Polyester-nylon composite modified cool fiber and preparation method thereof

Abstract

The invention relates to the technical field of preparation of polyester-nylon composite modified cool-feeling fibers, in particular to a polyester-nylon composite modified cool-feeling fiber and a preparation method thereof.The polyester-nylon composite modified cool-feeling fiber comprises an outer layer, a middle layer and an inner layer which are sequentially and concentrically arranged from outside to inside; the cross section of the outer layer and the cross section of the middle layer are arranged in a cross shape, the cross section of the inner layer is arranged in a circular shape, the outer layer is a photo-thermal regulation and control layer, the middle layer is a phase change energy storage layer, and the inner layer is an antibacterial functional layer. The middle layer is the phase change energy storage layer, the inner layer is the antibacterial functional layer, the photo-thermal regulation and control layer reflects infrared light, the phase change energy storage layer buffers temperature difference, and the characteristics of environment self-adaptive temperature control, long-acting antibacterial property and high cool feeling of the composite fiber are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of preparation of polyester-nylon composite modified cool fibers, and in particular to a polyester-nylon composite modified cool fiber and a preparation method thereof. Background Art

[0002] Cool composite fiber is made by adding a medium that absorbs heat slowly and dissipates heat quickly in nature to carriers such as polyester, nylon or regenerated cellulose fibers to prepare a cool functional masterbatch, which is then processed into fiber. When the skin touches the fabric woven from this fiber, the fiber can quickly transfer the heat from the skin surface to the fiber, giving people a cool feeling.

[0003] From the development principle, the development of cool fabrics can be divided into two categories: one is to improve the thermal conductivity of textiles and enhance the heat dissipation capacity; the other is to improve the moisture absorption and water conductivity of textiles to achieve the heat dissipation purpose through sweat evaporation.

[0004] For example, a Chinese patent with patent application number 202410264784.2 discloses an ES cool composite fiber and its preparation method, which enhances the heat dissipation capacity by improving the thermal conductivity of the fiber. However, whether it is to improve the thermal conductivity of the textile or to improve the hygroscopicity and water conductivity of the textile, in a high temperature and high humidity environment, although the thermal conductivity of the fabric is high, the heat dissipation and sweat evaporation are limited, and the cooling effect will be greatly reduced. Even after special treatment, the hygroscopicity of the textile material still has a certain upper limit. When the human body sweats a lot, the fabric may not be able to absorb and conduct all the sweat in time, causing sweat to accumulate on the skin surface, producing a sticky feeling, and reducing the coolness and comfort.

[0005] Therefore, there is an urgent need for a composite fiber that can solve the problem of passive temperature control and achieve the integrated effect of fiber cooling, antibacterial and temperature control adaptation. Summary of the invention

[0006] In response to the above problems, the present invention provides a polyester-nylon composite modified cool fiber and a preparation method. On the basis of the existing polyester-nylon composite cool fiber, a three-layer structure is adopted, in which the outer layer is a photothermal regulation layer, the middle layer is a phase change energy storage layer, and the inner layer is an antibacterial functional layer. The photothermal regulation layer reflects infrared light, and the phase change energy storage layer buffers the temperature difference, thereby realizing the environmental adaptive temperature control, long-lasting antibacterial and high coolness characteristics of the composite fiber.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A polyester-nylon composite modified cool fiber, comprising:

[0009] The outer layer, the middle layer and the inner layer are arranged concentrically from the outside to the inside, the cross-section of the outer layer is annular, the cross-section of the middle layer is cross-shaped, the cross-section of the inner layer is circular, and the outer layer is a photothermal regulation layer, the middle layer is a phase change energy storage layer, and the inner layer is an antibacterial functional layer.

[0010] As an improvement, the outer layer is a bio-based nylon modified with a nano-functional agent containing 1-5 wt %, and the nano-functional agent is a modified h-BN nanosheet.

[0011] The steps of preparing the modified h-BN nanosheets include:

[0012] Step s1, dispersing h-BN nanosheets with a thickness of 10-20 nm in an ethanol solution, wherein the concentration of the ethanol solution is controlled at 5 wt %, preferably premixed with a magnetic stirrer for 15 min at a stirring speed of 500 rpm;

[0013] Step s2, adding APTES, the mass ratio is h-BN: APTES = 1: 0.5, slowly adding APTES dropwise, keeping the solution pH = 5, adjusting with acetic acid, and then treating in an ultrasonic cleaner for 2 hours, the power is set to 300W, the frequency is 40kHz, preferably the temperature is 5±2°C throughout the process to avoid local overheating;

[0014] Step s3, after the reaction is completed, the mixture is centrifuged at a speed of 8000 rpm for 10 min and washed with ethanol three times until the conductivity of the filtrate is less than 10 μS / cm;

[0015] Step s4, drying in a vacuum oven at 60° C. for 12 h, with a vacuum degree of -0.1 MPa, to obtain APTES-modified h-BN nanosheets, which were then sieved through 200 mesh.

[0016] As an improvement, the middle layer is made of recycled polyester containing 5-10wt% of phase change microcapsules, and the phase change microcapsules are paraffin microcapsules.

[0017] The preparation steps of paraffin microcapsules include:

[0018] Step q1, heat paraffin with a phase transition temperature of 30°C to a molten state of 50°C, add 1wt% Tween-80 for emulsification, stir at a speed of 2000rpm, and then add ethyl orthosilicate, the mass ratio of paraffin:ethyl orthosilicate=3:1;

[0019] Step q2, slowly adding ammonia water under stirring conditions to make the pH = 10, catalyzing the hydrolysis and condensation of TEOS to form a core-shell structure, the reaction temperature is 40°C, and the time is 4h;

[0020] Step q3, using a probe-type ultrasonic crusher, with a frequency of 40 kHz, a power of 200 W, a pulse mode, 5 s on / 5 s off, and ultrasonic crushing for 30 min. During the crushing process, the temperature was controlled at <30° C. in an ice bath, and the particle size of the core-shell structure was controlled to be 300±50 nm, and the shell thickness was 25±5 nm.

