WO2024048192A1 - Coated electric wire and method for producing coated electric wire - Google Patents

Abstract

Provided is a coated electric wire comprising a flat electric-wire base and a coating layer formed on the outer periphery of the flat electric-wire base, wherein the coating layer comprises: a first layer, which is a layer formed from a liquid coating composition (1) comprising a polymer (1) having an amide group and/or an imide group, a second layer, which is a layer formed from either a liquid coating composition (2) comprising a polymer (2) having an amide group and/or an imide group and a fluoropolymer (2) or a powdery coating composition (2) comprising a polymer (2) having an amide group and/or an imide group and a fluoropolymer (2), and a third layer, which is a layer formed from a liquid coating composition (3) comprising a fluoropolymer (3-1) or a powdery coating composition (3) comprising a fluoropolymer (3-2).

Description

Covered wire and method for manufacturing coated wire

The present disclosure relates to a covered electric wire and a method for manufacturing the covered electric wire.

Patent Document 1 has a conductor and a first insulating layer formed on the outer periphery of the conductor, the first insulating layer is made of a thermosetting resin and a fluororesin, and the first insulating layer is made of a thermosetting resin and a fluororesin. A layer having a mass ratio of 90:10 to 10:90 with the fluororesin and formed by mixing a thermosetting resin solution and a fluororesin organosol, applying the resulting mixed solution onto a conductor, and baking it. An electric wire characterized by the following is described.

International Publication No. 2011/024809

An object of the present disclosure is to provide a coated wire that exhibits a low dielectric constant and a high partial discharge inception voltage, is unlikely to cause wrinkles in the coating layer even when bent, and has high adhesion strength between the rectangular wire base material and the coating layer. do.

According to the present disclosure, there is provided a covered electric wire including a rectangular electric wire base material and a coating layer formed on the outer periphery of the flat electric wire base material, wherein the coating layer includes one or both of an amide group and an imide group. a first layer formed from a liquid coating composition (1) containing a polymer compound (1) having A liquid coating composition (2) containing a fluorine-containing polymer compound (2), or a polymer compound (2) having one or both of an amide group and an imide group, and a fluorine-containing polymer compound (2). a second layer formed from a powder coating composition (2) containing a liquid coating composition (3) containing a fluorine-containing polymer compound (3-1) or a fluorine-containing polymer compound (3-2); ), and a third layer formed from a powder coating composition (3).

According to the present disclosure, it is possible to provide a coated wire that exhibits a low dielectric constant and a high partial discharge inception voltage, does not easily cause wrinkles in the coating layer even when bent, and has high adhesion strength between the rectangular wire base material and the coating layer. can.

Hereinafter, specific embodiments of the present disclosure will be described in detail, but the present disclosure is not limited to the following embodiments.

The covered electric wire of the present disclosure includes a rectangular electric wire base material and a coating layer formed on the outer periphery of the flat electric wire base material.

Fluorine-containing polymer compounds have non-adhesive properties, so when providing a coating layer containing a fluorine-containing polymer compound on a rectangular electric wire base material of a covered electric wire, the flat electric wire base material and the coating layer must be There is a problem that the adhesive does not adhere with sufficient strength. Therefore, when a conventional covered electric wire is bent or bent, there is a problem that the coating layer is lifted from the rectangular electric wire base material or wrinkles are generated in the coating layer.

On the other hand, if the coating layer is formed of a material that easily adheres to the rectangular wire base material, the dielectric constant of the coating layer of the covered wire will increase, the partial discharge inception voltage of the covered wire will decrease, and the electrical There is a problem in that it is difficult to obtain a coated wire with excellent performance.

The coated wire of the present disclosure appropriately combines the constituent materials and formation methods of the three layers. Therefore, the coated wire of the present disclosure exhibits a low dielectric constant and a high partial discharge inception voltage, and the coating layer is less likely to wrinkle even when bent, and the rectangular wire base material and the coating layer are in close contact with each other with high adhesion strength. There is.

(Flat wire base material)
The shape of the rectangular electric wire base material is not particularly limited as long as the cross section is the shape of a rectangular wire having a substantially rectangular shape. The corners of the cross section of the flat electric wire base material may be at right angles, or the corners of the cross section of the flat electric wire base material may be rounded. Further, the rectangular electric wire base material may be a single wire, a grouped wire, a stranded wire, etc. as long as the entire cross section is approximately rectangular, but a single wire is preferable.

The rectangular wire base material is not particularly limited as long as it is made of a conductive material, but it can be made of materials such as copper, copper alloy, aluminum, aluminum alloy, iron, silver, and nickel. Preferably, it is made of an alloy, aluminum or an aluminum alloy. Further, a rectangular electric wire base material plated with silver plating, nickel plating, etc. can also be used. As the copper, oxygen-free copper, low-oxygen copper, copper alloy, etc. can be used.

The width of the cross section of the flat electric wire base material may be 1 to 75 mm, and the thickness of the cross section of the flat electric wire base material may be 0.1 to 30 mm. The outer circumferential diameter of the rectangular electric wire base material may be 6.5 mm or more and 200 mm or less. Further, the ratio of width to thickness may be greater than 1 and less than or equal to 30.

The surface roughness Sz of the flat wire base material is preferably 0.2 to 12 μm, more preferably 1 μm or more, and even more preferably 5 μm, since the flat wire base material and the coating layer adhere more firmly. or more, and more preferably 10 μm or less.

The surface roughness of the flat wire base material can be adjusted by surface treating the flat wire base material using a surface treatment method such as etching treatment, blasting treatment, laser treatment, or the like. Further, the surface of the rectangular electric wire base material may be provided with irregularities by surface treatment. The distance between the convex and convex portions is preferably as small as possible, and is, for example, 5 μm or less. Further, regarding the size of the unevenness, for example, the area of each depression when cutting the protrusion on the unprocessed surface is 1 μm ² or less. The uneven shape may be a single crater-shaped uneven shape, or may be branched like an ant nest.

(covering layer)
The coated electric wire of the present disclosure includes a coating layer formed around the outer periphery of a rectangular electric wire base material, and the coating layer includes a first layer, a second layer, and a third layer. In the coated wire of the present disclosure, the first layer is usually formed on the outer periphery of the rectangular wire base material, the second layer is formed on the outer periphery of the first layer, and the third layer is formed on the outer periphery of the first layer. formed around the outer periphery of the layer.

The first layer, second layer, and third layer are all coating films formed from a coating composition. The first layer is a coating film formed from liquid coating composition (1). The second layer is a coating formed from liquid coating composition (2) or powder coating composition (2). The third layer is a coating formed from the liquid coating composition (3) or the powder coating composition (3).

The liquid coating composition contains a solvent along with a polymer compound or a fluorine-containing polymer compound. The powder coating composition contains powder of a polymer compound or a fluorine-containing polymer compound. In the present disclosure, whether the powder coating contains only powder of a polymer compound or only powder of a fluorine-containing polymer compound, the powder coating The term "powder coating composition" is used even when it does not contain multiple components.

The liquid coating composition (1) contains a polymer compound (1) having one or both of an amide group and an imide group. By applying the liquid coating composition (1) to the outer periphery of the rectangular electric wire base material to form the first layer, it is possible to form a first layer that adheres to the rectangular electric wire base material with high adhesion strength, Thereby, it is possible to form a coating layer that closely adheres to the rectangular wire base material with high adhesion strength, and it is possible to form a coating layer that does not easily wrinkle even when bent.

The liquid coating composition (2) contains a polymer compound (2) having one or both of an amide group and an imide group, and a fluorine-containing polymer compound (2). By applying the liquid coating composition (2) to the outer periphery of the first layer to form the second layer, the first layer can be coated without impairing the low dielectric constant and high partial discharge inception voltage of the coating layer. By sufficiently adhering to the third layer, it is possible to form a second layer that provides a coating layer with excellent interlayer strength.

The powder coating composition (2) includes a polymer compound (2) having one or both of an amide group and an imide group, and a fluorine-containing polymer compound (2). By applying the powder coating composition (2) to the outer periphery of the first layer to form the second layer, the first layer can be coated without impairing the low dielectric constant and high partial discharge inception voltage of the coating layer. By sufficiently adhering to the second layer and the third layer, it is possible to form a second layer that provides a coating layer with excellent interlayer strength.

The liquid coating composition (3) contains a fluorine-containing polymer compound (3-1). By applying the liquid coating composition (3) to the outer periphery of the second layer to form the third layer, a low relative dielectric constant and a high partial discharge inception voltage are imparted to the coating layer, and the coating layer is also bonded to the second layer. By adhering sufficiently, it is possible to form a third layer that provides a coating layer with excellent interlayer strength.

