JP2001204095A - Heat resistant voice coil and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a voice coil with high resistance to heat. SOLUTION: Adhesive paint obtained by blending and disolving three components of an alcohol soluble polyamide resin, an alcohol soluble alicyclic solid epoxy resin obtained by adding an epoxy group to a cyclohexane skeleton and an alcohol soluble resol type phenol resin with a methylol group into an alcoholic solvent, is used. This adhesive paint is applied to an insulated electric wire and a bobbin, baked into a semi-curing state to manufacture a self-bonding insulating electric wire and a pre-coated bobbin. A cylindrical bobbin is formed by the pre-coated bobbin, the self-bonding insulating electric wire is wound on the bobbin while applying an alcoholic solvent to the electric wire to manufacture a voice coil semifinished product where inter-coil-wires and the coil and the bobbin are adhered by swelling or dissolving the adhesive paint and the adhesive paint is completely cured by applying heat to the semifinished product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voice coil used for audio equipment, a vehicle-mounted speaker, and the like, and more particularly to a voice coil excellent in heat resistance and a method of manufacturing the same.

[0002]

2. Description of the Related Art A voice coil of a speaker is formed by rolling a bobbin material into a cylindrical shape to form a bobbin, then arranging and winding tightly insulated wires in a plurality of layers to form a coil, and bonding the coil and the bobbin with an adhesive. It has an integrated structure. Conventionally, in order to efficiently manufacture such a voice coil, a self-fusing insulated wire having an adhesive layer provided on an insulated wire and a pre-coated bobbin material having an adhesive layer provided on a bobbin material have conventionally been used. Is used. As the bobbin material, aluminum thin plate, polyimide film, aromatic polyamide nonwoven fabric,
A glass cloth base polyimide-impregnated laminated sheet or the like is used.

Conventionally, when manufacturing a voice coil,
A cylindrical bobbin is formed from a pre-coated bobbin material, and a self-fusing insulated wire is wound on the coil while applying an organic solvent (alcohol-based) thereon, thereby forming a coil in which the adhesive layer is swollen or dissolved, Thereafter, a heat treatment was performed to bond and integrate the coil lines and the coil and the bobbin.

As the organic solvent used for winding the coil, an alcoholic solvent such as methanol or ethanol having a low boiling point has been used in consideration of workability and environmental resistance. For this reason, the main component of the adhesive coating constituting the adhesive layer must swell or dissolve in an alcohol-based solvent. For this reason, an alcohol-soluble polyamide resin has been widely used for the adhesive coating. However, since this material is an aliphatic thermoplastic resin, and its thermally usable range is as low as 140 to 150 ° C., measures have been taken to improve heat resistance.

[0005] In recent years, in the field of audio equipment and in-vehicle speakers, there has been a demand for a voice coil capable of withstanding heat load with improved performance, miniaturization and higher output. Therefore, attempts have been made to improve the heat softening temperature by adding various curing components to an alcohol-soluble polyamide resin which is a main component of the adhesive. For example, the adhesive paint used for the voice coil of an in-vehicle speaker is composed of a novolak type epoxy resin or bismaleimide resin as a hardening component and an amino resin or the like as a hardening catalyst to improve the heat softening temperature of the main component and to improve heat resistance. Attempts have been made to improve the operability, but no voice coil has yet been developed that satisfies the three conditions of high output, small size and high heat resistance required for in-vehicle speakers.

[0006]

The adhesive coating used for the conventional heat-resistant voice coil is composed of an alcohol-soluble polyamide resin as a main component, a novolac epoxy resin as a hardening component,
A bismaleimide resin is blended as a heat-resistance imparting component, and an amino resin is blended as a curing catalyst, and these are dissolved in an organic solvent. Conventionally, this adhesive paint is applied to an electric wire and a bobbin material and baked to form a semi-cured adhesive layer, thereby producing a self-fusing insulated electric wire and a precoated bobbin material.

