Anti-ultraviolet nylon fabric and preparation method thereof

Abstract

The invention relates to the technical field of nylon fabrics, in particular to an anti-ultraviolet nylon fabric and a preparation method thereof.The preparation method comprises the steps that composite functional master batches are obtained, and ultraviolet response type mesoporous titanium dioxide and nylon 6 are compounded through a reactive extrusion technology to form master batches of a core-shell structure; fiber spinning is executed, the composite functional master batch and nylon 66 slices are blended and then subjected to melt spinning, and mesoporous titanium dioxide is directionally arranged in the fiber through electric field induction in the spinning process; construction of a bionic structure: performing vapor deposition treatment on the fiber fabric, and constructing a multi-layer shielding film formed by alternating zinc oxide nanocones and silicon dioxide aerogel on the surface of the fiber fabric; and determining the protection performance, and testing the transmittance of the fabric in the ultraviolet band and the ultraviolet protection factor. Through the synergistic effect of the directionally arranged mesoporous titanium dioxide in the fiber and the zinc oxide nanocone and the silicon dioxide aerogel layer in the multi-layer shielding film, the ultraviolet protection efficiency and reliability are improved.

Description

Technical Field

[0001] This invention relates to the field of nylon fabric technology, specifically to a UV-protective nylon fabric and its preparation method. Background Technology

[0002] With the increasing popularity of outdoor activities and the growing awareness of ultraviolet protection, the demand for UV-protective textiles is growing. Traditional UV-protective nylon fabrics mainly achieve their UV protection function by adding inorganic UV shielding agents, such as titanium dioxide and zinc oxide, during the spinning process or by applying finishing coatings to the fabric. However, inorganic nanoparticles tend to agglomerate during the spinning process, resulting in uneven dispersion and affecting the stability and durability of the UV protection effect. Finishing coatings are also prone to peeling off during washing and wearing, resulting in poor durability and affecting the fabric's feel and breathability.

[0003] In existing technologies, fabrics that rely solely on UV absorption mechanisms may experience performance degradation after long-term use, while fabrics that rely solely on reflection mechanisms are not effective at protecting against incident UV rays at specific angles. Furthermore, traditional UV-protective fabrics lack intelligent response characteristics and cannot adaptively adjust their protective performance according to UV intensity. Summary of the Invention

[0004] This invention addresses the technical problems existing in the prior art by providing a UV-protective nylon fabric and its preparation method.

[0005] The technical solution of this invention to solve the above-mentioned technical problems is as follows: A method for preparing UV-resistant nylon fabric, comprising the following steps:

[0006] To obtain a composite functional masterbatch, UV-responsive mesoporous titanium dioxide and nylon 6 are combined using reactive extrusion technology to form a masterbatch with a core-shell structure.

[0007] The fiber spinning process involves blending the composite functional masterbatch with nylon 66 chips and then performing melt spinning. During the spinning process, mesoporous titanium dioxide is oriented and arranged inside the fiber by electric field induction.

[0008] Biomimetic structure construction involves vapor deposition of fiber fabric to create a multilayer shielding film on its surface, consisting of alternating zinc oxide nanocones and silica aerogel.

[0009] To determine the protective performance, test the fabric's transmittance in the ultraviolet band and its ultraviolet protection factor.

[0010] In a preferred embodiment, the UV-responsive mesoporous titanium dioxide is prepared by using tetrabutyl titanate as a precursor and synthesizing mesoporous titanium dioxide with a pore size of 5-15 nm by sol-gel method under the action of the template agent hexadecyltrimethylammonium bromide, and loading benzotriazole UV absorbers accounting for 30% to 50% of the pore volume in its pores.

[0011] The process parameters for reactive extrusion technology are: twin-screw extruder temperature range 220-250℃, screw speed 200-400rpm, and feeding rate 10-20 kg / h.

[0012] In a preferred embodiment, the electric field-induced directional alignment is achieved by applying an alternating electric field with a frequency of 1-10 kHz and a field strength of 0.5-2 kV / cm before the melt passes through the spinneret, causing the mesoporous titanium dioxide to form a chain-like arrangement structure along the direction of the electric field due to its dielectric properties.

