A composite phase change fiber fabric

Abstract

This invention relates to the technical field of composite fiber fabrics, and in particular to a composite phase change fiber fabric comprising a five-layer structure stacked sequentially. The surface layer is a twisted fabric composed of plant-derived cellulose aerogel, organic phase change microcapsules, ultrafine denier polyester matrix, and carbon-based conductive material. Through chemical bonding, gradient distribution, and biomimetic structural design, this invention systematically solves the technical bottlenecks of traditional phase change materials, such as easy degradation of heat storage performance, difficulty in balancing moisture permeability and heat preservation, and easy peeling of functional layers. Its multi-level synergistic effect provides an innovative solution for intelligent temperature-regulating clothing that combines high stability, wearing comfort, and environmental adaptability, significantly superior to existing single-function or simple composite fabrics.

Description

Technical Field

[0001] This invention belongs to the technical field of composite fiber fabrics, and more specifically, relates to a composite phase change fiber fabric. Background Technology

[0002] With the development of smart wearable devices, traditional phase change temperature regulating materials face three major technical bottlenecks: First, physical mixing between phase change materials (such as paraffin) and the matrix can easily lead to phase separation and leakage. Second, there is an inherent contradiction between moisture permeability and heat preservation performance. Conventional waterproof and breathable membranes (such as PTFE membranes) have insufficient moisture permeability in high temperature and high humidity environments, while increasing porosity can lead to increased infrared radiation heat dissipation. Third, the introduction of conductive functional layers often damages the integrity of the fabric structure.

[0003] Therefore, there is an urgent need to develop a multifunctional composite fiber fabric that combines high phase change enthalpy retention, synergistic enhancement of moisture permeability and heat insulation, and deformable conductive network. Summary of the Invention

[0004] The purpose of this invention is to provide a composite phase change fiber fabric to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A composite phase change fiber fabric comprises a five-layer structure stacked sequentially: a surface layer, a twisted fabric composed of plant-derived cellulose aerogel, organic phase change microcapsules, ultrafine denier polyester matrix, and carbon-based conductive material, wherein the raw material mass ratio is: 30-35 parts plant-derived cellulose aerogel, 20-25 parts organic phase change microcapsules, 40-50 parts ultrafine denier polyester matrix, and 3-5 parts carbon-based conductive material; a bonding layer, a thermoplastic polyurethane adhesive layer with a sesame seed dot open-pore structure, the open pores penetrating the surface layer and the functional layer; a functional layer, a waterproof and breathable microporous membrane comprising TPU, PU, ​​and PTFE; a cushioning layer, a breathable polyurethane layer with a diamond-shaped mesh structure; and an inner layer, a moisture-wicking, quick-drying, tear-resistant polyester taffeta fabric.

[0007] It should be noted that the plant-derived cellulose aerogel in the surface layer forms a three-dimensional network framework to provide heat storage space. The phase change microcapsules are fixed in the pores of the three-dimensional network framework by chemical bonding. The carbon-based conductive material is coated on the surface of the ultrafine denier polyester fiber in an axial gradient form to form a conductive network, thus constituting the photothermal conversion layer. The sesame-dot pores in the bonding layer ensure unobstructed moisture permeability channels. The functional layer accelerates moisture discharge through capillary effect. The diamond-shaped mesh in the buffer layer maintains vapor permeability under pressure. The rough surface of the inner layer enhances the wicking effect.

[0008] In a further technical solution, the plant-derived cellulose aerogel is a three-dimensional network skeleton formed by high-pressure homogenization and defibraging of bamboo fibers, with 3-aminopropyltriethoxysilane grafted onto the inner surface of the pores.

[0009] It should be noted that high-pressure homogenization breaks down bamboo fibers into nanofibers. The amino group of the silane coupling agent (such as 3-aminopropyltriethoxysilane) provides the reaction site, and the carboxyl group of the carboxylated silica shell (phase change microcapsule) serves as the coupling target. The amino group (-NH2) of the silane coupling agent undergoes a condensation reaction with the carboxyl group (-COOH) of the phase change microcapsule shell to form an amide bond (-CONH-).

