JP3485950B2 - Multilayer insulated wire and method of manufacturing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-layer insulated wire having three or more insulating layers and a method for producing the same. More specifically, the insulating layers are appropriately peeled from each other, and when immersed in a solder bath. Since the insulating layer can be removed in a short time and solder can be attached to the conductor, it has excellent soldering characteristics.
The insulation characteristics of the insulation layer do not easily deteriorate over time, and
The present invention relates to a multilayer insulated electric wire which has excellent coil processability and is useful as a winding wire or a lead wire of a transformer incorporated in an electric / electronic device, etc.

[0002]

2. Description of the Related Art The structure of a transformer is based on the IEC standard (Internat
ional Electrotechnical Communication Standard) Pu
b. 950,65,335,601 etc. That is, in these standards, the enamel coating that covers the conductor in the winding is not recognized as an insulating layer, and at least three insulating layers are formed between the primary winding and the secondary winding, or it thickness is 0.4mm or more, along plane distance of the primary and secondary windings also differ by an applied voltage, it is 5mm or more, the primary side and the secondary side 300
It is specified that the device withstands 1 minute or more when 0V is applied.

For this reason, in the transformers that currently occupy the mainstream seat, the cross-sectional structure illustrated in FIG. 1 is adopted. That is, the bobbin 2 with the collar on the ferrite core 1
Is fitted, after the primary winding 4 which is enamelled is wound in a state in which an insulating barrier 3 is arranged to ensure along surface distance on the peripheral surface side end of the bobbin 2, the primary winding 4
Over, turning at least three layers wound insulating tape 5, further After disposing an insulating barrier 3 for securing along surface distance on the insulating tape layer, likewise enamelled secondary winding 6 is wound It is a rotated structure.

By the way, in recent years, as shown in FIG. 2, a transformer having no insulating barrier 3 or insulating tape layer 5 has begun to appear in place of the transformer having the sectional structure shown in FIG. Compared with the transformer of the structure of FIG. 1, this transformer is
It has the advantages that the entire device can be downsized and that the work of winding the insulating tape can be omitted.

In the case of manufacturing the transformer shown in FIG. 2, in the primary winding 4 and the secondary winding 6 used, at least three insulating layers 4b (on the outer circumference of one or both conductors 4a (6a)). 6b), 4c (6c), and 4d (6d) are formed, and it is necessary that the insulating layers can be separated from each other in relation to the IEC standard.

In such a winding, first, an insulating tape is wound around the outer periphery of a conductor to form a first insulating layer, and then an insulating tape is wound on the second insulating layer, It is known that a third insulating layer is sequentially formed to form an insulating layer having a three-layer structure in which layers are separated from each other (Actual Kaihei 3-1.
No. 06626). Further, there is known a winding in which a fluorine-based resin is sequentially extrusion-coated on the outer circumference of a conductor which is enamel-coated with polyurethane, and an extrusion-coated layer having a three-layer structure is used as an insulating layer as a whole (Actual Publication No. 3-56112). Issue).

[0007]

However, in the case of the former winding, since the winding work of the insulating tape is unavoidable, the production becomes remarkably low, which causes a problem that the manufacturing cost rises. In addition, the latter winding has the advantage that it has good heat resistance because the insulating layer is made of fluorine-based resin, but on the other hand, the adhesion between layers is poor, so it has a high reliability as an insulated wire. There is a problem of lack of sex.

That is, when the insulated wire is coiled, the insulated wire is wound around the coil bobbin while being guided by the guide nozzle. At this time, the insulated wire rubs against the guide nozzle and the insulating layer is peeled off from the conductor. A situation in which the layers of the respective insulating layers are separated easily occurs.
When the electric wire is wound around the coil bobbin in such a state, the insulating layer is broken due to rubbing between the wound insulated electric wires. In such a state, the electrical characteristics of the coil, for example, dielectric breakdown characteristics will be impaired.

