope of protection of the present invention.

[0035] Unless otherwise specified, the raw materials used in the examples of the present invention are all commercially available or available to those skilled in the art; unless otherwise specified, the methods used in the examples of the present invention are all methods known to those skilled in the art.

[0036] Example 1: A method for preparing an anti-ultraviolet textile material, the method comprising: (1) uniformly mixing polycaprolactam, polyether block amide and maleic anhydride in a mass ratio of 85:8:0.5, melt-stirring at a temperature of 240°C for 5 min, and granulating using a twin-screw extruder with a temperature of 240°C, a screw speed of 280 rpm and a feed rate of 14 kg / h to prepare a resin substrate.

[0037] (2) Nano zinc oxide, tetrabutyl titanate, ethanol and acetylacetone were uniformly mixed in a mass ratio of 4.8:3:48:1, and the mixture was ultrasonicated for 40 min. Next, the mixture was aged at 45 °C for 28 h, and finally calcined at 430 °C for 3 h to prepare nanoparticles. The nanoparticles were immersed in a modifying liquid at 38 °C for 2.25 h to prepare modified nanoparticles. The modifying liquid consisted of γ-aminopropyltriethoxysilane, ethanol and distilled water, wherein γ-aminopropyltriethoxysilane accounted for 3%VOL, distilled water accounted for 25%VOL, and the balance was ethanol.

[0038] (3) Citric acid and L-cysteine ​​were mixed in a mass ratio of 5:1, and pyrolyzed in an environment with a pressure of 2 KPa and a temperature of 180°C for 2.5 h to prepare a carbon source. The carbon source and polyethylene glycol were mixed in a mass ratio of 1:40, and reacted in an environment with a temperature of 35°C and a pH of 5 for 14 h to prepare carbonized polymer particles.

[0039] (4) The precursor contains 18 wt% of modified nanoparticles, 4 wt% of carbonized polymer particles, and the remainder is resin matrix. The precursor is prepared by a twin-screw extruder with a temperature of 220 °C, a screw speed of 240 rpm, and a vacuum degree of -0.08 MPa.

[0040] (5) Using the precursor as the raw material, a three-leaf spinneret with an aspect ratio of 3:1 was used for melt spinning with a single filament diameter of 18 μm. The fiber was cooled to room temperature under the environmental conditions of a wind speed of 0.5 m / s, a temperature of 15°C, and a humidity of 65%. The fiber was stretched to 3 times of its original length at a temperature of 80°C for the first stage stretching. The fiber was stretched to 1 times of the first stage stretching length at a temperature of 100°C for the second stage stretching to prepare an anti-ultraviolet textile material.

[0041] The anti-ultraviolet textile material prepared in this example is made into 150 g / m 2 The single-layer plain fabric was tested for performance, and the specific characterization results are as follows.

[0042] Dry UPF value test: Refer to the dry test sample test method in AATCC TM 183 "Textile Ultraviolet Protection Factor UPF Test Standard" to test the ability of textile fabrics to block ultraviolet radiation.

[0043] Wet UPF value test: Use 0.9% NaCl solution to simulate sweat infiltration, and the test method is the same as the dry UPF test.

[0044] Air permeability: Refer to the test method of ASTM D737 "Standard Test Method for Permeability of Textiles" to test the dry test sample, and then use 0.9% NaCl solution to simulate sweat infiltration of the test sample, so that the water content of the test sample is 30%, and then conduct wet air permeability test.

[0045] Capillary effect test: refer to the one-way combined test method in GB / T 21655.1 "Evaluation of moisture absorption and quick-drying properties of textiles" to test the wicking height of the fabric after 30 minutes.

[0046] Strength test after wet heat aging: The fabric is laid flat and fixed in a UV irradiation chamber with a temperature of 0.8 W / m 2 The samples were placed in a test box with a temperature of 60 ℃ and an initial humidity of 95% for 400 h, and the humidity in the test box was adjusted to 95% every 4 h. The retention rate of mechanical properties was then recorded.

[0047] Life test: The fabric is washed 50 times at 40°C according to ISO 6330 standard, and the dry UPF value of the fabric is tested.

