Antifouling coating composition

Abstract

The present invention provides a composition for forming a high-gloss coating film which exhibits good antifouling performance in spite of a relatively slow dissolution rate of the coating film, and which does not cause a coating film abnormality such as a crack even after being immersed in seawater for a long period of time.　The present invention specifically provides an antifouling coating composition which contains a copolymer A, a rosin ester B, and an antifouling agent C, wherein: the copolymer A is a copolymer of a monomer (a1) and an ethylenically unsaturated monomer (a2) other than the monomer (a1); the monomer (a1) is represented by general formula (1); and the rosin ester B is a reaction product of a polyhydric alcohol (b1) and rosin or a derivative thereof (b2).

Description

Antifouling paint composition

[0001] The present invention relates to an antifouling coating composition.

[0002] Aquatic fouling organisms such as barnacles, serpula, mussels, bryozoans, sea squirts, green laver, sea lettuce, slime, and the like attach to ships (particularly the bottom of the ship), fishing equipment such as fishing nets and fishing net accessories, and underwater structures such as power plant water pipes, causing problems such as impaired functionality and damaged appearance of the ships, etc. To prevent such problems, a technology is known in which an antifouling coating composition is applied to ships, etc. to form an antifouling coating film, and an antifouling agent is gradually released from the antifouling coating film, thereby providing long-term antifouling performance (Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2000-17203

[0004] However, even when the technology of Patent Document 1 is adopted, there are cases where the initial coating film dissolution is excessively large or coating film abnormalities such as cracks occur after a relatively short period of time, and further improvement is required. In addition, coating films formed using the technology of Patent Document 1 tend to have low gloss, and a high-gloss coating film surface is sometimes required to improve the aesthetic appearance of ships. The present invention has been made in consideration of these circumstances and provides a composition for forming a high-gloss coating film that exhibits good antifouling performance despite a relatively slow coating film dissolution rate and does not cause coating film abnormalities such as cracks even after long-term immersion in seawater.

[0005] According to the present invention, there is provided an antifouling coating composition containing a copolymer A, a rosin ester B, and an antifouling agent C, wherein the copolymer A is a copolymer of a monomer (a1) and an ethylenically unsaturated monomer (a2) other than the monomer (a1), the monomer (a1) being represented by general formula (1), and the rosin ester B is a reaction product of a polyhydric alcohol (b1) and a rosin or a derivative thereof (b2).

[0006] As a result of extensive research into solving the above problems, the present inventors have found that the above composition can solve the problems, and have thus completed the present invention.

[0007] The present invention will be described in detail below. In this specification, "(meth)acrylic" means acrylic or methacrylic.

[0008] 1. Antifouling Coating Composition The antifouling coating composition of the present invention comprises a copolymer A, a rosin ester B, and an antifouling agent C.

[0009] 1-1. Copolymer A 1-1-1. Composition of Copolymer A Copolymer A is a copolymer of monomer (a1) and polymerizable unsaturated monomer (a2) other than monomer (a1). Copolymer A contains monomer units derived from monomers (a1) and (a2).

[0010] <Monomer (a1)> The monomer (a1) is a triorganosilyl (meth)acrylate monomer and is represented by the general formula (1). (In the formula, R １ is a hydrogen atom or a methyl group, R ２ ~R ４ are the same or different and each represents a branched alkyl group having 3 to 8 carbon atoms or a phenyl group.

[0011] R ２ ~R ４ Examples of the branched alkyl group having 3 to 8 carbon atoms include an isopropyl group, an isobutyl group, an s-butyl group, a t-butyl group, a 1-ethylpropyl group, a 1-methylbutyl group, a 1-methylpentyl group, a 1,1-dimethylpropyl group, a 1,1-dimethylbutyl group, a thexyl group, a cyclohexyl group, a 1,1-dimethylpentyl group, a 1-methylhexyl group, a 1,1-dimethylhexyl group, a 1-methylheptyl group, a 2-methylbutyl group, a 2-ethylbutyl group, a 2,2-dimethylpropyl group, a cyclohexylmethyl group, a 2-ethylhexyl group, a 2-propylpentyl group, and a 3-methylpentyl group. Preferred as R2 to R4 are an isopropyl group, an s-butyl group, a t-butyl group, a phenyl group, and a 2-ethylhexyl group. Particularly preferred are an isopropyl group and a 2-ethylhexyl group.

