A thermal-infrared-resistant heat-insulating fabric and a preparation method thereof

Abstract

The application discloses a kind of heat-preventing infrared heat-insulating fabric and preparation method thereof, belong to textile material technical field, including the fiber base material is placed in plasma processing cavity, sulfur-containing gas is imported, and thiol active site is introduced on the surface of fiber base material, to obtain surface-activated fiber;Surface-activated fiber is immersed in the solution containing double-waveband heat-preventing infrared bifunctional side chain molecule, initiator is added, and by ultraviolet light irradiation or thermal initiation triggers click chemistry reaction, so that the click reaction section of the end of bifunctional side chain molecule and the thiol active site on the surface of fiber base material covalently bond, and double-waveband heat-preventing infrared molecule brush is grafted on the surface of fiber base material, to obtain grafting modification fiber and the like steps.The application solves the problem that traditional physical coating or laminated composite function layer and fiber matrix are only attached by adhesive or van der waals force, which leads to easy peeling, migration and sharp attenuation of infrared performance after multiple washing.

Description

Technical Field

[0001] This invention belongs to the field of textile materials technology, specifically relating to a heat-insulating fabric with infrared protection properties and its preparation method. Background Technology

[0002] With the widespread application of infrared detection technology in military camouflage, outdoor protection, and special clothing, infrared-resistant fabrics have become an important development direction for functional textiles. Existing technologies mainly achieve infrared-resistant functionality by adding low-emissivity fillers, reflective particles, or heat-insulating components to the surface of fibers or fabrics, followed by processes such as physical coating, lamination, or blend spinning.

[0003] However, the aforementioned technical approaches still have significant limitations in terms of functional durability, spectral coverage, and fabric performance. In existing physical coating or lamination processes, the functional materials and fibers adhere solely to adhesives or van der Waals forces, resulting in limited interfacial bonding. This makes them prone to cracking, detachment, or migration during friction, bending, and washing, leading to a rapid decline in infrared thermal protection performance with repeated use, making it difficult to meet long-term service requirements. Furthermore, existing technologies are typically designed for a single infrared band; sun-protective and heat-insulating fabrics emphasize high near-infrared reflectivity, while infrared stealth fabrics emphasize low mid- and far-infrared emissivity. These two functions are independent and incompatible, making it impossible to achieve comprehensive infrared thermal protection coverage across the entire spectrum in a single fabric layer. In addition, physical coatings or lamination require the introduction of additional functional layers, leading to increased fabric thickness, higher areal density, stiffer hand feel, and reduced breathability, thus limiting the application of infrared-protective fabrics in lightweight outdoor clothing and close-fitting gear. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention aims to provide a heat-insulating fabric with infrared protection properties and its preparation method. This solves the problems of easy detachment, migration, and rapid attenuation of infrared performance after repeated washing caused by the functional layer's adhesion to the fiber matrix relying solely on adhesives or van der Waals forces in traditional physical coatings or lamination composites. The specific solution is as follows: In a first aspect, embodiments of this application provide a method for preparing a heat-insulating fabric with infrared protection properties, comprising the following steps: Step 1: Place the fiber substrate in a plasma treatment chamber and introduce sulfur-containing gas to introduce thiol active sites on the surface of the fiber substrate to obtain surface-activated fibers; Step 2: Immerse the surface-activated fiber in a solution containing dual-band thermal infrared-resistant bifunctional side chain molecules, add an initiator, and trigger a click chemical reaction by ultraviolet light irradiation or thermal initiation, so that the click reaction segment at the end of the bifunctional side chain molecule covalently binds to the thiol active site on the surface of the fiber substrate, thereby grafting a dual-band thermal infrared-resistant molecular brush on the surface of the fiber substrate to obtain grafted modified fiber. Step 3: After washing and drying, the grafted modified fibers are warped, woven and heat-set to obtain a heat-insulating fabric with infrared protection properties.

[0005] In one embodiment, the fiber substrate is polyester filament, aramid filament or nylon filament, and the single filament fineness is 50D to 150D.

[0006] In one embodiment, the specific preparation process of the surface-activated fiber is as follows: The fiber substrate is wound onto a porous roller inside a plasma treatment chamber. Sulfur-containing gas is introduced into the chamber, and the surface-activated fiber is obtained by processing under conditions of radio frequency power, chamber vacuum, and gas flow rate.

[0007] In one embodiment, the sulfur-containing gas is a mixture of hydrogen sulfide and argon, and the volume ratio of hydrogen sulfide to argon is 1:8 to 1:10.

