Weather-resistant enameled copper wire and preparation method thereof

Abstract

The invention discloses a weather-resistant enameled copper wire and a preparation method thereof, and relates to the technical field of wires and cables. When the weather-resistant enameled copper wire is prepared, tung oil is used as a core material, and calcium ions and sodium alginate are combined to serve as a wall material to form tung oil-calcium alginate microcapsules; the preparation method comprises the following steps: reacting nano silicon dioxide with 3-chloropropyltrimethoxysilane, and then reacting with 2-(2, 4-dihydroxyphenyl)-2H-benzotriazole to prepare modified silicon dioxide; the preparation method comprises the following steps: reacting dodecafluoroheptyl methacrylate with diethanol amine, and then reacting with isophorone diisocyanate to prepare a polyurethane prepolymer; mixing tung oil-calcium alginate microcapsules, the modified silicon dioxide, a polyurethane prepolymer and 4, 4 '-methylenebis (2-chloroaniline), so as to obtain polyurethane paint; and infiltrating the copper wire with polyurethane paint, and drying to obtain the weather-resistant enameled copper wire. The weather-resistant enameled wire prepared by the invention has excellent weather resistance and corrosion resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of electric wires and cables, in particular to a weather-resistant enameled copper wire and a preparation method thereof. Background Art

[0002] In the field of modern wire and cable technology, enameled copper wire is a key component in power transmission and electrical equipment, and its performance directly impacts the reliability and service life of the equipment. Especially in outdoor environments or under special operating conditions, enameled copper wire must withstand a variety of harsh conditions, including UV radiation, rainwater erosion, and chemical corrosion. However, the paint used in traditional enameled copper wire often lacks weather resistance, water resistance, and corrosion resistance. After long-term use, the paint is prone to aging, powdering, cracking, and peeling. This can lead to copper wire oxidation, short circuits, and other faults, seriously affecting the normal operation of electrical equipment.

[0003] Although some improved methods for preparing enameled copper wire have been developed in the prior art, such as by adding certain fillers or modifiers to enhance the performance of the paint, these methods still have significant drawbacks. While some paints prepared by these methods improve a single property, such as weather resistance or corrosion resistance, it is difficult to achieve a synergistic improvement in multiple properties simultaneously. They also generally lack self-repairing capabilities, meaning that even minor damage to the paint cannot be repaired, leading to continued damage. Furthermore, some existing technologies have complex preparation processes and high costs, making them unsuitable for large-scale industrial production.

[0004] Therefore, developing a novel insulation system that combines excellent weather resistance, water and corrosion resistance, and self-healing capabilities, with a manufacturing process compatible with existing enameled wire production processes, is crucial for overcoming the bottleneck in the production of wire for high-end electrical equipment. This invention, through the design of a polyurethane paint system with a multi-component, synergistic modification, achieves an integrated improvement in both weather resistance and self-healing capabilities, providing a new solution for the reliable application of enameled copper wire in complex environments. Summary of the Invention

[0005] The object of the present invention is to provide an anti-migration and anti-aging photovoltaic encapsulation film and a preparation method thereof, so as to solve the problems existing in the prior art.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] A weather-resistant enameled copper wire is prepared by impregnating the copper wire with polyurethane paint and drying the same;

[0008] As an optimization, the polyurethane paint is prepared by mixing tung oil-calcium alginate microcapsules, modified silica, polyurethane prepolymer and 4,4'-methylenebis(2-chloroaniline);

[0009] As an optimization, the tung oil-calcium alginate microcapsules are formed by using tung oil as the core material and calcium ions and sodium alginate as the wall material;

[0010] As an optimization, the modified silica is prepared by reacting nano-silica with 3-chloropropyltrimethoxysilane and then reacting with 2-(2,4-dihydroxyphenyl)-2H-benzotriazole;

[0011] As an optimization, the polyurethane prepolymer is prepared by reacting dodecafluoroheptyl methyl methacrylate with diethanolamine and then reacting with isophorone diisocyanate.

[0012] A method for preparing a weather-resistant enameled copper wire comprises the following steps:

[0013] (1) Tung oil, OP-10 emulsifier and sodium alginate aqueous solution are mixed uniformly in a mass ratio of 1:(0.1-0.3):(90-110), stirred at 5000-7000 r / min for 6-8 minutes at room temperature to prepare an oil-in-water emulsion, added to a calcium chloride aqueous solution with a mass of 100-120 times that of the tung oil, stirred at 1000-3000 r / min for 4-6 minutes, washed with deionized water 3-5 times, filtered, and dried at 70-80°C for 20-30 hours to prepare tung oil-calcium alginate microcapsules;

