Repair method of coating film provided on marine vessel or underwater structure

Abstract

To provide a repair method of a coating film provided on a marine vessel or an underwater structure from which an antifouling layer that has good dryness and is excellent in peeling resistance can be obtained.SOLUTION: A repair method of a coating film provided on a marine vessel or an underwater structure includes a step (1) of forming a sealer layer, and a step (2) of forming an antifouling layer on the sealer layer, wherein the sealer layer is formed using an aqueous sealer composition containing an aqueous resin and water, and the antifouling layer is formed using a coating material for an antifouling layer containing a resin and an organic solvent.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for repairing a coating provided on a ship or underwater structure. [Background technology]

[0002] When ships and underwater structures are exposed to water for long periods of time, aquatic organisms such as oysters and barnacles attach to the bottom of the ship or the surface of the structure, increasing underwater resistance and reducing the ship's speed and fuel efficiency.

[0003] In order to prevent this phenomenon, after a base coat of rust-preventive paint is applied to ships and underwater structures, a special paint called an antifouling paint composition [AF (Anti-Fouling) paint] is applied as a top coat. By applying the antifouling paint composition, the bottom of the ship or the surface of the underwater structure is given a property that makes it difficult for aquatic organisms to adhere, i.e., an antifouling property.

[0004] However, if the bottom of a ship is exposed to water for a long period of time and is subjected to the resistance of water currents, the antifouling coating film gradually wears out, breaks, or peels off, making it difficult to maintain the antifouling performance. For this reason, it becomes necessary to carry out regular repair painting to repaint a new antifouling paint composition. And since removing the old coating film from the substrate surface prior to repair painting requires a lot of labor and time, a new paint is directly painted on the old coating film.

[0005] For example, Patent Document 1 discloses a method for restoring the fouling release activity of a damaged fouling release coating area on a metal substrate, the method comprising: (a) treating the damaged fouling release coating area under atmospheric conditions with an effective amount of an adhesion promoter composition in the form of a two-part condensation cure silicone RTV (room temperature curing) comprising (i) a silanol terminated polydiorganosiloxane and (ii) 0.5% to 5.5% by weight of an aminoalkyltrialkoxysilane, based on the weight of the silanol terminated polydiorganosiloxane, and (b) applying as a topcoat to the area treated in (a) above.

[0006] Furthermore, Patent Document 2 describes an embodiment in which a tar-epoxy anti-rust paint is applied, then a tar-vinyl sealer coat is applied, and then a coating composition for preventing biofouling, which uses a copolymer of an organosilyl group-containing monomer and a hemiacetal ester group-containing monomer, is applied on top of the applied coating. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2000-197851 A [Patent Document 2] Japanese Patent Application Publication No. 8-199095 Summary of the Invention [Problem to be solved by the invention]

[0008] However, in the methods described in Patent Documents 1 and 2, the lower coating film becomes a weak layer, and peeling may occur after the repair paint is applied. In addition, it takes a long time to dry the paint for the antifouling layer for repair after application, and an improvement in this respect has been desired.

[0009] The present invention has been made in consideration of the above problems, and an object of the present invention is to provide a method for repairing a coating film provided on a ship or underwater structure, which provides an antifouling layer that dries quickly and has excellent resistance to peeling. [Means for solving the problem]

[0010] The present inventors have intensively studied the above-mentioned problems, and as a result, have found that by treating a coating film before repair with an aqueous sealer composition containing water prior to application of a paint for an antifouling layer for repair painting, the drying property and peeling resistance of the antifouling layer formed by the subsequent repair painting are significantly improved.

[0011] That is, the present invention relates to a method for repairing a coating film provided on a ship or underwater structure as described below. A step (1) of forming a sealer layer on the surface of a coating film provided on a ship or underwater structure; and A method for repairing a coating film provided on a ship or underwater structure, comprising: (2) forming an antifouling layer on the sealer layer, The sealer layer is formed using an aqueous sealer composition containing an aqueous resin and water, The antifouling layer is formed using a paint for an antifouling layer containing a resin and an organic solvent. A method for repairing a coating on a ship or underwater structure. Effect of the Invention

[0012] According to the coating film repair method of the present invention, an antifouling coating film having excellent peeling resistance can be formed on the coating film before repair. In addition, the coating film repair method of the present invention has an advantage that the work period is short because the drying property during the formation of the antifouling layer is excellent. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] <How to repair coating> The coating repair method according to an embodiment of the present invention (hereinafter also referred to as this embodiment) is applied to ships or underwater structures. Examples of ships include passenger ships, cargo ships, tankers, fishing boats, boats, and yachts, and examples of underwater structures include water supply and drainage outlets of thermal and nuclear power plants, water gates, bridge piers, port facilities, undersea tunnels, canals, waterways, and the like. In the present invention, the ships and underwater structures, such as repaired ships, have a coating film (old coating film) before repair on their surfaces. There is no restriction on the degree to which the old coating film remains, and it may be either partial or complete. If the old coating film is significantly cracked or peeled off, a process of simply removing the old coating film may be carried out before carrying out the subsequent sealer layer formation process.