[0012] Examples of the monomer (a1) include triisopropylsilyl (meth)acrylate, triisobutylsilyl (meth)acrylate, tri-s-butylsilyl (meth)acrylate, triisopentylsilyl (meth)acrylate, triphenylsilyl meth(meth)acrylate, diisopropylphenylsilyl (meth)acrylate, diisopropylisobutylsilyl (meth)acrylate, diisopropyl-s-butylsilyl (meth)acrylate, diisopropylisopentylsilyl (meth)acrylate, isopropyldiisobutylsilyl (meth)acrylate, isopropyldi-s-butylsilyl (meth)acrylate, t-butyldiisobutylsilyl (meth)acrylate, and (meth)acrylate. Examples of the monomer (a1) include (meth)acrylic acid silyl esters such as t-butyldiisopentylsilyl (meth)acrylate, t-butyldiphenylsilyl (meth)acrylate, diisopropylthexylsilyl (meth)acrylate, diisopropylcyclohexylsilyl (meth)acrylate, tricyclohexylsilyl (meth)acrylate, tri-1,1-dimethylpentylsilyl (meth)acrylate, tri-2,2-dimethylpropylsilyl (meth)acrylate, tricyclohexylmethylsilyl (meth)acrylate, diisopropylcyclohexylmethylsilyl (meth)acrylate, tri-2-ethylhexylsilyl (meth)acrylate, and tri-2-propylpentylsilyl (meth)acrylate. These monomers (a1) can be used alone or in combination of two or more.

[0013] <Monomer (a2)> The monomer (a2) is an ethylenically unsaturated monomer other than the monomer (a1), and examples thereof include (meth)acrylic acid esters, vinyl compounds, aromatic compounds, and dialkyl ester compounds of dibasic acids.

[0014] Examples of (meth)acrylic acid esters include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-methoxypropyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, and 2-ethoxy (meth)acrylate. Ethyl, propylene glycol monomethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, glycidyl (meth)acrylate, furfuryl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, 2-[2-(2-hydroxyethoxy)ethoxy]ethoxy]ethyl methacrylate, mono(2-(meth)acryloyloxyethyl) succinate , N-(3-dimethylaminopropyl)(meth)acrylamide, 2-[2-(2-methoxyethoxy)ethoxy]ethyl (meth)acrylate, N,N'-dimethyl(meth)acrylamide, 2-(2-methoxyethoxy)ethyl (meth)acrylate, (meth)acrylic acid, hydroxypropyl acrylate, 2-(acetoacetyloxy)ethyl methacrylate, 2-(2-hydroxyethoxy)ethyl methacrylate, N-vinyl-2-pyrrolidone, 2-[2-(2-ethoxyethoxy)ethoxy]ethyl acrylate acrylates such as 2-(2-ethoxyethoxy)ethyl acrylate, 4-hydroxybutyl acrylate glycidyl ether, N-isopropylacrylamide, 2-(dimethylamino)ethyl acrylate, 2-(2-ethoxyethoxy)ethyl acrylate, 4-hydroxybutyl acrylate, tetrahydrofurfuryl acrylate, 3-chloro-2-hydroxypropyl acrylate, 2-[2-(2-ethoxyethoxy)ethoxy]ethyl methacrylate, N,N'-diethylacrylamide, and 3-methoxybutyl acrylate.

[0015] Examples of the vinyl compound include vinyl compounds having a functional group such as vinyl chloride, vinylidene chloride, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl benzoate, vinyl butyrate, butyl vinyl ether, lauryl vinyl ether, and N-vinylpyrrolidone.

