Thermal imaging and far infrared prevention fabric and preparation method thereof

Abstract

The invention relates to the technical field of textile materials, in particular to a thermal imaging and far infrared prevention fabric and a preparation method thereof.The fabric comprises a three-layer structure, the first layer is a base material bottom layer, the second layer is a reinforcing framework layer, and the third layer is a low-emissivity surface layer; the base material bottom layer comprises modified aramid fiber, the two sides of the modified aramid fiber are coated with low-emissivity slurry, and the low-emissivity slurry comprises nickel micro powder modified resin; the reinforced skeleton layer comprises a carbon fiber yarn and pre-oxidized fiber blend, and a conductive layer is attached to the surface of the carbon fiber yarn; the low-emissivity surface layer comprises nickel micro powder modified resin and ceramic micro powder. The preparation method of the fabric comprises the following steps: modifying the aramid fibers, pretreating the carbon fibers and the pre-oxidized fibers, coating by using low-emissivity slurry, bonding, and then carrying out hot press molding. The fabric can reflect 90% of radiant heat, and the emissivity lt of the spectrum at the wave band of 8-14 microns is achieved; the cable has excellent thermal imaging and far infrared prevention functions, has a flame retardant grade V0, and is suitable for various civil scenes.

Description

Technical Field

[0001] This invention relates to the field of textile materials technology, specifically to a heat-resistant, imaging-protective, far-infrared fabric and its preparation method. Background Technology

[0002] Currently, materials used for heat radiation protection offer good shielding against visible and near-infrared light. However, as thermal infrared detection technology matures, some textile fabrics with some heat-resistant infrared properties still have many shortcomings in blocking far-infrared rays. Their shielding effect is short-lived, their practicality is poor, and they are unsuitable for military camouflage, aerospace heat shielding, or thermal insulation protection requirements in specialized industries. Achieving good far-infrared shielding primarily involves reducing the infrared radiation characteristics of the target. Low-emissivity materials, a type of low-infrared radiation material, can reduce the infrared emissivity and infrared radiation characteristics of the target surface, making it less susceptible to detection and identification by infrared detection systems, thus achieving good thermal imaging protection and far-infrared shielding. Summary of the Invention

[0003] The purpose of this invention is to provide a heat-resistant, imaging-resistant, far-infrared fabric and its preparation method, so as to solve the problems mentioned in the background art.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A heat-resistant, imaging-protective, far-infrared fabric comprises a three-layer structure: a first layer is a substrate bottom layer, a second layer is a reinforcing skeleton layer, and a third layer is a low-emissivity surface layer. The substrate bottom layer comprises modified aramid fibers, both sides of which are coated with a low-emissivity slurry, the low-emissivity slurry comprising nickel micronized modified resin. The reinforcing skeleton layer comprises a blend of carbon fiber filaments and pre-oxidized filaments, the surface of which is coated with a conductive layer. The low-emissivity surface layer comprises nickel micronized modified resin and ceramic micronized powder.

[0005] The ceramic micro powder includes silicon carbide, boron nitride, or zirconium oxide. The ceramic micro powder is uniformly dispersed in the nickel micro powder modified resin, and the mass of the ceramic micro powder is 3% to 6% of the nickel micro powder modified resin.

[0006] The three-layer structure consists of a substrate bottom layer, a reinforcing skeleton layer, and a low emissivity surface layer from the inside out. The three-layer structure is formed by hot pressing, and the nickel micropowder modified resin permeates into the gaps between the modified aramid fibers.

[0007] The nickel micropowder modified resin is prepared by the following method: S1. Nickel-plated carbon fiber powder, nano copper powder, silver paste, flame retardant, and dispersant are ground and stirred at high speed in butyl ester solvent at a mass ratio of 6:3:1:0.5:0.2. After stirring evenly, acrylic resin is added to obtain a mixture, with the acrylic resin accounting for 50% of the mixture by mass. The mixture is stirred for 1 hour using a high-speed planetary mixer. After stirring evenly, the mixture is put into a horizontal sand mill for high-speed grinding for 1 hour. The ground slurry is then put into a three-roll mill for further grinding until the diameter of the solid particles is 1~5μm. The mixture is stirred evenly to obtain nickel micro powder slurry. S2. Polycarbonate-type polyurethane or fluorocarbon resin as the resin matrix is ​​dissolved in N,N-dimethylformamide, and a UV absorber pre-dissolved in a 10% mixed solvent of toluene and methyl ethyl ketone is added. Then, a defoamer is added, and the mixture is stirred until homogeneous to obtain a resin emulsion. The amounts of the UV absorber and defoamer are 0.15% and 0.1% of the resin matrix mass, respectively. S3. Mix the nickel micron powder slurry and the resin emulsion. The solid content in the nickel powder slurry is 15% to 20% of the main body of the resin. Disperse the mixture at a high speed of 1500 r / min for 15 minutes until it becomes a stable suspension to obtain nickel micron powder modified resin.