[0008] In one embodiment, the radio frequency power is 100W to 300W, the cavity vacuum degree is 10Pa to 50Pa, the gas flow rate is 50sccm to 200sccm, and the processing time is 3min to 10min.

[0009] In one embodiment, the dual-band thermal protection infrared dual-functional side chain molecule is composed of a click reaction segment, a flexible spacer base segment, a near-infrared reflective segment, a mid-far-infrared low emissivity segment, and a thermal insulation segment connected in sequence. The click reaction segment is a maleimide group, allyl group, or vinyl group; The flexible spacer block is a short chain of polyethylene glycol or a short chain of siloxane; Near-infrared reflective segments are organic conjugated segments containing metal oxide coordination structures; The mid- and far-infrared low emissivity segments are organic segments containing metal coordination structures; The heat-insulating and heat-resistant segments are long-chain siloxanes or phase-change alkane segments.

[0010] In one embodiment, the metal oxide in the near-infrared reflective segment is tin-antimony oxide, indium tin oxide, or zinc-aluminum oxide; the metal in the mid- and far-infrared low-emissivity segment is zinc, aluminum, copper, or nickel.

[0011] In one embodiment, in step two, the wavelength of the ultraviolet light irradiation is 365 nm, and the power density is 10 mW / cm². 2 ~50mW / cm 2 The irradiation time is 10 min to 30 min; or the temperature for thermal initiation is 40℃ to 60℃, and the reaction time is 2 h to 6 h.

[0012] In one embodiment, in step three, the weaving is carried out using an air-jet loom or a rapier loom, and the weave structure is plain weave, twill weave, or satin weave; the heat setting temperature is 160℃~180℃, the setting time is 30s~60s, and the overfeed rate is 2%~5%.

[0013] Secondly, embodiments of this application provide a heat-insulating fabric with infrared protection properties, which is prepared by a method for preparing a heat-insulating fabric with infrared protection properties. Beneficial effects

[0014] (1) This invention uses click chemical reaction to covalently bind the click reaction segment at the end of the bifunctional side chain molecule to the thiol active site on the surface of the fiber substrate, and grafts a dual-band thermal infrared protection molecular brush on the surface of the fiber substrate. This solves the problems of easy detachment, migration and sharp decay of infrared performance after multiple washes caused by the functional layer being attached to the fiber substrate by adhesive or van der Waals force alone in traditional physical coating or lamination composites. It achieves the synergy of molecular-level covalent anchoring on the fiber surface and full-band thermal infrared protection function. (2) This invention solves the problem of near-infrared reflection and mid-far-infrared low emissivity segments and heat insulation and heat-resistant segments in the dual-band thermal protection and infrared dual-functional side chain molecules by molecular-level integration of near-infrared reflective segments, mid-far-infrared low emissivity segments and heat insulation and heat-resistant segments in the existing technology by only adding low emissivity particles or heat insulation fillers, and realizes the full-band thermal protection and infrared integration of single fiber surface. (3) This invention solves the problems of heavy, stiff and poor breathability of fabric caused by traditional coating or lamination processes by fiber surface molecular brush grafting and coating-free weaving and shaping, and realizes the preparation of light, thin, soft and breathable heat-resistant infrared insulation fabric. Attached Figure Description

[0015] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, and the advantages of the present invention in the above and / or other aspects will become clearer.

[0016] Figure 1 The preparation process flow diagram provided for this application; Figure 2 The full-band infrared performance comparison chart provided for this application; Figure 3 A schematic diagram comparing the cross-sectional structures of the grafted modified fiber and the conventional coated fiber provided in this application; Figure 4 Near-infrared reflectance comparison chart provided for this application; Figure 5 The mid- and far-infrared emissivity comparison chart provided for this application; Figure 6 A comparison chart of thermal resistance values ​​provided for this application; Figure 7The air permeability comparison chart provided for this application; Figure 8 A comparison diagram of bending lengths provided for this application; Figure 9 A comparison chart showing the performance retention rate after washing provided in this application. Detailed Implementation

[0017] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present application.

[0018] To more clearly illustrate the purpose of this invention, the embodiments of this invention will be described in further detail: Existing infrared heat-resistant fabrics mostly rely on physical coatings or lamination to achieve their function. The coating is only attached to the fiber matrix by adhesives or van der Waals forces, resulting in thick, stiff fabrics with poor breathability. Furthermore, the functional layer is prone to peeling and migration after repeated washing, leading to a sharp decline in infrared performance. Some products only add low-emissivity particles or heat-insulating fillers, failing to achieve synergy between near-infrared reflection and mid-to-far-infrared low emissivity at the molecular level. This makes it difficult to achieve full-band infrared heat protection, and the lack of chemical bonding between the functional layer and the fiber results in insufficient durability.