When manufacturing a voice coil,
Forming a cylindrical bobbin with the pre-coated bobbin material, coil winding the self-fusing insulated wire on it while applying an alcohol-based solvent, thereby swelling or dissolving the semi-cured adhesive paint, A method has been adopted in which the wire between the coils and the coil and the bobbin are adhered to each other, and then a heat treatment is performed to complete the curing of the adhesive paint.

However, in the above adhesive coating, the novolak type epoxy resin blended as a curing component is not dissolved in an alcohol-based low-boiling solvent and is not compatible with the alcohol-soluble polyamide resin as a main component, so that the heat-softening of the main component is carried out. The required amount to raise the temperature could not be added, and as a result, the function as a curing component could not be sufficiently exhibited.
In addition, the bismaleimide resin added as a heat resistance-imparting component could not be dissolved in an alcohol-based solvent without separating the main component, the curing component, and the curing catalyst into layers, and the number of parts added was limited. Therefore, it has been difficult to significantly improve the heat resistance and to produce a voice coil having high output and high heat resistance.

[0009]

A speaker is an electro-acoustic converter for converting an electric signal into an acoustic signal. 95% of the electric power of the electric signal is converted to heat and is used for heating the voice coil. Therefore, the smaller the size and the higher the output, the more the heat radiation of the voice coil is suppressed, and the amount of heat generation increases.
It is not uncommon to reach temperatures as high as 400 ° C. Usually, the initial destruction due to the heat generation of the voice coil is such that first, the coil is separated from each other, and then the adhesive between the coil and the bobbin is broken.

When observing the thermal destruction phenomena between the lines of the voice coil and between the coil and the bobbin, the initial stage of the thermal destruction is as follows: (1) The coil portion of the voice coil generates heat and adheres due to the difference in thermal expansion between the coil and the bobbin material. Strain occurs at the interface. (2) The voice coil vibrates, and the heat generated softens the adhesive layer between the coil lines and the adhesive interface between the coil and bobbin, causing "shift". In the case of, the coil falls off the bobbin. When a voice current of an electric signal flows through the voice coil, the conductor of the coil generates heat, and the adhesive layer forming the coil is exposed to a high temperature. This heat generation phenomenon cannot be avoided due to the current speaker structure.

The bonding layer for bonding the components of the voice coil is made of an organic material, is thermally weak, and has a maximum usable temperature of:
In general, the limit is 200 ° C, and momentarily 300 to 350
C is the limit. At 300 to 350 ° C, thermal decomposition of the adhesive layer starts and carbonization is observed. Against this background, the speaker industry has demanded the development of a voice coil having a small size, high output, and high heat resistance. For that purpose, it is necessary to develop an adhesive paint that can withstand high temperatures.

It is necessary that the newly developed adhesive coating for voice coils not only be able to withstand high temperatures, but also be able to efficiently manufacture voice coils without impairing coil winding workability. Therefore, the main component of the adhesive paint must be alcohol-soluble, and the materials that can be used are limited.

According to the results of intensive studies based on various experiments, the composition of the adhesive coating material satisfying the above conditions shows that an alcohol-soluble polyamide resin is used as a matrix component, and a cured material that forms an interpenetrating three-dimensional network structure with the matrix component. It has been found that a combination of three components is effective, in which an alcohol-soluble alicyclic solid epoxy resin is blended as a component, and an alcohol-soluble resol-type phenol resin having a methylol group that reacts with the curing component is further blended.

All three components are dissolved in an alcohol solvent and have good compatibility. The adhesive layer obtained by baking the three-component adhesive paint on the insulated wire and the bobbin material in a semi-cured state does not stick at room temperature and has mechanical strength enough to withstand coil winding. Further, it has been found that this adhesive layer easily swells and dissolves in an alcohol-based solvent and exhibits solvent reactivation. After winding the coil, at a temperature of 180-200 ° C
The heat treatment for 30 to 40 minutes easily transferred to a completely cured state, and it was confirmed that a voice coil having good heat resistance can be manufactured.

