JPS60243172A - Self-fusible insulated wire and coil thereof - Google Patents

Abstract

PURPOSE:The titled electric wires that are produced by coating electroconductive wires with a polyhydroxy ether which composed of specific structural units, thus being suitable for use in deflecting yoke coils for motors, because it has good fluidity, lowers costs and shows little deformation after processing. CONSTITUTION:(A) A compound having 2 epoxy groups in the molecule and (B) another compound having 2 phenolic hydroxyls in the molecule, of which at least one has a structural unit of formula I, are allowed to react to give a coating mainly consisting of (C) polyhydroxy ether. The resulting coating is coated directly or after primer coating, on electroconductive wires, the coating is heat- cured, preferably further, electric current is passed through the wires for fusing to give the objective coils. The compound containing the structure of formula I is preferably used more than 25wt% and the compound of component A is that of formula II and component B is that of formula III or IV.

Description

Detailed Description of the Invention (Technical Field) The present invention relates to a self-bonding insulated wire that has a self-bonding function to an enameled wire used in motors, transformers, magnetic coils, etc., and a product manufactured therefrom. It concerns the coil.

(Prior art and its problems) Conventionally, coil molded bodies for electrical equipment, communication equipment, etc. have been made by winding insulated wires into a predetermined shape and then applying varnish treatment to bond and solidify the wires. However, recently, self-bonding insulated wires, which can fuse and solidify wires by heating or solvent treatment alone, are being used instead of impregnated varnish treatment.

Self-bonding insulated wire has a self-bonding layer mainly made of thermoplastic material on the insulating layer of enamelled wire, and is heated or treated with a solvent after or while winding the wire into a coil. As a result, the wires are bonded to each other and a coil is obtained, so that the impregnating varnish treatment can be omitted, and the following advantages are brought to the user.

■There is no need to worry about pollution or safety and health caused by using impregnated varnish.

■The coil molding cycle is faster, as exemplified by electrical heating, and manufacturing costs are reduced because no impregnating varnish is used.

■It is possible to solidify items with complex coil shapes and items that cannot be penetrated by impregnated varnish.

For this reason, there is a growing demand for self-bonding insulated wires, and there is a desire to develop materials with various characteristics to suit the process and usage conditions of customers. In particular, the deflection yoke coils used in televisions and the like have a special shape and strict dimensional accuracy, so customers have placed many demands on winding manufacturers.

A few years ago, we focused on increasing the deflection angle so that the heating deformation of the coil is small, that it has adhesive strength even at high temperatures (for example, around 130 degrees Celsius), and that the fluidity of self-fusing materials during heat treatment by energization during coil manufacturing is improved. In response to demands for better performance, winding wire manufacturers have responded by changing the self-bonding material from polyvinyl butyral to copolymerized nylon.

Recently, with the development of computers and the like, higher precision CRTs have been required, and deflection yoke coils that are less deformable than those of the past have become necessary. Current copolymerized nylon-based self-bonding materials have strong adhesion strength at high temperatures. Although it is a material with good fluidity, the material itself is soft. For this reason, when a deflection yoke coil is manufactured using a copolymerized nylon-based self-fusing insulated wire, there is a drawback that the coil is slightly deformed due to the spring pack force of the coil after the deflection yoke coil is manufactured. Current high precision CRT
The above-mentioned deformation poses a problem in response to this requirement.

On the other hand, self-bonding insulated wires using phenoxy as a self-bonding material are known, and if a deflection yoke coil is made using this, a coil with little deformation can be obtained. However, phenoxy has poor fluidity as a material during heat treatment, so compared to copolymerized nylon-based materials, it requires a larger current to fuse when energized, and unless the energization time is lengthened, the coils cannot fully adhere to each other between the wires. I can't get it. Therefore, a larger amount of thermal energy is required than when conventional copolymerized nylon is used, increasing the manufacturing cost of the coil.

Furthermore, there were also disadvantages in that passing a large current for a long period of time caused thermal deterioration of the insulating layer and short circuits between the wires.

As a result of intensive studies to eliminate these drawbacks, the inventors of the present invention have found that it is possible to manufacture a deflection yoke coil that has good fluidity similar to conventional copolymerized nylon systems and that has minimal deformation after molding. discovered a self-bonding insulated wire,
This has led to the present invention.

BACKGROUND OF THE INVENTION Recently, electrical equipment has become smaller and smaller, requiring higher reliability and lower manufacturing costs.

