A colorful thermal management fiber and its preparation method and thermal management fabric

Abstract

The present invention relates to the field of melt spinning and thermal management fiber technology, and discloses a colorful thermal management fiber and its preparation method and thermal management fabric, the method comprising: using a coupling agent as a modifier to perform the following modification treatment on two inorganic materials, an inorganic filler and an inorganic pigment, respectively, and then melt-blending them with a polymer to obtain a core masterbatch and a skin masterbatch, and then using the skin masterbatch and the core masterbatch as skin material and core material for coaxial skin-core spinning to obtain a colorful thermal management fiber. The thermal management fiber prepared by the present invention is a structural thermal management fiber. Compared with the thermal management fiber with a surface coating, it solves the problem of interface bonding between the substrate and the inorganic filler, and will not lose its photothermal conversion ability even if it is subjected to external friction or washing. At the same time, compared with ordinary photothermal conversion materials, it has a wider and stronger thermal regulation performance.

Description

Technical Field

[0001] The present invention relates to the technical field of melt spinning and thermal management fibers, and in particular to a multi-colored thermal management fiber and a preparation method thereof, and a thermal management fabric. Background Art

[0002] In cold regions or high-altitude mountainous areas, traditional heating methods that rely on fossil fuels like coal and oil not only consume non-renewable energy but also cause environmental pollution. To address this, researchers have developed a range of thermal management fabrics to sustainably maintain thermal comfort. Light, one of nature's most abundant energy sources, is an effective thermal management technology for heating and warmth through photothermal conversion.

[0003] Most photothermal conversion technologies utilize carbon-based materials (such as graphene and carbon black) with broad-spectrum absorption properties to achieve efficient photothermal conversion. However, the difficulty of dyeing dark colors and the weak dyeability of inert substrates such as polypropylene and polyester limit the application of colorful photothermal conversion fabrics. Furthermore, traditional pigment color development relies on broad-spectrum absorption properties, producing color by selectively absorbing specific wavelengths in the visible light region (380–780 nm). However, the strong absorption of the unique chemical bonds of traditional pigment molecules in the near-infrared wavelength range (780–2500 nm) causes infrared energy loss in the solar spectrum, reducing the photothermal conversion efficiency of the fabric and leading to incompatibility between photothermal conversion fabrics and colored fabrics. Furthermore, traditional pigments are prone to thermal degradation (such as fading of organic dyes) or microstructural damage due to thermal stress under long-term photothermal coupling, further limiting their practical application. Summary of the Invention

[0004] To address the incompatibility between traditional pigments' color development in the visible light band and their infrared thermal management, this invention utilizes inorganic fillers (such as zirconium carbide) that exhibit significant photothermal conversion capabilities in the near-infrared band, along with infrared-transparent pigments (such as nano-iron oxide, nano-Prussian blue, and nano-silicon powder) to address this technical issue. Infrared-transparent pigments achieve highly saturated color development by selectively absorbing visible light. Furthermore, their weak absorption and low scattering properties in the near-infrared band (780-2500 nm) allow for efficient transmission of most infrared light. Infrared-transparent pigments combine the broad-spectrum absorption and efficient photothermal conversion capabilities of inorganic fillers (such as zirconium carbide) to form a synergistic visible-infrared system. Inorganic fillers (such as zirconium carbide) fully capture near-infrared light that penetrates the pigment layer and converts it into heat, avoiding the energy loss associated with traditional pigments' broad-spectrum absorption. Furthermore, the pigments' stable visible light color development overcomes the single-color limitations of traditional photothermal materials. Furthermore, the high thermal conductivity of inorganic fillers (such as zirconium carbide) accelerates heat diffusion, preventing thermal degradation of the pigment caused by localized overheating. The pigment layer's strong absorption in the visible light region ensures the system's color and achieves a precise balance between color rendering and photothermal functionality. This synergistic effect achieves compatibility between visible and infrared wavelengths, thus resolving the incompatibility issue between photothermal conversion fabrics and colored fabrics.

[0005] Based on this, the present invention provides a method for preparing colorful thermal management fibers by melt spinning and its products, so as to solve the incompatibility problem between existing thermal management fabrics and colored fabrics, so as to improve the practicality of thermal management fabrics.

