JPH06223636A - Insulated wire - Google Patents

Abstract

PURPOSE:To achieve excellent terminal treatability and cable flexibility and to prevent disconnection of wire when it is pulled out of a bobbin. CONSTITUTION:An insulated wire has a conductor l and an ultraviolet-setting resin composition 2 to coat the outer periphery of the conductor 1. The ultraviolet-setting resin composition 2 is set by exposure to ultraviolet radiation. Paraffin is added to the ultraviolet-setting resin composition 2. Therefore the surface of an ultraviolet-set coating made of the ultraviolet-setting resin composition has smaller frictional resistance than usual.

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, with the miniaturization and weight reduction of computers, audios, automobiles, aircrafts, artificial satellites, etc., and with the high-density mounting, the electric wires and cables used for them have been further reduced in diameter and thickness. It has become to. One of the methods is thinning of the coating. The thinner the film is made by the extrusion method, the more easily the film becomes thinner, and the strain caused by the temperature difference between the coating material and the conductor is more likely to affect it, which is likely to cause a decrease in elongation. For this reason, the conductor is preheated well, but when the conductor becomes thin, the strength of the conductor is reduced by the heat of preheating, and the wire is likely to be broken due to the pressure of the material at the time of extrusion, which is not desirable. Enameled wire is very effective if it can be applied to such applications as an electric wire with a thin film thickness. However, enamel wire usually requires a coating and baking process.
Need to be repeated more than once, many things 50%
Since the materials are occupied by organic solvents, large-scale safety equipment is required, and because it is baked, it is not as easy as polyethylene or polyvinyl chloride, and the film peeling property is poor. Not desirable as a cable.

A solvent-free liquid liquid UV-crosslinking resin composition (UV-curing resin composition) has been attracting attention as a means for thin coating, and it is used as a coating material for optical fibers. Above all, urethane acrylate is used. It is known that many system materials are used. These UV-crosslinkable resin compositions are radical polymerization, ionic polymerization, cationic polymerization, etc. using UV rays, and the method of curing mainly by radical polymerization is well known. Since it is liquid, thin coating is easy and the curing speed is fast, which has a great effect on productivity. Further, it is solvent-free and has higher safety than thermosetting varnish used for enameled wire, and can be obtained by applying once or several times to obtain an arbitrary film thickness. In addition, the colorless and transparent resin composition has an advantage that coloring is easier than that of a thermosetting varnish.

[0004]

The UV-crosslinkable resin composition of the above-mentioned prior art is effective as a coating material for thin-walled, small-diameter electric wires. As the diameter of electric wires has been reduced, dozens or hundreds of bundled cables are connected at terminals by crimping or crimping using a connector. For connecting a connector of such a terminal, a method of unwinding twisted electric wires at the time of forming a cable and arranging the electric wires in parallel and connecting them is required, and slippage between the wires is required. Therefore, it is necessary to reduce the frictional resistance on the surface of the insulated wire and make it slippery. However, it is difficult to make the UV-crosslinkable material extremely hard, because the coating material of the insulated wire requires elongation, and the friction resistance of the surface of the hardened coating is large, and the thinner the wire, the more the contact area between the wires. Increase, and problems such as adhesion between lines occur.

Further, a cable in which many electric wires having a large surface friction resistance are bundled has a problem that the flexibility is extremely poor and the wireability is poor. In addition to this, when the thin wire is pulled out from the bobbin, there is a problem such as disconnection due to adhesion between the wires.

The present invention has been made in view of the above points, and an object of the present invention is to provide an insulated electric wire which is excellent in terminal processability and which is flexible in the cable and capable of preventing disconnection when the cable is pulled out from the bobbin. To do.

[0007]

The above object can be achieved by adding paraffin to an ultraviolet curable resin composition.

[0008]

Since the above means is provided, the friction resistance of the surface of the ultraviolet curable resin composition coated with the ultraviolet curable resin composition becomes smaller than in the conventional case.

The inventors of the present invention have conducted various studies based on the finding that an ultraviolet curable resin composition is used as a coating material.

The resin composition which is cured by irradiation with ultraviolet rays is intended for ultraviolet curable resin compositions,
Basically, it is composed of photopolymerizable oligomer, photopolymerizable monomer, photoinitiator and the like. What is a photopolymerizable oligomer (prepolymer)?
For example, epoxy acrylate type, epoxidized oil acrylate type, urethane acrylate type, polyester urethane acrylate type, polyether urethane acrylate type, polyester acrylate type, polyether acrylate type, vinyl acrylate type, silicone acrylate type, polybutadiene acrylate type, Various oligomers such as polystyrene ethylmethacrylate type, polycarbonate dicarbonate type, unsaturated polyester type, polyene / thiol type, etc., which have a functional group having an unsaturated double bond such as acryloyl group, methacryloyl group, allyl group, vinyl group 2 Have more than one. The oligomer may be fluorine-substituted, or two or more kinds of oligomers may be combined.

As the photopolymerizable monomer, a known compound having one or two or more functional groups such as acryloyl group, methacryloyl group, vinyl group and allyl group in the molecule can be used.

