Polyester enameled flat wire and its preparation method

Abstract

The application discloses polyester enameled flat wire with silk covering and a preparation method thereof, and relates to the technical field of conductive materials. The application utilizes phytic acid to modify the silk covering layer, and under the assistance of a microwave electromagnetic field, phytic acid forms an active intermediate to undergo an esterification reaction with hydroxyl groups on the surface of polyester, and then forms a phosphoric acid diester bond, so that the covering property of the conductor is enhanced, and the mechanical property and the insulation of the silk covering layer are improved. Then, a blend of organosiloxane, unsaturated polyester and nano metal oxide is sprayed on the surface of the silk covering layer, and the nano particles are more easily charged in the spraying process, so that the compactness and the uniformity of the coating are improved, and the mechanical property and the insulation of the wire are further improved. Finally, through high-temperature treatment, the phytic acid and the metal oxide undergo a condensation reaction to form a phosphoric acid metal complex, so that the mechanical property and the insulation are enhanced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of conductive materials, in particular to a polyester enameled silk-covered copper flat wire and a preparation method thereof. BACKGROUND

[0002] Flat wire, also known as flat wire, flattened wire, flat angle wire or ultra-narrow strip, refers to a special-shaped metal wire with a cross section approximating to a rectangular corner, a thickness of 0.025mm to 2mm and a width generally less than 5mm. The width-thickness ratio thereof is from 2:1 to 50:1. Since the flat wire is similar to a strip, it is also called an ultra-narrow flat strip. In recent years, with the continuous development of electronic, electrical, motor, transformer and automobile products towards miniaturization, ultra-thinning, ultra-small and high reliability, compared with common round wire, (1) under the condition of the same cross-sectional area, the coil of the micro enameled flat wire occupies less space than the coil of the round enameled wire, which can save space by 9-12%. The production of electronic and electrical products with smaller volume and lighter weight is less affected by the volume of the coil, obviously saving a lot of other materials; (2) under the condition of the same winding space, the coil of the micro enameled flat wire has a much higher slot fill rate than the coil of the round enameled wire, and the slot fill rate can be more than 95%. Therefore, the application of the micro enameled flat wire solves the long-term problem of improving the slot fill rate, so that the resistance is reduced and the capacitance is larger, which can better meet the requirements of large-capacitance high-load use occasions. Therefore, the demand for micro enameled copper flat wire is increasing rapidly year by year, more and more customers are trying to use it, and the application field is also rapidly expanding. Therefore, the research and application of high-performance copper flat wire will help to improve the performance and efficiency of new energy equipment and reduce energy consumption. SUMMARY

[0003] The present application aims to provide a polyester enameled silk-covered copper flat wire and a preparation method thereof to solve the problems in the prior art.

[0004] In order to solve the above technical problems, the present application provides the following technical scheme: a preparation method of a polyester enameled silk-covered copper flat wire, comprising the following steps:

[0005] (1) The polyester fiber is activated and pretreated, and then wrapped on the copper flat wire. Under the condition that the vacuum degree is 3Pa, nitrogen gas and atomized phytic acid are introduced for microwave low-temperature plasma treatment to obtain a silk-covered copper flat wire;

[0006] (2) The metal oxide is pretreated, and then blended with organosiloxane, unsaturated polyester and additives to obtain a paint. The paint is sprayed on the silk-covered copper flat wire by electrostatic air-assisted airless spraying process, and finally heat treated at 150-230℃ in a nitrogen atmosphere for 10-30min to obtain a polyester enameled silk-covered copper flat wire.

[0007] Further, the specific step of the activation pretreatment in step (1) is discharge low-temperature plasma treatment, and the process parameters are as follows: the working gas is argon, the gas pressure is 10-50 Pa, the power is 180 W, and the time is 8-15 min.

[0008] Further, the specification of the copper flat wire in step (1) is 0.5 mm x 2 mm.

[0009] Further, the winding angle in step (1) is 15-40°.

[0010] Further, the volume ratio of nitrogen and phytic acid in step (1) is 1:1.

