Antifouling coating composition

Abstract

The present invention provides an antifouling coating composition which retains antifouling properties for a long period of time even in cases where the antifouling coating composition is applied under circumstances where bubbles are relatively easily entrained such as airless spray.　The present invention provides an antifouling coating composition which contains a copolymer A, an antifouling chemical agent B, and a solvent C. The copolymer A is formed of a monomer (a) represented by general formula (1) and an ethylenically unsaturated monomer (b) other than the monomer (a), the monomer (a) including a compound in which n in the general formula (1) is 2 or more. The solvent C has an evaporation rate of 40 or less when that of butyl acetate is taken as 100, wherein the evaporation rate is calculated by the measurement method set forth in ASTM D3539-87.

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 alkoxycarbonyl methyl ester group-containing polymers described in Patent Documents 1 to 4 have extremely low coating film solubility, making it difficult for them to exhibit antifouling properties over a long period of time. To solve these problems, a technology has been proposed that dissolves the coating film and allows antifouling performance to be exhibited over a long period of time (Patent Document 5).

[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

[0006] It has been found that when an antifouling coating film made from the antifouling coating composition described in Patent Document 5 is applied in an environment where bubbles are relatively likely to be entrained, such as by airless spraying, the long-term antifouling performance of the obtained antifouling coating film is reduced.

[0007] The present invention has been made in view of the above circumstances, and provides an antifouling coating composition that maintains antifouling properties for a long period of time even when applied in an environment that is relatively prone to entraining bubbles, such as by airless spraying.

[0008] According to the present invention, there is provided an antifouling coating composition containing a copolymer A, an antifouling agent B, and a solvent C, wherein the copolymer A is a copolymer of a monomer (a) represented by general formula (1) and an ethylenically unsaturated monomer (b) other than the monomer (a), the monomer (a) includes a compound in which n in the general formula (1) is 2 or more, and the solvent C has an evaporation rate of 40 or less relative to butyl acetate being 100, the evaporation rate being calculated by the measurement method described in ASTM D3539-87.

[0009] As a result of extensive research into solving the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by a composition containing a copolymer A, an antifouling agent B, and a solvent C having an evaporation rate of 40 or less relative to butyl acetate being 100, and have thus completed the present invention.

[0010] The present invention will be described in detail below. In the following description, elements not specified in the claims are optional elements and can be omitted. Any number of "0"s (for example, one or two) may be added to the end of numerical values ​​disclosed in the following description. For example, one or two "0"s may be added after "1.4" to make it "1.40" or "1.400".

[0011] 1. Antifouling Coating Composition The antifouling coating composition of the present invention contains a copolymer A, an antifouling agent B, and a solvent C.

[0012] 1-1. Copolymer A Copolymer A is a copolymer of monomer (a) and an ethylenically unsaturated monomer (b) other than monomer (a), and contains monomer units derived from monomer (a) and monomer (b). 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, coating film solubility is particularly good.

[0013] 1-1-1. Monomer (a) Monomer (a) is represented by general formula (1).

[0014] 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 2 to 4 carbon atoms, and n represents an integer of 1 to 10.

[0015] R ２ is preferably hydrogen or a methyl group.

[0016] R ３ is, for example, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, or a t-butyl group, and is preferably an ethyl group.

[0017] 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.

[0018] 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.

[0019] 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 preferably 50 to 80% by mass, more preferably 55 to 75% by mass, and particularly preferably 60 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.

[0020] <Monomer (a1)> Monomer (a1) is a compound in which n is 1 in general formula (1). Examples of the monomer (a1) include ethyl (oxycarbonylmethyl) (meth)acrylate, isopropyl (oxycarbonylmethyl) (meth)acrylate, n-propyl (oxycarbonylmethyl) (meth)acrylate, n-butyl (oxycarbonylmethyl) (meth)acrylate, t-butyl (oxycarbonylmethyl) (meth)acrylate, ethyl (meth)acrylate [1-(oxycarbonyl)ethyl], isopropyl (meth)acrylate [1-(oxycarbonyl)ethyl], n-propyl (meth)acrylate [1-(oxycarbonyl)ethyl], n-butyl (meth)acrylate [1-(oxycarbonyl)ethyl], and t-butyl (meth)acrylate [1-(oxycarbonyl)ethyl], and preferably ethyl (meth)acrylate (oxycarbonylmethyl) and n-butyl (oxycarbonylmethyl) (meth)acrylate.

