A polyetheretherketone film wrapped Cu electromagnetic wire and its preparation method and application

Abstract

The present invention provides a polyetheretherketone film wrapped Cu electromagnetic wire and its preparation method and application, belonging to the technical field of electromagnetic wire. The present invention first magnetron sputters a transition layer on the surface of the copper electromagnetic wire and controls the type of the transition layer. Highly active Al, Ti, Cr or their alloys are used, which can form chemical bonds with functional groups in the polyetheretherketone film and form metallurgical bonds with the Cu layer, thereby improving the bonding force between the polyetheretherketone and Cu. Then, the polyetheretherketone film is coated. The polyetheretherketone has high stability, mechanical properties, insulation, high voltage breakdown resistance and corona resistance, and is relatively thin. Finally, heat treatment is performed to make the polyetheretherketone film uniform and dense, so that the prepared polyetheretherketone film wrapped Cu electromagnetic wire has excellent performance. The preparation method is simple and green and environmentally friendly.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic wires, and in particular to a polyetheretherketone film wrapped Cu electromagnetic wire, a preparation method thereof, and an application thereof. Background Art

[0002] Cu magnet wire is widely used in various transformers and new energy vehicle motors. With the development of an energy-saving society, these applications place higher demands on Cu magnet wire for winding coils, such as insulation, corona resistance, high temperature resistance, and high interfacial current density. To achieve this insulation and corona resistance, a series of polymer-coated Cu wires have been developed, including acetal enameled wire, polyester enameled wire, polyurethane enameled wire, polyesterimide / polyamide composite enameled wire, and polyesterimide / polyamideimide composite enameled wire. Acetal enameled wire offers the lowest heat resistance, generally operating below 105°C or 120°C; polyesterimide / polyamideimide composite enameled wire offers the highest heat resistance, operating up to 240°C. To improve the enameled wire's corona resistance, nanoparticles such as SiO2 and TiO2 are often added to the polymer lacquer to form a composite film.

[0003] New transformers and new energy vehicle motors currently require Cu magnet wire windings to have higher interfacial current density. This means reducing the thickness of the polymer coating applied to the Cu magnet wire. However, this in turn limits the wire's insulation and corona resistance. Therefore, thin coating film thicknesses are typically between 60-110 microns, while thick coating film thicknesses are typically between 100-160 microns.

[0004] In addition, the greening of the enameled wire production process has always been a difficult problem that has not been completely solved. In order to ensure uniform thickness and high production efficiency of the enameled wire, cresol or xylene are generally used as solvents in the enameled wire production process. Despite the subsequent catalytic combustion device, it is difficult to prevent the harm to people in the workshop. Although low-toxic solvent paints and water-soluble paints have been developed over the years, low-toxic solvent paints such as ethylene glycol ethers, diethylene glycol ethers and methyl pyrrolidone, and water-soluble paints including water-soluble polyester electrophoretic paints, water-dispersed polyester paints and water-soluble polyester imide paints, they are still not widely used due to analysis of production efficiency, cost and final product quality.

[0005] Therefore, how to prepare thinner and high-performance Cu electromagnetic wire in an environmentally friendly way has become a difficult problem in the existing technology. Summary of the Invention

[0006] The present invention aims to provide a polyetheretherketone film-wrapped Cu magnet wire, its preparation method, and its application. The preparation method provided by the present invention is environmentally friendly, and the resulting polyetheretherketone film-wrapped Cu magnet wire has a lower polyetheretherketone film thickness and exhibits excellent stability and mechanical properties.

[0007] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0008] The present invention provides a method for preparing a polyetheretherketone film wrapped Cu electromagnetic wire, comprising the following steps:

[0009] (1) performing magnetron sputtering on the surface of the copper electromagnetic wire to obtain a transition layer coated copper electromagnetic wire; the transition layer comprises an Al layer, a Ti layer, a Cr layer, an Al-Ti alloy layer, an Al-Cr alloy layer, a Ti-Cr alloy layer or an Al-Ti-Cr alloy layer;

[0010] (2) coating the surface of the transition layer-coated copper electromagnetic wire obtained in step (1) with a polyetheretherketone film to obtain a polyetheretherketone-coated copper electromagnetic wire;

[0011] (3) heat-treating the polyetheretherketone coated copper electromagnetic wire obtained in step (2) and then cooling it to obtain a polyetheretherketone film wrapped Cu electromagnetic wire.