Further, in the case of this insulating layer, it cannot be removed even by immersing it in a solder bath.
There is a problem that the insulating layer of the terminal has to be peeled off by a mechanical means with low reliability. In order to solve such a problem, polyethylene terephthalate (PET) resin, which has excellent electric insulation and heat resistance and is easily decomposed at the melting temperature of the solder, is extrusion-coated on the outer periphery of the conductor to form an insulating layer. Is being considered.

However, this PET resin exhibits its original heat resistance and mechanical properties only after being crystallized under appropriate orientation conditions, and when it is coated by extrusion, it has a high crystallinity. Cannot be obtained, and there is still room for improvement in the withstand voltage characteristics over time. Further, in the case of an electric wire in which all of the three insulating layers are formed of the PET resin, there is room for improvement in the insulation characteristics of the coil obtained by coiling the electric wire.

This problem is due to the PE formed as an insulating layer.
Due to the high friction coefficient of the surface of the T-based resin layer, the outermost layer is rubbed against each other due to the action of the winding tension applied to the electric wire during coil processing, and damage such as cracks easily occurs there. Since it is also made of PET resin, it has relatively good adhesion, and it is considered that cracks and the like generated in the outermost layer are likely to spread to the lower insulating layer due to the notch effect.

The present invention solves the above-mentioned problems in the three-layer insulated wire in which the insulating layer is made of PET resin, and the peelability between the insulating layers is appropriate, and the above IEC standard is satisfied. In addition, the deterioration of the electrical insulation of the insulating layer over time is smaller than that of conventional wires, and because the coil workability is even better, the insulation characteristics, etc. are not impaired during coil processing and reliability is improved. and an object thereof is to provide a multi-layer insulated wire and a manufacturing method thereof are excellent.

[0013]

In order to achieve the above-mentioned object, in the present invention, in a multi-layer insulated wire comprising a conductor and three or more insulating layers covering the conductor, 1 The second and second insulating layers contain (a) 5 to 40 parts by weight of an ethylene-based copolymer having a carboxylic acid or a metal salt of a carboxylic acid in a side chain with respect to 100 parts by weight of a thermoplastic linear polyester resin. Extrusion coating layer (hereinafter referred to as extrusion coating layer a) of a blended resin mixture, (b) Thermoplastic straight line formed by combining an alcohol component and a acid component, all or part of which is cyclohexanedimethanol Extruded coating layer containing a chain polyester resin as a main component (hereinafter referred to as extruded coating layer b), (c) Formed by combining an alcohol component and a acid component which are wholly or partially cyclohexanedimethanol An extruded coating layer of a resin mixture (hereinafter referred to as "50 parts by weight or less" of an ethylene-based copolymer having a carboxylic acid or a metal salt of a carboxylic acid in a side chain is blended with 100 parts by weight of the thermoplastic linear polyester resin , Extruded coating layer c), and when the insulating layers are formed, the lower extruded coating layer is formed.
At the time of completion, the surface of the extrusion coating layer is 100 ° C or lower.
After cooling, the multilayer insulated wire, wherein Rukoto upper layer of extruded covering layer has been formed is provided.

Further, in the present invention, 3 is formed on the surface of the conductor.
In the method for producing a multilayer insulated wire in which an insulating layer of at least one layer is formed by extrusion coating, at the time when the extrusion coating of a predetermined layer is completed,
There is provided a method for producing a multilayer insulated wire, which comprises performing an operation of cooling the surface of the extrusion coating layer to 100 ° C. or lower. Furthermore, in the present invention, the above-mentioned multilayer insulated wire is used.
Wind the first winding around the bobbin and
A transformer with at least a second winding wound on the side is provided
It In the multilayer insulated wire of the present invention, the first and second insulating layers from the conductor side are both extruded coating layer a and extruded coating layer b.
Alternatively, it may be formed of one kind selected from the extrusion coating layer c, but may be formed of another kind.

In this case, the extruded coating layer a as the first and second insulating layers is an insulated electric wire having particularly excellent soldering characteristics (hereinafter referred to as the first electric wire). . In addition, when the first and second insulating layers are the extruded coating layer b or the extruded coating layer c, it becomes an insulated electric wire having excellent heat resistance (hereinafter, referred to as a second electric wire). In the first electric wire and the second electric wire, the resin or resin mixture forming the first insulating layer and the second insulating layer may have different component compositions.

