Pest control construction method to aquatic organism

Abstract

To provide a practical construction method capable of effectively controlling aquatic organisms adhering onto an inner wall of a concrete channel without requiring a larger labor or costs.SOLUTION: A pest control construction method is for an existing concrete channel against aquatic organisms. The construction method includes: a step of applying a primer coating containing a resin component and a solvent, with a nonvolatile content concentration 75 mass% or less at application and a viscosity by Iwata cup method 30 seconds or less, onto an internal wall of the concrete channel exposed to the air in a state where part of the surface of the internal wall of the concrete channel is still wet; and a step of applying and curing a top coating containing a resin component and a silicone oil onto the surface with the primer coating applied at the step of applying.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for controlling aquatic organisms. [Background technology]

[0002] In the waterways of hydroelectric and thermal power plants, aquatic organisms such as aquatic insects such as caddisflies, moss such as water moss, and shellfish such as purple mussels, oysters, and barnacles attach to and live in the waterways and cause problems, so measures to prevent this are necessary. For this reason, various methods for preventing the attachment of aquatic organisms to the inside of power plant waterways have been researched. For example, Patent Document 1 discloses a method for preventing and / or controlling the attachment of aquatic insects and / or removing them, which comprises providing two or more conductive substrates in at least a part of a water path, arranging them to function as electrodes, and passing an electric current between the conductive substrates, thereby preventing and / or removing the attachment of aquatic insects, their larvae, or their nests to the conductive substrates.

[0003] Furthermore, Patent Document 2 proposes a method for inhibiting the adhesion of biological fouling, which is characterized by setting a predetermined amount of an adhesion inhibitor such as ozone to be added to fresh water flowing through a pipe and intermittently adding the adhesion inhibitor to the inside of the pipe, thereby inhibiting biological fouling from adhering to the inner wall of the pipe.

[0004] Furthermore, in Patent Document 3, the present applicant has proposed an antifouling method characterized by forming a thick-type anticorrosive coating film on the surface of an underwater structure and leaving an antifouling metal exposed on the surface of the thick-type anticorrosive coating film. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2006-247466 A [Patent Document 2] JP 2017-192901 A [Patent Document 3] Japanese Patent Application Laid-open No. 63-110269 Summary of the Invention [Problem to be solved by the invention]

[0006] In order to prevent and / or remove aquatic organisms from adhering to waterways, attempts have been made for a long time to use electrochemical devices or to impart antifouling properties to the inner wall surface of the pipes using paint. However, the control methods described in Patent Documents 1 and 2 require large-scale devices and the associated maintenance costs, and are not sufficient in terms of the effectiveness of controlling aquatic organisms. In addition, the method using paint described in Patent Document 3 involves applying a thick-coating anticorrosive paint using a trowel underwater, which takes a long time to treat a wide area and is uneconomical.

[0007] As described above, the conventional methods for controlling aquatic organisms are not practical, and so, at present, there is no choice but to periodically shut down the operation of the waterway and physically remove the attached aquatic organisms during the shutdown period. Specifically, in the case of a concrete waterway, a physical removal method is a method in which the aquatic organisms are manually removed using a tool such as a scraper while being washed with high-pressure water. However, with this method, a sheet must be laid over the entire bottom of the waterway before the removal work is performed, and the removed aquatic organisms and debris must be collected. In addition to this removal work, the labor required for the recovery work is enormous, and the waterway operation is also shut down for a very long time, so there is a need to develop a method for preventing the attachment of aquatic organisms to the waterway and for easily removing the attached aquatic organisms, i.e., a prevention method.

[0008] An object of the present invention is to provide a practical treatment method for effectively controlling aquatic organisms adhering to the inner walls of concrete waterways without requiring a great deal of effort or cost. [Means for solving the problem]

[0009] The present inventors have conducted extensive research into the above-mentioned problems, and have found that by applying a primer paint having a specific concentration and viscosity range to the inner wall surface of a concrete channel while the inner wall surface is still wet, the inner wall surface of the concrete channel can be modified to have excellent adhesion to a subsequent top coat paint, and by applying a specific top coat paint on top of the primer paint, the inner wall surface of the concrete channel can withstand wear caused by running water in water and exhibit aquatic organism control properties.

