Antifouling coating material composition

Abstract

Provided is an antifouling coating material composition capable of maintaining a stable coating film dissolution rate and maintaining stable antifouling performance over a long period of time in seawater at a low temperature.　The present invention provides an antifouling coating material composition comprising a copolymer A, a component B, and an antifouling chemical agent D. The copolymer A is a copolymer of monomers (a) represented by general formula (1) and ethylenically unsaturated monomers (b) other than the monomers (a). The monomers (a) include a compound in which n is two or more in the general formula (1). The monomers (b) include monomers (b1) comprising one or more selected from isobornyl acrylate and isobornyl methacrylate. The proportion of monomers (b1) with respect to the total of the monomers (a) and the monomers (b) is 5-50 mass%. The component B is at least one selected from the group consisting of rosins, rosin derivatives, and metal salts thereof.

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 (especially the bottom of ships), fishing equipment such as fishing nets and fishing net accessories, and underwater structures such as power plant water pipes, causing problems such as impairing the functionality of these ships and damaging their appearance.

[0003] To prevent such problems, a technique is known in which an antifouling coating composition is applied to a ship or the like to form an antifouling coating film, and an antifouling agent is gradually released from the antifouling coating film, thereby allowing the antifouling performance to be maintained for a long period of time (Patent Documents 1 to 4).

[0004] However, the antifouling coating films made of (meth)acrylic acid alkoxycarbonylmethyl ester group-containing polymers described in Patent Documents 1 to 4 have extremely low coating film solubility, making it difficult for them to maintain antifouling properties over a long period of time. To solve these problems, a technology has been proposed that dissolves the coating film and maintains antifouling performance over a long period of time (Patent Document 5). Furthermore, a technology has been proposed that improves coating film physical properties such as cracking and peeling (Patent Document 6).

[0005] Japanese Patent Publication No. 63-61989 Japanese Patent Application Laid-Open No. 2003-119420 Japanese Patent Application Laid-Open No. 2003-119419 Japanese Patent Application Laid-Open No. 2002-3776 WO2020 / 045211 WO2022 / 102492

[0006] Although the antifouling coating films made from the antifouling coating compositions described in Patent Documents 5 and 6 have improved coating film solubility and coating film physical properties, there is still room for improvement in coating film solubility in low-temperature sea areas, such as at temperatures of 15°C or less. Therefore, there has been a demand for an antifouling coating composition that can maintain excellent antifouling performance for a long period of time even in low-temperature sea areas.

[0007] The present inventors have attempted to use a rosin-based compound (rosin, rosin derivatives, rosin metal salts, metal salts of rosin derivatives, etc.) in combination as a means of improving the solubility of coating films in low-temperature sea areas, but this resulted in insufficient compatibility with the copolymer, and problems with poor coating film properties and paint stability, making it impossible to provide an antifouling coating composition that is practical for use in low-temperature sea areas.

[0008] The present invention has been made in view of the above circumstances, and aims to provide an antifouling coating composition that can maintain a stable coating film dissolution rate and stable antifouling performance over a long period of time in low-temperature seawater.

[0009] According to the present invention, there is provided an antifouling coating composition containing copolymer A, component B, and antifouling agent D, wherein copolymer A is a copolymer of monomer (a) represented by general formula (1) and ethylenically unsaturated monomer (b) other than monomer (a), monomer (a) comprises a compound in which n in general formula (1) is 2 or greater, monomer (b) comprises monomer (b1) consisting of one or more monomers selected from isobornyl acrylate and isobornyl methacrylate, the proportion of monomer (b1) to the total of monomer (a) and monomer (b) being 5 to 50 mass %, and component B is at least one selected from the group consisting of rosin, rosin derivatives, and metal salts thereof.

[0010] As a result of extensive research into solving the above problems, the present inventors have found that a composition containing copolymer A, component B, and antifouling agent D can solve the above problems, and have thus completed the present invention.

[0011] The present invention will be described in detail below. In this specification, (meth)acrylic acid ester means acrylic acid ester or methacrylic acid ester, and (meth)acrylic acid means acrylic acid or methacrylic acid.

[0012] 1. Antifouling Coating Composition The antifouling coating composition of the present invention contains copolymer A, component B, and antifouling agent D.

[0013] 1-1. Copolymer A Copolymer A is a copolymer of monomer (a) and monomer (b) which is an ethylenically unsaturated monomer other than monomer (a).