[0048]

[0049] Example 2: A method for preparing an anti-ultraviolet textile material, the method comprising: (1) uniformly mixing polycaprolactam, polyether block amide and maleic anhydride in a mass ratio of 88:11.5:0.5, melt-stirring the mixture at a temperature of 245°C for 4 min, and granulating the mixture using a twin-screw extruder at a temperature of 245°C, a screw speed of 300 rpm and a feed rate of 16 kg / h to prepare a resin substrate.

[0050] (2) Nano zinc oxide, tetrabutyl titanate, ethanol and acetylacetone were uniformly mixed in a mass ratio of 5:3.3:50:1, and the mixture was ultrasonicated for 35 min. Next, the mixture was aged at 50 °C for 24 h, and finally calcined at 450 °C for 2 h to prepare nanoparticles. The nanoparticles were immersed in a modifying liquid at 40 °C for 2 h to prepare modified nanoparticles, wherein the modifying liquid consisted of γ-aminopropyltriethoxysilane, ethanol and distilled water, wherein γ-aminopropyltriethoxysilane accounted for 4%VOL, distilled water accounted for 27%VOL, and the balance was ethanol.

[0051] (3) Citric acid and L-cysteine ​​were mixed in a mass ratio of 5.3:1, and pyrolyzed in an environment with a pressure of 2.5 KPa and a temperature of 200 °C for 2 h to prepare a carbon source. The carbon source and polyethylene glycol were mixed in a mass ratio of 1:50, and reacted in an environment with a temperature of 40 °C and a pH of 6 for 12 h to prepare carbonized polymer particles.

[0052] (4) The modified nanoparticles account for 20 wt% of the precursor, the carbonized polymer particles account for 5 wt% of the precursor, and the remainder is the resin matrix. The precursor is made by a twin-screw extruder with a temperature of 230 °C, a screw speed of 250 rpm, and a vacuum degree of -0.08 MPa.

[0053] (5) Using the precursor as the raw material, a three-leaf spinneret with an aspect ratio of 3:1 was used for melt spinning with a single filament diameter of 20 μm. The fiber was cooled to room temperature under the environmental conditions of a wind speed of 0.75 m / s, a temperature of 17.5 °C, and a humidity of 65%. The fiber was stretched to 3.5 times of its original length at a temperature of 85 °C for the first stage stretching. The fiber was stretched to 1.25 times of the first stage stretching length at a temperature of 110 °C for the second stage stretching to prepare an anti-ultraviolet textile material.

[0054] The anti-ultraviolet textile material prepared in this example is made into 150 g / m 2 The single-layer plain fabric was tested for performance, and the specific characterization results are as follows.

[0055]

[0056] Analysis of the above characterization results Compared with Example 1, Example 2 increases the content of polyether block amide by carefully adjusting the raw material ratio, preparation conditions and spinning parameters, thereby enhancing the flexibility and elasticity of the fiber. This makes the fabric more comfortable and durable while maintaining high strength and UV resistance. At the same time, increasing the preparation temperature of the nanoparticles and shortening the aging time help to obtain nanoparticles with smaller particle size and more uniform distribution, thereby further improving the UV resistance of the fiber. In addition, adjusting the preparation conditions of the carbonized polymer particles, such as increasing the pyrolysis temperature and adjusting the pH value of the reaction environment, helps to improve the interface bonding between the carbonized polymer and the fiber polymer, thereby improving the overall performance of the fiber. In the spinning process, by increasing the monofilament diameter and adjusting the draft multiple, the crystal morphology and structure of the fiber can be further optimized, so that the fiber maintains good air permeability and hygroscopicity while maintaining excellent physical properties. These fine adjustments work together in the preparation process of the fiber, so that the UV-resistant textile material prepared in Example 2 is significantly improved in various performance indicators.

[0057] Example 3: A method for preparing an anti-ultraviolet textile material, the method comprising: (1) uniformly mixing polycaprolactam, polyether block amide and maleic anhydride in a mass ratio of 92:15:0.5, melt-stirring at a temperature of 250°C for 3 min, and granulating using a twin-screw extruder with a temperature of 250°C, a screw speed of 320 rpm and a feed rate of 18 kg / h to prepare a resin substrate.

