KR102293861B1 - Coating method with surface treatment process for steel material structure and coating composition used therefor - Google Patents

Abstract

A steel structure coating method including a surface treatment process and a steel coating composition used therefor are disclosed. The steel structure coating method according to the present invention includes the steps of: treating the surface of a steel structure; and applying a topcoat paint to the steel structure, wherein the topcoat paint is provided as a two-component type paint using a mixture of a main agent and a curing agent, and the main agent of the topcoat paint includes 40 to 60 wt% of a modified fluororesin, 10 to 20 wt% of barium sulfate, and 7 to 13 wt% of titanium dioxide based on the total weight.

Description

Coating method for steel structure including surface treatment process and composition for steel coating used therefor

The present invention relates to a steel structure painting method and a composition for steel painting used therein, and more particularly, a surface treatment process of applying a heavy-duty paint to the surface of steel structures such as steel bridges, offshore structures, and steel plants. It relates to a coating method for steel structures including, and a composition for coating steel used therefor.

In recent years, as structures become larger, the use of steel structures (or steel structures) in bridges, offshore structures, and plant structures is increasing. Strength and durability must be ensured.

Generally, paints or coating materials are applied to the surface of such steel structures for aesthetics or corrosion prevention. The paint applied to the surface of the steel structure must have excellent properties such as weather resistance, chemical resistance, abrasion resistance, and contamination resistance, which can contribute to sufficiently securing the durability and safety of the steel structure. In particular, these characteristics are very important in a topcoat that comes into direct contact with a natural environment such as the atmosphere.

Related prior art documents include Registered Patent Publication No. 10-1619099 (Title of the invention: Steel coating construction method using an eco-friendly heavy-duty paint composition, Announcement date: May 10, 2016) and Registered Patent Publication No. 0-2164899 (Title of the invention: coating composition for steel and coating method for steel using the same, announcement date: October 13, 2020) and the like.

It is an object of the present invention to provide a composition for steel coating that has excellent weather resistance, chemical resistance, abrasion resistance, contamination resistance, etc., which can contribute to sufficiently securing the durability and safety of a steel structure, and a steel structure painting method using the same.

In addition, another object of the present invention is to perform the most appropriate surface treatment process for the surface of the steel structure in consideration of the size and condition of the work site, the required quality, and the given work time before applying the paint to the surface of the steel structure To provide a steel structure painting method that can improve the efficiency and quality of the overall painting operation.

The above object, according to the present invention, comprises the steps of treating the surface of a steel structure, and applying a top coat to the steel structure, wherein the top coat is a two-component type paint using a mixture of a main agent and a hardener Surface treatment characterized in that it contains 40 to 60% by weight of modified fluororesin, 10 to 20% by weight of barium sulfate, and 7 to 13% by weight of titanium dioxide as components based on the total weight of the top coat It is achieved by the steel structure painting method including the process.

Preferably, the main component of the top coat is 2 to 7% by weight of xylene, 2 to 7% by weight of 2-ethoxyethanol acetic acid, C.I. Pigment yellow 34 1-3 wt%, copper polychlorophthalocyanine green 0.3-0.8 wt% may be further included as a component.

Preferably, the subject of the top coat further comprises a pulverized plastic as a component, and the pulverized plastic is provided as a pulverized product prepared by pulverizing a waste foamed polyethylene material to a diameter of 0.1 to 5 mm, It may be included in 0.1 to 1% by weight based on the total weight of the subject.

Preferably, the surface treatment step is a step of removing corrosion products or foreign substances on the surface of the steel structure or removing an existing coating formed on the surface of the steel structure, among a sand blast method, a shot blast method, and a soda blast method. It may be performed by blasting equipment applying at least one method, using a power tool including a high pressure washer or grinder, or using a manual tool including a scraper or a spatula.

Preferably, the surface treatment step may be performed using a paint decomposition solution for decomposing the existing paint formed on the surface of the steel structure.

Preferably, the curing agent of the top coat is provided as a polyisocyanate curing agent, and a mixing ratio of the main agent and the curing agent in the top coat may be 4.5 to 5.5: 1 by volume.