[0014] (2) pre-modified silica, 2-(2,4-dihydroxyphenyl)-2H-benzotriazole, and sodium hydroxide aqueous solution were mixed uniformly in a mass ratio of 1:(2-6):(14-18), stirred at 80-100°C and 300-500r / min for 7-9h, and 6wt%-7wt% sodium bicarbonate aqueous solution with a mass of 10-12 times that of 2-(2,4-dihydroxyphenyl)-2H-benzotriazole was added, allowed to stand for 10-14h, filtered, and vacuum dried at 50-60°C for 7-9h to obtain modified silica;

[0015] (3) isophorone diisocyanate and a fluorinated chain extender are uniformly mixed in a mass ratio of 1:(0.4-0.6), and 0.01-0.05 times the mass of dibutyltin dilaurate of isophorone diisocyanate is added under stirring at 75-85°C and 300-500 r / min, and the mixture is stirred at 50-80°C and 200-300 r / min for 4-6 hours to obtain a polyurethane prepolymer;

[0016] (4) The polyurethane prepolymer, ethyl acetate, tung oil-calcium alginate microcapsules, modified silica and 4,4'-methylenebis(2-chloroaniline) were mixed uniformly in a mass ratio of 1:2:(0.1-0.2):(0.04-0.06):(0.15-0.20), and ultrasonically dispersed at 120-140°C for 10-20 minutes to prepare a polyurethane paint. The copper wire was soaked in the polyurethane paint and then taken out and dried under vacuum at 50-60°C for 3-4 hours to prepare a weather-resistant enameled copper wire.

[0017] As an optimization, the sodium alginate aqueous solution in step (1) is prepared by uniformly mixing sodium alginate powder and ultrapure water in a mass ratio of 1:200, stirring at 500-700 r / min for 18-22 minutes at room temperature, and standing for 10-14 hours to obtain the sodium alginate aqueous solution.

[0018] As an optimization, the calcium chloride aqueous solution in step (1) is prepared by uniformly mixing anhydrous calcium chloride powder and ultrapure water in a mass ratio of 1:10, and stirring at 200-400 r / min for 5-8 minutes at room temperature to obtain the calcium chloride aqueous solution.

[0019] As an optimization, the pre-modified silica in step (2) is prepared by uniformly mixing nano-silica and anhydrous ethanol in a mass ratio of 1:(20-30), adding silane hydrolyzate 8-10 times the mass of the nano-silica, stirring at 60-80°C and 300-500r / min for 1-2h, filtering, washing with anhydrous ethanol 3-5 times, and drying at 60-80°C under vacuum conditions for 7-8h to obtain pre-modified nano-silica.

[0020] As an optimization, the silane hydrolyzate is prepared by uniformly mixing 3-chloropropyltrimethoxysilane and deionized water in a mass ratio of 1:(20-30), stirring at 10-30° C. and 300-500 r / min for 20-30 minutes to prepare the silane hydrolyzate.

[0021] As an optimization, the mass fraction of the sodium hydroxide aqueous solution in step (2) is 3%.

[0022] As an optimization, the fluorine-containing chain extender in step (3) is prepared by mixing dodecafluoroheptyl methacrylate, diethanolamine and methanol in a mass ratio of 1:(0.3-0.5):(0.4-0.6), stirring under reflux at 400-600 r / min for 48-50 h, washing with deionized water 3-5 times, and distilling under reduced pressure to obtain the fluorine-containing chain extender.

[0023] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0024] In the preparation of weather-resistant enameled copper wire, the present invention comprises the following steps: using tung oil as a core material, combining calcium ions and sodium alginate as wall materials to form tung oil-calcium alginate microcapsules; reacting nano-silica with 3-chloropropyltrimethoxysilane and then reacting with 2-(2,4-dihydroxyphenyl)-2H-benzotriazole to obtain modified silica; reacting dodecafluoroheptyl methacrylate with diethanolamine and then reacting with isophorone diisocyanate to obtain a polyurethane prepolymer; mixing the tung oil-calcium alginate microcapsules, modified silica, the polyurethane prepolymer and 4,4'-methylenebis(2-chloroaniline) to obtain a polyurethane paint; and impregnating the copper wire with the polyurethane paint and drying the mixture to obtain the weather-resistant enameled copper wire.

