Insulated wire, method for manufacturing same, coil, and electronic device

Abstract

The invention provides an insulated wire, a method for manufacturing the insulated wire, and a coil and an electronic device using the insulated wire. The insulated wire includes a conductor and an insulating layer laminated on an outer peripheral side of the conductor. The insulating layer includes a liquid crystal polyester (A) and a polymer (B). The liquid crystal polyester (A) is obtained by reacting a first mixture, and the first mixture comprises an aromatic hydroxycarboxylic acid (a1), an aromatic dicarboxylic acid (a2), an aromatic amine (a3) having a phenolic hydroxyl group, and an aromatic diol (a4). The polymer (B) is selected from at least one of a group consisting of a polyimide precursor and an imidized polymer of the polyimide precursor, and the polymer (B) includes an ester group structure. Therefore, the insulated wire can have good coating property and flexibility.

Description

Technical Field

[0001] The present invention relates to an insulated wire, and more particularly to an insulated wire and a manufacturing method thereof, a coil and an electronic device. Background Art

[0002] In inverter-related devices (e.g., coils for electronic devices such as high-speed switch components, inverter motors, and transformers), insulated wires (e.g., enameled wires) having an insulating resin coating (insulating film) formed around the conductor are used as magnetic conductors.

[0003] In recent years, with the popularity of hybrid vehicles and electric vehicles, it is necessary to improve motor efficiency and operate motors and control converters at high voltages. When using insulated wires at such high voltages, partial discharge (corona discharge) occurs on the surface of the insulating film, causing degradation of the insulating film. In order to suppress this partial discharge, a resin with a low dielectric constant is used as a constituent material of the insulating film.

[0004] As described above, the insulated wire needs to have good coating properties to have a uniform insulating film layer. In addition, the demand for miniaturization and high output of rotary motors such as automobile motors is increasing, and it is necessary to wind the insulated wire on a small-sized bobbin, increase the winding density of the insulated wire, or put as many bent insulated wires as possible into a limited space such as a stator slot (status lot). Therefore, such insulated wires are required to have not only high coating properties but also high flexibility. Summary of the invention

[0005] In view of the above, one aspect of the present invention is to provide an insulated wire having high coating properties and excellent flexibility, comprising a conductor and an insulating layer, wherein the insulating layer comprises a liquid crystal polyester (A) and a polymer (B).

[0006] Another aspect of the present invention is to provide a method for manufacturing an insulated wire, which is used to manufacture the insulated wire of the above aspect.

[0007] Still another aspect of the present invention provides a coil and an electronic device, which include the insulated wire of the above aspect.

[0008] One aspect of the present invention provides an insulated wire, which includes a conductor and an insulating layer laminated on the outer peripheral side of the conductor. The insulating layer includes a liquid crystal polyester (A) and a polymer (B). The liquid crystal polyester (A) is obtained by reacting a first mixture, and the first mixture includes an aromatic hydroxycarboxylic acid (a1), an aromatic dicarboxylic acid (a2), an aromatic amine (a3) ​​having a phenolic hydroxyl group, and an aromatic diol (a4). The polymer (B) is at least one selected from the group consisting of a polyimide precursor and an imidized polymer of a polyimide precursor, and the polymer (B) is obtained by reacting a second mixture, and the second mixture includes a tetracarboxylic dianhydride component (b1) and a diamine component (b2), and the polymer (B) includes an ester structure. According to one embodiment of the present invention, the liquid crystal polyester (A) includes structural units of the following formulas (a1'), (a2'), (a3') and (a4'),

[0009] -O-Ar 1 -CO- (al')

[0010] -CO-Ar 2 -CO- (a2')

[0011] -NH-Ar 3 -O- (a3')

[0012] -O-Ar 3 -O- (a4')

[0013] In formula (a1'), Ar 1 represents a phenylene group, a naphthylene group or a biphenylene group;

[0014] In formula (a2'), Ar 2 represents a phenylene group, a naphthylene group, a biphenylene group, or a group formed by condensation of a plurality of aromatic groups; and

[0015] In formula (a3') and formula (a4'), Ar 3 It represents a phenylene group or a group formed by condensation of a plurality of aromatic groups.

[0016] According to one embodiment of the present invention, the compound having the formula (a3′) comprises an aromatic hydroxyamide.

[0017] According to an embodiment of the present invention, the tetracarboxylic dianhydride component (b1) includes tetracarboxylic dianhydride (b1-1) containing an ester group.

[0018] According to one embodiment of the present invention, the diamine component (b2) includes an ester-containing diamine (b2-1).

[0019] According to an embodiment of the present invention, based on the total amount of the liquid crystal polyester (A) and the polymer (B) being 100 wt %, the content of the polymer (B) is 20 wt % to 90 wt %.

[0020] According to an embodiment of the present invention, the aromatic diol (a4) is at least one compound selected from the group consisting of compounds including the following structural units.

[0021]

[0022]

[0023] Another aspect of the present invention is to provide a method for manufacturing an insulated wire, which can produce the above-mentioned insulated wire. The method includes a coating step to coat a liquid composition on the outer peripheral side of the conductor, wherein the liquid composition includes a liquid crystal polyester (A), a polymer (B) and a solvent. The method also includes a heating step to heat the conductor coated with the liquid composition.

[0024] Another aspect of the present invention is to provide a coil, which includes the insulated wire of the above aspect.

[0025] Another aspect of the present invention is to provide an electronic device, which includes the coil of the above aspect.

[0026] The insulating layer of the insulated wire of the present invention contains a specific liquid crystal polyester and a polymer, and thus has good coating properties and flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] none DETAILED DESCRIPTION

[0028] [Insulated wire]

[0029] The insulated wire of the present invention comprises: a conductor and an insulating layer laminated on the outer peripheral side of the conductor. The insulating layer comprises a liquid crystal polyester (A) and a polymer (B), and the film thickness uniformity D of the insulating layer is 5% or less. The following is a detailed description of each component of the insulated wire.

[0030] [conductor]

[0031] The conductor in the insulated wire can use a known conductor used for insulated wires without particular limitation. For example, the conductor can be a metal conductor such as a copper wire or an aluminum wire.