[0010] That is, the present invention provides: Item 1 A method for preventing and treating aquatic organisms in existing concrete waterways, comprising: A process of painting a primer paint containing a resin component and a solvent, having a non-volatile content concentration of 75% by mass or less at the time of painting, and having a viscosity of 30 seconds or less according to the Iwata Cup method on the inner wall surface of the concrete channel while a part of the inner wall surface of the concrete channel exposed to the air is still wet; and A process of painting a topcoat paint containing a resin component and silicone oil on the surface painted with the primer paint in the painting process, and curing the surface. A processing method having the following features. Section 2 A method for preventing and treating aquatic organisms in existing concrete waterways, comprising: A process (1) of draining the water inside the concrete waterway to expose the inner wall surface of the concrete waterway to the air; A process (2) of applying a primer paint containing a resin component and a solvent, having a non-volatile content concentration of 75% by mass or less at the time of application and having a viscosity of 30 seconds or less as measured by the Iwata Cup method, to the inner wall surface of the concrete channel while a portion of the inner wall surface of the concrete channel is still wet; A step (3) of applying a topcoat paint containing a resin component and silicone oil to the surface coated with the primer paint in the step (2) and curing the surface; and A process (4) of resuming water flow into the concrete channel and immersing the cured concrete channel inner wall surface in water; A processing method having the above structure. Section 3 3. The treatment method according to item 1 or 2, wherein the curing period from when the water in the concrete waterway is drained and the inner wall surface of the concrete waterway is exposed to the air until the primer paint is applied is about 0.05 to 7 days. Section 4 Item 3. The treatment method according to item 1 or 2, wherein the resin component contained in the primer paint contains an epoxy resin and a polyamine compound. Section 5 3. The treatment method according to claim 1 or 2, wherein the primer coating does not contain a pigment or has a pigment volume concentration of 15% or less. Section 6 3. The treatment method according to item 1 or 2, wherein after the primer coating, the surface is cured at room temperature for 0.05 to 15 days, and then step (3) is carried out. Section 7 Item 3. The treatment method according to item 1 or 2, wherein the resin component contained in the topcoat paint contains a polysiloxane resin. Section 8 3. The treatment method according to claim 1 or 2, wherein after the topcoat paint is applied, the surface is left to cure at room temperature for 1 to 10 days, and then step (4) is carried out. Section 9 3. The method according to claim 1 or 2, wherein the total number of days for the curing period from the start of drainage in step (1) to the resumption of water conveyance in step (4) is within 2 weeks. Item 10 10. The treatment method according to any one of items 1 to 9, wherein the concrete waterway is a waterway for supplying water to a hydroelectric power plant. Regarding. Effect of the Invention

[0011] The treatment method of the present invention can impart excellent aquatic organism control properties to the inner wall surface of a concrete waterway in a short period of time. In addition, since the treated surface by this method has resistance to abrasion by running water, it is possible to maintain the aquatic organism control properties for a long period of time. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Concrete Channel: The concrete waterway that is the subject of the treatment method of the present invention is an artificially constructed structure for flowing water, and is not limited in shape or use. Examples of the water source include fresh water such as rivers, lakes, and ponds. Specific examples include concrete waterway tunnels used for agricultural waterways, industrial waterways, water supply and sewerage, and waterways for hydroelectric power plants. The material of the waterway in the present invention is concrete, and when the waterway has already been installed and is in operation, it has a water flow inside.

[0013] The method of the present invention is useful for application to waterways (also called headraces or intakes) that supply water to hydroelectric power plants. The concrete surface of hydroelectric power plant waterways has an absorbent uneven surface, and when it contains fresh water, algae easily grow on it. When algae grow on the concrete surface, various aquatic insects attach to the algae. Caddisflies are well known as aquatic insects that live in freshwater areas supplied to hydroelectric power plants. Caddisflies are considered problematic as pests that nest or attach in large numbers to the walls of waterways, which are one of the causes of reduced power generation efficiency due to reduced water levels. The treatment method of the present invention is extremely effective in controlling aquatic insects such as caddisflies and plants such as algae, so it is worthwhile to carry out the method even if the operation of the existing concrete waterway is temporarily stopped.

[0014] In this specification, the aquatic organisms are a concept that includes not only animals that live in water, but also plants such as algae.

