JPH10134646A - Ammonia resistant insulated wire - Google Patents

Abstract

(57) [Problem] To provide an ammonia-resistant insulated wire which is excellent in ammonia resistance, has a high dielectric breakdown voltage, and can suppress an increase in the finished wire diameter. SOLUTION: An enamel coating 2 having a thickness of 2 to 20 μm is provided on a conductor 1, and an extruded resin coating 3 having a thickness of 30 to 100 μm is provided thereon.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ammonia-resistant insulated wire capable of withstanding use in an ammonia atmosphere.

[0002]

2. Description of the Related Art An enamel paint such as polyester, polyester imide, or polyimide amide is applied on a conductor.
The enameled wire that has been baked has good electrical properties,
Widely used for magnet wires. However, this type of enameled wire has a disadvantage that it cannot be used in an ammonia atmosphere such as an electric motor winding for an ammonia refrigerator, for example, the enamel coating is deteriorated and the flexibility is reduced.

[0003] For this reason, it is conceivable to use an insulated wire provided with an insulating layer by extruding a thermoplastic resin having good ammonia resistance, such as polyethylene, polypropylene, or fluororesin, on a conductor, for this type of application. However, in this case, when the thickness of the insulating layer is reduced to 100 μm or less, which is comparable to that of the enamel film of the enameled wire, the insulating layer essentially has a defect that a pinhole is generated.
If the thickness is not more than 00 μm, it cannot be used for this purpose. For this reason, there is a problem that the wire diameter becomes large and the coil becomes large.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an ammonia-resistant insulated wire having excellent ammonia resistance and capable of suppressing an increase in wire diameter.

[0005]

This problem can be solved by an insulated wire in which an enamel film is formed on a conductor by applying and baking, and a thermoplastic resin is extrusion-coated thereon to form an extruded resin film. .

[0006]

FIG. 1 shows an example of an ammonia-resistant insulated wire according to the present invention, wherein reference numeral 1 denotes a conductor. As the conductor 1, a conductor made of copper, copper alloy, aluminum, aluminum alloy, silver, gold, or the like, or a plated conductor obtained by plating these with nickel plating, tin plating, gold plating, or the like is used. 1-2mm
Of the degree. On this conductor 1, an enamel coating 2
Is provided.

The enamel film 2 is made of polyurethane, polyvinyl formal, epoxy, polyester, polyesterimide, polyhydantoin, polyamideimide,
It is formed by applying and baking an enamel paint such as polyimide on the conductor 1 a plurality of times, and having a thickness of 2 to 5
It is about 0 μm, preferably about 2 to 30 μm. The enamel film 2 only needs to have a thickness that does not cause pinholes, and does not need to be particularly thick.

An extruded resin film 3 is provided on the enamel film 2. The extruded resin film 3 is formed by extruding a thermoplastic resin on the conductor 1 provided with the enamel film 2 while inserting the conductor 1 into a mandrel of a crosshead die of an extruder. The thermoplastic resin is not particularly limited,
Those having excellent ammonia resistance are desirable. For example, saturated polyesters such as polyethylene, polypropylene, nylon (polyamide), polyethylene terephthalate, and polybutylene terephthalate, polyacetanol, polycarbonate, polyphenylene oxide, polyetheretherketone, polysulfone, and polyethersal Fluorine resins such as von, phenoxy, polyvinyl chloride, polychlorotrifluoroethylene, polyvinylidene fluoride, and FPA are used.

The thickness of the extruded resin film 3 is made thicker than the thickness of the enamel film 2 and has sufficient ammonia resistance and mechanical strength. Because it becomes fat and unfavorable,
Usually, it is about 30 to 100 μm.

