Aging-resistant hook-and-loop fastener material and process for producing the same

Abstract

The application relates to the technical field of high polymer materials, in particular to an anti-aging fastening material and a preparation process thereof. The application comprises the following steps: preparation of aluminum-doped zinc oxide, modification of the aluminum-doped zinc oxide by tannic acid, modification of nylon fibers by ferulic acid, and preparation of modified nylon masterbatch for fastening. In the application, the groups of tannic acid and the aluminum ions and zinc ions of the aluminum-doped zinc oxide are simultaneously chelated and dehydrated and condensed through the heat energy of the reflux reaction, so that a five-membered ring chelate is formed, a dense coating layer is formed on the surface, the composition of the coating layer is simple, but the chemical bond is very stable, the ultraviolet light stability of the aluminum-doped zinc oxide is enhanced, the coating layer can also produce hydrogen bond / π-π interaction with the nylon amide bond, the interface bonding strength is improved, the particle size is kept at the level without filter pressure fluctuation in the spinning process, and the volume resistivity of the nylon fiber is reduced.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to an aging-resistant hook and loop fastener material and its preparation process. Background Technology

[0002] Hook and loop fasteners, also known as Velcro or nylon fasteners, are mechanical fasteners that can be repeatedly opened and closed. They consist of two nylon straps: one with a hook and the other with a loop. When pressed together, the hook and loop interlock to form a strong connection, which can be separated by tearing. Due to their high strength and fatigue resistance, hook and loop fasteners are widely used in automotive interiors, medical equipment, and outdoor gear.

[0003] In the medical field, electrostatic interference can cause monitor readings to drift, and the amount of bacteria adhering to statically charged surfaces also increases significantly. When hook and loop fasteners are used for fixing ECG electrode leads, managing surgical machine cables, etc., antistatic treatment is required. Existing technologies for antistatic treatment of nylon hook and loop fasteners mainly include blending conductive fibers, coating the surface with antistatic agents, and modifying with block copolymers. Among these, blending conductive fibers involves incorporating conductive materials during the preparation of nylon fibers to reduce resistivity and achieve the antistatic capability required by antistatic standards. However, conventional antistatic agents such as carbon black and quaternary ammonium salts are prone to migration and precipitation, leading to a sharp increase in resistivity. Inorganic fillers, due to uneven doping, can cause particle agglomeration, resulting in a discontinuous conductive network. Especially under the influence of ultraviolet light, ultraviolet light can cause the amide bonds in nylon to break, leading to changes on the surface of the nylon fibers, stress concentration, interfacial peeling, and particle precipitation. Therefore, its electrostatic release efficiency will decrease sharply with aging, thus affecting its use. Therefore, this invention provides an aging-resistant hook and loop material and its preparation process to solve the problems existing in the above-mentioned technologies. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide an aging-resistant hook and loop fastener material and its preparation process.

[0005] A process for preparing an aging-resistant hook and loop fastener material includes the following steps:

[0006] S1: Preparation of aluminum-doped zinc oxide

[0007] Zinc citrate, urea and aluminum isopropoxide were mixed and added to an aqueous ethylene glycol solution. The mixture was subjected to hydrothermal reaction, allowed to stand and cool, centrifuged and filtered, the lower precipitate was retained, dried, ground and transferred to a muffle furnace for calcination to obtain aluminum-doped zinc oxide.

[0008] S2: Tannic acid-modified aluminum-doped zinc oxide

[0009] Aluminum-doped zinc oxide was placed in anhydrous ethanol, ultrasonically dispersed, then tannic acid was added, ultrasonic dispersion was continued, the mixture was stirred and refluxed, centrifuged and filtered to collect the precipitate, and vacuum dried to obtain tannic acid-modified aluminum-doped zinc oxide powder.

[0010] S3: Ferulic acid modified nylon fiber

[0011] Nylon masterbatch was immersed in NaOH solution and dried under vacuum to obtain activated nylon masterbatch. Ferulic acid was weighed and dissolved in anhydrous ethanol to prepare a mother liquor. The mother liquor, deionized water and acetic acid solution were mixed and stirred to obtain a working solution. The activated nylon masterbatch was immersed in the working solution and shaken. The product was washed three times and dried under vacuum to obtain modified nylon masterbatch.

