High-temperature-resistant insulating coating material for electromagnetic wire and preparation method and application of high-temperature-resistant insulating coating material

Abstract

The invention relates to a high-temperature-resistant insulating coating material for an electromagnetic wire as well as a preparation method and application thereof. The method comprises the steps that the surface of a wire is pretreated; the preparation method comprises the following steps: preparing raw materials of the glass component according to a ratio, melting glass, ball-milling and sieving to obtain glass powder, and then adding the ceramic component and the auxiliary additive component to obtain an inorganic filler; the preparation method comprises the following steps: mixing organic silicon resin, inorganic powder, a solvent, a pigment and an auxiliary agent in proportion to obtain uniform slurry; the method comprises the following steps: coating a wire with a coating, curing the wire after coating is completed, and naturally cooling the wire to room temperature after curing is completed. The electromagnetic wire surface coating can be prevented from aging, peeling, cracking, stripping and losing efficacy at the high temperature of 500 DEG C, the performance of high insulation, impact resistance, long service life and the like of the coating material in the high-temperature environment is improved, it is guaranteed that equipment can tolerate severe natural environments or machine part working environments, and the electromagnetic wire surface coating has high stability and long service life.

Description

Technical Field

[0001] The invention belongs to the field of high temperature resistant insulating coatings, and specifically relates to a high temperature resistant insulating coating material for electromagnetic wires, a preparation method and an application thereof. Background Art

[0002] Electromagnetic wires are widely used in the fields of electronics, electrical engineering, and mechanical engineering. For example, they are used in transformers, sensors, generators, etc. to improve the reliability and safety of equipment. With the development of the aerospace industry, the requirements for monitoring the working status of equipment and equipment in harsh environments are gradually increasing, and the requirements for performance and service life are gradually upgraded. Some equipment needs to be able to be used for a long time in high temperature (500°C and above) environments. It is very important to solve the key technical problems that restrict the further development of related electronic equipment, such as aging of the surface coating material of the electromagnetic wire, attenuation of electrical insulation performance, and oxidation of the coil under high temperature working conditions.

[0003] The technology involving the surface coating materials of electromagnetic wire mainly adopts two methods: organic coating and inorganic fiber winding. Among them, organic coating is mainly used in the use environment within room temperature to 125℃, and a few can be used in the use environment of 260℃ and above; for the use environment above 260℃, mica fiber cloth, glass fiber cloth and other inorganic fiber cloth insulation methods are used. Due to the characteristics of the glass material itself, its maximum use temperature is generally within 500℃. At the same time, the fiber winding process will greatly increase the diameter of a single coil, which will lead to a multiple reduction in the number of coil turns in a limited design space, affecting the stability and reliability of electronic equipment. Summary of the invention

[0004] In view of this, the main purpose of the present invention is to provide a high-temperature resistant insulating coating material for electromagnetic wire and a preparation method and application thereof. The problem to be solved is how to provide a high-temperature resistant insulating coating material for electromagnetic wire to prevent the surface coating of the electromagnetic wire from aging, peeling, cracking, peeling and failure at a high temperature of 500°C, and to improve the coating material's high insulation, impact resistance, long life and other performance in a high temperature environment, to ensure that the equipment can withstand harsh natural environments or machine working environments, and has high stability and a long service life.

[0005] The purpose of the present invention and the technical problem to be solved are achieved by adopting the following technical solutions. A method for preparing a high temperature resistant insulating coating material for electromagnetic wire proposed by the present invention comprises the following steps:

[0006] S1 substrate pretreatment: pretreat the surface of the conductor;

[0007] S2 Preparation of inorganic filler: The raw materials of the glass component are prepared in proportion, the glass is melted, and the glass powder is obtained after ball milling and sieving, and then the ceramic component and the auxiliary additive component are added to obtain the inorganic filler;

[0008] S3 coating slurry preparation: organic silicone resin, inorganic filler, solvent, pigment and additive are mixed in proportion to obtain a uniform slurry;

[0009] S4 coating: firstly, the conductor is coated with a coating, and after the coating is completed, the conductor is cured, and after the curing is completed, the conductor is naturally cooled to room temperature to obtain the high temperature resistant insulating coating material for the electromagnetic wire.

[0010] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

[0011] Preferably, in the aforementioned method for preparing a high-temperature resistant insulating coating material for electromagnetic wire, in step S1, the pretreatment includes a wire surface cleaning treatment and a wire material heat treatment; the wire surface cleaning treatment uses a grinding method to perform a first step of cleaning to remove the surface oxide layer and other adhering contaminants; anhydrous ethanol or acetone is used to perform a second step of cleaning the wire to remove surface grease, and the cleaned wire is dried; the wire material heat treatment includes vacuum treatment and oxidation treatment; the vacuum treatment includes: placing the wire in a vacuum furnace for high-temperature heating; the oxidation treatment includes: subjecting the wire to flame heating and surface micro-oxidation treatment.

