Antifouling agent for suppressing attachment of aquatic organisms, antifouling agent composition for suppressing attachment of aquatic organisms, cured product of antifouling agent for suppressing attachment of aquatic organisms, and antifouling coating film

Abstract

To provide an antifouling agent for suppressing attachment of aquatic organisms, an antifouling agent composition for suppressing attachment of aquatic organisms, a cured product of the antifouling agent for suppressing attachment of aquatic organisms, and an antifouling coating film capable of preventing attachment of aquatic organisms.SOLUTION: An antifouling agent for suppressing attachment of aquatic organisms is provided, the antifouling agent preventing attachment of aquatic organisms and comprising a metal oxide, wherein the metal of the metal oxide is samarium and / or gadolinium.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an antifouling agent for inhibiting the adhesion of aquatic organisms, an antifouling composition for inhibiting the adhesion of aquatic organisms, a cured product of the antifouling agent for inhibiting the adhesion of aquatic organisms, and an antifouling coating film. [Background technology]

[0002] A wide variety of aquatic organisms are likely to attach to the surfaces of substrates (ships, underwater structures, fishing nets, seawater supply and drainage pipes for factories, etc.) that are exposed to water (oceans, rivers, lakes, etc.) for long periods in the natural environment. When aquatic organisms attach to the surface of a substrate, they can damage its appearance and cause various problems.

[0003] For example, if the substrate is a ship, the adhesion of aquatic organisms to the ship can increase the resistance of the adhesion surface to water currents, resulting in a decrease in the ship's speed and increased fuel consumption. Furthermore, if the substrate is an underwater structure, the corrosion-resistant coating applied to the surface of the underwater structure can be damaged, resulting in damage such as reduced strength and functionality and a significantly shortened lifespan. Furthermore, if the substrate is a fishing net, such as an aquaculture net or fixed net, the mesh can be clogged by aquatic organisms, causing serious problems such as the death of farmed and caught organisms due to oxygen deprivation. Furthermore, the adhesion and proliferation of aquatic organisms to seawater supply and drainage pipes in factories, thermal power plants, and nuclear power plants can cause blockages in the pipes and a decrease in flow rate.

[0004] In order to prevent the adhesion of aquatic organisms that cause such problems, an antifouling coating film is formed by applying a composition containing an antifouling agent to the surface of a substrate. Examples of such antifouling agents include hydrolyzable silyl ester polymers, cuprous oxide, irgarol, and medetomidine (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2022-028627 Summary of the Invention [Problem to be solved by the invention]

[0006] Hydrolyzable silyl ester polymers are subject to pollution concerns due to hydrolysis and the elution of resin components. Cuprous oxide, currently the most widely used antifouling agent for inhibiting the adhesion of aquatic organisms, also poses concerns about the toxicity of copper to aquatic organisms due to the elution of copper. Furthermore, Irgarol and medetomidine pose even greater toxicity concerns than cuprous oxide, and the use of Irgarol is actually restricted. Given these circumstances, alternative substances are needed.

[0007] The problem to be solved by the present invention is to provide an antifouling agent for inhibiting the adhesion of aquatic organisms, an antifouling composition for inhibiting the adhesion of aquatic organisms, a cured product of the antifouling agent for inhibiting the adhesion of aquatic organisms, and an antifouling coating film, which are capable of preventing the adhesion of aquatic organisms. [Means for solving the problem]

[0008] As a result of extensive research to solve the above problems, the present inventors have found that specific metal oxides can be used as antifouling agents for inhibiting adhesion of aquatic organisms, and have thus completed the present invention.

[0009] That is, the present invention relates to an antifouling agent for inhibiting adhesion of aquatic organisms. 1. An antifouling agent for inhibiting adhesion of aquatic organisms, which contains a metal oxide and prevents adhesion of aquatic organisms, The antifouling agent for inhibiting adhesion of aquatic organisms, wherein the metal of the metal oxide is samarium and / or gadolinium. 2. The antifouling agent for inhibiting adhesion of aquatic organisms according to 1, wherein the aquatic organisms are barnacles, mussels, lugworms or golden mussels. 3. An antifouling composition for suppressing adhesion of aquatic organisms, comprising the antifouling agent for suppressing adhesion of aquatic organisms according to 1 or 2 and a solvent. 4. The antifouling composition for inhibiting biofouling according to 3, further comprising a binder resin. 5. A cured antifouling agent for suppressing adhesion of aquatic organisms, obtained by curing the antifouling agent composition for suppressing adhesion of aquatic organisms described in 4. An antifouling coating film formed from the cured product of the antifouling agent for inhibiting adhesion of aquatic organisms described in 6.5. 7. A substrate with an antifouling coating film, comprising a substrate and the antifouling coating film according to 6 provided on the surface of the substrate. 8. The substrate with an antifouling coating film according to 7, wherein the substrate is at least one selected from ships, underwater structures, fishing equipment, and water supply and drainage pipes. [Effects of the Invention]