[0032] As a preferred example of the conductor in the insulated wire of the present invention, a conductor having a rectangular cross section (flat shape) can be used, and a conductor having a square, circular or elliptical cross section can also be used.

[0033] In the flat conductor, it is preferred to have chamfers at four corners in order to suppress partial discharge at the corners. The radius of curvature of the chamfer is preferably 0.6 mm or less, more preferably 0.2 mm to 0.4 mm.

[0034] The size of the conductor is not particularly limited. If it is a flat conductor, the width (long side) of its rectangular cross section is preferably 1.0 mm to 5.0 mm, more preferably 1.4 mm to 4.0 mm, and the thickness (short side) is preferably 0.4 mm to 3.0 mm, more preferably 0.5 mm to 2.5 mm. The ratio of thickness to width (short side: long side) is preferably 1:1 to 1:4. If it is a conductor with a circular cross section, the cross-sectional diameter is preferably 0.3 mm to 3.0 mm, more preferably 0.4 mm to 2.7 mm.

[0035] [Insulation layer]

[0036] The insulating layer may be a single layer laminated on the conductor or may be a multilayer. The thickness of the insulating layer is 2 μm to 50 μm, preferably 10 μm to 50 μm, and more preferably 20 μm to 40 μm. When the insulating layer is a multilayer structure, the thickness of the insulating layer is calculated based on the total thickness of the multilayer insulating layers. When the thickness of the insulating layer is less than 2 μm, sufficient strength cannot be obtained; and when the thickness of the insulating layer is greater than 50 μm, sufficient flexibility cannot be obtained, and thus it is not good.

[0037] [Liquid crystal polyester (A)]

[0038] The liquid crystal polyester (A) of the present invention is obtained by reacting a first mixture. The first mixture comprises an aromatic hydroxycarboxylic acid (a1), an aromatic dicarboxylic acid (a2), an aromatic amine having a phenolic hydroxyl group (a3), and an aromatic diol (a4). Specifically, the liquid crystal polyester (A) of the present invention preferably comprises structural units of the following formulas (a1'), (a2'), (a3'), and (a4'),

[0039] -O-Ar 1 -CO- (a1')

[0040] -CO-Ar 2 -CO- (a2')

[0041] -NH-Ar 3 -O- (a3')

[0042] -O-Ar 3 -O- (a4')

[0043] In formula (a1'), Ar 1 represents a phenylene group, a naphthylene group or a biphenylene group;

[0044] In formula (a2'), Ar2 represents a phenylene group, a naphthylene group, a biphenylene group, or a group formed by condensation of a plurality of aromatic groups; and

[0045] In formula (a3') and formula (a4'), Ar 3 It represents a phenylene group or a group formed by condensation of a plurality of aromatic groups.

[0046] It should be noted that the above-mentioned "structural unit of formula (a1')" is derived from the structure of the above-mentioned "aromatic hydroxycarboxylic acid (a1)". The above-mentioned "structural unit of formula (a2')" is derived from the structure of the above-mentioned "aromatic dicarboxylic acid (a2)". The above-mentioned "structural unit of formula (a3')" is derived from the structure of the above-mentioned "aromatic amine having phenolic hydroxyl group (a3)". The above-mentioned "structural unit of formula (a4')" is derived from the structure of the above-mentioned "aromatic diol (a4)". The following specifically describes the compounds contained in the first mixture for preparing the liquid crystal polyester (A).

[0047] In some embodiments, the compound having the formula (a3′) comprises an aromatic hydroxyamide. When the liquid crystal polyester (A) comprises an aromatic hydroxyamide structure, it can have a higher molecular weight, increase viscosity, and adjust coating properties.

[0048] [Aromatic hydroxycarboxylic acid (a1)]

[0049] The aromatic hydroxycarboxylic acid (a1) may include structural units represented by the following formulae (a1′-1) to (a1′-5), wherein the aromatic ring may be substituted by a halogen atom, an alkyl group or an aromatic group.

[0050]

[0051] In formula (a1'-1) to formula (a1'-5), the alkyl group as the substituent in the aromatic ring is usually an alkyl group having 1 to 10 carbon atoms, preferably methyl, ethyl, n-propyl, or n-butyl. The aromatic group as the substituent in the aromatic ring is usually an aromatic group having 6 to 20 carbon atoms, preferably phenyl.

[0052] In some specific examples, the aromatic hydroxycarboxylic acid (a1) may be, for example, p-hydroxybenzoic acid, m-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 4-hydroxy-1-naphthoic acid or 4-(4-hydroxyphenyl)benzoic acid.

[0053] [Aromatic dicarboxylic acid (a2)]

[0054] The aromatic dicarboxylic acid (a2) may include structural units as shown in the following formulas (a2'-1) to (a2'-10), wherein the aromatic ring may be substituted by a halogen atom, an alkyl group or an aromatic group. The specific substituents are the same as those listed for the aromatic hydroxycarboxylic acid (a1) above, and will not be described in detail here.

[0055]

[0056]

[0057] In some specific examples, the aromatic dicarboxylic acid (a2) may be, for example, terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, biphenyl-4,4'-dicarboxylic acid, diphenyl ether-4,4'-dicarboxylic acid, diphenyl sulfide-4,4'-dicarboxylic acid, diphenyl sulfone-4,4'-dicarboxylic acid, dibenzophenone-4,4'-dicarboxylic acid, etc.

[0058] [Aromatic amine having phenolic hydroxyl group (a3)]

[0059] The aromatic amine (a3) ​​having a phenolic hydroxyl group may include structural units as shown in the following formulas (a3'-1) to (a3'-6), wherein the aromatic ring may be substituted by a halogen atom, an alkyl group or an aromatic group. The specific substituents are the same as those listed for the aromatic hydroxycarboxylic acid (a1) above, and will not be described in detail here.

[0060]

[0061] In some specific examples, the aromatic amine (a3) ​​having a phenolic hydroxyl group may be, for example, an aromatic hydroxylamine and an aromatic hydroxyamide. Aromatic hydroxylamines may be, for example, 3-aminophenol, 4-aminophenol, 4-amino-4'-hydroxybiphenyl, etc. Aromatic hydroxyamides may be, for example, 3-hydroxyacetanilide, 4-hydroxyacetanilide, etc. If the aromatic amine (a3) ​​having a phenolic hydroxyl group includes an aromatic hydroxyamide, the obtained liquid crystal polyester (A) may have a higher molecular weight, and the viscosity may be increased and the coating properties may be adjusted.