The present invention has been made based on the results of such studies. That is, the heat-resistant voice coil according to the present invention is a voice coil formed by winding a self-fusing insulated wire on a bobbin and bonding and integrating the wire between the coils and the coil and the bobbin. The adhesive layer that bonds between the epoxy resin and the bobbin reacts with the epoxy group of the alcohol-soluble alicyclic solid epoxy resin in which the epoxy group is added to the terminal group of the alcohol-soluble polyamide resin and the cyclohexane skeleton to form an interpenetrating three-dimensional network structure. And formed by reacting an epoxy group of the alicyclic solid epoxy resin with a methylol group of an alcohol-soluble resol type phenol resin.

Further, the method for producing a heat-resistant voice coil according to the present invention comprises an alcohol-soluble polyamide resin, an alcohol-soluble alicyclic solid epoxy resin having an epoxy group added to a cyclohexane skeleton, and an alcohol-soluble resol type phenol resin having a methylol group. A self-fusing insulated wire in which a thermosetting adhesive paint obtained by mixing and dissolving the three components in an alcohol-based solvent is applied to an insulated wire having a heat-resistant insulating film or a bare wire having no insulating film and baked in a semi-cured state. And, using a pre-coated bobbin material which is obtained by applying the thermosetting adhesive paint on the surface of a sheet-shaped bobbin material and baked in a semi-cured state, forming a cylindrical bobbin with the pre-coated bobbin material, The self-fusing insulated wire is wound around a coil while applying an alcohol-based solvent to swell or dissolve the adhesive paint. Is allowed to produce a voice coil blank adhered between the lines of the coils and between the coils and the bobbin, it is characterized in that thereafter curing said adhesive coating is subjected to heat treatment in the semi-finished product.

The alcohol-soluble polyamide resin which is a matrix component of the adhesive coating used in the present invention is specifically composed of three components of caprolactam, hexamethylenediammonium adipate and p.p'-diaminodicyclohexylmethandiammonium adipate. It is a copolyamide resin. More specifically, Ultramid-IC (trade name of BSF Japan) can be used.

The curing component forming an interpenetrating three-dimensional network structure with the polyamide resin of the matrix component used in the present invention is an alcohol-soluble alicyclic solid epoxy resin,
The required properties are (1) alcohol-soluble polyamide resin, which is a matrix component of the adhesive layer, and IPN structure (Inte
rpenetrating Polymer Network System (interpenetrating three-dimensional network structure); (2) soluble in methanol, ethanol or a mixed solvent that dissolves matrix components, and compatible with matrix components; 3) It is compatible with the alcohol-soluble resole type phenol resin having a methylol group which is a heat resistance imparting component, and both are cured under common heat curing conditions (at a curing temperature of 180 to 200 ° C. for 30 to 40 minutes), (4) The matrix component, the curing component, and the heat resistance-imparting component are methanol,
It is dissolved in ethanol or a mixed solvent thereof, a mixed solvent of benzyl alcohol and methanol, or a mixed solvent of cresylic acid and methanol, and does not undergo layer separation, does not gel at room temperature, and has good storage stability. is there.

The bisphenol A type and novolak type epoxy resins do not satisfy the characteristics (2) and (4) among the above (1) to (4) and are not suitable as a curing component. Similar to the alcohol-soluble polyamide resin as the matrix component, as a result of intensive studies on a curing component which is soluble in an alcohol-based solvent and forms an interpenetrating three-dimensional network structure with the matrix component, the alicycle having the chemical structure shown in the following chemical formula 2 It has been found that the solid epoxy resin of the formula is the only solid epoxy resin soluble in methanol, ethanol or a mixed solvent thereof, and has good compatibility with the alcohol-soluble polyamide resin as a matrix component.