[0014] The content of monomer (a) relative to the total of monomer (a) and monomer (b) is preferably 10 to 90 mass%, more preferably 20 to 70 mass%. Specific examples include 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, and 90 mass%, and may be within a range between any two of the values ​​exemplified here. In this case, the coating film solubility is particularly good.

[0015] The content of the monomer (b1) is 5 to 50 mass % of the total mass of the monomer (a) and the monomer (b), preferably 10 to 45 mass %, and more preferably 20 to 40. Specifically, for example, it is 5, 10, 15, 20, 25, 30, 35, 40, 45, or 50 mass %, and may be within a range between any two of the numerical values ​​exemplified here.

[0016] 1-1-1. Monomer (a) Monomer (a) is represented by general formula (1).

[0017] (In the formula, R １ represents hydrogen or a methyl group, and R ２ represents hydrogen, a methyl group, or a phenyl group, and R ３ represents an alkyl group having 1 to 8 carbon atoms which may be substituted with an alkoxy group having 1 to 8 carbon atoms or a phenyl group, or represents a phenyl group, and n represents an integer of 1 to 10.

[0018] R ２ is preferably hydrogen or a methyl group.

[0019] R ３ The alkyl group having 1 to 8 carbon atoms in R may or may not be substituted with a substituent. The substituent may be an alkoxy group having 1 to 8 carbon atoms or a phenyl group. ３ The number of carbon atoms in the alkoxy group or alkyl group is, for example, 1, 2, 3, 4, 5, 6, 7, or 8, and may be within a range between any two of the values ​​exemplified here. ３The alkyl group is, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a t-butyl group, a 2-ethylhexyl group, a cyclohexyl group, a benzyl group, a phenyl group, a 2-methoxyethyl group, a 4-methoxybutyl group, a vinyl group, or an allyl group, and is preferably a methyl group, an ethyl group, an isopropyl group, or an n-butyl group.

[0020] n represents an integer of 1 to 10, and n is, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, and may be within a range between any two of the numerical values ​​exemplified here.

[0021] The monomer (a) includes a compound in which n is 2 or more in the general formula (1). When the monomer (a) includes a compound in which n is 2 or more, the coating film solubility is increased. The monomer (a) may be composed solely of a compound in which n is 2 or more, or may be a mixture of a compound in which n is 1 and a compound in which n is 2 or more.

[0022] The monomer (a) is preferably composed of a monomer (a1) and a monomer (a2). The content of the monomer (a1) in the monomer (a) is 40 to 80% by mass, preferably 50 to 70% by mass. Compared to the monomer (a2), the monomer (a1) has the property of increasing the coating film strength and decreasing the coating film solubility. For this reason, if the content of the monomer (a1) is too low, the coating film strength tends to decrease, and the coating film surface condition may become more likely to deteriorate over a long period of time. On the other hand, if the content of the monomer (a1) is too high, the coating film solubility may decrease, resulting in a decrease in antifouling performance.

[0023] <Monomer (a1)> Monomer (a1) is a compound in which n is 1 in general formula (1). Examples of the monomer (a1) include methoxycarbonylmethyl (meth)acrylate, ethoxycarbonylmethyl (meth)acrylate, isopropoxycarbonylmethyl (meth)acrylate, n-propoxycarbonylmethyl (meth)acrylate, n-butoxycarbonylmethyl (meth)acrylate, t-butoxycarbonylmethyl (meth)acrylate, 2-ethylhexyloxycarbonylmethyl (meth)acrylate, cyclohexyloxycarbonylmethyl (meth)acrylate, benzyloxycarbonylmethyl (meth)acrylate, phenoxycarbonylmethyl (meth)acrylate, 2-methoxyethoxycarbonylmethyl (meth)acrylate, 4-methoxybutoxycarbonylmethyl (meth)acrylate, allyloxycarbonylmethyl (meth)acrylate, vinyloxycarbonylmethyl (meth)acrylate, 1-(methoxycarbonyl)(meth)acrylate,

[0123] Examples of the acrylate include 1-(ethoxycarbonyl)ethyl (meth)acrylate, 1-(n-propoxycarbonyl)ethyl (meth)acrylate, 1-(isopropoxycarbonyl)ethyl (meth)acrylate, 1-(n-butoxycarbonyl)ethyl (meth)acrylate, 1-(t-butoxycarbonyl)ethyl (meth)acrylate, α-(methoxycarbonyl)benzyl (meth)acrylate, and α-(ethoxycarbonyl)benzyl (meth)acrylate, and preferably, methoxycarbonylmethyl (meth)acrylate, ethoxycarbonylmethyl (meth)acrylate, isopropoxycarbonylmethyl (meth)acrylate, n-propoxycarbonylmethyl (meth)acrylate, n-butoxycarbonylmethyl (meth)acrylate, 1-(methoxycarbonyl)ethyl (meth)acrylate, and 1-(ethoxycarbonyl)ethyl (meth)acrylate.