[0010] According to the present invention, there can be provided an antifouling agent for inhibiting the adhesion of aquatic organisms, an antifouling composition for inhibiting the adhesion of aquatic organisms, a cured product of the antifouling agent for inhibiting the adhesion of aquatic organisms, and an antifouling coating film, which are capable of preventing the adhesion of aquatic organisms. DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment of the present invention will be described below. The present invention is not limited to the following embodiment, and can be implemented by making appropriate modifications within the scope that does not impair the effects of the present invention. The compounds in this specification may be derived from fossil resources or biological resources.

[0012] (Antifouling agent for preventing the adhesion of aquatic organisms) The antifouling agent for suppressing adhesion of aquatic organisms of the present invention contains a metal oxide, and the metal of the metal oxide is samarium and / or gadolinium. The metal oxide is preferably one or more selected from samarium oxide and gadolinium oxide. Because the metal oxides of samarium and / or gadolinium are stable in water, the metal components do not easily leach out like in cuprous oxide, and samarium and gadolinium are considered to pose less toxicity concerns than copper. However, not all metal oxides are stable in water. For example, lanthanum oxide becomes lanthanum hydroxide when immersed in water (or absorbs moisture over time). In the case of metal hydroxides, there is a concern that the metal components may leach out due to their high affinity for water.

[0013] In the present invention, "aquatic organisms" includes marine organisms and freshwater organisms, including shellfish. The aquatic organisms mentioned above refer to fouling organisms in a narrow sense. Fouling organisms are organisms that form colonies on artificial objects placed in water or in contact with water (especially on their surfaces), resulting in an undesirable effect on the artificial structure, which is called "fouling."

[0014] Specifically, the antifouling agent for suppressing the adhesion of aquatic organisms of the present invention can suppress the adhesion of organisms that lead a floating life in the sea or freshwater during their larval stage, but which, at a certain point, attach to a suitable substrate, metamorphose into adults, and switch to a settled lifestyle, and can suppress the settlement of, for example, barnacles, mussels, hydroids, jellyfish polyps, golden mussels, etc. In addition, the antifouling agent for suppressing the adhesion of aquatic organisms of the present invention can also suppress the settlement of lugworms, which have the ability to secrete calcareous matter and adhere to substrates.

[0015] The antifouling agent for inhibiting adhesion of aquatic organisms of the present invention contains the above-mentioned metal oxide. It is believed that when aquatic organisms begin to attach (adhere) to a coating surface using an adhesive component made of protein, the metal oxide coordinates to the nitrogen moiety or amide bond of the protein, denaturing the protein structure and thereby inhibiting adhesion of aquatic organisms to the coating surface.

[0016] The antifouling agent for inhibiting adhesion of aquatic organisms of the present invention may contain one type of metal oxide alone or two or more types of metal oxides.

[0017] The antifouling agent for suppressing the adhesion of aquatic organisms of the present invention may contain a metal oxide of samarium and / or gadolinium, for example, the antifouling agent for suppressing the adhesion of aquatic organisms of the present invention consists essentially of a metal oxide of samarium and / or gadolinium, or the antifouling agent for suppressing the adhesion of aquatic organisms of the present invention is a metal oxide of samarium and / or gadolinium. Here, "substantially consisting of" means that the proportion of metal oxides of samarium and / or gadolinium in the antifouling agent for suppressing adhesion of aquatic organisms of the present invention is 90 mass % or more, 95 mass % or more, or 99 mass % or more.

[0018] The metal oxides of samarium and / or gadolinium can be produced by known methods, and commercially available products may also be used.

[0019] (Antifouling composition for inhibiting adhesion of aquatic organisms) The antifouling composition for suppressing the adhesion of aquatic organisms of the present invention contains the antifouling agent for suppressing the adhesion of aquatic organisms of the present invention and a solvent, and preferably further contains a binder resin in addition to the antifouling agent for suppressing the adhesion of aquatic organisms of the present invention and a solvent.

