A breathable and UV-resistant polyester fabric and its preparation method

Abstract

This invention belongs to the field of knitted fabric technology, specifically relating to a breathable and UV-protective polyester fabric and its preparation method. The preparation method of the breathable and UV-protective polyester fabric includes: preparing an organic-inorganic hybrid composite modifier by in-situ polymerization of alkenyl-modified nano-zinc oxide, an organic UV absorber containing double bonds, and a hydroxyl-containing monomer; melt-blending and granulating this modifier with PET resin and polyethylene glycol diglycidyl ether to obtain a modified masterbatch; further blending with PET resin and melt-spinning to obtain FDY filaments; knitting to obtain a base fabric; and finally impregnating and heat-setting with a polyurethane finishing agent to obtain the finished fabric. This invention achieves nanoscale stable dispersion and long-lasting fixation of functional components in the fiber through chemical bonding and reactive compatibilization, endowing the fabric with highly efficient and broad-spectrum UV protection, excellent washability, and good breathability and moisture permeability, while also providing a soft and skin-friendly feel and excellent overall performance.

Description

Technical Field

[0001] This invention belongs to the field of knitted fabric technology, specifically relating to a breathable and UV-resistant polyester fabric and its preparation method. Background Technology

[0002] Polyester, a synthetic fiber widely used in clothing, home furnishings, and outdoor products, excels in strength, abrasion resistance, and dimensional stability due to its inherent chemical structure and physical properties. With increasing emphasis on sun protection during outdoor activities and daily commutes, endowing polyester fabrics with durable and efficient UV protection has become a key direction in textile functionalization research and development. Simultaneously, as a fabric worn close to the skin or as outerwear, good breathability and moisture permeability, along with wearing comfort, are also essential requirements. Therefore, developing a polyester fabric that synergistically achieves durable and efficient UV protection, excellent breathability and comfort, and reliable processing stability has significant practical value and market potential.

[0003] Currently, the mainstream technologies for imparting UV protection to polyester fabrics all have inherent limitations and cannot fully meet the aforementioned comprehensive performance requirements: 1. Coating / printing finishing method: The process is simple, involving applying a coating containing UV shielding agents to the fabric surface. However, the resulting continuous film severely clogs the fabric pores, leading to a sharp drop in breathability and moisture permeability, a stiff feel, and the coating and fiber substrate are mostly physically adhered, resulting in poor washability and abrasion resistance, and insufficient functional durability; 2. Blending spinning method: Blending UV absorbers or nano-shielding particles (such as ZnO, TiO2) with PET resin and then melt spinning allows functional components to be embedded inside the fiber, theoretically resulting in good durability. However, the inorganic nanoparticles have poor compatibility with the organic polyester matrix, are prone to agglomeration, affecting spinnability and causing a decline in fiber mechanical properties; and small-molecule organic UV absorbers are prone to decomposition, volatilization, or migration during high-temperature melt processing, making it difficult to guarantee functional efficiency and stability. Achieving nanoscale uniform dispersion and stable fixation of functional components in polyester has long been a technical bottleneck that has not been well resolved in this field. 3. Conventional finishing impregnation method: Functional additives are applied to the fabric surface through padding. Although this method causes little damage to the fibers, the functional components mainly rely on physical adsorption or van der Waals forces for adhesion, resulting in weak bonding with the fibers, poor wash fastness, and a sharp decline in performance after repeated washing. To meet the required protection standards, it is often necessary to increase the amount of additives, which may lead to new problems such as stiffening of the hand feel and poor environmental performance (such as formaldehyde release, APEO, etc.). If the goal is to maintain the durability of the function (such as using blended spinning), the feasibility of processing and fiber performance are often sacrificed, and it is difficult to effectively improve the stuffiness caused by hydrophobic polyester at the same time. If the goal is to maintain comfort and ease of processing (such as using lightweight finishing), the durability of the function is difficult to guarantee.

[0004] Therefore, there is an urgent need to explore a new solution that can synergistically achieve chemical bonding and stable dispersion of functional components during the fiber manufacturing stage, while simultaneously imparting durable hydrophilic comfort during the fabric finishing stage. Summary of the Invention