[0058] (2) Nano zinc oxide, tetrabutyl titanate, ethanol and acetylacetone were uniformly mixed in a mass ratio of 5.2:3.5:52:1, and the mixture was ultrasonicated for 30 min. Next, the mixture was aged at 55 °C for 20 h, and finally calcined at 470 °C for 1 h to prepare nanoparticles. The nanoparticles were immersed in a modifying liquid at 42 °C for 1.75 h to prepare modified nanoparticles, wherein the modifying liquid consisted of γ-aminopropyltriethoxysilane, ethanol and distilled water, wherein γ-aminopropyltriethoxysilane accounted for 5%VOL, distilled water accounted for 30%VOL, and the balance was ethanol.

[0059] (3) Citric acid and L-cysteine ​​were mixed in a mass ratio of 5.5:1, and pyrolyzed in an environment with a pressure of 3 KPa and a temperature of 220 °C for 1.5 h to prepare a carbon source. The carbon source and polyethylene glycol were mixed in a mass ratio of 1:60, and reacted in an environment with a temperature of 45 °C and a pH of 7 for 10 h to prepare carbonized polymer particles.

[0060] (4) The precursor contains 22 wt% of modified nanoparticles, 6 wt% of carbonized polymer particles, and the remainder is resin matrix. The precursor is prepared by a twin-screw extruder with a temperature of 235 °C, a screw speed of 260 rpm, and a vacuum degree of -0.08 MPa.

[0061] (5) The precursor was used as the raw material and a three-leaf spinneret with an aspect ratio of 3:1 was used for melt spinning with a single filament diameter of 22 μm. The fiber was cooled to room temperature under the environmental conditions of a wind speed of 1 m / s, a temperature of 20°C, and a humidity of 65%. The fiber was stretched to 4 times of its original length at a temperature of 90°C for the first stage stretching. The fiber was stretched to 1.5 times of the first stage stretching length at a temperature of 120°C for the second stage stretching to prepare an anti-ultraviolet textile material.

[0062] The anti-ultraviolet textile material prepared in this example is made into 150 g / m 2 The single-layer plain fabric was tested for performance, and the specific characterization results are as follows.

[0063]

[0064] Analysis of the above characterization results Compared with Example 1 and Example 2, Example 3 makes further adjustments in terms of raw material ratio, preparation conditions and spinning parameters to increase the content of polyether block amide, thereby enhancing the flexibility and elasticity of the fiber. This not only maintains the high strength and UV resistance of the fabric, but also makes it softer and more durable. At the same time, by increasing the preparation temperature of the nanoparticles and extending the aging time, it is helpful to obtain nanoparticles with suitable particle size and uniform distribution, thereby further enhancing its UV resistance while maintaining the high strength and toughness of the fiber. In addition, adjusting the preparation conditions of the carbonized polymer particles, such as increasing the pyrolysis temperature and further adjusting the pH value of the reaction environment, helps to further improve the interface bonding between the carbonized polymer and the fiber polymer, thereby improving the overall performance of the fiber. During the spinning process, by increasing the monofilament diameter and adjusting the draft multiple, the crystal morphology and structure of the fiber can be further optimized, so that the fiber maintains good air permeability and hygroscopicity while maintaining excellent physical properties.

[0065] Comparative Example 1: A method for preparing an anti-ultraviolet textile material. The specific preparation method is the same as that of Example 2. In this example, only the base material is changed. Pure polycaprolactam is used as the base material, and the mechanical properties are tested together with Example 2. The specific characterization results are as follows.

[0066]

[0067] After analyzing the above characterization data and comparing it with Example 2, it is found that pure polycaprolactam is used as the matrix material in the experimental setting of Comparative Example 1. The samples prepared in Comparative Example 1 show a downward trend in key mechanical performance indicators such as fracture strength, bending strength, tensile strength and elastic modulus. Fracture strength is used to measure the maximum stress that a material can withstand during the stretching process, reflecting the ability of the material to resist fracture damage; bending strength reflects the bearing capacity of the material when subjected to bending load; tensile strength intuitively shows the ultimate bearing performance of the material under the action of axial tensile force; elastic modulus characterizes the ratio of stress to strain of the material within the elastic deformation range, reflecting the ability of the material to resist elastic deformation. In Comparative Example 1, these important performance indicators are reduced to varying degrees compared with Example 2. The results show that in the preparation process of the textile material, the present invention can have a positive impact on the microstructure and intermolecular interaction inside the material by introducing polyether block amide and accurately adjusting the ratio between the raw materials. This effect can significantly improve the mechanical properties of the textile material, so that the material shows more excellent toughness and durability in practical applications.

