Acetal enameled gold film covered silk-covered wire and preparation method thereof

Abstract

The invention discloses an acetal enameled gold film covered silk-covered wire and a preparation method thereof, and relates to the technical field of conductive materials. The aramid fiber layer is modified by using a hot pressing process, the reaction strength of acid to aramid fibers is enhanced through hot pressing, and carboxyl generated by aramid fibers and a polar matrix on the surface of adjacent fibers are condensed in the process to form chemical crosslinking, so that the wrapping property of a wire is enhanced, and the tensile strength of the wire is improved. Then, iron ions and carboxyl on the surface of the aramid fiber form octahedral coordinate bonds, so that the shielding layer is not easy to fall off; the preparation method comprises the following steps: modifying magnetic particles by using 1, 4-diisothiocyanobutyl ester, enhancing the dispersity of nanoparticles in a matrix through a long chain of the magnetic particles, enhancing the toughness of acetal substances, enhancing the overall mechanical properties through the adsorption effect of the magnetic particles and iron ions on a metal layer, and improving the mechanical properties of the 1, 4-diisothiocyanobutyl ester. Sulfur atoms in the 2, 4-diisothiocyanobutyl ester and iron ions form a complex, so that the mechanical property is further enhanced.

Description

Technical Field

[0001] This invention relates to the field of conductive materials technology, specifically to an acetal-coated gold film-coated wire and its preparation method. Background Technology

[0002] With the improvement of the economy and people's living standards, the demand for enameled wire varnish is rapidly increasing in both military and civilian fields. As a coating with excellent electrical insulation properties, enameled wire varnish is an indispensable material for electrical equipment, and its quality directly affects the economic and technical indicators and service life of electrical equipment. Because motors and electrical appliances are always developing towards smaller size and higher power, enameled wire has a smooth surface, making it easy to wind coils, and its insulation layer is thin but has high electrical strength. The varnish film is firmly bonded to the conductor and has a certain degree of elasticity, preventing cracking when bent. Its good moisture resistance is also an advantage. When motors and electrical appliances operate under short-term overload conditions, the enameled wire is subjected to thermal shock as it rapidly cools from temperatures exceeding the maximum operating temperature to room temperature. Under high-speed conditions when used in high-speed electric drill motors, the paint film is simultaneously subjected to the combined effects of heat, mechanical and electrical factors. If the paint film undergoes thermoplastic deformation, it is prone to softening and breakdown. Furthermore, the miniaturization of motors and electrical appliances is an important trend in the development of electrical products. On the one hand, the heat resistance level of motor insulation needs to be continuously improved; on the other hand, the slot fill factor of the motor also needs to be increased, which requires continuously reducing the thickness of the paint film and improving the electrical resistance of the paint film. Summary of the Invention

[0003] The purpose of this invention is to provide an acetal enameled gold film-coated wire and its preparation method, so as to solve the problems existing in the prior art.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution: an acetal-coated gold film-wrapped wire, comprising the following preparation steps: (1) Mix 10wt% sulfuric acid solution and 15wt% phosphoric acid solution at a mass ratio of 1:1 to obtain an acid solution, and then use 20~50mL / m 2 Spray the coating onto the surface of the aramid fiber membrane and perform hot pressing treatment. Then wash it with deionized water 3 to 6 times, dry it at 40 to 80°C for 6 hours, and then wrap it around the copper core wire to obtain the insulating wire-wrapped layer. (2) Immerse the product obtained in step (1) in a 10 wt% ferric chloride aqueous solution for 30 min, then wash with deionized water 3-6 times, immerse in a 10 wt% hydrogen iodide aqueous solution for reduction treatment, wash again with deionized water 3-6 times, dry at 40-80℃ for 6 h, and finally apply 10 mL / m 2 Apply gold coating and cure at 200℃ for 10 minutes to obtain a gold film shielding layer; (3) Mix the magnetic particles and tetrahydrofuran, sonicate at 21 kHz for 15 min, adjust the pH of the solution to 5-7 with dilute hydrochloric acid, heat to 60-80℃, stir at 300 rpm, and add 1 wt% 1,4-diisothiocyanobutyl ester-tetrahydrofuran solution at 0.2-1 mL / s. Continue stirring for 4-8 h, filter, take the solid, and dry at 40-60℃ for 12 h to obtain the modified nanomaterial. (4) Mix epoxy-modified phenolic resin, modified nanomaterials and acetone evenly, and then coat them onto the product obtained in step (1) to obtain an insulating varnish layer.

