Water-repellent warm-keeping chinlon 6 hollow fiber and preparation method thereof

Abstract

The invention discloses a water-repellent warm-keeping chinlon 6 hollow fiber and a preparation method thereof, and belongs to the technical field of functional fiber materials. The preparation method comprises the following steps: preparing a water-repellent master batch from a fluorine-containing acrylic copolymer, polysiloxane, hydrophobic nano silicon dioxide, a chinlon 6 slice and an antioxidant, melting the water-repellent master batch and the chinlon 6 slice by adopting a melt spinning method, and spinning through an annular spinneret plate hole formed by two C-shaped grooves, so as to prepare the water-repellent warm-keeping chinlon 6 hollow fiber. The fiber has water repellency and heat preservation performance, is soft in texture, capable of absorbing sweat, quick to dry, light in weight, capable of keeping warm, good in water repellency effect and long in waterproof time, and has wide application prospects in the aspect of preparation of outdoor sportswear and high-cold waterproof clothes.

Description

Technical Field

[0001] This invention specifically relates to a water-repellent and heat-insulating nylon 6 hollow fiber and its preparation method, belonging to the field of functional fiber material technology. Background Technology

[0002] With economic development, people have a greater demand for outdoor activities and adventures, especially in extreme cold and humid environments. This has led to higher requirements for clothing, demanding not only lightweight warmth but also stain and water resistance. However, most clothing on the market, in order to improve warmth, is bulky and heavy, and often achieves waterproofing through fabric surface coatings or films. While this method improves the hydrophobicity of the fabric surface, it severely sacrifices moisture permeability. Sweat generated during exercise cannot escape in time, leading to stuffiness, damp cold, and even hypothermia, significantly reducing comfort.

[0003] At the fiber material level, hollow fiber is a promising new type of lightweight and warm fiber material. It features a continuous, tubular cavity in the axial direction, giving it excellent properties such as lightness, elasticity, heat insulation, and sound absorption, making it highly advantageous in various applications. However, while traditional hollow polyester or nylon staple fibers can reduce weight and create a still air layer to improve warmth, their hydrophilic skeleton easily absorbs ambient moisture or sweat. Once the moisture regain increases, water vapor penetrates the fiber cavity and condenses, causing a sharp increase in the fiber's thermal conductivity (water's thermal conductivity is much greater than air's), resulting in a rapid decrease in warmth retention. Simultaneously, water molecule penetration may also cause the hollow fiber structure to collapse and harden, further reducing the garment's bulk and durability. As described in Korean patents KR1020110106261 and KR1020110075073, hollow fibers are typically given water-repellent properties through finishing processes, such as coating the surface with polyurethane coatings or fluorinated water-resistant agents. However, fabrics made using this method are prone to the problem of water-repellent finishing agents peeling off after high-temperature washing or prolonged use, resulting in the failure of water-repellent and waterproof functions.

[0004] Therefore, developing a new type of hollow fiber that combines "durable water repellency and lightweight warmth" has become an urgent problem for the industry. Nylon 6 (PA6) has excellent mechanical strength, abrasion resistance, and spinnability. If an efficient and durable water-repellent mechanism can be introduced into it, it is expected to provide an important core material for the development of outdoor sportswear and high-altitude waterproof clothing. Summary of the Invention

[0005] To address the problems of poor water repellency and the inability to balance water repellency with breathability and comfort in traditional waterproof fibers, this invention provides a water-repellent and warm nylon 6 hollow fiber and its preparation method. This fiber combines water repellency and warmth retention, is soft, quick-drying, lightweight, warm, and has excellent water repellency and long-lasting waterproof properties, making it a promising candidate for applications in outdoor sportswear and cold-weather waterproof clothing.

[0006] The technical solution of the present invention is as follows: This invention provides a water-repellent and heat-retaining hollow nylon 6 fiber, which has a single-pore hollow structure and a circular cross-section. The raw materials of the water-repellent and heat-retaining nylon 6 fiber include nylon 6 chips and water-repellent masterbatch. The water-repellent masterbatch includes the following components: fluorinated acrylic copolymer, polysiloxane, hydrophobic nano-silica, nylon 6 chips, and antioxidant.

[0007] Preferably, the mass percentages of each component in the water-repellent masterbatch are as follows: 65% fluorinated acrylic copolymer, 14% polysiloxane modifier, 15% nylon 6 chips, 5.2% nano silica, and 0.8% antioxidant.

[0008] Preferably, the weight-average molecular weight of the fluorinated acrylic copolymer is between 80,000 and 120,000 g / mol, and the hydrophobic nano-silica is organosilane-modified nano-silica particles.