The powder coating composition (3) contains a fluorine-containing polymer compound (3-2). By applying the powder coating composition (3) to the outer periphery of the second layer to form the third layer, a low dielectric constant and a high partial discharge inception voltage are imparted to the coating layer, and the second layer By sufficiently adhering to the third layer, it is possible to form a third layer that provides a coating layer with excellent interlayer strength.

From the viewpoint of insulation properties, the thickness of the coating layer is preferably 30 to 200 μm, more preferably 40 μm or more, even more preferably 50 μm or more, more preferably 150 μm or less, and even more preferably 100 μm or less. be. If the thickness is too large, it may be difficult to downsize the device when the coated wire is used in a device such as a motor, and if the thickness is too small, sufficient insulation may not be obtained.

The thickness of the first layer is preferably 1 to 50 μm, more preferably 3 μm or more, from the viewpoint of sufficiently adhering the flat wire base material and the coating layer and forming a coating layer that does not easily wrinkle when bent. It is more preferably 6 μm or more, more preferably 40 μm or less, even more preferably 20 μm or less, and even more preferably 10 μm or less.

The thickness of the second layer is preferably set from the viewpoint of sufficiently adhering the second layer to the first layer and the third layer without impairing the low dielectric constant and high partial discharge inception voltage of the coating layer. is 5 to 100 μm, more preferably 10 μm or more, more preferably 60 μm or less, even more preferably 40 μm or less, and even more preferably 30 μm or less.

The thickness of the third layer is preferably 5 to 100 μm from the viewpoint of providing the coating layer with a low dielectric constant and high partial discharge inception voltage, and also ensuring sufficient adhesion between the third layer and the second layer. , more preferably 10 μm or more, still more preferably 15 μm or more, even more preferably 20 μm or more, more preferably less than 90 μm, still more preferably 80 μm or less.

When forming the third layer using the liquid coating composition (3), the thickness of the third layer can be made relatively small. The upper limit of the thickness of the third layer in this case is preferably 50 μm or less, more preferably 40 μm or less, and still more preferably 35 μm or less.

When forming the third layer using the powder coating composition (3), the thickness of the third layer can be made relatively large. The lower limit of the thickness of the third layer in this case is preferably more than 35 μm, more preferably more than 40 μm, and still more preferably more than 50 μm.

The dielectric constant of the coating layer is preferably 2.3 to 3.0, more preferably 2.9 or less, and even more preferably 2.8 or less. Since the coated wire of the present disclosure appropriately combines the constituent materials and formation methods of the three layers, the dielectric constant of the coating layer can be lowered.

The partial discharge inception voltage of the coating layer is preferably 1000 to 2100 (Vp), more preferably 1100 (Vp) or more, even more preferably 1200 (Vp) or more, and even more preferably 1300 (Vp). or more, and more preferably 2000 (Vp) or less. Since the covered electric wire of the present disclosure appropriately combines the constituent materials and formation methods of the three layers, it is possible to increase the partial discharge inception voltage of the coating layer.

As long as the coating layer includes the first layer, second layer, and third layer, it may further include other layers, but even if it does not include other layers, it can be used as desired. It is possible to obtain an effective coated wire.

(first layer)
The first layer is formed from a liquid coating composition (1) containing a polymer compound (1) having one or both of an amide group and an imide group. The liquid coating composition (1) may contain only the polymer compound (1) having either one or both of an amide group and an imide group.

The liquid coating composition (1) may contain a solvent in addition to the polymer compound (1). Examples of the solvent include water and organic solvents, with organic solvents being preferred. Examples of organic solvents include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-butyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropanamide, N,N-dimethylacetamide, N, Examples include N-dimethylformamide, cresol, and methyl isobutyl ketone.

The viscosity of the liquid coating composition (1) is preferably 10 to 10,000 (cP), more preferably 50 (cP) or more, and even more preferably It is 100 (cP) or more, more preferably 1000 (cP) or less, and still more preferably 500 (cP) or less. The viscosity of the liquid coating composition (1) can be adjusted by adjusting the content of the polymer compound (1) in the liquid coating composition (1).

The content of the polymer compound (1) in the liquid coating composition (1) is preferably 1 to 50% by weight, more preferably 10% by weight or more based on the mass of the liquid coating composition (1). and more preferably 40% by weight or less.

The liquid coating composition (1) may contain other components as necessary. Other ingredients include crosslinking agents, antistatic agents, heat stabilizers, foaming agents, foaming nucleating agents, antioxidants, surfactants, photopolymerization initiators, antiwear agents, surface modifiers, organic and inorganic various pigments, copper damage inhibitors, bubble preventers, adhesion promoters, lubricants, processing aids, colorants, phosphorus stabilizers, lubricants, mold release agents, sliding materials, ultraviolet absorbers, dyes and pigments, reinforcements. Examples include additives such as materials, anti-drip agents, fillers, curing agents, ultraviolet curing agents, and flame retardants. The content of other components in the liquid coating composition (1) is preferably less than 30% by weight, more preferably less than 30% by weight based on the mass of the polymer compound (1) in the liquid coating composition (1). is less than 10% by weight, more preferably 5% by weight or less, and the lower limit is not particularly limited, but may be 0% by weight or more. That is, the liquid coating composition (1) does not need to contain other components.

(Second layer)
The second layer is formed from a liquid coating composition (2) or a powder coating composition (2).

The liquid coating composition (2) contains a polymer compound (2) having one or both of an amide group and an imide group, and a fluorine-containing polymer compound (2). The liquid coating composition (2) may contain only a polymer compound (2) having one or both of an amide group and an imide group and a fluorine-containing polymer compound (2) as a polymer compound. .

The liquid coating composition (2) may contain a solvent in addition to the polymer compound (2) and the fluorine-containing polymer compound (2). Examples of the solvent include water and organic solvents. Examples of organic solvents include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-butyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropanamide, N,N-dimethylacetamide, N, Examples include N-dimethylformamide, cresol, and methyl isobutyl ketone.

The viscosity of the liquid coating composition (2) is preferably 10 to 10,000 (cP), more preferably 50 (cP) or more, and even more preferably It is 100 (cP) or more, more preferably 1000 (cP) or less, and still more preferably 500 (cP) or less. The viscosity of the liquid coating composition (2) can be adjusted by adjusting the contents of the polymer compound (2) and the fluorine-containing polymer compound (2) in the liquid coating composition (2).

The content of the polymer compound (2) and the fluorine-containing polymer compound (2) in the liquid coating composition (2) is preferably 1 to 90% by weight based on the mass of the liquid coating composition (2). The content is more preferably 10% by weight or more, and more preferably 80% by weight or less.

The powder coating composition (2) includes a polymer compound (2) having one or both of an amide group and an imide group, and a fluorine-containing polymer compound (2). The polymer compound (2) and the fluorine-containing polymer compound (2) in the powder coating composition (2) are usually both powders. The powder coating composition (2) contains only a polymer compound (2) having one or both of an amide group and an imide group and a fluorine-containing polymer compound (2) as a polymer compound. good.

The average particle size of the powder coating composition (2) is preferably 1 to 100 (μm), more preferably 5 μm or more, and even more preferably It is 10 μm or more, more preferably 90 μm or less, and still more preferably 80 μm or less.

In the liquid coating composition (2) or the powder coating composition (2), the volume ratio of the polymer compound (2) and the fluorine-containing polymer compound (2) is such that the coating layer has a low dielectric constant and a high partial discharge. From the viewpoint of sufficiently adhering the second layer to the first layer and the third layer without impairing the starting voltage, the ratio is preferably 10/90 to 90/10, more preferably 15/85 or more. Yes, and more preferably 85/15 or less.

The liquid coating composition (2) or powder coating composition (2) may contain other components as necessary. Other ingredients include crosslinking agents, antistatic agents, heat stabilizers, foaming agents, foaming nucleating agents, antioxidants, surfactants, photopolymerization initiators, antiwear agents, surface modifiers, organic and inorganic various pigments, copper damage inhibitors, bubble preventers, adhesion promoters, lubricants, processing aids, colorants, phosphorus stabilizers, lubricants, mold release agents, sliding materials, ultraviolet absorbers, dyes and pigments, reinforcements. Examples include additives such as materials, anti-drip agents, fillers, curing agents, ultraviolet curing agents, and flame retardants. The content of other components in the liquid coating composition (2) or powder coating composition (2) includes the polymer compound (2) in the liquid coating composition (2) or powder coating composition (2). ) and the fluorine-containing polymer compound (2), preferably less than 30% by weight, more preferably less than 10% by weight, even more preferably 5% by weight or less, and the lower limit is not particularly limited. may be 0% by weight or more. That is, the liquid coating composition (2) or the powder coating composition (2) does not need to contain other components.