[0005] This invention addresses the shortcomings of existing technologies by providing a breathable and UV-resistant polyester fabric. This solves the problems of poor spinnability and easy migration and failure of functional components caused by poor dispersion and low compatibility of functional components in traditional blending spinning methods; and the problems of poor UV protection and washability and stiff hand feel caused by weak bonding in conventional finishing methods.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a method for preparing a breathable and UV-resistant polyester fabric, comprising the following steps: Step 1: Disperse alkenyl-modified inorganic nanoparticles, 2-hydroxy-4-(methacryloyloxy)benzophenone, 2-(2′-hydroxy-5′-methacryloxyethylphenyl)-2H-benzotriazole, and 2-methyl-2-acrylate-2,3-dihydroxypropyl ester in an organic solvent, heat to the set temperature, add initiator solution dropwise, and react. After the reaction is complete, filter, wash, and dry to obtain the composite modifier. Step 2: PET resin, composite modifier, and polyethylene glycol diglycidyl ether are melt-blended, extruded and granulated to obtain modified polyester masterbatch; Step 3: PET resin and modified polyester masterbatch are mixed, melted, and extruded through shaped spinnerets. After cooling and solidification, the mixture is wound and drawn to obtain polyester FDY (fully drawn yarn) filaments. Step 4: Using polyester FDY filament as yarn, spin it into fabric using a knitting process to obtain the polyester fabric base fabric. Step 5: Impregnate the polyester fabric base with the finishing agent. After impregnation, heat to set, wash, and dry to obtain a breathable and UV-resistant polyester fabric.

[0007] Preferably, in step one, the mass ratio of alkenyl-modified inorganic nanoparticles, 2-hydroxy-4-(methacryloyloxy)benzophenone, 2-(2′-hydroxy-5′-methacryloxyethylphenyl)-2H-benzotriazole, 2-methyl-2-acrylate-2,3-dihydroxypropyl ester, organic solvent, and initiator solution is (30-50):(15-25):(20-30):(15-25):(150-250):(6-10), and the reaction conditions are to react for 3-6 hours at a set temperature; the set temperature is 65-85℃; the alkenyl-modified inorganic nanoparticles include alkenyl-modified nano zinc oxide; the organic solvent includes N,N-dimethylformamide (DMF); and the initiator solution includes dimethyl azobisisobutyrate (AIBME) solution.

[0008] Preferably, the alkenyl-modified inorganic nanoparticles may also be selected from alkenyl-modified nano-titanium dioxide.

[0009] Preferably, the dimethyl azobisisobutyrate solution is prepared by mixing dimethyl azobisisobutyrate and N,N-dimethylformamide in a mass ratio of 1:(8-12).

[0010] Preferably, the alkenyl-modified nano zinc oxide is prepared by the following steps: adding dried nano zinc oxide to an ethanol aqueous solution, sonicating and stirring, then adding γ-(methacryloyloxy)propyltrimethoxysilane (silane coupling agent KH-570), reacting, centrifuging and washing after the reaction, and drying to obtain alkenyl-modified nano zinc oxide.

[0011] Preferably, the mass ratio of the nano zinc oxide, aqueous ethanol solution, and γ-(methacryloyloxy)propyltrimethoxysilane is 10:(100-200):(2.5-3.5), and the reaction conditions are 60-80℃ for 1.5-2.5h.

[0012] Preferably, the ethanol aqueous solution is a 75wt% ethanol aqueous solution.

[0013] Preferably, in step two, the mass ratio of PET resin, composite modifier, and polyethylene glycol diglycidyl ether is 100:(6-10):(12-18), and the melt blending temperature is 255-265℃.

[0014] Preferably, the molecular formula of polyethylene glycol diglycidyl ether is C3H5O2-(C2H4O). n -C3H5O, where n=9 or n=13 or n=22.

[0015] Preferably, in step three, the mass ratio of PET resin to modified polyester masterbatch is 100:(30-50), the melting temperature is 265-275℃, the cross-sectional shape of the irregular spinneret includes a cross shape, the cooling and curing includes a side-blowing method with a wind speed of 0.55m / s and a wind temperature of 20℃, the winding speed is 2800-3800m / min, the draw ratio is 3.2-4 times, and the heat setting temperature is 140-160℃; the single filament fineness of the polyester FDY filament is 1-1.5dtex.

[0016] Preferably, the PET resin in step three is the same as that in step two.

[0017] Preferably, the raw materials in both step three and step two are dried.

[0018] Preferably, in step four, the basis weight of the polyester fabric is 80-120 g / m².2 .

[0019] Preferably, in step five, the mass ratio of polyester fabric base to finishing agent is 1:(15-25), the impregnation treatment is carried out at room temperature, with two dips and two nips, and the roll-off rate is 70%-80%; the heat setting conditions are heat setting at 150-160℃ for 60-90s.

[0020] Preferably, the finishing agent is prepared by the following steps: S1. Mix diisocyanate, polyethylene glycol, polypropylene glycol, dihydroxy-terminated polydimethylsiloxane, and catalyst, and react. After the reaction is complete, cool down to obtain polyurethane prepolymer. S2. Disperse the polyurethane prepolymer and crosslinking agent in an organic solvent to obtain the finishing agent.

