Anti-ultraviolet non-woven fabric and preparation process thereof

Abstract

The invention relates to the technical field of layered products, in particular to an anti-ultraviolet non-woven fabric and a preparation process thereof. Comprising the following steps: preparing a polydopamine / zinc oxide intercalated magnesium silicate nanosheet, preparing an anti-ultraviolet filler, treating a non-woven fabric, and spraying an anti-ultraviolet coating. According to the invention, zinc oxide is wrapped by polydopamine, the polydopamine is intercalated into a magnesium silicate nanosheet, the polydopamine is protonized in an acid environment to form positively charged amino groups, and the positively charged amino groups and electronegative oxygen-containing groups rich in the surface of a magnesium silicate laminate generate strong electrostatic attraction. The acting force directly drives the polydopamine-coated zinc oxide to enter magnesium silicate layers, the intercalation efficiency and the loading capacity are remarkably improved, phenolic hydroxyl groups of the polydopamine and silanol groups on the surface of magnesium silicate form a compact hydrogen bond network, growth of zinc oxide particles is strongly restrained in limited nanometer spaces among the magnesium silicate layers, the particle size of the zinc oxide particles is forced to be reduced to the quantum size range, and the performance of the zinc oxide particles is improved. Therefore, efficient capture of ultraviolet rays is achieved, and the anti-ultraviolet effect is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of layered products, in particular to an anti-ultraviolet non-woven fabric and a preparation process thereof. BACKGROUND

[0002] The non-woven fabric is a sheet material directly formed by orienting or randomly arranging fibers and bonding through mechanical, hot melt or chemical methods without the spinning and weaving process of traditional textiles. Its structural characteristics and manufacturing methods make it have unique advantages in outdoor scenes. Through processes such as melt blowing and spun-bonding, a three-dimensional interlaced fiber network is formed, in which the proportion of hydrophobic synthetic fibers is high, so it has the characteristics of moisture resistance, mold resistance, and stable physical performance in extreme environments, and is often used for outdoor sunshades or light-shielding cover films. However, long-term ultraviolet radiation in outdoor environments can cause chain degradation, causing the polymer molecular chain to break, such as the photolysis of polyester ester bonds, resulting in a decrease in the strength of the non-woven fabric. Untreated non-woven fabric has a UPF of only 5-10 and almost no ability to protect against ultraviolet rays, so it needs to be coated with an anti-ultraviolet coating to improve its anti-ultraviolet ability.

[0003] Traditional epoxy resin coating anti-ultraviolet fillers such as zinc oxide have weak bonding force with the epoxy resin matrix and are easily detached during the aging process, so it is necessary to intercalate zinc oxide into a carrier with good dispersing ability and then add it to the reducing resin coating. Kaolin is generally used as the carrier, and the surface of kaolin has a low hydroxyl group density, which can be easily dispersed in epoxy resin to reduce the risk of agglomeration, so that it can be better combined with the epoxy resin coating, thereby dispersing zinc oxide in the coating and improving the anti-ultraviolet ability. However, kaolin has good dispersing properties, but the surface of kaolin relies only on physical adsorption / hydrogen bonding to combine with epoxy resin, which can easily cause detachment from epoxy resin after long-term use, thereby reducing the anti-ultraviolet ability and the anti-aging ability. Therefore, the present application provides an anti-ultraviolet non-woven fabric and a preparation process thereof to solve the problems existing in the prior art. SUMMARY

[0004] In view of the deficiencies in the prior art, the purpose of the present application is to provide an anti-ultraviolet non-woven fabric and a preparation process thereof.

[0005] An anti-ultraviolet non-woven fabric comprises a non-woven fabric layer and an anti-ultraviolet coating coated on the upper surface of the non-woven fabric. The anti-ultraviolet coating is composed of an anti-ultraviolet filler, an epoxy resin, an MH-6616 curing agent and ethyl acetate. The anti-ultraviolet filler is prepared from polydopamine / zinc oxide intercalated magnesium silicate nanosheets, sodium dodecylbenzenesulfonate, aniline and 2-fluoroaniline.