[0021] Step q4, rotating speed 5000rpm, centrifugal separation for 10min, washing with ethanol three times, drying at 60℃, sieving through 400 mesh, to obtain paraffin microcapsules.

[0022] As an improvement, the inner layer is a bio-based nylon treated and modified with 1-3 wt % of a nano antibacterial agent, wherein the nano antibacterial agent is Zn-CuO nanoparticles.

[0023] The steps of preparing Zn-CuO nanoparticles include:

[0024] Step t1, using a sol-gel method, dissolving Cu(NO3)2·3H2O and Zn(NO3)2·6H2O in deionized water at a molar ratio of Zn:Cu=5%;

[0025] Step t2, adding citric acid as a complexing agent, the molar ratio of metal ion: citric acid = 1:1.5;

[0026] Step t3, stirring in a water bath at 80°C until a transparent sol is formed, and continuing to heat to 120°C to form a gel;

[0027] Step t4, in a muffle furnace, the gel was calcined at 400° C. for 2 h at a heating rate of 5° C. / min, and then naturally cooled and ground to obtain Zn-doped CuO nanoparticles with a particle size of less than 50 nm;

[0028] Step t5, the nanoparticles and stearic acid are ultrasonically dispersed in ethanol at a mass ratio of 1:0.2 for 30 minutes at an ultrasonic dispersion power of 200 W, and dried at 60° C. to obtain Zn-CuO nanoparticles.

[0029] In addition, the present invention also provides a method for preparing the above-mentioned polyester-nylon composite modified cool fiber, comprising the following steps:

[0030] Step a, pretreatment, drying the bio-based PA56 particles in a vacuum drying oven at 100°C for 6 hours to ensure that the moisture content is less than 0.02%, and drying the rPET particles in a drying oven at 140°C for 4 hours to ensure that the moisture content is less than 0.02%;

[0031] Step b, melt blending of the outer layer materials, premixing the dried bio-based PA56, 1-5wt% of the modified h-BN nanosheets accounting for 1-5wt% of the total mass and 0.5wt% of the antioxidant 1010 accounting for 0.5wt% of the total mass in a high-speed mixer for 5 minutes, and then adding the obtained mixture A to the first twin-screw extruder for melt blending, setting the temperature gradient of zones 1-5 of the first twin-screw extruder to 220 / 235 / 245 / 250 / 245°C, i.e., 220°C for the feeding zone, 235°C for the compression zone, 245°C for the melting zone, 250°C for the homogenizing zone, and 245°C for the die, preferably with a loss-in-weight feeder accuracy of ±0.5%, a feeding rate of 10kg / h, a screw speed of 150rpm, a melt pressure of 8±0.5MPa, and a melt temperature deviation of ±2°C;

[0032] Step c, melt blending of the middle layer materials, premixing the dried rPET, 5-10wt% of the paraffin microcapsules and 0.3wt% of the dispersant in a high-speed mixer for 5 minutes, preferably mixing them in a double cone mixer (inclination angle of 45°, screw speed of 30rpm) for 1h, adding the obtained mixture B to the second twin-screw extruder for melt blending, setting the temperature gradient of zones 1-5 of the second twin-screw extruder to 240 / 255 / 265 / 270 / 265°C, the feeding zone at 240°C, the compression zone at 255°C, the melting zone at 265°C, the homogenizing zone at 270°C, the die at 265°C, the screw speed at 120rpm, avoiding the rupture of the microcapsules, the melt pressure sensor for real-time monitoring, the pressure fluctuation <±5%, the microcapsule breakage rate <3%, and the melt viscosity of 3500±200Pa.s;

[0033] Step d, melt blending of the inner layer materials, premixing the dried bio-based PA56, 1-3wt% of the total mass of the Zn-CuO nano-antibacterial agent and 0.2wt% of the total mass of the coupling agent KH550 in a high-speed mixer (temperature 80°C) for 5 minutes, and then adding the obtained mixture C into the third twin-screw extruder for melt blending, setting the temperature gradient of zones 1-5 of the third twin-screw extruder to 230 / 240 / 250 / 255 / 250°C, i.e., 230°C for the feeding zone, 240°C for the compression zone, 250°C for the melting zone, 255°C for the homogenizing zone, 250°C for the die head, 180rpm for the screw speed, and 12±0.5g / 10min for the melt flow rate;

[0034] Step e, composite spinning, the first screw extruder, the second screw extruder and the third screw extruder respectively input the mixture A, the mixture B and the mixture C into the three-channel spinning nozzle, and the three-channel spinning nozzle ejects the spinning, the aperture of the nozzle of the three-channel spinning nozzle is 0.2mm, the outer / middle / inner aperture ratio of the nozzle is 15:60:25, the spinneret hole adopts a stepped guide groove design to reduce melt turbulence, the middle layer adopts a cross-shaped cross-section design, the guide groove depth is 0.1mm, the spinneret hole spacing is 0.5mm, the outer layer pressure is 8MPa, the metering pump frequency is 25Hz, the middle layer pressure is 12MPa, the metering pump frequency is 35Hz, the inner layer pressure is 7MPa, the metering pump frequency is 20Hz, the spinneret is cooled by a ring blowing device, the wind speed uniformity deviation is less than 5%, and the humidity sensor is used for real-time feedback control;

[0035] Step f, post-treatment, stretching and heat setting the composite fiber obtained by composite spinning, the first-level stretching is 80°C hot roller (diameter 300mm) stretching, the tension sensor controls the stretching multiple to 1.5±0.1 times, the second-level stretching is 120° hot plate (contact length 1.5m) stretching, the stretching rate is 50m / min, the stretching multiple is 2.0±0.1 times, the fiber retracts freely by 5% after heat setting, the internal stress is eliminated, and the treated composite fiber is subjected to light curing hydrophilic finishing;

[0036] Step g, deposition of a photothermal response layer: the composite fiber is treated with a tungsten oxide thin film by magnetron sputtering to form a photothermal response layer with a continuous gradient film thickness structure of 50nm±5nm on the surface of the composite fiber.