[0012] Preferably, in the aforementioned method for preparing a high temperature resistant insulating coating material for electromagnetic wire, in step S2, the amount of the glass component is 20 to 200 parts by mass, the amount of the ceramic component is 50 to 300 parts by mass, and the amount of the auxiliary additive component is 20 to 120 parts by mass.

[0013] Preferably, in the aforementioned method for preparing a high temperature resistant insulating coating material for electromagnetic wire, in step S2, the glass component is selected from at least two of silicon dioxide, barium oxide, calcium oxide, beryllium oxide and phosphorus pentoxide, and the cladding temperature ranges from 500 to 700°C.

[0014] Preferably, in the aforementioned method for preparing a high temperature resistant insulating coating material for electromagnetic wire, in step S2, the ceramic component is selected from at least one of aluminum oxide, magnesium oxide, titanium dioxide, gallium oxide, molybdenum oxide, zinc oxide, niobium oxide and tin oxide.

[0015] Preferably, in the aforementioned method for preparing a high temperature resistant insulating coating material for electromagnetic wire, in step S2, the auxiliary additive component is selected from at least one of sodium oxide, lithium oxide and mica powder.

[0016] Preferably, in the aforementioned method for preparing a high temperature resistant insulating coating material for electromagnetic wire, in step S2, the glass component is composed of silicon dioxide, barium oxide, calcium oxide, beryllium oxide and phosphorus pentoxide, and its composition by mass is: 50 to 100 parts of silicon dioxide, 20 to 70 parts of barium oxide, 10 to 60 parts of calcium oxide, 10 to 30 parts of beryllium oxide, and 80 to 150 parts of phosphorus pentoxide.

[0017] Preferably, in the aforementioned method for preparing a high temperature resistant insulating coating material for electromagnetic wire, in step S2, the ceramic component is composed of aluminum oxide, magnesium oxide, titanium dioxide, gallium oxide, molybdenum oxide, zinc oxide, niobium oxide and tungsten oxide, and its composition in parts by mass is: 80 to 200 parts of aluminum oxide, 10 to 50 parts of magnesium oxide, 10 to 60 parts of titanium dioxide, 10 to 30 parts of gallium oxide, 10 to 30 parts of molybdenum oxide, 50 to 150 parts of zinc oxide, 20 to 70 parts of niobium oxide, and 10 to 50 parts of tungsten oxide.

[0018] Preferably, in the aforementioned method for preparing a high temperature resistant insulating coating material for electromagnetic wire, in step S2, the auxiliary additive component is composed of sodium oxide, lithium oxide and mica powder, and its composition by mass is: 30 to 100 parts of sodium oxide, 10 to 60 parts of lithium oxide, and 10 to 100 parts of mica powder.

[0019] Preferably, in the aforementioned method for preparing a high temperature resistant insulating coating material for electromagnetic wire, in step S2, the ball milling medium is a zirconia ball; and the rotation speed of the ball mill is 200 to 400 r / min.

[0020] Preferably, in the aforementioned method for preparing a high temperature resistant insulating coating material for electromagnetic wire, in step S3, the silicone resin is a resin with fluidity, which is selected from at least one of methyl phenyl silicone resin, epoxy modified silicone resin and acrylic modified resin.

[0021] Preferably, in the aforementioned method for preparing a high temperature resistant insulating coating material for electromagnetic wire, in step S3, the solvent is selected from at least one of toluene, xylene, n-hexane, ethyl acetate, dimethyl ketone and deionized water.

[0022] Preferably, in the aforementioned method for preparing a high temperature resistant insulating coating material for electromagnetic wire, in step S3, the pigment is selected from at least one of copper chrome black, iron manganese black, iron oxide red and titanium dioxide.

[0023] Preferably, in the aforementioned method for preparing a high temperature resistant insulating coating material for electromagnetic wire, in step S3, the slurry is composed by mass of: 30 to 70 parts of silicone resin, 10 to 25 parts of inorganic powder, 20 to 80 parts of solvent, 5 to 15 parts of pigment, and 0.5 to 2 parts of additive.

[0024] Preferably, in the aforementioned method for preparing a high temperature resistant insulating coating material for electromagnetic wire, in step S3, the mixing specifically comprises: firstly, the silicone resin, solvent, inorganic filler and curing agent are subjected to low-speed shear mixing at 100 to 150 r / min, and then, the pigment and auxiliary agent are added and subjected to high-speed shear mixing at 400 to 600 r / min.

[0025] Preferably, in the aforementioned method for preparing a high temperature resistant insulating coating material for electromagnetic wire, in step S3, the auxiliary agent includes at least one of a dispersant, a leveling agent, a defoaming agent, a thickener and a binder.

[0026] Preferably, in the aforementioned method for preparing a high temperature resistant insulating coating material for electromagnetic wire, in step S4, the curing temperature is 200 to 300° C. and the curing time is 0.5 to 2 hours.

[0027] The purpose of the present invention and the technical problem to be solved are achieved by adopting the following technical solutions. The present invention proposes a high temperature resistant insulating coating material for electromagnetic wire, whose thermal expansion coefficient is 14 to 20×10 -6 / K; The electromagnetic wire is made of high temperature resistant insulating coating material by the above method.