(Third layer)
The third layer is formed from a liquid coating composition (3) or a powder coating composition (3).

The liquid coating composition (3) contains a fluorine-containing polymer compound (3-1). The liquid coating composition (3) may contain only the fluorine-containing polymer compound (3-1) as the polymer compound.

The liquid coating composition (3) may contain a solvent in addition to the fluorine-containing polymer compound (3-1). Examples of the solvent include water and organic solvents, with water being preferred. Examples of organic solvents include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-butyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropanamide, N,N-dimethylacetamide, N, Examples include N-dimethylformamide, cresol, and methyl isobutyl ketone.

The viscosity of the liquid coating composition (3) is preferably 10 to 10,000 (cP), more preferably 50 (cP) or more, and even more preferably It is 100 (cP) or more, more preferably 1000 (cP) or less, and still more preferably 500 (cP) or less. The viscosity of the liquid coating composition (3) can be adjusted by adjusting the content of the fluorine-containing polymer compound (3-1) in the liquid coating composition (3).

The content of the fluorine-containing polymer compound (3-1) in the liquid coating composition (3) is preferably 1 to 90% by weight, more preferably 1 to 90% by weight based on the mass of the liquid coating composition (3). It is 10% by weight or more, more preferably 80% by weight or less.

The powder coating composition (3) contains a fluorine-containing polymer compound (3-2). The fluorine-containing polymer compound (3-2) in the powder coating composition (3) is usually a powder. The powder coating composition (3) may contain only the fluorine-containing polymer compound (3-2) as the polymer compound.

The average particle size of the powder coating composition (3) is preferably 1 to 100 (μm), more preferably 5 μm or more, and even more preferably It is 10 μm or more, more preferably 90 μm or less, and even more preferably 80 μm or less.

The liquid coating composition (3) or powder coating composition (3) may contain other components as necessary. Other ingredients include crosslinking agents, antistatic agents, heat stabilizers, foaming agents, foaming nucleating agents, antioxidants, surfactants, photopolymerization initiators, antiwear agents, surface modifiers, organic and inorganic various pigments, copper damage inhibitors, bubble preventers, adhesion promoters, lubricants, processing aids, colorants, phosphorus stabilizers, lubricants, mold release agents, sliding materials, ultraviolet absorbers, dyes and pigments, reinforcements. Examples include additives such as materials, anti-drip agents, fillers, curing agents, ultraviolet curing agents, and flame retardants. The content of other components in the liquid coating composition (3) or powder coating composition (3) includes the fluorine-containing polymer compound in the liquid coating composition (3) or powder coating composition (3). It is preferably less than 30% by weight, more preferably less than 10% by weight, and even more preferably 5% by weight or less, based on the mass of (3-1) or the fluorine-containing polymer compound (3-2). Although the lower limit is not particularly limited, it may be 0% by weight or more. That is, the liquid coating composition (3) or the powder coating composition (3) does not need to contain other components.

(polymer compound)
Next, the polymer compound used for the coating layer of the covered electric wire will be explained. The polymer compounds described below can be suitably used as the polymer compound (1) forming the first layer and the polymer compound (2) forming the second layer.

In the present disclosure, a "polymer compound" has one or both of an amide group and an imide group, and preferably does not have a fluorine atom. The polymer compound can have an amide group (amide bond) or an imide group (imide bond) in the main chain or side chain of the polymer compound.

The polymer compound is preferably at least one selected from the group consisting of polyamideimide, polyetherimide, polyimide, and thermoplastic polyimide from the viewpoint of adhesion to the rectangular wire base material or adhesion to other layers. At least one selected from the group consisting of , polyamideimide, and polyimide is more preferred. Furthermore, as the polymer compound, two or more types of polymer compounds can be used in combination. For example, a combination of polyamideimide and polyimide can be used as the polymer compound.

Polyamide-imide is a resin consisting of a polymer having amide bonds and imide bonds in its molecular structure. Polyamideimides are not particularly limited, and include, for example, reactions between aromatic diamines having an amide bond in the molecule and aromatic tetravalent carboxylic acids such as pyromellitic acid; and reactions between aromatic trivalent carboxylic acids such as trimellitic anhydride. Consists of high molecular weight polymers obtained by various reactions such as reaction with diamines such as 4,4-diaminophenyl ether and diisocyanates such as diphenylmethane diisocyanate; reaction with diamines and dibasic acids having an aromatic imide ring in the molecule. Examples include resin. The polyamideimide is preferably a polymer having an aromatic ring in the main chain.

Polyimide is a resin made of a polymer that has imide bonds in its molecular structure. The polyimide is not particularly limited, and examples include resins made of high molecular weight polymers obtained by reaction of aromatic tetravalent carboxylic acid anhydrides such as pyromellitic anhydride. The polyimide is preferably a polymer having an aromatic ring in the main chain.

(Fluorine-containing polymer compound)
Next, the fluorine-containing polymer compound used for the coating layer of the covered electric wire will be explained. The fluorine-containing polymer compounds described below include a fluorine-containing polymer compound (2) forming a second layer, a fluorine-containing polymer compound (3-1) forming a third layer, and a fluorine-containing polymer compound (3-1) forming a third layer. It can be suitably used as the fluorine-containing polymer compound (3-2) to be formed.

A fluorine-containing polymer compound is a polymer compound having a fluorine atom. A fluorine-containing polymer compound is usually a polymer compound in which hydrogen atoms bonded to carbon atoms constituting the main chain are partially or completely replaced with fluorine atoms.

As the fluorine-containing polymer compound, a perfluorinated polymer compound is preferable because a coating layer exhibiting a lower dielectric constant and a higher partial discharge inception voltage can be obtained. In the present disclosure, a perfluoro-based polymer compound is a polymer compound in which the content of perfluoro monomer units is 90 mol% or more with respect to all polymerized units constituting the polymer compound.

In the present disclosure, a perfluoromonomer is a monomer that does not contain a carbon atom-hydrogen bond in its molecule. In addition to carbon atoms and fluorine atoms, perfluoromonomers may also be monomers in which some of the fluorine atoms bonded to carbon atoms are replaced with chlorine atoms, and in addition to carbon atoms, nitrogen atoms, oxygen atoms, It may contain a sulfur atom, a phosphorus atom, a boron atom, or a silicon atom. The perfluoromonomer is preferably a monomer in which all hydrogen atoms are replaced with fluorine atoms.

The dielectric constant of the fluorine-containing polymer compound is preferably 2.0 to 2.2, more preferably 2.0 to 2.2, since a coating layer exhibiting a lower dielectric constant and a higher partial discharge inception voltage can be obtained. 1 or less. The dielectric constant of the fluorine-containing polymer compound can be measured at 23° C.±2° C., relative humidity 50%, and frequency 1 KHz in accordance with JIS-C-2138.

As the fluorine-containing polymer compound, a fluororesin is preferable. In the present disclosure, fluororesin refers to partially crystalline fluoropolymers and fluoroplastics. The fluororesin has a melting point and is thermoplastic, but may be melt processable or non-melt processable.

Examples of fluororesins include polytetrafluoroethylene, tetrafluoroethylene (TFE)/fluoroalkyl vinyl ether (FAVE) copolymer, tetrafluoroethylene (TFE)/hexafluoropropylene (HFP) copolymer, and TFE/FAVE/HFP copolymer. Polymer, TFE/ethylene copolymer [ETFE], TFE/ethylene/HFP copolymer, ethylene/chlorotrifluoroethylene (CTFE) copolymer [ECTFE], polychlorotrifluoroethylene [PCTFE], CTFE/TFE Copolymer, polyvinylidene fluoride [PVdF], TFE/vinylidene fluoride (VdF) copolymer [VT], polyvinyl fluoride [PVF], TFE/VdF/CTFE copolymer [VTC], TFE/HFP/ Examples include VdF copolymer.

As the fluororesin, at least one selected from the group consisting of polytetrafluoroethylene, TFE/FAVE copolymer, TFE/HFP copolymer, and TFE/FAVE/HFP copolymer is particularly preferred.

Polytetrafluoroethylene (PTFE) may be non-melt processable PTFE or melt processable PTFE, but non-melt processable PTFE is preferable.

