JP5561238B2 - Insulated wire and manufacturing method thereof - Google Patents

Description

  The present invention relates to an insulated wire and a method for manufacturing the same, and more particularly to an insulated wire used for a coil of an electrical device such as a rotating electrical machine or a transformer, and a method for manufacturing the same.

  General insulated wires such as enamel-insulated insulated wires used in coils of electrical equipment such as rotating electrical machines and transformers have cross-sectional shapes that match the coil application and shape, such as round or rectangular conductors. It has a structure in which a single layer or a plurality of layers of insulating coatings are formed. As a method for forming an insulating coating on the conductor, there are a method of applying and baking an insulating paint in which a resin is dissolved in an organic solvent, and a method of extruding and coating a pre-prepared resin composition on the conductor.

  In recent years, due to the demand for miniaturization of electrical equipment, insulating coatings are required to have mechanical characteristics that can withstand severe processing stress, such as adhesion and wear resistance. In addition, inverter control and higher voltage are progressing in response to demands for higher efficiency and higher output in electrical equipment. As a result, the operating temperature of the coil tends to be higher than before, and the insulation coating is also required to have high heat resistance.

  Since a higher voltage such as an inverter surge voltage is applied to the coil in the electrical equipment, the insulation coating may be deteriorated or damaged by the occurrence of partial discharge. In order to prevent the deterioration and damage of the insulating coating due to this partial discharge, development of an insulating coating having a high partial discharge starting voltage is underway. In order to increase the partial discharge start voltage of the insulating coating, there are a method of using a resin having a low relative dielectric constant for the insulating coating and a method of increasing the thickness of the insulating coating.

  As an example, an insulating coating material for a winding having a configuration in which the relative dielectric constant of the insulating coating is lowered by applying an insulating paint containing a fluorine-based polyimide resin having a specific structure on the conductor has been proposed. (For example, refer to Patent Document 1). When the insulated wire is formed using the insulating paint made of the fluorine-based polyimide resin described in Patent Document 1, the relative dielectric constant is 2.3 to 2.8, and the relative dielectric constant of the insulating coating of a normal winding It is said that a lower relative dielectric constant can be imparted compared to the above, so that the heat generation amount of the insulating coating and the deterioration due to heat can be suppressed.

  As another example, an inverter surge-proof insulated wire that realizes thickening of the insulating layer for increasing the partial discharge starting voltage without lowering the adhesive strength between the conductor and the enamel layer has been proposed (for example, patent document) 2). The insulated wire described in Patent Document 2 has both an enamel baked layer on the conductor and an extrusion coating layer provided on the outside thereof, thereby ensuring both the partial discharge start voltage and the conductor / enamel layer adhesive strength. In addition, the adhesive force between the enamel baking layer and the extrusion coating layer is reinforced by further interposing an adhesive layer between the enamel baking layer and the extrusion coating layer.

  As yet another example, a multilayer insulated wire is proposed in which the insulating layer is composed of two or more extruded coating layers excellent in heat resistance and chemical resistance (see, for example, Patent Document 3).

JP 2002-56720 A Japanese Patent No. 4177295 International Publication No. 2005/106898

  However, the insulating coating made of the fluorine-based polyimide resin described in Patent Document 1 has low adhesion to the conductor. Therefore, for example, there is a concern that a phenomenon (coating floating) in which the insulating coating peels off from the conductor due to severe processing stress in a coil forming process or the like. This coating floating causes a dielectric breakdown.

  On the other hand, in the insulated wire described in Patent Document 2, it is considered that the partial discharge start voltage can be increased by increasing the thickness of the extrusion-coated resin layer. However, since the enamel baking layer and the extrusion coating layer are greatly different in properties and forming method of the resin composition, there is a problem that the manufacturing process tends to be complicated and the manufacturing cost tends to increase. Moreover, in order to ensure the adhesiveness of an enamel baking layer and an extrusion coating resin layer, when an adhesive layer is interposed between these layers, the manufacturing cost further increases.

  In addition, the multilayer insulated wire described in Patent Document 3 uses a thermoplastic resin for the extrusion coating layer of two or more layers, and it is necessary to avoid the complexity of the manufacturing process and the increase in manufacturing cost. There is no difference from the insulated wire described in Patent Document 2.

  Accordingly, an object of the present invention is to provide an insulated wire having a high partial discharge start voltage and excellent in heat resistance and adhesion, and a method for producing the same.