[0006] To achieve the above objectives, the present invention provides a method for preparing a multi-colored thermal management fiber, which comprises the following steps:

[0007] (1) Modification of inorganic materials

[0008] Two inorganic materials, an inorganic filler with light-to-heat conversion capability and a near-infrared transparent inorganic pigment, are subjected to the following modification treatments, respectively, wherein the inorganic filler is selected from a transition metal carbide, and the inorganic pigment is selected from at least one of silicon nanoparticles with a yellow surface color, nano-iron oxide particles with a red surface color, and nano-Prussian blue particles with a blue surface color;

[0009] A coupling agent is added to a mixed solvent of anhydrous ethanol and deionized water to prepare a coupling agent solution, and the pH range is adjusted to 3.0-4.0 with acetic acid to obtain a mixed solution; the inorganic material is soaked and cleaned in acetone, and the mixture is allowed to stand for stratification, and the lower layer of the nano-solution is placed in a vacuum oven and dried to constant weight, and then added to the mixed solution, first dispersed by ultrasonic oscillation, and then stirred at a constant temperature of 70-80° C., and finally vacuum filtered, washed with acetone, and dried to obtain the modified inorganic material;

[0010] (2) Preparation of core layer and skin layer masterbatch

[0011] The core layer masterbatch is obtained by melt blending the polymer and the modified inorganic filler; the skin layer masterbatch is obtained by melt blending the polymer and the modified inorganic pigment;

[0012] The polymer is selected from polyethylene terephthalate, polyamide, polyphenylene sulfide or polypropylene, and the polymer in the core layer masterbatch and the skin layer masterbatch is the same;

[0013] (3) Skin-core spinning

[0014] The sheath-core spinning process is adopted, and coaxial melt spinning is carried out using a sheath-core spinning assembly. The sheath masterbatch and the core masterbatch are extruded from the sheath-core spinning assembly as the sheath material and the core material respectively to obtain the spun fiber, and then the spun fiber is stretched and heat-set to obtain the thermal management fiber.

[0015] The present invention incorporates yellow silicon nanoparticles, red nano-iron oxide particles, and blue nano-Prussian blue particles as inorganic pigments into the fiber cortex. This allows the fiber to take on a color based on the inorganic pigments. For example, the silicon nanoparticles, nano-iron oxide particles, and nano-Prussian blue particles are combined to create a multicolored effect. This method of combining the three primary colors to create a multicolored effect is conventional and will not be elaborated upon here.

[0016] As a further preferred technical solution of the present invention, the transition metal carbide is selected from zirconium carbide or titanium carbide, and is a nanoparticle.

[0017] As a further preferred technical solution of the present invention, in step (1), the coupling agent is a silane coupling agent or a titanate coupling agent, and the mass fraction of the coupling agent is 20-50% of the mass fraction of the inorganic material.

[0018] As a further preferred technical solution of the present invention, step (2) further includes a polymer drying step before melt blending, which is specifically as follows:

[0019] The polymer was dried in a vacuum oven at 90 °C for 1-2 h, then dried at 110 °C and 130 °C for 1-2 h respectively, and the above operation was repeated several times. Finally, it was dried in a vacuum drum oven at 160 °C for 4-6 h.

[0020] As a further preferred technical solution of the present invention, in step (2), under the premise of ensuring that subsequent continuous core-skin spinning can be carried out, the ratio of the mass fraction of the inorganic filler in the core layer masterbatch to the mass fraction of the polymer is 1:1000~1:10, and the ratio of the mass fraction of the inorganic pigment in the skin layer masterbatch to the mass fraction of the polymer is 1:1000~1:10.

[0021] As a further preferred technical solution of the present invention, in step (3), the spinning temperature in the melt spinning process is 180~280°C, the cooling air temperature is 20~30°C, the wind speed is 0.3~0.5 m / s, and the spinning speed is 1500~3000 m / min.

[0022] As a further preferred technical solution of the present invention, in step (3), the stretching temperature is 80~120°C, the stretching ratio is 3~5 times, and the heat setting temperature is 180~220°C.

[0023] According to another aspect of the present invention, the present invention also provides a colorful thermal management fiber, which is prepared by the above method.

[0024] According to another aspect of the present invention, the present invention also provides a thermal management fabric, which is made of the above-mentioned colorful thermal management fiber.

[0025] Compared with the prior art, the present invention can achieve the following beneficial effects:

[0026] 1) The thermal management fiber prepared by the present invention is a structural thermal management fiber. Compared with thermal management fibers with surface coatings, it solves the problem of interface bonding between the substrate and the inorganic filler. Even if it is subjected to external friction or washing, it will not lose its photothermal conversion ability. At the same time, compared with ordinary photothermal conversion materials, it has a wider range and stronger thermal regulation performance.