[0014] <Paint film before repair (old paint film)> In the present invention, the old paint film is not limited to the type of paint as long as it is a paint film already provided on the ship or underwater structure, and may be a single layer or a multi-layer structure, with the outermost layer being the antifouling layer. If the old paint film has a multi-layer structure, one or more paint films may be provided below the antifouling layer.

[0015] The antifouling layer is a coating film formed from a conventionally known antifouling paint, for example, a coating film formed from an antifouling paint selected from a hydrolyzable antifouling paint, a hydration decomposition type antifouling paint, and a silicone type antifouling paint. The antifouling layer is preferably a coating film formed from a hydrolyzable antifouling paint or a hydration decomposition type antifouling paint, particularly a coating film formed from a hydrolyzable antifouling paint, which is a silyl polymer type antifouling paint, or a metal acrylic resin type antifouling paint having a metal carboxylate structure. These paints have high biological adhesion prevention properties and long durability, but therefore have a remarkable peeling property after repair painting. In the present invention, when the antifouling layer is a coating film formed from a hydrolyzable antifouling paint or a hydration decomposition type antifouling paint, particularly a coating film formed from a silyl polymer type antifouling paint or a metal acrylic resin type antifouling paint, which is a hydrolyzable antifouling paint, it is preferable in that it can exhibit a remarkable effect of preventing peeling after repair painting.

[0016] The silyl polymer contained in the silyl polymer-based antifouling coating material includes copolymers of polymerizable unsaturated monomers having a triorganosilyl ester group and other polymerizable unsaturated monomers.

[0017] As the polymerizable unsaturated monomer having a triorganosilyl ester group, a polymerizable unsaturated monomer having a triisopropylsilyl group is preferable. Specific examples include, for example, triisopropylsilyl (meth)acrylate, triisopropylsilyl 4-pentenoate, bis(triisopropylsilyl) maleate, methyl triisopropylsilyl maleate, ethyl triisopropylsilyl maleate, n-butyl triisopropylsilyl maleate, isobutyl triisopropylsilyl maleate, t-butyl triisopropylsilyl maleate, n-pentyl triisopropylsilyl maleate, isopentyl triisopropylsilyl maleate, 2-ethylhexyl triisopropylsilyl maleate, silyl maleate, Examples of the acrylate include cyclohexyltriisopropylsilyl, bis(triisopropylsilyl) fumarate, methyltriisopropylsilyl fumarate, ethyltriisopropylsilyl fumarate, n-butyltriisopropylsilyl fumarate, isobutyltriisopropylsilyl fumarate, n-pentyltriisopropylsilyl fumarate, isopentyltriisopropylsilyl fumarate, 2-ethylhexyltriisopropylsilyl fumarate, cyclohexyltriisopropylsilyl fumarate, and combinations thereof. In particular, triisopropylsilyl (meth)acrylate is preferred.

[0018] Other polymerizable unsaturated monomers include, for example, alkyl (meth)acrylate compounds such as methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and lauryl (meth)acrylate; alkoxyalkyl (meth)acrylate compounds such as 2-methoxyethyl (meth)acrylate, 2-methoxypropyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, and 2-ethoxyethyl (meth)acrylate; ethylene glycol monomethyl (meth)acrylate, (meth)acrylates having a polyoxyethylene chain with an alkoxy group at one molecular end, (meth)acrylates having a polyoxypropylene chain with an alkoxy group at one molecular end, and propylene (meth)acrylate. alkylene glycol alkyl (meth)acrylate compounds such as ethylene glycol monomethyl; hydroxyalkyl (meth)acrylate compounds such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, ε-caprolactone modified monoesters of (meth)acrylic acid and dihydric alcohols having 2 to 8 carbon atoms, allyl alcohol, and (meth)acrylates having a polyoxyethylene chain with a hydroxyl group at the molecular end; styrene; vinyl toluene; α-methylstyrene, vinyl propionate, vinyl acetate, and other vinyl compounds; carboxyl group-containing polymerizable unsaturated compounds such as (meth)acrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, crotonic acid, and β-carboxyethyl (meth)acrylate.

[0019] In this specification, "(meth)acrylate" means acrylate or methacrylate, "(meth)acrylic acid" means acrylic acid or methacrylic acid, "(meth)acryloyl" means acryloyl or methacryloyl, and "(meth)acrylamide" means acrylamide or methacrylamide.

[0020] Examples of the metal acrylic resin include reaction products of (meth)acrylic acid, other polymerizable unsaturated monomers, and divalent metal compounds. Water and organic solvents may be used during this reaction, if necessary. It is considered that the carboxyl group of (meth)acrylic acid reacts with the divalent metal to introduce a metal carboxylate structure into the acrylic resin. Examples of the other polymerizable unsaturated monomer include compounds exemplified as other polymerizable unsaturated monomers in the explanation of the silyl polymer, except for (meth)acrylic acid. Examples of divalent metal compounds include oxides or hydroxides of metals such as copper, zinc, calcium, magnesium, and iron.