[0005] Furthermore, the aramid fiber membrane mentioned in step (1) specifically has a strength of 50~100 g / m³. 2 Para-aramid nonwoven fabric.

[0006] Furthermore, the process parameters for the hot pressing treatment in step (1) are: temperature 300~400℃, pressure 10~20MPa, and time 5~15s.

[0007] Furthermore, the conditions for the reduction treatment in step (2) are: temperature of 60~100℃ and time of 30min.

[0008] Furthermore, the gold coating in step (2) comprises the following metal components and their mass percentages: gold 5~20%, iron 1~5%, platinum 0.1%, nickel 0.1%, and chromium 0.1%.

[0009] Further, the preparation method of the magnetic particles in step (3) is as follows: mix iron oxide nanoparticles, ethanol, and deionized water at a mass ratio of 0.15:100:80, stir at 500 rpm for 30 min, add tetraethyl orthosilicate at 3 times the mass of iron oxide nanoparticles, continue stirring for 30 min, then add concentrated ammonia at 10-30 times the mass of iron oxide nanoparticles, continue stirring for 2 h, then filter, take the solid, wash with anhydrous ethanol and deionized water 3 times each, and finally disperse in 1-10 wt% γ-aminopropyltriethoxysilane-ethanol solution at a bath ratio of 1:100, stir at 1000 rpm for 5-10 min, let stand for 3-6 h, filter, take the solid, and dry at 40-60℃ for 12 h to obtain the product.

[0010] Furthermore, in step (3), the mass ratio of the magnetic particles, tetrahydrofuran, and 1wt% 1,4-diisothiocyanobutyl ester-tetrahydrofuran solution is 0.1:100:50.

[0011] Furthermore, the epoxy-modified phenolic resin in step (4) is of type SR-FC51.

[0012] Furthermore, in step (4), the mass ratio of epoxy-modified phenolic resin, modified nanomaterial, and acetone is 100:1:3.

[0013] Furthermore, the thickness of the insulating varnish layer in step (4) is 0.08~0.15mm.

[0014] Compared with the prior art, the beneficial effects achieved by the present invention are: The conductor of this invention has a structure from the inside out as a conductive core, an insulating wire layer, a shielding layer, and an insulating varnish layer, in order to achieve wear resistance and high mechanical properties.

[0015] First, the aramid fiber layer is modified using a hot-pressing process. Hot pressing promotes the penetration and reaction of acid, and the increased activity of fiber molecular chains at high temperatures makes it easier for acidic media to penetrate the microcrystalline regions on the aramid surface, increasing the number of active sites. This, in turn, causes the amide groups in the aramid fiber backbone to decompose, generating polar groups such as carboxyl groups. During the hot-pressing process, the carboxyl groups generated undergo a condensation reaction with amino groups or other oxygen-containing groups on the surface of adjacent fibers to form new amide bonds, achieving chemical cross-linking between fibers, enhancing the encapsulation of the wire, and indirectly improving the electromagnetic shielding effect. Then, iron ions form octahedral coordination bonds with the carboxyl groups on the aramid surface, bridging adjacent molecular chains and significantly enhancing the interfacial bonding performance between them, making the shielding layer less prone to detachment. Finally, through reduction treatment, a mixed valence system of divalent and trivalent iron ions is formed, which is conducive to the hopping transport of electrons, thereby enhancing the shielding performance.