[0024] <Monomer (a2)> Monomer (a2) is a compound of general formula (1) in which n is at least 2. In general formula (1), n ​​is preferably 2 to 6 from the viewpoint of long-term antifouling properties.

[0025] Monomer (a2) preferably contains both a compound in which n is 2 and a compound in which n is 3 or greater. Specifically, the mass ratio (n(2) / n(2-10)) is preferably 0.4 to 0.8, more preferably 0.5 to 0.7, calculated on a solid content basis. In this case, stable coating film dissolution tends to be sustained. Specific examples of this value are 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, and 0.80, and may be within a range between any two of the values ​​exemplified here.

[0026] Examples of the monomer (a2) include methyl (meth)acrylate di(oxycarbonylmethyl), ethyl (meth)acrylate di(oxycarbonylmethyl), isopropyl (meth)acrylate di(oxycarbonylmethyl), n-propyl (meth)acrylate di(oxycarbonylmethyl), n-butyl (meth)acrylate di(oxycarbonylmethyl), t-butyl (meth)acrylate di(oxycarbonylmethyl), 2-ethylhexyl (meth)acrylate di(oxycarbonylmethyl), cyclohexyl (meth)acrylate di(oxycarbonylmethyl), di(oxycarbonylmethyl), benzyl (meth)acrylate di(oxycarbonylmethyl), phenyl (meth)acrylate di(oxycarbonylmethyl), 2-methoxyethyl (meth)acrylate di(oxycarbonylmethyl), 4-methoxybutyl (meth)acrylate di(oxycarbonylmethyl), allyl (meth)acrylate di(oxycarbonylmethyl), vinyl (meth)acrylate di(oxycarbonylmethyl), methyl (meth)acrylate di[1-(oxypolycarbonyl)ethyl], ethyl (meth)acrylate di[1-(oxypolycarbonyl)ethyl] )ethyl], n-propyl (meth)acrylate di[1-(oxypolycarbonyl)ethyl], isopropyl (meth)acrylate di[1-(oxypolycarbonyl)ethyl], n-butyl (meth)acrylate di[1-(oxypolycarbonyl)ethyl], t-butyl (meth)acrylate di[1-(oxypolycarbonyl)ethyl], methyl (meth)acrylate di[α-(oxycarbonyl)benzyl], ethyl (meth)acrylate di[α-(oxycarbonyl)benzyl], and preferably methyl (meth)acrylate di(oxycarbonyl) di(oxycarbonylmethyl)), ethyl (meth)acrylate di(oxycarbonylmethyl), isopropyl (meth)acrylate di(oxycarbonylmethyl), n-propyl (meth)acrylate di(oxycarbonylmethyl), n-butyl (meth)acrylate di(oxycarbonylmethyl), methyl (meth)acrylate di[1-(oxypolycarbonylethyl)], ethyl (meth)acrylate di[1-(oxypolycarbonylethyl)], methyl (meth)acrylate poly(oxycarbonylmethyl), ethyl (meth)acrylate poly(oxycarbonylmethyl),Isopropyl (meth)acrylate poly(oxycarbonylmethyl), n-propyl (meth)acrylate poly(oxycarbonylmethyl), n-butyl (meth)acrylate poly(oxycarbonylmethyl), t-butyl (meth)acrylate poly(oxycarbonylmethyl), 2-ethylhexyl (meth)acrylate poly(oxycarbonylmethyl), cyclohexyl (meth)acrylate poly(oxycarbonylmethyl), benzyl (meth)acrylate poly(oxycarbonylmethyl), phenyl (meth)acrylate poly(oxycarbonylmethyl), 2-methoxyethyl (meth)acrylate poly(oxycarbonylmethyl), 4-methoxybutyl (meth)acrylate poly(oxycarbonylmethyl), allyl (meth)acrylate poly(oxycarbonylmethyl), vinyl (meth)acrylate poly(oxycarbonylmethyl), methyl (meth)acrylate poly[1-(oxypolycarbonyl)ethyl], ethyl (meth)acrylate poly[1-(oxypolycarbonyl)ethyl], (meth) Examples thereof include n-propyl acrylate poly[1-(oxypolycarbonyl)ethyl], isopropyl (meth)acrylate poly[1-(oxypolycarbonyl)ethyl], n-butyl (meth)acrylate poly[1-(oxypolycarbonyl)ethyl], t-butyl (meth)acrylate poly[1-(oxypolycarbonyl)ethyl], methyl (meth)acrylate poly[α-(oxycarbonyl)benzyl], and ethyl (meth)acrylate poly[α-(oxycarbonyl)benzyl], and preferably (methyl) p) Examples thereof include methyl acrylate poly(oxycarbonylmethyl), ethyl (meth)acrylate poly(oxycarbonylmethyl), isopropyl (meth)acrylate poly(oxycarbonylmethyl), n-propyl (meth)acrylate poly(oxycarbonylmethyl), n-butyl (meth)acrylate poly(oxycarbonylmethyl), methyl (meth)acrylate poly[1-(oxypolycarbonylethyl)], and ethyl (meth)acrylate poly[1-(oxypolycarbonylethyl)].