[0016] Examples of aromatic compounds include styrene, vinyltoluene, and α-methylstyrene.

[0017] Examples of dialkyl ester compounds of dibasic acids include dimethyl maleate, dibutyl maleate, and dimethyl fumarate.

[0018] In the present invention, these monomers (a2) can be used alone or in combination of two or more. In particular, from the viewpoint of the physical properties of the coating film, (meth)acrylic acid esters are preferred as the monomer (a2). In particular, from the viewpoint of crack resistance, methyl methacrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, glycidyl (meth)acrylate, furfuryl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and the like are more preferred.

[0019] The content of the monomer (a1) in the copolymer A is preferably from 25 to 75% by mass, more preferably from 30 to 60% by mass.

[0020] The content of the monomer (a1) is preferably, for example, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70 or 75 mass %, and may be within a range between any two of the numerical values ​​exemplified here.

[0021] 1-1-2. Properties and Production Method of Copolymer A The weight-average molecular weight (Mw) of copolymer A is desirably 5,000 to 100,000. If the molecular weight is less than 5,000, the coating film of the antifouling coating becomes fragile and prone to peeling and cracking, while if it exceeds 100,000, the viscosity of the polymer solution increases, making it difficult to handle. Specific examples of Mw include 5,000, 10,000, 20,000, 25,000, 30,000, 40,000, 50,000, 60,000, 70,000, 80,000, 90,000, and 100,000, and may be within a range between any two of the values ​​exemplified here.

[0022] The Mw can be measured by, for example, gel permeation chromatography (GPC).

[0023] Copolymer A may be any of a random copolymer, an alternating copolymer, a periodic copolymer, and a block copolymer of monomer (a1) and monomer (a2).

[0024] Copolymer A can be obtained, for example, by polymerizing monomer (a1) and monomer (a2) in the presence of a polymerization initiator.

[0025] Examples of the polymerization initiator include azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl-2,2'-azobisisobutyrate, dimethyl 2,2'-azobisisobutyrate, and 2,2'-azobis(N-butyl-2-methylpropionamide); benzoyl peroxide, di-tert-butyl peroxide, tert-butyl peroxybenzoate, tert-butylperoxyisopropyl carbonate, t-butylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, di-t-hexyl peroxide, t-butylperoxy-2-ethylhexyl monocarbonate, di-t-butyl peroxide, and 1 Examples of suitable polymerization initiators include peroxides such as 1,3,3-tetramethylbutylperoxyneodecanoate, t-amylperoxyneodecanoate, t-hexylperoxypivalate, t-amylperoxypivalate, and 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate. These polymerization initiators can be used alone or in combination of two or more. Particularly preferred polymerization initiators are 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl 2,2'-azobisisobutyrate, and 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate. The molecular weight of Copolymer A can be adjusted by appropriately setting the amount of polymerization initiator used.

[0026] Examples of the polymerization method include solution polymerization, bulk polymerization, emulsion polymerization, suspension polymerization, non-aqueous dispersion polymerization, etc. Among these, solution polymerization or non-aqueous dispersion polymerization is particularly preferred in that copolymer A can be obtained simply and accurately.

[0027] In the polymerization reaction, an organic solvent may be used, if necessary. The organic solvent is not particularly limited, but examples thereof include aromatic hydrocarbon solvents such as xylene and toluene; aliphatic hydrocarbon solvents; ester solvents such as ethyl acetate, butyl acetate, isobutyl acetate, methoxypropyl acetate, and propylene glycol 1-monomethyl ether 2-acetate; alcohol solvents such as isopropyl alcohol, butyl alcohol, and propylene glycol monomethyl ether; ether solvents such as dioxane, diethyl ether, and dibutyl ether; and ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone. Among these, butyl acetate, isobutyl acetate, butyl alcohol, propylene glycol monomethyl ether, propylene glycol 1-monomethyl ether 2-acetate, toluene, and xylene are preferred. These solvents may be used alone or in combination of two or more.