[0027] 2) The preparation method of the present invention extrudes the modified core layer functional masterbatch and the skin layer masterbatch with the corresponding color through a core-skin spinning assembly to obtain a nascent fiber with the corresponding color without compromising the material's photothermal conversion ability. This is more practical than traditional thermal management fibers. In comparison, the resulting thermal management fiber can display a variety of colors without compromising its photothermal conversion ability, and the inorganic pigments used have the characteristics of being opaque to visible light and highly transparent in the infrared band.

[0028] 3) The preparation method of the present invention can achieve a colorful effect of the fiber through color compounding, that is, changing the content of the three primary colors (red, yellow, and blue) inorganic fillers, providing an important reference path for the development of colorful thermal management fibers and fabrics with practical application value. DETAILED DESCRIPTION

[0029] The following is a detailed description of the specific embodiments of the present invention. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0030] Unless otherwise defined, the technical terms used in the following examples have the same meanings as commonly understood by those skilled in the art to which this invention belongs. The experimental reagents used in the following examples, unless otherwise specified, are conventional biochemical reagents; the experimental methods described, unless otherwise specified, are conventional methods.

[0031] The following raw material parameters were selected: the intrinsic viscosity of polyethylene terephthalate (PET) was 0.675 dL / g; the melt index of polypropylene chips was 26.2 g / min; the particle size of zirconium carbide was 500 nm; the particle size of inorganic pigments (nano-silicon particles, nano-Prussian blue particles, nano-iron oxide particles) was 200 nm; and the silane coupling agent was KBM-403.

[0032] The diameter of the fiber obtained by using a conventional spinning assembly is 0.25 mm; the diameter of the fiber obtained by using a sheath-core spinning assembly is 0.25 mm, and the core layer diameter is 0.10 mm.

[0033] Comparative Example 1: Preparation of pure PET fiber and fabric

[0034] (1) Weigh 500 g of polyethylene terephthalate (PET) slices, place them in a vacuum drum oven, and dry them for later use.

[0035] (2) Melt spinning was performed through a conventional spinning assembly at a spinning temperature of 270 °C, a cold air temperature of 20 °C, a wind speed of 0.3 m / s, and a spinning speed of 2500 m / min to obtain nascent fibers; the nascent fibers were stretched and heat-set in sequence at a stretching temperature of 90 °C, a stretching ratio of 3 times, and a heat-setting temperature of 200 °C to finally obtain pure PET fibers with a grayish white surface color and a strength greater than 3.0 cN / dtex.

[0036] (3) The obtained PET fibers were combined and twisted, and then woven into plain fabrics with a warp and weft density of 200 threads / 10 cm using a braiding machine. The thermal management performance of the fabrics was then tested.

[0037] A solar simulator simulated standard sunlight irradiating the fiber, with the initial fabric temperature at -5.0°C and the exposure time at 300 seconds, recorded the surface temperature. Table 1 shows the light-to-heat conversion data for the fabric. Within 300 seconds of exposure, the surface temperature of the off-white fabric rose to 5.2°C. Table 2 shows the Lab values ​​of the fabric's surface color. The Lab values ​​for the off-white fabric are L: 92.5, a: -0.3, and b: +1.2.

[0038] Comparative Example 2: Preparation of PET fibers and fabrics doped with (0.5%) unmodified inorganic fillers

[0039] (1) Weigh 500 g of polyethylene terephthalate (PET) slices, place them in a vacuum drum oven, and dry them for later use.

[0040] (2) Weigh 2.5 g of zirconium carbide and mix it evenly with PET (the ratio of the mass fraction of the photothermal conversion inorganic filler to the mass fraction of polyethylene terephthalate is 1:200), and melt-blend and granulate it through a twin-screw extruder.

[0041] (3) Melt spinning was performed through a conventional spinning assembly at a spinning temperature of 270 °C, a cold air temperature of 20 °C, a wind speed of 0.3 m / s, and a spinning speed of 2500 m / min to obtain nascent fibers; the nascent fibers were stretched and heat-set in sequence at a stretching temperature of 90 °C, a stretching ratio of 3 times, and a heat-setting temperature of 200 °C to finally obtain PET fibers doped with (0.5%) unmodified inorganic fillers with a light gray surface color and a strength greater than 3.0 cN / dtex.

[0042] (4) The obtained PET fibers were combined and twisted, and then woven into plain fabrics with a warp and weft density of 200 threads / 10 cm using a braiding machine. The thermal management performance of the fabrics was then tested.

[0043] A solar simulator simulated standard sunlight exposure to fabric, with an initial fabric temperature of -5.0°C and an exposure time of 300 seconds. The surface temperature was then recorded. Table 1 shows the light-to-heat conversion data for the fabric. Within 300 seconds of exposure, the surface temperature of a light gray fabric rose to 41.7°C. Table 2 shows the Lab values ​​of the fabric's surface color. The Lab values ​​for the light gray fabric are L: 79.5, a: +0.4, and b: -0.9.