Non-melt processable PTFE typically has stretchability, fibrillation properties, and non-melt fabrication properties. Non-melt fabrication property refers to the property that the melt flow rate cannot be measured at a temperature higher than the crystallization melting point, that is, the property that it does not flow easily even in the melting temperature range, in accordance with ASTM D 1238 and D 2116.

PTFE may be a tetrafluoroethylene (TFE) homopolymer or may be a modified PTFE containing a TFE unit and a modified monomer unit. In the present disclosure, "modified PTFE" means a product obtained by copolymerizing TFE with a small amount of comonomer that does not impart melt processability to the resulting copolymer. The comonomer is not particularly limited, and examples thereof include hexafluoropropylene [HFP], chlorotrifluoroethylene [CTFE], perfluoro(alkyl vinyl ether) [PAVE], and the like. The proportion of the comonomer added to the modified PTFE varies depending on its type, but for example, it may be 0.001 to 1% by mass based on the total mass of TFE and a small amount of comonomer. preferable. In the present disclosure, the content of each monomer unit constituting PTFE can be calculated by appropriately combining NMR, FT-IR, elemental analysis, and fluorescent X-ray analysis depending on the type of monomer.

The standard specific gravity (SSG) of PTFE is preferably 2.280 or less, more preferably 2.210 or less, even more preferably 2.200 or less, and preferably 2.130 or more. . SSG can be measured by a water displacement method according to ASTM D 792 using a sample molded according to ASTM D 4895-89.

It is preferable that PTFE has a peak temperature in the range of 333 to 347°C. More preferably, the temperature is 335°C or higher and 345°C or lower. The peak temperature is the temperature corresponding to the maximum value in the heat of fusion curve when heated at a rate of 10 °C/min using a differential scanning calorimeter [DSC] for PTFE that has no history of being heated to a temperature of 300 °C or higher. be.

As the fluorine-containing polymer compound, a melt-processable fluorine-containing polymer compound can also be used. In particular, from the viewpoint of easily forming a layer having a desired thickness, the fluorine-containing polymer compound (3-2) contained in the powder coating composition (3) for forming the third layer can be melt-processed. It is preferable to use a fluorine-containing high molecular compound having a high molecular weight. In addition, from the viewpoint of easily forming a layer having a desired thickness, a melt-processable fluorine-containing polymer compound (2) contained in the powder coating composition (2) for forming the second layer is used. It is preferable to use a fluorine-containing polymer compound.

In this disclosure, melt processability means that the polymer can be melted and processed using conventional processing equipment such as extruders and injection molding machines. Therefore, melt processable fluorine-containing polymer compounds usually have a melt flow rate of 0.01 to 500 g/10 minutes.

The melt flow rate of the fluorine-containing polymer compound is preferably 0.1 to 100 g/10 minutes, more preferably 80 g/10 minutes or less, even more preferably 70 g/10 minutes or less, and preferably 5 g/10 minutes. It is 10 minutes or more, more preferably 10 g/10 minutes or more.

The melt flow rate of the fluorine-containing polymer compound is calculated per 10 minutes from a nozzle with an inner diameter of 2.1 mm and a length of 8 mm at 372°C and under a load of 5 kg using a melt indexer (manufactured by Yasuda Seiki Seisakusho Co., Ltd.) according to ASTM D1238. This is the value obtained as the mass of polymer flowing out (g/10 minutes).

The melting point of the fluorine-containing polymer compound is preferably 200 to 322°C, more preferably 230°C or higher, even more preferably 250°C or higher, and even more preferably 320°C or lower.

The melting point can be measured using a differential scanning calorimeter (DSC).

As the melt-processable fluorine-containing polymer compound, a melt-processable fluororesin is preferable. Examples of melt-processable fluororesins include tetrafluoroethylene (TFE)/fluoroalkyl vinyl ether (FAVE) copolymer, tetrafluoroethylene (TFE)/hexafluoropropylene (HFP) copolymer, and TFE/FAVE/HFP copolymer. combination, TFE/ethylene copolymer [ETFE], TFE/ethylene/HFP copolymer, ethylene/chlorotrifluoroethylene (CTFE) copolymer [ECTFE], polychlorotrifluoroethylene [PCTFE], CTFE/TFE copolymer Polymer, polyvinylidene fluoride [PVdF], TFE/vinylidene fluoride (VdF) copolymer [VT], polyvinyl fluoride [PVF], TFE/VdF/CTFE copolymer [VTC], TFE/HFP/VdF Examples include copolymers.

As the melt-processable fluororesin, at least one selected from the group consisting of TFE/FAVE copolymer, TFE/HFP copolymer, and TFE/FAVE/HFP copolymer is particularly preferred.

A TFE/FAVE copolymer is a copolymer containing tetrafluoroethylene (TFE) units and fluoroalkyl vinyl ether (FAVE) units.

The FAVE that constitutes the FAVE unit has the general formula (1):
CF ₂ =CFO(CF ₂ CFY ¹ O) _p - (CF ₂ CF ₂ CF ₂ O) _q - Rf (1)
(In the formula, Y ¹ represents F or CF ₃ , Rf represents a perfluoroalkyl group having 1 to 5 carbon atoms, p represents an integer of 0 to 5, and q represents an integer of 0 to 5.) A monomer represented by and general formula (2):
CFX=CXOCF ₂ OR ¹ (2)
(wherein, X is the same or different and represents H, F or _CF3 , and ^R1 represents at least one linear or branched atom selected from the group consisting of H, Cl, Br and I. A fluoroalkyl group having 1 to 6 carbon atoms which may contain 1 to 2 atoms, or 1 to 2 atoms of at least one selected from the group consisting of H, Cl, Br and I At least one type selected from the group consisting of monomers represented by (representing a cyclic fluoroalkyl group having 5 or 6 carbon atoms) can be mentioned.

Among these, FAVE is preferably a monomer represented by the general formula (1), consisting of perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether) (PEVE), and perfluoro(propyl vinyl ether) (PPVE). At least one selected from the group consisting of PEVE and PPVE is more preferable, at least one selected from the group consisting of PEVE and PPVE is even more preferable, and PPVE is particularly preferable.

The content of FAVE units in the TFE/FAVE copolymer is preferably 1.0 to 30.0 mol%, more preferably 1.2 mol% or more, and even more preferably 1.4 mol% or more, still more preferably 1.6 mol% or more, particularly preferably 1.8 mol% or more, more preferably 3.5 mol% or less, even more preferably 3. .2 mol% or less, still more preferably 2.9 mol% or less, particularly preferably 2.6 mol% or less.

The content of TFE units in the TFE/FAVE copolymer is preferably 99.0 to 70.0 mol%, more preferably 96.5 mol% or more, and even more preferably 96.8 mol% or more, still more preferably 97.1 mol% or more, particularly preferably 97.4 mol% or more, more preferably 98.8 mol% or less, even more preferably 98 mol% .6 mol% or less, still more preferably 98.4 mol% or less, particularly preferably 98.2 mol% or less.

In the present disclosure, the content of each monomer unit in the copolymer is measured by ¹⁹ F-NMR method.

The TFE/FAVE copolymer can also contain monomer units derived from monomers copolymerizable with TFE and FAVE. In this case, the content of the monomer copolymerizable with TFE and FAVE is preferably 0 to 29.0 mol%, more preferably 0.0 to 29.0 mol%, based on the total monomer units of the TFE/FAVE copolymer. The content is 1 to 5.0 mol%, more preferably 0.1 to 1.0 mol%.

Monomers copolymerizable with TFE and FAVE include HFP, CZ ¹ Z ² =CZ ³ (CF ₂ ) _n Z ⁴ (wherein Z ¹ , Z ² and Z ³ are the same or different, H or F, Z ⁴ represents H, F or Cl, and n represents an integer from 2 to 10), and CF ₂ =CF-OCH ₂ -Rf ¹ ( In the formula, Rf ¹ represents a perfluoroalkyl group having 1 to 5 carbon atoms. Among them, HFP is preferred.

The TFE/FAVE copolymer is preferably at least one selected from the group consisting of a copolymer consisting only of TFE units and FAVE units, and the above-mentioned TFE/HFP/FAVE copolymer. More preferred is a copolymer consisting only of the following.

The melting point of the TFE/FAVE copolymer is preferably 280 to 322°C, more preferably 285°C or higher, more preferably 320°C or lower, and even more preferably 315°C or lower. The melting point can be measured using a differential scanning calorimeter (DSC).