[0019] To address the aforementioned problems, this invention provides a method for preparing a heat-resistant infrared-insulating fabric. Through fiber surface molecular engineering and click chemistry grafting, a dual-band heat-resistant infrared molecular brush is constructed on the surface of a single fiber, achieving synergy between full-band heat protection and insulation. Simultaneously, covalent bond anchoring enhances durability, eliminating the need for a coating process, resulting in a lightweight, soft, and breathable heat-resistant infrared-insulating fabric. Furthermore, this invention provides a heat-resistant infrared-insulating fabric prepared using a specific method.

[0020] The complete process steps of this application are as follows, corresponding to... Figure 1 The process flow shown is as follows: Step 1: The fiber substrate is placed in a plasma treatment chamber, and a sulfur-containing gas is introduced to introduce thiol-active sites on the surface of the fiber substrate, resulting in surface-activated fibers. The purpose of this step is to introduce thiol-active sites on the fiber surface through low-temperature plasma treatment, providing a reaction basis for subsequent click chemistry grafting. At the same time, the plasma treatment only acts on the fiber surface to a depth of a few nanometers, without damaging the tensile strength and elongation at break of the fiber itself.

[0021] Step Two: Immerse the surface-activated fiber in a solution containing dual-band thermal infrared-resistant bifunctional side-chain molecules. Add an initiator and trigger a click chemistry reaction through ultraviolet light irradiation or thermal initiation. This causes the click reaction segments at the ends of the bifunctional side-chain molecules to covalently bond with the thiol active sites on the fiber substrate surface, forming a dual-band thermal infrared-resistant molecular brush on the fiber substrate surface, resulting in grafted modified fiber. The purpose of this step is to firmly anchor the bifunctional side-chain molecules to the fiber surface through the selective reaction between thiol groups and the click reaction segments, forming a molecular brush layer. Due to the high selectivity of the click chemistry reaction and the absence of byproducts, the specificity and uniformity of the grafting are ensured. After the reaction, the bifunctional side-chain molecules are connected to the fiber through covalent bonds, improving wash fastness.

[0022] Step 3: After washing and drying, the grafted modified fibers are warped, woven, and heat-set to obtain a heat-insulating fabric with infrared protection properties. The purpose of this step is to directly weave the grafted modified fibers into fabric without any coating, lamination, or composite finishing, thus obtaining a heat-insulating fabric with infrared protection properties. Since the functional layer is a molecular brush on the fiber surface rather than a coating sizing agent, the problems of sizing agent shedding, loom contamination, and unclear weft opening that occur during the weaving process, which are common in traditional coated fiber weaving, are avoided.

[0023] In one embodiment, the fiber substrate is polyester filament, aramid filament or nylon filament, and the single filament fineness is 50D to 150D.

[0024] In one embodiment, the specific preparation process of the surface-activated fiber is as follows: a fiber substrate is wound onto a porous roller inside a plasma treatment chamber, a sulfur-containing gas is introduced into the chamber, and the fiber is treated under conditions of radio frequency power, chamber vacuum, and gas flow rate to obtain the surface-activated fiber. The purpose of this specific preparation process is to ensure that all surfaces of the fiber are uniformly exposed to the plasma atmosphere through the rotation of the porous roller, thereby achieving the uniform introduction of thiol-active sites.

[0025] In one embodiment, the sulfur-containing gas is a mixture of hydrogen sulfide and argon, and the volume ratio of hydrogen sulfide to argon is 1:8 to 1:10.

[0026] In one embodiment, the radio frequency power is 100W to 300W, the cavity vacuum degree is 10Pa to 50Pa, the gas flow rate is 50sccm to 200sccm, and the processing time is 3min to 10min.

[0027] In one embodiment, the dual-band thermal protection infrared dual-functional side chain molecule is composed of a click reaction segment, a flexible spacer base segment, a near-infrared reflective segment, a mid- and far-infrared low emissivity segment, and a thermal insulation segment connected in sequence. The purpose of this molecular structure design is to integrate five functional units on the same molecular chain, so that a single molecular brush can simultaneously possess multiple functions such as click reaction activity, flexible connection, near-infrared reflection, mid- and far-infrared low emissivity, and thermal insulation, achieving multiple effects in one chain. In the dual-band thermal protection infrared dual-functional side chain molecule, the mass proportions of each part are as follows: click reaction segment accounts for 5% to 10%, flexible spacer base segment accounts for 20% to 30%, near-infrared reflective chain segment accounts for 25% to 35%, mid- and far-infrared low emissivity chain segment accounts for 20% to 30%, and heat insulation and heat-resistant chain segment accounts for 15% to 25%. The purpose of this proportion design is to balance the grafting stability and functional expression efficiency of the molecular brush. If the proportion of near-infrared reflective chain segment is less than 25%, the near-infrared reflectivity is insufficient. If it is higher than 35%, the molecular chain rigidity is too large, resulting in a hardened fiber feel.