[0015] Process (1): In the method of the present invention, step (1) is a preparation step for carrying out the next treatment step, that is, a step of draining the water inside the concrete waterway and exposing the inner wall surface of the concrete waterway to the air.

[0016] Process (2): Next, while a part of the concrete waterway inner wall surface is still wet, a primer paint is applied to the concrete waterway inner wall surface. In the present invention, the wet state of concrete refers to a state in which the hand is wet with water when the concrete surface is touched with a hand, and / or a state in which the concrete has a dark wet color. The color of concrete when wet with water is darker than that of dry concrete. This dark color is called a "wet color" and is well known. In addition, since concrete is porous, the wet concrete may contain water to a certain extent in a state in which the presence of water is visible in the holes (pores) that the concrete has. On the other hand, the dry state of concrete refers to a state in which the hand is not wet with water at all when the concrete surface is touched with a hand, and a dark wet color is not seen at all. The degree of wetness of the concrete waterway inner wall surface does not need to be uniform, and the entire surface of the concrete waterway inner wall surface may be wet, or there may be unevenness, or there may be partially dry areas. If there are dry areas, the area ratio is preferably at most about 30%. The primer coating can be applied sufficiently to dry concrete, but if the entire inner concrete wall surface is completely dry, the construction period will be long and the waterway will be out of operation for a long period, which is uneconomical and undesirable.

[0017] In addition, in the present invention, in order to efficiently and sufficiently control aquatic organisms in a short time, it is important that the inner wall surface of the concrete waterway is moderately wet. Although the reason is unclear, when the inner wall surface of the concrete waterway is wet, the penetration of the primer paint is improved. This is presumed to be because the non-volatile content concentration of the primer paint is 75% or less and the viscosity is 30 seconds or less, which makes it easier for the primer paint to penetrate into the concrete surface and concrete burrows, and makes it easier for the primer paint to spread on the wet concrete surface. In this way, in order to make the inner wall surface of the concrete waterway moderately wet so that the primer paint can easily penetrate, for example, it is preferable to set the curing period from when the water in the concrete waterway is drained and the inner wall surface of the concrete waterway is exposed to the air until the primer paint is applied at room temperature to about 0.05 to 7 days.

[0018] Next, the primer paint used in the method of the present invention will be described.

[0019] Primer paint: The primer coating contains a resin component and a solvent, has a non-volatile content of 75% by mass or less when applied, and has a viscosity of 30 seconds or less as measured by the Iwata cup method.

[0020] The primer paint used in the present invention has a non-volatile content of 75% by mass or less at the time of application and a viscosity of 30 seconds or less as measured by the Iwata cup method, so that the primer paint can fully penetrate the surface layer of the concrete when wet with water, while remaining on the surface to form a continuous film, which makes it easier for the concrete surface to adhere to the topcoat paint described below. If the non-volatile content of the primer coating exceeds 75% by mass, peeling or blistering occurs between the concrete surface and the primer coating film and / or between the primer coating film and the topcoat coating film, which is not preferable. Also, if the viscosity of the primer coating exceeds 30 seconds, peeling or blistering occurs between the concrete surface and the primer coating film and / or between the primer coating film and the topcoat coating film, which is not preferable.

[0021] The non-volatile content of the primer coating is preferably 5% by mass or more, 15% by mass or more, or 25% by mass or more, and preferably 65% ​​by mass or less, 55% by mass or less, or 50% by mass or less. The non-volatile content is the ratio (%) of the mass of the non-volatile content of the coating to the mass of the coating.

[0022] The viscosity of the primer coating, as measured by the Iwata cup method, is preferably 1 second or more, 3 seconds or more, or 5 seconds or more, and preferably 25 seconds or less, 20 seconds or less, or 15 seconds or less.

[0023] In this specification, the non-volatile content refers to the components excluding volatile components such as water and organic solvents, and is the component that will ultimately form the coating film. In this invention, the components remaining when 3.3 g of the sample is dried at 130°C for 1 hour are treated as non-volatile components. Measurement conditions other than the sample mass and drying temperature are in accordance with JIS K5601-1-2:2008. In cases where the primer paint is a two-component paint, a reaction may progress over time after sample preparation, so the measurement sample is prepared at 20°C and drying is started within 5 minutes after sample preparation.