[0009] The present invention also provides a method for preparing the above-mentioned water-repellent and heat-insulating nylon 6 hollow fibers, comprising the following steps: S1. After drying the fluorinated acrylic copolymer and polysiloxane modifier, the fluorinated acrylic copolymer, polysiloxane modifier, nylon 6 chips, hydrophobic nano silica and antioxidant are fully mixed in a high-speed mixer, then melt-blended in a co-rotating twin-screw extruder, and then granulated underwater and dried with hot air to obtain water-repellent masterbatch. S2. The water-repellent masterbatch and nylon 6 chips are mixed and heated and melted using a screw extruder. The resulting melt is then processed sequentially through a pre-filter, static mixer, distribution pipe, metering pump, spinning assembly, spinneret, side blowing chamber, oiling device, channel, first set of guide rollers, second set of guide rollers, steam box, and winding device to obtain filament bundles, thereby producing the water-repellent ultralight and warm nylon 6 fiber. The spinneret's spinneret holes are composed of two non-connected "C"-shaped grooves of the same depth, which are arranged facing each other, and the cross-section formed by their enclosing is a circular ring structure.

[0010] Furthermore, in step S1, the zone temperatures for melt blending in the screw extruder are 200℃, 215℃, 225℃, and 220℃, the screw speed is 250 rpm, and the vacuum degree is -0.08 MPa.

[0011] Furthermore, in step S2, the temperature at which the screw extruder heats and melts is 250℃~263℃.

[0012] Furthermore, the processing pressure of the spinning assembly in step S2 is 120 bar to 170 bar.

[0013] Furthermore, the processing conditions for the side-blowing chamber in step S2 are as follows: the side-blowing wind speed is 0.48 m / s to 0.55 m / s, the cooling temperature is 23℃, and the humidity is 75%.

[0014] Furthermore, in step S2, the winding speed of the winding device is 4100 m / min to 4200 m / min.

[0015] Furthermore, in step S2, the steam box is shaped at a temperature of 180°C.

[0016] Unlike existing technologies, this invention has the following advantages: 1. This invention uses a fluorinated acrylic copolymer, polysiloxane, hydrophobic nano-silica, nylon 6 chips, and an antioxidant to prepare a water-repellent masterbatch. The water-repellent masterbatch and nylon 6 chips are then melt-spun to produce water-repellent and heat-insulating hollow nylon 6 fibers. The fluorinated acrylic copolymer in the water-repellent masterbatch effectively reduces the surface energy of the resulting fiber through its fluorocarbon chain (-CF3), imparting good hydrophobicity to the fiber. The polysiloxane, through the flexibility and low polarity of its siloxane chain -Si-O-, effectively fills the micropores of the fiber, covering the micropore defects that the fluorinated acrylic copolymer fails to cover, reducing nanoscale defects, and further reducing the fiber surface energy. The nano-silica is selected from hydrophobic nano-silica obtained after modification with organosilane, which can construct hydrophobic micro-protrusions on the fiber surface to achieve a non-wetting state. The nylon 6 chips act like a transport vehicle, precisely delivering the functional components to the fiber surface. The antioxidant acts as a protective umbrella, inhibiting the thermal oxidative decomposition of the fluorinated / silicon components under high-temperature spinning. A schematic diagram of the mechanism of action of each component in the water-repellent masterbatch is shown below. Figure 1 As shown, through melt spinning, the present invention achieves uniform dispersion of the above-mentioned components of the water-repellent masterbatch on the surface of nylon 6 fiber and directional repair of surface micropore defects. Under the synergistic effect of the above-mentioned components, the fiber provided by the present invention has good durable hydrophobic and water-repellent properties.

[0017] 2. This invention uses a circular spinneret orifice composed of two non-connected, oppositely arranged "C"-shaped grooves for melt spinning. When the nylon 6 melt is extruded from the circular spinneret orifice, the surface tension drives the melt flow to close automatically, thus forming a continuous and stable single-hole hollow structure. The resulting fiber has high hollowness. The continuous cavity inside the fiber not only provides still air, effectively blocking air flow and improving the fabric's heat insulation effect, but also increases the fiber surface area per unit volume, reduces the fiber's specific gravity, and improves the fiber's bulkiness, making the fiber lightweight, smooth, and soft, greatly improving the wearing comfort of the water-repellent fiber fabric.

