JP2006269285A - Surface treatment method of aluminum wire for power transmission line or aluminum alloy wire and manufacturing method of power transmission line using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wire excelling in corrosion resistance, in relation to a surface treatment method of an aluminum wire or an aluminum alloy wire used for a power transmission line installed between iron towers or the like. <P>SOLUTION: This application is related to a surface treatment method of an aluminum wire or an aluminum alloy wire for a transmission line composed by applying a surface treatment agent containing a rosin compound to its surface, wherein the content of the rosin compound in the surface treatment agent is 10-20 mass%. When the wires are formed into an aerial transmission line, the transmission line is hardly broken and can provide sufficient corrosion resistance, that is, environmental barrier properties by the application of the rosin compound even in a strong acid atmosphere and even when chlorine ions and the like are present. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a surface treatment method for an aluminum wire or an aluminum alloy wire used as a conductor of a transmission line installed between steel towers and the like, and a method for manufacturing a transmission line using the same, and particularly to improve corrosion resistance. Is.

  The overhead power transmission line installed between the steel towers is required to be lightweight in order to reduce the construction cost of the steel tower and other facilities. Therefore, as a conductor of this power transmission line, aluminum or aluminum alloy which is lightweight and has a relatively high conductivity in the conductor is often used.

  On the other hand, this transmission line is loosened between the towers due to its own weight, and hangs down in the center between the towers, but in order to ensure safety, the part that hangs down according to the transmission voltage to the transmission line It is necessary to set the height from the ground above a predetermined height.

  However, if the height of the support point such as a steel tower is further increased for this purpose, the construction cost of the steel tower and other facilities will increase. Therefore, conventionally, a method has been used in which the tension applied to the power transmission line between the steel towers is increased to reduce the amount of looseness (sag). In this case, in order to increase the strength against the tension of the transmission line, an aluminum wire or an aluminum alloy wire is twisted on a concentric circle around a single wire or stranded wire of a galvanized steel wire or an aluminum-clad steel wire. The composite twisted wire (ACSR: Aluminum Conductor Steel Reinforced) is used as an overhead power transmission line.

  By the way, such an overhead power transmission line is required to have excellent environmental resistance because it is exposed to a natural environment such as sunlight and wind and snow. Therefore, the surface of the steel wire used for the steel core aluminum stranded wire such as ACSR is subjected to anticorrosion treatment such as galvanization or aluminum coating. On the other hand, aluminum wires and aluminum alloy wires have good corrosion resistance in a normal environment, so when used in a normal environment, it is common not to give special anti-corrosion treatment to their surfaces. It is.

  However, the corrosion resistance of aluminum wires and aluminum alloy wires is significantly reduced due to the presence of chlorine ions and the like. Therefore, in areas close to the ocean, there is a large amount of chlorine ions in the atmosphere, and this presence of chlorine ions and moisture has caused a problem that even an overhead power transmission line such as an ACSR is corroded. .

Therefore, the applicant has already proposed a method for improving the corrosion resistance of the overhead power transmission line by applying anti-corrosion grease to the metal part exposed to the outside air in order to cope with such a situation ( Patent Document 1).
JP 2001-006438 A

  Recently, however, corrosiveness to aluminum wires and aluminum alloy wires has been increasing in areas other than those affected by the ocean due to the effects of air pollution and acid rain, and overhead power transmission lines have been exposed to such an environment. Then, there is still a problem that the corrosion proceeds.

  Further, it was found that, even in such a severe environment, when the above-mentioned anti-corrosion grease is applied, a certain degree of anti-corrosion effect can be obtained, but in this environment, there is a problem that the grease itself deteriorates. . That is, since the grease is made of a polymer compound, the grease itself tends to deteriorate when exposed to ultraviolet rays of sunlight or heated.

  For this reason, in a corrosion-proof overhead power transmission line coated with grease, maintenance inspection such as replenishment of grease is required by periodically monitoring the condition of the grease. However, in an overhead power transmission line such as an ACSR, the conductor aluminum wire and aluminum alloy wire rapidly corrode in such a severe environment, so complete maintenance and inspection is impossible.

  Therefore, the present inventor diligently studied a material that can sufficiently withstand even in such a severe environment. As a coating material replacing grease, a surface treatment agent containing a rosin compound, for example, rosin potassium is optimal. I found. That is, the surface treatment agent containing a rosin compound can form a coating film having high adhesion on the surface of an aluminum wire or an aluminum alloy wire, and this coating film can be used in a strongly acidic atmosphere or It was found that even if chlorine ions exist, they are not easily destroyed and have excellent environmental barrier properties.

  The present invention has been made from such a viewpoint, and basically, a surface treatment method for an aluminum wire or an aluminum alloy wire for power transmission lines in which a surface treatment agent containing a rosin compound is applied to the surface, and this The present invention provides a method for manufacturing a power transmission line using the.

  The invention according to claim 1 is characterized in that a surface treatment agent containing a rosin compound is applied to the surface, and the content of the rosin compound in the surface treatment agent is 10 to 20% by mass. A surface treatment method of an aluminum wire or an aluminum alloy wire.

  The invention according to claim 2 is characterized in that a surface treatment agent containing a rosin compound is applied on the surface, and the kinematic viscosity of the surface treatment agent is 3 to 40 cSt, It exists in the surface treatment method of an alloy wire.

  According to a third aspect of the present invention, there is provided a method for manufacturing a power transmission line using the aluminum wire or the aluminum alloy wire for a power transmission line by the surface treatment method according to any one of the first to second aspects.