[0012] S4: Preparation of Hook & Loop Fasteners from Modified Nylon Masterbatch

[0013] Modified nylon masterbatch and tannic acid-modified aluminum-doped zinc oxide powder are mixed and added to a twin-screw extruder, then melt-blended and extruded through a twin-screw extruder. After being cooled by air, the mixture is granulated by a pelletizer and dried in a vacuum oven for later use. Finally, it is extruded through a melt spinning machine to obtain spun nylon fibers, which are the aging-resistant hook and loop fastener materials.

[0014] Furthermore, the preparation of S1 aluminum-doped zinc oxide includes the following steps:

[0015] Mix 2-3 parts by weight of zinc citrate, 1-1.5 parts by weight of urea, and 1.5-2.5 parts by weight of aluminum isopropoxide, then add the mixture to 50-60 parts by weight of ethylene glycol aqueous solution. Stir at 200-300 r / min for 30-35 min. Transfer the product to a hydrothermal reactor, heat to 180-190℃, and hydrothermally react for 6-6.5 h. Allow to cool to room temperature (22-24℃), centrifuge at 4000-4100 r / min for 5-10 min, filter, retain the lower precipitate, wash three times with deionized water and anhydrous ethanol respectively, and dry in an oven at 80-85℃. After drying, grind and transfer to a muffle furnace, heat to 550-570℃ at a heating rate of 2-3℃ / min, and calcine for 2-3 h to obtain aluminum-doped zinc oxide.

[0016] Furthermore, the S2 tannic acid-modified aluminum-doped zinc oxide process includes the following steps:

[0017] Take 10-15 parts by weight of aluminum-doped zinc oxide and add it to 50-55 parts by weight of anhydrous ethanol. Disperse it by sonication for 1-1.5 hours. Then add 0.2-0.3 parts by weight of tannic acid and continue to disperse by sonication for 1-1.5 hours. Stir and reflux at 300-350 r / min at 80-85℃ for 6-6.5 hours. Cool down to 5-10℃, wash three times with Tris buffer, then wash twice with ethanol. Centrifuge at 8000-8100 r / min for 5-10 minutes. Filter and collect the precipitate. Vacuum dry at 60-65℃ for 12-13 hours to obtain tannic acid modified aluminum-doped zinc oxide powder.

[0018] Furthermore, the S3 ferulic acid modified nylon fiber includes the following steps:

[0019] Nylon masterbatch was immersed in NaOH solution at a ratio of 1g:(30-35)mL and treated at 80-85℃ for 30-35min. After removal, it was washed with deionized water until neutral and then vacuum dried at 80-85℃ for 2-2.5h to obtain activated nylon masterbatch.

[0020] Weigh 1-2 parts by weight of ferulic acid and dissolve it in 100-105 parts by weight of anhydrous ethanol to prepare a mother liquor. Take 50-55 parts by weight of the mother liquor, 150-155 parts by weight of deionized water and 5-6 parts by weight of acetic acid solution and stir to obtain a working solution. Immerse the activated nylon masterbatch into the working solution at a material-to-liquid ratio of 1 g: (40-45) mL and place it in a constant temperature water bath shaker at 83-86℃ for 3.5-4 h. Wash the product three times with anhydrous ethanol at 4℃ to terminate the reaction. Extract with anhydrous ethanol in a Soxhlet extractor for 24-25 h to completely remove unreacted ferulic acid. Vacuum dry at 60-65℃ for 6-7 h to obtain modified nylon masterbatch.

[0021] Furthermore, the preparation of hook and loop fasteners using S4 modified nylon masterbatch includes the following steps:

[0022] Modified nylon masterbatch and tannic acid-modified aluminum-doped zinc oxide powder are mixed at a mass ratio of (8-10):(0.1-0.3) and added to a twin-screw extruder. The mixture is then melt-blended and extruded through the twin-screw extruder. After being cooled by air, the mixture is granulated by a pelletizer and dried in a vacuum oven for later use. The upper zone of the melt spinning machine is set to 180-185℃, the middle zone to 195-200℃, the spinning nozzle to 210-215℃, and the winding speed to 600-650 r / min. The resulting spun nylon fibers are obtained by extrusion through the melt spinning machine, which is the aging-resistant hook and loop fastener material.