[0062] [Aromatic diol (a4)]

[0063] The aromatic diol (a4) may include structural units as shown in the following formula (a4'-1) to formula (a4'-11), wherein the aromatic ring may be substituted by a halogen atom, an alkyl group or an aromatic group. The specific substituents are the same as the substituents listed for the aromatic hydroxycarboxylic acid (a1) above, and are not described in detail here. If the aromatic diol (a4) includes structural units as shown in the following formula (a4'-6) to formula (a4'-11), the insulated wire may have better flexibility.

[0064]

[0065]

[0066] In some specific examples, the aromatic diol (a4) may be, for example, hydroquinone, resorcinol, 2,6-naphthalene diol, 1,5-naphthalene diol, 4,4'-biphenyl diol, biphenyl-2,5-diol, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 4,4'-dihydroxydiphenyl ether, bis-(4-hydroxyphenyl) ketone, bis-(4-hydroxyphenyl) sulfone, 4,4'-dihydroxydiphenylmethane, etc.

[0067] [Usage amount of each liquid crystal polyester compound]

[0068] Relative to the first mixture for preparing the liquid crystal polyester (A), the usage amount of the aromatic hydroxycarboxylic acid (a1) compound is 10 mol% to 75 mol%, preferably 15 mol% to 70 mol%, and more preferably 20 mol% to 65 mol%.

[0069] Relative to the first mixture for preparing the liquid crystal polyester (A), the usage amount of the aromatic dicarboxylic acid (a2) is 5 mol % to 50 mol %, preferably 10 mol % to 45 mol %, and more preferably 15 mol % to 40 mol %.

[0070] The amount of the aromatic amine (a3) ​​having a phenolic hydroxyl group is 3 mol% to 45 mol%, preferably 5 mol% to 40 mol%, and more preferably 8 mol% to 35 mol% relative to the first mixture for preparing the liquid crystal polyester (A). If the aromatic amine (a3) ​​having a phenolic hydroxyl group is not included in the first mixture for preparing the liquid crystal polyester (A), the coating property of the insulated wire is poor.

[0071] The amount of the aromatic diol (a4) used is 3 mol% to 35 mol%, preferably 5 mol% to 30 mol%, and more preferably 8 mol% to 25 mol% relative to the first mixture for preparing the liquid crystal polyester (A). If the first mixture for preparing the liquid crystal polyester (A) does not contain the aromatic diol (a4), the flexibility and coating properties of the insulated wire are poor.

[0072] In the first mixture for preparing the liquid crystal polyester (A), the aromatic hydroxycarboxylic acid (a1), the aromatic dicarboxylic acid (a2), the aromatic amine having a phenolic hydroxyl group (a3) ​​and the aromatic diol (a4) may contain only one or more than two of each. In addition, the first mixture for preparing the liquid crystal polyester (A) may contain other compounds other than the aromatic hydroxycarboxylic acid (a1), the aromatic dicarboxylic acid (a2), the aromatic amine having a phenolic hydroxyl group (a3) ​​and the aromatic diol (a4), and the other compounds are preferably 10 mol% or less, more preferably 5 mol% or less relative to the first mixture.

[0073] [Method for producing liquid crystal polyester (A)]

[0074] The method for producing the liquid crystal polyester (A) of the present invention is not particularly limited. For example, an acylate can be obtained by acylation of an aromatic hydroxycarboxylic acid (a1), an aromatic amine (a3) ​​having a phenolic hydroxyl group, and an aromatic diol (a4) with an excess of fatty acid anhydride. The acylate is then polymerized with an aromatic hydroxycarboxylic acid (a1) and / or an aromatic dicarboxylic acid (a2) through an ester exchange / amide exchange reaction to obtain a liquid crystal polyester (A).

[0075] In the acylation reaction, the amount of fatty acid anhydride added is preferably 1.0 to 1.2 times the equivalent, and more preferably 1.05 to 1.1 times the equivalent, relative to the total amount of phenolic hydroxyl groups and amine groups. If the amount of fatty acid anhydride added is too little, there is a tendency for the reaction apparatus to be blocked due to the sublimation of the acylate or other reactants during polymerization reactions such as transesterification or transamide exchange; if the amount of fatty acid anhydride added is too much, there is a problem that the obtained liquid crystal polyester (A) is easily colored. As the reaction conditions for the acylation reaction, it is preferably reacted at 130°C to 180°C for 5 minutes to 10 hours, and more preferably reacted at 140°C to 160°C for 10 minutes to 3 hours.

[0076] In the acylation reaction, the fatty acid anhydride used is not particularly limited, and can be enumerated: diacetic anhydride, propionic anhydride, butyric anhydride, isobutyric anhydride, valeric anhydride, pivalic anhydride, 2-ethylhexanoic anhydride, dichloroacetic anhydride, trichloroacetic anhydride, monobromoacetic anhydride, dibromoacetic anhydride, tribromoacetic anhydride, monofluoroacetic anhydride, difluoroacetic anhydride, trifluoroacetic anhydride, glutaric anhydride, maleic anhydride, succinic anhydride, β-bromopropionic anhydride etc. Fatty acid anhydride can only use one or use two or more. From the viewpoint of price and operability, preferably diacetic anhydride, propionic anhydride, butyric anhydride or isobutyric anhydride, more preferably diacetic anhydride.

[0077] In the transesterification / amidation reaction, the acyl content of the acylate is preferably 0.8 to 1.2 times the equivalent relative to the carboxyl content. The reaction temperature of the transesterification / amidation reaction is preferably 400°C or less, more preferably 350°C or less. In addition, the heating rate of the reaction is preferably 0.1 to 50°C / min, more preferably 0.3 to 5°C / min. In addition, in order to shift the equilibrium between the reactants and the products, it is preferred that the by-product fatty acid or the unreacted fatty acid anhydride be distilled from the reaction system by evaporation or the like during the reaction.