The self-fusing insulated wire of the present invention has materials that are easy to fuse together,
It has excellent deformation resistance and hardness after fusion bonding, and is fully applicable not only to deflection yoke coils but also to other coils.

(Structure of the Invention) The present invention relates to a compound having two epoxy groups in the molecule (A
In polyhydroxyethers obtained by reacting a compound having two phenolic OH groups in the molecule (component B), a structural unit represented by the following chemical formula in at least one of component A and component B. A self-fusing insulated wire obtained by applying and baking a paint containing polyhydroxyethers as a main component onto a conductor directly or through another insulator, and a coil obtained using the same. It is something.

In the present invention, polyhydroxyether molecules obtained by reacting a compound having two epoxy groups in the molecule (component A) and a compound having two phenolic OH groups in the molecule (component B) are used. Chemical formula -■-CH in the structure
It is important to include 2-■-. Phenoxy, which is currently used as a self-fusing material in polyhydroxyethers, has the repeating structural unit shown below.

On the other hand, in the present invention, the chemical formula -■- is included in the molecular structure.
When CH2-■- is introduced to produce a polyhydroxyether having a repeating structural unit represented by the following chemical formula, for example, the fluidity of the material improves by the amount of the reduced CH3 group, making it easier to fuse. (If there is a CH3 group, the rotation of the main chain skeleton will be impaired due to steric hindrance, resulting in poor fluidity.) However, since the aromatic density remains unchanged, the hardness of the material, which is an excellent property of phenoxy, and the Its deformation resistance is not much different from that of phenoxy, and it is an excellent self-bonding material, making it particularly suitable for use in deflection yoke coils.

In the present invention, the method for introducing the structural unit represented by the chemical formula -■-CH2-〇- into polyhydroxyether is
■Compound with two epoxy groups in the molecule (component A)
(1) Introducing it as at least one component into a compound having two phenol groups and OH groups in its molecule (component B); or, of course, introducing it into both.

A typical compound having two epoxy groups in the molecule (component A) containing a structural unit represented by the chemical formula -〇-CH2-■- has the following general formula (n is an integer from 0 to 1O). → For example, Dainippon Ink & Chemicals Co., Ltd. (trade name: Ebicuron 830, Kasei Kasei Co., Ltd. (trade name: Epoto)), YDF
There are -170, 190, etc.

On the other hand, there is methane which has two phenolic OH groups in its molecule.

In the present invention, the compound containing the structural unit represented by the chemical formula -CH2-■- is preferably used in an amount of 25% by weight or more based on the obtained polyhydroxyether λ.

This is because if the amount is less than 25% by weight, the effect of improving the fluidity of the polyhydroxyether obtained will be small, and the effect will not be sufficiently exhibited in the case of heat fusing by electricity.

Among compounds having two epoxy groups in the molecule (component A), those that do not contain a structural unit represented by the chemical formula -〇-CH2-(E)- have the following general formula (1) (n is 0 to 0). 1
It is preferable to use an epoxy compound represented by (an integer up to 0) from the viewpoint of raw material cost and ease of acquisition.

Specifically, Shell Chemical Co., Ltd. trade name Epicote #828.
834, 1001, 1004, 100? Dow Chemical Company product name aERaao, 331.382, ssq,
557.660.661.662.664 Ciba Geigi Co., Ltd. Product name Araldite 6004.6005゜6010.
6020, 6030, 6040, 6060.6071.
6075.6084 Dainippon Ink Chemical Industry Co., Ltd. Product name Ebikuron 840° 850.860, 1050, 3050,
4.050 Tsukuto Kaseisha product name Evotote YD-128,
There are 134,011,018,014, etc.

Of the A components used in the present invention), the chemical formula -σCH2
Examples of compounds that do not contain the structural unit represented by -0- include compounds in which part of the hydrogen in the benzene nucleus of the epoxy compound represented by the above general formula 0) is replaced with bromine, such as Dainippon Ink Chemical Co., Ltd.'s trade name Eviclon. 152.1120. Tobu Kasei Co., Ltd. Product name: YDB-340, 400, 500, 70
Compound 1, which is a cyclohexane ring obtained by hydrogenating the benzene nucleus of an epoxy compound represented by 0 or the above general formula (1), for example, Taihei Nippon Ink Chemical Industry Co., Ltd. trade name Evicron 750
．． Santoto 1000.3000 (trade name, manufactured by Tobu Kasei Co., Ltd.), DER732 (trade name, Dow Chemical Co., Ltd., which is dieboxide of polypropylene glycol), and Diepoxide (trade name, Epicote #871, manufactured by Shell Chemical Co., Ltd., which is dieboxide of linole dimer acid) having a urethane bond. Of course, it is also possible to use a compound such as Epu 6.10.15 manufactured by Asahi Denka Co., Ltd.

