JPH06181008A - Insulated electric wire - Google Patents

Abstract

(57) [Summary] [Purpose] To provide an insulated wire using a tetrafluoroethylene-propylene copolymer as an insulator. [Structure] A coating layer in which barium stearate is mixed with a resin composition containing a tetrafluoroethylene-propylene-based copolymer as a main component is formed on the outer periphery of a tin-plated copper wire, and the coating layer is crosslinked.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulated wire using a tetrafluoroethylene-propylene copolymer as an insulator.

[0002]

2. Description of the Related Art Tetrafluoroethylene-propylene copolymers are known as crosslinkable fluorine-containing elastomer copolymers having a high degree of thermal stability, oil resistance, insulation, chemical resistance and flame retardancy. Therefore, it is possible to obtain an electric wire / cable having the above characteristics by coating the outer periphery of the conductor or the electric wire core with such a copolymer. Applications that take advantage of this feature include lead wires for motors and transformers, and insulated wires such as internal wiring for heat appliances.

[0003]

By the way, as a result of studying application of a resin composition containing a tetrafluoroethylene-propylene copolymer as a main component to an insulated wire, the following problems were pointed out. .

A resin composition containing a tetrafluoroethylene-propylene-based copolymer as a main component is coated on the outer periphery of a tin-plated copper wire which is usually used as a conductor, and a crosslinked wire is heated after varnishing or after heating. When used after leaving for 10 days or more, the tin-plated copper wire and the insulating coating adhere firmly,
It was confirmed that the terminal stripping by the wire stripper could not be performed.

The present invention has been made in view of the above circumstances, and mainly uses a tetrafluoroethylene-propylene-based copolymer which solves the above-mentioned drawbacks and facilitates separation of the tin-plated copper wire and the insulating coating. An object of the present invention is to provide an insulated electric wire having an insulating coating of a resin composition as a component.

[0006]

According to the present invention, a coating layer formed by mixing barium stearate with a resin composition containing a tetrafluoroethylene-propylene copolymer as a main component is formed on the outer periphery of a tin-plated copper wire. The coating layer is a crosslinked insulated wire.

[0007]

EXAMPLES In the present invention, as the tetrafluoroethylene-propylene-based copolymer, in addition to the main components tetrafluoroethylene and propylene, components copolymerizable therewith, such as ethylene, butene-1, isobutene,
Acrylic acid and its alkyl ester, methacrylic acid and its alkyl ester, vinyl fluoride, vinylidene fluoride, hexafluoroproben, chloroethyl vinyl ether, glycidyl vinyl ether, chlorotrifluoroethylene, perfluoroalkyl vinyl ether, etc. were appropriately contained. It may be one.

In such a copolymer, the content molar ratio of tetrafluoroethylene / propylene is 95 /
It is preferable to select from the range of 5 to 30/70, particularly 90/10 to 45/55 from the viewpoint of heat resistance and moldability,
In addition, the content of the components other than the main component that is appropriately added is preferably selected from the range of usually 50 mol% or less, particularly 30 mol% or less.

Barium stearate is mixed with the resin composition containing the above-mentioned tetrafluoroethylene-propylene copolymer as a main component, and the outer circumference of the tin-plated copper wire is extrusion-coated and then cross-linked. As the cross-linking method, chemical cross-linking with an organic peroxide, an amine or the like, or irradiation cross-linking with an ionizing radiation such as γ-ray or electron beam is adopted, and the cross-linking method is not particularly limited.

Specific examples of the organic peroxide include di-t-
Butyl peroxide, t-butyl cumyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,
5-di (t-butylperoxy) -hexyne-3,1,
3-bis- (t-butylperoxy-isopropyl) benzene and the like can be mentioned. Further, specific examples of amines include so-called alkyl polyamines such as hexamethylenediamine, tetraethylenepentamine and triethylenetetramine or salts thereof such as carbamic acid and cinnamylidenic acid, or biperazine, biperidine, hydridine, aniline and phenanthroline. Aromatic polyamines and salts thereof and the like. Also, allyl compounds, sulfur, organic amines, maleimides, methacrylates,
A crosslinking aid such as a divinyl compound can be used, and preferably an allyl compound such as diallyl phthalate, triallyl phosphoric acid, triallyl isocyanurate, and triallyl cyanurate can be employed.

The barium stearate to be mixed with the resin composition is not limited to this, and all stearic acid compounds such as sodium stearate, calcium stearate and zinc stearate are effective.

In the present invention, in addition to the above components, polyvinylidene fluoride, ethylene tetrafluoroethylene,
A fluororesin such as polytetrafluoroethylene or a fluororubber typified by a vinylidene fluoride-hexafluoropropylene copolymer may be appropriately mixed. Further, fillers such as MT carbon, FT carbon black, talc, clay, and silicic acid anhydride, and various additives such as reinforcing agents, pigments, lubricants, extrusion aids, antioxidants, stabilizers, etc. may be mixed.

Specific examples will be described below. An outer layer formed by mixing 0.3% by weight of barium stearate with a resin composition containing a tetrafluoroethylene-propylene copolymer as a main component and collecting 30 tin-plated copper wires having a wire diameter of 0.18 mm. 0.4mm on the circumference of 1.1mm diameter copper wire
Was extruded and coated at a thickness of 3 mm and cross-linked by electron beam irradiation to prepare an electric wire, which was used as a sample. In addition, as a comparative example, an electric wire was produced in the same manner as in the above example except that barium stearate was not added, and a sample of the comparative example was prepared.

For the electric wire samples of the above-prepared examples and comparative examples, the peeling force of the insulator (3 at the initial and 80 ° C.
(After heating for 36 hours) was evaluated. As shown in FIG. 2, a test method for this evaluation is as follows. As shown in FIG. 2, about 70 mm is taken as a sample of an electric wire of an example and a comparative example, an insulator of 5 mm is stripped from one end, and 25 mm is left as an insulator 2.
40 mm of the insulator on the other end side is stripped to expose the conductor 1. The force for pulling the conductor 1 in the direction indicated by the arrow on the left side until the insulator 3 is completely peeled off is measured by the chuck 3.

The results of this evaluation are shown in the graph of FIG. The vertical axis represents peeling force (kgf), and the horizontal axis represents time. As is clear from this figure, the peeling force of the example in which barium stearate was mixed did not increase so much even after the heat treatment. On the other hand, in the comparative example in which barium stearate was not mixed, the peeling force sharply increased.

[0016]

As described above, according to the electric wire of the present invention, an insulating coating made of a tin-plated copper wire after heat treatment and a resin composition containing a tetrafluoroethylene-propylene copolymer as a main component is used. An insulated wire that can be easily peeled off at the terminal is obtained. Therefore, it becomes an excellent insulated wire having a high degree of thermal stability, oil resistance, insulation, chemical resistance and flame retardancy.

[Brief description of drawings]

FIG. 1 is a graph showing evaluation results,

FIG. 2 is a schematic configuration diagram of a test device for evaluation.

[Explanation of symbols]

 1 conductor 2 insulator 3 chuck

Claims (1)

[Claims] 1. A coating layer in which barium stearate is mixed with a resin composition containing a tetrafluoroethylene-propylene-based copolymer as a main component is formed on the outer periphery of a tin-plated copper wire, and the coating layer is crosslinked. Insulated wire characterized by being