[0020]

Embedded image

The reason why the alcohol-soluble resol type phenol resin having a methylol group is used in combination as a heat-resistance-imparting component is that the terminal group (amide group or carboxyl group) of the alcohol-soluble polyamide resin of the matrix component is
It reacts with the epoxy group of the alcohol-soluble alicyclic solid epoxy resin as the curing component to form an interpenetrating three-dimensional network structure in which trifunctional epoxy molecules intrude into the main chain of the polyamide resin, and at the same time, unreacted epoxy groups The terminal methylol group of the alcohol-soluble resole type phenolic resin reacts, and the resole type phenolic resin having a methylol group added in excess causes a self-condensation reaction to create a stronger curing system, as a heat resistance imparting component. This is because it is effective.

The chemical structure of the alcohol-soluble alicyclic epoxy resin used in the present invention is represented by the following chemical formula:
A structure in which an epoxy group is added to a cyclohexane skeleton, specifically, EHPE-3150 (trade name of Daicel Chemical Industries, Ltd.), which can be cured with an amine compound, an acid anhydride, an imidazole compound, or the like. it can. The cured product of the alicyclic solid epoxy resin has a higher glass transition point than glycidyl ether type and novolak type epoxy resins, and by increasing the curing temperature, it is possible to produce a cured product having a higher glass transition temperature. . Particularly, the feature of this compound is that it is the only solid epoxy resin having an epoxy group and can be dissolved in a low-boiling alcohol solvent such as methanol or ethanol.

The resole type phenol resin having a methylol group used in the present invention is generally a reaction product of phenol and formalin at a temperature of 80 to 100 ° C. in the presence of a basic catalyst.
It is obtained by reacting for 1.5 to 3.0 hours. Specifically, PL-2105 (trade name of Gunei Chemical Industry Co., Ltd.) or the like can be used.

The heat-resistant adhesive coating used in the present invention comprises an alcohol-soluble polyamide resin (matrix component), an alcohol-soluble alicyclic solid epoxy resin (curing component),
It is obtained by dissolving three components of an alcohol-soluble resole type phenol resin having a methylol group (a heat-resistance-imparting component) with a mixed solvent of methanol and m-cresol or the like to form a coating. This adhesive coating is applied to an insulated wire having a heat-resistant insulating film (or a bare wire having no insulating film) and a bobbin material, and the adhesive layer baked in a semi-cured state does not stick,
It has mechanical strength, withstands the tension applied when winding the coil and the friction of the pulley surface of the winding machine, and easily swells and dissolves in methanol, ethanol or a mixed solvent of these, exhibits solvent reactivation, and adheres. A semi-finished voice coil product that exerts power and is bonded between coil wires and between a coil and a bobbin can be obtained.

In this semi-finished product, since the adhesive layer is in a semi-cured state, if the adhesive layer is subjected to a heat treatment at a temperature of 180 to 200 ° C. for 30 to 40 minutes, the adhesive layer is completely cured, and the coil and the bobbin are integrated. Become a voice coil with excellent characteristics.

The curing step will be described in detail. By applying an alcohol-based solvent, the adhesive layer in a semi-cured state swells and dissolves, the adhesive interface disappears, and at the same time as the alcohol-based solvent evaporates, a continuous adhesive layer is formed. The resulting voice coil semi-finished product is obtained. By heating this semi-finished product, the terminal groups (amino group, carboxyl group) of the alcohol-soluble polyamide resin react with the epoxy group added to the cyclohexane skeleton of the alicyclic solid epoxy resin, and the alcohol-soluble polyamide resin To form an interpenetrating three-dimensional network in which trifunctional epoxy molecules are entangled with each other. Thereafter, the methylol group of the resole type phenol resin reacts with the unreacted epoxy group of the curing component, and the excess unreacted heat-resistance imparting component causes a self-condensation reaction to form a stronger adhesive layer, Improve the performance.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail. In order to determine the preferred compounding ratio of the curing component and the heat-resistance-imparting component to the alcohol-soluble polyamide resin as the matrix component, adhesive coatings having the compounding ratios of four groups A, B, C, and D shown in Table 1 were produced.