[0025] First, tung oil is used as the core material, and calcium ions and sodium alginate are combined as the wall material to form tung oil-calcium alginate microcapsules. Tung oil is an environmentally friendly material. Its highly unsaturated conjugated system composed of long-chain unsaturated fatty acids can trigger rapid polymerization, forming a dense solid film through oxidation by oxygen in the air without the need for a catalyst. Tung oil also has good thermal stability and low viscosity. Sodium alginate is a natural polysaccharide molecular polymer composed of varying amounts of glucuronic acid and mannoate monomers. When calcium ions are added, the sodium ions on the glucuronic acid are replaced by calcium ions, and the aldehyde groups are superimposed on each other, causing the oxygen atoms to chelate to form alginate chains. The interaction between the chains eventually forms a stable three-dimensional network structure. Calcium alginate can form a film with excellent stability due to its insoluble network gel properties. Tung oil and calcium alginate are prepared into core-shell structured microcapsules and applied to enameled copper wire to prepare a paint with good corrosion resistance and self-healing properties. The self-healing process is that the core material of the tung oil-calcium alginate microcapsule flows out to fill the cracks in the paint, and the tung oil in the core material of the microcapsule at the crack reacts with oxygen to bond the cracks together again to complete the repair, blocking the corrosion factors from penetrating from the microcracks in the paint to the metal surface to cause direct corrosion to the metal, extending the service life of the paint and reducing the maintenance cost of paint protection.

[0026] Secondly, nano-silica is reacted with 3-chloropropyltrimethoxysilane and then reacted with 2-(2,4-dihydroxyphenyl)-2H-benzotriazole to obtain modified silica. Nano-silica is a commonly used inorganic sealing material with the characteristics of small size, large specific surface area, high surface activity and non-conductivity. By grafting the hydrophobic group 3-chloropropyltrimethoxysilane on the surface of nano-silica, the number of hydroxyl groups on its surface is reduced, making it hydrophilic to hydrophobic, thereby improving the compatibility between nano-silica and organic matter, thereby having excellent properties such as high strength, anti-friction and anti-corrosion, improving the interfacial bonding force between nano-silica and subsequent polyurethane prepolymer, and providing active sites for the next reaction. After the introduction of 2-(2,4-dihydroxyphenyl)-2H-benzotriazole, the UV absorber is bonded to the surface of silica through a chemical reaction, forming an "inorganic core-organic shell" hybrid structure, which gives the modified silica both physical shielding and chemical absorption dual UV resistance. The benzotriazole group can effectively absorb ultraviolet light of 280-400nm and convert light energy into heat energy through intramolecular electron transfer, thus preventing the polyurethane paint film from chain breakage due to ultraviolet radiation. At the same time, the inorganic skeleton of nano-silica can scatter incident light, further weakening the ability of ultraviolet penetration and slowing down the aging rate of the paint film. The modified silica is more evenly distributed in the paint film, and its rigid skeleton can serve as a physical reinforcement phase, improving the hardness and wear resistance of the paint film and reducing the generation of microcracks caused by external mechanical impact. The surface-grafted organic groups form a chemically cross-linked network with the polyurethane prepolymer, which enhances the overall density of the paint film and blocks the penetration path of corrosive media such as moisture and oxygen. This synergistic effect not only improves the weather resistance of the weather-resistant enameled copper wire, but also enhances the corrosion resistance of the weather-resistant enameled copper wire.

[0027] Finally, a polyurethane prepolymer was prepared by reacting dodecafluoroheptyl methacrylate, diethanolamine, and isophorone diisocyanate. Dodecafluoroheptyl methacrylate contains fluorocarbon groups, forming a low-surface-energy hydrophobic layer. Isophorone diisocyanate reacts with diethanolamine to form a polyurethane backbone. During the reaction, fluorocarbon chains are introduced into the polyurethane chain, forming a "hydrophobic-hydrophilic" block structure. The fluorocarbon chains are oriented to the surface, and the appropriate cross-linking density blocks water penetration, enhancing the water resistance of the weathering paint and thus improving the corrosion resistance of the enameled copper wire. A polyurethane paint was prepared by mixing tung oil-calcium alginate microcapsules, modified silica, a polyurethane prepolymer, and 4,4'-methylenebis(2-chloroaniline), achieving multiple protections through multi-component synergy. When tung oil-calcium alginate microcapsules rupture, they release tung oil, which oxidatively polymerizes to fill cracks and form a hydrophobic film. The calcium alginate network enhances the film's density, achieving self-healing and corrosion resistance. The benzotriazole groups of the modified silica absorb UV light through a photostabilization mechanism, while silane modification improves dispersibility, enhancing the overall film's density, blocking the permeation pathways of corrosive media like moisture and oxygen and enhancing weather resistance. The polyurethane prepolymer and curing agent crosslink to form a three-dimensional network containing fluorinated carbon chains. The low-surface-energy hydrophobic layer synergistically interacts with the tung oil for water resistance, reducing the risk of cracking. This reaction complements the strengths of each component, forming a composite paint with corrosion resistance, self-healing, and weathering properties, significantly extending the service life of the enameled copper wire. DETAILED DESCRIPTION