[0021] <Monomer (a2)> Monomer (a2) is a compound of general formula (1) in which n is 2 or greater. In general formula (1), n ​​is preferably 2 to 6 from the viewpoint of long-term antifouling properties. Monomer (a2) preferably includes both a compound in which n is 2 and a compound in which n is 3 or greater. Specifically, for example, the mass ratio (n(2) / n(2-10)) in terms of solid content is preferably 0.4 to 0.8, more preferably 0.5 to 0.7. 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.

[0022] Examples of the monomer (a2) include ethyl (meth)acrylate di(oxycarbonylmethyl), ethyl (meth)acrylate poly(oxycarbonylmethyl), isopropyl (meth)acrylate di(oxycarbonylmethyl), isopropyl (meth)acrylate poly(oxycarbonylmethyl), n-propyl (meth)acrylate di(oxycarbonylmethyl), n-propyl (meth)acrylate poly(oxycarbonylmethyl), n-butyl (meth)acrylate di(oxycarbonylmethyl), n-butyl (meth)acrylate poly(oxycarbonylmethyl), t-butyl (meth)acrylate di(oxycarbonylmethyl), t-butyl (meth)acrylate poly(oxycarbonylmethyl), Ethyl (meth)acrylate di[1-(oxycarbonyl)ethyl], ethyl (meth)acrylate poly[1-(oxycarbonyl)ethyl], isopropyl (meth)acrylate di[1-(oxycarbonyl)ethyl], isopropyl (meth)acrylate poly[1-(oxycarbonyl)ethyl], n-propyl (meth)acrylate di[1-(oxycarbonyl)ethyl], n-propyl (meth)acrylate poly[1-(oxycarbonyl)ethyl], n-butyl (meth)acrylate di[1-(oxycarbonyl)ethyl] , n-butyl (meth)acrylate poly[1-(oxycarbonyl)ethyl], t-butyl (meth)acrylate di[1-(oxycarbonyl)ethyl], t-butyl (meth)acrylate poly[1-(oxycarbonyl)ethyl], and preferred are ethyl (meth)acrylate di(oxycarbonylmethyl), ethyl (meth)acrylate poly(oxycarbonylmethyl), n-butyl (meth)acrylate di(oxycarbonylmethyl), and n-butyl (meth)acrylate poly(oxycarbonylmethyl).

[0023] 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 the monomer (b) used in the polymerization of copolymer A includes one or both of monomer (b1) and monomer (b2).

[0024] <Monomer (b1)> The monomer (b1) is represented by the general formula (2).

[0025] In the formula, R ４ is a hydrogen or methyl group, three R ５ are the same or different and each represents a branched alkyl group having 3 to 8 carbon atoms or a phenyl group.

[0026] The number of carbon atoms in the branched alkyl group is, for example, 3, 4, 5, 6, 7, or 8, and may be within a range between any two of the numerical values ​​exemplified here. Examples of branched alkyl groups include an isopropyl group, an isopropenyl 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. R ８ ~R １０ are preferably the same or different and are an isopropyl group, an isopropenyl group, an s-butyl group, a t-butyl group, a phenyl group, and a 2-ethylhexyl group, and particularly preferably an isopropyl group and a 2-ethylhexyl group.

[0027] Examples of the monomer (b1) 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 (b1) 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 (b1) can be used alone or in combination of two or more.

[0028] <Monomer (b2)> Monomer (b2) is obtained by removing monomer (b1) from monomer (b). In other words, monomer (b2) is a monomer not represented by either general formula (1) or (2). Examples of monomer (b2) include (meth)acrylic acid esters not represented by either general formula (1) or (2), vinyl compounds, aromatic compounds, and dialkyl ester compounds of dibasic acids. In this specification, (meth)acrylic acid esters refer to acrylic acid esters or methacrylic acid esters.

