A kind of mica tape precision wrapped electromagnetic wire and preparation method thereof

Abstract

The present invention relates to a mica tape precision wrapped electromagnetic wire and a preparation method thereof, and belongs to the technical field of wrapped electromagnetic wires. The present invention significantly improves the insulation performance of the insulating coating and the stability of the coating in a high temperature environment by adding low-priced, uniform-sized dolomite; the present invention further improves the insulation performance and stability of the coating by adding selenium disulfide, and the moisture-proof performance of selenium disulfide also enhances the resistance of the insulating layer to erosion by moisture, chemicals, etc.; the present invention slows down the aging speed of the coating by adding citric acid, and citric acid can improve the bonding force between the coating and the substrate, improve the adhesion and stability of the coating, and thus enhance the durability of the coating; the present invention improves the fluidity and coverage of the coating by adding palm wax, so that the prepared insulating coating can be better attached to the surface of the mica tape.

Description

Technical Field

[0001] The invention belongs to the technical field of wrapped electromagnetic wires and relates to a mica tape precision wrapped electromagnetic wire and a preparation method thereof. Background Art

[0002] High-voltage motors refer to motors with a rated voltage of more than 1000V. Commonly used voltages are 6000V and 10000V. High-voltage motors are produced because the motor power is proportional to the product of voltage and current. Therefore, when the power of low-voltage motors increases to a certain level, the current is limited by the allowable bearing capacity of the wire and it is difficult to increase it, or the cost is too high. It is necessary to increase the voltage to achieve high power output. The advantages of high-voltage motors are high power and strong impact resistance; the disadvantages are large inertia, and both starting and braking are difficult.

[0003] Electromagnetic wire is mainly used in the windings of transformers, motors and various electrical equipment, and is a key material for completing electromagnetic energy conversion. With the continuous development of electrical equipment, the performance requirements for electromagnetic wire are becoming higher and higher, especially in terms of insulation performance, mechanical strength, heat dissipation capacity, etc. Although the traditional electromagnetic wire manufacturing method can meet basic usage requirements, its performance may be affected under certain special environments, such as high temperature, high humidity, high voltage, etc.

[0004] Mica tape, as a material with excellent insulation and high temperature resistance, is widely used in the production of magnet wire. The mica tape wrapped magnet wire technology is to wrap mica tape around the conductor to form a solid insulation layer, thereby improving the insulation and high temperature resistance of the magnet wire. This technology can not only increase the service life of the magnet wire, but also improve the operating stability of electrical equipment.

[0005] As one of the indispensable and important parts inside the high-voltage motor, the wrapped electromagnetic wire needs to be insulated on the surface to meet the extreme environment when the high-voltage motor is operating. The insulation treatment is to separate the contact between the wires, and the greater purpose is to reduce the damage caused by the generation of corona. The present invention further insulates the surface of the mica tape to improve the performance of the mica tape wrapped electromagnetic wire. Summary of the invention

[0006] The invention aims to provide a mica tape precision wrapped electromagnetic wire and a preparation method thereof, which has the characteristics of good insulation performance and long service life.

[0007] The purpose of the present invention can be achieved through the following technical solutions:

[0008] A mica tape precision wrapped electromagnetic wire, the wrapped electromagnetic wire comprises an internal metal conductor and a mica tape with a modified insulating coating attached to the surface, wherein the preparation method of the mica tape with a modified insulating coating attached to the surface is as follows:

[0009] S1: by weight percentage, polyurethane resin 20-25%, epoxy resin 15-20%, phenolic resin 10-15%, dolomite 25-30%, silicon dioxide 3-5%, palm wax 1-3%, citric acid 1-3%, selenium disulfide 1-3%, rare earth element 1-3%, dispersant 1-2%, curing agent 1-2%, firstly mix the polyurethane resin, epoxy resin and phenolic resin according to proportion, mix well and heat to 180°C to make the mixture molten, stir at a speed of 300 r / min for 2 hours to obtain mixture A;