  The objects of the present invention can be achieved by the inventions described in the following [1] to [6].

[1] That is, the present invention relates to a conductor, a resin (A) made of a thermoplastic resin having a melting point of 200 ° C. or higher, and an olefin having a melt flow rate (MFR) of 1 g / 10 min or less. An insulated wire comprising a resin composition mixed with a resin (B) containing a copolymer resin and having an extrusion coating layer crosslinked by electron beam irradiation.

[2] In the resin composition according to [1], the resin (A) and the resin (B) are in a weight ratio of (B) / (A) = 30/70 to 70/30. It is preferable that they are mixed with each other.

[3] The resin (A) described in [1] or [2] is thermoplastic polyimide, polyether ether ketone, polyether ketone, polyphenylene sulfide, polybutylene naphthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene. It preferably consists of any one of terephthalates.

[4] [1] to [3] wherein the resin according to any one of (B) is preferably a resin comprising denatured with maleic acid and glycidyl methacrylate click relay bets anhydride is further included.

[5] In the present invention, a resin (A) comprising a thermoplastic resin having a melting point of 200 ° C. or higher and an olefin copolymer resin having a melt flow rate (MFR) of 1 g / 10 min or less on the conductor. A step of forming an insulating coating having an extrusion coating layer formed by extrusion coating a resin composition mixed with the resin (B) containing the resin, and the insulating coating including the extrusion coating layer is crosslinked by electron beam irradiation. And a process for producing an insulated wire, comprising: a step.

[6] It is preferable that the method further includes a step of heat-treating the insulating coating at 250 ° C. or higher and 300 ° C. or lower after the step of forming the insulating coating according to [5].

  ADVANTAGE OF THE INVENTION According to this invention, while having a high partial discharge start voltage, the insulated wire excellent in the heat resistance of an extrusion coating layer and the adhesiveness between a conductor and an extrusion coating layer, and its manufacturing method are obtained.

It is a schematic diagram which shows an example of the typical insulated wire which concerns on embodiment of this invention. It is a schematic diagram which shows another example of an insulated wire. It is a schematic diagram which shows another example of an insulated wire.

  Preferred embodiments of the present invention will be specifically described below with reference to the accompanying drawings.

(Configuration of insulated wire)
In FIG. 1, the code | symbol 10 which shows the whole has illustrated the typical insulated wire which concerns on this embodiment. The basic configuration of the insulated wire 10 includes a conductor 20 and an extrusion coating layer 30 that is a characteristic part in this embodiment.

  For example, a single wire of copper or a copper alloy may be used as the conductor 20, or a plurality of copper wires or a plurality of copper alloy wires may be formed by twisting together. As copper, oxygen-free copper, low-oxygen copper having a low oxygen content, or the like can be used. As an example of the cross-sectional shape of the conductor 20, an example having a circular cross-section is illustrated, but the cross-sectional shape is not limited to the illustrated example, and may be configured to have various cross-sectional shapes such as a rectangular cross-section.

  The insulated wire 10 is preferably used for a coil of an electric machine such as a rotating electric machine or a transformer. More specifically, insulation suitable for a coil or the like formed by connecting the ends of a plurality of insulated wires whose cross sections are deformed into a substantially U shape and have a short shape by a welding method such as TIG welding. It is an electric wire. In addition, in a coil formed by welding and joining the ends of a plurality of insulated wires deformed into a substantially U shape, in particular, in the axial direction of the stator core from the stator core. The ends of a plurality of insulated wires that are partly deformed in a stepped manner so that the protruding portion (also referred to as a coil end) of the insulated wire has a plurality of cut portions along the circumferential direction of the stator core. It may be a coil formed by connecting parts together.

  As shown in FIG. 1, the extrusion coating layer 30 is an insulating coating that is crosslinked by electron beam irradiation and is extrusion coated on the conductor 20, a resin (A) made of a thermoplastic resin having a melting point of 200 ° C. or higher, and It is comprised with the resin composition which mixed resin (B) containing the olefin copolymer resin whose melt flow rate (MFR) is 1 g / 10min or less. In this resin composition, the resin (A) and the resin (B) are preferably mixed in a weight ratio of (B) / (A) = 30/70 to 70/30.