[0078] In addition, the acylation reaction and the transesterification / transamidation reaction can be carried out in the presence of a catalyst. As the catalyst, substances that are conventionally known as catalysts for polyester polymerization can be used, for example, metal salts such as magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, potassium acetate, antimony trioxide, and organic compounds such as N,N-dimethylaminopyridine and N-methylimidazole. The catalyst is usually present during the acylation reaction, and it is not necessary to remove the catalyst even after the acylation reaction. If the catalyst is not removed, the next step of treatment can be directly carried out. In addition, the above catalyst can be further added when the next treatment is carried out.

[0079] The polymerization reaction of the transesterification / amidation reaction is usually carried out by melt polymerization, but melt polymerization and solid phase polymerization can also be used in combination. Solid phase polymerization can be carried out by a known solid phase polymerization method after extracting the polymer from the melt polymerization step, solidifying it and crushing it into powder or flakes. Specifically, it can be listed as a method of heat treatment in a solid phase state at 20°C to 350°C under a nitrogen environment for 1 hour to 30 hours. Solid phase polymerization can be carried out under stirring or in a static state without stirring. In addition, as long as an appropriate stirring mechanism is provided, the melt polymerization tank and the solid phase polymerization tank can be the same reaction tank. After solid phase polymerization, the obtained liquid crystal polyester can be granulated by a known method.

[0080] [Polymer (B)]

[0081] The insulating layer of the insulated wire of the present invention contains a polymer (B) in addition to the liquid crystal polyester (A) so that the insulated wire has better flexibility. If the insulating layer does not contain the polymer (B), the flexibility of the insulated wire is poor. The polymer (B) is at least one selected from the group consisting of a polyimide precursor and an imidized polymer of the polyimide precursor, wherein the polyimide precursor includes an ester structure. If the polymer (B) does not include an ester structure, the liquid crystal polyester (A) and the polymer (B) have poor compatibility and poor coating properties.

[0082] The polyimide precursor is obtained by reacting the second mixture, and the second mixture includes a tetracarboxylic dianhydride component (b1) and a diamine component (b2). The tetracarboxylic dianhydride component (b1) may include an ester-containing tetracarboxylic dianhydride (b1-1), and the diamine component (b2) may include an ester-containing diamine (b2-1). If the second mixture includes an ester-containing tetracarboxylic dianhydride (b1-1) and an ester-containing diamine (b2-1), the insulating layer may have better coating properties.

[0083] The ester group-containing tetracarboxylic dianhydride (b1-1) or ester group-containing diamine (b2-1) monomer preferably accounts for more than 20% of the molar number of the polyimide, and more preferably accounts for more than 50% of the molar number of the polyimide.

[0084] The ester-containing tetracarboxylic dianhydride (b1-1) may be, for example, p-phenylene bis(trimellitate) dianhydride, cyclohexane-1,4-diylbis(methylene)bis(trimellitate) dianhydride, ethylene bis(trimellitate) dianhydride, propyl bis(trimellitate) dianhydride or (4-phthalic anhydride) formyloxy-4-phthalic anhydride (5-Isobenzofurancarboxylicacid, 1,3-dihydro-1,3-dioxo-, 1,3-dihydro-1,3-dioxo-5-isobenzofuranylester).

[0085] The ester group-containing diamine (b2-1) may be, for example, 4-aminobenzoic acid 4-aminophenyl ester, 1,4-Benzenedicarboxylic acid bis(4-aminophenyl) ester or [4-(4-aminobenzoyl)oxyphenyl] 4-aminobenzoate.

[0086] In addition to the ester-containing tetracarboxylic dianhydride (b1-1) and the ester-containing diamine (b2-1), other types of monomers can also be selected to match the ester-containing monomer to adjust the desired properties. Other tetracarboxylic dianhydrides (b1-2) without ester groups can be selected from 1,2,4,5-Benzenetetracarboxylic anhydride (PMDA), 3,3',4,4'-biphenyl tetracarboxylic dianhydride (BPDA), 4,4'-oxydiphthalic anhydride (ODPA), 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride, 6-FDA), 3,3',4,4'-benzophenonetetracarboxylicdianhydride (Benzophenone-3,3',4,4'-tetracarboxylicdianhydride, BTDA), 1,2,3,4-cyclobutanetetracarboxylicdianhydride (1,2,3,4-cyclobutanetetracarboxylicdianhydride, CBDA), 4,4'-(4,4'-isopropylidene-diphenoxy)bis(phthalic anhydride, BPADA), 2,3,3',4'-biphenyltetracarboxylicdianhydride (2,3,3',4'-Biphenyltetracarboxylic diandhydride, α-BPDA), etc.

[0087] Other diamines (b2-2) without ester groups can be selected from p-phenylenediamine (1,4-diaminobenzene, PDA), 4,4'-diaminodiphenyl ether (4,4'-diaminodiphenylether, ODA), 3,4'-diaminodiphenyl ether (3,4'-diaminodiphenyl ether, 34ODA), 1,3-phenylenediamine (1,3-diaminobenzene, mPDA), 4,4'-diaminodiphenyl sulfone (44DDS), 3,3'-diaminodiphenyl sulfone (3,3'-diaminodiphenyl sulfone, ... sulfone, 33DDS), 4,4'-diamino-2,2'-dimethyl-1,1'-biphenyl (2,2'-dimethyl[1,1'--bipheny1]--4,4'--diamine, mTB), 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (2,2'-bis(trifluoromethy1)-4,4'-diaminobiphenyl, TFMB), 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane (2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, HFBAPP), 2,2-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether (2,2'-bis(trifluoromethy1)-4,4'-diaminodiphenyl ether, 6FODA), 2,2'-bis[4-(4-aminophenoxy)phenyl]propane (2,2-bis[4-(4-aminophenoxy)phenyl]propane, BAPP), 1,3-bis(3-aminophenoxy)benzene (1,3-bis(3-aminophenoxy)benzene, APB-N), 4,4'-bis(4-aminophenoxy)biphenyl (4,4'-bis(4-aminophenoxy)biphenyl, BAPB), 1,3-bis(4'-aminophenoxy) 1,3-bis(4'-aminophenoxy)benzene (TPER), 1,4-bis(4-aminophenoxy)benzene (TPEQ), 4,4'-diaminobenzanilide (44DABA), 2-(4-aminophenyl)-5-aminobenzoxazole (5BPOA), N,N'-(2,2'-bis(trifluoromethyl)-[1,1'-biphenyl]-4,4'-diyl)-(4-aminobenzamide) (N,N'-[2,2'-bis(trifluoromethyl)-[1,1'-bipheny1]-4,4'-diy1]bis[4-aminobenzamide], AB-TFMB).