[0021] Preferably, in step S1, the molar ratio of diisocyanate, polyethylene glycol, polypropylene glycol, and dihydroxy-terminated polydimethylsiloxane is (2-3):(0.65-0.95):(0.8-1.1):(0.35-0.65), the amount of catalyst added is 0.5%-1% of the total mass of diisocyanate, polyethylene glycol, polypropylene glycol, and dihydroxy-terminated polydimethylsiloxane, and the reaction conditions are under a nitrogen atmosphere at 80-90°C for 3-4 hours; the diisocyanate includes hexamethylene diisocyanate; the molecular weight of polyethylene glycol is 400-1000; the molecular weight of polypropylene glycol is 600-1500; the molecular weight of dihydroxy-terminated polydimethylsiloxane is 1500-2500; and the catalyst includes dibutyltin dilaurate.

[0022] Preferably, in step S2, the mass ratio of polyurethane prepolymer, crosslinking agent, and organic solvent is 100:(3-5):(400-600); the crosslinking agent includes 1,4-butanediol; and the organic solvent includes ethyl acetate.

[0023] Preferably, all raw materials in S1 and S2 are dehydrated and dried to prevent the moisture contained therein from reacting with isocyanate and affecting the synthesis of the target product.

[0024] The present invention also discloses a breathable and UV-resistant polyester fabric prepared by the above-described method for preparing breathable and UV-resistant polyester fabric.

[0025] Compared with existing technologies, the beneficial effects of this invention are as follows: This invention achieves efficient, uniform, and durable fixation of the UV-shielding component through a synergistic design of in-situ polymerization and reactive compatibilization. Alkenyl-modified inorganic nanoparticles, organic UV absorbers with polymerizable double bonds, and hydroxyl-containing monomers are covalently bonded through free radical polymerization to form an organic-inorganic hybrid structure. This not only solves the problems of easy agglomeration of nanoparticles and easy migration and precipitation of small organic molecules in traditional blending methods, but also, during the preparation of modified polyester masterbatch, the introduction of polyethylene glycol diglycidyl ether as a reactive compatibilizer allows its epoxy groups to react with the hydroxyl and carboxyl groups at the ends of the PET molecular chains and the hydroxyl groups introduced on the composite modifier during melt blending. This establishes a strong chemical bridge between the polyester matrix and the functional component, achieving nanoscale dispersion and chemical bonding of functional particles in the fiber. The uniformly dispersed and strongly interfacially bonded nanoparticles also serve as effective reinforcing and toughening points, improving the fiber's breaking strength and elongation, thereby endowing polyester fibers with stable and durable UV protection. This invention improves the fabric's ability and mechanical properties. Hexamethylene diisocyanate is used as the hard segment, polyethylene glycol / polypropylene glycol blend ether as the hydrophilic flexible segment, and dihydroxyl-terminated polydimethylsiloxane is introduced as the organosilicon soft segment to prepare a polyurethane prepolymer. After impregnation and heat setting, the polyurethane prepolymer can form an elastic film with the crosslinking agent, giving the fabric excellent smoothness and softness. Simultaneously, during the heat setting process, the polyurethane segments react with the polyester fibers to form a strong anchor. The introduction of hydrophilic polyethylene glycol segments... A dynamic hydrophilic layer is constructed on the fiber surface, which can effectively absorb and conduct sweat, significantly improving the inherent hydrophobic and stuffy feeling of polyester and enhancing the fabric's moisture-wicking performance. In addition, the capillary effect generated by the irregular cross-section of the fiber, together with the porous structure formed by the knitting process, ensures the fabric's excellent breathability. This achieves a high degree of unity between durable UV protection, excellent moisture-wicking and breathability, and a soft hand feel, from the functional durability of the fiber interior to the comfortable and skin-friendly feel of the fabric surface, and the high breathability of the fabric structure. Attached Figure Description

[0026] Figure 1 This is a transmission electron microscope (TEM) image of the composite modifier prepared in Example 2 of the present invention. Detailed Implementation

[0027] Example 1 This embodiment discloses a method for preparing alkenyl-modified nano zinc oxide, comprising the following steps: adding dried nano zinc oxide to a 75wt% ethanol aqueous solution, first sonicating at a frequency of 50kHz for 30min, then stirring at a speed of 1000r / min for 1h, then adding γ-(methacryloyloxy)propyltrimethoxysilane, reacting at 70℃ for 2h, after the reaction is completed, washing three times with ethanol by centrifugation, and then drying in a vacuum drying oven at 50℃ to constant weight to obtain alkenyl-modified nano zinc oxide; wherein, the mass ratio of nano zinc oxide, 75wt% ethanol aqueous solution, and γ-(methacryloyloxy)propyltrimethoxysilane is 10:150:3.