[0018] 3. Based on the aforementioned single-pore hollow structure and water-repellent masterbatch, the water-repellent and heat-retaining nylon 6 hollow fiber of the present invention effectively integrates the two properties of "water-repellent and dry" and "wet-state heat retention". In terms of "water-repellent and dry" performance, the present invention achieves chemical water repellency by using water-repellent masterbatch, while introducing a hollow physical structure into the fiber to form a solid-gas-liquid three-phase interface in its internal air cavity. This structure can reduce the solid-liquid contact area and block the capillary effect along the fiber axis, thereby significantly reducing the risk of longitudinal penetration of liquid water, achieving a physical water-repellent effect, and ultimately achieving physical-chemical dual water-repellent protection. In terms of "wet-state heat retention" performance, the water-repellent masterbatch of the present invention effectively isolates water vapor from penetrating the hollow fiber structure, improves the dryness of the internal air cavity of the hollow fiber in a humid environment, and thus overcomes the problem of the traditional hollow fiber's heat retention dropping sharply when damp or sweating.

[0019] 4. Under the synergistic effect of the above-mentioned single-pore hollow physical structure and the chemical composition of the water-repellent masterbatch, the water-repellent and warm nylon 6 hollow fiber of the present invention has multiple properties such as light weight, elasticity and warmth while effectively repelling water. It solves the problems of stuffiness, heaviness and poor moisture absorption of traditional water-repellent fabrics, and has broad application prospects in the preparation of outdoor sportswear. Attached Figure Description

[0020] Figure 1 This is a schematic diagram illustrating the working principle of water-repellent masterbatch.

[0021] Figure 2 This is a schematic diagram of the spinneret structure used in this invention.

[0022] Figure 3 This is a schematic diagram of the micropore structure of the spinneret of the present invention.

[0023] Figure 4 This is a magnified microscopic view of the spinneret orifice.

[0024] Figure 5 This is a cross-sectional view of the water-repellent and heat-retaining nylon 6 fiber described in this invention under a magnifying glass. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and preferred embodiments. The embodiments given are only for illustrating the present invention and are not intended to limit the scope of the present invention.

[0026] Unless otherwise specified, all materials and reagents used in the following examples are commercially available. Unless otherwise specified, the methods described in the following embodiments are conventional methods.

[0027] This invention addresses the problem of the inability to unify water repellency, warmth retention, and breathability in traditional waterproof fibers. Based on the composition formulation of water-repellent masterbatch and the design of a hollow fiber structure for warmth retention, it provides a water-repellent and warm nylon 6 hollow fiber and its preparation method.

[0028] A schematic diagram of the mechanism of action of each component in the water-repellent masterbatch is shown below. Figure 1 As shown, through melt spinning, this invention achieves uniform dispersion of components such as fluorinated acrylic copolymer, polysiloxane, hydrophobic nano-silica, nylon 6 chips and antioxidants on the surface of nylon 6 fibers and directional repair of surface micropore defects. Under the synergistic effect of the above components, the fiber provided by this invention has good hydrophobic and water-repellent properties.

[0029] Figure 2 This is a schematic diagram of the spinneret used in the hollow fiber of the present invention. The spinneret includes a substrate 1 and spinneret holes 2 located on the substrate 1. The schematic diagram and microscopic enlarged view of the spinneret holes 2 are shown below. Figure 3 , 4 As shown, the spinneret 2 is composed of two non-communicating "C"-shaped grooves 21 and 22 with the same depth. The "C"-shaped grooves 21 and 22 are arranged facing each other, and the cross-section formed by their enclosing is a circular structure. In the following embodiments, the spinneret specification in Example 1 is D88-34×2-2C(0.8×0.65)×0.4, the spinneret specification in Example 2 is 77-36-2C×0.4, and the spinneret specification in Example 3 is the same as that in Example 1, produced by twisting. The slit width between the "C"-shaped grooves 21 and 22 is 0.15~0.20 mm.

[0030] The following specific embodiments further illustrate the water-repellent and heat-retaining nylon 6 hollow fiber and its preparation method of the present invention.