Further, in the first and second insulating layers,
One layer is an extrusion coating layer a and the other layer is an extrusion coating layer b.
Alternatively, when the extruded coating layer c is used, the resulting multilayer insulated wire has a well-balanced soldering property and heat resistance. The resin mixture constituting the extrusion coating layer a contains a thermoplastic linear polyester resin and an ethylene copolymer, which will be described later, as essential components.

Among them, as the thermoplastic linear polyester resin , an aromatic dicarboxylic acid which is an acid component or a dicarboxylic acid in which a part thereof is substituted with an aliphatic dicarboxylic acid and an aliphatic diol which is an aliphatic alcohol component are used. What was obtained by the ester reaction of is used. Representative examples include polyethylene terephthalate resin (PET), polybutylene terephthalate resin (PBT), and polyethylene naphthalate resin.

Examples of the aromatic dicarboxylic acid used in the synthesis of the thermoplastic linear polyester resin include terephthalic acid, isophthalic acid, terephthaldicarboxylic acid, diphenylsulfonedicarboxylic acid, diphenoxyethanedicarboxylic acid, diphenylethercarboxylic acid, methylterephthalate. Acid, methyl isophthalic acid, etc. can be mentioned. Of these, terephthalic acid is particularly preferable.

Examples of the aliphatic dicarboxylic acid that partially replaces the aromatic dicarboxylic acid include succinic acid, adipic acid, sebacic acid and the like. The amount of substitution of these aliphatic dicarboxylic acids is the same as that of aromatic dicarboxylic acids.
It is preferably less than 0 mol%, particularly 20 mol%.
It is preferably less than. On the other hand, examples of the aliphatic diol used in the ester reaction include ethylene glycol, trimethylene glycol, tetramethylene glycol, hexanediol and decanediol. Of these, ethylene glycol and tetramethyl glycol are preferable. Moreover, as the aliphatic diol, a part thereof may be oxyglycol such as polyethylene glycol or polytetramethylene glycol.

The other essential component of the resin mixture constituting the extrusion coating layer a is, for example, an ethylene copolymer in which a side chain of polyethylene is bound with a carboxylic acid or a metal salt of a carboxylic acid. This ethylene-based copolymer functions to suppress crystallization of the thermoplastic linear polyester resin described above, thereby suppressing deterioration of the electrical characteristics of the formed insulating layer over time, and This contributes to ensuring good peelability between the second insulating layers.

Examples of the carboxylic acid bonded to the side chain of polyethylene include unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid and crotonic acid, maleic acid,
Unsaturated dicarboxylic acids such as fumaric acid and phthalic acid can be mentioned, and examples of these metal salts include Zn, N
Salts such as a, K, and Mg can be used. As such an ethylene-based copolymer, for example, a part of the carboxylic acid of the ethylene-methacrylic acid copolymer is made into a metal salt, and a resin generally called an ionomer (for example, Himilan; trade name, Mitsui Polychemical Co., Ltd. )), An ethylene-acrylic acid copolymer (for example, EAA; trade name, manufactured by Dow Chemical Co., Ltd.), an ethylene-based graft polymer having a carboxylic acid in a side chain (for example, Admer; trade name, Mitsui Petrochemical Industry ( Co., Ltd.).

In this resin mixture, the blending ratio of the thermoplastic linear polyester resin and the ethylene copolymer is
The latter is set in a range of 5 to 40 parts by weight with respect to the former 100 parts by weight. When the compounding amount of the latter is less than 5 parts by weight, there is no problem in heat resistance of the formed insulating layer, but the effect of suppressing crystallization of the thermoplastic linear polyester resin becomes small, and therefore the insulating layer of the insulating layer is not formed during coil processing. The so-called crazing phenomenon in which minute cracks occur on the surface frequently occurs. Further, the deterioration of the insulating layer with time progresses, causing a significant decrease in the dielectric breakdown voltage. On the other hand, the compounding amount is 40
When the amount is more than the weight part, the heat resistance of the insulating layer is significantly deteriorated. The preferable mixing ratio of both is 100 parts by weight of the former and 7 to 25 parts by weight of the latter.

