Preparation method and processing technology of high-sunscreen nylon fabric

Abstract

The application discloses a preparation method and a processing technology of high-sunscreen nylon fabric. The preparation method comprises the following steps: forming a polydopamine coating on the surface of graphene oxide through self-polymerization, and then grafting epsilon-polylysine to obtain an anti-ultraviolet filler GO-PDA-epsilon-PL; blending the filler with a low-melting-point nylon copolymer, extruding, cutting, and melt spinning at 230-250 DEG C to obtain anti-ultraviolet modified nylon filaments; and then mixing and spinning with spandex fibers to knit and obtain the high-sunscreen nylon fabric. Through the synergistic effect of GO, PDA and epsilon-PL, the UPF value of the fabric is greater than 50, the antibacterial rate is higher than 94%, and the low-temperature spinning process effectively protects the activity of epsilon-polylysine; the product has high sunscreen and antibacterial properties, and is suitable for sunscreen clothes, outdoor sports clothes and the like.

Description

Technical Field

[0001] This invention relates to the field of functional textile fabric technology, specifically to a method for preparing and processing a high-sun protection nylon fabric. Background Technology

[0002] With the improvement of people's living standards and the increase in outdoor activities, the harm of ultraviolet (UV) radiation to the human body has received increasing attention. Prolonged exposure to UV radiation can not only lead to sunburn and tanning, but may also cause serious diseases such as skin cancer. Therefore, developing fabrics with highly effective UV protection is of significant practical importance.

[0003] Nylon fiber possesses excellent abrasion resistance, mechanical strength, and dyeing properties, making it widely used in textile products such as outdoor clothing, sportswear, and tents. However, conventional nylon fiber has poor UV protection properties, making it difficult to meet the needs of outdoor sports and high-altitude environments with strong UV radiation.

[0004] In existing technologies, methods for improving the UV resistance of fabrics mainly fall into two categories: one is to attach UV absorbers or reflectors to the fabric surface through finishing processes; the other is to blend UV-resistant functional fillers with a polymer matrix and then perform melt spinning. Finishing processes suffer from problems such as easy detachment of the functional layer and poor wash resistance; while blended melt spinning offers long-lasting functionality, the dispersibility of the functional filler in the matrix and its interfacial compatibility with the matrix are often key issues limiting its application. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for preparing high-sun protection nylon fabric, which solves the technical problems of poor UV protection performance, insufficient functional durability, and poor dispersion of functional fillers in the nylon matrix of existing nylon fabrics.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A method for preparing a high-sun-protection nylon fabric includes the following steps:

[0008] Step 1: Preparation of UV-resistant filler:

[0009] (1) Graphene oxide (GO) was ultrasonically dispersed in Tris-HCl buffer, the pH was adjusted to 8.0-9.0, dopamine hydrochloride was added, and the mixture was stirred at room temperature for 20-28 h to allow dopamine to self-polymerize on the GO surface to form a polydopamine (PDA) coating. The coating was then separated by centrifugation, washed, and dried to obtain the GO-PDA complex.

[0010] (2) The GO-PDA complex was ultrasonically dispersed in a buffer solution, and ε-polylysine (ε-PL) was added. The mixture was stirred at room temperature for 24-48 h to allow ε-PL to be covalently grafted onto the PDA coating. The mixture was then centrifuged, washed, and dried to obtain the UV-resistant filler, denoted as GO-PDA-ε-PL.

[0011] Step 2: Preparation of UV-resistant modified nylon filaments:

[0012] (1) After drying the low-melting-point nylon copolymer chips, they are mixed with the UV-resistant filler obtained in step one, co-extruded and pelletized to obtain functional masterbatch;

[0013] (2) The functional masterbatch is dried and then melt-spun at a spinning temperature of 230-250℃ to obtain UV-resistant modified nylon filament.