[0028] The reaction temperature in the polymerization reaction may be appropriately set depending on the type of polymerization initiator, etc., and is usually 50 to 160° C., preferably 60 to 150° C. The polymerization reaction is preferably carried out in an atmosphere of an inert gas such as nitrogen gas or argon gas.

[0029] 1-2. Rosin Ester B Rosin ester B is a reaction product of a polyhydric alcohol (b1) and rosin or a derivative thereof (b2).

[0030] <Polyhydric alcohols (b1)> The polyhydric alcohols (b1) are organic compounds having two or more alcoholic hydroxy groups in one molecule. The number of carbon atoms in the polyhydric alcohols (b1) is preferably 2 to 5, specifically, for example, 2, 3, 4, or 5. The polyhydric alcohols (b1) are preferably dihydric to tetrahydric (dihydric, trihydric, or tetrahydric) alcohols. Therefore, the polyhydric alcohols (b1) are preferably at least one selected from dihydric to tetrahydric alcohols having 2 to 5 carbon atoms.

[0031] Examples of the polyhydric alcohols (b1) include alcohols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 2,4-pentanediol, 3-methyl-1,3-butanediol, 2,2-dimethyl-1,3-propanediol, 2-methyl-1,3-propanediol, 2-methylene-1,3-propanediol, 1,1-bis(hydroxymethyl)cyclopropane, glycerin, 1,2,3-butanetriol, 1,2,4-butanetriol, 2-(hydroxymethyl)propane-1,3-diol, trimethylolethane, erythritol, pentylene glycol, and pentaerythritol, with glycerin being particularly preferred.

[0032] <Rosin or Derivatives thereof (b2)> Examples of the rosin include gum rosin, tall oil rosin, wood rosin, etc. Examples of the rosin derivatives include disproportionated rosin, hydrogenated rosin, polymerized rosin, maleated rosin, rosin esters other than rosin ester B, etc.

[0033] The rosin ester B is produced, for example, by an esterification reaction or transesterification reaction between a polyhydric alcohol (b1) and a rosin or a derivative thereof (b2).

[0034] Specific examples of the rosin ester B include compounds such as rosin glycerin ester, disproportionated rosin glycerin ester, hydrogenated rosin glycerin ester, rosin pentaerythritol ester, disproportionated rosin pentaerythritol ester, hydrogenated rosin pentaerythritol ester, disproportionated maleic acid rosin ester, and polymerized rosin pentaerythritol, with rosin glycerin ester, hydrogenated rosin glycerin ester, rosin pentaerythritol ester, and hydrogenated rosin pentaerythritol ester being particularly preferred. These rosin esters B can be used alone or in combination of two or more.

[0035] As the rosin ester B, commercially available products can also be used, such as Permalyn 5095, Permalyn 5110, Foralyn 90, and Foralyn 110 (manufactured by Eastman Chemical Co.).

[0036] The content of rosin ester B in the composition of the present invention is not particularly limited, but in combination with copolymer A, from the viewpoints of aesthetic appearance and coating film solubility in particular, the content of rosin ester B is preferably 5 to 90 mass %, and particularly preferably 10 to 60 mass %, of the total mass of copolymer A and rosin ester B. Specific examples of this content are 5, 10, 20, 30, 40, 50, 60, 70, 80, and 90 mass %, and may be within a range between any two of the values ​​exemplified here.

[0037] 1-3. Antifouling Agent C Examples of the antifouling agent C include inorganic agents and organic agents.

[0038] Examples of inorganic agents include cuprous oxide, copper thiocyanate (common name: copper rhodanide), copper powder, etc. Among these, cuprous oxide and copper rhodanide are particularly preferred, and cuprous oxide that has been surface-treated with glycerin, sucrose, stearic acid, lauric acid, rishitin, mineral oil, etc. is more preferred in terms of long-term storage stability.

