JP2003338221A - Anticorrosive overhead wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anticorrosive wire free from the possibility of corrosion even when it is placed under an environment extremely high in corrosiveness. <P>SOLUTION: Grease having a water content of 300 ppm or lower or grease having a water content lower than 1000 ppm after left for 30 days in an atmosphere of a relative humidity of 100% and a temperature of 25°C is applied to or filled into an anticorrosive overhead wire. As the grease, for example, that using silicone oil as the base oil and hydrophobic silica as a thickening agent may be used. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overhead electric wire such as an overhead power transmission line, an overhead ground wire, and an optical fiber composite overhead ground wire, and its corrosion resistance is greatly improved.

[0002]

2. Description of the Related Art This type of overhead wire is composed of a single wire or a twisted wire of a galvanized steel wire or an aluminum covered steel wire, and a large number of aluminum wires or aluminum alloy wires are concentrically wound around the wire Composite stranded wire (ACS
R) is used. It is said that this composite stranded wire is lightweight, has high strength, and exhibits good corrosion resistance in a normal environment.

However, in areas near the ocean, areas with severe air pollution, etc., a large amount of corrosive substances such as salts and acids exist in the atmosphere, which corrode this overhead wire, so that the life of the overhead wire is extremely long. There is a problem of shortening. For this reason, in an overhead wire used in such a highly corrosive environment, grease such as synthetic mineral oil grease is applied to the surface of the overhead wire to cover the surface and shield it from the outside air.

However, even in the case of an overhead wire coated with such a grease, in a highly corrosive environment, the corrosive substance dissolves in water and permeates the grease.
In some cases, the aluminum wire on the surface of the overhead wire was corroded.

[0005]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to obtain an anticorrosion aerial wire which is free from the risk of corrosion even when placed in an environment with extremely high corrosiveness.

[0006]

This problem can be solved by applying or filling a grease having a low water content and a low water absorption. Specifically, a grease having a water content of 300 ppm by weight (hereinafter, all weight ratios) or less, or a relative humidity of 100% and a temperature of 25 ° C.
Water content is 1000pp after being left in the atmosphere for 30 days
Apply or fill with grease of less than m. A grease using silicone oil as a base oil and hydrophobic silica as a thickener can be used as a grease that satisfies the above requirements.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.
The grease to be applied or filled on the anticorrosion overhead electric wire of the present invention has an origin water content of 300 ppm or less before use or at the time of opening a can, or in an atmosphere of relative humidity 100% and temperature 25 ° C. A material having a water content of less than 1000 ppm after being left for 30 days is used. Here, the water content is measured by the known Karl Fischer method.

The water content of origin exceeds 300 ppm,
Also, the grease having a water content of 1000 ppm or more after being left in an atmosphere of relative humidity of 100% and a temperature of 25 ° C. for 30 days allows permeation of corrosive substances such as salt or acid dissolved in water, and as a result, It cannot be used because the corrosion of the aluminum wire of the anticorrosion overhead electric wire cannot be sufficiently prevented.

In selecting a grease satisfying the above requirements, it is necessary to employ a base oil constituting the grease and a thickener for thickening the base oil having a low water content and a low water absorption. As such a base oil,
For example, silicone oil can be used. Silicone oils are preferred because they have the further advantage of high weather resistance and electrical insulation. Examples of the silicone oil include dimethylsiloxane, methylphenylsiloxane,
Known materials such as a mixture thereof can be used.

The thickener may be, for example,
Hydrophobic silica is mentioned. This hydrophobic silica is manufactured by a dry method and has a low affinity with water. Hydrophilic silica produced by the hydrolysis method has a high affinity with water, and therefore does not sufficiently reduce the water absorption of the grease using it.

When the grease is prepared, it is preferable to adjust the compounding ratio of the base oil of the grease and the thickener so that the resulting grease has a consistency of 200 to 300. If the consistency is less than 200, the resulting grease tends to flow and cannot be used as grease.
Further, when it exceeds 300, the obtained grease becomes extremely hard and the workability is deteriorated, which is not preferable.

The grease used in the present invention may include, if necessary, a weathering agent such as carbon, hydrotalcite,
Known additives such as an acid acceptor such as magnesium hydroxide may be appropriately added.

The grease is applied to the surface of the overhead wire by an appropriate applying means. The coating thickness of 4 to 5 mm on average is sufficient. Further, the filling of the grease is performed by twisting the aluminum wires or the aluminum alloy wires of the composite twisted wire together while packing the grease between the wires and applying the grease overflowing to the outer surface to the entire surface.

A specific example will be shown below. Regarding various greases obtained by thoroughly mixing the thickener shown in Table 1 with silicone oil, the water content of the origin (hereinafter referred to as "water content A"), the relative humidity of 100%, and the atmosphere of temperature 25 ° C The water content (hereinafter referred to as "water content B") after being left in the tank kept at 30 days for 30 days was measured by a Karl Fischer moisture content measuring device.

The grease is applied to both sides of an aluminum plate in a thickness of about 1 mm, and the aluminum plate is
After dipping in mol / l hydrochloric acid at a temperature of 25 ° C. for 24 hours and then pulling up to remove the grease, the weight reduction rate was obtained. The weight reduction rate of 0.05% or less was evaluated as ⊚, 0.1% or less was evaluated as ◯, 5% or less was evaluated as Δ, and more than 5% was evaluated as x.

Further, the grease is "JCS399".
Tested by. "JCS399" is an electric wire industry association standard for evaluating grease for overhead wires. The results of the above tests are shown in Table 1.

[0017]

[Table 1]

From the results shown in Table 1, the water content A is 300 ppm.
With the grease having a water content B of less than 1000 ppm, the performance of protecting aluminum from acid is extremely high. Further, a grease having a water content A of more than 300 ppm and a water content B of 1000 ppm or more cannot sufficiently prevent acid permeation, and is inferior in anticorrosion performance.

[0019]

As described above, the corrosion-resistant overhead wire of the present invention has a moisture content of 300 ppm or less, or a moisture content of 1000 ppm after being left in an atmosphere having a relative humidity of 100% and a temperature of 25 ° C. for 30 days. Since it is applied or filled with a grease of less than the above value, it has extremely low water absorption and suppresses the penetration of water and corrosive substances into the surface of the overhead wire. Therefore, it exhibits high anticorrosion performance, and its life is not shortened even when placed in a highly corrosive environment. Further, when the base oil is silicone oil and the thickening agent is hydrophobic silica as the grease, the water absorption of the grease is further lowered, and the grease exhibits more excellent anticorrosion performance.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yuji Asano             1-5-1 Kiba Stock Exchange, Koto-ku, Tokyo             Inside Fujikura (72) Inventor Fumio Umemura             1-3-1, Uchisaiwaicho, Chiyoda-ku, Tokyo East             Inside Kyoden Electric Co., Ltd. (72) Inventor Takanori Nukaga             1-3-1, Uchisaiwaicho, Chiyoda-ku, Tokyo East             Inside Kyoden Electric Co., Ltd. F-term (reference) 5G307 EC02 EE01 EE02 EF02                 5G313 FA05 FC04 FC10 FD06

Claims (3)

[Claims] 1. An anticorrosion aerial wire, characterized by being coated or filled with grease having a water content of 300 ppm or less. 2. An anti-corrosion aerial cable characterized by being coated or filled with grease having a water content of less than 1000 ppm after being left for 30 days in an atmosphere having a relative humidity of 100% and a temperature of 25 ° C. 3. A grease, a base oil, a silicone oil,
The anticorrosion aerial wire according to claim 1 or 2, wherein hydrophobic silica is used as the thickener.