[0037] Among them, the photocuring hydrophilic finishing includes the following steps:

[0038] Step w1, according to the mass ratio, 50% of polyethylene glycol diacrylate with a molecular weight of 600, 3% of photoinitiator 1173, and 47% of deionized water were mixed evenly for 30 minutes under light-proof conditions, and filtered with a 5 μm filter membrane to obtain a coating liquid with a viscosity of 120±10 Pa.s (25° C.);

[0039] Step w2, immersing the fiber into the coating liquid by dipping method (the liquid level of the dipping tank is constant), the dipping time is 10 seconds, the roller pressure is 0.3 MPa, and the liquid squeezing rate is 80%;

[0040] Step w3: Use UV curing equipment (mercury lamp), wavelength 365nm, intensity 50±2mW / cm 2 , curing for 20 seconds, nitrogen protection (oxygen concentration <100ppm), nitrogen flow rate 10L / min, cured film thickness 2±0.5μm.

[0041] As an improvement, the magnetron sputtering tungsten oxide film processing includes the following steps:

[0042] Step r1, the fiber was plasma cleaned for 5 minutes at a power of 100 W and under Ar gas protection to remove surface impurities;

[0043] Step r2, DC magnetron sputtering, target-substrate distance 60 mm, substrate temperature 80±2°C, composite fiber conveying speed 10 mm / s, sputtering zone length 200 mm, initial sputtering power 90 W, power slope 0.5 W / s, film thickness 50±5 nm.

[0044] The film thickness d(x) is required to increase linearly from 45nm to 55nm along the substrate position x (x∈[0,200]mm), then the formula is:

[0045] d(x)=45+0.05x (unit: nm)

[0046] in,

[0047] x: base position (mm), range 0 to 200 mm;

[0048] Slope: 0.05 nm / mm, total thickness increment Δd=10 nm.

[0049] Parameter matching and power curve design:

[0050] (1) Motion parameters

[0051] Fiber winding speed: v = 10 mm / s;

[0052] Sputtering zone length: L = 200 mm;

[0053] Passing time: t total =L / v=20s

[0054] (2) Power curve derivation

[0055] Assume that the relationship between film thickness d(x) and power P(t) is a linear integral:

[0056]

[0057] To achieve d(x) = 45 + 0.05x, it is necessary to satisfy:

[0058] 1. Initial thickness: d = 45nm when x = 0, corresponding to the initial power P0;

[0059] 2. Slope matching: power increases linearly with time, that is, P(t) = P0 + at

[0060] Substituting the base position x=vt, we get:

[0061]

[0062] To simplify the design, the quadratic term is ignored (when α is small), and the approximation is:

[0063]

[0064] Combined with the target formula d(x) = 45 + 0.05x, it must meet the following requirements:

[0065] Initial thickness correction: by pre-sputtering the substrate or adjusting the initial power P0;

[0066] Slope Control:

[0067]

[0068] In the present invention, in order to achieve an initial thickness of 45 nm, the corresponding initial power P0 is 90 W. According to the target slope of 0.05 nm / mm, the power slope α needs to satisfy:

[0069]

[0070] Corrected to actually achievable linear growth:

[0071]

[0072] By adjusting and setting the magnetron sputtering as described above, the photothermal response layer of the present application with a continuous gradient film thickness structure of 50nm±5nm can be formed on the surface of the composite fiber.

[0073] The beneficial effects of the present invention are:

[0074] (1) The present invention adopts a three-layer structure based on the existing polyester-nylon composite cooling fiber, wherein the outer layer is a photothermal regulation layer, the middle layer is a phase change energy storage layer, and the inner layer is an antibacterial functional layer. The photothermal regulation layer reflects infrared light, and the phase change energy storage layer buffers the temperature difference, thereby achieving environmental adaptive temperature control, long-term antibacterial and high cooling properties of the composite fiber;

[0075] (2) The present invention also realizes dynamic temperature control. On the basis of the photothermal regulation layer, a photothermal response layer (WO3 light reflection layer) is also provided. The synergistic effect of the photothermal regulation layer, the photothermal response layer and the phase change energy storage layer is utilized to realize environmental adaptive regulation, further improving the dynamic temperature control capability of the composite fiber, and the Q-max value is ≥0.35J / cm 2 .s, contact temperature difference △T≥3.2℃, and the single composite fiber has cooling, antibacterial, moisture absorption and quick-drying properties at the same time, reducing the subsequent finishing process;

[0076] (3) When setting the photothermal response layer, the present invention fully considered the wavelength response conflict between the WO3 light reflection layer and the h-BN photothermal conversion function, developed a deposition film thickness gradient design structure, achieved a continuous gradient film thickness change of 50nm±5nm on the composite fiber surface, and then achieved selective reflection in the 400-800nm ​​band, avoiding the conflict with the h-BN photothermal conversion function.

[0077] In summary, the present invention has the advantages of dynamic temperature control, adaptive adjustment, and more prominent cool feeling in high temperature environment, and is particularly suitable for the technical field of preparation of cool composite fibers. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Figure 1 This is an enlarged photograph of the cross section of the polyester-nylon composite cooling fiber of Example 1 of the present invention;

[0079] Figure 2 This is an enlarged photo of the side wall of the polyester-nylon composite cooling fiber of Example 1 of the present invention;

[0080] Figure 3 This is a schematic diagram of the layered structure of the polyester-nylon composite cooling fiber according to Example 1 of the present invention;

[0081] Figure 4 This is a schematic diagram of the process of preparing a polyester-nylon composite cool fiber according to Example 2 of the present invention;

[0082] Figure 5 This is a schematic diagram of the gradient coating magnetron sputtering state of Example 2 of the present invention;

[0083] Figure 6 This is a schematic diagram of the three-channel spinning nozzle of Example 3 of the present invention;

[0084] Figure 7 This is a schematic diagram of the three-dimensional structure of the second distribution plate of Example 3 of the present invention;

[0085] Figure 8 This is a schematic diagram of the three-dimensional structure of the third distribution plate of Example 3 of the present invention;

[0086] Fig. 9 This is a schematic diagram of the three-dimensional structure of the fourth distribution plate of Example 3 of the present invention;

[0087] Fig.10 for Fig. 9 The schematic diagram of the structure is enlarged at X in the middle;

[0088] Fig.11 This is a schematic diagram of the three-dimensional structure of the fifth distribution plate of Example 3 of the present invention;

[0089] Fig.12 for Fig.11 The structure diagram at Y in the middle is enlarged;

[0090] Fig.13 This is a schematic diagram of the three-dimensional structure of the spinneret of Example 3 of the present invention. DETAILED DESCRIPTION

[0091] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0092] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0093] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0094] Embodiment 1:

[0095] like Figure 1-Figure 3 As shown, a polyester-nylon composite modified cool feeling fiber comprises:

[0096] The outer layer, the middle layer and the inner layer are arranged concentrically from the outside to the inside, the cross-section of the outer layer is annular, the cross-section of the middle layer is cross-shaped, the cross-section of the inner layer is circular, and the outer layer is a photothermal regulation layer, the middle layer is a phase change energy storage layer, and the inner layer is an antibacterial functional layer.