[0021] The hydration decomposition type antifouling paint may include an antifouling paint containing a hydration decomposition type acrylic resin, for example, a resin obtained by copolymerizing an alkoxyalkyl (meth)acrylate compound and another polymerizable unsaturated monomer. Examples of the alkoxyalkyl (meth)acrylate compound include the above-mentioned compounds, and examples of the other polymerizable unsaturated monomer include the compounds exemplified as the other polymerizable unsaturated monomer in the explanation of the silyl polymer, except for the alkoxyalkyl (meth)acrylate compound.

[0022] The antifouling paint may contain various components used in general antifouling paints, such as an antifouling agent, rosin, coloring pigment, extender pigment, dehydrating agent, plasticizer, thixotropic agent (anti-sagging agent), defoamer, organic solvent, etc.

[0023] In the coating film repair method according to the present embodiment, the old coating film may have any single-layer coating film or composite coating film on the lower layer side of the antifouling layer. In the case of a single-layer coating film, the lower coating film may be, for example, an epoxy resin-based coating film, and in the case of a composite coating film, a coating film consisting of a vinyl resin-based coating film and an epoxy resin-based coating film. By using an epoxy resin-based coating film as the lower coating film, the rust prevention properties of the substrate can be improved, and the adhesion with the antifouling layer can be improved. In addition, it is preferable that the vinyl resin-based coating film is provided between the antifouling coating film and the epoxy resin-based coating film from the viewpoint of adhesion.

[0024] The epoxy resin coating film is preferably a coating film formed from an epoxy resin paint. The epoxy resin coating film may be a single layer or a composite coating film in which layers with different compositions, such as a binder coat and a primer coat, are laminated. The epoxy resin paint usually contains an epoxy resin and a polyamine compound.

[0025] Examples of epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, phenol novolac type epoxy resins, cresol type epoxy resins, dimer acid modified epoxy resins, aliphatic epoxy resins, and alicyclic epoxy resins.

[0026] Examples of the polyamine compound include aliphatic polyamines such as ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, and poly(oxypropylene)diamine; aromatic polyamines such as xylylenediamine, diaminodiphenylmethane, and phenylenediamine; alicyclic polyamines such as 1,3-bisaminomethylcyclohexane and isophoronediamine; and modified products of these polyamines, such as epoxy adducts, ketimines, polyamidoamines, Mannich compounds, and Michael addition compounds. Also included are epoxy adducts and dimer acid modified products of the polyamidoamines.

[0027] The vinyl resin coating film is preferably a coating film formed from a vinyl resin paint. The vinyl resin paint usually contains a vinyl resin. The vinyl resin may be a resin obtained by copolymerizing a vinyl monomer such as vinyl chloride, vinyl acetate, vinyl alcohol, styrene, or ethylene.

[0028] The epoxy resin coating film or vinyl resin coating film may contain various components used in general paints, such as modifying resins other than epoxy resins or vinyl resins, extender pigments, coloring pigments, rust-preventive pigments, hardening accelerators, plasticizers, thixotropic agents (anti-sagging agents), dispersants, etc.

[0029] Next, a coating film repair method according to an embodiment of the present invention will be described.

[0030] <Sealer layer formation process (1)> Step (1) of the coating film repair method according to the embodiment of the present invention is a step of forming a sealer layer on the surface of the coating film provided on the ship or underwater structure. The present invention is characterized in that an aqueous sealer composition containing an aqueous resin and water is used to form the sealer layer. By using an aqueous sealer composition containing water as a diluting medium, the crack resistance and peel resistance of the antifouling layer formed in the next step are improved, and it is also effective in improving the drying speed of the paint for the antifouling layer. Although the reason is unclear, it is presumed that the old coating film is weakened due to deterioration over time, and the applied aqueous sealer composition penetrates into the deteriorated old coating film, improving the physical properties of the old coating film and improving the adhesion between the base material and the antifouling layer. If a sealer composition containing an organic solvent as a diluting medium is applied, the effect of improving the crack resistance and peel resistance of the antifouling layer after repair painting is rather poor, which is not preferable.

[0031] The aqueous resin contained in the aqueous sealer composition is a water-soluble resin or a water-dispersible resin. In this specification, the water-soluble resin is a resin that dissolves in water and whose aqueous resin solution is transparent to the naked eye. In addition, in this specification, the water-dispersible resin is a resin that is dispersed in water and whose aqueous resin dispersion is cloudy to the naked eye.

[0032] Specific examples of the aqueous resin include acrylic resins, vinyl resins, polyolefin resins, silicone resins, polyurethane resins, epoxy resins, phenolic resins, polyester resins, alkyd resins, polycarbonate resins, polyisocyanate compounds, polyamine compounds, and combinations thereof. Two or more of these resins may be modified or graft-polymerized. When the resin is in the form of dispersed particles, it may be either a single layer or a multi-layer such as a core-shell type. As the water-based resin, epoxy resins and acrylic resins are preferred from the viewpoint of crack resistance and peel resistance of the antifouling layer after repair coating, and among them, water-based epoxy resins and water-based acrylic resins are useful.