[0023] Furthermore, the ethylene glycol aqueous solution is prepared by mixing ethylene glycol and deionized water at a mass ratio of (2-2.5):1.

[0024] Furthermore, the pH of the Tris buffer is 8.3-8.5.

[0025] Furthermore, the concentration of the NaOH solution is 5-10 wt%, and the concentration of the acetic acid solution is 0.1-0.15 mol / L.

[0026] An aging-resistant hook and loop fastener material, which is prepared by the above-mentioned aging-resistant hook and loop fastener preparation process.

[0027] The present invention has the following advantages:

[0028] 1. This invention prepares aluminum-doped zinc oxide using zinc citrate and aluminum isopropoxide. Compared to zinc oxide prepared by the traditional nitrate method, the tricarboxyl groups of citric acid can simultaneously chelate zinc and aluminum ions to form a molecular-level complex. Urea provides a gradual increase in pH during the hydrothermal reaction, allowing zinc and aluminum ions to precipitate simultaneously, resulting in more uniform aluminum doping. Furthermore, the zinc ions in zinc citrate are structurally surrounded by citric acid molecules, while aluminum isopropoxide can hydrolyze in the system to form Al–O–Al oligomers, which also have alkoxy polar shells. The two can form a Zn–O–Al network through hydrogen bonding / chelation during the hydrothermal reaction in solution, resulting in a more uniform aluminum doping after calcination. Aluminum ions are directly embedded in the zinc oxide lattice, improving doping uniformity and avoiding aluminum segregation and the formation of impurity phases. This method, with its controllable molecular pre-assembly and self-templating pore formation, improves the uniformity of aluminum composition in aluminum-doped zinc oxide, reduces particle size, and the more uniform distribution of aluminum-doped zinc oxide can form a more effective conductive network, thereby releasing static electricity more effectively. In nylon fibers, uniformly dispersed aluminum-doped zinc oxide can accelerate the release of static charge and reduce static accumulation. Small-diameter aluminum-doped zinc oxide particles can be more evenly distributed on the fiber surface and inside the nylon fiber, further enhancing the antistatic effect and thus improving the antistatic effect of hook and loop fasteners.

[0029] 2. This invention utilizes the heat energy of a reflux reaction to drive the tannic acid groups to undergo chelation-dehydration condensation with the aluminum and zinc ions of aluminum-doped zinc oxide, forming a five-membered ring chelate. This results in a dense coating layer on the surface. This coating layer has a simple composition but possesses highly stable chemical bonds, enhancing the UV stability of the aluminum-doped zinc oxide. This layer can also generate hydrogen bonds / π-π interactions with nylon amide bonds, improving interfacial bonding strength and maintaining the particle size at a level free from pressure fluctuations during spinning. Simultaneously, the uniformly embedded aluminum-doped zinc oxide provides carrier channels, while the tannic acid layer on top, in conjunction with the aluminum-doped zinc oxide, distributes the passing particles as microcapacitors in the electrical channels, thereby reducing the volume resistivity of the nylon fiber. This maintains antistatic properties while ensuring fiber spinnability without sacrificing photostability, guaranteeing the aging resistance of the hook and loop material.

[0030] 3. This invention modifies nylon masterbatch with ferulic acid. First, under heating conditions, NaOH solution is used to slightly hydrolyze the amide bonds on the surface of the nylon molecular chain, breaking some of the molecular chain and exposing more free amino and carboxyl groups on the surface of the nylon masterbatch. The active groups of ferulic acid react with the free amino and carboxyl groups, transforming a chemically inert long nylon chain into an active chain with multiple functional arms. This improves the interfacial bonding force on the surface of the nylon masterbatch, resulting in better affinity with the surface of aluminum-doped zinc oxide particles. Furthermore, the active chain surface has more than one type of functional group, and its interfacial bonding force is not concentrated in one place but is uniformly dispersed on the chain. Therefore, it can reduce stress concentration points and improve the stability of the prepared nylon fiber, i.e., hook and loop material, making the hook and loop material less prone to decomposition and more resistant to aging. Attached Figure Description

[0031] Figure 1 This is a flowchart illustrating the preparation process of the aging-resistant hook and loop fastener material of the present invention. Detailed Implementation

[0032] 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.