[0006] A preparation process of an anti-ultraviolet non-woven fabric comprises the following steps: S1: preparing polydopamine / zinc oxide intercalated magnesium silicate nanosheets Zinc oxide was dispersed, ultrasonicated, and dried to obtain pretreated zinc oxide. The pretreated zinc oxide was then dispersed again, and dopamine hydrochloride was added. The mixture was centrifuged in the dark, washed, and dried to obtain polydopamine-coated zinc oxide. Magnesium silicate nanosheets were added to hydrochloric acid solution, stirred, washed, and dried. Then, they were added to TMAOH aqueous solution and ultrasonicated to obtain a monolayer nanosheet dispersion. Polydopamine-coated zinc oxide was dispersed in Tris buffer solution, acetic anhydride was added, and after the reaction, it was redispersed in deionized water to obtain a polydopamine-coated zinc oxide dispersion. The polydopamine-coated zinc oxide dispersion was added dropwise to the monolayer nanosheet dispersion, and the mixture was heated to react. Magnesium chloride solution was added, and the mixture was stirred, centrifuged, washed, and freeze-dried to obtain polydopamine / zinc oxide intercalated magnesium silicate nanosheets. S2: Preparation of UV-resistant fillers Sodium dodecylbenzenesulfonate was dissolved in sulfuric acid solution to obtain sodium dodecylbenzenesulfonate sulfuric acid solution. Sodium dodecylbenzenesulfonate sulfuric acid solution, zinc oxide intercalated magnesium silicate nanosheets, aniline and 2-fluoroaniline were mixed, and then ammonium persulfate was added to react and obtain UV-resistant filler. S3: Treat the nonwoven fabric and spray it with an anti-UV coating. A composite acetic acid treatment solution was prepared by mixing glacial acetic acid, KH-550, ammonium persulfate, acrylic acid, and deionized water. The nonwoven fabric was then immersed in the composite acetic acid treatment solution to obtain an acetic acid-treated nonwoven fabric. The UV-resistant filler was mixed with epoxy resin and MH-6616 curing agent in ethyl acetate and stirred to obtain a coating solution. The coating solution was then sprayed onto the surface of the acetic acid-treated nonwoven fabric using a spray gun. Finally, the coating was cured at room temperature to obtain a UV-resistant nonwoven fabric.

[0007] Furthermore, the preparation of polydopamine / zinc oxide intercalated magnesium silicate nanosheets by S1 includes the following steps: S1.1: Disperse 1-3 parts by mass of zinc oxide in 100-105 parts by mass of 0.1-0.15M hydrochloric acid solution, sonicate for 30-40 min, then remove and wash until neutral, vacuum dry at 60-65℃ for 6-6.5 h to obtain pretreated zinc oxide. Disperse 0.5-1 parts by mass of pretreated zinc oxide in 200-205 parts by mass of Tris buffer solution with pH 8.5-8.7, sonicate for 30-35 min, then add 0.25-0.5 parts by mass of dopamine hydrochloride, keep at 25-30℃ and shake for 24-25 h under light-protected conditions, then centrifuge at 8000-8100 r / min for 10-15 min, wash three times with deionized water and twice with anhydrous ethanol, and dry at 40-45℃ for 12 h to obtain polydopamine-coated zinc oxide. S1.2: Add 1-2 parts by weight of magnesium silicate nanosheets to 100-105 parts by weight of 1.0M hydrochloric acid solution, stir at 70-75℃ for 24-25h, wash with deionized water until neutral, dry at 60-65℃ for 20-25min, then add 100-105 parts by weight of 20% TMAOH aqueous solution, sonicate for 30-35min to obtain a single-layer nanosheet dispersion; S1.3: Disperse polydopamine-coated zinc oxide in 50-55 parts by weight of Tris buffer solution with a pH of 5-5.2, add 0.1-0.2 parts by weight of acetic anhydride, react at 25-30℃ for 1-1.5 h, wash three times with deionized water, and redisperse in deionized water with a pH of 5-5.2 to obtain polydopamine-coated zinc oxide dispersion; add the polydopamine-coated zinc oxide dispersion dropwise to the monolayer nanosheet dispersion, stir at 60-65℃ for 12-13 h, then heat to 120-125℃ for 6-6.5 h, add 20-25 parts by weight of magnesium chloride solution, stir at 80-85℃ for 2-2.5 h, centrifuge, wash, and freeze-dry to obtain polydopamine / zinc oxide intercalated magnesium silicate nanosheets.

[0008] Furthermore, the preparation of UV-resistant fillers by S2 includes the following steps: Dissolve 0.8-1.2 parts by weight of sodium dodecylbenzenesulfonate in 150-155 parts by weight of sulfuric acid solution to obtain sodium dodecylbenzenesulfonate sulfuric acid solution. Then, transfer the sodium dodecylbenzenesulfonate sulfuric acid solution to a reaction flask and mix it with 0.4-0.5 parts by weight of zinc oxide intercalated magnesium silicate nanosheets, 0.9-1.1 parts by weight of aniline and 1-1.3 parts by weight of 2-fluoroaniline. Dissolve 4.5-4.8 parts by weight of ammonium persulfate in 50-55 parts by weight of sulfuric acid solution and add it to the reaction flask. Maintain the temperature of the reaction flask at 30-35℃ and the stirring speed at 1200-1300 r / min. After reacting for 4-4.5 h, filter and wash with deionized water, and dry in a freeze dryer for 24-25 h to remove residual moisture to obtain the UV-resistant filler.