[0013] The conditions for vapor deposition are as follows: under vacuum of 10-100 Pa and substrate temperature of 80-120℃, a zinc oxide nanocone array with a thickness of 50-200 nm is first deposited, and then a silica aerogel layer with a thickness of 100-300 nm is covered by chemical vapor deposition. This process is repeated 3 to 5 times.

[0014] In a preferred embodiment, the testing criteria for protective performance include:

[0015] The average transmittance of the tested fabric in the 315-400nm UV-A and 280-315nm UV-B bands did not exceed 2%.

[0016] The fabric has a UPF value of 200 or higher, and the UPF retention rate is still no less than 90% after 50 standard washes.

[0017] In a preferred embodiment, during the preparation of the UV-responsive mesoporous titanium dioxide, the amount of the template agent hexadecyl ammonium bromide is 10% to 30% of the mass of tetrabutyl titanate, the pH value of the sol-gel reaction system is controlled between 2.0 and 4.5, the reaction temperature is maintained at 35-75°C, and the curing time is 10 to 40 hours.

[0018] The loading of benzotriazole UV absorbers is achieved by vacuum impregnation, with an impregnation pressure of 0.01-0.05 MPa, an impregnation temperature of 60-90℃, and an impregnation time of 2-6 hours, to ensure that the UV absorbers are fully filled into the mesoporous channels.

[0019] In a preferred embodiment, during the electric field-induced directional alignment process, the waveform of the alternating electric field is either a square wave or a sine wave, the electrode spacing is set to 5–20 mm, and the electric field application time is controlled to be 0.5–3.0 seconds.

[0020] The dielectric constant of mesoporous titanium dioxide under the action of an electric field needs to reach 20-50, and its volume fraction in the nylon matrix is ​​3% to 8%. This electric field parameter enables the mesoporous titanium dioxide to complete the directional assembly of the chain structure before the melt cools and solidifies, forming a continuous ultraviolet shielding network.

[0021] In a preferred embodiment, the growth of the zinc oxide nanocone array in the vapor deposition process is achieved by a hydrothermal method, the reaction solution is a mixed solution of zinc nitrate and hexamethylenetetramine with a concentration of 0.05-0.2 mol / L, the growth temperature is 80-95℃, and the growth time is 1-4 hours.

[0022] The deposition of the silica aerogel layer uses tetraethyl orthosilicate as a precursor, with the deposition rate controlled at 5-15 nm / min. Ammonia gas is introduced as a catalyst during the deposition process, and the porosity of the aerogel layer is maintained at 85%-95%, thereby constructing a multilayer shielding structure with a gradient refractive index.

[0023] In a preferred embodiment, the standard washing conditions use 4A type laundry detergent, a washing temperature of 30-50℃, and a washing time of 20-40 minutes. During the test, at least 3-8 samples from different locations are selected for measurement.

[0024] This invention also provides a UV-protective nylon fabric, wherein the fabric constitutes a protective system through a combination of oriented mesoporous titanium dioxide within the fibers and a multi-layered shielding film on the surface. The oriented mesoporous titanium dioxide within the fibers forms a continuous shielding network distributed along the fiber axis, with a distribution density of 5 × 10⁻⁶. 4 -2×10 6 The number of fibers per mm² is 1.2-4.0, and the ratio of chain structure length to fiber diameter is 1.2-4.0.

[0025] The surface multilayer shielding film is composed of alternating zinc oxide nanocone arrays and silica aerogel layers, with a total thickness of 0.3-3.0 μm and an interfacial bonding strength of not less than 3-8 MPa between each layer.