[0097] As an improvement, the outer layer is a bio-based nylon modified with a nano-functional agent containing 1-5 wt %, and the nano-functional agent is a modified h-BN nanosheet.

[0098] The steps of preparing the modified h-BN nanosheets include:

[0099] Step s1, dispersing h-BN nanosheets with a thickness of 10-20 nm in an ethanol solution, wherein the concentration of the ethanol solution is controlled at 5 wt %, preferably premixed with a magnetic stirrer for 15 min at a stirring speed of 500 rpm;

[0100] Step s2, adding APTES, the mass ratio is h-BN: APTES = 1: 0.5, slowly adding APTES dropwise, keeping the solution pH = 5, adjusting with acetic acid, and then treating in an ultrasonic cleaner for 2 hours, the power is set to 300W, the frequency is 40kHz, preferably the temperature is 5±2°C throughout the process to avoid local overheating;

[0101] Step s3, after the reaction is completed, the mixture is centrifuged at a speed of 8000 rpm for 10 min and washed with ethanol three times until the conductivity of the filtrate is less than 10 μS / cm;

[0102] Step s4, drying in a vacuum oven at 60° C. for 12 h, with a vacuum degree of -0.1 MPa, to obtain APTES-modified h-BN nanosheets, which were then sieved through 200 mesh.

[0103] As an improvement, the middle layer is made of recycled polyester containing 5-10wt% of phase change microcapsules, and the phase change microcapsules are paraffin microcapsules.

[0104] The preparation steps of paraffin microcapsules include:

[0105] Step q1, heat paraffin with a phase transition temperature of 30°C to a molten state of 50°C, add 1wt% Tween-80 for emulsification, stir at a speed of 2000rpm, and then add ethyl orthosilicate, the mass ratio of paraffin:ethyl orthosilicate=3:1;

[0106] Step q2, slowly adding ammonia water under stirring conditions to make the pH = 10, catalyzing the hydrolysis and condensation of TEOS to form a core-shell structure, the reaction temperature is 40°C, and the time is 4h;

[0107] Step q3, using a probe-type ultrasonic crusher, with a frequency of 40 kHz, a power of 200 W, a pulse mode, 5 s on / 5 s off, and ultrasonic crushing for 30 min. During the crushing process, the temperature was controlled at <30° C. in an ice bath, and the particle size of the core-shell structure was controlled to be 300±50 nm, and the shell thickness was 25±5 nm.

[0108] Step q4, rotating speed 5000rpm, centrifugal separation for 10min, washing with ethanol three times, drying at 60℃, sieving through 400 mesh, to obtain paraffin microcapsules.

[0109] As an improvement, the inner layer is a bio-based nylon treated and modified with 1-3 wt % of a nano antibacterial agent, wherein the nano antibacterial agent is Zn-CuO nanoparticles.

[0110] The steps of preparing Zn-CuO nanoparticles include:

[0111] Step t1, using a sol-gel method, dissolving Cu(NO3)2·3H2O and Zn(NO3)2·6H2O in deionized water at a molar ratio of Zn:Cu=5%;

[0112] Step t2, adding citric acid as a complexing agent, the molar ratio of metal ion: citric acid = 1:1.5;

[0113] Step t3, stirring in a water bath at 80°C until a transparent sol is formed, and continuing to heat to 120°C to form a gel;

[0114] Step t4, in a muffle furnace, the gel was calcined at 400° C. for 2 h at a heating rate of 5° C. / min, and then naturally cooled and ground to obtain Zn-doped CuO nanoparticles with a particle size of less than 50 nm;

[0115] Step t5, the nanoparticles and stearic acid are ultrasonically dispersed in ethanol at a mass ratio of 1:0.2 for 30 minutes at an ultrasonic dispersion power of 200 W, and dried at 60° C. to obtain Zn-CuO nanoparticles.

[0116] Embodiment 2:

[0117] like Figure 4 As shown, in addition, referring to Example 1, Example 2 of the present invention also provides a method for preparing a polyester-nylon composite modified cool fiber of Example 1, comprising the following steps:

[0118] Step a, pretreatment, drying the bio-based PA56 particles in a vacuum drying oven at 100°C for 6 hours to ensure that the moisture content is less than 0.02%, and drying the rPET particles in a drying oven at 140°C for 4 hours to ensure that the moisture content is less than 0.02%;

[0119] Step b, melt blending of the outer layer materials, premixing the dried bio-based PA56, 1-5wt% of the modified h-BN nanosheets accounting for 1-5wt% of the total mass and 0.5wt% of the antioxidant 1010 accounting for 0.5wt% of the total mass in a high-speed mixer for 5 minutes, and then adding the obtained mixture A to the first twin-screw extruder for melt blending, setting the temperature gradient of zones 1-5 of the first twin-screw extruder to 220 / 235 / 245 / 250 / 245°C, i.e., 220°C for the feeding zone, 235°C for the compression zone, 245°C for the melting zone, 250°C for the homogenizing zone, and 245°C for the die, preferably with a loss-in-weight feeder accuracy of ±0.5%, a feeding rate of 10kg / h, a screw speed of 150rpm, a melt pressure of 8±0.5MPa, and a melt temperature deviation of ±2°C;