[0033] Example 1:

[0034] A preparation process for an aging-resistant hook and loop fastener material, such as Figure 1 As shown, it includes the following steps:

[0035] S1: Preparation of aluminum-doped zinc oxide

[0036] Two parts by mass of zinc citrate, one part by mass of urea, and 1.5 parts by mass of aluminum isopropoxide were mixed and added to 50 parts by mass of ethylene glycol aqueous solution. The mixture was stirred at 200 r / min for 30 min. The product was then transferred to a hydrothermal reactor, heated to 180 °C, and hydrothermally reacted for 6 h. After cooling to room temperature of 22 °C, the mixture was centrifuged at 4000 r / min for 5 min, filtered, and the lower precipitate was retained. The precipitate was then washed three times with deionized water and anhydrous ethanol, and dried in an oven at 80 °C. After drying, the precipitate was ground and transferred to a muffle furnace. The temperature was increased to 550 °C at a rate of 2 °C / min, and calcined for 2 h to obtain aluminum-doped zinc oxide.

[0037] The ethylene glycol aqueous solution was prepared by mixing ethylene glycol and deionized water at a mass ratio of 2:1.

[0038] S2: Tannic acid-modified aluminum-doped zinc oxide

[0039] Take 10 parts by weight of aluminum-doped zinc oxide and add it to 50 parts by weight of anhydrous ethanol. Disperse it by sonication for 1 hour. Then add 0.2 parts by weight of tannic acid and continue to disperse by sonication for 1 hour. Stir and reflux at 300 r / min at 80℃ for 6 hours. Cool down to 5℃, wash three times with Tris buffer solution with pH 8.3, wash twice with ethanol, and centrifuge at 8000 r / min for 5 minutes. Filter and collect the precipitate. Vacuum dry at 60℃ for 12 hours to obtain tannic acid modified aluminum-doped zinc oxide powder.

[0040] S3: Ferulic acid modified nylon fiber

[0041] Nylon masterbatch was immersed in a 5wt% NaOH solution at a material-to-liquid ratio of 1g:30mL, treated at 80℃ for 30min, removed and washed with deionized water until neutral, and then vacuum dried at 80℃ for 2h to obtain activated nylon masterbatch.

[0042] Weigh 1 part by mass of ferulic acid and dissolve it in 100 parts by mass of anhydrous ethanol to prepare a mother liquor. Take 50 parts by mass of the mother liquor, 150 parts by mass of deionized water and 5 parts by mass of 0.1 mol / L acetic acid solution and stir to obtain a working solution. Immerse the activated nylon masterbatch in the working solution at a material-to-liquid ratio of 1 g: 40 mL and place it in a constant temperature water bath shaker at 83°C for 3.5 h. Wash the product three times with anhydrous ethanol at 4°C to terminate the reaction. Extract with anhydrous ethanol in a Soxhlet extractor for 24 h to completely remove unreacted ferulic acid. Dry under vacuum at 60°C for 6 h to obtain modified nylon masterbatch.

[0043] S4: Preparation of Hook & Loop Fasteners from Modified Nylon Masterbatch

[0044] Modified nylon masterbatch and tannic acid-modified aluminum-doped zinc oxide powder were mixed at a mass ratio of 8:0.1 and added to a twin-screw extruder. The mixture was then melt-blended and extruded through the twin-screw extruder. After being cooled by air, the mixture was granulated by a pelletizer and dried in a vacuum oven for later use. The upper zone of the melt spinning machine was set to 180°C, the middle zone to 195°C, the spinning nozzle to 210°C, and the winding speed to 600 r / min. The resulting spun nylon fibers were obtained by extrusion through the melt spinning machine, which is the aging-resistant hook and loop fastener material.

