JP4897259B2 - Anticorrosion coating method for power transmission towers - Google Patents

Description

  The present invention relates to an anticorrosion coating method for steel materials constituting a power transmission tower.

  Since power transmission towers are often installed in harsh environments where they are exposed to wind and rain and are prone to rust, hot-dip galvanized steel is used as the steel that constitutes them. Rust appears on the treated surface. Therefore, anti-corrosion coating is applied to the surface of the steel material constituting the power transmission tower after a predetermined period. However, over time, choking due to deterioration of the top coat film and cracking of the surface occur, and furthermore, rust that appears on the surface of the steel material floats on the surface of the paint film, or moisture penetrates into the paint film and the steel material. Zinc elutes at the interface, and peeling or floating of the coating film occurs. In addition, even if the above rust and cracking of the surface do not occur, if the appearance of the coating surface changes in color (fading), the aesthetics deteriorate, lack of environmental harmony, functional color such as aerial colors, etc. Strong repainting may be required. Therefore, under such circumstances, it is necessary to periodically repeat the anticorrosion coating (repainting) every predetermined coating cycle. This repainting is preferably performed just before rusting in consideration of economy.

In order to prevent an electric shock accident during the work, the anti-corrosion coating work at this site must be performed by powering off the overhead transmission line supported by the transmission tower to which the anti-corrosion coating is to be applied. This power failure of the power transmission line is usually performed by distributing the power supplied to the power transmission line to another power transmission line. However, when trouble occurs in the other power transmission lines, there is a possibility that power supply will be hindered, resulting in a power outage in the demand area. In order to reduce this risk as much as possible, there is a circumstance that the power transmission line cannot be interrupted for a long time. Therefore, it is necessary to complete this anticorrosion painting work in a short time, and the work period is usually within one day.

  In order to ensure long-term anticorrosion, the anticorrosion coating is usually performed by overcoating such as undercoating and overcoating, or undercoating, intermediate coating and overcoating. In order to perform anti-corrosion coating by repeatedly applying the paint in the limited time as described above, the paint needs to have excellent quick drying properties. There are limited types of paints that satisfy such requirements for quick drying, and conventionally, modified vinyl resin-based paints, oil-based paints, and the like have been used. For example, modified vinyl resin-based paints are used for both undercoating and overcoating. In aluminum paints and acrylic-modified alkyd resin-based paints, a quick-drying zinc chromate primer is applied to the substrate in advance, and the primer is dried. In general, an aluminum paint or an alkyd resin-based paint is overcoated on the coating surface. However, the modified vinyl resin-based paints and oil paints are not sufficient for long-term corrosion resistance and weather resistance, and it is necessary to perform anticorrosion coating (repainting) work in a relatively short time. Moreover, because there is a restriction on the power transmission stop time, there is a problem that the method of repeatedly applying the same type of anticorrosive paint in each repainting work has to be taken, and as a result, the repainting cycle cannot be prolonged. .

  On the other hand, examples of the paint excellent in long-term corrosion resistance and weather resistance of the coating film include epoxy resin-based paints, urethane resin-based paints, and fluororesin-based paints. Urethane resin-based paints and fluororesin-based paints are usually used for intermediate coating and top coating, and for that purpose, it is necessary to undercoat using an epoxy resin-based coating to form a coating film of the coating. However, the epoxy resin-based paint has the above-mentioned advantages but has a difficulty in drying. For example, when coating is performed in an environment where the temperature is 20 ° C., the interval until the coating surface can be overcoated usually takes about 18 hours. Prolonged further. Therefore, if you try to use this epoxy resin-based paint for the undercoating of transmission tower steel, you must inevitably lengthen the power transmission stop time and use these paints with the problem that the waiting time for workers will also be longer. There was also a problem that it was difficult to do.

In addition, the epoxy resin-based paint is usually a two-component type which is mixed for use and used for coating. Generally, the usable time of the paint is short, the mixing ratio thereof is changed, or by using a curing accelerator, The pot life may be shortened. Therefore, there has been a problem that the amount of paint used increases and the coating cost and transportation cost increase. Furthermore, epoxy resin paints include aromatics such as xylene and toluene, ketones such as methyl isobutyl ketone (MIBK), alcohols such as butanol, esters such as butyl acetate, and ethers such as carbitol. Since it contains an organic solvent having a functional group and high dissolving power, there is a difficulty in adhesion to vinyl resin-based and aluminum-based old coating films.
Japanese Patent Laid-Open No. 2001-40280

In view of such circumstances, the present invention can complete an anti-corrosion coating operation in which at least two recoating operations are performed in about 12 hours, and can obtain a coating film excellent in long-term anti-corrosion properties and weather resistance. It aims at providing the anticorrosion coating method which can lengthen the period of this.