[0088] [Method for producing polyamic acid]

[0089] The preparation method of polyamic acid comprises the following steps: firstly dissolving a mixture in a solvent, wherein the mixture comprises a tetracarboxylic dianhydride component (b1) and a diamine component (b2), and carrying out a polymerization reaction at a temperature of 0°C to 100°C for 1 hour to 24 hours. Then, the reaction solution is subjected to reduced pressure distillation by an evaporator to obtain polyamic acid, or the reaction solution is poured into a large amount of poor solvent to obtain a precipitate. Then, the precipitate is dried by reduced pressure drying to obtain polyamic acid.

[0090] The solvent used in the polymerization reaction is not particularly limited, as long as it can dissolve the reactants and products. Preferably, the solvent includes but is not limited to (1) aprotic polar solvents: N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethyl urea or hexamethylphosphoric acid triamide, etc.; (2) phenolic solvents: m-cresol, xylenol, phenol or halogenated phenols, etc. Preferably, based on the total amount of the mixture used being 100 parts by weight, the amount of the solvent used in the polymerization reaction ranges from 200 parts by weight to 2,000 parts by weight; more preferably, from 300 parts by weight to 1,800 parts by weight.

[0091] In particular, in the above-mentioned polymerization reaction, a proper amount of poor solvent can be used as a solvent, as long as the polyamic acid is not precipitated. The poor solvent can be used alone or in combination, and the poor solvent includes but is not limited to (1) alcohols: methanol, ethanol, isopropanol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol or triethylene glycol, etc.; (2) ketones: acetone, methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone, etc.; (3) esters: methyl acetate, ethyl acetate, butyl acetate, diethyl oxalate, diethyl malonate or ethylene glycol ethyl ether acetate, etc.; (4) ethers : diethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol n-propyl ether, ethylene glycol isopropyl ether, ethylene glycol n-butyl ether, ethylene glycol dimethyl ether or diethylene glycol dimethyl ether, etc.; (5) halogenated hydrocarbons: dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene or o-dichlorobenzene, etc.; (6) hydrocarbons: tetrahydrofuran, hexane, heptane, octane, benzene, toluene or xylene, etc.; or (7) any combination of the above. Preferably, based on the total amount of the diamine component used being 100 parts by weight, the amount of the lean solvent used is in the range of 0 to 60 parts by weight; more preferably, the amount of the lean solvent used is in the range of 0 to 50 parts by weight.

[0092] [Method for producing polyimide]

[0093] The preparation method of polyimide comprises the following steps: dissolving a mixture in a solvent, wherein the mixture includes a tetracarboxylic dianhydride component (b1) and a diamine component (b2), performing a polymerization reaction to form polyamic acid, and further heating and performing a dehydration closed cycle reaction in the presence of a dehydrating agent and a catalyst, so that the amic acid functional group generated during the polymerization reaction is converted into an imide functional group (i.e., imidization).

[0094] The polymerization reaction and the dehydration dead cycle reaction can adopt the reaction temperature and reaction time of the previous operation in the relevant field. Preferably, the operating temperature range of the polymerization reaction is 0°C to 100°C. Preferably, the operating time range of the polymerization reaction is 1 hour to 24 hours. Preferably, the operating temperature range of the dehydration dead cycle reaction is 30°C to 200°C, and the operating time range of the dehydration dead cycle reaction is 0.5 hour to 50 hours.

[0095] Specific examples of the solvent used in the dehydration dead cycle reaction include, but are not limited to, N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol n-propyl ether, ethylene glycol isopropyl ether, ethylene glycol n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, or N,N-dimethylformamide or N,N-dimethylacetamide (N,N-dimethyl acetamide), etc. Preferably, based on 100 parts by weight of polyamic acid, the amount of the solvent used in the dehydration dead cycle reaction ranges from 200 parts by weight to 2,000 parts by weight. More preferably, the amount of the solvent used in the dehydration dead cycle reaction ranges from 300 parts by weight to 1,800 parts by weight.

[0096] The dehydrating agent used in the dehydration dead cycle reaction is selected from anhydride compounds: acetic anhydride, propionic anhydride or trifluoroacetic anhydride, etc. Based on 1 mol of polyamic acid resin, the amount of the dehydrating agent used ranges from 0.01 mol to 20 mol. The catalyst used in the dehydration dead cycle reaction is selected from (1) pyridine compounds: pyridine, trimethylpyridine or dimethylpyridine, etc.; (2) tertiary amine compounds: triethylamine, etc. Based on 1 mol of the dehydrating agent, the amount of the catalyst used ranges from 0.5 mol to 10 mol.

[0097] The polymer (B) of the present invention has a weight average molecular weight of 10,000 to 90,000, preferably 12,000 to 75,000, and more preferably 15,000 to 60,000, as measured by gel permeation chromatography (GPC) and calculated based on polystyrene.

[0098] [Manufacturing method of insulated electric wire]

[0099] In the insulated wire, based on 100 wt % of the total amount of the liquid crystal polyester (A) and the polymer (B), the content of the polymer (B) is 20 wt % to 90 wt %, preferably 25 to 85 wt %, and more preferably 30 to 80 wt %.

[0100] The method for manufacturing an insulated wire may include the following steps: (1) a coating step, coating the outer peripheral side of a conductor with a liquid composition comprising a liquid crystal polyester (A), a polymer (B) and an aprotic solvent; and (2) a heating step, heating the conductor coated with the liquid composition. Each step is described in detail below.

[0101] (1) Coating step

[0102] In the coating step, a liquid composition comprising the liquid crystal polyester (A), the polymer (B) and the aprotic solvent of the present invention is directly or via another layer applied to the outer peripheral side of the conductor. Here, the conductor may have another primer layer formed on the surface by a known method before the coating step.