[0120] Step c, melt blending of the middle layer materials, premixing the dried rPET, 5-10wt% of the paraffin microcapsules and 0.3wt% of the dispersant in a high-speed mixer for 5 minutes, preferably mixing them in a double cone mixer (inclination angle of 45°, screw speed of 30rpm) for 1h, adding the obtained mixture B to the second twin-screw extruder for melt blending, setting the temperature gradient of zones 1-5 of the second twin-screw extruder to 240 / 255 / 265 / 270 / 265°C, the feeding zone at 240°C, the compression zone at 255°C, the melting zone at 265°C, the homogenizing zone at 270°C, the die at 265°C, the screw speed at 120rpm, avoiding the rupture of the microcapsules, the melt pressure sensor for real-time monitoring, the pressure fluctuation <±5%, the microcapsule breakage rate <3%, and the melt viscosity of 3500±200Pa.s;

[0121] Step d, melt blending of the inner layer materials, premixing the dried bio-based PA56, 1-3wt% of the total mass of the Zn-CuO nano-antibacterial agent and 0.2wt% of the total mass of the coupling agent KH550 in a high-speed mixer (temperature 80°C) for 5 minutes, and then adding the obtained mixture C into the third twin-screw extruder for melt blending, setting the temperature gradient of zones 1-5 of the third twin-screw extruder to 230 / 240 / 250 / 255 / 250°C, i.e., 230°C for the feeding zone, 240°C for the compression zone, 250°C for the melting zone, 255°C for the homogenizing zone, 250°C for the die head, 180rpm for the screw speed, and 12±0.5g / 10min for the melt flow rate;

[0122] Step e, composite spinning, the first screw extruder, the second screw extruder and the third screw extruder respectively input the mixture A, the mixture B and the mixture C into the three-channel spinning nozzle, and the three-channel spinning nozzle ejects the spinning, the aperture of the nozzle of the three-channel spinning nozzle is 0.2mm, the outer / middle / inner aperture ratio of the nozzle is 15:60:25, the spinneret hole adopts a stepped guide groove design to reduce melt turbulence, the middle layer adopts a cross-shaped cross-section design, the guide groove depth is 0.1mm, the spinneret hole spacing is 0.5mm, the outer layer pressure is 8MPa, the metering pump frequency is 25Hz, the middle layer pressure is 12MPa, the metering pump frequency is 35Hz, the inner layer pressure is 7MPa, the metering pump frequency is 20Hz, the spinneret is cooled by a ring blowing device, the wind speed uniformity deviation is less than 5%, and the humidity sensor is used for real-time feedback control;

[0123] Step f, post-treatment, stretching and heat setting the composite fiber obtained by composite spinning, the first-level stretching is 80°C hot roller (diameter 300mm) stretching, the tension sensor controls the stretching multiple to 1.5±0.1 times, the second-level stretching is 120° hot plate (contact length 1.5m) stretching, the stretching rate is 50m / min, the stretching multiple is 2.0±0.1 times, the fiber retracts freely by 5% after heat setting, the internal stress is eliminated, and the treated composite fiber is subjected to light curing hydrophilic finishing;

[0124] Step g, deposition of a photothermal response layer: the composite fiber is treated with a tungsten oxide thin film by magnetron sputtering to form a photothermal response layer with a continuous gradient film thickness structure of 50nm±5nm on the surface of the composite fiber.

[0125] Among them, the photocuring hydrophilic finishing includes the following steps:

[0126] Step w1, according to the mass ratio, 50% of polyethylene glycol diacrylate with a molecular weight of 600, 3% of photoinitiator 1173, and 47% of deionized water were mixed evenly for 30 minutes under light-proof conditions, and filtered with a 5 μm filter membrane to obtain a coating liquid with a viscosity of 120±10 Pa.s (25° C.);

[0127] Step w2, immersing the fiber into the coating liquid by dipping method (the liquid level of the dipping tank is constant), the dipping time is 10 seconds, the roller pressure is 0.3 MPa, and the liquid squeezing rate is 80%;

[0128] Step w3: Use UV curing equipment (mercury lamp), wavelength 365nm, intensity 50±2mW / cm 2 , curing for 20 seconds, nitrogen protection (oxygen concentration <100ppm), nitrogen flow rate 10L / min, cured film thickness 2±0.5μm.

[0129] As an improvement, the magnetron sputtering tungsten oxide film processing includes the following steps:

[0130] Step r1, the fiber was plasma cleaned for 5 minutes at a power of 100 W and under Ar gas protection to remove surface impurities;

[0131] Step r2, DC magnetron sputtering, target-substrate distance 60 mm, substrate temperature 80±2°C, composite fiber conveying speed 10 mm / s, sputtering zone length 200 mm, initial sputtering power 90 W, power slope 0.5 W / s, film thickness 50±5 nm.

[0132] like Figure 5 As shown, the film thickness d(x) is required to increase linearly from 45nm to 55nm along the substrate position x (x∈[0,200]mm), then the formula is:

[0133] d(x)=45+0.05x (unit: nm)

[0134] in,

[0135] x: base position (mm), range 0 to 200 mm;

[0136] Slope: 0.05 nm / mm, total thickness increment Δd=10 nm.

[0137] Parameter matching and power curve design:

[0138] (2) Motion parameters

[0139] Fiber winding speed: v = 10 mm / s;

[0140] Sputtering zone length: L = 200 mm;

[0141] Passing time: t total =L / v=20s

[0142] (3) Power curve derivation

[0143] Assume that the relationship between film thickness d(x) and power P(t) is a linear integral:

[0144] (k is the deposition rate constant)

[0145] To achieve d(x) = 45 + 0.05x, it is necessary to satisfy:

[0146] 1. Initial thickness: d = 45nm when x = 0, corresponding to the initial power P0;

[0147] 2. Slope matching: power increases linearly with time, that is, P(t) = P0 + at

[0148] Substituting the base position x=vt, we get:

[0149]

[0150] To simplify the design, the quadratic term is ignored (when α is small), and the approximation is:

[0151]

[0152] Combined with the target formula d(x) = 45 + 0.05x, it must meet the following requirements:

[0153] Initial thickness correction: by pre-sputtering the substrate or adjusting the initial power P0;

[0154] Slope Control:

[0155]

[0156] In the present invention, in order to achieve an initial thickness of 45 nm, the corresponding initial power P0 is 90 W. According to the target slope of 0.05 nm / mm, the power slope α needs to satisfy:

[0157]

[0158] Corrected to actually achievable linear growth:

[0159]

[0160] By adjusting and setting the magnetron sputtering as described above, the photothermal response layer of the present application with a continuous gradient film thickness structure of 50nm±5nm can be formed on the surface of the composite fiber.