[0020] The lower limit of the content of the antifouling agent for suppressing the adhesion of aquatic organisms of the present invention in the antifouling composition for suppressing the adhesion of aquatic organisms of the present invention is not particularly limited, and may be, for example, 1 mass % or more relative to the total mass of the antifouling composition for suppressing the adhesion of aquatic organisms, preferably 5% or more, more preferably 10% or more, and even more preferably 30% or more. The upper limit of the content of the antifouling agent for suppressing adhesion of aquatic organisms is not particularly limited, and may be, for example, 90% by mass or less, preferably 80% by mass or less, more preferably 60% by mass or less, and even more preferably 50% by mass or less, relative to the total mass of the antifouling agent composition for suppressing adhesion of aquatic organisms.

[0021] The solvent contained in the antifouling composition for suppressing the adhesion of aquatic organisms of the present invention is added for the purpose of adjusting the viscosity of the antifouling composition for suppressing the adhesion of aquatic organisms, and may be either an aqueous medium or an oil-based medium.

[0022] Specific examples of the solvent include water, 1-butanol, isobutanol, 1-pentanol, 2 -Methyl-2-pentanol, 3-methyl-3-pentanol, methyl ethyl ketone, monofunctional alcohols such as methanol, ethanol, n-propyl alcohol, and isopropyl alcohol, various diols, polyhydric alcohols such as glycerin, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, and 1,12-dodecane Diols such as propylene glycol, 1,2 butanediol, 3-methyl-1,3 butanediol, 1,2 pentanediol, 2-methyl-1,3 propanediol, 1,2 hexanediol, dipropylene glycol, diethylene glycol, aromatic diols which are adducts of bisphenol A and alkylene oxides having 2 or 3 carbon atoms (average number of added moles: 1 to 16), alicyclic diols such as hydrogenated bisphenol A, polyoxypropylene-2 ,2-bis(4-hydroxyphenyl)propane, polyoxyethylene-2,2-bis(4-hydroxyphenyl)propane, cyclohexanediol, ethylene glycol monomethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monoisobutyl ether, propylene glycol monomethyl ether, propylene glycol monopropyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether, ethyl carbitol, γ-butyrolactone, various fatty acids, etc.

[0023] The solvent contained in the antifouling composition for inhibiting adhesion of aquatic organisms of the present invention may be one type alone or two or more types.

[0024] The solvent content in the antifouling composition for suppressing the adhesion of aquatic organisms of the present invention is not particularly limited, and may be appropriately set so that the solids concentration of the antifouling composition for suppressing the adhesion of aquatic organisms is in the range of 30 to 80 mass %, for example.

[0025] When the antifouling agent composition for suppressing the adhesion of aquatic organisms of the present invention contains a binder resin, the content of the antifouling agent for suppressing the adhesion of aquatic organisms of the present invention is not particularly limited, and for example, the metal oxide derived from the antifouling agent for suppressing the adhesion of aquatic organisms may be contained in a range of 0.01 to 80 parts by mass per 100 parts by mass of the resin solid content, preferably in a range of 0.01 to 60 parts by mass per 100 parts by mass of the resin solid content, and more preferably in a range of 0.1 to 60 parts by mass per 100 parts by mass of the resin solid content. Here, the term "resin solid content" means the total amount of solid content such as binder resin contained in the antifouling composition for suppressing the adhesion of aquatic organisms.

[0026] The binder resin contained in the antifouling composition for suppressing the adhesion of aquatic organisms of the present invention is not particularly limited, and any type of resin, such as an emulsion-based resin, a latex-based resin, a thermosetting resin, or an active energy ray-curable resin, can be used.

[0027] The binder resin may be either a water-soluble resin or a water-insoluble resin (solvent-based resin). In this application, the term "water-soluble resin" means that the amount of water required to dissolve 1 g of resin at 20° C. is less than 10 ml. The term "water-insoluble resin" refers to a resin that is not one of the aforementioned "water-soluble resins."

[0028] Specific examples of binder resins include acrylic resin, vinyl acetate resin, styrene resin, vinyl chloride resin, olefin resin, urethane resin, urea resin, urethane urea resin, acrylic urethane resin, epoxy resin, melamine resin, phenol resin, polyester resin, alkyd resin, silicone resin, polyphenylene sulfide resin, acrylonitrile / styrene copolymer resin, acrylonitrile / butadiene copolymer resin, and acrylonitrile / butadiene / styrene copolymer (ABS) resin. The binder resin also includes modified versions of the above resins, and for example, in the case of phenolic resin, it also includes rosin-modified phenolic resin.