[0024] The viscosity means the viscosity at the time when the primer paint is prepared for use in painting. In this specification, the viscosity is measured using an Iwata cup. In the Iwata cup method, an NK-2 viscosity cup manufactured by Anest Iwata Corporation is used as the viscosity cup. The viscosity cup has an orifice at its bottom. The viscosity specified in this invention is measured by first submerging the cup in the sample, then lifting the cup from the sample, and measuring the time (seconds) from when the cup is lifted to when the outflow of the sample in the cup stops. In cases where the primer paint is a two-component paint, a reaction may progress over time after sample preparation, so the viscosity measurement is performed using a primer paint adjusted to 25°C just before painting as a sample, and the measurement is completed within 5 minutes.

[0025] The viscosity of the primer paint can be adjusted during the production and application of the primer paint. Specifically, it can be adjusted by the content of non-volatile matter contained in the primer paint, the type of resin, the paint composition, the amount of solvent, etc. In addition, a known thickener may be added to adjust the viscosity.

[0026] Resin Components: The resin component contained in the primer coating is a coating film-forming component, and is not particularly limited, and can be exemplified by resins and crosslinkers commonly used in the coating industry, regardless of whether they are water-based, solvent-based, or solventless.Specific examples include acrylic resins, epoxy resins, polysiloxane resins, polyester resins, polyether resins, rosin resins, petroleum resins, coumarone resins, phenolic resins, urethane resins, melamine resins, urea resins, cellulose resins, xylene resins, alkyd resins, aliphatic hydrocarbon resins, butyral resins, maleic acid resins, fumaric acid resins, vinyl resins, polyamine compounds, polyisocyanate compounds, and combinations thereof.In terms of adhesion to wet concrete surfaces, it is particularly preferable that the resin component contains an epoxy resin and a polyamine compound.

[0027] Epoxy resins are resins having two or more epoxy groups in one molecule. Specific examples include bisphenol A type epoxy resins, bisphenol F type epoxy resins, novolac type epoxy resins, epoxy resins modified with modifiers such as dimer acids and fatty acids, and combinations of these. From the viewpoint of adhesion to wet concrete and topcoat paints described below, the epoxy resin is preferably bisphenol A type epoxy resin. The epoxy equivalent of the bisphenol A type epoxy resin is preferably 160 g / eq or more, 180 g / eq or more, and preferably 1000 g / eq or less, 500 g / eq or less. The epoxy equivalent means the number of grams (g / eq) of a resin containing 1 gram equivalent of epoxy groups. In this specification, the epoxy equivalent means the value published by the manufacturer or the epoxy equivalent measured in accordance with JIS K 7236:2009.

[0028] The polyamine compound is a compound having two or more amino groups in one molecule. Specific examples of the polyamine compound include aliphatic polyamines, alicyclic polyamines, aromatic polyamines, polyamides of these polyamines and modified products thereof, epoxy adducts to which an epoxy compound is added, Mannich modified products, and combinations of these.

[0029] The polyamine compound is a compound having two or more amino groups in one molecule, and specific examples thereof include aliphatic polyamines, alicyclic polyamines, and aromatic polyamine compounds. Examples of aliphatic polyamines include diethylenetriamine, dipropylenetriamine, tetraethylenepentamine, bis(cyanoethyl)diethylenetriamine, and bishexamethylenetriamine. Examples of alicyclic polyamines include 4-cyclohexanediamine, 4,4'-methylenebiscyclohexylamine, norbornanediamine (NBDA / 2,5- and 2,6-bis(aminomethyl)-bicyclo[2,2,1]heptane), and isophoronediamine (IPDA / 3-aminomethyl-3,5,5-trimethylcyclohexylamine). Examples of aromatic polyamines include m-xylylenediamine (MXDA), phenylenediamine, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenyl ether, and 4,4'-diaminodiphenyl sulfone.

[0030] The active hydrogen equivalent of such a polyamine compound is preferably 40 or more, or 80 or more, and preferably 1,000 or less, or 600 or less. The active hydrogen equivalent is the number of grams (g / eq) of a resin containing 1 gram equivalent of active hydrogen. In this specification, the active hydrogen equivalent is a value published by the manufacturer or a value measured in accordance with JIS K-7237:1986.