Next, the material constituting the extrusion coating layer b is
All or part of the alicyclic alcohol component and the acid component are combined.
It is a thermoplastic linear polyester resin formed by the combination. Among them preferred are heat formed by condensing all or a portion starve Kurohe <br/> Kisanjimetano Le an acid component
A thermoplastic linear polyester resin, specifically, poly cyclohexane dimethylene terephthalate resin (PC
T) can be raised. This resin is PET
It has better heat resistance than

Considering suppression of a decrease in dielectric breakdown voltage due to deterioration of the insulating layer with time, examples of the modified resin include polyamide resin, polycarbonate resin,
The polyurethane resin, it is preferable to blend 10 to 100 parts by weight per 100 parts by weight of the thermoplastic linear polyester resin. As such a PCT resin,
For example, EKTAR-DN, EKTAR-DA, EKT
AR-GN (trade name, manufactured by Toray Industries, Inc.) can be preferably used.

The resin mixture constituting the extrusion coating layer c is, for example,
For example, it is a resin mixture of the above-mentioned PCT resin and an ethylene copolymer which is an essential material in the resin mixture used for forming the extrusion coating layer a. In this resin mixture,
The mixing ratio of the PCT resin and the ethylene copolymer is set to 50 parts by weight or less with respect to 100 parts by weight of the former.

If the amount of the latter compounded is more than 50 parts by weight, the excellent heat resistance of the PCT resin will be deteriorated and the heat resistance of the formed insulating layer will be problematic. The preferable blending ratio of both is 5 to 30 parts by weight of the latter with respect to 100 parts by weight of the former. The third insulating layer in the multilayer insulated wire of the present invention is formed of a thermoplastic polyamide resin or a resin mixture containing the thermoplastic polyamide resin as a main component. The third insulating layer has a relatively small friction coefficient on the surface and is excellent in mechanical strength, so that damage such as cracks in the outermost layer during coil processing of the electric wire can be minimized. . In addition, since the adhesiveness to the second insulating layer (polyester resin layer) is low, even if the outermost layer is damaged, the damage is prevented from spreading to the second insulating layer. As a result, it is possible to prevent deterioration of the insulation characteristics after the coil processing.

Further, the third insulating layer is used in the case where the amount of the polyethylene-based copolymer compounded at the time of forming the extrusion coating layer a or the extrusion coating layer c is small, or in the extrusion coating layer b or the extrusion coating layer c. It also acts to mitigate the deterioration with time of the dielectric breakdown voltage that tends to occur when the amount of the resin used , for example, the alicyclic alcohol component used when manufacturing the PCT-based resin , such as cyclohexanedimethanol is small. .

As the thermoplastic polyamide resin, for example, 4-nylon, 6-nylon, 10-nylon, 1
1-nylon, 12-nylon, 4,6-nylon,
Examples thereof include 6,6-nylon, 6,10-nylon, 6,12-nylon, and copolymerized nylon thereof (all are trade names manufactured by DuPont). Especially,
4,6-Nylon is preferable because it has excellent heat resistance.

In addition, for example, in these polyamide resins,
One or more of ethylene-methacrylic acid copolymer, ethylene-acrylic acid copolymer, polyethylene, the above-mentioned thermoplastic linear polyester resin, polyurethane resin and polycarbonate resin may be mixed. In this case, the mixing ratio is preferably 3 to 50 parts by weight with respect to 100 parts by weight of the polyamide resin.

In the electric wire of the present invention, the first and second insulating layers are both PCT-based in which the alicyclic alcohol component, especially cyclohexanedimethanol is substituted by 60 mol% or more. It is made of a resin mixture in which 20 parts by weight or less of a polyethylene copolymer having a Zn salt of a carboxylic acid in a side chain is mixed with 100 parts by weight of a resin, and a third insulating layer is made of 4,6-nylon. These are useful because they can improve the heat resistance class of electric wires from the class E (120 ° C) level to the class B (130 ° C) level.