[0008] Wherein, the flame retardant in S1 includes nitrogen-phosphorus flame retardants, and the dispersant includes fatty acid dispersants; The ultraviolet absorber in S2 includes UV-531, and the defoamer includes polysiloxanes.

[0009] This invention also provides the following technical solution: a method for preparing a heat-resistant, imaging-resistant, far-infrared fabric, comprising the following steps: The first step is to treat the aramid fiber with oxygen plasma at a power of 300W for 30 minutes to obtain modified aramid fiber. The second step is to pre-oxidize the pre-oxidized fiber at 280°C to deposit a nano-silver layer on the surface of the carbon fiber as a conductive layer. The third step involves coating the modified aramid fiber with nickel micropowder modified resin as a low emissivity slurry and curing it at 120°C to obtain the substrate bottom layer. The thickness of a single layer of the low emissivity slurry is 100μm. The pre-oxidized filament and carbon fiber filament blend treated in the second step are then covered on the upper layer of the low emissivity slurry to form a reinforcing skeleton layer. The nickel micropowder modified resin with dispersed ceramic micropowder is coated on top of the reinforcing skeleton layer as a low emissivity surface layer. The fourth step involves hot-pressing the product from the third step at 180°C and 10MPa to obtain the heat-resistant imaging and far-infrared-proof fabric.

[0010] The method for depositing the nano-silver layer in the second step specifically includes the following steps: The carbon fiber filaments were soaked in acetone solvent for 10-15 minutes to remove impurities, then air-oxidized at 50°C for 8 minutes, then immersed in a solution of silver nanoparticles mixed with silver nitrate and glucose, reacted at 60-70°C for 12 minutes, washed, dried at 60-70°C for 16 minutes, and then heat-treated at 100-150°C for 5 minutes.

[0011] In the third step, the pre-oxidized yarn and carbon fiber yarn blend is covered by weft knitting.

[0012] Due to the adoption of the above technical solution, the technical progress achieved by this invention compared to the prior art is as follows: 1. Oxygen plasma treatment of aramid fibers introduces polar groups such as hydroxyl and carboxyl groups on their surface, which improves the resin bonding force and enhances the interfacial adhesion between the subsequent resin slurry and the fiber, preventing the low emissivity slurry from falling off.

[0013] 2. The pre-oxidation treatment of the pre-oxidized fiber increases the limiting oxygen index to over 45, enhancing its high temperature resistance, up to 1200℃. A nano-silver layer is attached to the surface of the carbon fiber fiber to form a conductive network, which can assist in static dissipation and enhance the electromagnetic shielding effect.

[0014] 3. Strengthening the skeleton layer can improve the tensile strength of the fabric, with a breaking strength of ≥600N in the warp and ≥450N in the weft; and a tearing strength of ≥60N in the warp and ≥40N in the weft.

[0015] 4. The fabric can reflect 90% of radiant heat, achieving an emissivity of <0.4 in the 8-14μm spectral band. It has excellent heat protection, imaging, and far-infrared protection functions, and a flame retardant rating of V0, making it suitable for various civilian and military applications. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the fabric of the present invention; Figure 2 This is a flowchart of the fabric preparation method of the present invention; Figure 3 This is a flowchart of the method for preparing nickel micropowder modified resin according to the present invention; Figure 4 This is the shielding effectiveness curve of the fabric of the present invention.

[0017] In the figure: 1-Substrate bottom layer; 2-Reinforcing skeleton layer; 3-Low emissivity surface layer; 11-Modified aramid fiber; 12-Low emissivity slurry; 21-Blend of carbon fiber filament and pre-oxidized filament; 22-Conductive layer. Detailed Implementation

[0018] The present invention will be further described in detail below with reference to embodiments: like Figure 1 As shown, the present invention provides a heat-resistant imaging and far-infrared protective fabric, comprising a three-layer structure: a first layer is a substrate bottom layer 1, a second layer is a reinforcing skeleton layer 2, and a third layer is a low-emissivity surface layer 3; the substrate bottom layer 1 comprises modified aramid fibers 11, both sides of which are coated with a low-emissivity slurry 12, the low-emissivity slurry 12 comprising nickel micropowder modified resin; the reinforcing skeleton layer 2 comprises a blend of carbon fiber filaments and pre-oxidized filaments 21, with a conductive layer 22 attached to the surface of the carbon fiber filaments; the low-emissivity surface layer 3 comprises nickel micropowder modified resin and ceramic micropowder.