[0044] By comparing Examples 1 and 2, it can be seen from the data in Table 1 that within the same irradiation time, the temperature difference between the two fabrics is 38.1°C. Therefore, adding zirconium carbide as a photothermal conversion filler and melt blending can significantly improve the photothermal conversion capacity of the fabric.

[0045] Comparative Example 3: Preparation of PET fiber and fabric doped with (0.5%) modified inorganic filler

[0046] (1) Weigh 500 g of polyethylene terephthalate (PET) slices, place them in a vacuum drum oven, and dry them for later use.

[0047] (2) Weigh 2.5g of zirconium carbide and 0.5g of silane coupling agent; soak the inorganic filler zirconium carbide for photothermal conversion in acetone for cleaning, wait for stratification, and place the lower layer of nano-solution in a vacuum oven to dry to constant weight; then prepare a solution of anhydrous ethanol and deionized water in a mass ratio of 1:1, add the coupling agent to prepare a coupling agent solution, adjust the pH to 4 with acetic acid, add the inorganic filler, and ultrasonically oscillate for 30min. The solution after ultrasonication is then stirred at a constant temperature of 80℃ for 2h. Finally, the solution is vacuum filtered, washed with acetone 3 times, and dried to constant weight to obtain the modified zirconium carbide.

[0048] (3) The modified zirconium carbide and PET are mixed evenly (the ratio of the mass fraction of the photothermal conversion inorganic filler to the mass fraction of polyethylene terephthalate is 1:200), and melt-blended and granulated through a twin-screw extruder.

[0049] (4) Melt spinning was performed through a conventional spinning assembly at a spinning temperature of 270 °C, a cold air temperature of 20 °C, a wind speed of 0.3 m / s, and a spinning speed of 2500 m / min to obtain nascent fibers; the nascent fibers were stretched and heat-set in sequence at a stretching temperature of 90 °C, a stretching ratio of 3 times, and a heat-setting temperature of 200 °C to finally obtain PET fibers doped with (0.5%) modified inorganic fillers with a light gray surface color and a strength greater than 3.0 cN / dtex.

[0050] (5) The obtained PET fibers were drawn and twisted, and then woven into plain fabrics with a warp and weft density of 200 threads / 10 cm using a braiding machine. The thermal management performance of the fabrics was then tested.

[0051] A solar simulator simulated standard sunlight irradiating fabric with an initial fabric temperature of -5.0°C for 300 seconds, and the surface temperature was recorded. Table 1 shows the light-to-heat conversion data for the fabric. Within 300 seconds of exposure, the surface temperature of a light gray fabric rose to 43.3°C. Table 2 shows the Lab values ​​of the fabric's surface color. The Lab values ​​for the light gray fabric are L: 79.5, a: +0.4, and b: -0.9.

[0052] Comparing Comparative Examples 2 and 3, as shown in Table 1, shows that the temperature difference between the two fabrics during the same irradiation time was 1.6°C, indicating that the modification of the inorganic filler improves the compatibility between the polymer substrate and the inorganic filler, thereby enhancing the overall light-to-heat conversion capacity of the fiber material. Similarly, the effect of modifying the inorganic pigment, as demonstrated in Comparative Examples 2 and 3, was also verified. It was found that modifying the inorganic pigment also improves the compatibility between the polymer substrate and the inorganic pigment, resulting in a more uniform color distribution across the fiber material and a certain improvement in light-to-heat conversion capacity.

[0053] Comparative Examples 4-9: Preparation of PET Fiber and Fabric Doped with Modified Inorganic Fillers

[0054] Based on the preparation method of Comparative Example 2, a series of PET fibers and fabrics were prepared by only changing the doping amount of the modified inorganic filler zirconium carbide to 0.02%, 0.05%, 0.1%, 0.2%, 0.8%, and 1.0%. The corresponding thermal management performance test results are shown in Tables 1 and 2.

[0055] Example 1: Preparation of Nano-Silicon / ZrC (0.5%) / PET Fiber and Fabric

[0056] (1) Weigh 500 g of polyethylene terephthalate (PET) slices, place them in a vacuum drum oven, and dry them for later use.

