Preparation method of light-storage thermal-sensation polyester fiber

Abstract

The invention relates to the field of polyester fibers, and particularly discloses a preparation method of a light thermal storage polyester fiber, according to the light thermal storage polyester fiber, uniform distribution of a core layer material and an outer layer material is achieved through a twin-screw extrusion and co-extrusion spinning technology, and the thermal stability of the fiber is improved; and the problem that the nano material with the wide infrared spectrum absorption rate contained in the core layer is easy to fall off is solved under the protection of the outer layer, and meanwhile, the dispersity is improved and the compatibility with a polyester base material is enhanced by treating the nano material. And the outer layer is used for modifying resin to form a structure with higher light absorption capacity, so that the overall photo-thermal conversion efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the field of polyester fibers, and particularly relates to a method for preparing light-heat storage polyester fibers. Background Art

[0002] Light-absorbing, heat-generating fibers primarily utilize far-infrared, visible, and near-infrared radiation from the sun, or from common lighting sources, converting it into heat energy to achieve active warmth and insulation. Their core advantages lie in lightweight warmth: they are lighter than traditional down / cotton and offer higher warmth retention efficiency; and comfort: they are more breathable than moisture-absorbing, heat-generating fibers. Therefore, they hold great promise for applications in clothing insulation, building energy conservation and insulation, and agricultural planting. Currently, light-absorbing, heat-generating fibers mostly use inorganic powders as their photothermal storage materials. For example, patent application CN115074859A discloses a highly efficient heat-generating and heat-insulating composite fiber. This composite fiber converts light energy into heat energy using nano-heating particles. Based on this, a helical structure is created by combining two fibers with different shrinkage rates. For the same length, the helical structured fiber has a larger light-absorbing area and a better heat-generating and heat-insulating effect. Another example, patent CN106939442B blends a thermoplastic elastomer with cellulose acetate butyrate and stretches it into an elastic fiber. Then, an inorganic heat-generating powder is introduced to create a self-heating elastic nanofiber.

[0003] Considering the problems of washing and falling off and uneven dispersion of polyester fibers mixed with inorganic powders, the present invention aims to provide a light-heat storage polyester fiber that is tightly combined and evenly dispersed. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, the present invention improves the textile process to produce a two-layer, light-storage thermal-sensitive polyester fiber. The core layer utilizes nanomaterials with a broad infrared spectrum absorptivity to absorb light and generate heat, while the outer layer protects against the easy shedding of the nanomaterials. Furthermore, the nanomaterials are treated to improve their dispersibility and compatibility with the polyester substrate. Furthermore, the outer layer, through resin modification, creates a structure with enhanced light absorption, thereby improving overall light-to-heat conversion efficiency.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A first aspect of the present invention provides a method for preparing a light-heat storage polyester fiber, comprising the following steps:

[0007] The inner layer polyester and the reactive light-absorbing material are passed through a hopper into a twin-screw extruder for uniform extrusion to obtain an inner layer melt; the modified outer layer polyester is passed through a hopper into a twin-screw extruder for uniform extrusion to obtain an outer layer melt; the inner layer melt and the outer layer melt are respectively quantitatively delivered to the spinning assembly by a metering pump, and finally co-extruded from the spinneret to form filaments, which are cooled by side-blown air and then oiled by an oil roller, and finally wound, and then stretched, oriented and crystallized to obtain the light-heat storage polyester fiber;

[0008] The preparation steps of the reactive light-absorbing material are as follows:

[0009] The powder is preheated in a kneader at 100-130° C., and then a coupling agent is added and stirred for 8-12 minutes. After cooling, a reactive light-absorbing material is obtained.

[0010] Of the solar radiation wavelengths received by Earth, wavelengths less than 400nm belong to the ultraviolet region; 400-700nm is the visible spectrum; and 700-2500nm is the near-infrared region. To enhance the photothermal conversion response, photothermal fibers must efficiently capture solar energy across all wavelengths and rapidly convert it into thermal energy. This invention utilizes a composite melt-spinning technique to produce a photothermal polyester fiber with an inner and outer layer structure. This method simplifies the production process and eliminates the need for solvent addition and recovery. The core layer contains a nanomaterial with broad infrared spectrum absorptivity, protected by the outer layer, which prevents it from easily falling off. Furthermore, the nanomaterial is treated to improve its dispersibility and compatibility with the polyester substrate. The outer layer material maintains excellent transparency, facilitating the core layer's absorption and utilization of light. Furthermore, by optimizing coextrusion technology, the aforementioned two-layer structure can be further enhanced with a specific shape, such as a hollow structure, to further enhance the fiber's thermal insulation and heat storage capacity.