[0039] Examples of organic agents include 2-mercaptopyridine-N-oxide copper (generic name: copper pyrithione), 2-mercaptopyridine-N-oxide zinc (generic name: zinc pyrithione), zinc ethylene bisdithiocarbamate (generic name: zineb), 4,5-dichloro-2-n-octyl-3-isothiazolone (generic name: Sheenain 211), 3,4-dichlorophenyl-N,N-dimethylurea (generic name: diuron), 2-methylthio-4-t-butylamino-6-cyclopropylamino-s-triazine (generic name: Irgarol 1051), 2-(p-chlorophenyl)-3-cyano-4-bromo-5-trifluoromethylpyrrole (generic name: Econea 28), and 4-[1-(2,3-dimethylphenyl)ethyl]-1H-imidazole (generic name: medetomidine). These antifouling agents can be used alone or in combination of two or more.

[0040] The content of the antifouling agent in the composition of the present invention is not particularly limited, but is usually preferably 0.1 to 60 mass % in terms of solid content, and is preferably, for example, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, or 60 mass %, and may be within a range between any two of the values ​​exemplified here.

[0041] Other Additives Furthermore, if necessary, other resin components other than copolymer A, elution modifiers, plasticizers, pigments, dyes, antifoaming agents, dehydrating agents, thixotropic agents, organic solvents, etc. may be added to the resin for antifouling coating materials of the present invention to form an antifouling coating material.

[0042] Examples of other resin components include (meth)acrylic resins, polyester resins, vinyl resins, petroleum resins, metal-containing resins, zwitterionic compound-containing resins, silicone resins, and alicyclic hydrocarbon resins.

[0043] Examples of the elution modifier include rosin, hydrogenated rosin, disproportionated rosin, maleated rosin, polymerized rosin, naphthenic acid, cycloalkenyl carboxylic acid, bicycloalkenyl carboxylic acid, versatic acid, trimethylisobutenylcyclohexene carboxylic acid, and metal salts thereof, or the alicyclic hydrocarbon resins. These can be used alone or in combination of two or more.

[0044] Examples of the plasticizer include phosphate esters, phthalate esters, adipate esters, sebacate esters, epoxidized soybean oil, alkyl vinyl ether polymers, polyalkylene glycols, t-nonyl pentasulfide, petrolatum, polybutene, tris(2-ethylhexyl) trimellitate, silicone oil, chlorinated paraffin, diisononyl cyclohexane-1,2-dicarboxylate, triethyl acetylcitrate, tributyl acetylcitrate, dipropylene glycol dibenzoate, etc. These can be used alone or in combination of two or more.

[0045] Examples of the dehydrating agent include calcium sulfate, synthetic zeolite adsorbents, orthoesters, silicates such as tetramethoxysilane and tetraethoxysilane, isocyanates, carbodiimides, carbodiimidazoles, etc. These can be used alone or in combination of two or more.

[0046] 2. Method for Producing Antifouling Coating Composition The antifouling coating composition of the present invention can be produced, for example, by mixing and dispersing a mixture containing copolymer A, rosin ester B, antifouling agent C, and other additives using a disperser. As the disperser, for example, a machine that can be used as a fine grinder can be suitably used. For example, a commercially available homomixer, sand mill, bead mill, disperser, etc. can be used. Alternatively, the mixture can be mixed and dispersed using a vessel equipped with a stirrer to which glass beads for mixing and dispersing have been added.

[0047] 3. Antifouling Treatment Method, Antifouling Coating Film, and Coated Article The antifouling treatment method of the present invention uses the above-mentioned antifouling paint composition to form an antifouling coating film on the surface of an article to be coated. According to the antifouling treatment method of the present invention, the antifouling coating film gradually dissolves from the surface, constantly renewing the coating surface, thereby preventing the adhesion of aquatic fouling organisms. Examples of articles to be coated include ships (particularly ship bottoms), fishing equipment, underwater structures, etc. The thickness of the antifouling coating film may be appropriately set depending on the type of article to be coated, the ship's sailing speed, seawater temperature, etc. For example, when the article to be coated is the bottom of a ship, the thickness of the antifouling coating film is typically 50 to 700 μm, preferably 100 to 600 μm.