[0029] Examples of (meth)acrylic acid esters not represented by either general formula (1) or (2) 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, 2-ethoxyethyl (meth)acrylate, propylene glycol monomethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, and methyl (meth)acrylate. Examples of (meth)acrylic acid esters include 2-hydroxypropyl 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-hydroxyethyl (meth)acrylate, 2-[2-(2-methoxyethoxy)ethoxy]ethyl (meth)acrylate, and N,N'-dimethyl(meth)acrylamide.

[0030] 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.

[0031] Examples of aromatic compounds include styrene, vinyltoluene, and α-methylstyrene.

[0032] Examples of dialkyl ester compounds of dibasic acids include dimethyl maleate, dibutyl maleate, and dimethyl fumarate.

[0033] In copolymer A, these monomers (b) can be used alone or in combination of two or more. From the viewpoint of coating film solubility and coating film physical properties, it is preferable that monomer (b) contains a (meth)acrylic acid ester of monomer (b1) or monomer (b2). From the viewpoint of crack resistance, it is preferable that monomer (b) contains a (meth)acrylic acid ester of monomer (b2), and more preferably contains methyl (meth)acrylate, 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, or the like. From the viewpoint of coating film solubility, the monomer (b) preferably contains a monomer (b1), and more preferably contains triisopropylsilyl (meth)acrylate, t-butyldiphenylsilyl (meth)acrylate, tri-2-ethylhexylsilyl (meth)acrylate, or the like.

[0034] 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, 25,000, 30,000, 35,000, 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.

[0035] The Mw can be measured by, for example, gel permeation chromatography (GPC).

[0036] Copolymer A may be any of a random copolymer, an alternating copolymer, a periodic copolymer, and a block copolymer of monomer (a1), monomer (a2), and monomer (b).

[0037] Copolymer A can be obtained, for example, by polymerizing monomer (a1), monomer (a2), and monomer (b) in the presence of a polymerization initiator.

[0038] 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, and t-butylperoxy-2-ethoxybenzoate. Examples of the polymerization initiator include peroxides such as diethylhexanoate, 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, t-amylperoxypivalate, and 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate. These polymerization initiators can be used alone or in combination of two or more.

[0039] 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. By appropriately setting the amount of polymerization initiator used, the molecular weight of copolymer A can be adjusted. Furthermore, a chain transfer agent can be used to adjust the molecular weight of the resulting polymer. Examples of 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 thereof include aromatic hydrocarbon solvents such as xylene (68) and toluene (195); aliphatic hydrocarbon solvents; ester solvents such as ethyl acetate (525), butyl acetate (100), isobutyl acetate (150), and propylene glycol 1-monomethyl ether 2-acetate (44); alcohol solvents such as isopropyl alcohol (205), butyl alcohol (45), and propylene glycol monomethyl ether (66); ether solvents such as dioxane (165) and diethyl ether (1100); and ketone solvents such as methyl ethyl ketone (465) and methyl isobutyl ketone (145).

[0042] Among these, butyl acetate (100), isobutyl acetate (150), butyl alcohol (45), propylene glycol monomethyl ether (66), propylene glycol 1-monomethyl ether 2-acetate (44), toluene (195), and xylene (68) are preferred. The values ​​in parentheses indicate evaporation rates. Furthermore, solvent C may be used in addition to these solvents. These solvents may be used alone or in combination of two or more.

[0043] 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.

[0044] 1-2. Antifouling Agent B Examples of antifouling agents include inorganic agents and organic agents.

[0045] 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. 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.

[0046] The content of the antifouling agent B 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 B 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.

[0047] 1-3. Solvent C Solvent C of the present invention is a solvent having an evaporation rate of 40 or less, where butyl acetate is taken as 100. The evaporation rate in the present invention is obtained by the measurement method described in ASTM D3539-87. When butyl acetate is taken as 100, the evaporation rate of solvent C is, for example, 0.01 to 40, preferably 0.05 to 20, and more preferably 0.1 to 15. Specific examples of this evaporation rate include 0.01, 0.05, 0.1, 0.2, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, and 40, and may be in a range between any two of the values ​​exemplified here.