[0011] In some embodiments, the inner layer polyester is any one of PET (polyethylene terephthalate), PTT (polypropylene terephthalate), PBT (polybutylene terephthalate), PLA (polylactic acid), PCL (polycaprolactone), PU (polyurethane), and PEN (polyethylene naphthalate).

[0012] In some embodiments, the coupling agent is any one of a silane coupling agent, a titanate coupling agent, and an aluminate coupling agent.

[0013] Preferably, the coupling agent is an aluminate coupling agent.

[0014] The present invention adopts an aluminate coupling agent to treat the light-absorbing material. The aluminate coupling agent has the advantages of being non-toxic, odorless, environmentally friendly, and having low production costs. Compared with liquid coupling agents such as silane coupling agents and titanate coupling agents that need to be diluted, the aluminate coupling agent can be directly added as a solid. In addition, the aluminate coupling agent has better thermal stability than titanate coupling agents and silane coupling agents, and is convenient for high-temperature processing in a kneader.

[0015] In some embodiments, the coupling agent accounts for 0.5-2% by weight of the powder.

[0016] The present invention controls the amount of coupling agent used to avoid the formation of multi-layer physical adsorption on the surface of the powder, which leads to a decrease in the mechanical properties of the composite material.

[0017] In some embodiments, the powder comprises CuS and Al2O3.

[0018] CuS has a high absorption coefficient and a narrow band gap, efficiently absorbing visible and near-infrared light and converting it into heat. Al2O3 exhibits excellent absorption in the far-infrared region. The combination of CuS and Al2O3 provides enhanced absorption across a wider spectral range. Furthermore, both types of powders are lighter in color than carbon materials, reducing dyeing issues for textiles.

[0019] In some embodiments, the mass ratio of CuS to Al2O3 is 1:(0.8-1.2).

[0020] The present invention achieves light absorption in a wider spectral range by controlling the ratio of CuS and Al2O3, thereby improving the overall light-to-heat conversion efficiency.

[0021] In some embodiments, the modified outer layer polyester is prepared as follows:

[0022] The dried PET and the modifier are mixed in an internal mixer at 250-300°C at a rotation speed of 40-80 r / min. After the torque is stabilized, the material is taken out to obtain the modified outer layer polyester.

[0023] In some embodiments, the mass ratio of the PET to the modifier is 1:(0.5-0.8).

[0024] In some embodiments, the modifying agent comprises PMDA and PBO.

[0025] In some embodiments, the mass ratio of PMDA to PBO is 1:(0.3-0.5).

[0026] The applicant discovered that the synergistic effect of PMDA and PBO can enhance PET's UV absorption capacity, thereby improving the photothermal conversion efficiency of light-storage thermal polyester fibers. This may be due to the fact that both PMDA and PBO contain aromatic ring structures, which enhance intermolecular electron transfer through π-π interactions. This not only improves the material's thermal stability and mechanical properties, but also enhances UV absorption. Furthermore, the simultaneous addition of PMDA and PBO expands PET's conjugated system. The face-to-face interactions between the conjugated planar structures affect the electron transitions in the frontier molecular orbitals, resulting in a red shift in the aggregated state electronic spectrum relative to the theoretical single-molecule chain, thus forming a structure with higher light absorption capacity.

[0027] In some embodiments, the stretching ratio is (2.2-4.2):1.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The twin-screw extrusion and co-extrusion spinning technology is used to achieve uniform distribution of the core layer and outer layer materials, thereby improving the thermal stability of the fiber. In addition, the core layer of the light-storage thermal-sensitive polyester fiber with an inner and outer layer structure contains nanomaterials with a wide infrared spectrum absorption rate, which solves the problem of easy shedding under the protection of the outer layer.

[0030] 2. Nanomaterials with wide infrared spectrum absorption rate use CuS and Al2O3. The combination of the two provides a wider absorption spectrum range. In addition, these two types of powders are lighter in color than carbon materials, which can reduce the dyeing troubles on textiles.

[0031] 3. The surface modification of CuS and Al2O3 by aluminate coupling agent significantly improves their dispersion in the polyester matrix and avoids agglomeration, thereby improving the spinnability of the fiber and ensuring the quality of the final product.