In the multilayer insulated wire of the present invention, the outer periphery of the conductor is extrusion-coated with the resin or resin mixture for the first layer to form the first insulating layer having a desired thickness, and then the first layer. A resin or resin mixture for the second layer is extrusion-coated on the outer periphery of the insulating layer to form a second insulating layer having a desired thickness.
It is manufactured by extrusion-coating the outer periphery of the third insulating layer with a polyamide resin for the third layer to form the third insulating layer having a desired thickness.

At this time, the resin mixture used for the extrusion coating of the first layer and the second layer may have the same composition for each layer, or the components may be mixed within the above-mentioned permissible compounding ratio. The composition may be changed. The total thickness of the three insulating layers formed is 100 μm.
It is preferable to control the thickness below, and if the thickness of the second insulating layer is twice or more the thickness of the thicker one of the other insulating layers, the electrical characteristics specified by IEC standard 950 can be easily realized. can do.

Furthermore, when forming each extrusion coating layer forming the insulating layer, the surface of the extrusion coating layer is formed by a method such as water cooling or air cooling when the extrusion coating of the lower layer is completed.
It is effective to form the upper extrusion coating layer after cooling to 00 ° C. or lower, since the peelability between the upper and lower extrusion coating layers is improved. This cooling operation is particularly preferably performed at the time when the extrusion coating of the first layer is completed.

In the multi-layer insulated wire of the present invention, since all three or more insulating layers are formed by the extrusion coating method of the resin mixture, the productivity at the time of production becomes very high. Further, the delamination property is good, and at the time of processing the terminal, direct soldering can be performed. The first layer, the second insulating layer, poly <br/> ester trees crystallization of fat PCT resins as the base resin is suppressed, therefore, the deterioration of such electric properties of the insulating layer very Hard to happen.

Furthermore, since the outermost layer of the multi-layer insulated wire of the present invention is formed of polyamide resin or a resin mixture containing it as a main component, the coefficient of friction of the outer surface is small, and therefore the outermost layer during coil processing is used. Damage to the outer layer is suppressed. Further, deterioration with time of the first layer and the second layer is also alleviated. The multilayer insulated wire described above has the structure of a transformer.
Good electrical characteristics specified by IEC standard 950
It is possible to realize it with excellent coil workability. Therefore
When the multi-layer insulated wire is used in a transformer,
Insulation tape between windings and insulation to ensure edge distance
Obtaining a transformer with excellent coil workability without the need for edge barriers
be able to.

[0036]

EXAMPLES Example 1 and Comparative Examples 1 to 11 The components shown in Table 1 were kneaded at the indicated proportions (parts by weight) to prepare resin blends for each extrusion coating layer. An annealed copper wire having a wire diameter of 0.6 mm is prepared as a conductor, and the outer periphery thereof is extrusion-coated with the above resin mixture to form a first-layer extrusion coating layer with the indicated thickness, and then a second-layer extrusion coating. A layer was formed, and the outer periphery of the second layer was extrusion-coated with the above resin mixture to produce a three-layer insulated wire.

When manufacturing the product of Example 1, the surface after each extrusion coating was water-cooled to 100 ° C. or lower. Further, each insulating layer of the electric wire of Comparative Example 4 is formed by winding the indicated insulating film.

[0038]

[Table 1]

With respect to the above 12 kinds of three-layer insulated wires, various characteristics were measured with the following specifications. Solderability: The portion of the wire at the end of about 40 mm is immersed in molten solder at a temperature of 400 ° C, and the time (seconds) until the solder adheres to the immersed portion of 30 mm is measured. The shorter this time is, the better the solderability is.

The electrically insulating: 2-layer coated immediately after production, per each wire of a three-layer coating, using a bare copper wire to one according to two twisting method of stipulated in JISC3003, the breakdown voltage at that time Measurement. The electric wire coated with three layers was left in the atmosphere for one year, and then the dielectric breakdown voltage was measured by the same method as above to examine the change over time in the electrical insulation property.

