JPH066920Y2 - Anticorrosion tape for overhead insulated wire - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a rust preventive tape for aerial insulated wires which is useful as a material for preventing corrosion of conductors of aerial high voltage distribution lines and the like.

[Conventional technology and its problems]

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. Polyethylene insulators are called OE cables, and cross-linked polyethylene ones are called OC cables.

In such aerial high-voltage distribution lines, breakage accidents due to stress corrosion of conductors have been seen in recent years, and as a countermeasure, a water-tight insulated wire in which the gap between hard copper stranded conductors is filled with a water-tight mixture to prevent rainwater from entering. In addition, a compressed conductor type insulated electric wire in which a hard copper stranded wire conductor is compressed to reduce residual stress has begun to be used.

Water-tight insulated wires require a water-tight mixture to be filled in the stranded wire gap when twisting hard copper strands, so the mixture is scattered around the twisting machine, which not only worsens the working environment, but also the twisting speed. Productivity is poor, such as markedly reduced.

Although the residual stress of the compressed conductor type insulated wire is reduced and the space factor of the conductor is increased, there is a slight gap in the stranded wire, and there is a concern that rainwater may enter. It is also less flexible.

On the other hand, as an attempt to prevent stress corrosion of the conductor, there is a method of using benzotriazole, which is a volatile corrosion inhibitor of copper. As those, (1) a method of directly attaching benzotriazole onto a hard copper stranded wire conductor, (2) a method of using a mixture film of benzotriazole and a synthetic resin formed on one surface of a plastic film substrate as a separator layer. , (3) a method of mixing benzotriazole into a plastic insulator layer, and (4) a combination thereof has been put into practical use. However, all of these methods using benzotriazole have the following drawbacks.

(1) The method of directly attaching benzotriazole onto the conductor is not a preferable environment for the worker because the alcohol solution of benzotriazole is used in the twisting step,
Further, there is a drawback that the rust preventive effect cannot be maintained for a long time.

(2) A method in which a plastic film having a mixed coating of benzotriazole and synthetic resin formed on one side is used as a separator layer, benzotriazole is mixed with synthetic resin in order to prevent benzotriazole from falling off. Is melted at a high temperature during extrusion of the plastic insulation layer in the insulated wire manufacturing process and adheres to the conductor, requiring wiping off when connecting the wires, which significantly reduces workability and attaches the required amount of benzotriazole. It is difficult to do so, and the rust preventive effect cannot be maintained for a long time.

(3) The method of mixing benzotriazole into the plastic insulator layer is not a preferable environment for workers because the gas of benzotriazole volatilizes to the surroundings when the insulator layer is extruded and the gas emits an offensive odor. Further, since a separator layer such as a polyester film is interposed between the insulator and the conductor of the insulated wire, vaporization of benzotriazole in the insulator to the conductor side is significantly hindered, and there is a drawback that the rust preventive effect cannot be exhibited. .

[Means for solving problems]

The present invention has been devised by focusing on such a conventional problem, and has a good rust preventive effect for a long period of time. It is intended to provide a novel rust preventive tape for aerial insulated wires, which is excellent in peelability from conductors during wire connection work while preventing corrosion.

That is, according to the present invention, as shown in FIG. 1, a fiber cloth 1 in which benzotriazole is impregnated and adhered without using a binder, a plastic film 4 capable of withstanding the temperature at the time of extruding an insulator of an aerial insulated wire, and an aerial A rust preventive tape for aerial insulated wires, characterized in that an insulator of an insulated wire and a heat-fusible plastic layer 5 that is heat-sealed are laminated in this order. In the figure, reference numeral 2 is an adhesive used as necessary when the fiber cloth 1 and the plastic film 4 are bonded together.

The plastic film 4 used in the present invention is preferably a polyester film, a nylon film or the like, which can be easily wound around a hard copper stranded wire conductor, can withstand the high temperature when the plastic insulator is extruded, and can be applied between the conductors of the insulator. It has the function of preventing depression.

The heat-fusible plastic layer 5 is made of polyethylene such as low-density polyethylene (LDPE), high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), and ultra-low-density polyethylene (ULDPE), ethylene acrylic acid copolymer Coalesced, ethylene methacrylic acid copolymer,
It is heat-sealed with a cable insulator such as ethylene-ethyl acrylate copolymer, ethylene copolymer such as ethylene-vinyl acetate copolymer, ionomer resin, etc. And is fused with an insulator.

The heat-fusible plastic layer 5 can be provided on the plastic film 4 directly or through an adhesive by extrusion laminating or laminating.