[0011] Further, the process parameters of the microwave low-temperature plasma treatment in step (1) are as follows: the gas pressure is 70-180 Pa, the power is 70-130 W, and the time is 15-28 min.

[0012] Further, the parameters of the electrostatic air-assisted gasless spraying process in step (2) are as follows: the voltage is 60-90 kV, the pressure is 0.3-0.5 MPa, the spraying distance is 150-300 mm, and the conveying chain speed is 4-6 m / min.

[0013] Further, the mass ratio of the metal oxide, organosiloxane, unsaturated polyester, and additive in step (2) is 0.05-0.15:10:0.2-0.6:0.35.

[0014] Further, the organosiloxane in step (2) is at least one of methacryloyloxysilane, epoxy silane, and octadecyl triethoxysilane.

[0015] Further, the specific step of the pretreatment in step (2) is as follows: the metal oxide and 5 wt% sodium hydroxide aqueous solution are mixed at a mass ratio of 1:10 and subjected to ball milling treatment under argon protection, and the process parameters are as follows: the ball milling medium is steel ball, the ball-to-material ratio is 20:1, the rotation speed is 500-1000 rpm, the time is 5-9 h, the deionized water is washed for 5 times, and the drying is performed at 60°C for 10 h; the metal oxide is at least one of aluminum oxide, magnesium oxide, yttrium oxide, and germanium oxide.

[0016] Compared with the prior art, the application has the beneficial effects that: the application uses phytic acid to modify the silk layer, first, the surface of the polyester is bombarded by plasma to activate it and provide more adsorption sites, then, under the assistance of the microwave electromagnetic field, the phytic acid forms active intermediates to esterify with the hydroxyl groups on the surface of the polyester, and then forms phosphoric acid diester bonds to link adjacent fibers to realize the chemical bonding and recombination between the fibers, thereby enhancing the wrapping of the conductor and improving the mechanical properties and insulation of the silk layer, then, the blend of organosiloxane, unsaturated polyester and nano metal oxide is sprayed on the surface of the silk layer by electrostatic air-assisted airless spraying, the nanoparticles are more easily charged during the spraying process, and their insulation can reduce the charge neutralization between the powder particles, thereby prolonging the charging duration and improving the density and uniformity of the coating, thereby further improving the mechanical properties and insulation of the conductor, and finally, through high temperature treatment, the crosslinking degree between the insulation layers is enhanced, wherein the active groups of the phytic acid condense with the hydroxyl groups on the surface of part of the metal oxides to form metal phosphate complexes, thereby improving the mechanical properties and insulation of the conductor. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the application.

[0018] In order to more clearly illustrate the method provided by the application, the following embodiments are described in detail. In the following embodiments, the test methods of various indexes of the polyester enameled copper-clad flat wire produced are as follows:

[0019] Insulation: Take the same size of the examples and the comparative examples to test their conductivity according to GB / T17650.2.

[0020] Mechanical properties: Take the same size of the examples and the comparative examples to test their tensile strength according to GB / T6109.2.

[0021] Example 1: (1) The polyester fibers with a diameter of 50 μm are subjected to discharge low-temperature plasma treatment, and the process parameters are as follows: the working gas is argon, the gas pressure is 10 Pa, the power is 180 W, and the time is 8 min, then the polyester fibers are wound on the 0.5 mm x 2 mm copper flat wire at an angle of 15°, and under the condition that the vacuum degree is 3 Pa, nitrogen gas and atomized phytic acid are introduced at a flow rate of 0.06 L / min, and microwave low-temperature plasma treatment is carried out, and the process parameters are as follows: the gas pressure is 70 Pa, the power is 70 W, and the time is 15 min, to obtain the silk-coated copper flat wire; the volume ratio of the nitrogen gas to the phytic acid is 1:1.