[0009] Furthermore, S3 processes the nonwoven fabric and applies an anti-UV coating, including the following steps: S3.1: Mix 60-65% glacial acetic acid, 5-8% KH-550, 1-2% ammonium persulfate, 8-10% acrylic acid and deionized water to make up the balance, and stir at 100-120 r / min for 10-15 min to obtain a composite acetic acid treatment solution. S3.2: Immerse the nonwoven fabric in a composite acetic acid treatment solution and control the temperature at 40-45℃. The bath ratio of the nonwoven fabric to the composite acetic acid treatment solution is 1g:(20-25)mL. Vacuum-assisted permeation at -0.08MPa for 5-10min, followed by immersion at normal pressure for 20-25min. Remove the nonwoven fabric and cure it with hot air at 120-125℃ for 3-5min to obtain acetic acid-treated nonwoven fabric. S3.3: Mix 0.08-0.12 parts by weight of UV-resistant filler, 1.5-1.8 parts by weight of epoxy resin, and 0.5-0.8 parts by weight of MH-6616 curing agent in 5-8 parts by weight of ethyl acetate. Stir at 200-300 r / min for 10-12 min to obtain a coating liquid. Spray the coating liquid onto the surface of the acetic acid-treated nonwoven fabric with a spray gun. Finally, cure the coating at room temperature for 12-13 h to obtain a UV-resistant nonwoven fabric.

[0010] Furthermore, the power of the ultrasonic treatment is 300W.

[0011] Furthermore, the concentration of the magnesium chloride solution is 0.5-0.55M.

[0012] Furthermore, the concentration of the sulfuric acid solution is 1.2-1.5M.

[0013] The present invention has the following advantages: 1. This invention encapsulates zinc oxide with polydopamine and intercalates it into magnesium silicate nanosheets. In an acidic environment, polydopamine protonates to form positively charged amino groups, which strongly electrostatically attract the negatively charged oxygen-containing groups abundant on the surface of the magnesium silicate layers. This force directly drives the polydopamine-encapsulated zinc oxide into the magnesium silicate interlayer, significantly improving intercalation efficiency and loading. The phenolic hydroxyl groups of polydopamine form a dense hydrogen bond network with the silanol groups on the magnesium silicate surface, while the quinone groups generated during the hydrothermal process further condense with the silanol groups to form covalent bonds. This multi-level bonding fundamentally strengthens the interfacial binding energy, preventing particle desorption. The limited nanospace within the magnesium silicate layers strongly constrains the growth of zinc oxide particles, forcing their particle size to decrease to the quantum size range. In this state, the electronic band structure of zinc oxide changes, the band gap widens, and the ultraviolet absorption boundary blue-shifts, thereby achieving efficient ultraviolet capture and thus achieving an anti-ultraviolet effect.

[0014] 2. This invention combines zinc oxide intercalated magnesium silicate nanosheets with aniline and 2-fluoroaniline to prepare UV-resistant fillers. The layered structure of magnesium silicate acts as a nanoreactor, guiding the aniline monomers to directionally polymerize within a confined space, forming highly ordered polyaniline molecular chains. This ordered arrangement significantly improves carrier mobility, avoiding the chain entanglement defects of traditional polyaniline. The strong electronegativity of the fluorine atoms in 2-fluoroaniline optimizes the electron distribution of the aniline conjugated structure, enhancing UV absorption capacity. Simultaneously, the polyaniline quinone imine structure captures UV-excited reactive oxygen species, whose electrons are rapidly transferred to the magnesium silicate layers via the ordered molecular chains. Energy is dissipated through magnesium ion redox cycles, blocking the photodegradation chain reaction of epoxy resin, thus achieving both UV resistance and aging resistance.

[0015] 3. This invention prepares a composite acetic acid treatment solution and soaks non-woven fabric in it. Acetic acid selectively dissolves the amorphous regions on the surface of the non-woven fabric fibers, forming micron-level pores and grooves, creating micropores and interlaced grooves. During the curing process, epoxy resin penetrates into the pores. Under external force, it resists peeling through micropore interlocking, and the interface separation requires overcoming the geometric locking energy barrier. Acetic acid protons attack the polyester ester bonds, breaking them to generate new carboxyl and hydroxyl groups. These polar groups undergo ring-opening reactions with the epoxy groups of the epoxy resin. The polar surface after acetic acid treatment forms a dense hydrogen bond network with epoxy molecules. The treated fiber surface forms a carboxyl and hydroxyl enrichment layer, which can dynamically break and recombine under humid and hot conditions. Both of these processes simultaneously improve the bonding ability between the coating and the non-woven fabric, further enhancing the aging resistance of the non-woven fabric. Attached Figure Description

[0016] Figure 1 This is a process flow diagram for preparing the UV-resistant nonwoven fabric of the present invention; Figure 2 This is a SEM image of the polydopamine / zinc oxide intercalated magnesium silicate nanosheets prepared in Example 1 of the present invention; Figure 3 The image shows the XRD pattern of the polydopamine / zinc oxide intercalated magnesium silicate nanosheets prepared in Example 1 of this invention. Detailed Implementation

[0017] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of this invention.