[0028] Example 2 This embodiment discloses a method for preparing a breathable and UV-resistant polyester fabric, including the following steps: Step 1: Disperse alkenyl-modified nano zinc oxide, 2-hydroxy-4-(methacryloyloxy)benzophenone, 2-(2′-hydroxy-5′-methacryloxyethylphenyl)-2H-benzotriazole, and 2-methyl-2-acrylate-2,3-dihydroxypropyl ester in N,N-dimethylformamide. Heat to 65°C, add dimethyl azobisisobutyrate solution dropwise, and react at 65°C for 6 hours. After the reaction is complete, filter, wash with ethanol, and place in a 5-layer container. The composite modifier was dried to constant weight in a vacuum drying oven at 0℃; wherein the mass ratio of the alkenyl-modified nano zinc oxide, 2-hydroxy-4-(methacryloyloxy)benzophenone, 2-(2′-hydroxy-5′-methacryloyloxyethylphenyl)-2H-benzotriazole, 2-methyl-2-acrylate-2,3-dihydroxypropyl ester, N,N-dimethylformamide, and dimethyl azobisisobutyrate solution was 30:15:20:15:150:6; Figure 1 As shown, in the obtained composite modifier, the nano zinc oxide particles are uniformly coated by the polymerized organic phase without obvious agglomeration; the dimethyl azobisisobutyrate solution is prepared by mixing dimethyl azobisisobutyrate and N,N-dimethylformamide at a mass ratio of 1:8. Step 2: PET resin, composite modifier, and polyethylene glycol diglycidyl ether are melt-blended at a mass ratio of 100:6:12. The melt-blending temperature is 255℃. The mixture is then extruded and granulated to obtain modified polyester masterbatch. Step 3: Mix PET resin and modified polyester masterbatch at a mass ratio of 100:30, melt at a melting temperature of 265℃, and extrude through shaped spinnerets with a cross-shaped cross section. Cool and solidify using a side-blowing method at a wind speed of 0.55 m / s and a wind temperature of 20℃. Wind at a speed of 3500 m / min and draw at a draw ratio of 3.8 times to obtain polyester FDY filament with a single filament fineness of 1.5 dtex. Step 4: Using polyester FDY filament as yarn, spin it into fabric using a knitting process to obtain the polyester fabric base fabric. The weight of the polyester fabric base fabric is 100g / m². 2 ; Step 5: The polyester fabric base is immersed in the finishing agent for impregnation treatment. The mass ratio of polyester fabric base to finishing agent is 1:15. The impregnation treatment is carried out at room temperature, with two dips and two nipples, and a nip rate of 70%. After impregnation, it is heated and set at 150°C for 90 seconds. After washing with ethanol at room temperature, it is dried in a ventilated place at room temperature to obtain a breathable and UV-resistant polyester fabric.

[0029] The finishing agent is prepared by the following steps: S1. Hexamethylene diisocyanate, polyethylene glycol, polypropylene glycol, dihydroxy-terminated polydimethylsiloxane, and dibutyltin dilaurate are mixed. The molar ratio of hexamethylene diisocyanate, polyethylene glycol, polypropylene glycol, and dihydroxy-terminated polydimethylsiloxane is 2:0.65:0.8:0.35. The amount of dibutyltin dilaurate added is 0.5% of the total mass of diisocyanate, polyethylene glycol, polypropylene glycol, and dihydroxy-terminated polydimethylsiloxane. The mixture is reacted at 80°C for 4 hours under a nitrogen atmosphere. After the reaction is completed, the mixture is cooled to room temperature to obtain a polyurethane prepolymer. S2. Disperse the polyurethane prepolymer and 1,4-butanediol in ethyl acetate at a mass ratio of 100:3:400 to obtain the finishing agent.

[0030] Example 3 This embodiment discloses a method for preparing a breathable and UV-resistant polyester fabric, including the following steps: Step 1: Alkenyl-modified nano zinc oxide, 2-hydroxy-4-(methacryloyloxy)benzophenone, 2-(2′-hydroxy-5′-methacryloxyethylphenyl)-2H-benzotriazole, and 2-methyl-2-acrylate-2,3-dihydroxypropyl ester were dispersed in N,N-dimethylformamide. The mixture was heated to 85°C, and a dimethyl azobisisobutyrate solution was added dropwise. The mixture was reacted at 85°C for 3 hours. After the reaction was completed, the mixture was filtered, washed with ethanol, and dried in a vacuum drying oven at 50°C to constant weight to obtain the composite modifier. The mass ratio of the alkenyl-modified nano zinc oxide, 2-hydroxy-4-(methacryloyloxy)benzophenone, 2-(2′-hydroxy-5′-methacryloyloxyethylphenyl)-2H-benzotriazole, 2-methyl-2-acrylate-2,3-dihydroxypropyl ester, N,N-dimethylformamide, and dimethyl azobisisobutyrate solution is 50:25:30:25:250:10; the dimethyl azobisisobutyrate solution is prepared by mixing dimethyl azobisisobutyrate and N,N-dimethylformamide at a mass ratio of 1:12. Step 2: PET resin, composite modifier, and polyethylene glycol diglycidyl ether are melt-blended at a mass ratio of 100:10:18 and at a melt-blending temperature of 265℃. The mixture is then extruded and granulated to obtain modified polyester masterbatch. Step 3: Mix PET resin and modified polyester masterbatch at a mass ratio of 100:50, melt at a melting temperature of 275℃, and extrude through shaped spinnerets with a cross-shaped cross section. Cool and solidify using a side-blowing method at a wind speed of 0.55 m / s and a wind temperature of 20℃. Wind at a speed of 3500 m / min and draw at a draw ratio of 3.8 times to obtain polyester FDY filament with a single filament fineness of 1.5 dtex. Step 4: Using polyester FDY filament as yarn, spin it into fabric using a knitting process to obtain the polyester fabric base fabric. The weight of the polyester fabric base fabric is 100g / m². 2 ; Step 5: The polyester fabric base is immersed in the finishing agent for impregnation treatment. The mass ratio of polyester fabric base to finishing agent is 1:25. The impregnation treatment is carried out at room temperature, with two dips and two nips, and a nip-out rate of 80%. After impregnation, it is heated and set at 160℃ for 60s. After washing with ethanol at room temperature, it is ventilated and dried at room temperature to obtain a breathable and UV-resistant polyester fabric.