In the cable connection work, it is desirable that the anticorrosion tape be easily peeled off from the cable conductor. For this purpose, the fiber cloth 1, the plastic film 4 and the heat-fusible plastic layer 5 which compose the anticorrosion tape are well adhered to each other. It is desirable that the heat-fusible plastic layer 5 adheres well to the cable insulation.

Therefore, in order to improve the adhesive strength, it is effective to corona-treat the surface of the plastic film 4 if necessary. The condition for corona treatment is a charge density of 50 W / m ² / mi
It is preferably n or more.

The fiber cloth 1 provided on one surface of the plastic film 4 refers to 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, spun-bond polyester non-woven fabric and spun-bond nylon non-woven fabric, and further warp yarns having a thickness of 50 denier or 70 denier. Number of drives 100 / inch
A thin woven fabric such as nylon taffeta or tetron taffeta having a weft threading number 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 gaps, a large amount of benzotriazole can be impregnated and adhered to the spaces, and they adhere. Since benzotriazole does not fall off and has heat resistance, it has the characteristics that it can withstand the high temperature during extrusion of the plastic insulator layer and can be easily peeled off from the conductor when connecting the insulated wire.

When the fiber cloth 1 contains the low melting point fiber, the plastic film 4 and the fiber cloth 1 can be bonded by simple hot roll pressure bonding, but the bonding strength is very weak, so the plastic film 4 and the fiber cloth 1 are bonded using the adhesive 2. This is advantageous because higher adhesive strength can be obtained and processing can be performed at high speed. The adhesive 2 preferably has a non-hygroscopic property because it does not adversely affect rust prevention as well as a function of giving a necessary adhesive strength. As the adhesive 2, a known polyurethane-based two-component reactive adhesive, polyurethane-liquid-reactive (moisture-curable) adhesive, saturated polyester resin adhesive, or the like is used. As a laminating method, a dry laminating method or a thermal laminating method is preferable.

In the present invention, the adhesion amount of benzotriazole to be impregnated, attached to the fiber fabric 1 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 that further adhesion is not economically preferable. It may discolor the copper conductor.

The anticorrosion tape of the present invention is wound around the conductor with the surface on the side of the fiber cloth 1 facing the conductor along the length and the like, and the plastic insulating layer is extruded on the heat-fusible plastic layer 4. . Further, the thickness of the rust preventive tape of the present invention is 0.15 mm or less, preferably 0.13 mm or less, in consideration of the outer diameter of the insulated wire.
0.05mm or more is desirable.

[Action]

The rust preventive tape of the present invention can be impregnated and adhered with a rust preventive agent necessary for exhibiting a rust preventive effect for a long period of time.
In addition, since synthetic resin that serves as a binder is not used for impregnating / adhering benzotriazole to the fiber cloth, it does not adhere to the conductor, and the plastic film gives a suitable waist suitable for wrapping around the conductor, and between the conductors of the insulator. It has the function of being easily peeled off from the conductor during the work of connecting the insulated electric wire because the heat-fusible plastic layer is firmly adhered to the insulator of the insulated electric wire.

〔Example〕

 Next, the present invention will be described with reference to examples.

Example 1 A polyurethane-based two-component reactive adhesive (Seika Bond manufactured by Dainichiseika Kogyo Co., Ltd.) was applied to one side of a 25-micron-thick polyester film (Lumirror manufactured by Toray) with a gravure coater to about 5 parts.
g / m ² (dry weight) After adhering and drying at 70 ° C. for 2 minutes,
Wet polyester non-woven fabric with adhesive
/ M ² ) were laminated by a dry laminating method 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 μm on the surface opposite to the side in contact with the non-woven fabric via a polyester resin adhesive.

Next, the non-woven 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.

Example 2 Same as Example 1 except that a nylon film was used as the plastic film, ethylene ethyl acrylate copolymer was used as the heat-fusible plastic layer, and the amount of benzotriazole attached to the polyester nonwoven fabric was 10 g / m ^2. Then, the anticorrosion tape was obtained.

Comparative Example 1 A doctor film was coated on one surface of a 30-micron-thick polyester film (Toray Lumirror) with a coating solution consisting of 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. Then, it was dried at 70 ° C. for 3 minutes to obtain a conventional type anticorrosion tape to which benzotriazole was attached at 1 g / m ² .
Its thickness was 0.04 mm.

Comparative Example 2 The polyester film and the polyester non-woven fabric used in Example 1 were laminated in the same manner as in Example 1,
It was a complex. 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 give 5 g / m ^{2 of} benzotriazole. A conventional type anti-corrosion tape attached was obtained. The thickness was 0.09 mm.

Next, the four types of antirust tapes obtained in Examples 1 and 2 and Comparative Examples 1 and 2 were subjected to the following test.