[0161] Embodiment 3:

[0162] like Figures 6 to 13 As shown, referring to Example 2, the present invention further provides a three-channel spinning nozzle used in the composite spinning step, the spinning nozzle comprises a first distribution plate 11, a second distribution plate 12, a third distribution plate 13, a fourth distribution plate 14, a fifth distribution plate 15 and a spinneret 16 in sequence;

[0163] The first distribution plate 11 is provided with a first feed channel 111 for inputting mixture A, a second feed channel 112 for inputting mixture B, and a third feed channel 113 for inputting mixture C;

[0164] The second distribution plate 12 and the first distribution plate 12 have concave end surfaces corresponding to the first distribution plate 12, which are provided with a first diverter groove 121 for receiving the mixture A, a second diverter groove 122 for receiving the mixture B, and a third diverter groove 123 for receiving the mixture C, wherein the first diverter groove 121 is correspondingly connected to the first feed channel 111, the first diverter groove 121 is located at the edge of the second distribution plate 12, the second diverter groove 122 is connected to the second feed channel 112, the second diverter groove 122 is located at the center of the second distribution plate 12, the third diverter groove 123 is connected to the third feed channel 113, the third diverter groove 123 is located between the first diverter groove 121 and the second diverter groove 122, and the first diverter groove 121 is provided with uniformly distributed first diverter holes 124 at the bottom, the second diverter groove 122 is provided with uniformly distributed second diverter holes 125 at the bottom, and the third diverter groove 123 is provided with uniformly distributed third diverter holes 126 at the bottom;

[0165] The end surfaces of the third distribution plate 13 and the second distribution plate 12 are uniformly provided with a plurality of first distribution grooves 131, second distribution grooves 132 and third distribution grooves 133 arranged in a waist shape. The first distribution groove 131 is arranged corresponding to the first diverter hole 124, the second distribution groove 132 is arranged corresponding to the second diverter groove 122, and the third distribution groove 133 is arranged corresponding to the third diverter groove 123. The first distribution groove 131 is provided with a first through hole 134, the second distribution groove 132 is provided with a second through hole 135, and the third distribution groove 133 is provided with a third through hole 136;

[0166] The fourth distribution plate 14 is provided with a first material area 141, a second material area 142, and a third material area 143. The first material area 141 is connected to the first through hole 134, the second material area 142 is connected to the second through hole 135, and the third material area 143 is connected to the third through hole 136. The first material area 141 has first flow holes 144 evenly distributed at the bottom, the second material area 142 has second flow holes 145 evenly distributed at the bottom, and the third material area 143 has third flow holes 146 evenly distributed at the bottom.

[0167] The fifth distribution plate 15 is provided with a recessed mixing area 151, which is connected to the third flow hole 146, and a plurality of mixing holes 152 are evenly distributed in the mixing area 151, and the mixture B and the mixture C are mixed at the mixing hole 152, and the mixing hole 152 includes a circular material hole 153 in the center and a cross material hole 154 on the outside, and the circular material hole 153 and the cross material hole 154 are separated and arranged, and the circular material hole 153 is connected to the third flow hole 146 in a one-to-one correspondence, and the cross material hole 154 is connected to the mixing area 151. In addition, a distribution trough 155 connected to the first flow hole 144 is provided at the edge of the fifth distribution plate 15, and a through flow hole 156 is provided at the bottom of the distribution trough 155;

[0168] There are several spray holes 161 evenly distributed on the spinneret 16, which are arranged one by one corresponding to the mixing holes 152. Surrounding the spray holes 161, a mixing area 162 is recessed on the end surface of the spinneret 16 corresponding to the fifth distribution plate 15. The mixing area 162 is connected to the flow hole 156, and the mixture A, mixture B and mixture C are mixed at the spray hole 161 and sprayed out for spinning.

[0169] Preparation Example 1:

[0170] Step a, pretreatment, drying the bio-based PA56 particles in a vacuum drying oven at 100°C for 6 hours to ensure that the moisture content is less than 0.02%, and drying the rPET particles in a drying oven at 140°C for 4 hours to ensure that the moisture content is less than 0.02%;

[0171] Step b, melt blending of the outer layer materials, premixing the dried bio-based PA56, 1 wt% of the modified h-BN nanosheets and 0.5 wt% of the antioxidant 1010 in a high-speed mixer for 5 minutes, adding the obtained mixture A to the first twin-screw extruder for melt blending, and setting the temperature gradient of zones 1-5 of the first twin-screw extruder to 220 / 235 / 245 / 250 / 245°C;

[0172] Step c, melt blending of the intermediate layer materials, premixing the dried rPET, 5wt% of paraffin microcapsules and 0.3wt% of the dispersant in a high-speed mixer for 5 minutes, adding the obtained mixture B to the second twin-screw extruder for melt blending, and setting the temperature gradient of zones 1-5 of the second twin-screw extruder to 240 / 255 / 265 / 270 / 265°C;

[0173] Step d, melt blending of the inner layer materials, premixing the dried bio-based PA56, 1 wt% of the total mass of the Zn-CuO nano-antibacterial agent, and 0.2 wt% of the total mass of the coupling agent KH550 in a high-speed mixer for 5 minutes, adding the obtained mixture C into the third twin-screw extruder for melt blending, and setting the temperature gradient of zones 1-5 of the third twin-screw extruder to 230 / 240 / 250 / 255 / 250°C;

[0174] Step e, composite spinning, the first screw extruder, the second screw extruder and the third screw extruder respectively input the mixture A, the mixture B and the mixture C into the three-channel spinning nozzle, and the three-channel spinning nozzle ejects the spinning, the aperture of the nozzle of the three-channel spinning nozzle is 0.2 mm, and the outer / middle / inner aperture ratio of the nozzle is 15:60:25;

[0175] Step f, post-treatment, stretching and heat-setting the composite fiber obtained by composite spinning, and performing photocuring and hydrophilic finishing on the treated composite fiber;

[0176] Step g, deposition of a photothermal response layer: the composite fiber is treated with a tungsten oxide thin film by magnetron sputtering to form a photothermal response layer with a continuous gradient film thickness structure of 50nm±5nm on the surface of the composite fiber.