As a compound which does not contain a structural unit having two phenolic OH groups in its molecule, it is preferable to use chemical formula (enyl)propane from the viewpoint of raw material cost and ease of labor.

Examples of those containing no structural unit include those represented by the general formula, and more specifically, 1.2-bis(4-hydroxyphenyl)ethane, 4.4'-dihydroxydiphenylsulfone, 4.4'- Dihydroxydiphenyl ether, 2.2-bis(4-hy,troxy-3.5-dibromophenyl)furopane, 2.2-bis(4-hydroxy-3-bromophenyl)propa7.4.4-(α-methylbenzylidene) ) Diphenols, etc.

There are also hydroquinone, which has the general formula HO-(E)-OH, in which the OH group is in the para position, resorcinol in the meta position, and catechol in which the OH group is in the ortho position. Of course, these compounds may be substituted with an alkyl group, an alkenyl group, a halogen, or the like.

Furthermore, dihydroxynaphthalene and the like can also be used as other compounds having two phenolic OH groups in the molecule.

In the present invention, a mpholyhydroxy ether containing a structural unit represented by 1-CH2-■- is blended with a phenoxy resin, and the compound containing a structural unit represented by 1-CH2-■- accounts for 25% by weight of the entire polymer. Of course, it is also possible to use it in this way.

The polyhydroxy ethers referred to in the present invention are 2 in the molecule.
A compound having two phenolic OH groups (component B) and a diepoxide obtained from a compound having two phenolic OH groups in the molecule (component A) are mixed in a solvent or without a solvent in the presence of a basic catalyst. It is obtained by reaction.

The reaction is between the epoxy group of component A and the phenolic O of component B.
The reaction is carried out in the absence of a solvent or in the following solvent at an equivalent ratio with respect to H group in the range of 0.95 to 1.05, more preferably in the range of 0.98 to 1.02.

As reaction solvents, acetic acid 74solp, phenylcellosolve, 7losolve, calpitol, methylcarpitol,
Real glycol ethers represented by butyl carpitol, ketones such as methyl isobutyl ketone, cyclohexanone, acetophenone, benzophenone, aldehydes such as furfural, nitrites such as acetonitrile, phenylacetonitrile, propane dinitrile, benzonitrile, nitrobenzene, Examples include nitro compounds such as 1-chloro-2-nitrobenzene, 1-chloro-3-nitrobenzene, sulfoxides such as dimethyl sulfoxide, and sulfones such as Schifta tetramethylene sulfone.

However, it goes without saying that those that react with epoxy groups or phenolic OH groups or those that cause side reactions are not suitable.

As a reaction catalyst, sodium phenoxide, 2.2-
Alkali metal phenoxides such as monosodium salt of bis(4-hydroxyphenyl)furopane and monosodium salt of di'-dihydroxydiphenylsulfone, alkali metal alkoxides such as sodium methoxide and sodium ethoxide, sodium hydride, and sodium polyhydride. metal hydrides such as triethylamine, n-propylamine, 1so-propylamine, -
n-butylamine, tert-butylamine, n-hexylamine, n-octylamine, cyclohexylamine, guanidine, guanidine derivative, methylamine, methylamine derivative, ethylamine, ethylamine derivative, piperidine, piperidine derivative pyrrolidone, N-methylpyrrolidone, morpholine , triethylenediamine,
hexamethylenediamine, pyridine, imidazoles,
1.8-diazabicyclo(5,4,0) undecene-
7, or 1,8-diazabicyclo(5,
4,0) Undecane-7 phenol salt, 2-ethylhexanoate, oleate, etc. can be mentioned. The catalyst is 0.01 to 10% relative to bisphenols.
It is used in a range of 0 molar percentage, preferably 0.02 to 5 molar percentage.

The reaction temperature is preferably between 80° C. and 200° C., but may be outside this range, and if necessary, the solution reaction can be carried out under pressure at a temperature higher than the boiling point of the solvent.