[0068] Comparative Example 2: A method for preparing an anti-ultraviolet textile material. The specific preparation method is the same as that of Example 2. In this example, only the core-shell structure of the nanoparticles is changed. Group A uses an equal amount of TiO2 spherical particles to replace the modified nanoparticles, and Group B uses an equal amount of ordinary TiO2 / ZnO physical mixed particles with a particle size of 200 nm to replace the modified nanoparticles. The same partial performance tests as in Example 2 are performed, and the specific characterization results are as follows.

[0069]

[0070] Analyzing the above characterization results, both Group A and Group B showed a significant decrease in wet UPF value, strength retention rate after wet heat aging, and UPF value after 50 washes. After Group A used TiO2 spherical particles to replace the modified nanoparticles, the wet UPF value dropped to 45.2, the strength retention rate after wet heat aging dropped to 68%, and the UPF value after 50 washes dropped to 36.5. After Group B used ordinary TiO2 / ZnO physical mixed particles with a particle size of 200 nm to replace the modified nanoparticles, the performance indicators dropped more significantly, the wet UPF value was only 33.4, the strength retention rate after wet heat aging was only 51%, and the UPF value after 50 washes was only 33.3. In the functionalized core-shell nanocomposite system described in the present invention, the multi-scale synergistic protection mechanism with ZnO@TiO2 heterojunction nanocrystals as the core realizes the synergistic optimization of ultraviolet shielding efficiency, material durability and wet heat stability. In the present invention, the band engineering regulation of the heterojunction interface is used to promote the effective separation and cross-interface directional migration of photogenerated electron-hole pairs through the heterojunction channel, significantly improving the absorption and conversion efficiency of ultraviolet photons. Secondly, the strain buffering effect of the core-shell structure and the geometric strengthening effect of the trilobal shaped fibers jointly construct a multi-level stress dissipation network. The wet-heat cycle experiment verified that the composite system exhibited excellent creep resistance. Finally, the present invention uses a silane coupling agent-mediated surface grafting modification to achieve covalent bonding of nanoparticles and polymer matrices. This chemical bonding mechanism effectively suppresses the interfacial debonding phenomenon under wet-heat conditions.

[0071] Comparative Example 3: A commercially available UV-resistant textile material, whose main component is nylon, was subjected to the same partial performance tests as in Example 2, and the specific characterization results are as follows.

[0072]

[0073] Analyzing the above characterization results, all the test data of commercially available anti-ultraviolet textile materials are lower than those of the materials prepared in Example 2. The static pore structure of commercially available anti-ultraviolet textile materials causes a sharp attenuation of wet air permeability. In addition, the single ultraviolet shielding mechanism triggers the recombination of photogenerated carriers, accelerates the photo-oxidative degradation of the polymer matrix, and affects the service life of the fabric. In the present invention, the textile is provided with a pore maintenance effect by optimizing the raw materials, so that the textile has a ventilation mechanism that is less affected by humidity. And by constructing a multi-stage ultraviolet energy dissipation system, while ensuring that the textile has a strong anti-ultraviolet effect, its mechanical properties are significantly optimized, and the service life of the fiber product is extended. Finally, the synergistic enhancement of the mechanical properties and functionality of the material is achieved by restricting the fiber spinning conditions. Not only is the wet air permeability retention rate of the textile improved, but also the service life of the textile in extreme environments is extended.