[0048] The following examples will further clarify the features of the present invention. However, the present invention is not limited to these examples. In each production example, example, and comparative example, % indicates % by mass. Numerical values ​​for compositions in tables indicate % by mass. The weight average molecular weight (Mw) is a value determined by GPC (polystyrene equivalent). The GPC conditions are as follows: Apparatus: HLC-8220GPC manufactured by Tosoh Corporation Column: 2 TSKgel Super HZM-M Flow rate: 0.35 mL / min Detector: RI Column thermostatic bath temperature: 40°C Eluent: THF The heating residue is a value measured in accordance with JIS K 5601-1-2:1999 (ISO 3251:1993) "Paint component testing method - heating residue."

[0049] 1. Production Examples Production Example 1 (Production of Copolymer Solution A-1) A four-neck flask equipped with a thermometer, a condenser, a stirrer, and a dropping funnel was charged with 32 g of xylene, and nitrogen gas was introduced. The temperature was maintained at 88°C while stirring. To this was added dropwise over 3 hours a mixture of 40 g of triisopropylsilyl methacrylate, 27.5 g of 2-methoxyethyl acrylate, 32.5 g of methyl methacrylate, and 0.42 g of 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate. The mixture was then stirred at 88°C for 1 hour, after which 0.1 g of 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate was added twice every 20 minutes to complete the polymerization reaction. 64 g of xylene was added, and the mixture was cooled to room temperature to obtain Copolymer Solution A-1. The viscosity of the obtained copolymer solution A-1 was 580 mPa·s (25° C.), the heating residue was 50.8%, and the Mw was 49,000.

[0050] <Production Examples 2 to 7 (Production of Copolymer Solutions A-2 to A-6, and Comparative Copolymer Solution R-1)> Using the monomer mixtures shown in Table 1, polymerization reactions were carried out in the same manner as in Production Example 1. The reaction temperature, solvent amount, and initiator amount were appropriately adjusted to obtain copolymer solutions A-2 to A-6 and comparative copolymer solution R-1 shown in Table 1. The viscosity, heating residue, and Mw of each of the resulting polymer solutions are shown in Table 1.

[0051]

[0052] <Production Example 8 (Production of Comparative Copolymer Solution R-2)> 200 g of Laroflex MP-25 (BASF) and 300 g of xylene were placed in a flask equipped with a thermometer, a reflux condenser, and a stirrer, and the mixture was stirred at 70 to 80°C for 1 hour to obtain Comparative Copolymer Solution R-2 (solid content 40%).

[0053] Production Example 9 (Production of Rosin Ester Solution B-1) 300 g of rosin glycerin ester and 300 g of xylene were placed in a flask equipped with a thermometer, a reflux condenser, and a stirrer, and the mixture was stirred at 70 to 80°C for 1 hour to obtain a rosin ester solution B-1 (a brown, transparent liquid, solid content: 50%).

[0054] <Production Examples 10 to 12 (Production of Rosin Ester Solutions B-2 to B-3, and Z-1)> Rosin ester solutions B-2 to B-3 and Z-1 were obtained using the rosin esters shown in Table 2 in the same manner as in Production Example 9. The resulting solutions are shown in Table 2.

[0055]

[0056] Production Example 13 (Production of Gum Rosin Solution) 300 g of Chinese gum rosin (WW) and 300 g of xylene were placed in a flask equipped with a thermometer, a reflux condenser, and a stirrer, and the mixture was stirred at 70 to 80°C for 1 hour to obtain a xylene solution of gum rosin (brown, transparent liquid, solid content: 50%).

[0057] Production Example 14 (Production of Hydrogenated Rosin Solution) 300 g of hydrogenated rosin produced in China and 300 g of xylene were placed in a flask equipped with a thermometer, a reflux condenser, and a stirrer, and the mixture was stirred at 70 to 80°C for 1 hour to obtain a xylene solution of hydrogenated rosin (brown, transparent liquid, solid content: 50%).