[0028] In one embodiment, the preparation process of the dual-band thermally protective infrared bifunctional side-chain molecule is as follows: The first step is to prepare the click reaction segment and the flexible spacer block: hydroxyl-terminated polyethylene glycol and maleimide propionic acid are esterified under the catalysis of dicyclohexylcarbodiimide and 4-dimethylaminopyridine at a reaction temperature of 25°C for 12 hours to obtain a maleimide-terminated polyethylene glycol monohydroxy compound. This product has a maleimide group at one end, which is the click reaction segment, and the polyethylene glycol chain is the flexible spacer block. The hydroxyl group retained at the end is the active end, and the number average molecular weight is 400 to 1000.

[0029] The second step involves coupling the near-infrared reflective segment: the hydroxyl terminus of the above product is esterified with a carboxyl-containing near-infrared reflective segment precursor under the catalysis of dicyclohexylcarbodiimide and 4-dimethylaminopyridine at 30°C for 8 hours to obtain a triblock intermediate. The near-infrared reflective segment precursor is a tin-antimony oxide functional particle with surface-grafted conjugated double bonds and terminal carboxyl groups. This functional particle is prepared by surface modification of tin-antimony oxide nanoparticles. After the reaction, the triblock intermediate retains the carboxyl groups of the near-infrared reflective segment at its terminal end.

[0030] The third step involves coupling the mid- and far-infrared low-emissivity segments: The terminal carboxyl group of the near-infrared reflective segment of the above-mentioned triblock intermediate is amidated with an amino-containing mid- and far-infrared low-emissivity segment precursor at 0°C to 5°C for 4 hours to obtain a tetrablock intermediate. The mid- and far-infrared low-emissivity segment precursor is a zinc coordination complex with an amino group at its terminal, prepared by complexing zinc acetylacetone with a fluorosiloxane ligand. After the reaction, the tetrablock intermediate retains the amino group of the mid- and far-infrared low-emissivity segment at its terminal.

[0031] Step 4: Coupling the thermal insulation and heat-resistant segment: The terminal amino group of the mid-to-far-infrared low-emissivity segment of the above tetrablock intermediate is reacted with isocyanate-terminated polydimethylsiloxane at 70°C for 3 hours under the catalysis of dibutyltin dilaurate to obtain a complete dual-band thermal infrared-resistant bifunctional side chain molecule. The precursor of the thermal insulation and heat-resistant segment is isocyanate-terminated polydimethylsiloxane.

[0032] After the reaction, the molecules were precipitated, washed, and dried to obtain a dual-band thermal protection infrared bifunctional side chain molecule with a number-average molecular weight of 5,000 to 15,000 and a polydispersity index of 1.2 to 1.8. The molecule is linearly connected in the following order: click reaction segment, flexible spacer block segment, near-infrared reflective segment, mid- and far-infrared low emissivity segment, and thermal insulation segment.

[0033] In one embodiment, the click reaction segment is a maleimide group, allyl group, or vinyl group. The function of this segment is to selectively click with thiol groups on the fiber surface to form stable thioether covalent bonds, firmly anchoring the molecular brush to the fiber surface. The mechanism of the click reaction segment is as follows: the maleimide double bond undergoes a Michael addition reaction with the thiol groups on the fiber surface to form stable thioether bonds with bond energies exceeding 280 kJ / mol, higher than van der Waals forces, ensuring that the molecular brush does not detach during repeated washing and friction. The reaction rate constant is 0.15 L / (mol·s) at 30°C, and the reaction selectivity exceeds 95%, avoiding uneven grafting caused by side reactions.