[0177] Preparation Example 2:

[0178] The same as Preparation Example 1, except that the mass fraction of the modified h-BN nanosheets is 3wt%, the mass fraction of the paraffin microcapsules is 8wt%, and the mass fraction of the Zn-CuO nano antibacterial agent is 2wt%.

[0179] Preparation Example 3:

[0180] The same as Preparation Example 1, except that the mass fraction of the modified h-BN nanosheets is 5wt%, the mass fraction of the paraffin microcapsules is 10wt%, and the mass fraction of the Zn-CuO nano-antibacterial agent is 3wt%.

[0181] Preparation Example 4:

[0182] Same as Preparation Example 1, except that the mass fraction of the modified h-BN nanosheets is 3 wt %.

[0183] Preparation Example 5:

[0184] The same as Preparation Example 1, except that the mass fraction of the paraffin microcapsules is 8wt%.

[0185] Preparation Example 6:

[0186] Same as Preparation Example 1, except that the mass fraction of the Zn-CuO nano antibacterial agent is 3wt%.

[0187] Comparative Example 1:

[0188] Same as Preparation Example 1, except that the mass fraction of modified h-BN nanosheets is less than 1wt%, 0.9wt%, the mass fraction of paraffin microcapsules is less than 5wt%, 4.9wt%, and the mass fraction of Zn-CuO nano antibacterial agent is 1wt%, 0.9wt%.

[0189] Comparative Example 2:

[0190] Same as Preparation Example 1, except that the mass fraction of modified h-BN nanosheets is greater than 5wt%, 5.1wt%, the mass fraction of paraffin microcapsules is greater than 10wt%, 10.1wt%, and the mass fraction of Zn-CuO nano-antibacterial agent is greater than 3wt%, 3.1wt%.

[0191] The above-mentioned preparation examples 1-3 and comparative examples 1-2 were tested. According to JISL1096 "Test method for cooling performance of textiles" at an ambient temperature of 25°C and a relative humidity of 65%, the instantaneous cooling sensation was tested. According to ISO11092 "Physiological effects of textiles - Determination of thermal resistance and moisture resistance under steady-state conditions" at 25°C, the contact temperature difference was tested. According to GB / T14337 "Test method for tensile properties of chemical fiber filaments", the holding distance was 20mm.

[0192] Tensile speed: 100mm / min, pre-tension: 0.5cN / dtex, fiber monofilament sampling, 30 fibers in each group were tested and the average value was taken, breaking strength and breaking elongation were tested, according to GB / T14344 "Test method for elastic recovery of chemical fiber filaments", the fiber was stretched to 3% deformation and kept for 1 minute, and then unloaded and left to stand for 3 minutes to test the elastic recovery rate, according to GB / T8629 "Household washing and drying procedures for textile testing" after 50 standard washes, the cool feeling retention rate was tested, according to GB / T 20944.3 "Evaluation of antibacterial properties of textiles Part 3: Oscillation method" after 50 washes, the antibacterial rate of Staphylococcus aureus was tested, and the test results are shown in Table 1 below.

[0193] Table 1

[0194]

[0195]

[0196] By comparing Preparation Examples 1-6 with Comparative Examples 1-2, it can be seen that the synergistic effect of h-BN nanosheets, paraffin microcapsules and Zn-CuO antibacterial agents can regulate the temperature control parameters of the polyester-nylon composite modified cool fiber and improve the antibacterial ability.

[0197] By comparing Preparation Example 1 with Preparation Example 4, it can be seen that the addition of h-BN nanosheets improves the thermal conductivity and photothermal response, which will improve the parameters such as the instantaneous coolness and contact temperature difference of the polyester-nylon composite modified cool fiber. However, the increase in the content of h-BN nanosheets will affect the interface bonding of the polyester-nylon composite modified cool fiber, resulting in a decrease in the strength of the polyester-nylon composite modified cool fiber.

[0198] Furthermore, by comparing Preparation Example 1 with Preparation Example 5, it can be seen that the addition of paraffin microcapsules increases the phase change enthalpy value and prolongs the temperature control duration, which will promote the contact temperature difference and the cool feeling retention rate. The rupture and leakage of microcapsules will have an adverse effect on the fiber flexibility.

[0199] In summary, through the comparison of Preparation Examples 1-6, it can be seen that in order to balance the temperature control ability and strength of the polyester-nylon composite modified cooling fiber, the preferred mass fractions of h-BN nanosheets and paraffin microcapsules are 3wt% and 8wt%, respectively. Under this parameter, the prepared balanced polyester-nylon composite modified cooling fiber has better instantaneous cooling, contact temperature difference and cooling retention rate, and can also obtain stronger strength.

[0200] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A polyester-nylon composite modified cool fiber, characterized in that: include: An outer layer (1), a middle layer (2) and an inner layer (3) are arranged concentrically from the outside to the inside, the cross-section of the outer layer (1) is arranged in a ring shape, the cross-section of the middle layer (2) is arranged in a cross shape, the cross-section of the inner layer (3) is arranged in a circular shape, and the outer layer (1) is a photothermal regulation layer, the middle layer (2) is a phase change energy storage layer, and the inner layer (3) is an antibacterial functional layer.

2. The polyester-nylon composite modified cool fiber according to claim 1, characterized in that: The outer layer (1) is a bio-based nylon modified with a nano-functional agent containing 1-5 wt %, wherein the nano-functional agent is a modified h-BN nanosheet.

3. The polyester-nylon composite modified cool fiber according to claim 1, characterized in that: The middle layer (2) is made of recycled polyester containing 5-10 wt% of phase change microcapsules, and the phase change microcapsules are paraffin microcapsules.

