JP7265603B2 - Steel structure repair method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a repair method for repairing a steel structure made of steel materials or the like.

Conventionally, zinc-rich coating containing a large amount of zinc has been widely used to prevent corrosion of steel structures such as bridges, steel towers, viaducts, tanks, plants, and bridge piers. Zinc is known to have high anticorrosion properties because it is a metal with a lower potential than iron and has a sacrificial anticorrosion action. Steel structures need to be coated with undercoat, middle coat, and top coat in addition to zinc-rich paint containing zinc in order to protect the base material, iron and steel, from rust. For each painting, the previous process is completed and the next process is performed after the coating film has dried, so it takes several days to complete the entire painting process, and partial repairs have the same anti-corrosion performance as general parts. It was difficult to give

In particular, when repainting steel structures, catch clamps are used for scaffolding construction, but since the parts where catch clamps are installed cannot be repainted, they must be repaired after the scaffolding is dismantled. Since the repair requires surface preparation and drying processes, it takes several more days after repainting is completed, and because it involves work at high places, it is troublesome and dangerous. Therefore, there is a need for a method of repairing steel structures that can be easily repaired in a short time and that has high corrosion resistance equivalent to that of ordinary painted parts.

Patent Document 1 is an invention relating to an inorganic zinc-rich paint that can be used for heavy-duty anti-corrosion coating of steel structures and that can form a coating film capable of suppressing the generation of bubbles without performing a mist coating process. The invention of Patent Document 1 eliminated the need for the mist coating process, but required the undercoating process, the intermediate coating process, and the topcoating process on top of the zinc-rich paint, and was not a process-saving repair method.

Patent Document 2 further improves sacrificial corrosion resistance and the like by containing oxide particles containing at least one element selected from the group consisting of Si, Al and Mg and at least three types of zinc powder with different shapes. However, this invention also did not provide a process-saving repair method.

Patent Document 3 has a layer structure consisting of (a) an adhesive layer that contains zinc powder and can be imparted with conductivity when pressed, (b) a zinc plate, (c) a resin film, and (d) a stainless steel plate. The present invention relates to a method for preventing corrosion in a piping frame, in which a corrosion-resistant member is adhered to the pipe so that its adhesive layer is in contact with the pipe, and the pipe is placed on the frame. The invention of Patent Document 3 aims to provide a corrosion prevention method that effectively delays the progress of localized corrosion in the frame of a pipe, and that can extend the life of the entire pipe with simple construction. . Although this invention has made it possible to improve the anti-corrosion properties of tubular objects, it is not suitable for repairing steel structures with complicated shapes because they include stainless steel plates.

In Patent Document 4, a primer liquid containing zinc powder and a partial hydrolyzate of an alkyl silicate is applied to the outer surface of a structure and dried to form a primer layer, and then the primer layer is coated with a support and a The present invention relates to an anti-corrosion coating method characterized in that an anti-corrosion tape or sheet comprising a pressure-sensitive adhesive layer is adhered and laminated. The invention of Patent Document 4 provides an anti-corrosion coating method for metal pipes and structures that can exhibit an excellent anti-corrosion effect even at high temperatures. There was room for improvement in performance.

Japanese Patent Application Laid-Open No. 2002-194284 JP 2006-282856 A JP-A-60-204311 JP-A-9-242982

The object of the present invention was made in view of the above-mentioned conventional problems. To provide a structure repair method.

As a result of intensive studies, the present inventors have found that the surface to be repaired of the steel structure is provided with a topcoat base material and one surface of the topcoat base material, and a pressure-sensitive adhesive containing a metal having a lower potential than iron. The present inventors have found that the above problems can be solved by applying a repair adhesive tape having a layer and applying a predetermined topcoat paint thereon to form a paint film, and have completed the following invention. In addition, in the present invention, even if cracks occur in the topcoat paint or topcoat substrate due to aging after painting, in addition to sacrificial corrosion protection by a metal having a base potential than iron contained in the adhesive layer, the adhesive Due to the self-healing performance of the layer, it is possible to re-block oxygen and moisture, which are corrosive factors, and to highly protect the surface of steel structures from corrosion.