[0048] Specific examples of solvent C include ethylene glycol propyl ether (evaporation rate 0.2), diethylene glycol butyl ether (also known as butyl carbitol, evaporation rate 0.4), diisobutyl ketone (evaporation rate 20), cyclohexanone (evaporation rate 25), isophorone (evaporation rate 3), ethyl 3-ethoxypropionate (evaporation rate 34), and butyl cellosolve (evaporation rate 10).

[0049] The content of solvent C in the antifouling coating composition is, for example, 1 to 20 mass %, preferably 2 to 10 mass %, specifically, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 mass %, and may be in a range between any two of the values ​​exemplified here.

[0050] The content of solvent C in the total solvent is, for example, 5 to 100 mass%, preferably 10 to 60 mass%, and more preferably 15 to 40 mass%. Specific examples of this content include 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, and 100 mass%, and may be within a range between any two of the values ​​exemplified here.

[0051] 1-4. Other Additives Furthermore, if necessary, resin components other than copolymer A, elution modifiers, plasticizers, pigments, dyes, antifoaming agents, dehydrating agents, thixotropic agents, organic solvents other than solvent C, and the like can be added to the resin for antifouling coating materials of the present invention to form an antifouling coating material.

[0052] Examples of other resin components include copolymer S and polymer P. Copolymer S is a copolymer of monomer (b1) and monomer (b2) and contains monomer units derived from monomer (b1) and monomer (b2). The content of monomer (b1) relative to the total of monomer (b1) and monomer (b2) 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, coating film solubility is particularly good.

[0053] The polymerization method, initiator, solvent, temperature, other conditions, and method for measuring Mw can be the same as those described for Copolymer A.

[0054] The content of Copolymer B in the composition of the present invention is not particularly limited, but the mass ratio (copolymer S / copolymer A) of the content to Copolymer A, calculated as solid content, is usually 0.1 to 0.9, preferably 0.3 to 0.7. This mass ratio may be, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, or 0.9, and may be within a range between any two of the values ​​exemplified here.

[0055] Polymer P is a polymer obtained by polymerizing the monomer (b2). In the present invention, the monomer (b2) can be used alone or in combination of two or more types. In particular, from the viewpoint of compatibility with Copolymer A, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, furfuryl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, benzyl (meth)acrylate, and the like are preferred. The polymerization method, initiator, solvent, temperature, other conditions, and Mw measurement method, etc., can be the same as those described above for Copolymer A.

[0056] The content of polymer P in the composition of the present invention is not particularly limited, but the mass ratio (polymer P / copolymer A) of the content of polymer P to copolymer A, calculated as solid content, is usually 0.1 to 0.5, and preferably 0.1 to 0.3. This mass ratio may be, for example, 0.1, 0.2, 0.3, 0.4, or 0.5, and may be within a range between any two of the values ​​exemplified here.

[0057] Examples of elution modifiers include monocarboxylic acids and their salts, such as rosin, rosin derivatives, naphthenic acid, cycloalkenylcarboxylic acids, bicycloalkenylcarboxylic acids, versatic acid, trimethylisobutenylcyclohexenecarboxylic acid, and metal salts thereof, or the alicyclic hydrocarbon resins. These can be used alone or in combination of two or more. Examples of the rosin derivatives include hydrogenated rosin, disproportionated rosin, maleated rosin, formylated rosin, and polymerized rosin. Examples of the alicyclic hydrocarbon resins include commercially available products such as Quinton 1500, 1525L, and 1700 (trade names, manufactured by Nippon Zeon Co., Ltd.). Among these, rosin, rosin derivatives, naphthenic acid, versatic acid, trimethylisobutenylcyclohexenecarboxylic acid, and metal salts thereof are preferred.

[0058] Examples of dehydrating agents 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.

