Coating film structure of steel material

Abstract

To provide a coating film structure of a steel material in which a topcoat material is composed of a transparent material that expands and contracts in accordance with bending, etc. of the steel material, and therefore it is possible to prevent damage to the steel material due to corrosion, rust, crack, etc. even upon occurrence of fracture, crack, peeling, etc. in an undercoat material, and it is also possible to visually observe the damage to the steel material due to corrosion, rust, crack, etc., and resultant fracture, crack, peeling, etc. in the undercoat material, thereby facilitating maintenance.SOLUTION: A coating film structure of a steel material includes: an undercoat material 2 applied to a steel material 1; and a topcoat material 3 applied to the undercoat material 2. The undercoat material 2 is composed of a colored material whose degree of shrinkage is not greater than that of the steel material 1. The topcoat material 3 is composed of a transparent material whose degree of shrinkage is greater than that of the steel material 1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a coating film structure for steel materials used, for example, in bridges. [Background technology]

[0002] Various coating structures have been proposed for this type of steel material.

[0003] For example, Patent Document 1 discloses a corrosion prevention method in which a corrosion-resistant base layer is formed on the surface of the steel material that constitutes a steel structure, a polyimide layer is formed on top of that, and then an epoxy resin paint is applied as a resin paint, and further a fluororesin paint is applied to form a rust-preventing layer. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-205260 Summary of the Invention [Problem to be solved by the invention]

[0005] However, common coating materials such as epoxy resins have low elasticity and are therefore unable to conform to the bending of steel materials, resulting in problems such as cracks, fissures, and peeling.

[0006] Furthermore, if cracks occur in the steel material when the adhesion between the coating and the steel material is lost, there is also the problem that it is difficult to visually confirm the cracks.

[0007] The present invention was made based on the above circumstances, and its purpose is to provide a coating structure for steel material in which the top coat is made of a transparent material that expands and contracts in response to the bending of the steel material, thereby preventing damage to the steel material due to corrosion, rust, etc. even if cracks, fissures, peeling, etc. occur in the primer coat, and furthermore, damage to the steel material due to corrosion, rust, cracks, etc., and the resulting cracks, fissures, peeling, etc. in the primer coat can be visually observed, thereby making maintenance easy. [Means for solving the problem]

[0008] In order to solve the above problems, the coating film structure for steel material according to the present invention comprises a primer applied to the steel material and a top coat applied to the primer, the primer being made of a colored material whose expansion rate is equal to or less than that of the steel material, and the top coat being made of a transparent material whose expansion rate is greater than that of the steel material. [Effects of the Invention]

[0009] According to the coating structure for steel material of the present invention, the top coat is made of a transparent material that expands and contracts in response to the bending of the steel material, so that even if cracks, fissures, peeling, etc. occur in the primer coat, damage to the steel material due to corrosion, rust, etc. can be prevented.Furthermore, damage caused by corrosion, rust, cracks, etc. of the steel material, as well as the resulting cracks, fissures, peeling, etc. in the primer coat can be visually observed, thereby making maintenance easy. [Brief explanation of the drawings]

[0010] The drawings illustrate particular embodiments of the present invention, including essential features of the invention as well as alternative and preferred embodiments. [Figure 1] 1 is a cross-sectional view showing a coating structure of a steel material according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view for explaining the effect of the coating film structure of the steel material. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0012] In FIG. 1, reference numeral 1 denotes a steel material such as a bridge or road.

[0013] The surface of this steel material 1 is subjected to surface preparation such as removing rust by scraping, and then coated with a primer material 2.

[0014] It is preferable that this undercoat material 2 be excellent in ultraviolet resistance, adhesion to the steel material 1, and adhesion to the topcoat material 3 described below.

[0015] The undercoat material 2 is made of a colored material whose expansion rate is equal to or less than that of the steel material 1 .

[0016] The undercoat material 2 may be a colored material obtained by coloring a colorless material.

[0017] An example of the undercoat material 2 is an epoxy resin paint (linear expansion coefficient 6.5, elongation rate approximately 1%) such as AE Seal (trade name, manufactured by Aizole Technica Co., Ltd.).

