KR101681329B1 - Insulated Wire With High Heat Resistance - Google Patents

Abstract

The insulated electric wire of the present invention comprises a conductor wire; And at least two insulating coating layers formed on the outside of the conductor line, the polyamide imide resin layer being an outermost layer of the insulating coating layer; And a polybenzimidazole resin layer which is a lower layer in contact with the outermost layer.
These insulated wires are used for insulating wires which are used for conventional welding, and they are made of polyimide having low heat resistance and polyimide having poor long-term storage property. Thus, insulating coatings having high heat resistance and easy storage for long time are used , And the coating of the insulated wire is not damaged even if welding is performed.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to an insulated wire for a wire having excellent heat resistance.

Recently, as the size and weight reduction tendency of electric or electronic devices has increased, there has been a demand for smaller and lighter motors of higher performance. In order to satisfy such a requirement, it is necessary to increase the dotted line of the insulated electric wire wound around the motor core. In order to increase the dot coverage of insulated wires, the use of flat insulated wires to remove the pores between the insulated wires that occur during the winding of existing annular insulated wires is increasing. It is possible to achieve high integration, high output and high efficiency by increasing the dotted line of insulated wire when manufacturing motors with square insulated wires. In addition, since the rectangular insulated wire can be aligned and wound, noise can be reduced. Conventional rectangular insulated wires are manufactured by applying polyurethane insulating paint, polyester insulating paint, polyester imide insulating paint, and the like to the outer periphery of the flat wire of copper, copper alloy, aluminum and the like several times and curing. Or rolling a round wire to produce a flat wire, applying an insulating paint to the outside according to a certain rule, and curing it to produce a flat wire. There is also a method of coating and curing a round wire, rolling it, and transforming it into a square insulated wire.

As a high performance motor or alternator is miniaturized, there is no gap between the coil and the core, and magnetic field loss is reduced. As a result, performance improvement and miniaturization are possible. In this case, since it is difficult to wind the wire directly over a long length, a short conductor is formed in the partial shape of the coil and welding is conducted between the conductors to form a whole circuit. In order to form such a coil, a connection between the conductors is required. Generally, in order to connect a conductor, electric welding such as fusing or TIG welding is performed on a portion where welding has been performed, thereby causing damage (partial damage, foaming) of a covering material such as polyester used at this time. In order to avoid this, coating materials such as polyester imide and polyimide are used in a part of the insulating layer to prevent film damage. Such coating materials include polyester. Polyesterimide, polyamideimide and polyimide have been used.

However, polyester imide and polyester insulation paints, which have been used for welding purposes, have somewhat lower heat resistance (180 grade). In particular, in the case of a polyimide insulating coating which is formed by curing a polyamic acid to form a polyimide, the polyester imide has a disadvantage in that storage stability is deteriorated due to a short storage period of the polyamic acid.

Accordingly, it is an object of the present invention to provide an insulating material having high heat resistance and easy storage property in order to avoid damage of a coating film during welding.

The insulated electric wire of the present invention comprises a conductor wire; And at least two insulating coating layers formed on the outside of the conductor line, the polyamide imide resin layer being an outermost layer of the insulating coating layer; And a polybenzimidazole resin layer which is a lower layer in contact with the outermost layer.

Further, the insulated electric wire of the present invention has at least three insulating coating layers, and the lowermost layer of the insulating coating layer may be a polyamide imide resin layer.

Such a conductor wire may be made of low oxygen copper or oxygen free copper having an oxygen content of 30 ppm or less.

In the insulated electric wire of the present invention, it is preferable that the thickness of the polybenzimidazole resin layer of the insulating cover layer is 10 to 40% of the total thickness of the insulated wire.

The insulated electric wire of the present invention complements the disadvantages of polyimide having low heat resistance and polyimide having low heat resistance, which is a coating film for insulated wires used for existing welding, and is excellent in heat resistance and long- , The coating film of the insulated electric wire is not damaged even if welding is performed.