[0028] The purpose of the present invention and the technical problem to be solved are achieved by adopting the following technical solutions. The present invention proposes an electromagnetic wire, which comprises a conductor connected from the inside to the outside, a pre-processed interface and a coating, wherein the coating is composed of a high temperature resistant insulating coating material, and the thermal expansion coefficient of the high temperature resistant insulating coating material is 14 to 20×10 -6 / K.

[0029] The purpose of the present invention and the technical problem to be solved are achieved by adopting the following technical solutions. The present invention proposes an electronic device, the electronic device comprises an electromagnetic wire, the electromagnetic wire comprises a wire connected from the inside to the outside, a pre-processed interface and a coating, the coating is composed of a high temperature resistant insulating coating material, and the thermal expansion coefficient of the high temperature resistant insulating coating material is 14 to 20×10 -6 / K.

[0030] By means of the above technical solution, the present invention provides a high temperature resistant insulating coating material for electromagnetic wire and a preparation method and application thereof, which have at least the following advantages:

[0031] 1. The high temperature resistant insulating coating material for electromagnetic wire provided by the present invention has excellent high temperature resistance. This formula gives full play to the role of the glass component in the coating material as a densification sintering aid for the ceramic skeleton material, and improves the overall temperature resistance of the coating material through microcrystallization treatment of the glass phase, so that it can meet the use requirements of the equipment to operate normally for 1000 hours at a high temperature of 500°C;

[0032] 2. The high temperature resistant insulating coating material for electromagnetic wire provided by the present invention has excellent flexibility. By adding water-based silicone resin to increase the toughness and plasticity of the slurry, the surface coating of the conductor is still flexible at room temperature after curing, meeting the requirements for conductor winding, and can be wound on the surface of a stator with a diameter of 20 mm or more, and the surface coating of the conductor does not crack or fall off;

[0033] 3. The high temperature resistant insulating coating material for electromagnetic wire provided by the present invention has a coating thickness of 22-27 μm, no cracks on the surface, a high temperature resistance of 500°C for more than 1000 hours, and a high temperature breakdown voltage of ≥1.25KV@500°C;

[0034] 4. The electromagnetic wire provided by the present invention has extremely high stability and a long service life for the electronic equipment used. In a harsh natural environment or machine working environment, the equipment can operate normally for a long time.

[0035] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 are cross-sectional views of electromagnetic wires according to some embodiments of the present invention;

[0037] Figure 2 The effect diagram of the coating and winding of the electromagnetic wire surface in some embodiments of the present invention;

[0038] Among them, 1-conductor; 2-pretreatment interface; 3-coating; 4-oxygen-free copper conductor; 5-electromagnetic wire; 6-conductor winding. DETAILED DESCRIPTION

[0039] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of a high temperature resistant insulating coating material for electromagnetic wire and its preparation method and application according to the present invention, its specific implementation method, structure, characteristics and effects in combination with the preferred embodiment. In the following description, different "one embodiment" or "embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0040] The following materials or reagents, unless otherwise specified, were commercially available.

[0041] Some embodiments of the present invention provide a method for preparing a high temperature resistant insulating coating material for an electromagnetic wire, comprising the following steps:

[0042] S1 Substrate pretreatment: In order to improve the wettability and interface bonding between the wire and the encapsulation / sealing material, the wire surface needs to be pretreated, including wire surface cleaning and wire material heat treatment;

[0043] In the above step S1, the surface cleaning treatment of the wire is preferably performed by grinding to remove the surface oxide layer and other adhering contaminants. The wire is preferably cleaned in the second step by anhydrous ethanol or acetone to remove surface grease. The cleaned wire is placed in a vacuum drying oven for drying. The heat treatment of the wire material is preferably performed by vacuum treatment and oxidation treatment. The vacuum treatment is to place the wire in a vacuum furnace at a temperature of 500 to 700 ° C and a vacuum degree of -0.1 to -0.02 MPa for 30 minutes to 60 minutes to improve the plasticity, toughness and fatigue strength of the material and improve the surface quality of the metal. The oxidation treatment is to flame-heat the wire surface for micro-oxidation treatment at a temperature range of 700 to 900 ° C for 1 to 2 hours. When the temperature is higher than 900 ° C, the temperature is too high, resulting in excessive oxidation; on the contrary, if the temperature is lower than 700 ° C, the oxidation film is too thin, which will cause poor interface bonding effect and easy to generate bubbles. If the time is less than 1 hour, the time is too short and the oxidation is insufficient; if the time is greater than 2 hours, the time is too long, which increases the time cost and equipment cost.