[0103] In some embodiments, the aprotic solvent can be a halogen solvent such as 1-chlorobutane, chlorobenzene, 1,1-dichloroethane, 1,2-dichloroethane, chloroform, 1,1,2,2-tetrachloroethane; an ether solvent such as diethyl ether, tetrahydrofuran, 1,4-dioxane; a ketone solvent such as acetone, cyclohexanone; an ester solvent such as ethyl acetate; a lactone solvent such as γ-butyrolactone; a carbonate solvent such as ethyl carbonate and propylene carbonate; an amine solvent such as triethylamine and pyridine; a nitrile solvent such as acetonitrile and succinonitrile; an amide solvent such as N,N'-dimethylformamide, N,N'-dimethylacetamide, tetramethylurea, N-methyl-2-pyrrolidone; a nitro solvent such as nitromethane and nitrobenzene; a sulfide solvent such as dimethyl sulfoxide and cyclopentane sulfone; and a phosphoric acid solvent such as hexamethylphosphoramide and tri-n-butyl phosphate.

[0104] The above solvents can be used alone or in combination of two or more. Among them, from the viewpoint of environmental impact, it is preferred to use a solvent that does not contain halogen atoms, and from the viewpoint of solubility, it is preferred to use a solvent with a dipole moment of 3 to 5. Specifically, it is preferred to use amide solvents such as N, N'-dimethylformamide, N, N'-dimethylacetamide, tetramethylurea, N-methyl-2-pyrrolidone; lactone solvents such as γ-butyrolactone. It is more preferred to use solvents such as N, N'-dimethylformamide, N, N'-dimethylacetamide, N-methyl-2-pyrrolidone.

[0105] The concentration of the liquid crystal polyester in the liquid composition can be appropriately selected according to the purpose, preferably 0.5 mass % to 50 mass %, more preferably 5 mass % to 30 mass %. When the concentration of the liquid crystal polyester is less than 0.5 mass %, it may be difficult to apply uniformly due to the low viscosity of the solution, and more heat needs to be supplied to dry the solvent, resulting in increased costs; and when the concentration of the liquid crystal polyester exceeds 50 mass %, it may be difficult to apply uniformly due to the high viscosity of the solution, and the liquid composition itself is also easy to colloid, which is not good.

[0106] Furthermore, a liquid composition obtained by dissolving a liquid crystal polyester in a solvent may be used as a coating liquid as it is, but it is preferably passed through a filter or the like to remove minute foreign matter contained in the solution.

[0107] Furthermore, the liquid composition may include components such as other resins, other solvents, other fillers or additives in addition to the above-mentioned liquid crystal polyester and aprotic solvent.

[0108] The method of applying the liquid composition to the outer circumference of the conductor can be, for example, a method using a coating device having a liquid composition tank for storing the liquid composition and a coating die. According to the coating device, when the conductor is inserted into the liquid composition tank, the liquid composition adheres to the outer circumference of the conductor and then passes through the coating die, so that the liquid composition has a substantially uniform thickness.

[0109] (2) Heating step

[0110] In the heating step, the liquid composition applied on the conductor or the linear body of the primer layer formed in the coating step is heated to form an insulating layer. The solvent in the liquid composition is volatilized by the heating to form an insulating layer with excellent electrical, mechanical and thermal properties.

[0111] The device used in the heating step is not particularly limited, and may be, for example, a cylindrical baking oven that is long in the direction of travel of the conductor. The heating method is also not particularly limited, and may be, for example, hot air heating, infrared heating, high frequency heating, and other known methods.

[0112] The heating conditions of the heating step are preferably heating at 300°C or more for 10 seconds or more and less than 3 hours, more preferably heating at 300°C or more for 10 seconds or more and less than 15 minutes, and particularly preferably heating at 300°C or more for 10 seconds or more and less than 30 seconds. By heating at high temperature for a short time, the thermal conductivity in the thickness direction of the insulating layer can be further improved. If the heating time is less than 10 seconds, the evaporation of the solvent and the formation of the insulating layer are insufficient, and the appearance, electrical properties, mechanical properties and thermal properties of the insulated wire may deteriorate. In principle, even if the heating time is shortened by increasing the heating temperature to a higher temperature, the same amount of heat can be provided to the insulating layer, but excessive rapid heating will cause blistering and degradation of the mechanical properties of the insulating layer. The upper limit of the heating temperature is not particularly limited, but due to the deterioration of the properties of the insulated wire, productivity, cost, etc., the upper limit is, for example, 400°C. On the other hand, if the heating time exceeds 3 hours, not only the thermal conductivity in the thickness direction of the insulating layer is reduced, but also the properties of the insulated wire are reduced, which is not good in terms of productivity, cost, etc.

[0113] In addition, the insulated wire formed by the heating step may be further heated as required. By further heating, the electrical, mechanical and thermal properties of the insulated wire may be improved. The heating device is not particularly limited, and for example, batch heating may be performed after the insulated wire is manufactured using the above-mentioned heating device. The heating method is not particularly limited, and may be performed by known methods such as hot air heating, infrared heating, and high-frequency heating.

[0114] The above-mentioned coating step and heating step are usually repeated multiple times. By repeating the coating step and heating step, the thickness of the insulating layer can be increased. At this time, the aperture of the coating mold should be appropriately adjusted according to the number of repetitions.

[0115] [Coil and electronic equipment]

[0116] The insulated wire of the present invention can be used as a coil in various electronic devices and other fields requiring electrical properties (voltage resistance). For example, the insulated wire of the present invention can be used in motors, transformers, etc. to form high-performance electronic devices. It is particularly suitable for use as a winding of a drive motor of a hybrid vehicle (HV) or an electric vehicle (EV). As described above, according to the present invention, an electronic device using the insulated wire of the present invention as a coil, such as a drive motor of an HV or an EV, can be provided.

[0117] The coil of the present invention may have a shape suitable for various electronic devices, for example, a coil shape obtained by winding the insulated wire of the present invention, or a shape obtained by bending the insulated wire of the present invention and then electrically connecting specific portions.

[0118] The coil formed by winding the insulated wire of the present invention is not particularly limited. For example, a long insulated wire can be wound into a spiral coil. In such a coil, the number of windings of the insulated wire is not particularly limited. Usually, an iron core or the like is used when winding the insulated wire.