The glass transition temperature (Tg) of the TFE/FAVE copolymer is preferably 70 to 110°C, more preferably 80°C or higher, and even more preferably 100°C or lower. Glass transition temperature can be measured by dynamic viscoelasticity measurement.

A TFE/HFP copolymer is a copolymer containing tetrafluoroethylene (TFE) units and hexafluoropropylene (HFP) units.

The content of HFP units in the TFE/HFP copolymer is preferably 0.1 to 30.0 mol%, more preferably 0.7 mol% or more, and even more preferably It is 1.4 mol% or more, and more preferably 10.0 mol% or less.

The content of TFE units in the TFE/HFP copolymer is preferably 70.0 to 99.9 mol%, more preferably 90.0 mol% or more, and more preferably It is 99.3 mol% or less, more preferably 98.6 mol%.

The TFE/HFP copolymer can also contain monomer units derived from monomers copolymerizable with TFE and HFP. In this case, the content of the monomer copolymerizable with TFE and HFP is preferably 0 to 29.9 mol %, more preferably 0.9 mol %, based on the total monomer units of the TFE/HFP copolymer. The content is 1 to 5.0 mol%, more preferably 0.1 to 1.0 mol%.

Monomers copolymerizable with TFE and HFP include FAVE, CZ ¹ Z ² =CZ ³ (CF ₂ ) _n Z ⁴ (wherein Z ¹ , Z ² and Z ³ are the same or different, H or F, Z ⁴ represents H, F or Cl, and n represents an integer from 2 to 10), and CF ₂ =CF-OCH ₂ -Rf ¹ ( In the formula, Rf ¹ represents a perfluoroalkyl group having 1 to 5 carbon atoms. Among them, FAVE is preferred.

The melting point of the TFE/HFP copolymer is preferably 200 to 322°C, more preferably 210°C or higher, even more preferably 220°C or higher, particularly preferably 240°C or higher, and more preferably 320°C or higher. ℃ or less, more preferably less than 300°C, particularly preferably 280°C or less.

The glass transition temperature (Tg) of the TFE/HFP copolymer is preferably 60 to 110°C, more preferably 65°C or higher, and even more preferably 100°C or lower.

The fluorine-containing polymer compound may have a functional group.

The functional group is preferably at least one selected from the group consisting of a carbonyl group-containing group, an amino group, a hydroxy group, a -CF ₂ H group, an olefin group, an epoxy group, and an isocyanate group.

A carbonyl group-containing group is a group containing a carbonyl group (-C(=O)-) in its structure. Examples of carbonyl group-containing groups include:
Carbonate group [-O-C(=O)-OR ³ (wherein R ³ is an alkyl group having 1 to 20 carbon atoms or an alkyl group having 2 to 20 carbon atoms containing an ether-bonding oxygen atom) ],
Acyl group [-C(=O)-R ³ (wherein R ³ is an alkyl group having 1 to 20 carbon atoms or an alkyl group having 2 to 20 carbon atoms containing an ether-bonding oxygen atom)]
Haloformyl group [-C(=O)X ⁵ , X ⁵ is a halogen atom],
Formyl group [-C(=O)H],
Formula: -R ⁴ -C(=O)-R ⁵ (wherein, R ⁴ is a divalent organic group having 1 to 20 carbon atoms, and R ⁵ is a monovalent organic group having 1 to 20 carbon atoms. a group represented by ), which is an organic group of
Formula: -O-C(=O)-R ⁶ (wherein R ⁶ is an alkyl group having 1 to 20 carbon atoms or an alkyl group having 2 to 20 carbon atoms containing an ether-bonding oxygen atom) A group represented by
carboxyl group [-C(=O)OH],
Alkoxycarbonyl group [-C(=O)OR ⁷ (wherein R ⁷ is a monovalent organic group having 1 to 20 carbon atoms)],
Carbamoyl group [-C(=O)NR ⁸ R ⁹ (wherein R ⁸ and R ⁹ may be the same or different, and are a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms) )],
Acid anhydride bond [-C(=O)-OC(=O)-],
etc. can be given.

Specific examples of R ³ include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, and the like. Specific examples of the above R ⁴ include a methylene group, -CF ₂ - group, -C ₆ H ₄ - group, etc., and specific examples of R ⁵ include a methyl group, an ethyl group, a propyl group, an isopropyl group, Examples include butyl group. Specific examples of R ⁷ include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, and the like. Further, specific examples of R ⁸ and R ⁹ include a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a phenyl group, and the like.

The hydroxy group is a group represented by -OH or a group containing a group represented by -OH. In the present disclosure, -OH constituting a carboxyl group is not included in a hydroxy group. Examples of the hydroxy group include -OH, methylol group, and ethylol group.

An olefinic group is a group having a carbon-carbon double bond. As an olefin group, the following formula:
-CR ¹⁰ =CR ¹¹ R ¹²
(In the formula, R ¹⁰ , R ¹¹ and R ¹² may be the same or different and are a hydrogen atom, a fluorine atom, or a monovalent organic group having 1 to 20 carbon atoms.) At least one functional group selected from the group consisting of -CF=CF ₂ , -CH=CF ₂ , -CF=CHF, -CF=CH ₂ and -CH=CH ₂ is preferred.

The isocyanate group is a group represented by -N=C=O.

Furthermore, examples of the functional group include non-fluorinated alkyl groups or partially fluorinated alkyl groups such as -CH ₃ group and -CFH ₂ group.

The number of functional groups in the fluorine-containing polymer compound is preferably 5 to 2000 per 10 ⁶ carbon atoms. The number of functional groups per 10 ⁶ carbon atoms is more preferably 50 or more, still more preferably 100 or more, particularly preferably 200 or more, more preferably 1000 or less, and The number is preferably 800 or less, particularly preferably 700 or less, and most preferably 500 or less.

Further, the number of functional groups of the fluorine-containing polymer compound may be less than 5 per 10 ⁶ carbon atoms, and may be 0 to 4, since a coating layer with excellent electrical properties can be formed. In particular, when the fluorine-containing polymer compound has melt processability, it is preferable to have the number of functional groups within the above numerical range.

The above-mentioned functional group is a functional group present at the main chain end or side chain end of the fluorine-containing polymer compound, and a functional group present in the main chain or side chain, preferably at the main chain end. . Examples of the above-mentioned functional groups include -CF=CF ₂ , -CF ₂ H, -COF, -COOH, -COOCH ₃ , -CONH ₂ , -OH, -CH ₂ OH, etc., and -CF ₂ H, -COF , -COOH, -COOCH ₃ and -CH ₂ OH is preferred. -COOH includes a dicarboxylic acid anhydride group (-CO-O-CO-) formed by bonding two -COOHs.

Infrared spectroscopy can be used to identify the type of functional group and measure the number of functional groups.

Specifically, the number of functional groups is measured by the following method. First, the copolymer is melted at 330 to 340° C. for 30 minutes and compression molded to produce a film with a thickness of 0.20 to 0.25 mm. This film is analyzed by Fourier transform infrared spectroscopy to obtain an infrared absorption spectrum of the copolymer and a difference spectrum from a fully fluorinated base spectrum free of functional groups. From the absorption peak of a specific functional group appearing in this difference spectrum, the number N of functional groups per 1×10 ⁶ carbon atoms in the copolymer is calculated according to the following formula (A).
N=I×K/t (A)
I: Absorbance K: Correction coefficient t: Film thickness (mm)

For reference, absorption frequencies, molar extinction coefficients, and correction coefficients for the functional groups in the present disclosure are shown in Table 1. Furthermore, the molar extinction coefficient was determined from FT-IR measurement data of a low-molecular model compound.

The absorption frequencies of -CH ₂ CF ₂ H, -CH ₂ COF, -CH ₂ COOH, -CH ₂ COOCH _{3 and} -CH ₂ CONH ₂ are shown in the table, respectively. The absorption frequency is several tens of Kaiser (cm ^-1 ) lower than that of COOH free, -COOH bonded, -COOCH ₃ , and -CONH ₂ .
Therefore, for example, the number of functional groups in -COF is the number of functional groups determined from the absorption peak at absorption frequency 1883 cm ^-1 due to -CF ₂ COF and the absorption peak at absorption frequency 1840 cm ^-1 due to -CH ₂ COF. This is the sum of the calculated number of functional groups.

The number of functional groups mentioned above may be the total number of -CF=CF ₂ , -CF ₂ H, -COF, -COOH, -COOCH ₃ , -CONH ₂ and -CH ₂ OH, -CF ₂ H, -COF, It may be the total number of -COOH, -COOCH ₃ and -CH ₂ OH.

