JPH05258613A - Insulated electric cable - Google Patents

Abstract

PURPOSE:To provide an insulated electric cable with high heat resistance and mechanical strength by applying a paint containing mainly specified polyamide prepared by reaction of terephthalic acid, hexamethylenediamine, caprolactam to a conductor and baking it. CONSTITUTION:A polyamide having a chemical structure shown as the formula and melting point 290-300 deg.C is prepared by reaction of terephthalic acid, hexamethylenediamine, and caprolactam. A paint mainly containing the polyamide is applied to a conductor directly or having another insulator between them and baked. As a result an insulated electric cable bearing polyamide overcoat which has high heat resistance, that is softening resistance and deterioration resistance, and mechanical strength, that is flexibility and reciprocal wear resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulated wire.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for enameled wires with excellent mechanical winding properties for the purpose of downsizing electrical equipment, speeding up coil winding work, and reducing the coil defect rate. To improve the mechanical winding property, the outer diameter of the wire is made thinner, the flexibility is increased, the mechanical strength of the coating is increased, and the enamel wire is made slippery (self-lubricating). ..

Conventionally, as one of the methods for increasing the strength of the enamel wire coating, a method of baking polyamide on the upper layer of the enamel coating has been generally performed. As polyamide, 6.6 nylon (melting point 250 ° C.), 6 nylon (melting point 2)
15 ° C), 6.10 nylon (melting point 210 ° C), 11 nylon (melting point 185 ° C), 12 nylon (melting point 178)
However, 6.6 nylon is particularly often used from the viewpoint of mechanical strength and film softening property (higher melting point is less likely to soften).

As the enamel wire, the method of this polyamide overcoat is mainly applied to a polyester wire and a polyurethane wire whose coating film has a slightly poor mechanical strength.

[0005]

Since the H-type ester imide wire has a slightly inferior mechanical strength of the film, it may be possible to use this polyamide overcoat. However, since the heat resistance of 6.6 nylon is inferior, F- It could not be put to practical use for H class equipment.

The present invention has been made in view of the above points, and it is an object of the present invention to provide a polyamide overcoat insulated wire capable of improving heat resistance and mechanical strength.

[0007]

[Means for Solving the Problems] The above object is to have a melting point of 290 to 290, which has a chemical structure of the following chemical formula 2 in which terephthalic acid, hexamethylenediamine and caprolactam are reacted on a conductor.
This can be achieved by coating and baking a paint mainly composed of polyamide at 300 ° C. directly or through another insulating material.

[0008]

[Chemical 2]

[0009]

Since the above means is provided, heat resistance and mechanical strength are improved.

As a material having the structure of the above chemical formula 2, there is "Ultramid T" (BASF, West Germany) and the like. The melting point of Ultramid T is 295 ° C, which is about 45 ° C higher than that of conventional 6.6 nylon, and the equilibrium water absorption (23 ° C) is 5.7%, which is lower than 8.2% of 6.6 nylon.

In order to impart surface slipperiness, low molecular weight polyethylene, Teflon oligomer, fatty acid polyester, etc. may be added in an amount of 0.1 to 10 parts by weight.

Further, the dispersion stability may be improved by reacting the terminal of the low molecular weight polyethylene with a carboxylic acid (R-COOH) and the terminal of the polyamide with an amino group (-NH ₂ ).

[0013]

EXAMPLES Next, the present invention will be specifically described by way of examples. In this example, a paint mainly composed of a polyamide having a chemical structure of the following chemical formula 3 and having a melting point of 290 to 300 ° C., which is obtained by reacting terephthalic acid, hexamethylenediamine, and caprolactam on a conductor, is directly applied or baked through another insulating material. It was

[0014]

[Chemical 3]

By doing so, heat resistance and mechanical strength are improved, and a polyamide overcoated insulated wire capable of improving heat resistance and mechanical strength can be obtained.

Table 1 shows the results of examining the enameled wire characteristics of the coating compositions for the examples and comparative examples.

[0017]

[Table 1]

In the table, the conductor diameter is 1.0 in the examples and comparative examples.
mm, the film thickness is 35 μm, and an H-type ester imide wire (hereinafter referred to as EIW) is used, and the upper polyamide layer has a film thickness of 3
The test line was baked to have a thickness of ˜4 μm. The characteristics of the enameled wire were measured according to JIS-C3003. A description will be given below based on Table 1.

Example 1 Ultramid T (BASF
A coating composition prepared by dissolving (manufactured by the same company) in cresylic acid / xylol (= 8/2) at a concentration of 15% was baked at 4 μm on the upper layer of EIW.

Example 2 To 100 parts by weight of Ultramid T, 3 parts by weight of a low molecular weight polyethylene having a --COOH group at the end (mp107 ° C.) was added, and the mixture was reacted in cresol at 100 to 200 ° C., then cresylic acid / The paint dissolved in xylol (= 8/2) at a concentration of 15% was baked at 4 μm on the upper layer of EIW.

Comparative Example 1 EIW alone.

[Comparative Example 2] CM3001N manufactured by Toray Industries, Inc. as a 6.6 nylon resin was mixed with cresylic acid / xylol (=
The paint dissolved in a concentration of 15% on 8/2) was baked at 4 μm on the upper layer of EIW.

As is clear from the table, Examples 1 and 2 are excellent in heat resistance and mechanical strength, and can provide polyamide overcoated enameled wire excellent in heat resistance and mechanical strength.
It is industrially useful.

[0024]

As described above, the present invention has a melting point of 290 to 30 having a chemical structure represented by the following chemical formula 4 in which terephthalic acid, hexamethylenediamine and caprolactam are reacted on a conductor.
Since a paint mainly composed of polyamide at 0 ° C was applied and baked directly or through another insulating material, heat resistance and mechanical strength were improved, and polyamide capable of improving heat resistance and mechanical strength was obtained. An overcoated insulated wire can be obtained.

[0025]

[Chemical 4]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location H01B 3/30 M 9059-5G

Claims (1)

[Claims] 1. A coating mainly composed of a polyamide having a chemical structure of the following chemical formula 1 and having a melting point of 290 to 300 ° C., which is obtained by reacting terephthalic acid, hexamethylenediamine and caprolactam, on a conductor, directly or through another insulating material. An insulated wire characterized by being baked. [Chemical 1]