Heat resistance: JISC for 3-layer coated wire and bare copper wire
Twist two in accordance with 3003, in that state, the temperature 20
After heat treatment at 0 ° C for 7 days, measure the dielectric breakdown voltage. The larger this value is, the better the heat resistance is. Crazing resistance: After the wire is left in the atmosphere for 6 months, the wire is aligned and mechanically wound on a coil reel having a diameter of 12 mm, and it is observed whether or not crazing occurs on the surface of the wire.

Delamination: About 50 cm in the longitudinal direction of the insulating layer
After cutting it with a cutter knife, make a notch along the entire circumference in the circumferential direction of the wire, fix one end of the wire to the twister and sandwich the other end with the chuck of the twister to fix the wire. It was held straight, the chuck was rotated in this state, the electric wire was twisted in the longitudinal direction, and the number of rotations at which the three insulating layers were separated into each layer was examined. The peeling is performed at the time when a part of the coating film in the cut portion in the circumferential direction can be peeled off. The smaller the number of rotations, the better the delamination property.

Coil workability: A wire is aligned and wound (50 turns) on a conductive square core having a square cross section with a side of 7 mm while applying a tension of 6 kg using a processing machine, and between the wire and the square core. Measures the time until dielectric breakdown occurs when a voltage of 3000 V is applied to. This test has 10 coils each
The results are evaluated by the average value. The longer this time is, the less the insulating layer is damaged during coil processing, that is, the better the coil processability is. The guide nozzle used had a tip hole diameter larger than the outer diameter of the electric wire by 0.05 mm, and the linear velocity was set to 20 m / min.

Observation of appearance after winding: Similar to the case of the coil workability test, the coils were processed by aligning and winding, and for each of the obtained 10 coils, the electric wire was unwound from the square core and the surface thereof was removed. It was observed and the number of breakages in the insulating layer was examined. The above results are collectively shown in Table 2.

[0045]

[Table 2]

The following is clear from Table 2. 1) The first and second layers are formed by a resin mixture composed of an ethylene-based copolymer having a carboxylic acid or the like in the side chain (hereinafter referred to as a modifier) and a thermoplastic polyester resin, and the third layer is formed by heat. Example 1 and a plastic polyamide resin
The insulated wires of Comparative Examples 1 to 4 are particularly excellent in soldering characteristics, and are also excellent in other characteristics.

Also, in the case of the insulated wires of the above-mentioned respective examples, during the above-mentioned delamination test, delamination first occurred in the third and second layers, and then in the first layer. Then, the second layer was peeled from the insulating layer. This means that when an external force is applied to the wire, the insulating layer is peeled from the outside and is prevented from peeling toward the inside. Therefore, the electric wires of these examples have high reliability.

2) At the time of production, the insulated electric wire of Example 1 provided with a step of water cooling after extrusion coating is excellent in delamination. 3) The insulated wire of Comparative Example 5 , in which the thermoplastic polyester resin alone was used to form the first layer and the second layer without blending the above-mentioned modifier, shows remarkable changes in characteristics over time. Also, the coil processability is poor. The poor coil processability is considered to be because the outermost layer is formed of the thermoplastic linear polyester resin.

4) On the other hand, the insulated wire of Comparative Example 6 formed by using the resin mixture in which the modifier is blended in excess (50 parts by weight) has poor heat resistance. 5) In Comparative Example 7 , in addition to the first and second layers, the third layer also has an insulating layer formed of a thermoplastic polyester resin containing a modifier. Since the third layer of this insulated wire is not formed of the thermoplastic polyamide resin, the coil workability is poor.

6) The insulated electric wire of Comparative Example 8 in which a film is wound to form an insulating layer cannot be soldered. Also, the breakdown voltage is low and the insulation characteristics are poor. Further, the outermost layer has irregularities, and the result of the coil processability is also poor. 7) The insulated wire of Comparative Example 9 in which the insulating layer is formed of a completely different resin (Teflon) cannot be soldered. Further, the interlayer peelability is 8 times, and the adhesion between layers is too bad.