  Based on the above objectives, the present inventor has conducted extensive studies, and as a result, a specific moisture-curable resin paint having a long-term corrosion resistance and weather resistance comparable to that of an epoxy resin paint is a conventional vinyl resin. The present invention was completed by obtaining the knowledge that it can be attached to a coating film such as a resin paint or aluminum paint.

According to the present invention, the object of the present invention is to adjust the substrate surface of the steel coating surface, and undercoat the substrate adjustment surface with a moisture curable resin paint whose semi-curing drying time is adjusted within about 4 hours according to the environmental temperature conditions. Then, when the semi-cured and dried state is reached, the anti-corrosion paint is overcoated on the surface of the undercoat coating film.

  The steel material coating surface is a modified vinyl resin paint or aluminum paint coating surface, and the anticorrosion coating method of the present invention can be more suitably used for these old coating surfaces.

According to the present invention, in the anticorrosion coating of a power transmission tower, a specific moisture-curing resin paint having a quick drying property is further adjusted as an undercoating paint by adjusting the semi-curing drying time within about 4 hours according to the environmental temperature conditions. Since the coating is performed, the intermediate coating or the top coating can be further applied to the surface of the undercoat film that has been cured in a short time. Thereby, loss time can be reduced and the coating cost can be reduced. In addition, coatings with excellent long-term corrosion resistance and weather resistance can be used for intermediate coatings and top coatings, and coatings with such excellent performance can be laminated, so the cycle of anticorrosion coating can be extended. . As a result, when viewed from a long-term span, it is possible to reduce the transportation cost of materials and the like related to repainting work and the number of power transmission interruptions.

  The anticorrosion coating method of the present invention is to prepare a base on the anticorrosion coating surface of a steel material deteriorated by rusting, and after forming an undercoat film with a moisture-curable resin paint on the base adjustment surface, at least once anticorrosion Overpainting is performed using paint. Hereinafter, the anticorrosion coating method of the present invention will be described in more detail.

  As the steel material constituting the power transmission tower, angle steel having a rust-proofing treatment on the surface thereof such as carbon steel is usually used, but in the present invention, the type and shape of the steel material are not particularly limited. For example, the types of steel materials include carbon steel, various alloy steels, stainless steel, etc. The shapes include round steel, angle steel, flat steel, groove steel, I-shaped steel, H-shaped steel, etc. Examples include steel pipes.

  The steel material may have already been subjected to anticorrosion coating on the surface thereof, or may have been subjected to rust prevention treatment as described above. However, in the present invention, the former anticorrosion coating is already at least 1 Targeted steel materials that have been recirculated. In the case of a power transmission tower, this anticorrosion coating is usually one in which a vinyl resin paint or an oil paint is applied multiple times.

  For such a steel material coated surface, the substrate is adjusted by dividing it into a floating rust on the painted surface and a part where the coating film is deteriorated and an active film part (a part where the coating film is not deteriorated). The substrate adjustment is intended to improve the adhesion with the anticorrosion coating newly constructed on the old coating.

  For the deteriorated part of the old paint film, depending on the degree of floating rust or deterioration of the old paint film, for example, a known method such as keren treatment or blast treatment is used as appropriate. Remove the film. Keren treatment is a method of removing the rusted part and deteriorated coating film using waste cloth, electric disk sander, wire brush, scraper, sandpaper, etc. This is a method of removing rust and a deteriorated coating film on a painted surface by spraying a spraying (polishing) material having a small particle diameter with compressed air.

  In addition, the dust, oil, salt, etc. stuck to the active film portion is coarsened with a wire brush, scraper, sandpaper, etc., and then removed using a waste or the like. When dust or the like is firmly attached to the active film surface, it may be roughened using an electric disk sander or the like.

  In this way, after adjusting the surface of the old painted surface of the steel material, undercoating is performed using a moisture curable resin paint. Examples of the moisture curable resin coating include polyurethane resin, epoxy resin-ketimine curing, alkyl silicate resin, and alkyl alkoxysilane resin. In the present invention, it is preferable to use a moisture-curable polyurethane resin coating, and it is more preferable to use a one-pack type. As these moisture curable resin coatings, those produced by various known production methods can be suitably used.