[0028] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] Example 1:

[0030] A method for preparing a weather-resistant enameled copper wire, comprising the following steps:

[0031] (1) Sodium alginate powder and ultrapure water were mixed at a mass ratio of 1:200, stirred at 500 r / min for 22 min at room temperature, and allowed to stand for 10 h to obtain a sodium alginate aqueous solution; anhydrous calcium chloride powder and ultrapure water were mixed at a mass ratio of 1:10, stirred at 200 r / min for 9 min at room temperature to obtain a calcium chloride aqueous solution; tung oil, OP-10 emulsifier and sodium alginate aqueous solution were mixed at a mass ratio of 1:0.1:90, stirred at 5000 r / min for 8 min at room temperature to obtain an oil-in-water emulsion, which was added to a calcium chloride aqueous solution with a mass of 100 times that of tung oil, stirred at 1000 r / min for 6 min, washed with deionized water three times, filtered, and dried at 70°C for 30 h to obtain tung oil-calcium alginate microcapsules;

[0032] (2) 3-chloropropyltrimethoxysilane and deionized water were mixed at a mass ratio of 1:20, stirred at 10°C, 300 r / min for 30 min to prepare a silane hydrolyzate; nano-silica and anhydrous ethanol were mixed at a mass ratio of 1:20, silane hydrolyzate 8 times the mass of nano-silica was added, stirred at 60°C, 300 r / min for 2 h, filtered, washed with anhydrous ethanol 3 times, and dried at 60°C under vacuum for 9 h to obtain Pre-modified nano-silica; pre-modified silica, 2-(2,4-dihydroxyphenyl)-2H-benzotriazole, and 3wt% sodium hydroxide aqueous solution were mixed in a mass ratio of 1:2:14, stirred at 80 ° C and 300 r / min for 9 h, and 6wt% sodium bicarbonate aqueous solution with a mass of 10 times that of 2-(2,4-dihydroxyphenyl)-2H-benzotriazole was added, allowed to stand for 10 h, filtered, and dried in vacuo at 50 ° C for 9 h to obtain modified silica;

[0033] (3) Dodecafluoroheptyl methacrylate, diethanolamine and methanol were mixed in a mass ratio of 1:0.3:0.4, refluxed and stirred at 400 r / min for 50 h, washed with deionized water three times, and distilled under reduced pressure to obtain a fluorinated chain extender; isophorone diisocyanate and the fluorinated chain extender were mixed in a mass ratio of 1:0.4, stirred at 75°C and 300 r / min, and 0.01 times the mass of dibutyltin dilaurate of isophorone diisocyanate was added, and stirred at 50°C and 200 r / min for 6 hours to obtain a polyurethane prepolymer;

[0034] (4) The polyurethane prepolymer, ethyl acetate, tung oil-calcium alginate microcapsules, modified silica and 4,4'-methylenebis(2-chloroaniline) were mixed uniformly in a mass ratio of 1:2:0.1:0.04:0.15, and ultrasonically dispersed at 120°C for 20 minutes to prepare a polyurethane paint. The copper wire was soaked in the polyurethane paint and then taken out and dried at 50°C under vacuum conditions for 4 hours to prepare a weather-resistant enameled copper wire.

[0035] Example 2:

[0036] A method for preparing a weather-resistant enameled copper wire, comprising the following steps:

[0037] (1) Sodium alginate powder and ultrapure water were mixed at a mass ratio of 1:200, stirred at 600 r / min for 20 min at room temperature, and allowed to stand for 12 h to obtain a sodium alginate aqueous solution; anhydrous calcium chloride powder and ultrapure water were mixed at a mass ratio of 1:10, stirred at 300 r / min for 7 min at room temperature to obtain a calcium chloride aqueous solution; tung oil, OP-10 emulsifier and sodium alginate aqueous solution were mixed at a mass ratio of 1:0.2:100, stirred at 6000 r / min for 7 min at room temperature to obtain an oil-in-water emulsion, which was added to a calcium chloride aqueous solution with a mass of 110 times that of tung oil, stirred at 2000 r / min for 5 min, washed with deionized water 4 times, filtered, and dried at 75°C for 25 h to obtain tung oil-calcium alginate microcapsules;