[0018] Example 1: A process for preparing a UV-resistant nonwoven fabric, such as Figure 1 As shown, it includes the following steps: S1: Preparation of polydopamine / zinc oxide intercalated magnesium silicate nanosheets S1.1: Disperse 1 part by mass of zinc oxide in 100 parts by mass of 0.1M hydrochloric acid solution, sonicate for 30 min, then remove and wash until neutral, and vacuum dry at 60℃ for 6 h to obtain pretreated zinc oxide. Disperse 0.5 parts by mass of pretreated zinc oxide in 200 parts by mass of Tris buffer solution with pH 8.5, sonicate for 30 min, then add 0.25 parts by mass of dopamine hydrochloride, and keep at 25℃ for 24 h under light-protected conditions. Then centrifuge at 8000 r / min for 10 min, wash three times with deionized water, wash twice with anhydrous ethanol, and dry at 40℃ for 12 h to obtain polydopamine-coated zinc oxide. S1.2: Add 1 part by mass of magnesium silicate nanosheets to 100 parts by mass of 1.0M hydrochloric acid solution, stir at 70℃ for 24h, wash with deionized water until neutral, dry at 60℃ for 20min, then add 100 parts by mass of 20% TMAOH aqueous solution, sonicate for 30min to obtain a single-layer nanosheet dispersion. S1.3: Polydopamine-coated zinc oxide was dispersed in 50 parts by weight of Tris buffer solution at pH 5, and 0.1 parts by weight of acetic anhydride was added. The mixture was reacted at 25°C for 1 h, washed three times with deionized water, and redispersed in deionized water at pH 5 to obtain a polydopamine-coated zinc oxide dispersion. The polydopamine-coated zinc oxide dispersion was added dropwise to a monolayer nanosheet dispersion, stirred at 60°C for 12 h, and then heated to 120°C for 6 h. 20 parts by weight of 0.5M magnesium chloride solution were added, and the mixture was stirred at 80°C for 2 h. After centrifugation, washing, and freeze-drying, polydopamine / zinc oxide intercalated magnesium silicate nanosheets were obtained. The scanning electron microscope image is shown below. Figure 2 As shown, the XRD pattern is as follows Figure 3 As shown.

[0019] S2: Preparation of UV-resistant fillers 0.8 parts by mass of sodium dodecylbenzenesulfonate were dissolved in 150 parts by mass of a 1.2M sulfuric acid solution to obtain a sodium dodecylbenzenesulfonate sulfuric acid solution. Then, the sodium dodecylbenzenesulfonate sulfuric acid solution was transferred to a reaction flask and mixed with 0.4 parts by mass of zinc oxide intercalated magnesium silicate nanosheets, 0.9 parts by mass of aniline and 1 part by mass of 2-fluoroaniline. 4.5 parts by mass of ammonium persulfate were dissolved in 50 parts by mass of sulfuric acid solution and added to the reaction flask. The reaction flask temperature was maintained at 30°C and the stirring speed was 1200 r / min. After reacting for 4 h, the mixture was filtered and washed with deionized water and dried in a freeze dryer for 24 h to remove residual moisture, thus obtaining the UV-resistant filler.

[0020] S3: Treat the nonwoven fabric and spray it with an anti-UV coating. S3.1: Mix 60% glacial acetic acid, 5% KH-550, 1% ammonium persulfate, 8% acrylic acid and deionized water to make up the balance, and stir at 100 r / min for 10 min to obtain a composite acetic acid treatment solution. S3.2: Immerse the nonwoven fabric in the composite acetic acid treatment solution and control the temperature at 40℃. The bath ratio of the nonwoven fabric to the composite acetic acid treatment solution is 1g:20mL. Vacuum-assisted permeation at -0.08MPa for 5min, followed by immersion at normal pressure for 20min. Remove the nonwoven fabric and cure it with hot air at 120℃ for 3min to obtain the acetic acid-treated nonwoven fabric. S3.3: Mix 0.08 parts by weight of UV-resistant filler, 1.5 parts by weight of epoxy resin, and 0.5 parts by weight of MH-6616 curing agent in 5 parts by weight of ethyl acetate. Stir at 200 r / min for 10 min to obtain a coating liquid. Spray the coating liquid onto the surface of the acetic acid-treated nonwoven fabric with a spray gun. Finally, cure the coating at room temperature for 12 h to obtain a UV-resistant nonwoven fabric.