  The above one-component moisture curable polyurethane (MCU) resin coating is mainly composed of a resin in which an isocyanate group (-NCO group) obtained by reacting a polyol and a polyisocyanate to urethane-bond all hydroxyl groups is left. Including. The polyisocyanate preferably has three or more functional groups and a weight average molecular weight between crosslinks of 500 to 1500 (Mw). The paint is produced by adding extender pigments and coloring pigments which are not reactive with isocyanate and have no water content and moisture absorption. Examples of the extender pigment include talc, calcium carbonate, barium sulfate, and mica-like iron oxide. Examples of the color pigment include titanium oxide, bengara, carbon black, and phthalocyanine blue. These pigments may be blended alone or in combination of two or more in the above resin. Examples of such one-component moisture-curable polyurethane (MCU) resin paints include Paine # 8010S (trade name, manufactured by Chuden Kogyo Co., Ltd.) and V Gran (trade name, manufactured by Dainippon Paint Co., Ltd.). .

  The curing reaction of the moisture-curable polyurethane resin-based paint is based on the ring-opening polymerization reaction of the moisture-curable polyurethane resin contained as a main agent in the paint, and is cured by reacting with moisture in the environment such as moisture. To do. The curing reaction can be outlined as follows. The above-mentioned resin has an isocyanate group as a reactive group at the terminal, and this reactive group reacts with moisture in the air or moisture on the substrate adjustment surface to generate carbamic acid. This carbamic acid is very active and decomposes to produce amine and carbon dioxide. The produced amine reacts with the isocyanate groups of the moisture-curing polyurethane resin present in the surroundings, and a tough cured product (coating film) having a three-dimensional network structure is produced by urea bonding. This curing reaction mechanism is shown below.

  As this moisture curable resin coating material, a semi-curing drying time of about 4 hours under a 20 ° C. environment and a touch drying time of about 2 hours can be suitably used. In general, the drying time tends to be longer when the temperature is lower than the above temperature and shorter when the temperature is higher. For example, when it is desired to shorten the drying time in an extremely low temperature environment such as −5 ° C., a predetermined curing accelerator can be used. Examples of the curing accelerator include a mixed solution of 10 parts by weight of triethylenediamine and 90 parts by weight of the high boiling point organic solvent, and the addition amount is preferably about 1 to 3% by weight with respect to the total amount of the paint. .

  Also, an antifoam solution can be added to the paint. Examples of such an antifoaming agent solution include a silicon-based antifoaming agent. Specifically, silicon YSA6402 (trade name, manufactured by Toshiba Silicon Corporation), silicon KF69 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), or the like can be suitably used. These are usually diluted 100 times with a high-boiling organic solvent described later and added to the coating composition.

This moisture curable resin coating material may be used for coating as it is, or may be used for coating after dilution and viscosity adjustment. In the latter case, a hydrocarbon-based organic solvent can be suitably used as the diluent. Of these, aromatic hydrocarbon organic solvents are preferable, and those having a high boiling point are more preferable. Here, the “high boiling point” aromatic hydrocarbon-based organic solvent has a distillation range of 160 to 180 ° C., contains 95% by volume or more of a heavy aromatic compound, and complies with Japan Paint Industry Association Standard JPIA-4. The equivalent shall be said. Examples of such high-boiling aromatic hydrocarbon solvents include Solvesso 100-grade Swazol 1000 (trade name, manufactured by Maruzen Petrochemical Co., Ltd.), Nisseki Hysol 100 (trade name, manufactured by Shin Nippon Petrochemical Co., Ltd.), Ipsol 100 (product) Name, manufactured by Idemitsu Kosan Co., Ltd.). Although the amount of the solvent added depends on the target viscosity, it can be set to about 5 to 30% by weight with respect to the total amount of the paint after dilution.