[0016] Secondly, magnetic particles are modified with 1,4-diisothiocyanobutyl ester. Under acidic conditions, the isothiocyanate groups on one side of 1,4-diisothiocyanobutyl ester undergo a condensation reaction with the hydroxyl groups on the silica shell, resulting in the grafting of 1,4-diisothiocyanobutyl ester onto the magnetic particles. Its long chain enhances the dispersibility of the nanoparticles in the matrix and simultaneously improves the toughness of the acetal. Furthermore, the steric hindrance effect of the thio groups further enhances the toughness of the acetal resin. Subsequently, it is coated onto a metal layer. Through the adsorption of iron ions between the magnetic particles and the metal layer, the interfacial bonding between the two is enhanced, thereby improving the overall mechanical properties. Moreover, the sulfur atoms in 1,4-diisothiocyanobutyl ester form stable complexes with iron ions, further enhancing the mechanical properties of the matrix.

[0017] The gold coating is composed of metal resin acid salt, nitrorosin, and tetrachloronaphthalene, with a mass ratio of 50:20:20. The gold coating includes the following metal components and their mass percentages: gold 5-20%, iron 1%, platinum 0.1%, nickel 0.1%, and chromium 0.1%. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] To more clearly illustrate the method provided by the present invention, the following embodiments are provided in detail. The test methods for various indicators of the acetal enameled gold film-coated wire prepared in the following embodiments are as follows: Mechanical properties: Using examples and comparative examples of the same size, the scratch force and breakdown voltage of the samples were tested in accordance with GB / T6109.22.

[0020] Example 1; (1) A 10wt% sulfuric acid solution and a 15wt% phosphoric acid solution were mixed at a mass ratio of 1:1 to obtain an acid solution, and then the solution was prepared at a concentration of 20 mL / m 2 Spray at 50g / m 2 The surface of the para-aramid nonwoven fabric is subjected to hot pressing treatment with the following process parameters: temperature 300℃, pressure 10MPa, time 5s. After washing with deionized water 3 times and drying at 40℃ for 6 hours, the copper core wire is wrapped to obtain the insulating wire-wrapped layer. (2) The product obtained in step (1) is immersed in a 10 wt% ferric chloride aqueous solution for 30 min, then washed three times with deionized water, and then immersed in a 10 wt% hydrogen iodide aqueous solution at 60 °C for reduction treatment for 30 min. It is then washed three times again with deionized water, dried at 40 °C for 6 h, and finally treated with 10 mL / m 2 A gold coating is applied and cured at 200℃ for 10 minutes to obtain a gold film shielding layer. The gold coating is composed of metal resin acid salts, nitrorosin, and tetrachloronaphthalene, with a mass ratio of 50:20:20. The gold coating includes the following metal components and their mass percentages: gold 5%, iron 1%, platinum 0.1%, nickel 0.1%, and chromium 0.1%. The metal resin acid salt is composed of sulfurized balsam gold, iron isooctanoate, platinum isooctanoate, nickel isooctanoate, chromium isooctanoate, and additives, wherein the additives account for 50% of the mass percentage of the metal resin acid salt. The sulfurized balsam gold is obtained by reacting sulfurized balsam with a 20wt% gold chloride solution, with a molar ratio of sulfurized balsam to 20wt% gold chloride solution of 5:6. The additives are composed of acrylic resin B-725, terpineol, and sodium citrate, with a mass ratio of 5:1:0.5. (3) Mix iron oxide nanoparticles, ethanol, and deionized water at a mass ratio of 0.15:100:80, stir at 500 rpm for 30 min, add tetraethyl orthosilicate at a mass ratio of 3 times that of the iron oxide nanoparticles, continue stirring for 30 min, then add concentrated ammonia at a mass ratio of 10 times that of the iron oxide nanoparticles, continue stirring for 2 h, then filter, take the solid, wash it 3 times each with anhydrous ethanol and deionized water, and finally disperse it in a 1 wt% γ-aminopropyltriethoxysilane-ethanol solution at a bath ratio of 1:100, stir at 1000 rpm for 5 min, let stand for 3 h, and then filter. The solid was filtered, collected, and dried at 40℃ for 12 hours to obtain magnetic particles. The magnetic particles and tetrahydrofuran were mixed, sonicated at 21 kHz for 15 minutes, and the pH of the solution was adjusted to 5 with dilute hydrochloric acid. The temperature was raised to 60℃, and the mixture was stirred at 300 rpm. At the same time, 1 wt% 1,4-diisothiocyanobutyl ester-tetrahydrofuran solution was added at 0.2 mL / s. After stirring for 4 hours, the solid was filtered, collected, and dried at 40℃ for 12 hours to obtain modified nanomaterials. The mass ratio of the magnetic particles, tetrahydrofuran, and 1 wt% 1,4-diisothiocyanobutyl ester-tetrahydrofuran solution was 0.1:100:50. (4) The epoxy-modified phenolic resin SR-FC51, the modified nanomaterials and acetone are mixed evenly and then coated on the product obtained in step (1) to obtain an insulating varnish layer with a thickness of 0.08 mm; the mass ratio of the epoxy-modified phenolic resin SR-FC51, the modified nanomaterials and acetone is 100:1:3.