That is, the present invention provides the following [1] to [10].
[1] A method of repairing the surface of a metal material that constitutes a part of a steel structure and contains at least one selected from the group consisting of iron and alloys containing iron,
A repair pressure-sensitive adhesive tape comprising a topcoat substrate and an adhesive layer provided on one side of the topcoat substrate and containing a metal having a potential lower than that of iron on the surface of the metal material to be repaired. , a step of bonding with the adhesive layer as a bonding surface;
A method for repairing a steel structure, comprising the step of applying a topcoat paint on the topcoat base material to form a paint film.
[2] The method for repairing a steel structure according to [1] above, wherein the metal having a potential lower than that of iron is zinc.
[3] The steel structure repair method according to [1] or [2] above, wherein the content of zinc in the adhesive layer is 0.5 to 50% by mass.
[4] The steel structure according to any one of [1] to [3] above, wherein the adhesive layer contains a conductive material other than the metal and has a resistance value of 10 ⁸ Ω or less. Repair method.
[5] Any one of [1] to [4] above, wherein the pressure-sensitive adhesive layer has a thickness in the range of 20 μm to 1000 μm, and the topcoat substrate has a thickness in the range of 10 μm to 120 μm. Steel structure repair method.
[6] The steel structure repair method according to any one of [1] to [5] above, wherein the surface to be repaired has an average surface roughness (Rzjis) of 80 μm or less.
[7] The steel structure repair method according to any one of [1] to [6] above, wherein the surface of the topcoat base material to be coated with the topcoat has a plurality of recesses with a depth of 1 to 50 μm.
[8] The top coat contains at least one or more resins selected from acrylic resins, urethane resins, butadiene resins, silicone resins, fluorine resins, vinyl ester resins, and epoxy resins, or is an inorganic paint. The steel structure repair method according to any one of [1] to [7].
[9] The topcoat has a viscosity of 0.1 to 10,000 (Pa s, 23 ° C.) at a shear rate of 0.1 s ^-1 , and a viscosity of 0.05 to 10 (Pa s, 23 ° C.) at a shear rate of 1000 s ^-1 Pa s, 23° C.), the steel structure repair method according to any one of the above [1] to [8].
[10] The method for repairing a steel structure according to any one of [1] to [9] above, wherein the PVC (pigment volume concentration) of the topcoat is within the range of 10 to 40.

According to the present invention, it is possible to provide a method for repairing a steel structure that is capable of improving weather resistance and maintaining high corrosion resistance even after long-term use, while reducing the number of steps.

BRIEF DESCRIPTION OF THE DRAWINGS It is typical sectional drawing which shows the steel structure repair method which concerns on one Embodiment of this invention.

The present invention will be described below with reference to embodiments.
The steel structure repair method of the present invention is a method for repairing the surface of a metal material that constitutes a part of a steel structure, and as shown in FIG. It comprises a step (A1) of bonding the adhesive tape 10 for repair, and a step (A2) of applying a topcoat paint over the adhesive tape 10 for repair to form a coating film 30. - 特許庁

Hereinafter, the steel structure repair method of the present invention will be described in detail.
<Step (A1)>
The repair adhesive tape 10 includes a topcoat base material 12 and an adhesive layer 11 provided on one surface of the topcoat base material 12 . In step (A1), the repair pressure-sensitive adhesive tape 10 is adhered to the repair target surface 20A of the metal material 20 using the pressure-sensitive adhesive layer 11 as the adherence surface.