The above-mentioned functional group is introduced into the fluorine-containing polymer compound by, for example, a chain transfer agent or a polymerization initiator used when producing the fluorine-containing polymer compound. For example, when alcohol is used as a chain transfer agent or a peroxide having a -CH ₂ OH structure is used as a polymerization initiator, -CH ₂ OH is introduced at the end of the main chain of the fluorine-containing polymer compound. be done. Further, by polymerizing a monomer having a functional group, the functional group is introduced into the end of the side chain of the fluorine-containing polymer compound. The fluorine-containing polymer compound may contain units derived from a monomer having a functional group.

Examples of the monomer having a functional group include a dicarboxylic acid anhydride group ((-CO-O-CO-) and a cyclic carbonized monomer having a polymerizable unsaturated group in the ring) described in JP-A No. 2006-152234. Hydrogen monomers, monomers having a functional group (f) described in International Publication No. 2017/122743, etc. are mentioned. Examples of monomers having a functional group include monomers having a carboxy group (maleic, etc.). monomers having an acid anhydride group (itaconic anhydride, citraconic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, maleic anhydride, etc.); Examples include monomers having a hydroxyl group or an epoxy group (hydroxybutyl vinyl ether, glycidyl vinyl ether, etc.).

The fluorine-containing polymer compound can be produced by conventionally known methods such as, for example, appropriately mixing monomers serving as its constituent units and additives such as a polymerization initiator, and performing emulsion polymerization or suspension polymerization. .

(Method for manufacturing coated wire)
The coated wire of the present disclosure is, for example,
Forming a first layer by applying the liquid coating composition (1) to the outer periphery of the rectangular electric wire base material,
Forming a second layer by applying a liquid coating composition (2) or a powder coating composition (2) to the outer periphery of the first layer,
The third layer can be manufactured by applying the liquid coating composition (3) or the powder coating composition (3) to the outer periphery of the second layer to form the third layer.

The method of forming a layer by applying a liquid coating composition is not particularly limited, and examples include methods such as spray coating, roll coating, coating with a doctor blade, dip coating, and impregnation coating.

A layer may be formed by applying the liquid coating composition and then drying and/or baking the resulting coating film. Drying can be carried out by a conventionally known method, and is preferably carried out at a temperature of 60 to 200°C for 5 to 60 minutes. The firing can be carried out by a conventionally known method, but it is preferably carried out for 5 to 60 minutes at a temperature equal to or higher than the melting point or curing temperature of the polymer compound or fluorine-containing polymer compound. The baking may be performed each time the coating composition is applied, or after the coating composition is applied multiple times to form a plurality of layers (coating films).

The method of forming a layer by applying the powder coating composition is not particularly limited, and examples include methods such as electrostatic coating and fluidized dip coating.

The layer may be formed by applying the powder coating composition and then baking the resulting coating film. The firing can be carried out by a conventionally known method, but it is preferably carried out for 5 to 60 minutes at a temperature equal to or higher than the melting point or curing temperature of the polymer compound or fluorine-containing polymer compound. The baking may be performed each time the coating composition is applied, or after the coating composition is applied multiple times to form a plurality of layers (coating films).

The coated electric wire of the present disclosure is, for example, a LAN cable, a USB cable, a Lightning cable, an HDMI cable, a QSFP cable, an aerospace electric wire, an underground power transmission cable, a submarine power cable, a high-voltage cable, a superconducting cable, a wrapped electric wire, and an automobile. Electrical wires, wire harnesses and electrical components, electric wires for robots and FA, electric wires for OA equipment, electric wires for information equipment (optical fiber cables, LAN cables, HDMI cables, lightning cables, audio cables, etc.), internal wiring for communication base stations, large Current internal wiring (inverters, power conditioners, storage battery systems, etc.), electronic equipment internal wiring, small electronic equipment/mobile wiring, moving part wiring, electrical equipment internal wiring, measuring equipment internal wiring, power cables (for construction, wind/solar It can be suitably used for photovoltaic power generation, etc.), control/instrumentation wiring cables, motor cables, etc.

The coated wire of the present disclosure can be wound and used as a coil. The coated wire and coil of the present disclosure can be suitably used in electrical equipment or electronic equipment such as motors, generators, and inductors. Further, the coated wire and coil of the present disclosure can be suitably used for on-vehicle electrical equipment or on-vehicle electronic equipment, such as on-vehicle motors, on-vehicle generators, and on-vehicle inductors.

Although the embodiments have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the claims.

<1> According to the first aspect of the present disclosure,
A covered electric wire comprising a flat electric wire base material and a coating layer formed on the outer periphery of the flat electric wire base material,
The coating layer is
A first layer formed from a liquid coating composition (1) containing a polymer compound (1) having one or both of an amide group and an imide group;
A liquid coating composition (2) containing a polymer compound (2) having one or both of an amide group and an imide group, and a fluorine-containing polymer compound (2), or either an amide group or an imide group A second layer formed from a powder coating composition (2) containing a polymer compound (2) having one or both of them, and a fluorine-containing polymer compound (2);
A third layer formed from a liquid coating composition (3) containing a fluorine-containing polymer compound (3-1) or a powder coating composition (3) containing a fluorine-containing polymer compound (3-2) and,
A covered electric wire is provided.
<2> According to the second aspect of the present disclosure,
Provided is a covered wire according to the first aspect, wherein the polymer compound (1) or the polymer compound (2) is at least one selected from the group consisting of polyamideimide, polyetherimide, polyimide, and thermoplastic polyimide. .
<3> According to the third aspect of the present disclosure,
The covered electric wire according to the first or second aspect, wherein the fluorine-containing polymer compound (2), the fluorine-containing polymer compound (3-1), or the fluorine-containing polymer compound (3-2) is a perfluorinated polymer compound. is provided.
<4> According to the fourth aspect of the present disclosure,
The first to third fluorine-containing polymer compounds (2), fluorine-containing polymer compounds (3-1), or fluorine-containing polymer compounds (3-2) have a dielectric constant of 2.0 to 2.2. A covered electric wire according to any of the above aspects is provided.
<5> According to the fifth aspect of the present disclosure,
A covered electric wire according to any one of the first to fourth aspects is provided, wherein the fluorine-containing polymer compound (3-2) has a melting point of 250 to 320°C.
<6> According to the sixth aspect of the present disclosure,
A covered electric wire according to any one of the first to fifth aspects is provided, wherein the volume ratio of the polymer compound (2) to the fluorine-containing polymer compound (2) is from 10/90 to 90/10.
<7> According to the seventh aspect of the present disclosure,
There is provided a covered electric wire according to any one of the first to sixth aspects, wherein the material forming the rectangular electric wire base material is at least one selected from the group consisting of copper, copper alloy, aluminum, and aluminum alloy.
<8> According to the eighth aspect of the present disclosure,
There is provided a covered electric wire according to any one of the first to seventh aspects, wherein the flat electric wire base material has a surface roughness Sz in a range of 0.2 to 12 μm.
<9> According to the ninth aspect of the present disclosure,
There is provided a covered electric wire according to any one of the first to eighth aspects, wherein the thickness of the coating layer is 30 to 200 μm, and the dielectric constant of the coating layer is 2.3 to 3.0.
<10> According to the tenth aspect of the present disclosure,
There is provided a covered wire according to any one of the first to ninth aspects, wherein the second layer has a thickness of 10 to 100 μm.
<11> According to the eleventh aspect of the present disclosure,
There is provided a covered wire according to any one of the first to tenth aspects, wherein the partial discharge inception voltage of the coating layer is 1000 to 2100 (Vp).
<12> According to the twelfth aspect of the present disclosure,
The fluorine-containing polymer compound (2), the fluorine-containing polymer compound (3-1), or the fluorine-containing polymer compound (3-2) has 5 to 1000 functional groups per 10 ⁶ carbon atoms. A covered electric wire according to any of the eleventh aspects is provided.
<13> According to the thirteenth aspect of the present disclosure,
A covered electric wire according to any one of the first to eleventh aspects is provided, in which the fluorine-containing polymer compound (3-2) has 0 to 4 functional groups per 10 ⁶ carbon atoms.
<14> According to the fourteenth aspect of the present disclosure,
There is provided a covered electric wire according to any one of the first to thirteenth aspects, wherein the fluorine-containing polymer compound (3-2) has a melt flow rate (MFR) of 0.1 to 100 g/10 minutes.
<15> According to the fifteenth aspect of the present disclosure,
A covered electric wire according to any one of the first to fourteenth aspects is provided, wherein the liquid coating composition (2) or the liquid coating composition (3) has a viscosity of 10 to 10,000 (cP).
<16> According to the sixteenth aspect of the present disclosure,
A covered electric wire according to any one of the first to fifteenth aspects is provided, wherein the powder coating composition (2) or the powder coating composition (3) has an average particle size of 1 to 100 (μm).
<17> According to the seventeenth aspect of the present disclosure,
A first layer is formed on the outer periphery of the flat wire base material, a second layer is formed on the outer periphery of the first layer, and a third layer is formed on the outer periphery of the second layer. A covered electric wire according to any one of the first to sixteenth aspects is provided.
<18> According to the eighteenth aspect of the present disclosure,
A method for manufacturing a covered electric wire according to any one of the first to seventeenth aspects, comprising:
Forming a first layer by applying a liquid coating composition (1) to the outer periphery of the rectangular electric wire base material,
Forming a second layer by applying a liquid coating composition (2) or a powder coating composition (2) to the outer periphery of the first layer,
A manufacturing method is provided in which the third layer is formed by applying the liquid coating composition (3) or the powder coating composition (3) to the outer periphery of the second layer.
<19> According to the nineteenth aspect of the present disclosure,
A motor including a covered electric wire according to any one of the first to seventeenth aspects is provided.

