JPH05258618A - Insulated electric cable - Google Patents

Abstract

PURPOSE:To provide an insulated electric cable in which grains or foams are not formed even if there are scars in a conductor by forming 6 thermally plastic resin layer between a conductor and a thermosetting polyamide imide resin layer formed on the conductor. CONSTITUTION:A thermally plastic resin layer/such as polyimide resin, etc., is formed on a conductor. On the layer, a thermosetting polyamide imide resin layer synthesized from an aromatic tertiary basic acid and an aromatic isocianate is formed by coating and baking. Consequently, a thermally plastic resin layer is formed between the conductor and the thermosetting polyamide imide resin layer and thus even in the case there are scars in the conductor, an insulated electric cable with good enamel wire properties and high quality is obtained without formation of grains and foams during the formation of the thermosetting polyamide imide resin layer.

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, various kinds of synthetic resin coated enameled wires have been put to practical use due to the development of polymer chemistry. In terms of heat resistance, polyvinyl formal wire (A type), polyurethane wire (E
To B type), polyester wire (B to F type), polyester imide wire (F to H type), polyamide imide wire (H to C)
Class), polyimide wire (C class), all heat resistance class can be covered.

In particular, the polyamide-imide wire has an excellent balance of heat resistance, mechanical properties, and refrigerant resistance, and has sufficient performance as a general-purpose enamel wire.
It is widely used for heat-resistant equipment such as electrical components, wiper motors, class F motors, refrigerator motors, and refrigerant resistance.

[0004]

In the above-mentioned prior art, especially the polyamide-imide enameled wire has very poor baking workability,
Furthermore, if there are scratches on the conductor, it is very likely that particles and foaming will occur at that portion. Enameled wire with particles and foaming has a low value as a product and the work efficiency is very poor.

At present, it is considered that about half or more of the appearance defects of polyamide-imide enameled wires are due to scratches on the conductor.

The present invention has been made in view of the above points, and it is an object of the present invention to provide an insulated electric wire capable of preventing generation of particles and foaming even when the conductor is damaged. .

[0007]

The above object is achieved by providing a thermoplastic resin layer between the conductor and the thermosetting polyamide-imide resin layer.

[0008]

Since the above-mentioned means is provided, even if the conductor is scratched, particles and foaming will not occur.

[0009]

EXAMPLES Next, the present invention will be specifically described by way of examples. In this example, a thermoplastic resin layer was provided between the conductor and the thermosetting polyamide-imide resin layer. By doing so, even if there is a scratch on the conductor, particles and foaming will not occur, and even if there is a scratch on the conductor, particles,
It is possible to obtain an insulated electric wire capable of preventing foaming.

Table 1 shows the results of the examination of the enamel wire characteristics (appearance, flexibility, softening resistance, dielectric breakdown voltage, thermal shock resistance) depending on the presence or absence of conductor scratches in Examples and Comparative Examples.

[0011]

[Table 1]

In the examples and comparative examples shown in the table, a copper wire having a conductor diameter of 1.0 mm was used. In the comparative example, a thermosetting polyamide-imide resin was applied and baked so that the film thickness was 40 μm. A plastic resin was extruded to a thickness of 10 μm to form a lower layer, and a thermosetting polyamide-imide resin was applied and baked thereon to a thickness of 30 μm to obtain a test enameled wire. A flaw on the conductor is 0.2 mm wide and 10 mm long in the longitudinal direction of the conductor.
mm and the depth was 0.3 mm. afterwards,
The characteristic test of the enamel wire was conducted according to JISC-3003. A description will be given below based on Table 1.

[Example 1] TPI manufactured by Mitsui Toatsu Chemical Co., Inc. was extrusion formed on a scratched conductor, and NPI DAI synthesized from trimellitic anhydride and 4-4'-diphenylmethane diisocyanate was formed on the TPI. Using -500-30 (nonvolatile content 30%, viscosity 11d · Pa · S (30 ° C)) in a baking furnace with a furnace length of 6 m, the coating temperature was 380 ° C and the linear speed was 20 m / min. Obtained.

[Example 2] VICTREX. PEEK is extruded, and D is formed on it.
AI-500-30 was applied and baked to obtain a test line.

Example 3 Tormolon manufactured by Amoco Co., Ltd. was extruded on a scratched conductor, and DAI-500-3 was formed thereon.
0 was applied and baked to obtain a test line.

[Embodiment 4] DAI-500 of Embodiment 1
HI-406-30 manufactured by Hitachi Chemical Co., Ltd. was used in place of 30.

[Embodiment 5] DAI-500-of Embodiment 2
HI-406-30 was used instead of 30.

[Embodiment 6] DAI-500-of Embodiment 3
HI-406-30 was used instead of 30.

[Comparative Example 1] DAI-5 was formed on a conductor having no scratch.
00-30 was applied and baked (furnace length, furnace temperature, linear velocity, etc. were the same as in Example 1) to obtain test lines.

Comparative Example 2 Using HI-406-30, a conductor having no scratch was coated and baked in the same manner as in Comparative Example 1.

[Comparative Example 3] DAI using a scratched conductor
Similarly to Comparative Example 1, -500-30 was applied and baked to obtain a test line.

[Comparative Example 4] Using a scratched conductor, HI-
406-30 was coated and baked as in Comparative Example 3.

As is clear from the table, in Examples 1 to 6 in which a thermoplastic resin is formed on a conductor by extrusion, foaming does not occur even if the conductor has a scratch, and a comparative example having a scratch on the conductor. Enamel characteristics are superior to 3 and 4.

As described above, the polyamide-imide enameled wire of this embodiment is a conventional polyamide-imide coating (DAI).
-500-30, HI-406-30) has the same characteristics as an enameled wire obtained by coating and baking it on a conductor without damage, and even if there is a damage on the conductor, foaming does not occur and it is industrially useful.

As the thermoplastic resin for extrusion molding, it is suitable to use one having a heat resistance of H or more in terms of heat resistance. As such, Mitsui Toatsu Chemical Co., Ltd. TPI (polyimide resin),
Sumitomo Chemical VICTREX. Examples include PEEK (polyether ether ketone resin) and Torlon (polyamideimide resin) manufactured by Amoco. The lower layer formed by extrusion is preferably as thin as possible in order to prevent deterioration of the properties of the polyamide-imide enameled wire.

Thermosetting Polyamideimide Resin (Paint) Synthesized from Aromatic Tribasic Acid and Aromatic Isocyanate
Examples thereof include DAI-500 manufactured by Nitto Denko Corporation, HI-406 manufactured by Hitachi Chemical Co., Ltd., and NH-AI manufactured by Totoku Paint Co., Ltd. These are widely used as aromatic polyamideimides.

[0027]

As described above, according to the present invention, since the thermoplastic resin layer is provided between the conductor and the thermosetting polyamide-imide resin layer, even if the conductor is scratched, particles and foaming do not occur. As a result, it is possible to obtain an insulated electric wire which is capable of preventing generation of particles and foaming even when the conductor is scratched.

Claims (1)

[Claims] 1. An insulated wire having a thermosetting polyamideimide resin layer formed on a conductor, wherein a thermoplastic resin layer is provided between the conductor and the thermosetting polyamideimide resin layer. Characterized insulated wire.