[0031] The finishing agent is prepared by the following steps: S1. Hexamethylene diisocyanate, polyethylene glycol, polypropylene glycol, dihydroxy-terminated polydimethylsiloxane, and dibutyltin dilaurate are mixed. The molar ratio of hexamethylene diisocyanate, polyethylene glycol, polypropylene glycol, and dihydroxy-terminated polydimethylsiloxane is 3:0.95:1.1:0.65. The amount of dibutyltin dilaurate added is 1% of the total mass of diisocyanate, polyethylene glycol, polypropylene glycol, and dihydroxy-terminated polydimethylsiloxane. The mixture is reacted at 90°C for 3 hours under a nitrogen atmosphere. After the reaction is completed, the mixture is cooled to room temperature to obtain a polyurethane prepolymer. S2. Disperse the polyurethane prepolymer and 1,4-butanediol in ethyl acetate at a mass ratio of 100:5:600 to obtain the finishing agent.

[0032] Example 4 This embodiment discloses a method for preparing a breathable and UV-resistant polyester fabric, including the following steps: Step 1: Alkenyl-modified nano zinc oxide, 2-hydroxy-4-(methacryloyloxy)benzophenone, 2-(2′-hydroxy-5′-methacryloxyethylphenyl)-2H-benzotriazole, and 2-methyl-2-acrylate-2,3-dihydroxypropyl ester were dispersed in N,N-dimethylformamide. The mixture was heated to 75°C, and a dimethyl azobisisobutyrate solution was added dropwise. The reaction was carried out at 75°C for 4.5 hours. After the reaction was completed, the mixture was filtered, washed with ethanol, and dried in a vacuum drying oven at 50°C to constant weight to obtain the composite modifier. The mass ratio of the alkenyl-modified nano zinc oxide, 2-hydroxy-4-(methacryloyloxy)benzophenone, 2-(2′-hydroxy-5′-methacryloxyethylphenyl)-2H-benzotriazole, 2-methyl-2-acrylate-2,3-dihydroxypropyl ester, N,N-dimethylformamide, and dimethyl azobisisobutyrate solution is 40:20:25:20:200:8; the dimethyl azobisisobutyrate solution is prepared by mixing dimethyl azobisisobutyrate and N,N-dimethylformamide at a mass ratio of 1:10. Step 2: PET resin, composite modifier, and polyethylene glycol diglycidyl ether are melt-blended at a mass ratio of 100:8:15. The melt-blending temperature is 260℃. The mixture is then extruded and granulated to obtain modified polyester masterbatch. Step 3: Mix PET resin and modified polyester masterbatch at a mass ratio of 100:40, melt at a melting temperature of 270℃, and extrude through shaped spinnerets with a cross-shaped cross section. Cool and solidify using a side-blowing method at a wind speed of 0.55 m / s and a wind temperature of 20℃. Wind at a speed of 3500 m / min and draw at a draw ratio of 3.8 times to obtain polyester FDY filament with a single filament fineness of 1.5 dtex. Step 4: Using polyester FDY filament as yarn, spin it into fabric using a knitting process to obtain the polyester fabric base fabric. The weight of the polyester fabric base fabric is 100g / m². 2 ; Step 5: The polyester fabric base is immersed in the finishing agent for impregnation treatment. The mass ratio of polyester fabric base to finishing agent is 1:20. The impregnation treatment is carried out at room temperature, with two dips and two nips, and a nip-out rate of 75%. After impregnation, it is heated and set at 155℃ for 75 seconds. After washing with ethanol at room temperature, it is dried in a ventilated place at room temperature to obtain a breathable and UV-resistant polyester fabric.