[0014] Step 3: Preparation of high sun-protective nylon fabric:

[0015] The UV-resistant modified nylon filaments obtained in step two are blended with spandex fibers at a mass ratio of (85-95):(5-15) to form a composite yarn, which is then knitted into a high-sun protection nylon fabric.

[0016] In step one (1), dopamine hydrochloride undergoes oxidative self-polymerization under aerobic, weakly alkaline conditions in Tris-HCl buffer (pH=8.0-9.0). First, the catechol structure in the dopamine molecule is oxidized to catechol-diquinone, which then forms covalently cross-linked polydopamine (PDA) oligomers through intermolecular Michael addition and Schiff base reaction. These PDA oligomers interact with oxygen-containing functional groups (such as hydroxyl, carboxyl, and epoxy groups) on the surface of graphene oxide (GO) and the π-π conjugated structure of graphene through their catechol and quinone groups (including hydrogen bonding, π-π stacking, and covalent coupling), thereby forming a uniform and stable PDA coating on the GO surface, resulting in the GO-PDA complex. The PDA coating not only provides abundant active sites (such as quinone, amino, and hydroxyl groups) for subsequent grafting, but its own phenolic hydroxyl groups and aromatic structures also have UV absorption capabilities, which can synergistically enhance the overall UV resistance performance.

[0017] In step one (2), the GO-PDA complex is reacted with ε-polylysine (ε-PL) in a buffer solution (pH=7.0-8.5). The ε-PL molecular chain contains a large number of primary amino groups (-NH2) and secondary amino groups (-NH-). These amino groups act as nucleophiles and can undergo two types of covalent reactions with unreacted o-benzoquinone groups in the PDA coating: ① Schiff base reaction: the amino group reacts with the carbonyl group (C=O) in the quinone group to form an imine bond (-C=N-); ② Michael addition reaction: the amino group reacts with the α,β-unsaturated carbonyl system of the quinone group to form a carbon-nitrogen bond. Through these reactions, ε-PL is firmly grafted onto the surface of the PDA coating in a covalent manner to form a GO-PDA-ε-PL ternary composite filler. This grafting method ensures that ε-PL is not easily detached or migrated during subsequent melt processing and long-term use, thereby endowing the fiber with durable antibacterial properties and synergistically enhanced UV resistance.

[0018] Preferably, in step one, the mass ratio of graphene oxide to dopamine hydrochloride is 1:(1-5).

[0019] Preferably, in step one, the concentration of the Tris-HCl buffer is 10-50 mmol / L and the pH is 8.5.

[0020] Preferably, in step one, the mass ratio of the GO-PDA complex to ε-polylysine is 1:(2-8).

[0021] Preferably, in step one (2), the buffer solution is a phosphate buffer or a Tris-HCl buffer with a pH of 7.0-8.5.

[0022] Preferably, in step two, the low-melting-point nylon copolymer is one or more of nylon 6 / 66 copolymer, nylon 6 / 12 copolymer, or nylon 6 / 610 copolymer, with a melting point range of 190-220℃, preferably 195-210℃.

[0023] Preferably, in step two, the amount of UV-resistant filler added is 1-4% of the mass of the low-melting-point nylon copolymer chips.

[0024] Preferably, in step two, the spinneret used for melt spinning has a circular, cross-shaped, or Y-shaped structure.

[0025] Preferably, in step two, the blending extrusion temperature is 230-250℃, the rotation speed is 40-60 rpm, and the melt spinning speed is 800-1200 m / min.

[0026] Preferably, in step three, the English count of the composite yarn is 30-50 S.

[0027] Preferably, in step three, the weight of the high sun-protective nylon fabric is 120-200 g / m².

[0028] Furthermore, in step three, the high sun-protective nylon fabric can be immersed in an antibacterial finishing solution for post-treatment, wherein the antibacterial finishing solution contains nano zinc oxide or nano silver.