[0026] In a preferred embodiment, the distribution density of the oriented mesoporous titanium dioxide within the fibers of the fabric is 10. 5～ 10 6 Pieces / mm²

[0027] A further improvement of this invention lies in the following: by constructing a shell-structured masterbatch and inducing directional alignment with an electric field, stable dispersion and assembly of mesoporous titanium dioxide are achieved within the fiber, forming an ultraviolet absorption network. A multilayer shielding film consisting of alternating zinc oxide nanocones and silica aerogels is constructed on the fabric surface using a vapor deposition process, forming multiple layers of protection. The interfacial strength between the vapor-deposited film and the fiber is higher than that of traditional coatings, improving its washability. Furthermore, the surface of the multilayer shielding film has a micro-nano porous structure, which ensures that air and water vapor can pass freely while providing protection.

[0028] The beneficial effects of this invention are as follows: This invention improves the protection efficiency and reliability of ultraviolet rays by the synergistic effect of the mesoporous titanium dioxide arranged in the fiber, the zinc oxide nanocones in the multilayer shielding film, and the silica aerogel layer. The mesoporous titanium dioxide is induced by an electric field to form a chain-like structure in the fiber, which ensures the stability of the functional structure. The multilayer shielding film has interfacial bonding strength, which improves the washability and wear resistance of the protective layer. Attached Figure Description

[0029] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] In the description of this application, the term "for example" is used to mean "used as an example, illustration, or description." Any embodiment described as "for example" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use the invention. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that the invention can be made without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the invention with unnecessary detail. Therefore, the invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0032] like Figure 1 This embodiment provides: a UV-resistant nylon fabric and its preparation method, including the following steps:

[0033] To obtain a composite functional masterbatch, UV-responsive mesoporous titanium dioxide and nylon 6 are combined using reactive extrusion technology to form a masterbatch with a core-shell structure.

[0034] The fiber spinning process involves blending the composite functional masterbatch with nylon 66 chips and then performing melt spinning. During the spinning process, mesoporous titanium dioxide is oriented and arranged inside the fiber by electric field induction.

[0035] Biomimetic structure construction involves vapor deposition of fiber fabric to create a multilayer shielding film on its surface, consisting of alternating zinc oxide nanocones and silica aerogel.

[0036] To determine the protective performance, test the fabric's transmittance in the ultraviolet band and its ultraviolet protection factor.

[0037] Furthermore, the UV-responsive mesoporous titanium dioxide is prepared using tetrabutyl titanate as a precursor. Under the action of the template agent cetyltrimethylammonium bromide, mesoporous titanium dioxide with a pore size of 5-15 nm is synthesized by sol-gel method, and benzotriazole UV absorbers occupying 30% to 50% of the pore volume are loaded in its pores.

[0038] The process parameters for reactive extrusion technology are: twin-screw extruder temperature range 220-250℃, screw speed 200-400rpm, and feeding rate 10-20 kg / h.

[0039] It should be noted that the specific process for synthesizing mesoporous titanium dioxide with a pore size of 5-15 nm and loading it with a UV absorber using the sol-gel method is as follows:

[0040] Weigh the structure-directing agent hexadecyltrimethylammonium bromide at a ratio of 10%-25% of the mass of tetrabutyl titanate, and dissolve it in a mixed solvent of deionized water and anhydrous ethanol at a volume ratio of 1:2 to 1:4. Place the above system in a constant temperature water bath at 40-70°C and stir continuously at a magnetic stirring speed of 200-500 rpm until completely dissolved to obtain a clear and transparent template agent solution. In this solution, hexadecyltrimethylammonium bromide molecules will self-assemble into micelles. Use these micelles as templates to form mesoporous structures. Adjust the pH of the above template solution to between 2.5 and 4.0 using dilute nitric acid or dilute hydrochloric acid.

[0041] Under continuous stirring and constant temperature conditions, tetrabutyl titanate is uniformly added dropwise to the template agent solution after pH adjustment using a constant pressure dropping funnel. The total molar ratio of tetrabutyl titanate to solvent needs to be controlled within the range of 1:150. During the dropwise addition, tetrabutyl titanate undergoes a hydrolysis reaction to generate an intermediate containing Ti-OH.