[0010] In a further technical solution, the organic phase change microcapsule has a core-shell structure, with the core being n-octadecane and the shell being carboxylated hollow mesoporous silica.

[0011] It should be noted that the mesoporous shell allows the phase change material to expand in volume, and the amino groups of the silane coupling agent and the carboxyl groups of the microcapsule shell form amide bonds through a condensation reaction.

[0012] In a further technical solution, the carbon-based conductive material comprises graphene-coated carbon fibers that are distributed in an axial gradient on the surface of polyester fibers.

[0013] It should be noted that gradient coverage avoids breakage of the conductive network, and high coverage at both ends enhances the electrode effect.

[0014] In a further technical solution, the ultrafine denier polyester matrix is ​​a cross-shaped cross-section fiber with a nanoscale groove structure on its surface.

[0015] It should be noted that the groove structure increases the specific surface area, guiding the aerogel to fill in a specific direction through capillary action.

[0016] A further technical solution is that the sesame seed dot opening structure of the bonding layer includes a main hole and an auxiliary hole, the main hole diameter is 80-120μm, the auxiliary hole diameter is 20-50μm, and the ratio of the number of main holes to auxiliary holes is 1:3.

[0017] It should be noted that the main hole maintains the moisture permeability, while the auxiliary hole prevents interlayer delamination caused by stress concentration.

[0018] In a further technical solution, the PTFE nanofibers in the functional layer are radially interwoven into the TPU / PU matrix to form tortuous moisture-permeable channels.

[0019] It should be noted that the radial arrangement forms a labyrinthine moisture permeability path, while simultaneously blocking the penetration of liquid water.

[0020] In a further technical solution, the buffer layer has permeable micropores at the rhomboid grid nodes, with a pore size of 30-50μm.

[0021] In a further technical solution, the inner layer of polyester tar fabric is subjected to plasma etching treatment to form a multi-level rough structure on the surface.

[0022] It should be noted that the multi-level rough structure accelerates sweat diffusion by increasing the specific surface area and the number of capillaries.

[0023] In a further technical solution, the waterproof and breathable microporous membrane of the functional layer also contains uniformly dispersed infrared reflective particles, which are a core-shell composite of titanium dioxide and zinc oxide.

[0024] It should be noted that after the surface carbon-based conductive material converts light energy into heat energy, the titanium dioxide / zinc oxide core-shell particles in the functional layer enhance the thermal insulation in the following ways: the titanium dioxide core reflects the long-wave infrared radiation emitted by the human body, while the zinc oxide shell absorbs and scatters the medium and short-wave infrared radiation, forming a thermal radiation barrier. The high-concentration gradient design of the surface layer preferentially reflects the cold radiation from the external environment.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] High heat storage and washability are achieved through the stable immobilization of phase change microcapsules using a three-dimensional network framework of plant-derived cellulose aerogel and chemical bonding technology. Compared with traditional physical adsorption methods, this invention significantly improves the interfacial bonding strength, enabling the material to maintain excellent heat storage performance even after repeated washing, thus solving the technical problems of easy detachment and rapid performance degradation of traditional phase change materials.

[0027] The invention achieves a breakthrough balance between moisture permeability and thermal insulation through a unique moisture-permeable channel design and a gradient distribution of infrared reflective particles within the functional layer. Compared to conventional waterproof and breathable membranes, this invention can efficiently expel moisture while effectively blocking internal and external heat radiation, thus realizing dynamic thermal comfort regulation in hot and humid environments.

[0028] The deformable design of the conductive network and the innovative gradient conductive network construction strategy endow the material with excellent flexibility and deformation adaptability. Under dynamic usage scenarios such as stretching and bending, the conductivity is stable and reliable. At the same time, it works synergistically with the photothermal conversion layer to significantly improve energy utilization efficiency and overcome the shortcomings of traditional conductive fabrics that are stiff and easily damaged.

[0029] The multi-layered structure achieves synergistic effects through a five-layer composite structure from the outer layer to the inner layer. The biomimetic design enables functional synergy: the open design of the bonding layer enhances the interlayer bonding force and avoids clogging of the moisture-permeable channels; the mesh structure of the buffer layer maintains breathability under pressure and improves wearing comfort; and the micro-nano rough surface of the inner layer accelerates sweat wicking and avoids a damp feeling against the skin.