[0059] 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 a copolymer, an antifouling agent, other additives, etc., using a disperser. The mixture is preferably a mixture in which various materials, such as the copolymer and the antifouling agent, are dissolved or dispersed in a solvent. Suitable dispersers include those that can be used as fine grinders. Examples of suitable dispersers include commercially available homomixers, sand mills, bead mills, and dispersers. Alternatively, the mixture may be mixed and dispersed in a container equipped with a stirrer to which glass beads, etc., for mixing and dispersing are added.

[0060] 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.

[0061] 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. 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."

[0062] 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 123 g (1.00 mol) of ethyl 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 the addition was complete, the mixture was stirred at 70 to 80°C for 6 hours. After the reaction was complete, 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 142.3 g of Monomer a1-1.

[0063] <Production Examples 2 to 5 (Production of Monomers a1-2 to a1-5)> Monomers a1-2 to a1-5 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 5 are shown in Table 1.

[0064]

[0065] 1-2. Production Example of Monomer (a2) <Production Example 6 (Production of Monomer a2-1)> (First Reaction) 199 g (1.71 mol) of sodium monochloroacetate, 209 g (1.71 mol) of ethyl 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. The solvent was then removed by vacuum concentration, yielding 269 g of ethoxycarbonylmethyl chloroacetate.

[0066] (Second Reaction) Next, a four-neck flask equipped with a thermometer, a condenser, a stirrer, and a dropping funnel was charged with 200 g (1.11 mol) of ethoxycarbonylmethyl chloroacetate, which was the product of the first reaction, 80 g (1.11 mol) of acrylic acid, 0.1 g of 4-methoxyphenol, and 500 g of ethyl acetate, and 112 g (1.11 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 227.5 g of monomer a2-1.

[0067] <Production Examples 5 to 30 (Production of Monomers a2-2 to a2-25)> Monomers a2-2 to a2-25 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 6. The reaction conditions and yields of Production Examples 6 to 30 are shown in Table 2.

[0068]

[0069] Details of the raw materials in Tables 1 and 2 are as follows: CAMe: methyl chloroacetate CAEt: ethyl chloroacetate CAnBu: normal butyl chloroacetate CACh: cyclohexyl chloroacetate AA: acrylic acid MAA: methacrylic acid TEA: triethylamine MEHQ: 4-methoxyphenol CANa: sodium monochloroacetate NMP: N-methyl-2-pyrrolidone

[0070] 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 80 g of xylene and 20 g of 1-butanol as solvents, 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 the monomers (a1), (a2), and (b) 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. 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 three times every hour. The mixture was then 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.

[0071] <Production Examples P2 to P7 (Production of Copolymer Solutions A-2 to A-7)> Copolymer solutions A-2 to A-7 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 Table 3 were used instead. The heating residue and Mw of each polymer are shown in Table 3. The numerical values ​​for the amounts of raw materials blended in the table are in grams.

[0072]

[0073] 1-4. Other Production Examples <Production Example D1 (Production of Gum Rosin Solution D-1)> 300 g of Chinese gum rosin (WW) and 310 g of xylene were placed in a flask equipped with a thermometer, a reflux condenser, and a stirrer, and the mixture was refluxed under reduced pressure at 70 to 80°C for 1 hour to dehydrate, yielding a xylene solution of gum rosin (brown, transparent liquid, solids content: 50%). The heating residue of the resulting solution was 50.3%.

[0074] <Production Example D2 (Production of Gum Rosin Zinc Salt Solution D-2)> 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 acid in the rosin would form a zinc salt, and the mixture was refluxed and dehydrated under reduced pressure at 70 to 80°C for 3 hours. The mixture was then cooled and filtered to obtain a xylene solution of gum rosin zinc salt (dark brown, transparent liquid, solids content: 50%). The heating residue of the resulting solution was 50.2%.

[0075] <Production Example D3 (Production of Hydrogenated Rosin Solution D-3)> 250 g of hydrogenated rosin (Foral™ AX-E, manufactured by Eastman Corporation) and 250 g of xylene were placed in a flask equipped with a thermometer, a reflux condenser, and a stirrer, and the mixture was refluxed and dehydrated under reduced pressure at 70 to 80°C for 1 hour to obtain a xylene solution of hydrogenated rosin (yellow, transparent liquid, solid content: 50%). The heating residue of the obtained solution was 50.3%.