[0033] The finishing agent is prepared by the following steps: S1. Hexamethylene diisocyanate, polyethylene glycol, polypropylene glycol, dihydroxy-terminated polydimethylsiloxane, and dibutyltin dilaurate are mixed. The molar ratio of hexamethylene diisocyanate, polyethylene glycol, polypropylene glycol, and dihydroxy-terminated polydimethylsiloxane is 2.5:0.8:0.95:0.5. The amount of dibutyltin dilaurate added is 0.8% of the total mass of diisocyanate, polyethylene glycol, polypropylene glycol, and dihydroxy-terminated polydimethylsiloxane. The mixture is reacted at 85°C for 3.5 hours under a nitrogen atmosphere. After the reaction is completed, the mixture is cooled to room temperature to obtain a polyurethane prepolymer. S2. Disperse the polyurethane prepolymer and 1,4-butanediol in ethyl acetate at a mass ratio of 100:4:500 to obtain the finishing agent.

[0034] Comparative Example 1 The only difference between Comparative Example 1 and Example 2 is that, in step one, when preparing the composite modifier, the effective components (i.e., alkenyl-modified nano zinc oxide, 2-hydroxy-4-(methacryloyloxy)benzophenone, 2-(2′-hydroxy-5′-methacryloyloxyethylphenyl)-2H-benzotriazole, and 2-methyl-2-acrylate-2,3-dihydroxypropyl ester) do not undergo polymerization reaction, but are only physically mixed.

[0035] Comparative Example 2 The only difference between Comparative Example 2 and Example 2 is that, in step two, when preparing the modified polyester masterbatch, polyethylene glycol diglycidyl ether is not added. The missing polyethylene glycol diglycidyl ether is partially made up by PET resin, that is, the mass content of the composite modifier in the modified polyester masterbatch remains unchanged.

[0036] Comparative Example 3 The only difference between Comparative Example 3 and Example 2 is that in step five, a commercially available amino silicone oil softener (with an effective substance content of 35%) was used to prepare a finishing agent (concentration of 20g / L) to impregnate the polyester fabric base.

[0037] In the above examples and comparative examples, the average particle size of the nano zinc oxide was 50 nm; the PET resin was in powder form with a melting point of 247 °C; and the molecular formula of polyethylene glycol diglycidyl ether was C3H5O2-(C2H4O). n -C3H5O, n=13; the molecular weight of polyethylene glycol is 600; the molecular weight of polypropylene glycol is 1000; the molecular weight of dihydroxy-terminated polydimethylsiloxane is 2000.

[0038] Test case The performance of the breathable and UV-resistant polyester fabric samples prepared in Examples 2-4 and Comparative Examples 1-3 was tested: (1) UV protection performance test: The UV transmittance (UVA, UVB) and UV protection factor (UPF) of the fabric samples were measured according to the standard GB / T18830-2009 "Determination of UV Protection Performance of Textiles". The samples were washed according to the 5A procedure in the standard GB / T8629-2017 "Domestic Washing and Drying Procedures for Textile Testing" (using standard detergent, 40°C), dried after washing, and the UPF value was retested. The results of the determination of UPF, UVA transmittance, UVB transmittance, and UPF value retention rate (%) after 10 standard washes are shown in Table 1.

[0039] As shown in Table 1, the polyester fabric prepared by this invention has good UV protection performance. Compared with Example 2, in Comparative Example 1, the functional components did not form chemical bonds through polymerization during the preparation of the composite modifier. This made them prone to aggregation, migration, and detachment during subsequent processing and use, resulting in low initial protective efficacy and severely insufficient durability, leading to a significant decrease in UV protection performance. In Comparative Example 2, the lack of polyethylene glycol diglycidyl ether as a reactive compatibilizer resulted in poor compatibility and interfacial bonding between the composite modifier and the PET matrix, leading to uneven dispersion and weak bonding of the functional components in the fiber, resulting in loss during washing and a significant decrease in UV protection performance. In Comparative Example 3, a commercially available softener was used for finishing. This softener itself does not have UV absorption function and mainly affects the fabric's feel, having no significant impact on the fabric's UV protection performance. The fabric's UV protection performance mainly depends on the fiber matrix.

[0040] (2) Air permeability test: The air permeability (mm / s) of the fabric sample was measured using a fabric air permeability meter under a pressure difference of 100 Pa, in accordance with the standard GB / T5453-2025 "Textiles - Determination of Air Permeability of Fabrics". The test results are shown in Table 2.