8) The wire of Comparative Example 10 in which the first and third insulating layers are made of polyamide resin has poor coil processability. This is because the adhesion between the insulating layer and the conductor is not good, and the different types of resin are in contact with the first and second layers, and the second and third layers, respectively. Is considered to be very bad. The electric wire of Comparative Example 10 has a low dielectric breakdown voltage. It is considered that this is because there are two insulating layers made of polyamide resin.

9) The electric wire of Comparative Example 11 in which the second and third layers are made of polyamide resin has a poor dielectric breakdown characteristic as in Comparative Example 10 . Examples 2 and 3 and Comparative Examples 12 to 14 The components shown in Table 3 were kneaded at the indicated ratios to prepare resin blends for each extrusion coating layer.

An annealed copper wire having a wire diameter of 0.6 mm was prepared as a conductor, and the outer periphery thereof was extrusion-coated with the above resin mixture to form a first extruded coating layer with the indicated thickness, and then a second layer. Was formed on the outer periphery of the second layer, and the resin mixture was extrusion-coated on the outer periphery of the second layer to produce a three-layer insulated wire. In addition, when manufacturing Examples 2 and 3 , after each extrusion coating step, the surface thereof was water-cooled to 100 ° C. or lower.

[0054]

[Table 3]

With respect to these three-layer insulated wires, various characteristics were measured with the same specifications as in Example 1 . However, the heating temperature in the heat resistance test was set to 230 ° C. The above results are shown in Table 4.

[0056]

[Table 4]

The following is clear from Table 4. 1) Example in which the first and second layers were formed of PCT resin
The insulated wires of Nos. 2 and 3 and Comparative Example 12 have excellent characteristics. Particularly, good results were obtained even though the heat resistance test was carried out at a high temperature of 230 ° C., and it is understood that these Examples 2, 3 and Comparative Example 12 have excellent heat resistance. The insulated wires of Examples 2 and 3 and Comparative Example 12 were sequentially peeled off from the outer insulating layer in the same manner as in Example 1 .

2) In Example 2 , the first layer and the second layer were formed of the PCT resin alone, but they showed good characteristics. When the PCT-based resin is used, the problem of aging can be ignored (see Comparative Example 1 above). However, in order to obtain such good characteristics, it is considered necessary to form the third layer with a thermoplastic polyamide resin (see Comparative Example 2 ).

3) Example in which a cooling step was provided after extrusion coating
The second and third insulated electric wires have excellent delamination properties. 4) The insulated wire of Comparative Example 12 in which the outermost layer was formed of PET resin showed a large change with time. It is considered that this is because the outermost layer is formed of the PET resin instead of the polyamide resin, so that the deterioration of the PCT is likely to proceed.
Moreover, this was inferior in coil workability.

5) Comparative example in which the modifier is excessively blended
The insulated wire of No. 14 has reduced heat resistance. From the above, the three insulating layers 4b, 4c and 4d and the conductor
The multi-layer insulated wire according to the present invention having 4a is primaryly mounted on the bobbin.
It is wound as a winding, and is wound on the outside of the wound primary winding.
It has three insulating layers 6b, 6c, 6d and a conductor 6a.
A case where the multilayer insulated wire according to the present invention is wound as a secondary winding
In the pressure device (Fig. 2), these multilayer insulated wires are IEC standard 95
Insulation from the point where the electrical characteristics specified by 0 can be realized
The insulation between the primary winding and the secondary winding with tape is unnecessary,
In addition, no insulating barrier is required to secure the edge distance.
You can

[0061]

As is clear from the above description, the multilayer insulated wire of the present invention has high productivity at the time of manufacture because all the insulating layers are formed by extrusion coating, and the insulating layers are soldered. It has excellent characteristics, heat resistance, crazing resistance, delamination resistance, and electrical insulation, and its characteristics do not deteriorate over time. Therefore, it is useful as a winding wire or lead wire for a transformer with a new structure that satisfies the IEC standard. Since the outermost layer is a coating layer containing a polyamide resin as a main component, its friction coefficient is small. Therefore, during coil processing, the outermost layer is less likely to be damaged, and deterioration of insulation characteristics after coil processing is less likely to occur. Moreover, according to the method of the present invention, a multilayer insulated wire can be efficiently manufactured.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a transformer having a conventional structure.