[0031] Example 1 This embodiment provides a method for preparing water-repellent and heat-retaining nylon 6 hollow fibers, including the following steps: S1. After vacuum drying the fluorinated acrylic copolymer and polysiloxane modifier at 80℃ for 4 h, the components are mixed in the following mass percentages: 65% fluorinated acrylic copolymer, 14% polysiloxane modifier, 15% nylon 6 chips, 5.2% hydrophobic nano silica, and 0.8% antioxidant. The mixture is then melt-blended in a high-speed mixer for 15 min, followed by melt blending in a co-rotating twin-screw extruder. The extruder temperature zones are 200℃, 215℃, 225℃, and 220℃, the screw speed is 250 rpm, and the vacuum degree is -0.08 MPa. Finally, the melt is subjected to underwater pelletizing and hot air drying to obtain hydrophobic masterbatch. The weight-average molecular weight of the selected fluorinated acrylic copolymer can be 80,000~120,000 g / mol. In this embodiment, a fluorinated acrylic copolymer with a weight-average molecular weight of 8,000 g / mol is used. The hydrophobic nano silica in this embodiment is organosilane-modified nano silica particles. S2. The water-repellent masterbatch and nylon 6 chips are mixed at a mass ratio of 10:90, and then melted at 250°C using a screw extruder. The resulting melt is then processed sequentially through a pre-filter, static mixer, distribution pipe, metering pump, spinning assembly, spinneret, side blowing chamber, oiling device, channel, first set of guide rollers, second set of guide rollers, steam box, and winding device to obtain filament bundles. The spinning assembly pressure is 170 bar; the side blowing air velocity is 0.48 m / s; the side blowing air cooling temperature is 23°C; the side blowing air humidity is 75%; the winding speed is 4100 m / min; and the steam box setting temperature is 180°C, thereby producing the water-repellent ultralight and warm nylon 6 fiber.

[0032] The water-repellent and heat-retaining nylon 6 hollow fiber prepared in this embodiment has a single-pore hollow structure and a circular cross-section. Its cross-sectional image under a magnifying glass is shown below. Figure 5 As shown.

[0033] Example 2 This embodiment provides a method for preparing water-repellent and heat-retaining nylon 6 hollow fibers, including the following steps: S1. After vacuum drying the fluorinated acrylic copolymer and polysiloxane modifier at 80℃ for 4 h, the components are mixed in the following mass percentages: 65% fluorinated acrylic copolymer, 14% polysiloxane modifier, 15% nylon 6 chips, 5.2% hydrophobic nano silica, and 0.8% antioxidant. The mixture is then melt-blended in a high-speed mixer for 15 min, followed by melt blending in a co-rotating twin-screw extruder. The extruder temperature zones are 200℃, 215℃, 225℃, and 220℃, the screw speed is 250 rpm, and the vacuum degree is -0.08 MPa. Finally, the melt is subjected to underwater pelletizing and hot air drying to obtain hydrophobic masterbatch. In this embodiment, the fluorinated acrylic copolymer has a weight-average molecular weight of 100,000 g / mol, and the hydrophobic nano silica in this embodiment is organosilane-modified nano silica particles. S2. The water-repellent masterbatch and nylon 6 chips are mixed at a mass ratio of 10:90, and then melted at 263°C using a screw extruder. The resulting melt is then processed sequentially through a pre-filter, static mixer, distribution pipe, metering pump, spinning assembly, spinneret, side blowing chamber, oiling device, duct, first set of guide rollers, second set of guide rollers, steam box, and winding device to obtain filament bundles. The spinning assembly pressure is 120 bar; the side blowing air velocity is 0.55 m / s; the side blowing air cooling temperature is 23°C; the side blowing air humidity is 75%; the winding speed is 4200 m / min; and the steam box setting temperature is 180°C, thereby producing the water-repellent ultralight and warm nylon 6 fiber.

[0034] The water-repellent and heat-insulating nylon 6 hollow fiber prepared in this embodiment has a single-hole hollow structure, and its cross-section is similar to that of Example 1, which is circular.

[0035] Example 3 This embodiment provides a method for preparing water-repellent and heat-retaining nylon 6 hollow fibers, including the following steps: S1. After vacuum drying the fluorinated acrylic copolymer and polysiloxane modifier at 80℃ for 4 h, the components are mixed in the following mass percentages: 65% fluorinated acrylic copolymer, 14% polysiloxane modifier, 15% nylon 6 chips, 5.2% hydrophobic nano silica, and 0.8% antioxidant. The mixture is then melt-blended in a high-speed mixer for 15 min, followed by melt blending in a co-rotating twin-screw extruder. The extruder temperature zones are 200℃, 215℃, 225℃, and 220℃, the screw speed is 250 rpm, and the vacuum degree is -0.08 MPa. Finally, the melt is subjected to underwater pelletizing and hot air drying to obtain hydrophobic masterbatch. In this embodiment, the fluorinated acrylic copolymer has a weight-average molecular weight of 8000 g / mol, and the hydrophobic nano silica in this embodiment is organosilane-modified nano silica particles. S2. The water-repellent masterbatch and nylon 6 chips are mixed at a mass ratio of 10:90, and then melted at 258°C using a screw extruder. The resulting melt is then processed sequentially through a pre-filter, static mixer, distribution pipe, metering pump, spinning assembly, spinneret, side blowing chamber, oiling device, channel, first set of guide rollers, second set of guide rollers, steam box, and winding device to obtain filament bundles. The spinning assembly pressure is 160 bar; the side blowing air velocity is 0.5 m / s; the side blowing air cooling temperature is 23°C; the side blowing air humidity is 75%; the winding speed is 4150 m / min; and the steam box setting temperature is 180°C, thereby producing the water-repellent ultralight and warm nylon 6 fiber.