[0044] Preparation of S2 inorganic filler: The raw materials of the glass component are prepared according to the proportion, and the glass is melted. After ball milling and screening, glass powder is obtained. The ball milling rate is 200-300r / min, and the time is 1-2h. After screening through a 300-mesh sieve, glass powder is obtained. If the rotation speed is less than 200r / min, the ball milling rate is too small and the crushing cannot be successful; if the rotation speed is greater than 300r / min, the ball milling rate is too large and the crushing uniformity cannot be guaranteed; if the time is less than 1h, the time is too short and all the powder cannot be crushed; if the time is greater than 2h, the time is too long, the powder adheres to the inner wall of the ball mill and the ball milling effect is poor; the sieve is 300 mesh to ensure that the powder particle size meets the standards required for later sintering and testing. Then, ceramic components and auxiliary additive components are added to obtain inorganic fillers; the glass melting temperature is 1300-1600°C, and the melting temperature is determined according to the raw material formula. The temperature range of 1300-1600°C can ensure that the raw materials become glass melts; the glass melting time is 1-2h. If it is less than 1h, the time is too short to ensure that all the raw materials are molten, and the glass products after leaving the kiln may be internally uneven and the quality of the glass powder may be poor; if it is more than 2h, the time is too long, which may increase unnecessary time and equipment costs.

[0045] In the above step S2, the inorganic filler is composed of the following parts by mass: 20 to 200 parts of glass component, which can match the corresponding expansion coefficient and promote the densification sintering of ceramic component as a sintering aid; 50 to 300 parts of ceramic component, which is a skeleton material and is mainly used to improve the heat resistance, high temperature electrical insulation and intrinsic strength of the coating; 20 to 120 parts of auxiliary additive component, which is a functional additive to improve the role of inorganic powder in the coating and improve the overall performance of the coating, such as improving the water resistance and insulation performance of the material. Among them, the glass component can be selected from at least two of silicon dioxide, barium oxide, calcium oxide, beryllium oxide and phosphorus pentoxide, and its cladding temperature range is 500 to 700 ° C. When the temperature is lower than 500 ° C, it is difficult to meet the requirement of the coating to withstand a high temperature of 500 ° C. When the temperature is higher than 700 ° C, the overall formula will be greatly adjusted, which will have an impact on other properties. Preferably, the glass component can be composed of silicon dioxide, barium oxide, calcium oxide, beryllium oxide and phosphorus pentoxide, and its composition by mass is: 50-100 parts of silicon dioxide, 20-70 parts of barium oxide, 10-60 parts of calcium oxide, 10-30 parts of beryllium oxide, and 50-120 parts of phosphorus pentoxide. Silicon dioxide can improve viscosity, chemical stability and thermal stability. If its content is too low, it cannot achieve the desired effect. If the content is too high, it will reduce the expansion coefficient; the main functions of barium oxide and calcium oxide are stabilizers, which can increase chemical stability and mechanical strength; beryllium oxide can improve strength and toughness and can be added in small amounts; phosphorus pentoxide can improve corrosion resistance and heat resistance, and the P2O5-CaO system can improve bending strength and toughness. Phosphorus pentoxide is the main substance in the glass component. If the content is low, it cannot play a corresponding role. The ceramic component can be selected from at least one of aluminum oxide, magnesium oxide, titanium dioxide, gallium oxide, molybdenum oxide, zinc oxide, niobium oxide and tin oxide. Preferably, the ceramic component can be composed of aluminum oxide, magnesium oxide, titanium dioxide, gallium oxide, molybdenum oxide, zinc oxide, niobium oxide and tungsten oxide, and its composition by mass is: 80-200 parts of aluminum oxide, 10-50 parts of magnesium oxide, 10-60 parts of titanium dioxide, 10-30 parts of gallium oxide, 10-30 parts of molybdenum oxide, 50-150 parts of zinc oxide, 10-40 parts of niobium oxide, and 10-50 parts of tungsten oxide.Aluminum oxide and zinc oxide can improve and strengthen the structure of the glass system, enhance chemical stability and mechanical strength, so they can be used as effective enhanced skeleton materials and are the main components of ceramic components. If their proportion is too small, they cannot play the above role; magnesium oxide reacts with silicon oxide in glass to form MgO-SiO2 composite, which can increase the lattice spacing and improve strength. Magnesium oxide can also adjust the oxidant-reducing agent balance in the glass and improve chemical stability. Magnesium oxide is an alkaline substance and is almost not corroded by alkaline substances. It has strong corrosion resistance to alkaline metal slag and can effectively improve the corrosion resistance and stability of the coating; titanium dioxide can adjust chemical stability and thermal stability while ensuring strength and hardness. Magnesium oxide and titanium dioxide are functional powders in ceramic components, and the amount of addition should not be too much. On this basis, by introducing gallium oxide, niobium oxide, molybdenum oxide and tungsten oxide, the surface tension can be reduced, and the high-temperature wetting ability of the glass component inside the coating on the surface of the metal substrate can be improved. Such oxides should not be added too much, and only a small amount is needed to reduce the surface tension. The auxiliary additive component can be selected from at least one of sodium oxide, lithium oxide and mica powder. Preferably, the auxiliary additive component can be composed of sodium oxide, lithium oxide and mica powder, and its composition by mass is: 30-100 parts of sodium oxide, 10-60 parts of lithium oxide, and 10-100 parts of mica powder. Sodium oxide and lithium oxide are fluxing agents and can increase the thermal expansion coefficient. Mica powder can be used to improve weather resistance.