[0012] Preferably, the thickness of the transition layer in step (1) is 2 to 100 nm.

[0013] Preferably, the back vacuum degree of the magnetron sputtering in step (1) is less than 1×10 -3 Pa, the Ar pressure of magnetron sputtering is 0.1~2Pa, and the magnetron sputtering rate is 5~100nm / min.

[0014] Preferably, a bias voltage is also applied during magnetron sputtering in step (1).

[0015] Preferably, the bias voltage is 50-500V.

[0016] Preferably, the coating in step (2) is performed using a wrapping machine.

[0017] Preferably, the thickness of the polyetheretherketone film in step (2) is 2 to 20 μm.

[0018] Preferably, the heat treatment temperature in step (3) is 350-420° C., and the heat treatment time is 1-10 minutes.

[0019] The present invention provides a polyetheretherketone film wrapped Cu electromagnetic wire prepared by the preparation method described in the above technical solution.

[0020] The present invention also provides the use of the polyetheretherketone film wrapped Cu electromagnetic wire described in the above technical solution in a transformer or a new energy vehicle motor.

[0021] The present invention provides a preparation method of a copper electromagnetic wire wrapped with a polyetheretherketone film, comprising the following steps: (1) performing magnetron sputtering on the surface of the copper electromagnetic wire to obtain a transition layer-coated copper electromagnetic wire; the transition layer comprises an Al layer, a Ti layer, a Cr layer, an Al-Ti alloy layer, an Al-Cr alloy layer, a Ti-Cr alloy layer or an Al-Ti-Cr alloy layer; (2) coating the surface of the transition layer-coated copper electromagnetic wire obtained in the step (1) with a polyetheretherketone film to obtain a polyetheretherketone-coated copper electromagnetic wire; (3) subjecting the polyetheretherketone-coated copper electromagnetic wire obtained in the step (2) to heat treatment and then cooling to obtain a copper electromagnetic wire wrapped with a polyetheretherketone film. The present invention first magnetron sputters a transition layer on the surface of the copper electromagnetic wire and controls the type of the transition layer. Highly active Al, Ti, Cr, or their alloys are used to form chemical bonds with the functional groups in the polyetheretherketone film and to form a metallurgical bond with the Cu layer, thereby improving the bonding strength between the polyetheretherketone and Cu. The polyetheretherketone film is then coated. The polyetheretherketone film has high stability, mechanical properties, insulation, high-voltage breakdown resistance, and corona resistance, and is relatively thin. Finally, a heat treatment is performed to make the polyetheretherketone film uniform and dense, thereby making the prepared polyetheretherketone film-wrapped Cu electromagnetic wire have excellent performance, a simple preparation method, and environmentally friendly. The results of the embodiment show that the polyetheretherketone film-wrapped Cu electromagnetic wire prepared by the present invention has excellent insulation properties, and the polyetheretherketone film will not separate until it is repeatedly bent 180° for more than 24 times. DETAILED DESCRIPTION

[0022] The present invention provides a method for preparing a polyetheretherketone film wrapped Cu electromagnetic wire, comprising the following steps:

[0023] (1) performing magnetron sputtering on the surface of the copper electromagnetic wire to obtain a transition layer coated copper electromagnetic wire; the transition layer comprises an Al layer, a Ti layer, a Cr layer, an Al-Ti alloy layer, an Al-Cr alloy layer, a Ti-Cr alloy layer or an Al-Ti-Cr alloy layer;

[0024] (2) coating the surface of the transition layer-coated copper electromagnetic wire obtained in step (1) with a polyetheretherketone film to obtain a polyetheretherketone-coated copper electromagnetic wire;

[0025] (3) heat-treating the polyetheretherketone coated copper electromagnetic wire obtained in step (2) and then cooling it to obtain a polyetheretherketone film wrapped Cu electromagnetic wire.