  According to the surface treatment method of the aluminum wire for power transmission lines or the aluminum alloy wire of the present invention, since the surface treatment agent containing a rosin compound is applied to the surface of these wires, compared with the grease for corrosion resistance, Higher excellent corrosion resistance is obtained. That is, in the case of a surface treatment agent containing a rosin compound, a coating film with high adhesion is formed on the surface of the wire when the moisture evaporates after application. This is because the coating film is not easily broken even in a strongly acidic atmosphere or in the presence of chlorine ions and exhibits excellent environmental barrier properties.

  Further, according to the method for manufacturing a power transmission line of the present invention, since the aluminum wire or the aluminum alloy wire for power transmission line coated with the surface treatment agent containing the rosin compound is used, the above action causes strong acidity. Even in the atmosphere or in the presence of chlorine ions, it is difficult to corrode and excellent corrosion resistance, that is, environmental barrier corrosion resistance can be obtained.

  In the surface treatment agent containing the rosin compound of the present invention, for example, rosin potassium, the content of rosin potassium is 10 to 20% by mass, the remaining is made of water, and the kinematic viscosity at room temperature is 3 to 40 cSt. . As the rosin compound, rosin sodium and the like can also be used.

  Here, the reason why the content of rosin potassium is 10 to 20% by mass is that when the content is less than 10% by mass, the kinematic viscosity (viscosity / specific gravity) is low, so that it tends to sag from the wire after coating. is there. If there is dripping, the film thickness of the coating film varies, and sufficient environmental barrier properties cannot be obtained. On the other hand, when the content exceeds 20% by mass, the kinematic viscosity is increased, and a coating film having excessive viscosity is formed on the surface of the wire, although there is no problem in corrosion resistance. This is because there is a concern about the deterioration of workability. In addition, the appearance of the transmission line may be impaired. That is, when the concentration of rosin potassium is high, a thick coating film of pine tan (dark blue) is obtained. In addition, the kinematic viscosity under normal temperature (about 25 degreeC) ensures 3-40 cSt value by setting it as content of the said range.

  In the application of the surface treatment agent thus formed, the surface treatment agent is sprayed on the aluminum wire or aluminum alloy wire until the rough drawn wire is drawn and wound on the bobbin, or the surface treatment agent is brushed. Application may be performed by painting or the like, or an aluminum wire or an aluminum alloy wire may be applied through a tank filled with a surface treatment agent. And if necessary, it leads to a drying process, it is made to dry (natural drying in air | atmosphere is also possible), and a desired coating film will be obtained if a water | moisture content is removed.

A desired aerial power transmission line can be obtained by twisting the outer periphery of a galvanized steel wire or an aluminum-clad steel wire as a normal ACSR by using the aluminum wire or aluminum alloy wire to which this coating film is applied.
<Examples and comparative examples>

  First, as shown in Table 1, water was dissolved as a solvent so that potassium rosin had various contents. The kinematic viscosity at room temperature (about 25 ° C.) of this aqueous solution (surface treatment agent) was measured with an Ubbelohde viscometer. Next, in the twisting step of the aluminum wire in the manufacturing process of the ACSR that becomes the power transmission line, the surface treatment agent having the various rosin potassium contents is applied to the surface of the aluminum wire by spraying with a spray nozzle, It was made to dry and the coating film was formed (Examples 1-2, Comparative Examples 1-2). In the case of Comparative Example 3, an ACSR was manufactured using an untreated aluminum wire.

Thereafter, the obtained ACSR was cut into a length of 500 mm, and in order to avoid corrosion due to exposure of the end face, both ends were coated with a resin (for example, epoxy resin) to obtain a sample for a corrosion test.
These were subjected to a salt water cycle test for 3000 hours in accordance with the “corrosion resistance test method for plating” defined in JIS-H8502. The dry and wet cycle conditions were salt spray 2 hours → dry 4 hours → wet 2 hours. After this test, the sample was subjected to cross-sectional observation, and the maximum pitting corrosion depth generated on the aluminum wire was measured. These results are also shown in Table 1 above.

  From Table 1, in the case of ACSR (Examples 1 and 2) according to the method of the present invention, since a surface treatment agent containing appropriate rosin potassium was applied, a good coating film was formed and maximum pitting corrosion was observed. It can be seen that the depth is small, and in particular, excellent corrosion resistance, that is, environmental barrier properties, is obtained as compared with an untreated aluminum wire (Comparative Example 3).

On the other hand, in the case of ACSR (Comparative Example 1) coated with a surface treatment agent (less than 10% by mass, less than 10% by mass) with a low content of rosin potassium, it was assumed that the sag from the wire rod was low because the kinematic viscosity was low. It can be seen that the formation of the coating film is insufficient and the maximum pitting depth is considerably large. On the other hand, in the case of ACSR (Comparative Example 2) coated with a surface treatment agent (25% by mass exceeding 20% by mass) containing too much rosin potassium, the kinematic viscosity is high and a sufficient coating film is formed. However, the appearance of a pine-ani color was seen in the appearance of the ACSR. There was also a reduction in workability in the stranded wire process.

Claims (3)

A surface of an aluminum wire or an aluminum alloy wire for power transmission lines, wherein a surface treatment agent containing a rosin compound is applied to the surface, and the content of the rosin compound in the surface treatment agent is 10 to 20% by mass Processing method. A surface treatment method for an aluminum wire for power transmission lines or an aluminum alloy wire, wherein a surface treatment agent containing a rosin compound is applied to the surface, and the kinematic viscosity of the surface treatment agent is 3 to 40 cSt. A method for manufacturing a power transmission line, comprising using an aluminum wire or an aluminum alloy wire for a power transmission line by the surface treatment method according to any one of claims 1 to 2.