[0031] The content of the resin component is preferably 75 parts by mass or less, 55 parts by mass or less, or 50 parts by mass or less, based on 100 parts by mass of the primer paint at the time of application, and preferably 5 parts by mass or more, or 15 parts by mass or more.

[0032] solvent: The solvent may be an organic solvent or water. As the organic solvent, organic solvents used in the field of paints can be used without restrictions. Specific examples include aromatic organic solvents, ketone organic solvents, ether organic solvents, alcohol organic solvents, ester organic solvents, and weak solvents. Examples of aromatic organic solvents include xylene and toluene, examples of ketone organic solvents include methyl isobutyl ketone and cyclohexanone, examples of ether organic solvents include propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate, examples of alcohol organic solvents include isopropyl alcohol and isobutyl alcohol, and examples of weak solvents include gasoline, kerosene, coal tar naphtha (including solvent naphtha), petroleum ether, petroleum naphtha, petroleum benzine, turpentine oil, and mineral spirits (including mineral thinner, petroleum spirits, white spirits, and mineral turpentine). From the viewpoint of penetration into wet concrete and adhesion of the primer coating film, the solvent preferably includes a weak solvent. Alternatively, the preferred solvents include a combination of an aromatic organic solvent, an ether organic solvent, a ketone organic solvent, and an alcohol organic solvent. A further preferred example of the solvent is a combination of an aromatic organic solvent, an ether organic solvent, a ketone organic solvent, an alcohol organic solvent, and a weak solvent.

[0033] From the viewpoint of penetration into wet concrete, the content of the solvent is preferably 25 parts by mass or more, preferably 35 parts by mass or more, 55 parts by mass or more, and preferably 95 parts by mass or less, 85 parts by mass or less, based on 100 parts by mass of the primer paint at the time of application.

[0034] Other Ingredients: The primer coating may further contain, in addition to the resin component and the solvent, a pigment, a silane coupling agent, a plasticizer, a film-forming assistant, a rust inhibitor, a curing accelerator, an anti-settling agent, and the like. Pigments: Examples of pigments include color pigments such as titanium oxide, zinc oxide, alumina, carbon black, graphite, black iron oxide, iron-manganese composite oxide, iron-copper-manganese composite oxide, iron-chromium-cobalt composite oxide, copper-chromium composite oxide, copper-manganese-chromium composite oxide, ferric oxide (red oxide), molybdate orange, permanent red, permanent carmine, anthraquinone red, perylene red, quinacridone red, yellow iron oxide, titanium yellow, fast yellow, benzimidazolone yellow, chrome green, cobalt green, phthalocyanine green, ultramarine blue, Prussian blue, cobalt blue, phthalocyanine blue, quinacridone violet, dioxazine violet, aluminum pigments, and pearl pigments; and extender pigments such as calcium carbonate, talc, barium sulfate, mica, clay, silica, and aluminum hydroxide.

[0035] In the method of the present invention, from the viewpoint of adhesion of the primer coating film to the concrete surface and the topcoat coating film described below, it is desirable that the primer paint does not contain pigment or contains a small amount of pigment. In terms of pigment volume concentration, it is preferably 15% or less, more preferably 5% or less, and particularly preferably 0.5% or less. In this specification, the pigment volume concentration is the volume ratio of the pigment to the total solid content of all resins and all pigments in the paint. The specific gravity of the pigment, which is the basis for calculating the volume of the pigment, is the value published by the manufacturer or according to the "Paint Raw Materials Handbook 9th Edition" (Japan Paint Manufacturers Association), and the specific gravity of the resin solids is approximately 1. Because the primer paint contains a small amount of pigment, particularly colored pigment, it maintains adhesion to the inner wall surface of the concrete waterway, while also having the effect of making visible the areas where the primer paint has been applied, its degree of penetration into the concrete, and any areas that have not been painted with the subsequent topcoat paint.

[0036] Examples of silane coupling agents include 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2-(2-aminoethyl)aminoethyl)aminopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-isocyanatopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and N-phenyl-3-aminopropyltrimethoxysilane, and combinations thereof.

[0037] When the primer coating contains a silane coupling agent, the content of the silane coupling agent based on 100 parts by mass of the non-volatile content of the primer coating is, from the viewpoint of improving adhesion to wet concrete and the topcoat coating film, preferably 0.01 parts by mass or more, 0.05 parts by mass or more, and preferably 10 parts by mass or less, 5 parts by mass or less.