[0034] In one embodiment, the flexible spacer block is a short-chain polyethylene glycol (PEG) or a short-chain siloxane. The function of this flexible spacer block is to connect the click reaction segment and the functional chain segment, ensuring the softness of the fiber surface after molecular brush grafting and preventing the fiber from becoming stiff due to rigid functional chains. The mechanism of the flexible spacer block is as follows: the PEG or siloxane short chains form a flexible skeleton of the molecular brush on the fiber surface, with the chain length controlled between 10 nm and 25 nm. This length is sufficient to allow the functional chain segment to extend into the external space of the fiber surface, while avoiding intermolecular entanglement and aggregation caused by excessively long chains. The glass transition temperature of the flexible spacer block is lower than room temperature, ensuring that the fabric maintains its softness at room temperature.

[0035] In one embodiment, the near-infrared reflective segment is an organic conjugated segment containing a metal oxide coordination structure. The function of this near-infrared reflective segment is to achieve high reflectivity of near-infrared solar radiation, blocking heat from entering the fabric at its source. The mechanism of the near-infrared reflective segment is as follows: the conjugated double bond structure on the surface of the tin-antimony oxide nanoparticles forms a π-electron delocalization system, generating a plasmonic resonance absorption and re-emission effect in the near-infrared band with wavelengths from 0.75 μm to 1.4 μm, causing incident radiation in this band to be reflected back into external space, with a reflectivity exceeding 80%. Simultaneously, the nanoparticle size is controlled between 20 nm and 50 nm, a size much smaller than the near-infrared wavelength, avoiding energy loss due to Mie scattering.

[0036] In one embodiment, the mid-to-far infrared low emissivity segment is an organic segment containing a metal coordination structure. The function of this mid-to-far infrared low emissivity segment is to form a low emissivity interface in the mid-to-far infrared band, reducing the probability of thermal imaging detection. The mechanism of action of the mid-to-far infrared low emissivity segment is as follows: the energy level difference of the zinc ion d-orbital electron transition in the zinc coordination complex corresponds to the mid-to-far infrared photon energy, forming selective absorption and low emission characteristics; in the 3μm to 5μm and 8μm to 14μm bands, the vibrational rotational energy level transition probability of the zinc coordination structure is low, causing the surface emissivity to drop below 0.40; the introduction of fluorosiloxane ligands further reduces the emission cross-section of the molecular segment in the infrared band.

[0037] In one embodiment, the heat-insulating and heat-resistant segment is a long-chain siloxane or phase-change alkane segment. The function of this segment is to form a thermal barrier on the fiber surface, blocking heat transfer along the fiber's axial and radial directions. The mechanism of action of the heat-insulating and heat-resistant segment is as follows: the large Si-O-Si bond angle and high bond energy in the long-chain siloxane molecular segment result in a low thermal vibration frequency, which scatters heat-conducting phonons, reducing the thermal conductivity coefficient to below 0.15 W / (m·K). Simultaneously, the hydrophobicity and low surface energy of the siloxane segment allow the molecular brush layer to form a dense arrangement on the fiber surface, reducing heat loss through air convection.

[0038] When dual-band thermal and infrared-resistant dual-functional side-chain molecules are grafted onto the fiber surface via click chemistry, the molecular brushes are arranged radially with a grafting density of 0.5 strands / nm. 2 ~2.0 lines / nm 2 At this density, the molecular brush layer thickness is 5nm to 10nm. A synergistic effect is formed between adjacent molecular brush segments. Near-infrared reflective segments form a dense reflective layer facing outward. Mid- and far-infrared low-emissivity segments are distributed below the reflective layer to form a low-emissivity interface. Thermal insulation and heat-resistant segments fill the gaps between the molecular brushes to form a thermal resistance network. The three-layer structure forms a gradient thermal and infrared protection functional layer in the direction perpendicular to the fiber surface.

[0039] In one embodiment, the metal oxide in the near-infrared reflective segment is tin-antimony oxide, indium tin oxide, or zinc-aluminum oxide; the metal in the mid- and far-infrared low-emissivity segment is zinc, aluminum, copper, or nickel.

[0040] In one embodiment, in step two, the wavelength of the ultraviolet light irradiation is 365 nm, and the power density is 10 mW / cm². 2 ~50mW / cm 2 The irradiation time is 10 min to 30 min. Alternatively, the temperature for thermal initiation is 40℃ to 60℃, and the reaction time is 2 h to 6 h.

[0041] In one embodiment, in step three, the weaving is performed using an air-jet loom or a rapier loom, and the weave structure is plain, twill, or satin. The heat setting temperature is 160℃~180℃, the setting time is 30s~60s, and the overfeed rate is 2%~5%.