[0027] 1-1-2. Monomer (b) Monomer (b) is an ethylenically unsaturated monomer other than monomer (a). Monomer (b) can be classified into monomer (b1) and monomer (b2), and monomer (b) used in the polymerization of copolymer A contains at least monomer (b1).

[0028] <Monomer (b1)> Monomer (b1) is one or more compounds selected from isobornyl acrylate and isobornyl methacrylate. By including monomer (b1) in the monomers used to polymerize copolymer A, it is possible to improve the compatibility between copolymer A and component B. In addition, isobornyl acrylate and isobornyl methacrylate have the property of not easily reducing the hardness of the coating film formed using the antifouling coating composition of the present invention.

[0029] The proportion of the monomer (b1) relative to the total of the monomer (a) and the monomer (b) is 5 to 50% by mass, preferably 10 to 45% by mass, and more preferably 20 to 40% by mass. Specific examples of this proportion include 5, 10, 15, 20, 25, 30, 35, 40, 45, and 50% by mass, and may be within a range between any two of the values ​​exemplified here. If this proportion is too small, the effect of improving the compatibility between copolymer A and component B tends to be insufficient, while if this proportion is too large, the coating film dissolution or antifouling performance tends to be insufficient.

[0030] <Monomer (b2)> The monomer (b2) is obtained by removing the monomer (b1) from the monomer (b). Examples of the monomer (b2) include (meth)acrylic acid esters, vinyl compounds, aromatic compounds, and dialkyl ester compounds of dibasic acids.

[0031] Examples of the (meth)acrylic acid ester as the monomer (b2) include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, t-butyl acrylate, t-butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, lauryl acrylate, lauryl methacrylate, benzyl acrylate, benzyl methacrylate, phenyl acrylate, phenyl methacrylate, (Meth)acrylic acid esters such as cyclohexyl acrylate, cyclohexyl methacrylate, stearyl acrylate, stearyl methacrylate, 2-methoxyethyl acrylate, 2-methoxyethyl methacrylate, 2-ethoxyethyl acrylate, 2-ethoxyethyl methacrylate, 3-methoxybutyl acrylate, 3-methoxybutyl methacrylate, 2-(2-ethoxyethoxy)ethyl acrylate, 2-(2-ethoxyethoxy)ethyl methacrylate, 2-phenoxyethyl acrylate, 2-phenoxyethyl methacrylate, tetrahydrofurfuryl acrylate, tetrahydrofurfuryl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, and cyclic trimethylolpropane formal acrylate; and (meth)acrylic acid silyl esters such as triisopropylsilyl acrylate and triisopropylsilyl methacrylate.

[0032] Examples of the vinyl compound that is the monomer (b2) include vinyl compounds having a functional group, such as vinyl chloride, vinylidene chloride, vinyl benzoate, vinyl butyrate, butyl vinyl ether, and lauryl vinyl ether.

[0033] Examples of the aromatic compound that is the monomer (b2) include styrene, vinyltoluene, and α-methylstyrene.