[0042] After the addition is complete, continue to stir the reaction at a constant temperature of 40-70℃ for 12-36 hours. During this period, the intermediates generated by hydrolysis undergo condensation through dehydration or de-alcoholization reactions to form an inorganic titanium dioxide network framework. This framework grows around and in the gaps of the hexadecyltrimethylammonium bromide micelle template, encapsulating the template agent to form a stable sol. The resulting sol is sealed and allowed to stand for aging to form a gel with a mesoporous structure.

[0043] The aged gel was filtered or centrifuged and washed several times with large amounts of deionized water and anhydrous ethanol to remove most of the free template agent and byproducts.

[0044] After washing, the wet gel is dried at 60-100℃ and then calcined at a rate of 1-5℃ / min. Finally, it is kept at 450-550℃ in air for 2-5 hours to completely decompose and remove hexadecyltrimethylammonium bromide molecules, leaving pores in the spaces originally occupied by the hexadecyltrimethylammonium bromide micelles, thus forming a mesoporous structure. By controlling the concentration of hexadecyltrimethylammonium bromide, the reaction pH, and calcination, the pore size is controlled within the range of 5-15nm.

[0045] The mesoporous titanium dioxide powder obtained after calcination is placed in a vacuum impregnation device, and an ethanol solution of benzotriazole ultraviolet absorber is prepared. Under a vacuum of 0.01-0.05 MPa and a temperature of 60-90°C, the ultraviolet absorber solution is introduced and completely impregnates the mesoporous titanium dioxide powder, and the process is maintained for 2-6 hours.

[0046] Furthermore, the electric field-induced directional arrangement is achieved by applying an alternating electric field with a frequency of 1-10 kHz and a field strength of 0.5-2 kV / cm before the melt passes through the spinneret, causing the mesoporous titanium dioxide to form a chain-like arrangement structure along the direction of the electric field due to its dielectric properties.

[0047] The conditions for vapor deposition are as follows: under vacuum of 10-100 Pa and substrate temperature of 80-120℃, a zinc oxide nanocone array with a thickness of 50-200 nm is first deposited, and then a silica aerogel layer with a thickness of 100-300 nm is covered by chemical vapor deposition. This process is repeated 3 to 5 times.

[0048] Furthermore, the testing standards for protective performance include:

[0049] The average transmittance of the tested fabric in the 315-400nm UV-A and 280-315nm UV-B bands did not exceed 2%.

[0050] The fabric has a UPF value of 200 or higher, and the UPF retention rate is still no less than 90% after 50 standard washes.

[0051] Furthermore, in the preparation process of the UV-responsive mesoporous titanium dioxide, the amount of the template agent hexadecyl ammonium bromide is 10% to 30% of the mass of tetrabutyl titanate, the pH value of the sol and gel reaction system is controlled between 2.0 and 4.5, the reaction temperature is maintained at 35-75℃, and the curing time is 10 to 40 hours.

[0052] The loading of benzotriazole UV absorbers is achieved by vacuum impregnation, with an impregnation pressure of 0.01-0.05 MPa, an impregnation temperature of 60-90℃, and an impregnation time of 2-6 hours, to ensure that the UV absorbers are fully filled into the mesoporous channels.

[0053] Furthermore, during the electric field-induced directional alignment process, the waveform of the alternating electric field is either a square wave or a sine wave, the electrode spacing is set to 5–20 mm, and the electric field application time is controlled to be 0.5–3.0 seconds.

[0054] The dielectric constant of mesoporous titanium dioxide under the action of an electric field needs to reach 20-50, and its volume fraction in the nylon matrix is ​​3% to 8%. This electric field parameter enables the mesoporous titanium dioxide to complete the directional assembly of the chain structure before the melt cools and solidifies, forming a continuous ultraviolet shielding network.

[0055] Furthermore, in the vapor deposition process, the growth of the zinc oxide nanocone array is achieved by a hydrothermal method. The reaction solution is a mixed solution of zinc nitrate and hexamethylenetetramine with a concentration of 0.05–0.2 mol / L, the growth temperature is 80–95 °C, and the growth time is 1–4 hours.