[0026] The invention performs magnetron sputtering on the surface of the copper electromagnetic wire to form a transition layer to obtain the transition layer coated copper electromagnetic wire.

[0027] The present invention has no particular limitation on the source and structure of the copper magnet wire, and commercially available products known to those skilled in the art may be used.

[0028] In the present invention, the copper magnet wire is preferably surface cleaned before use. The present invention has no particular limitation on the surface cleaning operation, and a surface cleaning technique well known to those skilled in the art can be used.

[0029] In the present invention, the transition layer comprises an Al layer, a Ti layer, a Cr layer, an Al-Ti alloy layer, an Al-Cr alloy layer, a Ti-Cr alloy layer, or an Al-Ti-Cr alloy layer. When the transition layer is an Al-Ti alloy layer, an Al-Cr alloy layer, a Ti-Cr alloy layer, or an Al-Ti-Cr alloy layer, the present invention does not specifically limit the content of each element in the alloy layer; any proportion is acceptable. The present invention controls the type of transition layer, employing highly active Al, Ti, Cr, or their alloys as the transition layer, which can both form chemical bonds with the functional groups in the polyetheretherketone film and form a metallurgical bond with the Cu layer, thereby enhancing the bonding strength between the polyetheretherketone and Cu.

[0030] In the present invention, the thickness of the transition layer is preferably 2 to 100 nm, more preferably 5 to 50 nm, and even more preferably 10 to 30 nm. By limiting the thickness of the transition layer to the above range, the present invention can further improve the bonding strength between the copper magnet wire and the polyetheretherketone film.

[0031] In the present invention, the target material for magnetron sputtering is preferably a pure Al target, a pure Ti target, a pure Cr target, an Al-Ti alloy target, an Al-Cr alloy target, a Ti-Cr alloy target, or an Al-Ti-Cr alloy target. The present invention has no particular limitation on the shape of the target material, and a target material with a shape familiar to those skilled in the art can be used.

[0032] In the present invention, the target material is preferably pre-sputtered before use; the pre-sputtering time is preferably 1 to 5 minutes.

[0033] In the present invention, the back vacuum degree of the magnetron sputtering is preferably less than 1×10 -3Pa; the Ar pressure of the magnetron sputtering is preferably 0.1-2 Pa, more preferably 0.2-1.2 Pa; the magnetron sputtering rate is preferably 5-100 nm / min, more preferably 10-50 nm / min, and further preferably 10-20 nm / min. In the present invention, it is also preferred to apply a bias voltage during the magnetron sputtering, and the bias voltage is preferably 50-500 V, more preferably 100-300 V. The present invention has no special limitation on the time of the magnetron sputtering, as long as the thickness of the transition layer is within the above range. The present invention limits the various parameters of magnetron sputtering within the above range, which can make the transition layer more uniform, better bonded to the polyetheretherketone film, and further improve the bonding strength of the electromagnetic wire.

[0034] The present invention preferably controls the magnetron sputtering power to control the magnetron sputtering rate. The present invention preferably first fixes the magnetron sputtering power at 200W, starts the copper magnet wire for magnetron sputtering for 20 minutes, then increases the power to 500W, stabilizes for 2 minutes, moves the copper magnet wire and sputters for another 20 minutes, then increases the power by 300W each time, and sputters on the copper magnet wire for 20 minutes each until the power reaches 10kW. The copper magnet wire is removed and embedded in a polymer matrix. The thickness of the sputtered film is measured using a scanning electron microscope to obtain a quantitative relationship between sputtering power and sputtering rate.

[0035] In the present invention, the copper magnet wire is relatively long. Preferably, an unwinding device is provided on one side of the magnetron sputtering chamber, and a rewinding device is provided on the other side to control the movement speed of the copper magnet wire. In the present invention, the movement speed of the copper magnet wire is preferably 50 to 1000 mm / min.

[0036] After obtaining the transition layer coated copper electromagnetic wire, the present invention coats the surface of the transition layer coated copper electromagnetic wire with a polyetheretherketone film to obtain the polyetheretherketone coated copper electromagnetic wire.

