JPS6328476A - Rust inhibitive method for steel structure - Google Patents

Abstract

PURPOSE:To enable the efficient rust inhibitive application to the submerged part of a steel structure by packing a rust inhibitive paint into a box body which has a specific surface shape and is subjected to a release treatment on the inside surface, fixing such box body to the surface to be subjected to the rust inhibitive treatment and removing the box body after curing of the rust inhibitive paint. CONSTITUTION:The reaction curing type rust inhibitive paint (e.g., two-pack type non-solvent epoxy resin paint of an underwater curing type) is packed into the box body which is formed to the shape complying with the surface shape of the steel structure to be subjected to rust inhibition and is subjected to the release treatment by wax or the like on the inside surface. Such box body is fixed to the steel structure in such a manner that the rust inhibitive paint packed therein contacts the surface to be subjected to the rust inhibitive treatment. The box body is removed quickly after the rust inhibitive paint packed therein makes reaction curing. As a result, the efficient application of the rust inhibitive treatment to the submerged part of the steel structure is permitted.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for efficiently applying anti-corrosion coating to steel structures, particularly those constructed in harsh corrosive environments such as oceans and rivers, and in areas with fast water flow. Regarding.

Recently, various steel structures (for example, long sentries, pipelines, submarine bases, oil field drilling equipment, port facilities, etc.) have been constructed or are being constructed in series.

Such steel structures have submerged parts that are constantly submerged in water,
It can be roughly divided into the tidal area, which may or may not be submerged in water depending on the ebb and flow of the tide, the splash area, where droplets are collected due to water waves, and the upper part exposed to the atmosphere, but corrosion occurs in each area. The environments are not the same, and it is important to apply excellent anti-corrosion treatment to these environments.The present invention aims This relates to a method useful for anticorrosion construction in underwater areas (referred to as underwater areas).In particular, splash areas are more prone to corrosion than other areas, and electrolytic corrosion protection is also difficult.

Conventionally, corrosion prevention work for underwater parts of IFr legs and existing steel structures has been carried out by, for example, diving under water with a dipper and manually applying an underwater curing type anticorrosive paint.

However, the footing conditions in the underwater area are extremely poor, and in areas with fast-flowing water, the underwater curable paint often peels off before it hardens, resulting in inefficiency.

In order to improve these problems, we have already proposed attaching a wire mesh or the like to the corrosion-proofing area in advance and applying an underwater hardening type anti-corrosion paint so that it adheres to the surface of the steel structure through the mesh of the wire mesh. However, from a practical point of view, the coating workability in areas with strong water currents was not sufficient.

This fact is true not only for marine structures, but also for steel structures built on rivers, lakes, etc., although there are differences in degree.
There are problems similar to those mentioned above. Therefore, there is a strong demand for an efficient corrosion protection construction method for the underwater parts of these steel structures.

Therefore, the present inventors investigated a method of applying anti-corrosion treatment to the underwater part by on-site construction. The inventors have discovered that all of the above-mentioned defects can be eliminated by fixing the anti-corrosion coating on a surface and removing the box after the anti-corrosion coating has hardened, thereby completing the present invention.

In other words, Kibatsu F! A#i is a method of applying corrosion protection mainly to the underwater part of steel structures, in which reaction-hardening corrosion protection is applied to the inside of a box body formed by mold release treatment on the inner surface and matching the surface shape of the steel structure to be anti-corrosion applied. Filling with paint, then fixing this box to the fI4 structure so that the filled anticorrosive paint contacts the surface to be anticorrosion-treated, and promptly removing the box after the filled anticorrosive paint has reacted and hardened. The present invention relates to a method for preventing corrosion of steel structures.

Steel structures that are subjected to anti-corrosion treatment according to the present invention are mainly used in underwater parts (from submerged parts to splashed parts), including water (including seawater).
This is where it is influenced by. Whether it is repairing an existing steel structure or repairing an RR joint, as a pre-treatment of the anti-corrosion construction area, if there is any deposits such as insects, shellfish, algae, etc. or rust, it is removed. It is preferable to keep it.

There are no particular restrictions on the surface shape of M4 structures that can be anti-corrosion-treated using the method of the present invention. Examples include shapes that include one or a combination of two or more.