[0033] The aqueous epoxy resin is preferably one in which an epoxy resin having an epoxy group is emulsified and dispersed in an aqueous medium. The epoxy resin may be the same compound as the compound exemplified in the description of the old coating film. From the viewpoint of the peeling resistance and drying property of the antifouling layer after repair coating, the epoxy equivalent is preferably in the range of 1000 g / eq or less, more preferably in the range of 100 to 800 g / eq.

[0034] Epoxy equivalent refers to the number of grams of resin containing 1 gram equivalent of epoxy groups (g / eq), and refers to the epoxy equivalent measured according to the manufacturer's published value or JIS K 7236 (2009).

[0035] The aqueous epoxy resin may be, for example, a resin obtained by emulsifying and dispersing the epoxy resin in the presence of an emulsifying component derived from polyoxyalkylene.The emulsifying component derived from polyoxyalkylene may, for example, be polyoxyalkylene alkyl ether compounds such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene tridecyl ether, polyoxyethylene oleyl ether; polyoxyalkylene alkyl phenyl ether compounds such as polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether; polyoxyalkylene alkyl ester compounds such as polyoxyethylene monolaurate, polyoxyethylene monostearate, polyoxyethylene monooleate; sorbitan compounds such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monooleate, polyethylene glycol, polypropylene glycol, and other nonionic polyoxyalkylene compounds; epoxy modified polyoxyalkylene compounds obtained by modifying the polyoxyalkylene compounds with the epoxy resin; and combinations thereof.

[0036] Examples of the epoxy-modified polyoxyalkylene compound include a reaction product of polyoxyethylene glycol, an epoxy resin having a hydroxyl group and an epoxy group, a monohydric alcohol, and a compound having at least two isocyanate groups in one molecule.

[0037] Examples of the epoxy resin having a hydroxyl group and an epoxy group include bisphenol type epoxy resins such as bisphenol A type epoxy resins and bisphenol F type epoxy resins, with bisphenol A type epoxy resins being particularly preferred.

[0038] The monohydric alcohol is used for blocking the isocyanate group in the modified epoxy resin, and examples thereof include monohydric alcohols such as ethanol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether.

[0039] As the compound having at least two isocyanate groups in one molecule, aliphatic, alicyclic or aromatic polyisocyanate compounds known per se can be used, such as hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated 4,4-diphenylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, etc., biuret products and isocyanurate products of these polyisocyanate compounds, and combinations thereof.

[0040] The epoxy-modified polyoxyalkylene compound can be produced according to a method known per se, for example, by mixing the above-mentioned components and reacting them until substantially no unreacted isocyanate groups remain.

[0041] The epoxy resin modified with the above-mentioned polyoxyalkylene compound is used as a dispersion stabilizing resin, and the epoxy resin is emulsified and dispersed in an aqueous medium to obtain a water-dispersed epoxy resin emulsion.

[0042] When the aqueous sealer composition contains an aqueous epoxy resin as the aqueous resin, it is preferable that the aqueous polyamine compound is contained. The aqueous polyamine compound may be a compound obtained by dispersing or dissolving a polyamine compound or a modified product thereof in water, and a commercially available product may be used. Examples of the polyamine compound include aliphatic polyamines such as ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, triaminopropane, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, isophoronediamine, and 1,3-bisaminomethylcyclohexane; aromatic polyamines such as phenylenediamine, metaxylylenediamine, paraxylylenediamine, and diaminodiphenylmethane; polyoxyethylenediamine, polyoxypropylenediamine, triethyleneglycoldiamine, and tripropyleneglycoldiamine. Examples of the modification include amidation, Mannich modification, and epoxy adduct formation.

[0043] The aqueous acrylic resin is preferably an acrylic resin emulsified and dispersed in an aqueous medium.

[0044] The acrylic resin may be a copolymer of a polymerizable unsaturated monomer containing an alkyl (meth)acrylate compound. The emulsion dispersion method may be a method of dispersing the acrylic resin in an aqueous medium in the presence of an emulsifying component, or a method of emulsion-polymerizing a polymerizable unsaturated monomer containing an alkyl (meth)acrylate compound in the presence of water and an emulsifying component. The alkyl (meth)acrylate compound may be the compound exemplified in the description of the old coating film above. In addition, other polymerizable unsaturated monomers that are copolymerized with the alkyl (meth)acrylate compound include, for example, alkylene glycol alkyl (meth)acrylate compounds such as ethylene glycol monomethyl (meth)acrylate, (meth)acrylate having a polyoxyethylene chain with an alkoxy group at one molecular end, (meth)acrylate having a polyoxypropylene chain with an alkoxy group at one molecular end, and propylene glycol monomethyl (meth)acrylate; 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxypropyl (meth)acrylate, and the like. hydroxyalkyl (meth)acrylate compounds such as ε-caprolactone modified monoesters of (meth)acrylic acid and dihydric alcohols having 2 to 8 carbon atoms, allyl alcohol, and (meth)acrylates having a polyoxyethylene chain with a hydroxyl group at the molecular end; styrene; vinyl toluene; vinyl compounds such as α-methylstyrene, vinyl propionate, and vinyl acetate; carboxyl group-containing polymerizable unsaturated compounds such as (meth)acrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, crotonic acid, and β-carboxyethyl (meth)acrylate.