[0021] Example 2: A process for preparing a UV-resistant nonwoven fabric, such as Figure 1 As shown, it includes the following steps: S1: Preparation of polydopamine / zinc oxide intercalated magnesium silicate nanosheets S1.1: Disperse 3 parts by mass of zinc oxide in 105 parts by mass of 0.1M hydrochloric acid solution, sonicate for 30 min, then remove and wash until neutral, and vacuum dry at 60℃ for 6 h to obtain pretreated zinc oxide. Disperse 1 part by mass of pretreated zinc oxide in 205 parts by mass of Tris buffer solution with pH 8.5, sonicate for 30 min, then add 0.5 parts by mass of dopamine hydrochloride, and keep at 25℃ for 24 h under light-protected conditions. Then centrifuge at 8000 r / min for 10 min, wash three times with deionized water, wash twice with anhydrous ethanol, and dry at 40℃ for 12 h to obtain polydopamine-coated zinc oxide. S1.2: Add 2 parts by mass of magnesium silicate nanosheets to 105 parts by mass of 1.0M hydrochloric acid solution, stir at 70℃ for 24h, wash with deionized water until neutral, dry at 60℃ for 20min, then add 105 parts by mass of 20% TMAOH aqueous solution, sonicate for 30min to obtain a single-layer nanosheet dispersion. S1.3: Polydopamine-coated zinc oxide was dispersed in 55 parts by mass of Tris buffer solution with a pH of 5, and 0.2 parts by mass of acetic anhydride was added. The mixture was reacted at 25°C for 1 h, washed three times with deionized water, and redispersed in deionized water with a pH of 5 to obtain a polydopamine-coated zinc oxide dispersion. The polydopamine-coated zinc oxide dispersion was added dropwise to a monolayer nanosheet dispersion, stirred at 60°C for 12 h, and then heated to 120°C for 6 h. 25 parts by mass of 0.5M magnesium chloride solution were added, and the mixture was stirred at 80-85°C for 2 h. The mixture was centrifuged, washed, and freeze-dried to obtain polydopamine / zinc oxide intercalated magnesium silicate nanosheets.

[0022] S2: Preparation of UV-resistant fillers 1.2 parts by mass of sodium dodecylbenzenesulfonate were dissolved in 155 parts by mass of a 1.2M sulfuric acid solution to obtain a sodium dodecylbenzenesulfonate sulfuric acid solution. Then, the sodium dodecylbenzenesulfonate sulfuric acid solution was transferred to a reaction flask and mixed with 0.5 parts by mass of zinc oxide intercalated magnesium silicate nanosheets, 1.1 parts by mass of aniline and 1.3 parts by mass of 2-fluoroaniline. 4.8 parts by mass of ammonium persulfate were dissolved in 55 parts by mass of sulfuric acid solution and added to the reaction flask. The reaction flask temperature was maintained at 30°C and the stirring speed was 1200 r / min. After reacting for 4 h, the mixture was filtered and washed with deionized water and dried in a freeze dryer for 25 h to remove residual moisture, thus obtaining the UV-resistant filler.

[0023] S3: Treat the nonwoven fabric and spray it with an anti-UV coating. S3.1: Mix 65% glacial acetic acid, 8% KH-550, 2% ammonium persulfate, 10% acrylic acid and deionized water to make up the balance, and stir at 100 r / min for 10 min to obtain a composite acetic acid treatment solution. S3.2: Immerse the nonwoven fabric in the composite acetic acid treatment solution and control the temperature at 40℃. The bath ratio of the nonwoven fabric to the composite acetic acid treatment solution is 1g:25mL. Vacuum-assisted permeation at -0.08MPa for 5min, followed by immersion at normal pressure for 20min. Remove the nonwoven fabric and cure it with hot air at 120℃ for 3min to obtain the acetic acid-treated nonwoven fabric. S3.3: Mix 0.12 parts by weight of UV-resistant filler, 1.8 parts by weight of epoxy resin, and 0.8 parts by weight of MH-6616 curing agent in 8 parts by weight of ethyl acetate. Stir at 200 r / min for 10 min to obtain a coating liquid. Spray the coating liquid onto the surface of the acetic acid-treated nonwoven fabric with a spray gun. Finally, cure the coating at room temperature for 12 h to obtain a UV-resistant nonwoven fabric.