[Metal material]
The metal material 20 that forms the repair target surface 20A is a metal material containing at least one selected from the group consisting of iron and alloys containing iron. Specific examples of alloys containing iron include nickel-chromium steel, nickel-chromium-molybdenum steel, chromium steel, chromium-molybdenum steel, manganese steel, and other alloy steels, and various steel materials, such as carbon steel. Since steel is generally used in steel structures, steel is preferable as the metal material 20 .
Steel structures are generally coated with antirust paint, anticorrosion paint, etc. on metal materials such as steel materials at the time of completion, in order to impart antirust and anticorrosion properties. formed. Such a coating film 25 is damaged by being partially peeled off or scratched due to deterioration over time or due to construction work or repairs performed on the steel structure. In the present invention, the adhesive tape 10 for repair may be adhered to the portion where the pre-repair coating 25 is damaged.
Examples of steel structures include, but are not limited to, bridges, steel towers, viaducts, tanks, plants, bridge piers, and the like.

Further, before the step (A1), the metal material 20 of the steel structure, which is the surface 20A to be repaired, may be subjected to surface adjustment such as polishing. By performing base preparation, the pre-repair coating 25 that has conventionally existed on the surface 20A to be repaired can be removed, and the adhesive tape for repair can be attached directly to the surface of the steel material. In general, when applying paint, it is preferable to increase the surface roughness to some extent from the viewpoint of increasing the adhesion of the paint, but in the present invention, the surface to be repaired 20A is smoothed. Thus, the adhesiveness of the pressure-sensitive adhesive layer 11 to the metal material 20 can be improved.
The average surface roughness (Rzjis) of the surface to be repaired 20A is preferably 80 μm or less, more preferably 40 μm or less, from the viewpoint of enhancing surface smoothness. The average surface roughness (Rzjis) is a ten-point average roughness measured according to JIS B 0601:2001.

[Adhesive tape for repair]
The adhesive layer 11 used for the repair adhesive tape contains a metal having a lower potential than iron. The adhesive layer 11 has a sacrificial anti-corrosion property by containing a metal having a potential lower than that of iron (hereinafter also referred to as a "sacrificial anti-corrosion metal"), and the metal material to which the repair adhesive tape 10 is attached. 20 corrosion resistance is ensured. In addition, the pressure-sensitive adhesive layer 11 containing the sacrificial anti-corrosion metal does not significantly impair the flexibility of the repair pressure-sensitive adhesive tape 10, and has good adhesion to the metal material 20. It becomes easier to ensure corrosion resistance.

Moreover, the pressure-sensitive adhesive layer 11 may further contain a conductive material other than the sacrificial anticorrosion metal. The adhesive layer 11 contains a conductive material, so that the conductivity is increased. Specifically, the resistance value of the adhesive layer 11 is preferably 10 ⁸ Ω or less. Therefore, the electrons emitted when the sacrificial anti-corrosion metal is ionized can be sufficiently transferred to the metal material 20, and even if the content of the sacrificial anti-corrosion metal in the adhesive layer 11 is not increased, a favorable Sacrificial corrosion resistance is guaranteed.

(A metal with a lower potential than iron)
Examples of metals having potentials less noble than iron (sacrificial anticorrosion metals) include cadmium, chromium, zinc, manganese, and aluminum. Among these, zinc and aluminum are preferred, and zinc is particularly preferred. By using zinc, sacrificial corrosion resistance becomes excellent.
The sacrificial anti-corrosion metal may be dispersed in the pressure-sensitive adhesive layer 11 as a filler in any form such as particle form, scale form, spindle form, etc., but it is preferable to include particle form. The sacrificial anti-corrosion metal is in the form of particles, so that it can be easily dispersed in the pressure-sensitive adhesive layer 11 without substantially reducing the adhesiveness of the pressure-sensitive adhesive layer 11 .
In the present specification, the particle shape means that the ratio of the length in the long axis direction to the length in the short axis direction (aspect ratio) is small, for example, the aspect ratio is 3 or less, preferably 2 or less. The shape of the particles is not particularly limited, but may be spherical or amorphous such as powder. The particle size of the metal is, for example, 1 to 500 μm, preferably 1 to 200 μm. In addition, in this specification, the particle size means the average particle size measured by the laser diffraction method.
The content of the sacrificial anti-corrosion metal is, for example, 0.5 to 50% by mass, preferably 1 to 40% by mass, based on the total amount of the adhesive layer 11.