[0034] Examples of the dialkyl ester compound of a dibasic acid, which is the monomer (b2), include dibutyl maleate.

[0035] 1-1-3. Properties and Production Method of Copolymer A The weight-average molecular weight (Mw) of copolymer A is desirably 5,000 to 300,000. 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 300,000, the viscosity of the polymer solution increases, making it difficult to handle. Specific examples of Mw include 5,000, 10,000, 20,000, 30,000, 40,000, 50,000, 60,000, 70,000, 80,000, 90,000, 100,000, 200,000, and 300,000, and may be within a range between any two of the values ​​exemplified here.

[0036] The Mw can be measured by, for example, gel permeation chromatography (GPC).

[0037] Copolymer A may be any of a random copolymer, an alternating copolymer, a periodic copolymer, and a block copolymer of monomer (a1), monomer (a2), monomer (b1), and monomer (b2).

[0038] Copolymer A can be obtained, for example, by polymerizing monomer (a1), monomer (a2), monomer (b1), and monomer (b2) in the presence of a polymerization initiator.

[0039] 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, and tert-butyl peroxide. Dibenzoate, tert-butylperoxyisopropyl carbonate, t-butylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, di-t-hexyl peroxide, t-butylperoxy-2-ethylhexyl monocarbonate, di-t-butyl peroxide, 1,1,3,3-tetramethylbutylperoxyneodecanoate, t-amylperoxyneodecanoate, t-hexylperoxypivalate, Examples of suitable polymerization initiators include peroxides such as t-amyl peroxypivalate and 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate. These polymerization initiators can be used alone or in combination of two or more. As the polymerization initiator, 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 are particularly preferred. The molecular weight of Copolymer A can be adjusted by appropriately setting the amount of polymerization initiator used. Furthermore, a chain transfer agent can be used to adjust the molecular weight of the resulting polymer. Examples of suitable chain transfer agents include mercaptans such as n-dodecyl mercaptan; thioglycolic acid esters such as octyl thioglycolate; α-methylstyrene dimer; and terpinolene.

[0040] 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.

[0041] In the polymerization reaction, an organic solvent may be used if necessary. The organic solvent is not particularly limited, but examples 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 can be used alone or in combination of two or more. The reaction temperature in the polymerization reaction can be appropriately set depending on the type of polymerization initiator, etc., and is typically 50 to 160°C, preferably 60 to 150°C.

[0042] The polymerization reaction is preferably carried out in an atmosphere of an inert gas such as nitrogen gas or argon gas.

[0043] 1-2. Component B Component B is at least one selected from the group consisting of rosin, rosin derivatives, and metal salts thereof. Examples of rosin include gum rosin and tall oil rosin. Examples of rosin derivatives include hydrogenated rosin and disproportionated rosin. Examples of rosin metal salts include rosin zinc salt, rosin copper salt, and rosin calcium salt. Examples of rosin derivative metal salts include hydrogenated rosin zinc salt, hydrogenated rosin copper salt, hydrogenated rosin calcium salt, disproportionated rosin zinc salt, disproportionated rosin copper salt, and disproportionated rosin calcium salt. Component B is preferably gum rosin, rosin zinc salt, hydrogenated rosin, or hydrogenated rosin zinc salt.

[0044] The content of Component B in the composition of the present invention is not particularly limited, but is usually 5 to 50 mass %, preferably 10 to 45 mass %, and more preferably 20 to 40 mass %, relative to the solid content of Copolymer A. Specific examples of this ratio are 5, 10, 15, 20, 25, 30, 35, 40, 45, and 50 mass %, and may be within a range between any two of the numerical values ​​exemplified here.

[0045] 1-3. Antifouling Agent D Examples of the antifouling agent D include inorganic agents and organic agents. 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, or the like is more preferred in terms of long-term storage stability.

[0046] 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.

[0047] The content of the antifouling agent D in the composition of the present invention is not particularly limited, but is usually 0.1 to 60.0 mass % in terms of solid content. The content of the antifouling agent D is, 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.

[0048] 1-4. Other Additives Furthermore, to the resin for antifouling coating materials of the present invention, resin components other than copolymer A, elution modifiers other than component B, plasticizers, pigments, dyes, antifoaming agents, dehydrating agents, thixotropic agents, organic solvents, etc. can be added as necessary to prepare an antifouling coating material.

