JPH0767550B2 - Antifouling method - Google Patents

Description

The present invention relates to a method for preventing aquatic organisms from attaching to the surface of an underwater structure.

When underwater organisms such as barnacles, sea bream, serpra, and squirts grow on the walls of underwater structures such as sluices, headrace channels (pipes), steel pipe piles, steel sheet piles, concrete piles, concrete bridge piers, the function of the structure itself The water flow rate, anticorrosion property, etc. are reduced. Conventionally, as a method for preventing the adhesion of aquatic organisms to these underwater structures, an antifouling paint containing an antifouling agent component such as an organotin compound or cuprous oxide is directly or pre-coated on the structure to form an anticorrosion coating film. Although it has been painted, it has a short effective antifouling period, is difficult to apply in water, and has a defect that the antifouling coating film peels off when the attached aquatic organisms are removed.

Therefore, the present inventor has conducted diligent research for the purpose of eliminating these defects, the purpose by forming a thick coating anticorrosion coating film exposed antifouling metal in the antifouling portion of the underwater structure And the present invention has been completed.

That is, the present invention applies a thick coating type anticorrosive paint to the surface of an underwater structure, and while the coating film is uncured, a part of the coating film is exposed so that an antifouling metal is exposed from the coating film surface. It relates to an antifouling method for an underwater structure, which comprises embedding in the inside and then hardening the coating film.

The underwater structure in the present invention is a structure built in water (including seawater) or a structure for handling water, and it is necessary that the structure is mainly stationary in the water or on the surface of the water or is high even when moving. However, if it is in contact with water continuously or intermittently for a long period of time, and if aquatic organisms adhere to it, for example, the cooling efficiency will decrease due to a decrease in the amount of water in the cooling water conduit (road) of the power plant. Defects such as a decrease in the amount of power generation and difficulty in opening and closing operation at various floodgates occur, and this adhesion must be prevented.Specifically, as things built in water, for example, floodgates, steel pipe piles, Concrete piles, piers, floating piers,
There are buoys, floating bases, etc., and structures for handling water include headraces (steel and concrete), and cooling water canals for thermal power plants and hydroelectric power plants.

The thick coating type anticorrosive paint used in the present invention is known per se, and for example, the paints described below are suitable.

Water-curable two-part solventless epoxy resin paint This is a two-part paint that mixes the resin component and the curing agent component evenly when used, and has a limited pot life (about 20 ° C at about 2 Therefore, it is preferable to apply the composition to the structure immediately after mixing both components. For example, the resin component is preferably an epoxy resin of 20000 poise / 25 ° C. or higher, and the curing agent component is preferably a water-soluble polyamine or amine adduct of 10,000 poise / 25 ° C. or higher.

The epoxy resin as a resin component is semi-solid or liquid at room temperature, has at least two epoxy groups in one molecule, and has an epoxy equivalent of about 140 to 400 and a molecular weight of about 500 or less are particularly preferable. Include aromatic di- and poly-
One or more glycidyl ethers are considered to be suitable for maintaining curability, adhesion and coating strength. If necessary, an aliphatic epoxide, alicyclic epoxide, etc. may be added to make the coating flexible. Properties, adhesion, etc. are adjusted. Specific examples of the aromatic diglycidyl ether include bisphenol A type epoxy resins (for example, Epicoat 828 and Epicoat 834 manufactured by Shell Chemical Company, DER331 and DE manufactured by Dow Chemical Company).
R337), bisphenol F type epoxy resin (eg, Dainippon Ink and Chemicals, Inc. Epicron 830, Epicron 850, etc.), aromatic polyglycidyl ether for novolac epoxy resin (eg, Dow Chemical Company DEN4).
31, DEN438) and the like.

As the curing agent component, a water-soluble polyamine or an amine adduct is avoided, and a polyamine or an aminopolyamide resin that is as hydrophobic as possible to react with an epoxy group at room temperature can be used. For example, laccamide 9-263 manufactured by Dainippon Ink and Chemicals, Inc., Fuji Kasei Kogyo Co., Ltd.'s tomide 255, tomide 205L, modified heterocyclic diamine, etc. are available.

Furthermore, in order to accelerate the curing reaction in water, triphenyl phosphite and phosphate can be appropriately used, if necessary, and a thickener (for example, asbestos), an extender pigment (for example, talc, silica, etc.). Sand, silica stone, mica, etc.), color pigments (yellow lead, red iron oxide, carbon black, etc.) are used as necessary for adjusting the viscosity.

Since this paint is easily hardened in water and has excellent corrosion resistance, it is suitable for construction of the underwater portion of an existing underwater structure, but it can be used on land.

Two-component solventless epoxy resin paint for land-based curing This paint is a two-part type consisting of a resin component and a curing agent component like the above-mentioned paint, and it is necessary to apply immediately after mixing both components, The viscosities of both components are preferably the same as above. In addition, the same components as those described above are used in terms of composition except that no curing accelerator in water is used.

Unsaturated epoxy ester resin paint for land curing This paint is mainly composed of unsaturated epoxy resin, vinyl monomer, polymerization initiator and filler, and its viscosity is preferably 10,000 poise / 25 ° C or more. .

The unsaturated epoxy ester resin is, for example, one in which a polymerizable unsaturated double bond is introduced into an epoxy resin skeleton formed by reacting an epoxy resin with a carboxylic acid having a polymerizable unsaturated double bond, and as an epoxy resin, Is preferably an epoxy equivalent of about 300 to 1000, a molecular weight of about 400 to 3000,
Acrylic acid and methacrylic acid are suitable as the unsaturated carboxylic acid. Styrene, vinyltoluene, acrylic ester, methacrylic ester and the like can be used as the vinyl monomer, and a normal peroxide is used as the polymerization initiator. Further, as the filler, talc, asbestos, glass flakes and the like are suitable.