[0021] Example 2; (1) A 10wt% sulfuric acid solution and a 15wt% phosphoric acid solution were mixed at a mass ratio of 1:1 to obtain an acid solution, and then the solution was prepared at a concentration of 35 mL / m 2 Spray at 80g / m 2 The surface of the para-aramid nonwoven fabric is subjected to hot pressing treatment with the following process parameters: temperature 350℃, pressure 15MPa, time 10s. After washing with deionized water 5 times and drying at 60℃ for 6h, the copper core wire is wrapped to obtain the insulating wire layer. (2) The product obtained in step (1) is immersed in a 10 wt% ferric chloride aqueous solution for 30 min, then washed 5 times with deionized water, and then immersed in a 10 wt% hydrogen iodide aqueous solution at 80 °C for reduction treatment for 30 min. It is then washed 5 times again with deionized water, dried at 60 °C for 6 h, and finally treated with 10 mL / m 2A gold coating is applied and cured at 200℃ for 10 minutes to obtain a gold film shielding layer. The gold coating is composed of metal resin acid salts, nitrorosin, and tetrachloronaphthalene, with a mass ratio of 50:20:20. The gold coating includes the following metal components and their mass percentages: gold 12%, iron 3%, platinum 0.1%, nickel 0.1%, and chromium 0.1%. The metal resin acid salt is composed of sulfurized balsam gold, iron isooctanoate, platinum isooctanoate, nickel isooctanoate, chromium isooctanoate, and additives, wherein the additives account for 50% of the mass percentage of the metal resin acid salt. The sulfurized balsam gold is obtained by reacting sulfurized balsam with a 20wt% gold chloride solution, with a molar ratio of sulfurized balsam to 20wt% gold chloride solution of 5:6. The additives are composed of acrylic resin B-725, terpineol, and sodium citrate, with a mass ratio of 5:1:0.5. (3) Mix iron oxide nanoparticles, ethanol, and deionized water at a mass ratio of 0.15:100:80, stir at 500 rpm for 30 min, add tetraethyl orthosilicate at a mass ratio of 3 times that of the iron oxide nanoparticles, continue stirring for 30 min, then add concentrated ammonia at a mass ratio of 20 times that of the iron oxide nanoparticles, continue stirring for 2 h, then filter, take the solid, wash it 3 times each with anhydrous ethanol and deionized water, and finally disperse it in a 6 wt% γ-aminopropyltriethoxysilane-ethanol solution at a bath ratio of 1:100, stir at 1000 rpm for 8 min, let stand for 5 h, and then filter. The solid was filtered, collected, and dried at 50℃ for 12 hours to obtain magnetic particles. The magnetic particles and tetrahydrofuran were mixed, sonicated at 21 kHz for 15 minutes, and the pH of the solution was adjusted to 6 with dilute hydrochloric acid. The temperature was raised to 70℃, and the mixture was stirred at 300 rpm. At the same time, 1 wt% 1,4-diisothiocyanobutyl ester-tetrahydrofuran solution was added at 0.6 mL / s. After stirring for 6 hours, the solid was filtered, collected, and dried at 50℃ for 12 hours to obtain modified nanomaterials. The mass ratio of the magnetic particles, tetrahydrofuran, and 1 wt% 1,4-diisothiocyanobutyl ester-tetrahydrofuran solution was 0.1:100:50. (4) The epoxy-modified phenolic resin SR-FC51, the modified nanomaterials and acetone are mixed evenly and then coated on the product obtained in step (1) to obtain an insulating varnish layer with a thickness of 0.11 mm; the mass ratio of the epoxy-modified phenolic resin SR-FC51, the modified nanomaterials and acetone is 100:1:3.