(Conductive material)
Examples of conductive materials include one or more selected from carbon-based materials, metal-based materials, metal oxide-based materials, ionic polymers, and conductive polymers.
Carbon-based materials include carbon black, graphite, graphene, carbon nanotubes, acetylene black, and the like. Examples of metal-based materials include metals whose potential is nobler than that of iron, such as gold, silver, copper, nickel, or alloys containing these, or iron. Examples of metal oxide materials include indium tin oxide (ITO), antimony trioxide (ATO), fluorine-doped tin oxide (FTO), and zinc oxide. Examples of conductive polymers include polyacetylene, polypyrrole, PEDOT (polyethylenedioxythiophene), PEDOT/PSS (composite of polyethylenedioxythiophene and polystyrenesulfonic acid), polythiophene, polyaniline, poly(p-phenylene), polyfluorene, Examples include polycarbazole, polysilane, and derivatives thereof. Examples of ionic polymers include sodium polyacrylate and potassium polyacrylate.
These conductive materials may be used singly, or two or more of them may be used in combination.

The conductive material is not particularly limited as long as it can be dispersed or compatible with the adhesive layer 11. For example, it is preferably in the form of particles or compatible with the adhesive described later. The particle-shaped conductive material has a particle size of, for example, 1 to 200 μm.
The content of the conductive material in the adhesive layer 11 is, for example, 1 to 50 parts by mass, preferably 2 parts by mass, with respect to 100 parts by mass of the adhesive, from the viewpoint of excellent adhesion to metal materials and sacrificial corrosion resistance. ~30 parts by mass.
The thickness of the adhesive layer 11 is not particularly limited, but is, for example, 20 μm to 1 cm, preferably 20 μm to 900 μm, more preferably 50 to 700 μm.

(adhesive)
The adhesive layer 11 is formed by blending an adhesive with a sacrificial anti-corrosion metal or a sacrificial anti-corrosion metal and a conductive material. Examples of adhesives used for the adhesive layer 11 include acrylic adhesives, rubber adhesives, urethane adhesives, silicone adhesives, and the like. These may be used alone or in combination. Among these, it is preferable to use an acrylic adhesive. The use of an acrylic pressure-sensitive adhesive makes it easier to adjust the adhesive strength within a desired range, and makes it easier to improve the adhesiveness to metal materials.

[Topcoat substrate]
Examples of the topcoat substrate 12 include acrylic resins, vinyl chloride resins, ABS resins (acrylonitrile-butadiene-styrene copolymer), styrene resins, polycarbonate resins, polyethylene terephthalate, ester resins such as polyethylene naphthalate, Examples include polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymers, amide resins, and polyurethane resins, among which acrylic resins are preferred. By using an acrylic resin or the like, the solvent of the topcoat paint is prevented from soaking into the topcoat base material, and a decrease in adhesion of the pressure-sensitive adhesive layer 11 to the surface to be repaired 20A is prevented. The base material may be a single-layer resin film made of the above resin, or may be a multi-layer resin film.

Examples of acrylic resins include acrylic resins such as polymethyl (meth) acrylate, polybutyl (meth) acrylate, methyl (meth) acrylate-butyl (meth) acrylate copolymer, and methyl (meth) acrylate-styrene copolymer. mentioned. These acrylic resins may be used alone or in combination of two or more.
In the present invention, "(meth)acrylate" means "acrylate" or "methacrylate".