[0045] The amount of the aqueous resin contained in the aqueous sealer composition is suitably within the range of 5 to 75 parts by mass, or 10 to 60 parts by mass, in terms of the non-volatile mass of the aqueous resin, based on 100 parts by mass of the aqueous sealer composition at the time of application.

[0046] In this specification, the non-volatile content is the residue remaining after removing volatile components such as organic solvents, and can be measured according to the JIS K 5601 1-2 (2008) standard (heating temperature: 125° C., heating time: 60 minutes).

[0047] The amount of water contained in the aqueous sealer composition is preferably within a range of 20 to 90 parts by mass, or 20 to 60 parts by mass, based on 100 parts by mass of the aqueous sealer composition.

[0048] The aqueous sealer composition may contain, in addition to the aqueous resin and water, components such as color pigments, extender pigments, dispersants, thickeners, defoamers, film-forming assistants, preservatives, and pH adjusters.

[0049] Examples of the extender pigment include calcium carbonate, talc, barium sulfate, mica, clay, silica, and aluminum hydroxide. From the viewpoint of drying speed and peeling resistance after repair coating, it is preferable to include calcium carbonate and talc.

[0050] When an extender pigment is contained, the amount of the extender pigment in the aqueous sealer composition is preferably 20 to 60% in terms of pigment volume concentration. The pigment volume concentration is the volume ratio of the pigment to the total non-volatile content of all resins and all pigments in the paint. The specific gravity of the pigment shall use the catalog value, and if the catalog value is not clear, it shall be based on the "Paint Raw Materials Handbook 9th Edition" (Japan Paint Manufacturers Association), and the specific gravity of the resin non-volatile content shall be approximately 1.

[0051] The aqueous sealer composition can be applied by a general application method such as brush, roller, air spray, or airless spray. Drying after application is usually performed at room temperature, but forced drying may be performed as necessary. Room temperature refers to a temperature at which no temperature manipulation such as forced heating or cooling is performed, although it varies depending on the atmospheric temperature of the environment in which application is performed. The drying time is preferably 3 to 72 hours, more preferably 6 to 48 hours.

[0052] When the aqueous sealer composition is applied to the old coating film, the aqueous sealer composition penetrates into the old coating film while forming a sealer layer on the old coating film. The aqueous sealer composition is applied so that the thickness of the formed sealer layer is preferably 10 to 500 μm, more preferably 20 to 250 μm, in terms of dry film thickness. In this specification, the dry film thickness is a value measured by an electromagnetic film thickness meter.

[0053] <Anti-stain layer forming process (2)> In the coating film repair method according to an embodiment of the present invention, an antifouling layer is formed on the sealer layer formed in the above step (1).

[0054] The antifouling layer is formed by using a paint for the antifouling layer, which contains a resin and an organic solvent. The paint for the antifouling layer is an organic paint that uses an organic solvent as a dilution medium.

[0055] The resin used in the paint for the antifouling layer is a resin that is soluble in an organic solvent or dispersible in an organic solvent. In this specification, a resin that is soluble in an organic solvent is a resin that makes the resin solution transparent to the naked eye. In addition, in this specification, a resin that is dispersible in an organic solvent is a resin that exists in a dispersed state in an organic solvent and makes the resin dispersion cloudy to the naked eye.

[0056] Specific examples of the resin include hydrolyzable resins such as silyl polymers and metal acrylic resins having a metal carboxylate structure, hydration-decomposable resins, silicone resins, resin acids such as rosin, and combinations thereof, with hydrolyzable resins and / or hydration-decomposable resins being preferred.

[0057] Examples of the silyl polymer include resins similar to the silyl polymers mentioned in the description of the old coating film. Examples of resins having a metal carboxylate structure include the same resins as the metal acrylic resins mentioned in the description of the old coating film.

[0058] Examples of the hydration decomposition type resin include the same resins as the hydration decomposition type acrylic resins mentioned in the explanation of the old paint film.

[0059] The amount of the resin contained in the paint for the antifouling layer is preferably 10 to 80 parts by mass, and particularly preferably 20 to 70 parts by mass, based on 100 parts by mass of the paint for the antifouling layer.

[0060] As the organic solvent contained in the paint for the antifouling layer, organic solvents known in the paint field can be used, and specific examples include aromatic solvents such as toluene and xylene, ketone solvents such as methyl isobutyl ketone and cyclohexanone, ester solvents, ether solvents such as propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate, alcohol solvents such as isopropyl alcohol, etc. The amount of the organic solvent contained in the paint for the antifouling layer is preferably such that the total nonvolatile content of the paint for the antifouling layer is 20 to 90 mass%.