[0030] This invention systematically solves the technical bottlenecks of traditional phase change materials, such as easy decay of heat storage performance, difficulty in balancing moisture permeability and heat preservation, and easy peeling of functional layers, through chemical bonding, gradient distribution and biomimetic structural design. Its multi-level synergistic effect provides an innovative solution for intelligent temperature-regulating clothing that combines high stability, wearing comfort and environmental adaptability, which is significantly better than existing single-function or simple composite fabrics. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0033] Figure 1 This is a comparison chart of the test results of the phase transition enthalpy of Examples 1-3 and Comparative Examples 1-4 in this invention;

[0034] Figure 2 This is a comparison chart of the test results of moisture permeability of Examples 1-3 and Comparative Examples 1-4 in this invention;

[0035] Figure 3 This is a comparison chart of the test results of conductivity in Examples 1-3 and Comparative Examples 1-4 of the present invention;

[0036] Figure 4 This is a comparison chart of the test results of infrared reflectivity of Examples 1-3 and Comparative Examples 1-4 in this invention;

[0037] Figure 5 This is a comparison chart of the test results of wash resistance retention rate between Examples 1-3 and Comparative Examples 1-4 in this invention;

[0038] Figure 6 This is an electron microscope image of the organic phase change microcapsules in this invention;

[0039] Figure 7 This is an electron microscope image of the three-dimensional network skeleton formed by high-pressure homogenization and defiberization of bamboo fibers in this invention. Detailed Implementation

[0040] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0041] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0042] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0043] I. The preparation process of the surface layer is as follows:

[0044] Step 1: Preparation of plant-derived cellulose aerogels

[0045] Raw material processing: Bamboo fiber was treated with 5wt% NaOH solution at 80℃ for 2 hours to remove lignin;

[0046] High-pressure homogenization and fiber decomposition: The treated bamboo fibers are dispersed in deionized water (solid content 1wt%) and homogenized 10 times at 150MPa to obtain a nanofiber suspension;

[0047] Freeze-drying: Pre-freeze at -50℃ for 24 hours, then freeze-dry under vacuum for 48 hours to obtain a three-dimensional network aerogel;

[0048] Silane coupling agent grafting: The aerogel was immersed in a 3-aminopropyltriethoxysilane / ethanol solution (concentration 5wt%), reacted at 60℃ for 6h, and then washed and dried.

[0049] Step 2: On the synthesis of organic phase change microcapsules

[0050] Core preparation: n-octadecane and Span80 emulsifier (mass ratio 95:5) are melt-mixed at 70℃ and ultrasonically emulsified (power 300W, 10min) to form an O / W emulsion;

[0051] Shell coating: Tetraethyl orthosilicate (TEOS) and carboxylated silane coupling agent (molar ratio 3:1) were added to the emulsion, the pH was adjusted to 9, hydrolysis and condensation were carried out at 60℃ for 6 h, and centrifugation and washing were performed to obtain carboxylated silica shell microcapsules.

[0052] Step 3: Pretreatment of Ultrafine Denier Polyester Matrix

[0053] Fiber modification: Cross-shaped cross-section ultrafine denier polyester (0.8D) is plasma treated (power 100W, time 3min) to form nanogrooves on the surface;

[0054] Carbon-based conductive material coating: Graphene / carbon fiber dispersion (graphene content 30wt%) is coated in a gradient coating process (0.5mg / cm² at the center, increasing to 1.2mg / cm² at both ends).

[0055] Step 4: The lamination process for the outer fabric is as follows:

[0056] Blended spinning: Aerogel (30-35 parts), microcapsules (20-25 parts), ultrafine denier polyester (40-50 parts) and carbon-based materials (3-5 parts) are mixed according to the formula and melt-spun through a twin-screw extruder (temperature 250℃).

[0057] Warp and weft twisting: 2 / 2 twill weave, warp density 80 yarns / cm, weft density 60 yarns / cm, twist number 800 twists / m.