Claims

1. A method for preparing an anti-ultraviolet textile material, characterized in that: The method comprises: (1) The polymer, copolymer and organic acid anhydride are uniformly mixed in proportion, melt-blended and granulated to prepare a resin matrix; (2) mixing nano inorganic salt, organic titanium, alcohol compound and ketone compound in a uniform proportion to prepare nano particles, and immersing the nano particles in a modification liquid to prepare modified nano particles; (3) uniformly mixing an acyclic carboxylic acid and an amino acid in proportion, and performing pyrolysis to prepare a carbon source, and uniformly mixing the carbon source and a polymer elastomer in proportion to prepare carbonized polymer particles; (4) mixing the resin substrate, modified nanoparticles and carbonized polymer particles uniformly in proportion, and melting the particles to prepare a precursor; (5) Using the precursor as raw material for melt spinning, cooling and drawing, and preparing UV-resistant textile materials; The polymer in step (1) is polycaprolactam; The copolymer in step (1) is a polyether block amide; The organic acid anhydride in step (1) is maleic anhydride; The polymer, copolymer and organic anhydride in step (1) are uniformly mixed in a mass ratio of (85-92): (8-15): 0.5; The nano inorganic salt in step (2) is nano zinc oxide; The organic titanium in step (2) is tetrabutyl titanate; The alcohol compound in step (2) is ethanol; The ketone compound in step (2) is acetylacetone; In step (2), the nano inorganic salt, organic titanium, alcohol compound and ketone compound are uniformly mixed in a mass ratio of (4.8-5.2): (3-3.5): (48-52): 1; The specific steps of preparing the nanoparticles in step (2) are as follows: firstly, ultrasonicating the mixture for 30 to 40 minutes, secondly, aging the mixture in an environment at a temperature of 45 to 55°C for 20 to 28 hours, and finally, calcining the mixture in an environment at a temperature of 430 to 470°C for 1 to 3 hours; The modified liquid in step (2) is composed of γ-aminopropyltriethoxysilane, ethanol and distilled water, wherein the γ-aminopropyltriethoxysilane accounts for 3-5%VOL, the distilled water accounts for 25-30%VOL, and the balance is ethanol; The immersion in step (2) is carried out in an environment with a temperature of 38 to 42°C for 1.75 to 2.25 hours; The acyclic carboxylic acid in step (3) is citric acid; The amino acid in step (3) is L-cysteine; The acyclic carboxylic acid and the amino acid in step (3) are uniformly mixed in a mass ratio of (5-5.5):1; The pyrolysis in step (3) is carried out in an environment with a pressure of 2 to 3 KPa and a temperature of 180 to 220°C for 1.5 to 2.5 hours; The polymer elastomer in step (3) is polyethylene glycol; Step (3) The carbon source and the polymer elastomer are uniformly mixed in a mass ratio of 1: (40-60); The carbonized polymer prepared in step (3) is reacted in an environment with a temperature of 35 to 45°C and a pH of 5 to 7 for 10 to 14 hours; In the precursor of step (4), the mass proportion of modified nanoparticles is 18-22 wt%, the mass proportion of carbonized polymer particles is 4-6 wt%, and the balance is resin substrate.

2. The method for preparing an anti-ultraviolet textile material according to claim 1, characterized in that: The melt blending in step (1) is performed by melt stirring at a temperature of 240 to 250° C. for 3 to 5 minutes; The granulation in step (1) is carried out using a twin-screw extruder with a temperature of 240-250°C, a screw speed of 280-320 rpm, and a feed rate of 14-18 kg / h.

3. The method for preparing an anti-ultraviolet textile material according to claim 1, characterized in that: The molten plasmid in step (4) is produced by a twin-screw extruder with a temperature of 220-235°C, a screw speed of 240-260 rpm, and a vacuum degree of -0.08 MPa.

4. The method for preparing an anti-ultraviolet textile material according to claim 1, characterized in that: The melt spinning in step (5) uses a three-leaf spinneret with an aspect ratio of 3:1, and the diameter of the single filament is 18 to 22 μm; The cooling in step (5) is cooling to room temperature under the environmental conditions of wind speed of 0.5-1 m / s, temperature of 15-20°C and humidity of 65%; The stretching in step (5) is a multi-stage stretching, wherein the first stage stretching is to stretch the fiber to 3 to 4 times of its original length at a temperature of 80 to 90°C; and the second stage stretching is to stretch the fiber to 1 to 1.5 times of the first stage stretching length at a temperature of 100 to 120°C.

5. An anti-ultraviolet textile material obtained by the method according to any one of claims 1 to 4.

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