A known coating method can be used for applying the paint to the substrate adjustment surface. Examples of such known coating methods include airless spray coating, brush coating, and roller coating. The standard coating amount is usually about 0.19 kg / m ^{2 in} the case of airless spray coating, and about 0.15 kg / m ^{2 in} the case of brush coating. Moreover, it is good to make it a coating film thickness be 20-80 micrometers by the dry coating film thickness, Preferably it is 30-70 micrometers, More preferably, it is 40-60 micrometers. The thicker the coating, the better the durability of the coating. However, if the thickness is less than the above range, there is a problem with the durability of the coating. It is not preferable. In particular, in the case of airless spray coating, a coating thickness of 80 μm or more can be obtained. However, the generation of gas due to the urethane reaction causes pinholes on the coating surface, resulting in poor coating appearance.

  This moisture-curable polyurethane resin-based paint can be suitably used in anticorrosion coating work for power transmission towers, which is less affected by temperature in the environment and is often performed from autumn to winter. In addition, by using the one-component paint in this way, the pot life is not limited by the mixing ratio as in the case of the two-component paint. In addition, this paint has an advantage that the coating base selectivity is small and any base can be applied.

  After the coating film of the moisture curable resin coating is in a semi-cured and dried state, the anticorrosion coating is applied to the coating surface at least once. As the anticorrosion paint, known intermediate paints and topcoat paints can be used. Therefore, the above-mentioned coating surface can be further coated once or twice or more times, but preferably on the above-mentioned coating surface. A direct (i.e. once) weather resistant top coat may be used. Examples of the weather-resistant top coating include fluororesin-based coatings, chlorinated rubber-based top coatings, polyurethane resin-based top coatings, acrylic top coatings, silicon alkyd top coatings, and silicone acrylic top coatings. Can be selected and used for painting.

  The anticorrosion coating method of the present invention can be applied not only to the power transmission tower, but also to a steel structure such as a bridge or an offshore structure, and can be directly applied to the surface of a zinc-treated steel immediately after production. Needless to say.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. In the following examples, “parts” are based on weight unless otherwise specified. Moreover, the used coating materials are as follows, and the following evaluation methods were also used for the evaluation methods of various physical properties.
[Used paint]
The following undercoat and topcoat were used for the test.
(1) Moisture curable polyurethane resin paint

(2) Modified vinyl resin paint

(2) Quick-drying zinc chromate primer

(3) Acrylic alkyd resin paint

(4) Aluminum paint
JIS K5492 equivalent (5) Chlorinated rubber base coating
Equivalent to JIS K5639 “Topcoat” (6) Polyurethane resin-based topcoat
JIS K5657 “Topcoat” equivalent (7) Fluororesin-based topcoat
JIS K5659 “Topcoat” equivalent

(8) Modified epoxy resin paint

[Evaluation methods]
(1) Film thickness measurement The film thickness of the coating film was measured using a film thickness meter (model SME-2, electromagnetic induction type, manufactured by Sanko Electronics Laboratory).

(2) Paint workability JIS K 5600 1-1. Conforms to brush coating K 5600 1-5.

(3) Low temperature property Evaluation was made based on whether or not overcoating can be performed in a predetermined time after applying the undercoat paint in an environment of -5 ° C and 50% relative humidity.
○: Topcoat can be applied within 8 hours after undercoating △: Slightly difficult to apply, but overcoating is possible within 8 hours ×: Cannot be overcoated even if left for more than 8 hours

(4) Under high humidity Evaluation was made based on whether or not an abnormality occurred in the coating film when coated in an environment of normal temperature (23 ° C.) and relative humidity of 99%.
○: No change is observed in the coating film, and the drying is good.
(Triangle | delta): Drying is favorable to such an extent that glossiness (glossiness is lost and it looks whitish) is recognized.
X: Whitening of the coating film is recognized and film forming property is not recognized.

(5) Dryability Evaluation was made based on whether or not overcoating was possible within a predetermined time in a normal temperature (23 ° C.) environment.
○: Drying is fast and overcoating is possible within 4 hours. Δ: Drying is slightly inferior, but overcoating is possible within 4 hours. X: Drying is slow and cannot be overcoated in 1 day.

(6) Adhesion Hold a two-pack type epoxy resin adhesive (TE2220 (trade name), manufactured by Toray Fine Chemical Co., Ltd.) on the coating surface and fix the jig. Adhesion was evaluated using a testing machine ADHESION TESTER (manufactured by ELECOMTER).