[0041] As shown in Table 2, the polyester fabric prepared by this invention has good breathability. The hydrophilic segments contained in the finishing agent give the fabric a soft feel without hindering air circulation due to film formation, thus ensuring the breathability and comfort of the fabric. Compared with Example 2, in Comparative Example 1, the functional components of the physical mixture are unevenly distributed inside or on the surface of the fiber, and may even partially block the fiber pores or affect the regularity of the yarn structure due to agglomeration, thereby reducing the overall breathability of the fabric; in Comparative Example 2, the lack of compatibilizer leads to poor dispersion of functional components, which may have a negative impact on melt rheology and spinning process, thereby affecting the uniformity of fiber morphology and fabric structure, ultimately resulting in a decrease in breathability; in Comparative Example 3, a commercially available softener is used to finish the polyester fabric base. The commercially available amino silicone oil is hydrophobic, and the continuous film formed on the fiber surface will change the pore structure of the fabric and hinder air circulation, resulting in a decrease in breathability.

[0042] (3) Mechanical property testing: Using a universal testing machine, the breaking strength (N) and breaking elongation (%) of the fabric samples were determined according to standard GB / T3923.1-2013 "Textiles - Tensile properties of fabrics - Part 1: Determination of breaking strength and elongation at break (strip method)". The test results are shown in Table 3.

[0043] As shown in Table 3, the polyester fabric prepared by this invention has good mechanical properties. Compared with Example 2, in Comparative Example 1, physical mixing led to severe agglomeration of functional components and the formation of stress defect points in the fibers, resulting in a decrease in breaking strength. However, its elongation at break was still higher than that of Comparative Example 2, proving the toughening and modification effect of polyethylene glycol diglycidyl ether on the PET matrix in the system. In Comparative Example 2, the lack of polyethylene glycol diglycidyl ether resulted in poor interfacial bonding and the PET matrix was not made flexible, thus reducing its elongation at break and resulting in poor overall mechanical properties. In Comparative Example 3, the use of commercially available softeners to finish the polyester fabric mainly affected the softness and breathability of the fabric, without significantly affecting its mechanical properties.

[0044] (4) Softness test: The bending stiffness (cN·cm) of the fabric sample was determined according to the national standard GB / T18318.1-2009 "Determination of bending properties of textiles - Part 1: Inclined plane method"; the fabric sample was washed according to procedure 5A in standard GB / T8629-2017 "Home washing and drying procedures for textile testing" (using standard detergent, 40℃), dried after washing, and the bending stiffness was re-measured. The results of the bending stiffness, the bending stiffness after 10 standard washes, and the increase rate of bending stiffness after washing (%) are shown in Table 4.

[0045] As shown in Table 4, the polyester fabric prepared by this invention has good softness. Compared with Example 2, in Comparative Example 1, the polyethylene glycol diglycidyl ether contained in the modified polyester masterbatch system produced a certain degree of flexibility modification to the PET matrix. However, since the functional components were only physically mixed, the nanoparticles were severely aggregated and easily lost during washing, exposing defects inside the fibers and causing the fabric to feel hard. In Comparative Example 2, the lack of polyethylene glycol diglycidyl ether not only deprived the PET matrix of the opportunity for flexible segment modification, resulting in a decrease in the initial softness of the fabric, but also weakened the interface bonding between the functional components and the matrix, making it easier to lose during washing and reducing the durability of softness. In Comparative Example 3, commercially available softeners were used to treat the polyester fabric base. Relying on physical adsorption, it could provide excellent immediate softness, but due to the lack of chemical bonding with the fibers, the wash fastness was extremely poor.

[0046] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a breathable and ultraviolet resistant polyester fabric, characterized in that, It comprises the following steps: Step one, dispersing alkenyl modified inorganic nanoparticles, 2-hydroxy-4- (methacryloyloxy) benzophenone, 2- (2'-hydroxy-5'-methacryloyloxy ethyl phenyl) -2H-benzotriazole, 2-methyl-2-acrylic acid-2, 3-dihydroxypropyl ester in an organic solvent, heating to a set temperature, adding initiator solution dropwise, reacting, after the reaction is completed, filtering, washing, drying to obtain a composite modifier; Step two, melt blending PET resin, composite modifier and polyethylene glycol diglycidyl ether, extruding and granulating to obtain modified polyester master batch; Step three, mixing PET resin and modified polyester master batch, melting, extruding through a special-shaped spinneret, cooling and solidifying, winding, drawing to obtain polyester FDY filament; Step four, spinning the polyester FDY filament into a fabric by using a knitting process to obtain a polyester fabric base cloth; Step five, immersing the polyester fabric base cloth in a finishing agent for immersion treatment, after the immersion is completed, heating and setting, washing and drying to obtain a breathable and ultraviolet-proof polyester fabric.