4. The polyester-nylon composite modified cool fiber according to claim 1, characterized in that: The inner layer (3) is a bio-based nylon treated and modified with 1-3 wt% of a nano antibacterial agent, wherein the nano antibacterial agent is Zn-CuO nanoparticles.

5. A method for preparing a polyester-nylon composite modified cool fiber according to any one of claims 1 to 4, characterized in that: The following steps are involved: Step a, pretreatment, drying the bio-based PA56 particles in a vacuum drying oven at 100°C for 6 hours to ensure that the moisture content is less than 0.02%, and drying the rPET particles in a drying oven at 140°C for 4 hours to ensure that the moisture content is less than 0.02%; Step b, melt blending of the outer layer materials, premixing the dried bio-based PA56, 1-5wt% of the modified h-BN nanosheets accounting for 1-5wt% of the total mass, and 0.5wt% of the antioxidant 1010 accounting for 0.5wt% of the total mass in a high-speed mixer for 5 minutes, adding the obtained mixture A to the first twin-screw extruder for melt blending, and setting the temperature gradient of zones 1-5 of the first twin-screw extruder to 220 / 235 / 245 / 250 / 245°C; Step c, melt blending of the intermediate layer materials, premixing the dried rPET, 5-10wt% of paraffin microcapsules and 0.3wt% of the dispersant in a high-speed mixer for 5 minutes, adding the obtained mixture B to the second twin-screw extruder for melt blending, and setting the temperature gradient of zones 1-5 of the second twin-screw extruder to 240 / 255 / 265 / 270 / 265°C; Step d, melt blending of the inner layer materials, premixing the dried bio-based PA56, 1-3wt% of the total mass of the Zn-CuO nano-antibacterial agent, and 0.2wt% of the total mass of the coupling agent KH550 in a high-speed mixer for 5 minutes, adding the obtained mixture C into the third twin-screw extruder for melt blending, and setting the temperature gradient of zones 1-5 of the third twin-screw extruder to 230 / 240 / 250 / 255 / 250°C; Step e, composite spinning, the first screw extruder, the second screw extruder and the third screw extruder respectively input the mixture A, the mixture B and the mixture C into the three-channel spinning nozzle, and the three-channel spinning nozzle ejects the spinning, the aperture of the nozzle of the three-channel spinning nozzle is 0.2 mm, and the outer / middle / inner aperture ratio of the nozzle is 15:60:25; Step f, post-treatment, stretching and heat-setting the composite fiber obtained by composite spinning, and performing photocuring and hydrophilic finishing on the treated composite fiber; Step g, deposition of a photothermal response layer: the composite fiber is treated with a tungsten oxide thin film by magnetron sputtering to form a photothermal response layer with a continuous gradient film thickness structure of 50nm±5nm on the surface of the composite fiber.

6. The preparation method according to claim 5, characterized in that: The preparation steps of modified h-BN nanosheets include: Step s1, dispersing h-BN nanosheets with a thickness of 10-20 nm in an ethanol solution, wherein the concentration of the ethanol solution is controlled at 5 wt %; Step s2, adding APTES, the mass ratio of h-BN:APTES=1:0.5, treating in an ultrasonic cleaning machine for 2 hours, the power is set to 300W, the frequency is 40kHz; Step s3: After the reaction is completed, the mixture is centrifuged at a speed of 8000 rpm for 10 min and washed with ethanol three times; Step s4, drying in a vacuum oven at 60° C. for 12 h to obtain APTES-modified h-BN nanosheets.

7. The preparation method according to claim 5, characterized in that: The preparation steps of Zn-CuO nanoparticles include: Step t1, using a sol-gel method, dissolving Cu(NO3)2·3H2O and Zn(NO3)2·6H2O in deionized water at a molar ratio of Zn:Cu=5%; Step t2, adding citric acid as a complexing agent, the molar ratio of metal ion: citric acid = 1:1.5; Step t3, stirring in a water bath at 80°C until a transparent sol is formed, and continuing to heat to 120°C to form a gel; Step t4, calcining the gel at 400° C. for 2 h to obtain Zn-doped CuO nanoparticles; Step t5: Ultrasonic disperse the nanoparticles and stearic acid in ethanol at a mass ratio of 1:0.2 for 30 minutes, and dry at 60° C. to obtain Zn-CuO nanoparticles.

8. The preparation method according to claim 5, characterized in that: The preparation steps of paraffin microcapsules include: Step q1, heat paraffin with a phase transition temperature of 30°C to a molten state, and add ethyl orthosilicate, with a mass ratio of paraffin:ethyl orthosilicate = 3:1; Step q2, slowly adding ammonia water under stirring conditions to make the pH = 10, catalyzing the hydrolysis and condensation of TEOS to form a core-shell structure; Step q3, using an ultrasonic crusher with a frequency of 40 kHz and a power of 200 W, ultrasonic crushing treatment was performed for 30 min to control the particle size of the core-shell structure to be 300 ± 50 nm; Step q4, centrifugation at a rotation speed of 5000 rpm for 10 min, washing with ethanol three times, and drying at 60° C. to obtain paraffin microcapsules.

9. The preparation method according to claim 5, characterized in that: Light-curing hydrophilic finishing includes the following steps: Step w1, according to the mass ratio, 50% of polyethylene glycol diacrylate with a molecular weight of 600, 3% of photoinitiator 1173, and 47% of deionized water are mixed evenly; Step w2, immersing the fiber into the coating liquid by dipping method, the dipping time is 10 seconds, and the liquid extraction rate is 80%; Step w3: Use UV curing equipment with a wavelength of 365nm and an intensity of 50mW / cm 2 , cure for 20 seconds.

10. The preparation method according to claim 5, characterized in that: The magnetron sputtering tungsten oxide film processing includes the following steps: Step r1, the fiber was plasma cleaned for 5 minutes at a power of 100 W and Ar gas protection to remove surface impurities; Step r2, DC magnetron sputtering, target-substrate distance 60 mm, substrate temperature 80±2°C, composite fiber conveying speed 10 mm / s, sputtering zone length 200 mm, initial sputtering power 90 W, power slope 0.5 W / s, film thickness 50±5 nm.

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