Next, embodiments of the present disclosure will be described with examples, but the present disclosure is not limited to these examples.

Each numerical value in Examples was measured by the following method.

(Surface roughness Sz)
Surface roughness Sz in a field of 8000 μm ² was measured using a laser microscope.

(Number of functional groups)
The fluorine-containing polymer compound was melted at 330 to 340° C. for 30 minutes and compression molded to produce a film with a thickness of 0.20 to 0.25 mm. This film was scanned 40 times using a Fourier transform infrared spectrometer [FT-IR (product name: Model 1760X, manufactured by PerkinElmer) and analyzed to obtain an infrared absorption spectrum. A difference spectrum was obtained from the base spectrum that does not exist. From the absorption peak of a specific functional group appearing in this difference spectrum, the number N of functional groups per 10 ⁶ carbon atoms in the fluorine-containing polymer compound was calculated according to the following formula (A).

N=I×K/t (A)
I: Absorbance K: Correction coefficient t: Film thickness (mm)

For reference, absorption frequencies, molar extinction coefficients, and correction coefficients for the functional groups in the present disclosure are shown in Table 2. Furthermore, the molar extinction coefficient was determined from FT-IR measurement data of a low-molecular model compound.

(viscosity)
The viscosity of the coating composition was measured using a B-type viscometer (BII-type viscometer manufactured by Toki Sangyo Co., Ltd.) as described in JIS Z8803. Rotating rotor #4 was used for the measurement. The measurement temperature was 25°C.

(Average particle size)
The average particle size of the powder coating composition was measured using a laser diffraction/scattering particle size distribution analyzer manufactured by Nikkiso Co., Ltd. The median particle size (median diameter) in the volume-based particle size distribution was defined as the average particle size.

(Melt flow rate (MFR))
According to ASTM D1238, using a melt indexer (manufactured by Yasuda Seiki Seisakusho Co., Ltd.), the mass (g /10 minutes) was calculated.

(melting point)
It was determined as the temperature corresponding to the maximum value in the heat of fusion curve when the temperature was raised at a rate of 10° C./min using a differential scanning calorimeter (DSC).

(Coating thickness)
Measured with a micrometer.

(relative permittivity)
The relative dielectric constant (ε) of the entire coating layer was calculated from the following formula by obtaining the capacitance using LCR Hitester 3522-50 manufactured by HIOKI.
C=Ca+Cb
(In the formula, C is the capacitance per unit length of the coating (pf/m), which is the combination of the capacitance Ca of the flat part and the capacitance Cb of the corner part.)
Ca=(ε/ε ₀ )×2×(L ₁ +L ₂ )/T
Cb=(ε/ε ₀ )×2πε ₀ /Log{(r+T)/r}/r
(In the formula, ε ₀ is the permittivity of vacuum, L ₁ is the length of the long side of the flat part of the flat wire base material, L ₂ is the length of the short side of the flat part of the flat wire base material _{, and} T is the entire wire is the coating thickness, and r is the radius of curvature of the conductor corner.)

(Partial discharge inception voltage (PDIV))
A test piece was prepared by overlapping two coated electric wires (length 140 mm), including the long sides of their cross-sectional shapes, over a length of 100 mm with no gap. After that, the coating film of 10 mm from the end of the sample was removed, and using a partial discharge measuring device (DAC-PD-7 manufactured by Souken Electric Co., Ltd.), the distance between the rectangular wire base materials of the two covered wires was measured in an atmosphere of 50% relative humidity. The measurement was performed by applying a 50 Hz sine wave alternating current voltage. Assuming a voltage increase rate of 50 V/sec, a voltage decrease rate of 50 V/sec, and a voltage holding time of 0 sec, the voltage at which a discharge of 10 pC or more occurred was defined as the partial discharge inception voltage.

(bending test)
When both sides of a point 10 mm from the base point were bent R2 in the major axis direction using a U-shaped coil, the coating layer was rated ◯ if no lifting wrinkles were generated, and the rated × was if wrinkles were generated.

(Adhesion strength between base material and coating layer)
Measurement was performed using AGS-J Autograph (50N) (manufactured by Shimadzu Corporation). Two pieces were cut approximately parallel to each other by 50 mm in the long axis direction, and the coating was cut at right angles in the short axis direction at both ends, and the ends were peeled off by 10 mm, and then sandwiched between upper chucks. The conductor was fixed at the bottom so that its long surface was horizontal. When the device was moved in the tensile direction, a jig was used that moved in the lateral direction according to the distance moved in the vertical direction, and the angle was adjusted so that the peeled film was always perpendicular to the long conductor. The tensile stress when the film was pulled at 100 mm/min until it was peeled off by 30 mm was measured, and the maximum point stress was taken as the adhesion strength. If the adhesion strength was 0.1 N/mm or more, it was determined that the adhesion was sufficient and was rated as ○. Less than 0.1 N/mm was marked as x.

Example 1
Liquid coating composition A was applied to the outer periphery of a rectangular copper wire base material having a surface roughness Sz of 1.8 μm and baked to form a first layer. Furthermore, liquid coating composition B was applied to the outer periphery and baked to form a second layer. Furthermore, liquid coating composition G was applied to the outer periphery and baked to form a third layer. A method for forming a first layer using liquid coating composition A, a method for forming a second layer using liquid coating composition B, and a method for forming a third layer using liquid coating composition G. Details will be described later. Various properties of the obtained covered wire were measured. The results are shown in Table 3.

Examples 2-8
A covered wire was obtained in the same manner as in Example 1, except that the compositions for forming the first layer, second layer, and third layer were changed as shown in Table 3. Various properties of the obtained covered wire were measured. The results are shown in Table 3.

Comparative example 1
A covered wire was obtained in the same manner as in Example 3 except that the first layer was not formed. Various properties of the obtained covered wire were measured. The results are shown in Table 3.

Formation of the first layer using liquid coating composition A:
PAI varnish (resin content: 20% by weight) in which polyamideimide (PAI) was dissolved in 3-methoxy-N,N-dimethylpropanamide was used as liquid coating composition A. This viscosity was 341 cP.
This liquid coating composition A was spray coated, dried at 100°C for 15 minutes, and then baked at 230°C for 20 minutes to obtain a coating film with a thickness of 10 μm.

Formation of the second layer using liquid coating composition B:
Polyamideimide (PAI) varnish (resin content: 34% by weight) was poured into water to precipitate PAI. This was pulverized using a ball mill to obtain an aqueous dispersion of PAI (solid content: 20% by weight). A water dispersion composition of PTFE (solid content: 60% by weight, number of functional groups: 18 per 10 ⁶ carbon atoms) and water were added to this to form a liquid coating composition with PAI/PTFE = 25/75 (volume %). I got item B. This viscosity was 138 cP.
This liquid coating composition B was spray coated, dried at 100°C for 15 minutes, and then baked at 380°C for 20 minutes to obtain a coating film with a thickness of 19 μm.