  When the resin (B) containing an olefin copolymer resin having an MFR of 1 g / 10 min or less is used, a decrease in the elastic modulus is suppressed, and even at a molding temperature higher than the melting point of the resin composition, the extrusion coating layer 30 is hard to deform, and the extrusion moldability of the extrusion coating layer 30 is good. A partial discharge start voltage higher than the partial discharge start voltage (900 Vp) described in the above-mentioned conventional Patent Document 2 can be obtained, and insulation properties and adhesion between the conductor 20 and the extrusion coating layer 30 can be improved. Become. In addition, the melt flow rate of resin (B) can be measured by the method based on JISK7210, for example. Moreover, melting | fusing point of resin (A) can be measured by the method based on JISK7122.

  The thermoplastic resin (A) having a melting point (Tm) of 200 ° C. or more and the resin (B) containing an olefin copolymer resin are in a weight ratio of (B) / (A) = 30/70 to 70/30. By mixing in the range, the deterioration of the discharge deterioration as an insulating coating structure having a partial discharge start voltage higher than the conventional partial discharge start voltage while further maintaining the adhesion between the conductor 20 and the extrusion coating layer 30. Occurrence can be prevented.

  As the resin (A) having a melting point of 200 ° C. or higher, for example, a resin made of engineering plastic or super engineer plastic can be used. Examples of these plastics include, for example, thermoplastic polyimide (Tm: 338 ° C.), polyether ether ketone (Tm: 334 ° C.), polyether ketone (Tm: 373 ° C.), polyphenylene sulfide (Tm: 285 ° C.), poly Engineering plastics such as butylene naphthalate (Tm: 243 ° C), polybutylene terephthalate (Tm: 224 ° C), polyethylene naphthalate (Tm: 269 ° C), polyethylene terephthalate (Tm: 258 ° C), or super engineer plastics .

As the resin (A), it is desirable to use polyether ether ketone, polyether ketone or polyphenylene sulfide having a low dielectric constant in order to obtain a high partial discharge starting voltage of 1500 V _P or higher, which is higher than the conventional partial discharge starting voltage, for example. .

  On the other hand, examples of the resin (B) containing an olefin copolymer resin having an MFR of 1 g / 10 min or less include polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-methyl acrylate copolymer. , Ethylene copolymers such as ethylene glycidyl methacrylate copolymer, isotactic polypropylene, syndiotactic polypropylene, polymethylpentene, and ethylene glycidyl methacrylate copolymer.

  As the resin (B), for example, a resin group having maleic anhydride or a glycidyl group is desirably mixed. Examples thereof include polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl acrylate copolymer, ethylene copolymer such as ethylene glycidyl methacrylate copolymer, isotactic polypropylene, It is preferable to include one or more resins obtained by modifying a resin made of syndiotactic polypropylene, polymethylpentene, ethylene glycidyl methacrylate copolymer, etc. with maleic anhydride, glycidyl methacrylate or the like.

  In addition, antioxidant, a copper damage inhibitor, a lubricant, a coloring agent, etc. can be added to the resin composition obtained by mixing the resin (A) and the resin (B). Moreover, although it is possible to make the thickness of the extrusion coating layer 30 which has this resin composition thinner than a normal extrusion coating layer, it is 30 micrometers or more as thickness of the extrusion coating layer 30 shown in FIG. Is preferred.

(Insulated wire manufacturing method)
The insulated wire 10 configured as described above can be effectively obtained by a manufacturing method having the following steps (A) and (B).
(A) a step of extrusion-coating a resin composition obtained by mixing the resin (A) and the resin (B) on the conductor 20 to form an insulation coating having an extrusion coating layer; and (b) an extrusion coating layer. A step of crosslinking an insulating coating containing

  In this crosslinking treatment step, an extrusion coating layer 30 having a resin composition obtained by mixing the resin (A) and the resin (B) is formed by extrusion coating, and then the insulation coating of the extrusion coating layer 30 is applied to an electron beam. It is important to perform a crosslinking treatment by irradiation. However, when the coil of the electrical equipment is formed using the insulated wire 10, the crosslinking treatment process is performed before the coil forming process.

  In order to cross-link only the thermoplastic resin (A) having a melting point of 200 ° C. or higher by electron beam irradiation, it is necessary to irradiate a high dose of electron beam. However, as in this embodiment, by mixing the resin (A) and the resin (B) containing the olefin copolymer resin, it becomes easy to crosslink, and even with a low dose electron beam, the crosslinking is not caused. It becomes possible. Thereby, since the deformation | transformation of the extrusion coating layer 30 by the molding temperature higher than melting | fusing point of the resin composition which mixed resin (A) and resin (B) can be suppressed, the extrusion moldability of the extrusion coating layer 30 is good. The insulation performance of the extrusion coating layer 30 can be ensured.