[0022] Example 3; (1) A 10wt% sulfuric acid solution and a 15wt% phosphoric acid solution were mixed at a mass ratio of 1:1 to obtain an acid solution, and then the solution was diluted with 50 mL / m 2 Spray at 100g / m 2 The surface of the para-aramid nonwoven fabric is subjected to hot pressing treatment with the following process parameters: temperature 400℃, pressure 20MPa, time 15s. After washing with deionized water 6 times and drying at 80℃ for 6 hours, the copper core wire is wrapped to obtain the insulating wire layer. (2) The product obtained in step (1) is immersed in a 10 wt% ferric chloride aqueous solution for 30 min, then washed 6 times with deionized water, and then immersed in a 10 wt% hydrogen iodide aqueous solution at 100 °C for reduction treatment for 30 min. It is then washed 6 times with deionized water again, dried at 80 °C for 6 h, and finally discharged at 10 mL / m 2 A gold coating is applied and cured at 200℃ for 10 minutes to obtain a gold film shielding layer. The gold coating is composed of metal resin acid salts, nitrorosin, and tetrachloronaphthalene, with a mass ratio of 50:20:20. The gold coating includes the following metal components and their mass percentages: gold 20%, iron 5%, platinum 0.1%, nickel 0.1%, and chromium 0.1%. The metal resin acid salt is composed of sulfurized balsam gold, iron isooctanoate, platinum isooctanoate, nickel isooctanoate, chromium isooctanoate, and additives, wherein the additives account for 50% of the mass percentage of the metal resin acid salt. The sulfurized balsam gold is obtained by reacting sulfurized balsam with a 20wt% gold chloride solution, with a molar ratio of sulfurized balsam to 20wt% gold chloride solution of 5:6. The additives are composed of acrylic resin B-725, terpineol, and sodium citrate, with a mass ratio of 5:1:0.5. (3) Mix iron oxide nanoparticles, ethanol, and deionized water at a mass ratio of 0.15:100:80, stir at 500 rpm for 30 min, add tetraethyl orthosilicate at a mass ratio of 3 times that of the iron oxide nanoparticles, continue stirring for 30 min, then add concentrated ammonia at a mass ratio of 30 times that of the iron oxide nanoparticles, continue stirring for 2 h, then filter, take the solid, wash it 3 times each with anhydrous ethanol and deionized water, and finally disperse it in a 10 wt% γ-aminopropyltriethoxysilane-ethanol solution at a bath ratio of 1:100, stir at 1000 rpm for 10 min, and let it stand for 6 h. The solid was filtered, dried at 60℃ for 12 hours to obtain magnetic particles. The magnetic particles and tetrahydrofuran were mixed, sonicated at 21 kHz for 15 minutes, and the pH of the solution was adjusted to 7 with dilute hydrochloric acid. The temperature was raised to 80℃, and the mixture was stirred at 300 rpm. At the same time, 1 wt% 1,4-diisothiocyanobutyl ester-tetrahydrofuran solution was added at 1 mL / s. After stirring for 8 hours, the solid was filtered, dried at 60℃ for 12 hours to obtain modified nanomaterials. The mass ratio of the magnetic particles, tetrahydrofuran, and 1 wt% 1,4-diisothiocyanobutyl ester-tetrahydrofuran solution was 0.1:100:50. (4) Mix epoxy-modified phenolic resin SR-FC51, modified nanomaterials and acetone evenly, and then coat it on the product obtained in step (1) to obtain an insulating varnish layer with a thickness of 0.15 mm; the mass ratio of epoxy-modified phenolic resin SR-FC51, modified nanomaterials and acetone is 100:1:3.