The degree of polymerization of the polymer is 0.5 g/d6 in m-cresol.
The reduced specific viscosity [ηsp/c) measured at a concentration of 0.2 to
It is desirable that it be 1.0'd 17g. If the reduced specific viscosity is less than 0.2, it will have poor flexibility when used as an electric wire.
．． If it is 0 or more, fluidity will be poor during fusion, resulting in poor fusion properties.

If you want to obtain a highly concentrated paint due to regulations on discharged organic solvents for environmental protection or for economic reasons, the degree of polymerization should be kept relatively low, and when equivalent amounts of epoxy groups and phenolic OH groups are present, it can be used as is or at any time. If one of them is in excess, add the compound represented by the above chemical formula and a compound having two phenolic OH groups in the molecule as a paint so that the epoxy group and the phenolic OH group are equivalent. It would also be possible to achieve a high degree of polymerization by adding it to the inside and continuing the reaction during coating and baking during the manufacture of electric wires.

Next, paints containing polyhydroxyethers as a main component of the present invention include polyether sulfone resin, polysulfone resin, phenoxy resin, polycarbonate resin, polyphenylene oxide resin, polystyrene resin, polyurethane resin, polyamide resin, polyester resin, and polyvinyl formal. It is also possible to add resins, silicone resins, phenolic resins, melamine resins, urea resins, etc. to the extent that they do not adversely affect the fluidity of the material, and are used as plasticizers.

It is possible to improve the wire characteristics to some extent by adding appropriate amounts of one or more of silicone, low molecular weight polyethylene, surfactants, pigments, dyes, organic and inorganic fillers, etc., and this is also within the scope of the present invention. It is something that can be done.

When producing the paint containing polyhydroxyethers as the main component of the present invention, the above-mentioned reaction solvents can be used as the solvent and dispersant for the paint components, and in addition, m-cresol, N, N-
Dimethylformamide, N-methylpyrrolidone, methylethylketone, xylene, naphtha, etc. can also be used to adjust solubility and viscosity.

The paint can be used at any concentration, but a range of 5% to 95% is preferred, and a range of 205% 2e to 8096 is more effectively used.

The present paint is formed into a film directly on the conductor or via another insulator to produce the self-bonding insulated wire of the present invention.

The method for forming the film is to apply a solution or molten paint onto the wire, adjust the film thickness with a die, felt, etc.1, bake in a baking oven,
Alternatively, a film may be formed and dried in a coagulation system, or, if a solvent is not included, simply coated with a molten paint and then cooled.

The method for fusing the self-fusing insulated wire of the present invention is preferably fusing by heating, and is fusing by heating by applying a special current to a coil that requires hardness after fusing. Great effect when used with deflection yoke coils.

EXAMPLES Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to the following examples. The reduced specific viscosity (ηsp/c) in the following examples is calculated by adding m-cresol to the obtained polyhydric ether solution of the present invention.
．． It was diluted to a concentration of 5g resin/100ml solvent and measured at 80°C.

[Example 1] Dainippon Ink & Chemicals Co., Ltd. trade name Ebicuron 880 (hereinafter abbreviated as Ebicuron 880. Poxy equivalent: 173) 178
．． 0g, bisphenol A (2,2-bis(4-hydroxydiphenyl)propane, reagent-grade molecular weight 228.3
) 1141 g, ) So n-butylamine (mix and dissolve in a round bottom flask with a reagent tube, then adjust the temperature to 150°C
The temperature was raised to 100 mL and reacted for 10 hours. After the reaction was completed, heating was stopped and 400 g of DM was added to obtain a yellowish-brown transparent solution with a resin content of 8,096. The reduced specific viscosity (ηsp/c) of this resin is 0.4
It was 2. Next, in an enameled wire baking furnace, apply H-type polyesterimide (trade name: Isomitsu LV, manufactured by Schenectady Co., Ltd.) 7 times to the copper wire with a diameter of 0.5 m, and apply this resin solution 3 times under the baking conditions of polyesterimide insulating paint. A self-bonding insulated wire was obtained.

The wire characteristics of the self-bonding insulated wire of this example are shown in Table IK.

[Example 2] Evicron 880 173.0g, bisphenol F (
Bis(4-hydroxyphenyl)methane, molecular weight 200
．． 2) 100.1g, )so n-butylamine 46
After reacting with 273 g of gDM in the same manner as in Example 1, 364 g of DM was added to obtain a yellow-brown transparent solution with a resin content of 3096. The reduced specific viscosity (ηsp/c) of this resin is 0.
It was 39. Subsequently, a self-bonding insulated wire was obtained in the same manner as in Example 1.