[0028]

[Table 1]

The matrix components used were caprolactam, hexamethylene diammonium adipate, p.
Alcohol-soluble polyamide resin composed of three components of p'-dicyclohexylmethanediammonium adipate (Ultramid-I manufactured by BSF Japan)
C), and the curing component is an alcohol-soluble alicyclic solid epoxy resin (EHPE-3150 of Daicel Chemical Industries)
Wherein the heat-resistance imparting component is an alcohol-soluble resol-type phenol resin (PL-2105 of Gunei Chemical Industry).

Further, in order to determine the minimum and maximum amounts of the heat-resistance imparting component and the curing component constituting the adhesive paint, Table 2 was used.
Was prepared.

[0031]

[Table 2]

(1) Production of Adhesive Coating Material The three components were weighed so as to have the mixing ratios shown in Tables 1 and 2, and a mixed solvent of methanol and m-cresol (mixing ratio 50:50).
Was added, and the mixture was heated to 60 to 65 ° C. in a separable four-necked flask and stirred and dissolved for 3 hours to produce an adhesive paint.

(2) Manufacture of self-fusing insulated wire Using an ordinary baked wire manufacturing apparatus, apply the adhesive paint manufactured in (1) on an insulating film of a polyester insulated copper wire having a conductor diameter of 0.18 mmφ2, It was baked and dried in a semi-cured state to produce a self-fusing insulated wire.

(3) Production of precoated bobbin material An adhesive paint having a compounding ratio of D4 in Table 1 was applied to an aluminum thin plate and baked and dried in a semi-cured state to produce a precoated bobbin material.

(4) Manufacture of voice coil A cylindrical bobbin is formed from the precoated bobbin material manufactured in (3), and a methanol solvent is applied to the surface of the bobbin.
The self-fusing insulated wire manufactured in (2) is aligned and wound tightly in two layers while applying a methanol solvent to the surface to swell and dissolve the adhesive layer in a semi-cured state. Was manufactured. Thereafter, the semi-finished product was placed in a drying furnace and subjected to a heat curing treatment at 200 ° C. for 40 minutes to produce a voice coil in which the coil wire and the coil and the bobbin were bonded.

(5) Measurement of Adhesive Force Between Coil Lines of Voice Coil A cylindrical coil jig having bearings embedded at both ends is inserted into a bobbin of the voice coil, and the voice coil is supported so that it can rotate without friction. This was set in a chamber of a tensile tester equipped with a thermostat, and the force required to peel the wire between the first and second layers of the coil was increased to room temperature, 150 ° C, and 200 ° C.
The measurement was performed at each temperature atmosphere of ° C. A strain gauge strain gauge was used for the measurement, and the results were recorded on a pen recorder. Table 3 shows the adhesive force between the coil wires of the voice coil using the adhesive paint having the compounding ratio shown in Table 1. The measured value is the average of 10 points.

[0037]

[Table 3]

(6) Evaluation of General Properties of Self-fusing Insulated Wire and Adhesive Paint Table 4 shows the general properties of the adhesive paint having the compounding ratio shown in Table 2 and the self-fusing insulated wire using the same.

[0039]

[Table 4]

Table 4 shows that the adhesive layer had cracks and bobbin tackiness.
Comprehensively judging the stability of the adhesive layer, F2 to F5, G
3, G5, and D4 were evaluated as usable as self-fusing insulated wires, and the bond strength between coil wires of the voice coil was measured. Table 5 shows the results.

[0041]

[Table 5]

The coil wire strength shown in Table 5 was obtained by a simple measuring method used for measuring the coil wire strength of the voice coil. The measuring method is as follows. After winding the coil, the outermost wire loop of the heat-cured voice coil is unwound for 5 turns, hung in a constant temperature bath with the winding jig (weight 43 g) attached, and heated from room temperature to 250 ° C at a heating rate of 7 ° C. The temperature is raised at a rate of ° C / min. When the temperature reaches 250 ° C, the temperature is maintained for 15 minutes. After the elapse of 15 minutes, the coil is taken out of the thermostat and the length at which the coil ends are peeled off is measured and expressed in cm. It is. It is determined that the shorter the peeled length of the coil end is, the higher the heat resistant adhesive strength is.