[0029] The binder resin contained in the antifouling composition for suppressing the adhesion of aquatic organisms of the present invention may be one type alone or two or more types.

[0030] The content of the binder resin in the antifouling composition for suppressing the adhesion of aquatic organisms of the present invention is not particularly limited, and may be appropriately set, for example, in the range of 10 to 100 mass % relative to the total mass of the resin solids in the antifouling composition for suppressing the adhesion of aquatic organisms.

[0031] The antifouling composition for inhibiting the adhesion of aquatic organisms of the present invention only needs to contain the antifouling agent for inhibiting the adhesion of aquatic organisms of the present invention and a solvent, and may also contain a binder resin and other additives within a range that does not impair the effects of the present invention. Examples of such other additives include pigments, matting agents, curing agents, curing accelerators, plasticizers, antifoaming agents, dispersants, leveling agents, thickeners, antioxidants, weathering agents, flame retardants, antistatic agents, lubricants, and preservatives.

[0032] (Hardened antifouling agent for preventing adhesion of aquatic organisms) The antifouling composition for inhibiting the adhesion of aquatic organisms of the present invention can be applied to the surface of a substrate, and the resulting coating film can be cured by a method suitable for the antifouling composition for inhibiting the adhesion of aquatic organisms (thermal curing, active energy ray curing, etc.) to form a cured product of the antifouling composition for inhibiting the adhesion of aquatic organisms.

[0033] (Anti-fouling coating film) As for the method for applying the antifouling composition for inhibiting the adhesion of aquatic organisms, any known and used coating method can be used, and examples thereof include conventionally known methods such as roll coating, electrostatic coating, bar coating, gravure coating, knife coating, dipping coating, spray coating such as airless spray coating and air spray coating, shower coating, brush coating, and roller coating.

[0034] (Substrate with antifouling coating) In the case of a substrate with an antifouling coating film, the substrate to be coated is not particularly limited, and for example, in the case of a substrate such as a ship, examples thereof include FRP, steel, wood, and aluminum alloy, and in the case of a steel ship or aluminum ship in particular, the surface may be coated with a primer, an anticorrosion paint, and, if necessary, a binder paint. Other common substrates include paper, synthetic paper, steel plate, aluminum foil, glass, wood, woven fabric, knitted fabric, nonwoven fabric, gypsum board, wooden board, resin substrate, etc.

[0035] Specific examples of the resin substrate include polyethylene terephthalate (PET) film, polystyrene film, polyamide film, polyacrylonitrile film, polyethylene film (LLDPE: low-density polyethylene film, HDPE: high-density polyethylene film), polypropylene film (CPP: unstretched polypropylene film, OPP: biaxially oriented polypropylene film), polyvinyl alcohol film, ethylene-vinyl alcohol copolymer film, polycarbonate film, polyethylene terephthalate film, polymethyl methacrylate film, polystyrene film, polyester film, polyolefin film, epoxy resin film, melamine resin film, triacetyl cellulose resin film, polyvinyl alcohol film, ABS resin film, norbornene-based resin film, cyclic olefin-based resin film, polyimide resin film, polyvinyl fluoride resin film, polyvinylidene fluoride resin film, ethylene-vinyl acetate copolymer film, etc. The resin substrate to be used may be subjected to a surface treatment such as a corona treatment.

[0036] The antifouling composition for inhibiting the adhesion of aquatic organisms obtained using the antifouling agent for inhibiting the adhesion of aquatic organisms of the present invention, the cured antifouling agent for inhibiting the adhesion of aquatic organisms obtained using the antifouling agent for inhibiting the adhesion of aquatic organisms of the present invention, and the antifouling coating film and substrate with an antifouling coating film obtained using the antifouling agent for inhibiting the adhesion of aquatic organisms of the present invention can be suitably used as substrates having antifouling properties for inhibiting the adhesion of aquatic organisms, and are usable in a wide range of applications, including ships, as well as underwater structures at least part of whose outer surface is placed or installed underwater, such as wave-dissipating blocks, breakwaters, coastal roads, undersea tunnels, port facilities, canals, waterways, quays and parts of bridges, fishing equipment such as fishing nets, ropes, floats and buoys, piping such as seawater supply and drainage pipes, water intake facilities and cooling water conveyance pipes in factories, thermal power plants and nuclear power plants, industrial water system facilities and undersea bases. [Example]

[0037] The present invention will be specifically described below with reference to examples and comparative examples. The present invention is not limited to the following examples.