[0061] The paint for the antifouling layer may contain various components used in general paint for antifouling layers, such as an antifouling agent, a coloring pigment, an extender pigment, a dehydrating agent, a plasticizer, a thawing agent (anti-sagging agent), and an antifoaming agent, in addition to the resin and the organic solvent.

[0062] The coating material for the antifouling layer can be applied by a general coating method such as brush, roller, air spray, or airless spray. Drying after application is usually performed at room temperature, but forced drying may be performed as necessary. The drying time is preferably 1 to 14 days, and more preferably about 1 to 7 days. The coating film repair method according to the embodiment of the present invention has good drying properties, so the coating film can be sufficiently dried within the above drying time.

[0063] The thickness of the antifouling layer is preferably 50 to 1000 μm, more preferably 100 to 750 μm, in terms of dry thickness.

[0064] <Binder Coat Layer Forming Process> In the coating film repair method according to the embodiment of the present invention, after the sealer layer is formed in step (1), a binder coat layer may be formed using a paint for a binder coat layer before step (2) from the viewpoint of peeling resistance of the antifouling layer. The paint for a binder coat layer is a paint different from the aqueous sealer composition and the paint for the antifouling layer, and preferably contains a resin and an organic solvent. Examples of the resin include an acrylic resin, an epoxy resin, a vinyl resin, an alkyd resin, and a polyamine compound, and preferably contains an epoxy resin and a polyamine compound.

[0065] The amount of the non-volatile content of the resin contained in the binder coat layer paint is preferably 10 to 80 parts by mass, particularly 20 to 70 parts by mass, based on 100 parts by mass of the binder coat layer paint at the time of application.

[0066] Examples of the epoxy resin and polyamine compound include the same epoxy resin and polyamine compound as those mentioned in the explanation of the old coating film.

[0067] The organic solvent may be the same as the compounds exemplified in the description of the paint for the antifouling layer. The amount of the organic solvent contained in the paint for the binder coat layer is preferably such that the total non-volatile content of the paint for the binder coat layer is 20 to 90% by mass.

[0068] The paint for the binder coat layer may contain various components used in paints, such as coloring pigments, extender pigments, anti-rust pigments, plasticizers, thixotropic agents (anti-sagging agents), defoamers, and hardeners.

[0069] The paint for the binder coat layer can be applied by a general application method such as brush, roller, air spray, airless spray, etc. Drying after application is usually performed at room temperature, but forced drying may be performed as necessary. The drying time is preferably 2 to 48 hours, more preferably 5 to 24 hours.

[0070] The thickness of the binder coat layer is preferably 10 to 500 μm, and more preferably 20 to 250 μm, in terms of dry thickness.

[0071] <Manufacturing method for a ship or underwater structure with a repaired coating> A method for manufacturing a ship or underwater structure having a repaired coating according to an embodiment of the present invention includes a step (1) of forming a sealer layer on the surface of the coating provided on the ship or underwater structure, and a step (2) of forming an anti-fouling layer on the sealer layer formed by step (1). The coating film provided on the ship or underwater structure is an antifouling coating film, the sealer layer is formed using an aqueous sealer composition containing an aqueous resin and water, and the antifouling layer is formed using a paint for antifouling layers containing a resin and an organic solvent. Steps (1) and (2) are the same as those in the method for repairing a coating film provided on a ship or underwater structure according to the embodiment of the present invention described above, including preferred aspects.

[0072] <Ships or underwater structures, coatings> The ship or underwater structure according to the embodiment of the present invention is provided with a coating film formed by the coating film repair method according to the embodiment of the present invention. The coating film according to the embodiment of the present invention comprises, in this order, a coating film before repair (old coating film) having an antifouling coating film, a sealer layer which is a hardened product of an aqueous sealer composition, and an antifouling layer. By providing a sealer layer of an aqueous sealer composition between the old coating film and the antifouling layer, a repair coating film with significantly improved crack resistance and peel resistance can be obtained.

[0073] As mentioned above, the present specification discloses the following: [1] A step (1) of forming a sealer layer on the surface of a coating film provided on a ship or underwater structure; and A method for repairing a coating film provided on a ship or underwater structure, comprising: (2) forming an antifouling layer on the sealer layer, The sealer layer is formed using an aqueous sealer composition containing an aqueous resin and water, The antifouling layer is formed using a paint for an antifouling layer containing a resin and an organic solvent. A method for repairing a coating on a ship or underwater structure. [2] A method for repairing a coating film according to [1], comprising, after step (1), a step of forming a binder coat layer on the sealer layer using a paint for the binder coat layer containing a resin and an organic solvent. [3] The method for repairing a coating film according to [1] or [2], wherein the aqueous resin contained in the aqueous sealer composition includes an aqueous epoxy resin and an aqueous polyamine compound. [4] The method for repairing a coating film according to any one of [1] to [3], wherein the aqueous sealer composition contains an extender pigment. [5] The method for repairing a coating film according to any one of [1] to [4], wherein the resin contained in the paint for the antifouling layer includes at least one of a hydrolyzable resin and a hydration decomposition resin. [6] A ship or underwater structure provided with a coating film formed by the coating film repair method according to any one of [1] to [5]. [7] A step (1) of forming a sealer layer on the surface of a coating film provided on a ship or underwater structure; and A method for producing a ship or underwater structure having a repaired coating film, comprising the step (2) of forming an antifouling layer on the sealer layer, The sealer layer is formed using an aqueous sealer composition containing an aqueous resin and water, A method for producing a ship or underwater structure having a repaired coating film, wherein the antifouling layer is formed using a paint for an antifouling layer containing a resin and an organic solvent. EXAMPLES

[0074] 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.