The photopolymerization initiator has a function of initiating a polymerization reaction of a photopolymerizable oligomer or monomer, and has a role of receiving a UV ray to generate a free radical. This free radical is necessary for ultraviolet crosslinking, and the photopolymerization initiator is a substance that easily absorbs a specific wavelength by irradiation with ultraviolet to be in an electronically excited state to generate a radical. For example, benzoin ether type, ketal type, acetophenone type,
There are benzophenone type and thioxanthone type, and various photopolymerization initiators can be used depending on the purpose.

Paraffin is a mixture of paraffin hydrocarbons CnH2n + 2, which is not particularly specified, but preferably has a low melting point.

Liquid paraffin is paraffin hydrocarbon C
a saturated chain hydrocarbon having nH2n + 2, n = 5 to 15
If so, it is not particularly specified. By using liquid paraffin, it is easy to uniformly disperse in the liquid UV curable resin composition, and a thin film layer is formed on the surface of the coating layer during or after the formation of the cured coating layer to reduce the frictional resistance of the surface and the line spacing. Can be prevented from sticking. The addition amount is not particularly specified, but is preferably 0.1 to 5% by weight or less. 0.
If it is 1% by weight or less, the effect of reducing frictional resistance and the effect of preventing adhesion between lines cannot be obtained, and if it is 5% by weight or more, the curability and mechanical properties of the cured coating layer deteriorate.

Further, by adding beeswax, the frictional resistance can be further reduced. Beeswax is a mixture of compounds which are said to be more than 100 kinds, mainly composed of higher alcohol esters of long chain fatty acids, and are not particularly specified.
However, when the beeswax is added, it is desirable that the ultraviolet-curable resin composition is added while being heated to a temperature higher than the melting point of the beeswax and then once melted.

In addition to these, if necessary, a photoinitiator aid, an adhesion preventive agent, a thixotropy imparting agent, a filler, a plasticizer, a non-reactive polymer, a colorant, a flame retardant, a flame retardant aid, a softening inhibitor, a mold release agent. Agents, desiccants, dispersants, wetting agents, suspending agents, thickeners,
Antistatic agent, antistatic agent, antifungal agent, rodentproofing agent, antitermite agent,
Matting agents, anti-blocking agents, anti-skinning agents, and other various inorganic compounds and organic compounds can be used in combination.

From the above, it was found that paraffin should be added to the ultraviolet curable resin composition. Therefore, in the present invention, paraffin is added to the ultraviolet curable resin composition. By doing so, it is possible to provide an insulated electric wire having excellent terminal processability and capable of preventing the breakage of the cable when it is pulled out from the bobbin and the flexibility of the cable.

[0018]

EXAMPLES Next, the present invention will be specifically described by way of examples.

Example 1 100 parts by weight of urethane acrylate oligomer U-122A (manufactured by Shin-Nakamura Chemical) and 10 parts of isobornyl methacrylate (manufactured by Kyoeisha Oil and Fat Chemical Co., Ltd.)
A bare annealed copper wire was used as a UV-crosslinkable resin composition consisting of 0 parts by weight, 10 parts by weight of a photoinitiator 2,2-dimethoxy-2-phenylacetophenone (manufactured by Ciba Geigy) and 5 parts by weight of solid paraffin (manufactured by Matsumura Oil Co., Ltd.). Conductor 0.05 (1/0.
05) After coating on the surface, it was cured by passing through an ultraviolet irradiation furnace to obtain an insulated electric wire having an insulation thickness of 15 μm.

Example 2 100 parts by weight of urethane acrylate oligomer U-122M (manufactured by Shin-Nakamura Chemical Co., Ltd.), 50 parts by weight of isobornyl methacrylate, and 2,2-photoinitiator.
An ultraviolet-crosslinkable resin composition consisting of 7.5 parts by weight of dimethoxy-2-phenylacetophenone and 5 parts by weight of liquid paraffin (Matsumura Oil Co., Ltd .; Ryu Para E) was used as a bare annealed copper wire conductor.
After being coated on 05 (1 / 0.05), it was cured by passing through an ultraviolet irradiation furnace to obtain an insulated electric wire having an insulation thickness of 16 μm.

Example 3 100 parts by weight of urethane acrylate oligomer U-122M, 50 parts by weight of isobornyl methacrylate, and 2,2-dimethoxy-2- photoinitiator.
An ultraviolet-crosslinkable resin composition comprising 7.5 parts by weight of phenylacetophenone, 3 parts by weight of liquid paraffin (Matsumura Oil Co., Ltd .; Ryu Para E), and 2 parts by weight of beeswax is used as a bare soft copper wire conductor 0.0
After coating 5 (1 / 0.05), it was cured by passing through an ultraviolet irradiation furnace to obtain an insulated electric wire having an insulation thickness of 16 μm.