[0038] Processing steps: In the method of the present invention, the wet concrete waterway inner wall surface is treated with the primer paint. The primer paint can be applied to the concrete waterway inner wall surface by a known application method such as air spray application, airless spray application, roller application, brush application, trowel application, spatula application, etc., so that the primer paint is absorbed into the concrete inner wall surface and a continuous film is formed on the concrete inner wall surface. As a curing method after painting, the material may be left at room temperature or may be heated or cooled. Room temperature refers to a temperature at which no temperature operation such as forced heating or cooling is performed, although it varies depending on the atmospheric temperature.

[0039] In the present invention, in order to make it easier to apply a topcoat paint to the concrete inner wall surface treated with a primer paint, and to make the formed topcoat paint film firmly adhere to the primer paint film and less likely to peel off due to water flow, it is preferable to carry out step (3) of applying a topcoat paint after curing at room temperature for 0.05 to 15 days after application of the primer paint.

[0040] Process (3): Topcoat: The topcoat paint used in step (3) of the treatment method of the present invention is a paint containing a resin component and silicone oil. In the method of the present invention, by carrying out the treatment according to the above-mentioned step (2) on wet concrete and painting the topcoat paint, the concrete coating surface does not peel off due to water flow, and provides and maintains aquatic organism control properties for a long period of time.

[0041] Resin Components: The resin component contained in the topcoat paint is a film-forming component, and is not particularly limited, and may be the resin and crosslinking agent exemplified in the description of the primer paint. In particular, the resin component of the topcoat paint preferably contains a polysiloxane resin from the viewpoint of aquatic organism control. In particular, room temperature curable liquid organopolysiloxane is preferred. The room temperature curable liquid polysiloxane is an organopolysiloxane that has reactive functional groups in the molecule, and the reactive functional groups react with each other or react with a crosslinking agent having a functional group capable of reacting with the reactive functional groups to form a silicone rubber with a three-dimensional crosslinking structure and harden.

[0042] Examples of reactive functional groups include hydroxyl groups, oxime groups, acyloxy groups, alkoxy groups, alkenyloxy groups, amino groups, amide groups, and aminooxy groups. The room temperature curable liquid organopolysiloxane is liquid when applied and forms silicone rubber after curing, so that the topcoat coating film can have rubber elasticity and is considered to be effective in controlling aquatic organisms. The room temperature curable liquid organopolysiloxane may be any of the conventionally known ones, which are commercially available, such as the one-component liquid rubber (RTV rubber) KE series manufactured by Shin-Etsu Chemical Co., Ltd. and the DOWSIL series manufactured by Toray Dow.

[0043] Silicone oil: The silicone oil floats to the surface of the topcoat film and contributes to preventing adhesion of aquatic organisms, and specific examples include dimethyl silicone oil, methylphenyl silicone oil, methylhydrogen silicone oil, etc. These silicone oils also include modified silicone oils to which an amino group, an epoxy group, a carbinol group, a mercapto group, a carboxyl group, a methacryl group, a polyether group, a phenol group, a silanol group, an acrylic group, an acid anhydride group, an aralkyl group, a fluoroalkyl group, a long-chain alkyl group, a fatty acid ester, a fatty acid amide, etc. are added. The silicone oil may be commercially available, such as "KF-96", "KF-50", "X-22-2516", "X-22-4272", and "KF-6020" (all manufactured by Shin-Etsu Chemical Co., Ltd.), "FZ-2203", and "FZ-2160" (all manufactured by Toray Dow Co., Ltd.).

[0044] From the viewpoint of aquatic organism control, the content of the silicone oil is preferably 0.5 parts by mass or more, or 5 parts by mass or more, based on 100 parts by mass of the topcoat paint, and is preferably within the range of 50 parts by mass or less, or 45 parts by mass or less.

[0045] Other Ingredients: In addition to the resin component and silicone oil, the topcoat paint may contain, as necessary, an inorganic filler, a silane coupling agent, an antifouling agent, a curing catalyst, a dehydrating agent, a coloring pigment, an organic solvent, a thickener, etc. Examples of the antifouling agent that is blended as necessary include medetomidine, tralopyril, cuprous oxide, zinc oxide, copper pyrithione, zinc pyrithione, and combinations thereof.