2. The preparation method of the breathable anti-ultraviolet polyester fabric according to claim 1, characterized in that, In step one, the mass ratio of alkenyl modified inorganic nanoparticles, 2-hydroxy-4- (methacryloyloxy) benzophenone, 2- (2'-hydroxy-5'-methacryloyloxy ethyl phenyl) -2H-benzotriazole, 2-methyl-2-acrylic acid-2, 3-dihydroxypropyl ester, organic solvent and initiator solution is (30-50) : (15-25) : (20-30) : (15-25) : (150-250) : (6-10), the reaction condition is 3-6h at a set temperature; the set temperature is 65-85℃; the alkenyl modified inorganic nanoparticles comprise alkenyl modified nano zinc oxide; the organic solvent comprises N, N-dimethylformamide; the initiator solution comprises dimethyl 2, 2'-azobis (2-methylpropionamide) solution.

3. The preparation method of the breathable anti-ultraviolet polyester fabric according to claim 2, characterized in that, The alkenyl modified nano zinc oxide is prepared by the following steps: adding dry treated nano zinc oxide into an ethanol aqueous solution, ultrasonicating and stirring, then adding γ- (methacryloyloxy) propyl trimethoxysilane, reacting, after the reaction is completed, centrifuging and washing, and drying to obtain alkenyl modified nano zinc oxide; the mass ratio of nano zinc oxide, ethanol aqueous solution and γ- (methacryloyloxy) propyl trimethoxysilane is 10: (100-200) : (2.5-3.5), and the reaction condition is 1.5-2.5h at 60-80℃.

4. The preparation method of the breathable anti-ultraviolet polyester fabric according to claim 1, characterized in that, The mass ratio of the PET resin, the composite modifier and the polyethylene glycol diglycidyl ether in the second step is 100: (6-10): (12-18), and the temperature of the melt blending is 255-265℃; the molecular formula of the polyethylene glycol diglycidyl ether is C3H5O2-(C2H4O) n -C3H5O, wherein n=9 or n=13 or n=22.

5. The preparation method of the breathable anti-ultraviolet polyester fabric according to claim 1, characterized in that, In step three, the mass ratio of PET resin and modified polyester master batch is 100: (30-50), the melting temperature is 265-275℃, the shape of the cross section of the special-shaped spinneret comprises a cross shape, the cooling and solidification comprises using a side blowing method, the wind speed is 0.55m / s, the wind temperature is 20℃, the winding speed is 2800-3800m / min, the drawing multiple is 3.2-4 times, and the heat setting temperature is 140-160℃; the filament fineness of the polyester FDY filament is 1-1.5dtex.

6. The preparation method of the breathable anti-ultraviolet polyester fabric according to claim 1, characterized in that, In the fourth step, the weight of the polyester fabric base cloth is 80-120 g / m 2 .

7. The preparation method of the breathable anti-ultraviolet polyester fabric according to claim 1, characterized in that, In the fifth step, the mass ratio of the polyester fabric base cloth to the finishing agent is 1: (15-25), the dipping treatment is carried out at room temperature, two-dipping and two-rolling are adopted, and the rolling rate is 70%-80%; the heating setting conditions are that heating setting is carried out at a temperature of 150-160℃ for 60-90s.

8. The preparation method of the breathable anti-ultraviolet polyester fabric according to claim 7, characterized in that, The finishing agent is prepared by the following steps: S1, mixing diisocyanate, polyethylene glycol, polypropylene glycol, double-hydroxyl-terminated polydimethylsiloxane and a catalyst, reacting, cooling after the reaction, and obtaining a polyurethane prepolymer; S2, dispersing the polyurethane prepolymer and a crosslinking agent in an organic solvent to obtain the finishing agent.

9. The preparation method of the breathable anti-ultraviolet polyester fabric according to claim 8, characterized in that, In the S1, the molar ratio of diisocyanate, polyethylene glycol, polypropylene glycol and double-hydroxyl-terminated polydimethylsiloxane is (2-3):(0.65-0.95):(0.8-1.1):(0.35-0.65), the amount of the catalyst added is 0.5%-1% of the mass of diisocyanate, polyethylene glycol, polypropylene glycol and double-hydroxyl-terminated polydimethylsiloxane, the reaction conditions are that the reaction is carried out at a temperature of 80-90℃ for 3-4h in a nitrogen atmosphere; the diisocyanate includes hexamethylene diisocyanate; the molecular weight of the polyethylene glycol is 400-1000; the molecular weight of the polypropylene glycol is 600-1500; the molecular weight of the double-hydroxyl-terminated polydimethylsiloxane is 1500-2500; the catalyst includes dibutyltin dilaurate; in the S2, the mass ratio of the polyurethane prepolymer, the crosslinking agent and the organic solvent is 100:(3-5):(400-600); the crosslinking agent includes 1,4-butanediol; the organic solvent includes ethyl acetate.

10. A breathable and ultraviolet-proof polyester fabric prepared by the preparation method of the breathable and ultraviolet-proof polyester fabric according to any one of claims 1-9.

Images