[0010] S2: dolomite and silicon dioxide are mixed in proportion, and ground in a ball mill at a speed of 400 r / min for 4 h to obtain a mixture B;

[0011] S3: Add mixture B to mixture A, continue stirring at 180°C and 300 r / min for 2 h, cool to 120°C, then add palm wax, citric acid, selenium disulfide, rare earth elements, dispersant, and curing agent in proportion, stir for 2 h, then slowly cool to room temperature, and stand for 12 h to obtain a modified insulating coating;

[0012] S4: drying the mica tape at 80°C for 12 hours, laying the completely dried mica tape flat and immersing it in the modified insulating coating prepared in S3 for 1 hour, taking it out and laying it flat after immersion;

[0013] S5: The soaked mica tape is dried by laser irradiation. The laser power of the laser irradiation is 300 W, the temperature is 50° C., the irradiation time is 1 hour, and after drying, it is allowed to stand for 12 hours to obtain a mica tape with a modified insulating coating attached to the surface.

[0014] Furthermore, the metal conductor is one of copper, aluminum and silver.

[0015] Furthermore, the rare earth element in S1 is one or more of La, Ce, and Pr.

[0016] Furthermore, the dispersant in S1 is polyethylene glycol, and its molecular weight is 800-1000.

[0017] Furthermore, the curing agent in S1 is one of diisocyanate and triisocyanate.

[0018] A method for preparing a mica tape precision wrapped electromagnetic wire, the process of the method for preparing a mica tape precision wrapped electromagnetic wire is as follows:

[0019] S61: Processing the metal conductor by a rolling and drawing method, stretching the metal conductor to a diameter of 0.1 mm;

[0020] S62: Applying a layer of adhesive on the surface of the conductor by spraying;

[0021] S63: Wrap the mica tape with a modified insulating coating on the surface around the conductor, and dry it at 80° C. for 12 hours under a nitrogen atmosphere to obtain a mica tape precision wrapped electromagnetic wire.

[0022] Furthermore, the parameters of the spraying method in S62 are a spraying distance of 100-150 mm and a spraying rate of 60-120 mm / s.

[0023] Furthermore, the wrapping gap range of the mica tape in S63 is 0.1-0.3 mm.

[0024] As an inorganic mineral material, dolomite has good insulation properties. Adding it to the insulating coating can significantly improve the insulation resistance of the coating; dolomite has excellent high temperature resistance. Adding dolomite to the insulating coating can significantly improve the stability of the coating in a high temperature environment and prevent the coating performance from degrading or failing due to high temperature; the addition of dolomite can enhance the hardness and wear resistance of the insulating coating, making it more durable; dolomite has good dispersion in the coating and can be tightly combined with other components in the coating, thereby improving the adhesion between the coating and the substrate and reducing the risk of peeling or cracking of the coating; in addition, dolomite also has the advantages of low price and environmental protection.

[0025] However, the particle size and distribution of dolomite are crucial to the uniformity and consistency of the insulating coating. If the particles are too large or unevenly distributed, the coating surface may be uneven, or even have voids or cracks, thereby affecting the insulating performance and service life of the coating. Therefore, the present invention grinds the dolomite using a ball mill to obtain dolomite particles with uniform particle size.

[0026] The present invention also adds selenium disulfide to further improve the insulation performance of the insulating coating. Selenium disulfide has good electrical insulation performance, it can improve the overall insulation strength of the insulating layer, effectively prevent current leakage, and ensure the safe and stable operation of the circuit; selenium disulfide also has excellent heat resistance. The addition of selenium disulfide can significantly improve the high temperature resistance of the insulating layer, so that it can maintain stable performance under extreme conditions; selenium disulfide also has certain moisture-proof performance, it can enhance the insulation layer's resistance to erosion by moisture, chemicals, etc., thereby extending the service life of the insulation layer.