[0022] (2) the alumina, 5wt% sodium hydroxide solution is mixed according to the mass ratio 1:10 and is carried out ball milling treatment under the protection of argon, its process parameters: the ball milling medium is steel ball, the ball material ratio is 20:1, the rotating speed is 500rpm, the time is 5h, it is washed 5 times with deionized water, it is dried at 60℃ for 10h, then it is blended with octadecyl triethoxysilane, unsaturated polyester, additive, the paint is obtained; then it is sprayed on the silk covered copper flat wire through the electrostatic air assisted airless spraying process, its parameters: the voltage is 60kV, the pressure is 0.3MPa, the spraying distance is 150mm, the conveying chain speed is 4m / min, the polyester enameled silk covered copper flat wire is obtained after spraying, finally it is kept at 150℃ in nitrogen atmosphere for 10min; the mass ratio of the alumina, octadecyl triethoxysilane, unsaturated polyester, additive is 0.05:10:0.2:0.35; the unsaturated polyester is 199C p-benzenic heat-resistant resin; the additive is composed of styrene, peroxide cyclohexanone, polyethylene glycol with the molecular weight of 800, and the mass ratio is 0.15:0.1:0.1.

[0023] Example 2; (1) the polyester fiber with the diameter of 50μm is carried out discharge low temperature plasma treatment, its process parameters: the working gas is argon, the gas pressure is 30Pa, the power is 180W, the time is 12min, then it is wrapped around the 0.5mm×2mm copper flat wire according to the angle of 30°, the nitrogen gas and atomized phytic acid are introduced at 0.06L / min under the condition of the vacuum degree of 3Pa, the silk covered copper flat wire is obtained after microwave low temperature plasma treatment, its process parameters: the gas pressure is 130Pa, the power is 100W, the time is 21min; the volume ratio of the nitrogen gas and phytic acid is 1:1;

[0024] (2) the alumina, 5wt% sodium hydroxide solution is mixed according to the mass ratio 1:10 and is carried out ball milling treatment under the protection of argon, its process parameters: the ball milling medium is steel ball, the ball material ratio is 20:1, the rotating speed is 800rpm, the time is 7h, it is washed 5 times with deionized water, it is dried at 60℃ for 10h, then it is blended with octadecyl triethoxysilane, unsaturated polyester, additive, the paint is obtained; then it is sprayed on the silk covered copper flat wire through the electrostatic air assisted airless spraying process, its parameters: the voltage is 85kV, the pressure is 0.4MPa, the spraying distance is 230mm, the conveying chain speed is 5m / min, the polyester enameled silk covered copper flat wire is obtained after spraying, finally it is kept at 190℃ in nitrogen atmosphere for 20min; the mass ratio of the alumina, octadecyl triethoxysilane, unsaturated polyester, additive is 0.1:10:0.4:0.35; the unsaturated polyester is 199C p-benzenic heat-resistant resin; the additive is composed of styrene, peroxide cyclohexanone, polyethylene glycol with the molecular weight of 800, and the mass ratio is 0.15:0.1:0.1.

[0025] Example 3; (1) the polyester fiber with a diameter of 50 μm is subjected to discharge low-temperature plasma treatment, the process parameters are as follows: the working gas is argon, the gas pressure is 50 Pa, the power is 180 W, and the time is 15 min, and then the polyester fiber is wound around the copper flat wire with a size of 0.5 mm x 2 mm at an angle of 40° to obtain a silk-covered copper flat wire; the silk-covered copper flat wire is subjected to microwave low-temperature plasma treatment in a nitrogen atmosphere, the process parameters are as follows: the gas pressure is 180 Pa, the power is 130 W, and the time is 28 min, and the volume ratio of the nitrogen gas to the phytic acid is 1:1;

[0026] (2) the aluminum oxide and 5 wt% sodium hydroxide aqueous solution are mixed at a mass ratio of 1:10 and subjected to ball milling treatment under argon protection, the process parameters are as follows: the ball milling medium is steel ball, the ball-to-material ratio is 20:1, the rotation speed is 1000 rpm, and the time is 9 h, the silk-covered copper flat wire is washed with deionized water for 5 times and dried at 60 °C for 10 h, and then the silk-covered copper flat wire is sprayed with a paint prepared by blending the aluminum oxide, octadecyl triethoxysilane, unsaturated polyester and additive, the parameters of the electrostatic air-assisted airless spraying process are as follows: the voltage is 90 kV, the pressure is 0.5 MPa, the spraying distance is 300 mm, and the conveying chain speed is 6 m / min, and finally the polyester enameled silk-covered copper flat wire is obtained by heating at 230 °C in a nitrogen atmosphere for 30 min; the mass ratio of the aluminum oxide, octadecyl triethoxysilane, unsaturated polyester and additive is 0.15:10:0.6:0.35; the unsaturated polyester is 199C p-phenylene heat-resistant resin; the additive is composed of styrene, peroxide cyclohexanone and polyethylene glycol with a molecular weight of 800, and the mass ratio is 0.15:0.1:0.1.