The thickness of the topcoat substrate 12 is preferably 10 to 120 μm, more preferably 20 to 100 μm, even more preferably 30 to 80 μm. When the thickness of the topcoat base material 12 is at least the lower limit, the strength of the topcoat base material 12 is ensured, and weather resistance and the like tend to be good. In addition, it is possible to prevent the solvent contained in the overcoat paint from permeating into the adhesive tape 10 for repair.
On the other hand, when the thickness of the topcoat substrate 12 is equal to or less than the upper limit value, the followability to the step of the repair target surface 20A is improved, the adhesion of the adhesive layer 11 to the repair target surface 20A, and the coating of the topcoat substrate 12. The adhesion of the film 30 is likely to be improved, and the anti-corrosion property is likely to be ensured even after a long period of time has passed since the repair.

It is preferable that the topcoat substrate 12 is formed with a plurality of concave portions by embossing or the like. The recesses are preferably formed at least on the surface of the topcoat substrate 12 to be coated with the topcoat. When the topcoat base material 12 is formed with concave portions, the adhesiveness with the coating film 30 is improved, the workability at the time of construction is improved, and the coating film 30 is difficult to peel off over a long period of time after construction.
As a method for embossing the topcoat base material 12, an embossing method using heat and pressure is usually used. The embossing method by heating and pressurization is a method of heating and softening the surface of the various resin films described above, applying pressure with an embossing plate to shape the uneven pattern of the embossing plate, cooling, and fixing. A sheet-fed or rotary embossing machine can be used.

The depth of recesses formed by embossing or the like is preferably 1 to 50 μm, more preferably 2 to 30 μm, even more preferably 5 to 20 μm. Adhesiveness with the coating film 30 improves that the depth of a recessed part is more than the said lower limit. On the other hand, when the depth of the concave portion is equal to or less than the upper limit value, the topcoat base material 12 is less likely to be torn, which is preferable. The depth of the recess means the average value of the depth from the flat surface of the surface of the topcoat substrate 12 to the bottom of the recess, and the average value of the depths of 20 arbitrarily selected recesses may be calculated. .

The front surface, back surface, or both surfaces of the topcoat substrate 12 are subjected to corona discharge treatment, plasma treatment, primer layer formation, or the like in order to improve the adhesion of the adhesive layer 11 and the coating film 30 to the topcoat substrate 12. may
The topcoat base material 12 may contain various additives such as stabilizers, plasticizers, colorants, ultraviolet absorbers, hindered amine light stabilizers, and extender pigments, if necessary. In addition, the topcoat base material 12 may be colored, and in that case, a known coloring agent can be used.

In addition, the bonding surface of the repair pressure-sensitive adhesive tape 10 may be protected by attaching a release sheet before being bonded to the repair target surface 20A. As the release sheet, at least one surface of a substrate such as a resin film is subjected to a release treatment with a silicone-based release agent or the like.

<Step (A2)>
In step (A2), the topcoat paint (paint composition) is applied onto the topcoat base material 12 to form the paint film 30 . In the present invention, by forming the coating film 30 with the top coating, the weather resistance is improved and the corrosion resistance is ensured even after a long period of time has passed since the construction. In addition, since the topcoat paint contains a pigment, which will be described later, color matching with the pre-repair coating film 25 around the surface to be repaired 20A, which has already been painted, can also be performed.

(Topcoat paint)
The topcoat to be coated on the topcoat substrate 12 is a resin paint containing at least one resin selected from urethane resin, acrylic resin, butadiene resin, silicone resin, fluorine resin, vinyl ester resin, epoxy resin, or the like, or Inorganic paint etc. are mentioned. Each resin paint may be either one-pack type or two-pack type.

Also, the paint preferably contains a pigment. Various pigments such as coloring pigments and extender pigments can be used as the pigment, and it is preferable to use both of them. Suitable examples of color pigments include inorganic pigments such as titanium oxide, carbon black, black iron oxide, red iron oxide, yellow iron oxide and cobalt blue, and organic pigments such as phthalocyanine pigments and azo pigments. The coloring pigment may be appropriately selected according to the color of the pre-repair coating film 25 around the repair target surface 20A of the steel structure.
Examples of extender pigments include calcium carbonate, silica, alumina, hydrated alumina, magnesia, talc, clay, barium sulfate, barium carbonate, wollastonite, ceramic powder, glass fiber powder, white carbon, and magnesium silicate. mentioned.
These pigments may be used alone or in combination of two or more.
In the present invention, the PVC (pigment volume concentration) of the top coat is preferably within the range of 10-40.