[0027] In the present invention, the stability of the insulating layer is improved by adding palm wax. Adding palm wax to the insulating coating can improve the waterproof, moisturizing and thickening capabilities of the coating. This helps to enhance the durability of the coating. At the same time, the thickening effect of palm wax can also improve the fluidity and coverage of the coating, so that the prepared insulating coating can better adhere to the surface of the mica tape.

[0028] Citric acid has excellent antioxidant properties and can effectively prevent the material in the coating from deteriorating due to oxidation. The present invention adds citric acid to the insulating coating, which helps to slow down the aging speed of the coating, thereby enhancing its durability; citric acid also has certain antibacterial and anti-mildew properties, which can reduce the erosion of microorganisms on the coating and further extend the service life of the coating; citric acid may also improve the bonding force between the coating and the substrate, and improve the adhesion and stability of the coating, which is also an important factor in improving the durability of the coating.

[0029] Beneficial effects of the present invention:

[0030] The present invention significantly improves the insulation performance of the insulating coating and the stability of the coating in a high temperature environment by adding low-cost dolomite with uniform particle size; the present invention further improves the insulation performance and stability of the coating by adding selenium disulfide, and the moisture-proof performance of selenium disulfide also enhances the resistance of the insulating layer to corrosion by moisture, chemical substances and the like; the present invention slows down the aging speed of the coating by adding citric acid, and the citric acid can improve the bonding force between the coating and the substrate, improve the adhesion and stability of the coating, and thus enhance the durability of the coating; the present invention improves the fluidity and coverage of the coating by adding palm wax, so that the prepared insulating coating can be better adhered to the surface of the mica tape. DETAILED DESCRIPTION

[0031] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in combination with the embodiments.

[0032] The ratio of the modified insulating coating is as follows:

[0033] Ratio 1: polyurethane resin 20%, epoxy resin 20%, phenolic resin 10%, dolomite 30%, silica 5%, palm wax 3%, citric acid 3%, selenium disulfide 3%, rare earth element La 3%, dispersant PEG-1000 2%, diisocyanate 1%;

[0034] Ratio 2: polyurethane resin 25%, epoxy resin 15%, phenolic resin 15%, dolomite 25%, silica 5%, palm wax 3%, citric acid 3%, selenium disulfide 3%, rare earth element La 3%, dispersant PEG-1000 2%, diisocyanate 1%;

[0035] Ratio 3: polyurethane resin 25%, epoxy resin 20%, phenolic resin 10%, dolomite 30%, silica 3%, palm wax 3%, citric acid 3%, selenium disulfide 1%, rare earth element La 3%, dispersant PEG-1000 1%, diisocyanate 1%;

[0036] Ratio 4: polyurethane resin 20%, epoxy resin 20%, phenolic resin 15%, dolomite 30%, silica 5%, palm wax 1%, citric acid 1%, selenium disulfide 3%, rare earth element La 1%, dispersant PEG-1000 2%, diisocyanate 2%;

[0037] Ratio 5: polyurethane resin 20%, epoxy resin 20%, phenolic resin 15%, dolomite 30%, silica 5%, palm wax 3%, citric acid 3%, selenium disulfide 1%, rare earth element La 1%, dispersant PEG-1000 1%, diisocyanate 1%;

[0038] Comparative ratio 1: polyurethane resin 20%, epoxy resin 20%, phenolic resin 10%, dolomite 30%, silica 5%, rare earth element La 3%, dispersant PEG-1000 2%, diisocyanate 1%, deionized water 9%;

[0039] Comparative ratio 2: polyurethane resin 20%, epoxy resin 20%, phenolic resin 10%, dolomite 30%, silicon dioxide 5%, citric acid 3%, selenium disulfide 3%, rare earth element La 3%, dispersant PEG-1000 2%, diisocyanate 1%, deionized water 3%;