[0019] The ceramic powder is zirconium oxide, and its mass is 4% of the nickel powder-modified resin.

[0020] The three-layer structure consists of a substrate bottom layer 1, a reinforcing skeleton layer 2, and a low emissivity surface layer 3, from the inside out. The three-layer structure is formed by hot pressing, and nickel micropowder modified resin is infiltrated into the gaps of modified aramid fibers 11.

[0021] like Figure 3 As shown, the nickel micron powder modified resin is prepared by the following method: S1. Nickel-plated carbon fiber powder, nano copper powder, silver paste, flame retardant, and dispersant are ground and stirred at high speed in butyl ester solvent at a mass ratio of 6:3:1:0.5:0.2. After stirring evenly, acrylic resin is added to obtain a mixture. The mass of acrylic resin accounts for 50% of the mixture. The mixture is stirred for 1 hour using a high-speed planetary mixer. After stirring evenly, the mixture is put into a horizontal sand mill for high-speed grinding for 1 hour. The ground slurry is put into a three-roll mill for further grinding until the diameter of solid particles is less than 5μm. The mixture is stirred evenly to obtain nickel micro powder slurry. Among them, the flame retardant used is melamine phosphate, a nitrogen-phosphorus flame retardant, and the dispersant used is oleamidopropyl betaine, a fatty acid dispersant.

[0022] S2. Polycarbonate-type polyurethane as the resin matrix is ​​dissolved in N,N-dimethylformamide, and a UV absorber pre-dissolved in a 10% mixed solvent of toluene and methyl ethyl ketone is added. Then, a defoamer is added, and the mixture is stirred evenly to obtain a resin emulsion. The amounts of UV absorber and defoamer are 0.15% and 0.1% of the mass of the resin matrix, respectively. Among them, UV-531 is used as the ultraviolet absorber, and dimethyl silicone oil emulsion, a polysiloxane-based defoamer, is used as the defoamer.

[0023] S3. Mix the nickel micron powder slurry and resin emulsion obtained in the first two steps. The solid content in the nickel powder slurry is 18% of the mass of the resin. Disperse the mixture at a high speed of 1500 r / min for 15 minutes until it becomes a stable suspension to obtain nickel micron powder modified resin.

[0024] like Figure 2As shown, a method for preparing a heat-resistant, imaging-protective, far-infrared fabric includes the following steps: Step 1: Prepare modified aramid fiber 11 by subjecting aramid fiber to oxygen plasma treatment at a power of 300W for 30 minutes to obtain modified aramid fiber 11. The second step involves processing the pre-oxidized filament and carbon fiber filament. The pre-oxidized filament is pre-oxidized at 280°C, and a nano-silver layer is deposited on the surface of the carbon fiber filament as a conductive layer 22. The specific steps for depositing the nano-silver layer are as follows: the carbon fiber filament is soaked in acetone solvent for 10-15 minutes to remove impurities, then air-oxidized at 50°C for 8 minutes, then immersed in a solution of silver nanoparticles mixed with silver nitrate and glucose, reacted at 60°C for 12 minutes, washed, dried at 70°C for 16 minutes, and then heat-treated at 120°C for 5 minutes to stabilize the silver layer.

[0025] The third step involves coating and bonding. The modified aramid fiber 11 is cut into 150cm wide strips. Nickel micronized modified resin is used as a low emissivity slurry 12 and coated on both sides of the modified aramid fiber 11. The substrate bottom layer 1 is cured at 120°C. The thickness of a single layer of low emissivity slurry 12 is 100μm. The pre-oxidized yarn and carbon fiber yarn blend 21 treated in the second step is covered on the upper low emissivity slurry 12 by weft knitting to form a reinforcing skeleton layer 2. Nickel micronized modified resin with dispersed ceramic micronized powder is coated on the reinforcing skeleton layer 2 as a low emissivity surface layer 3. The fourth step is hot pressing, in which the composite material product from the third step is hot pressed at 180℃ and 10MPa to obtain a heat-resistant, imaging-resistant, and far-infrared-resistant fabric.

[0026] The heat-resistant, imaging, and far-infrared-resistant fabric was tested according to GJB6190-2008 "Test Method for Shielding Effectiveness of Electromagnetic Shielding Materials". The results are as follows: Figure 4 As shown.

[0027] It should be noted that, in the description of this disclosure, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joint" 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; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0028] The present invention has been described in detail above. However, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, any modifications or improvements that do not depart from the spirit of the present invention are within the scope of protection of the present invention.