[0042] Figure 3 This is a schematic diagram comparing the cross-sectional structures of grafted modified fibers and conventional coated fibers. Figure 3 The left image shows grafted modified fibers, with a molecular brush layer grafted onto the outer surface of the fiber substrate. The molecular brush layer is several nanometers thick and is firmly anchored to the fiber substrate through covalent bonds. The right image shows conventional coated fibers, with a physical coating covering the outer surface of the fiber substrate. The physical coating thickness is 20μm to 50μm and is physically attached through van der Waals forces or adhesives. Figure 3 It is known that the thickness of the molecular brush layer of the present invention is only 1 / 1000 to 1 / 100 of the thickness of the physical coating, and chemical anchoring is achieved through covalent bonds, thus solving the problem of easy cracking and peeling of the physical coating.

[0043] Figure 2 This is a comparison chart of full-band infrared performance. Figure 2 The left image shows the reflectance comparison curve for the near-infrared band, and the right image shows the emissivity comparison curve for the mid- and far-infrared bands. Figure 2 It is evident that the fabric of this invention achieves a reflectivity of 82% in the near-infrared band, higher than the 45% of coated fabrics and the 18% of conventional fabrics; while its emissivity in the mid- and far-infrared bands drops to 0.40, lower than the 0.55 of coated fabrics and the 0.88 of conventional fabrics. These results demonstrate that this invention, through the molecular design of the molecular brush layer, simultaneously achieves high near-infrared reflectivity and low mid- and far-infrared emissivity on the surface of a single fiber, overcoming the defect of band segmentation in existing technologies.

[0044] The following detailed description of the method for preparing the heat-insulating fabric with infrared protection of this application is based on specific embodiments. The raw materials in each embodiment all conform to the aforementioned proportion range, and the process steps refer to the aforementioned complete process steps, with only some parameters differing.

[0045] Example 1 The method for preparing a heat-insulating fabric with infrared protection provided in this embodiment includes the following specific steps: Step 1: The fiber substrate is placed in a plasma treatment chamber, and a sulfur-containing gas is introduced to introduce thiol-active sites on the surface of the fiber substrate, resulting in surface-activated fibers. The fiber substrate is polyester filament with a single filament fineness of 75D; the sulfur-containing gas is a mixture of hydrogen sulfide and argon, with a volume ratio of hydrogen sulfide to argon of 1:9; the radio frequency power is 200W, the chamber vacuum degree is 30Pa, the gas flow rate is 100sccm, and the treatment time is 5min.

[0046] Step 2: Immerse the surface-activated fiber in a solution containing dual-band thermal and infrared-resistant bifunctional side-chain molecules, add an initiator, and trigger a click chemical reaction by ultraviolet light irradiation. The wavelength of the ultraviolet light irradiation is 365nm, and the power density is 25mW / cm². 2 The irradiation time was 20 minutes. After the reaction was completed, the fibers were removed, washed, and dried to obtain grafted modified fibers.

[0047] Step 3: After washing and drying, the grafted modified fibers are warped, woven and heat-set. The weaving is done on an air-jet loom with a plain weave structure. The heat-setting temperature is 170℃, the setting time is 45s, and the overfeed rate is 3%, resulting in a heat-insulating fabric with infrared protection properties.

[0048] The preparation steps of Examples 2 to 7 and Comparative Examples 1 to 3 are based on Example 1. Each example changes only one process parameter, while the other parameters are completely consistent with Example 1. The specific differences are shown in Table 1.

[0049] Comparative Example 1 did not undergo plasma treatment or click chemical grafting, Comparative Example 2 did not undergo click chemical grafting, and Comparative Example 3 used the traditional coating method.

[0050] Table 1

[0051] The fabrics prepared in Examples 1 to 7 and Comparative Examples 1 to 3 of this invention were subjected to performance tests. The test indicators included near-infrared reflectance, mid- and far-infrared emissivity, thermal resistance, air permeability, bending length, and performance retention after washing. The results are shown in Table 2. Figures 4-9 .

[0052] Table 2

[0053] Combining the data in Tables 1 and 2, the influence of each parameter on performance can be derived, and the specific analysis is as follows.

[0054] 1. The impact of radio frequency power In Table 1, Examples 2 and 3 only differ in their radio frequency (RF) power: Example 2 uses 100W and Example 3 uses 300W. Other parameters remain the same as Example 1's 200W. Corresponding to the performance data in Table 2: Example 2 has a near-infrared reflectance of 75%, a mid-to-far-infrared emissivity of 0.48, and a thermal resistance of 0.15, lower than Example 1. This is because the lower RF power results in insufficient plasma activation intensity, lower thiol group introduction density, and insufficient grafting density. Example 3 has a near-infrared reflectance of 80% and a mid-to-far-infrared emissivity of 0.42, similar to Example 1 but without significant improvement. Furthermore, at 300W, slight etching may occur on the fiber surface, resulting in a slightly rougher feel. This indicates that 200W is the optimal RF power, balancing activation effect and fiber surface integrity. This improves near-infrared reflectance by 9.3% compared to Example 2 and increases performance retention after washing by 10.6%, achieving a balance between sufficient fiber surface activation and uniform molecular brush grafting.