[0038] (2) 3-chloropropyltrimethoxysilane and deionized water were mixed at a mass ratio of 1:25, stirred at 20°C and 400 r / min for 25 minutes to prepare a silane hydrolyzate; nano-silica and anhydrous ethanol were mixed at a mass ratio of 1:25, 9 times the mass of nano-silica was added to the silane hydrolyzate, stirred at 70°C and 400 r / min for 1.5 hours, filtered, washed with anhydrous ethanol 4 times, and dried at 70°C under vacuum for 9 hours to prepare a silane hydrolyzate. To obtain pre-modified nano-silica; the pre-modified silica, 2-(2,4-dihydroxyphenyl)-2H-benzotriazole, and 3wt% aqueous sodium hydroxide solution were mixed in a mass ratio of 1:4:16, stirred at 90 ° C and 400 r / min for 8 h, and 6wt% aqueous sodium bicarbonate solution with a mass of 11 times that of 2-(2,4-dihydroxyphenyl)-2H-benzotriazole was added, allowed to stand for 12 h, filtered, and dried in vacuo at 55 ° C for 8 h to obtain modified silica;

[0039] (3) Dodecafluoroheptyl methacrylate, diethanolamine and methanol were mixed in a mass ratio of 1:0.4:0.5, refluxed and stirred at 500 r / min for 49 h, washed with deionized water 4 times, and distilled under reduced pressure to obtain a fluorinated chain extender; isophorone diisocyanate and the fluorinated chain extender were mixed in a mass ratio of 1:0.5, stirred at 80°C and 400 r / min, and 0.03 times the mass of dibutyltin dilaurate of isophorone diisocyanate was added, and stirred at 65°C and 250 r / min for 5 hours to obtain a polyurethane prepolymer;

[0040] (4) The polyurethane prepolymer, ethyl acetate, tung oil-calcium alginate microcapsules, modified silica and 4,4'-methylenebis(2-chloroaniline) were mixed uniformly in a mass ratio of 1:2:0.15:0.05:0.18, and ultrasonically dispersed at 130°C for 15 minutes to prepare a polyurethane paint. The copper wire was soaked in the polyurethane paint and then taken out and dried at 55°C under vacuum conditions for 3.5 hours to prepare a weather-resistant enameled copper wire.

[0041] Example 3:

[0042] A method for preparing a weather-resistant enameled copper wire, comprising the following steps:

[0043] (1) Sodium alginate powder and ultrapure water were mixed at a mass ratio of 1:200, stirred at 700 r / min for 18 min at room temperature, and allowed to stand for 14 h to obtain a sodium alginate aqueous solution; anhydrous calcium chloride powder and ultrapure water were mixed at a mass ratio of 1:10, stirred at 400 r / min for 5 min at room temperature to obtain a calcium chloride aqueous solution; tung oil, OP-10 emulsifier and sodium alginate aqueous solution were mixed at a mass ratio of 1:0.3:110, stirred at 7000 r / min for 6 min at room temperature to obtain an oil-in-water emulsion, which was added to a calcium chloride aqueous solution with a mass of 120 times that of tung oil, stirred at 3000 r / min for 4 min, washed with deionized water 5 times, filtered, and dried at 80°C for 20 h to obtain tung oil-calcium alginate microcapsules;

[0044] (2) 3-Chloropropyltrimethoxysilane and deionized water were mixed at a mass ratio of 1:30, stirred at 30°C and 500 r / min for 20 min to prepare a silane hydrolyzate; nano-silica and anhydrous ethanol were mixed at a mass ratio of 1:30, 10 times the mass of nano-silica was added to the silane hydrolyzate, stirred at 80°C and 500 r / min for 1 h, filtered, washed with anhydrous ethanol 5 times, and dried at 80°C for 7 h under vacuum conditions to obtain Pre-modified nano-silica; pre-modified silica, 2-(2,4-dihydroxyphenyl)-2H-benzotriazole, and 3wt% sodium hydroxide aqueous solution were mixed in a mass ratio of 1:6:18, stirred at 100 ° C and 500 r / min for 7 h, 7wt% sodium bicarbonate aqueous solution with a mass of 12 times that of 2-(2,4-dihydroxyphenyl)-2H-benzotriazole was added, allowed to stand for 14 h, filtered, and dried in vacuo at 60 ° C for 7 h to obtain modified silica;

[0045] (3) Dodecafluoroheptyl methacrylate, diethanolamine and methanol were mixed in a mass ratio of 1:0.5:0.6, refluxed and stirred at 600 r / min for 48 h, washed with deionized water 5 times, and distilled under reduced pressure to obtain a fluorinated chain extender; isophorone diisocyanate and the fluorinated chain extender were mixed in a mass ratio of 1:0.6, stirred at 85°C and 500 r / min, and 0.05 times the mass of dibutyltin dilaurate of isophorone diisocyanate was added, and stirred at 80°C and 300 r / min for 4 hours to obtain a polyurethane prepolymer;

[0046] (4) The polyurethane prepolymer, ethyl acetate, tung oil-calcium alginate microcapsules, modified silica and 4,4'-methylenebis(2-chloroaniline) were mixed uniformly in a mass ratio of 1:2:0.2:0.06:0.20, and ultrasonically dispersed at 140°C for 10 minutes to prepare a polyurethane paint. The copper wire was soaked in the polyurethane paint and then taken out and dried at 60°C under vacuum conditions for 3 hours to prepare a weather-resistant enameled copper wire.