[0046] Preparation of S3 coating slurry: Evenly mix silicone resin, inorganic powder, solvent, pigment and additives, wherein 30-70 parts of silicone resin, 10-25 parts of inorganic filler, 20-80 parts of solvent, 2-10 parts of pigment and 0.5-2 parts of additives are used to obtain a uniform slurry. Silicone resin can increase the toughness and plasticity of the slurry, so that the wire is still flexible at room temperature after encapsulation, meeting the winding requirements; inorganic fillers are used to improve the high temperature resistance, electrical insulation, density and mechanical properties of the coating; solvents can improve the viscosity of the slurry and adjust the fluidity of the coating according to the solvent content; pigments are high temperature resistant pigments, which can improve the high temperature resistance of the coating. The additives include at least one of a dispersant, a leveling agent, a defoamer, a thickener and a binder, which can improve the performance of the coating, such as the uniformity, viscosity, fluidity, etc. of the coating, and comprehensively improve the quality of the coating. The proportion of each component is adjusted according to its role. Silicone resin is the main toughening substance in the slurry and needs to occupy a large proportion to ensure the flexibility of the coating after curing; inorganic filler is the main high temperature resistant and electrical insulating substance and needs to reach a certain proportion to play a role; the solvent is adjusted according to the viscosity and fluidity of the coating; pigments and additives act as auxiliary functional materials and account for a relatively small proportion.

[0047] In the above step S3, the uniform mixing is to firstly perform low-speed shear mixing of the silicone resin, solvent and inorganic filler at a rate of 100 to 150 r / min, first perform preliminary mixing of the slurry to make the inside of the slurry more uniform, then add pigments and other additives for high-speed shear mixing at a rate of 400 to 600 r / min, and add a smaller component during the secondary mixing to make it evenly dispersed in the slurry to achieve a better mixing effect and improve the quality of the coating. The shear mixing rate is determined according to the mixing effect and the uniformity of the coating.

[0048] In order to ensure the uniformity inside the coating and the fluidity of the final product, the silicone resin is a resin with fluidity, which can be selected from at least one of methylphenyl silicone resin, epoxy modified silicone resin and acrylic modified resin. The resin type is determined according to the performance required by the coating. Among the polymer resins, a resin with good insulation, high temperature resistance and high flexibility needs to be selected. The solvent can be selected from at least one of toluene, xylene, n-hexane, ethyl acetate, dimethyl ketone and deionized water. The solvent selects its corresponding solvent according to the selected resin. If the raw material is a water-soluble resin, deionized water can be directly added for adjustment. The pigment can be selected from at least one of copper chrome black, iron manganese black, iron oxide red and titanium dioxide. The pigment is a high temperature resistant pigment, which can improve the high temperature resistance of the coating. The auxiliary agent includes at least one of a dispersant, a leveling agent, a defoamer, a thickener and a binder. The auxiliary agent can improve the performance of the coating, such as the uniformity, viscosity, fluidity, etc. of the coating, and comprehensively improve the quality of the coating.

[0049] S4 coating: The wire is coated by dipping method, and the coating viscosity is 100-200mPa·s. If the coating viscosity is too high, the coating fluidity is poor and it cannot be evenly coated on the surface of the wire. If the coating viscosity is too low, the bonding force between the coating and the wire is insufficient, and the coating cannot be fully coated. After the coating is completed, the wire is placed in a high-temperature oven at a temperature of 200-300°C for 0.5-2h. The curing temperature and time depend on the properties of the coating. It is necessary to ensure that the solvent is completely volatilized and the coating is cured on the surface of the wire. If the time is less than 0.5h or the temperature is less than 200°C, the curing time is short or the temperature is low, and this effect cannot be achieved. If the time is greater than 2h or the temperature is greater than 300°C, the curing time is too long or the temperature is too high, the solvent will evaporate too quickly, and the coating will crack during the curing process. After curing, it is naturally cooled to room temperature to obtain the high temperature resistant insulating coating material for electromagnetic wire.

[0050] In the above technical scheme, the present invention adopts a glass + ceramic oxide two-phase composite method through a comprehensive design of inorganic coating components, and obtains microcrystalline glass / ceramic composite powder through a multi-platform sintering path of nucleation + sealing + crystallization, thereby achieving an improvement in the intrinsic strength of the electrical insulation coating material, especially the improvement of high-temperature strength and high-temperature electrical insulation performance, and meeting the flexibility requirements by adding organic matter. This formula can be used to prepare a highly uniform, strongly bonded, high-temperature resistant insulating coating. In addition, the coating also has excellent thermal shock resistance, impact resistance, and moisture resistance. It can match the expansion coefficient of the coating material with that of the metal conductor, and adjust the proportion of organic matter in the formula so that the electromagnetic wire can be wound on a stator with a diameter of 20 mm or more, which can increase the number of turns and meet the accuracy requirements of equipment use.