The topcoat paint (coating composition) may contain an organic solvent or water for purposes such as adjusting the viscosity. Examples of organic solvents include aromatic hydrocarbons, aliphatic hydrocarbons, ketones, acetic esters, ethers, alcohol solvents, and mineral spirits.

In the present invention, the topcoat paint contains a dispersant, an antifoaming agent, a thickener, a leveling agent, an anti-settling agent, an anti-sagging agent, an anti-algae agent, an anti-mold agent, a preservative, an ultraviolet absorber, and a light stabilizer. You may mix|blend suitably additives, such as, as needed.

The viscosity of the topcoat paint is preferably 0.1 to 10,000 Pa·s at a shear rate of 0.1 s ⁻¹ and preferably 0.05 to 10 Pa·s at a shear rate of 1,000 s ⁻¹ . When the viscosity at each shear rate is within the above range, the coating workability and sagging are excellent, so that a coating film having the required thickness can be easily formed in one coating. From these points of view, the viscosity at a shear rate of 0.1 s ⁻¹ is more preferably 0.2 to 7,000 Pa·s, still more preferably 0.5 to 5,000 Pa·s. Further, the viscosity at a shear rate of 1,000 s ⁻¹ is more preferably 0.08 to 8 Pa·s, still more preferably 0.1 to 6 Pa·s.
In the present invention, the viscosity of the topcoat paint is measured after adjusting the liquid temperature to 23° C. using a rheometer ARES manufactured by TA Instruments. In the case of the two-liquid curing type, it is the viscosity immediately after mixing the two liquids (the main agent and the curing agent).
The thickness of the coating film 30 formed by the top coating is preferably 15 μm or more.

[Method of applying topcoat]
The method of applying the topcoat paint is not particularly limited, but the topcoat paint is applied to the topcoat substrate 12 by ordinary coating means such as spray coating, roller coating, and brush coating, and natural drying or forced drying is performed. A coating film 30 is preferably formed. In addition, the top coating may be applied so as to form a coating film 30 on the surface of the top coating base material 12, but as shown in FIG. It can also be painted to match the surface.

EXAMPLES The present invention will be described in more detail below using examples, but the present invention is not limited to these examples.

(Example 1)
[Preparation of repair adhesive tape]
An adhesive layer having a thickness of 600 μm made of an adhesive composition containing 15 parts by mass of zinc particles (13% by mass based on the total amount of the adhesive layer) is added to 100 parts by mass of the adhesive having the formulation shown in Table 1. It was formed on one side of the substrate. The topcoat substrate was made of an acrylic resin film having a thickness of 50 μm, and the other surface of the topcoat substrate was embossed, and the depth of the concave portion was 5 μm.

* Each component in Table 1 is as follows.
Olefin polymer: trade name "L-1253", manufactured by Kuraray Co., Ltd., hydrogenated polybutadiene tackifying resin 1 having a (meth)acryloyl group at one end: trade name "Arcon P140", manufactured by Arakawa Chemical Industries, Ltd., water Additive petroleum resin, softening point 140°C
Tackifier resin 2: trade name “Arcon P100”, manufactured by Arakawa Chemical Industries, Ltd., hydrogenated petroleum resin, softening point 100 ° C.
Fine particles: trade name “Celstar Z-27” manufactured by Tokai Kogyo Co., Ltd. Glass balloon Cross-linking agent: trade name “TEAI-1000” manufactured by Nippon Soda Co., Ltd. Polymerization initiator: 2,2-dimethoxy-2-phenylacetophenone

[Preparation of test sample]
As a test plate, a repair adhesive tape is attached to a grit blasted steel plate (150 x 70 x 3.2 mm) with a surface preparation level of ISO 8501-1 Sa2.5 so that the adhesive layer becomes the bonding surface. rice field. After that, a paint obtained by mixing the main agent and the curing agent shown in Tables 2 to 4 is applied as a topcoat on the topcoat base material of the adhesive tape for repair, and the thickness after drying is 25 to 25 using a brush. It was applied so as to have a thickness of 35 μm and was dried for 7 days in a constant temperature room maintained at a temperature of 23° C. and a relative humidity of 50% to form a coating film and obtain a test sample.