As described above, from the measurement results in Tables 3 to 5, as for the addition amount of the curing component to the matrix component, the higher the addition amount, the higher the heat-resistant adhesive strength, and the smaller the addition amount, the more easily the bobbin sticking occurs. Further, the heat resistant adhesive strength does not change linearly with an increase in the amount of the hardening component added, but there is an optimum amount of the hardening component to be added. In addition, as the amount of the heat-resistance-imparting component added to the matrix component increases, the heat-resistant adhesive strength increases as the amount increases, but the adhesive layer becomes hard and the flexibility is impaired, so that cracks are easily generated in the adhesive layer.

From the above experimental results, it is found that the addition number of the alcohol-soluble alicyclic solid epoxy resin as a curing component is 20 to 100 parts by weight of the alcohol-soluble polyamide resin.
Preferably it is 90 parts by weight. If the amount is less than 20 parts by weight, the adhesive layer sticks and bobbin sticking occurs. If the amount exceeds 90 parts by weight, the adhesive strength between the coil wires, particularly the adhesive strength between the wires when heated at 200 ° C., tends to decrease.

An alcohol-soluble resole type phenol resin having a methylol group which is a heat-resistance-imparting component,
It is preferable that the number of parts added is in the range of 95 to 200 parts by weight based on 100 parts by weight of the alcohol-soluble polyamide resin.
If the amount is less than 95 parts by weight, the heat resistance of the adhesive strength between the coil wires is reduced. On the other hand, if it exceeds 200 parts by weight, the adhesive layer loses flexibility and cracks occur in the adhesive layer when processed into a self-fusing insulated wire.

According to the above examination results, the preferred compounding ratio of the three components is 100 parts by weight of the alcohol-soluble polyamide resin and 20 parts by weight of the alcohol-soluble alicyclic solid epoxy resin.
To 90 parts by weight, and 95 to 200 parts by weight of an alcohol-soluble resol type phenol resin. In particular, considering the production efficiency and the like, the mixing ratio of the three components, which is considered most preferable, is 50 to 60 parts by weight of the alcohol-soluble alicyclic solid epoxy resin and 100 to 100 parts by weight of the alcohol-soluble polyamide resin,
150150 parts by weight. Table 6 shows the typical compounding ratio.

[0047]

[Table 6]

The three components having the above mixing ratio were dissolved in a methanol solvent as described above to produce an adhesive coating having a concentration of 30%. This adhesive paint is applied on the insulation film of two types of polyester insulated wire with conductor diameter of 0.18mmφ and baked in a semi-cured state,
A self-fusing insulated wire was manufactured. Table 7 shows the general characteristics of the obtained self-fusing insulated wire.

[0049]

[Table 7]

Separately, an adhesive paint having the compounding ratio shown in Table 6 was applied to an aluminum thin plate, baked and dried in a semi-cured state to produce a precoated bobbin material. Using the precoated bobbin material and the self-fusing insulated wire shown in Table 7, a voice coil was manufactured by the method described above. The adhesive strength between wires of the obtained voice coil was measured by a simple heat resistance measurement method. Table 8 shows the results.

[0051]

[Table 8]

The voice coils of Examples 1 and 2 having the adhesive strength between the coil wires shown in Table 8 were mounted on a speaker, and the input power was increased by 5 W every 5 minutes, and the temperature and input wattage until the voice coil was destroyed. The number was measured, and the heat resistance of the voice coil was evaluated. For comparison, a voice coil using a commercially available SV wire as a self-fusing insulated wire for a heat-resistant voice coil was manufactured (Comparative Example 1).
The same evaluation test was performed. Table 9 shows the results.

[0053]

[Table 9]

According to the results of the input resistance test of the voice coil shown in Table 9, in Example 1, the maximum input at which three samples normally operate was 190 W, the coil temperature was 377 to 395 ° C., and the input was 195. Two samples are broken by W. Similarly, it can be seen that Example 2 withstands a maximum input of 175 W and a coil temperature of 370 to 374 ° C. This is the maximum input of Comparative Example 1
W indicates that the heat resistance is significantly improved as compared with the coil temperature of 336 to 349 ° C.