[0051] Some embodiments of the present invention also provide a high temperature resistant insulating coating material for electromagnetic wire, the thermal expansion coefficient of which is 14 to 20×10 -6 / K; The electromagnetic wire is made of high temperature resistant insulating coating material by the above method.

[0052] Some embodiments of the present invention also provide an electromagnetic wire, such as Figure 1 As shown, the electromagnetic wire comprises a conductor 1, a pre-processed interface 2 and a coating 3 connected in sequence from the inside to the outside, wherein the coating 3 is composed of a high temperature resistant insulating coating material, and the thermal expansion coefficient of the high temperature resistant insulating coating material is 14 to 20×10 -6 / K. The wire 1 can be selected from an oxygen-free copper wire 4 with a diameter of 0.2 to 0.5 mm. Figure 2 It can be seen that the oxygen-free copper wire 4 with a diameter of 0.2 to 0.5 mm is coated after the above-mentioned substrate pretreatment to obtain an electromagnetic wire 5 with good flexibility. The electromagnetic wire 5 is then tightly wound on a stator with a diameter of 1.5 to 2 cm to obtain a wire winding 6. During and after the winding process, there is no peeling or cracking on the surface of the electromagnetic wire.

[0053] Some embodiments of the present invention further provide an electronic device, the electronic device comprising an electromagnetic wire, the electromagnetic wire comprising a wire 1, a pre-processed interface 2 and a coating 3 connected in sequence from the inside to the outside, the coating 3 being composed of a high temperature resistant insulating coating material, the thermal expansion coefficient of the high temperature resistant insulating coating material being 14 to 20×10 -6 / K.

[0054] The specific implementation methods of the present invention are further described in detail below in conjunction with the embodiments, but it should not be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by technicians in this field based on the above-mentioned contents of the present invention still fall within the scope of protection of the present invention.

[0055] Unless otherwise specified, the materials, reagents, etc. involved below are all commercially available products well known to those skilled in the art; unless otherwise specified, the methods described are all methods well known in the art. Unless otherwise defined, the technical terms or scientific terms used should have the common meanings understood by ordinary technicians in the field to which the present invention belongs.

[0056] Example 1

[0057] This embodiment provides a method for preparing a high temperature resistant insulating coating material for an electromagnetic wire, comprising the following steps:

[0058] S1 substrate pretreatment: pretreatment of the conductor surface, the conductor surface cleaning treatment includes: first cleaning by grinding to remove the surface oxide layer and other adhering pollutants, second cleaning of the conductor by anhydrous ethanol or acetone to remove surface grease, the cleaned conductor is placed in a vacuum drying oven at 600°C for 60 minutes, and then the conductor is subjected to flame heating surface micro-oxidation treatment at a temperature of 850°C for 1.5 hours;

[0059] S2 Preparation of inorganic filler: The raw materials of the glass component are prepared in proportion, and the glass is melted at 1580°C. After ball milling and screening, glass powder is obtained. The ball milling process is 220r / min, and the ball milling is 90min. Then, it is screened with a 300-mesh screen. Then, the ceramic component and the auxiliary additive component are added to obtain the inorganic filler. The composition of the inorganic filler in parts by mass is: 50 parts of glass component, 85 parts of ceramic component, and 35 parts of auxiliary additive component; the glass powder is in parts by mass. The composition of the said ceramic powder in parts by mass is: 80 parts of silicon dioxide, 20 parts of barium oxide, 15 parts of calcium oxide, 10 parts of beryllium oxide, and 100 parts of phosphorus pentoxide; the composition of the said ceramic powder in parts by mass is: 160 parts of aluminum oxide, 20 parts of magnesium oxide, 10 parts of titanium dioxide, 10 parts of gallium oxide, 15 parts of molybdenum oxide, 85 parts of zinc oxide, 25 parts of niobium oxide, and 15 parts of tin oxide; the composition of the said auxiliary additive component in parts by mass is: 40 parts of sodium oxide, 20 parts of lithium oxide, and 15 parts of mica powder;

[0060] Preparation of S3 coating slurry: 50 parts by mass of silicone resin, 40 parts by mass of inorganic filler, 50 parts by mass of solvent, 5 parts by mass of pigment and 2 parts by mass of additives are mixed, and the mixture is uniformly mixed using a planetary ball mill. The silicone resin, solvent and inorganic filler are first subjected to low-speed shear mixing at a rate of 100 r / min for 1 hour, and then the pigment and other additives are added for high-speed shear mixing at a rate of 500 r / min for 8 hours to obtain a uniform slurry; wherein the silicone resin is water-soluble methylphenyl silicone resin; the solvent is deionized water; the pigment is titanium dioxide; the additives are composed of the following in parts by mass: 1 part of leveling agent; 0.5 part of defoaming agent; 2 parts of dispersant;

[0061] S4 coating: The conductor is first coated by dipping method, and the coating viscosity is 140mPa·s -1 After the coating is completed, the wire is cured at 280° C. for 2 hours, and naturally cooled to room temperature after curing to obtain the high temperature resistant insulating coating material for the electromagnetic wire.