[0047] Comparative Example 1:

[0048] The difference between the preparation method of the weather-resistant enameled copper wire of Comparative Example 1 and Example 2 is that step (1) is not performed and tung oil-calcium alginate microcapsules are not added in step (4). The remaining steps are the same as those of Example 2.

[0049] Comparative Example 2:

[0050] The preparation method of the weather-resistant enameled copper wire of Comparative Example 2 differs from that of Example 2 in that step (2) is not performed and modified silicon dioxide is not added in step (4). The remaining steps are the same as those of Example 2.

[0051] Comparative Example 3:

[0052] The preparation method of the weather-resistant enameled copper wire of Comparative Example 3 differs from that of Example 2 only in step (3), which is modified as follows: isophorone diisocyanate and ethylene glycol are uniformly mixed in a mass ratio of 1:0.5, and then 0.03 times the mass of dibutyltin dilaurate is added to the mixture under stirring at 80°C and 400 rpm. The mixture is stirred at 65°C and 250 rpm for 5 hours to obtain a polyurethane prepolymer. The remaining steps are the same as those of Example 2.

[0053] Test Example 1

[0054] Corrosion resistance test

[0055] Testing Method: The polyurethane paints obtained in each example and comparative example were applied to tinplate sheets and cured at 50-60°C for 24 hours. The weather-resistant paint samples were then subjected to corrosion resistance testing in a salt spray chamber according to the national standard GB / T6458-86, "Metallic Coatings - Neutral Salt Spray Test." The test solvent in the salt spray chamber was a 5% sodium chloride solution with a pH controlled between 6.5 and 7.2. The chamber temperature was set at 35°C and the relative humidity was >95%. All prepared samples must first be scratched diagonally on the paint-covered surface with a scalpel and left to stand at room temperature for 24 hours. The enameled copper wire samples are placed on the rack in the salt spray test chamber, with the paint-covered surface facing up and at a 30° angle to the vertical. The painted samples cannot come into contact with the chamber, nor can each sample come into contact with the other. A certain distance must be left to avoid cross-contamination of droplets on the samples. During the test, the salt spray must fall freely on the coating-covered surface of the sample and cannot be sprayed directly onto the test surface of the sample. After the test, the sample is removed and placed at room temperature to dry naturally for 30-60 minutes. The salt spray residue on the surface of the sample is gently rinsed with clean water below 40°C. After cleaning, the sample is dried naturally again. The time when the sample starts to corrode is recorded to judge the corrosion resistance. The results are shown in Table 1.

[0056] Table 1

[0057] Corrosion start time / min Corrosion start time / min Example 1 600 Comparative Example 1 180 Example 2 648 Comparative Example 2 520 Example 3 580 Comparative Example 3 500

[0058] From the comparison of the experimental data of Examples 1-3 and Comparative Examples 1-3 in Table 1, it can be found that the weather-resistant enameled copper wire prepared in the present invention has good corrosion resistance.

[0059] By comparison, the corrosion onset time of Examples 1-3 is longer than that of Comparative Example 1, which shows that when tung oil and calcium alginate are prepared into core-shell microcapsules and applied to enameled copper wire, the core tung oil of the tung oil-calcium alginate microcapsules flows out to form a protective film, which blocks the corrosion factors from penetrating from the microcracks in the paint to the metal surface and causing direct corrosion to the metal, thereby extending the service life of the paint, reducing the maintenance cost of paint protection, and improving the corrosion resistance of the weather-resistant enameled copper wire; the core tung oil of the tung oil-calcium alginate microcapsules flows out to fill the cracks in the paint, and the tung oil in the core material of the microcapsules at the cracks reacts with oxygen to produce a curing reaction to bond the cracks together again to repair the coating, thereby preventing the corrosive medium from contacting the metal device through the defects in the coating, thereby improving the corrosion resistance of the weather-resistant enameled copper wire.

[0060] By comparison, the corrosion start time of Examples 1-3 is longer than that of Comparative Example 2, indicating that the modified silica enhances the overall density of the paint film, blocks the penetration path of corrosive media such as moisture and oxygen, and thus improves the corrosion resistance of the weather-resistant enameled copper wire.