[0058] Example 1, Components for preparing the surface layer:

[0059] The aerogel (30 parts), organic phase change microcapsules (20 parts), ultrafine denier polyester (40 parts) and carbon-based material (3 parts) are mixed according to the formula and melt-spun through a twin-screw extruder.

[0060] Example 2, Components for preparing the surface layer:

[0061] The aerogel (33 parts), organic phase change microcapsules (23 parts), ultrafine denier polyester (45 parts) and carbon-based material (4 parts) were mixed according to the formula and melt-spun through a twin-screw extruder.

[0062] Example 3, Components for preparing the surface layer:

[0063] The aerogel (35 parts), organic phase change microcapsules (25 parts), ultrafine denier polyester (50 parts) and carbon-based material (5 parts) are mixed according to the formula and melt-spun through a twin-screw extruder.

[0064] Comparative Example 1: Components for preparing the surface layer:

[0065] The aerogel (28 parts), organic phase change microcapsules (20 parts), ultrafine denier polyester (40 parts) and carbon-based material (3 parts) are mixed according to the formula and melt-spun through a twin-screw extruder.

[0066] Comparative Example 2: Components for preparing the surface layer:

[0067] The aerogel (30 parts), organic phase change microcapsules (18 parts), ultrafine denier polyester (40 parts) and carbon-based material (3 parts) are mixed according to the formula and melt-spun through a twin-screw extruder.

[0068] Comparative Example 3: Components for preparing the surface layer:

[0069] The aerogel (30 parts), organic phase change microcapsules (20 parts), ultrafine denier polyester (55 parts) and carbon-based material (3 parts) are mixed according to the formula and melt-spun through a twin-screw extruder.

[0070] Comparative Example 4: Components for preparing the surface layer:

[0071] The aerogel (30 parts), organic phase change microcapsules (20 parts), ultrafine denier polyester (40 parts) and carbon-based material (6 parts) are mixed according to the formula and melt-spun through a twin-screw extruder.

[0072] II. The preparation process of the bonding layer is as follows:

[0073] Material: Thermoplastic polyurethane (TPU, melt index 15g / 10min);

[0074] Opening molding: TPU melt is calendered through a template (temperature 180℃). The template is designed with main holes (Φ100μm) and auxiliary holes (Φ35μm), with a hole density of main:auxiliary = 1:3.

[0075] Lamination: The surface layer and the functional layer are bonded together by hot pressing (pressure 0.5MPa, temperature 160℃, time 30s).

[0076] III. The functional layer fabrication process is as follows:

[0077] Matrix blending: TPU / PU (mass ratio 7:3) blended with PTFE nanofibers (10wt%);

[0078] Radial arrangement: PTFE fibers are radially distributed through electrospinning (voltage 25kV, receiving distance 15cm);

[0079] Infrared particle dispersion: Titanium dioxide / zinc oxide core-shell particles (particle size 80nm, shell thickness 15nm) are incorporated into the film layer at a gradient concentration (7wt% for the surface layer and 4wt% for the bottom layer).

[0080] Microporous molding: A moisture-permeable channel with a pore size of 0.1-0.3μm is formed by using a phase separation method (coagulation bath is water / ethanol=1:1).

[0081] IV. The preparation process of the buffer layer is as follows:

[0082] Diamond mesh forming: A diamond mesh (side length 2mm, line width 0.2mm) is formed by laser engraving of breathable polyurethane (breathability 8000g / (m²·24h)).

[0083] Microhole fabrication: Laser drilling at grid nodes (hole diameter 40μm, density 50 holes / cm²).

[0084] V. The preparation process of the inner layer is as follows:

[0085] Fabric treatment: Polyester Kelp fabric (weight 150g / m²) is etched by argon plasma (power 150W, time 5min) to form primary pits (depth 1.5μm, Φ4μm) and secondary protrusions (height 300nm, spacing 80nm).

[0086] Tear resistance treatment: Impregnated with polyurethane coating (10% solid content), the tear strength is increased to 45N after drying (GB / T3917.3).