[0056] The deposition of the silica aerogel layer uses tetraethyl orthosilicate as a precursor, with the deposition rate controlled at 5-15 nm / min. Ammonia gas is introduced as a catalyst during the deposition process, and the porosity of the aerogel layer is maintained at 85%-95%, thereby constructing a multilayer shielding structure with a gradient refractive index.

[0057] Furthermore, the standard washing conditions use 4A type laundry detergent, a washing temperature of 30-50℃, and a washing time of 20-40 minutes. During the test, at least 3-8 samples from different locations are selected for measurement.

[0058] This invention also provides a UV-resistant nylon fabric, wherein the fabric constitutes a protective system through a combination of oriented mesoporous titanium dioxide within the fibers and a multilayer shielding film on the surface. The oriented mesoporous titanium dioxide within the fibers forms a continuous shielding network distributed along the fiber axis, with a distribution density of 5 × 10⁻⁶. 4 -2×10 6 The number of fibers per mm² is 1.2-4.0, and the ratio of chain structure length to fiber diameter is 1.2-4.0.

[0059] The surface multilayer shielding film is composed of alternating zinc oxide nanocone arrays and silica aerogel layers, with a total thickness of 0.3-3.0 μm and an interfacial bonding strength of not less than 3-8 MPa between each layer.

[0060] It should be noted that the construction process of the multi-layer shielding film is as follows:

[0061] S1. Clean the woven nylon fabric to remove surface impurities, and then dry it.

[0062] S2. Dissolve zinc nitrate and hexamethylenetetramine in deionized water at a concentration of 0.05-0.2 mol / L to form a growth solution. Immerse the treated fabric in the growth solution and react at 80-95℃ for 1-4 hours to form a vertically oriented zinc oxide nanocone array on the fiber surface. After the reaction is complete, remove the fabric, wash and dry it to obtain an intermediate product of zinc oxide nanocone array with a thickness of 50-200 nm.

[0063] S3. The fabric with zinc oxide nanocone array is placed in a deposition device and processed under a vacuum of 10-100 Pa and a substrate temperature of 80-120 °C. Tetraethyl orthosilicate is used as a precursor. Under the catalysis of ammonia, a layer of silica aerogel is deposited on the surface of zinc oxide nanocone array by chemical vapor deposition. The deposition rate is controlled at 5-15 nm / min to form a silica aerogel layer with a thickness of 100-300 nm and a porosity of 85%-95%.

[0064] S4. Repeat S2 and S3 3-5 times to form a multilayer shielding structure with alternating zinc oxide nanocone arrays and silica aerogel layers. Control the deposition parameters of each layer to ensure that the interfacial bonding strength between each layer is not less than 3-8 MPa. Finally, a multilayer shielding film with a total thickness of 0.3-3.0 μm is obtained. Heat treat the fabric after deposition.

[0065] Furthermore, the distribution density of the oriented mesoporous titanium dioxide within the fibers of the fabric is 10. 5～ 10 6 Pieces / mm²

[0066] Example 1 (Standard Nylon Fabric)

[0067] This invention provides a method for preparing UV-resistant nylon fabric, comprising the following steps:

[0068] Preparation of composite functional masterbatch: 100g of tetrabutyl titanate was used as a precursor, and 15g of cetyltrimethylammonium bromide was added as a template agent. Mesoporous titanium dioxide with a pore size of 8-12nm was synthesized by sol-gel method under the conditions of pH=3.2 and temperature of 55℃. The synthesized mesoporous titanium dioxide was vacuum impregnated for 4 hours under the conditions of pressure of 0.03MPa and temperature of 75℃. Benzotriazole UV absorber accounting for 40% of the pore volume was loaded. The modified mesoporous titanium dioxide was mixed with nylon 6 at a mass ratio of 1:4 and reacted and extruded through a twin-screw extruder under the conditions of 235℃, screw speed of 300rpm and feed rate of 15kg / h to obtain the structural composite masterbatch.