[0032] 4. PMDA and PBO are introduced into the outer polyester system. The aromatic ring structures of PMDA and PBO can enhance the electron transfer ability between molecules through π-π interactions, thereby improving the thermal stability and mechanical properties of the material as well as its ability to absorb ultraviolet rays. At the same time, the addition of PMDA and PBO can expand the conjugated system of PET, and the face-to-face interactions between the conjugated planar structures can affect the electron transition mode of the frontier molecular orbitals, resulting in a red shift in the aggregated state electronic spectrum relative to the theoretical single molecule chain, thereby forming a structure with higher light absorption ability. DETAILED DESCRIPTION

[0033] The present invention will be described below in conjunction with specific embodiments. It should be noted that the following examples are illustrative of the present invention and are intended only to illustrate the present invention and are not intended to limit the present invention. Other combinations and various modifications within the scope of the present invention may be made without departing from the spirit or scope of the present invention.

[0034] It is worth noting that the raw materials used in the following preparation examples and examples, unless otherwise specified, can be obtained from any commercially available manufacturer.

[0035] Preparation Example 1

[0036] The preparation steps of reactive light-absorbing material A are as follows: preheating the powder in a kneader at 110°C, the powder containing CuS and Al2O3 in a mass ratio of 1:1, then adding 1% of the weight of the powder as an aluminate coupling agent JTW-18 and stirring for 10 minutes, and obtaining reactive light-absorbing material A after cooling.

[0037] Preparation Example 2

[0038] The preparation steps of reactive light-absorbing material B are different from those of Preparation Example 1 in that the powder contains CuS and Al2O3 in a mass ratio of 1:0.7.

[0039] Preparation Example 3

[0040] The preparation steps of reactive light-absorbing material C are different from those of Preparation Example 1 in that the powder contains CuS and Al2O3 in a mass ratio of 1:1.3.

[0041] Preparation Example 4

[0042] The preparation steps of the modified outer layer polyester A are as follows: dried PET and a modifier are mixed in a mass ratio of 1:0.65 in an internal mixer at 275°C and a speed of 60 r / min. The modifier contains PMDA and PBO in a mass ratio of 1:0.4. After the torque stabilizes, the material is taken out to obtain the modified outer layer polyester A.

[0043] Preparation Example 5

[0044] The preparation steps of the modified outer layer polyester B are different from those of Preparation Example 4 in that the modifier is PMDA.

[0045] Preparation Example 6

[0046] The preparation steps of the modified outer layer polyester C are different from those of Preparation Example 4 in that the modifier is PBO.

[0047] Example 1

[0048] A method for preparing a light-heat-storage polyester fiber comprises the following steps:

[0049] The inner layer polyester PET and the reactive light-absorbing material A are passed through a hopper into a twin-screw extruder for uniform extrusion to obtain an inner layer melt; the modified outer layer polyester A is passed through a hopper into a twin-screw extruder for uniform extrusion to obtain an outer layer melt; the inner layer melt and the outer layer melt are respectively quantitatively delivered to the spinning assembly by a metering pump, and finally co-extruded from the spinneret to form filaments, which are cooled by side blowing and then oiled by an oil roller, and finally wound, and then stretched (stretching ratio is 3.2:1) for orientation-induced crystallization to obtain light-heat storage polyester fibers.

[0050] Example 2

[0051] This embodiment provides a method for preparing a light-heat-storage polyester fiber. The specific implementation method is the same as that of Example 1, except that the reactive light-absorbing material A is replaced by an equal amount of reactive light-absorbing material B.

[0052] Example 3

[0053] This embodiment provides a method for preparing a light-heat-storage polyester fiber. The specific implementation method is the same as that of Example 1, except that the reactive light-absorbing material A is replaced by an equal amount of reactive light-absorbing material C.

[0054] Example 4

[0055] This embodiment provides a method for preparing a light-heat-storage polyester fiber. The specific implementation method is the same as that of Example 1, except that the modified outer layer polyester A is replaced by an equal amount of modified outer layer polyester B.

[0056] Example 5

[0057] This embodiment provides a method for preparing light-heat storage polyester fiber. The specific implementation method is the same as that of Example 1, except that the modified outer layer polyester A is replaced by an equal amount of modified outer layer polyester C.

[0058] Comparative Example 1

[0059] This comparative example provides a method for preparing a light-storage heat-sensitive polyester fiber. The specific implementation method is the same as that of Example 1, except that the reactive light-absorbing material A is replaced by an equal amount of powder, and the powder contains CuS and Al2O3 in a mass ratio of 1:1.