[0037] In the present invention, the coating is preferably performed by a wrapping machine. In the present invention, the wrapping machine is preferably a single-layer wrapping machine.

[0038] The present invention has no special limitation on the parameters of the wrapping machine. The parameters of the wrapping machine well known to those skilled in the art can be used to evenly and densely wrap the polyetheretherketone film on the surface of the transition layer-coated copper magnet wire.

[0039] In the present invention, the thickness of the polyetheretherketone film is preferably 2 to 20 μm. In the present invention, the polyetheretherketone film can be stable at 320°C, does not react with air, and has high strength (80 to 100 MPa) and excellent plasticity (80 to 120% elongation). It also has excellent insulation, high voltage breakdown resistance, and corona resistance. More importantly, it has been possible to achieve stable production of films with a thickness of 10 μm, thereby improving the various properties of the magnet wire.

[0040] After obtaining the polyetheretherketone coated copper electromagnetic wire, the present invention performs heat treatment on the polyetheretherketone coated copper electromagnetic wire and then cools it to obtain the polyetheretherketone film wrapped Cu electromagnetic wire.

[0041] In the present invention, the temperature of the heat treatment is preferably 350-420° C., more preferably 380-400° C.; the time of the heat treatment is preferably 1-10 min, more preferably 4-6 min.

[0042] In the present invention, the heat treatment is preferably performed in a continuous heat treatment furnace. The heat treatment time is preferably controlled by controlling the speed of the magnet wire. In the present invention, the speed of the magnet wire is preferably 5 to 5000 mm / min. By limiting the heat treatment temperature and time to the aforementioned ranges, the present invention can achieve a dense film with uniform thickness.

[0043] In the present invention, the polyetheretherketone-coated copper magnet wire is preferably placed in a mold before heat treatment. In the present invention, the dimensions of the mold are preferably consistent with the dimensions of the wrapped magnet wire. By placing the wrapped magnet wire in a mold before heat treatment and controlling the dimensions of the mold, the magnet wire film can have a uniform thickness and a smooth surface.

[0044] In the present invention, the cooling is preferably air cooling, and the cooling rate of the air cooling is preferably 40-60° C. / s. In the present invention, the cooling rate of the air cooling is relatively fast, which can make the film thickness more uniform.

[0045] The present invention first magnetron sputters a transition layer on the surface of the copper electromagnetic wire and controls the type of the transition layer. Highly active Al, Ti, Cr or their alloys are used, which can form chemical bonds with functional groups in the polyetheretherketone film and form metallurgical bonds with the Cu layer, thereby improving the bonding force between the polyetheretherketone and Cu. Then, the polyetheretherketone film is coated. The polyetheretherketone has high stability, mechanical properties, insulation, high-voltage breakdown resistance and corona resistance, and is relatively thin. Finally, heat treatment is performed to make the polyetheretherketone film uniform and dense, so that the prepared polyetheretherketone film wrapped around the Cu electromagnetic wire has excellent performance. The preparation method is simple and green and environmentally friendly.

[0046] The present invention provides a polyetheretherketone film wrapped Cu electromagnetic wire prepared by the preparation method described in the above technical solution.

[0047] The polyetheretherketone film wrapped Cu electromagnetic wire prepared by the invention has excellent insulation and bonding strength.

[0048] The present invention also provides the use of the polyetheretherketone film wrapped Cu electromagnetic wire described in the above technical solution in a transformer or a new energy vehicle motor.

[0049] The present invention has no special limitation on the operation of the application, and the application technical solutions well known to those skilled in the art can be adopted.

[0050] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0051] Example 1

[0052] (1) A pure Al cylindrical target was installed in the magnetron sputtering chamber, and a Cu round wire was continuously run through the magnetron sputtering area to test the quantitative relationship between the magnetron sputtering power and the sputtering rate. When the vacuum degree of the magnetron sputtering chamber reached 3×10 - 4 Pa, filled with high-purity Ar gas. During the entire magnetron sputtering process, the flowing Ar gas pressure was 0.5 Pa. The Al target was started for pre-sputtering for 3 minutes, and the sputtering power was fixed at 200 W. Then the unwinding and rewinding of the Cu wire were started, and the sputtering time was 20 minutes. The magnetron sputtering power of the Al target was continued to be increased to 500 W, stabilized for 2 minutes, and the Cu wire was continued to be moved and magnetron sputtered for 20 minutes. In the same way, until the magnetron sputtering power of the Al target was increased to 10 kW, the Cu wire was taken out, and the corresponding wire was embedded in the polymer matrix. The thickness of the Al film was measured using a scanning electron microscope, and a series of quantitative relationships between the magnetron sputtering power and the Al magnetron sputtering rate were obtained.