[0049] Examples of elution modifiers include monocarboxylic acids and their salts, such as 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. Commercially available alicyclic hydrocarbon resins include Quinton 1500, 1525L, and 1700 (trade names, manufactured by Nippon Zeon Co., Ltd.). Among these, naphthenic acid, versatic acid, trimethylisobutenylcyclohexene carboxylic acid, and metal salts thereof are preferred. Examples of dehydrating agents include calcium sulfate, synthetic zeolite adsorbents, orthoesters, silicates such as tetramethoxysilane and tetraethoxysilane, isocyanates, carbodiimides, carbodiimidazoles, and the like. These can be used alone or in combination of two or more.

[0050] 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, component B, antifouling agent D, other additives, etc., using a disperser. The mixture is preferably a mixture in which various materials such as copolymer A, component B, and antifouling agent D are dissolved or dispersed in a solvent. As the disperser, for example, one 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 container equipped with a stirrer to which glass beads for mixing and dispersing have been added.

[0051] 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.

[0052] The following examples will further clarify the features of the present invention. However, the present invention is not limited to these examples. The weight average molecular weight (Mw) is a value determined by GPC (polystyrene equivalent value). 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."

[0053] 1. Production Examples 1-1. Production Example of Monomer (a1) <Production Example 1 (Production of Monomer a1-1)> A four-necked flask equipped with a thermometer, a condenser, a stirrer, and a dropping funnel was charged with 109 g (1.00 mol) of methyl chloroacetate, 72 g (1.00 mol) of acrylic acid, 0.1 g of 4-methoxyphenol, and 500 g of ethyl acetate, and 101 g (1.00 mol) of triethylamine was added dropwise with stirring while maintaining the temperature at 40°C or below. After completion of the dropwise addition, the mixture was stirred at 70 to 80°C for 6 hours. After completion of the reaction, the organic layer was washed with tap water, aqueous hydrochloric acid, and aqueous sodium bicarbonate in that order, and the solvent was then distilled off by concentration under reduced pressure to obtain 129.7 g of Monomer a1-1. <Production Examples 2 to 3 (Production of Monomers a1-2 to a1-3)> Monomers a1-2 to a1-3 were obtained by carrying out reactions using the raw materials shown in Table 1 in the same manner as in Production Example 1. The reaction conditions and yields of Production Examples 1 to 3 are shown in Table 1.

[0054]

[0055] 1-2. Production Example of Monomer (a2) <Production Example 4 (Production of Monomer a2-1)> (First Reaction) 215 g (1.85 mol) of sodium monochloroacetate, 201 g (1.85 mol) of methyl chloroacetate, and 300 g of N-methyl-2-pyrrolidone were placed in a four-necked flask equipped with a thermometer, a condenser, and a stirrer, and the mixture was stirred for 6 hours at 70 to 80° C. After completion of the reaction, 500 ml of toluene was placed in the reaction solution, and the organic layer was washed with tap water, hydrochloric acid, and sodium bicarbonate water in that order, and the solvent was then removed by vacuum concentration to obtain 262 g of methoxycarbonylmethyl chloroacetate.

[0056] (Second Reaction) Next, a four-neck flask equipped with a thermometer, a condenser, a stirrer, and a dropping funnel was charged with 200 g (1.20 mol) of methoxycarbonylmethyl chloroacetate, which was the product of the first reaction, 87 g (1.20 mol) of acrylic acid, 0.1 g of 4-methoxyphenol, and 500 g of ethyl acetate, and 122 g (1.20 mol) of triethylamine was added dropwise with stirring while maintaining the temperature at 40°C or less. After completion of the dropwise addition, the mixture was stirred at 70 to 80°C for 6 hours. After completion of the reaction, the organic layer was washed with tap water, hydrochloric acid, and sodium bicarbonate water in that order, and the solvent was then distilled off by concentration under reduced pressure to obtain 230.6 g of monomer a2-1.

[0057] <Production Examples 5 to 18 (Production of Monomers a2-2 to a2-15)> Monomers a2-2 to a2-15 shown in Table 2 were obtained by carrying out reactions using the raw materials shown in Table 2 in the same manner as in Production Example 4. The reaction conditions and yields of Production Examples 4 to 18 are shown in Table 2.