[0045] Example 2:

[0046] A preparation process for an aging-resistant hook and loop fastener material, such as Figure 1 As shown, it includes the following steps:

[0047] S1: Preparation of aluminum-doped zinc oxide

[0048] Three parts by mass of zinc citrate, 1.5 parts by mass of urea, and 2.5 parts by mass of aluminum isopropoxide were mixed and added to 60 parts by mass of ethylene glycol aqueous solution. The mixture was stirred at 200 r / min for 30 min. The product was then transferred to a hydrothermal reactor, heated to 180 °C, and hydrothermally reacted for 6 h. After cooling to room temperature (22 °C), the mixture was centrifuged at 4000 r / min for 5 min, filtered, and the lower precipitate was retained. The precipitate was then washed three times with deionized water and anhydrous ethanol, and dried in an oven at 80 °C. After drying, the precipitate was ground and transferred to a muffle furnace. The temperature was increased to 550 °C at a rate of 2 °C / min, and calcined for 2 h to obtain aluminum-doped zinc oxide.

[0049] The ethylene glycol aqueous solution was prepared by mixing ethylene glycol and deionized water at a mass ratio of 2.5:1.

[0050] S2: Tannic acid-modified aluminum-doped zinc oxide

[0051] Take 15 parts by weight of aluminum-doped zinc oxide and add it to 55 parts by weight of anhydrous ethanol. Disperse it by sonication for 1 hour. Then add 0.3 parts by weight of tannic acid and continue to disperse by sonication for 1 hour. Stir and reflux at 300 r / min at 80℃ for 6 hours. Cool down to 5℃, wash three times with Tris buffer solution with pH 8.3, wash twice with ethanol, and centrifuge at 8000 r / min for 5 minutes. Filter and collect the precipitate, and vacuum dry at 60℃ for 12 hours to obtain tannic acid modified aluminum-doped zinc oxide powder.

[0052] S3: Ferulic acid modified nylon fiber

[0053] Nylon masterbatch was immersed in a 5wt% NaOH solution at a material-to-liquid ratio of 1g:30mL, treated at 80℃ for 30min, removed and washed with deionized water until neutral, and then vacuum dried at 80℃ for 2h to obtain activated nylon masterbatch.

[0054] Weigh 2 parts by mass of ferulic acid and dissolve it in 105 parts by mass of anhydrous ethanol to prepare a mother liquor. Take 55 parts by mass of the mother liquor, 155 parts by mass of deionized water and 6 parts by mass of 0.1 mol / L acetic acid solution and stir to obtain a working solution. Immerse the activated nylon masterbatch in the working solution at a material-to-liquid ratio of 1 g: 45 mL and place it in a constant temperature water bath shaker at 83°C for 3.5 h. Wash the product three times with anhydrous ethanol at 4°C to terminate the reaction. Extract with anhydrous ethanol in a Soxhlet extractor for 24 h to completely remove unreacted ferulic acid. Dry under vacuum at 60°C for 6 h to obtain modified nylon masterbatch.

[0055] S4: Preparation of Hook & Loop Fasteners from Modified Nylon Masterbatch

[0056] Modified nylon masterbatch and tannic acid-modified aluminum-doped zinc oxide powder were mixed at a mass ratio of 10:0.3 and added to a twin-screw extruder. The mixture was then melt-blended and extruded through the twin-screw extruder. After being cooled by air, the mixture was granulated by a pelletizer and dried in a vacuum oven for later use. The upper zone of the melt spinning machine was set to 180°C, the middle zone to 195°C, the spinning nozzle to 210°C, and the winding speed to 600 r / min. The resulting spun nylon fibers were obtained by extrusion through the melt spinning machine, which is the aging-resistant hook and loop fastener material.

[0057] Example 3:

[0058] A preparation process for an aging-resistant hook and loop fastener material, such as Figure 1 As shown, it includes the following steps:

[0059] S1: Preparation of aluminum-doped zinc oxide

[0060] Two parts by mass of zinc citrate, one part by mass of urea, and 1.5 parts by mass of aluminum isopropoxide were mixed and added to 50 parts by mass of ethylene glycol aqueous solution. The mixture was stirred at 300 r / min for 35 min. The product was then transferred to a hydrothermal reactor, heated to 190 °C, and hydrothermally reacted for 6.5 h. After cooling to room temperature (24 °C), the mixture was centrifuged at 4100 r / min for 10 min, filtered, and the lower precipitate was retained. The precipitate was then washed three times with deionized water and anhydrous ethanol, and dried in an oven at 85 °C. After drying, the precipitate was ground and transferred to a muffle furnace. The temperature was increased to 570 °C at a rate of 3 °C / min, and calcined for 3 h to obtain aluminum-doped zinc oxide.