[0038] (Examples 1-6 and Comparative Examples 1-10: Preparation of Test Samples) 3.31 g of synthetic resin (product name: V343-306SA, manufactured by DIC Graphics Corporation, solids concentration: 25%, solvent weight ratio: methyl ethyl ketone / ethyl acetate / toluene = 35 / 20 / 20), 10.58 g of polyurethane resin (product name: Sanprene IB-D12, manufactured by Sanyo Chemical Industries, Ltd., solids concentration: 30%, solvent weight ratio: methyl ethyl ketone / isopropanol = 47 / 23) as a binder resin, the antifouling agents shown in Tables 1 and 2 in the amounts shown in Tables 1 and 2, 0.5 g of methyl ethyl ketone (manufactured by Kanto Chemical Co., Inc.), 0.5 g of toluene (manufactured by Kanto Chemical Co., Inc.), and 80 g of 1 / 8-inch steel beads were placed in a plastic bottle and shaken for 30 minutes in a paint conditioner to obtain an antifouling agent composition for inhibiting the adhesion of aquatic organisms. The prepared antifouling composition for inhibiting adhesion of aquatic organisms was applied to a 188 μm thick PET film substrate using an applicator so that the wet film thickness was 254 μm. The obtained substrate was then dried at room temperature for one week and cut into a 5 cm x 5 cm piece to produce a substrate coated with the antifouling composition for inhibiting adhesion of aquatic organisms, which was then used as a test specimen.

[0039] The obtained test pieces were subjected to the following antifouling evaluation, and the results are shown in Tables 1 and 2. (Stain-Resistant Evaluation Method) The test specimens prepared above were fixed to a vinyl chloride sample holder, a weight was attached to the sample holder, and the holder was then hung by a rope from the quay at an outdoor test site to conduct an antifouling evaluation test. The test specimens were placed so that they were always submerged in seawater, and after a specific test period, the samples were pulled up and the number of barnacles and / or lugworms attached was counted. Table 1 shows the results for a one-month test period, and Table 2 shows the results for a two-month test period.

[0040] [Table 1]

[0041] [Table 2]

[0042] In Tables 1 and 2, the column "Amount Added" indicates the amount of antifouling agent added relative to the resin solid content of the composition.

[0043] The metal oxides used as antifouling agents in Tables 1 and 2 were also evaluated for their morphological stability as metal oxides by the following method. The results are shown in Table 3.

[0044] (Oxide morphology stability evaluation) 1 g of the metal oxide shown in Table 3 was immersed in a vial filled with 10 mL of water for one day, then filtered, and the morphology of the metal oxide after immersion was confirmed by thermogravimetric analysis (TGA). If the metal oxide morphology was maintained, it was evaluated as "Good", and if it became a metal hydroxide, it was evaluated as "Poor".

[0045] [Table 3]

[0046] Tables 1 and 2 show that samarium oxide and gadolinium oxide have a lower number of aquatic organisms attached to them than cuprous oxide, which is currently the mainstream antifouling agent for preventing the attachment of aquatic organisms, and therefore provide high antifouling properties. Lanthanum oxide also provides higher antifouling properties than cuprous oxide, but it becomes lanthanum hydroxide when immersed in water, raising concerns about the elution of lanthanum components into the sea.

Claims

1. An antifouling agent for inhibiting adhesion of aquatic organisms, which contains a metal oxide and prevents adhesion of aquatic organisms, The antifouling agent for inhibiting adhesion of aquatic organisms, wherein the metal of the metal oxide is samarium and / or gadolinium.

2. 2. The antifouling agent for inhibiting adhesion of aquatic organisms according to claim 1, wherein the aquatic organisms are barnacles, mussels, lugworms or golden mussels.

3. An antifouling composition for suppressing adhesion of aquatic organisms, comprising the antifouling agent for suppressing adhesion of aquatic organisms according to claim 1 or 2 and a solvent.

4. The antifouling composition for suppressing adhesion of aquatic organisms according to claim 3, further comprising a binder resin.

5. A cured antifouling agent for suppressing adhesion of aquatic organisms, obtained by curing the antifouling agent composition for suppressing adhesion of aquatic organisms according to claim 4.

6. An antifouling coating film formed from the cured product of the antifouling agent for inhibiting adhesion of aquatic organisms according to claim 5.

7. A substrate with an antifouling coating film, comprising: a substrate; and the antifouling coating film according to claim 6 provided on the surface of the substrate.

8. The substrate with an antifouling coating film according to claim 7, wherein the substrate is at least one selected from the group consisting of ships, underwater structures, fishing equipment, and water supply and drainage pipes.

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