In such an ammonia-resistant insulated wire, since the enamel coating 2 is provided inside the extruded resin coating 3, the thickness of the extruded resin coating 3 is reduced, and a pinhole is formed in the extruded resin coating 3. Even if it occurs, since the enamel film 2 from which no pinhole is originally formed is present inside this, there is no pinhole in the insulator as a whole, and there is no deterioration in characteristics such as a decrease in dielectric breakdown voltage due to this. Extruded resin film 3
Is obtained by extrusion coating a thermoplastic resin having good ammonia resistance, so that it has good ammonia resistance and does not deteriorate in an ammonia atmosphere. Further, since the thickness of the extruded resin film 3 can be reduced by ignoring the occurrence of pinholes, the finished diameter of the obtained ammonia-resistant insulated wire does not need to be large, and this is wound around a coil. However, the size of the coil does not increase.

Hereinafter, the operation and effect will be clarified by showing specific examples. (Example) A polyvinyl formal paint was applied on a 1.0 mm-diameter soft copper conductor and baked to obtain a thickness of 2 μm, 5 μm, and 1 μm.
A 0 μm enamel film was formed, and a polyether ether ketone (trade name “Victrex”, manufactured by Sumitomo Chemical Co., Ltd.) was extrusion-coated thereon, and a thickness of 48 μm and 45 μm was formed.
Extruded resin films of m and 40 μm were formed, and ammonia-resistant insulated wires each having a finished diameter of 1.10 mm were produced.

For these insulated wires, JISC300
The appearance, dimensions, pinholes, and dielectric breakdown voltage were measured according to 3. The ammonia resistance of these three types of insulated wires was evaluated as follows. The bottom of the glass desiccator was filled with concentrated ammonia water (concentration: 28% by weight), and six kinds of insulated wires were hung on the top. The desiccator was sealed and left in an oven at a temperature of 60 ° C. for one month. After the period was over, the roll was taken out of the desiccator, washed, and observed for corrosion with a naked eye and a stereomicroscope.

(Comparative Example) Polyetheretherketone was directly extrusion-coated on a soft copper conductor having a diameter of 1.0 mm to a thickness of 1 mm.
Extruded resin films of 50 μm, 100 μm, and 50 μm were formed to produce three types of insulated wires. These three types of insulated wires were also evaluated in the same manner as in the example. Table 1 shows the results.

[0014]

[Table 1]

From the results shown in Table 1, it can be seen that in the case of the present invention, no pinholes are generated even if the thickness of the extruded resin film is small, the dielectric breakdown voltage is high, and the ammonia resistance is good. Recognize.

[0016]

As described above, the ammonia-resistant insulated wire of the present invention has an enamel film and an extruded resin film provided on a conductor. Even when occurs, the extruded resin film can be made sufficiently thin without reaching the conductor by the inner enamel film, and the finished wire diameter can be prevented from increasing. In addition, since the extruded resin film is formed by extrusion coating of a thermoplastic resin, the extruded resin film has excellent ammonia resistance and can withstand use in an ammonia atmosphere.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an example of an ammonia-resistant insulated wire of the present invention.

[Explanation of symbols]

 1 ... conductor, 2 ... enamel film, 3 ... extruded resin film

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Shigeru Amano 9-1 Futaba-cho, Numazu-shi, Shizuoka Prefecture Inside Fujikura Numazu Plant (72) Inventor Keiji Nakano 9-1-1, Futaba-cho, Numazu-shi, Shizuoka Co., Ltd. Fujikura Numazu Plant (72) Inventor Yoshimasa Hatanaka 9-1 Futaba-cho, Numazu City, Shizuoka Prefecture Fujikura Numazu Plant

Claims (2)

[Claims] 1. An ammonia-resistant insulated wire characterized in that an enamel paint is applied to a conductor and baked to form an enamel coating, and a thermoplastic resin is extrusion-coated on the enamel coating to provide an extruded resin coating. . 2. An enamel film having a thickness of 2 μm to 20 μm.
2. The ammonia-resistant insulated wire according to claim 1, wherein the thickness of the extruded film is 30 to 100 [mu] m.