It is important that this manufacturing method further includes the following step (c).
(C) After the extrusion coating layer 30 is formed by extrusion coating, before the insulating coating of the extrusion coating layer 30 is crosslinked by electron beam irradiation, the extrusion coating layer 30 is heated at 250 ° C. or more and 300 ° C. or less. Heat treatment process.

  By performing the heat treatment under this temperature condition, the partial discharge start voltage higher than the conventional partial discharge start voltage (900 Vp), for example, a high portion of 1500 Vp or higher is obtained without reducing the adhesion between the conductor 20 and the extrusion coating layer 30. A discharge start voltage can be realized.

  After the resin composition in which the resin (A) and the resin (B) are mixed is extrusion-coated on the conductor 20 to form the extrusion coating layer 30, it is higher than the glass transition temperature (Tg) of the resin composition. When heat treatment is performed at a temperature of, for example, 250 ° C. or higher, the adhesion between the conductor 20 and the extrusion coating layer 30 can be strengthened. If the heat treatment is carried out at the glass transition temperature or higher, there is a remarkable effect.

  As described above, since the resin (B) uses an olefin copolymer resin having an MFR of 1 g / 10 min or less, the extrusion coating layer 30 is used even at a molding temperature extremely higher than the melting point of the resin composition. Is difficult to deform, the extrusion moldability of the extrusion coating layer 30 is improved, and the adhesion between the conductor 20 and the extrusion coating layer 30 can be improved. In addition, the weight ratio of the thermoplastic resin (A) having a melting point of 200 ° C. or higher and the resin (B) containing an olefin copolymer resin is (B) / (A) = 30/70 to 70/30. Therefore, it is possible to obtain the insulated wire 10 having a partial discharge start voltage higher than the conventional partial discharge start voltage while further maintaining the adhesion.

(Effect of embodiment)
According to the insulated wire 10 according to the above-described embodiment, the insulation coating formed by extrusion coating on the conductor 20 is a resin (A) made of a thermoplastic resin having a melting point of 200 ° C. or higher, and an olefin system having an MFR of 1 g / 10 min or less. Since it is comprised with the resin composition which mixed resin (B) containing a copolymer resin, even if the thickness of the extrusion coating layer 30 is thin, it has a high partial discharge start voltage. In addition, the adhesiveness between the conductor 20 and the extrusion coating layer 30 is excellent, and it becomes possible to suppress deformation due to a high molding temperature and a decrease in insulation performance without reducing the adhesiveness.

[Modification]
As is apparent from the above description, the insulated wire and the method for manufacturing the insulated wire according to the present invention have been described based on the above-described embodiment. Such first and second modifications are also possible. 2 and 3, the same member names and symbols are assigned to substantially the same members as those in the above embodiment. Therefore, the detailed description regarding these members is omitted.

(First modification)
Even in the first modification, there is no change in the basic configuration of the insulated wire 10 according to the above embodiment. In FIG. 2, the difference from the above embodiment is that in the above embodiment, the first extrusion coating layer 30 formed by extrusion coating on the conductor 20 is formed as a first modification. In this case, the second extrusion coating layer 31 of the second layer is formed on the first extrusion coating layer 30.

  As shown in FIG. 2, in the insulated wire 11 according to the first modification, a first extrusion coating layer 30 is formed by extrusion coating on the conductor 20, and a second extrusion coating layer 31 is formed on the first extrusion coating layer 30. Is formed by extrusion coating. As this 2nd extrusion coating layer 31, like the resin (A) which concerns on the said 1st Embodiment, for example, thermoplastic polyamideimide, thermoplastic polyimide, polyetheretherimide, polyetherimide, polyphenylene sulfide, etc. Made of resin. The thickness of the first extrusion coating layer 30 in the insulated wire 11 is preferably 20 μm or more, and the thickness of the second extrusion coating layer 31 is preferably 30 μm or more.

  By forming the extrusion coating layers 30 and 31, the wear resistance can be improved. Therefore, for example, when forming a coil of an electrical device, even if a strong external force (tension) is applied in the winding process or the like, it is possible to prevent the occurrence of coating cracks or micro cracks on the surface of the insulating coating layer. Is possible.

