JPH0672121U - Overhead insulated wire - Google Patents

Abstract

(57) [Summary] [Structure] Fiber cloth 2 obtained by impregnating and adhering benzotriazole onto a copper stranded wire conductor 1 without using a binder.
Anticorrosion tape 2 in which a, adhesive 2b, plastic film 2c, and heat-fusible plastic layer 2d are laminated in this order
Was wrapped around it, and the plastic insulator 3 was extrusion-coated thereon to heat-bond the insulator 3 and the heat-fusible plastic layer 2d. [Effect] Since the fiber cloth contains a large amount of benzotriazole, the anticorrosion effect can be maintained for a long period of time, and the stress corrosion of the conductor can be prevented. Since the anticorrosion tape is adhered to the plastic insulator instead of adhering to the conductor, the anticorrosion tape can be removed together with the insulator, and the connection workability is excellent. It also has excellent repeated bending properties.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an aerial insulated wire in which conductor corrosion is prevented.

[0002]

[Prior art]

 The overhead high voltage distribution line is a plastic insulated wire with a voltage of 3,300 V to 33,000 V, and its structure has a basic structure in which a separator layer and a plastic insulator layer are sequentially provided on a hard copper stranded wire conductor. A polyethylene insulating layer is called an OE cable and a crosslinked polyethylene layer is called an OC cable.

In such aerial high-voltage distribution lines, breakage accidents due to stress corrosion of conductors have been observed in recent years. As a countermeasure against this, a watertight admixture is filled in the gaps between the hard copper stranded conductors to prevent rainwater from entering. Water-tight insulated electric wires and compressed conductor insulated electric wires that compress hard copper stranded wire conductors to reduce residual stress are beginning to be used. Water-tight insulated wires require a water-tight mixture to be filled in the twist wire gap when twisting hard copper strands, so the mixture scatters around the twisting machine, significantly deteriorating the working environment, and Productivity is poor, such as a significant decrease in speed. Although the residual stress of the compressed conductor type insulated wire is reduced and the space factor of the twisted wire is increased, there is a slight gap between the twisted wires, so there is a concern that rainwater may enter, and the wire is flexible. Also inferior.

On the other hand, as an attempt to prevent the stress corrosion of the conductor, there is a method of using benzotriazole which is a vaporizable rust preventive agent for copper. They include a method of directly attaching benzotriazole onto a hard copper stranded conductor, a method of using a mixture film of benzotriazole and synthetic resin formed on one surface of a plastic film base material as a separator layer, and a plastic method. A method of mixing benzotriazole into the insulating layer and a combination thereof have been put into practical use. However, each of these methods using benztriazole has the following drawbacks.

The method of directly depositing benzotriazole on the conductor is not suitable for an operator because an alcohol solution of benzotriazole is used in the twisting process, and has a drawback that the rust preventive effect cannot be maintained for a long period of time.

A method of using a plastic film having a mixed coating of benzotriazole and a synthetic resin formed on one surface as a separator layer is to mix with a synthetic resin in order to prevent the benzotriazole from falling off. Since it melts at the high temperature during extrusion of the plastic insulation layer in the insulated wire manufacturing process and adheres to the conductor, wiping is required when connecting the wires, which significantly lowers workability and reduces the amount of benzone required. It is difficult to attach triazole, and the rust preventive effect cannot be maintained for a long time.

The method of mixing benzotriazole into the plastic insulator layer is not a preferable environment for the worker because the gas of benzotriazole volatilizes to the surroundings when the insulator layer is extruded and the gas emits an offensive odor. Furthermore, since a separator layer such as a polyester film is interposed between the insulator and the conductor of the insulated wire, the vaporization of benzotriazole in the insulator to the conductor side is significantly hindered, and the rust prevention effect can be sufficiently exhibited. There are some drawbacks.

[0008]

[Means for Solving the Problems]

 The present invention has been devised by focusing on such conventional problems.It maintains a good rust-prevention effect for a long period of time, prevents stress corrosion of the conductor, and removes it from the conductor during wire connection work. It is intended to provide a new aerial insulated wire with excellent ease of handling.