[0055] 2. Effect of the volume ratio of hydrogen sulfide to argon In Table 1, Examples 4 and 5 only differ in their volume ratio of hydrogen sulfide to argon: Example 4 uses a ratio of 1:8, and Example 5 uses a ratio of 1:10. Other parameters remain the same as Example 1's ratio of 1:9. Table 2 shows that Example 4 has a near-infrared reflectance of 81% and a mid-to-far-infrared emissivity of 0.41, similar to Example 1. The slightly higher proportion of hydrogen sulfide leads to a slightly increased thiol group introduction density, but excessively high concentrations result in a slight decrease in plasma stability. Example 5 has a near-infrared reflectance of 80% and a mid-to-far-infrared emissivity of 0.42, similar to Example 1. The slightly lower proportion of hydrogen sulfide leads to a slightly decreased thiol group introduction density. A 1:9 volume ratio is the optimal balance between plasma stability and thiol group introduction density, resulting in a near-infrared reflectance of 82% and a mid-to-far-infrared emissivity reduced to 0.40. After water washing, the performance retention rate reaches 94%, achieving a synergistic effect between activation efficiency and process stability.

[0056] 3. Effect of ultraviolet power density In Table 1, Examples 6 and 7 only differ in ultraviolet power density; Example 6 has a power density of 10 mW / cm². 2 Example 7 is 50mW / cm 2 Other parameters are the same as those in Example 1, which is 25 mW / cm. 2 Consistent. Table 2 data shows that: Example 6 has a near-infrared reflectance of 78% and a mid-to-far-infrared emissivity of 0.45. Due to the low power density, the click chemical reaction rate is insufficient, and the grafting density is low. Example 7 has a near-infrared reflectance of 83%, a mid-to-far-infrared emissivity of 0.39, a thermal resistance of 0.19, and a performance retention rate of 95% after washing, which is better than Example 1, but 50mW / cm 2 Approaching the initiator's tolerance limit, prolonged irradiation can easily lead to yellowing of the fiber surface. 25mW / cm 2To achieve the optimal ultraviolet power density, the reaction rate and fiber color stability can be balanced, resulting in a near-infrared reflectance of 82%, a mid- and far-infrared emissivity of 0.40, and a performance retention rate of 94% after washing. This achieves a synergy between efficient molecular brush grafting and the preservation of the fiber's intrinsic properties.

[0057] 4. Verification of the necessity of key processes The key processes of this application are omitted in Comparative Examples 1, 2, and 3 in Table 1, and their necessity can be verified by the corresponding performance data in Table 2.

[0058] Comparative Example 1, without plasma treatment and click chemical grafting, had a near-infrared reflectance of 18%, a mid-far-infrared emissivity of 0.88, a thermal resistance of 0.05, and a performance retention rate of 45% after washing. Compared with Example 1, the performance difference was significant, proving that molecular brush grafting on the fiber surface is the core to achieve the thermal infrared protection function. Comparative Example 2 did not undergo click chemical grafting, but only plasma treatment. The near-infrared reflectance was 35%, the mid-far-infrared emissivity was 0.72, the thermal resistance was 0.08, and the performance retention rate after washing was 55%. Due to the lack of a molecular brush layer, there were only a few active sites on the fiber surface, and a dense functional layer could not be formed. This proves that click chemical grafting is a necessary step to achieve full-band thermal infrared protection. Comparative Example 3 uses a traditional coating method, where tin-antimony oxide powder and polyurethane adhesive are mixed to form a coating slurry, which is then applied to the surface of the base fabric. The slurry exhibits a near-infrared reflectance of 45%, a mid-to-far-infrared emissivity of 0.55, a thermal resistance of 0.12, an air permeability of 45, a bending length of 4.8, and a performance retention rate of 60% after washing. Compared to Example 1, Comparative Example 3 shows a reduction in air permeability of over 75%, a more than doubling of bending length, and performance degradation after washing. This demonstrates that the present invention, through covalent anchoring of molecular brushes on the fiber surface, solves the problems of traditional physical coatings being thick, rigid, having poor air permeability, and insufficient durability, achieving a balance between thermal infrared protection and wearability.