[0061] By comparison, the corrosion start time of Examples 1-3 is longer than that of Comparative Example 3, indicating that the polyurethane prepolymer and the curing agent are cross-linked to form a three-dimensional network containing fluorine-carbon chains, and the low surface energy hydrophobic layer and tung oil cooperate to be water-resistant, reduce the risk of cracking, and improve the corrosion resistance of the weather-resistant enameled copper wire.

[0062] Test Example 2

[0063] Weather resistance test

[0064] Test method: Take samples of the same size as the weather-resistant enameled copper wire obtained in each embodiment and the comparative example material, and conduct ultraviolet aging test according to GB / T14522-2008, with a light source wavelength of 313nm and a light irradiation intensity of (0.71±0.02) (W / m 2 ), illumination temperature (60±3)°C, illumination cycle 4h; condensation temperature (50±3)°C, condensation cycle 4h, i.e., UV-B program. After aging for 3000h, the degree of chalking and discoloration was recorded according to GB / T1766-2018 to judge the aging and weathering resistance of the paint coating. The results are shown in Table 2

[0065] Table 2

[0066] Grades of chalking and discoloration Grades of chalking and discoloration Example 1 Powdering level 1, color change level 1 Comparative Example 1 Powdering level 1, color change level 1 Example 2 Powdering level 1, color change level 1 Comparative Example 2 Powdering level 2, color change level 2 Example 3 Powdering level 1, color change level 1 Comparative Example 3 Powdering level 1, color change level 1

[0067] From the comparison of the experimental data of Examples 1-3 and Comparative Examples 1-3 in Table 2, it can be found that the weather-resistant enameled copper wire prepared in the present invention has good weather resistance.

[0068] By comparison, Examples 1-3 have lower levels of powdering and discoloration than Comparative Example 2, indicating that after the introduction of 2-(2,4-dihydroxyphenyl)-2H-benzotriazole, the ultraviolet absorber is bonded to the surface of silica through a chemical reaction to form an "inorganic core-organic shell" hybrid structure, so that the modified silica has both physical shielding and chemical absorption dual anti-ultraviolet capabilities. The benzotriazole group can effectively absorb ultraviolet light of 280-400nm and convert light energy into heat energy through intramolecular electron transfer, thereby avoiding chain breakage of the polyurethane paint film due to ultraviolet radiation. At the same time, the inorganic skeleton of nano-silica can scatter incident light, further weakening the ultraviolet penetration ability and delaying the aging rate of the paint film, thereby improving the weather resistance of the weather-resistant enameled copper wire.

[0069] Test Example 3

[0070] Water resistance test

[0071] Test method: Pour the polyurethane paint of the embodiment and comparative example into a polytetrafluoroethylene mold and cure at 50-60°C for 24 hours. Cut the cured coating into 25mm x 25mm squares and weigh them (m1). Soak them in deionized water at room temperature for 24 hours. Use absorbent paper to remove moisture from the coating surface and weigh them (m2). The water absorption rate is calculated as (m2 - m1) / m1 x 100%. The results are shown in Table 3.

[0072] Table 3

[0073] Water absorption / % Water absorption / % Example 1 0.55 Comparative Example 1 0.86 Example 2 0.52 Comparative Example 2 0.74 Example 3 0.78 Comparative Example 3 1.32

[0074] From the comparison of the experimental data of Examples 1-3 and Comparative Examples 1-3 in Table 3, it can be found that the weather-resistant enameled copper wire prepared in the present invention has good water resistance.

[0075] By comparison, the water absorption rates of Examples 1-3 are lower than that of Comparative Example 3, indicating that the polyurethane prepolymer is prepared by reacting dodecafluoroheptyl methyl methacrylate, diethanolamine, and isophorone diisocyanate. The dodecafluoroheptyl methyl methacrylate contains a fluorocarbon group to form a low surface energy hydrophobic layer. Isophorone diisocyanate reacts with diethanolamine to form a polyurethane skeleton. During the reaction, fluorocarbon chains are introduced into the polyurethane chains to form a "hydrophobic-hydrophilic" block structure. The fluorocarbon chains are oriented to the surface, and an appropriate cross-linking density prevents water penetration, slows down the rusting of the copper wire, and improves the water resistance of the weather-resistant enameled copper wire.

[0076] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A weather-resistant enameled copper wire, characterized in that: The copper wire is impregnated with polyurethane paint and dried to obtain a weather-resistant enameled copper wire; The polyurethane paint is prepared by mixing tung oil-calcium alginate microcapsules, modified silicon dioxide, polyurethane prepolymer and 4,4'-methylenebis(2-chloroaniline); The tung oil-calcium alginate microcapsules are formed by using tung oil as the core material and calcium ions and sodium alginate as the wall material. The modified silicon dioxide is prepared by reacting nano silicon dioxide with 3-chloropropyltrimethoxysilane and then reacting with 2-(2,4-dihydroxyphenyl)-2H-benzotriazole; The polyurethane prepolymer is prepared by reacting dodecafluoroheptyl methyl methacrylate with diethanolamine and then reacting with isophorone diisocyanate.