In the present invention, the box body is used to efficiently form an anticorrosive paint base on the underwater part of a steel structure so that it will not be washed away by water flow. That is, when a box filled with anti-corrosive paint is placed in water, the anti-corrosive paint filled with I! 4. When applied and fixed in contact with the anti-corrosion treated surface of a steel structure, the anti-corrosion paint can be efficiently coated not only on the flat anti-corrosion treated surface of the steel structure, but also on other shaped surfaces, without leaving any gaps. Since the body is fixed, the anti-corrosion paint filled inside will not peel off and flow out even in waters with strong currents. After the anti-corrosion paint has almost or completely hardened, the box body is removed.
An anticorrosive paint film layer is firmly adhered to the anticorrosion-treated surface of a steel structure.

Therefore, this box may have any shape and size as long as it can be filled with the anticorrosion paint and cover a part or the entire surface of the anticorrosion-treated surface of the steel structure. Specifically, the box shaped to follow the unevenness of the S structure surface makes effective use of the anticorrosive paint so that an anticorrosive paint coating base with a thickness of one stage or more can be formed on the anticorrosion-treated surface. However, in the present invention, when the box is covered, even if it is a cube or rectangular parallelepiped in which the distance between the top of the convex part of the steel structure in that part and the inner surface of the box is 1 space or more. I can't go back.

In addition, since the anticorrosive paint filled in this box is hardened and removed beforehand, it is undesirable for the anticorrosive paint to adhere to the inner surface of the box. Therefore, in order to prevent this, the inner surface of the box has been treated with It is necessary to do so. The mold release treatment method is not particularly limited, but specific examples include the following methods.

(1) Attach a adhesive tape whose back has been treated with a release agent such as silicone resin or wax. (2) Apply 1 to 60 weight of lubricant such as silicone oil, olefin oil, diester oil, polyethylene wax, or liquid paraffin. % compounded paint is applied.

(3) r-glycidoxyglobiltrimethoxysilane,
Apply a silica/coupling agent such as r-methacryloxypropyltrimethoxysilane, vinyltrichlorosilane, N-β(aminoethyl)r-aminepropyltrimethoxysilane.

(4) Coating a composition containing an organopolysiloxane resin and an alkali gold-like compound as main components, and further containing liquid paraffin or solid paraffin as necessary (JP-A No. 59-25868, No. 60-206888). issue)
.

(5) The main component is a polymer containing a (meth)acrylic single noble substance containing a perfluoroalkyl group, and further contains the necessary KE.
Coating a composition containing the same alkali metal compound (JP-A-61-23656, JP-A-61-23657, JP-A-JP-A-950)
78, same 95077).

(6) A composition containing an organopolysiloxane resin and an alkali metal compound as main components (Special M 61-510
69) (7) Coating a composition containing an alkali metal compound and a hydrophobic silicone compound (Japanese Unexamined Patent Publication No. 61-57659).

8) Cover with a film or sheet made of polyethylene, vinyl, etc.

The material of the box body is not particularly limited, and examples include metal, plastic, and wood. Furthermore, in order to facilitate removal of the box after the anticorrosive paint has hardened, it is preferable that one or more sides of the box be openable and closable.

Next, the anti-corrosion paint to be filled in the box may be any reaction-curing type paint that exhibits excellent anti-corrosion properties in the harsh environments mentioned above.Although known types can be used, for example, underwater-curing type paints can be used. Two-component solvent-free epoxy resin paints are preferred - they have a limited pot life because they are two-component and require uniform mixing of the resin and curing agent components during use.
(about 2 hours at 20° C.), it is preferable to fill the container immediately after mixing both components. This paint has, for example, a resin component of 20,000 voids/25°C or higher and a hardener component of 1
It is desirable that the temperature is 0,000 voids/25°C or higher. t
The epoxy resin of the M@ component is semi-solid or liquid at room temperature, has at least two epoxy groups in one molecule, has an epoxy equivalent of about 140 to 400, and has a molecular weight of about 5.
00 or less is particularly preferable.