Formation of the second layer using liquid coating composition C:
Polyimide (PI) varnish (resin content: 29% by weight) was poured into water to precipitate PI. This was pulverized using a ball mill to obtain an aqueous dispersion of PI (solid content: 20% by weight). A water dispersion composition of PTFE (solid content: 60% by weight, number of functional groups: 18 per 10 ⁶ carbon atoms) and water were added to this to form a liquid coating composition with PI/PTFE = 30/70 (volume%). I got item C. This viscosity was 145 cP.
This liquid coating composition C was spray coated, dried at 100°C for 15 minutes, and then baked at 380°C for 20 minutes to obtain a coating film with a thickness of 21 μm.

Formation of the second layer using liquid coating composition D:
PFA powder (TFE/PPVE copolymer, number of functional groups: 220 per ¹⁰ carbon atoms, MFR: 27 g/10 min, melting point: 301°C, average particle size) on polyamideimide (PAI) varnish (resin content: 34% by weight) diameter: 24 μm) and 3-methoxy-N,N-dimethylpropanamide to obtain a liquid coating composition D with PAI/PFA=25/75 (volume %). This viscosity was 367 cP.
This liquid coating composition D was spray-painted, dried at 100°C for 15 minutes, and then baked at 380°C for 20 minutes to obtain a coating film with a thickness of 22 μm.

Formation of the second layer using powder coating composition E:
Polyamideimide (PAI) powder (average particle size 20 μm) and PFA powder (TFE/PPVE copolymer, number of functional groups: 220 per 10 ⁶ carbon atoms, MFR: 27 g/10 min, melting point: 301°C, average particle size: 24 μm) to obtain powder coating composition E with PAI/PFA=20/80 (volume %). The average particle size was 23 μm.
This powder coating composition E was applied electrostatically and baked at 380° C. for 20 minutes to obtain a coating film with a thickness of 20 μm.

Formation of the second layer using powder coating composition F:
Polyamideimide (PAI) powder (average particle size 20 μm) and FEP powder (TFE/HFP copolymer, number of functional groups: 625 per 10 ⁶ carbon atoms, MFR: 38 g/10 min, melting point: 258 ° C., average particle size: 41 μm) to obtain a powder coating composition F with PAI/FEP=20/80 (volume %). The average particle size was 26 μm.
This powder coating composition F was applied electrostatically and baked at 320° C. for 20 minutes to obtain a coating film with a thickness of 18 μm.

Formation of the third layer using liquid coating composition G:
Water was added to an aqueous dispersion composition of PTFE (solid content: 60% by weight, number of functional groups: 18 per 10 ⁶ carbon atoms) to obtain a liquid coating composition G. This viscosity was 292 cP.
This liquid coating composition G was spray coated, dried at 100°C for 15 minutes, and then baked at 380°C for 20 minutes to obtain a coating film with a thickness of 28 μm.

Formation of the third layer using liquid coating composition H:
Water was added to an aqueous dispersion composition of PFA (TFE/PPVE copolymer) (solid content: 60% by weight, number of functional groups: 133 per 10 ⁶ carbon atoms) to obtain a liquid coating composition H. This viscosity was 224 cP.
This liquid coating composition H was spray coated, dried at 100°C for 15 minutes, and then baked at 380°C for 20 minutes to obtain a coating film with a thickness of 31 μm.

Formation of the third layer using powder coating composition I:
PFA powder (TFE/PPVE copolymer, number of functional groups: 220 per ¹⁰⁶ carbon atoms, MFR: 27 g/10 min, melting point: 301°C, average particle size: 24 μm) was used as powder coating composition I. .
This powder coating composition I was applied electrostatically and baked at 380° C. for 20 minutes to obtain a coating film with a thickness of 47 μm.

Formation of the third layer using powder coating composition J:
PFA powder (TFE/PPVE copolymer, number of functional groups: 2 per 10 ⁶ carbon atoms, MFR: 28 g/10 min, melting point: 301°C, average particle size: 23 μm) was used as powder coating composition J. .
This powder coating composition J was applied electrostatically and baked at 380° C. for 20 minutes to obtain a coating film with a thickness of 75 μm.

Formation of the third layer using powder coating composition K:
FEP powder (TFE/HFP copolymer, number of functional groups: 625 per ¹⁰⁶ carbon atoms, MFR: 38 g/10 min, melting point: 258°C, average particle size: 41 μm) was used as powder coating composition K. .
This powder coating composition K was applied electrostatically and baked at 320° C. for 20 minutes to obtain a coating film with a thickness of 52 μm.

Claims (19)

1. A covered electric wire comprising a flat electric wire base material and a coating layer formed on the outer periphery of the flat electric wire base material,
   The coating layer is
   A first layer formed from a liquid coating composition (1) containing a polymer compound (1) having one or both of an amide group and an imide group;
   A liquid coating composition (2) containing a polymer compound (2) having one or both of an amide group and an imide group, and a fluorine-containing polymer compound (2), or either an amide group or an imide group A second layer formed from a powder coating composition (2) containing a polymer compound (2) having one or both of them, and a fluorine-containing polymer compound (2);
   A third layer formed from a liquid coating composition (3) containing a fluorine-containing polymer compound (3-1) or a powder coating composition (3) containing a fluorine-containing polymer compound (3-2) and,
   Insulated electrical wires.
2. The covered wire according to claim 1, wherein the polymer compound (1) or the polymer compound (2) is at least one selected from the group consisting of polyamideimide, polyetherimide, polyimide, and thermoplastic polyimide.
3. The covered electric wire according to claim 1 or 2, wherein the fluorine-containing polymer compound (2), the fluorine-containing polymer compound (3-1), or the fluorine-containing polymer compound (3-2) is a perfluorinated polymer compound. .
4. Claims 1 to 3, wherein the fluorine-containing polymer compound (2), the fluorine-containing polymer compound (3-1), or the fluorine-containing polymer compound (3-2) has a dielectric constant of 2.0 to 2.2. The covered electric wire described in any of the above.
5. The covered electric wire according to any one of claims 1 to 4, wherein the fluorine-containing polymer compound (3-2) has a melting point of 250 to 320°C.
6. The covered electric wire according to any one of claims 1 to 5, wherein the volume ratio of the polymer compound (2) to the fluorine-containing polymer compound (2) is 10/90 to 90/10.
7. The covered electric wire according to any one of claims 1 to 6, wherein the forming material of the rectangular electric wire base material is at least one selected from the group consisting of copper, copper alloy, aluminum, and aluminum alloy.
8. The covered electric wire according to any one of claims 1 to 7, wherein the flat electric wire base material has a surface roughness Sz in a range of 0.2 to 12 μm.
9. The covered electric wire according to any one of claims 1 to 8, wherein the thickness of the coating layer is 30 to 200 μm, and the dielectric constant of the coating layer is 2.3 to 3.0.
10. The covered electric wire according to any one of claims 1 to 9, wherein the second layer has a thickness of 10 to 100 μm.
11. The covered electric wire according to any one of claims 1 to 10, wherein the partial discharge inception voltage of the coating layer is 1000 to 2100 (Vp).
12. Claim 1: The fluorine-containing polymer compound (2), the fluorine-containing polymer compound (3-1), or the fluorine-containing polymer compound (3-2) has 5 to 1000 functional groups per 10 ⁶ carbon atoms. The covered electric wire according to any one of items 1 to 11.
13. The coated electric wire according to any one of claims 1 to 11, wherein the fluorine-containing polymer compound (3-2) has 0 to 4 functional groups per 10 ⁶ carbon atoms.
14. The coated wire according to any one of claims 1 to 13, wherein the fluorine-containing polymer compound (3-2) has a melt flow rate (MFR) of 0.1 to 100 g/10 minutes.
15. The coated wire according to any one of claims 1 to 14, wherein the liquid coating composition (2) or the liquid coating composition (3) has a viscosity of 10 to 10,000 (cP).
16. The coated electric wire according to any one of claims 1 to 15, wherein the powder coating composition (2) or the powder coating composition (3) has an average particle size of 1 to 100 (μm).
17. A first layer is formed on the outer periphery of the rectangular electric wire base material, a second layer is formed on the outer periphery of the first layer, and a third layer is formed on the outer periphery of the second layer. Item 17. The covered electric wire according to any one of Items 1 to 16.
18. A method for manufacturing a covered electric wire for manufacturing the covered electric wire according to any one of claims 1 to 17, comprising:
    Forming a first layer by applying a liquid coating composition (1) to the outer periphery of the rectangular electric wire base material,
    Forming a second layer by applying a liquid coating composition (2) or a powder coating composition (2) to the outer periphery of the first layer,
    A manufacturing method in which a third layer is formed by applying a liquid coating composition (3) or a powder coating composition (3) to the outer periphery of the second layer.
19. A motor comprising the covered electric wire according to any one of claims 1 to 17.