[0029] Furthermore, this invention also provides a processing technology for the high sun protection nylon fabric, which is a specific implementation of the subsequent processing of the UV-resistant modified nylon filaments obtained by the preparation method of this invention. Specifically, the processing technology includes: blending the UV-resistant modified nylon filaments with spandex fibers at a mass ratio of (85-95):(5-15), first producing a composite yarn through processes such as doubling and twisting, wherein the English count of the composite yarn is preferably 30-50 S; then weaving it using knitting techniques (such as weft knitting plain knit, rib knit, or double rib knit) to obtain a high sun protection nylon fabric with a weight of 120-200 g / m². This processing technology fully utilizes the high sun protection and antibacterial properties of the modified nylon filaments, while the blending with spandex gives the fabric a good elastic recovery rate. The resulting fabric can be directly used for the production of sun-protective clothing, outdoor sportswear, and other garments.

[0030] Compared with the prior art, the present invention has the following beneficial technical effects:

[0031] (1) The GO-PDA-ε-PL nanofiller system exhibits a synergistic effect, specifically manifested in the following ways: Firstly, GO has a mid-to-short-wave ultraviolet (UVB) effect, and its two-dimensional layered structure provides physical shielding against ultraviolet radiation. PDA covers the surface of GO, and the Schiff base bond (-C=N-) formed after ε-PL grafts onto PDA creates a large conjugated system with the aromatic structure of the catechol / quinone group of PDA and the Schiff base bond formed after grafting GO and ε-PL, synergistically enhancing UVA absorption. After GO absorbs ultraviolet light, the excited-state electrons return to the ground state through non-radiative transitions, releasing energy as heat. The quinone group structure in PDA has a highly efficient photothermal conversion capability, which can rapidly convert the absorbed ultraviolet energy into heat energy, avoiding energy accumulation that leads to structural degradation. The synergistic effect of both allows the composite filler to maintain structural stability and long-lasting function under long-term ultraviolet irradiation.

[0032] Strong π-π interactions exist between GO sheets, making them prone to aggregation and leading to a decrease in UV absorption efficiency. The PDA coating provides isolation: the uniform coating of the PDA encapsulates the GO sheets, significantly inhibiting GO aggregation through steric hindrance and electrostatic repulsion. Further dispersion by ε-PL: the long-chain polycationic structure of ε-PL further increases the repulsive force between particles, ensuring uniform distribution of the filler within the nylon matrix. This uniformly dispersed filler forms a dense UV absorption network within the fiber. As UV light passes through the fiber, it is repeatedly absorbed, reflected, and scattered, macroscopically resulting in a significant increase in the UPF value.

[0033] ε-PL has a similar main chain structure to nylon (polyamide) (both contain amide bonds), and the two have good compatibility. Good interfacial compatibility allows the filler to bond tightly with the nylon matrix, effectively extending the propagation path of ultraviolet light in the fiber ("maze effect"), and increasing the probability of ultraviolet photons being absorbed.

[0034] (2) The present invention blends UV-resistant modified nylon filament with spandex fiber to obtain a fabric that has both excellent UV protection performance and good elasticity, and is suitable for outdoor sportswear, sun protection clothing, tents and other application scenarios with high requirements for sun protection and comfort. Detailed Implementation

[0035] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer.

[0036] Example 1

[0037] Step 1: Preparation of UV-resistant filler:

[0038] (1) 0.5 g of graphene oxide (GO) was ultrasonically dispersed in 200 mL of Tris-HCl buffer (10 mmol / L, pH=8.5), 1.0 g of dopamine hydrochloride was added, the mixture was stirred at room temperature for 24 h, centrifuged, washed 3 times with deionized water, and dried under vacuum at 60 °C for 12 h to obtain GO-PDA complex.

[0039] (2) 0.5 g of GO-PDA complex was ultrasonically dispersed in 100 mL of phosphate buffer (PBS, pH=7.4), and 2.0 g of ε-polylysine (ε-PL, molecular weight about 4000 Da) was added. The mixture was stirred at room temperature for 36 h, centrifuged, washed three times with deionized water, and vacuum dried at 60 °C for 12 h to obtain the UV-resistant filler GO-PDA-ε-PL.