[0087] Comparison of data between surface layer examples 1-3 and comparative examples 1-4:

[0088] Performance testing standards

[0089] Performance test results:

[0090] Data Analysis:

[0091] 1. Validation of group allocation ratio optimization

[0092] Phase transition enthalpy: Examples 1-3 are all >175J / g, while Comparative Examples 1-3 have a significantly lower phase transition enthalpy (↓10%-18%) due to the imbalance of component ratio, proving that 30-35 parts of aerogel and 20-25 parts of microcapsules in the claims are the optimal range.

[0093] Moisture permeability: Comparative Example 3 (excessive ultrafine denier polyester matrix) showed a sharp drop in moisture permeability of 32%, indicating that 40-50 parts of ultrafine denier polyester matrix can balance structural strength and porosity.

[0094] 2. Functional layer synergy

[0095] Infrared reflectivity: Examples 1-3 are all >85%, due to the gradient distribution of core-shell particles achieving bidirectional thermal radiation blocking (human body + environment).

[0096] Conductivity: Comparative Example 4 (excess carbon-based material) showed high conductivity, but deteriorated moisture permeability and washability, verifying that 3-5 parts were the critical value for balancing photothermal conversion and moisture permeability.

[0097] 3. Key factors for durability

[0098] Wash resistance: The wash resistance retention rates of Examples 1-3 are >90%, which is significantly higher than that of the comparative examples (76-88%). This is mainly attributed to: chemical bonding (amide bonds) preventing microcapsule detachment and gradient conductive network avoiding stress concentration and breakage.

[0099] The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and to design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A composite phase change fiber fabric, characterized in that, It includes a five-layer structure stacked sequentially. The surface layer is a twisted fabric composed of plant-derived cellulose aerogel, organic phase change microcapsules, ultrafine denier polyester matrix, and carbon-based conductive material. The raw material mass ratio is as follows: 30-35 parts plant-derived cellulose aerogel, 20-25 parts organic phase change microcapsules, 40-50 parts ultrafine denier polyester matrix, and 3-5 parts carbon-based conductive material. The carbon-based conductive material includes graphene-coated carbon fibers that are distributed in an axial gradient on the surface of the polyester fibers. A bonding layer, a thermoplastic polyurethane adhesive layer with a sesame seed dot open-cell structure, wherein the open cells penetrate the surface layer and the functional layer; The functional layer comprises a waterproof and breathable microporous membrane made of TPU, PU, ​​and PTFE. Buffer layer, a breathable polyurethane layer with a diamond-shaped grid structure; Inner layer: moisture-wicking, quick-drying, tear-resistant polyester PVC fabric.

2. The composite phase change fiber fabric as described in claim 1, characterized in that: The plant-derived cellulose aerogel is a three-dimensional network skeleton formed by high-pressure homogenization and defibrillation of bamboo fibers, with 3-aminopropyltriethoxysilane grafted onto the inner surface of the pores.

3. The composite phase change fiber fabric as described in claim 1, characterized in that: The organic phase change microcapsules have a core-shell structure, with the core being n-octadecane and the shell being carboxylated hollow mesoporous silica.

4. The composite phase change fiber fabric as described in claim 1, characterized in that: The ultrafine denier polyester matrix is ​​a cross-shaped cross-section fiber with a nanoscale groove structure on its surface.

5. The composite phase change fiber fabric as described in claim 1, characterized in that: The sesame seed dot opening structure of the bonding layer includes main holes and auxiliary holes. The main holes have a diameter of 80-120μm, and the auxiliary holes have a diameter of 20-50μm. The ratio of the number of main holes to auxiliary holes is 1:

3.

6. The composite phase change fiber fabric as described in claim 1, characterized in that: In the functional layer, PTFE nanofibers are radially interwoven into the TPU / PU matrix to form tortuous moisture-permeable channels.

7. The composite phase change fiber fabric as described in claim 1, characterized in that: The buffer layer has permeable micropores at the diamond-shaped grid nodes, with a pore size of 30-50μm.

8. The composite phase change fiber fabric as described in claim 1, characterized in that: The inner layer of polyester woven fabric is plasma etched to form a multi-level rough structure on the surface.

9. The composite phase change fiber fabric as described in claim 1, characterized in that: The waterproof and breathable microporous membrane of the functional layer also contains uniformly dispersed infrared reflective particles, which are a core-shell composite of titanium dioxide and zinc oxide.

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