[0061] The ethylene glycol aqueous solution was prepared by mixing ethylene glycol and deionized water at a mass ratio of 2:1.

[0062] S2: Tannic acid-modified aluminum-doped zinc oxide

[0063] Take 10 parts by weight of aluminum-doped zinc oxide and add it to 50 parts by weight of anhydrous ethanol. Disperse it by sonication for 1.5 h. Then add 0.2 parts by weight of tannic acid and continue to disperse by sonication for 1.5 h. Stir and reflux at 350 r / min at 85 °C for 6.5 h. Cool down to 10 °C, wash three times with Tris buffer solution with pH 8.5, wash twice with ethanol, and centrifuge at 8100 r / min for 10 min. Filter and collect the precipitate, and vacuum dry at 65 °C for 13 h to obtain tannic acid modified aluminum-doped zinc oxide powder.

[0064] S3: Ferulic acid modified nylon fiber

[0065] Nylon masterbatch was immersed in a 5wt% NaOH solution at a ratio of 1g:30mL and treated at 85℃ for 35min. After removal, it was washed with deionized water until neutral and then vacuum dried at 85℃ for 2.5h to obtain activated nylon masterbatch.

[0066] Weigh 1 part by mass of ferulic acid and dissolve it in 100 parts by mass of anhydrous ethanol to prepare a mother liquor. Take 50 parts by mass of the mother liquor, 150 parts by mass of deionized water and 5 parts by mass of 0.15 mol / L acetic acid solution and stir to obtain a working solution. Immerse the activated nylon masterbatch in the working solution at a material-to-liquid ratio of 1 g: 40 mL and place it in a constant temperature water bath shaker at 86 °C for 4 h. Wash the product three times with anhydrous ethanol at 4 °C to terminate the reaction. Extract with anhydrous ethanol in a Soxhlet extractor for 25 h to completely remove unreacted ferulic acid. Dry under vacuum at 65 °C for 7 h to obtain modified nylon masterbatch.

[0067] S4: Preparation of Hook & Loop Fasteners from Modified Nylon Masterbatch

[0068] Modified nylon masterbatch and tannic acid-modified aluminum-doped zinc oxide powder were mixed at a mass ratio of 8:0.1 and added to a twin-screw extruder. The mixture was then melt-blended and extruded through the twin-screw extruder. After being cooled by air, the mixture was granulated by a pelletizer and dried in a vacuum oven for later use. The upper zone of the melt spinning machine was set to 185°C, the middle zone to 200°C, the spinning nozzle to 215°C, and the winding speed to 650 r / min. The resulting spun nylon fibers were obtained by extrusion through the melt spinning machine, which is the aging-resistant hook and loop fastener material.

[0069] Comparative Example 1:

[0070] Compared with Example 1, the difference of Comparative Example 1 is that zinc citrate is not added in step S1, but zinc nitrate is used instead of zinc citrate. The other steps remain the same, and it is referred to as Comparative Example 1.

[0071] Comparative Example 2:

[0072] Compared with Example 1, Comparative Example 2 differs in that aluminum isopropoxide is not added in step S1, but aluminum hydroxide is used instead of aluminum isopropoxide. The remaining steps remain unchanged, and it is referred to as Comparative Example 2.

[0073] Comparative Example 3:

[0074] Compared with Example 1, Comparative Example 3 differs in that tannic acid is not added in step S2, while the other steps remain unchanged, and is referred to as Comparative Example 3.

[0075] Comparative Example 4:

[0076] Compared with Example 1, Comparative Example 4 differs in that ferulic acid is not added in step S3, while the other steps remain unchanged, and is referred to as Comparative Example 4.

[0077] Comparative Example 5:

[0078] Comparative Example 5 is a commercially available nylon fiber material.