That is, as shown in FIG. 1, the aerial insulated wire of the present invention comprises a fiber cloth 2a in which benzotriazole is impregnated and adhered to the outer periphery of a copper stranded wire conductor 1 without using a binder, and an insulator. A rust preventive tape 2 in which a plastic film 2c capable of withstanding the temperature at the time of extrusion and a heat-fusible plastic layer 2d were laminated in this order was wound with the fiber cloth 2a inside and the plastic insulation was applied to the outer periphery. The body 3 is extruded and covered, and the plastic insulator 3 and the heat-fusible plastic layer 2d of the anticorrosion tape are heat-fused. In the figure, 2b is an adhesive which is used as needed when the fiber cloth 2a and the plastic film 2c are bonded together.

As the plastic film 2c used in the present invention, a polyester film or a nylon film is preferable, which can be easily wound around a hard copper stranded wire conductor, can withstand a high temperature when a plastic insulator is extruded, and can be a conductor wire. It has the function of preventing the insulator from falling into the gap.

The heat-fusible plastic layer 2d is made of, for example, low-density polyethylene (LDPE), high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), ultra-low-density polyethylene (ULDPE), or other polyethylene, ethylene acrylic. An acid copolymer, an ethylene methacrylic acid copolymer, an ethylene ethyl acrylate copolymer, an ethylene copolymer such as an ethylene vinyl acetate copolymer, and an ionomer resin, which are heat-sealed with a cable insulator, Insulator layer It is fused with the insulator at the temperature of extrusion coating or crosslinking. The heat-fusible plastic layer 2d can be provided on the plastic film 2c directly or via an adhesive by extrusion laminating or laminating.

In the wire connection work, it is desirable that the anticorrosion tape 2 can be easily peeled off from the conductor 1. For this purpose, the fiber cloth 2a, the plastic film 2c, and the heat-fusible plastic material that constitute the anticorrosion tape 2 are desired. It is desirable that the layer 2d has good adhesion, and further that the heat-fusible plastic layer 2d has good adhesion to the plastic insulator 3.

In order to improve the adhesive strength, it is effective to corona-treat the surface of the plastic film 2c as necessary. The corona treatment condition is preferably a charge density of 50 W / m ² / min or more.

The fiber cloth 2a provided on one surface of the plastic film 2c means a woven cloth or a non-woven cloth, which is hereinafter referred to as a fiber cloth. The material of the fiber cloth is preferably polyester fiber or nylon fiber, and examples of the fiber cloth include non-woven fabrics such as wet process polyester non-woven fabric, spunbond polyester non-woven fabric, and spunbond nylon non-woven fabric, for example, 50 denier and 70 denier in thickness. A thin woven fabric such as nylon taffeta or tetron taffeta having a warp thread count of 100 / inch and a weft thread count of 70 / inch is used. Since these fiber cloths do not contain impurities and do not adversely affect the conductor, and since there are innumerable spaces in the fiber gap, it is possible to impregnate and adhere a large amount of benzotriazole to the spaces. The benzotriazole does not fall off and is heat resistant, so it can withstand the high temperatures during extrusion of the plastic insulator and can be easily peeled off from the conductor during the connection work of the insulated wire.

The plastic film 2c and the fiber cloth 2a can be pasted together by a simple heat roll press bonding when the fiber cloth 2a contains low melting point fibers, but since the pasting has a very weak adhesive strength, It is advantageous to use the adhesive 2b for bonding, because a higher adhesive strength can be obtained and processing can be performed at high speed. The adhesive 2b preferably has non-hygroscopic property because it does not adversely affect rust prevention as well as having a function of giving necessary adhesive strength. As the adhesive 2b, a known polyurethane-based two-component reactive adhesive, polyurethane-based one-component reactive (moisture-curing) adhesive, saturated polyester resin adhesive or the like is used. The laminating method is preferably a dry laminating method or a thermal laminating method.