[0023] Comparative Example 1; The difference between Comparative Example 1 and Example 2 is that step (1) is different. Step (1) is changed to: 80g / m 2 The copper core wire is wrapped with para-aramid nonwoven fabric to obtain an insulating wire-wrapped layer; the remaining steps are the same as in Example 2.

[0024] Comparative Example 2; The difference between Comparative Example 2 and Example 2 is that step (3) is omitted, and step (4) is changed to: mixing iron oxide nanoparticles, ethanol, and deionized water at a mass ratio of 0.15:100:80, stirring at 500 rpm for 30 min, adding tetraethyl orthosilicate at 3 times the mass of iron oxide nanoparticles, stirring for another 30 min, then adding concentrated ammonia at 20 times the mass of iron oxide nanoparticles, stirring for another 2 h, then filtering, taking the solid, washing it 3 times each with anhydrous ethanol and deionized water, and finally mixing it at a bath ratio of 1:1. 00 was dispersed in a 6wt% γ-aminopropyltriethoxysilane-ethanol solution, stirred at 1000 rpm for 8 min, allowed to stand for 5 h, filtered, and the solid was dried at 50 °C for 12 h to obtain magnetic particles; epoxy-modified phenolic resin SR-FC51, magnetic particles, and acetone were mixed evenly and then coated onto the product obtained in step (1) to obtain an insulating varnish layer with a thickness of 0.11 mm; the mass ratio of epoxy-modified phenolic resin SR-FC51, magnetic particles, and acetone was 100:1:3. The remaining steps were the same as in Example 2.

[0025] Example of effect Table 1 below shows the performance analysis results of the acetal enameled gold film-coated wires using Examples 1 to 3 and Comparative Examples 1 to 2 of the present invention.

[0026] Table 1

[0027] A comparison of the experimental data from the examples and comparative examples in Table 1 reveals that this invention utilizes a hot-pressing process to modify the aramid fiber layer. Hot pressing promotes the penetration and reaction of acidic solutions, and the increased activity of fiber molecular chains at high temperatures allows acidic media to more easily penetrate the microcrystalline regions on the aramid surface, increasing active sites. This, in turn, promotes the decomposition of amide groups in the aramid fiber backbone, generating polar groups such as carboxyl groups. During hot pressing, the generated carboxyl groups undergo condensation reactions with amino groups or other oxygen-containing groups on the surface of adjacent fibers, forming new amide bonds. This achieves chemical cross-linking between fibers, enhancing the encapsulation of the wire and indirectly improving the electromagnetic shielding effect. Subsequently, iron ions form octahedral coordination bonds with the carboxyl groups on the aramid surface, bridging adjacent molecular chains. Then, 1,4-diisothiocyanate... 1,4-Diisothiocyanobutyl ester modified magnetic particles, under acidic conditions, undergo a condensation reaction between the isothiocyanate group on one side of 1,4-diisothiocyanobutyl ester and the hydroxyl group on the silica shell, resulting in the grafting of 1,4-diisothiocyanobutyl ester onto the magnetic particles. Its long chain enhances the dispersibility of the nanoparticles in the matrix and simultaneously improves the toughness of the acetal. Furthermore, the steric hindrance effect of the thio groups further enhances the toughness of the acetal resin. Subsequently, it is coated onto a metal layer, where the adsorption of iron ions between the magnetic particles and the metal layer strengthens the interfacial bonding, thereby enhancing the overall mechanical properties. Moreover, the sulfur atoms in 1,4-diisothiocyanobutyl ester form stable complexes with iron ions, further enhancing the mechanical properties of the matrix.

[0028] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No markings in the claims should be construed as limiting the scope of the claims.