[0057] (2) Weigh 2.5g of zirconium carbide and 0.5g of silane coupling agent; first soak the inorganic filler zirconium carbide (ZrC) for photothermal conversion in acetone for cleaning, wait for stratification, and place the lower layer of nano-solution in a vacuum oven to dry to constant weight; then prepare a solution of anhydrous ethanol and deionized water in a mass ratio of 1:1, add the coupling agent to prepare a coupling agent solution, adjust the pH to 4 with acetic acid, add the inorganic filler, and ultrasonically oscillate for 30min. The sonicated solution is then stirred at a constant temperature of 80℃ for 2h. Finally, the solution is vacuum filtered, washed with acetone three times, and dried to constant weight to obtain the modified zirconium carbide.

[0058] 2.5 g of yellow nano-silicon particles were weighed and modified in the same manner as that used to modify zirconium carbide to obtain modified nano-silicon.

[0059] (3) The modified zirconium carbide and PET are mixed evenly (the ratio of the mass fraction of zirconium carbide to the mass fraction of polyethylene terephthalate is 1:200), melt-blended and granulated through a twin-screw extruder, and dried to obtain the core layer masterbatch for use.

[0060] The modified nano-silicon is evenly mixed with PET (the ratio of the mass fraction of nano-silicon to the mass fraction of polyethylene terephthalate is 1:200), melt-blended and granulated through a twin-screw extruder, and dried to obtain the skin masterbatch for use.

[0061] (4) The sheath-core spinning process was adopted, and the sheath-core spinning assembly was used for coaxial melt spinning. The sheath masterbatch and the core masterbatch were used as the sheath material and the core material respectively. The spinning temperature was 270 °C, the cold blowing temperature during the spinning process was 20 °C, the wind speed was 0.3 m / s, and the spinning speed was 2500 m / min to obtain the nascent fiber; the nascent fiber was stretched and heat-set in sequence, with the stretching temperature being 90 °C, the stretching ratio being 3 times, and the heat setting being 200 °C. Finally, the surface color of the nano-silicon / ZrC (0.5%) / PET fiber with a sheath-core structure and a strength greater than 3.0 cN / dtex was obtained.

[0062] (5) The obtained PET fibers were drawn and twisted, and then woven into plain fabrics with a warp and weft density of 200 threads / 10 cm using a braiding machine. The thermal management performance of the fabrics was then tested.

[0063] A solar simulator simulated standard sunlight irradiating the fiber, with an initial fabric temperature of -5.0°C and an exposure time of 300 seconds, recorded the surface temperature. Table 1 shows the fabric's light-to-heat conversion data. Within 300 seconds of exposure, the surface temperature of a yellow fabric rose to 43.1°C. Table 2 shows the Lab values ​​of the fabric's surface color. The Lab values ​​for the yellow fabric are L: 85.2, a: -5.3, and b: +48.5.

[0064] Example 2: Preparation of Nano-Prussian Blue / ZrC (0.5%) / PET Fiber and Fabric

[0065] The same preparation method as in Example 1 was adopted, except that 2.5 g of the yellow nano-silicon particles in Example 1 were replaced with an equal amount of blue nano-Prussian blue particles, thereby obtaining blue nano-Prussian blue / ZrC (0.5%) / PET fibers and corresponding fabrics.

[0066] A solar simulator simulated standard sunlight irradiating the fiber, with an initial fabric temperature of -5.0°C and an exposure time of 300 seconds. The surface temperature was then recorded. Table 1 shows the light-to-heat conversion data for the fabric. Within 300 seconds of exposure, the surface temperature of a blue fabric rose to 42.4°C. Table 2 shows the Lab values ​​of the fabric's surface color. The Lab values ​​for the blue fabric were L: 62.7, a: -12.8, and b: -35.2.

[0067] Example 3: Preparation of Nano-FeO / ZrC (0.5%) / PET Fiber and Fabric

[0068] The same preparation method as in Example 1 was adopted, except that 2.5 g of the yellow nano-silicon particles in Example 1 were replaced with an equal amount of red nano-iron oxide particles, ultimately obtaining red nano-iron oxide / ZrC (0.5%) / PET fibers and corresponding fabrics.

[0069] A solar simulator simulated standard sunlight irradiating the fabric with an initial fabric temperature of -5.0°C for 300 seconds, and the surface temperature was recorded. Table 1 shows the light-to-heat conversion data for the fabric. Within 300 seconds of exposure, the surface temperature of a red fabric rose to 42.9°C. Table 2 shows the Lab values ​​of the fabric's surface color. The Lab values ​​for the red fabric were L: 55.4, a: +38.6, and b: +15.3.

[0070] By comparing Example 3 with Examples 1, 2, and 3, it can be seen from the data in Table 1 that within the same irradiation time, the temperature difference between the four different fabrics does not exceed 1°C, indicating that the high absorption of zirconium carbide in the near-infrared band gives it excellent photothermal conversion ability, and the added near-infrared transparent inorganic pigment does not affect the photothermal conversion ability of the fabric.