[0075] <Manufacture of paints for repair painting> Manufacturing Examples 1-15 Sealer compositions (S-1) to (S-9), binder coat layer paints (BC-1) to (BC-3), and antifouling layer paints (A-1), hydration decomposition type acrylic resin antifouling paint (A-2), and hydrolysis type zinc acrylic resin antifouling paint (A-3) were produced with the formulations shown in Tables 1 to 3 below. Note that the sealer compositions (S-1) to (S-8) are water-based sealer compositions, and (S-9) is an organic sealer composition using an organic solvent as a dilution medium.

[0076] [Table 1]

[0077] 50% epoxy emulsion: Dispersion of bisphenol A type epoxy resin with an epoxy equivalent of 500 dispersed in water with bisphenol A type epoxy resin, polyoxyethylene glycol, tolylene diisocyanate and diethylene glycol monoethyl ether reaction product, containing water 50% acrylic emulsion: Emulsion polymer of styrene / methyl methacrylate / 2-ethylhexyl acrylate / vinyltrimethoxysilane / acrylic acid, containing water 60% Polyamine: Amine value 335, water-soluble aliphatic polyamine, contains water Polyamidoamine: Amine value 335, organic solvent-based aliphatic polyamine Epoxy resin: Bisphenol A type epoxy resin with an epoxy equivalent of 500 Calcium carbonate: specific gravity 2.7 Talc: specific gravity 2.8

[0078] [Table 2]

[0079] Epoxy resin: Bisphenol A type epoxy resin with an epoxy equivalent of 500 70% Polyamine Compound: Aliphatic polyamidoamine, amine value 155 Ethylene-vinyl acetate copolymer: Vinyl acetate content 41% by mass, weight average molecular weight 142,000

[0080] [Table 3]

[0081] 60% Silyl Polymer: Triisopropylsilyl methacrylate / Methoxyethyl acrylate / Methoxyethyl methacrylate / Methyl methacrylate / n-Butyl acrylate copolymer in xylene 60% acrylic resin: methoxyethyl acrylate / methyl methacrylate copolymer in xylene 60% Zinc Acrylate: Zinc oxide / methoxyethyl acrylate / methyl methacrylate / ethyl acrylate / methacrylic acid reaction product in water / butyl acetate / n-butanol

[0082] <Creating old paint boards> A commercially available epoxy / amine organic solvent-based two-component anticorrosive paint was applied to a sandblasted steel plate measuring 300 mm long x 100 mm wide x 1.6 mm thick, so that the dry film thickness was 200 μm, and the plate was dried at 25 ° C for one day. A commercially available epoxy / amine organic solvent-based two-component paint for binder coat layer was applied thereon to a dry film thickness of 100 μm, and the plate was dried at 25 ° C for one day. A commercially available silyl methacrylate hydrolysis-type antifouling paint, hydration-decomposition-type acrylic antifouling paint, or crosslinked zinc acrylic hydrolysis-type antifouling paint was applied to a dry film thickness of 250 μm. Then, in order to bring the old coating film closer to a deteriorated state, the plate was dried at a higher temperature of 40 ° C for 30 days to obtain an old coating film plate.

[0083] <Repair painting> <An example of repair painting after applying a sealant to the old paint film and forming an anti-fouling layer> [Examples 1 to 16 and Comparative Example 1] Onto the prepared old coating plate, any of the sealing compositions (S-1) to (S-9) shown in Table 4 or Table 5 was applied so as to give a dry film thickness of 50 μm, and after drying at 23° C. for 24 hours, any of the antifouling layer paints (A-1) to (A-3) prepared in the above manufacturing example was applied so as to give a dry film thickness of 500 μm, and dried at 23° C. for 2 days to prepare a test coating plate, and evaluation of peel resistance and drying properties was carried out.

[0084] [Comparative Example 2] In the above Example 1, a test plate was prepared in the same manner as in Example 1, except that the sealer composition (S-1) was not applied, and the paint for the antifouling layer (A-1) was directly applied onto the old coating film, and the peel resistance and drying properties were evaluated.

[0085] The results are shown in Tables 4 and 5 below.