[0053] (2) After cleaning the surface of a roll of Cu electromagnetic wire, place it in the unwinding device of the magnetron sputtering chamber, pass it through the magnetron sputtering area, and fix the Cu electromagnetic wire on the other side of the rewinding mechanism. Then, evacuate the entire magnetron sputtering equipment. When the vacuum degree of the magnetron sputtering chamber reaches 3×10 -4Pa, filled with high-purity Ar gas. During the entire magnetron sputtering process, the flowing Ar gas pressure was 0.5 Pa. The Al target was started for pre-sputtering for 3 minutes, and then the unwinding and rewinding mechanisms were started to make the Cu electromagnetic wire run in the magnetron sputtering chamber. The magnetron sputtering rate of the fixed Al target was 10 nm / min, and the moving rate of the Cu electromagnetic wire in the chamber was 800 mm / min, obtaining a 15 nm thick Al layer transition layer.

[0054] (3) After the Cu / Al electromagnetic wire is taken out, a 10-micron PEEK film is evenly and densely wound around the Cu / Al electromagnetic wire in a single layer using a wrapping machine. The wire is then placed in a mold and passed through a continuous heat treatment furnace. The furnace temperature is set at 380°C, the heat treatment time is 5 minutes, and the electromagnetic wire travel speed is 2000 mm / min. Finally, after being taken out of the furnace, it is forced to cool with air cooling (cooling rate is 50°C / s) and then rolled up to obtain a Cu electromagnetic wire wrapped with polyetheretherketone film, which is recorded as Cu / Al / PEEK electromagnetic wire.

[0055] Comparative Example 1

[0056] The transition layer in Example 1 was omitted, and other parameters were the same as those in Example 1 to obtain a Cu / PEEK electromagnetic wire.

[0057] The resistivity of the Cu / Al / PEEK electromagnetic wire prepared in Example 1 was measured by four-probe resistance method and was 1.8×10 15 Ω·m, showing excellent insulation performance.

[0058] The interfacial bonding strength of PEEK / Cu can be simply evaluated by the number of times the Cu wire is repeatedly bent 180° before separation of the Cu and PEEK films occurs. In Comparative Example 1, the Cu / PEEK magnet wire separated after a single 180° bend. However, the Cu / Al / PEEK magnet wire prepared in Example 1 only separated the PEEK after 24 180° bends, significantly exceeding the requirements for transformer or motor magnet wire winding processes.

[0059] Example 2

[0060] (1) A pure Ti cylindrical target was installed in the magnetron sputtering chamber, and a Cu round wire was continuously run through the magnetron sputtering area to test the quantitative relationship between the magnetron sputtering power and the sputtering rate. When the vacuum degree of the magnetron sputtering chamber reached 3×10 - 4Pa, filled with high-purity Ar gas. During the entire magnetron sputtering process, the flowing Ar gas pressure was 0.8 Pa. The Ti target was started for pre-sputtering for 3 minutes, and the sputtering power was fixed at 200 W. Then the unwinding and rewinding of the Cu wire were started, and the sputtering time was 20 minutes. The magnetron sputtering power of the Ti target was continued to be increased to 500 W, stabilized for 2 minutes, and the Cu wire was continued to be moved and magnetron sputtered for 20 minutes. In the same way, until the magnetron sputtering power of the Ti target was increased to 10 kW, the Cu wire was taken out, and the corresponding wire was embedded in the polymer matrix. The thickness of the Ti film was measured using a scanning electron microscope, and a series of quantitative relationships between the magnetron sputtering power and the Ti magnetron sputtering rate were obtained.