[0036] The water-repellent and heat-insulating nylon 6 hollow fiber prepared in this embodiment has a single-hole hollow structure, and its cross-section is similar to that of Example 1, which is circular.

[0037] Performance testing The performance indicators of the water-repellent and heat-insulating nylon 6 hollow fibers prepared in Examples 1-3 are shown in Table 1. The contact angle of water droplets on the surface of different fabric samples is between 137° and 145°, and all samples show good water-repellent and hydrophobic properties.

[0038] Table 1. Physical properties of water-repellent and heat-retaining nylon 6 hollow fibers provided in Examples 1-3

Claims

1. A water-repellent and heat-retaining nylon 6 hollow fiber, characterized in that, The water-repellent and heat-retaining nylon 6 fiber has a single-pore hollow structure with a circular cross-section; the raw materials of the water-repellent and heat-retaining nylon 6 fiber include nylon 6 chips and water-repellent masterbatch; wherein, the water-repellent masterbatch includes the following components: fluorinated acrylic copolymer, polysiloxane, hydrophobic nano silica, nylon 6 chips, and antioxidant.

2. The nylon 6 hollow fiber according to claim 1, characterized in that, The mass percentages of each component in the water-repellent masterbatch are as follows: 65% fluorinated acrylic copolymer, 14% polysiloxane modifier, 15% nylon 6 chips, 5.2% hydrophobic nano silica, and 0.8% antioxidant.

3. The nylon 6 hollow fiber according to claim 1, characterized in that, The weight-average molecular weight of the fluorinated acrylic copolymer is 80,000 to 120,000 g / mol; the hydrophobic nano-silica is organosilane-modified nano-silica particles.

4. A method for preparing water-repellent and heat-retaining nylon 6 hollow fiber as described in any one of claims 1 to 3, characterized in that, Includes the following steps: S1. After drying the fluorinated acrylic copolymer and polysiloxane modifier, the fluorinated acrylic copolymer, polysiloxane modifier, nylon 6 chips, hydrophobic nano silica and antioxidant are fully mixed in a high-speed mixer, then melt-blended in a co-rotating twin-screw extruder, and then granulated underwater and dried with hot air to obtain water-repellent masterbatch. S2. The water-repellent masterbatch and nylon 6 chips are mixed and heated and melted using a screw extruder. The resulting melt is then processed sequentially through a pre-filter, static mixer, distribution pipe, metering pump, spinning assembly, spinneret, side blowing chamber, oiling device, channel, first set of guide rollers, second set of guide rollers, steam box, and winding device to obtain filament bundles, thereby producing the water-repellent ultralight and warm nylon 6 fiber. The spinneret's spinneret holes are composed of two non-connected "C"-shaped grooves of the same depth, which are arranged facing each other and form a hollow circular cross-section.

5. The method for preparing water-repellent and heat-retaining nylon 6 hollow fiber according to claim 4, characterized in that, In step S1, the zone temperatures for melt blending in the screw extruder are 200℃, 215℃, 225℃, and 220℃, the screw speed is 250 rpm, and the vacuum degree is -0.08 MPa.

6. The method for preparing water-repellent and heat-retaining nylon 6 hollow fiber according to claim 4, characterized in that, In step S2, the temperature at which the screw extruder heats and melts is 250℃~263℃.

7. The method for preparing water-repellent and heat-retaining nylon 6 hollow fiber according to claim 4, characterized in that, In step S2, the processing pressure of the spinning assembly is 120 bar to 170 bar.

8. The method for preparing water-repellent and heat-retaining nylon 6 hollow fiber according to claim 4, characterized in that, The processing conditions for the side-blowing chamber in step S2 are as follows: the side-blowing wind speed is 0.48 m / s to 0.55 m / s, the cooling temperature is 23℃, and the humidity is 75%.

9. The method for preparing water-repellent and heat-retaining nylon 6 hollow fiber according to claim 4, characterized in that, In step S2, the winding speed of the winding device is 4100 m / min to 4200 m / min.

10. The method for preparing water-repellent and heat-retaining nylon 6 hollow fiber according to claim 4, characterized in that, In step S2, the steam box is shaped at a temperature of 180°C.

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