[0119] [Example]

[0120] 1. Synthesis Example of Liquid Crystal Polyester (A)

[0121] Synthesis Example A-1

[0122] Nitrogen was introduced into a reaction vessel equipped with a nitrogen inlet, a stirrer, a heater, a condenser and a thermometer, and then 5.0 mol of 6-hydroxy-2-naphthoic acid (a1-1), 2.5 mol of terephthalic acid (a2-1), 1.5 mol of 3-hydroxyacetanilide (a3-1), 1.0 mol of 4,4'-biphenol (a4-1) and 11.0 mol of acetic anhydride were added.

[0123] Next, the above components are slowly stirred under a nitrogen stream to raise the temperature of the solution to 140°C, and react at this temperature for 3 hours. Then, the by-product acetic acid and unreacted acetic anhydride are distilled off from the reaction system, and the solution is heated to 300°C at a heating rate of 1.0°C / min, and then decompressed at 300°C. After reacting at 300°C for 1 hour, the product is taken out of the reaction vessel and cooled to room temperature. The cooled product is crushed with a pulverizer to obtain a powdered liquid crystal polyester (A-1).

[0124] 10 g of the powdery liquid crystal polyester (A-1) was added to 82 g of N-methyl-2-pyrrolidone and heated to 160° C. to completely dissolve it, thereby obtaining a brown transparent solution.

[0125] Synthesis Examples A-2 to A-5 and Comparative Synthesis Examples A'-1 and A'-2

[0126] Synthesis Examples A-2 to A-5 and Comparative Synthesis Examples A'-1 and A'-2 use the same preparation method as the preparation method of the liquid crystal polyester (A-1) of Synthesis Example A-1, except that Synthesis Examples A-2 to A-5 and Comparative Synthesis Examples A'-1 and A'-2 change the type and amount of the first mixture, and Comparative Synthesis Example A'-1 does not use aromatic diol (a4), and Comparative Synthesis Example A'-2 does not use aromatic amine (a3) ​​having phenolic hydroxyl groups. The formulas are shown in Table 1, and are not described here.

[0127] 2. Synthesis Example of Polymer (B)

[0128] Synthesis Example B-1

[0129] A nitrogen inlet, a stirrer, a condenser and a thermometer are set on a four-necked conical flask with a volume of 500 ml, and nitrogen is introduced. Then, 0.025 mol of p-aminophenyl benzoate (abbreviated as b2-1-1) and 70 grams of N-methyl-2-pyrrolidone (abbreviated as NMP) are added, and stirred at room temperature until dissolved. Next, 0.024 mol of p-phenylene-diphenyltrimethylolpropane tetracarboxylic dianhydride (abbreviated as b1-1-1) and 30 grams of NMP are added, and the reaction is carried out at room temperature for 2 hours. After the reaction is completed, the reaction solution is poured into 1500 ml of water to precipitate the polymer, the obtained polymer is filtered, and the steps of washing and filtering are repeated three times with methanol. After that, the product is placed in a vacuum oven and dried at a temperature of 60°C to obtain polymer (B-1).

[0130] Synthesis Examples B-2 to B-5 and Comparative Synthesis Example B'-1

[0131] Synthesis Examples B-2 to B-5 and Comparative Synthesis Example B'-1 use the same preparation method as the preparation method of the polymer (B-1) of Synthesis Example B-1, except that the type and amount of the second mixture are changed in Synthesis Examples B-2 to B-5 and Comparative Synthesis Example B'-1, and Comparative Synthesis Example B'-1 uses other tetracarboxylic dianhydrides (b1-2) without ester groups and other diamines (b2-2) without ester groups. Their formulas are shown in Table 2, and are not described here.

[0132] 3. Examples of Liquid Compositions

[0133] Examples 1 to 5 and Comparative Examples 1 to 4

[0134] In Examples 1 to 5 and Comparative Examples 1 to 4, the liquid crystal polyester (A) solution, polymer (B) and an appropriate amount of aprotic solvent prepared in the above synthesis examples are mixed, stirred and degassed to obtain a liquid composition. The formulations and evaluation results of the liquid crystal polyester (A) and polymer (B) used in Examples 1 to 5 and Comparative Examples 1 to 4 are shown in Table 3.

[0135] [Evaluation method]

[0136] Production of insulated wire

[0137] After the liquid composition was directly applied to the outer circumference of a copper conductor having a diameter of 1.0 mm through a die, the copper conductor was passed through a cylindrical baking furnace at a constant linear speed for heating to form an insulating layer on the outer circumference of the copper conductor.

[0138] In the baking oven, the copper conductor is heated in an environment of 300°C or above for 15 seconds. The above steps are repeated to form a 30 mm thick film on the outer peripheral side of the copper conductor. μ m insulation layer.

[0139] Flexibility

[0140] The insulated wire was wound around a round rod with a diameter of 1.0 mm, and the wires were wound in close contact with each other. The number of windings at which cracks appeared on the insulation layer was used as the evaluation method, and the evaluation was performed according to the following criteria.

[0141] ◎: Number of windings ≥ 15

[0142] ○: 10≤Number of winding turns<15

[0143] △: 7≤Number of winding turns<10

[0144] ×: Number of winding turns <7

[0145] Coating properties

[0146] The outer diameter of the obtained insulated wire is measured using a laser outer diameter measuring machine. The thickness of the insulating layer itself is obtained by subtracting the diameter of the copper conductor itself from the measured outer diameter value. Next, the film thickness uniformity D of the insulating layer is calculated using the following formula (1), and D is used as a method for evaluating the coating property. The smaller the D, the worse the coating property.

[0147] D=(D max -D min )×100% / (D avg ×2) Formula (1)

[0148] In formula (1), D max Indicates the maximum thickness of the insulation layer, D min Indicates the minimum thickness of the insulation layer, D avg Indicates the average thickness of the insulation layer.