[0086] [Table 4]

[0087] [Table 5]

[0088] <An example of repair painting where the old paint film was treated with a sealer, then a binder coat layer was formed, followed by a stain-resistant layer> [Examples 17 to 48 and Comparative Example 3] On the prepared old coating plate, one of the sealing compositions (S-1) to (S-9) shown in Table 1 was applied to a dry film thickness of 50 μm and dried at 23° C. for 24 hours. Then, one of the binder coat layer paints (BC-1) to (BC-3) shown in Table 2 was applied to a dry film thickness of 100 μm and dried at 23° C. for 10 hours. Then, one of the antifouling layer paints (A-1) to (A-3) shown in Table 3 was applied to a dry film thickness of 500 μm and dried at 23° C. for 2 days to prepare a test coating plate, and the peeling resistance and drying properties were evaluated.

[0089] [Comparative Example 4] A test plate was prepared in the same manner as in Example 17, except that the sealer composition (S-1) was not applied, and the binder coat layer paint (BC-2) was applied directly onto the old coating film.

[0090] The results are shown in Tables 6 to 9 below.

[0091] [Table 6]

[0092] [Table 7]

[0093] [Table 8]

[0094] [Table 9]

[0095] <Evaluation test> (*) Peeling resistance after repair painting Using a commercially available scratch tester (product name: Scoot PF-SCT-02, manufactured by Profid Co., Ltd.), a stainless steel indenter was used to scratch the test coated plate by gradually increasing the load at a speed of 20 mm / sec until the load reached 50 N while moving the table 80 mm, thereby measuring the peel load (the load at which the steel plate was exposed) and evaluating it according to the following criteria. A higher peel load (N) value indicates better resistance to peeling from the steel plate. S: 50N or more A: 40 or more and less than 50N B: 30 or more and less than 40N C: 20 to less than 30N D: 10 to less than 20N E: Less than 10N

[0096] (*) Drying speed of antifouling topcoat paint for repair painting The surface of the test plate was touched with a finger, and the drying property of the antifouling layer paint after repair painting was evaluated according to the following criteria. A: No marks on the stain-resistant layer, no stickiness B: No marks on the stain-resistant layer, slight adhesion C: There are some marks on the stain-resistant layer, and it is slightly sticky. D: Marks are clearly visible on the stain-resistant layer, and there is noticeable adhesion

[0097] <Consideration> As can be seen from the results shown in Tables 4 to 9, the repaired painted bodies (Examples 1 to 48) in which the old paint film was treated with an aqueous sealer composition containing water and then painted with a paint for an anti-fouling layer were found to have both good peel resistance and drying properties of the anti-fouling layer. On the other hand, when the old paint film was treated with an organic solvent-based sealer composition (Comparative Example 1), and when the old paint film was not treated with a sealer and a paint for an anti-fouling layer was directly applied to the old paint film (Comparative Example 2), no repaired painted body was obtained that showed good evaluation results for either the peeling resistance or drying properties of the anti-fouling layer. It was also found that if the old coating film was treated with an aqueous sealer composition, the peel resistance and drying properties of the anti-fouling layer were maintained even if an organic solvent-based binder coat was applied and then a paint for the anti-fouling layer was applied (Examples 17 to 48). On the other hand, when the old paint film was treated with an organic solvent-based sealer composition, an organic solvent-based binder coat was applied, and then the paint for the anti-fouling layer was applied (Comparative Example 3), and when no sealer treatment was performed, an organic solvent-based binder coat was directly applied to the old paint film, and then the paint for the anti-fouling layer was applied (Comparative Example 4), no repaired painted body was obtained that showed good evaluation results for either the peeling resistance or drying properties of the anti-fouling layer.

Claims

1. A step (1) of forming a sealer layer on the surface of a coating film provided on a ship or underwater structure; and A method for repairing a coating film provided on a ship or underwater structure, comprising: (2) forming an antifouling layer on the sealer layer, The sealer layer is formed using an aqueous sealer composition containing an aqueous resin and water, The antifouling layer is formed using a paint for an antifouling layer containing a resin and an organic solvent. A method for repairing a coating on a ship or underwater structure.

2. 2. The method for repairing a coating film according to claim 1, further comprising, after the step (1), a step of forming a binder coat layer on the sealer layer using a paint for a binder coat layer containing a resin and an organic solvent.

3. The method for repairing a coating film according to claim 1 or 2, wherein the aqueous resin contained in the aqueous sealer composition comprises an aqueous epoxy resin and an aqueous polyamine compound.

4. 3. The method for repairing a coating film according to claim 1, wherein the aqueous sealer composition contains an extender pigment.

5. 3. The method for repairing a coating film according to claim 1, wherein the resin contained in the paint for forming an antifouling layer comprises at least one of a hydrolyzable resin and a hydration decomposition type resin.

6. A ship or underwater structure provided with a coating film formed by the coating film repair method according to claim 1 or 2.

7. A step (1) of forming a sealer layer on the surface of a coating film provided on a ship or underwater structure; and A method for producing a ship or underwater structure having a repaired coating film, comprising the step (2) of forming an antifouling layer on the sealer layer, The sealer layer is formed using an aqueous sealer composition containing an aqueous resin and water, A method for producing a ship or underwater structure having a repaired coating film, wherein the antifouling layer is formed using a paint for an antifouling layer containing a resin and an organic solvent.

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