Preferably, the steel structure painting method further comprises the step of applying a light/middle combined paint to the steel structure after the surface treatment step and before the top coat application step, It is provided as a two-component type paint using a mixture of a hardener and an epoxy resin 25 to 35% by weight, talc (non-asbestos type) 20 to 30% by weight, carbonic acid, based on the total weight 10 to 20% by weight of calcium may be included as a component.

Preferably, the subject of the light / medium combination paint may further comprise 5 to 15 wt% of xylene, 5 to 15 wt% of titanium dioxide, and 1 to 5 wt% of isopropyl alcohol as components based on the total weight.

Preferably, the curing agent of the light/medium combined paint is provided as a polyamide curing agent, and in the light/medium combined paint, the mixing ratio of the main agent and the curing agent may be 2.5 to 3.5: 1 by volume.

The above object, according to the present invention, is provided as a two-component paint using a mixture of a main agent and a curing agent, and the main agent is, based on the total weight, 40 to 60 wt% of a modified fluororesin, 10 to 20 wt% of barium sulfate, and dioxide It is achieved by a composition for coating steel, characterized in that it contains 7 to 13% by weight of titanium as a component.

Preferably, the main agent is 2-7% by weight of xylene, 2-7% by weight of 2-ethoxyethanol acetic acid, C.I. Pigment yellow 34 1-3 wt%, copper polychlorophthalocyanine green 0.3-0.8 wt% may be further included as a component.

According to the composition for coating steel according to the present invention and the steel structure coating method using the same, a physically and chemically stable coating film is formed on the surface of the steel structure, and the properties required for steel coating such as weather resistance, chemical resistance, wear resistance, and contamination resistance are excellent. Therefore, it can contribute to sufficiently securing the durability and safety of the steel structure, and also exhibits the effect of excellent gloss in terms of aesthetics.

In addition, the present invention performs the most appropriate surface treatment process for the surface of the steel structure in consideration of the size and condition of the work site, the required quality, and the given work time before applying the paint to the surface of the steel structure. It can improve the efficiency and quality of painting work.

1 is a process flow chart for explaining a steel structure painting method according to an embodiment of the present invention.

In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings illustrating preferred embodiments of the present invention and the contents described in the accompanying drawings.

Hereinafter, the present invention will be described in detail by describing preferred embodiments of the present invention with reference to the accompanying drawings. However, in describing the present invention, a description of a function or configuration already known will be omitted in order to clarify the gist of the present invention.

1 is a process flow chart for explaining a steel structure painting method according to an embodiment of the present invention. Hereinafter, the steel structure painting method according to the present invention will be described in detail with reference to FIG. 1 .

The steel structure painting method according to the present invention can be applied to painting work on steel structures in bridges, offshore structures, coastal structures, ships, pylons, water purification plants, sewage treatment plants, chemical plants, and the like. In addition, the steel structure painting method according to the present invention can be applied to the painting work for the new construction steel structure, as well as the repair painting work for the steel structure.

Referring to FIG. 1, the steel structure painting method according to this embodiment includes a surface treatment step (S110), a light/middle coating application step (S120), and a fluororesin-based top coat application step (S130).

The surface treatment step (S110) removes foreign substances such as corrosion products (rust) or dust on the surface of the steel structure before the full-scale painting operation, that is, before applying the paint to the steel structure, but in the case of the repair painting operation, the steel structure It is a step to remove the existing paint or paint formed on the surface of the If there are foreign substances such as corrosive organisms or dust on the surface of the steel structure, or if there is an existing damaged (partially peeled or peeled) painting, if a new painting is performed, the painting may not be done properly and defects may occur. It is preferable to perform this surface treatment step (S110) prior to a full-scale painting operation.

Specifically, the surface treatment step S110 may be performed by a blasting equipment that applies at least one of a sand blast method, a shot blast method, and a soda blast method. Here, the blast method refers to a surface treatment method in which the surface of the work object is polished or polished by spraying an abrasive at a high pressure through a nozzle. Representatively, such a blast method includes a sand blast method, a shot blast method, a soda blast method, and the like. The sand blasting method generally uses sand as an abrasive. Recently, in addition to sand, ceramic powders such as aluminum oxide and silicon carbide, glass beads, plastic powder, etc. are also used as abrasives. The shot blasting method is a method in which an abrasive strikes the surface of an object with an abrasive with a fine particle material made of metal or non-metal, such as a shot or grit, in general. The soda blasting method is one of the wet blasting methods and is a method in which baking soda is generally mixed with water and used as an abrasive.