[0024] Example 3: A process for preparing a UV-resistant nonwoven fabric, such as Figure 1 As shown, it includes the following steps: S1: Preparation of polydopamine / zinc oxide intercalated magnesium silicate nanosheets S1.1: Disperse 1 part by mass of zinc oxide in 100 parts by mass of 0.15M hydrochloric acid solution, sonicate for 40 min, then remove and wash until neutral, and vacuum dry at 65℃ for 6.5 h to obtain pretreated zinc oxide. Disperse 0.5 parts by mass of pretreated zinc oxide in 200 parts by mass of Tris buffer solution with pH 8.7, sonicate for 35 min, then add 0.25 parts by mass of dopamine hydrochloride, and keep at 30℃ for 25 h under light-protected conditions. Then centrifuge at 8100 r / min for 15 min, wash three times with deionized water and twice with anhydrous ethanol, and dry at 45℃ for 12 h to obtain polydopamine-coated zinc oxide. S1.2: Add 1 part by mass of magnesium silicate nanosheets to 100 parts by mass of 1.0M hydrochloric acid solution, stir at 75℃ for 25h, wash with deionized water until neutral, dry at 65℃ for 25min, then add 100 parts by mass of 20% TMAOH aqueous solution, sonicate for 35min to obtain a single-layer nanosheet dispersion. S1.3: Polydopamine-coated zinc oxide was dispersed in 50 parts by mass of Tris buffer solution with a pH of 5.2, and 0.1 parts by mass of acetic anhydride was added. The mixture was reacted at 30°C for 1.5 h, washed three times with deionized water, and redispersed in deionized water with a pH of 5.2 to obtain a polydopamine-coated zinc oxide dispersion. The polydopamine-coated zinc oxide dispersion was added dropwise to a monolayer nanosheet dispersion, stirred at 65°C for 13 h, and then heated to 125°C for 6.5 h. 20 parts by mass of 0.55 M magnesium chloride solution were added, and the mixture was stirred at 85°C for 2.5 h. The mixture was centrifuged, washed, and freeze-dried to obtain polydopamine / zinc oxide intercalated magnesium silicate nanosheets.

[0025] S2: Preparation of UV-resistant fillers 0.8 parts by mass of sodium dodecylbenzenesulfonate were dissolved in 150 parts by mass of a 1.5M sulfuric acid solution to obtain a sodium dodecylbenzenesulfonate sulfuric acid solution. Then, the sodium dodecylbenzenesulfonate sulfuric acid solution was transferred to a reaction flask and mixed with 0.4 parts by mass of zinc oxide intercalated magnesium silicate nanosheets, 0.9 parts by mass of aniline, and 1 part by mass of 2-fluoroaniline. 4.5 parts by mass of ammonium persulfate were dissolved in 50 parts by mass of sulfuric acid solution and added to the reaction flask. The reaction flask temperature was maintained at 35°C, the stirring speed was 1300 r / min, and the reaction was carried out for 4.5 h. After filtration and washing with deionized water, the mixture was dried in a freeze dryer for 25 h to remove residual moisture, and the UV-resistant filler was obtained.

[0026] S3: Treat the nonwoven fabric and spray it with an anti-UV coating. S3.1: Mix 60% glacial acetic acid, 5% KH-550, 1% ammonium persulfate, 8% acrylic acid and deionized water to make up the balance, and stir at 120 r / min for 15 min to obtain a composite acetic acid treatment solution. S3.2: Immerse the nonwoven fabric in the composite acetic acid treatment solution and control the temperature at 45℃. The bath ratio of the nonwoven fabric to the composite acetic acid treatment solution is 1g:20mL. Vacuum-assisted permeation at -0.08MPa for 10min, followed by immersion at normal pressure for 25min. Remove the nonwoven fabric and cure it with hot air at 125℃ for 5min to obtain the acetic acid-treated nonwoven fabric. S3.3: Mix 0.08 parts by weight of UV-resistant filler, 1.5 parts by weight of epoxy resin, and 0.5 parts by weight of MH-6616 curing agent in 5 parts by weight of ethyl acetate. Stir at 300 r / min for 12 min to obtain a coating liquid. Spray the coating liquid onto the surface of the acetic acid-treated nonwoven fabric with a spray gun. Finally, cure the coating at room temperature for 13 h to obtain a UV-resistant nonwoven fabric.

[0027] Comparative Example 1: Compared with Example 1, the difference of Comparative Example 1 is that in step S1.1, dopamine hydrochloride is not added, and pretreated zinc oxide is directly used to coat zinc oxide instead of polydopamine for subsequent steps. The other steps remain unchanged, and it is referred to as Comparative Example 1.

[0028] Comparative Example 2: Compared with Example 1, the difference of Comparative Example 2 is that magnesium silicate nanosheets are not used in step S1.2, but kaolin is used instead of magnesium silicate nanosheets. The other steps remain the same, and it is referred to as Comparative Example 2.

[0029] Comparative Example 3: Compared with Example 1, Comparative Example 3 differs in that aniline is not added in step S2, while the other steps remain unchanged, and is referred to as Comparative Example 3.

[0030] Comparative Example 4: Compared with Example 1, Comparative Example 4 differs in that glacial acetic acid is not added in step S3.1, but KH-550 is used instead of glacial acetic acid. The remaining steps remain unchanged, and it is referred to as Comparative Example 4.

[0031] Comparative Example 5: Comparative Example 5 is a commercially available nonwoven fabric with an anti-UV coating.

[0032] The UV protection performance of Examples 1-3, Comparative Examples 1-3, and Comparative Example 5 was tested using the method described in GB / T18830 "Evaluation of UV Protection Performance of Textiles". The UPF values ​​were calculated, and the results are shown in Table 1.