Table 1 shows the wire characteristics of the self-bonding insulated wire of this example.

[Example 3] Epoxy resin trade name Epicote #828 manufactured by Shell Chemical Co., Ltd.
(Epoxy equivalent, 8%, 100.1 g of nephrol F
, tri-n-butylamide 74.6g, DM286
After reacting with g in the same manner as in Example 1, DM381
g was added to obtain a yellow-brown transparent solution with a resin content of 3096. The reduced specific viscosity (ηsp/c) of this resin was 086. Subsequently, a self-bonding insulated wire was obtained in the same manner as in Example 1.

Table 1 shows the wire characteristics of the self-bonding insulated wire of this example.

[Example 4] Evicron 83086.5g, Epicote #82893
．． 0g.

After reacting 114.1 g of bisphenol A, 46 g of n-butylamine, and 294 g of DM in the same manner as in Example 1, 390 g of pM was added, and the resin content was 3096 g.
A black transparent solution was obtained. Reduced specific viscosity of this resin (ηsp/
c) was 0.44. Subsequently, a self-bonding insulated wire was obtained in the same manner as in Example 1.

Table 1 shows the wire characteristics of the self-bonding insulated wire of this example.

[Comparative Example 1] 300 g of phenoxy resin (Union Carbide Co., Ltd. trade name: Phenoxy DKHH average molecular weight of approximately 40,000) was added to DM700.
A pale yellow transparent solution with a resin content of 80% was obtained.

Subsequently, a self-bonding insulated wire was obtained in the same manner as in Example 1.

Table 1 shows the wire characteristics of the self-bonding insulated wire of this comparative example.

[Comparative Example 2] 12-6 copolyamide (1) having a reduced specific viscosity (ηsp/c) of 1.71 (weight composition ratio of 12-nylon component and 6-nylon component constituting the copolyamide) (8=2, the same applies hereafter) 240gr and the reduced specific viscosity is 1.
24, 12-6-6.6 (weight composition ratio 1:1:1)
160g of copolymerized polyamide (n) was mixed with a mixed solvent of phenol and m-cresol (2:8 by weight).
The polymer solution obtained by heating at 170"CX for 5 hours in 1200gr was diluted with 750gr Kijirol to obtain a uniform transparent paint with a concentration of 1796 and a viscosity (measured with a B-type viscometer, at 80°C, hereinafter the same) of 1640cps. .

Subsequently, a self-bonding insulated wire was obtained in the same manner as in Example 1. Table 1 shows the wire characteristics of the self-bonding insulated wire of this comparative example.

[Example 5] The self-bonding insulated wires obtained in Examples 1 to 4 and Comparative Examples 1 to 2 were tightly wound around a mandrel with a diameter of 5.0 mm and placed in a constant temperature oven at a predetermined temperature under a load of 125 gr. The sample was left for 20 minutes in
Measured based on 19.

Table 2 shows the relationship between the fusing temperature and the adhesion strength of the self-fusing insulated wires of each Example and Comparative Example.

Table 2 Relationship between fusing temperature and adhesion strength of self-fusing insulated wire [
Example 6] The self-bonding insulated wires obtained in Examples 1 to 4 and Comparative Examples 1 to 2 were wound tightly around a mandrel with a diameter of 5.0 mm for 175 turns to obtain a constant IOA under a load of 125 gr. A current was applied for a predetermined period of time to heat the sample.

The coil obtained by heating was used as a sample, and the adhesion force was measured according to ASTM-
Measured based on D2519. Table 3 shows the relationship between the current application time and the adhesion strength of the self-bonding insulated wires of each Example and Comparative Example.

Table 3 Relationship between energizing seconds and fusing strength of self-fusing insulated wires [
Example 7] Films of the self-adhesive paints obtained in Examples 1 to 4 and Comparative Examples 1 to 2 were produced by baking them in a constant temperature bath at 200°C for 2 hours.

The elastic modulus and temperature characteristics of the films of each Example and Comparative Example were measured at a frequency of 11 Hz using a dynamic viscoelasticity measuring device (Pyblon) manufactured by Toyo Baldwin. Table 4 shows the obtained elastic modulus temperature characteristics.