[0058]

[0059] Details of the raw materials in Tables 1 and 2 are as follows: CAMe: methyl chloroacetate CAEt: ethyl chloroacetate AA: acrylic acid MAA: methacrylic acid TEA: triethylamine MEHQ: 4-methoxyphenol CANa: sodium monochloroacetate NMP: N-methyl-2-pyrrolidone

[0060] 1-3. Production Examples of Copolymer Solution <Production Example P1 (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 50 g of xylene and 50 g of butyl acetate as solvents, and nitrogen gas was introduced. The mixture was maintained at 88°C while stirring. To this was added a mixture of the monomers (a1), (a2), (b1), and (b2) in the amounts (g) shown in Table 3, and 2.0 g (initial addition) of 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate as a polymerization initiator. While maintaining the temperature at 88°C, the mixture was added dropwise over 3 hours. After stirring at 88°C for 1 hour, 0.1 g of 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate was added three times every hour. The mixture was further stirred at the same temperature for 2 hours, and then cooled to room temperature to obtain Copolymer Solution A-1. The heating residue and Mw of A-1 are shown in Table 3.

[0061] <Production Examples P2 to P20 (Production of Copolymer Solutions A-2 to 17, H-1 to 3)> Copolymer solutions A-2 to 17 and H-1 to 3 were obtained by carrying out a polymerization reaction in the same manner as in Production Example P1, except that the monomers, polymerization initiators, and solvents shown in Tables 3 to 6 were used instead. The heating residue and Mw of each polymer are shown in Tables 3 to 6. The unit of the numerical values ​​for the amounts of raw materials blended in the tables is g.

[0062]

[0063]

[0064]

[0065]

[0066] 1-4. Production Examples of Component B <Production Example B1 (Production of Gum Rosin Solution)> 300 g of Chinese gum rosin (WW) and 310 g of xylene were placed in a flask equipped with a thermometer, reflux condenser, and stirrer, and the mixture was refluxed under reduced pressure at 70-80°C for 1 hour to dehydrate. Approximately 160 g of xylene was then distilled off under reduced pressure at 70-80°C to obtain a xylene solution of gum rosin (brown, transparent liquid). The residual content of the resulting solution was measured and found to be 68.6%, so 12.7 g of xylene and 150 g of butyl acetate were added and dissolved uniformly to obtain a 50 wt% / 50 wt% xylene / butyl acetate solution of gum rosin. The residual content of the resulting solution was 50.1%.

[0067] Preparation Example B2 (Preparation of Gum Rosin Zinc Salt Solution) 240 g of Chinese gum rosin (WW) and 360 g of xylene were placed in a flask equipped with a thermometer, reflux condenser, and stirrer. 120 g of zinc oxide was added so that all of the resin acids in the rosin were converted to zinc salts. The mixture was refluxed and dehydrated under reduced pressure at 70-80°C for 3 hours. The mixture was then cooled and filtered to obtain a xylene solution of gum rosin zinc salt (a clear, dark brown liquid). The solution was then heated again, and approximately 160 g of xylene was distilled off under reduced pressure at 70-80°C, yielding a xylene solution of gum rosin zinc salt (a clear, brown liquid). The residual content of the resulting solution was measured and found to be 70.1%. 22.0 g of xylene and 150 g of butyl acetate were added and homogenized to obtain a 50 wt% / 50 wt% xylene / butyl acetate solution of gum rosin zinc salt. The heating residue of the obtained solution was 50.3%.

[0068] 2. Examples 1 to 23 and Comparative Examples 1 to 3 (Production of Coating Compositions) The components shown in Tables 7 to 10 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 1.5 to 2.5 mm to produce coating compositions.

[0069]

[0070]

[0071]

[0072]

[0073] Details of the components in the table are as follows: <Anti-fouling agents> Cuprous oxide: Trade name "NC-301" (manufactured by Nisshin Chemco Co., Ltd.) Copper pyrithione: Trade name "Copper Omadin" (manufactured by LONZA Corporation)

[0074] <Dissolution adjuster> Gum rosin solution: The one produced in Production Example B1 was used. Gum rosin zinc salt solution: The one produced in Production Example B2 was used.

[0075] <Pigments> Bengala: Trade name "Bengara Kingyoku" (manufactured by Morishita Bengala Kogyo Co., Ltd.) Talc: Trade name "Talc MS" (manufactured by Nippon Talc Co., Ltd.) 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.)