[0033] The UV aging resistance of Examples 1-3 and Comparative Examples 3-5 was tested according to the method in GB / T16422.2-2022 Plastics Laboratory Light Source Exposure Test Method Part 2: Xenon Arc Lamp, under the condition of 0.55 W / m 2 At a wavelength of 340 nm, an ambient temperature of 60 °C, an ambient humidity of 50% RH, and an irradiation time of 400 h, the coating was observed to see if it peeled off from the nonwoven fabric, and the percentage of peeled area was statistically analyzed, as shown in Table 2.

[0034] Table 1

[0035] Table 2

[0036] As can be seen from Table 1, the UPF values ​​of Examples 1-3 are significantly higher than those of all comparative examples, indicating that polydopamine and magnesium silicate nanosheets are key components that synergistically enhance UV resistance. The addition of aniline also contributes to the improvement of UV resistance. Comparative Example 5, as a commercially available product, has a lower UPF value than the examples, indicating that the formulation design of the examples is superior to the prior art.

[0037] As can be seen from Table 2, Examples 1-3 showed no peeling after 400 hours of xenon lamp aging, while all comparative examples showed peeling. Comparative Example 3, which lacked aniline, and Comparative Example 4, which replaced glacial acetic acid with KH-550, had a higher peeling area ratio, ranging from 3.4% to 3.8%, indicating that aniline and glacial acetic acid are crucial for the interfacial bonding stability between the coating and the nonwoven fabric. Although the peeling area of ​​the commercially available product Comparative Example 5 was relatively small, at 1.2%, peeling still occurred, further verifying the long-term stability advantage of the formulations in the examples.

[0038] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims. Parts not described in detail in this specification are prior art known to those skilled in the art.

Claims

1. A UV-resistant nonwoven fabric, characterized in that, Includes a nonwoven fabric layer and an anti-UV coating applied to the surface of the nonwoven fabric; The UV-resistant coating consists of UV-resistant filler, epoxy resin, MH-6616 curing agent and ethyl acetate; The UV-resistant filler is prepared from polydopamine / zinc oxide intercalated magnesium silicate nanosheets, sodium dodecylbenzenesulfonate, aniline and 2-fluoroaniline.

2. A process for preparing an ultraviolet-resistant nonwoven fabric, characterized in that, Includes the following steps: S1: Preparation of polydopamine / zinc oxide intercalated magnesium silicate nanosheets Zinc oxide was dispersed, ultrasonicated, and dried to obtain pretreated zinc oxide. The pretreated zinc oxide was then dispersed again, and dopamine hydrochloride was added. The mixture was centrifuged in the dark, washed, and dried to obtain polydopamine-coated zinc oxide. Magnesium silicate nanosheets were added to hydrochloric acid solution, stirred, washed, and dried. Then, they were added to TMAOH aqueous solution and ultrasonicated to obtain a monolayer nanosheet dispersion. Polydopamine-coated zinc oxide was dispersed in Tris buffer solution, acetic anhydride was added, and after the reaction, it was redispersed in deionized water to obtain a polydopamine-coated zinc oxide dispersion. The polydopamine-coated zinc oxide dispersion was added dropwise to the monolayer nanosheet dispersion, and the mixture was heated to react. Magnesium chloride solution was added, and the mixture was stirred, centrifuged, washed, and freeze-dried to obtain polydopamine / zinc oxide intercalated magnesium silicate nanosheets. S2: Preparation of UV-resistant fillers Sodium dodecylbenzenesulfonate was dissolved in sulfuric acid solution to obtain sodium dodecylbenzenesulfonate sulfuric acid solution. Sodium dodecylbenzenesulfonate sulfuric acid solution, zinc oxide intercalated magnesium silicate nanosheets, aniline and 2-fluoroaniline were mixed, and then ammonium persulfate was added to react and obtain UV-resistant filler. S3: Treat the nonwoven fabric and spray it with an anti-UV coating. A composite acetic acid treatment solution was prepared by mixing glacial acetic acid, KH-550, ammonium persulfate, acrylic acid, and deionized water. The nonwoven fabric was then immersed in the composite acetic acid treatment solution to obtain an acetic acid-treated nonwoven fabric. The UV-resistant filler was mixed with epoxy resin and MH-6616 curing agent in ethyl acetate and stirred to obtain a coating solution. The coating solution was then sprayed onto the surface of the acetic acid-treated nonwoven fabric using a spray gun. Finally, the coating was cured at room temperature to obtain a UV-resistant nonwoven fabric.