[0018] Furthermore, a top coat material 3 is applied to the surface of this undercoat material 2.

[0019] This topcoat material 3 is preferably excellent in waterproofness, water repellency, weather resistance, adhesion, and moisture permeability.

[0020] Moreover, this topcoat material 3 is, for example, a polymer-based permeable waterproof material, and is made of a transparent material whose expansion rate is greater than that of the steel material 1.

[0021] The topcoat material 3 may be a semi-transparent material.

[0022] Examples of this topcoat material 3 include acrylic ester resin paint (linear expansion coefficient 6.0, elongation rate approximately 20%) such as Aizole EX (trade name, manufactured by Aizole Technica Co., Ltd.), as well as epoxy resin paint, acrylic resin paint, and fluororesin paint.

[0023] According to the above configuration, the primer 2 has an expansion rate equal to or less than that of the steel material 1, and the top coat 3 has an expansion rate greater than that of the steel material 1. Therefore, as shown in Figure 2, if the steel material 1 is bent, the primer 2 attached to the steel material 1 will not be able to expand or contract in accordance with the bending of the steel material 1, which may result in cracks 4, fissures 5, peeling 6, etc. However, the top coat 3 will expand and contract in accordance with the bending of the steel material 1.

[0024] In other words, the topcoat material 3 can expand and contract in accordance with the bending of the steel material 1, so even if cracks 4, fissures 5, peeling 6, etc. occur in the undercoat material 2, cracks 4, fissures 5, peeling 6, etc. will not occur, and damage such as corrosion and rust to the steel material 1 can be prevented.

[0025] Moreover, since the top coat material 3 is made of a transparent material, damage such as corrosion, rust, and cracks in the steel material 1, as well as the resulting cracks 4, fissures 5, and peeling 6 in the primer material 2 can be visually observed.

[0026] This means that when maintaining steel material 1, damage such as corrosion, rust, and cracks in steel material 1, as well as resulting cracks 4, 5, and peeling 6 in the primer 2, can be easily photographed and confirmed using a drone equipped with a camera, and image analysis using AI is also easily possible.

[0027] Therefore, the present invention has the following advantages over conventional steel coating methods:

[0028] 1) It will be possible to quickly check for and respond to any deterioration due to aging or structural damage, and it will also be easier to take photos using drones equipped with cameras and analyze the images using AI, contributing to improved monitoring and automated inspections.

[0029] 2) The improved adhesion due to the coating's elasticity reduces the amount of rust and corrosion that precede peeling, significantly reducing the amount of scraping work required when repainting, contributing to improved maintenance and reduced environmental impact.

[0030] 3) It will be possible to repaint using a one-component water-based material, and in the future it will be possible to spray over the paint using a drone, etc., which will contribute to improving maintenance and reducing the environmental impact.

[0031] The disclosure of the present invention described above can be summarized at least as follows.

[0032] In other words, the coating film structure for steel material according to the present invention comprises a primer applied to the steel material and a top coat applied to the primer, the primer being made of a colored material whose expansion rate is equal to or less than that of the steel material, and the top coat being made of a transparent material whose expansion rate is greater than that of the steel material.

[0033] The present invention can include at least the following embodiments, which can be adopted separately or in combination with each other.

[0034] (1) The top coat is made of a polymer-based penetrating waterproofing material.

[0035] (2) The topcoat is composed of acrylic ester resin paint. [Explanation of symbols]

[0036] 1 Steel material 2 Primer 3 Topcoat

Claims

1. A primer applied to the steel material; A topcoat material to be applied to the undercoat material; Equipped with The undercoat material is made of a colored material whose expansion rate is equal to or less than the expansion rate of the steel material, The topcoat material is made of a transparent material whose expansion rate is greater than that of the steel material. A coating film structure for steel material characterized by the above.

2. 2. The coating film structure for steel material according to claim 1, wherein the top coating material is made of a polymer-based penetrating waterproofing material.

3. 3. The coating film structure for steel material according to claim 1, wherein the top coating material is made of an acrylic ester resin paint.

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