[0027] Comparative Example 1; the difference between Comparative Example 1 and Example 2 is that step (1) is different, and step (1) is changed to: the polyester fiber with a diameter of 50 μm is subjected to discharge low-temperature plasma treatment, the process parameters are as follows: the working gas is argon, the gas pressure is 30 Pa, the power is 180 W, and the time is 12 min, and then the polyester fiber is wound around the copper flat wire with a size of 0.5 mm x 2 mm at an angle of 30° to obtain a silk-covered copper flat wire; the remaining steps are the same as those of Example 2.

[0028] Comparative Example 2; Comparative Example 2 is different from Example 2 in that step (2) is changed to: octadecyl triethoxysilane, unsaturated polyester, additive are blended to obtain a paint; then the paint is sprayed on the enameled copper rectangular wire by electrostatic air-assisted airless spraying process, the parameters of which are: voltage 85 kV, pressure 0.4 MPa, spraying distance 230 mm, conveying chain speed 5 m / min, and then the enameled copper rectangular wire is obtained by heating at 190 °C in a nitrogen atmosphere for 20 min; the mass ratio of the octadecyl triethoxysilane, the unsaturated polyester, and the additive is 10:0.4:0.35; the unsaturated polyester is 199C p-phenylene heat-resistant resin; the additive is composed of styrene, cyclohexanone peroxide, and polyethylene glycol with a molecular weight of 800, and the mass ratio is 0.15:0.1:0.1; the rest of the steps are the same as those of Example 2.

[0029] Comparative Example 3; Comparative Example 3 is different from Example 2 in that step (2) is changed to: aluminum oxide, 5 wt% sodium hydroxide aqueous solution are mixed in a mass ratio of 1:10 and ball-milled under argon protection, the process parameters of which are: steel ball as the ball-milling medium, ball-to-material ratio 20:1, rotation speed 800 rpm, time 7 h, washed with deionized water for 5 times, and dried at 60 °C for 10 h, and then blended with octadecyl triethoxysilane, unsaturated polyester, and additive to obtain a paint; then the paint is sprayed on the enameled copper rectangular wire with a thickness of 0.1 mm, and then the enameled copper rectangular wire is obtained by heating at 190 °C in a nitrogen atmosphere for 20 min; the mass ratio of the aluminum oxide, the octadecyl triethoxysilane, the unsaturated polyester, and the additive is 0.1:10:0.4:0.35; the unsaturated polyester is 199C p-phenylene heat-resistant resin; the additive is composed of styrene, cyclohexanone peroxide, and polyethylene glycol with a molecular weight of 800, and the mass ratio is 0.15:0.1:0.1;

[0030] Effect Example

[0031] The performance analysis results of the enameled copper rectangular wire using the polyester paint of Examples 1 to 3 and Comparative Examples 1 to 3 of the present application are shown in Table 1 below.

[0032] Table 1

[0033]

[0034] From the comparison of the experimental data of the examples and the comparative examples in Table 1, it can be found that, by using phytic acid to modify the silk coating layer, under the action of the microwave electromagnetic field, active intermediates are formed to esterify with the hydroxyl groups on the surface of the polyester, and then form phosphoric acid diester bonds, so that the adjacent fibers are linked, thereby enhancing the wrapping of the conductor, improving the mechanical properties and insulation of the silk coating layer, and then using the blend of organosiloxane, unsaturated polyester and nano metal oxide to spray on the surface of the silk coating layer, through electrostatic air-assisted airless spraying, the nanoparticles are more easily charged during the spraying process, and their insulation can reduce the charge neutralization between powder particles, thereby improving the density and uniformity of the coating, thereby further improving the mechanical properties and insulation of the conductor, and finally through high temperature treatment, the crosslinking degree between the insulation layers is enhanced, the active groups of phytic acid and the hydroxyl groups on the surface of part of the metal oxides condense to form metal phosphate complexes, thereby improving the mechanical properties and insulation of the conductor.