3. The preparation process of an ultraviolet-resistant nonwoven fabric according to claim 2, characterized in that, The preparation of polydopamine / zinc oxide intercalated magnesium silicate nanosheets by S1 includes the following steps: S1.1: Disperse 1-3 parts by mass of zinc oxide in 100-105 parts by mass of 0.1-0.15M hydrochloric acid solution, sonicate for 30-40 min, then remove and wash until neutral, vacuum dry at 60-65℃ for 6-6.5 h to obtain pretreated zinc oxide. Disperse 0.5-1 parts by mass of pretreated zinc oxide in 200-205 parts by mass of Tris buffer solution with pH 8.5-8.7, sonicate for 30-35 min, then add 0.25-0.5 parts by mass of dopamine hydrochloride, keep at 25-30℃ and shake for 24-25 h under light-protected conditions, then centrifuge at 8000-8100 r / min for 10-15 min, wash three times with deionized water and twice with anhydrous ethanol, and dry at 40-45℃ for 12 h to obtain polydopamine-coated zinc oxide. S1.2: Add 1-2 parts by weight of magnesium silicate nanosheets to 100-105 parts by weight of 1.0M hydrochloric acid solution, stir at 70-75℃ for 24-25h, wash with deionized water until neutral, dry at 60-65℃ for 20-25min, then add 100-105 parts by weight of 20% TMAOH aqueous solution, sonicate for 30-35min to obtain a single-layer nanosheet dispersion; S1.3: Disperse polydopamine-coated zinc oxide in 50-55 parts by weight of Tris buffer solution with a pH of 5-5.2, add 0.1-0.2 parts by weight of acetic anhydride, react at 25-30℃ for 1-1.5 h, wash three times with deionized water, and redisperse in deionized water with a pH of 5-5.2 to obtain polydopamine-coated zinc oxide dispersion; add the polydopamine-coated zinc oxide dispersion dropwise to the monolayer nanosheet dispersion, stir at 60-65℃ for 12-13 h, then heat to 120-125℃ for 6-6.5 h, add 20-25 parts by weight of magnesium chloride solution, stir at 80-85℃ for 2-2.5 h, centrifuge, wash, and freeze-dry to obtain polydopamine / zinc oxide intercalated magnesium silicate nanosheets.

4. The preparation process of an ultraviolet-resistant nonwoven fabric according to claim 3, characterized in that, The preparation of UV-resistant fillers by S2 includes the following steps: Dissolve 0.8-1.2 parts by weight of sodium dodecylbenzenesulfonate in 150-155 parts by weight of sulfuric acid solution to obtain sodium dodecylbenzenesulfonate sulfuric acid solution. Then, transfer the sodium dodecylbenzenesulfonate sulfuric acid solution to a reaction flask and mix it with 0.4-0.5 parts by weight of zinc oxide intercalated magnesium silicate nanosheets, 0.9-1.1 parts by weight of aniline and 1-1.3 parts by weight of 2-fluoroaniline. Dissolve 4.5-4.8 parts by weight of ammonium persulfate in 50-55 parts by weight of sulfuric acid solution and add it to the reaction flask. Maintain the temperature of the reaction flask at 30-35℃ and the stirring speed at 1200-1300 r / min. After reacting for 4-4.5 h, filter and wash with deionized water, and dry in a freeze dryer for 24-25 h to remove residual moisture to obtain the UV-resistant filler.

5. The preparation process of an ultraviolet-resistant nonwoven fabric according to claim 4, characterized in that, S3 involves the following steps to treat nonwoven fabrics and apply an anti-UV coating: S3.1: Mix 60-65% glacial acetic acid, 5-8% KH-550, 1-2% ammonium persulfate, 8-10% acrylic acid and deionized water to make up the balance, and stir at 100-120 r / min for 10-15 min to obtain a composite acetic acid treatment solution. S3.2: Immerse the nonwoven fabric in a composite acetic acid treatment solution and control the temperature at 40-45℃. The bath ratio of the nonwoven fabric to the composite acetic acid treatment solution is 1g:(20-25)mL. Vacuum-assisted permeation at -0.08MPa for 5-10min, followed by immersion at normal pressure for 20-25min. Remove the nonwoven fabric and cure it with hot air at 120-125℃ for 3-5min to obtain acetic acid-treated nonwoven fabric. S3.3: Mix 0.08-0.12 parts by weight of UV-resistant filler, 1.5-1.8 parts by weight of epoxy resin, and 0.5-0.8 parts by weight of MH-6616 curing agent in 5-8 parts by weight of ethyl acetate. Stir at 200-300 r / min for 10-12 min to obtain a coating liquid. Spray the coating liquid onto the surface of the acetic acid-treated nonwoven fabric with a spray gun. Finally, cure the coating at room temperature for 12-13 h to obtain a UV-resistant nonwoven fabric.

6. The preparation process of an ultraviolet-resistant nonwoven fabric according to claim 3, characterized in that, The power of the ultrasonic treatment is 300W.

7. The preparation process of an ultraviolet-resistant nonwoven fabric according to claim 3, characterized in that, The concentration of the magnesium chloride solution is 0.5-0.55M.

8. The preparation process of an ultraviolet-resistant nonwoven fabric according to claim 4, characterized in that, The concentration of the sulfuric acid solution is 1.2-1.5M.

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