[0076] <Other additives> Disparlon A603-20X: amide-based thixotropic agent: trade name "Disparlon A603-20X" (manufactured by Kusumoto Chemicals Co., Ltd.) Tricresyl phosphate: (manufactured by Daihachi Chemical Industry Co., Ltd.) Tetraethoxysilane: trade name "Ethyl Silicate 28" (manufactured by Colcoat Co., Ltd.)

[0077] 3. Tests All of the coating compositions of the Examples and Comparative Examples were placed in sealed containers within one hour of production and left to stand for 30 days in a thermostatic chamber set at 50°C (accelerated aging treatment) before use. The coating compositions that had undergone the above-mentioned treatment were subjected to the following tests.

[0078] Test Example 1 (Compatibility Test) A compatibility test was conducted on the copolymer solutions A-1 to A-17 and H-1 to H-3 obtained in the Production Examples. For the gum rosin solution obtained in Production Example B1, 5 g of the copolymer solution and 5 g of the gum rosin solution were placed in a 20 ml transparent screw tube, mixed thoroughly, and then allowed to stand for 5 days, after which the state was observed. For the gum rosin zinc salt solution obtained in Production Example B2, 8 g of the copolymer solution and 2 g of the gum rosin zinc salt solution were placed in a 20 ml transparent screw tube, mixed thoroughly, and then allowed to stand for 5 days, after which the state was observed.

[0079] Based on the observation results, the compatibility of the copolymers with the gum rosin solution and gum rosin zinc salt solution was evaluated according to the following criteria, and the results are shown in Tables 3 to 6. The copolymers contained in copolymer solutions A-1 to A-17 had good compatibility with the rosin solution and rosin zinc salt solution and did not separate into two layers, but comparative copolymer solutions H-1 to H-3 had poorer compatibility with the gum rosin solution and gum rosin zinc salt solution than the copolymers contained in copolymer solutions A-1 to A-17, became very turbid, and all separated into two layers after being left to stand for 5 days.

[0080] 〇: Clear △: Cloudy ×: Separated into two layers

[0081] 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 paint (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 then dried 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 450 μm, and the coating was dried at 40°C for 3 days to prepare test panels.

[0082] 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 15°C, the pH at 8.0 to 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 Keyence Corporation VK-X100 shape measuring laser microscope, and the dissolved coating film thickness was calculated from the difference to obtain the amount of coating film dissolved per month (μm / month), and the solubility of the coating film was evaluated.

[0083] The evaluation results are shown in Tables 7 to 10. In order to maintain excellent antifouling performance over a long period of time, a coating film dissolution amount of approximately 1.5 to 10 (μm / month) per month is required. However, the coating films formed using the coating compositions of the present invention (Examples 1 to 23) showed a dissolution amount sufficient to maintain excellent antifouling performance over the entire period of the rotary test, even though the test was conducted at a low temperature of 15°C.

[0084] On the other hand, for the coating films formed using the coating compositions of Comparative Examples 1 to 3, there was a period during the rotary test in which the amount of coating film dissolution per month was less than 1.5 μm / month, which was insufficient for maintaining excellent antifouling performance. It is believed that the low seawater temperature of 15°C during the rotary test caused the amount of coating film dissolution to be low.

[0085] In Comparative Examples 1 to 3, the compatibility between the copolymers in the copolymer solutions H-1 to H-3 used and the gum rosin was very poor, so in the rotary test at a low temperature of 15°C, the gum rosin was unable to sufficiently promote dissolution of the coating film, resulting in an insufficient amount of coating film dissolved.

Claims

1. An antifouling coating composition comprising copolymer A, component B, and antifouling agent D, wherein copolymer A is a copolymer of monomer (a) represented by general formula (1) and ethylenically unsaturated monomer (b) other than monomer (a), monomer (a) comprises a compound in which n in general formula (1) is 2 or more, monomer (b) comprises monomer (b1) consisting of one or more monomers selected from isobornyl acrylate and isobornyl methacrylate, the proportion of monomer (b1) to the total of monomer (a) and monomer (b) being 5 to 50 mass %, and component B being at least one selected from the group consisting of rosin, rosin derivatives, and metal salts thereof. (In the formula, R １ represents hydrogen or a methyl group, R ２ represents hydrogen, a methyl group, or a phenyl group; R ３ represents an alkyl group having 1 to 8 carbon atoms which may be substituted with an alkoxy group having 1 to 8 carbon atoms or a phenyl group, or represents a phenyl group, and n represents an integer of 1 to 10.

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