[0079] The antistatic properties of Examples 1-3, Comparative Examples 1-3, and Comparative Example 5 were tested using the methods described in GB / T12703-2021 Test Method for Electrostatic Properties of Textiles. The surface resistivity was statistically analyzed, and the results are shown in Table 1.

[0080] 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 340nm, ambient temperature 60℃, ambient humidity 50%RH, and irradiation time of 250h, the yellowing was observed and recorded, and samples were taken for tensile testing to calculate the strength retention rate, as shown in Table 2.

[0081] Table 1

[0082]

[0083] Table 2

[0084]

[0085] As can be seen from Table 1, the surface resistivity of Comparative Example 1 increased to 10 after zinc nitrate was replaced with zinc citrate and Comparative Example 2 was replaced with aluminum isopropoxide. 12 In Ω·cm, the resistivity of the present invention is the same as that of Comparative Example 5, a commercially available product. The raw material combination of the present invention has a lower resistivity and superior antistatic properties, while the resistivity of Comparative Example 3, which is tannic acid-free, increases to 10 Ω·cm. 11 The Ω·cm value was slightly better than that of Comparative Example 1 and Comparative Example 2, but still higher than that of the Example 1, indicating that the presence or absence of tannic acid also affects the antistatic ability.

[0086] As can be seen from Table 2, both Comparative Example 3 (without tannic acid) and Comparative Example 4 (without ferulic acid) showed yellowing, and the strength retention rates of Comparative Example 3 and Comparative Example 4 decreased to 83% and 82%, respectively. In contrast, Examples 1-3 showed no yellowing and had a retention rate of ≥92%, indicating that both tannic acid-modified aluminum-doped zinc oxide and ferulic acid-modified nylon fibers affected the aging resistance.

[0087] 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 preparation process for an aging-resistant hook and loop fastener material, characterized in that, Includes the following steps: S1: Preparation of aluminum-doped zinc oxide Zinc citrate, urea and aluminum isopropoxide were mixed and added to an aqueous ethylene glycol solution. The mixture was subjected to hydrothermal reaction, allowed to stand and cool, centrifuged and filtered, the lower precipitate was retained, dried, ground and transferred to a muffle furnace for calcination to obtain aluminum-doped zinc oxide. S2: Tannic acid-modified aluminum-doped zinc oxide Aluminum-doped zinc oxide was placed in anhydrous ethanol, ultrasonically dispersed, then tannic acid was added, ultrasonic dispersion was continued, the mixture was stirred and refluxed, centrifuged and filtered to collect the precipitate, and vacuum dried to obtain tannic acid-modified aluminum-doped zinc oxide powder. S3: Ferulic acid modified nylon fiber Nylon masterbatch was immersed in NaOH solution and dried under vacuum to obtain activated nylon masterbatch. Ferulic acid was weighed and dissolved in anhydrous ethanol to prepare a mother liquor. The mother liquor, deionized water and acetic acid solution were mixed and stirred to obtain a working solution. The activated nylon masterbatch was immersed in the working solution and shaken. The product was washed three times and dried under vacuum to obtain modified nylon masterbatch. S4: Preparation of Hook & Loop Fasteners from Modified Nylon Masterbatch Modified nylon masterbatch and tannic acid-modified aluminum-doped zinc oxide powder are mixed and added to a twin-screw extruder, then melt-blended and extruded through a twin-screw extruder. After being cooled by air, the mixture is granulated by a pelletizer and dried in a vacuum oven for later use. Finally, it is extruded through a melt spinning machine to obtain spun nylon fibers, which are the aging-resistant hook and loop fastener materials.

2. The preparation process of the aging-resistant hook and loop fastener material according to claim 1, characterized in that, The preparation of S1 aluminum-doped zinc oxide includes the following steps: Mix 2-3 parts by weight of zinc citrate, 1-1.5 parts by weight of urea, and 1.5-2.5 parts by weight of aluminum isopropoxide, then add the mixture to 50-60 parts by weight of ethylene glycol aqueous solution. Stir at 200-300 r / min for 30-35 min. Transfer the product to a hydrothermal reactor, heat to 180-190℃, and hydrothermally react for 6-6.5 h. Allow to cool to room temperature (22-24℃), centrifuge at 4000-4100 r / min for 5-10 min, filter, retain the lower precipitate, wash three times with deionized water and anhydrous ethanol respectively, and dry in an oven at 80-85℃. After drying, grind and transfer to a muffle furnace, heat to 550-570℃ at a heating rate of 2-3℃ / min, and calcine for 2-3 h to obtain aluminum-doped zinc oxide.