Claims

1. A heat-resistant, imaging-protective, far-infrared-proof fabric, characterized in that, The fabric comprises a three-layer structure: a first layer is a substrate bottom layer, a second layer is a reinforcing skeleton layer, and a third layer is a low-emissivity surface layer. The substrate bottom layer comprises modified aramid fibers, both sides of which are coated with a low-emissivity slurry, which comprises nickel micronized modified resin. The reinforcing skeleton layer comprises a blend of carbon fiber filaments and pre-oxidized filaments, with a conductive layer attached to the surface of the carbon fiber filaments. The low-emissivity surface layer comprises the nickel micronized modified resin and ceramic micronized powder.

2. The heat-resistant imaging and far-infrared protective fabric according to claim 1, characterized in that, The three-layer structure consists of a substrate bottom layer, a reinforcing skeleton layer, and a low emissivity surface layer from the inside out. The three-layer structure is formed by hot pressing, and the nickel micropowder modified resin permeates into the gaps between the modified aramid fibers.

3. The heat-resistant imaging and far-infrared protective fabric according to claim 1, characterized in that, The nickel micropowder modified resin is prepared by the following method: S1. Nickel-plated carbon fiber powder, nano copper powder, silver paste, flame retardant, and dispersant are ground and stirred at high speed in butyl ester solvent. After stirring evenly, acrylic resin is added. After stirring the mixture evenly, high-speed grinding is continued until the diameter of solid particles is 1~5μm. Nickel micro powder slurry is obtained by stirring evenly. S2. Dissolve the resin matrix in N,N-dimethylformamide, add the ultraviolet absorber pre-dissolved in 10% of a mixed solvent of toluene and butanone, add the defoamer, and stir evenly to obtain a resin emulsion. S3. Mix the nickel micron powder slurry and the resin emulsion, and stir at high speed until a stable suspension is formed to obtain nickel micron powder modified resin.

4. The heat-resistant imaging and far-infrared protective fabric according to claim 3, characterized in that, In S1, the mass ratio of nickel-plated carbon fiber powder, nano copper powder, silver paste, flame retardant, and dispersant is 6:3:1:0.5:0.2, and the amount of acrylic resin is 50% of the mixture; in S2, the resin matrix includes polycarbonate-type polyurethane or fluorocarbon resin, and the amounts of ultraviolet absorber and defoamer are 0.15% and 0.1% of the resin matrix mass, respectively.

5. The heat-resistant imaging and far-infrared protective fabric according to claim 3, characterized in that, The solid content in the nickel powder slurry is 15% to 20% of the mass of the resin body.

6. The heat-resistant imaging and far-infrared protective fabric according to claim 3, characterized in that, The flame retardant in S1 includes nitrogen-phosphorus flame retardants, and the dispersant includes fatty acid dispersants; the ultraviolet absorber in S2 includes UV-531, and the defoamer includes polysiloxanes.

7. The heat-resistant imaging and far-infrared protective fabric according to claim 1, characterized in that, The ceramic micro powder includes silicon carbide, boron nitride, or zirconium oxide. The ceramic micro powder is uniformly dispersed in the nickel micro powder modified resin, and the mass of the ceramic micro powder is 3% to 6% of the nickel micro powder modified resin.

8. A method for preparing a heat-resistant imaging and far-infrared protective fabric according to any one of claims 1-7, characterized in that, Includes the following steps: The first step is to treat the aramid fiber with oxygen plasma at a power of 300W for 30 minutes to obtain modified aramid fiber. The second step is to pre-oxidize the pre-oxidized fiber at 280°C to deposit a nano-silver layer on the surface of the carbon fiber as a conductive layer. The third step involves coating the modified aramid fiber with nickel micropowder modified resin as a low emissivity slurry and curing it at 120°C to obtain the substrate bottom layer. The thickness of a single layer of the low emissivity slurry is 100μm. The pre-oxidized filament and carbon fiber filament blend treated in the second step is then covered on the upper layer of the low emissivity slurry to form a reinforcing skeleton layer. A nickel micropowder modified resin with dispersed ceramic micropowder is coated on top of the reinforcing skeleton layer as a low emissivity surface layer. The fourth step involves hot-pressing the product from the third step at 180°C and 10MPa to obtain the heat-resistant imaging and far-infrared-proof fabric.

9. The method for preparing a heat-resistant imaging and far-infrared protective fabric according to claim 8, characterized in that, The method for depositing the silver nanolayer described in the second step includes the following steps: The carbon fiber filaments were soaked in acetone solvent for 10-15 minutes, then air-oxidized at 50°C for 8 minutes, and then immersed in a solution of silver nanoparticles mixed with silver nitrate and glucose. The mixture was reacted at 60-70°C for 12 minutes, washed and dried, and then heat-treated at 100-150°C for 5 minutes.

10. The method for preparing a heat-resistant imaging and far-infrared protective fabric according to claim 8, characterized in that, In the third step, the pre-oxidized yarn and carbon fiber yarn blend is covered by weft knitting.

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