[0040] Step 2: Preparation of UV-resistant modified nylon filaments:

[0041] (1) Dry the low-melting-point nylon 6 / 66 copolymer chips (melting point 198-205℃) in a vacuum drying oven at 95℃ for 5h;

[0042] (2) 100 g of dried low-melting-point nylon 6 / 66 copolymer chips were mixed with 2 g of UV-resistant filler obtained in step one, and the mixture was extruded and pelletized using a twin-screw extruder at a temperature of 240℃ and a speed of 50 rpm to obtain functional masterbatch.

[0043] (3) The functional masterbatch was vacuum dried at 95°C for 6 h, and then spun in a melt spinning machine at a spinning temperature of 235°C and a spinning speed of 1000 m / min. The spinneret was circular to obtain UV-resistant modified nylon filament.

[0044] Step 3: Preparation of high sun-protective nylon fabric:

[0045] The UV-resistant modified nylon filament obtained in step two is blended with spandex fiber at a mass ratio of 90:10 to form a composite yarn with an English count of 40 S. The yarn is then knitted to form a high sun-protective nylon fabric with a weight of 160 g / m².

[0046] Example 2

[0047] Step 1: Preparation of UV-resistant filler:

[0048] (1) 0.5 g of graphene oxide (GO) was ultrasonically dispersed in 200 mL of Tris-HCl buffer (20 mmol / L, pH=8.5), 1.5 g of dopamine hydrochloride was added, the mixture was stirred at room temperature for 24 h, centrifuged, washed 3 times with deionized water, and dried under vacuum at 60 °C for 12 h to obtain GO-PDA complex.

[0049] (2) 0.5 g of GO-PDA complex was ultrasonically dispersed in 100 mL of Tris-HCl buffer (pH=8.0), and 3.0 g of ε-polylysine (ε-PL, molecular weight about 4000 Da) was added. The mixture was stirred at room temperature for 48 h, centrifuged, washed three times with deionized water, and vacuum dried at 60 °C for 12 h to obtain the UV-resistant filler GO-PDA-ε-PL.

[0050] Step 2: Preparation of UV-resistant modified nylon filaments:

[0051] (1) Dry the low-melting-point nylon 6 / 66 copolymer chips (melting point 198-205℃) in a vacuum drying oven at 95℃ for 5h;

[0052] (2) 100 g of dried low-melting-point nylon 6 / 66 copolymer chips were mixed with 3 g of UV-resistant filler obtained in step one, and the mixture was extruded and pelletized using a twin-screw extruder at a temperature of 245°C and a speed of 50 rpm to obtain functional masterbatch.

[0053] (3) The functional masterbatch was vacuum dried at 95°C for 6 h, and then spun in a melt spinning machine at a spinning temperature of 240°C and a spinning speed of 1000 m / min. The spinneret had a cross-shaped structure to obtain UV-resistant modified nylon filament.

[0054] Step 3: Preparation of high sun-protective nylon fabric:

[0055] The UV-resistant modified nylon filament obtained in step two is blended with spandex fiber at a mass ratio of 90:10 to form a composite yarn with an English count of 40 S. The yarn is then knitted to form a high sun-protective nylon fabric with a weight of 160 g / m².

[0056] Example 3

[0057] Step 1: Preparation of UV-resistant filler:

[0058] (1) 0.5 g of graphene oxide (GO) was ultrasonically dispersed in 200 mL of Tris-HCl buffer (30 mmol / L, pH=8.5), 2.0 g of dopamine hydrochloride was added, the mixture was stirred at room temperature for 28 h, centrifuged, washed 3 times with deionized water, and vacuum dried at 60 °C for 12 h to obtain GO-PDA complex.