[0069] Fiber spinning: The composite masterbatch and nylon 66 chips are blended at a mass ratio of 1:9 and processed by melt spinning equipment. An electrode spacing of 10 mm is set in front of the spinneret, and a sinusoidal alternating electric field with a frequency of 5 kHz and a field strength of 1.2 kV / cm is applied for 1.5 seconds.

[0070] Constructing a biomimetic structure: The woven fabric is placed in a vacuum deposition device, and a multi-layer shielding film is constructed under vacuum conditions of 50 Pa and substrate temperature of 100 °C.

[0071] Example 2 (High-performance UV-resistant nylon fabric)

[0072] This invention provides a method for preparing UV-resistant nylon fabric, comprising the following steps:

[0073] Preparation of composite functional masterbatch: 100g of tetrabutyl titanate was used as a precursor, and 22g of cetyltrimethylammonium bromide was added as a template agent. Mesoporous titanium dioxide with a pore size of 10-15nm was synthesized by sol-gel method under the conditions of pH=3.8 and temperature of 65℃. The synthesized mesoporous titanium dioxide was vacuum impregnated for 5 hours under the conditions of pressure of 0.04MPa and temperature of 85℃. Benzotriazole UV absorber accounting for 45% of the pore volume was loaded. The modified mesoporous titanium dioxide was mixed with nylon 6 at a mass ratio of 1:3 and reacted and extruded through a twin-screw extruder under the conditions of 245℃, screw speed of 350rpm and feed rate of 15kg / h to obtain the structural composite masterbatch.

[0074] Fiber spinning: The composite masterbatch and nylon 66 chips are blended at a mass ratio of 1:4 and processed by melt spinning equipment. An electrode spacing of 8 mm is set in front of the spinneret, and a sinusoidal alternating electric field with a frequency of 8 kHz and a field strength of 1.8 kV / cm is applied for 2 seconds.

[0075] Constructing a biomimetic structure: The woven fabric is placed in a vacuum deposition device, and a multi-layer shielding film is constructed under vacuum conditions of 30 Pa and substrate temperature of 110 °C.

[0076] Example 3 (High-performance, cost-effective UV-protective nylon fabric)

[0077] This invention provides a method for preparing UV-resistant nylon fabric, comprising the following steps:

[0078] Preparation of composite functional masterbatch: 100g of tetrabutyl titanate was used as a precursor, and 12g of cetyltrimethylammonium bromide was added as a template agent. Mesoporous titanium dioxide with a pore size of 5-10nm was synthesized by sol-gel method under the conditions of pH=2.8 and temperature of 45℃. The synthesized mesoporous titanium dioxide was vacuum impregnated for 3 hours under the conditions of pressure of 0.02MPa and temperature of 65℃. Benzotriazole UV absorber accounting for 35% of the pore volume was loaded. The modified mesoporous titanium dioxide was mixed with nylon 6 at a mass ratio of 1:5 and reacted and extruded through a twin-screw extruder under the conditions of 225℃, screw speed of 250rpm and feed rate of 15kg / h to obtain the structural composite masterbatch.

[0079] Fiber spinning: The composite masterbatch and nylon 66 chips are blended at a mass ratio of 1:12 and processed by melt spinning equipment. An electrode spacing of 15mm is set in front of the spinneret, and a sinusoidal alternating electric field with a frequency of 2kHz and a field strength of 0.8kV / cm is applied for 1 second.

[0080] Constructing a biomimetic structure: The woven fabric is placed in a vacuum deposition device, and a multi-layer shielding film is constructed under vacuum conditions of 80 Pa and substrate temperature of 90 °C.