[0062] Example 2

[0063] The difference between this embodiment and embodiment 1 is that in step S2 of this embodiment, the content of the ceramic component in the inorganic filler is 90 parts by mass; in step S3, the content of the inorganic filler is 50 parts by mass, and the content of the pigment is 6 parts; the remaining steps and parameters are the same as in embodiment 1.

[0064] Example 3

[0065] The difference between this embodiment and embodiment 1 is that in step S3 of this embodiment, the content of the silicone resin is 65 parts by mass, and the content of the solvent is 70 parts by mass; the remaining steps and parameters are the same as those in embodiment 1.

[0066] Example 4

[0067] The difference between this embodiment and embodiment 1 is that in step S3 of this embodiment, the content of the inorganic filler is 55 parts by mass, and the content of the pigment is 7 parts by mass; the remaining steps and parameters are the same as those in embodiment 1.

[0068] Example 5

[0069] The difference between this embodiment and embodiment 1 is that in step S2 of this embodiment, the composition of the inorganic filler in parts by mass is: 70 parts of glass component, 95 parts of ceramic component, and 30 parts of auxiliary additive component; the remaining steps and parameters are the same as in embodiment 1.

[0070] Example 6

[0071] The difference between this embodiment and embodiment 1 is that in step S2 of this embodiment, the content of the auxiliary additive component is 25 parts by mass; the remaining steps and parameters are the same as those in embodiment 1.

[0072] Comparative Example 1

[0073] The difference between this comparative example and Example 1 is that in step S2 of this comparative example, the content of the glass component is 10 parts by mass; the remaining steps and parameters are the same as Example 1; due to the low content of glass powder, the bonding effect thereof is poor, the adhesion of the coating material is poor, resulting in surface cracking and poor high temperature resistance.

[0074] Comparative Example 2

[0075] The difference between this comparative example and Example 2 is that in step S2 of this comparative example, the content of the ceramic component is 15 parts by mass; the remaining steps and parameters are the same as Example 1; due to the low content of ceramic powder, a dense inorganic film cannot be formed under high temperature environment, and cannot withstand a high temperature of 500°C, resulting in cracking of the coating and insulation failure.

[0076] The high temperature resistant insulating coating material for the electromagnetic wire obtained in Examples 1-6 and the coating material of Comparative Examples 1-2 were tested for thickness, surface morphology, temperature resistance and high temperature breakdown voltage. The test results are shown in Table 1.

[0077] Test method: The coating thickness is tested according to GB / T 13452.2-2008 "Determination of film thickness of paints and varnishes";

[0078] The surface morphology is tested according to GB / T 4074.3-2008 "Test methods for winding wires Part 3: Mechanical properties";

[0079] The high temperature breakdown voltage test is carried out in accordance with GB / T 4074.5-2008 "Winding Wire Test Methods Part 5: Electrical Properties";

[0080] The high temperature resistance time is tested according to GJB 360B-2009 "Test Methods for Electronics and Electronic Components".

[0081] Table 1 Comparison of coating properties of high temperature resistant insulating coating materials for electromagnetic wires of Examples 1-6 and coating materials of Comparative Examples 1-2

[0082]

[0083] It can be seen from the data in Table 1 that the coating thickness of the high temperature resistant insulating coating material for electromagnetic wire of Examples 1-6 of the present invention is 22-27 μm, there is no cracking on the surface, the high temperature resistance time of 500°C is more than 1000h, and the high temperature breakdown voltage is ≥1.25KV@500°C. In order to ensure the accuracy of the use of instruments and equipment, the number of coil turns should not be too small. While ensuring the quality of the coating, the impregnation process and the viscosity of the coating are controlled so that the coating thickness reaches an ideal value and there is no crack on the coating surface; ceramic aggregates and other functional additives are key substances for the high temperature resistance and insulation of the coating. At high temperatures, the ceramic component forms a dense inorganic film, which protects the electromagnetic wire; the glass component plays a decisive role in improving the adhesion between the substrate and the coating, and ensuring effective bonding between the substrate and the coating can avoid cracking and peeling of the coating.

[0084] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0085] The numerical range described in the present invention includes all the numerical values ​​within the range, and includes the range value formed by any two numerical values ​​within the range. Different numerical values ​​of the same indicator appearing in all embodiments of the present invention can be arbitrarily combined to form a range value.

[0086] The technical features in the claims and / or the specification of the present invention may be combined, and the combination is not limited to the combination obtained by reference in the claims. The technical solution obtained by combining the technical features in the claims and / or the specification is also within the protection scope of the present invention.

[0087] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a high temperature resistant insulating coating material for electromagnetic wire, characterized in that: The following steps are involved: S1 substrate pretreatment: pretreat the surface of the conductor; S2 Preparation of inorganic filler: The raw materials of the glass component are prepared in proportion, the glass is melted, and the glass powder is obtained after ball milling and sieving, and then the ceramic component and the auxiliary additive component are added to obtain the inorganic filler; S3 coating slurry preparation: organic silicone resin, inorganic powder, solvent, pigment and additives are mixed in proportion to obtain a uniform slurry; S4 coating: firstly, the conductor is coated with a coating, and after the coating is completed, the conductor is cured, and after the curing is completed, the conductor is naturally cooled to room temperature to obtain the high temperature resistant insulating coating material for the electromagnetic wire.