[Example 4] Urethane methacrylate oligomer EB8400 (manufactured by Daicel UCB) 100
50 parts by weight of dicyclopentanyl methacrylate (manufactured by Hitachi Chemical Co., Ltd.), 7.5 parts by weight of photoinitiator 2,2-dimethoxy-2-phenylacetophenone, and liquid paraffin (Matsumura Sekiyu KK; para Para 350P). ) 3 parts by weight,
A bare annealed copper wire conductor 0.05 (1 / 0.05) was coated with an ultraviolet-crosslinkable resin composition consisting of 2 parts by weight of beeswax and then cured through an ultraviolet irradiation furnace to obtain an insulated electric wire having an insulation thickness of 16 μm.

Comparative Example 1 100 parts by weight of urethane acrylate oligomer U-122A, 100 parts by weight of isobornyl methacrylate and 2,2-dimethoxy-photoinitiator.
An ultraviolet-curable resin composition comprising 10 parts by weight of 2-phenylacetophenone was used as a bare annealed copper wire conductor 0.05 (1 / 0.0
5) After coating the above, it was cured by passing through an ultraviolet irradiation furnace to obtain an insulated electric wire having an insulation thickness of 15 μm.

These Examples 1, 2, 3, 4 and Comparative Example 1
Table 1 shows the characteristics of the insulated wire.

[0025]

[Table 1]

Each electric wire characteristic was evaluated by the following test methods.

(1) Surface friction coefficient The surface friction resistance was measured using the Heidon method.

(2) Adhesion between wires To evaluate the adhesion between wires, an insulated electric wire having a conductor diameter of 0.05 mm was wound around a bobbin, and the insulated electric wire was drawn from the bobbin at a wire speed of 5
It was drawn out at 0 to 100 m / min and judged by the presence or absence of the occurrence of wire breakage. The occurrence of disconnection was rated as ×, and the absence of disconnection was rated as ○.

(3) Breakdown voltage The breakdown voltage between wires was measured by the twisted pair method.

(4) Adhesion The insulated wire is taken to have a fixed length, and after being rapidly extended,
The presence or absence of cracks was examined by observing the image twice. No cracks were rated as O and cracks were rated as X.

(5) Surface hardness The surface hardness is JIS S600 according to JIS D0202.
It measured using the pencil shown by 6.

As is clear from Table 1, in Examples 1 to 4 according to the present invention, the surface friction resistance was smaller than that of Comparative Example 1 and good results were obtained without adhesion between the lines.
In Examples 1 and 2, the frictional resistance in Example 2 was smaller, and the effect of liquid paraffin can be seen. Further, it can be seen from Examples 2 and 3 that the surface friction resistance can be further reduced by combining liquid paraffin and beeswax.

The structure of the insulated wire according to this embodiment is shown in FIG. In FIG. 1A, a conductor (single wire) 1 is coated with an ultraviolet curable resin composition 2. In the same figure (b), a plurality of twisted conductors (stranded wires) 1 are coated with an ultraviolet curable resin composition 2. In the same figure (c), (b) is covered with the collective plating layer 3. In the figure (d) is (a)
A plurality of twisted wires are collectively covered with the sheath 4. In the same figure (e), a plurality of twisted (b) are collectively covered with the sheath 4.

As described above, according to this example, by adding paraffin to the UV-crosslinkable resin composition, the surface frictional resistance can be easily reduced, the adhesion between the wires can be prevented, and the thin wire can be prevented. In addition to preventing disconnection when the bobbin is pulled out, the flexibility of the cable when a large number of insulated electric wires are bundled can be maintained.

[0035]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, since paraffin is added to the ultraviolet curable resin composition, the frictional resistance of the ultraviolet curable resin composition on the surface of the ultraviolet curable coating becomes smaller than the conventional one, and the terminal treatment is performed. It is possible to obtain an insulated electric wire having excellent properties and capable of preventing the breakage of the cable when it is pulled out from the bobbin and the flexibility of the cable.

[Brief description of drawings]

FIG. 1 shows an embodiment of an insulated wire of the present invention, (a) is a longitudinal side view showing a state in which a conductor (single wire) is coated with an ultraviolet curable resin composition, and (b) is a twisted conductor. (C) is a vertical sectional side view showing a state in which the (strand) is coated with the ultraviolet curable resin composition, (C) is a vertical sectional side view showing a state in which (B) is coated with the collective plating layer, and (D) is (A). FIG. 4 is a vertical cross-sectional side view showing a state in which a plurality of twisted strands is covered with a sheath, and (e) is a vertical cross-sectional side view showing a state in which a plurality of twisted strands (b) is covered with a sheath.

[Explanation of symbols]

 1 conductor 2 UV curable resin composition

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Norio Takahata 5-1-1 Hidakacho, Hitachi City, Ibaraki Prefecture Hitachi Cable Ltd. Power Systems Research Center

Claims (3)

[Claims] 1. An insulated wire having a conductor and an ultraviolet curable resin composition coating the outer periphery of the conductor, wherein the ultraviolet curable resin composition is an insulated wire cured by irradiation with ultraviolet rays. An insulated wire characterized by the addition of paraffin to the product. 2. The insulated wire according to claim 1, wherein the paraffin is liquid paraffin. 3. The insulated wire according to claim 1, wherein the paraffin is liquid paraffin to which beeswax is added.