[0071] Comparative Example 10: Preparation of carbon black (0.5%) / PET fiber and fabric

[0072] Based on the preparation method of PET fiber and fabric doped with modified inorganic filler (0.5%) in Comparative Example 3, the difference of this comparative example is that the inorganic filler zirconium carbide raw material is replaced with an equal amount of carbonized zirconium carbide, and finally a PET fiber and corresponding fabric with a black surface color are obtained.

[0073] A solar simulator simulated standard sunlight irradiating fabric with an initial fabric temperature of -5.0°C for 300 seconds, and the surface temperature was recorded. Table 1 shows the fabric's light-to-heat conversion data. Within 300 seconds of exposure, the surface temperature of a black fabric rose to 45.7°C. Table 2 shows the Lab values ​​of the fabric's surface color. The Lab values ​​for the black fabric are L: 55.2, a: +0.2, and b: -0.5.

[0074] By comparing Comparative Example 3 with Comparative Example 10, according to the data in Table 1: within the same irradiation time, the temperature difference between the two fabrics is 2.4°C, indicating that the photothermal conversion ability of carbon black is stronger than that of zirconium carbide.

[0075] By comparing Comparative Example 3 with Comparative Example 10, and from the data in Table 2 and Table 3: comparing the Lab value and the color description, it can be seen that, at the same ratio, the surface color of the fabric with added carbon black is darker and more difficult to dye.

[0076] Example 4: Preparation of Nano-Silicon / Carbon Black (0.5%) / PET Fiber and Fabric

[0077] This embodiment is based on the process of Comparative Example 10, and adjusts the addition of inorganic pigments to prepare sheath-core fibers, and compares and verifies whether the addition of inorganic pigments affects the light-to-heat conversion capacity of carbon black / inorganic pigments / PET fibers and fabrics.

[0078] This example adopts the same preparation method as Example 1, with the only difference being that 2.5 g of zirconium carbide in Example 1 is replaced with an equal amount of carbon black, ultimately obtaining nano-silicon / carbon black (0.5%) / PET fibers and corresponding fabrics having a yellow surface color.

[0079] A solar simulator simulated standard sunlight irradiating the fiber. The initial fabric temperature was -5.0°C, and the exposure time was 300 seconds. The surface temperature was then recorded. Table 1 shows the light-to-heat conversion data for the fabric. Within 300 seconds of exposure, the surface temperature of the yellow fabric rose to 33.2°C. Table 2 shows the Lab values ​​of the fabric's surface color. The Lab values ​​for the yellow fabric were L: 68.3, a: -4.5, and b: +40.7.

[0080] Comparing Example 4 with Comparative Example 10, as shown in Table 1, reveals that, for the same exposure time, the temperature difference between the two fabrics was 12.5°C. This indicates that carbon black's excellent photothermal conversion capability stems from its broad spectrum absorption. However, the color of the fabric surface affects carbon black's visible light absorption, thereby affecting its photothermal conversion capability. Therefore, the performance of carbon black as an inorganic filler is significantly inferior to that of ZrC.

[0081] By comparing Example 1 with Example 4, and from the data in Table 2 and Table 3: comparison of Lab values ​​and color descriptions, under the same proportion, carbon black as an inorganic filler in the core layer will have a certain impact on the color development of the nano-silicon powder in the skin layer.

[0082] Comparative Example 11: Preparation of ZrC (1%) / PP Fiber and Fabric

[0083] (1) Weigh 500g of polypropylene (PP) slices, place them in a vacuum drum oven, and dry them for later use.

[0084] (2) Weigh 5.0 g of zirconium carbide and 1.5 g of silane coupling agent; soak the inorganic filler zirconium carbide for photothermal conversion in acetone for cleaning, wait for stratification, and place the lower layer of nano-solution in a vacuum oven to dry to constant weight; then prepare a solution of anhydrous ethanol and deionized water in a mass ratio of 1:1, add the coupling agent to prepare a coupling agent solution, adjust the pH to 4 with acetic acid, add the inorganic filler, and ultrasonically oscillate for 30 minutes. The solution after ultrasonication is then stirred at a constant temperature of 80 °C for 2 hours. Finally, the solution is vacuum filtered, washed with acetone three times, and dried to constant weight to obtain the modified zirconium carbide.

[0085] (3) The modified zirconium carbide and PET are mixed evenly (the ratio of the mass fraction of the photothermal conversion inorganic filler to the mass fraction of polyethylene terephthalate is 1:100), and melt-blended and granulated through a twin-screw extruder.