Alternatively, the surface treatment step (S110) is performed using a power tool including a high-pressure washer or grinder to remove corrosion products or foreign substances on the surface of the steel structure or to remove the existing paint formed on the surface of the steel structure. Alternatively, it may be performed using a manual tool including a scraper or a spatula. It is desirable to select these power tools or manual tools in consideration of the size and condition of the work site, the required quality, and the given work time.

Alternatively, the surface treatment step (S110) may be performed using a paint decomposition solution to remove the existing paint formed on the surface of the steel structure. Specifically, after a certain period of time after spraying and applying the coating decomposition solution on the surface of the steel structure, the existing coating may be dissolved and removed by the coating decomposition solution. In addition, residual foreign substances are partially left on the surface of the steel structure in which the existing coating has been dissolved, and these residual foreign substances can be removed by spraying high-pressure washing water, air, dry ice, etc. on the surface of the steel structure. In this case, any one of currently commercialized products may be used as the coating decomposition solution.

The light/middle-use paint application step (S120) is a step of applying a light/middle-use paint to the steel structure on which the surface treatment has been completed. Here, as the name suggests, the combined undercoat/middle coat is a paint that simultaneously exhibits the functions of a base coat and an intermediate paint. Since it is not necessary to separately perform the undercoat application step and the intermediate paint application step, the overall painting operation is simplified and relatively work This has the advantage of saving time. However, the present invention is not limited thereto, and may be applied in a manner of performing the intermediate paint application step after performing the undercoat coating step. For reference, it is preferable that the light/middle paint application step (S120) is performed immediately after completing the surface treatment step (S110), which is the previous process, to prevent re-contamination.

In this embodiment, the paint for both light and medium use is a two-component type paint using a mixture of 'epoxy resin' and 'polyamide' curing agent, which is the main subject, and has excellent water resistance, salt water resistance, durability, abrasion resistance and adhesion, and is It is a non-glossy light/middle coating that can be applied with a thick film and has excellent paint workability and drying properties, and has excellent adhesion to non-ferrous metals.

At this time, in the light/middle coating, the main agent and the curing agent are preferably mixed in a ratio of 2.5 to 3.5: 1 (volume ratio), and the most preferable mixing ratio of the main agent and the curing agent is 3 by volume; 1 is For reference, since the content may sink due to the high specific gravity of the main material, it is preferable to mix the hardener and stir it evenly again after stirring using an appropriate power tool. If necessary, use a designated diluent It may be diluted to less than 10% and stirred.

And, in the light/middle paint application step (S120), the light/middle paint is sprayed using airless or air spray (nozzle diameter: 0.019 to 0.025 in, spray pressure: 2,000 to 3,000 psi) to the surface of the steel structure. In the case of partial and repair painting work, it may be applied to the surface of the steel structure using a brush or roller. At this time, it is preferable that the coating film thickness of the light / medium combined paint is formed on the surface of the steel structure in a range of 90 to 110 μm, and the most preferred coating film thickness of the light / medium combined paint is 100 is μm. For reference, the light/middle paint application step (S120) is generally performed once, but may be performed twice in a special environment (eg, an environment with strong sea breeze), and the pot life of the light/medium combined paint is 20 ° C. about 8 hours from

The fluororesin-based topcoat application step (S130) is a step of applying a fluororesin-based topcoat to the steel structure on which the light/middle coating has been applied. In this embodiment, the top coat is a two-component type paint using a mixture of a 'fluororesin' with excellent weather resistance and a main material including a pigment, and a 'polyisocyanate' curing agent. It has excellent color retention, acid resistance, alkali resistance, solvent resistance, It is a fluororesin-based topcoat with excellent performance in salt water resistance and stain resistance.