Specifically, one or more aromatic di- and polyglycidyl ethers are considered suitable for maintaining curability, adhesion, and coating strength, and if necessary, core aliphatic epoxides and resins are used. The flexibility and adhesion of the coating film are adjusted by adding cyclic compound-based epoxides. Specific examples of aromatic glycidyl ethers include bisphenol A epoxy resins (e.g., Epicor 828, manufactured by Shell Chemical Company), Epicort 834, DER331, DER3 manufactured by Dow Chemical Company.
37), bisphenol F type epoxy resins (for example, Epiclon 830, Epiclon 850, manufactured by Dainippon Ink and Chemicals), and novolac epoxy resins (for example, DEN431, DEN438, manufactured by Dow Chemical Company) for aromatic polyglycidyl ethers. As a curing agent component, avoid water-soluble polyamines or amine adducts, and use hydrophobic polyamines or aminopolyamide resins that react with epoxy groups at room temperature. In addition, to accelerate the curing reaction in water, triphenyl phosphite and phosphates can be used as appropriate, and thickeners (for example, asbestos) can be used as needed. ), preservatives (e.g., talc, silica sand, silica powder, mica, etc.), coloring pigments (yellow, red iron, carbon black, etc.), etc. are used as necessary to adjust the viscosity. hardens easily.

In the anticorrosion method according to the present invention, first, the inside of the box is filled with an anticorrosion paint. Although the size of the box varies depending on the MMi structure to be subjected to anti-corrosion treatment, it is preferably a size that is easy to handle underwater and by hand. However, the shape also differs depending on the shape of the anticorrosion-treated surface, but 4.
Any material that can uniformly form anti-corrosive paint or sills on the edges etc. will suffice.

Next, when the box filled with anti-corrosion paint is pressed against the anti-corrosion treated surface of the underwater part of the steel structure so that the anti-corrosion paint comes into contact with the anti-corrosion treated surface mainly underwater, the filled anti-corrosion paint is applied to the anti-corrosion treated surface. If a flat surface or other shaped surface is coated uniformly and the box is fixed in water, the anticorrosive paint and paint inside will be washed away by the flow of water.
Cures and hardens without coming out. Since the inner surface of the box body is treated with 4 coats of vinegar, the box body can be easily removed and rinsed after the anti-corrosion paint has reacted and hardened. Peeling off due to flow, etc.i
The anticorrosive paint layer is formed uniformly through reaction and hardening.

The method of fixing the box underwater is not particularly limited and varies depending on the steel structure and the shape and size of the box, but for example, it may be fixed using clamps or wedges, or tied with ropes or wires. It is also possible.

It is particularly preferable to carry out the corrosion prevention method of the present invention in water where the water flow is fast. For example, when constructing a bridge pier in the ocean, when applying anti-corrosion coating to the underwater parts such as the pier and the hood installed around it, the current in the vicinity is 9 noft (9 noft).
16.6 km per hour) and swells, so with conventional painting methods, the paint was often washed away before it hardened underwater, but with the present invention, the anticorrosive paint is filled into the box body. Furthermore, since the box is fixed until the paint hardens, the anticorrosive paint will never leak out.

In addition, in the present invention, the box used for fixing is removed and anticorrosion is achieved only with the anticorrosive paint, so the anticorrosive paint layer can be formed into a continuous film with no gap force, and the box can be used repeatedly. It was extremely economical.

Example 1 An underwater-curable two-component epoxy resin-based anticorrosive paint (resin component: 35,000
Voids/25℃, Polyamide 16000 Voids/25℃
, manufactured by Kansai Paint Co., Ltd., product name equivalent to Napco Valya N)
A box (size 35 x 55 m, depth 3.5 cm) is filled with a uniformly mixed and separated mixture (the inner surface is covered with adhesive tape treated with a release agent on the back side, the size is 35 x 55 m, and the depth is 3.5 cm), and anticorrosive paint is used. KaEf was applied so that it was in contact with the bolted joint and fixed with a clamp. The current in this area was about 9 knots, and the swells were strong, but the crimped box did not wash away.

When the box body is removed from the rear about 2 hours, the epoxy resin paint with excellent anti-corrosion properties has hardened to a thick thickness on the bolt joints, and is firmly bonded, so there is no chance of f1 intoxication due to the 'M flow. There wasn't.

Claims (1)

[Claims] A reaction hardening type anti-corrosion paint is filled inside a box body which is made to match the surface shape of the steel structure to be anti-corrosioned and whose inner surface is subjected to mold release treatment, and then this box body is coated with the surface to be anti-corrosioned by the filled anti-corrosion paint. A method for preventing corrosion of a steel structure, characterized in that the box is fixed to the steel structure so as to be in contact with the box, and the box is removed immediately after the filled anticorrosion paint has reacted and hardened.