(Second modification)
Even in the second modification, there is no change in the basic configuration of the insulated wire 10 according to the above-described embodiment. In FIG. 3, in the insulated wire 12 according to the second modified example, the first extruded coating layer 30 of the first layer is formed by extrusion coating on the conductor 20, and then on the first extrusion coating layer 30. The point which formed the 2nd extrusion coating layer 31 of the 2nd layer, and also formed the 3rd extrusion coating layer 32 of the 3rd layer on the 2nd extrusion coating layer 31 differs greatly from the above-mentioned embodiment. .

  The 2nd and 3rd extrusion coating layers 31 and 32 of insulated wire 12 concerning this 2nd modification consist of resin (A) concerning the 1st embodiment of the above. The thickness of each of the first and third extrusion coating layers 31 and 32 formed by extrusion coating of the three extrusion coating layers on the conductor 20 is 20 μm or more, and the thickness of the second extrusion coating layer 31 is as follows. It is preferable that it is 30 micrometers or more.

  By forming the extrusion coating layers 30 to 32, it is possible to further improve the wear resistance and further prevent the occurrence of coating cracks and minute cracks on the surface of the insulating coating layer. In addition, when it is set as the insulation coating structure of 3 layers or more, it is preferable to set as the total thickness of an extrusion coating layer in the range of 70-100 micrometers.

  Hereinafter, as a more specific embodiment of the present invention, an insulated wire will be described in detail with reference to Table 1 with examples and comparative examples. In addition, in this Example, the typical example of an insulated wire is given and, of course, this invention is not limited to these Examples.

  Samples of Examples 1 to 8 and Comparative Examples 1 to 4 having various extrusion coating layers were produced. These samples were compared and evaluated for adhesion and heat resistance. The components of the extrusion coating layer, the processing conditions, and the insulating coating thickness in these samples are summarized in Table 1 below.

(Production of insulated wires)
A plurality of copper wires having an outer diameter of 1.25 mm are prepared as conductors, and 12 types of resin compositions containing the components shown in Table 1 are formed on the copper wires at an extrusion temperature of about 300 to 370 ° C. using an extruder. An extrusion coating layer was formed by extrusion coating. After the formation of this extrusion coating layer, a first heat treatment was performed through an electric furnace having a temperature (set temperature) of 200 to 300 ° C. Further, the extruded coating layer was subjected to a second heat treatment at 250 ° C. or more and 300 ° C. or less to produce an insulated wire having a circular cross section having an insulation coating thickness of about 100 μm. Except for Comparative Example 1, for Examples 1 to 8 and Comparative Examples 2 to 4, after the second heat treatment, the resin composition of the extrusion coating layer was irradiated with an electron beam having a dose of 30 Mrad as a crosslinking treatment. The insulated wire was produced by performing.

  The 12 types of insulated wires produced as described above were measured for partial discharge starting voltage and tested for adhesion and heat resistance.

(Measurement of partial discharge start voltage)
In measuring the partial discharge start voltage of the obtained insulated wire, first, two insulated wires were cut out with a length of 500 mm, twisted together while applying a tension of 39 N (4 kgf), and the range of 120 mm at the center of the insulated wire A twisted pair sample having 6 twists was prepared. Next, the 10 mm part which is the edge part of this sample was peeled with the abisofix apparatus. Then, in order to dry an insulating film, it hold | maintained for 30 minutes in a 120 degreeC thermostat, and left to stand for 18 hours until it became room temperature in the desiccator.

  The partial discharge starting voltage was measured using a partial discharge automatic test system (manufactured by Soken Denki Co., Ltd., DAC-6024). The measurement conditions were an atmosphere with a relative humidity of 50% at 25 ° C., and the twisted pair sample was charged while increasing the voltage of 50 Hz at 10 to 30 V / s. The voltage at which 50 pC discharge was generated 50 times per second in the twisted pair sample was used as the partial discharge start voltage. The measurement results are summarized in Table 1 below.

(Evaluation of adhesion)
This adhesion was evaluated by carrying out a rapid extension test based on JIS C3003. As a result of the rapid extension test, if the length of the insulation coating floats (peel) is 2 mm or less from the breaking point, ◎ marks (excellent), 2-20 mm marks ○ mark (pass), longer than 20 mm Was evaluated as x mark (failed). The evaluation results are summarized in Table 1 below.