Hereinafter, the present invention will be described in detail. The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms and the inventor may appropriately define the concept of the term in order to best describe its invention It should be construed as meaning and concept consistent with the technical idea of the present invention.

The insulated electric wire of the present invention comprises a conductor wire; And at least two insulating coating layers formed on the outside of the conductor line, the polyamide imide resin layer being an outermost layer of the insulating coating layer; And a polybenzimidazole resin layer which is a lower layer in contact with the outermost layer.

The polybenzimidazole resin is a thermoplastic resin having excellent physical and thermal properties and having a Tg of 417 DEG C or higher. The insulated electric wire of the present invention is provided with an insulating coating layer made of a polybenzimidazole resin and is superior in heat resistance to an insulated electric wire using a polyester imide resin and a polyester resin. Particularly, a polyester imide resin is formed by curing a polyamic acid There is no problem of the cost merit of storage that occurs when a polyimide resin is used.

The polyamide-imide resin is an improvement of polyamide-based resin with poor moldability. It has heat resistance up to 260 ° C and can be injection-molded, and has high tensile strength and impact strength. Therefore, it is suitable for an insulated wire requiring heat resistance.

Further, the insulated electric wire of the present invention has at least three insulating coating layers, and the lowermost layer of the insulating coating layer may be a polyamide imide resin layer.

Such conductor wires are not limited to specific types, but may be made of low oxygen copper or oxygen free copper having an oxygen content of 30 ppm or less.

In the insulated electric wire of the present invention, it is preferable that the thickness of the polybenzimidazole resin layer of the insulating cover layer is 10 to 60% of the total thickness of the insulated wire.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to examples. However, the embodiments according to the present invention may be modified into various other forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. The embodiments of the present invention are provided to enable those skilled in the art to more fully understand the present invention.

Example

Example 1

A coating film was formed from the lowest layer in the order of polyamideimide (HI 406), polybenzimidazole (cerazol) and polyamideimide resin (HI 406) in a cyclic oxygen free copper of 1.5 mm in diameter, and the total coating thickness was 45 μm . The polybenzimidazole varnish was prepared by diluting celazole with a solvent having a viscosity of 5 to 15 poise to a concentration of 1 to 20% using DMAC solvent. The film thicknesses of the respective layers were as shown in Table 1 below. Coating dice were used to coat multiple coatings on 12 occasions, and the coatings were run at 20 m / min using a 10-m long bobbin.

Example 2-3

Was prepared in the same manner as in Example 1, and the thicknesses of the respective films were measured as shown in Table 1 below.

Comparative Example 1

The lowest layer and upper layer were formed with polyamideimide (HI 406) on the circular anoxic copper of Φ1.5 mm and the total film thickness was 50 ㎛. The film thicknesses of the respective layers were as shown in Table 1 below. Multiple coatings were applied 12 times using a coating die, and the coating was carried out at a line speed of 20 mpm using a 10 m long bobbin.

Example 4

(HI 406), polybenzimidazole (cerazol) and polyamide-imide resin (HI 406) as the lowest layers in the square oxygen-free copper having a size of 1.3x2.5 mm and an edge R of 0.5 mm, Was 45 mu m. The film thicknesses of the respective layers were as shown in Table 1 below. Multiple coatings were applied 12 times using a coating die, and the coating was carried out at a line speed of 10 mpm using a 10-m long bobbin.

Example 5

(HI 406), polybenzimidazole cellosol) and polyamideimide resin (HI 406) were sequentially formed from the lowest layer in the square oxygen-free copper having a size of 2.2 x 3.3 mm and edge R 0.8 mm, The thickness was 45 탆. The film thicknesses of the respective layers were as shown in Table 1 below. Multiple coatings were done over 12 times using a coating die, and the coating was carried out at a linear velocity of 7 mpm using a 10 m long sintering furnace.