[0081] Example 4 (High-protection UV-resistant nylon fabric)

[0082] This invention provides a method for preparing UV-resistant nylon fabric, comprising the following steps:

[0083] Preparation of composite functional masterbatch: 100g of tetrabutyl titanate was used as a precursor, and 25g of cetyltrimethylammonium bromide was added as a template agent. Mesoporous titanium dioxide with a pore size of 12-15nm was synthesized by sol-gel method under the conditions of pH=4.0 and temperature of 70℃. The synthesized mesoporous titanium dioxide was vacuum impregnated for 6 hours under the conditions of pressure of 0.05MPa and temperature of 90℃. Benzotriazole UV absorber accounting for 50% of the pore volume was loaded. The modified mesoporous titanium dioxide was mixed with nylon 6 at a mass ratio of 1:2.5 and reacted and extruded by twin-screw extruder under the conditions of 250℃, screw speed of 400rpm and feed rate of 15kg / h to obtain the structural composite masterbatch.

[0084] Fiber spinning: The composite masterbatch and nylon 66 chips are blended at a mass ratio of 1:3 and processed by melt spinning equipment. An electrode spacing of 6 mm is set in front of the spinneret, and a sinusoidal alternating electric field with a frequency of 10 kHz and a field strength of 2.0 kV / cm is applied for 2.5 seconds.

[0085] Constructing a biomimetic structure: The woven fabric is placed in a vacuum deposition device, and a multi-layer shielding film is constructed under vacuum conditions of 20 Pa and substrate temperature of 120 °C.

[0086] Based on Examples 1-4, the following table can be derived:

[0087] Table 1

[0088] Process parameters Example 1 Example 2 Example 3 Example 4 Mesoporous titanium dioxide:Nylon 6 mass ratio 1:4 1:3 1:5 1:2.5 Masterbatch: Nylon 66 mass ratio 1:9 1:4 1:12 1:3 electric field frequency 5 8 2 10 electric field strength 1.2 1.8 0.8 2.0 vacuum degree 50 30 80 20 Base temperature 100 110 90 120

[0089] As shown in Table 1:

[0090] The ratio of mesoporous titanium dioxide to nylon 6 directly determines the density of ultraviolet shielding units per unit volume. The blending ratio of masterbatch to nylon 66 determines the uniformity of fiber distribution. Electric field parameters promote the directional alignment of nanoparticles into a continuous shielding network through dielectrophoresis. Deposition conditions optimize the compactness of the film by controlling molecular motion energy and collision frequency. The substrate temperature affects the migration ability of molecules on the surface and the bonding strength of the film. A higher functional component ratio requires strong electric field parameters to achieve effective dispersion.

[0091] It should be noted that the descriptions of each embodiment in the above embodiments have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0092] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0093] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for preparing a UV-resistant nylon fabric, characterized in that, Includes the following steps: To obtain a composite functional masterbatch, UV-responsive mesoporous titanium dioxide and nylon 6 are combined using reactive extrusion technology to form a masterbatch with a core-shell structure. The fiber spinning process involves blending the composite functional masterbatch with nylon 66 chips and then performing melt spinning. During the spinning process, mesoporous titanium dioxide is oriented and arranged inside the fiber by electric field induction. Biomimetic structure construction involves vapor deposition of fiber fabric to create a multilayer shielding film on its surface, consisting of alternating zinc oxide nanocones and silica aerogel. To determine the protective performance, test the fabric's transmittance in the ultraviolet band and its ultraviolet protection factor.

2. The method for preparing an ultraviolet-resistant nylon fabric according to claim 1, characterized in that, The UV-responsive mesoporous titanium dioxide was prepared by using tetrabutyl titanate as a precursor and synthesizing mesoporous titanium dioxide with a pore size of 5-15 nm by sol-gel method under the action of the template agent hexadecyltrimethylammonium bromide. Benzotriazole UV absorbers accounting for 30% to 50% of the pore volume were loaded in the pores. The process parameters for reactive extrusion technology are: twin-screw extruder temperature range 220-250℃, screw speed 200-400rpm, and feeding rate 10-20 kg / h.