At this time, in the top coat, the main agent and the curing agent are preferably mixed in a ratio of 4.5 to 5.5: 1 (volume ratio), and the most preferable mixing ratio of the main agent and the curing agent is 5 by volume; 1 is For reference, it is preferable to use the top coat by sufficiently stirring it using an appropriate power tool to make it uniform, and if necessary, it can be used by diluting the specified diluent to within 5%. However, it should be noted that if the dilution is excessive, flowability problems may occur.

And, in the top coat application step (S130), the top coat is airless or air sprayed (nozzle diameter: 0.019 to 0.025 in, spray pressure: 2,000 to 3,000 psi), as in the previous step, the light/middle combination paint application step (S120). It can be applied to the surface of the steel structure by spraying using a brush or roller in the case of partial and repair painting work. At this time, in the top coat application step (S130), the thickness of the top coat is preferably formed to be 40 to 60 µm on the surface of the steel structure through two coats, and the most preferred coat thickness of the top coat is 50 µm (one time). 25㎛ when painting). For reference, the pot life of the top coat is about 6 hours at 20°C.

Hereinafter, specific components and contents of the composition for coating steel according to the present invention will be described in detail through preferred embodiments. The composition for steel coating according to the present invention is a fluororesin-based top coating used in the top coating step 130 in the steel structure coating method described above, and a low/middle combination used in the low/middle coating application step (S120) contains paint. For reference, the present invention has the greatest technical characteristics in the fluororesin-based topcoat composition.

< Composition and content of fluororesin-based topcoat >

The top coat of the present invention may be provided as a two-component type paint using a mixture of a main material including a 'fluororesin' and a pigment and a 'polyisocyanate' curing agent.

Here, the main material of the top coat may include 40 to 60% by weight of the modified fluororesin, 10 to 20% by weight of barium sulfate, and 7 to 13% by weight of titanium dioxide based on the total weight (100% by weight). In addition, based on the total weight (100% by weight) of the top coat, xylene 2-7% by weight, 2-ethoxyethanol acetic acid 2-7% by weight, C.I. Pigment yellow 34 1 to 3% by weight, copper polychlorophthalocyanine green (Copper Pollychlorophthalocyanine Green) 0.3 to 0.8% by weight may be further included as a component.

For reference, barium sulfate, titanium dioxide, xylene, 2-ethoxyethanol acetate, C.I. The Chemical Abstract Service (CAS) numbers for Pigment yellow 34 and copper polychlorophthalocyanine green are '7727-43-7', '13463-67-7', '1330-20-7', and '111-15-9, respectively. ', '1344-37-2' and '1328-53-6'.

On the other hand, the subject of the top coat may further include a pulverized plastic as a component thereof, wherein the pulverized plastic is provided as a pulverized product prepared by pulverizing a waste foamed polyethylene material to a diameter of 0.1 to 5 mm. It is preferable to contain 0.1 to 1% by weight based on the total weight (100% by weight) of the main subject. The plastic pulverized material is made of expanded polyethylene, and specifically, it is a method of recycling waste expanded polyethylene materials that have been used as insulation and cushioning materials. will be. This waste expanded polyethylene pulverized material is a thermoplastic material with a high specific surface area, and it improves the workability of the top coating and reduces the heat of hydration of the coating film formed by the top coating, thereby preventing peeling due to shrinkage of the coating.

[Table 1] and [Table 2] below summarize the results of testing the chemical resistance and drying time for such top coats.

When the top coat of the present invention having the above components and contents is applied as a top coat to a steel structure due to the fluororesin having excellent weather resistance, corrosion does not easily occur even in various climatic environments, so the durability and safety of the steel structure are sufficiently secured In addition, there is an advantage in that it can contribute to the luster of the aesthetics.

<Low/middle-use paint composition and content of >

The paint for both light and medium use of the present invention may be provided as a two-component type paint using a mixture of 'epoxy resin' and a 'polyamide' curing agent, which is the main subject.

Here, the main material of the light/medium combination paint comprises 25 to 35% by weight of epoxy resin, 20 to 30% by weight of talc (non-asbestos type), and 10 to 20% by weight of calcium carbonate based on the total weight (100% by weight). may be included as an ingredient. In addition, the subject of the light/middle coating paint contains 5-15 wt% of xylene, 5-15 wt% of titanium dioxide, and 1-5 wt% of isopropyl alcohol based on the total weight (100 wt%) can do.