2. The method for preparing a high temperature resistant insulating coating material for electromagnetic wire according to claim 1, characterized in that: In step S1, the pretreatment includes cleaning the surface of the wire and heat treatment of the wire material; the wire surface cleaning is performed by polishing to remove the surface oxide layer and other adhering pollutants; the wire is cleaned by anhydrous ethanol or acetone to remove surface grease, and the cleaned wire is dried; The heat treatment of the conductor material includes vacuum treatment and oxidation treatment; The vacuum treatment includes: placing the wire in a vacuum furnace for high-temperature heating; the oxidation treatment includes: subjecting the wire to flame heating and surface micro-oxidation treatment.

3. The method for preparing a high temperature resistant insulating coating material for electromagnetic wire according to claim 1, characterized in that: In step S2, the amount of the glass component is 20 to 200 parts by mass, the amount of the ceramic component is 50 to 300 parts by mass, and the amount of the auxiliary additive component is 20 to 120 parts by mass.

4. The method for preparing a high temperature resistant insulating coating material for electromagnetic wire according to claim 3, characterized in that: In step S2, the glass component is selected from at least two of silicon dioxide, barium oxide, calcium oxide, beryllium oxide and phosphorus pentoxide, and the cladding temperature range is 500-700°C; the ceramic component is selected from at least one of aluminum oxide, magnesium oxide, titanium dioxide, gallium oxide, molybdenum oxide, zinc oxide, niobium oxide and tin oxide; the auxiliary additive component is selected from at least one of sodium oxide, lithium oxide and mica powder.

5. The method for preparing a high temperature resistant insulating coating material for electromagnetic wire according to claim 4, characterized in that: In step S2, the glass component is composed of silicon dioxide, barium oxide, calcium oxide, beryllium oxide and phosphorus pentoxide, and its composition by mass is: 50-100 parts of silicon dioxide, 20-70 parts of barium oxide, 10-60 parts of calcium oxide, 10-30 parts of beryllium oxide, and 80-150 parts of phosphorus pentoxide; in step S2, the ceramic component is composed of aluminum oxide, magnesium oxide, titanium dioxide, gallium oxide, molybdenum oxide, zinc oxide, niobium oxide and tungsten oxide, and its composition by mass is: The composition by mass is: 80-200 parts of aluminum oxide, 10-50 parts of magnesium oxide, 10-60 parts of titanium dioxide, 10-30 parts of gallium oxide, 10-30 parts of molybdenum oxide, 50-150 parts of zinc oxide, 20-70 parts of niobium oxide, and 10-50 parts of tungsten oxide; the auxiliary additive component is composed of sodium oxide, lithium oxide and mica powder, and its composition by mass is: 30-100 parts of sodium oxide, 10-60 parts of lithium oxide, and 10-100 parts of mica powder.

6. The method for preparing a high temperature resistant insulating coating material for electromagnetic wire according to claim 1, characterized in that: In step S2, the ball milling medium is zirconium oxide ball; the rotation speed of the ball mill is 200-400r / min; in step S3, the silicone resin is a resin with fluidity, which is selected from at least one of methyl phenyl silicone resin, epoxy modified silicone resin and acrylic modified resin; the solvent is selected from at least one of toluene, xylene, n-hexane, ethyl acetate, dimethyl ketone and deionized water; the pigment is selected from at least one of copper chrome black, iron manganese black, red iron oxide and titanium dioxide; the additive includes at least one of a dispersant, a leveling agent, a defoamer, a thickener and a binder.

7. The method for preparing a high temperature resistant insulating coating material for electromagnetic wire according to claim 1, characterized in that: In step S3, the composition of the slurry in parts by mass is: 30-70 parts of silicone resin, 10-25 parts of inorganic powder, 20-80 parts of solvent, 5-15 parts of pigment, and 0.5-2 parts of additives; the mixing specifically includes: firstly performing low-speed shear mixing of the silicone resin, solvent, inorganic filler and curing agent at 100-150r / min, and then adding the pigment and the additive and performing high-speed shear mixing at 400-600r / min; in step S4, the curing temperature is 200-300°C and the time is 0.5-2h.

8. A high temperature resistant insulating coating material for electromagnetic wire, characterized in that: Its thermal expansion coefficient is 14~20×10 -6 / K; The high temperature resistant insulating coating material for electromagnetic wire is prepared by the method according to any one of claims 1-7.

9. An electromagnetic wire, characterized in that: The electromagnetic wire adopts a high temperature resistant insulating coating material, and the thermal expansion coefficient of the high temperature resistant insulating coating material is 14 to 20×10 -6 / K.

10. An electronic device, characterized in that: The electronic device comprises an electromagnetic wire, the electromagnetic wire is made of a high temperature resistant insulating coating material, and the thermal expansion coefficient of the high temperature resistant insulating coating material is 14 to 20×10 -6 / K.

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