[0046] Painting Method: The topcoat paint is applied to the inner wall surface of the concrete waterway treated in step (2) by a known coating method, such as air spray coating, airless spray coating, roller coating, brush coating, trowel coating, spatula coating, etc. As a curing method, it may be left at room temperature or may be subjected to heating or cooling operation.

[0047] In the present invention, from the viewpoint of forming a topcoat coating film that is firmly attached to the primer coating film and is resistant to abrasion by running water, it is preferable to carry out step (4) after curing the topcoat paint at room temperature for 1 to 10 days after application of the topcoat paint.

[0048] Process (4): In the method of the present invention, after the topcoat paint is applied and cured, the water is again directed into the concrete waterway and the treated inner wall surface of the concrete waterway is immersed in water. In the present invention, the inner wall surface of the concrete waterway treated with the primer paint and topcoat paint is immersed in water again, which makes the composite coating film less likely to peel off from the concrete and has the effect of maintaining the aquatic organism control properties. In addition, in the method of the present invention, it is useful that the total curing period from the start of drainage in step (1) to the resumption of water conveyance in step (4) is within 2 weeks. According to the method of the present invention, aquatic organism control properties can be effectively imparted for a long period with a minimum of downtime. It should be noted that steps (1) to (4) may be performed by different entities, for example, steps (1) and (4) by an electric power company or a construction company, and steps (2) and (3) by a painting contractor. However, when a plurality of related entities jointly perform steps (1) to (4) on the same concrete waterway inner wall to implement the treatment method of the present invention, the treatment method of the present invention is also deemed to have been implemented. EXAMPLES

[0049] The present invention will be described in more detail below with reference to Production Examples, Examples, and Comparative Examples, but the present invention is not limited thereto. In each example, "parts" means parts by mass, and "%" means % by mass.

[0050] <Primer paint> Manufacturing Examples 1-9 A two-liquid type primer paint was manufactured by preparing a base paint and a hardener according to the composition shown in Table 1 below. In the test, the components were mixed and stirred according to the composition shown below to obtain primer paints (P-1) to (P-9). The property values ​​in the table were measured according to the method described in the specification.

[0051] [Table 1]

[0052] (Note 1) Epoxy resin A solution: bisphenol A type epoxy resin, xylene solution with epoxy equivalent of 475g / eq. (Note 2) Epoxy resin B: Bisphenol A type epoxy resin, epoxy equivalent 190g / eq (Note 3) Copper phthalocyanine blue: specific gravity 1.5 (Note 4) Titanium white: specific gravity 4.1 (Note 5) Silica: specific gravity 2.2 (Note 6) Polyamine compound A: Epoxy adduct of polyamine, active hydrogen equivalent 250g / eq (Note 7) Polyamine compound B: Modified aliphatic polyamine, active hydrogen equivalent 178g / eq.

[0053] <Topcoat paint> As topcoat paints, the following topcoat paints (T-1) to (T-5) were used.

[0054] [Table 2]

[0055] <Creating test specimens and evaluation tests> Examples 1 to 27 and Comparative Examples 1 to 12 A concrete plate measuring 50 x 50 x 2 cm was submerged in water at 23°C for 7 days, and after the water was sufficiently absorbed, it was taken out and left in a constant temperature and humidity chamber at 23°C and 90% relative humidity for the period shown in Table 3 (curing period before primer coating) for curing. Under the conditions of this test, the concrete plate was not completely dry even after the longest curing time, and water was found to be on the hand when the concrete surface was touched with a hand, and the entire area was visibly wet, and was in a completely wet state. Then, while the surface of the concrete was still wet with water, each primer paint shown in Table 1 was applied with a brush so that the water in the concrete voids was replaced with the primer paint and the concrete surface after treatment was covered with a continuous primer coating. After that, the specimens were cured at 23°C for the period shown in Table 3 (curing period before topcoat painting), and then the topcoat paint shown in Table 2 was air spray painted under conditions such that the dry film thickness was 150 μm, and the specimens were cured at 23°C for 7 days to obtain test specimens (X-1) to (X-39). Two specimens were prepared for each condition, one for the water immersion test and one for the water channel panel test. Table 3 shows the preparation conditions of the specimens and the results of the evaluation tests.