[0040] Comparative ratio 3: polyurethane resin 20%, epoxy resin 20%, phenolic resin 10%, dolomite 30%, silica 5%, palm wax 3%, selenium disulfide 3%, rare earth element La 3%, dispersant PEG-1000 2%, diisocyanate 1%, deionized water 3%;

[0041] Comparative ratio 4: polyurethane resin 20%, epoxy resin 20%, phenolic resin 10%, dolomite 30%, silica 5%, palm wax 3%, citric acid 3%, rare earth element La 3%, dispersant PEG-1000 2%, diisocyanate 1%, deionized water 3%;

[0042] The preparation method of the mica tape with a modified insulating coating attached to the surface is as follows:

[0043] S1: First, polyurethane resin, epoxy resin and phenolic resin are mixed in proportion, and after being evenly mixed, they are heated to 180° C. to make the mixture molten, and stirred at a speed of 300 r / min for 2 h to obtain a mixture A;

[0044] S2: dolomite and silicon dioxide are mixed in proportion, and ground in a ball mill at a speed of 400 r / min for 4 h to obtain a mixture B;

[0045] S3: Add mixture B to mixture A, continue stirring at 180°C at a speed of 300 r / min for 2 hours, cool to 120°C, then add palm wax, citric acid, selenium disulfide, rare earth element La, PEG-1000, and diisocyanate in proportion, stir for 2 hours, then slowly cool to room temperature, and stand for 12 hours to obtain a modified insulating coating;

[0046] S4: drying the mica tape at 80°C for 12 hours, laying the completely dried mica tape flat and immersing it in the modified insulating coating prepared in S3 for 1 hour, taking it out and laying it flat after immersion;

[0047] S5: The soaked mica tape is dried by laser irradiation. The laser power of the laser irradiation is 300 W, the temperature is 50° C., the irradiation time is 1 hour, and after drying, it is allowed to stand for 12 hours to obtain a mica tape with a modified insulating coating attached to the surface.

[0048] Example 1

[0049] The process of preparing the mica tape precision wrapped electromagnetic wire is as follows:

[0050] S61: Processing the metal conductor by a rolling and drawing method, stretching the metal conductor to a diameter of 0.1 mm;

[0051] S62: A layer of adhesive is applied on the conductor surface by spraying, with a spraying distance of 130 mm and a spraying rate of 100 mm / s;

[0052] S63: Wrap a mica tape with a modified insulating coating having a ratio of 1 attached to the surface on the conductor, and dry it at 80° C. for 12 hours under a nitrogen atmosphere to obtain a mica tape precision wrapped electromagnetic wire.

[0053] The difference between Example 2 and Example 1 is that the mica tape with a modified insulating coating having an adhesion ratio of 2 is used in S63, and the remaining steps are the same.

[0054] The difference between Example 3 and Example 1 is that the mica tape with a modified insulating coating having an adhesion ratio of 3 is used in S63, and the remaining steps are the same.

[0055] The difference between Example 4 and Example 1 is that the mica tape with a modified insulating coating having an adhesion ratio of 4 is used in S63, and the remaining steps are the same.

[0056] The difference between Example 5 and Example 1 is that the mica tape with a modified insulating coating having an adhesion ratio of 5 is used in S63, and the remaining steps are the same.

[0057] The difference between Comparative Example 1 and Example 1 is that the mica tape with the modified insulating coating of Comparative Example 1 is used in S63, and the remaining steps are the same.

[0058] The difference between Comparative Example 2 and Example 1 is that the mica tape with the modified insulating coating of Comparative Example 2 is used in S63, and the other steps are the same.

[0059] The difference between Comparative Example 3 and Example 1 is that the mica tape with the modified insulating coating of Comparative Example 3 is used in S63, and the other steps are the same.

[0060] The difference between Comparative Example 4 and Example 1 is that the mica tape with the modified insulating coating of Comparative Example 4 is used in S63, and the other steps are the same.

