JPH03179613A - Insulated electric wire and its anticorrosive - Google Patents

Abstract

PURPOSE:To prevent the breaking of an insulated electric wire resulting from stress and corrosion by applying the reacted product of benzotriazole and an epoxy system plasticizer to the surface of each of hard copper-wires, and laying a vinyl chloride composition insulator on the applied coat. CONSTITUTION:The reacted product (a) of benzotriazole and an epoxy system plasticizer, as an anticorrosive, is applied to the surface of each of hard copper- wires 1, and the insulator of a vinyl chloride composition 3 is laid on the applied coat. In this case, there is caused no transfer of the plasticizer to each of PVC insulated electric wires because the non-transferential anticorrosive (a) is applied to the wire. For this reason, the corrosion resistance of a conductor 2 to a sulfide may not be deteriorated. The corrosion resistance of the conductor 2 to the sulfide, even if the insulator 3 is made of a PVC composition, can thus be maintained for effectively impeding corrosion of the conductor to obtain an insulated electric wire having its high reliability over a long period of time.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a vinyl insulated electric wire strung outdoors,
The present invention relates to an insulated wire that prevents stress corrosion and disconnection, and an anticorrosive agent therefor.

[Conventional technology and its issues]

Residual stress is generated in the conductor of this type of insulated wire during the wire drawing and wire twisting processes, and when rainwater enters into the insulated wire (between the conductor and its covering insulation), the residual stress causes Corrosion of the conductor is promoted by corrosive substances (sulfides) in rainwater, resulting in so-called stress corrosion. This stress corrosion occurs intensively in the cutout portion of the conductor, leading to wire breakage. This phenomenon is widely known as stress corrosion disconnection.

Conventionally, the following measures have been taken to prevent stress corrosion and disconnection.

- Rolls are applied to the twisted conductor to compress it, converting the residual stress caused by tension and bending that occurs during twisting into compressive stress, making stress corrosion less likely to occur.

■Fill the gap between the conductor and the insulator with a watertight compound to prevent water from entering the gap.

(2) Applying benzotriazole (BTA) or a reaction product of BTA and amine as an anti-corrosion agent (anti-sulfuration agent) onto the conductor.

(2) Apply a mixture of BTA and an epoxy, phthalic acid, or phosphoric acid plasticizer onto the conductor.

However, since the above-mentioned method (2) does not prevent corrosion itself, the method (2), which is not effective, and the method (2), which is unproductive due to the troublesome work of filling the watertight compound, directly prevent corrosion of the conductor. Although it is effective for preventing
The prevention effect is inferior to that of method ■.

For this reason, method (2) is the most effective, but if the insulator covering the conductor is a vinyl chloride (PVC) composition, the plasticizer will migrate (be eaten) by the PVCMi composition, resulting in sulfide formation. Resistance is impaired and conductors corrode due to water intrusion.

This mechanism is explained by the fact that plasticizers such as dioctyl phthalate (DOP) and salt paraffin (chlorinated paraffin) are mixed into the PVCL composition, but when mixed in a typical amount, it becomes saturated. Moreover, since PVC has good compatibility with plasticizers, when it comes into contact with plasticizers, it rapidly absorbs them. For this reason, it is thought that the plasticizer applied on the conductor is eaten by the PVC&II composition forming the insulator.

In view of the above, an object of the present invention is to effectively prevent stress corrosion due to water immersion in an insulated wire whose insulator is made of a PvC composition.

[Means for solving the problems of the invention] The above Li! In order to solve the problem, in the anticorrosive agent according to the present invention, BTA is used as in the above measures (1) and (2), but an epoxy-based plasticizer is used and they are reacted. For example, it consists of the following general formula.

The anticorrosive agent consisting of this general formula has the following reaction formula (plasticizer:
For example, it can be obtained by epoxidized soybean oil (1'1loOEL). In this reaction formula, BTA and -100EL react in the absence of a solvent (catalyst) and when heated, for example, heated to about 130°C + 10"C. If a solvent is used, both are present in the solvent. For example, tetrahydrofuran (T) (F) may be used as long as it dissolves in the solvent.In this case, it may be heated at room temperature, but it is preferable to heat it, for example, to about 60°C or higher.For both solvents, The weight ratio is appropriately selected through experiments, taking into account reactivity, corrosion resistance, etc.