[0058] 2. Examples and Comparative Examples (Production of Coating Compositions) The components shown in Tables 3 to 6 were blended in the proportions (mass %) shown in the same tables, and the resulting mixture was mixed and dispersed with glass beads having a diameter of 2 mm to produce coating compositions.

[0059]

[0060]

[0061]

[0062]

[0063] Details of the components in Tables 2 to 6 are as follows:

[0064] <Rosin Ester B> Rosin glycerin ester: trade name "Permalyn 5095" (manufactured by Eastman Chemical Company) Hydrogenated rosin glycerin ester: trade name "Foralyn 90" (manufactured by Eastman Chemical Company) Hydrogenated rosin pentaerythritol ester: trade name "Foralyn 110" (manufactured by Eastman Chemical Company) Rosin methyl ester: trade name "Metalyn 200" (manufactured by Eastman Chemical Company)

[0065] <Dissolution adjuster> Gum rosin solution: The one produced in Production Example 13 was used. Hydrogenated rosin solution: The one produced in Production Example 14 was used.

[0066] <Anti-fouling agent C> Cuprous oxide: trade name "NC-301" (manufactured by Nisshin Chemco Co., Ltd.) Copper pyrithione: trade name "Copper Omadine" (manufactured by LONZA Corporation) Zineb: [ethylenebis(dithiocarbamate)]zinc (manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) Sea Nine: trade name "Sea Nine 211", 4,5-dichloro-2-octyl-4-isothiazolin-3-one (manufactured by R&H), active ingredient 30% xylene solution Medetomidine: (±)-4-[1-(2,3-dimethylphenyl)ethyl]-1H-imidazole (manufactured by Wako Pure Chemical Industries, Ltd.)

[0067] <Pigments and other additives> Zinc oxide: trade name "Zinc Oxide Type 2" (manufactured by Seido Chemical Industry Co., Ltd.) Titanium oxide: trade name "FR-41" (manufactured by Furukawa Co., Ltd.) Red iron oxide: trade name "Red Iron Gold" (manufactured by Morishita Bengara Kogyo Co., Ltd.) Talc: trade name "Talc MS" (manufactured by Nippon Talc Co., Ltd.) Ethyl silicate: trade name "Ethyl Silicate 28" (manufactured by Colcoat Co., Ltd.) Chlorinated paraffin: trade name "Cereclor 42" (manufactured by INEOS) Diisononyl cyclohexane-1,2-dicarboxylate: trade name "HEXAMOLL (registered trademark) DINCH (registered trademark)" (manufactured by BASF) Acetyl triethyl citrate: manufactured by Tokyo Chemical Industry Co., Ltd. Dipropylene glycol dibenzoate: manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Disparlon A603-20X: amide-based thixotropic agent: trade name "Disparlon A603-20X" (manufactured by Kusumoto Chemicals Co., Ltd.) Disparlon 4200-20: polyethylene oxide-based thixotropic agent: trade name "Disparlon 4200-20" (manufactured by Kusumoto Chemicals Co., Ltd.)

[0068] Test Example 1 (Anti-fouling Test) The coating compositions obtained in the Examples and Comparative Examples were applied to both sides of a rigid PVC plate (100 x 200 x 2 mm) to a dry coating thickness of approximately 300 μm. The resulting coating was dried at room temperature (25°C) for 3 days to prepare a test plate having a dry coating thickness of approximately 300 μm. This test plate was immersed 1.5 m below sea level in Owase City, Mie Prefecture, and the fouling of the test plate due to deposits was observed after 12 months and 24 months.

[0069] The evaluation was carried out by visually observing the condition of the coating surface and was judged according to the following criteria: ◎: No adhesion of fouling organisms such as shellfish or algae, and almost no slime. 〇: No adhesion of fouling organisms such as shellfish or algae, and a thin layer of slime (enough to make the coating surface visible) which can be removed by lightly wiping with a brush. △: No adhesion of fouling organisms such as shellfish or algae, but a thick layer of slime to the extent that the coating surface is not visible, and which cannot be removed even by vigorously wiping with a brush. ×: A level of adhesion of fouling organisms such as shellfish or algae.