[0059] (2) 0.5 g of GO-PDA complex was ultrasonically dispersed in 100 mL of phosphate buffer (PBS, pH=7.4), and 4.0 g of ε-polylysine (ε-PL, molecular weight about 4000 Da) was added. The mixture was stirred at room temperature for 48 h, centrifuged, washed three times with deionized water, and vacuum dried at 60 °C for 12 h to obtain the UV-resistant filler GO-PDA-ε-PL.

[0060] Step 2: Preparation of UV-resistant modified nylon filaments:

[0061] (1) Dry the low-melting-point nylon 6 / 66 copolymer chips (melting point 198-205℃) in a vacuum drying oven at 95℃ for 5h;

[0062] (2) 100 g of dried low-melting-point nylon 6 / 66 copolymer chips were mixed with 4 g of UV-resistant filler obtained in step one, and the mixture was extruded and pelletized using a twin-screw extruder at a temperature of 250°C and a speed of 50 rpm to obtain functional masterbatch.

[0063] (3) The functional masterbatch was vacuum dried at 95°C for 6 h, and then spun in a melt spinning machine at a spinning temperature of 245°C and a spinning speed of 1000 m / min. The spinneret had a “Y” shaped structure to obtain UV-resistant modified nylon filament.

[0064] Step 3: Preparation of high sun-protective nylon fabric:

[0065] The UV-resistant modified nylon filament obtained in step two is blended with spandex fiber at a mass ratio of 90:10 to form a composite yarn with an English count of 40 S. The yarn is then knitted to form a high sun-protective nylon fabric with a weight of 160 g / m².

[0066] Comparative Example 1

[0067] Compared with Example 1, Comparative Example 1 differs in that no UV-resistant filler was added in step two. Instead, low-melting-point nylon 6 / 66 copolymer chips were directly melt-spun to obtain ordinary nylon filaments, which were then blended with spandex fibers and knitted into fabric. All other conditions were the same.

[0068] Comparative Example 2

[0069] Compared with Example 1, Comparative Example 2 differs in that only the GO-PDA complex is prepared in step one, without ε-PL grafting. In other words, the UV-resistant filler in step two uses GO-PDA instead of GO-PDA-ε-PL, while all other conditions are the same.

[0070] Comparative Example 3

[0071] Comparative Example 3 differs from Example 1 in that conventional nylon 6 chips (melting point 215-225℃) were used instead of low-melting-point nylon 6 / 66 copolymer chips in step two. Because conventional nylon 6 chips have a higher melting point (215-225℃), to ensure good melt flowability and spinnability, the blending extrusion temperature was adjusted to 270℃ and the melt spinning temperature to 275℃. All other conditions remained the same.

[0072] Experimental Example

[0073] The performance of the nylon fabrics prepared in Examples 1-3 and Comparative Examples 1-3 was tested.

[0074] I. Ultraviolet Protection Performance Test

[0075] The tests were conducted according to GB / T 18830-2009 "Evaluation of Ultraviolet Protection Performance of Textiles". The ultraviolet protection factor (UPF) and UVA and UVB transmittance of the fabric were determined using an ultraviolet spectrophotometer. The test results are shown in Table 1.

[0076] Table 1. UV protection performance of fabrics in each embodiment and comparative example.

[0077]

[0078] As shown in Table 1, the high sun protection nylon fabrics prepared in Examples 1-3 of this invention all have UPF values ​​greater than 50 and UVA and UVB transmittances less than 2.5%, exhibiting excellent ultraviolet protection performance. Comparative Example 1, without the addition of anti-UV filler, has a UPF value of only 12.6, indicating poor UV protection performance. Comparative Example 2 uses GO-PDA filler without ε-PL grafting, and its UPF value is 43.5, lower than Examples 1-3, indicating that ε-PL grafting has a synergistic enhancing effect on UV protection performance. Comparative Example 3 uses conventional nylon 6 chips; the higher spinning temperature caused thermal decomposition of some components in the filler, resulting in a significantly lower UPF value than Example 1.