Comparative Example 2

A single layer of H type polyester was coated on the square oxygen-free copper with a size of 1.3x2.5 mm and an edge R of 0.5 mm, and the coating thickness was 45 μm. The film thicknesses of the respective layers were as shown in Table 1 below. Multiple coatings were applied 12 times using a coating die, and the coating was carried out at a line speed of 10 mpm using a 10-m long bobbin.

Comparative Example 3

Size 2.2 x 3.3 mm, edge R 0.8 mm, and the coating thickness was 45 탆. The film thicknesses of the respective layers were as shown in Table 1 below. Multiple coatings were done over 12 times using a coating die, and the coating was carried out at a linear velocity of 7 mpm using a 10 m long sintering furnace.

Test example. Property evaluation

Flexibility test

The insulated wires prepared in Example 1-5 and Comparative Example 1-3 were bent to have a diameter of 2 2.5 mm and a degree of flexure of 180 캜 to be evaluated in Table 2 below.

In the case of Examples 1-5, the polyamide imide layer was used for the upper and lower layers, and the bending properties were excellent in these two layers. However, in Comparative Example 1-3, the flexibility was poor. Such bending properties are closely related to adhesion properties and flexibility.

Instantaneous heat resistance (fusing)

The insulated wires prepared in Examples 1-5 and 1-3 were crossed at right angles and the upper and lower portions of the chopped portion were sandwiched by the electrodes and welded at a current of 200 A (0.5 s). The results are shown in Table 2 below. Good quality means that the film does not burn.

Instantaneous heat resistance (TIG)

The terminals of the two insulated wires manufactured in Example 1-5 and Comparative Example 1-3 were peeled from each other by 5 mm, TIG welding was carried out at a current of 50 A (0.5 s) The results are shown in Table 2 below. Good means that the film swelling is 1 mm or less and the insulating layer film is not damaged.

Breakdown Voltage (BDV); Room temperature

The in-situ voltages of the insulated wires prepared in Example 1-5 and Comparative Example 1-3 were measured at room temperature and are shown in Table 2 below.

Breakdown Voltage (BDV); 230 ℃, 5 days

The insulated wires prepared in Example 1-5 and Comparative Example 1-3 were aged at 230 ° C for 5 days, and the internal voltage was measured. The results are shown in Table 2 below.

The evaluation of the in-situ voltage at room temperature is to confirm the insulation ability at room temperature. In the case of the in-situ voltage evaluation at high temperature, the insulation ability is confirmed at high temperature. When the heat resistance is low, the deformation of the insulating layer is accompanied by the high temperature, so that the in-train voltage is evaluated to be low at high temperature.

The results of the evaluation of the in-situ voltage of the Examples show that the polybenzimidazole having excellent heat resistance has a high value as a result of evaluation after aging at high temperature for 5 days, whereas in Comparative Example 2, For products containing esters, the values are low.

However, in the case of Comparative Example 1, the high in-range voltage value at high temperature is because the PAI layer exhibits similar performance by securing the insulating ability at a high temperature. However, it is difficult to utilize it as a product that can be welded because other characteristics lead to bad results.

Claims (4)

Conductor wire; And at least three insulating coating layers formed on the outside of the conductor line,
A polyamide imide resin layer as an outermost layer of the insulating coating layer; A polybenzimidazole resin layer which is a lower layer in contact with the outermost layer; And a polyamide imide resin layer which is the lowermost layer of the insulating coating layer,
The conductor wire is made of low oxygen copper or oxygen free copper having an oxygen content of 30 ppm or less,
The thickness of the polybenzimidazole resin layer of the insulating coating layer is 10 to 60% of the total thickness of the insulating wires,
When the terminals of two insulated wires are peeled off in a thickness of 5 mm, and each of them is touched in parallel and subjected to Tig welding under a current condition of 50 A (0.5 s), the film swelling of the weld portion is measured to be less than 1 mm Wherein the insulated wire is an insulated wire. delete delete delete