[0059] In summary, the specific implementation method of this application, through a complete logical chain of parameter design, performance testing, pattern analysis, and application verification, proves the innovation, stability, and practicality of the process. It not only solves the technical pain points of traditional heat-resistant infrared fabrics, such as single function, thick coating, and poor durability, but also meets the comprehensive requirements of being lightweight, soft, breathable, and washable, and has broad promotional value.

[0060] Finally, it should be noted that the above experimental examples are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred experimental examples, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a heat-insulating fabric with infrared protection properties, characterized in that, Includes the following steps: Step 1: Place the fiber substrate in a plasma treatment chamber and introduce sulfur-containing gas to introduce thiol active sites on the surface of the fiber substrate to obtain surface-activated fibers; Step 2: Immerse the surface-activated fiber in a solution containing dual-band thermal infrared-resistant bifunctional side chain molecules, add an initiator, and trigger a click chemical reaction by ultraviolet light irradiation or thermal initiation, so that the click reaction segment at the end of the bifunctional side chain molecule covalently binds to the thiol active site on the surface of the fiber substrate, thereby grafting a dual-band thermal infrared-resistant molecular brush on the surface of the fiber substrate to obtain grafted modified fiber. Step 3: After washing and drying, the grafted modified fibers are warped, woven and heat-set to obtain a heat-insulating fabric with infrared protection properties.

2. The method for preparing a heat-insulating fabric with infrared protection properties according to claim 1, characterized in that, The fiber substrate is polyester filament, aramid filament or nylon filament, and the single filament fineness is 50D to 150D.

3. The method for preparing a heat-insulating fabric with infrared protection properties according to claim 1, characterized in that, The sulfur-containing gas is a mixture of hydrogen sulfide and argon, and the volume ratio of hydrogen sulfide to argon is 1:8 to 1:

10.

4. The method for preparing a heat-insulating fabric with infrared protection properties according to claim 1, characterized in that, The specific preparation process of the surface-activated fiber is as follows: The fiber substrate is wound onto a porous roller inside a plasma treatment chamber. Sulfur-containing gas is introduced into the chamber, and the surface-activated fiber is obtained by processing under conditions of radio frequency power, chamber vacuum, and gas flow rate.

5. The method for preparing a heat-insulating fabric with infrared protection properties according to claim 4, characterized in that, The radio frequency power is 100W to 300W, the cavity vacuum degree is 10Pa to 50Pa, the gas flow rate is 50sccm to 200sccm, and the processing time is 3min to 10min.

6. The method for preparing a heat-insulating fabric with infrared protection properties according to claim 1, characterized in that, The dual-band thermal protection infrared dual-functional side chain molecule is composed of a click reaction segment, a flexible spacer base segment, a near-infrared reflective chain segment, a mid-far-infrared low emissivity chain segment, and a thermal insulation chain segment connected in sequence. The click reaction segment is a maleimide group, allyl group, or vinyl group; The flexible spacer block is a short chain of polyethylene glycol or a short chain of siloxane; The near-infrared reflective chain segment is an organic conjugated chain segment containing a metal oxide coordination structure; The mid- and far-infrared low emissivity segment is an organic segment containing a metal coordination structure; The heat-insulating and heat-resistant segments are long-chain siloxanes or phase-change alkane segments.

7. The method for preparing a heat-insulating fabric with infrared protection according to claim 6, characterized in that, The metal oxide in the near-infrared reflective segment is tin-antimony oxide, indium tin oxide, or zinc-aluminum oxide; the metal in the mid- and far-infrared low-emissivity segment is zinc, aluminum, copper, or nickel.

8. The method for preparing a heat-insulating fabric with infrared protection properties according to claim 1, characterized in that, In step two, the wavelength of the ultraviolet light irradiation is 365 nm, and the power density is 10 mW / cm². 2 ~50mW / cm 2 The irradiation time is 10 min to 30 min; or the temperature of the heat initiation is 40℃ to 60℃, and the reaction time is 2 h to 6 h.

9. The method for preparing a heat-insulating fabric with infrared protection properties according to claim 1, characterized in that, In step three, the weaving is carried out using an air-jet loom or a rapier loom, and the weave structure is plain weave, twill weave, or satin weave; the heat setting temperature is 160℃~180℃, the setting time is 30s~60s, and the overfeed rate is 2%~5%.

10. A heat-insulating fabric with infrared protection properties, characterized in that, It is prepared by the method for preparing a heat-insulating fabric with infrared protection as described in any one of claims 1 to 9.

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