[0086] (4) Melt spinning was performed through a conventional spinning assembly at a spinning temperature of 180 °C, a cold air temperature of 25 °C, a wind speed of 0.4 m / s, and a spinning speed of 1500 m / min to obtain nascent fibers; the nascent fibers were stretched and heat-set in sequence at a stretching temperature of 130 °C, a stretching ratio of 3 times, and a heat-setting temperature of 180 °C to finally obtain PP fibers doped with (1%) modified inorganic fillers with a light gray surface color and a strength greater than 3.0 cN / dtex.

[0087] (5) The obtained PP fibers were drawn and twisted, and then woven into plain fabrics with a warp and weft density of 200 threads / 10 cm using a braiding machine. The thermal management performance of the fabrics was then tested.

[0088] A solar simulator simulated standard sunlight irradiating the fiber, with an initial fabric temperature of -5.0°C and an exposure time of 300 seconds, recorded the surface temperature. Table 1 shows the fabric's light-to-heat conversion data. Within 300 seconds of exposure, the surface temperature of a light-gray fabric rose to 49.8°C. Table 2 shows the Lab values ​​of the fabric's surface color. The Lab values ​​for the light-gray fabric are L: 53.6, a: +0.3, and b: -0.8.

[0089] Example 5: Preparation of Prussian Blue / ZrC (1%) / PP Fiber and Fabric

[0090] This embodiment is based on the process of Comparative Example 11, and adjusts the addition of inorganic pigments to prepare sheath-core fibers, and compares and verifies whether the addition of inorganic pigments affects the light-to-heat conversion capacity of carbon black / inorganic pigments / PP fibers and fabrics.

[0091] (1) Weigh 500g of polypropylene (PP) slices and place them in a vacuum drum oven to dry them for later use.

[0092] (2) Weigh 5.0g zirconium carbide and 1.5g silane coupling agent; first soak the inorganic filler zirconium carbide (ZrC) for photothermal conversion in acetone for cleaning, wait for stratification, and place the lower layer of nano-solution in a vacuum oven to dry to constant weight; then prepare a solution of anhydrous ethanol and deionized water in a mass ratio of 1:1, add the coupling agent to prepare a coupling agent solution, adjust the pH to 4 with acetic acid, add the inorganic filler, and ultrasonically vibrate for 30min. The sonicated solution is then stirred at a constant temperature of 80℃ for 2h. Finally, the solution is vacuum filtered, washed with acetone 3 times, and dried to constant weight to obtain the modified zirconium carbide;

[0093] 5.0 g of nano-Prussian blue particles with a blue surface color were weighed and modified using the same method as that for modifying zirconium carbide to obtain modified nano-Prussian blue.

[0094] (3) The modified zirconium carbide and PP are mixed evenly (the ratio of the mass fraction of zirconium carbide to the mass fraction of polyethylene terephthalate is 1:200), melt-blended and granulated by a twin-screw extruder, and dried to obtain the core layer masterbatch for use;

[0095] The modified nano-Prussian blue was evenly mixed with PP (the ratio of nano-silicon mass fraction to polyethylene terephthalate mass fraction was 1:200), melt-blended and granulated through a twin-screw extruder, and dried to obtain a skin masterbatch for use.

[0096] (4) The sheath-core spinning process was adopted, and the sheath-core spinning assembly was used for coaxial melt spinning. The sheath masterbatch and the core masterbatch were used as the sheath material and the core material respectively. The spinning temperature was 180 °C, the cold blowing temperature during the spinning process was 25 °C, the wind speed was 0.4 m / s, and the spinning speed was 1500 m / min to obtain the nascent fiber; the nascent fiber was stretched and heat-set in sequence, with the stretching temperature being 130 °C, the stretching ratio being 3 times, and the heat setting being 180 °C. Finally, the nano Prussian blue / ZrC (1%) / PP fiber with a blue surface color, a strength greater than 3.0 cN / dtex, and a sheath-core structure was obtained.

[0097] (5) The obtained PP fibers were drawn and twisted, and then woven into plain fabrics with a warp and weft density of 200 threads / 10 cm using a braiding machine. The thermal management performance of the fabrics was then tested.

[0098] A solar simulator simulated standard sunlight irradiating the fiber, with an initial fabric temperature of -5.0°C and an exposure time of 300 seconds, recorded the surface temperature. Table 1 shows the fabric's light-to-heat conversion data. Within 300 seconds of exposure, the surface temperature of a blue fabric rose to 49.4°C. Table 2 shows the Lab values ​​of the fabric's surface color. The Lab values ​​for the blue fabric were L: 59.3, a: -14.4, and b: -40.1.