(7) Accelerated weather resistance According to JIS K5600-7-7 (xenon lamp method), xenon lamp light was irradiated for 1000 hours, and the weather resistance of the irradiated surface of the coating film was evaluated by the appearance of the coating film and the adhesion of the coating film.
The appearance of the coating film was determined visually.
○: No coating film abnormality such as cracking, peeling, swelling, etc. was observed, and gloss reduction and rust generation were small.
△: Little change in appearance, but change in gloss is observed. ×: Many cracks, peeling, and swelling are observed, and rust is observed. Judged as follows.
○: No delamination is observed, and the adhesion state is good. Δ: Partial delamination is observed. ×: Delamination is observed on the entire surface.

(8) Salt sprayability After spraying salt water for 1000 hours in accordance with JIS K5600-7-1, the salt spray resistance of the coating film salt spray surface was evaluated by the appearance of the coating film and the adhesion of the coating film. The evaluation criteria are the same as (7) above.

(9) Moisture resistance After operating for 500 hours in accordance with JIS K5600-7-2 (continuous condensation method), the moisture resistance of the coating film test surface was evaluated by the same method as in (7) above. The evaluation was based on the adhesion of the coating film. The evaluation criteria are the same as (7) above.

[Preparation method of old paint film]
The hot-dip galvanized steel sheet was coated as described in Table 6 “Old paint film”. In the table, the "modified vinyl resin", undercoating, overcoating with modified vinyl resin paint is obtained by applying the (both film thickness 30 [mu] m), the term "aluminum-based", quick-drying Jinkukurome DOO as a primer A primer (with a coating thickness of 25 μm) is applied, and then an aluminum paint (with a coating thickness of 15 μm) is applied as an overcoat. In addition, the "acrylic alkyd resin system", after applying a fast drying Jinkukurome preparative primer (coating thickness 25 [mu] m) as a primer, which was coated with acrylic-modified alkyd resin paint (film thickness 30 [mu] m) as a top coat “Hot galvanized” is a galvanized steel sheet used as it is.

  The coating film on the steel sheet obtained as described above is left for 2000 hours under irradiation of a xenon lamp to deteriorate the coating film surface, and then exposed to the outdoors for one year. The coating after the exposure was regarded as an actual exposure for 5 years, and was used for the test as an old coating. The weather resistance test with a xenon lamp was based on JIS K5600-7-7.

Example 1
The surface of the old coating film of the hot-dip galvanized steel sheet on which a modified vinyl resin-based old coating film is formed is prepared, and after the surface is cleaned, a moisture-curable polyurethane resin-based coating is used as the undercoat with a coating thickness of 50 μm. When a semi- cured and dried state was reached, a chlorinated rubber-based top coating was applied as a top coat to a coating thickness of 30 μm to obtain a test specimen.

Example 2
After the surface of the hot-dip galvanized steel sheet on which the aluminum-based old coating film has been formed is adjusted and the surface is cleaned, a moisture-curable polyurethane resin-based paint is applied to the coating thickness of 50 μm as the undercoat. When a semi- cured and dried state was reached, a chlorinated rubber-based top coating was applied as a top coat to a coating thickness of 30 μm to obtain a test specimen.

Example 3
After the surface of the hot-dip galvanized steel sheet on which the acrylic alkyd resin-based old coating film has been formed is prepared and the surface is cleaned, a moisture-curable polyurethane resin-based coating is used as the undercoat with a coating thickness of 50 μm. When a semi- cured and dried state was reached, a chlorinated rubber-based top coating was applied as a top coat to a coating thickness of 30 μm to obtain a test specimen.

Reference Examples 1-3
Each test specimen was obtained by directly applying the undercoat and topcoat of Examples 1 to 3 to the same coating thickness on the surface of the hot-dip galvanized steel sheet.

Comparative Examples 1-3
In the same way as the conventional repainting method, on each old paint film surface of modified vinyl resin system, aluminum system and acrylic alkyd resin system,
(1) Modified vinyl resin-based paint of the same type for both undercoat and topcoat (both film thickness is 30 μm)
(2) Undercoat fast drying Jinkukurome preparative primer (coating thickness 25 [mu] m), overcoated aluminum paint (film thickness 15 [mu] m)
(3) an undercoat fast drying Jinkukurome preparative primer (coating thickness 25 [mu] m), topcoat acrylic-modified alkyd resin paint (film thickness 30 [mu] m)
The test bodies of Comparative Examples 1 to 3 were obtained.