FIG. 2 is a cross-sectional view showing an example of a transformer having a structure having a three-layer insulated wire as a winding wire.

[Explanation of symbols] 1 Ferrite core 2 bobbins 3 Insulation barrier 4 primary winding 4a conductor 4b, 4c, 4d insulating layer 5 insulating tape 6 secondary winding 6a conductor 6b, 6c, 6d insulating layer

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Isamu Kobayashi 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. (72) Mitsuru Inoue 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Industry Co., Ltd. (72) Inventor Nobuyuki Nakamura 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Inside Furukawa Electric Co., Ltd. (56) Reference JP 59-130008 (JP, A) JP 56- 112019 (JP, A) Actual development 3-110721 (JP, U) Actual development 4-101315 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01B 7/02 H01B 3 / 30 H01B 13/14 H01F 5/06 H01F 27/28

Claims (9)

(57) [Claims] 1. In a multi-layer insulated wire comprising a conductor and three or more insulating layers covering the conductor, the first and second insulating layers from the conductor side are (a) an aliphatic alcohol component and an acid. Resin obtained by blending 5 to 40 parts by weight of an ethylene-based copolymer having a carboxylic acid or a metal salt of a carboxylic acid in a side chain with 100 parts by weight of a thermoplastic linear polyester resin formed by combining components. Extrusion coating layer of admixture, (b) Extrusion coating layer containing, as a main component, a thermoplastic linear polyester resin formed wholly or partially by combining an alicyclic alcohol component and an acid component, (c) all Alternatively, an ethylene-based copolymer having a carboxylic acid or a metal salt of a carboxylic acid in a side chain with respect to 100 parts by weight of a thermoplastic linear polyester resin partially formed by binding an alicyclic alcohol component and an acid component 50 layers An extrusion coating layer of a resin mixture containing less than 1 part by weight of the resin mixture, wherein the third insulating layer is a thermoplastic polyamide resin or an extrusion coating of a resin mixture containing a thermoplastic polyamide resin as a main component. When forming each of the above-mentioned insulating layers, the surface of the extrusion coating layer is covered with 1 layer at the time when the extrusion coating of the lower layer is completed.
A multi-layer insulated electric wire having good exfoliation between insulating layers and good coil workability, which is characterized in that an extruded coating layer as an upper layer is formed after cooling to 00 ° C or lower. 2. The multilayer insulated wire according to claim 1, wherein the alicyclic alcohol component is cyclohexanedimethanol. 3. The multilayer insulated wire according to claim 1, wherein both the first insulating layer and the second insulating layer are the extruded coating layer of (a). 4. The multi-layer insulated wire according to claim 1, wherein the first insulating layer and the second insulating layer are both extruded coating layers of (b) or (c). 5. The multilayer insulated wire according to claim 1, wherein the thickness of the second insulating layer is at least twice the thickness of the thicker insulating layer of the first insulating layer or the third insulating layer. . 6. The multilayer insulated wire according to claim 1, wherein the third insulating layer is made of 4,6-nylon. 7. The electric wire is held linearly in a state in which a cut along the longitudinal direction of the electric wire and a cut along the circumferential direction are formed in the insulating layer, and the electric wire is held with the longitudinal direction of the electric wire as a central axis. The multi-layer insulated wire of claim 1, wherein when twisted, the layers of the insulating layer separate from each other before the conductor breaks. 8. When manufacturing the multi-layer insulated wire according to claim 1, an operation of cooling the surface of the insulating layer to 100 ° C. or lower after forming the first insulating layer by extrusion coating from the conductor side. A method for producing a multi-layer insulated wire, which is characterized in that peeling between insulating layers is good and coil workability is good. 9. A transformer in which a first winding is wound around a bobbin, and at least a second winding is wound outside the first winding, the transformer comprising: At least one is the multi-layer insulated wire according to any one of claims 1 to 6, and is a transformer.