(Examples 2-6)
The procedure was carried out in the same manner as in Example 1, except that the zinc content in the pressure-sensitive adhesive layer was changed as shown in Table 2.

(Example 7)
The procedure was carried out in the same manner as in Example 1, except that aluminum particles were used instead of the metal having a potential less noble than that of iron contained in the pressure-sensitive adhesive layer.

(Examples 8 and 9)
The same procedures as in Example 1 were carried out, except that the thickness of the pressure-sensitive adhesive layer was changed as shown in Table 3.

(Examples 10-13)
It was carried out in the same manner as in Example 1, except that the thickness of the overcoated base material and the depth of the recesses formed by embossing were changed as shown in Table 3.

(Examples 14-17)
It was carried out in the same manner as in Example 1, except that the main agent of the top coat and the composition of the curing agent were changed as shown in Table 4.

(Example 18)
It was carried out in the same manner as in Example 1, except that a test plate with an average surface roughness of 75 μm was used.

(Comparative example 1)
The procedure was carried out in the same manner as in Example 1, except that zinc was not added to the pressure-sensitive adhesive layer.

(Comparative example 2)
It was carried out in the same manner as in Example 1, except that no paint was applied.

[Adhesion test]
In the test samples obtained in the above Examples and Comparative Examples, the adhesiveness of the pressure-sensitive adhesive layer to the steel plate was evaluated according to the following evaluation criteria.
A: Adhesion of the pressure-sensitive adhesive layer to the steel plate was good.
B: Adhesion of the pressure-sensitive adhesive layer to the steel plate was at a practically usable level.
C: Adhesion of the pressure-sensitive adhesive layer to the steel plate was low.

[Adhesion test]
In the test samples obtained in the above examples and comparative examples, the adhesion of the paint film to the topcoat substrate was evaluated according to JIS K5600-5.6: 1999 (25 squares at 2 mm intervals), and according to the following evaluation criteria. evaluated.
A: No peeling was observed in any lattice.
B: There was peeling within 15% of the entire lattice.
C: More than 15% of all grids had peeling.

[Corrosion resistance test]
In the test samples obtained in the above Examples and Comparative Examples, the anticorrosiveness to steel plates was evaluated by the JIS K5600-7-1:1999 salt spray test and evaluated according to the following evaluation criteria.
A: There was no abnormality around the cross-cut portion, and the corrosion resistance was good.
B: Although red rust and blistering with a diameter of less than 2 mm occurred around the cross-cut portion, the corrosion resistance was at a practically usable level.
C: Red rust and blisters with a diameter of 2 mm or more occurred around the cross-cut portion, and the corrosion resistance was low.

[Weather resistance test]
The weather resistance of the test samples obtained in the above examples and comparative examples was evaluated by the accelerated weather resistance test (1000 hours) described in JIS K5600-7-7 and evaluated according to the following evaluation criteria.
A: The gloss retention after 1000 hours was 70% or more.
B: The gloss retention after 1000 hours was 50% or more and less than 70%.
C: The gloss retention after 1000 hours was less than 50%.