<Rust-proof test> The pickled copper tape is hermetically sealed with rust-proof tape. This sample is kept in a constant temperature and humidity chamber at 60 ° C and 95% RX for 6 hours ←
→ Heat cycle at 20 ° C and 65% RX x 6 hours for 30
In addition to the day, the presence or absence of rust on the copper tape was investigated.

<Plastic insulator extrusion simulation test> Prepare male / female molds of height 20mm, length 100mm, width 100mm, line hard copper wires in line at the bottom of the female mold, and place the benzotriazole adhesion surface on it. Place the anticorrosion tape (length 100 mm × width 100 mm) toward the bottom side, put about 100 g of polyethylene insulator pellets on the anticorrosion tape, put the male mold together and set it on the press machine at 180 ° C for 2 minutes. It was preheated and pressed under a pressure of 20 kg / cm ² for 3 minutes. After the press was completed, the mold was allowed to cool to room temperature, the male mold was removed, and it was examined whether the rustproof 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.

Further, it was used as a separator layer of the anticorrosion tape insulated electric wire obtained in Example 1 and Comparative Example 1, and its characteristics were evaluated.

Example 3 A 150 mm ² copper conductor was longitudinally coated with the anticorrosion tape obtained in Example 1, and a cross-linked polyethylene composition was extrusion-coated on the copper anti-corrosion tape, and then pressure-crosslinked at 180 ° C. to form an insulated wire. Obtained.

Comparative Example 3 An insulated electric wire was obtained in the same manner as in Example 3 using the anticorrosive tape obtained in Comparative Example 1.

The following evaluations were carried out on the two types of insulated wires obtained in Example 3 and Comparative Example 3.

<Rust prevention test> The obtained insulated electric wire is kept at 60 ° C and 95% R in a constant temperature and humidity chamber.
A heat cycle of X × 6 hours ← → 20 ° C. and 65% RX × 6 hours was applied for 30 days, and the presence or absence of rust on the copper 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 removing the insulating layer of the insulated wire from the conductor, it was investigated whether or not the rust-preventive tape could be peeled off cleanly without remaining on the conductor.

<Adhesion with Insulator> It was investigated by performing a peel test whether the rust-preventive tape was firmly adhered to the insulator layer.

<Repeating Bend Property> For peeling property from the conductor and adhesion property to the insulating layer, 30
The bend was added 20 times to mm and the stability was evaluated.

The above results are summarized in Table 2.

[Effect] As can be seen from the results shown in Tables 1 and 2, when the anticorrosion tape of the present invention is applied as a separator layer to an aerial insulated wire, it is easily peeled off from the conductor, and the insulator does not fall, especially the insulator layer. It is also excellent in repeated bendability due to its excellent adhesion to. Also, the dielectric strength is 4 kV or more,
It has excellent electrical characteristics with a volume resistivity of 1 × 10 ¹⁴ Ω · cm or more.

Further, the anticorrosion tape of the present invention can be made long and can be supplied in the form of a tape, has an appropriate rigidity, and is convenient for winding on a conductor. Further, since it contains a large amount of benzotriazole as compared with the conventional separator, the rust preventive effect can be maintained for a long period of time, and the stress corrosion of the conductor can be prevented.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of an anticorrosion tape according to the present invention. 1 ... Benzotriazole-attached fiber cloth 2 ... Adhesive 4 ... Plastic film 5 ... Heat-fusible plastic layer

Continuation of the front page (72) Inventor, Yoshiaki Tanaka, 1820 Harakami, Shintomi-cho, Kasuya-gun, Fukuoka Inside the Shingu Factory, Fukuoka Cross Industry Co., Ltd. Fukuoka Cross Industry Co., Ltd. Shingu Factory (56) Reference JP-A-55-14267 (JP, A)

Claims (5)

[Scope of utility model registration request] 1. A fiber cloth impregnated and adhered with benzotriazole without using a binder, a plastic film capable of withstanding the temperature of an insulator of an aerial insulated wire during extrusion, and an insulator of the aerial insulated wire by heat fusion. A rust preventive tape for aerial insulated wires, which is laminated with a heat-fusible plastic layer in this order. 2. The rust preventive tape for aerial insulated wires according to claim 1, wherein the amount of impregnated / adhered benzotriazole to the fiber cloth is 3 to 15 g / m ² . 3. A rust preventive tape for aerial insulated wires according to claim 1, characterized in that at least one surface of the plastic film is corona-treated. 4. A rust preventive tape for an overhead insulated wire according to claim 1 or 3, wherein the plastic film is a polyester film. 5. A rust preventive tape for an overhead insulated wire according to claim 1, wherein the heat-fusible plastic layer is made of low density polyethylene.