[0061] (2) After cleaning the surface of a roll of Cu electromagnetic wire, it is loaded into the unwinding device of the magnetron sputtering chamber, passed through the magnetron sputtering area, and fixed on the other side of the reeling mechanism. The entire magnetron sputtering equipment is evacuated. When the vacuum degree of the magnetron sputtering chamber reaches 3×10 -4 Pa, filled with high-purity Ar gas. During the entire magnetron sputtering process, the flowing Ar gas pressure was 0.5 Pa. The Ti target was started for pre-sputtering for 3 minutes, and then the unwinding and rewinding mechanisms were started to make the Cu electromagnetic wire run in the magnetron sputtering chamber. The magnetron sputtering rate of the fixed Ti target was 10 nm / min, the bias voltage was 150 V, and the moving rate of the Cu electromagnetic wire in the chamber was 300 mm / min, obtaining a 20 nm thick Ti layer transition layer;

[0062] (3) After the Cu / Ti electromagnetic wire is taken out, a 10-micron PEEK film is evenly and densely wound around the Cu / Ti electromagnetic wire in a single layer using a wrapping machine. The wire is then placed in a mold and passed through a continuous heat treatment furnace. The furnace temperature is set at 400°C, the heat treatment time is 3 minutes, and the electromagnetic wire travel speed is 4500 mm / min. Finally, after being taken out of the furnace, it is forced to cool with air cooling (cooling rate is 50°C / s) and then rolled up to obtain a Cu electromagnetic wire wrapped with polyetheretherketone film, which is recorded as Cu / Ti / PEEK electromagnetic wire.

[0063] The resistivity of the Cu / Ti / PEEK electromagnetic wire prepared in Example 2 was measured by four-probe resistance method and was 3.2×10 15 Ω·m, showing excellent insulation performance.

[0064] The Cu / Ti / PEEK electromagnetic wire prepared in Example 2 was bent repeatedly 180° for 32 times before PEEK peeling occurred, which completely exceeded the requirements of the transformer or motor electromagnetic wire winding process.

[0065] In summary, the present invention magnetron sputters a transition layer on the surface of the copper electromagnetic wire, controls the type of the transition layer, and then covers it with a polyetheretherketone film, performs heat treatment and then cools it. The obtained polyetheretherketone film wrapped Cu electromagnetic wire has excellent insulation and bonding strength.

[0066] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing a polyetheretherketone film wrapped Cu magnet wire, comprising the following steps: (1) magnetron sputtering a transition layer on the surface of a copper electromagnetic wire to obtain a transition layer-coated copper electromagnetic wire; the transition layer comprises an Al layer, a Ti layer, a Cr layer, an Al-Ti alloy layer, an Al-Cr alloy layer, a Ti-Cr alloy layer or an Al-Ti-Cr alloy layer; the thickness of the transition layer is 2 to 100 nm; (2) coating the surface of the transition layer-coated copper electromagnetic wire obtained in step (1) with a polyetheretherketone film to obtain a polyetheretherketone-coated copper electromagnetic wire; the thickness of the polyetheretherketone film is 2 to 20 μm; (3) heat-treating the polyetheretherketone coated copper electromagnetic wire obtained in step (2) and then cooling it to obtain a polyetheretherketone film wrapped Cu electromagnetic wire; The back vacuum degree of the magnetron sputtering in step (1) is less than 1×10 -3 Pa, the Ar pressure of magnetron sputtering is 0.1-2 Pa, and the magnetron sputtering rate is 5-100 nm / min; the temperature of the heat treatment in step (3) is 350-420° C., and the heat treatment time is 1-10 min.

2. The preparation method according to claim 1, characterized in that In the step (1), a bias voltage is also applied during magnetron sputtering.

3. The preparation method according to claim 2, characterized in that The bias voltage is 50-500V.

4. The preparation method according to claim 1, characterized in that The coating in step (2) is performed using a wrapping machine.

5. The polyetheretherketone film wrapped Cu electromagnetic wire prepared by the preparation method according to any one of claims 1 to 4.

6. Use of the polyetheretherketone film wrapped Cu electromagnetic wire according to claim 5 in transformers or new energy vehicle motors.