[0055]

As described above, according to the present invention, an alcohol-soluble polyamide resin is used as a matrix component, an alcohol-soluble alicyclic solid epoxy resin is used as a curing component, and an alcohol having a methylol group is used as a heat-resistance-imparting component. A self-fusing insulated wire and a pre-coated bobbin material, which are applied to an insulated wire and bobbin material and baked in a semi-cured state by using an adhesive paint consisting of three components to which a soluble resol type phenol resin is added, is used for coil winding. And the adhesive layer is swollen and dissolved with an alcohol-based solvent to obtain a semi-finished voice coil product in which the coil wires and the coil and the bobbin are well bonded. Furthermore, by performing heat treatment after coil winding, an interpenetrating three-dimensional network structure is formed in which the alcohol-soluble alicyclic solid epoxy resin molecules of the curing component are entangled with the main chain of the alcohol-soluble polyamide resin of the matrix component. At the same time, the unreacted epoxy group of this curing component reacts via the methylol group of the alcohol-soluble resol-type phenol resin having a methylol group to form a stronger curing system,
A voice coil with significantly improved heat resistance can be obtained. Therefore, it can greatly contribute to miniaturization and high output of the speaker.

Claims (6)

[Claims] 1. A voice coil formed by winding a self-fusing insulated wire on a bobbin and bonding and bonding between the coil and between the coil and the bobbin. The adhesive layer reacts with the terminal group of the alcohol-soluble polyamide resin and the epoxy group of the alcohol-soluble alicyclic solid epoxy resin having an epoxy group added to the cyclohexane skeleton to form an interpenetrating three-dimensional network structure; A heat-resistant voice coil comprising a reaction product of an epoxy group of a cyclic solid epoxy resin and a methylol group of an alcohol-soluble resole type phenol resin. 2. An alcohol-soluble polyamide resin, an alcohol-soluble alicyclic solid epoxy resin having an epoxy group added to a cyclohexane skeleton, and an alcohol-soluble resol-type phenol resin having a methylol group are mixed and dissolved in an alcohol-based solvent. A thermosetting adhesive paint is applied to an insulated wire having a heat-resistant insulating film or a bare wire having no insulating film, and baked in a semi-cured state. Applying a thermosetting adhesive paint and using a pre-coated bobbin material baked in a semi-cured state, forming a cylindrical bobbin with the pre-coated bobbin material, and forming the self-fusing insulated wire on the alcohol-based Winding the coil while applying a solvent, swelling or dissolving the adhesive paint to make contact between the coil wire and the coil and bobbin. The voice coil semifinished product manufacture, subsequent manufacturing process of the heat-resistant voice coil, characterized in that curing the adhesive coating is subjected to heat treatment in the semi-finished product. 3. The method for producing a heat-resistant voice coil according to claim 2, wherein the alcohol-soluble alicyclic solid epoxy resin comprises one represented by the following general formula (1). Embedded image 4. An alcohol-soluble polyamide resin comprising three components of caprolactam, hexamethylenediammonium adipate and p.p'-dicyclohexylmethanediammonium adipate.
Or the manufacturing method of the heat-resistant voice coil of 3. 5. An adhesive paint comprising 20 to 90 parts by weight of an alcohol-soluble alicyclic solid epoxy resin and 95 to 200 parts by weight of an alcohol-soluble resole type phenol resin with respect to 100 parts by weight of an alcohol-soluble polyamide resin. The method for manufacturing a heat-resistant voice coil according to claim 2. 6. An adhesive paint comprising 50 to 60 parts by weight of an alcohol-soluble alicyclic solid epoxy resin and 140 to 150 parts by weight of an alcohol-soluble resol type phenol resin with respect to 100 parts by weight of an alcohol-soluble polyamide resin. The method for manufacturing a heat-resistant voice coil according to claim 2.