Comparative Examples 4-6
In Comparative Examples 1 to 3, the undercoat paint applied on each old paint film was changed to a modified epoxy resin paint, and the top coat was changed to a chlorinated rubber system, a urethane system, and a fluorine system, respectively. Test bodies of Examples 4 to 6 were obtained. The coating thicknesses of these undercoat and topcoat were both 30 μm.

  These evaluation results are shown in Table 1.

As is clear from Table 6, it was shown that the coating films of the repaints of Examples 1 to 3 were excellent in both the coating workability and the coating film performance.
On the other hand, in the case of Comparative Examples 1 to 3, the appearance of the coating workability (low temperature and high humidity) and the coating film performance are generally inferior, and when the zinc chromate primer is used as the undercoat, the coating film performance, particularly adhesion Was also shown to be inferior. Moreover, in the case of Comparative Examples 4-6, although the coating-film performance is generally favorable, it was shown that it is inferior to coating workability (drying property), and a long time is required for the coating work.

  Based on the above results, in order to investigate the actual time required for the anticorrosion coating and the state of the coating film, the steel coating surface of the transmission tower, which has passed seven years after the anticorrosion coating with the modified vinyl resin paint, has already been applied. After the substrate was adjusted on the entire surface as follows, the anticorrosion coating shown in Examples 4 and 5 and Comparative Example 7 was performed.

Example 4
Dirt, oil, and the like were removed using waste cloth, Magiclon (registered trademark, manufactured by Sankyo Rikagaku Co., Ltd.), etc., and the substrate was adjusted. The substrate-adjusted surface was brush-coated with a moisture-curable polyurethane resin paint having the composition shown in Table 1 as an undercoat so as to have a film thickness of 50 μm and dried for 4 hours. Thereafter, a polyurethane resin-based topcoat paint diluted as a topcoat at a predetermined dilution rate was applied with a brush so that the film thickness was 30 μm. As a result, the state of the coated film after coating was good, and the repainting could be completed within 12 hours of power transmission stop time.

Example 5
Corrosion-proof coating was applied in winter on a similar power transmission tower that had passed seven years since the last anti-corrosion coating. The anticorrosion coating was performed in the same manner as in Example 1 except that 2 parts of a curing accelerator was added to 100 parts by weight of a moisture-curable polyurethane resin-based paint that was an undercoat paint.
As a result, the same result as in Example 4 was obtained.

Comparative Example 7
Similarly, about the power transmission tower which passed for 7 years, the steel material coating surface was brush-coated with the modified epoxy resin-based paint shown in Table 5 so that the coating thickness was 30 μm, and then the primer was applied. Then, 18 hours were required as drying time until it became possible to brush-apply the polyurethane resin-type top coat. As a result, the repainting work took 2 days, and 2 days were required as the power transmission stoppage time.

  Further, as is clear from Examples 4 and 5, when the anticorrosion coating method of the present invention is actually used on the steel coating surface of the transmission tower, the two times of the undercoating and topcoating operations can be completed in 12 hours. In contrast, in Comparative Example 7, the painting work took 2 days, and the power outage time took 2 days. Also from these results, it is clear that overcoating can be performed in a short time by using the anticorrosion coating method of the present invention.

As described above, the anticorrosion coating method of the present invention is suitable for the repainting work of the transmission tower, which has not been able to make the repainting cycle longer due to time restrictions.

Claims (6)

After adjusting the surface of the steel coated surface, and undercoating the moisture-curing resin coating with the semi-curing drying time adjusted within about 4 hours according to the environmental temperature conditions on this surface-adjusting surface, the semi -cured dry state is reached. Then, an anticorrosion coating method for a power transmission tower, characterized in that an anticorrosion coating is repeatedly applied to the surface of the undercoat.   The anti-corrosion coating method according to claim 1, wherein the moisture curable resin paint is a polyurethane resin system.   The anti-corrosion coating method according to claim 1, wherein the moisture curable resin coating is a one-component coating.   The anticorrosion coating method according to any one of claims 1 to 3, wherein the anticorrosion coating is a weather-resistant top coating.   The power transmission according to claim 4, wherein the weather-resistant top coating is a polyurethane resin-based top coating, a fluororesin-based top coating, a chlorinated rubber-based top coating, an acrylic top coating, a silicon alkyd top coating, or a silicon acrylic top coating. Anti-corrosion painting method for steel towers.   The anticorrosion coating method according to any one of claims 1 to 5, wherein the steel material coating surface is a surface of a modified vinyl resin-based paint or an aluminum paint coating film.