[0016] In the present invention, the adhesion amount of benzotriazole to be impregnated, attached to fabric 2a is in the range of 3g / m ² ~15g / m ² is preferred. If it is less than 3 g / m ² , the amount of benzotriazole is too small to keep the anticorrosion effect for a long time, and if it is 15 g / m ² or more, the anticorrosion effect becomes saturated, so further adhesion is not economically preferable. In some cases, the copper conductor may be discolored.

The anticorrosion tape 2 is wound vertically around the conductor 1 with the surface of the fiber cloth 2a side facing the conductor 1 side, and the plastic insulator 3 is pressed onto the heat-fusible plastic layer 2d. Is coated. The thickness of the anticorrosion tape 2 is 0.15 mm or less, preferably 0.13 mm or less and 0.05 mm or more, in consideration of the outer diameter of the insulated wire.

[0018]

[Action]

 The aerial insulated wire of the present invention is capable of impregnating and adhering a rust preventive agent necessary for exhibiting a rust preventive effect to a fiber cloth of a rust preventive tape for a long period of time, and impregnating the fiber cloth with benzotriazole.・ Because the synthetic resin that serves as a binder is not used for adhesion, the rustproof tape and the conductor do not adhere, and the plastic film gives a proper elasticity to prevent the insulator from falling between the conductor wires and further heat fusion. Since the adhesive plastic layer firmly adheres to the plastic insulator, the rust-preventive tape can be easily peeled off from the conductor together with the insulator during the work of connecting the insulated wire.

[0019]

【Example】

Next, the present invention will be described with reference to examples. (1) A polyurethane-based two-component reactive adhesive (SEIKABOND manufactured by Dainichiseika Kogyo Co., Ltd.) was attached to one side of a 25-micron-thick polyester film (Toray Lumirror) with a gravure coater at about 5 g / m ² (dry weight). After drying at 70 ° C. for 2 minutes, a wet polyester non-woven fabric (weight per unit area: 40 g / m ² ) was attached by a dry laminating method via an adhesive and cured at 40 ° C. for 2 days.

Next, low density polyethylene as a heat-fusible plastic layer was extrusion-laminated to a thickness of 15 microns on the opposite surface of the polyester film via a polyester resin adhesive. Next, the nonwoven fabric surface of the obtained composite was impregnated with a denatured alcohol solution of benzotriazole and dried at 70 ° C. for 1.5 minutes to obtain a rust-preventive tape having 5 g / m ^{2 of} benzotriazole attached. The thickness of this tape was about 0.10 mm.

(2) Nylon film is used as the plastic film, ethylene ethyl acrylate copolymer is used as the heat-fusible plastic layer, and the amount of benzotriazole attached to the polyester non-woven fabric is set to 10 g / m ^2. Was subjected to the same treatment as (1) to obtain a rust preventive tape.

(3) A coating solution containing 5 parts by weight of polyvinyl butyral (manufactured by Sekisui Chemical Co., Ltd.), 1 part by weight of benzotriazole, and 20 parts by weight of denatured alcohol on one side of a 30-micron-thick polyester film (Lumirror made by Toray). Doctor coating, and dried at 70 ° C. for 3 minutes to obtain a conventional type rust-preventive tape having 1 g / m ^{2 of} benzotriazole attached. Its thickness was 0.04 mm.

(4) The polyester film and the polyester nonwoven fabric used in (1) were laminated in the same manner as in (1) to obtain a composite. The non-woven fabric surface of this composite was doctor-coated with a coating solution consisting of 5 parts by weight of polyvinyl butyral, 2 parts by weight of benzotriazole, and 20 parts by weight of denatured alcohol, and dried at 70 ° C for 3 minutes to obtain 5 g of benzotriazole. A conventional type rust-preventive tape with an adhesion of / m ² was obtained. The thickness was 0.09 mm.

Next, the four types of rustproof tapes obtained in (1) to (4) were subjected to the following tests. <Rust prevention test> The pickled copper tape is hermetically sealed with rust prevention tape. A heat cycle of 60 ° C./95% RH × 6 hours ← → 20 ° C./65% RH × 6 hours was added to this sample for 30 days in a constant temperature and humidity chamber, and the presence or absence of rust on the copper tape was investigated.