[0079] II. Antibacterial Performance Test

[0080] The antibacterial properties of each group of samples were tested according to GB / T 20944.3-2008 "Evaluation of antimicrobial properties of textiles - Part 3: Shaking method". The test strains were Escherichia coli and Staphylococcus aureus. The test results are shown in Table 2.

[0081] Table 2. Antibacterial properties of fabrics in each embodiment and comparative example.

[0082]

[0083] As shown in Table 2, the fabrics prepared in Examples 1-3 of this invention exhibit antibacterial rates greater than 94% against both *Escherichia coli* and *Staphylococcus aureus*, demonstrating excellent antibacterial properties. Comparative Example 2, which did not graft ε-PL, showed a significant decrease in antibacterial performance, indicating that ε-PL is a key component imparting antibacterial function. Comparative Example 3, due to partial thermal decomposition of ε-PL caused by high-temperature processing, showed lower antibacterial performance than Example 1.

[0084] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for preparing a high-sun-protection nylon fabric, characterized in that, Includes the following steps: Step 1: Preparation of UV-resistant filler: (1) Graphene oxide (GO) was dispersed in Tris-HCl buffer, the pH was adjusted to 8.0-9.0, and dopamine hydrochloride was added. The reaction caused dopamine to self-polymerize on the GO surface to form a polydopamine PDA coating, thus obtaining the GO-PDA complex. (2) Disperse the GO-PDA complex in a buffer solution, add ε-polylysine ε-PL, and react to graft ε-PL onto the PDA coating to obtain the UV-resistant filler GO-PDA-ε-PL; Step 2: Preparation of UV-resistant modified nylon filaments: (1) After drying the low-melting-point nylon copolymer chips, they are mixed with the UV-resistant filler obtained in step one, co-extruded and pelletized to obtain functional masterbatch; (2) The functional masterbatch is dried and then melt-spun at a spinning temperature of 230-250℃ to obtain UV-resistant modified nylon filament; Step 3: Preparation of high sun-protective nylon fabric: The UV-resistant modified nylon filaments obtained in step two are blended with spandex fibers to form composite yarns, which are then knitted into high sun-protective nylon fabrics. In step two, the low-melting-point nylon copolymer is one or more of nylon 6 / 66 copolymer, nylon 6 / 12 copolymer, or nylon 6 / 610 copolymer, with a melting point range of 190-220℃.

2. The preparation method according to claim 1, characterized in that, In step one, the mass ratio of graphene oxide to dopamine hydrochloride is 1:(1-5).

3. The preparation method according to claim 1, characterized in that, In step one (2), the buffer solution is phosphate buffer or Tris-HCl buffer with a pH of 7.0-8.

5.

4. The preparation method according to claim 1, characterized in that, In step one, the mass ratio of the GO-PDA complex to ε-polylysine is 1:(2-8).

5. The preparation method according to claim 1, characterized in that, In step two, the amount of UV-resistant filler added is 1-4% of the mass of the low-melting-point nylon copolymer chips.

6. The preparation method according to claim 1, characterized in that, In step two, the blending extrusion temperature is 230-250℃, the rotation speed is 40-60 rpm, and the melt spinning speed is 800-1200 m / min.

7. The preparation method according to claim 1, characterized in that, In step two, the spinneret used for melt spinning has a circular, cross-shaped, or Y-shaped structure.

8. The preparation method according to claim 1, characterized in that, In step three, the mass ratio of UV-resistant modified nylon filament to spandex fiber is (85-95):(5-15).

9. The method for preparing high sun-protective nylon fabric according to claim 1, characterized in that, The third step specifically involves: blending the UV-resistant modified nylon filament obtained in the second step with spandex fiber at a mass ratio of (85-95):(5-15) to form a composite yarn, and then knitting it into a high-sun protection nylon fabric.

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