[0056] [Table 3]

[0057] [Table 4]

[0058] (*) Total number of days for curing from when the concrete slab is removed until it is immersed in water Assuming a period during which the waterway would be stopped, the total number of days for the curing period from when the concrete slab was submerged and then pulled out until the start of the water immersion test described below was recorded.

[0059] (*) Water immersion test Each test specimen was immersed in water at 23° C. for 30 days, and after removal, the condition was visually observed and evaluated according to the following criteria.

[0060] Bulging and peeling from the concrete surface ◎: No swelling or peeling from the concrete surface ○: Some swelling from the concrete surface is observed, but no peeling at all △: Some swelling and peeling from the concrete surface are observed. ×: Both swelling and peeling from the concrete surface are significantly observed. Blistering and peeling between primer / topcoat layers ◎: No blistering or peeling between the primer and topcoat layers ◯: Some swelling between the primer and topcoat layers is observed, but no peeling at all △: Slight swelling and peeling between the primer and topcoat layers are observed. ×: Both swelling and peeling between the primer / topcoat layers are significantly observed.

[0061] (*) Water channel panel test Each test specimen was attached to the headrace of a hydroelectric power plant and immersed in water for 180 days, after which it was removed and its condition was evaluated based on the following criteria. Algae resistant ◎: No algae stains are found 〇: There is a thin layer of algae attached, but the base material is visible. △: Algae is attached to the surface, and the base material is not visible, but no algae growth is observed. ×: Algae adhesion is so severe that the base material is no longer visible and the growth of algae can be seen. insect repellent ◎: No insects are found on the surface ○: Very few insects are found attached △: Insects are attached, and the attachment area is less than 30% ×: Insects are attached significantly, and the attachment area exceeds 30%.

Claims

1. A method for preventing and treating aquatic organisms in existing concrete waterways, comprising: A process of applying a primer paint containing a resin component and a solvent, having a non-volatile content concentration of 75% by mass or less at the time of application and having a viscosity of 30 seconds or less as measured by the Iwata Cup method, to the inner wall surface of the concrete channel while a part of the inner wall surface of the concrete channel exposed to the air is still wet; and A process of painting a topcoat paint containing a resin component and silicone oil on the surface painted with the primer paint in the painting process, and curing the surface. A processing method having the following features.

2. A method for preventing and treating aquatic organisms in existing concrete waterways, comprising: A process (1) of draining the water inside the concrete waterway to expose the inner wall surface of the concrete waterway to the air; A step (2) of applying a primer paint containing a resin component and a solvent, having a non-volatile content concentration of 75% by mass or less at the time of application and having a viscosity of 30 seconds or less as measured by the Iwata Cup method, to the inner wall surface of the concrete channel while a part of the inner wall surface of the concrete channel is still wet; A step (3) of applying a topcoat paint containing a resin component and silicone oil to the surface coated with the primer paint in the step (2) and curing the surface; and A process (4) of resuming water flow into the concrete waterway and immersing the cured concrete waterway inner wall surface in water; A processing method having the following features.

3. The treatment method according to claim 1 or 2, wherein the curing period from when the water in the concrete waterway is drained and the inner wall surface of the concrete waterway is exposed to the air until the application of the primer paint is 0.05 to 7 days.

4. 3. The method according to claim 1, wherein the resin component contained in the primer coating comprises an epoxy resin and a polyamine compound.

5. 3. The method according to claim 1 or 2, wherein the primer coating does not contain a pigment or has a pigment volume concentration of 15% or less.

6. 3. The method according to claim 1 or 2, wherein after the application of the primer paint, the surface is left to cure at room temperature for 0.05 to 15 days, and then the step (3) is carried out.

7. 3. The method according to claim 1, wherein the resin component contained in the topcoat paint comprises a polysiloxane resin.

8. The treatment method according to claim 1 or 2, wherein after the topcoat paint is applied, the surface is left to cure at room temperature for 1 to 10 days, and then step (4) is carried out.

9. 3. The method according to claim 1 or 2, wherein the total number of days for the curing period from the start of drainage in step (1) to the resumption of water conveyance in step (4) is within two weeks.

10. The method according to any one of claims 1 to 9, wherein the concrete waterway is a waterway for supplying water to a hydroelectric power plant.

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