3. The method for preparing a UV-resistant nylon fabric according to claim 1, characterized in that, The electric field-induced directional arrangement is achieved by applying an alternating electric field with a frequency of 1-10 kHz and a field strength of 0.5-2 kV / cm before the melt passes through the spinneret, causing mesoporous titanium dioxide to form a chain-like arrangement structure along the direction of the electric field due to its dielectric properties. The conditions for vapor deposition are as follows: under vacuum of 10-100 Pa and substrate temperature of 80-120℃, a zinc oxide nanocone array with a thickness of 50-200 nm is first deposited, and then a silica aerogel layer with a thickness of 100-300 nm is covered by chemical vapor deposition. This process is repeated 3 to 5 times.

4. The method for preparing a UV-resistant nylon fabric according to claim 1, characterized in that, The testing standards for protective performance include: The average transmittance of the tested fabric in the 315-400nm UV-A and 280-315nm UV-B bands did not exceed 2%. The fabric has a UPF value of 200 or higher, and the UPF retention rate is still no less than 90% after 50 standard washes.

5. The method for preparing an ultraviolet-resistant nylon fabric according to claim 2, characterized in that, In the preparation of the UV-responsive mesoporous titanium dioxide, the amount of the template agent hexadecyl ammonium bromide is 10% to 30% of the mass of tetrabutyl titanate, the pH value of the sol and gel reaction system is controlled between 2.0 and 4.5, the reaction temperature is maintained at 35-75℃, and the curing time is 10 to 40 hours. The loading of benzotriazole UV absorbers is achieved by vacuum impregnation, with an impregnation pressure of 0.01-0.05 MPa, an impregnation temperature of 60-90℃, and an impregnation time of 2-6 hours, to ensure that the UV absorbers are fully filled into the mesoporous channels.

6. The method for preparing a UV-resistant nylon fabric according to claim 3, characterized in that, During the electric field-induced directional alignment process, the waveform of the alternating electric field is either a square wave or a sine wave, the electrode spacing is set to 5–20 mm, and the electric field application time is controlled to be 0.5–3.0 seconds. The dielectric constant of mesoporous titanium dioxide under the action of an electric field needs to reach 20-50, and its volume fraction in the nylon matrix is ​​3% to 8%. This electric field parameter enables the mesoporous titanium dioxide to complete the directional assembly of the chain structure before the melt cools and solidifies, forming a continuous ultraviolet shielding network.

7. The method for preparing a UV-resistant nylon fabric according to claim 3, characterized in that, In the vapor deposition process, the growth of zinc oxide nanocone arrays is achieved by hydrothermal method. The reaction solution is a mixed solution of zinc nitrate and hexamethylenetetramine with a concentration of 0.05-0.2 mol / L. The growth temperature is 80-95℃ and the growth time is 1-4 hours. The deposition of the silica aerogel layer uses tetraethyl orthosilicate as a precursor, with the deposition rate controlled at 5-15 nm / min. Ammonia is introduced as a catalyst during the deposition process, and the porosity of the aerogel layer is maintained at 85%-95%.

8. The method for preparing a UV-resistant nylon fabric according to claim 4, characterized in that, The standard washing conditions used 4A type laundry detergent, a washing temperature of 30-50℃, and a washing time of 20-40 minutes. During the test, at least 3-8 samples from different locations were selected for measurement.

9. A method for preparing an ultraviolet-resistant nylon fabric according to any one of claims 1-8, characterized in that, The fabric forms a protective system through a combination of oriented mesoporous titanium dioxide within the fibers and a multi-layered shielding film on the surface. The oriented mesoporous titanium dioxide within the fibers forms a continuous shielding network distributed along the fiber axis, with a distribution density of 5 × 10⁻⁶. 4 -2×10 6 The number of fibers per mm² is 1.2-4.0, and the ratio of chain structure length to fiber diameter is 1.2-4.

0. The surface multilayer shielding film is composed of alternating zinc oxide nanocone arrays and silica aerogel layers, with a total thickness of 0.3-3.0 μm and an interfacial bonding strength of not less than 3-8 MPa between each layer.

10. The UV-resistant nylon fabric according to claim 9, characterized in that, The distribution density of the oriented mesoporous titanium dioxide within the fibers of the fabric is 10. 5～ 10 6 Pieces / mm²

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