[0099] By comparing Example 5 with Comparative Example 11, according to the data in Table 1: within the same irradiation time, the temperature difference between the two fabrics does not exceed 1°C, indicating that the high absorption of zirconium carbide in the near-infrared band gives it excellent photothermal conversion ability, and the added near-infrared transparent inorganic pigment (ZrC) does not affect the photothermal conversion ability of the fabric.

[0100] The light-to-heat conversion data, Lab values, and RGB color values ​​of the thermal management fabrics with different component ratios obtained in the above embodiments and comparative examples are summarized in Tables 1, 2, and 3.

[0101] Table 1: Light-to-heat conversion data of thermal management fabrics with different composition ratios

[0102]

[0103] Table 2: Lab values ​​of thermal management fabrics with different composition ratios

[0104]

[0105] Table 3: RGB values ​​of thermal management fabrics with different composition ratios

[0106]

[0107] Although specific embodiments of the present invention are described above, those skilled in the art should understand that these are merely examples and that various changes or modifications may be made to the embodiments without departing from the principles and essence of the present invention. The scope of protection of the present invention is limited only by the appended claims.

Claims

1. A method for preparing a colorful thermal management fiber, characterized in that: The following steps are involved: (1) Inorganic material modification Two inorganic materials, an inorganic filler and an inorganic pigment, are subjected to the following modification treatments, respectively, wherein the inorganic filler is selected from zirconium carbide or titanium carbide, and the inorganic pigment is selected from at least one of silicon nanoparticles with a yellow surface color, nano iron oxide particles with a red surface color, and nano Prussian blue particles with a blue surface color; A coupling agent is added to a mixed solvent of anhydrous ethanol and deionized water to prepare a coupling agent solution, and the pH range is adjusted to 3.0-4.0 with acetic acid to obtain a mixed solution; the inorganic material is soaked and cleaned in acetone, and the mixture is allowed to stand for stratification, and the lower layer of the nano-solution is placed in a vacuum oven and dried to constant weight, and then added to the mixed solution, first dispersed by ultrasonic oscillation, and then stirred at a constant temperature of 70-80° C., and finally vacuum filtered, washed with acetone, and dried to obtain the modified inorganic material; (2) Preparation of core layer and skin layer masterbatch The core layer masterbatch is obtained by melt blending the polymer and the inorganic filler modified according to step (1); the skin layer masterbatch is obtained by melt blending the polymer and the inorganic pigment modified according to step (1); The polymer is selected from polyethylene terephthalate, polyamide, polyphenylene sulfide or polypropylene, and the polymer in the core layer masterbatch and the skin layer masterbatch is the same; (3) Skin-core spinning Coaxial melt spinning is performed using a sheath-core spinning assembly, and the sheath masterbatch and the core masterbatch are extruded from the sheath-core spinning assembly as the sheath material and the core material respectively to obtain spun fibers, which are then stretched and heat-set to obtain thermal management fibers.

2. The method for preparing the colorful thermal management fiber according to claim 1, characterized in that: In step (1), the coupling agent is a silane coupling agent or a titanate coupling agent, and the mass fraction of the coupling agent is 20 to 50% of the mass fraction of the inorganic material.

3. The method for preparing the colorful thermal management fiber according to claim 1, characterized in that: In step (2), a drying step of the polymer is also included before melt blending, which is specifically as follows: The polymer was dried in a vacuum oven at 90°C for 1-2 hours, then dried at 110°C and 130°C for 1-2 hours respectively, and the above operation was repeated several times, and finally dried in a vacuum drum oven at 160°C for 4-6 hours.

4. The method for preparing the colorful thermal management fiber according to claim 1, characterized in that: In step (2), the mass ratio of the inorganic filler in the core layer masterbatch to the polymer is 1:1000 to 1:10, and the mass ratio of the inorganic pigment in the skin layer masterbatch to the polymer is 1:1000 to 1:

10.

5. The method for preparing the colorful thermal management fiber according to claim 1, characterized in that: In step (3), the spinning temperature during the melt spinning process is 180-280° C., the cooling air blowing temperature is 20-30° C., the wind speed is 0.3-0.5 m / s, and the spinning speed is 1500-3000 m / min.

6. The method for preparing the colorful thermal management fiber according to claim 1, characterized in that: In step (3), the stretching temperature is 80-120°C, the stretching ratio is 3-5 times, and the heat setting temperature is 180-220°C.

7. A colorful thermal management fiber, characterized in that: The method is prepared according to any one of claims 1 to 6.

8. A thermal management fabric, characterized in that The colorful thermal management fiber according to claim 7 is used.

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