(Plasticizer) (BTA) 1---→ -CH-CI - This anti-corrosion agent is non-migratory (the plasticizer is not eaten away),
The present invention relates to an insulated wire in which a conductor is coated with this. That is, the surface of the hard copper wire is coated with a reaction product of benzotriazole and an epoxy plasticizer, and the hard copper wire is coated with vinyl chloride a.

[Function] Since the insulated wire constructed as described above is coated with a non-migratory anticorrosive agent, the plasticizer will not migrate to the PVC insulated wire. Resistance does not deteriorate.

〔Example〕

First, WlooEL and BTA were mixed in a solvent-free solution at +30+10'C according to the weight ratio (molar ratio in parentheses) shown in Table 1.
As a result of reaction polymerization under the conditions shown in Table 1, a reaction product consisting of unreacted BTA, reacted BTA, and reacted h100EL in the weight ratio shown in the lower column of the same table was obtained, which was further dissolved in a solvent to obtain a stock solution of an anticorrosive agent.

Note that l'1100EL has an average molecular weight of about 1000 and a number of epoxy groups of about 4. For this reason, BTA and Wloo
If EL is completely reactively polymerized, the reaction molar ratio will be approximately 4=1.

Weight ratio (Next, the above stock solution is diluted 20 times with 1. 1. First, the diluted stock solution a is
As shown in the figure, when the 19 hard copper wires are concentrically twisted, the diluted stock solution A is drip-applied again at the time when the center 7 wires are twisted and when the outer layer 19 wires are twisted, On this twisted conductor 2 (60 m'' hard copper twisted M), an insulating coating 3 made of PVCM material was applied by known extrusion molding to obtain an insulated wire P.

[Confirmation of effect]

Insulating IMF obtained as described above (Example 1 shown in Table 1.
Samples with a length of 1100a were taken from each conductor 2 (20 times diluted solution a of 2.3 was dripped onto the conductor 2), the insulator 3 of each sample was stripped off, and each conductor 2 was
3 in 100 pp aqueous sodium sulfide solution (20°C)
It was soaked for 0 seconds. When each conductor 2 was visually observed for discoloration, no abnormality was found in any of them.

In addition, after leaving the sample collected in the same manner as above in a constant temperature bath at 80 ± 1°C for 30 days, it was taken out, the insulator 3 was stripped off, and the conductor 2 was treated with a 100 μm sodium sulfide aqueous solution (20 μm) in the same manner as above. ℃) for 30 seconds, the conductor 2 was observed for discoloration, and no abnormality was observed.

By the way, as in the above method (■), 100EL for BTA
The conductor coated with a mixture of the following and dissolved in isopropyl alcohol was heated for 30 days in a constant temperature bath at 80±1°C, and when the conductor was immersed in the sodium sulfide aqueous solution for 30 seconds, the plasticizer was removed. It was eaten by PVC&ll materials and lost its resistance to sulfides, resulting in discoloration.

[Effect] Since the present invention is configured as described above, the insulator is PvC.
Even with the composition, the conductor's sulfide resistance is maintained and corrosion is effectively inhibited. Therefore, according to the present invention, it is possible to provide an insulated wire that is highly reliable over a long period of time.

[Brief explanation of drawings]

The drawings are t! ! FIG. 2 is a partially cutaway perspective view of one embodiment of the edge wire. 1... Hard copper wire, 2... Conductor,
3...Insulator (pVc & Il), a...
... Reaction product coating liquid (diluted stock solution, anticorrosive agent), P ... Insulated wire.

Claims (2)

[Claims] (1) An insulated electric wire characterized in that the surface of a hard copper wire is coated with a reaction product of benzotriazole and an epoxy plasticizer, and the hard copper wire is coated with a vinyl chloride composition. (2) Corrosion inhibitor for insulated wires consisting of the following general formula. ▲Contains mathematical formulas, chemical formulas, tables, etc.▼