[0060] Performance testing:

[0061] The fibers provided in Examples 1-5 and Comparative Example 1 were woven into 100×100 mm 2 Fabric, using AAA grade solar simulator, irradiated for 30 minutes and tested the temperature rise value. After removing the light source, the time taken for the temperature to return to the original temperature was recorded. The results are shown in Table 1.

[0062] Table 1 Performance test results

[0063] Temperature rise value (℃) Heating maintenance time (min) Temperature rise after washing 50 times (℃) Example 1 19.3 124 19.1 Example 2 17.7 119 17.6 Example 3 16.4 121 16.4 Example 4 18.2 118 18.0 Example 5 18.5 122 18.5 Comparative Example 1 15.2 113 14.9

[0064] As shown in Table 1, the fabrics woven from the fibers provided in Examples 1-5 and Comparative Example 1 exhibit similar heat-retention durations, demonstrating that the present invention, through process optimization and material improvements, has resulted in fibers with excellent thermal insulation properties. Furthermore, the temperature rise value remained relatively stable after 50 washes, demonstrating that the polyester fibers provided by the present invention address the issue of shedding during washing. The polyester fibers provided in Example 1 exhibited a high temperature rise value and demonstrated excellent light-to-heat conversion efficiency. Compared to Example 1, Examples 2-3 varied the mass ratio of CuS and Al₂O₃ in the reactive light-absorbing material, which partially reduced the temperature rise value. This may be due to the imbalance in light absorption across different spectral ranges caused by the altered ratio of CuS and Al₂O₃. Compared to Example 1, Examples 4-5 modified the outer polyester layer with PMDA and PBO, respectively, affecting the outer polyester's light absorption structure and resulting in a lower temperature rise value. As shown in Example 1 and Comparative Example 1, the absence of coupling agent treatment on the light-absorbing material hinders its uniform distribution, leading to a decrease in light absorption efficiency, as evidenced by a decrease in temperature rise value.

[0065] The embodiments and comparative examples described above do not impose any form of limitation on the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the present profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical content disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a light-heat storage polyester fiber, characterized in that: The following steps are involved: The inner layer polyester and the reactive light-absorbing material are passed through a hopper into a twin-screw extruder for uniform extrusion to obtain an inner layer melt; the modified outer layer polyester is passed through a hopper into a twin-screw extruder for uniform extrusion to obtain an outer layer melt; the inner layer melt and the outer layer melt are respectively quantitatively delivered to the spinning assembly by a metering pump, and finally co-extruded from the spinneret to form filaments, which are cooled by side-blown air and then oiled by an oil roller, and finally wound, stretched, and crystallized by orientation induction to obtain the light-heat storage polyester fiber; The preparation steps of the reactive light-absorbing material are as follows: The powder is preheated in a kneader at 100-130° C., and then a coupling agent is added and stirred for 8-12 minutes. After cooling, a reactive light-absorbing material is obtained.

2. The method for preparing the light-heat storage polyester fiber according to claim 1, characterized in that: The inner layer polyester is any one of PET, PTT, PBT, PLA, PCL, PU, ​​and PEN.

3. The method for preparing the light-heat storage polyester fiber according to claim 1, characterized in that: The coupling agent is any one of a silane coupling agent, a titanate coupling agent, and an aluminate coupling agent.

4. The method for preparing the light-heat storage polyester fiber according to claim 1, characterized in that: The coupling agent accounts for 0.5-2% of the weight of the powder.

5. The method for preparing the light-heat storage polyester fiber according to claim 1, characterized in that: The powder contains CuS and Al2O3.

6. The method for preparing the light-heat storage polyester fiber according to claim 5, characterized in that: The mass ratio of CuS to Al2O3 is 1:(0.8-1.2).

7. The method for preparing the light-heat storage polyester fiber according to claim 1, characterized in that: The preparation steps of the modified outer polyester are as follows: The dried PET and the modifier are mixed in an internal mixer at 250-300°C at a rotation speed of 40-80 r / min. After the torque is stabilized, the material is taken out to obtain the modified outer layer polyester.

8. The method for preparing the light-heat storage polyester fiber according to claim 7, characterized in that: The mass ratio of the PET to the modifier is 1:(0.5-0.8).

9. The method for preparing the light-heat storage polyester fiber according to claim 7, characterized in that: The modifier comprises PMDA and PBO.

10. The method for preparing the light-heat storage polyester fiber according to claim 1, characterized in that: The stretching ratio is (2.2-4.2):1.