Resins 1 to 3 and curing agents 1 to 3 in Tables 2 to 4 are as follows.
Resin 1: Acrylic A-829, NV = 60% by mass (DIC Corporation)
Resin 2: Acrylic A-837, NV = 50% by mass (DIC Corporation)
Resin 3: Barnock WE-301, NV = 45% by mass (DIC Corporation)
Curing agent 1: Duranate TPA-100, NV = 100 mass% (Asahi Kasei Chemical)
Curing agent 2: Duranate TSA-100, NV = 100 mass% (Asahi Kasei Chemical)
Curing agent 3: Barnock DNW-6000, NV = 100% by mass (DIC Corporation)

As is clear from the above examples, according to the steel structure repair method of the present invention, the weather resistance and corrosion resistance are good, and the adhesion of the paint film to the topcoat substrate and the adhesion of the adhesive layer to the steel plate Where the adhesion is good, high corrosion resistance is maintained even after a long period of time after repair.

REFERENCE SIGNS LIST 10 repair adhesive tape 11 adhesive layer 12 topcoat substrate 20 metal material 20A surface to be repaired 25 coating before repair 30 paint coating

Claims (15)

A method for repairing the surface of a metal material that constitutes a part of a steel structure and contains at least one selected from the group consisting of iron and alloys containing iron,
A repair pressure-sensitive adhesive tape comprising a topcoat substrate and an adhesive layer provided on one side of the topcoat substrate and containing a metal having a potential lower than that of iron on the surface of the metal material to be repaired. , a step of bonding with the adhesive layer as a bonding surface;
A step of applying a topcoat paint on the topcoat substrate to form a paint film ,
A steel structure repair method in which the surface of the topcoat base material to be coated with the topcoat has a plurality of recesses with a depth of 1 to 50 μm . 2. The method of repairing a steel structure according to claim 1, wherein said metal having a potential lower than that of iron is zinc. The steel structure repair method according to claim 2, wherein the content of zinc in the adhesive layer is 0.5 to 50% by mass. The method for repairing a steel structure according to any one of claims 1 to 3, wherein the adhesive layer contains a conductive material other than the metal and has a resistance value of 10 ⁸ Ω or less. The steel structure repair method according to any one of claims 1 to 4, wherein the pressure-sensitive adhesive layer has a thickness in the range of 20 µm to 1000 µm, and the topcoat substrate has a thickness in the range of 10 µm to 120 µm. The steel structure repair method according to any one of claims 1 to 5, wherein the surface to be repaired has an average surface roughness (Rzjis) of 80 µm or less. The topcoat paint contains at least one resin selected from acrylic resins, urethane resins, butadiene resins, silicone resins, fluorine resins, vinyl ester resins, and epoxy resins, or is an inorganic paint, claims 1- 7. The steel structure repair method according to any one of 6 . The topcoat paint has a viscosity of 0.1 to 10,000 (Pa s, 23 ° C.) at a shear rate of 0.1 s ^-1 , and a viscosity of 0.05 to 10 (Pa s) at a shear rate of 1000 s ^-1 . , 23°C), the steel structure repair method according to any one of claims 1 to 7 . The steel structure repair method according to any one of claims 1 to 8 , wherein the topcoat paint has a PVC (pigment volume concentration) in the range of 10 to 40. The steel structure repair method according to any one of claims 1 to 9 , wherein the metal having a potential lower than that of iron has any one of a particle shape, a scale shape, and a spindle shape. The method for repairing a steel structure according to any one of claims 1 to 10 , wherein the metal having an electric potential lower than that of iron is particles and has an aspect ratio of 3 or less. The method for repairing a steel structure according to any one of claims 1 to 11 , wherein the average particle size of the metal having a potential lower than that of iron is 1 to 500 µm. The steel according to any one of claims 1 to 12 , wherein the adhesive in the adhesive layer is selected from the group consisting of acrylic adhesives, rubber adhesives, urethane adhesives, and silicone adhesives. Structure repair method. The method for repairing a steel structure according to any one of claims 1 to 13 , wherein the topcoat paint contains a pigment selected from the group consisting of coloring pigments and extender pigments. The method for repairing a steel structure according to any one of claims 1 to 14 , wherein the top coat contains at least one of an organic solvent and water.

Images