For reference, the Chemical Abstract Service (CAS) numbers for epoxy resin, talc (non-asbestos type), calcium carbonate, xylene, titanium dioxide and isopropyl alcohol are '25036-25-3' and '14807-96-, respectively. 6', '471-34-1', '1330-20-7', '13463-67-7' and '67-63-0'.

[Table 3] and [Table 4] below summarize the results of testing the chemical resistance and drying time for these low/middle coatings.

The present invention is not limited to the above-described embodiments, and it is apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, it should be said that such modifications or variations belong to the claims of the present invention.

Claims (11)

treating the surface of the steel structure; and
Including; applying a top coat to the steel structure;
The top coat is provided as a two-component type paint using a mixture of a main agent and a curing agent,
The main component of the top coat contains 40 to 60% by weight of modified fluororesin, 10 to 20% by weight of barium sulfate, and 7 to 13% by weight of titanium dioxide, based on the total weight,
The main component of the top coat is xylene 2-7 wt %, acetic acid 2-ethoxyethanol 2-7 wt %, CI Pigment yellow 34 1-3 wt %, copper polychlorophthalocyanine green 0.3-0.8 wt %, based on the total weight % of the steel structure painting method including the surface treatment process, characterized in that it further comprises as a component.
delete According to claim 1,
The subject of the top coat further comprises a pulverized plastic as a component,
The pulverized plastic is provided as a pulverized product prepared by pulverizing waste foamed polyethylene material to a diameter of 0.1 to 5 mm, and surface treatment, characterized in that it is included in an amount of 0.1 to 1% by weight based on the total weight of the main material of the top coat. Steel structure painting method including process.
According to claim 1,
The surface treatment step,
A step of removing corrosion products or foreign substances on the surface of the steel structure or removing the existing paint formed on the surface of the steel structure,
It is performed by a blasting equipment that applies at least one of a sand blast method, a shot blast method, and a soda blast method, or
performed using a power tool, including a high-pressure washer or grinder, or
A steel structure painting method including a surface treatment process, characterized in that it is performed using a manual tool including a scraper or a spatula.
According to claim 1,
The surface treatment step,
Steel structure painting method including a surface treatment process, characterized in that it is carried out using a paint decomposition solution for decomposing the existing paint formed on the surface of the steel structure.
According to claim 1,
The curing agent of the top coat is provided as a polyisocyanate curing agent,
In the top coat, the mixing ratio of the main agent and the curing agent is 4.5 to 5.5: 1 by volume in a steel structure painting method including a surface treatment process.
According to claim 1,
After the surface treatment step and before the top coat application step,
Further comprising; applying a paint for both light and medium to the steel structure
The light/middle-use paint is provided as a two-component paint using a mixture of a main agent and a curing agent,
The theme of the above light/middle coating paint is,
Steel structure painting including a surface treatment process, characterized in that it contains 25 to 35% by weight of epoxy resin, 20 to 30% by weight of talc (non-asbestos type), and 10 to 20% by weight of calcium carbonate based on the total weight Method.
8. The method of claim 7,
The theme of the above light/middle coating paint is,
5 to 15% by weight of xylene, 5 to 15% by weight of titanium dioxide, and 1 to 5% by weight of isopropyl alcohol based on the total weight.
9. The method of claim 8,
The curing agent of the light / medium combination paint is provided as a polyamide curing agent,
A steel structure painting method including a surface treatment process, characterized in that the mixing ratio of the main agent and the hardener is 2.5 to 3.5: 1 in volume ratio in the light / medium combined use paint.
It is provided as a two-component paint using a mixture of the main agent and hardener.
The subject includes 40 to 60% by weight of the modified fluororesin, 10 to 20% by weight of barium sulfate, and 7 to 13% by weight of titanium dioxide based on the total weight,
The subject further contains xylene 2-7% by weight, acetic acid 2-ethoxyethanol 2-7% by weight, CI Pigment yellow 34 1-3% by weight, copper polychlorophthalocyanine green 0.3-0.8% by weight as components A composition for coating steel, characterized in that
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