Table 4 Elastic modulus temperature characteristics of self-fusing insulated wires (unit of elastic modulus d Y n/cm [Example 8] Self-fusing insulated wires produced in Examples 1 to 4 and Comparative Examples 1 to 2) A deflection yoke coil was manufactured by winding a coil using a deflection yoke coil winding machine.The resulting deflection yoke coil was placed on a smooth plate, and the gap (△ h: removal deformation) was measured.The results are shown in Table 5.

Figure 1 shows the fabricated deflection yoke coil. a,
b, c are 40mm, 90mm, 60mm respectively
It was the size of

Table 5. Deformation of the deflection yoke coil (effects of the invention) From Table 2.3, the self-bonding insulated wire of the present invention is phenoxy,
It can be seen that it can be fused at a lower temperature than the copolymerized nylon type, and can be electrically fused in approximately the same amount of time as the copolymerized nylon type. Also, as shown in Table 4, it is harder than copolymerized nylon from room temperature to 90°C, and is almost as hard as phenoxy from room temperature to 70°C. When a deflection yoke coil is actually manufactured, as shown in Table 1, the amount of deformation of the coil is smaller than that of the current copolymerized nylon-based coil. Therefore, the self-fusing insulated wire of the present invention is suitable for use in deflection yoke coils with little deformation used in high-precision CRTs.

Naturally, it can be applied to other coils manufactured by heat fusion, and its industrial value as a new self-bonding insulated wire is great.

[Brief explanation of drawings]

1 and 2 show a deflection yoke coil according to the present invention. Figure 1 shows an outline of the deflection yoke coil. In this coil, a, b, and c in the figure are 40 mm and 90 m, respectively.
The size is 60a+m. FIG. 2 illustrates the amount of deformation (Δh) taken out. 1. Deflection yoke coil, 2. Smooth Board Patent Attorney Satoshi Tsukasa

Claims (9)

[Claims] (1) In polyhydroxyethers obtained by reacting a compound having two epoxy groups in the molecule (component A) and a compound having two phenolic OH groups in the molecule (component B), A A paint containing polyhydroxyethers as a main component, characterized by using a compound having a structural unit represented by the following chemical formula % in at least one of the component and B component, is applied directly onto the conductor or other insulating material. Self-bonding insulated wire made by coating and baking a material. (2) Chemical formula in A component and B component -〇-CH2-(E)
2. The self-bonding insulated wire according to claim 1, wherein the f-arsenic metal containing the structural unit represented by - is used in an amount of 25% by weight or more based on the obtained polyhydroxyether. (3) The self-fusing insulated wire according to claim 1, wherein the component A contains a compound having a structural unit represented by the chemical formula -CH2-■-. (4) The compound having the structural position represented by the chemical formula −〇= CH2=O− in component A has the following chemical formula (n is 0 to IO
The self-bonding insulated wire according to claim 3, which is a compound represented by the following integers up to . (5) The self-fusing insulated wire according to claim 4, wherein component B is a compound represented by the following chemical formula. (6) The self-fusing insulated wire according to claim 4, wherein component B is a compound represented by the following chemical formula (% formula %). (7) The self-fusing insulated wire according to claim 1, wherein component B contains a compound having a structural unit represented by the chemical formula -()-CIi2-0-. (8) A patent claim in which the compound having a structural unit represented by the chemical formula -(E)-CH2-■- in component B is a compound represented by the following chemical formula HO-(E)-CH2-(E)-OH. Self-bonding insulated wire according to scope 7. (9) The self-bonding insulated wire according to claim 8, wherein component A is a compound represented by the following chemical formula (n is an integer from 0 to 10). Q (the epoxy group of the IIA component and the phenolic O of the B component)
The equivalent ratio with H group is in the range of 0.95 to 1.05, and the degree of polymerization of the polyhydroxyether obtained by the reaction is 0.2 to 1, odff/g in reduced specific viscosity. The self-bonding insulated wire according to item 1. (In polyhydroxyethers obtained by reacting a compound having two epoxy groups in the molecule (component A) and a compound having two phenolic OH groups in the molecule (component B), component A and B A paint mainly composed of polyhydroxyethers, characterized by using a compound having a structural unit represented by the chemical formula % below as at least one of its components, is applied directly onto the conductor or through another insulator. A coil manufactured by heat fusion using a self-fusing insulated wire that is coated and baked. (Coil according to claim 11 manufactured by heat fusion by applying 14 current.) Claim 1 which is a coil
The coil described in item 2.