[0061] The insulation properties of the mica tape precision wrapped electromagnetic wires prepared in the embodiments of the present invention and the comparative examples were tested. The conductivity of the test samples was tested according to GB / T 17650.2-2021. The lower the conductivity, the better the insulation properties. The experimental data are summarized in the following table.

[0062]

[0063] Through experiments, it is found that the mica tape precision wrapped electromagnetic wire prepared in Example 1 has the best performance.

[0064] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A mica tape precision wrapped electromagnetic wire, characterized in that: The wrapped electromagnetic wire comprises an internal metal conductor and a mica tape with a modified insulating coating attached to the surface, wherein the preparation method of the mica tape with a modified insulating coating attached to the surface is as follows: S1: by weight percentage, polyurethane resin 20-25%, epoxy resin 15-20%, phenolic resin 10-15%, dolomite 25-30%, silicon dioxide 3-5%, palm wax 1-3%, citric acid 1-3%, selenium disulfide 1-3%, rare earth element 1-3%, dispersant 1-2%, curing agent 1-2%. First, the polyurethane resin, epoxy resin and phenolic resin are mixed in proportion, and after mixing evenly, they are heated to 180° C. to make the mixture in a molten state, and stirred at a speed of 300 r / min for 2 hours to obtain a mixture A; S2: dolomite and silicon dioxide were mixed in proportion, and ground in a ball mill at a speed of 400 r / min for 4 h to obtain a mixture B; S3: Add mixture B to mixture A, continue stirring at 300 r / min for 2 h at 180°C, cool to 120°C, add palm wax, citric acid, selenium disulfide, rare earth elements, dispersant and curing agent in proportion, stir for 2 h, then slowly cool to room temperature, and stand for 12 h to obtain a modified insulating coating; S4: drying the mica tape at 80°C for 12 hours, laying the completely dried mica tape flat and immersing it in the modified insulating coating prepared in S3 for 1 hour, taking it out and laying it flat after immersion; S5: The soaked mica tape is dried by laser irradiation. The laser power of the laser irradiation is 300 W, the temperature is 50° C., the irradiation time is 1 hour, and after drying, it is allowed to stand for 12 hours to obtain a mica tape with a modified insulating coating attached to the surface.

2. The mica tape precision wrapped electromagnetic wire according to claim 1, characterized in that: The metal conductor is one of copper, aluminum and silver.

3. The mica tape precision wrapped electromagnetic wire according to claim 1, characterized in that: The rare earth element in S1 is one or more of La, Ce and Pr.

4. The mica tape precision wrapped electromagnetic wire according to claim 1, characterized in that: The dispersant in S1 is polyethylene glycol, and its molecular weight is 800-1000.

5. The mica tape precision wrapped electromagnetic wire according to claim 1, characterized in that: The curing agent in S1 is one of diisocyanate and triisocyanate.

6. A method for preparing a mica tape precision wrapped electromagnetic wire, based on the mica tape precision wrapped electromagnetic wire according to any one of claims 1 to 5, characterized in that: The process of preparing the mica tape precision wrapped electromagnetic wire is as follows: S61: Processing the metal conductor by a rolling and drawing method, stretching the metal conductor to a diameter of 0.1 mm; S62: Applying a layer of adhesive on the surface of the metal conductor by spraying; S63: Wrap the mica tape with a modified insulating coating on the surface around the metal conductor, and dry it at 80° C. for 12 hours under a nitrogen atmosphere to obtain a mica tape precision wrapped electromagnetic wire.

7. The method for preparing a mica tape precision wrapped electromagnetic wire according to claim 6, characterized in that: The parameters of the spraying method in S62 are a spraying distance of 100-150 mm and a spraying rate of 60-120 mm / s.

8. The method for preparing a mica tape precision wrapped electromagnetic wire according to claim 6, characterized in that: The wrapping gap range of the mica tape in S63 is 0.1-0.3 mm.

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