3. The preparation process of the aging-resistant hook and loop fastener material according to claim 2, characterized in that, S2 tannic acid-modified aluminum-doped zinc oxide includes the following steps: Take 10-15 parts by weight of aluminum-doped zinc oxide and add it to 50-55 parts by weight of anhydrous ethanol. Disperse it by sonication for 1-1.5 hours. Then add 0.2-0.3 parts by weight of tannic acid and continue to disperse by sonication for 1-1.5 hours. Stir and reflux at 300-350 r / min at 80-85℃ for 6-6.5 hours. Cool down to 5-10℃, wash three times with Tris buffer, then wash twice with ethanol. Centrifuge at 8000-8100 r / min for 5-10 minutes. Filter and collect the precipitate. Vacuum dry at 60-65℃ for 12-13 hours to obtain tannic acid modified aluminum-doped zinc oxide powder.

4. The preparation process of an aging-resistant hook and loop fastener material according to claim 3, characterized in that, S3 ferulic acid modified nylon fiber includes the following steps: Nylon masterbatch was immersed in NaOH solution at a ratio of 1g:(30-35)mL and treated at 80-85℃ for 30-35min. After removal, it was washed with deionized water until neutral and then vacuum dried at 80-85℃ for 2-2.5h to obtain activated nylon masterbatch. Weigh 1-2 parts by weight of ferulic acid and dissolve it in 100-105 parts by weight of anhydrous ethanol to prepare a mother liquor. Take 50-55 parts by weight of the mother liquor, 150-155 parts by weight of deionized water and 5-6 parts by weight of acetic acid solution and stir to obtain a working solution. Immerse the activated nylon masterbatch into the working solution at a material-to-liquid ratio of 1 g: (40-45) mL and place it in a constant temperature water bath shaker at 83-86℃ for 3.5-4 h. Wash the product three times with anhydrous ethanol at 4℃ to terminate the reaction. Extract with anhydrous ethanol in a Soxhlet extractor for 24-25 h to completely remove unreacted ferulic acid. Vacuum dry at 60-65℃ for 6-7 h to obtain modified nylon masterbatch.

5. The preparation process of an aging-resistant hook and loop fastener material according to claim 3, characterized in that, The preparation of hook and loop fasteners using S4 modified nylon masterbatch includes the following steps: Modified nylon masterbatch and tannic acid-modified aluminum-doped zinc oxide powder are mixed at a mass ratio of (8-10):(0.1-0.3) and added to a twin-screw extruder. The mixture is then melt-blended and extruded through the twin-screw extruder. After being cooled by air, the mixture is granulated by a pelletizer and dried in a vacuum oven for later use. The upper zone of the melt spinning machine is set to 180-185℃, the middle zone to 195-200℃, the spinning nozzle to 210-215℃, and the winding speed to 600-650 r / min. The resulting spun nylon fibers are obtained by extrusion through the melt spinning machine, which is the aging-resistant hook and loop fastener material.

6. The preparation process of an aging-resistant hook and loop fastener material according to claim 2, characterized in that, The ethylene glycol aqueous solution is prepared by mixing ethylene glycol and deionized water at a mass ratio of (2-2.5):

1.

7. The preparation process of an aging-resistant hook and loop fastener material according to claim 3, characterized in that, The pH value of Tris buffer is 8.3-8.

5.

8. The preparation process of an aging-resistant hook and loop fastener material according to claim 4, characterized in that, The concentration of NaOH solution is 5-10 wt%, and the concentration of acetic acid solution is 0.1-0.15 mol / L.

9. An aging-resistant hook and loop fastener material, characterized in that, It is prepared by the aging-resistant hook and loop fastener preparation process of any one of claims 1-8.

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