[0035] It will be apparent to those skilled in the art that the application is not limited to the details of the above-exemplified embodiments and can be implemented in other concrete forms without departing from the spirit or essential characteristics of the application. Therefore, the embodiments should be considered in all respects as illustrative and not restrictive, and the scope of the application is defined by the appended claims rather than the above description, and it is intended to encompass all changes falling within the meaning and scope of the equivalent elements of the claims. Any mark in the claims should not be considered as limiting the involved claims.

Claims

1. A method for producing a polyester enameled flat wire, characterized by, The method comprises the following steps: (1) the polyester fiber is activated and pretreated, and then wrapped on the copper flat wire, and under the condition that the vacuum degree is 3 Pa, nitrogen and phytic acid are introduced to carry out microwave low-temperature plasma treatment, and a silk-wrapped copper flat wire is obtained; the specific steps of the activation pretreatment are: discharge low-temperature plasma treatment; (2) the metal oxide is pretreated, and then blended with organosiloxane, unsaturated polyester and additives to obtain a paint; the paint is sprayed on the silk-wrapped copper flat wire by an electrostatic air-assisted airless spraying process, and finally, the polyester enameled silk-wrapped copper flat wire is obtained by heating at 150-230 DEG C in a nitrogen atmosphere for 10-30 min; the specific steps of the pretreatment are: the metal oxide and 5wt% sodium hydroxide aqueous solution are mixed in a mass ratio of 1:10 and ball milled under argon protection, washed with deionized water for 5 times, and dried at 60 DEG C for 10 h; the metal oxide is at least one of aluminum oxide, magnesium oxide, yttrium oxide and germanium oxide.

2. A method of manufacturing a polyester enamelled flat wire according to claim 1, characterized in that, The process parameters of the activation pretreatment in step (1) are: the working gas is argon, the gas pressure is 10-50 Pa, the power is 180 W, and the time is 8-15 min.

3. The method for preparing a polyester enameled copper-coated flat wire according to claim 1, characterized in that, The specification of the copper flat wire in step (1) is 0.5 mm x 2 mm.

4. The method for preparing a polyester enameled copper-coated flat wire according to claim 1, characterized in that, The wrapping angle in step (1) is 15-40 DEG.

5. The method for preparing a polyester enameled copper-coated flat wire according to claim 1, characterized in that, The volume ratio of nitrogen to phytic acid in step (1) is 1:

1.

6. The method for preparing a polyester enameled copper-coated flat wire according to claim 1, characterized in that, The process parameters of the microwave low-temperature plasma treatment in step (1) are: the gas pressure is 70-180 Pa, the power is 70-130 W, and the time is 15-28 min.

7. The method for preparing a polyester enameled copper-coated flat wire according to claim 1, characterized in that, The parameters of the electrostatic air-assisted airless spraying process in step (2) are: the voltage is 60-90 kV, the pressure is 0.3-0.5 MPa, the spraying distance is 150-300 mm, and the conveying chain speed is 4-6 m / min.

8. The method for preparing a polyester enameled wire coated with copper flat wire according to claim 1, characterized in that, The mass ratio of the metal oxide, organosiloxane, unsaturated polyester and additives in step (2) is 0.05-0.15:10:0.2-0.6:0.

35.

9. The method for preparing a polyester enameled wire coated with copper flat wire according to claim 1, characterized in that, The organosiloxane in step (2) is at least one of methacryloyloxysilane, epoxy silane and octadecyl triethoxysilane.

10. The method for preparing a polyester enameled copper-coated flat wire according to claim 1, characterized in that, The process parameters of the ball milling treatment in step (2) are: the ball milling medium is steel ball, the ball-to-material ratio is 20:1, the rotation speed is 500-1000 rpm, and the time is 5-9 h.

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