2. A method for preparing a weather-resistant enameled copper wire, characterized in that: The preparation method of the weather-resistant enameled copper wire comprises the following preparation steps: (1) Tung oil, OP-10 emulsifier and sodium alginate aqueous solution are mixed uniformly in a mass ratio of 1:(0.1-0.3):(90-110), stirred at 5000-7000 r / min for 6-8 minutes at room temperature to prepare an oil-in-water emulsion, added to a calcium chloride aqueous solution with a mass of 100-120 times that of the tung oil, stirred at 1000-3000 r / min for 4-6 minutes, washed with deionized water 3-5 times, filtered, and dried at 70-80°C for 20-30 hours to prepare tung oil-calcium alginate microcapsules; (2) pre-modified silica, 2-(2,4-dihydroxyphenyl)-2H-benzotriazole, and sodium hydroxide aqueous solution were mixed uniformly in a mass ratio of 1:(2-6):(14-18), stirred at 80-100°C and 300-500r / min for 7-9h, and 6wt%-7wt% sodium bicarbonate aqueous solution with a mass of 10-12 times that of 2-(2,4-dihydroxyphenyl)-2H-benzotriazole was added, allowed to stand for 10-14h, filtered, and vacuum dried at 50-60°C for 7-9h to obtain modified silica; (3) isophorone diisocyanate and a fluorinated chain extender are uniformly mixed in a mass ratio of 1:(0.4-0.6), and 0.01-0.05 times the mass of dibutyltin dilaurate of isophorone diisocyanate is added under stirring at 75-85°C and 300-500 r / min, and the mixture is stirred at 50-80°C and 200-300 r / min for 4-6 hours to obtain a polyurethane prepolymer; (4) The polyurethane prepolymer, ethyl acetate, tung oil-calcium alginate microcapsules, modified silica and 4,4'-methylenebis(2-chloroaniline) were mixed uniformly in a mass ratio of 1:2:(0.1-0.2):(0.04-0.06):(0.15-0.20), and ultrasonically dispersed at 120-140°C for 10-20 minutes to prepare a polyurethane paint. The copper wire was soaked in the polyurethane paint and then taken out and dried under vacuum at 50-60°C for 3-4 hours to prepare a weather-resistant enameled copper wire.

3. The method for preparing a weather-resistant enameled copper wire according to claim 2, wherein: The sodium alginate aqueous solution in step (1) is prepared by uniformly mixing sodium alginate powder and ultrapure water in a mass ratio of 1:200, stirring at 500-700 r / min for 18-22 minutes at room temperature, and standing for 10-14 hours to obtain the sodium alginate aqueous solution.

4. The method for preparing a weather-resistant enameled copper wire according to claim 2, wherein: The calcium chloride aqueous solution in step (1) is prepared by uniformly mixing anhydrous calcium chloride powder and ultrapure water in a mass ratio of 1:10, and stirring at 200-400 r / min for 5-8 minutes at room temperature to obtain the calcium chloride aqueous solution.

5. The method for preparing a weather-resistant enameled copper wire according to claim 2, wherein: The pre-modified silica in step (2) is prepared by uniformly mixing nano-silica and anhydrous ethanol in a mass ratio of 1:(20-30), adding silane hydrolyzate 8-10 times the mass of the nano-silica, stirring at 60-80°C and 300-500r / min for 1-2h, filtering, washing with anhydrous ethanol 3-5 times, and drying at 60-80°C under vacuum conditions for 7-8h to obtain pre-modified nano-silica.

6. The method for preparing a weather-resistant enameled copper wire according to claim 5, characterized in that: The silane hydrolyzate is prepared by uniformly mixing 3-chloropropyltrimethoxysilane and deionized water in a mass ratio of 1:(20-30), stirring at 10-30° C. and 300-500 r / min for 20-30 minutes, and preparing the silane hydrolyzate.

7. The method for preparing a weather-resistant enameled copper wire according to claim 2, wherein: The mass fraction of the sodium hydroxide aqueous solution in step (2) is 3%.

8. The method for preparing a weather-resistant enameled copper wire according to claim 2, wherein: The fluorine-containing chain extender in step (3) is prepared by mixing dodecafluoroheptyl methacrylate, diethanolamine and methanol in a mass ratio of 1:(0.3-0.5):(0.4-0.6), stirring under reflux at 400-600 r / min for 48-50 hours, washing with deionized water for 3-5 times, and distilling under reduced pressure to obtain the fluorine-containing chain extender.