[0070] Test Example 2 (Rotary Test) A rotating drum measuring 515 mm in diameter and 440 mm in height was attached to the center of the tank and rotated by a motor. A cooling device was also installed to maintain a constant seawater temperature, and an automatic pH controller was installed to maintain a constant seawater pH. Test panels were prepared according to the following method. First, an anti-rust coating (epoxy vinyl-based A / C) was applied to a titanium plate (71 x 100 x 0.5 mm) to a dry thickness of approximately 100 μm and allowed to dry to form an anti-rust coating film. The coating compositions obtained in the Examples and Comparative Examples were then applied to a dry film thickness of approximately 400 μm and dried at 40°C for 3 days to prepare test panels. The prepared test panels were fixed to the rotating drum of the rotating device of the above-mentioned equipment so that they were in contact with seawater, and the rotating drum was rotated at a speed of 20 knots. During this time, the seawater temperature was maintained at 25°C and the pH at 8.0-8.2, and the seawater was replaced every two weeks. The remaining film thickness of each test panel was measured initially and every six months after the start of the test using a one-shot 3D shape measuring instrument VR-5000 (manufactured by Keyence Corporation), and the average amount of dissolved film per month (μm / month) was obtained by calculating the dissolved film thickness from the difference between the measured values.

[0071] Furthermore, when measuring the remaining film thickness after 12 months and 24 months of the rotary test, the surface of each coating film was observed with the naked eye and with a microscope to evaluate the surface condition of the coating film. The evaluation of the surface condition of the coating film was based on the following criteria: ◯: No abnormalities at all △: Hair cracks are partially observed on the coating film surface ×: Hair cracks are observed all over the coating film surface XX: Cracks are observed on the coating film surface

[0072] Test Example 3 (Gloss Measurement) The coating compositions obtained in the Examples and Comparative Examples were applied to one side of a frosted glass plate (100 × 200 × 1 mm) to give a dry coating film thickness of approximately 200 μm. The resulting coating was dried at 40° C. for 1 day to produce a test plate having a dry coating film thickness of approximately 200 μm.

[0073] The gloss value of the dried coating surface was measured at 60 degrees using a Micro Trigloss (gloss meter manufactured by BYK Gardner). Generally, the higher the gloss value, the glossier the coating surface and the more aesthetically pleasing it is. Therefore, coatings that showed high gloss values ​​in this test were evaluated as being preferable.

[0074] <Test Results> The results of Test Examples 1 to 3 show that the coating films of the Examples, which were formed using compositions containing Copolymer A and Rosin Ester B, exhibited higher gloss values ​​than the coating films of the Comparative Examples, which did not contain at least one of Copolymer A and Rosin Ester B, and exhibited good antifouling performance despite the relatively small amount of coating film dissolution, and did not develop coating film abnormalities such as cracks even after long-term immersion in seawater.

Claims

1. An antifouling coating composition comprising a copolymer A, a rosin ester B and an antifouling agent C, wherein the copolymer A is a copolymer of a monomer (a1) and an ethylenically unsaturated monomer (a2) other than the monomer (a1), the monomer (a1) is represented by general formula (1), and the rosin ester B is a reaction product of a polyhydric alcohol (b1) and a rosin or a derivative thereof (b2). (In the formula, R １ is a hydrogen atom or a methyl group, R ２ ~R ４ are the same or different and each represents a branched alkyl group having 3 to 8 carbon atoms or a phenyl group.

2. The antifouling coating composition according to claim 1, wherein the content of said rosin ester B in the total mass of said copolymer A and said rosin ester B is 5 to 90 mass %.

3. The antifouling coating composition according to claim 1 or 2, wherein the polyhydric alcohol (b1) is at least one selected from dihydric, trihydric and tetrahydric alcohols having 2 to 5 carbon atoms.