[0149] ◎:D≤3%

[0150] ○: 3% <D≤5%

[0151] △: 5% <D≤7%

[0152] ×: D>7%

[0153] Table 1

[0154]

[0155] a1-1 6-Hydroxy-2-naphthoic acid

[0156] a1-2 Para-hydroxybenzoic acid

[0157] a1-3 m-Hydroxybenzoic acid

[0158] a2-1 Terephthalic acid

[0159] a2-2 Isophthalic acid

[0160] a2-3 2,6-naphthalene dicarboxylic acid

[0161] a3-1 3-Hydroxyacetaniline

[0162] a3-2 4-Hydroxyacetaniline

[0163] a3-3 3-aminophenol

[0164] a3-4 4-aminophenol

[0165] a3-5 4-amino-4′-hydroxybiphenyl a4-1 4,4'-biphenylene glycol

[0166] a4-2 4,4'-dihydroxydiphenyl ether

[0167] a4-3 4,4'-dihydroxydiphenylmethane

[0168] a4-4 Hydroquinone

[0169] Table 2

[0170]

[0171] b1-1-1-p-phenylene-bis(triphenylene) ester tetracarboxylic dianhydride

[0172] b1-1-2 Ethylene-bis(triphenylene) ester tetracarboxylic dianhydride

[0173] b1-1-3 (4-phthalic anhydride) methyloxy-4-phthalic acid ester

[0174] b1-2-1 Pyromellitic dianhydride

[0175] b2-1-1 p-aminobenzoic acid p-aminophenyl ester

[0176] b2-1-2 Bis(p-aminophenyl) terephthalate

[0177] b2-1-3[4-(4-aminobenzyl)oxyphenyl]4-aminobenzoate

[0178] b2-2-2 p-phenylenediamine

[0179] Table 3

[0180]

[0181] The above results show that if the aromatic diol (a4) is not added during the synthesis of the liquid crystal polyester (A), the obtained liquid composition has poor flexibility and coating properties when used for insulating wires.

[0182] If the aromatic amine (a3) ​​having a phenolic hydroxyl group is not added during the synthesis of the liquid crystal polyester (A), the coating properties of the obtained liquid composition when used for an insulated wire are poor.

[0183] Furthermore, the liquid composition without using the polymer (B) has poor flexibility after being coated on an insulated wire.

[0184] If the ester-containing tetracarboxylic dianhydride (b1-1) or the ester-containing diamine (b2-1) is not used in the synthesis of the polymer (B), the liquid crystal polyester (A) and the polymer (B) have poor compatibility, resulting in poor coating properties of the liquid composition.

[0185] Secondly, when the liquid crystal polyester (A) prepared using the aromatic diol (a4) with a specific structure is used to form a liquid composition, the flexibility is better when it is used for insulating wires.

[0186] If a liquid composition formed by using a polymer (B) obtained from an ester-containing tetracarboxylic dianhydride (b1-1) and an ester-containing diamine (b2-1) and a liquid crystal polyester (A) is used, its coating property on the insulated wire is better.

[0187] Although the present invention uses specific compounds, compositions, reaction conditions, processes, analysis methods or specific instruments as examples to explain the insulated wire and its manufacturing method, coil and electronic device of the present invention, anyone with ordinary knowledge in the technical field to which the present invention belongs will understand that the present invention is not limited to these. Without departing from the spirit and scope of the present invention, the insulated wire and its manufacturing method, coil and electronic device of the present invention may also be carried out using other compounds, compositions, reaction conditions, processes, analysis methods or instruments.

[0188] Although the present invention has been disclosed as above with several embodiments, they are not intended to limit the present invention. Anyone with ordinary knowledge in the technical field to which the present invention belongs can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the scope of the attached patent application.

Claims

1. An insulated wire, characterized in that: Include: Conductors; and an insulating layer, laminated on the outer peripheral side of the conductor, wherein the insulating layer comprises a liquid crystal polyester (A) and a polymer (B), The liquid crystal polyester (A) is obtained by reacting a first mixture, wherein the first mixture includes an aromatic hydroxycarboxylic acid (a1), an aromatic dicarboxylic acid (a2), an aromatic amine having a phenolic hydroxyl group (a3) ​​and an aromatic diol (a4); The polymer (B) is selected from at least one of the group consisting of a polyimide precursor and an imidized polymer of the polyimide precursor, and the polymer (B) is obtained by reacting a second mixture, the second mixture comprises a tetracarboxylic dianhydride component (b1) and a diamine component (b2), and the polymer (B) comprises an ester structure.

2. The insulated wire according to claim 1, wherein: The liquid crystal polyester (A) comprises at least one of the structural units of the following formula (a1'), formula (a2'), formula (a3') and formula (a4'), -O-Ar 1 -CO- (a1') -CO-Ar 2 -CO- (a2') <h2 style=";text-align:left;direction:ltr">-NH-Ar<h2 style=";text-align:left;direction:ltr"> 3 <h2 style=";text-align:left;direction:ltr"> -O- (a3') -O-Ar 3 -O- (a4') In formula (a1'), Ar 1 represents a phenylene group, a naphthylene group or a biphenylene group; In formula (a2'), Ar 2 represents a phenylene group, a naphthylene group, a biphenylene group, or a group formed by condensation of a plurality of aromatic groups; and In formula (a3') and formula (a4'), Ar 3 It represents a phenylene group or a group formed by condensation of a plurality of aromatic groups.

3. The insulated wire according to claim 2, wherein: The compound having the formula (a3') contains an aromatic hydroxyamide.

4. The insulated wire according to claim 1, wherein: The tetracarboxylic dianhydride component (b1) includes an ester group-containing tetracarboxylic dianhydride (b1-1).

5. The insulated wire according to claim 1, wherein: The diamine component (b2) includes an ester group-containing diamine (b2-1).

6. The insulated wire according to claim 1, wherein: Based on a total amount of the liquid crystal polyester (A) and the polymer (B) being 100 wt %, the content of the polymer (B) is 20 wt % to 90 wt %.

7. The insulated wire according to claim 1, wherein: The aromatic diol (a4) is at least one compound selected from the group consisting of compounds including the following structural units.

8. A method for manufacturing an insulated wire, characterized in that: To obtain the insulated wire as claimed in any one of claims 1 to 7, wherein the manufacturing method of the insulated wire comprises: a coating step of coating a liquid composition on the outer peripheral side of the conductor, wherein the liquid composition comprises the liquid crystal polyester (A), the polymer (B) and a solvent; and The heating step heats the conductor coated with the liquid composition.

9. A coil, characterized in that: The insulated wire according to any one of claims 1 to 7 is included.

10. An electronic device, characterized in that: The invention comprises the coil as claimed in claim 9.

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