Claims

1. A type of acetal-coated gold film-covered wire, characterized in that, The preparation steps include the following: (1) Mix 10wt% sulfuric acid solution and 15wt% phosphoric acid solution at a mass ratio of 1:1 to obtain an acid solution, and then use 20~50mL / m 2 Spray the coating onto the surface of the aramid fiber membrane and perform hot pressing treatment. Then wash it with deionized water 3 to 6 times, dry it at 40 to 80°C for 6 hours, and then wrap it around the copper core wire to obtain the insulating wire-wrapped layer. (2) Immerse the product obtained in step (1) in a 10 wt% ferric chloride aqueous solution for 30 min, then wash it 3-6 times with deionized water, immerse it in a 10 wt% hydrogen iodide aqueous solution for reduction treatment, and after cleaning and drying, use 10 mL / m 2 Apply gold coating and cure at 200℃ for 10 minutes to obtain a gold film shielding layer; (3) Mix the magnetic particles and tetrahydrofuran, sonicate at 21 kHz for 15 min, adjust the pH of the solution to 5-7 with dilute hydrochloric acid, heat to 60-80℃, stir at 300 rpm, and add 1 wt% 1,4-diisothiocyanobutyl ester-tetrahydrofuran solution at 0.2-1 mL / s. Continue stirring for 4-8 h, filter, take the solid, and dry at 40-60℃ for 12 h to obtain the modified nanomaterial. (4) Mix epoxy-modified phenolic resin, modified nanomaterials and acetone evenly, and then coat them onto the product obtained in step (1) to obtain an insulating varnish layer.

2. The acetal-coated gold film-wrapped wire according to claim 1, characterized in that, The aramid fiber membrane mentioned in step (1) specifically has a strength of 50~100 g / m³. 2 Para-aramid nonwoven fabric.

3. The acetal-coated gold film-wrapped wire according to claim 1, characterized in that, The process parameters for hot pressing in step (1) are: temperature 300~400℃, pressure 10~20MPa, and time 5~15s.

4. The acetal-coated gold film-wrapped wire according to claim 1, characterized in that, The conditions for the reduction treatment in step (2) are: temperature of 60~100℃ and time of 30min.

5. The acetal-coated gold film-wrapped wire according to claim 1, characterized in that, The gold coating in step (2) comprises the following metal components and their mass percentages: gold 5-20%, iron 1-5%, platinum 0.1%, nickel 0.1%, and chromium 0.1%.

6. The acetal-coated gold film-wrapped wire according to claim 1, characterized in that, The preparation method of the magnetic particles in step (3) is as follows: Iron oxide nanoparticles, ethanol, and deionized water are mixed at a mass ratio of 0.15:100:80 and stirred at 500 rpm for 30 min. Tetraethyl orthosilicate with a mass of 3 times that of the iron oxide nanoparticles is added and stirred for another 30 min. Then, concentrated ammonia with a mass of 10 to 30 times that of the iron oxide nanoparticles is added and stirred for another 2 h. The mixture is then filtered and the solid is taken. It is washed 3 times each with anhydrous ethanol and deionized water. Finally, it is dispersed in a 1 to 10 wt% γ-aminopropyltriethoxysilane-ethanol solution at a bath ratio of 1:100 and stirred at 1000 rpm for 5 to 10 min. The mixture is allowed to stand for 3 to 6 h, filtered, and the solid is taken. It is then dried at 40 to 60 ℃ for 12 h to obtain the final product.

7. The acetal-coated gold film-wrapped wire according to claim 1, characterized in that, The mass ratio of the magnetic particles, tetrahydrofuran, and 1wt% 1,4-diisothiocyanobutyl ester-tetrahydrofuran solution in step (3) is 0.1:100:

50.

8. The acetal-coated gold film-wrapped wire according to claim 1, characterized in that, The epoxy-modified phenolic resin used in step (4) is model SR-FC51.

9. The acetal-coated gold film-wrapped wire according to claim 1, characterized in that, The mass ratio of epoxy-modified phenolic resin, modified nanomaterials, and acetone in step (4) is 100:1:

3.

10. The acetal-coated gold film-wrapped wire according to claim 1, characterized in that, The thickness of the insulating varnish layer in step (4) is 0.08~0.15mm.

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