The viscosity of thick coating type anticorrosion paint is about 10,000 ~
It is preferably 50,000 poise.

Specific examples of the antifouling metal in the present invention include metals such as copper and tin and those coated or plated with these metals. The antifouling metal is powdery, linear, rod-shaped,
It can be used in a mesh shape, a plate shape, or the like.

The method of forming a thick coating anticorrosive paint coating film on the underwater structure, and exposing the antifouling metal to the surface of the coating film is not particularly limited and may be any, for example, coating the undercoat structure with the coating material, A part of the coating film is embedded in the coating film so that the antifouling metal is exposed from the coating surface while the coating film is uncured, and the coating film is cured. That is, the thick coating type anticorrosive paint can be applied directly by hand, or by using a trowel, spatula, roller or the like. The thickness of the coating film can be selected according to the purpose, but it is preferably 2 mm or more, particularly 2 to 20 mm. In addition, the coating may be applied directly to the existing structure underwater in water, or may be applied after landing on land. or,
In the case of new installation, it can be painted in advance, or it can be painted after installation in water. Then, while the coating film is uncured, the antifouling metal is embedded. Specifically, a thick coating type anticorrosive paint is applied to an underwater structure to a film thickness of 2 mm or more, and the coating film is uncured. A method of embedding a part of the antifouling metal in the inside and exposing the rest from the coating surface is preferable, for example, spraying a granular antifouling metal on the surface of the uncured coating film, or a linear or rod-like shape. It is desirable to embed an antifouling metal such as a mesh or plate in the coating film so that a part of the metal cannot be easily removed by hand. These embedding operations may be underwater or on land. In the present invention, about 40 of the thick coating type anticorrosive coating film surface to prevent the adhesion of aquatic organisms
%, Especially about 60 to 90%, is preferably exposed with an antifouling metal. Alternatively, the metal antifouling agent can be preliminarily mounted on the net in sheet form on land, and embedded in water in the uncured film of the thick coating anticorrosion paint that has already been applied, which can be powdery, linear, or rod-shaped. Suitable for antifouling metal such as.

Further, in the present invention, the exposure ratio of the antifouling metal on the thick coating type anticorrosive coating surface can be arbitrarily selected depending on the type and amount of aquatic organisms in the application water area, but the antifouling metal is applied to the coating film. It is also important to fix it so that it will not fall off, and it is important for the antifouling property to be exhibited, and the exposed area of the antifouling metal is about 40% of the antifouling part.
Above all, it is particularly preferably 60 to 90%.

The antifouling coating film formed by such an antifouling method exhibits an antifouling effect for a long period of time as compared with painting an antifouling paint containing an antifouling agent such as an organic tin compound, and is applied in water. Even if aquatic organisms adhere, it is possible to remove aquatic organisms without peeling off the antifouling agent or the like.

Hereinafter, the present invention will be described with reference to Examples and Comparative Examples.

Example 1 A marine construct (diameter removed from deposits of shellfish, insects, algae, etc.)
A zinc-plated wire mesh (wire diameter 0.3 mm, mesh size 5 x 5 mm) is attached to a 1 m steel cylinder, and a two-component epoxy resin paint (resin component 35000 poise / 25) is put through the mesh from above.
℃, polyamide 16000 poise / 25 ℃, Kansai Paint Co.,
The product name Napco Barrier N (equivalent to Napco Barrier N) was applied by hand in water so as to adhere uniformly. The coating film thickness was about 5-8 mm. Next, a copper wire mesh (wire diameter 0.
3 mm, mesh size 1 × 1 mm) was attached so as not to fall off, and cured in water.

Comparative Example 1 Chlorinated rubber * 1) 15 parts Chlorinated n-paraffin * 2) 8 Cuprous oxide 25 TPT Hydroxide 7 Benzi pattern 5 Zinc white 5 Talc 5 Xylene 30 100 Dissolve the chlorinated rubber in xylene with the above formulation, Each raw material was added to and mixed with each other, and then dispersed using a speed line mill to prepare an antifouling paint.

* 1) Asahi Denka Kogyo Co., Ltd. (Adeka Chloride Rubber CR-10) * 2) Adeka Argus Chemical Co., Ltd. (Adeka Sizer E-
450) This antifouling paint was applied to the above-mentioned marine construct (same as above) by brushing on the ground in 2 times so as to be 3 g / 100 cm ² .

Performance test results The antifouling treated constructs obtained in the above Examples and Comparative Examples were immersed in seawater, and the adhesion of marine organisms was observed.

As a result, almost no adhesion of aquatic organisms was observed in both of the samples after soaking for one year, but after two years or more, the sample of the Example had slightly more adhered than that of the first year, whereas the Comparative Example. There were more aquatic organisms attached than in the case. Further, regarding the antifouling property after removing the attached aquatic organisms, the example showed the same antifouling property as before, whereas the comparative example showed almost no antifouling property.

Claims (1)

[Claims] 1. A submerged structure surface is coated with a thick coating type anticorrosive paint, and a part of the anticorrosion metal is exposed in the coating film so that the antifouling metal is exposed from the surface of the coating film while the coating film is uncured. A method for antifouling an underwater structure, which comprises: embedding in an aqueous solution and then curing the coating film.