(Evaluation of heat resistance)
In evaluating the heat resistance, first, two insulated wires having a length of 500 mm are cut out and twisted together while applying a tension of 39 N (4 kgf), and the twisted wire is twisted 6 times in the range of 120 mm at the center of the insulated wire. A twisted pair sample was prepared. Next, this twisted pair sample was heated by being kept at 350 ° C. for 5 minutes in an aging tester (manufactured by Toyo Seiki Co., Ltd., Gear Oven STD60P). Thereafter, the partial discharge start voltage was measured by a partial discharge start voltage test. Evaluation was made with a mark indicating that the partial discharge starting voltage was less than 20% lower than the value measured by the above test as ◯, and a drop of 20% or more as X. The evaluation results are summarized in Table 1 below.

  As apparent from Table 1 below, as shown in Examples 1 to 8, a resin composition in which a resin (A) made of engineering plastic or super engineer plastic and a resin (B) containing an olefin copolymer resin are mixed. After the extrusion coating layer was formed on the conductor using an object, the one in which the extrusion coating layer was irradiated with an electron beam had a partial discharge start voltage of 1500 Vp or higher, which was higher than those of Comparative Examples 1 to 4. The adhesion test and the heat resistance test were also good results as compared with Comparative Examples 1 to 4.

  On the other hand, in the comparative example 1 which contains resin (B) whose MFR is outside the specified range and does not irradiate with an electron beam, the partial discharge start voltage is higher than the partial discharge start voltage values of Examples 1 to 8. Became a low value, and heat resistance was also inferior.

  On the other hand, in the comparative examples 2 to 4 in which the extruded coating layer was irradiated with an electron beam but the resin (B) containing the olefin copolymer resin was not mixed, the partial discharge was higher than the partial discharge start voltage of Examples 1 to 8. The starting voltage became a low value. In Comparative Examples 2 and 3, the adhesion test and the heat resistance were also inferior.

  From the above, the insulated wires of Examples 1 to 8 have a high partial discharge start voltage even when the thickness of the extrusion coating layer is thin, and the adhesion between the conductor and the extrusion coating layer, and the extrusion coating layer It can be understood that a product having excellent heat resistance and practically no hindrance can be obtained.

  In addition, in the said Example, although the cross-sectional shape of the copper conductor used the circular thing, even if it uses the copper conductor which has a rectangular-shaped cross section, for example, the insulated wire with a high partial discharge start voltage is similar to the said Example Can be obtained.

  As is clear from the above description, not all the combinations of features described in the above embodiments, modifications, and examples are necessarily essential to the means for solving the problems of the present invention. It should be noted that, of course, various configurations are possible within the scope of the technical idea of the present invention.

10-12 ... insulated wire, 20 ... conductor, 30-32 ... extruded coating layer

Claims (6)

Conductors,
A resin (A) made of a thermoplastic resin having a melting point of 200 ° C. or higher and a resin (B) containing an olefin copolymer resin having a melt flow rate (MFR) of 1 g / 10 min or less provided on the conductor is mixed. An insulating coating comprising an extruded coating layer comprising a resin composition and crosslinked by electron beam irradiation;
An insulated wire characterized by comprising:   2. The resin composition according to claim 1, wherein the resin (A) and the resin (B) are mixed in a weight ratio of (B) / (A) = 30/70 to 70/30. Insulated wire.   The resin (A) is composed of any one of thermoplastic polyimide, polyether ether ketone, polyether ketone, polyphenylene sulfide, polybutylene naphthalate, polybutylene terephthalate, polyethylene naphthalate, and polyethylene terephthalate. Insulated wire as described. The resin (B), the insulated wire according to claim 1, resin obtained modified with maleic acid and glycidyl methacrylate click relay bets anhydride is further included. A resin in which a resin (A) made of a thermoplastic resin having a melting point of 200 ° C. or higher and a resin (B) containing an olefin copolymer resin having a melt flow rate (MFR) of 1 g / 10 min or less are mixed on a conductor. Forming an insulating coating having an extruded coating layer formed by extrusion coating the composition;
A step of crosslinking the insulating coating containing the extrusion coating layer by electron beam irradiation;
The manufacturing method of the insulated wire characterized by including.   The method for manufacturing an insulated wire according to claim 5, further comprising a step of heat-treating the insulating coating at 250 ° C or higher and 300 ° C or lower after the step of forming the insulating coating.

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