[0076] Production Example D4 (Production of Hydrogenated Rosin Zinc Salt Solution D-4) 400 g of a hydrogenated rosin xylene solution (solids content: 50%) and 50 g of xylene were placed in a flask equipped with a thermometer, a reflux condenser, and a stirrer. 100 g of zinc oxide was added so that all of the resin acid in the hydrogenated rosin would form a zinc salt, and the mixture was refluxed and dehydrated under reduced pressure at 70 to 80°C for 3 hours. The mixture was then cooled and filtered to obtain a xylene solution of hydrogenated rosin zinc salt (dark brown, transparent liquid, solids content: 50%). The heating residue of the resulting solution was 50.2%.

[0077] 2. Examples 1 to 18 and Comparative Examples 1 to 3 (Production of Coating Compositions) Coating compositions were produced by blending the components shown in Tables 4 to 6 in the proportions (mass%) shown in the tables, and mixing and dispersing them with glass beads having a diameter of 1.5 to 2.5 mm. The values ​​in parentheses in Tables 4 to 6 are evaporation rates.

[0078]

[0079]

[0080]

[0081] Details of the components in the table are as follows:

[0082] <Anti-fouling agent B> Cuprous oxide: trade name "NC-301" (manufactured by Nisshin Chemco Co., Ltd.) Copper pyrithione: trade name "Copper Omadine" (manufactured by LONZA Corporation) Medetomidine: (±)-4-[1-(2,3-dimethylphenyl)ethyl]-1H-imidazole (manufactured by Wako Pure Chemical Industries, Ltd.)

[0083] <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.)

[0084] <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.)

[0085] 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 coatings that had undergone the above-mentioned treatments were subjected to the following tests. The evaluation results are shown in Tables 4 to 6.

[0086] Test Example 1 (Anti-fouling Test) The coating compositions obtained in the Examples and Comparative Examples were placed in tin cans, pumped using an airless pump set at 0.6 MPa, and spray-applied to test panels at a discharge pressure of 10 MPa. The test panels were rigid PVC panels (100 x 200 x 2 mm), and the coating was applied to a dry coating thickness of approximately 300 μm. The resulting coating was dried at room temperature (25°C) for 3 days to produce test panels with a dry coating thickness of approximately 300 μm. The test panels were immersed 1.5 m below sea level in Owase City, Mie Prefecture, and the test panels were observed for fouling by attached matter after 18 months and 36 months. Evaluation was performed by visually observing the condition of the coating surface and rated according to the following criteria: ⊚: No adhesion of fouling organisms such as shellfish or algae, and almost no slime. ○: No adhesion of fouling organisms such as shellfish or algae, and a thin layer of slime (enough to make the coating surface visible) that 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 that makes the coating surface invisible, and cannot be removed by vigorously wiping with a brush. ×: A level of adhesion of fouling organisms such as shellfish or algae

[0087] <Test Results> Examples 1 to 18 showed good results in the antifouling test. On the other hand, Comparative Example 1, which does not contain Component C, a constituent component of the present invention, and ３ In Comparative Examples 2 and 3, in which the alkyl group having 2 to 4 carbon atoms was not used, thick slime that was difficult to remove or organisms such as shellfish adhered to the surface, resulting in poor antifouling properties.

Claims

1. An antifouling coating composition containing copolymer A, antifouling agent B, and solvent C, wherein copolymer A is a copolymer of monomer (a) represented by general formula (1) and ethylenically unsaturated monomer (b) other than monomer (a), and monomer (a) includes a compound in which n in general formula (1) is 2 or more, and solvent C has an evaporation rate of 40 or less relative to butyl acetate being 100, the evaporation rate being calculated by the measurement method described in ASTM D3539-87. (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 2 to 4 carbon atoms, and n represents an integer of 1 to 10.

2. A coated article having an antifouling coating film formed on its surface using the antifouling coating composition according to claim 1.

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