<Plastic Insulator Extrusion Simulation Test> Prepare male / female molds having a height of 20 mm, a length of 100 mm, and a width of 100 mm. Hard copper wires are arranged in a line at the bottom of the female mold, and benzotriazole is placed on top of them. Place the rust-preventive tape (100 mm in length x 100 mm in width) with the adhesion side facing down, put about 100 g of polyethylene insulation pellets on the rust-preventive tape, match the male die, and set it on the press machine to set 180 It was preheated at 0 ° C. for 2 minutes and pressed under a pressure of 20 kg / cm ² for 3 minutes. After the pressing was completed, the mold was allowed to cool to room temperature, the male mold was removed, and it was examined whether the anticorrosion tape was easily peeled off from the hard copper wire and whether the polyethylene insulator leaked to the hard copper wire side. The above results are summarized in Table 1.

[0026]

[Table 1]

Next, an insulated wire using the anticorrosive tape obtained in (1) and (3) as a separator layer was manufactured, and its characteristics were evaluated.

Example 1 A 150 mm ² copper stranded wire conductor was vertically coated with the rust-preventive tape obtained in (1), and a cross-linkable polyethylene composition was extrusion-coated on the rust-preventive tape, and then pressure-crosslinked at 180 ° C. To obtain an insulated wire.

Comparative Example 1 An insulated electric wire was obtained in the same manner as in Example 1 using the anticorrosive tape obtained in (3). The following evaluations were performed on the two types of insulated electric wires obtained in Example 1 and Comparative Example 1.

<Rust prevention test> The obtained insulated electric wire was subjected to a heat cycle of 60 ° C./95% RH × 6 hours ← → 20 ° C./65% RH × 6 hours in a thermo-hygrostat for 30 days, and copper twisting was performed. The occurrence of rust on the wire conductor was investigated. <Leakage of Insulator> The insulated wire was disassembled and examined to see if the insulator leaked into the conductor.

<Peelability from Conductor> When the insulating layer of the insulated wire was removed from the conductor, it was investigated whether the rust-preventive tape could be peeled off cleanly without remaining on the conductor. <Adhesion with Insulator> A peel test was conducted to investigate whether or not the anticorrosion tape was firmly attached to the insulator.

<Repeated Bending Property> Regarding the peelability from the conductor and the adhesion to the insulating layer, the stability was evaluated by adding the bend 20 times to 30 mmφ. The above results are summarized in Table 2.

[0033]

[Table 2]

[0034]

As described above, the aerial insulated wire of the present invention can maintain the anticorrosion effect for a long period of time because the fiber cloth of the anticorrosion tape can contain a large amount of benzotriazole. It is possible to prevent stress corrosion. Also, since the rust preventive tape does not adhere to the conductor but adheres well to the plastic insulator with the heat-fusible plastic layer, it is possible to remove the rust preventive tape together with the conductor when connecting the insulated wire. Excellent connection workability. In addition, the plastic insulator and anti-corrosion tape adhere well to each other, giving it excellent repeatability.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of an overhead insulated wire according to the present invention.

[Explanation of symbols]

 1: Copper stranded wire conductor 2: Anticorrosion tape 2a: Benzotriazole-attached fiber cloth 2b: Adhesive 2c: Plastic film 2d: Heat-fusible plastic layer 3: Plastic insulator

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshinori Tanaka 1820 Harakami, Shintomi-cho, Kasuya-gun, Fukuoka Prefecture Inside the Shingu Factory, Fukuoka Cross Industry Co., Ltd. Hara 1820 Fukuoka Cross Industry Co., Ltd. Shingu Factory

Claims (1)

[Scope of utility model registration request] 1. A fiber cloth in which benzotriazole is impregnated and adhered to the outer periphery of a copper stranded wire conductor without using a binder, a plastic film capable of withstanding the temperature at the time of extrusion of an insulator, and a heat-fusible plastic layer. However, the anticorrosion tape laminated in this order is wrapped with the fiber cloth inside and the outer periphery is extruded and covered with a plastic insulator to heat the plastic insulator and the heat-fusible plastic layer of the anticorrosion tape. An aerial insulated wire characterized by being fused.